MECHANICAL INTERCONNECTION OF MULTIPLE ROTATABLE DEVICES (MIMRD)

Abstract

Mechanical interconnection of multiple rotatable devices that includes: a gear train, at least three rotatable devices, one or more first stages, and one or more second stages, a first element, i.e. a geared element or a planet carrier, of one of the second stages forming a torque resisting means being blocked or impeded in a controllable way. The third rotatable device interacting with a second element, i.e. a gearwheel, or a planet carrier, of one of the second stages.

Claims

1. A mechanical interconnection of multiple rotatable devices, comprising: a gear train for transmitting or interchanging speed and/or torque between the rotatable devices, at least three rotatable devices interconnected or interacting with the gear train for delivering rotational power to and/or receiving rotational power from the gear train; wherein the gear train of the mechanical interconnection of multiple rotatable devices comprises: one or more first stages; and one or more second stages, wherein each first stage is coupled to one of the one or more second stages and is a speed reducer or a speed increaser serving as a pre-gearing for connecting a rotatable device to the concerned second stage, at least two rotatable devices, i.e. a first rotatable device and a second rotatable device of the at least three rotatable devices, both being connected to a second stage and at least one of the first and the second rotatable device connected to the concerned second stage by the first stage; wherein each second stage is a differential gearing comprising a planetary gear train system which is executed in a quasi duplicated form composed of an input side and an output side, comprising respectively a first set and a second set of planetary gearing, which are mutually quasi identical but slightly different from one another, wherein the first set and the second set of planetary gearing together comprises at least three duo's of two elements of the same type, i.e. a geared element or a planet carrier, whereby one element of each duo is part of the first set while the other element of this duo is part of the second set, wherein each duo is of a different type of element, wherein the at least three duo's comprise at least a duo of planet carriers and a duo of planet gears, wherein the first set and the second set of planetary gearing interact respectively with first and second interacting gearing of respectively the input side and the output side and which sets are supported in a rotatable manner either each on their own separated planet carrier or together on a common planet carrier, each set of planetary gearing being composed of a number of planetary gearing elements which are disposed circumferentially and spaced from one another on their supporting planet carrier, at least a first duo of the aforementioned at least three duo's being linked to form a linking mechanism between the first set and the second set of planetary gearing for transmission of torque and/or speed between the input side and the output side; wherein at least a first element, i.e. a geared element or a planet carrier, of a second duo of the aforementioned at least three duo's of at least one of the second stages is forming a torque resisting or torque controlling means in that it is permanently blocked or impeded in a controllable way or provides a controllable torque to the gear train of the mechanical interconnection of multiple rotatable devices; and, wherein the third rotatable device of the at least three rotatable devices is interconnected or interacting with at least one second element, i.e. a gearwheel or a planet carrier, of the aforementioned second duo of at least one of the second stages, whereby wherein a differential gain-K, or K, of the operating pitch diameters of the elements of the afore-mentioned at least three duo's fulfils:
K?[0,7?1[?]1?1,4]; wherein the differential gain-K is defined as: K=(D.sub.2,a/D.sub.1,a)*(D.sub.1,b/D.sub.2,b) for ring or sun differential gearings, wherein: D.sub.2,a is the operating pitch diameter of the element of the aforementioned second duo belonging to the first set of planetary gearing; D.sub.1,a is the operating pitch diameter of the element of the aforementioned first duo belonging to the first set of planetary gearing; D.sub.2,b is the operating pitch diameter of the element of the aforementioned second duo belonging to the second set of planetary gearing; D.sub.1,b is the operating pitch diameter of the element of the aforementioned first duo belonging to the second set of planetary gearing; wherein the differential gain-K is defined as: K=(D.sub.1,a/(D.sub.2,a?D.sub.3,b))*((D.sub.2,b?D.sub.3,b)/D.sub.1,b) for carrier differential gearings, wherein: D.sub.2,a is the operating pitch diameter of the element of the aforementioned second duo belonging to the first set of planetary gearing; D.sub.1,a is the operating pitch diameter of the element of the aforementioned first duo belonging to the first set of planetary gearing; D.sub.2,b is the operating pitch diameter of the element of the aforementioned second duo belonging to the second set of planetary gearing; D.sub.1,b is the operating pitch diameter of the element of the aforementioned first duo belonging to the second set of planetary gearing; D.sub.3,a is the operating pitch diameter of the element of the afore-mentioned third duo belonging to the first set of the planetary gearing when the first duo comprises a set of two rings; D.sub.3,b is the operating pitch diameter of the element of the afore-mentioned third duo belonging to the second set of the planetary gearing when the first duo comprises a set of two rings; D.sub.3,a is the negative of the operating pitch diameter of the element of the afore-mentioned third duo belonging to the first set of the planetary gearing when the first duo comprises a set of two sun gears; D.sub.3,b is the negative of the operating pitch diameter of the element of the afore-mentioned third duo belonging to the second set of the planetary gearing when the first duo comprises a set of two sun gears; wherein the differential gain-K is defined as: K=(D.sub.2,a/(D.sub.3,b))*((D.sub.3,b)/D.sub.2,b) for complex carrier differential gearings, wherein: D.sub.2,a is the operating pitch diameter of the element of the aforementioned second duo belonging to the first set of planetary gearing; D.sub.2,b is the operating pitch diameter of the element of the aforementioned second duo belonging to the second set of planetary gearing; D.sub.3,a is the operating pitch diameter of the element of the afore-mentioned third duo belonging to the first set of the planetary gearing, whereby the third duo is a duo of planet gears; D.sub.3,b is the operating pitch diameter of the element of the afore-mentioned third duo belonging to the second set of the planetary gearing, whereby the third duo is a duo of planet gears.

2. The mechanical interconnection of multiple rotatable devices according to claim 1, wherein the first set and the second set of planetary gearing of a second stage of the mechanical interconnection of multiple rotatable devices each comprise a number of planetary gearing elements which are of a certain set type, which set types are one of the following: a) a first set type comprising a number of separate, simple planetary gearwheels; b) a second set type comprising a number of separate, compound planetary gearwheels; or c) a third set type comprising a number of planetary gearwheel components of a set of compound planetary gearwheels.

3. The mechanical interconnection of multiple rotatable devices according to claim 1, wherein the first and the second interacting gearing of each second stage of the mechanical interconnection of multiple rotatable devices are of a certain interacting gearing type, which interacting gearing types are one of the following: a) a first interacting gearing type being a single, separate gearwheel; b) a second interacting gearing type being a single gearwheel component of a compound interacting gearwheel; c) a third interacting gearing type being a pair of single, separated gearwheels; d) a fourth interacting gearing type being a pair of gearwheel components, each pair of gearwheel components being composed of a first single gearwheel component, i.e. gearwheel component of a compound ring wheel, and a second single gearwheel component, i.e. gearwheel component of a compound sun wheel; or e) a fifth interacting gearing type being a pair of gearwheel elements of which a first gearwheel element is a gearwheel component of a compound interacting gearwheel and a second gearwheel element which is a single separate gearwheel.

4. The mechanical interconnection of multiple rotatable devices according to claim 3, wherein the first and the second interacting gearing of each second stage of the mechanical interconnection of multiple rotatable devices taken together are one of the following: a) a pair of ring wheels or a pair of gearwheel components of a compound ring wheel; b) a pair of sun wheels or a pair of gearwheel components of a compound sun wheel; c) two pairs of single, separated gearwheels, each pair being a combination of a ring wheel and a sun wheel; d) a pair of compound gearwheels composed of a compound ring wheel and a compound sun wheel; or e) a set of gearwheel elements composed of one gearwheel element which is a compound interacting gearwheel and of a pair of gearwheel elements which are each a single separate gearwheel.

5. The mechanical interconnection of multiple rotatable devices according to claim 1, any of the preceding claims, characterized in that the linking mechanism of a second stage of the mechanical interconnection of multiple rotatable devices is realised in one of the following ways: a) the linking mechanism is formed by a fixed interconnection of corresponding, constitutive components of the first and second sets of planetary gearing forming compound planetary linkage gearwheels which are supported on a single common planet carrier; b) the linking mechanism is formed by a fixed interconnection of the first and second interacting gearing, forming a compound interacting gearwheel or a pair of compound interacting gearwheels, while the first and second set of planetary gearing are each respectively supported on their own, separated planet carriers; c) the linking mechanism is formed by a single common planet carrier which supports the first and second set of planetary gearing, each set respectively being composed of a number of first and second compound planetary gearwheels which are not fixedly interconnected; or d) the linking mechanism is formed by a fixed interconnection of a non-common planet carrier of either the input side or the output side with the interacting gearing of the other of said input side and output side.

6. The mechanical interconnection of multiple rotatable devices according to claim 5, wherein in the case the input side and the output side of the second stage of the mechanical interconnection of multiple rotatable devices are linked by a compound interacting gearwheel, the compound interacting gearwheel is one of the following: a) a compound ring wheel; b) a compound sun wheel; or c) a compound interacting gearing comprising a sun wheel component and a ring wheel component interconnected to one another or made as a single monolithic piece.

7. (canceled)

8. The mechanical interconnection of multiple rotatable devices according to claim 1, wherein the input side and output side of a second stage of the mechanical interconnection of multiple rotatable devices each comprise an element or set of elements forming together a pair of separated, quasi identical, but slightly different elements or sets of elements, so to form a second stage which is one of the following: a) a so-called ring differential gearing in the case the pair of elements is a pair of separated ring wheels forming the first and second interacting gearing, while corresponding components of the first and second set of planetary gearing are fixedly interconnected and are supported on a single, common planet carrier; b) a so-called sun differential gearing in the case the pair of elements is a pair of separated sun wheels forming the first and second interacting gearing, while corresponding components of the first and second set of planetary gearing are fixedly interconnected and are supported on a single, common planet carrier; c) a so-called carrier differential gearing in the case the pair of elements is a pair of separated planet carriers, each planet carrier of the pair supporting one of the first and second set of planetary gearing, while these first and second set of planetary gearing are linked by a fixed interconnection of the first and second interacting gearing or of one of these interacting gearings with one of the planet carriers; or d) a so-called complex common carrier differential gearing in the case the pair of sets of elements is a pair of sets of compound planetary gearwheels, the input side and the output side being linked by a single common planet carrier.

9. The mechanical interconnection of multiple rotatable devices according to claim 8, wherein the concerned second stage is a complex common carrier differential gearing, wherein the first set of planetary gearing is executed as a first set of compound planetary gearwheels and the second set of planetary gearing is executed as a second set of compound planetary gearwheels, wherein the first set of compound planetary gearwheels and the second set of compound planetary gearwheels are separated from one another and mounted in a rotatable manner at a distance from one another on planet shafts provided on the single, common planet carrier, wherein the first interacting gearing consists of a pair of separated gearwheels, i.e. a sun wheel and a ring wheel, which respectively interact with first planetary gearwheel components and second planetary gearwheel components of pairs of planetary gearwheel components by which a compound planetary gearwheel of the first set of compound planetary gearing is composed and wherein the second interacting gearing also consists of a pair of separated gearwheels, i.e. a sun wheel and a ring wheel, which respectively interact with first planetary gearwheel components and second planetary gearwheel components of pairs of planetary gearwheel components by which a compound planetary gearwheel of the second set of compound planetary gearing is composed.

10. (canceled)

11. The mechanical interconnection of multiple rotatable devices according to claim 1, wherein the first stage is of a planetary gear train type comprising at least: a first stage input shaft which is interconnected with or formed by an outgoing shaft of a rotatable device of the mechanical interconnection of multiple rotatable devices and on which a first stage input gearwheel such as a sun wheel, bevel gear or hypoid gearwheel is mounted fixedly; and one or more first stage output elements which interact with the first stage input gearwheel directly or indirectly through an intermediate gear mechanism and which are intended for interaction or interconnection with elements of a second stage.

12. The mechanical interconnection of multiple rotatable devices according to claim 11, wherein the one or more first stage output elements are one of the following: a) a single first stage output sun wheel of the planetary gear train type first stage; b) a set of first stage output planetary gearwheels of the planetary gear train type first stage; c) a single first stage planet carrier of the planetary gear train type first stage; or d) a single first stage output ring wheel of the planetary gear train type first stage.

13. The mechanical interconnection of multiple rotatable devices according to claim 11, wherein the first stage of a planetary gear train type is connected to a second stage by fixedly connecting the one or more first stage output elements to the planetary gearwheels or gearing elements of the first set of second stage planetary gearing, in particular to the planetary gearing elements of the input side of that second stage.

14. The mechanical interconnection of multiple rotatable devices according to claim 11, wherein the first stage of a planetary gear train type comprises additionally a ring wheel which is forming additional torque resisting or torque controlling means by being fixedly mounted in a housing or to a ground or being impeded in a controllable way and which is interacting with each planetary gearwheel of a set of first stage output planetary gearwheels and wherein the first stage of a planetary gear train type is linked to a second stage by having the planetary gearwheels of the set of first stage output planetary gearwheels been mounted in a rotatable manner on planet shafts: a) of a planet carrier of the second stage without being fixedly connected with the corresponding planetary gearwheels of a set of second stage planetary gearwheels of that second stage, or b) of a planet carrier of the concerned first stage which is fixedly connected to a sun wheel of the concerned second stage.

15. The mechanical interconnection of multiple rotatable devices according to claim 11, wherein the first stage of a planetary gear train type comprises additionally a planet carrier which is a first stage output planet carrier and which is fixedly mounted on a gear wheel of the second stage that is interacting with the first set or the second set of planetary gearing of that second stage.

16. The mechanical interconnection of multiple rotatable devices according to claim 1, wherein the mechanical interconnection of multiple rotatable devices comprises a pair of second stages, which are for purposes of referencing to them hereafter called primary second stage and secondary second stage, which are respectively connected to the first rotatable device and the second rotatable device of the mechanical interconnection of multiple rotatable devices through a first stage of a pair of first stages of the mechanical interconnection of multiple rotatable devices, wherein the second stages are linked to one another in one of the following ways: a) by a compound stage linking gearwheel of which a first compound stage linking gearwheel component is interacting with one of the sets of planetary gearing of the primary second stage and of which a second compound stage linking gearwheel component is interacting with one of the sets of planetary gearing of the secondary second stage; or b) by interconnection of a gear wheel of the primary second stage which interacts with a set of planetary gearing of that primary second stage and a planet carrier of the secondary second stage of that pair of second stages.

17. The mechanical interconnection of multiple rotatable devices according to claim 16, wherein the other set of planetary gearing of the primary second stage is interacting with a gearwheel which is forming a torque resisting or torque controlling means and wherein a set of planetary gearing of the secondary second stage is interacting with the third rotatable device.

18. (canceled)

19. The mechanical interconnection of multiple rotatable devices according to claim 1, wherein the mechanical interconnection of multiple rotatable devices is executed in a symmetrical way or quasi-symmetrical way, with exception of the first element and of the third rotatable device.

20. The mechanical interconnection of multiple rotatable devices according to claim 1, wherein the afore-mentioned first element is forming a torque resisting or torque controlling means, which is a ring wheel, a sun wheel or a planet carrier which is fixedly connected to a housing of the mechanical interconnection of multiple rotatable devices, to the ground or to any fixed point.

21. The mechanical interconnection of multiple rotatable devices according to claim 1, wherein the afore-mentioned first element is a ring wheel, a sun wheel or a planet carrier which is mounted in a rotatable manner and which is provided with a mechanism comprising a braking mechanism or a clutch which is interacting or can interact with the rotatable ring wheel, sun wheel or planet carrier.

22. (canceled)

23. (canceled)

24. (canceled)

25. The mechanical interconnection of multiple rotatable devices according to claim 1, wherein at any moment during functioning of the mechanical interconnection of multiple rotatable devices at least one of the rotatable devices is providing positive power to the gear train for driving it and at least one other rotatable device is providing negative power or taking power from the gear train.

26. The mechanical interconnection of multiple rotatable devices according to claim 25, wherein at any moment during functioning of the mechanical interconnection of multiple rotatable devices positive or negative power is given to the gear train by the third rotatable device and respectively negative or positive power is given to the gear train by the first and second rotatable devices.

27. (canceled)

28. (canceled)

29. (canceled)

30. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0094] With the intention of better showing the characteristics of the present disclosure, hereafter, as an example without any restrictive character whatsoever, some embodiments of a mechanical interconnection of multiple rotatable devices (MIMRDs) according to the present disclosure, are described, with reference to the accompanying illustrations, wherein:

[0095] FIG. 1 is a schematic representation of a rather general embodiment of a MIMRD in accordance with the present disclosure;

[0096] FIG. 2 is a schematic view of an embodiment of a MIMRD in accordance with the present disclosure in which less elements are incorporated;

[0097] FIG. 3 is a schematic view of another embodiment of a MIMRD in accordance with the present disclosure in which less elements are incorporated;

[0098] FIG. 4 is a general schematic representation of a second stage of a MIMRD in accordance with the present disclosure;

[0099] FIG. 5 represents schematically another embodiment of a second stage of a MIMRD in accordance with the present disclosure;

[0100] FIG. 6 represents schematically another embodiment of another second stage of a MIMRD in accordance with the present disclosure;

[0101] FIG. 7 represents schematically another embodiment of another second stage of a MIMRD in accordance with the present disclosure;

[0102] FIG. 8 represents schematically another embodiment of another second stage of a MIMRD in accordance with the present disclosure;

[0103] FIG. 9 represents schematically another embodiment of another second stage of a MIMRD in accordance with the present disclosure;

[0104] FIG. 10 represents schematically another embodiment of another second stage of a MIMRD in accordance with the present disclosure;

[0105] FIG. 11 represents still another embodiment of a second stage of a MIMRD;

[0106] FIG. 12 represents still another embodiment of a second stage of a MIMRD;

[0107] FIG. 13 represents schematically still another embodiment of a second stage of a MIMRD in accordance with the present disclosure;

[0108] FIG. 14 is a general schematic representation of a first stage of a MIMRD in accordance with the present disclosure;

[0109] FIG. 15 is a schematic representation of another embodiment of a MIMRD in accordance with the present disclosure;

[0110] FIG. 16 is a schematic representation of another embodiment of a MIMRD in accordance with the present disclosure;

[0111] FIG. 17 is a schematic representation of another embodiment of a MIMRD in accordance with the present disclosure;

[0112] FIG. 18 is a schematic representation of another embodiment of a MIMRD in accordance with the present disclosure;

[0113] FIG. 19 is a schematic representation of another embodiment of a MIMRD in accordance with the present disclosure; and

[0114] FIG. 20 is a schematic representation of another embodiment of a MIMRD in accordance with the present disclosure.

DETAILED DESCRIPTION

[0115] FIG. 1 is a general schematic representation of a mechanical interconnection of multiple rotatable devices (MIMRD) 1 in accordance with the present disclosure, different building blocks by which such a MIMRD 1 can be composed being illustrated without their further internal features.

[0116] The MIMRD 1 comprises at least three rotatable devices 2, 3 and 4 which are interconnected or interacting with one another by of the gear train 5.

[0117] These rotatable devices 2 to 4 deliver rotational power to and/or receive rotational power from the gear train 5 and speed and/or torque is transmitted or interchanged between the rotatable devices 2 to 4 by the gear train 5.

[0118] The rotatable devices 2 to 4 can be of all kind and can for example be electrical actuators or generators, or a wind turbine and so on.

[0119] The gear train 5 of the MIMRD 1 comprises one or more first stages and one or more second stages.

[0120] In FIG. 1 there are two first stages 6 and 7, and two second stages 8 and 9, which are linked to one another for transmitting speed and torque.

[0121] Each first stage 6 or 7 is coupled to one of the second stages, respectively 8 and 9, and is a speed reducer or a speed increaser serving as a pre-gearing for connecting a rotatable device, in this case respectively rotatable device 2 and rotatable device 3, to their corresponding second stage 8 and 9.

[0122] According to the present disclosure in the MIMRD 1 there are at least two rotatable devices, i.e. a first rotatable device 2 and a second rotatable device 3 of the at least three rotatable devices 2 to 4, which are connected to a second stage.

[0123] At least one of this first rotatable device 2 and this second rotatable device 3 is connected to the concerned second stage by a first stage, but in FIG. 1 both rotatable devices 2 and 3 are connected to their second stage 8 and 9 by a first stage, respectively first stage 6 and first stage 7.

[0124] Furthermore, according to the present disclosure, at least a first element 10, which is a geared element or a planet carrier, of at least one of the second stages, is forming a torque resisting means 11 in that it is permanently blocked or impeded in a controllable way or a torque controlling means 11, which allows to set or control the torque on the implicated first element 10.

[0125] In this example of FIG. 1 the second stage 8 comprises the first element 10 that is forming a torque resisting means 11 by being fixedly connected to the ground.

[0126] According to the present disclosure the third rotatable device 4 of the at least three rotatable devices 2 to 4 of the MIMRD 1 is interconnected or interacting with at least one second element 12, which is also a gearwheel or a planet carrier, of at least one of the second stages 8 or 9, i.e. of the second stage 9 in this case.

[0127] FIG. 2 illustrates very schematically an alternative embodiment of a MIMRD 1 in accordance with the present disclosure, wherein this time the MIMRD 1 comprises only one second stage 8, the first rotatable device 2 and the second rotatable device 3 being connected to this single second stage 8 each by a first stage, respectively first stage 6 and first stage 7.

[0128] The single second stage 8 comprises the first element 10 serving as a torque resisting or torque controlling means 11 as well as the second element 12 which is interacting with the third rotatable device 4.

[0129] FIG. 3 illustrates an even more reduced version of the MIMRD 1 of FIG. 2, wherein this time the second rotatable device 3 is directly connected to the second stage 8, without the use of an intermediate first stage.

[0130] In other embodiments of a MIMRD 1 of the present disclosure it is of course not excluded to add more rotatable devices, first stages and second stages.

[0131] The second stages 8 and 9 form a very important part of the MIMRD 1 and can be executed in very different manners.

[0132] FIG. 4 illustrates however schematically which elements are for forming such a second stage 8 or 9 of the MIMRD 1.

[0133] A second stage 8 or 9 is according to the present disclosure a differential gearing comprising a planetary gear train system 13 which is executed in a quasi-duplicated form composed of an input side 14 and an output side 15.

[0134] The input side 14 comprises a first set of planetary gearing 16 and the output side 15 comprises a second set of planetary gearing 17, which are mutually quasi identical but slightly different from one another.

[0135] The first set of planetary gearing 16 and the second set of planetary gearing 17 interact respectively with first and second interacting gearing 18 and 19 of respectively the input side 14 and the output side 15.

[0136] The sets of planetary gearing 16 and 17 are supported in a rotatable manner either each on their own separated planet carrier 20 and 21 or together on a common planet carrier 22.

[0137] Each set of planetary gearing 16 and 17 is furthermore composed of a number of planetary gearing elements 23 and 24 which are disposed circumferentially and spaced from one another on their supporting planet carrier 20, 21 or 22.

[0138] The first set of planetary gearing 16 and the second set of planetary gearing 17 are linked to form a linking mechanism 25 for transmission of torque and/or speed between the input side 14 and the output side 15.

[0139] Different more practically elaborated embodiments of second stages 8 or 9 are now described in more detail by FIGS. 5 to 14.

[0140] In some embodiments of a MIMRD of the present disclosure the first set of planetary gearing of each second stage of the MIMRD is linked with the second set of planetary gearing of that second stage by a linking mechanism.

[0141] In the case of the second stage 8 or 9 of the MIMRD 1 represented in FIG. 5 the first set of planetary gearing 16 and the second set of planetary gearing 17 each comprise a number of planetary gearing elements 23 and 24 which are of a certain set type.

[0142] This set type is such that the concerned set comprises a number of planetary gearwheel components 26 and 27 of a set of compound planetary gearwheels 28.

[0143] The first and the second interacting gearing 18 and 19 are of a certain interacting gearing type, which interacting gearing type in the case of FIG. 5 consists each time of a single, separate gearwheel, respectively ring wheel 29 and ring wheel 30.

[0144] The first and the second interacting gearing 18 and 19 taken together are therefore in this case a pair of ring wheels 30 and 31.

[0145] The linking mechanism 25 between the input side 14 and the output side 15 is formed by a fixed interconnection 32 of corresponding, constitutive components 26 or 27 of the first and second sets of planetary gearing 16 and 17 forming compound planetary linkage gearwheels 28 which are supported on a single common planet carrier 22.

[0146] In the case of FIG. 5 the input side 14 and the output side of the second stage 8 or 9 of the MIMRD 1 each comprise an element 29 and 30 forming together a pair 31 of separated, quasi identical, but slightly different elements 29 and 30, so to form a second stage 8 or 9 which is a so-called ring differential gearing 33, since the pair 31 of elements 29 and is a pair 31 of separated ring wheels 29 and 30 forming the first and second interacting gearing 18 and 19, while corresponding components 26 and 27 of the first and second set of planetary gearing 16 and 17 are fixedly interconnected and are supported on a single, common planet carrier 22.

[0147] In this case the differential gain-K is calculated as follows (where by D.sub.x is the operating pitch diameter of the element with reference number x in FIG. 5):

K=(D.sub.18/29/D.sub.23/26)*(D.sub.24/27/D.sub.19/30)

[0148] Indeed, the first duo which forms the linking mechanism 25 comprises the elements with reference numbers 23/26 and 24/27, whereas the second duo comprises the elements 18/29 and 19/30. The third duo comprises in this case the common carrier 22.

[0149] It is this K value that has to fulfill the requirement that

K?[0,7?1[?]1?1,4]

[0150] Further note that the following relation is valid:

D.sub.18/29?D.sub.23/26=D.sub.22=D.sub.19/30?D.sub.24/27

[0151] This relation shows how the operating pitch diameter of the carrier 22 can be determined.

[0152] The second stage 8 or 9 of the MIMRD 1 represented in FIG. 6 has a lot of similarities, but is slightly different in that this time the first and second interacting gearing 18 and 19, are each formed by a single, separated gearwheel, which is this time a sun wheel 34 or 35, instead of a ring wheel 29 or 30.

[0153] This second stage 8 or 9 constitutes therefore a so-called sun differential gearing 36 since it comprises a pair 31 of separated sun wheels 34 and 35 forming the first and second interacting gearing 18 and 19, while corresponding components 26 and 27 of the first and second set of planetary gearing 16 and 17 are fixedly interconnected and are supported on a single, common planet carrier 22.

[0154] In this case the differential gain-K is calculated as follows (where by D.sub.x is the operating pitch diameter of the element with reference number x in FIG. 5):

K=(D.sub.18/34/D.sub.23/26)*(D.sub.24/27/D.sub.19/35)

[0155] Indeed, the first duo which form the linking mechanism 25 comprises the elements with reference numbers 23/26 and 24/27, whereas the second duo comprises the elements 18/34 and 19/35.

[0156] Also in this case the third duo comprises the carrier 22.

[0157] Further note that the following relation is valid:

D.sub.18/34+D.sub.23/26=D.sub.22=D.sub.19/35+D.sub.24/27

[0158] This relation shows how the operating pitch diameter of the carrier 22 can be determined.

[0159] FIG. 7 illustrates still another type of second stage 8 or 9, the first set and the second set of planetary gearing 16 and 17 each comprising a number of planetary gearing elements 37 and 38 which are of a certain other set type, than in the preceding cases.

[0160] This time the set type is such that a set comprises a number of separate, simple planetary gearwheels 37 and 38.

[0161] Also the first and the second interacting gearing 18 and 19 are of a certain different interacting gearing type, which interacting gearing type is such that the concerned interacting gearing 18 or 19 is a single gearwheel component 39 or 40 of a compound interacting gearwheel 41.

[0162] The first and the second interacting gearing 18 and 19 of the second stage 8 or 9 of the MIMRD 1 taken together form in this case a compound ring wheel 42.

[0163] The linking mechanism 25 linking the input side 14 to the output side 15 is in this example of FIG. 7 formed by a fixed interconnection 43 of the first and second interacting gearing 18 and 19, forming a compound interacting gearwheel 42, while the first and second set of planetary gearing 16 and 17 are each respectively supported on their own, separated planet carriers 20 and 21.

[0164] Therefore, the input side 14 and output side 15 of a second stage 8 or 9 of the MIMRD 1 each comprise an element, which is represented in this case by a planet carrier 20 or 21, forming together a pair 31 of separated, quasi identical, but slightly different elements 20 and 21, so to form a second stage 8 or 9 which is a so-called carrier differential gearing 44.

[0165] In this case the pair 31 of separated elements 20 and 21 is a pair of separated planet carriers 20 and 21, each planet carrier 20 or 21 of the pair supporting one of the first and second set of planetary gearing 16 and 17, which are each composed of a number of separate, simple planetary gearwheels 37 and 38, while these first and second set of planetary gearing 16 and 17 are linked by a fixed interconnection 43 of the first and second interacting gearing 18 and 19.

[0166] In this case the differential gain-K is calculated as follows (where by D.sub.x is the operating pitch diameter of the element with reference number x in FIG. 5):

K=(D.sub.18/39/(D.sub.20/31?D.sub.23/37))*((D.sub.21/31?D.sub.24/38)/D.sub.19/40)

[0167] The first duo comprises the elements with reference numbers 18/39 and 19/40. The second duo comprises the element with reference numbers 20/31 and 21/31. The third duo comprises the elements 23/37 and 24/38, i.e. the planet gearings.

[0168] Further note that the following relations are valid:

D.sub.18/39?D.sub.23/37=D.sub.20/31

D.sub.19/40?D.sub.24/38=D.sub.21/31

[0169] In FIG. 8 a similar carrier differential gearing 44 is illustrated, wherein the first and the second interacting gearing 18 and 19 are again of a certain interacting gearing type, which interacting gearing type is such that the concerned interacting gearing 18 or 19 is a single gearwheel component 39 or 40 of a compound interacting gearwheel 41.

[0170] This compound interacting gearwheel 41 is however in this case a compound sun wheel 45.

[0171] The modification of the embodiment of a second stage 8 or 9 of a MIMRD 1 represented in FIG. 7 into the embodiment represented in FIG. 8 is therefore somewhat similar as a modification starting from an embodiment as represented in FIG. 5 so to form the embodiment represented in FIG. 6.

[0172] In this case the differential gain-K is calculated as follows (where by D.sub.x is the operating pitch diameter of the element with reference number x in FIG. 5):

K=(D.sub.18/39/(D.sub.20/31?D.sub.23/37))((D.sub.21/31?D.sub.24/38)/D.sub.19/40)

[0173] The first duo comprises the elements with reference numbers 18/39 and 19/40. The second duo comprises the element with reference numbers 20/31 and 21/31. The third duo comprises the elements 23/37 and 24/38, i.e. the planet gearings.

[0174] Since in this case the first duo comprises two sun gears, the value D.sub.23/39 and D.sub.24/38 is now equal to the negative operational pitch diameter of these elements.

[0175] Further note that the following relations are valid:

D.sub.18/39?D.sub.23/37=D.sub.20/31

D.sub.19/40?D.sub.24/38=D.sub.21/31

[0176] FIG. 9 illustrates still another type of second stage 8 or 9, which can be considered as a combination of the embodiments illustrated in FIGS. 7 and 8.

[0177] The input side 14 and output side 15 of the second stage 8 or 9 of the MIMRD 1 each comprise again an element, which is represented by a planet carrier 20 or 21, forming together a pair 31 of separated, quasi identical, but slightly different elements 20 and 21, so to form a second stage 8 or 9 which is again a so-called carrier differential gearing 44.

[0178] The first set and the second set of planetary gearing 16 and 17 each comprise a number of planetary gearing elements 37 and 38 which are of a certain set type, this set type being again such that a set comprises a number of separate, simple planetary gearwheels 37 and 38.

[0179] This time however, the first and the second interacting gearing 18 and 19 are of a certain different interacting gearing type, since this second stage 8 or 9 comprises the combination of interacting gearing 18 and 19 of the examples of FIGS. 7 and 8.

[0180] This means that in the embodiment of FIG. 9 the interacting gearing type is such that the concerned interacting gearing 18 or 19 is each time composed of a pair of gearwheel components 95 or 96.

[0181] Hereby, each pair of gearwheel components 95 or 96 is composed of a first single gearwheel component 97, i.e. gearwheel component 39 respectively 40 of a compound ring wheel 42, and a second single gearwheel component 98, i.e. gearwheel component 39 respectively 40 of a compound sun wheel 45.

[0182] It is clear that in this embodiment of FIG. 9 the separate, simple planetary gearwheels 37 and 38 of the first set and the second set of planetary gearing 16 and 17 each interact with a pair of gearwheel components 97 and 98 of the interacting gearing 18 and 19 and not anymore with a single gearwheel component 97 or 98 as was the case in the preceding examples of FIGS. 7 and 8.

[0183] The first and the second interacting gearing 18 and 19 of the second stage 8 or 9 of the MIMRD 1 taken together form in this case a pair of compound gearwheels 41 composed of a compound ring wheel 42 and a compound sun wheel 45.

[0184] The linking mechanism 25 linking the input side 14 to the output side 15 is in this example of FIG. 9 formed by a fixed interconnection 43 of the first and second interacting gearing 18 and 19, forming a pair of compound interacting gearwheels 42 and 45, while the first and second set of planetary gearing 16 and 17 are still each respectively supported on their own, separated planet carriers 20 and 21.

[0185] In the case represented in FIG. 9, the compound ring wheel 42 with inner toothing is also provided with outer toothing 86 which interacts with a pinion wheel 87.

[0186] This pinion wheel 87 can interact with other components of the MIMRD 1 or with other components which are possibly not a part of the MIMRD 1, for example in a way similar to what is the case in FIG. 19.

[0187] The example illustrated in FIG. 10 of a second stage 8 or 9 of a MIMRD 1 of the present disclosure has a lot of similarities with the preceding example of FIG. 9 in that the second stage comprises again a pair 31 of separated, quasi identical, but slightly different planet carriers 20 and 21.

[0188] The linking mechanism 25 linking the input side 14 to the output side 15 of the second stage 8 or 9 is in this example of FIG. 10 also formed by a fixed interconnection 43 of parts of the first and second interacting gearing 18 and 19, while the first and second set of planetary gearing 16 and 17 are each respectively supported on their own, separated planet carriers 20 and 21.

[0189] So, the second stage 8 or 9 represented in FIG. 10 also forms again a so-called carrier differential gearing 44.

[0190] The interacting gearing 18 and 19 of the second stage 8 or 9 of FIG. 10 has also a similarity with the interacting gearing 18 or 19 represented in FIG. 9 in that they each interact with a number of separated, simple planetary gearwheels, respectively planetary gearwheels 37 and 38, and that the interacting gearing 18 or 19 are each composed of more than a single element, contrary to what was the case in the examples of FIGS. 5 to 8.

[0191] Nevertheless, the interacting gearing 18 and 19 are of an interacting gearing type which are this time each a pair of gearwheel elements 99 respectively 100 of which a first gearwheel element 101 is a gearwheel component 39 respectively of a compound interacting gearwheel 41 and a second gearwheel element 102 is a single separate gearwheel 102.

[0192] In the case represented in FIG. 10, the first gearwheel element 101 of the pairs of gearwheel elements 99 respectively 100, is each time a gearwheel component 101 of a compound interacting gearwheel 41, in particular a gearwheel component 39 respectively 40 of a compound gearwheel 41 which is a compound ring wheel 42.

[0193] Furthermore, the second gearwheel element 102 of the pairs of gearwheel elements 99 respectively 100, is each time a single separate gearwheel 102, in particular a sun wheel 34 respectively a sun wheel 35.

[0194] In another equivalent embodiment of a second stage 8 or 9 in accordance with the present disclosure the interacting gearing 18 and 19 could also exist of pairs of gearwheel elements 99 and 100, wherein the first gearwheel element 101 of each pair is a gearwheel component 101 of a compound interacting gearwheel 41, but wherein the compound interacting gearwheel 41 is a compound sun wheel 45.

[0195] In such an embodiment the second gearwheel elements 102 of each pair 99 or 100 also form a single separate gearwheel 102 which are however in this case each formed by a ring wheel 29 respectively a ring wheel 30.

[0196] In both cases, the first interacting gearing 18 and the second interacting gearing 19 of each second stage 8 and 9 of the MIMRD 1 taken together are a set of gearwheel elements composed of one gearwheel element which is a compound interacting gearwheel 41 and of a pair of gearwheel elements which are each a single separate gearwheel 102.

[0197] FIG. 11 illustrates still another carrier differential gearing 44, which is not claimed as part of the present disclosure.

[0198] In this case the first and the second interacting gearing 18 and 19 are again of a certain interacting gearing type, which is such that the concerned interacting gearing 18 or 19 is a single gearwheel component 39 or 40 of a compound interacting gearwheel 41.

[0199] The interacting gearing 18 or 19 form a compound interacting gearwheel 41 comprising a sun wheel component 46 and a ring wheel component 47 interconnected to one another or made as a single monolithic piece or they form a combination of a ring wheel 47 and a sun wheel 46 which are fixedly interconnected.

[0200] This compound interacting gearwheel 41 is forming the linking mechanism 25 between the input side 14 and the output side 15 of the second stage 8 or 9.

[0201] Another possible variation of a second stage 8 or 9 executed as a carrier differential gearing 44, which is not claimed as part of the present disclosure and which is illustrated in FIG. 12, comprises again a pair 31 of separated, quasi identical, but slightly different elements 20 and 21, which are separate planet carriers 20 and 21, each planet carrier 20 or 21 of the pair 31 supporting one of the first and second set of planetary gearing 16 or 17, while these first and second set of planetary gearing 16 and 17 are linked by a fixed interconnection 43 of one of the first and second interacting gearings 18 or 19 with one of the planet carriers 20 or 21.

[0202] In the represented example the linking mechanism 25 is formed by a fixed interconnection 43 of the planet carrier 21 and the sun wheel 35, which forms the first interacting gearing 18 and which can also be considered as a sun wheel component 46 of the fixed interconnection 43.

[0203] Still another embodiment of a second stage 8 or 9 of the MIMRD 1 is represented in FIG. 13.

[0204] The input side 14 and the output side 15 of the second stage 8 or 9 each comprise this time a set of elements, respectively set of elements 48 and set of elements 49, forming together a pair 31 of separated, quasi identical, but slightly different sets of elements 48 and 49.

[0205] This embodiment of a second stage 8 or 9 forms a so-called complex common carrier differential gearing 50, since in this case the pair 31 of sets of elements 48 and 49 is a pair 31 of sets of compound planetary gearwheels 48 and 49, the input side 14 and the output side 15 being linked by a single common planet carrier 22 on which the compound planetary gearwheels 48 and 49 are mounted in a rotatable manner.

[0206] Each set of compound planetary gearwheels 48 and 49 represents a set of planetary gearing 16 and 17 of the second stage 8 or 9 which is in this case composed of a number of separate, compound planetary gearwheels 51 and 52 which are disposed circumferentially and spaced from one another on the common supporting planet carrier 22.

[0207] The first set of compound planetary gearwheels 48 and the second set of compound planetary gearwheels 49 are separated from one another and mounted in a rotatable manner at a distance D from one another on planet shafts 53 provided on the single, common planet carrier 22.

[0208] The linking mechanism 25 is formed by the single common planet carrier 22 which supports the first and second set of planetary gearing 16 and 17, each set respectively being composed of a number of first and second compound planetary gearwheels 51 and 52 which are not fixedly interconnected.

[0209] The first interacting gearing 18 and the second interacting gearing 19 are also quite different in this case and are of another interacting gearing type, which is for each interacting gearing 18 or 19 a pair 54 of single, separated gearwheels 55 and 56.

[0210] The gearwheels 55 are in this case sun wheels 55, while the gearwheels 56 are ring wheels 56.

[0211] As a consequence, the first and the second interacting gearing 18 and 19 taken together consist of two pairs 54 of single, separated gearwheels 55 and 56, each pair being a combination of a ring wheel 56 and a sun wheel 55.

[0212] The first interacting gearing 18 consists of a pair 54 of separated gearwheels, i.e. a sun wheel 55 and a ring wheel 56, which respectively interact with first planetary gearwheel components 57 and second planetary gearwheel components 58 of pairs of planetary gearwheel components 57 and 58 by which a compound planetary gearwheel 51 of the first set 48 of compound planetary gearwheels 51 is composed.

[0213] Similarly, the second interacting gearing 19 also consists of a pair 54 of separated gearwheels, i.e. a sun wheel 55 and a ring wheel 56, which respectively interact with first planetary gearwheel components 57 and second planetary gearwheel components 58 of pairs of planetary gearwheel components 57 and 58 by which a compound planetary gearwheel 52 of the second set 49 of compound planetary gearwheels 52 is composed.

[0214] In the example of FIG. 13, the outermost planetary gearwheel components 57 of the compound planetary gearwheels 51 and 52 respectively at the input side 14 and the output side 15 of the second stage 8 or 9 are the above-mentioned first planetary gearwheel components 57 which are meshing with one of the sun wheels 55, while the innermost planetary gearwheel components 58 of the compound planetary gearwheels 51 and 52 are the above-mentioned second planetary gearwheel components 58 which are interacting with one of the ring wheels 55.

[0215] It is of course not excluded from the present disclosure to modify the configuration by interchanging the positions of the interacting gearwheels 55 and 56 and/or the first or second planetary gearwheel components 57 and 58.

[0216] In this case, two types of differential gain-K values can be calculated, depending on which elements make up the second duo, i.e. which elements are the output element and the grounded element.

[0217] In the first case the differential gain-K is calculated as follows (where by D.sub.x is the operating pitch diameter of the element with reference number x in FIG. 5):

K=(D.sub.56(16)/D.sub.58(16))(D.sub.58(17)/D.sub.56(17))

[0218] Whereby 56 (16) refers to the element 56 of the first set 16 of planetary gearing and so on.

[0219] In this case, the third duo comprises the elements with reference numbers 58 (16) and 58 (17), whereas the second duo comprises the elements 56 (16) and 56 (17). The first duo comprises this case the common carrier 22.

[0220] Further note that the following relation is valid:

D.sub.56(16)?D.sub.58(16)=D.sub.22=D.sub.56(17)?D.sub.58(17)

[0221] In the second case the differential gain-K is calculated as follows (where by D.sub.x is the operating pitch diameter of the element with reference number x in FIG. 5):

K=(D.sub.55(16)/D.sub.57(16))*(D.sub.57(17)/D.sub.55(17))

[0222] Whereby 55 (16) refers to the element 55 of the first set 16 of planetary gearing and so on.

[0223] In this case, the third duo comprises the elements with reference numbers 57 (16) and 57 (17), whereas the second duo comprises the elements 55 (16) and 55 (17). The first duo comprises this case the common carrier 22.

[0224] Further note that the following relation is valid:

D.sub.55(16)+D.sub.57(16)=D22=D22=D.sub.55(17)+D.sub.55(17)

[0225] In both the afore-mentioned cases, care has to be taken to choose the correct planet gearwheel. Indeed, as in this case the planet gears are a compound planet gearwheels, one has to choose that planet gearwheel of the compound planet gearwheel that interacts with the element of the second duo.

[0226] In some embodiments of a MIMRD 1 of the present disclosure each second stage 8 or 9 of the MIMRD 1 is of a type as described before, i.e. of one of the following types: [0227] a) a so-called ring differential gearing 33; [0228] b) a so-called sun differential gearing 36; [0229] c) a so-called carrier differential gearing 44; or, [0230] d) a so-called complex common carrier differential gearing 50.

[0231] The second stages 8 or 9 of the MIMRD 1 are the core of the mechanism, but as explained before, at least one and in general two rotatable devices 2 and 3 of the MIMRD 1 are connected to such a second stage 8 or 9 by a first stage 6 or 7, which forms a speed reducing mechanism or a speed increasing mechanism.

[0232] FIG. 14 shows a kind of block diagram that represents a first stage 6 or 7 which is connected to a rotatable device 2 or 3 and which is connected to or interacting with a second stage 8 or 9.

[0233] According to some embodiments of the present disclosure, such a first stage 6 or 7 is of a planetary gear train (PGT) type.

[0234] Hereby, the first stage 6 or 7 comprises a first stage input shaft 59 which is interconnected with or formed by an outgoing shaft 60 of a rotatable device 2 or 3 of the MIMRD 1.

[0235] On this first stage input shaft 59 a first stage input gearwheel 61 such as a sun wheel 62, a bevel gear 63 or hypoid gearwheel 64 is mounted fixedly.

[0236] The first stage 6 or 7 furthermore comprises one or more first stage output elements 65 which interact with the first stage input gearwheel 61 directly or indirectly through an intermediate gear mechanism 66.

[0237] These one or more first stage output elements 65 are intended for interaction or interconnection with elements of the concerned second stage 8 or 9.

[0238] The one or more first stage output elements 65 can be any element of a typical PGT type first stage 6 or 7, such as a single first stage output sun wheel 67, a set of first stage output planetary gearwheels 68, a single first stage planet carrier 69 or a single first stage output ring wheel 70.

[0239] Of course it is not excluded from the present disclosure to apply first stages 8 or 9 which are a speed reducer or speed increaser and which are executed in a completely other way.

[0240] In a typical embodiment of a MIMRD 1 of the present disclosure a first stage 6 or 7 of a PGT type is connected to a second stage 8 or 9 by fixedly connecting the one or more first stage output elements 65 to the planetary gearwheels or gearing elements 23 and 24 of the first set 16 of second stage planetary gearing, in particular to the planetary gearing elements 23 of the input side 14 of that second stage 8 or 9.

[0241] However, other ways of connecting or realizing interaction between a first stage 6 or 7 and a second stage 8 or 9 of a MIMRD 1 are also not excluded from the present disclosure.

[0242] Some more practically elaborated embodiments of MIMRDs 1 in accordance with the present disclosure will now be described by FIGS. 15 to 20.

[0243] The first example of FIG. 15 corresponds to the situation described in general terms with respect to FIG. 1.

[0244] The MIMRD 1 comprises a pair of second stages 8 and 9, i.e. primary second stage 8 and secondary second stage 9, which are respectively connected to the first rotatable device 2 and the second rotatable device 3 of the MIMRD 1 through a first stage 6 respectively first stage 7 of a pair of first stages 6 and 7 of the MIMRD 1.

[0245] In a typical interpretation of the situation of FIG. 15, the first and second rotatable devices 2 and 3 can be intended for driving the gear train 5 of the MIMRD 1 and serve as an input for this gear train 5.

[0246] Therefore, the first and second rotatable devices 2 and 3 can for example be an electric actuator, a combustion engine or any other device that can deliver power to the gear train 5.

[0247] The third rotatable device 4 is connected to or interacting with the secondary second stage 9 and is in this case typically a device that is driven by the gear train 5 of the MIMRD 1 and forms in that case an output of the gear train 5.

[0248] The third rotatable device 4 can for example be a pump, a compressor, a mechanism of a joint in a robot or a prosthesis or any other load that needs to be driven by the first and second rotatable devices 2 and 3 of the MIMRD 1.

[0249] Nevertheless, the opposite can also be true and the third rotatable device 4 could for example be a wind turbine which is driven by the wind and which drives the gear train 5 for delivering power to only one of the first and second rotatable devices 2 and 3 or both rotatable devices 2 and 3, which can be for example electric generators for generating electric power, but any other rotatable device serving as a load could also be applied.

[0250] In that case the third rotatable device 4 serves as an input for the gear train 5 and the other two rotatable devices 2 and 3 as an output.

[0251] The role of being input or output can be taken by any of the rotatable device 2 to 4 and can also change during functioning of the MIMRD 1.

[0252] It is also important to understand that any of the rotatable devices 2 to 4 can also serve as a kind of controlling means by which the transmission ratio is set between the other two rotatable devices.

[0253] In a possible embodiment of a MIMRD 1 of the present disclosure at any moment during functioning of the MIMRD 1 at least one of the rotatable devices 2 to 4 is providing positive power to the gear train 5 for driving it and at least one other rotatable device 2 to 4 is providing negative power or taking power from the gear train 5.

[0254] For example, a MIMRD 1 can be such that at any moment during functioning of the MIMRD 1 positive or negative power is given to the gear train 5 by the third rotatable device 4 and respectively negative or positive power is given to the gear train 5 by the first and second rotatable devices 2 and 3.

[0255] Both second stages 8 and 9 are in the example of FIG. 15 of the ring differential gearing type 33, as described with respect to FIG. 5.

[0256] These second stages 8 and 9 are linked to one another by a compound stage linking gearwheel 71 of which a first compound stage linking gearwheel component 72 is interacting with one of the sets 16 or 17 of planetary gearing of the primary second stage 8 and of which a second compound stage linking gearwheel component 73 is interacting with one of the sets 16 or 17 of planetary gearing of the secondary second stage 9.

[0257] The compound stage linking gearwheel 71 is in this case a compound ring wheel 74.

[0258] The compound stage linking gearwheel 71 can of course also be a fixed interconnection of separate gearwheels 72 and 73.

[0259] In the example of FIG. 15 the first compound stage linking gearwheel component 72 and the second compound stage linking gearwheel component 73 are meshing with the planetary gearwheel components 26 of the first set 16 of planetary gearing of the corresponding second stages 8 or 9 and they are therefore the first interacting gearing 18 of the concerned second stages 8 and 9.

[0260] The planetary gearwheel components 27 of the second set 17 of planetary gearing of the primary second stage 8 are meshing with the ring wheel 30 that is forming the second interacting gearing 19 and which is fixedly mounted in a housing 75 of the MIMRD 1 or which is fixedly connected to a ground 75.

[0261] This ring wheel 30 is therefore the first element 10 of the MIMRD 1 which serves as a torque resisting or torque controlling means 11 by being blocked and being fixedly arranged to the surroundings of the MIMRD 1.

[0262] The planetary gearwheel components 27 of the second set 17 of planetary gearing of the secondary second stage 9 are meshing with the ring wheel 30, which is forming the second interacting gearing 19 of the secondary second stage 9 and which is fixedly connected to the third rotatable device 4.

[0263] As a consequence, this ring wheel 30 of the second set 17 of planetary gearing of the secondary second stage 9 forms, in the terminology of this present disclosure, a second element 12 of the MIMRD 1.

[0264] The first and second rotatable devices 2 and 3 are linked to their corresponding second stages 8 and 9 by first stages 6 and 7 which are in this example executed in a complete similar way as PGT type first stages 6 and 7.

[0265] These first stages 6 and 7 are fixedly connected on the outgoing shafts 60 of their rotatable device 2 or 3, which shafts 60 also form the first stage input shafts 59.

[0266] A first stage input gearwheel 61 in the form of a sun wheel 62 is mounted fixedly on each of these first stage input shafts 59.

[0267] In the case of FIG. 15 there is no intermediate gear mechanism 66 and the first stage output elements 65, which are in this case a set of first stage output planetary gearwheels 68, are meshing directly with the first stage input gearwheel 61 or sun wheel 62.

[0268] The first stage output planetary gearwheels 68 are connected by a fixed connection 76 to the planetary gearwheels or gearing elements 23 and 24 of the first set 16 and second set 17 of second stage planetary gearing, in particular to the planetary gearing elements 24 of the output side 15 of that second stage 6 or 7.

[0269] As a consequence, the first stage output planetary gearwheels 68 of both first stages 6 and 7 are supported in a rotatable manner on the common planet carrier 22 of the concerned second stage 8 or 9.

[0270] It is clear that the configuration of FIG. 15 is very symmetrical and can be used as a CVT or IVT.

[0271] The torque resisting or torque controlling means 11 is clearly the complement of the third rotatable device 4.

[0272] So, when the first and second rotatable devices 2 and 3 turn more or less at the same speed, the third rotatable device 4 will also rotate at a speed similar to the speed of the torque resisting or torque controlling means 11, thus at a speed which is close to zero depending on the degree of symmetry of the configuration.

[0273] On the other hand, when the first rotatable device 2 is not turning or turning in an opposite sense compared to the second rotatable device 3, while the second rotatable device 3 is turning at high speed, a high transmission ratio can be easily obtained.

[0274] This clarifies a bit the very interesting characteristics of a MIMRD 1 of this present disclosure.

[0275] Another important aspect of a MIMRD 1 of the present disclosure as illustrated in FIG. 15, but also in general, is that the planetary gearwheels or gearwheel components 26, 27 and 68 of the MIMRD 1 are each intermeshing with only one other gearwheel.

[0276] In that way the concerned gearwheels can be very precisely executed in order to cope with loads exerted in them, resulting in an increased efficiency of the gear train 5.

[0277] FIG. 16 illustrates another embodiment of a MIMRD 1 in accordance with the present disclosure, which is exactly the same as the embodiment of FIG. 15, except that the torque resisting or torque controlling means 11 are arranged in a different way.

[0278] This time, the ring wheel 30 which forms the second interacting gearing 19 of the primary second stage 8 is still the first element 10 of the MIMRD1, but it is not mounted fixedly in a housing 75 and is not fixedly connected to a ground 75, so that it is still rotatable with respect to such a housing 75 or ground.

[0279] Nevertheless, in this example on the outside of this ring wheel 30 an outer toothing 77 is provided which interacts with a pinion 78, which is mounted on the outgoing axis of an actuator or driver 79.

[0280] The actuator or driver 79 itself is controlled by a device 80 which can be a simple braking mechanism 80 or a clutch or any more complicated system by which torque and speed of the outgoing axis can be set.

[0281] According to the present disclosure the first element is a ring wheel, a sun wheel or a planet carrier which is mounted in a rotatable manner and which is provided with a mechanism comprising a braking mechanism or a clutch which is interacting or can interact with the rotatable ring wheel, sun wheel or planet carrier, whereby the braking mechanism comprises a combination of a motor or actuator and a brake. It is clear that in that way a torque resisting or rather a torque controlling means 11 is obtained that is not just blocking the movement of the ring wheel 30, but which can be used to impede the movement of the ring wheel 30 in a controllable way or even for setting the torque on the ring wheel 30 even in an active way, i.e. by driving the ring wheel by the actuator 79.

[0282] Of course, with this configuration of FIG. 16 the possibilities of controlling the interaction between the different rotatable devices 2 to 4 are very much increased.

[0283] The embodiment of a MIMRD 1 of the present disclosure illustrated in FIG. 17 is quite different and can be considered as a practical example of the schematic configuration of FIG. 2, since in this case there is only one second stage 8 and the first and second rotatable devices 2 and 3 are connected to this second stage 8 through first stages 6 and 7.

[0284] This single second stage 8 is again of the ring differential gearing type 33.

[0285] The connection of the first rotatable device 2 with this second stage 8 is identical to what is displayed in FIG. 15.

[0286] Since there are no two second stages 8 and 9, there is no need for a compound stage linking gearwheel 71.

[0287] For the same reason the third rotatable device 4 can only be connected or be in interaction with the only present second stage 8.

[0288] So, in this example the third rotatable device 4 is fixedly connected to the ring wheel 29 which is the first interacting gearing 18 of the second stage 8.

[0289] This ring wheel 29 therefore forms the second element 12 of the MIMRD 1 in the terminology of this present disclosure.

[0290] The first stage 7 connecting the second rotatable device 3 to the single second stage 8 is also of a PGT type, but it is slightly different.

[0291] This first stage 7 is similar to the first stage 6, but comprises additionally a ring wheel 81 which is forming an additional torque resisting or torque controlling means by being fixedly mounted in a housing 82 or to a ground 82.

[0292] The ring wheel 81 of this first stage 7 is interacting with each planetary gearwheel 83 of a set of first stage output planetary gearwheels 68 of the first stage 7.

[0293] The first stage 7 is linked to the second stage 8 in a different manner than the first stage 6.

[0294] In particular, the set of first stage output planetary gearwheels 68 formed by the planetary gearwheels 83 is mounted in a rotatable manner on planet shafts 90 of the common planet carrier 22 of the second stage 8 without being fixedly connected with the corresponding planetary gearwheels 26 or 27 of a set of second stage planetary gearwheels 16 or 17 of the second stage 8, as is on the contrary the case in the other first stage 6.

[0295] The second stage 8 is also provided with torque resisting or torque controlling means 11, which are the same as in FIG. 15, a ring wheel 30 being fixedly connected to a housing or ground 75.

[0296] This embodiment of a MIMRD 1 of the present disclosure is clearly executed in a somewhat simplified form, if compared with the embodiments of FIGS. 15 and 16.

[0297] But one can understand that still a very interesting configuration is obtained by which the interaction between the rotatable devices 2 to 4 can be arranged, certainly as far as controlling the mutual transmission ratio or transmission torque is concerned.

[0298] This embodiment is also very interesting in cases where the available space is very limited, such as in joints of prostheses or robotic arms and so on.

[0299] FIG. 18 illustrates an even still more reduced version of a MIMRD 1 in accordance with the present disclosure, which is a more practical elaboration of the schematic presentation of FIG. 3.

[0300] This embodiment of a MIMRD 1 according to the present disclosure is almost the same as the embodiment of FIG. 17.

[0301] A first difference however is that the second rotatable device 3 is not connected to the second stage 8 by a first stage 7, but this time the second rotatable device 3 is connected directly to this single second stage 8.

[0302] This corresponds indeed with the general representation of FIG. 3.

[0303] Actually the second rotatable device 3 is directly driving the common planet carrier 22 of the second stage 8.

[0304] The second rotatable device 3 is also provided with a brake 84.

[0305] Another difference with the embodiment of FIG. 17 is that in FIG. 18 the ring wheel 30 of the second stage 8 is not connected to the ground or housing 75 but mounted in a rotatable manner.

[0306] This ring wheel 30 is however still forming a torque resisting means or torque controlling means 11 in that it is provided with a brake 85 by which its movement can be impeded.

[0307] FIG. 19 illustrates still another embodiment of a MIMRD 1 in accordance with the present disclosure.

[0308] The MIMRD 1 comprises only one single second stage 8 which is of a carrier differential gearing type 44 having a compound interacting gearing 41 which is a compound ring wheel 42, similar to what was the case in FIG. 7.

[0309] This compound ring wheel 42 is provided at the outside with outer toothing 86, which is meshing with a pinion wheel 87 mounted fixedly on an outgoing shaft 88 of the third rotatable device 4.

[0310] The compound ring wheel 42 can therefore be considered as the second element 12 of the MIMRD 1.

[0311] The first stages 6 and 7 are similar to the first stages 6 and 7 illustrated in FIGS. 15 and 16, with a first stage input gearwheel 61 in the form of a sun wheel 62 that is fixedly mounted on a first stage input shaft 59.

[0312] The sun wheel 62 meshes with a set of first stage output planetary gearwheels 68 forming the first stage output elements 65, which are connected to the corresponding set of planetary gearwheels 37 or 38 of the second stage 8 by a fixed interconnection 76 and which are supported in a rotatable manner on the concerned planet carrier 20 or 21.

[0313] The planet carrier 20 which supports the first set of planetary gearing 16 of the second stage 8 is fixedly connected to a housing 89 or the ground 89 and is therefore forming the first element 10 of the MIMRD 1 that is forming a torque resisting or torque controlling means 11 of the MIMRD 1.

[0314] FIG. 20 illustrates another embodiment of a MIMRD 1 in accordance with the present disclosure, which comprises again two second stages 8 and 9, which are respectively executed as a sun differential gearing 36 and a ring differential gearing 33.

[0315] The first rotatable device 2 is linked to the primary second stage 8 by a first stage 6, which is exactly the same as the first stage 7 in FIG. 17 and which is also linked in the same way by having the set of first stage output planetary gearwheels 68 been mounted on planet shafts 90 of the common planet carrier 22 of the primary second stage 8.

[0316] The primary second stage 8 is a sun differential gearing having as first and second interacting gearing 18 and 19 a sun wheel 34 and a sun wheel 35.

[0317] The sun wheel 35 is fixedly connected to a ground, housing or fixed point 91 and is forming the first element 10 of the MIMRD 1 that is a torque resisting or torque controlling means 11.

[0318] The second rotatable device 3 is connected to the secondary second stage 9 by first stage 7 in exactly the same manner as is illustrated in FIG. 15.

[0319] The primary second stage 8 and the secondary second stage 9 are however interconnected in another way by a compound stage linking gearwheel 71 which is a compound gearing 92 comprising a sun wheel component 93 and a ring wheel component 94 interconnected to one another or made as a single monolithic piece.

[0320] One understands that in still another embodiment of a MIMRD 1 wherein a primary second stage 8 and a secondary second stage 9 are both sun differential gearings 36, the link between these second stages 8 and 9 can be made by a compound stage linking gearwheel 71 which is a compound sun wheel.

[0321] Many other embodiments of a MIMRD 1 in accordance with the present disclosure are possible and are not excluded from the present disclosure.

[0322] It is also clear that the dimensions, such as heights and lengths, of elements represented in the figures, such as dimensions of planet carriers and gearwheels, are in no way to be considered as a limitation and those elements can have very varying dimensions differing from what is represented in different pictures of the application or elements can have relative dimensions which are different from what is represented in a single picture.

[0323] Moreover, it should also be clear that one or more of the afore-mentioned geared elements of the gear train 5, can be designed as roller without teeth.

[0324] These geared elements can include, but are not limited to, the planetary gear train system 13, the first set 16 and a second set 17 of planetary gearing, the first and second interacting gearing 18,19 each composed of a number of planetary gearing elements 23,24, the first element 10 being a geared element 30,35 and/or the second element 12 being a gearwheel 29,42.

[0325] In this way a rolling contact between these elements is realised instead of a contact by teeth.

[0326] Also, when these geared elements are provided with teeth, these teeth can be executed very small.

[0327] The present disclosure is in no way limited to the embodiments of a mechanical interconnection of multiple rotatable devices 1 as described above and represented in the drawings, but such a mechanical interconnection of multiple rotatable devices 1 may be realised in different shapes and dimensions, without departure from the scope of the present disclosure.