Drive including a transmission driven by an electric motor

Abstract

A drive includes a transmission driven by an electric motor. A drive shaft of the transmission has multiple eccentric regions with differing widths in the axial direction, in which the high points thereof are offset relative to one another in the circumferential direction. The respective eccentric region is radially surrounded by a respective cam disk region, e.g., of a housing part of the transmission. Respective rollers are accommodated in respective recesses of a cage and arranged with a radial degree of freedom. The cage is rotationally fixed to the output shaft of the transmission. The output shaft along with the cage is rotatably mounted both relative to the cam disk regions and relative to the drive shaft. During operation, the respective rollers are made to roll and/or slide on the respective cam disk region by the respective eccentric region. The eccentric regions are arranged behind one another in the axial direction such that the dynamic imbalance is minimized and/or eliminated.

Claims

1. A drive, comprising: a transmission adapted to be driven by an electric motor, the transmission including a drive shaft having eccentric regions, each eccentric region being radially surrounded by a respective cam disk region of a first housing part of the transmission, respective rollers being accommodated in respective recesses of a cage and arranged with a radial degree of freedom; wherein the cage is rotationally fixed to an output shaft of the transmission; wherein the first housing part is connected to a second housing part; wherein the output shaft along with the cage is rotatably mounted both relative to the cam disk regions and relative to the drive shaft; wherein the output shaft has a wedge-shaped and/or V-shaped groove that is uninterrupted and/or fully circumferential in a circumferential direction, in which rolling bodies are accommodated; wherein a V-shaped recess is delimitated in an axial direction by the first housing part and against the axial direction by a second housing part.

2. The drive according to claim 1, wherein the drive shaft is arranged as a hollow shaft, at least two of the eccentric regions having differing widths in the axial direction, high points of the at least two of the eccentric regions being offset relative to one another in the circumferential direction; wherein the respective recesses radially pass through the cage and are evenly spaced from one another in the circumferential direction; wherein a first rolling region of the rolling body is arranged on a flank of the wedge-shaped or V-shaped groove and a second rolling region of the rolling body is arranged on the first housing part or on the second housing part; wherein the V-shaped recess is arranged radially outside the V-shaped groove; wherein the second housing part includes axial bores adapted to connect to a device to be driven by the transmission of the drive; wherein the output shaft includes axial bores at an axial end region facing away from the cage and adapted to connect to a rotatably mounted part of the device to be driven; wherein the rolling bodies are adapted to roll and/or slide on the respective cam disk region by the respective eccentric region during operation of the drive; wherein widths B_i of the eccentric regions and circumferential angle positions _i of the high points associated with the respective eccentric region are formed such that a sum of all products B_i * cos(_i) is eliminated and that a sum of all products B_i * sin(_i) is eliminated, i represents a number of the eccentric regions; wherein the eccentric regions are arranged behind one another in the axial direction to minimize and/or eliminate dynamic imbalance.

3. The drive according to claim 1, wherein a stiffening ring is provided on the cage on a side facing away from the axial bores of the output shaft, the stiffening ring being aligned coaxially to the cage and coaxially to the output shaft, a radial wall thickness of the cage in a region covered by the stiffening ring in the axial direction being greater than a wall thickness of the cage outside the region.

4. The drive according to claim 1, wherein first recesses of the cage are rectangular in shape, relief notches project in the axial direction in corner regions of the rectangular recesses, and a distance between two relief notches measured in the circumferential direction decreases monotonically in the axial direction and/or with increasing distance from the rectangular recesses.

5. The drive according to claim 1, wherein first recesses of the cage are rectangular slot-shaped, a respective axial end region of the slot-shaped recess is rounded and/or semicircular, on a first spacer ring, radially projecting nubs project into the first recesses and axially delimit first rollers that are accommodated in the first recesses.

6. The drive according to claim 5, wherein a first one of the nubs of the first spacer ring projects into the first recess and axially delimits a respective first roller accommodated in the first recess, and a second one of the nubs of the first spacer ring next adjacent to the first one of the nubs of the first spacer ring projects into a respective second recess of the cage and axially delimits a second roller accommodated in the second recess, the second recess being axially spaced from the first recess.

7. The drive according to claim 1, wherein an inner radius of a first cam disk region depends periodically on a circumferential angle, and the first cam disk region in the axial direction includes a region covered by a respective first roller in the axial direction.

8. The drive according to claim 1, wherein an outer radius of the drive shaft in the respective eccentric region depends on a circumferential angle.

9. The drive according to claim 1, wherein an axial region covered by the respective eccentric region at least overlaps with an axial region covered by the cam disk region, the cam disk region touching the same roller as the respective eccentric region.

10. The drive according to claim 1, wherein the drive shaft is rotationally fixed to a rotor shaft of the electric motor and/or is adapted to be driven by the rotor shaft of the electric motor via at least one gear stage, a first toothed part being rotationally fixed to the rotor shaft and a second toothed part being rotationally fixed to the drive shaft.

11. The drive according to claim 1, wherein the cam disk regions are arranged on an inside of the first housing part of the transmission, the first housing part is connected to a second housing part, rolling bodies of a bearing arrangement of the output shaft are delimited by the first housing part, by the second housing part, and by the output shaft.

12. The drive according to claim 11, wherein the output shaft has a V-shaped annular groove arranged fully circumferential in the circumferential direction, i in which the rolling bodies are accommodated, and a further V-shaped recess arranged fully circumferential in the circumferential direction, in which the rolling bodies are accommodated and which has an orientation reversed to the V-shaped annular groove, is formed and/or edged by the first and second housing part.

13. The drive according to claim 1, wherein a bearing is arranged on a first one of the eccentric regions, on which first rollers roll and/or slide directly or on which a ring is fitted, on which the first rollers roll and/or slide.

14. The drive according to claim 1, wherein an inner radius of the respective cam disk region depends periodically on a circumferential angle, an outer radius of the shaft in the respective eccentric region depends on circumferential angle, an axial region covered by the respective eccentric region at least overlaps with an axial region covered by the respective associated cam disk region, and/or a respective bearing is and on the respective eccentric region.

15. The drive according to claim 1, wherein the cam disk regions are arranged in the first housing part, which is connected to the second housing part, in which a bearing arrangement is accommodated that rotatably supports the output shaft, a respective inner ring of the bearing arrangement being accommodated on the output shaft and a respective outer ring of the bearing being accommodated in the second housing part.

16. The drive according to claim 1, wherein a shaft seal ring is arranged in the output shaft, the shaft seal ring sealing toward the drive shaft, a further shaft seal ring being arranged in the second housing part, the further shaft seal ring sealing toward the output shaft.

17. The drive according to claim 1, wherein a third housing part, arranged as an adapter housing, is connected to the first housing part, by connecting screws evenly spaced in the circumferential direction, the third housing part being connected to a housing of the electric motor that is adapted to drive a first gear wheel that is in mesh with a second gear wheel that is rotationally fixed to the drive shaft, the third housing part at least partially surrounding the first and second gear to form the housing.

18. A drive, comprising: a transmission adapted to be driven by an electric motor, a drive shaft of the transmission including multiple eccentric regions with differing widths in an axial direction, high points of the eccentric regions being offset relative to one another in a circumferential direction, each eccentric region being radially surrounded by a respective cam disk region; wherein, corresponding to the different widths of the eccentric regions, rollers with differing widths in the axial direction are accommodated in respective recesses of a cage and arranged with a radial degree of freedom; wherein the cage is rotationally fixed to an output shaft of the transmission; wherein the output shaft and the cage are rotatably mounted both relative to the cam disk regions and relative to the drive shaft; wherein the first housing part is connected to a second housing part; wherein the output shaft includes a wedge-shaped and/or V-shaped groove that is uninterrupted and/or fully circumferential in the circumferential direction, in which rolling bodies are accommodated; wherein a V-shaped recess is delimited in an axial direction by the first housing part and against the axial direction by the second housing part; wherein the rolling bodies are adapted to roll and/or slide on the respective cam disk regions by the respective eccentric regions during operation of the drive; wherein the rolling bodies and/or the eccentric regions with differing widths are arranged behind one another in the axial direction to minimize and/or eliminate dynamic imbalance.

19. The drive according to claim 18, wherein the recesses radially passing through the cage; wherein a first rolling region of the rolling body is arranged on a flank of the groove and a second rolling region of the rolling body is arranged on the first housing part or on the second housing part; wherein the recess is arranged radially outside the groove; wherein the second housing part has axial bores adapted to connect to a device to be driven by the transmission of the drive; wherein the output shaft includes axial bores at an axial end region facing away from the cage adapted to connect to a rotatably mounted part of the device to be driven; wherein widths C_i of the rolling bodies and widths C_i of and circumferential angular positions _i of high points associated with the respective eccentric region are arranged such that a sum of all products C_i * cos(_i) is eliminated and that a sum of all products C_i * sin(_i) is eliminated, i representing numbers the eccentric regions; and wherein the cage is rotationally fixed to the output shaft.

20. A drive, comprising: a transmission adapted to be driven by an electric motor and including a drive shaft having a first eccentric region radially surrounded by a first cam disk region; wherein first rollers are accommodated in first recesses of a cage and arranged with a radial degree of freedom; wherein the drive shaft includes a second eccentric region radially surrounded by a second cam disk region; wherein second rollers are accommodated in second recesses of the cage and arranged with a radial degree of freedom; wherein the drive shaft includes a third eccentric region is radially surrounded by a third cam disk region; wherein third rollers are accommodated in third recesses of the cage and arranged with a radial degree of freedom; wherein the cage is rotationally fixed to an output shaft of the transmission; wherein the first eccentric region is arranged in an axial direction between the second and the third eccentric region; wherein the output shaft and the cage are rotatably mounted both relative to the cam disk regions and relative to the drive shaft; wherein the first housing part is connected to a second housing part; wherein the output shaft has a wedge-shaped and/or V-shaped groove that is uninterrupted and/or fully circumferential in a circumferential direction, in which rolling bodies are accommodated; wherein a V-shaped recess is delimited in the axial direction by the first housing part and against the axial direction by the second housing part; and wherein the rolling bodies are adapted to roll and/or slide on the respective cam disk region by the respective eccentric region during operation.

21. The drive according to claim 20, wherein a sum of an axial width of the second eccentric region and the third eccentric region equals an axial width of the first eccentric region.

22. The drive according to claim 20, wherein the first recesses radially pass through the cage; wherein the second recesses radially pass through the cage; wherein the third recesses radially pass through the cage; wherein the axial direction is parallel to an axis of rotation of the drive shaft; wherein a first rolling region of the rolling body is arranged on a flank of the groove and a second rolling region of the rolling body is arranged on the first housing part or on the second housing part; wherein the recess is arranged radially outside the groove; wherein the second housing part has axial bores adapted to connect to a device to be driven by the transmission; wherein the output shaft has axial bores at an axial end region facing away from the cage and adapted to connect to a rotatably mounted part of the device to be driven; and wherein the first rollers are adapted to roll and/or slide on the first cam disk region by the first eccentric region, the second rollers are adapted to roll and/or slide on the second cam disk region by the second eccentric region, and the third rollers are adapted to roll and/or slide on the third cam disk region by the third eccentric region.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a cross-sectional view of a drive.

(2) FIG. 2 is a partial cross-sectional view of the drive.

(3) FIG. 3 is a partial cross-sectional view of the drive.

(4) FIG. 4 is a perspective view of a cage 4 in which first rollers 3 and second rollers 4 are accommodated and roll and/or slide on the first housing part 2.

(5) FIG. 5 is a cross-sectional view of the first housing part 2, in which only the row formed by the first rollers 3 is illustrated.

(6) FIG. 6 is a further cross-sectional view of the first housing part 2, in which the row formed by the first rollers 3 and the row formed by the second rollers 4 are illustrated.

(7) FIG. 7 is a perspective view of the cage 4.

(8) FIG. 8 is a perspective view of a further drive, in which three rows of rollers are provided, which are partially removed.

(9) FIG. 9 is a perspective view with the rolling elements of the eccentric bearings in place.

(10) FIG. 10 illustrates the rollers 3 of the drive, with the cage connected to the output shaft 10 removed.

(11) The cage is illustrated in FIG. 11, in contrast to FIG. 10.

(12) FIG. 12 is a cross-sectional view of the drive.

(13) FIG. 13 illustrates a tip relief and root relief for the contour of a cam disk of the drive.

(14) FIG. 14 illustrates the output shaft 10 of the example illustrated in FIG. 8.

(15) FIG. 15 is a top view of a region of the cage.

(16) FIG. 16 is an enlarged view of a recess of the cage.

(17) FIG. 17 is an enlarged view of another recess of the cage.

(18) FIG. 18 is a cross-sectional view of the bearing arrangement of the output shaft 10 in more detail, in which a ball 180 is used as a rolling body instead of a cylinder or a barrel.

(19) FIG. 19 illustrates an alternative cage 10, in which the recesses are provided without notches and spacer rings (190, 191) clamp into the recesses of the cage 10 with their nubs projecting radially outwards.

(20) The cage 10 is hidden in FIG. 20, in contrast to FIG. 19.

(21) FIG. 21 is a perspective view of a third spacer ring 190.

(22) FIG. 22 is a perspective view of a first spacer ring 190.

DETAILED DESCRIPTION

(23) As illustrated in FIGS. 1 to 6, a first gear 12 is rotationally fixed to the rotor shaft of an electric motor 11 and drives a second gear 13, which meshes with the first gear.

(24) The second gear 13 is rotationally fixed to the hollow shaft 1, which has a first eccentric region 8 and a second eccentric region 9 axially spaced therefrom.

(25) In the respective eccentric region (8, 9), the outer radius as a function of the circumferential angle is not constant, but depends on the circumferential angle. For example, the function has a single maximum and a single minimum.

(26) The hollow shaft 1 is arranged as an input shaft and can also be referred to as a drive shaft.

(27) The circumferential angle associated with the maximum of the first eccentric region 8 is at a distance in the circumferential direction from the circumferential angle associated with the maximum of the second eccentric region 9.

(28) The outer circumference of the respective eccentric region (8, 9) is circular-cylindrical, i.e., circular, for example. This means that a first bearing 5 can be placed on the first eccentric region 8 and a second bearing 7 on the second eccentric region 9.

(29) The first bearing 5 can be arranged as a ball bearing and the second bearing 7 also as a ball bearing.

(30) First rollers are provided on the outer circumference of the first bearing 5, which either roll and/or slide directly on the outer ring of the first bearing 5 or on a ring pushed onto the outer ring of the first bearing 5.

(31) These first rollers 3 are held in a cage 4 and are thus spaced apart from one another in the circumferential direction. This is because the cage 4 has a recess for each first roller 3, in which recess the roller 3 is accommodated. The recesses are, for example, shaped in the same manner, e.g., identically, and/or arranged at the same radial distance and/or cover the same axial region.

(32) The second rollers 6 are also held axially spaced from the first rollers 3 in a cage 4 and are thus spaced apart from each other in the circumferential direction. This is because the cage 4 has a second recess for every second roller 6, in which this second roller 6 is accommodated. The second recesses are, e.g., shaped in the same manner, for example, identically, and/or arranged at the same radial distance and/or cover the same axial region.

(33) Each of the first and second rollers thus touches the respective eccentric region radially inwards.

(34) The first rollers touch a first cam disk region formed on the inside of a first housing part 2 radially outwards and roll on it.

(35) This first cam disk region has an inner radius that is periodically dependent on the circumferential angle, e.g., sinusoidally dependent. The cam disk region is formed in one piece, i.e., in one part, with the housing part 2.

(36) The cam disk region has a discrete rotational symmetry, e.g., the count of which is equal to the number of complete periods formed in the circumferential direction.

(37) The associated axis of symmetry of the rotational symmetry is identical to the axis of rotation of the hollow shaft 1.

(38) The second rollers 6 touch a second cam disk region formed on the inside of the first housing part 2 radially outwards and roll on it.

(39) This second cam disk region has an inner radius that is periodically dependent on the circumferential angle, e.g., sinusoidally dependent. The second cam disk region is formed in one piece, i.e., in one part, with the housing part 2.

(40) The second cam disk region has a discrete rotational symmetry, e.g., the count of which is equal to the number of complete periods of the second cam disk region formed in the circumferential direction.

(41) The associated axis of symmetry of the rotational symmetry of the second cam disk region is identical to the axis of rotation of the hollow shaft 1.

(42) The second cam disk region is arranged axially next to the first cam disk region.

(43) As shown in FIGS. 1 to 6, the second cam disk region is configured in the same manner as the first cam disk region, i.e., it is not offset in the circumferential direction. The sinusoidal dependence of the inner radius of the second cam disk region on the circumferential angle is thus identical to the sinusoidal dependence of the inner radius of the first cam disk region on the circumferential angle.

(44) For example, however, the second cam disk region is offset in the circumferential direction by half a period length relative to the first cam disk region. For example, the offset is thus 180/M, where M is the number of periods of the cam disk region in the circumferential direction. Alternatively, an offset of 180 is also possible, in which, for example, the offset of the eccentric regions to each other may but need not be omitted. For example, further rows of rollers are provided axially spaced from the first and second, which also roll or slide on the cam disk region, in which the associated eccentric regions are offset by 360/N, in which N is the number of roller rows.

(45) As illustrated in FIGS. 1 to 6, the second cam disk region is arranged in the same manner as the first cam disk region and the entire cam disk region can thus be manufactured readily and cost-effectively.

(46) The number of periods and also the eccentricity enable a high transmission ratio with high torque.

(47) As illustrated in FIGS. 1 to 6, the cage 4 surrounds the shaft 1. For this purpose, the smallest radial distance of the cage 4 at each axial position is thus greater than the largest radial distance of the shaft 1 in the axial region covered by the cage 4.

(48) At each axial position, the radial distance region covered by the cage 4 is arranged radially spaced from the radial distance region covered by the shaft 1 and/or radially spaced and/or further out.

(49) The axial direction is aligned parallel to the axis of rotation of the shaft 1. The mentioned radial distances are thus always related to the axial axis. The circumferential direction and the circumferential angle are also related to this axial direction.

(50) The cage 4 is arranged in one piece, i.e., in one part, with the output shaft 10.

(51) Thus, the cage 4 is formed in a first axial region of this part and the output shaft 10 is formed axially adjacent to the cage 4 on the output side, which output shaft 10 has axial bores on its axial end face, which are arranged as threaded bores. This means that a device to be driven with its rotatably mounted element can be screw-connected to the shaft 1.

(52) The output shaft 10 can also be referred to as an outputting shaft.

(53) The output shaft 10 is mounted towards the shaft 1 by a further bearing 16 and rotatably mounted towards the housing, e.g., towards a second housing part 17 connected to the first housing part 2, by two bearings (14), which are, for example, arranged as angular contact bearings.

(54) In this manner, the cage 4 together with the output shaft 10 is made to rotate as smoothly as possible.

(55) To reduce imbalance and further improve smooth running, the first and second eccentric regions 8 and 9 are configured identically but offset by 180 to each other in the circumferential direction. If additional eccentric regions and correspondingly assigned roller rows are used, a circumferential offset of 360/N between two adjacent roller rows is possible, in which the number of roller rows is equal to the number of eccentric regions.

(56) Furthermore, a shaft seal ring 15 is provided towards the shaft 1, e.g., radially inwards, and a further shaft seal ring 18 is provided towards the housing, e.g., radially outwards towards the housing.

(57) The shaft seal ring 15 is accommodated by the output shaft 10 and its sealing lip runs on a finely machined region of the shaft 1.

(58) The shaft seal ring 18 is accommodated in the second housing part 17 and its sealing lip runs on the output shaft 10 or on a ring fitted on the output shaft 10.

(59) The bearings of the bearing arrangement 14, which are, for example, arranged as angular contact bearings, are accommodated with their outer ring in the second housing part 17 and are fitted with their inner ring onto the output shaft 10.

(60) The inner ring of the additional bearing 16, e.g., the roller bearing, e.g., the ball bearing, is fitted onto the shaft 1. The outer ring of the additional bearing 16 is accommodated in the output shaft 10.

(61) The inner ring of the first bearing 5 is fitted onto the first eccentric region 8.

(62) The inner ring of the second bearing 7 is fitted onto the second eccentric region 9.

(63) The outer ring of the first bearing 5 or a ring part fitted onto this outer ring is arranged as a rolling surface for the first rollers 3.

(64) The outer ring of the second bearing 7 or a ring part fitted onto this outer ring is arranged as a rolling surface for the second rollers 6.

(65) A third housing part 19 at least partially surrounds the spur gear stage formed by the first and second gears (12, 13). The third housing part 19 is connected to the housing of the electric motor driving the first gear 12.

(66) The first housing part 2 and the second housing part 10 are arranged on the side of the third housing part 19 facing away from the electric motor 11. The first housing part 2 is arranged between the second housing part 10 and the third housing part 19. The first, second, and third housing parts (19, 2, 10) are connected by means of connecting screws 20 passing through these three housing parts (19, 2, 10).

(67) As illustrated in FIGS. 1 to 7, e.g., in FIGS. 4 and 7, the first rollers 3 and also the recesses of the cage 4 accommodating the first rollers 3 form a first row in the circumferential direction.

(68) Similarly, the second rollers 6 and also the recesses of the cage 4 accommodating the second rollers 6 form a second row in the circumferential direction.

(69) The first rollers 3 are regularly spaced from one another in the circumferential direction, e.g., evenly spaced. Similarly, the second rollers 6 are spaced from one another in the circumferential direction, e.g., evenly spaced.

(70) The rollers (3, 6) of each roller row are all located on a circle or the axes of the rollers (3, 6) are located on an imaginary cylinder. The center of this circle respectively lies on the axis of the associated eccentric region or the axis of this respective cylinder is concentric with the associated eccentric region. Accordingly, the cylinder axes are arranged parallel but radially offset to each other. The first roller 3 is in contact with the first eccentric region 8 and the second rollers 6 are in contact with the second eccentric region 9. The two rows are thus not coaxially aligned with each other. In addition, the cylinder containing the axes of rotational symmetry of the first rollers 3 is axially spaced from the cylinder containing the axes of rotational symmetry of the second rollers 6.

(71) In the circumferential direction, however, the first row is offset from the second row by half a period length of the first rollers 3 within the first row.

(72) Each second roller 6 thus has an offset angle of 180/N to a respective first roller 3, where N is the number of first rollers 3 arranged in the first row.

(73) In this manner, a lower torque ripple is achieved.

(74) For example, further rows with further rollers and associated cam disk arrangements are provided.

(75) FIG. 8 illustrates an example of another drive in which three rows of rollers are provided.

(76) As illustrated in FIG. 8, the input hollow shaft 1 has a first eccentric region 80, which is arranged axially between a second and a third eccentric region (81, 82).

(77) The high point of the first eccentric region 80 is offset by 180 in the circumferential direction to the high points of the second and third eccentric regions (81, 82), which high points are respectively arranged at the same circumferential position.

(78) In the axial direction, the first eccentric region 80 is wider than the second eccentric region 81.

(79) In the axial direction, the first eccentric region 80 is wider than the third eccentric region 82.

(80) For example, the sum of the axial widths of the second and third eccentric regions (81, 82) is equal to the axial width of the first eccentric region 80.

(81) Thus, a particularly well-balanced solution is achieved.

(82) A rolling bearing is respectively slid onto each of the eccentric regions (80, 81, 82), which are referred to below as eccentric bearings.

(83) A first eccentric bearing, whose rolling bodies 16 are designed as a cylindrical roller or barrel, is pushed onto the first eccentric region. The rolling bodies (83, 87) of the second and third eccentric bearing are also configured as cylindrical rollers or barrels.

(84) The output shaft 10 has a flange block interface on the output side, i.e., an interface that is suitable for robot applications. Axial bores, which are arranged as threaded bores and are spaced apart from one another in the circumferential direction, are available on the output shaft 10.

(85) At its end region axially facing away from the flange block interface, the output shaft 10 has a tubular region that is configured as a cage and radially surrounds the eccentric bearings (80, 81, 82).

(86) The respective rollers (16, 88, 89) are accommodated in recesses (141, 142, 143) of the cage and are arranged so as to be movable in a radial direction relative to the cage. Thus, the range of movement of the rollers (16, 88, 89) is delimited radially inwards by the respective outer ring of the respective eccentric bearing and radially outwards by a respective cam disk contour, which is formed on the inside of the first housing part 2. The first of the cam disk contours is in turn offset by 180 in the circumferential direction to the other two cam disk contours, which run in the same manner to each other, i.e., without offset.

(87) The first rollers 16 thus roll on the first cam disk contour and the second rollers 88 roll on the second cam disk contour. The third rollers 89 roll on the third cam disk contour.

(88) In the axial direction, the first cam disk contour is arranged between the second and third cam disk contour.

(89) A second housing part 17 is connected to the first housing part 2 and surrounds the flange block interface of the output shaft 10.

(90) The second and third rollers (88, 89), which differ in width from the first roller 16, are thus arranged such that the dynamic imbalance is minimized or eliminated.

(91) Cylindrical or barrel-shaped rolling bodies 14 are provided for mounting the output shaft 10 along with the cage, the cylindrical axis of which rolling bodies 14 intersects with the axis of rotation of the output shaft 10, e.g., having an angle of between 10 and 80 to the axis of rotation of the output shaft 10.

(92) The running surface of the rolling body 14 is formed on the second housing part 17 on the one hand and on the output shaft 10 on the other.

(93) For example, the output shaft 10 forms an inner ring and the second housing part forms the outer ring of the bearing arrangement of the output shaft 10.

(94) In addition, the first housing part 2 delimits the rolling body 14, e.g., in the direction of the cylindrical axis of the rolling body 14.

(95) The rolling body 14 is thus delimited by the first housing part 2, the second housing part 17 and the output shaft 10.

(96) To accommodate the rolling body 14, the output shaft 10 has a V-shaped annular groove, e.g., the annular axis of which is aligned coaxially with the axis of rotation of the output shaft 10.

(97) By the rolling body 14, the V-shaped annular groove of the output shaft 10 and the V-shaped recess, the walls of which are formed by the first housing part 2 and the second housing part 17, the bearing of the output shaft corresponds to a crossed roller or four-point bearing arrangement. Both radial and axial forces are absorbed by the bearing arrangement. For example, the bearing arrangement also absorbs moments directed in this manner.

(98) As illustrated in FIG. 18, a rolling body 180 designed as a ball can be used instead of the cylindrical or barrel-shaped rolling body 14.

(99) As illustrated in FIG. 13, the respective cam disk contour has a tip relief 131 at the radially inwardly projecting tip regions of a nominal curve 130, e.g., a nominal contour, of the cam disk and a root relief 132 at the root regions of this nominal curve 130. For example, the root regions are the regions of the nominal curve 130 that are radially furthest away from the axis of rotation of the output shaft 10.

(100) The input shaft 1 is oriented coaxially to the output shaft 10.

(101) The output shaft 10, e.g., its cage, has a circumferentially continuous stiffening ring 90 at its axial end region facing away from the flange block interface. For example, the stiffening ring 90 projects radially outwards on the cage.

(102) In this manner, the thin-walled cage is reinforced and achieves a higher load capacity and load-bearing capacity. The radial wall thickness of the cage is smaller than the radial wall thickness in the remaining region of the output shaft 10, e.g., in the axial region which is covered by the rolling bodies 14.

(103) The cage has three rows of recesses (141, 142, 143) corresponding to the rows of rollers.

(104) In the circumferential direction, the recesses (141, 142, 143) of the respective row are evenly spaced from one another and in the same axial position.

(105) The first row of recesses 141 is arranged axially between the second row of recesses 142 and the third row of recesses 143. In particular, the row of second recesses 142 is offset relative to the row of first recesses 141 in the circumferential direction. The row of second recesses 142 is not offset relative to the row of third recesses 141 in the circumferential direction.

(106) As illustrated in FIGS. 15 to 17, the recesses (141, 142, 143) have relief notches at their four corner regions, for example. The edges of the first recesses 141, which edges are arranged axially on both sides, are thus dovetail-shaped.

(107) Respectively two of the relief notches are curved. For example, the relief notches of each such pair are curved such that they are directed towards each other.

(108) Each first recess 141 has a rectangular region, the corner regions of which are adjoined by relief notches which, on the one hand, i.e., on a first side of the rectangular region, project in the axial direction, in which the distance between the two relief notches on the first side decreases monotonically, e.g., strictly monotonically, as the axial position increases, e.g., more and more in the axial direction, and, on the other hand, i.e., on the other side of the rectangular region, project against the axial direction, in which the distance between the two relief notches on this other side decreases monotonically, e.g., strictly monotonically, as the axial position decreases, e.g., more and more against the axial direction.

(109) The curved shape is, for example, composed of radii R.

(110) The first rollers 3 are delimited in the axial direction by the respective first and the respective other side of the rectangular region.

(111) In contrast to the first recesses 141, the second recesses 142 only have a single pair of relief notches facing each other. The other respective pair, which on the side of the second recesses 142 facing away from the first recesses, has relief notches aligned substantially parallel to each other.

(112) As illustrated in FIGS. 19 to 22, the cage can also be provided with rounded rectangular slot-shaped recesses. The axial delimitation of the first rollers 3 is achieved by a first spacer ring 191, the radially projecting nubs of which project into respective first fillets of the rectangular slot-shaped recesses and thus axially delimit the respective roller 3, in which a further spacer ring projects with its nubs into the respective other fillet.

(113) The nub of the spacer ring that is closest to a nub of the first spacer ring projecting into the fillet of the first recess projects into the fillet of a respective third recess to delimit a respective third roller 89.

(114) The nub of the further spacer ring that is closest to a nub of the further spacer ring projecting into the second fillet of the first recess projects into the fillet of a respective second recess to delimit a respective second roller 88.

(115) A second spacer ring 190 respectively projects with its radially projecting nubs into a fillet of the respective second recess and axially delimits the respective second roller 88.

(116) A third spacer ring 190 respectively projects with its radially projecting nubs into a fillet of the respective third recess of the cage and axially delimits the respective third roller 89.

(117) As illustrated in FIGS. 19 to 22, four spacer rings are thus required for three rows of rollers, each of which spacer rings is, e.g., manufactured as a plastic injection-molded part. The nubs of the respective spacer ring (190, 191) are regularly spaced from one another in the circumferential direction.

(118) The nubs are flat on the side axially delimiting the respective roller and rounded in accordance with the fillet on the side facing away from the roller axially delimited by the nub. In this manner, the end face of the respective cylindrical or barrel-shaped roller touches the flat region of the respective nub.

(119) For example, the rollers (16, 88, 89) have different widths in the axial direction and are arranged behind one another such that the dynamic imbalance is reduced or eliminated.

(120) When using N rows of rollers, the widths C_i of the rollers are selected such that the sum of the products of the respective width C_i and the cosine value of the circumferential position of the high point assigned to the respective eccentric region is eliminated, as is the sum of the products of the respective width C_i and the sine value of the circumferential position of the high point assigned to the respective eccentric region.

(121) It is permissible, for example, for two of the roller rows to have the same width and for the eccentric regions assigned to the two roller rows to have the identical circumferential angle position of their high points. A high point of a further eccentric region, which is assigned to a third row of rollers, may have a different position to this.

(122) The rollers of roller rows whose associated eccentric region has the same circumferential angle position of its high point have the same axial width in total as the sum of the axial width of other rollers of other roller rows whose associated eccentric region has a different circumferential angle position of its high point in common.

(123) In the circumferential direction, the high points of the eccentric regions are arranged such that the radial forces resulting from the rolling contacts of the rollers during operation cancel each other out.

(124) In the axial direction, the high points of the eccentric regions are arranged such that the moments of the radial forces resulting from the rolling contacts of the rollers during operation cancel each other out.

(125) In the arrangement illustrated in FIG. 8, the rollers of the different roller rows are of unequal width in the axial direction, e.g., have different widths. The axial width of the first, i.e., middle, roller is equal to the sum of the axial widths of the rollers in the other two roller rows.

(126) The high points of the axially outer eccentric regions are arranged at the same circumferential angle position.

LIST OF REFERENCE NUMERALS

(127) 1 Hollow shaft with eccentric regions 2 First housing part 3 First roller 4 Cage for first rollers 1 and second rollers 6 5 First bearing, e.g., rolling bearing, e.g., ball bearing 6 Second roller 7 Second bearing, e.g., rolling bearing, e.g., ball bearing 8 First eccentric region of the hollow shaft 1 9 Second eccentric region of the hollow shaft 1 10 Output shaft 11 Electric motor 12 First gear 13 Second gear 14 Bearing arrangement, e.g., barrel-shaped rolling bodies 15 Inner shaft seal ring 16 Further bearing, e.g., rolling bearing, e.g., ball bearing 17 Second housing part 18 Outer shaft seal ring 19 Third housing part 20 Connecting screws 80 First eccentric region 81 Second eccentric region 82 Third eccentric region 83 Third roller 84 Bearing ring of the third eccentric bearing 85 Bearing ring of the second eccentric bearing 86 Bearing ring, e.g., inner ring, of the first eccentric bearing 87 Rolling body of the second eccentric bearing 88 Second roller 89 Third roller 90 Stiffening ring 130 Nominal curve of the cam disk 131 Tip relief 132 Root relief 141 Recess for accommodating the first roller 6 142 Recess for accommodating the second roller 88 143 Recess for accommodating the third roller 89 144 Running surface for the rolling body 87 of the second eccentric bearing 145 Notch, e.g., shaped pocket end 180 Ball as rolling body of the second eccentric bearing 190 Third spacer ring with nubs 191 First spacer ring with nubs 192 Second spacer ring with nubs