ALL-ELECTRIC DRIVE UNIT FOR A VEHICLE, IN PARTICULAR A SELF-PROPELLED WORKING MACHINE, AND METHOD FOR ITS OPERATION

Abstract

In order to be able to supply the traction drive on the one hand and the working unit (210) on the other hand with the energy required in each case independently of one another in a purely electrically driven vehicle (200), in particular a self-travelling working machine (200), a fully electric drive unit (100) is provided which supplies both, with a planetary gear unit (1) which is driven by two separately controllable electric machines (E1, E2) and thus, considered on its own, acts as a summing gear.

Because of an additional power output (NA1), which is coupled to one of the two E-machines (E1) and/or the corresponding drive input into the planetary gear (1) with a fixed transmission ratio, the working unit (210) can be supplied via this power output (NA1), while the speed of the traction drive is independently controlled via the differential speed between the sun gear (2) and the ring gear (3), which are driven by the two E-machines (E1, E2).

The sum of the planetary gear and the power output (NA1) thus acts primarily as a power divider gear.

Claims

1. An all-electric drive unit (100) for a self-travelling working machine (200) with a carrier vehicle (220) and a working unit (210) integrated or demountably arranged thereon, wherein the drive unit (100) comprises: a power split gearbox (50) with a planetary gear (1) with rotatable elements including sun gear (2), ring gear (3) and planet carrier (4), wherein one of these three rotatable elements can be used as the main output of the planetary gear (1), two drive sources, each of which is operatively connected to one of the other two of the said three rotatable elements (2, 3, 4) of the planetary gear (1) and is capable of driving the latter a control (100*) capable of centrally controlling the two drive sources independently of each other, characterized by two E-machines (E1, E2) as drive sources, the E-machines (E1, E2) being controllable independently of one another, at least one power output (NA1) which is operatively connected to one of the two E-machines (E1 or E2), in a fixed transmission ratio.

2. The drive unit according to claim 1, characterized in that the maximum power of the more powerful E-machine (e.g. E1) is greater than that of the less powerful E-machine (e.g. E2) by a maximum of 500%, preferably only by a maximum of 300%, in particular both E-machines (E1, E2) have the same maximum power.

3. The drive unit according to claim 1, characterized in that the maximum speed of the faster of the planet carrier on the one hand and the power output on the other hand is at most 500%, better only by at most 300%, higher than that of the slower of the two, in particular the maximum speed of the planet carrier on the one hand and of the power output on the other hand is the same.

4. The drive unit according to claim 1, characterized in that the planet carrier (4) is operatively connectable to drive wheels (221a, b) of a vehicle, in particular a carrier vehicle (220), or the at least one power output (NA1) can be operatively connected to the working unit (210).

5. The drive unit according to claim 1, characterized in that one E-machine (E1, E2) is operatively connected to the sun gear (2) and the other E-machine (E2, E1) is operatively connected to the ring gear (3), or the two E-machines (E1, E2) can be switched over in the direction of rotation.

6. The drive unit according to claim 1, characterized in that the power output (NA1) is a power output shaft (ZW1), and/or the power output (NA1) can be uncoupled via a clutch (5).

7. The drive unit according to claim 1, characterized in that the two E-machines (E1, E2) are arranged axially parallel, in particular concentrically to one another, in particular with the planetary gear unit (1) at one of the two end faces of the e-machine group.

8. The drive unit according to claim 1, characterized in that in the case of coaxially arranged e-machines (E1, E2), the e-machine (E1 or E2) further away from the planetary gear (1) is operatively connected, in particular axially, to the power output (NA1).

9. The drive unit according to claim 1, characterized in that a torque detector (14) is arranged on at least one of the output drives (HA, NA1, NA2, NA3), preferably only on one output drive, preferably only on the main output drive (HA), and/or the planet carrier (4) is operatively connected to a power divider gear (VG), in particular a differential.

10. The drive unit according to claim 1, characterized in that with the main output (HA), arranged coaxially or in parallel, a clutch (5), and/or a brake (13) is operatively connected, and the working unit (210) or one of its energy-consuming sub-units during operation is used as brake (13).

11. A fully-electrically driven vehicle, in particular a self-travelling working machine (200), characterized in that the drive unit of the self-travelling working machine (200) is an all-electric drive unit (100) according to claim 1.

12. The vehicle according to claim 11, characterized in that the planet carrier (4) is operatively connected to the drive wheels (222a, b) of a carrier vehicle (220), the at least one power output (NA1) is operatively connected in particular to the working unit (210),

13. The vehicle according to claim 11 characterized in that the driven axle (221) together with the all-electric drive unit (100) is an integrated, jointly manageable, drive axle assembly (222).

14. A method of controlling a self-travelling working machine (200) having a carrier vehicle (220) and a working unit (210) mounted thereon, and a drive unit (100) driving both, comprising: A) for primary operation of the working unit (210) during slow travel or even standstill of the carrier vehicle (220) the sun gear (2) and ring gear (3) are each driven in opposite directions by one of the two E-machines (E1, E2) so that the difference in speed determines the speed of the planet carrier (4) and thus of the driving wheels (222a, b) the two E-machines (E1, E2), in particular the E-machine (E1) coupled to the power output (NA1), are controlled in such a way that the working unit (210) coupled to the power output (NA1) receives the power and/or speed momentarily required and/or B) for primary fast driving of the carrier vehicle (220) sun gear (2) and ring gear (3) are driven continuously in the same direction of rotation by one of the two E-machines (E1, E2) each, so that the sum of the two speeds determines the speed of the planet carrier (4) and thus of the driving wheels (221a, b).

15. The method according to claim 14, characterized in that when the vehicle, in particular the carrier vehicle (220) and the non-driven working unit (210), are started up both electric machines (E1, E2) are set in rotation simultaneously, i.e. at a distance of less than 2 seconds, but from the beginning synchronously.

16. The method according to claim 14 characterized in that during transition from slow to fast travel of the carrier vehicle (220), when the working unit (210) is driven, at least initially, the following steps are carried out the differential speed of the two electric motors (E1, E2) is increased, starting from the opposite direction of rotation, at the same time the speed of one of the two E-machines (E1) is reduced to zero, switched over to the opposite direction of rotation and driven in this other direction of rotation, in particular during the zero passage of the E-machine (E1), the speed or the torque of the other E-machine (E2) is further increased, in such a way that the speed of the planet carrier (4) does not drop during the zero passage, preferably increases further.

17. The method according to claim 14, characterized in that for a reversing operation of the carrier vehicle (200), with opposite directions of rotation of sun gear (2) and ring gear (3) to be maintained as well as of the electric motors (E1, E2) coupled thereto, their speeds are changed in such a way that alternately one or the other of them has the higher speed, this change in each case bringing about a reversal of the direction of travel of the planet carrier (4) and thus of the vehicle (200).

18. The method according to claim 14, characterized in that at least one of the two electric machines (E1, E2) driven by the power split gearbox (50) is used as a generator and charges a battery connected thereto.

19. The method according to claim 14, characterized in that power from a working unit connected thereto, can be introduced into the power split gearbox (50) via at least one of the power outputs (NA1, NA2, NA3).

Description

EXAMPLES OF EMBODIMENTS

[0076] Embodiments according to the invention are described in more detail below by way of example. They show:

[0077] FIG. 1a, b: two designs of the drive unit,

[0078] FIG. 1c: an axial view of the planetary gear shown in FIG. 1a,

[0079] FIG. 2: a self-propelled working unit with the drive unit from FIG. 1a-c,

[0080] FIG. 3: a drive axle assembly with the drive unit of FIGS. 1a-c,

[0081] FIG. 4a, b: supplemented variants of the embodiment shown in FIG. 1a.

[0082] FIG. 1a shows a side view of a first embodiment of the drive unit 100 according to the invention consisting of a power split gearbox 50—in the form of a classic planetary gear unit 1 and at least one first secondary output drive NA1—and two E-machines E1, E2 arranged axially parallel to each other as drive sources, which in normal operation drive on the one hand the sun gear 2 by means of a shaft 7 and on the other hand the ring gear 3 of the planetary gear 1 by means of a shaft 8, while the planet carrier 4 of the planetary gear 1 serves as the main output drive HA in the form of a shaft 6 fixed thereto for rotation.

[0083] The secondary output drive NA1 is coupled to the axle 7, which is non-rotatably connected to the sun gear 2, and/or to the first electric machine E1, which is connected to it, in a fixed speed ratio.

[0084] In addition, in this case, another secondary output drive NA2 is provided directly or indirectly on the axle 7—which is coupled in a rotationally fixed manner to the rotor of the E-machine E1—which is also coupled to the E-machine E1 in a fixed speed ratio, which in this case can be, for example, a PTO-shaft ZW1.

[0085] Likewise, another secondary output drive NA3 may be coupled in a fixed speed ratio with axle 8 and/or the first E-machine E2 connected to it.

[0086] Each of the secondary output drives may be separable from the planetary gear 1 via a clutch 5, as shown in this case only on the secondary output drives NA2 and NA3.

[0087] In particular, the view of the planetary gear 1 in axial direction 10—the axis of rotation of the sun gear 2—according to FIG. 1c makes clear that this is a classic planetary gear, in which the internally toothed ring gear 3 is arranged concentrically to the externally toothed sun gear 2 and both are in mesh via the planet gears 4a to d, in this case four, which are mounted rotatably about their axes of rotation on a planet carrier 4, which is operatively connected to the axle 6, in particular non-rotatably connected.

[0088] Both electric machines E1, E2 are connected to the control 100* via signal lines 9.

[0089] FIG. 1b shows in the same view as FIG. 1a a 2nd embodiment of the drive unit 100 according to the invention, which differs from the 1st embodiment essentially in that it is a coaxial arrangement of the two E-machines E1, E2, in which the axle 7, which connects the sun gear 2 to the E-machine E1, extends through the hollow center of the E-machine E2, which is located in the axial direction 10 between the E-machine E1 and the planetary gear 50. The E-machine E2 is non-rotatably connected to the ring gear 3 by connecting elements 8.

[0090] In order to achieve a simple compact design, in this 2nd embodiment the two E-machines E1 and 2 are arranged on one end face of the planetary gear 50, preferably on the side of the planetary gear 50 opposite the main output drive HA of the planetary gear 50.

[0091] In the first embodiment according to FIG. 1a, on the other hand, the two E-machines E1, E2 are arranged on opposite end faces of the planetary gear 1, axially parallel to each other, so that the axle 7, which connects the planetary gear 1, in particular its sun gear 2, to the E-machine E1, and the axle 8, which couples the E-machine E2 to the planetary gear unit 50, run parallel to each other. In this case, the axle 8 is connected in a rotationally fixed manner to a gear whose external teeth mesh with external teeth additionally present on the ring gear 3.

[0092] FIG. 4a, b show a supplemental equipment on the main output drive 6 of the embodiment according to FIG. 1a, whereby this supplemented equipment on the main output drive 6 can also be present on any other embodiment of the drive unit according to the invention, in particular the planetary gear according to the invention:

[0093] According to FIG. 4b, in the output drive downstream of the main output drive HA in its axle 6, on the one hand, a brake 13 is arranged, i.e. non-rotatably connected to this axle 6, and downstream thereof a clutch 5 is arranged in this output drive.

[0094] The main output drive HA can be additionally braked by the brake 13—in this case embodied as a conventional disc brake with a brake disc 13a coupled in a rotationally fixed manner to the main output drive HA, i.e. the output shaft 6, against which brake shoes 13b can be pressed in the axial direction on both sides.

[0095] By means of the clutch 5, energy consumers driven by the main output drive HA can be completely decoupled from the latter.

[0096] The clutch 5 can instead and/or additionally be arranged upstream of the brake 13 in order to be able to uncouple the brake from the main output drive HA of the power divider gear.

[0097] In the case of the embodiment according to FIG. 4b, the same applies, in particular functionally, as explained for FIG. 4a, but here the brake 13 and clutch 5 are arranged in a separate auxiliary drive of the main output drive 6, which is coupled to the main output drive HA at a fixed speed ratio via a gear connection.

[0098] In both cases, a torque sensor 14 can be present at the main output drive HA, which can measure the torque and thus the power taken at this output.

[0099] Thus, even if such a torque sensor 14 is present only at this main output drive HA or only at one of the auxiliary output drives, the power distribution to all outputs within the drive unit can be determined by the control 100*.

[0100] FIG. 2 shows the drive unit 100 of FIG. 1a installed in a self-travelling working machine 200:

[0101] Here, the main output drive HA in the form of the axle 6 is operatively connected to the driven rear axle or the two driven axles of the carrier vehicle 220 via a respective power divider gear VG, while the secondary output drive NA1 is coupled to the working unit 210 mounted on the carrier vehicle 220, in particular releasably coupled by means of a clutch not shown here.

[0102] The working unit 210 in this case is a boom working unit in the form of a cantilever mower. The cantilever arm 211, which comprises a plurality of arm parts 211a to 211d connected to one another in an articulated manner, is attached on the vehicle side to a guide shoe 214, which can be moved in a controlled manner in the horizontal transverse direction 11 along a guide rail 215 attached in front of the front end of the carrier vehicle 220.

[0103] The working head 212—here a mowing head 212 for mowing the vegetation next to the edge of the roadway of roads—is attached to the free end of the cantilever arm facing away from the vehicle 211, which in this embodiment is in its storage position on the loading area of the carrier vehicle 220 behind its driver's cab, i.e. in its transport position.

[0104] The arm parts 211a to 211d can be adjusted in their mutual angular position in a controlled manner by means of length-adjustable, in particular telescopic, actuating elements arranged therebetween, in this case hydraulically or electrically operable, working cylinder units 213, which are each fastened with one of their ends to one of the arm parts and with their other end directly or indirectly to the next arm part, in each case away from the pivot joints therebetween, so that by changing the length of the actuating elements the intermediate angle between the arm parts can be changed.

[0105] By pivoting the vehicle-side end of the cantilever arm 211 about a vertical pivot axis relative to the guide shoe 214, the working group 212 can be brought into the desired position, usually laterally next to or laterally in front of the carrier vehicle 220 in working use.

[0106] By means of the drive unit 100 according to the invention, the travel speed of the carrier vehicle 220 can be controlled independently of the power delivered to the working unit 210 via the secondary output drive NA1 by controlling the speed and thus power of the two E-machines E1, E2.

[0107] For the simplified construction of a self-travelling working machine 200, FIG. 3 shows how the drive unit 100 according to the invention, together with a power divider gear VG coupled to the shaft 6 of the main power output drive HA, which on the other hand is operatively connected to the driven axle 221, can form a ready-made drive axle assembly 222 which can be handled together and which, during assembly of the carrier vehicle 220, need only be inserted and fixed in its chassis.

LIST OF REFERENCES

[0108] 1 planetary gear [0109] 2 sun gear [0110] 3 ring gear [0111] 4 planet carrier [0112] 4a-d planet gear [0113] 5 clutch [0114] 6 axle [0115] 7 axle [0116] 8 connecting element [0117] 9 signal line [0118] 10 axial direction, axis of rotation [0119] 11 1. transverse direction [0120] 12 2nd transverse direction [0121] 13 brake [0122] 13a brake disk [0123] 13b brake shoe [0124] 14 power sensor, torque sensor [0125] 50 power split gearbox [0126] 100 drive unit [0127] 100* control [0128] 200 self-travelling working machine [0129] 210 working unit, cantilever mower [0130] 211 cantilever arm [0131] 211a-d arm part [0132] 212 working head, mowing head [0133] 213 working cylinder unit [0134] 214 guide shoe [0135] 215 front rail [0136] 220 carrier vehicle [0137] 221 drive axle [0138] 221a, b driven wheel [0139] 222 drive axle assembly [0140] E1, E2 e-machine [0141] HA main output drive [0142] NA1, /2, /3 secondary output drive [0143] VG power divider gear [0144] ZW1, ZW2 power output shaft, PTO-shaft