Wheel hub drives, especially tumbler drives

Abstract

The present invention relates to a wheel hub drive (1), in particular a tumbler drive, which comprises a drive motor (2), a reducer (3) driven by the drive motor (2), a hub (6) driven by the reducer (3), in particular a tumbler wheel (4), a hub support (5) and a brake device (150). The drive motor (2) has a driven shaft (16) arranged coaxially with respect to an input shaft (11) of the reducer (3). The brake device (150) is arranged axially between the drive motor (2) and the reducer (3) and radially inside the wheel hub support (5).

Description

[Technical field]

[0001] The present invention relates to a wheel hub drive, in particular a tumbler drive, which comprises a drive motor, a reducer driven by the drive motor, a hub driven by the reducer, in particular a tumbler wheel, a hub support and a brake device.

[0002] Wheel hub drives configured as tumbler drives are used on crawler or tracked vehicles, for example mobile construction machines, for example excavators, bulldozers, mobile crawler work platforms, mobile crawler boring machines or dump trucks.

[0003] Wheel hub drives configured as tumbler drives for crawler vehicles conventionally have a hydraulic motor as the drive motor. Due to the high power density of the hydraulic motor and the compact dimensions of the hydraulic motor, a tumbler drive with a hydraulic motor allows a high ground clearance of the crawler vehicle and a corresponding clearance between the left and right tumbler drives of the crawler or tracked vehicle. A high ground clearance and a correspondingly large clearance between the left and right tumbler drives of the crawler or tracked vehicle are necessary in the case of crawler or tracked vehicles configured as mobile construction machines used on construction sites and on rough terrain due to good rough terrain maneuverability.

[0004] In small crawler or tracked vehicles with limited power requirements and limited time use in urban areas, such as mini excavators or mini dump trucks or small mobile crawler aerial work platforms or small mobile crawler boring machines, it is desirable to use electric, in particular battery-powered, drives instead of internal combustion engine drives due to increasing exhaust gas regulations. In small crawler or tracked vehicles with battery-powered drives, in order to meet the requirements imposed on the ground clearance and the passing width between the left and right tumbler drives of the crawler or tracked vehicle, it is possible to use a compact tumbler drive with a hydraulic motor as the drive motor, which is supplied with pressure medium by an electrically driven hydraulic pump. However, such a battery-powered drive concept leads to high construction costs.

[0005] It is known to provide the wheel hub drive described at the beginning with a braking device which is arranged on the drive motor axially opposite the reducer and which acts on the driven shaft of the drive motor, but such an arrangement of the braking device on the end of the drive motor opposite the reducer increases the axial construction length of the wheel hub drive, which reduces the passage width between the left and right wheel hub drives of the crawler or caterpillar vehicle.

[0006] The problem underlying the invention is to provide a wheel hub drive for crawler or tracked vehicles which has compact dimensions.

[0007] This object is achieved according to the invention in that the drive motor has a driven shaft arranged coaxially to the input shaft of the reducer and the brake device is arranged axially between the drive motor and the reducer and radially inside the wheel hub support. By incorporating the brake device axially between the drive motor and the reducer and radially inside the wheel hub support, the advantage is obtained that the brake device utilizes the construction space inside the wheel hub support between the drive motor and the reducer, so that the axial construction length of the wheel hub drive is not increased by the brake device and a large passage width is obtained between the left and right wheel hub drives of a crawler or tracked vehicle.

[0008] According to an advantageous embodiment of the invention, the reducer is configured as a multi-stage planetary gear, the input shaft of the reducer is configured as the sun gear shaft of the input planetary gear, and the brake device is configured as a multi-disc brake with at least one stator friction plate and at least one rotor friction plate, the at least one stator friction plate being arranged on the wheel hub support in a rotation-resistant manner but axially displaceable, and the at least one rotor friction plate being arranged on the sun gear shaft of the input planetary gear or on the planetary carrier of the input planetary gear. A multi-disc brake in which at least one stator friction plate is arranged on the wheel hub support in a rotation-resistant manner but axially displaceable can be easily integrated into the wheel hub support between the drive motor and the reducer. In this case, the at least one rotor friction plate can also be arranged on the sun gear shaft of the input planetary gear in a rotation-resistant manner but axially displaceable. This results in a high-speed multi-disc brake in which the rotor friction plate rotates at the rotation speed of the input shaft of the reducer configured as the sun gear shaft. Alternatively, at least one rotor friction plate can be arranged on the planetary frame of the input planetary gear set so as to be non-rotatable relative to the planetary gear set but axially displaceable. This results in a medium-speed multi-plate brake in which the rotor friction plate rotates at a lower rotation speed of the planetary frame of the input planetary gear set than the rotation speed of the input shaft of the reducer formed as the sun gear shaft. In such a medium-speed multi-plate brake, reduced churning losses can be achieved in comparison with a high-speed multi-plate brake due to the reduced rotation speed of the rotor friction plate immersed in the reducer oil of the reducer, and thus a high efficiency of the wheel hub drive can be achieved. Furthermore, in the medium-speed multi-plate brake, additional cooling of the brake system can be dispensed with.

[0009] According to a preferred embodiment of the invention, the brake device is configured as a spring brake, which is pressurized by a spring device in the direction of a braking position and by a release actuator in the direction of a release position. Such a spring brake is preferably used as a parking brake that is only operated when the vehicle is stationary. Since such a spring brake acting as a parking brake operates with low heat input and almost without wear, such a spring brake can also be arranged in a location that is not easily accessible, axially between the drive motor and the reducer and radially inside the wheel hub support.

[0010] The spring brake can also be electrically pressurized, for example by a magnet, into the release position. According to an advantageous embodiment of the invention, the spring brake can be hydraulically pressurized into the release position, and the release actuator is formed as a brake piston which is pressurized in the direction of the release position by the actuating brake release pressure generated in the brake release pressure chamber. A spring brake which can be hydraulically pressurized into the release position reduces the required construction space for the brake piston and allows simple arrangement between the drive motor and the reducer and inside the wheel hub carrier.

[0011] With regard to the space-saving installation of the brake piston, an advantage is achieved according to an advantageous embodiment of the invention if the brake piston is arranged coaxially relative to the input shaft of the reducer.

[0012] According to an advantageous embodiment of the invention, the drive motor is attached to the wheel hub support by means of a motor housing cover and the release actuator is arranged in the motor housing cover, which gives particular advantages, since the motor housing cover of the drive motor and the release actuator of the brake device form a unit that can be easily attached to and detached from the wheel hub support.

[0013] Advantageously, the motor housing cover has a longitudinal bore in which the brake piston is longitudinally displaceable, and a brake release pressure chamber is formed between the longitudinal bore and the brake piston, which allows the brake piston to be simply arranged in the motor housing cover and forms the brake release pressure chamber.

[0014] Advantageously, a brake pressure line for conducting the brake release pressure is arranged in the motor housing of the drive motor, including the motor housing cover, and the brake pressure line leads from the brake release pressure chamber to a brake port provided in the motor housing. By means of such a brake pressure line formed in the motor housing, the brake release pressure can be conducted simply to the brake release pressure chamber.

[0015] According to an alternative and equally advantageous embodiment of the invention, the release actuator is arranged in the wheel hub support.

[0016] Advantageously, the wheel hub support has a longitudinal bore in which the brake piston is longitudinally displaceable, and a brake release pressure chamber is formed between the longitudinal bore and the brake piston. By means of such a longitudinal bore, the brake piston can be simply arranged in the wheel hub support and the brake release pressure chamber can be formed.

[0017] Advantageously, a brake pressure line for conducting the brake release pressure is arranged in the wheel hub support, which leads from the brake release pressure chamber to a connecting port in the wheel hub support. By means of such a brake pressure line formed in the wheel hub support, the brake release pressure can be conducted simply to the brake release pressure chamber.

[0018] According to an improved embodiment of the invention, a brake pressure line arranged in the motor housing of the drive motor is connected to the connection port of the wheel hub support, and this brake pressure line is guided to a brake port provided in the motor housing, so that the brake release pressure can be guided from the brake port arranged in the motor housing to the brake release pressure chamber.

[0019] According to an advantageous embodiment of the invention, the spring device is formed by at least one disk spring. The disk spring has compact dimensions in the axial direction and therefore allows a further advantage in terms of a small axial construction length of the wheel hub drive. If at least two disk springs are provided, these are preferably arranged in a series stack. This allows a larger spring displacement to be obtained, which in turn increases the opening stroke and thus the clearance of the friction plates of the multi-disc brake in the opening position of the brake device. This allows a reduced churning loss of the rotor friction plates rotating in the reducer oil of the reducer to be achieved.

[0020] According to an advantageous embodiment of the invention, the drive motor is configured as an electric motor, which is provided with a liquid cooling device with a cooling fluid circuit for cooling. Thus, a liquid-cooled electric motor with a liquid cooling device with a cooling fluid circuit is used as the drive motor of the wheel hub drive. The cooling fluid circuit preferably circulates the cooling fluid between a pump and a heat exchanger. An electric motor cooled by a liquid cooling device with a cooling fluid circuit can be operated with high currents. The liquid cooling device therefore makes it possible to increase the sustained torque of the electric motor. With the liquid cooling device, the heat dissipation to the surroundings no longer takes place via internal heat conduction / heat radiation / heat transfer at the poorly ventilated surfaces of the electric motor, as in air cooling devices, but is realized via a significantly more effective heat transport by mass transport of the cooling liquid, so that an acceptable constant temperature can be guaranteed in the electric motor despite a significantly increased current density. The liquid cooling device therefore makes it possible to reduce the dimensions of the electric motor of the wheel hub drive and to generate high torques with a compact electric motor with respect to its dimensions, in particular in the axial and / or radial dimensions. Such a compact liquid-cooled electric motor can be arranged with its driven shaft coaxially to the input shaft of the reduction gear of the wheel hub drive, so that a wheel hub drive with a liquid-cooled electric motor as drive motor allows a high ground clearance and a large pass-through width between the left and right wheel hub drives of a vehicle.Since only one controller or converter is required to supply the electric motor from the traction battery, an electric wheel hub drive for electrically, in particular battery-operated crawler or tracked vehicles can be provided which has compact dimensions and low construction costs overall, so that the requirements imposed on the ground clearance and the pass-through width between the left and right wheel hub drives can be met by the electric wheel hub drive according to the invention in electrically, in particular battery-operated crawler or tracked vehicles.

[0021] According to an advantageous embodiment of the invention, the liquid cooling device of the electric motor comprises a driven shaft cooling device, which has an axial passage on the driven shaft, which is formed as a coolant passage for the cooling fluid of the liquid cooling device, in particular oil, and is connected to a cooling fluid inlet and a cooling fluid outlet. Such a driven shaft cooling device of the electric motor forms a heat sink in the center of the electric motor. This heat sink allows especially the bearings of the driven shaft of the electric motor and the shaft sealing rings of the driven shaft of the electric motor, which are exposed to temperature risks due to thermal radiation of the coil ends, rotor losses and inherent rotation losses. This driven shaft cooling device thus allows an appropriate cooling of the shaft-rotor group of the electric motor, which generates high temperatures. Liquid cooling with a cooling fluid, for example oil, allows a high cooling performance with little effort.

[0022] According to an advantageous embodiment of the invention, the axial passage is formed as a central blind hole in the driven shaft, a tube is arranged concentrically in the blind hole, an annular gap is formed between the tube and the blind hole, the tube interior is flow-connected to the annular gap, the tube is connected to a cooling fluid inlet of the cooling fluid circuit, and the annular gap is connected to a cooling fluid outlet of the cooling fluid circuit, so that the cooling fluid of the cooling fluid circuit can be fed through the tube interior of the tube and can be discharged again through the annular gap surrounding the tube, so that an effective cooling of the driven shaft is achieved.

[0023] According to a preferred embodiment of the invention, the liquid cooling device of the electric motor alternatively or additionally comprises a stator cooling device for a stator arranged in the motor housing, which allows the stator of the electric motor, which is subject to high temperatures, to be cooled precisely. Liquid cooling with a cooling fluid, for example oil, allows a high cooling performance with minimal effort.

[0024] According to an advantageous embodiment of the invention, the motor housing comprises a coolant passage for a cooling fluid, in particular oil, of the liquid cooling device, which extends along the stator. A further improvement of the cooling of the stator is made possible by the coolant passage for the cooling fluid, which is formed in the motor housing and extends along the stator.

[0025] When the coolant passages extend from the first coil end of the stator to the second coil end of the stator, the stator can be effectively cooled along its entire length, including the coil ends at the axial ends of the stator.

[0026] Preferably, the coolant passage is connected to a cooling fluid inlet arranged on the motor housing and to a cooling fluid outlet arranged on the motor housing, which allows the coolant passage to be easily connected to the cooling fluid circuit.

[0027] According to an advantageous embodiment of the invention, the coolant passage is formed as a spiral groove in a sleeve arranged radially between the stator and the motor housing. By means of such a sleeve with a spiral groove, which is appropriately mounted, for example pressed into, the motor housing, the coolant passage running along the stator can be easily produced in the motor housing.

[0028] The invention further relates to a crawler vehicle comprising at least one wheel hub drive according to the invention.

[0029] According to an advantageous embodiment of the invention, the crawler vehicle has an electric, in particular battery-electric drive system, in which a traction battery supplies electric energy to the electric motor of the wheel hub drive. The electric wheel hub drive according to the invention, which has a compact construction due to the arrangement of the brake device and the liquid cooling device of the electric motor, makes it possible to provide an electric wheel hub drive with compact dimensions and low construction costs for crawler vehicles or tracked vehicles operated electrically, in particular battery-electrically, which results in a high ground clearance and a large passing width between the left and right wheel hub drives of the tracked vehicle. The electric wheel hub drive according to the invention is particularly suitable for small crawler vehicles or tracked vehicles, for example mini excavators, mini dump trucks, small mobile crawler aerial work platforms or small mobile crawler boring machines.

[0030] The present invention provides a series of advantages.

[0031] By arranging and assembling the brake device axially between the drive motor and the reducer and radially inside the wheel hub support, the advantage is obtained that compact dimensions of the wheel hub drive in the axial direction can be obtained, since the brake device optimally utilizes the construction space inside the wheel hub support between the drive motor and the reducer.

[0032] If the brake device is configured as a parking brake, which operates almost without wear, the brake device can also be arranged in areas that are not easily accessible inside the wheel hub support between the drive motor and the reduction gear.

[0033] Furthermore, the additional liquid cooling of the electric motor provides for a compact size of the electric motor and thus an electric wheel hub drive with compact dimensions. Furthermore, the additional liquid cooling of the electric motor allows the electric motor to be operated at a higher current density and thus to generate a higher torque due to the defined heat dissipation, which in turn increases the utilization of the electric motor (higher power output). The defined liquid cooling of the electric motor, which is laid in a safe tube towards and away from the wheel hub drive, ensures that the wheel hub drive is effectively cooled and does not overheat even in the deepest rough terrain, for example in mud, water or bog.

[0034] Further advantages and details of the invention will now be explained in greater detail with the aid of exemplary embodiments shown in the schematic drawings. [Brief description of the drawings]

[0035] [Figure 1] 1 is a vertical sectional view of a first embodiment of a wheel hub drive device according to the present invention. [Diagram 2] FIG. 2 is a longitudinal sectional view of an improved version of the wheel hub drive device of FIG. 1. [Diagram 3] FIG. 4 is a vertical sectional view of a wheel hub drive device according to a second embodiment of the present invention. [Figure 4] FIG. 11 is a vertical sectional view of a third embodiment of a wheel hub drive device according to the present invention. [Diagram 5] FIG. 10 is a vertical sectional view of a wheel hub drive device according to a fourth embodiment of the present invention.

[0036] 1 to 5 show a wheel hub drive 1 according to the invention for a crawler or caterpillar vehicle. The wheel hub drive 1 is configured as an electric tumbler drive. Identical components are provided with identical reference symbols in the figures. The crawler or caterpillar vehicle preferably has an electric, for example battery-electric, drive system.

[0037] The wheel hub drive device 1 according to the present invention shown in Figures 1 to 5 has a drive motor 2, a reduction gear 3 driven by the drive motor 2, and a hub 6 driven by the reduction gear 3. A tumbler wheel (not shown) provided for driving the crawler of a crawler vehicle or the rubber crawler of an endless track vehicle may be attached to the hub 6.

[0038] The wheel hub drive 1 has a hub support 5 attached to a vehicle frame (not shown) of a crawler or caterpillar vehicle. A hub 6 is supported on the hub support 5 so as to be rotatable about a rotation axis D by a bearing member 7 which in the illustrated embodiment is formed by a rolling bearing.

[0039] The hub carrier 5 and the hub 6 form a gear assembly chamber 10 in which the reducer 3 is arranged. In the illustrated embodiment, the reducer 3 is designed as a multi-stage planetary gear.

[0040] The input shaft 11 of the reducer 3 is formed by the sun gear shaft S1 of the input planetary gear set 3a of the reducer 3. The planetary frame P1 of the input planetary gear set 3a supports the planetary gear PR1. This planetary gear PR1 meshes with the sun gear shaft S1 and the internal gear tooth row H of the hub support 5. The planetary frame P1 drives the sun gear shaft S2 of the intermediate planetary gear set 3b. The planetary frame P2 of the intermediate planetary gear set 3b supports the planetary gear PR2. This planetary gear PR2 meshes with the sun gear shaft S2 and the internal gear tooth row H of the hub support 5. The planetary frame P2 drives the sun gear shaft S3 of the output planetary gear set 3c. The planetary frame P3 of the output planetary gear set 3c is supported by the internal gear tooth row H of the wheel hub support 5 so as not to rotate relative to the wheel hub support 5, and supports the planetary gear PR3. The planetary gear PR3 meshes with the sun gear shaft S3 and the internal gear teeth row H1 of the driven hub 6, and drives the sun gear shaft S3 and the hub 6.

[0041] The input shaft 11 formed as the sun gear shaft S1 is arranged coaxially with respect to the rotation axis D. Furthermore, the sun gear shafts S2, S3 are arranged coaxially with respect to the rotation axis D.

[0042] In the exemplary embodiment shown, the drive motor 2 is configured as an electric motor 12. The electric motor 12 has a motor housing 13 which is attached to the hub support 5. A stator 14 of the electric motor 12 is mounted in the motor housing 13. In the exemplary embodiment shown, the stator 14 has coil ends 14a, 14b at both axial ends. A rotor 15 of the electric motor 12 is also arranged in the motor housing 13. The rotor 15 is mounted on a rotatable driven shaft 16 of the drive motor 2.

[0043] The rotatable driven shaft 16 of the drive motor 2 is arranged coaxially with the input shaft 11 of the reducer 3 and therefore with the rotation axis D.

[0044] The driven shaft 16 is connected at a first end portion on the reduction gear 3 side to the input shaft 11 of the reduction gear 3 so as not to rotate relative to the input shaft 11.

[0045] The driven shaft 16 is rotatably supported in the motor housing 13 in the region of a first end by a first bearing 20 and in the region of a second end opposite the first end by a second bearing 21. The bearings 20, 21 are formed by rolling bearings in the illustrated embodiment.

[0046] The motor housing 13 has, in the embodiment shown, a tubular housing part 23 in which the stator 14 is mounted. A first end motor housing cover 24 is mounted on this housing part 23, which has a bracket in which the first bearing 20 is arranged. A second end motor housing cover 25 is further mounted on the housing part 23, which has a bracket in which the second bearing 21 is arranged. Together with the two motor housing covers 24, 25, the housing part 23 forms a rotor assembly chamber 27 in which the rotating rotor 15 of the electric motor 12 is arranged.

[0047] The end face side motor housing cover 24 is attached to one end face of the wheel hub support 5 .

[0048] In the region of the first end of the driven shaft 16, adjacent to the first support member 20, a shaft seal device 40 is arranged between the driven shaft 16 and the motor housing cover 24, which seals the rotor assembly chamber 27 from the gear assembly chamber 10.

[0049] In the region of the second end of the driven shaft 16 , adjacent to the second bearing 21 , a shaft sealing device 41 is arranged between the driven shaft 16 and the motor housing cover 25 .

[0050] 1 to 5, the hub support 5 further includes a protective tube 46 attached thereto, in which the motor housing 13 of the drive motor 2 is located.

[0051] In order to obtain compact axial and radial dimensions of the electric motor 12, which allows a high ground clearance and a large passage width between the left and right wheel hub drives of the crawler or tracked vehicle, the electric motor 12 is provided with a liquid cooling device with a cooling fluid circuit for its cooling.

[0052] 1 to 5, the liquid cooling device for the electric motor 12 comprises a driven shaft cooling device for the driven shaft 16. The driven shaft cooling device comprises an axial passage 50 provided in the driven shaft 16. The axial passage 50 is configured as a coolant passage for a cooling fluid, in particular oil, of the liquid cooling device and is connected to a cooling fluid inlet 60 and a cooling fluid outlet 61. The cooling fluid inlet 60 and the cooling fluid outlet 61 are arranged in the motor housing cover 25.

[0053] The axial passage 50 extends into the driven shaft 16 from a second end of the driven shaft 16 opposite the first end at which the driven shaft 16 is connected to the input shaft 11 of the reducer 3 .

[0054] In Figures 1 to 5, the axial passage 50 extends in the axial direction of the driven shaft 16 from the end face 51 of the second end of the driven shaft 16, past the second support member 21 and the rotor 15, to the area of ​​the first support member 20.

[0055] The axial passage 50 is formed as a central blind hole in the driven shaft 16. The central blind hole is machined into the driven shaft 16 from an end face 51. A tube 52, which is attached to the motor housing cover 25, is arranged concentrically in the central blind hole. Between the tube 52 and the blind hole an annular gap 53 is formed. The tube interior of the tube 52 is flow-connected to the annular gap 53.

[0056] The tube 52 is connected in the region of a second end of the driven shaft 16 facing away from the gearbox 3 to a cooling fluid inlet 60 of the cooling fluid circuit arranged on the motor housing cover 25 and in the region of a first end of the driven shaft 16 is connected by at least one recess to an annular gap 53 which is connected to a cooling fluid outlet 61 of the cooling fluid circuit.

[0057] The shaft seal 41 seals off a connecting chamber 62 from the rotor assembly chamber 27, into which the annular gap 53 opens and into which a cooling fluid outlet 61 of the cooling fluid circuit, which is arranged in the motor housing cover 25, is connected.

[0058] 1 to 5, the tube 52 is arranged so as to protrude freely into the region of the first end of the driven shaft 16. A recess is formed at the inner end of the tube 52 as an open end face 66, by means of which the inner tube chamber of the tube 52 is flow-connected to the annular gap 53.

[0059] The driven shaft cooling device of Figures 1 to 5 works as follows.

[0060] Via the cooling fluid inlet 60, a cold cooling fluid is introduced into the tube interior of the tube 52 at the first end. The cold cooling fluid flows axially through the tube 52 and enters the annular gap 53 via the open end face 66 of the tube 52. In this annular gap 53, the cooling fluid flows in the opposite direction to the end face 51 of the driven shaft 16. This cools the driven shaft 16, both bearings 20, 21 and both shaft sealing devices 40, 41. By means of the driven shaft cooling device, the electric motor 12 is cooled from the inside by volumetric convection. From the end face 51 of the driven shaft 16, the heated pressure medium flows into the connecting chamber 62 and is led out from this connecting chamber 62 to the cooling fluid outlet 61. In a heat exchanger connected to this cooling fluid outlet 61, the cooling fluid can be cooled again and fed to the cooling fluid inlet 60.

[0061] In FIGS. 1 to 5, the liquid cooling device for the electric motor 12 further comprises a stator cooling device for the stator 14 arranged in the motor housing 13.

[0062] 1 to 5, for the stator cooling device, the motor housing 13 is provided with a coolant passage 110 for the cooling fluid, in particular oil, of the liquid cooling device, which extends along the stator 14. This coolant passage 110 extends from a first coil end 14a of the stator 14 to a second coil end 14b of the stator 14 and is connected to a cooling fluid inlet 100 arranged in the motor housing 13 and a cooling fluid outlet 101 arranged in the motor housing 13.

[0063] The coolant passage 110 is preferably formed as a spiral groove in a sleeve 115 arranged radially between the stator 14 and the motor housing 13. The stator 14 is arranged on the inner wall of the sleeve 115. The outer wall of the sleeve 115 is machined with a spiral groove. The sleeve 115 is preferably press-fitted into the tubular housing part 23 of the motor housing 13, so that the coolant passage 110 is formed between the outer wall of the sleeve 115 and the inner wall of the housing part 23.

[0064] The stator cooling device of FIGS. 1 to 5 works as follows.

[0065] 1 to 5, a low-temperature cooling fluid is introduced into a refrigerant passage 110 in the region of the first coil end 14a via the cooling fluid inlet 100 and flows through the refrigerant passage 110. This cools the stator 14 and its coil ends 14a, 14b. The heated cooling fluid is discharged to a cooling fluid outlet 101 in the region of the second coil end 14b. In a heat exchanger connected to the cooling fluid outlet 101, the cooling fluid may be cooled again and supplied to the cooling fluid inlet 100.

[0066] In the wheel hub drive 1 according to the invention of Figures 1 to 5, the brake device 150 is arranged axially between the drive motor 2 and the reducer 3 of the wheel hub drive 1 and radially inside the wheel hub support 5. This allows the wheel hub drive 1 to be further optimized with respect to compact dimensions in the axial direction and allows a large passage width to be obtained between the left and right wheel hub drives of the crawler or tracked vehicle.

[0067] In the illustrated embodiment, the brake device 150 is formed as a multi-plate brake having at least one stator friction plate 151 and at least one rotor friction plate 152. In Figs. 1 to 5, at least one stator friction plate 151 is arranged on the wheel hub support 5 so as to be non-rotatable relative to the wheel hub support 5 and movable in the axial direction. In Figs. 1 to 3, at least one rotor friction plate 152 is arranged on the planetary frame P1 of the input planetary gear set 3a so as to be non-rotatable relative to the wheel hub support 5 and movable in the axial direction. Thus, the multi-plate brake of Figs. 1 to 3 is formed as a medium-speed rotation type multi-plate brake in which at least one rotor friction plate 152 rotates at the rotation speed of the planetary frame P1. In Figs. 4 and 5, at least one rotor friction plate 152 is arranged on the sun gear shaft S1 of the input planetary gear set 3a so as to be non-rotatable relative to the wheel hub support 5 and movable in the axial direction. Therefore, the multi-plate brake of Figures 4 and 5 is formed as a high-speed rotation type multi-plate brake in which at least one rotor friction plate 152 rotates at the rotational speed of the input shaft 11, which is formed as the sun gear shaft S1 of the reducer 3.

[0068] 1 to 5, the braking device 150 is configured as a spring brake which is biased towards a braking position by a spring device 160 and towards a release position by a release actuator 161.

[0069] 1 to 5, the spring brake can be hydraulically pressurized into a release position. For this purpose, the release actuator 161 is formed as a brake piston 162 which is pressurized in the direction of the release position by an actuating brake release pressure generated in a brake release pressure chamber 163.

[0070] Alternatively, the spring brake may be configured to be electrically, for example magnetically, pressurizable into the released position.

[0071] 1 to 5, the braking piston 162 is disposed coaxially with the input shaft 11 of the reducer 3. In FIG.

[0072] 1, 2 and 4, the release actuator 161 is located within the motor housing cover 24 which mounts the drive motor 2 to the wheel hub support 5. In FIG.

[0073] For this purpose, the motor housing cover 24 is provided with a stepped longitudinal bore 164 in which a brake piston 162 configured as a stepped piston is arranged so as to be longitudinally movable. Between this longitudinal bore 164 and the brake piston 162, a brake release pressure chamber 163 is furthermore formed.

[0074] In order to pressurize the brake release pressure chamber 163 with the brake release pressure, a brake pressure line 165 for guiding the brake release pressure is arranged in the motor housing 13 of the drive motor 2. This brake pressure line 165 leads from the brake release pressure chamber 163 to a brake port 166 provided in the motor housing 13. In FIGS. 1, 2 and 4, this brake port 166 is arranged in the motor housing cover 25. The brake pressure line 165 is formed by a radially arranged hole 170 in the motor housing cover 24 connected to the brake release pressure chamber 163, a hole 171 in the axial direction in the housing part 23 connected to this hole 170, and a hole 172 in the motor housing cover 25 connected to this hole 171 and to the brake port 166.

[0075] In FIGS. 3 and 5 the release actuator 161 is located within the wheel hub support 5 .

[0076] For this purpose, the wheel hub support 5 is provided with a stepped longitudinal bore 180 in which a brake piston 162 configured as a stepped piston is arranged so as to be longitudinally displaceable. Between this longitudinal bore 180 and the brake piston 162, a brake release pressure chamber 163 is formed.

[0077] In order to pressurize the brake release pressure chamber 163 with the brake release pressure, a brake pressure line 190 for guiding the brake release pressure is arranged in the wheel hub support 5. This brake pressure line 190 leads from the brake release pressure chamber 163 to a connection port 191 provided in the wheel hub support 5. In the embodiment of Figures 3 and 5, this connection port 191 is arranged on the end face of the wheel hub support 5 on the side of the motor housing cover 24.

[0078] A brake pressure line 200 arranged in the motor housing 13 of the drive motor 2 is connected to the connection port 191 of the wheel hub support 5. This brake pressure line 200 leads to a brake port 201 provided in the motor housing 13. In FIGS. 3 and 5, the brake port 201 is arranged in the motor housing cover 25. The brake pressure line 200 is formed by a radially arranged hole 202 in the motor housing cover 24 connected to the connection port 191, an axially arranged hole 203 in the housing part 23 connected to this hole 202, and a hole 204 in the motor housing cover 25 connected to this hole 203 and to the brake port 201.

[0079] 1, 2 and 4, the friction plates of the braking device 150 are supported in the braking position of the braking device 150 on a stop disk 210. This stop disk 210 is arranged opposite the brake piston 162 and is mounted in the wheel hub support 5 in a rotationally non-rotatable and axially fixed manner.

[0080] 3 and 5, the friction plates of the braking device 150 are supported in the braking position of the braking device 150 against an abutment surface 215 which is arranged opposite the brake piston 162 and which is formed on the wheel hub support 5.

[0081] 1, 3 to 5, the spring arrangement 160 for operating the brake piston 162 into the braking position is formed by a single disc spring 220. For this purpose, this disc spring 220 is supported on the motor housing cover 24 and presses the brake piston 162 to the right as viewed in FIGS. 1, 3 to 5 into the braking position.

[0082] In Fig. 2, the spring device 160 for actuating the brake piston 162 into the braking position is formed by a number of disc springs 221, 222, two in the embodiment shown, arranged in a series stack. For this purpose, the disc spring 221 is supported on the motor housing cover 24, and the disc spring 22 supported by the disc spring 221 presses the brake piston 162 to the right in Fig. 2 into the braking position.

[0083] The disc springs shown in FIG. 2 may also be used in the embodiment of FIGS.

Claims

1. A wheel hub drive (1), in particular a tumbler drive, comprising: a drive motor (2); a reducer (3) driven by the drive motor (2); a hub (6) driven by said reducer (3), in particular a tumbler wheel (4); a hub support (5); A braking device (150) A wheel hub drive device (1) comprising: The wheel hub drive device (1) is characterized in that the drive motor (2) has a driven shaft (16) arranged coaxially with the input shaft (11) of the reducer (3), and the brake device (150) is arranged axially between the drive motor (2) and the reducer (3) and radially inside the wheel hub support (5).

2. The reducer (3) is formed as a multi-stage planetary gear device (3a, 3b, 3c), The input shaft (11) of the reducer (3) is formed as a sun gear shaft (S1) of an input planetary gear device (3a), The brake device (150) is configured as a multi-disc brake having at least one stator friction plate (151) and at least one rotor friction plate (152), The at least one stator friction plate (151) is arranged on the wheel hub support (5) so as to be non-rotatable relative to the wheel hub support (5) and movable in the axial direction; 2. The wheel hub drive device (1) according to claim 1, wherein the at least one rotor friction plate (152) is arranged on the sun gear shaft (S1) of the input planetary gear set (3 a) or on a planetary frame (P1) of the input planetary gear set (3 a) so as to be non-rotatable relative to the sun gear shaft (S1) and axially movable.

3. 3. The wheel hub drive device (1) according to claim 1 or 2, characterized in that the brake device (150) is configured as a spring brake, which is pressurized in the direction of the braking position by a spring device (160) and in the direction of the release position by a release actuator (161).

4. 4. The wheel hub drive device (1) according to claim 3, characterized in that the spring brake can be hydraulically pressurized to the release position, and the release actuator (161) is formed as a brake piston (162) that is pressurized in the direction of the release position by an operating brake release pressure generated in a brake release pressure chamber (163).

5. 5. The wheel hub drive device (1) according to claim 4, characterized in that the brake piston (162) is arranged coaxially with respect to the input shaft (11) of the reducer (3).

6. The wheel hub drive device (1) according to claim 4, characterized in that the drive motor (2) is attached to the wheel hub support (5) by a motor housing cover (24), and the release actuator (161) is arranged within the motor housing cover (24).

7. 7. The wheel hub drive device (1) according to claim 6, characterized in that the motor housing cover (24) has a longitudinal hole (164) in which the brake piston (162) is arranged so as to be longitudinally movable, and the brake release pressure chamber (163) is formed between the longitudinal hole (164) and the brake piston (162).

8. 8. The wheel hub drive device (1) according to claim 7, characterized in that a brake pressure line (165) for guiding brake release pressure is arranged in the motor housing (13) of the drive motor (2), and the brake pressure line (165) is guided from the brake release pressure chamber (163) to a brake port (166) provided in the motor housing (13).

9. 5. Wheel hub drive (1) according to claim 4, characterized in that the release actuator (161) is arranged in the wheel hub support (5).

10. 10. The wheel hub drive device (1) according to claim 9, characterized in that the wheel hub support (5) has a longitudinal hole (180) in which the brake piston (162) is arranged so as to be longitudinally movable, and the brake release pressure chamber (163) is formed between the longitudinal hole (180) and the brake piston (162).

11. 11. The wheel hub drive device (1) according to claim 10, characterized in that a brake pressure line (190) for guiding brake release pressure is arranged in the wheel hub support (5), and the brake pressure line (190) is led from the brake release pressure chamber (163) to a connection port (191) provided in the wheel hub support (5).

12. 12. The wheel hub drive device (1) according to claim 11, characterized in that a brake pressure line (200) arranged in a motor housing (13) of the drive motor (2) is connected to the connection port (191) of the wheel hub support (5), and the brake pressure line (200) is led to a brake port (201) provided in the motor housing (13).

13. 4. Wheel hub drive (1) according to claim 3, characterized in that the spring device (160) is formed by at least one disc spring (220; 221, 222).

14. 3. The wheel hub drive device (1) according to claim 1 or 2, characterized in that the drive motor (2) is configured as an electric motor (12), which is provided with a liquid cooling device with a cooling fluid circuit for cooling.

15. 15. The wheel hub drive (1) according to claim 14, characterized in that the liquid cooling device of the electric motor (12) comprises a driven shaft cooling device, the driven shaft cooling device having an axial passage (50) provided in the driven shaft (16), the axial passage (50) being formed as a refrigerant passage for a cooling fluid, in particular oil, of the liquid cooling device, and connected to a cooling fluid inlet (60) and a cooling fluid outlet (61).

16. 16. The wheel hub drive device (1) according to claim 15, characterized in that the axial passage (50) is formed as a central blind hole in the driven shaft (16), a pipe (52) is arranged concentrically in the blind hole, an annular gap (53) is formed between the pipe (52) and the blind hole, an inner chamber of the pipe is flow-connected to the annular gap (53), the pipe (52) is connected to the cooling fluid inlet (60) of the cooling fluid circuit, and the annular gap (53) is connected to the cooling fluid outlet (61) of the cooling fluid circuit.

17. 3. Wheel hub drive (1) according to claim 1 or 2, characterized in that the liquid cooling device for the electric motor (12) comprises a stator cooling device for the stator (14) arranged in the motor housing (13).

18. Wheel hub drive (1) according to claim 17, characterized in that the motor housing (13) comprises a coolant passage (110) for the cooling fluid, in particular oil, of the liquid cooling device, which extends along the stator (14).

19. 19. The wheel hub drive device (1) according to claim 18, characterized in that the coolant passage (110) extends from a first coil end (14a) of the stator (14) to a second coil end (14b) of the stator (14).

20. 19. The wheel hub drive device (1) according to claim 18, characterized in that the coolant passage (110) is connected to a cooling fluid inlet (100) arranged in the motor housing (13) and a cooling fluid outlet (101) arranged in the motor housing (13).

21. The wheel hub drive device (1) according to claim 18, characterized in that the refrigerant passage (110) is formed as a spiral groove formed in a sleeve (115) arranged radially between the stator (14) and the motor housing (13).

22. A crawler vehicle equipped with at least one wheel hub drive (1) according to claim 1 or 2.

23. 23. A crawler vehicle according to claim 22, characterized in that it has an electric, in particular battery-electric, drive system in which a traction battery supplies electrical energy to the electric motor of the wheel hub drive (1).

Images