Tumbler drive and tracked vehicle equipped with tumbler drive

Abstract

The present invention relates to a tumbler drive (1) including a drive motor (2), a reduction gear (3) driven by the drive motor (2), and a hub (6), in particular a sprocket wheel (4), driven by the reduction gear (3). The drive motor (2) is configured as an electric motor (12), the rotor shaft (16) of the electric motor (12) connected to the rotor (15) of the electric motor (12) is arranged coaxially with the input shaft (11) of the reduction gear (3), and the electric motor (12) is provided with a liquid cooling section including a cooling fluid circuit for cooling.

Description

[Technical field]

[0001] The invention relates to a tumbler drive which comprises a drive motor, a reduction gear driven by the drive motor and a hub, in particular a sprocket wheel, driven by the reduction gear. [Background technology]

[0002] Tumbler drives are used in tracked or crawler vehicles, for example in construction machines such as power shovels, bulldozers, mobile crawler work platforms, mobile crawler drills or large trucks.

[0003] Tumbler drives for tracked vehicles conventionally have a hydraulic motor as the drive motor. Due to the high power density of the hydraulic motor and its compact dimensions, a tumbler drive with a drive motor configured as a hydraulic motor allows a high ground clearance of the crawler vehicle and a corresponding passage between the left and right tumbler drives of the tracked or crawler vehicle. A high ground clearance and a correspondingly large passage between the left and right tumbler drives of the tracked or crawler vehicle are mandatory for good off-road mobility in tracked or crawler vehicles configured as mobile construction machines used on construction sites and off-road.

[0004] In small tracked or crawler vehicles for time-limited city use with limited power requirements, such as small excavators or small dump trucks or small mobile crawler work platforms or small mobile crawler drilling machines, it is desirable to replace the internal combustion engine drive with an electric, in particular battery-electric drive, due to the increasingly stringent emission regulations. In small tracked or crawler vehicles with battery-electric drives, in order to meet the requirements for the ground clearance and the passage between the left and right tumbler drives of the tracked or crawler vehicle, it is possible to use a compact tumbler drive with a hydraulic motor as drive motor, which is supplied with pressure medium by an electrically driven hydraulic pump. However, battery-electric drive concepts of this kind lead to high construction costs. Summary of the Invention [Problem to be solved by the invention]

[0005] The problem underlying the invention is to provide a tumbler drive for electrically, in particular battery-electrically operated, tracked or crawler vehicles, which has compact dimensions and low construction costs. [Means for solving the problem]

[0006] This object is achieved according to the invention in that the drive motor is configured as an electric motor, the rotor shaft of the electric motor, which is connected to the rotor of the electric motor, is arranged coaxially with the input shaft of the reduction transmission, and the electric motor is provided with a liquid cooling section including a cooling fluid circuit for cooling.

[0007] The idea according to the invention is to use a liquid-cooled electric motor as the drive motor of the tumbler drive, the liquid cooling of which comprises a cooling fluid circuit, which preferably circulates the cooling fluid between the pump and the heat exchanger. The electric motor cooled by the liquid cooling comprising a cooling fluid circuit can be operated with high currents. The liquid cooling can therefore increase the continuous torque of the electric motor. With the liquid cooling, the heat rejection to the surroundings is no longer via internal heat conduction / radiation / transfer at the poorly ventilated surfaces of the electric motor, as in the case of air cooling, but via a substantially effective heat transport via mass transport of the cooling liquid, so that an acceptable steady-state temperature in the electric motor can be guaranteed despite significantly higher current densities. The liquid cooling can therefore make it possible to reduce the dimensions of the electric motor of the tumbler drive and to generate high torques with an electric motor that is compact in dimensions, in particular in the axial and / or radial dimensions. The rotor shaft of such a compact, liquid-cooled electric motor can be arranged coaxially with the input shaft of the reduction gear of the tumbler drive, so that the tumbler drive allows a high ground clearance and a large passage between the left and right tumbler drives of the vehicle with the liquid-cooled electric motor as the drive motor. Since only a controller or converter is required to power the electric motor from the traction battery, an electric tumbler drive for an entirely electrically, in particular battery-electrically operated, tracked or crawled vehicle can be provided, which electric tumbler drive has compact dimensions and low construction costs, so that the requirements for ground clearance and the passage between the left and right tumbler drives can be met by the electric tumbler drive according to the invention in an electrically, in particular battery-electrically operated, tracked or crawled vehicle.

[0008] According to an advantageous embodiment of the invention, the liquid cooling of the electric motor has a rotor shaft cooling, which has an axial channel in the rotor shaft, which is formed as a coolant channel for a cooling fluid, in particular oil, of the liquid cooling and is connected to a cooling fluid supply and a cooling fluid outlet. A rotor shaft cooling of this kind allows the shaft-rotor assembly of the electric motor, where high temperatures occur, to be intentionally cooled. Liquid cooling with a cooling fluid, for example oil, allows a high cooling output with little effort.

[0009] According to an advantageous embodiment of the invention, the rotor shaft is connected at a first end to the input shaft of the reduction gear so as not to rotate relative to the input shaft of the reduction gear and the axial channel extends into the rotor shaft from a second end of the rotor shaft located opposite the first end, so that the axial channel is machined into the rotor shaft from an end face of the second end of the rotor shaft located opposite the reduction gear, which makes it possible to produce the axial channel of the rotor shaft cooling section simply and inexpensively.

[0010] According to an advantageous refinement of the invention, the rotor shaft is rotatably supported in the motor housing by a first bearing in the region of a first end and by a second bearing in the region of a second end, and the axial channel extends in the axial direction of the rotor shaft from an end face of the second end of the rotor shaft over the second bearing and the rotor into the region of the first bearing, so that both bearings of the rotor shaft can be cooled by the rotor shaft cooler, and a reduced temperature can be achieved at both bearings.

[0011] Because the axial channel of the rotor shaft cooling section extends up to the area of ​​the first support and thus up to the area of ​​the first end of the rotor shaft where the rotor shaft is non-rotatably connected to the input shaft of the reduction transmission, the heat input of the electric motor into the transmission oil of the reduction transmission can be further limited or avoided, and thus the lubricant temperature usage limit of the transmission oil of the reduction transmission can be reliably maintained.

[0012] According to an advantageous refinement of the invention, insofar as one shaft seal ring is arranged on the rotor shaft in each of the areas of the first bearing and the second bearing, the rotor shaft cooling section furthermore makes it possible to effectively cool the shaft seal ring, which is highly temperature-influenced, and to reduce the temperatures at both shaft seal rings.

[0013] According to a preferred embodiment of the invention, the axial channel is formed in the rotor shaft as a central blind hole in which the tube is arranged concentrically, an annular gap is formed between the tube and the blind hole, the tube interior is fluidly connected to the annular gap, so that the cooling fluid of the cooling fluid circuit can be fed through the tube interior of the tube and discharged again through the annular gap surrounding the tube, so that an effective cooling of the rotor shaft is achieved.

[0014] With regard to the simple connection of the tube and the annular gap to the cooling fluid circuit, according to one configuration of the invention, advantages arise if the tube is connected to the cooling fluid supply of the cooling fluid circuit in the region of the second end of the rotor shaft, the tube is connected to the annular gap by at least one notch in the region of the first end of the rotor shaft, and the annular gap is connected to the cooling fluid outlet of the cooling fluid circuit.

[0015] In one advantageous embodiment of the invention, the cooling fluid supply of the cooling fluid circuit has a connection to which a tube is attached and which is arranged on the end cover of the motor housing, by means of which the tube can be easily held and connected to the cooling fluid supply.

[0016] According to an advantageous refinement of the invention, the rotor shaft is provided with a brake device at the second end, which is arranged in a brake mounting chamber formed between a bearing shield, in which the second bearing is mounted, and a cover on the end face side of the motor housing, so that the tumbler drive can be simply provided with a brake device for braking the rotor shaft, for example a stopping brake, which is easily accessible via the cover for maintenance work.

[0017] In accordance with an advantageous refinement of the invention, the brake system can be further cooled simply by means of a liquid cooler, insofar as the brake assembly chamber is connected to the annular gap and the cooling fluid outlet of the cooling fluid circuit is connected to the brake assembly chamber.

[0018] According to an advantageous embodiment of the invention, the cooling fluid outlet of the cooling fluid circuit has a connecting hole arranged in the cover or in the connecting body of the motor housing and connected to the brake assembly chamber, by means of which the brake assembly chamber, which is connected to the annular gap, can be simply connected to the cooling fluid outlet.

[0019] According to a preferred embodiment of the invention, the liquid cooling of the electric motor alternatively or additionally comprises a stator cooling of a stator arranged in the motor housing, which allows the stator of the electric motor, which is subject to high temperatures, to be selectively cooled. The cooling of the electric motor with a cooling fluid, for example oil, allows a high cooling output with minimal effort.

[0020] According to an advantageous embodiment of the invention, for this purpose the stator and / or the stator end coils are arranged in a coolant chamber of the motor housing, which is sealed against the rotor assembly chamber of the motor housing and which is connected to a coolant supply and a coolant outlet for the cooling fluid of the liquid cooling part, in particular oil. The coolant chamber, in which the stator and / or the stator end coils are arranged, can thus be easily circulated by a cooling fluid flow in order to achieve cooling of the stator of the electric motor as well as the stator end coils, and splash losses due to the cooling fluid present in the rotor assembly chamber can be avoided.

[0021] As long as the coolant chamber extends from the first coil end to the second coil end, the cooling fluid supply is arranged in the area of ​​the first coil end of the stator and the cooling fluid outlet is arranged in the area of ​​the second coil end of the stator, the stator can be effectively cooled at the axial end of the stator together with the coil ends over its entire length.

[0022] According to an advantageous embodiment of the invention, the motor housing is provided with a coolant channel for a cooling fluid, in particular oil, of the liquid cooling section, which runs along the stator. The coolant channel for the cooling fluid formed in the motor housing and running along the stator makes it possible to further improve the cooling of the stator.

[0023] As long as the coolant channels extend from the first coil end of the stator to the second coil end of the stator, the stator can be effectively cooled at each end of the coil along its entire length and at the axial ends of the stator.

[0024] The coolant channels are advantageously connected to a cooling fluid supply arranged on the motor housing and to a cooling fluid outlet arranged on the motor housing, which allows the coolant channels to be easily connected to the cooling fluid circuit.

[0025] According to an advantageous embodiment of the invention, the coolant channel is formed as a spiral groove, which is formed 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 channel running along the stator in the motor housing can be easily produced.

[0026] The invention further relates to a tracked vehicle equipped with at least one tumbler drive according to the invention.

[0027] According to an advantageous embodiment of the invention, the tracked vehicle has an electric, in particular battery-electric, drive system. In the electric drive system, a traction battery supplies the electric motor of the tumbler drive with electrical energy. The electric tumbler drive according to the invention, which has a compact design due to the liquid cooling of the electric motor, makes it possible to provide an electric tumbler drive with compact dimensions and low construction costs in an electrically, in particular battery-electrically operated tracked or crawled vehicle. This tumbler drive creates a high ground clearance and a large passage between the left and right tumbler drives of the crawler vehicle. The electric tumbler drive according to the invention is particularly suitable for small tracked or crawler vehicles, for example small excavators, small dump trucks, small mobile crawler work platforms or small mobile crawler drilling machines.

[0028] The present invention provides a number of advantages: The liquid cooling of the electric motor provides an electric tumbler drive with compact dimensions and furthermore makes it possible to cool the brake system and the reduction gear of the tumbler drive in addition to the electric motor itself.

[0029] Due to the liquid cooling of the electric motor, the mechanical bearings of the rotor shaft are no longer loaded above the lubricant temperature limit, which also applies to the shaft sealing rings in the rotor shaft as well as the transmission oil in the reduction gear. These components (bearings, shaft sealing rings, transmission oil in the reduction gear) benefit greatly in terms of their service life, since operating 10°C below the permissible limit temperature means that their service life is doubled.

[0030] Liquid cooling of an electric motor reduces the temperature of the electric motor and therefore reduces the electrical losses of the electric motor. Aluminum and copper losses due to resistance increase by 4‰ per degree Celsius, so the reduced temperature of the electric motor reduces its energy consumption.

[0031] Liquid cooling of the electric motor allows the electric motor to be operated at a higher current density and therefore generate a higher torque due to the defined heat dissipation, which leads to better utilization of the electric motor (greater power output).

[0032] When oil is used as the cooling fluid, the cooling fluid may be used as an insulator and corrosion inhibitor.

[0033] A defined liquid cooling section offset within the safety hose towards and away from the tumbler drive ensures that the tumbler drive is effectively cooled and does not overheat, even in very low ground, e.g. in soil, water or mud.

[0034] Liquid cooling of the electric motor allows for an increased indication of the time limit of the power that the electric motor should apply.

[0035] Further advantages and details of the invention are explained in more detail on the basis of an exemplary embodiment illustrated in the schematic drawing. [Brief description of the drawings]

[0036] [Figure 1] 1 is a vertical sectional view showing a first embodiment of a tumbler drive device according to the present invention. [Diagram 2] FIG. 4 is a vertical sectional view showing a second embodiment of a tumbler drive device according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] 1 and 2 respectively show an electric tumbler drive 1 according to the invention for a tracked or crawler vehicle. Identical components are provided with identical reference numbers. The tracked or crawler vehicle preferably has an electric, for example battery-electric, drive system.

[0038] The tumbler drive 1 according to the invention comprises a drive motor 2, a reduction gear 3 driven by the drive motor 2, and a hub driven by the reduction gear 3, which in the illustrated embodiment is configured as a sprocket wheel 4. The sprocket wheel 4 is used to drive a track chain K of a tracked vehicle or a rubber chain K of a crawler vehicle.

[0039] The tumbler drive 1 has a hub carrier 5, which is attached to a vehicle frame (not shown in detail) of a tracked or crawler vehicle. A hub 6 is rotatably supported on the hub carrier 5 about a rotation axis D by means of a bearing 7, which in the illustrated embodiment is formed by a rolling bearing. The rotatable hub 6 is provided with a sprocket wheel 4.

[0040] The hub carrier 5 and the hub 6 form a transmission assembly chamber 10 in which the reduction transmission 3 is arranged. In the illustrated embodiment, the reduction transmission 3 is configured as a multi-stage planetary gear transmission, in which the sun shaft forms the input shaft 11 and the driven ring gear is formed by the hub 6. The input shaft 11 is arranged coaxially with the rotation axis D.

[0041] In the tumbler drive device 1 according to the present invention, 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 carrier 5. A stator 14 of the electric motor 12 is attached inside the motor housing 13. In the illustrated embodiment, the stator 14 has coil ends 14a, 14b at both axial ends, respectively. A rotor 15 of the electric motor 12 is further arranged inside the motor housing 13, and the rotor 15 is attached to a rotatable rotor shaft 16.

[0042] The rotatable rotor shaft 16 of the electric motor 12 is arranged coaxially with respect to the input shaft 11 of the reduction transmission 3 and thus with respect to the axis of rotation D.

[0043] The rotor shaft 16 is connected at a first end facing the reduction transmission 3 to the input shaft 11 of the reduction transmission 3 so as to be non-rotatable relative to the input shaft 11 .

[0044] The rotor 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.

[0045] The motor housing 13 in the illustrated embodiment has a tubular housing part 23 in which the stator 14 is mounted. A first end bearing shield 24, in which the first bearing 20 is arranged, and an end cover 25 are mounted on the housing part 23, which has a second bearing shield 26 in which the second bearing 21 is arranged. The housing part 23 with the bearing shield 24 and the cover 25 forms a rotor assembly chamber 27 in which the rotating rotor 15 of the electric motor 12 is arranged.

[0046] At the second end, the rotor shaft 16 is provided with a brake device 30, which is arranged in a brake assembly chamber 31 formed between a second bearing shield 26, in which the second bearing 21 is assembled, and a cover 25 at the end face of the motor housing 13. In the illustrated embodiment, the brake device 30 is designed as a multi-disc brake, which has rotor discs which are connected alternately to the rotor shaft 16 in a rotationally immovable manner and a stator disc which is connected to the cover 25 in a rotationally immovable manner. In the illustrated embodiment, the brake device 30 is designed as a spring-storage brake, which is biased into the braking position by a spring device 32. In the illustrated embodiment, the spring-storage brake can be hydraulically biased into the release position, for which purpose a brake piston 33 is provided, which is arranged axially displaceable between the bearing shield 26 and the cover 25 and which is biased towards the release position by a hydraulic brake release pressure which occurs in a brake release pressure chamber 34. The spring device 32 is arranged in the second bearing shield 26 in the illustrated embodiment and urges the brake piston 33 towards the braking position. Alternatively, the spring-loaded brake can be electrically biased, for example by a magnet, towards the release position.

[0047] In the region of the first end of the rotor shaft 16, adjacent to the first bearing 20, a shaft seal ring 40 is arranged between the rotor shaft 16 and the bearing shield 24, by which the rotor assembly chamber 27 is sealed against the transmission assembly chamber 10.

[0048] In the region of the second end of the rotor shaft 16, adjacent to the second bearing 21, a shaft seal ring 41 is arranged between the rotor shaft 16 and the bearing shield 26, by which the rotor assembly chamber 27 is sealed against the brake assembly chamber 31.

[0049] 1 and 2, a bearing sensor 45 is further provided at one of the two bearings 20 or 21. The bearing sensor 45 can be used for detecting the rotation speed of the electric motor 12 and / or for controlling the speed of the vehicle.

[0050] In FIGS. 1 and 2, a protective tube 46 is further attached to the hub carrier 5, and the motor housing 13 of the electric motor 12 is located within this protective tube 46.

[0051] In order to achieve the compact dimensions of the electric motor 12, which allows for a high ground clearance and a large passage between the left and right tumbler drives of the tracked or crawler vehicle, the electric motor 12 is provided with a liquid cooling section for cooling the electric motor 12, which includes a cooling fluid circuit.

[0052] 1 and 2, the liquid cooling of the electric motor 12 comprises a rotor shaft cooling, which comprises an axial channel 50 in the rotor shaft 16 which is formed as a coolant channel for a cooling fluid, in particular oil, of the liquid cooling and which is connected to a cooling fluid supply 60 and a cooling fluid outlet 61.

[0053] The axial channel 50 extends into the rotor shaft 16 from a second end of the rotor shaft 16 that is located opposite the first end at which the rotor shaft 16 is connected to the input shaft 11 of the reduction transmission 3.

[0054] In Figures 1 and 2, the axial channel 50 extends in the axial direction of the rotor shaft 16 from the end face 51 of the second end of the rotor shaft 16, across the second bearing 21 and the rotor 15, into the area of ​​the first bearing 20.

[0055] The axial channel 50 is formed as a central blind hole in the rotor shaft 16, which is machined into the rotor shaft 16 from an end face 51. A tube 52 is concentrically arranged in the central blind hole. An annular gap 53 is formed between the tube 52 and the blind hole. The tube interior of the tube 52 is fluidly connected to the annular gap 53.

[0056] The tube 52 is connected in the region of a second end of the rotor shaft 16 opposite the reduction transmission 3 to a cooling fluid supply 60 of the cooling fluid circuit and in the region of a first end of the rotor shaft 16 is connected by at least one notch to an annular gap 53, which is connected to a cooling fluid outlet 61 of the cooling fluid circuit.

[0057] In FIG. 1 , the tube 52 is held in the region of the first end of the rotor shaft 16 and at least one notch formed as a transverse notch 65 is provided in the tube 52, by means of which the inner chamber of the tube 52 is fluidly connected to the annular gap 53.

[0058] In FIG. 2 , the tube 52 is arranged so as to protrude freely in the region of the first end of the rotor shaft 16, and the recess is formed as an open end face 66 at the inner end of the tube 52, by means of which the inner chamber of the tube 52 is fluidly connected to the annular gap 53.

[0059] In Figures 1 and 2, the cooling fluid supply section 60 of the cooling fluid circuit has a connecting body 70 to which a tube 52 is attached, and the connecting body 70 is arranged on the cover 25 on the end face side of the motor housing 13.

[0060] 1, the connection 70 is formed by a pipe pin 71 which is arranged in an axial bore of the cover 25 and is provided with a connecting pipe fitting 72 for a cooling fluid supply line. The pipe pin 71 extends through the cover 25 and is inserted into the pipe interior of the pipe 52.

[0061] In Fig. 2, the connection 70 is formed by a tube pin 71, which is arranged in a closing cover 75 arranged in the cover 25. The closing cover 75 has an axial bore 76 connected to the tube pin 71, to which a cooling fluid supply line can be connected. The tube 52 is inserted and held in the tube pin 71. The tube pin 71 is arranged in the axial channel 50 in such a way that an annular gap 53 remains between the tube pin 71 and the axial channel 50.

[0062] 1 and 2, the brake assembly chamber 31 is connected to the annular gap 53. A cooling fluid outlet 61 of the cooling fluid circuit is connected to the brake assembly chamber 31.

[0063] In FIG. 1, a pipe pin 80 is provided for this purpose, which is arranged in a connecting hole 81 in the cover 25 which connects to the brake assembly chamber 31 and which is equipped with a connecting pipe piece 82 for the cooling fluid outlet line.

[0064] In FIG. 2, the connection body 70, which is configured for this purpose as a closing cover 75, has a connection bore 83 which is connected to the brake assembly chamber 31 and to which a cooling fluid outlet line can be connected.

[0065] In order to connect the brake release pressure chamber 34 to a brake pressure line which provides the brake release pressure, in FIG. 1 a pipe pin 90 is provided which is arranged in a connecting hole in the cover 25 which is connected to the brake release pressure chamber 34 and which is equipped with a connecting pipe piece 91 for the brake pressure line.

[0066] 2, in order to connect the brake release pressure chamber 34 to a brake pressure line which provides the brake release pressure, the cover 25 is provided with a connection hole 93 which is connected to the brake release pressure chamber 34. To this connection hole 93, the brake pressure line can be connected.

[0067] The rotor shaft cooling section shown in Figures 1 and 2 functions as follows.

[0068] Via the cooling fluid supply 60, cold cooling fluid is introduced into the tube interior of the tube 52 at the first end. It flows axially through the tube 52 and into the annular gap 53 via the transverse recess 65, as shown in FIG. 1, or via the open end face 66, as shown in FIG. 2. In the annular gap 53, the cooling fluid flows back to the end face 51 of the rotor shaft 16, thereby cooling the rotor shaft 16, both bearings 20, 21 and both shaft seal rings 40, 41. By means of the rotor shaft cooler, the electric motor 12 is cooled from the inside by volumetric flow convection. From the end face 51 of the rotor shaft 16, the pressure medium flows into the brake assembly chamber 31, thus cooling the brake device 30, and the warmed cooling fluid is led off at the cooling fluid outlet 61. In a heat exchanger connected to the cooling fluid outlet 61, the cooling fluid can be cooled again and fed to the cooling fluid supply 60.

[0069] In FIGS. 1 and 2, the liquid cooling of the electric motor 12 further comprises a stator cooling of a stator 14 arranged in the motor housing 13 .

[0070] 1 and 2, for stator cooling, the stator 14 and both coil ends 14a, 14b are arranged in a coolant chamber 28 of the motor housing 13, which is sealed against the rotor assembly chamber 27 of the motor housing 13 and which is connected to a cooling fluid supply 100 and a cooling fluid outlet 101 for the cooling fluid of the liquid cooling, in particular oil. The coolant chamber 28 is formed at the coil ends 14a, 14b by means of separators 29a, 29b formed or arranged on the motor housing 13 and are fluidly connected to one another in a manner not shown in detail. The cooling fluid supply 100 is arranged on the motor housing 13 in the region of the first coil end 14a of the stator 14, and the cooling fluid outlet 101 is arranged on the motor housing 13 in the region of the second coil end 14b of the stator 14.

[0071] 1, for stator cooling, the motor housing 13 is additionally provided with a coolant channel 110 extending along the stator 14 for a cooling fluid, in particular oil, of the liquid cooling section. The coolant channel 110 extends from the first coil end 14a of the stator 14 to the second coil end 14b of the stator 14 and is connected to a cooling fluid supply 100 arranged in the motor housing 13 and to a cooling fluid outlet 101 arranged in the motor housing 13.

[0072] The coolant channel 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 channel 110 is formed between the outer wall of the sleeve 115 and the inner wall of the housing part 23.

[0073] The stator cooling section of Figures 1 and 2 functions as follows.

[0074] Via the cooling fluid supply 100, in Figures 1 and 2, cold cooling fluid is introduced into the coolant chamber 28 in the region of the end coils 14a. The cold cooling fluid flows axially through the coolant chamber 28, thereby cooling the stator 14 and its end coils 14a, 14b. The warmed cooling fluid reaches the coolant chamber 28 in the region of the end coils 14b and is led off at the cooling fluid outlet 101. In a heat exchanger connected to the cooling fluid outlet 101, the cooling fluid can be cooled again and fed to the cooling fluid supply 100.

[0075] In FIG. 1, additionally cold cooling fluid can be introduced into the coolant channels 110 in the region of the first end coil 14a via the cooling fluid supply 100. The cooling fluid flows through the coolant channels 110, thereby cooling the stator 14 and its end coils 14a, 14b. The warmed cooling fluid is led off at the cooling fluid outlet 101 in the region of the second end coil 14b. In a heat exchanger connected to the cooling fluid outlet 101, the cooling fluid can be cooled again and fed to the cooling fluid supply 100.

[0076] The tumbler drive 1 according to the invention provides an electric tumbler drive for a tracked vehicle with compact dimensions, high ground clearance and a high passage between the left and right tumbler drives 1 of the vehicle, with an integrated electric motor 12, a multi-stage reduction gear 3, a braking device 30 configured as a stopping brake and a liquid cooling system, which makes it possible to cool, in addition to the electric motor 12, the reduction gear 3 and the braking device 30, as well as the bearings 20, 21 of the rotor shaft 16 and the shaft seal rings 40, 41.

Claims

1. A tumbler drive (1) comprising a drive motor (2), a reduction gear (3) driven by the drive motor (2), and a hub (6), in particular a sprocket wheel (4), driven by the reduction gear (3), The tumbler drive device (1), characterized in that the drive motor (2) is configured as an electric motor (12), a rotor shaft (16) of the electric motor (12) connected to a rotor (15) of the electric motor (12) is arranged coaxially with respect to an input shaft (11) of the reduction transmission device (3), and the electric motor (12) is provided with a liquid cooling section including a cooling fluid circuit for cooling.

2. 2. The tumbler drive according to claim 1, characterized in that the liquid cooling part of the electric motor (12) has a rotor shaft cooling part, which has an axial channel (50) in the rotor shaft (16), which is formed as a coolant channel for a cooling fluid, in particular oil, of the liquid cooling part and is connected to a cooling fluid supply (60) and a cooling fluid outlet (61).

3. 3. The tumbler drive device according to claim 2, characterized in that the rotor shaft (16) is connected at a first end to the input shaft (11) of the reduction transmission (3) so as to be non-rotatable relative to the input shaft (11), and the axial channel (50) extends into the rotor shaft (16) from a second end of the rotor shaft (16) located opposite the first end.

4. 4. The tumbler drive device according to claim 3, characterized in that the rotor shaft (16) is rotatably supported in the motor housing (13) by a first bearing (20) in the region of the first end and is rotatably supported in the motor housing (13) by a second bearing (21) in the region of the second end, and the axial channel (50) extends in the axial direction of the rotor shaft (16) from an end face (51) of the second end of the rotor shaft (16), over the second bearing (21) and the rotor (15), into the region of the first bearing (20).

5. 5. The tumbler drive according to claim 4, characterized in that a shaft sealing ring (40, 41) is arranged on the rotor shaft (16) in the region of the first bearing (20) and in the region of the second bearing (21).

6. 5. The tumbler drive device according to claim 4, characterized in that the axial channel (50) is formed in the rotor shaft (16) as a central blind hole, a tube (52) is concentrically arranged in the blind hole, an annular gap (53) is formed between the tube (52) and the blind hole, and the tube interior is fluidly connected to the annular gap (53).

7. 7. A tumbler drive according to claim 6, characterized in that the tube (52) is connected to the cooling fluid supply (60) of the cooling fluid circuit in the region of the second end of the rotor shaft (16), the tube (52) is connected to the annular gap (53) by means of at least one notch in the region of the first end of the rotor shaft (16), and the annular gap (53) is connected to the cooling fluid outlet (61) of the cooling fluid circuit.

8. 8. The tumbler drive device according to claim 7, characterized in that the cooling fluid supply part (60) of the cooling fluid circuit has a connecting body (70) to which the pipe (52) is attached, and the connecting body (70) is arranged on a cover (25) on the end face side of the motor housing (13).

9. 9. The tumbler drive device according to claim 8, characterized in that the rotor shaft (16) is provided with a brake device (30) at the second end, the brake device (30) being arranged in a brake mounting chamber (31) formed between a bearing shield (26) in which the second bearing (21) is mounted and a cover (25) on the end face side of the motor housing (13).

10. 10. A tumbler drive according to claim 9, characterized in that the brake mounting chamber (31) is connected to the annular gap (53) and the cooling fluid outlet (61) of the cooling fluid circuit is connected to the brake mounting chamber (31).

11. 11. The tumbler drive device according to claim 10, characterized in that the cooling fluid outlet (61) of the cooling fluid circuit has a connection hole (81; 83) arranged in the cover (25) of the motor housing (13) or in the connecting body (70), said connection hole (81; 83) being connected to the brake assembly chamber (31).

12. 2. A tumbler drive device according to claim 1, characterized in that the liquid cooling of the electric motor (12) comprises a stator cooling of a stator (14) arranged in the motor housing (13).

13. 13. A tumbler drive according to claim 12, characterized in that the stator (14) and / or the coil ends (14a; 14b) of the stator (14) are arranged in a coolant chamber (28) of the motor housing (13) sealed against a rotor assembly chamber (27) of the motor housing (13), the coolant chamber (28) being connected to a cooling fluid supply (100) and a cooling fluid outlet (101) for a cooling fluid, in particular oil, of the liquid cooling section.

14. 14. The tumbler drive device according to claim 13, characterized in that the coolant chamber (28) extends from the first coil end (14a) to the second coil end (14b) of the stator (14), the cooling fluid supply (100) is arranged in the region of the first coil end (14a) of the stator (14) and the cooling fluid outlet (101) is arranged in the region of the second coil end (14b) of the stator (14).

15. 15. A tumbler drive according to claim 12, characterized in that the motor housing (13) is provided with a coolant channel (110) for a cooling fluid, in particular oil, of the liquid cooling section, running along the stator (14).

16. 16. The tumbler drive of claim 15, wherein the coolant channel (110) extends from a first coil end (14a) of the stator (14) to a second coil end (14b) of the stator (14).

17. 16. A tumbler drive according to claim 15, characterized in that the coolant channel (110) is connected to a cooling fluid supply (100) arranged in the motor housing (13) and to a cooling fluid outlet (101) arranged in the motor housing (13).

18. 16. The tumbler drive device according to claim 15, characterized in that the coolant channel (110) is formed as a spiral groove, which is formed in a sleeve (115) arranged radially between the stator (14) and the motor housing (13).

19. 2. A tracked vehicle equipped with at least one tumbler drive (1) according to claim 1.

20. 20. The tracked vehicle according to claim 19, characterized in that the tracked vehicle has an electric, in particular battery-electric, drive system, in which a traction battery supplies electrical energy to the electric motor of the tumbler drive (1).

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