Bearing unit for a drive device for a forklift truck, drive device and forklift truck

Abstract

Bearing unit (3) for a drive device (1) for a forklift truck, wherein the bearing unit (3) has a first bearing section (15) which can be attached to a section of a frame of the forklift truck in a rotationally fixed manner and has a second bearing section (19) which can be pivoted about a pivot axis (17) relative to the first bearing section (15) and can be fixed to a section of a housing (13) of the drive device (1) in a rotationally fixed manner, wherein the first storage section (15) has a first storage area (21) and the second storage section (19) has a second storage area (23) which is adjacent to the first storage area (21), wherein when the second bearing section (19) pivots relative to the first bearing section (15) about the pivot axis (17), the first contact surface (21) and the second contact surface (23) slide against each other, wherein the first installation area (21) has a first installation area section (25) and the second installation area (23) has a second installation area section (27), and wherein the first contact surface (21) and the second contact surface (23) are shaped and arranged relative to each other in such a way that forces acting along the pivot axis (17) as well as forces acting perpendicular to the pivot axis (17) can be transmitted between the first bearing section (15) and the second bearing section (19) via the first contact surface section (25) and the second contact surface section (27).

Description

[0001] The present invention relates to a bearing unit for a drive device, a drive device for a forklift truck and a forklift truck.

[0002] Bearing units for drive systems of industrial trucks are known from the prior art. Industrial trucks are often driven by an electric drive, which can also be referred to as a drive unit. The drive unit is configured for the industrial truck so that it can cause the truck to move. Typically, the drive unit comprises an electric motor, a brake, and a gearbox. A wheel is also mounted on the drive unit, which can be set into rotation by means of the electric motor and the gearbox. In motor mode, the electric motor converts electrical energy into mechanical energy. The gearbox then converts this mechanical energy into torque and speed, which is supplied to the wheel as drive energy for the industrial truck.This drive energy can be used to accelerate the forklift, to compensate for mechanical losses (e.g., rolling resistance), or to overcome inclines. During braking, also known as regenerative braking, the energy flow is reversed. The electric motor can then operate as a generator, extracting kinetic energy from the forklift and converting it into electrical energy, which can be stored in the forklift's battery. The brake can be used as a holding brake and as an emergency stop brake.

[0003] Drive units often feature a bearing unit that allows for the pivoting mounting of a drive unit housing, such as a gearbox housing of the drive unit, relative to the frame of the industrial truck. By pivoting the housing relative to the truck frame, the direction of travel can be adjusted.

[0004] For example, DE 10 2006 021 676 A1 discloses a drive for a forklift truck. The drive has a bearing unit to enable a steering movement. The bearing unit is thus provided for the drive, which can also be referred to as a drive device, and the drive is for a forklift truck. The bearing unit has a first bearing section that can be rotationally fixed to a section of a frame of the forklift truck and a second bearing section that can be pivoted about a pivot axis relative to the first bearing section and can be rotationally fixed to a section of a housing of the drive device. The bearing unit has two tapered roller bearings arranged axially offset from each other. DE 10 2005 053 804 A1 discloses a torsional vibration damper that has a bearing unit which can, for example, have a tapered roller bearing or a sliding bearing element.CH 430 341 A and DE 10 2012 210 247 A1 each disclose a bearing unit which may, for example, comprise a tapered roller bearing or a plain bearing.

[0005] In general, it is desirable to ensure a spatially compact design for storage units for a drive device for a forklift truck.

[0006] It is therefore the object of the present invention to provide a bearing unit for a drive device for a forklift truck with a spatially compact design.

[0007] According to a first aspect of the invention, the aforementioned problem is solved by a bearing unit with the features of claim 1. The bearing unit is configured for a drive device for a forklift truck. The bearing unit has a first bearing section that can be mounted non-rotatably on a section of a frame of the forklift truck. Furthermore, the bearing unit has a second bearing section that can be pivoted about a pivot axis relative to the first bearing section and mounted non-rotatably on a section of a housing of the drive device. The first bearing section has a first contact surface, and the second bearing section has a second contact surface. The second contact surface rests against the first contact surface. When the second bearing section is pivoted about the pivot axis relative to the first bearing section, the first contact surface and the second contact surface slide against each other.The first mounting surface has a first mounting surface section. The second mounting surface has a second mounting surface section. The first mounting surface and the second mounting surface are shaped and arranged relative to each other in such a way that forces acting along the pivot axis as well as forces acting perpendicular to the pivot axis can be transmitted between the first bearing section and the second bearing section via the first mounting surface section and the second mounting surface section.

[0008] The bearing unit is configured for the drive unit of the industrial truck. Because the bearing unit is configured for the drive unit, it ensures that the drive unit housing can be pivoted relative to the truck frame. By pivoting the housing relative to the frame, the direction of travel of the industrial truck can be adjusted. The drive unit can also be referred to as a steerable drive unit. The frame can also be referred to as the vehicle frame.

[0009] The bearing unit has a first bearing section that can be attached to the section of the frame of the industrial truck in a rotationally fixed manner, and the bearing unit has a second bearing section that can be pivoted about the pivot axis relative to the first bearing section and attached to the section of the housing of the drive device in a rotationally fixed manner.Because the first bearing section can be fixedly attached to the frame section of the industrial truck in a rotationally fixed manner, and the second bearing section is pivotable about the pivot axis relative to the first bearing section and can be fixedly attached to a section of the drive unit housing, it is ensured that, with the aid of the bearing unit, when the first bearing section is fixedly attached to the frame section of the industrial truck and the second bearing section is fixedly attached to the housing section of the drive unit, the drive unit housing can pivot about the pivot axis relative to the frame of the industrial truck. If, in connection with the present invention, a first component is pivotable relative to a second component, this also implies that the second component is pivotable relative to the first component.The configuration, in which the second bearing section is pivotable relative to the first bearing section about the pivot axis, also implies that the first bearing section is pivotable relative to the second bearing section about the pivot axis. Since the first bearing section can be fixed to the frame section of the forklift truck in a rotationally rigid manner, the frame of the forklift truck can be considered a fixed reference point in space, allowing the second bearing section to pivot relative to the fixed first bearing section about the pivot axis.

[0010] The first bearing section has the first contact surface, and the second bearing section has the second contact surface. The second contact surface rests against the first contact surface. Because the second contact surface rests against the first contact surface, forces can be transmitted between the first and second bearing sections. In the context of the present invention, when a first component rests against a second component, this also implies that the second component rests against the first component. Thus, the configuration in which the second contact surface rests against the first contact surface also implies that the first contact surface rests against the second contact surface.Preferably, the second contact surface lies flat against the first contact surface, which means that, especially in contrast to a point or line contact as is the case with rolling bearings, the first and second contact surfaces are subjected to comparatively little stress and can very well absorb high loads, especially at low sliding speeds or when stationary.

[0011] When the second bearing section pivots relative to the first bearing section around the pivot axis, the first and second contact surfaces slide against each other. Therefore, the bearing unit can also be called a plain bearing, plain bearing unit, or sliding bearing arrangement. Because the first and second contact surfaces slide against each other, the bearing unit offers low wear, excellent emergency running properties during dry running, and low sensitivity to contamination. Ideally, the bearing unit does not require dynamic or static operating pressure to build up a lubricating film between the first and second contact surfaces.

[0012] The first planting area comprises the first planting area section, and the second planting area comprises a second planting area section. Preferably, the first planting area section constitutes the first planting area, and the second planting area section constitutes the second planting area, such that the first planting area consists of the first planting area section, and the second planting area consists of the second planting area section. Alternatively, and more preferably, the first planting area comprises one or more additional planting area sections besides the first planting area section. Similarly, and more preferably, the second planting area comprises one or more additional planting area sections besides the second planting area section.

[0013] The first contact surface and the second contact surface are shaped and arranged relative to each other in such a way that forces acting along the pivot axis as well as forces acting perpendicular to the pivot axis can be transmitted between the first bearing section and the second bearing section via the first contact surface section and the second contact surface section.Because forces acting along the pivot axis as well as forces acting perpendicular to the pivot axis can be transmitted between the first and second bearing sections via the first and second bearing surface sections, a particularly compact design of the bearing unit is ensured, especially in contrast to a bearing unit where each of the first and second bearing surfaces has a separate bearing surface section for transmitting forces acting along the pivot axis and a further, distinct bearing surface section for transmitting forces acting perpendicular to the pivot axis.

[0014] The preferred forces are those acting along the pivot axis, weight forces of the industrial truck acting downwards towards the ground.

[0015] In summary, it can be stated that the storage unit can be used to provide a storage unit for a drive device for a forklift truck with a spatially compact design.

[0016] In one embodiment, the first contact surface section and the second contact surface section are both frustoconical. This frustoconical design ensures that both forces acting along the pivot axis and forces acting perpendicular to the pivot axis can be transmitted between the first and second bearing sections using a simple construction.

[0017] In one embodiment, the first contact surface section points radially towards the pivot axis, and the second contact surface section points radially away from the pivot axis. If the first contact surface section points radially towards the pivot axis and the second contact surface section points radially away from the pivot axis, the first bearing section preferably surrounds the second bearing section completely around the pivot axis, so that the first bearing section protects the second bearing section from impacts acting radially towards the pivot axis.

[0018] In one embodiment, the first contact surface section points radially away from the pivot axis, and the second contact surface section points radially towards the pivot axis. If the first contact surface section points radially away from the pivot axis and the second contact surface section points radially towards the pivot axis, the second bearing section preferably surrounds the first bearing section completely around the pivot axis, so that the second bearing section protects the first bearing section from impacts acting radially towards the pivot axis.

[0019] In one embodiment, the first bearing section has a first ring section comprising the first contact surface, and the second bearing section has a second ring section comprising the second contact surface. By having the first ring section comprising the first contact surface and the second ring section comprising the second contact surface, a mechanically robust bearing unit is provided.

[0020] In one embodiment, the bearing unit has a holding unit connected to the first bearing section and featuring a projection extending towards the pivot axis. This projection is designed to secure the second bearing section against movement away from the first bearing section along the pivot axis. By providing this holding unit, which is connected to the first bearing section and features a projection extending towards the pivot axis, the bearing unit ensures that, during operation of the industrial truck, particularly under very high tilting moments such as those occurring when cornering, the first and second bearing surfaces remain in contact and slide against each other.

[0021] In one embodiment, the housing is a gearbox housing of the drive device. Preferably, the gearbox housing defines a cavity in which different components of the gearbox unit are arranged. In an alternative embodiment of the bearing unit, the housing is a housing of the electric machine.

[0022] According to a second aspect of the invention, the aforementioned problem is solved by a drive device with the features of claim 8. The drive device is configured for a forklift truck. The drive device comprises a bearing unit according to the first aspect and a housing. The second bearing section is rotationally fixed to a section of the housing. The features, technical effects, and / or advantages described in connection with the bearing unit according to the first aspect of the invention also apply, at least analogously, to the drive device according to the second aspect of the invention, so that a corresponding repetition is omitted here.

[0023] In one embodiment, the housing is a gearbox housing of the drive device. Preferably, the gearbox housing defines a cavity in which different components of the gearbox unit are arranged. In an alternative embodiment of the drive device, the housing is a housing of the electric machine.

[0024] According to a third aspect of the invention, the aforementioned problem is solved by a forklift truck with the features of claim 10. The forklift truck has a drive device according to the second aspect. Furthermore, the forklift truck has a frame. The first bearing section is rotationally fixed to a section of the frame. The second bearing section is rotationally fixed to a section of the housing of the drive device. The features, technical effects, and / or advantages described in connection with the bearing unit according to the first aspect of the invention and those described in connection with the drive device according to the second aspect of the invention also apply, at least analogously, to the forklift truck according to the third aspect of the invention, so that a corresponding repetition is omitted here. Fig. Figure 1 shows a schematic representation of an embodiment of a drive device according to the invention, Fig. Figure 2 shows a schematic representation of a section of an embodiment of a bearing unit according to the invention, as shown in Fig. 1 drive device shown, Fig. Figure 3 shows a schematic representation of a section of the in Fig. 2. Partially illustrated embodiment of the bearing unit according to the invention, and Fig. Figure 4 also shows a schematic representation of a section of the in Fig. 2. Partially illustrated embodiment of the bearing unit according to the invention.

[0025] Fig. Figure 1 shows a schematic representation of an embodiment of a drive device 1 according to the invention. Fig. Figure 2 shows a schematic representation of a section of an embodiment of a bearing unit 3 according to the invention, as shown in Fig. 1 shown drive device 1, Fig. Figure 3 shows a schematic representation of a section of the in Fig. 2. Partially illustrated embodiment of the bearing unit 3 according to the invention, and Fig. Figure 4 also shows a schematic representation of a section of the in Fig. 2. Partially illustrated embodiment of the bearing unit according to the invention 3.

[0026] The drive unit 1 is configured for a forklift truck, enabling it to propel the truck forwarding vehicle. The drive unit 1 includes the bearing unit 3. It also comprises an electric motor 5, a brake 7 (which may be an electromagnetically released spring-applied brake), and a gearbox 9. Furthermore, a wheel 11 is mounted on the drive unit 1, which can be set into rotation by means of the electric motor 5 and the gearbox 9. The electric motor 5 converts electrical energy into mechanical energy during motor operation. The gearbox 9 converts the mechanical energy into torque and rotational speed, which is then supplied to the wheel 11 as drive energy for the forklift truck.This drive energy can be used to accelerate the industrial truck, to compensate for mechanical losses (e.g., rolling resistance), or to overcome inclines. During braking, which can also be referred to as regenerative braking, the energy flow is reversed. The electric motor 5 can then operate as a generator, extracting kinetic energy from the industrial truck and converting it into electrical energy, which can be stored in the truck's battery. The brake 7 can be used as a holding brake and as an emergency stop brake.

[0027] The bearing unit 3 is configured for the drive device 1 such that the bearing unit 3 ensures a pivotable mounting of a housing 13 of the drive device 1, which in the illustrated example is a gearbox housing of the gearbox unit 9 of the drive device 1, relative to a frame of the industrial truck (not shown). In an alternative embodiment of the bearing unit 3 (not shown), the housing 13 is a housing of the electric machine 5. By pivoting the housing 13 about a pivot axis 17 relative to the frame of the industrial truck, the direction of travel of the industrial truck can be adjusted. The drive device 1 can also be referred to as a steerable drive device 1.The bearing unit 3 has a first bearing section 15 which can be attached to a section of the frame of the industrial truck in a non-rotatable manner and a second bearing section 19 which can be pivoted about the pivot axis 17 relative to the first bearing section 15 and which can be attached to a section of the housing 13 of the drive device 1 in a non-rotatable manner.By allowing the first bearing section 15 to be fixedly attached to the frame section of the industrial truck and the second bearing section 19 to pivot about the pivot axis 17 relative to the first bearing section 15 and to be fixedly attached to a section of the housing 13 of the drive device 1, it is ensured that, with the aid of the bearing unit 3, when the first bearing section 15 is fixedly attached to the frame section of the industrial truck and the second bearing section 19 is fixedly attached to the housing 13 of the drive device 1, the housing 13 of the drive device 1 is pivotable about the pivot axis 17 relative to the frame of the industrial truck. If, in connection with the present invention, a first component is pivotable relative to a second component, this also implies that the second component is pivotable relative to the first component.The configuration thus includes the fact that the second bearing section 19 is pivotable about the pivot axis 17 relative to the first bearing section 15, and also that the first bearing section 15 is pivotable about the pivot axis 17 relative to the second bearing section 19. Since the first bearing section 15 can be fixed to the section of the forklift truck frame, the forklift truck frame can be considered a stationary reference point, allowing the second bearing section 19 to pivot about the pivot axis 17 relative to the stationary first bearing section 15. The second bearing section 19, together with the electric motor 5, the brake 7, the gearbox 9, and the vehicle wheel 11, is pivotable about the pivot axis 17 relative to the first bearing section 15.Preferably, a drawbar is provided which is connected to the electric motor 5, the brake 7, or the transmission unit 9 and via which a steering torque can be applied, so that the second bearing section 19, together with the electric motor 5, the brake 7, the transmission unit 9, and the vehicle wheel 11, pivots about the pivot axis 17 relative to the first bearing section 15. In an embodiment of the bearing unit 3 (not shown), the steering torque can be applied via a steering gear ring that is rotationally fixed to the second bearing section 19. Alternatively, a transmission upper part with a connection option for a steering chain can be provided instead of the steering gear ring.

[0028] The first bearing section 15 has a first contact surface 21, and the second bearing section 19 has a second contact surface 23. The second contact surface 23 abuts the first contact surface 21. Because the second contact surface 23 abuts the first contact surface 21, forces can be transmitted between the first bearing section 15 and the second bearing section 19. In the context of the present invention, when a first component abuts a second component, this also implies that the second component abuts the first component. Thus, the configuration in which the second contact surface 23 abuts the first contact surface 21 also implies that the first contact surface 21 abuts the second contact surface 23.

[0029] When the second bearing section 19 pivots relative to the first bearing section 15 about the pivot axis 17, the first contact surface 21 and the second contact surface 23 slide against each other. Therefore, the bearing unit 3 can also be referred to as a sliding bearing or sliding bearing unit or sliding bearing arrangement.

[0030] The first mounting surface 21 has a first mounting surface section 25, and the second mounting surface 23 has a second mounting surface section 27. In the illustrated embodiment, the first mounting surface section 25 forms the first mounting surface 21, and the second mounting surface section 27 forms the second mounting surface 23.

[0031] The first contact surface 21 and the second contact surface 23 are shaped and arranged relative to each other in such a way that forces acting along the pivot axis 17 as well as forces acting perpendicular to the pivot axis 17 can be transmitted between the first bearing section 15 and the second bearing section 19 via the first contact surface section 25 and the second contact surface section 27.Because forces acting along the pivot axis 17 as well as forces acting perpendicular to the pivot axis 17 can be transmitted between the first bearing section 15 and the second bearing section 19 via the first contact surface section 25 and the second contact surface section 27, a particularly spatially compact design of the bearing unit 3 is ensured, in particular in contrast to a bearing unit 3 in which a contact surface section for the transmission of forces acting along the pivot axis 17 and a further contact surface section, different from this contact surface section, for the transmission of forces acting perpendicular to the pivot axis 17 are provided for both the first contact surface 21 and the second contact surface 23.

[0032] The vertically acting wheel load, which is caused by the weight of the industrial truck and the contact of the vehicle wheel 11 with a floor on which the vehicle wheel 11 rolls when the industrial truck moves across the floor, is transferred from the vehicle wheel 11 to the gearbox housing and from the gearbox housing to the second bearing section 19 and from the second bearing section 19 to the first bearing section 15 in the form of a force acting along the pivot axis 17.

[0033] The first contact surface section 25 is frustoconical in shape, and the second contact surface section 27 is also frustoconical in shape. This frustoconical shape of the first contact surface section 25 and the second contact surface section 27 ensures, with a simple design, that both forces acting along the pivot axis 17 and forces acting perpendicular to the pivot axis 17 can be transmitted between the first bearing section 15 and the second bearing section 19.

[0034] The first contact surface section 25 is designed in such a frustoconical shape that it is defined by a section of the lateral surface of the frustocone. This frustoconical design ensures that when the second bearing section 19 pivots relative to the first bearing section 15 about the pivot axis 17, the first contact surface 21 and the second contact surface 23 slide particularly smoothly against each other. Furthermore, the section of the lateral surface extends circumferentially around the pivot axis 17.Because the section of the cylindrical surface extends circumferentially around the pivot axis 17, it is ensured that forces acting perpendicular to the pivot axis 17 from all directions perpendicular to the pivot axis 17 can be transmitted by the first bearing section 15. The first contact surface section 25 can also be referred to as the inner conical surface.

[0035] The second contact surface section 27 is designed in such a frustoconical shape that it is defined by a section of the lateral surface of the frustocone. This frustoconical design ensures that when the second bearing section 19 pivots relative to the first bearing section 15 about the pivot axis 17, the first contact surface 21 and the second contact surface 23 slide particularly smoothly against each other. Furthermore, the section of the lateral surface extends circumferentially around the pivot axis 17.Because the section of the cylindrical surface extends circumferentially around the pivot axis 17, it is ensured that forces acting perpendicular to the pivot axis 17 from all directions perpendicular to the pivot axis 17 can be transmitted by the second bearing section 19. The second contact surface section 27 can also be referred to as the outer conical surface.

[0036] The first contact surface section 25 points radially towards the pivot axis 17, and the second contact surface section 27 points radially away from the pivot axis 17. If the first contact surface section 25 points radially towards the pivot axis 17 and the second contact surface section 27 points radially away from the pivot axis 17, the first bearing section 15 preferably surrounds the second bearing section 19 circumferentially around the pivot axis 17, so that the first bearing section 15 protects the second bearing section 19 from impacts acting radially towards the pivot axis 17 on the first bearing section 15.

[0037] In an alternative embodiment of the drive device 1 according to the invention (not shown), the first contact surface section 25 points radially away from the pivot axis 17, and the second contact surface section 27 points radially towards the pivot axis 17. When the first contact surface section 25 points radially away from the pivot axis 17 and the second contact surface section 27 points radially towards the pivot axis 17, the second bearing section 19 preferably surrounds the first bearing section 15 circumferentially around the pivot axis 17, so that the second bearing section 19 protects the first bearing section 15 from impacts acting radially towards the pivot axis 17 on the second bearing section 19.

[0038] The first bearing section 15 has a first ring section 29, which has the first contact surface 21, and the second bearing section 19 has a second ring section 31, which has the second contact surface 23. Because the first bearing section 15 has the first ring section 29, which has the first contact surface 21, and the second bearing section 19 has the second ring section 31, which has the second contact surface 23, a mechanically robust bearing unit 3 is provided. The first bearing section 15 is designed as an outer ring rotating around the pivot axis 17, and the second bearing section 19 is designed as an inner ring rotating around the pivot axis 17. The combination of outer and inner rings provides a mechanically robust bearing unit 3.

[0039] Furthermore, the bearing unit 3 has a holding unit 33, which is connected to the first bearing section 15 and has a projection 35 extending towards the pivot axis 17, designed to secure the second bearing section 19 against movement away from the first bearing section 15 along the pivot axis 17. Because the bearing unit 3 has the holding unit 33, which is connected to the first bearing section 15 and has the projection 35 extending towards the pivot axis 17, designed to secure the second bearing section 19 against movement away from the first bearing section 15 along the pivot axis 17, it is ensured that, during operation of the industrial truck, particularly under very high tilting moments, such as those occurring when cornering, the first contact surface 21 and the second contact surface 23 remain in contact and slide against each other.The retaining unit 33 is designed as a retaining ring that extends circumferentially around the pivot axis 17. The projection 35 also extends circumferentially around the pivot axis 17. Because the retaining ring and the projection 35 extend circumferentially around the pivot axis 17, a mechanically robust locking mechanism is provided to prevent the first bearing section 15 and the second bearing section 19 from being separated. The retaining unit 33 can also transmit axial forces acting against the vertical wheel load and large tilting moments from the bearing unit 3, at least temporarily under special load conditions.

[0040] The holding unit 33 is connected to the first bearing section 15 by means of screws which are in Fig. 3 and Fig. 4 are shown, one of which is screw 37 in Fig. 2 is shown, connected. Fig. Figure 4 shows several bores, one of which is located in the first bearing section 15 and the other in the holding unit 33, each designated by reference numeral 39. For each pair of bores, where one bore 39 is located in the first bearing section 15 and the other in the holding unit 33, a screw 37 is provided. This screw is inserted into the corresponding bores and is screwed to a corresponding section of the first bearing section 15 and to a corresponding section of the holding unit 33. The bores and screws arranged circumferentially around the pivot axis 17 ensure a simple and mechanically robust connection between the first bearing section 15 and the holding unit 33. In particular, the screws and bores prevent the first bearing section 15 from lifting off the second bearing section 19, even under very high tilting moments.

[0041] As previously described, the first contact surface 21 and the second contact surface 23 slide against each other when the second bearing section 19 pivots relative to the first bearing section 15 about the pivot axis 17. The second bearing section 19 has a sliding layer 41, which forms the second contact surface 23 and is connected to a base body 43 of the second bearing section 19. Since the second bearing section 19 has the sliding layer 41, which forms the second contact surface 23 and is connected to the base body 43 of the second bearing section 19, if the sliding layer 41 wears, it can be replaced without having to replace the entire second bearing section 19, so that the base body 43 of the second bearing section 19 can be reused.Preferably, the sliding layer 41 extends circumferentially around the pivot axis 17, so that the first contact surface 21 and the second contact surface 23 can slide against each other particularly advantageously about the pivot axis 17 when the second bearing section 19 pivots relative to the first bearing section 15. Preferably, the sliding layer 41 comprises or is made of polytetrafluoroethylene (PTFE). When the sliding layer 41 comprises or is made of polytetrafluoroethylene (PTFE), particularly advantageous sliding is ensured between the first contact surface 21 and the second contact surface 23 when the second bearing section 19 pivots relative to the first bearing section 15 about the pivot axis 17. In an alternative embodiment of the bearing unit 3 (not shown), the sliding layer 41 comprises or is made of sintered iron, sintered bronze, polyamide, or another material.If the sliding layer 41 comprises sintered iron, sintered bronze, polyamide or another material, or is formed from sintered iron, sintered bronze, polyamide or another material, particularly advantageous sliding is ensured when pivoting the second bearing section 19 relative to the first bearing section 15 about the pivot axis 17 between the first contact surface 21 and the second contact surface 23.

[0042] A gap 45 is provided around the pivot axis 17 between a surface of the projection 35, which extends in a plane perpendicular to the pivot axis 17 and circumferentially around the pivot axis 17 and points towards the first contact surface 21, and a further surface of the second bearing section 19, which extends in a further plane perpendicular to the pivot axis 17 and circumferentially around the pivot axis 17 and points towards the projection 35. The gap 45 ensures that the holding unit 33 can be provided and that the first contact surface 21 and the second contact surface 23 can still slide against each other with low friction.

[0043] Furthermore, a sealing unit 47, which can also be referred to as a seal, is provided. The sealing unit 47 extends circumferentially around the pivot axis 17 and is connected to the second bearing section 19 around the pivot axis 17. The sealing unit 47 extends circumferentially around the pivot axis 17 from the second bearing section 19 in a direction from the pivot axis 17 towards an end section that extends around the pivot axis 17, projects beyond and abuts the first bearing section 15, and can also be referred to as a sealing lip. The sealing unit 47 prevents the ingress of water, dust, and foreign objects towards the area where the first contact surface 21 and the second contact surface 23 abut each other. When the bearing unit 3 is installed in a forklift truck, the sealing unit 47 prevents the ingress of water, dust, and foreign objects in the direction of gravity, i.e., from above. Fig. Figure 2 also shows a flange 49 and a gearbox cover 51.

[0044] Preferably, grease is provided between the first contact surface 21 and the second contact surface 23, so that the first contact surface 21 and the second contact surface 23 are lubricated with grease, allowing them to slide against each other with particularly low friction. In an embodiment not shown, the first contact surface 21 and / or the second contact surface 23 are provided with lubrication grooves and / or lubrication pockets that receive lubricant and release it for lubrication of the first contact surface 21 and the second contact surface 23. Furthermore, in an embodiment not shown, a grease nipple is provided through which additional grease can be introduced between the first contact surface 21 and the second contact surface 23 for relubrication.

[0045] One aspect of the present invention is the drive device 1 already described. The drive device 1 comprises the bearing unit 3 and the housing 13 already described. Furthermore, the second bearing section 19 is attached to the aforementioned section of the housing 13 by means of screws, one of which, screw 37, is located in Fig. 2 is shown, 33 is attached in a rotationally fixed manner. Fig.Figure 3 shows several bores in the second bearing section 19, one of which is marked with reference numeral 35. A screw 37 is provided for each bore 39, which is inserted into the corresponding bore 39 and screwed to a corresponding section of the housing 13. The bores and screws arranged circumferentially around the pivot axis 17 ensure a simple and mechanically robust connection between the second bearing section 19 and the housing 13. The features, technical effects, and / or advantages described in connection with the bearing unit 3 also apply, at least analogously, to the drive device 1, so a corresponding repetition is omitted here.

[0046] Another aspect of the present invention is the aforementioned, but not shown in the figures, industrial truck. The industrial truck has the drive device 1 already described. The industrial truck has the frame already mentioned. The first bearing section 15 is rotationally fixed to the aforementioned section of the frame. As already described, the second bearing section 19 is rotationally fixed to the aforementioned section of the housing 13 of the drive device 1. The features, technical effects, and / or advantages described in connection with the bearing unit 3 and the drive device 1 also apply, at least analogously, to the industrial truck, so a corresponding repetition is omitted here.

[0047] In an alternative embodiment not shown, the first bearing section 15 is rotationally fixed to the aforementioned section of the housing 13, and the second bearing section 19 is rotationally fixed to the aforementioned section of the frame. Preferably, the orientation of the first contact surface 21 and the second contact surface 23 are reversed so that the vertical wheel load can be absorbed by the bearing unit 3.

[0048] In an alternative embodiment not shown, one or more shims rotating around the pivot axis 17 are provided and arranged between the first bearing section 15 and the holding unit 33. During maintenance, the shim(s) can be reduced in thickness in a direction parallel to the pivot axis 17 or removed entirely, depending on the size of the gap 45 resulting from any wear of the sliding layer 41, thus compensating for any wear of the sliding layer 41. The shim can also be referred to as a fitting part, and the shims can also be referred to as fitting parts. Reference sign 1 Drive device 3 storage units 5 electric machine 7 Brake 9 Gear unit 11 Vehicle wheel 13 Housing of the drive device 15 first camp section 17 Swivel axis 19 second camp section 21 first investment area 23 second planting area 25 first section of the plant area 27 second section of the plant area 29 first ring section 31 second ring section 33 Holding unit 35 lead 37 screw 39 bore 41 Sliding layer 43 Base body of the second bearing section 45 gap 47 Sealing unit 49 flange 51 Gearbox cover

Claims

[1] Bearing unit (3) for a drive device (1) for a forklift truck, wherein the bearing unit (3) comprises a first bearing section (15) which can be attached to a section of a frame of the forklift truck in a rotationally fixed manner and has a second bearing section (19) which can be pivoted about a pivot axis (17) relative to the first bearing section (15) and can be fixed to a section of a housing (13) of the drive device (1) in a rotationally fixed manner, wherein the first storage section (15) has a first storage area (21) and the second storage section (19) has a second storage area (23) which is adjacent to the first storage area (21), wherein when the second bearing section (19) pivots relative to the first bearing section (15) about the pivot axis (17), the first contact surface (21) and the second contact surface (23) slide against each other, wherein the first installation area (21) has a first installation area section (25) and the second installation area (23) has a second installation area section (27), and wherein the first contact surface (21) and the second contact surface (23) are shaped and arranged relative to each other in such a way that forces acting along the pivot axis (17) as well as forces acting perpendicular to the pivot axis (17) can be transmitted between the first bearing section (15) and the second bearing section (19) via the first contact surface section (25) and the second contact surface section (27). [2] Bearing unit (3) according to the preceding claim, wherein the first contact surface section (25) is frustoconical and the second contact surface section (27) is frustoconical. [3] Bearing unit (3) according to one of the preceding claims, wherein the first contact surface section (25) points in a radial direction towards the pivot axis (17) and the second contact surface section (27) points in a radial direction away from the pivot axis (17). [4] Bearing unit (3) according to one of claims 1 or 2, wherein the first contact surface section (25) points in a radial direction away from the pivot axis (17) and the second contact surface section (27) points in a radial direction towards the pivot axis (17). [5] Bearing unit (3) according to one of the preceding claims, wherein the first bearing section (15) has a first ring section (29) having the first contact surface (21) and the second bearing section (19) has a second ring section (31) having the second contact surface (23). [6] Bearing unit (3) according to one of the preceding claims, wherein the bearing unit (3) has a holding unit (33) which is connected to the first bearing section (15) and has a projection (35) extending towards the pivot axis (17) which is designed to secure the second bearing section (19) against movement along the pivot axis (17) away from the first bearing section (15). [7] Bearing unit (3) according to one of the preceding claims, wherein the housing (13) is a gearbox housing of the drive device (1). [8] Drive device (1) for a forklift truck, wherein the drive device (1) comprises a bearing unit (3) according to one of the preceding claims and a housing (13), wherein the second bearing section (19) is fixedly attached to a section of the housing (13). [9] Drive device (1) according to claim 8, wherein the housing (13) is a gearbox housing of the drive device (1). [10] Industrial truck with a drive device (1) according to one of claims 8 or 9, wherein the industrial truck has a frame, wherein the first bearing section (15) is fixed to a section of the frame in a rotationally fixed manner, and wherein the second bearing section (19) is fixed to a section of the housing (13) of the drive device (1) in a rotationally fixed manner.

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