Drive unit with oil storage housing

Abstract

A drive unit has an output shaft and a transmission with an input element (4), a housing (60) and an oil storage housing (62). The input element (4) is designed to receive a torque, and the output shaft is mechanically operatively connected to the transmission in order to output a torque from the transmission. The oil storage housing (62) is secured to the housing (60) and forms an oil storage chamber. The oil storage chamber is located outside a transmission receiving area in which the transmission is provided, and the oil storage chamber is offset in the axial direction with respect to the transmission. The oil storage chamber surrounds at least part of the output shaft in the radial direction.

Description

[0001] Drive unit with oil storage housing

[0002] Technical area

[0003] The present invention relates to a drive unit with an oil storage housing and to a vehicle with a drive unit.

[0004] State of the art

[0005] Drive units with an oil reservoir housing for a vehicle are known. Oil from the oil reservoir housing can be used to lubricate and cool drive unit components. However, the oil reservoir housing requires a large amount of space, which limits other requirements, such as providing ground clearance for a vehicle.

[0006] Description of the invention

[0007] It is an object of the present invention to provide an improved drive unit with an oil storage housing.

[0008] The object is achieved by a drive unit having the features of claim 1. Advantageous further developments are the subject of the dependent claims.

[0009] A drive unit has an output shaft, a transmission with an input element, a housing, and an oil storage housing. The transmission can be used to drive at least one drive wheel in a vehicle. The input element is designed to absorb torque. The input element can be designed to absorb torque from a drive machine, for example an electric machine or an internal combustion engine. The output shaft is mechanically connected to the transmission for outputting torque from the transmission. The oil storage housing is fastened to the housing. The oil storage housing forms an oil storage chamber. The oil storage chamber is arranged outside a transmission receiving chamber in which the transmission is arranged. The transmission receiving chamber can be formed by the housing. The oil storage chamber is arranged offset from the transmission in an axial direction.The oil storage chamber surrounds the output shaft in a radial direction, at least in sections.

[0010] If two elements are attached to each other, they are firmly connected by one or more connection points. The movement of one element can then essentially cause the same movement in the other element. Additional elements can be provided between the elements.

[0011] If two elements are mechanically operatively connected, they are directly or indirectly coupled to one another in such a way that a movement of one element causes a reaction in the other element. For example, a mechanical operative connection can be provided by a positive or frictional connection. The mechanical operative connection can correspond to the meshing of corresponding toothings of the two elements. Additional elements, such as one or more spur gear stages, can be provided between the elements. A permanently rotationally fixed connection between two elements, on the other hand, is understood to be a connection in which the two elements are rigidly coupled to one another in all intended states, e.g. of a gearbox. The elements can be present as individual components that are connected to one another in a rotationally fixed manner or as a single piece.A switching element, such as a clutch or brake, can be used to selectively establish or break a rotationally fixed connection between two elements.

[0012] The oil storage chamber can completely enclose the output shaft. The oil storage chamber can partially enclose the output shaft. The oil storage chamber can be U-shaped. The oil storage chamber can become smaller towards an upper side in a direction of gravity. For example, a cross-sectional area of ​​the oil storage chamber can become smaller towards the top in the direction of gravity. The oil storage chamber can project beyond the second output shaft in the axial direction. The oil storage chamber can intersect the second output shaft in the axial direction. The oil storage chamber can be configured to be arranged within the housing in the radial direction. The oil storage chamber can be configured as a space separate from the transmission receiving space. The oil storage chamber can have a cover. The oil storage chamber can be fluid-tightly sealed with respect to an outside of the transmission housing and the oil storage housing.

[0013] A radial clearance, such as a space, can be provided between the output shaft and the oil reservoir housing. The space can be configured, for example, to accommodate a propeller shaft that can be connected to the output shaft in a rotationally fixed manner.

[0014] This allows for ample ground clearance for the vehicle. When installed transversely, the drive unit can be compactly integrated into the vehicle in a longitudinal direction.

[0015] The drive unit may include an oil pump. The oil pump may be configured to supply transmission elements or elements of the drive unit, such as bearing units. The oil pump may be configured to fill the oil storage chamber with oil. The oil pump may be configured to fill the oil storage chamber with oil from the transmission housing. The oil pump may be a tandem pump.

[0016] In one embodiment, the oil storage chamber can be toroidal in shape, at least in sections. A cross-sectional area can have a greater extent in the radial direction than in the axial direction. The oil storage chamber can be annular or elliptical. The oil storage chamber can have an annular or elliptical cross-sectional area. The oil storage chamber can be rotationally symmetrical. The oil storage chamber can be rotationally symmetrical with respect to a rotational axis of the output shaft. The oil storage chamber can be designed to narrow upwards in the direction of gravity. The oil storage chamber can be designed to narrow upwards in the axial direction in the direction of gravity. In one embodiment, a vent opening can be provided for venting the oil storage chamber.The vent opening can be configured to allow excess pressure to escape, for example when the drive unit is heated. The vent opening can be designed as a bore. The vent opening can extend in the axial direction. The vent opening can extend in the radial direction. The vent opening can extend through the oil storage housing. The vent opening can open into the housing. The vent opening can extend from the oil storage space through the housing to the gear receiving space. The vent opening can extend from the oil storage space through the oil storage housing and the housing to the gear receiving space. The vent opening can be in fluid communication with the housing via a fluid connection element, for example a hose or a pipe.

[0017] In one embodiment, the vent opening can be arranged above the output shaft. The vent opening can be arranged at the top in the direction of gravity. The vent opening can be arranged at an upper end region of the oil storage chamber. This allows the amount of oil that can escape from the oil storage chamber via the vent opening during longitudinal or lateral acceleration of the drive unit to be kept to a minimum.

[0018] In one embodiment, the vent opening can be arranged in a central region of the oil storage chamber. This embodiment can be combined with the arrangement of the vent opening above the output shaft. The vent opening can be arranged slightly offset from the output shaft in the radial direction. If the oil storage chamber is designed to be rotationally symmetrical, then the vent opening can be designed in the geometric center, for example, with respect to a transverse direction, above the output shaft. This allows the amount of oil that can escape from the oil storage chamber via the vent opening during longitudinal or transverse acceleration of the drive unit to be kept uniformly low. In one embodiment, the oil storage chamber can be formed by the housing and the oil storage housing.Both sections of the casing and sections of the oil storage casing may provide boundary surfaces for the oil storage space.

[0019] In one embodiment, the housing can have a gear cover that covers the housing and, together with the oil storage housing, forms the oil storage space. Both sections of the gear cover and sections of the oil storage housing can provide boundary surfaces for the oil storage space. The oil storage space can be formed by the gear cover, other sections of the housing, and the oil storage housing. The gear cover can be arranged on a gear side of the drive unit. The gear side can be formed by a side of the drive unit in the axial direction on which the gear is arranged. The gear cover can be bolted to the housing. The oil storage housing can be attached to the gear cover from the outside on a gear side. The gear cover can be bolted to the housing together with the oil storage housing. The gear cover can seal the housing in a fluid-tight manner.

[0020] In one embodiment, the drive unit can further comprise a drive motor. The drive motor can be formed by an electric machine, for example with a stator and a rotor. The oil storage chamber can be arranged outside a drive receiving chamber in which the drive motor is arranged. The drive receiving chamber can be formed by the housing. The oil storage chamber can be arranged offset in the axial direction from the drive motor. The drive motor can be arranged on a drive side relative to the transmission. The drive side can be opposite the transmission side in the axial direction. The housing can have a drive cover. The drive cover can be arranged on the drive side relative to the housing. The drive cover can be arranged opposite the transmission cover in the axial direction relative to the transmission. The drive cover can seal the housing in a fluid-tight manner.The drive cover can be bolted to the housing. In one embodiment, the drive unit can further comprise a first output shaft. The output shaft can be formed by a second output shaft. The transmission can comprise a first gear set and a second gear set. The first gear set can be mechanically operatively connected to the second gear set. The first gear set can be mechanically operatively connected to the input element for receiving torque. The first gear set can be mechanically operatively connected to the first output shaft for outputting torque. The second gear set can be mechanically operatively connected to the second output shaft for outputting torque. The transmission can comprise a differential feature. The transmission can be configured to split torque from the input element between the first output shaft and the second output shaft.

[0021] In one embodiment, the first gear set may be formed by a first planetary gear set having a first element, a second element, and a third element. The second gear set may be formed by a second planetary gear set having a first element, a second element, and a third element. The first element of the first planetary gear set may be rotationally connected to the first input member. The second element of the first planetary gear set may be rotationally connected to the first output shaft. The third element of the first planetary gear set may be rotationally connected to the first element of the second planetary gear set. The second element of the second planetary gear set may be rotationally connected to the housing. The third element of the second planetary gear set may be rotationally connected to the second output shaft.

[0022] The first planetary gear set may include a first sun gear, a first planet carrier, a first planet pin, a first planet gear, and a first ring gear. The first sun gear may mesh with the first planet gear. The first planet gear may mesh with the first ring gear. The first planet gear may be rotatably supported on the first planet pin. The first planet pin may be connected to the first planet carrier. The second planetary gear set may include a second sun gear, a second planet carrier, a second planet pin, a second planet gear, and a second ring gear. The second sun gear may mesh with the second planet gear. The second planet gear may mesh with the second ring gear. The second planet gear may be rotatably supported on the second planet pin. The second planet pin may be connected to the second planet carrier.

[0023] The first planetary gear set and the second planetary gear set can be arranged in the same plane in the axial direction. The second planetary gear set can be arranged outside the first planetary gear set in the radial direction. The first planetary gear set and the second planetary gear set can be arranged offset from one another in the axial direction.

[0024] The first and second planetary gear sets can be designed as minus planetary gears or as plus planetary gears.

[0025] If the first or second planetary gear set is designed as a negative planetary gear set, the respective second element can be formed by the planet carrier. The respective third element can be formed by the ring gear.

[0026] If the first or second planetary gear set is designed as a positive planetary gear set, the respective second element can be formed by the ring gear. The respective third element can be formed by the planet carrier.

[0027] In one embodiment, the first sun gear of the first planetary gear set can be rotationally fixedly connected to the input element. The first planet carrier of the first planetary gear set can be rotationally fixedly connected to the first output shaft. The first ring gear of the first planetary gear set can be rotationally fixedly connected to the first sun gear of the second planetary gear set. The second ring gear of the second planetary gear set can be rotationally fixedly connected to the second output shaft. The second planet carrier of the second planetary gear set can be rotationally fixedly connected to the housing. Then, the first planetary gear set and the second planetary gear set can each be configured as a minus planetary gear set. In one aspect, a vehicle has a drive unit according to one of the preceding embodiments and at least two drive wheels. The drive unit is configured to drive the drive wheels.One of the drive wheels is configured to drive the vehicle via the first output shaft. The other of the drive wheels is configured to drive the vehicle via the second output shaft.

[0028] Joints can be arranged between each of the first output shaft and the second output shaft and the respective first drive wheel and the second drive wheel to achieve a steering angle or a spring travel, or a combination thereof. The drive motor can be an electric motor or an internal combustion engine.

[0029] Short description of the characters

[0030] Figure 1 shows a sectional view of a schematic representation of an embodiment of a drive unit.

[0031] Figure 2 shows a plan view of the schematic representation of the embodiment of the drive unit.

[0032] Figure 3 shows a side view of a schematic representation of the embodiment of the drive unit.

[0033] Figure 4 shows a plan view of the schematic representation of the embodiment of the drive unit.

[0034] Detailed description of embodiments

[0035] Figure 1 shows a sectional view of a schematic representation of an embodiment of a drive unit. The drive unit has a first output shaft 5, an output shaft formed by a second output shaft 6, a housing 60, an oil reservoir housing 62, a drive motor with a stator 70 and a rotor 71, and a transmission. The transmission has an input element 4, a first gear set, in this case a first planetary gear set 10, and a second gear set, in this case a second planetary gear set 20.

[0036] The input element 4 is designed to receive torque from the drive motor. The first output shaft 5 and the second output shaft 6 are each mechanically operatively connected to the transmission for outputting torque from the transmission. The oil storage housing 62 is fastened to the housing 60 via a transmission cover 61 and forms an oil storage chamber. The oil storage chamber is arranged outside a transmission receiving chamber in which the transmission is arranged. The oil storage chamber is arranged offset in the axial direction from the transmission. The oil storage chamber is arranged outside a drive receiving chamber in which the drive motor is arranged. The oil storage chamber is arranged offset in the axial direction from the drive motor. The oil storage chamber surrounds the second output shaft 6 in a toroidal shape in a radial direction.The drive unit can be used to drive drive wheels of a vehicle via at least one of the first output shaft 5 and the second output shaft 6. This allows a space in the radial direction between the second output shaft and the oil reservoir housing to be used to connect a propeller shaft for driving one of the drive wheels.

[0037] A vent opening 63, shown in Figure 3, is arranged at an upper end region of the oil storage chamber relative to a direction of gravity. The vent opening is arranged in a central region of the oil storage chamber relative to a transverse direction, shown in Figure 2. This has the advantage that the amount of oil that can escape from the oil storage chamber via the vent opening during longitudinal or transverse acceleration is minimal.

[0038] Further details of the drive unit are described below.

[0039] The first planetary gear set 10 includes a first sun gear, a first planet carrier, a number of first planet pinions, a number of first planet gears, and a first ring gear. The first sun gear meshes with one of the first planet gears. One of the first planet gears meshes with the first ring gear and is rotatably mounted on one of the first planet pinions. The first planet pinions are connected to the first planet carrier.

[0040] The second planetary gear set 20 includes a second sun gear, a second planet carrier 22, a number of second planet pinions, a number of second planet gears, and a second ring gear. The second sun gear meshes with one of the second planet gears. One of the second planet gears meshes with the second ring gear and is rotatably mounted on one of the second planet pinions. The second planet pinions are connected to the second planet carrier 22. The second planet carrier 22 is non-rotatably connected to the housing 60.

[0041] The rotor 71 is mechanically connected to the gearbox via the input element 4. The gearbox is arranged in an axial direction between the drive motor and the gearbox cover 61.

[0042] The first output shaft 5 and the second output shaft 6 are arranged coaxially with the input element 4. The first output shaft 5 extends in the axial direction through the input element 4 and the rotor 71. The first output shaft 5 and the second output shaft 6 extend in opposite directions in the axial direction.

[0043] The gear cover 61 is connected to the housing 60 in a rotationally fixed manner. The gear cover 61 closes the housing 60 on one gear side, the right side in Figure 1 . The oil reservoir housing 62 is connected to the gear cover 61 and the housing 60 in a rotationally fixed manner via screw connections. The screw connections are arranged in a circumferential direction equidistant from a rotational axis of the second output shaft 5. The screw connections extend in the axial direction through the oil reservoir housing 62 and the gear cover 61. The housing 60 is closed on a drive side, the left side in Figure 1 , by a drive cover 64. The drive cover 64 is connected to the housing 60 via screw connections. Each of the screw connections has a screw with a screw axis that is aligned in the axial direction.

[0044] The second output shaft 6 is rotatably mounted on the transmission cover 61 via a second output shaft 6 bearing 42. The second output shaft 6 bearing 42 is arranged on an inner circumference of a portion of the transmission cover 61. The second output shaft 6 bearing 42 is arranged on an outer circumference of a portion of the second output shaft 6.

[0045] The rotor 71 is rotatably supported on an intermediate wall via a rotor bearing 44. The rotor bearing 44 is arranged on the transmission side in the axial direction with respect to the rotor 71. The rotor bearing 44 is arranged between the drive machine and the transmission. The rotor bearing 44 is arranged on an inner circumference of a portion of the intermediate wall of the housing 60. The rotor bearing 44 is arranged on an outer circumference of a portion of the rotor 71. The rotor 71 is rotatably supported on the drive cover 64 via a second rotor bearing 45. The second rotor bearing 45 is arranged on the drive side with respect to the rotor 71. The second rotor bearing 45 is arranged on an inner circumference of a portion of the drive cover 64. The second rotor bearing 45 is arranged on an outer circumference of a portion of the rotor 71.

[0046] The first output shaft 5 is rotatably supported on the drive cover 64 via a bearing 41 for the first output shaft 5, on the left in Fig. 1 . The bearing 41 for the first output shaft 5 is arranged on the drive side with respect to the second rotor bearing 45. The bearing 41 for the first output shaft 5 is arranged on an inner circumference of a portion of the drive cover 64. The bearing 41 for the first output shaft 5 is arranged on an outer circumference of a portion of the first output shaft 5. An outer circumference of the bearing 41 for the first output shaft 5 has a smaller diameter than an outer circumference of the second rotor bearing 45.

[0047] Figure 2 shows a top view of the schematic representation of the embodiment of the drive unit. The top view shows the second output shaft 6, which extends through the gear cover 61 and the toroidal oil reservoir housing 62 to an outer side of the drive unit. Screw connections of the oil reservoir housing 62, distributed in the circumferential direction, are shown in Figure 2.

[0048] Figure 3 shows a side view of a schematic representation of the embodiment of the drive unit. Figure 3 schematically shows the vent opening 63, in this case a bore extending in the axial direction from the oil storage chamber to the transmission receiving chamber through the oil storage housing 62 and the transmission cover 61.

[0049] When the vehicle accelerates laterally to the left, for example, when cornering, the oil in the oil reservoir is pushed to the right. This creates an inclined oil level in the oil reservoir, slanting upwards to the right, below the vent hole.

[0050] When the vehicle accelerates laterally to the right, for example, when cornering, the oil in the oil reservoir is pushed to the left. This creates an inclined oil level in the oil reservoir, slanting downwards to the right and extending above the vent hole. Oil can leak from the vent hole until the oil level drops below the vent hole.

[0051] The volume of oil escaping through the vent opening is small due to the design of the oil storage space and the position of the vent hole.

[0052] Figure 4 shows a plan view of the schematic representation of the embodiment of the drive unit.

[0053] When the vehicle accelerates longitudinally to the left, for example when the vehicle is braking, the oil in the oil storage chamber is pushed to the right. This creates an inclined oil level in the oil storage chamber, diagonally downwards to the left and running above the vent hole. Oil can then escape from the vent hole until a reduced oil level is reached, which runs below the vent hole. When the vehicle accelerates longitudinally to the right, for example when the vehicle's speed increases, the oil in the oil storage chamber is pushed to the left. This creates an inclined oil level in the oil storage chamber, diagonally downwards to the right and running above the vent hole. Oil can then escape from the vent hole until a reduced oil level is reached, which runs below the vent hole.

[0054] The volume of oil escaping through the vent hole is small due to the design of the oil storage chamber and the position of the vent hole. The escaping volume is formed by an outer section of the toroidal oil storage chamber. The volume of the outer section is many times smaller than the volume of the remaining toroidal oil storage chamber. A cross-sectional area of ​​the oil storage chamber perpendicular to the direction of gravity decreases towards the top. Therefore, the volume of oil escaping through the vent hole is small due to the design of the oil storage chamber and the position of the vent hole. Furthermore, the escaping volume is small regardless of the direction of acceleration in the longitudinal direction.

[0055] Reference symbol

[0056] Input element

[0057] First output wave

[0058] Second output shaft

[0059] First planetary gear set

[0060] Second planetary gear set

[0061] Second planet carrier

[0062] Bearing for the first output shaft

[0063] Bearing for the second output shaft

[0064] Rotor bearing second rotor bearing

[0065] Housing

[0066] Gearbox cover

[0067] Oil storage housing

[0068] vent opening

[0069] Drive cover

[0070] stator

[0071] rotor

Claims

Patent claims 1. Drive unit with an output shaft, a gearbox which has an input element (4), a housing (60) and an oil storage housing (62), wherein the input element (4) is designed to absorb a torque, the output shaft is mechanically operatively connected to the transmission for outputting a torque from the transmission, the oil storage housing (62) is fastened to the housing (60) and forms an oil storage space, the oil storage space is arranged outside a transmission receiving space in which the transmission is arranged, the oil storage space is arranged offset in the axial direction to the transmission, and the oil storage space surrounds the output shaft at least in sections in a radial direction.

2. Drive unit according to claim 1, characterized in that the oil storage space is at least partially toroidal.

3. Drive unit according to one of the preceding claims, characterized in that a vent opening is provided for venting the oil storage space.

4. Drive unit according to claim 3, characterized in that the vent opening is arranged above the output shaft.

5. Drive unit according to claim 3 or 4, characterized in that the vent opening is arranged in a central region of the oil storage space.

6. Drive unit according to one of the preceding claims, characterized in that the oil storage space is formed by the housing (60) and the oil storage housing (62).

7. Drive unit according to one of the preceding claims, characterized in that the housing (60) has a gear cover (61) which covers the housing (60) and which, together with the oil storage housing (62), forms the oil storage space.

8. Drive unit according to one of the preceding claims, characterized in that the drive unit further comprises a drive machine, the oil storage space is arranged outside a drive receiving space in which the drive machine is arranged, and the oil storage space is arranged offset in the axial direction to the drive machine.

9. Drive unit according to one of the preceding claims, characterized in that the drive unit further comprises a first output shaft (5) and the output shaft is formed by a second output shaft (6), the transmission has a first gear set and a second gear set, the first gear set is mechanically operatively connected to the second gear set, the first gear set is mechanically operatively connected to the input element (4) for receiving a torque, the first gear set is mechanically operatively connected to the first output shaft (5) for outputting a torque from the transmission, and the second gear set is mechanically operatively connected to the second output shaft (6) for outputting a torque from the transmission.

10. Drive unit according to claim 9, characterized in that the first gear set is formed by a first planetary gear set (10) with a first element, a second element and a third element and the second gear set is formed by a second planetary gear set (20) with a first element, a second element and a third element, the first element of the first planetary gear set (10) is connected in rotation with the input element (4), the second element of the first planetary gear set (10) is connected in rotation with the first output shaft (5), the third element of the first planetary gear set (10) is connected in rotation with the first element of the second planetary gear set (20), and the second element of the second planetary gear set (20) is connected in rotation with the Housing (60) is connected, and the third element of the second planetary gear set (20) is rotationally connected to the second output shaft (6).

11. Drive unit according to claim 10, characterized in that the input element (4) is rotationally connected to a first sun gear of the first planetary gear set (10), a first planet carrier of the first planetary gear set (10) is rotationally connected to the first output shaft (5), a first ring gear of the first planetary gear set (10) is rotationally connected to a first sun gear of the second planetary gear set (20), a second ring gear of the second planetary gear set (20) is rotationally connected to the second output shaft (6), and a second planet carrier (22) of the second planetary gear set (20) is rotationally connected to the housing (60).

12. Vehicle with a drive unit, at least two drive wheels and a drive unit according to one of the preceding claims, wherein the drive unit is arranged to drive the drive wheels, one of the drive wheels for driving the vehicle via the first Output shaft (5) is arranged, and the other of the drive wheels is arranged to drive the vehicle via the second output shaft (6).

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