GEARING UNIT FOR A DRIVE ASSEMBLY AND METHOD FOR MOUNTING THE GEARING UNIT

Abstract

During operation of a wet-running gearbox, vapours and/or air can arise in a housing of the gearbox, which can increase an internal pressure in the housing and thus can influence the operating safety of the gearbox. The problem addressed by the invention is that of creating a gearing unit, which is distinguished by an advantageous arrangement of a venting device.

To this end, a gearing unit 1 for a drive assembly is specified having: a gearing device 4 for converting a drive torque of the drive assembly, the gearing device 4 having an input shaft 8, and the input shaft 8 defining a main axis H; a gearing housing 2 for accommodating the gearing device 4, the gearing housing 2 defining an accommodation space 3 for the gearing device 4; and a venting device 10 for venting the accommodation space 3, the venting device 10 being mounted on the gearing housing 2, wherein the venting device 10 is arranged coaxially with the main axis H and on an axial end face of the input shaft 8.

Claims

1. A gearing unit for a drive assembly, comprising: a gearing housing defining an accommodation space; a gearing device housed in the gearing housing and configured to convert a drive torque of the drive assembly, the gearing device including an input shaft defining a main axis; a venting device being mounted on the gearing housing and extending through the gearing housing to the accommodation space; wherein the venting device is arranged coaxially to the main axis and on an axial end side of the input shaft.

2. The gearing unit according to claim 1, wherein the venting device includes a venting channel, wherein the venting channel includes an axial channel section extending coaxially to the main axis in the accommodation space and across an axial distance between the axial end side of the input shaft and the gearing housing.

3. The gearing unit according to claim 2, wherein the venting channel includes an inlet opening and an outlet opening, wherein the venting channel includes an ascending portion between the inlet opening and the outlet opening.

4. The gearing unit according to claim 2, wherein the venting channel includes a radial channel section extending radially from the main axis and adjoining the axial channel section outside of the accommodation space.

5. The gearing unit according to claim 2, wherein the input shaft includes a recess on the axial end side, wherein the recess extends coaxially with the main axis, and wherein the axial channel section includes an axial end arranged within the recess and spaced apart from the input shaft.

6. The gearing unit according to claim 5, wherein the recess is designed as a conical bore.

7. The gearing unit according to claim 1, further comprising a closure cover, wherein the gearing housing includes a mounting opening, the input shaft being mounted within the mounting opening, wherein the closure cover closes the mounting opening, and wherein the venting device is integrated into the closure cover.

8. The gearing unit according to claim 7, wherein the closure cover is configured to engage with the mounting opening only when the closure cover is inserted into the mounting opening in a specified orientation.

9. The gearing unit (1) according to claim 1, wherein gearing device is designed as a multi-stage spur gear, wherein the input shaft is geared to an output shaft via an intermediate shaft.

10. A method for mounting a gearing unit as recited in claim 1, the method, comprising: providing a first housing component; forming a gear wheel assembly by meshing an intermediate shaft and an output shaft; inserting the gear wheel assembly into the first housing component; connecting a second housing component to the first housing component wherein the second housing component and the first housing component define the accommodation space therebetween, wherein the gear wheel assembly is arranged in the accommodation space; inserting the input shaft into the accommodation space coaxially to the main axis via a mounting opening arranged in at least one of the first or second housing components, wherein the input shaft is brought into meshing engagement with the intermediate shaft; inserting a closure cover into the mounting opening, wherein the closure cover closes the mounting opening, wherein a venting device is integrated in the closure cover and is arranged coaxially to the main axis and on one axial end side of the input shaft, the venting device extending through the closure cover to the accommodation space.

11. A gearing unit, comprising: a housing including a first housing component and a second housing component connected to the first housing component, the first and second housing components defining an accommodation space therebetween; the second housing component including a mounting opening extending circumferentially about a main axis and through the second housing component to the accommodation space; a closure cover engaged with and closing the mounting opening; and a venting device integrated into the closure cover and extending axially through the closure cover, the venting device arranged coaxially to the main axis; wherein the accommodation space is in fluid communication with an environment external to the housing via the venting device.

12. The gearing unit according to claim 11, wherein the first housing component is sealed to the second housing component.

13. The gearing unit according to claim 11, further comprising an input shaft disposed in the mounting opening, the input shaft being arranged coaxially to the main axis.

14. The gearing unit according to claim 13, wherein the input shaft includes an end and a recess extending axially from the end and away from the closure cover.

15. The gearing unit according to claim 14, wherein the venting device includes an inlet disposed in the recess.

16. The gearing unit according to claim 15, wherein the inlet is radially spaced from the recess.

17. The gearing unit according to claim 11, wherein the venting device includes an inlet disposed in the accommodation space and an outlet disposed outside of the accommodation space, and wherein the venting device includes a venting channel extending from the inlet to the outlet, at least a portion of the venting channel extending along an ascending course between the inlet and the outlet.

18. The gearing unit according to claim 11, wherein the venting device includes an axial channel coaxially to the main axis, the axial channel extending through the closure cover.

19. The gearing unit according to claim 18, wherein the venting device includes a radial channel extending radially to the main axis, the radial channel adjoining the axial channel outside of the accommodation space.

20. The gearing unit according to claim 11, wherein the closure cover is configured to engage with the mounting opening only when the closure cover is inserted into the mounting opening in a specified orientation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Further features, advantages, and effects of the disclosure are set out in the following description of the preferred exemplary embodiments of the disclosure. In the figures:

[0035] FIG. 1 shows a perspective representation of a gearing unit as an exemplary embodiment of the disclosure;

[0036] FIG. 2 shows a detailed sectional representation of the gearing unit from FIG. 1;

[0037] FIG. 3a shows a further detailed sectional representation of the gearing unit from FIG. 1;

[0038] FIG. 3b shows a perspective representation of a closure cover with an integrated venting device for the gearing unit from FIG. 1;

[0039] FIGS. 4a-e show different mounting steps of a method for mounting the gearing unit from FIG. 1.

DETAILED DESCRIPTION

[0040] FIG. 1 shows a perspective representation of a gearing unit 1 as an exemplary embodiment of the disclosure, which is designed and/or suitable for a drive assembly of a vehicle. For example, the vehicle is designed as a purely electric vehicle or as a hybrid vehicle.

[0041] The gearing unit 1 transmits a drive torque to one or more vehicle wheels, wherein the drive torque is generated and/or provided, for example, by a drive unit, for example an electric motor. The gearing unit 1 is and/or can be geared to the drive unit, not shown.

[0042] The gearing unit 1 has a gearing housing 2 which, composed of a first and a second housing component 2a,b, defines an accommodation space 3 for a gearing device 4. The gearing device 4 is designed as a transmission gear, which is suitable for translating the drive torque. In particular, the gearing device 4 has a transmission ratio of I>1, such that the drive torque transmitted to the gearing device 4 at a gearbox output is increased or a speed at the gearbox output is reduced.

[0043] For example, the two housing components 2a, b are made of cast aluminum and are detachably connected to one another in an axial direction AR in relation to a main axis H. For this purpose, the two housing components 2a, b are supported on one another in the axial direction AR and are screwed together via multiple screw means 5. The first housing component 2a also has an end shield 6, which at the same time forms a motor shield for the drive unit, in particular the electric motor.

[0044] The second housing component 2b has a cylindrical mounting opening 7, wherein an input shaft 8 of the gearing device 4 is mounted via the mounting opening 7, as shown in FIG. 2. The mounting opening 7 is made in the second housing component 2b coaxially to the main axis H and is closed in the axial direction AR with respect to the main axis H by a closure cover 9.

[0045] The gearing unit 1 has a venting device 10, which vents the accommodation space 3. The venting device 10 is formed by a venting channel 11, which is integrated coaxially to the main axis H in the closure cover 9. The venting channel 11 fluidically connects the accommodation space 3 with an environment, so that air and/or vapor located in the accommodation space 3 can escape via the venting channel 11 into the environment or possibly a connected venting system.

[0046] The specific configuration and the function of the venting device 10 are explained in the following FIG. 2, which shows a detailed view of the gearing unit 1 in a longitudinal section along the main axis H.

[0047] The gearing device 4 is designed as a two-stage spur gear, wherein the input shaft 8 is in meshing engagement with an intermediate shaft 12 to form a first spur gear stage. For this purpose, the input shaft 8 has a drive wheel section 13 and the intermediate shaft 12 has a first intermediate wheel section 14, which engage with one another. The drive wheel section 13 is designed as an external tooth system formed on the input shaft 8. The first intermediate wheel section 14 is designed, for example, as a gear wheel which is non-rotatably connected to the intermediate shaft 12.

[0048] As can be seen from FIG. 2, the input shaft 8 is arranged coaxially to the main axis H in the gearing housing 2 and is rotatably supported on the second housing component 2b via a bearing device 15, for example a grooved ball bearing, within the mounting opening 7. In particular, the main axis H is defined by an axis of rotation of the input shaft 8. The input shaft 8 transmits the drive torque from the drive unit to the gearing device 4, wherein the input shaft 8 is geared to the drive unit for this purpose. For example, the input shaft 8 can be designed as an engine shaft of the electric motor.

[0049] The position of the venting device 10 in the gearing unit 1 is aligned centrally to the input shaft 8 and thus also centrally to the electric drive unit. The venting device 10 is arranged immediately adjacent to the main axis H on an axial end side of the input shaft 8. During operation, the highest speed always occurs on the input shaft 8, and due to the high speed, the oil is conveyed outwards and thus away from the venting device 10 by the centrifugal force. This prevents, or at least reduces, the penetration of oil, oil mist, or oil foam into the venting channel 11.

[0050] The input shaft 8 has a recess 16 on the axial end side, which is made in an end face of the input shaft 8. The recess 16 is designed as a conical bore, which extends into the input shaft 8 coaxially in relation to the main axis H.

[0051] The venting channel 11 has an axial channel section 11a and a radial channel section 11b, wherein the axial channel section 11a runs coaxially to the main axis H in the accommodation space 3 and is accommodated in the recess 16 at the end with a radial and an axial spacing. The radial channel section 11b adjoins the axial channel section 11b in a radial direction, for example at an angle of 90 degrees, outside the gearing housing 2, in particular after the closure cover 9.

[0052] The axial channel section 11a has an inlet opening E at its free end and the radial channel section 11b has an outlet opening A at its free end. An air flow path L thus runs from the accommodation space 3 via an annular gap formed between the recess 16 and the axial channel section 11 a to the inlet opening E and via the venting channel 11 to the outlet opening A. The venting channel 11 has an ascending portion between the inlet opening E and the outlet opening A. For this purpose, the radial channel section 11b is directed upwards in an installation situation or is oriented in a 12 o'clock position in relation to an imaginary clock face arranged coaxial to the main axis H. The ascending portion in the venting channel 11 ensures that any oil in the axial channel section 11a is held back by the outlet opening A and can flow back into the accommodation space 3 if necessary. At the location of the outlet opening A, the radial channel section 11b also has a hose connection for connecting a venting hose.

[0053] In order to be able to ensure lubrication of the bearing device 15, a fluid channel 17 is integrated into the gearing housing 2, in particular the second housing component 2b, which channels the oil located in the accommodation space 3 to the axial end side of the input shaft 8.

[0054] In order to seal the accommodation space 3 or the mounting opening 7 in the axial direction AR against oil escaping, the closure cover 9 is sealed in the radial direction via a sealing device 18 with respect to the second housing component 2b. The sealing device 18 is designed, for example, as a sealing ring which is mounted on the closure cover 9 on the peripheral side.

[0055] FIG. 3a shows a detailed view of the gearing unit 1 in a further sectional view through the fluid channel 17. The fluid channel 17 is designed as a through-hole, which is introduced into the second housing component 2b and is closed to the outside by a sealing plug 19. In addition, the through-hole has an opening 20 in the direction of the accommodation space 3 in order to fluidically connect a first housing area 3a to a second housing area 3b. In this case, for example, an oil inlet is arranged in the first housing area 3a, which is used to fill the accommodation space 3 with the oil. The bearing device 15 is arranged in the second housing region 3b, wherein lubrication of the bearing device 15 is ensured by the fluid channel 17.

[0056] FIG. 3b shows a perspective view of the closure cover 9 with the integrated venting channel 11 to form the venting device 10. The closure cover 9 and the venting channel 11 are made from a common material section, for example a common plastic injection molding. The axial channel section 11 a is arranged in the center of the closure cover 9, wherein the closure cover 9 adjoins the axial channel section 11a as a radially outwardly directed flange in relation to the main axis H.

[0057] Further tore, the closure cover 9 has a form-fitting contour 21 which can be brought into engagement with a counter-contour, not shown, arranged on the second housing component 2b. The form-fitting contour 21 is designed as a web directed in the axial direction, wherein it is possible for the counter-contour to be designed as a corresponding groove which is introduced into the second housing component 2b. The form-fitting contour 21 and the counter-contour can be in engagement with one another in a mounted state according to the poka-yoke principle, so that the closure cover 9 can only be inserted into the mounting opening 7 in a single orientation. In particular, in the mounted state, the radial channel section 11b is directed upwards, wherein the form-fitting contour 21 can ensure that the venting device 11 is installed in the correct position.

[0058] FIGS. 4a to 4e show different mounting steps for mounting the gearing unit 1. A first mounting step is shown in FIG. 4a, wherein the first housing component 2a is provided in the first mounting step. The first housing component 2a forms a first housing half, which is open in the axial direction AR in relation to the main axis H and forms part of the accommodation space 3.

[0059] FIG. 4b shows a second mounting step, in which a pre-adjusted gear wheel assembly 22 is inserted into the accommodation space 3 of the first housing component 2a. The gear wheel assembly 22 comprises the intermediate shaft 12 with the intermediate wheel section 14 as a first intermediate wheel non-rotatably connected to the intermediate shaft 12, and a further intermediate wheel section (covered by the intermediate wheel section 14) as a second intermediate wheel non-rotatably connected to the intermediate shaft 12. Furthermore, the gear wheel assembly 22 comprises an output shaft 23 for forming the gear output and an output wheel section 24, wherein the output wheel section 24 is designed as a gear wheel which is non-rotatably connected to the output shaft 23. In an intermediate step, the intermediate shaft 12 and the output shaft 23 are aligned prior to being joined in the first housing component 2a and the output gear section 24 is brought into meshing engagement with the further intermediate gear section to form a second spur gear stage. The gear wheel assembly 22 is then inserted into the first housing component 2a, wherein the intermediate shaft 12 and the output shaft 23 are mounted in the first housing component 2a.

[0060] FIG. 4c shows a third mounting step, in which the second housing component 2b is connected to the first housing component 2a. The second housing component 2b forms a second housing half, which is open in the opposite axial direction GR with respect to the main axis H and forms part of the accommodation space 3. In an intermediate step, a sealant can be arranged at the connection point, for example the housing flange, of the first and/or second housing component 2a, b in order to seal the two housing components 2a, b together. For example, the sealing means can be in the form of a flat gasket or a sealing composite. The second housing component 2b is then placed on the first housing component 2a in the opposite axial direction GR and screwed to the first housing component 2a via the screw means 4.

[0061] FIG. 4d shows a fourth mounting step, in which the input shaft 8 is inserted into the gearing housing 2 via the mounting opening 7, wherein the input shaft 8 is brought into meshing engagement with the intermediate gear section 14 via the drive wheel section 13, as shown in FIG. 2a, to form the first spur gear stage. In an intermediate step, the bearing device 15 and a further bearing device (covered by the gearing housing 2) are pressed onto the input shaft 8 on both sides. The input shaft 8 with the bearing devices 15 pressed thereon is then inserted into the gearing housing 2 in the axial direction AR with respect to the main axis H via the mounting opening 7, wherein the input shaft 8 is guided out of the gearing housing 2 again on the side of the bearing plate 6 and forms the gearbox input.

[0062] FIG. 4e shows a fifth mounting step, in which the mounting opening 7 is closed by the closure cover 9 and the integrated venting device 10 is arranged coaxially to the main axis H on the axial end side of the input shaft 8. For this purpose, the closure cover 9 can be pressed into the mounting opening 7, wherein the venting device 10 is positioned in the correct position in the mounting opening 7 via the form-fitting contour 21.

[0063] Thus, a method is proposed which simplifies mounting of the gearing device 4, in which only the intermediate shaft 12 and the output shaft 23 have to be aligned before joining in the gearing housing 2. A complex alignment of the shafts 8, 12, 23 before they are joined into the gearing housing 2 can thus be dispensed with.

LIST OF REFERENCE SYMBOLS

[0064] 1 Gearing unit [0065] 2 Gearing housing [0066] 2a, b Gearing housing components [0067] 3 Accommodation space [0068] 3a, b Housing areas [0069] 4 Gearing device [0070] 5 Screw means [0071] 6 End shield [0072] 7 Mounting opening [0073] 8 Input shaft [0074] 9 Closing cover [0075] 10 Venting device [0076] 11 Venting channel [0077] 11a, b Channel sections [0078] 12 Intermediate shaft [0079] 13 Drive wheel section [0080] 14 Intermediate wheel section [0081] 15 Bearing device [0082] 16 Recess [0083] 17 Fluid channel [0084] 18 Sealing device [0085] 19 Closure stop [0086] 20 Opening [0087] 21 Form-fitting contour [0088] 22 Gear wheel assembly [0089] 23 Output shaft0 [0090] A Output opening [0091] E Input opening [0092] H Main axis [0093] L Air flow path [0094] AR Axial direction [0095] GR Axial opposite direction