Bevel gear differential with a star-shaped bearing plate

Abstract

A device (1) is proposed, comprising a bevel gear differential (2), wherein the bevel gear differential (2) has at least one compensating gear (3) and two output gears (4), and the at least one compensating gear (3) has a bevel gear pin (5) for mounting the at least one compensating gear (3), wherein the mounting of the at least one compensating gear (3) with its bevel gear pin (5) is formed by a star-shaped bearing plate (6), the wall (7) of which is smaller in the axial direction than the diameter of the bevel gear pin (5), and the bearing plate (6) supports the end (8) of the bevel gear pin (5) oriented toward the rotational axis of the bevel gear differential (2).

Description

[0001] Title of the application

[0002] Bevel gear differential with a star-shaped bearing plate.

[0003] Description

[0004] The invention relates to a bevel gear differential with a star-shaped bearing plate.

[0005] DE 10 2007 040 479 A1 discloses a differential gear with a summing shaft for distributing torques to a first differential member and to a second differential member via at least one planetary bevel gear, wherein the planetary bevel gear is operatively connected in such a way that the planetary bevel gear is in tooth mesh with a first toothing on the first differential member and with a second toothing on the second differential member, wherein the axis of rotation of the planetary bevel gear is perpendicular to the axis of rotation of the summing shaft and the axis of rotation of each differential member, wherein the summing shaft is designed as a spur gear in which the at least one planetary bevel gear is mounted.

[0006] WO 2020 069 692 A1 discloses a differential with differential gears, a drive gear and at least one cover, wherein the drive gear has external circumferential toothing around an axis of rotation and is provided with internal bearing points, the differential gears are mounted at the bearing points in the drive gear and the differential is closed on one side with the cover, wherein the differential gears are held in the drive gear by means of the cover and that the cover and the drive gear are attached to each other without the effect of any further fastening means only by at least one material-fit connection in such a way that at least the differential formed from the differential gears, the drive gear and the cover is a self-supporting unit.

[0007] DE 102023 121 334 A1 shows a bevel gear pin star in one-piece design. The prior art shows three-armed bevel gear pins designed in one piece as differential pins in bevel gear differentials.

[0008] The task is to improve the existing bevel gear differential.

[0009] The problem is solved according to the invention by a device with a bevel gear differential, wherein the bevel gear differential has at least one differential gear and two output gears and the at least one differential gear has a bevel gear pin for bearing the at least one differential gear, in that the bearing of the at least one differential gear with its bevel gear pin is formed by a star-shaped bearing plate, the wall of which is smaller in the axial direction than the diameter of the bevel gear pin and the bearing plate supports the end of the bevel gear pin oriented towards the axis of rotation of the bevel gear differential.

[0010] At least one compensating gear comprises exactly one or more compensating gears, each compensating gear having its own bevel gear pin. The bevel gear pin can be rotationally fixed to the compensating gear, or the compensating gear can be rotatably mounted on the bevel gear pin.

[0011] The bevel gear bolt - and thus indirectly also its compensating gear - is received at least at one end of the bevel gear bolt by the bearing plate through a specially provided receptacle.

[0012] The wall thickness of the bearing plate (in the axial direction of the bevel gear differential, i.e., along the axis of rotation of the bevel gear differential) is smaller than the diameter of at least one bevel gear pin. This saves axial installation space according to the invention.

[0013] The bearing plate supports the end of the bevel gear pin oriented towards the axis of rotation of the bevel gear differential. If several bevel gear pins are supported by the bearing plate with their ends oriented towards the axis of rotation, the bearing plate advantageously replaces the bevel gear pin star known from the prior art and, due to its plate-like design, provides more axial installation space, allowing the bevel gear differential to be built smaller in the axial direction. The freed-up installation space allows, for example, the optimization of lubricant flow, especially at low temperatures. Thus, an assembly consisting of the bevel gear pin and the bearing plate is provided.

[0014] In addition to the space savings achieved by the invention, the bevel gear pin bearing becomes more economical thanks to the bearing plate, since the bearing plate can be designed as a stamped or fine-blanked sheet metal part.

[0015] Particularly when combining a bevel gear differential with a planetary gear set featuring stepped planets, a further advantage arises in the mounting of the bevel gear differential. When integrating bevel gear differentials with such planetary gear sets, the use of three compensating bevel gears leads to the maximum possible axial nesting, since at least one compensating gear can be positioned between two planets of the planetary gear set in the circumferential direction. Therefore, the bevel gear differential should, in this context, be at least partially positioned within the smaller step of the stepped planet.

[0016] Furthermore, according to the invention, it is advantageous with regard to power transmission that the torque is introduced directly into the center of the bevel gear differential and that the bearing plate according to the invention allows the use of three simple, cylindrical bevel gear bolts, preferably of identical design. The circumferential power transmission from one bevel gear bolt to another is advantageously achieved via the area of ​​the radially projecting tip of the star-shaped bearing plate. The radially projecting tip(s) can be designed differently.

[0017] The design of a simple cylindrical bevel gear bolt, made possible by the bearing plate and advantageously inserted into a recess in the bearing plate, eliminates the need to construct the planet carrier of the planetary gear and / or the housing part of the bevel gear differential in multiple parts to axially fix the bevel gear bolt using two components. Closed receptacles for the bevel gear bolt can be incorporated into the planet carrier or the housing part of the bevel gear differential, thereby improving the power transmission from the planet carrier or housing part to the bevel gear bolt. The cylindrical portion of the bevel gear bolt can thus preferably be inserted in a bore.By completely enclosing the cylindrical portion of the bevel gear bolt in the bore using a single component, a bore lining can be formed, enabling higher forces or smaller dimensions.

[0018] The planet carrier of the planetary gear and / or the housing part of the bevel gear differential no longer need to be designed as a single unit or in two parts to accommodate the bevel gear pin. This can now be accomplished by a single component consisting of a bearing plate and a bevel gear pin.

[0019] Due to its plate-like design, the bearing plate according to the invention has the advantage that the applied torque can be supported closer to the force introduction point in the planet carrier / housing part on the bevel gear pin - with an almost constant mass of the assembly consisting of bevel gear pin and bearing plate compared to the one-piece bevel gear pin star from the prior art.

[0020] The invention advantageously enables a simple bore for receiving the bevel gear pin in the planet carrier / housing part instead of milling and the higher torque transmission performance through the closed geometry formed by a component on the bevel gear pin.

[0021] In one embodiment of the invention, the bearing plate and the bevel gear pins engage with each other via a bearing receptacle and form a demountable assembly. This facilitates the installation of the bevel gear pins in fully cylindrical receptacles, for example radial bores, of a planetary gear carrier.

[0022] In a first variant, the bearing receptacle is designed as a slot in the bearing plate. Torque can be transmitted circumferentially between the bevel gear pin and the bearing plate via a line contact through this slot. In a second variant, the bearing receptacle is designed as a slot in the bevel gear pin. The bevel gear pin thus rides on the bearing plate. Torque transmission is now preferably introduced into the bevel gear differential only via the star-shaped bearing plate from a planetary gear set.

[0023] Preferably, the bevel gear pins are inserted into a fully cylindrical receptacle in the planet carrier. Thus, in contrast to the slot-shaped receptacle known in the prior art, an idealized line contact is no longer formed, but rather a surface contact, which reduces the load at this contact point and allows either the dimensional design to be reduced or an increased load transmission to be achieved.

[0024] In a further embodiment, the device also includes a planetary gear set upstream of the bevel gear differential as a load stage, wherein the torque of the planetary gear set is introduced into the bearing plate via the load stage bolts of the planetary gear set.

[0025] Continuing this design, the bearing plate has annular extensions arranged on its stem to absorb the torque. These extensions are in direct engagement with the load-step bolts. The annular extensions, projecting radially from the star shape of the bearing plate, have an axial through-hole into which the end of the load-step bolt can engage. One load-step bolt is also supported by the planet carrier of the planetary gear and carries a stepped planet. Advantageously, the force is thus transmitted directly and immediately from the load-step bolt to the annular extension and therefore to the bearing plate.

[0026] In an alternative embodiment, the device further comprises a planetary gear set upstream of the bevel gear differential as a load stage, wherein the torque of the planetary gear set is introduced into the bearing plate via the planet carrier of the planetary gear set. Further developing this alternative embodiment, the bearing plate has star-shaped extensions arranged on its stem to receive the torque, which are in direct engagement with the planet carrier. The star-shaped extensions projecting radially from the star shape of the bearing plate have an end form that can engage in a recess complementary to the planet carrier. The engagement of the star-shaped extension in this recess transmits the torque from the planetary gear set to the bearing plate and thus into the bevel gear differential.Advantageously, the force is thus transferred directly and immediately from the planetary support to the star extension and thus to the bearing plate.

[0027] In one embodiment of the invention, the bearing plate can have a crank in the axial direction at its star-shaped ends. This allows for greater design freedom in the axial positioning of the bearing plate relative to the torque application by a planetary gear according to the aforementioned embodiments.

[0028] Since the bearing plate is preferably made from a sheet metal part, both the outer stem shape and a crank can be easily formed.

[0029] Character description

[0030] Further embodiments of the invention are explained in more detail with reference to the figures. These show:

[0031] Figure 1 shows the prior art of a combined transmission consisting of a reduction stage with planetary gears and a bevel gear nested therein.

[0032] Figure 2 shows a cross-section along the section line AA of the gear from Figure 1, looking towards the bevel gear bolt star.

[0033] Figure 3 shows a first embodiment of the assembly according to the invention, consisting of a bevel gear pin and a bearing plate, installed in a combined gearbox; Figure 4 shows the first embodiment according to Figure 3 of the assembly according to the invention, consisting of a bevel gear pin and a bearing plate.

[0034] Figure 5 shows a cross-section along the section line BB according to Figure 3,

[0035] Figure 6 shows a cross-section along the section line CC according to Figure 3,

[0036] Figure 7 shows a second embodiment of the assembly according to the invention, consisting of a bevel gear pin and a bearing plate.

[0037] Figure 8 shows a cross-section through a combined gearbox from Figure 5 with the installed second embodiment according to Figure 7.

[0038] Figure 1 shows the prior art of a combined transmission consisting of a reduction stage with planetary gears and a bevel gear nested within it. Such a design, in particular of the one-piece bolt star 16, is known from the prior art, for example from DE 102023 121 334 A1.

[0039] The reduction gear is designed as a planetary gear 9 with stepped planets 10, and the bevel gear is a bevel gear differential 2, both of which are enclosed by the device 1. The device 1 comprises a planet carrier 11 of the planetary gear 9 and a housing part 12 of the bevel gear differential 2. The planet carrier 11 carries several stepped planets 10. The housing part 12 is rotationally fixed to the planet carrier 11. The planet carrier 11 carries one of the output gears 4 of the bevel gear differential 2 and thus also constitutes a housing part of the bevel gear differential 2. The device 1 rotates about a pivot axis 13.

[0040] The device 1 is used in electromechanical axle drive trains in which the electric motor is arranged coaxially to the gearbox. Preferably, to achieve a high power density, the device 1 has three stepped planets 10 of the planetary gear set 9 and three differential gears 3 of the bevel gear differential 2, wherein the differential gears 3 and the stepped planets 10 are arranged alternately relative to each other in the circumferential direction and partially overlap in the axial direction – along the axis of rotation 13 – and thus both gearboxes (planetary gear set 9 and bevel gear differential 2) are nested within each other.

[0041] The bolt star 16 is inserted into the receptacles 15 of the planet carrier 11 by being axially guided to the planet carrier 11. For this to occur, the receptacles 15 must be open in the axial direction to allow access of the bolt star 16 to the receptacle 15. To ensure that the bolt star 16 is axially secured, in this embodiment each axially open side of the receptacle 15 is covered by the housing part 12, thus locking the bolt star 16 in its degree of freedom in the axial direction.

[0042] Figure 2 shows a cross-section along section line AA of the gear unit from Figure 1, looking towards the bolt star 16. The star-shaped design of the bolt star 16 is clearly visible, from whose center three cylindrical extensions radiate outwards, offset from each other at an angle of 120°. The conical compensating gears 3 are placed onto the bolt star 16, and then the bolt star 16 is inserted into the receptacles 15. Each receptacle 15 is positioned on the angle-dividing line between the angular positions of two stepped planets 10.

[0043] Figure 3 shows a first embodiment of the assembly according to the invention, consisting of a bevel gear pin 5 and a bearing plate 6, installed in a combined transmission. The combined transmission shown in Figure 1 was adopted for illustrative purposes. The device 1 thus comprises the reduction gear, designed as a planetary gear 9 with stepped planets 10, and the bevel gear transmission, designed as a bevel gear differential 2.

[0044] The difference to the embodiment according to Figures 1 and 2 lies in the bearing plate 6 according to the invention with separately formed bevel gear bolts 5 instead of the bolt star 16.

[0045] By using the bearing plate 6, axial installation space can be freed up in the center near the axis of rotation 13 compared to the prior art solution, which can then be used, for example, to improve lubricant flow in the bevel gear differential 2. The bearing plate 6 is preferably a stamped or fine-blanked sheet metal part.

[0046] The bearing plate 16 according to the invention introduces the torque directly into the center of the bevel gear differential 2 and enables the use of cylindrical bevel gear pins 5 as individual components, which are significantly simplified in their manufacture. The bearing plate 6 has annular extensions 18 integrally molded into it, with each annular extension 18 being assigned to a load-stage pin 17. Each annular extension 18 has a circular bore 19 adapted to the outer surface of the load-stage pin 17, into which the load-stage pin 17 engages. Since the load-stage pin(s) 17 transmit the torque from the planetary gear 9 to the bevel gear differential 2, improved power transmission is now possible, as this does not occur via the planet carrier 11 of the planetary gear 9 or a housing part 12 of the bevel gear differential 2, but rather via a bore formed between the load-stage pin 17 and the bore 19.

[0047] Furthermore, due to the simple cylindrical components of the bevel gear pin 5, the receptacles 15 can be designed as radial bores instead of as U-shaped slots open axially on one side, as shown in Figures 1 and 2. This also creates a bore, which significantly improves the contact and load between the bevel gear pin 5 and its receptacle 15.

[0048] In this embodiment, however, the U-shaped, slot-like recess 15 from Figures 1 and 2 has been adopted in the illustration in the first step, since the torque is already transmitted much more effectively into the bevel gear differential 2 via the annular extensions 18. Therefore, the assembly parting line 14 also remains in this form. The transmission of the torque via the annular extensions 18 relieves the load on the transmission contact between the bevel gear pins 5 in the receptacles 15.

[0049] Figure 4 shows the first embodiment of the assembly according to the invention, consisting of a bevel gear pin 5 and a bearing plate 6 as shown in Figure 3. In this embodiment, the bearing plate 6 is triangular in shape and has annular projections 18 at the vertices of the triangle and bearing receptacles 20 for the bevel gear pins 5 on the side edges of the triangle. The bearing receptacles 20 are configured either, in a first variant, such that the bearing plate 6 has a slot for each bevel gear pin 5 into which the bevel gear pin 5 is inserted, or, in a second variant, such that the bevel gear pin 5 has a slot at its end with which the bevel gear pin 5 is mounted onto the bearing plate 6. Advantageously, in the second variant, the bevel gear pin 5 is secured against rotation to the bearing plate 6, so that the flats 21 formed by the bevel gear pin 5 for oil guidance into the compensating gear 3 always retain the optimal alignment.In the first variant, the bevel gear bolt 5 can rotate in the slot of the bearing plate 6 around its own axis of symmetry, thereby improving the power transmission to both the bearing plate 6 and the receptacle 15 of the planet carrier 11 through any changes in contact and increasing the service life.

[0050] In the radial direction from the bearing plate 6 to the individual annular processes 18, the plate has a bend 22. This allows the part “bearing plate 6” to be offset from the part “annular process 18” in the axial direction.

[0051] Figure 5 shows a cross-section along section line BB according to Figure 3. The cross-section allows a view into the interior of the bevel gear differential 2, looking towards the planetary gear set 9, which is recognizable by the visible stepped planets 10. The bevel gear pins 5 are each inserted into the receptacles 15 formed by the planet carrier 11 and bear at least circumferentially in this receptacle 15 so that a torque can be transmitted from the planet carrier 11 to the bevel gear differential 2.

[0052] The bearing plate 6 has three receptacles 20, each of which engages with a tapered gear pin 5. The bearing receptacles 20 are slot-shaped, as already explained with the first variant in the description of Figure 4. The bearing plate 6 is axially fixed by the ring extensions 18, which are cut away here.

[0053] Figure 6 shows a cross-section along section line CC according to Figure 3. The annular extensions 18, visible in this section plane and preferably a single-material part of the bearing plate 6, engage the ends of the load-step bolts 17 – each annular extension 18 engages one load-step bolt 17. Each annular extension 18 has a bore 19 into which the load-step bolt 17 engages. This allows the torque to be transmitted directly from the load-step bolts 17 to the annular extensions 18 and thus to the bearing plate 6. This relieves the contact between the bevel gear bolt 5 in its receptacle 15 and therefore also the area around the receptacle 15 and the planet carrier 11.

[0054] The slot-shaped bearing receptacles 20 are also clearly visible, and due to the perspective, they are spaced away from the bevel gear pin 5 in this section plane. Thus, it is clear from the illustration in Figure 5 that the bevel gear pin 5 forms a linear contact with its bearing receptacle 20.

[0055] Figure 7 shows a second embodiment of the assembly according to the invention, consisting of bevel gear pins 5 and bearing plate 6. In this second embodiment, the bearing plate 6 is also triangular in shape, but unlike the embodiment shown in Figure 4, it does not have annular projections 18 at the vertices of the triangle. The bearing receptacles 20 for the bevel gear pins 5, located on the side edges of the triangle, have been retained. The bearing receptacles 20 are either, in a first variant, such that the bearing plate 6 has a slot for each bevel gear pin 5 into which the bevel gear pin 5 is inserted, or, in a second variant, such that the bevel gear pin 5 has a slot at its end with which the bevel gear pin 5 is mounted onto the bearing plate 6. The first variant is shown in this illustration.

[0056] The star-shaped ends of the bearing plate 6 are designed as star extensions 23. An axial curvature is not present here, but is possible.

[0057] Figure 8 shows a cross-section through a combined transmission from Figure 5 with the installed second embodiment according to Figure 7. The combined transmission shown in Figure 1 was used for illustrative purposes. Referring to the special feature of the second embodiment from Figure 7, namely the bearing plate 6 with the star extensions 23, the star extensions 23 can engage in complementary receptacles 24 of the planet carrier 11, which are designed to be suitable for torque transmission. Thus, the torque from the planetary gear 9 can be transmitted directly via the planet carrier 11 to the bearing plate 6 and into the bevel gear differential 2 as a load-stage transmission. [List of reference symbols]

[0058] device

[0059] bevel gear differential

[0060] Compensating wheel

[0061] output gear

[0062] bevel gear bolt

[0063] Storage plate

[0064] wall

[0065] End

[0066] planetary gear

[0067] Tiered Planet

[0068] Planetary carrier

[0069] Housing part

[0070] axis of rotation

[0071] Assembly separation plane

[0072] Bolt receptacle

[0073] Bolt star

[0074] Load step bolts

[0075] Ring process

[0076] Drilling

[0077] Storage recording

[0078] flattening

[0079] Goiter

[0080] stellate process

Claims

Patent claims 1. Device (1) with a bevel gear differential (2), wherein the bevel gear differential (2) has at least one compensating gear (3) and two output gears (4) and the at least one compensating gear (3) has a bevel gear pin (5) for bearing the at least one compensating gear (3), characterized by the fact that the bearing of at least one compensating gear (3) with its bevel gear pin (5) is formed by a star-shaped bearing plate (6) whose wall (7) is smaller in the axial direction than the diameter of the bevel gear pin (5) and the bearing plate (6) supports the end (8) of the bevel gear pin (5) oriented towards the axis of rotation of the bevel gear differential (2).

2. Device (1) according to claim 1, characterized by the fact that the bearing plate (6) and the bevel gear bolts (5) engage with each other via a bearing receptacle (20) and form an assembly.

3. Device (1) according to claim 2, characterized by the fact that the bearing receptacle (20) is designed as a slot in the bearing plate (6).

4. Device (1) according to claim 2, characterized by the fact that the bearing receptacle (20) is designed as a slot in the bevel gear bolt (5).

5. Device (1) according to any one of the preceding claims, characterized by the fact that the bevel gear pins (5) are inserted in a fully cylindrical receptacle (15) of the planet carrier (11).

6. Device (1) according to any one of the preceding claims, characterized in that the device (1) further comprises a planetary gear set (9) as a load stage upstream of the bevel gear differential (2), wherein the torque of the planetary gear set (9) is introduced into the bearing plate (6) via the load stage bolts (17) of the planetary gear set (9).

7. Device (1) according to claim 6, characterized by the fact that The bearing plate (6) has ring extensions (18) arranged on the star shape of the bearing plate (6) to receive the torque, which are in direct engagement with the load step bolts (17).

8. Device (1) according to any one of the preceding claims, characterized by the fact that The device (1) further comprises a planetary gear set (9) upstream of the bevel gear differential (2) as a load stage, wherein the torque of the planetary gear set (9) is introduced into the bearing plate (6) via the planet carrier (11) of the planetary gear set (9).

9. Device (1) according to claim 8, characterized by the fact that The bearing plate (6) has star extensions (23) arranged on the star shape of the bearing plate (6) to receive the torque, which are in direct engagement with the planet carrier (11).

10. Device (1) according to any one of the preceding claims, characterized by the fact that the bearing plate (6) has a bend (22) at its star-shaped ends in the axial direction.

Images