reversing transmission unit

Abstract

The invention relates to a reversing gear unit (100) having a drive shaft (1), an output shaft (2), a first and a second intermediate shaft (3, 4) and a clutch device (7). The drive shaft (1) and the output shaft (2) can either be coupled to one another via the first and the second intermediate shaft (3, 4) in a first clutch state or directly via the clutch device (7) in a second clutch state. An intermediate gear (5, 6) is arranged between the drive shaft (1) and the respectively assigned intermediate shaft (3, 4), so that a rotational direction change of the output shaft (2) can be caused by switching from the first clutch state to the second clutch state. The intermediate gears (5, 6) each have a first intermediate gear toothing (51, 61) and a second intermediate gear toothing (52, 62), wherein the first intermediate gear toothing (51, 61) meshes with a drive gear (11) arranged in a rotationally fixed manner on the drive shaft (1) and the second intermediate gear toothing (52, 62) meshes with a first intermediate shaft toothing (31, 41) arranged in a rotationally fixed manner on the assigned intermediate shaft (3, 4).

Description

Technical Field

[0001] This invention relates to a reversing transmission unit. Background Technology

[0002] A commutator stage for motor vehicles or rail vehicles is known from DE 10 2012 207 976 A1. Through power distribution, in a first clutch state of the associated clutch assembly, force and / or torque can be transmitted from the drive shaft to the output shaft via two parallel power paths, each via an intermediate shaft. This can advantageously influence the dimensions of the commutator stage. In a second clutch state of the aforementioned clutch assembly, drive power can be transmitted from the drive shaft to the output shaft via another power path through the clutch assembly. Here, gears are arranged as intermediate gears between the drive shaft and the respective associated intermediate shafts in the two parallel power paths, wherein, in the first clutch state, the intermediate gears cause a change in the rotational direction of the output shaft. Summary of the Invention

[0003] The objective of this invention is to further improve such commutation stages or commutation drive units. In particular, the production, installation, and attachment of such commutation drive units should be optimized.

[0004] This task is accomplished by the commutation drive unit described in this invention. Further advantageous embodiments of the invention will be described below.

[0005] Therefore, a reversing drive unit is proposed, comprising a drive shaft and an output shaft coaxially arranged with the drive shaft, first and second intermediate shafts, and a clutch device. The two intermediate shafts can advantageously be arranged parallel to the drive shaft. In a first clutch state of the mentioned clutch device, the drive shaft and the output shaft are coupled to each other via a first power path extending through the first intermediate shaft and a second power path extending through the second intermediate shaft. Thus, in this first clutch state, power is distributed to two parallel power paths, thereby allowing for smaller dimensions of the components in the two power paths and providing advantages for specific applications while considering the size and arrangement of the reversing drive unit.

[0006] In the second clutch state of the clutch assembly, the drive shaft and output shaft are coupled to each other via a third power path extending through the clutch assembly. Therefore, no power distribution occurs in the second clutch state. The third power path no longer extends through the intermediate shaft, but instead extends directly from the drive shaft through the clutch assembly to the output shaft, which is arranged coaxially with the drive shaft. In other words, the third power path extends along the central axis of the reversing transmission unit, which is arranged coaxially with both the drive shaft and the output shaft.

[0007] Currently, to achieve the reversal of rotational direction required for the reversing function of the reversing transmission unit, intermediate gears are arranged between the drive shaft and corresponding intermediate shafts in the first and second power paths, respectively, so that switching from the first clutch state to the second clutch state can cause a change in the rotational direction of the output shaft. In addition to the first and second clutch states, a third clutch state can also be provided, in which the power flow between the drive shaft and the output shaft is mechanically interrupted. In the case of a clutch device with a shift sleeve, the third clutch state may, for example, correspond to the intermediate or neutral position of the shift sleeve.

[0008] The intermediate gears in the two power paths each have a first intermediate gear tooth section and a second intermediate gear tooth section. The first intermediate gear tooth section meshes with a drive gear arranged anti-rotatingly on the drive shaft, and the second intermediate gear tooth section meshes with a first intermediate shaft tooth section arranged anti-rotatingly on a corresponding intermediate shaft. For this purpose, the two intermediate gear tooth sections are axially offset from each other. Therefore, the two intermediate gear tooth sections are spatially separated from each other. Unlike the meshing between the intermediate gear and the intermediate shaft tooth section, the meshing between the drive gear on the drive shaft and the intermediate gear occurs in a different axial plane. The advantage of this is that alternating loads in the form of root stress occur on the intermediate gears. Instead, pulsating loads occur only at all meshing points, meaning that root bending always occurs in the same direction. Therefore, the root is subjected to a smaller load. The individual tooth sections can thus be made narrower and manufactured with less cost. Therefore, for example, the manufacturing step of shot peening the root to achieve the required safety regarding root stress under alternating loads can be omitted. For example, the axial structural space required for the additional meshing stage between the teeth of the second intermediate gear and the teeth of the intermediate shaft can be advantageously utilized so that the shift sleeve or other parts of the clutch device can also be arranged within this axial structural space, thereby minimizing the extension of the total length of the reversing transmission in the axial direction.

[0009] Another advantage regarding the gear ratio is that it can be selectively influenced by correspondingly determining the teeth of the two intermediate gears. Particularly advantageously, this allows for a gear ratio of exactly -1.0 in the first clutch state, i.e., in both the first and second power paths. This, in turn, results in the precise existence of the same gear ratio in both the first and second clutch states, since a gear ratio of 1.0 also exists in the described second clutch state. Therefore, this reversing transmission unit can precisely achieve the same gear ratio for two opposite directions of travel. This is often required, for example, in rail vehicles that require two equally matched directions of travel. Equal directions of travel mean having the same total gear ratio stage and therefore the same speed range in both directions. The structural limitations associated with the desired -1.0 gear ratio in the conventional reversing stage mentioned at the beginning arise because the meshing of the drive gear and intermediate gear on the drive shaft is arranged in an axial plane and lacks a gear stage in which the gear ratio can be adjusted.

[0010] The power flow can be guided from the intermediate shaft to the output shaft via a second intermediate shaft tooth on each intermediate shaft and via an output gear meshing therewith, wherein the output gear is connected to the output shaft in a way that resists relative rotation.

[0011] The first and second intermediate shaft teeth on each intermediate shaft can have the same number of teeth, and preferably this is also true in other respects. Thus, the first and second intermediate shaft teeth on each intermediate shaft can be manufactured in the same process. Machining the first and second intermediate shaft teeth in one process avoids or at least significantly reduces the pitch error between the two teeth. Pitch error between the intermediate shaft teeth of the intermediate shaft arises because the intermediate shaft teeth are produced in separate processes or manufacturing steps. The smaller this pitch error, the more evenly the power is distributed to the first and second power paths, that is, more evenly to the two intermediate shafts, or the radial displacement of the output gear of the floating support is reduced. Furthermore, this can completely or at least almost compensate for the axial force within the helical gear or meshing portion. Additionally, tooling and machining costs can be reduced by using identical intermediate shaft teeth, because the same tools can be used to manufacture teeth with the same module and the same helix angle.

[0012] Therefore, it is possible to implement the first and second intermediate shaft teeth in the same way, because the drive gear is arranged with an axial distance relative to the first intermediate shaft teeth due to the axial offset of the two intermediate gear teeth. Thus, radial overlap, i.e., the radial overlap between the drive gear and the first intermediate shaft teeth, is possible. That is, the radial dimension of the first intermediate shaft teeth is not limited by the radial dimension or diameter of the drive gear. Furthermore, the required transmission ratio in the first and second power paths can be achieved by appropriately selecting the first and second intermediate gear teeth, thereby eliminating the need for additional transmission ratio changes caused by different intermediate shaft teeth.

[0013] Preferably, the output gear is supported on the output shaft with radial clearance. In other words, the output gear can be supported on the output shaft with radial clearance or radial freedom. This support is also known as a floating support and causes the power flow to be evenly distributed on the first and second power paths. That is, in the first clutch state, at least approximately 50 percent of the drive power is directed to each of the two intermediate shafts. A more or less uniform power distribution can already be achieved by the same intermediate shaft teeth on each intermediate shaft as described above. For the correspondingly high requirements of their respective applications, a nearly perfectly uniform power distribution can be ensured by means of the radial clearance at the output gear on the output shaft.

[0014] According to another embodiment, the first and second intermediate shaft teeth on each intermediate shaft and the first and second intermediate gear teeth on each intermediate gear can have the same number of teeth. This further reduces complexity in construction and manufacturing costs. In this embodiment, the same implementation of the first and second intermediate gear teeth is also possible. Thus, the first and second intermediate gear teeth can be manufactured in a single process, preferably as a single-piece intermediate gear. By machining the first and second intermediate gear teeth in one process, pitch errors between the two teeth, which would occur in separate processes or manufacturing steps, can be avoided. The smaller this pitch error, the more evenly the power is distributed on the first and second power paths, and the less radial displacement of the output gear of the floating support is reduced. Furthermore, this can completely or at least almost compensate for the axial force within the helical gear teeth. Additionally, tooling and machining costs can be reduced by using identical intermediate shaft teeth, since the same tools can be used to manufacture teeth with the same module and the same helix angle.

[0015] In another embodiment of the invention, the first and second intermediate shafts are axially offset relative to their respective associated intermediate gear shafts in a direction toward the output side of the reversing drive unit. The lower side of the reversing drive unit is understood as the output side, i.e., the end of the output shaft extends from the housing of the reversing drive unit on this side. The axial offset of the intermediate shafts toward the output side facilitates the attachment of the reversing drive unit to other transmissions, particularly to the main drive of the corresponding drivetrain. In a preferred embodiment, the reversing drive unit is configured and adapted for attachment to a conventional shift transmission, such as a power shift transmission or an automated shift transmission. For attachment to other transmissions, a mounting flange is provided on the drive side of the reversing drive unit. The free structural space gained by the offset intermediate shafts allows for the advantageous embedding and arrangement of tightening elements for the bolted flange, thereby enabling the bolted flange to have a smaller radial dimension.

[0016] An intermediate gear shaft is a shaft on which intermediate gears are arranged. Here, the intermediate gears can be rotatably supported on intermediate gear shafts that are fixed relative to the housing. In this case, the intermediate gear shaft can also be referred to as a bolt or shaft. Alternatively, an intermediate gear shaft can be used, rotatably supported in the housing portion of the reversing transmission unit, on which intermediate gears are arranged in a manner resistant to relative rotation. This intermediate gear shaft can also be manufactured as a single piece with the corresponding intermediate gear, i.e., a pinion shaft. Regarding the required structural space, the first alternative can be implemented more compactly because, in particular, the support portion in the form of a rolling bearing can be arranged radially within the teeth of the intermediate gear shaft. Therefore, an advantage in structural space in the axial direction is obtained compared to the second alternative.

[0017] The clutch assembly is preferably arranged coaxially with the output shaft. In particular, the clutch assembly may include an axially movable shift sleeve, in which, in a second clutch state, the end of the drive shaft is connected to the end of the output shaft arranged coaxially with the drive shaft via the shift sleeve. Attached Figure Description

[0018] The invention and its advantages will now be described in more detail with reference to the embodiments shown in the accompanying drawings.

[0019] Figure 1 A schematic diagram of the reversing transmission unit according to the present invention is shown;

[0020] Figure 2 A cross-sectional view of a segment of the reversing transmission unit according to the present invention is shown;

[0021] Figure 3 A cross-sectional view of a segment of the reversing transmission unit according to the invention is shown in another cross-sectional plane;

[0022] Figure 4 A cross-sectional view of a segment of the reversing drive unit according to the invention is shown in another cross-sectional plane. Detailed Implementation

[0023] Figure 1 The reversing drive unit 100 shown includes a drive shaft 1 and an output shaft 2 arranged coaxially with the drive shaft 1. Both the drive shaft 1 and the output shaft 2 are arranged in a manner rotatable about the central axis 8 of the reversing drive unit 100. In operation, driving power is introduced into the reversing drive unit 100 in the form of torque and rotational motion via the drive shaft 1. For this purpose, the drive shaft 1 can be connected, for example, to the output shaft of another transmission device arranged before the reversing drive unit 100 in the vehicle's drive system. The driving power is transmitted to other components of the vehicle's drive system via the output shaft 2. For this purpose, a connecting flange 22 is arranged at the output end of the output shaft 2, through which the output shaft 2 can be connected, for example, to a universal joint. The multi-part output shaft 2 includes a central shaft 27 and a main shaft 28 supported thereon, which are interconnected against relative rotation.

[0024] The reversing drive unit 100 also includes Figure 1 The housing 9 is shown schematically only in sections at several locations. The housing 9 surrounds and protects the components of the reversing drive unit 100. Furthermore, the shaft of the reversing drive unit 100 is supported within and within the housing 9. The drive shaft 1 extends from the housing 9 on the drive side 10, while the output shaft 2 extends from the housing 9 on the opposite output side 20.

[0025] The reversing transmission unit 100 is, in principle, a structural form corresponding to an intermediate shaft transmission device. Therefore, the reversing transmission unit 100 has first and second intermediate shafts 3 and 4. The two intermediate shafts 3 and 4 are arranged parallel to the drive shaft 1 and the output shaft 2.

[0026] Multiple clutch states can be adjusted using the clutch device 7. In the first clutch state of the clutch device 7, the drive shaft 1 and the output shaft 2 are coupled to each other via a first power path 30 and a second power path 40. The first power path 30 and the second power path 40 are constructed substantially identically and arranged symmetrically with respect to the central axis 8. Here, all driving power is distributed to the two power paths 30 and 40. The first power path 30 extends from the drive shaft 1 to the output shaft 2 via a first intermediate shaft 3. The second power path 40 extends from the drive shaft 1 to the output shaft 2 via a second intermediate shaft 3. Intermediate gears 5 and 6 are respectively arranged between the drive shaft 1 and the corresponding intermediate shaft 3 or 4 in the first and second power paths 30 and 40. The intermediate gears 5 and 6 cause the rotation direction of the output shaft 2 to be reversed relative to the rotation direction of the drive shaft 1 in the first clutch state. Therefore, the reversing function is achieved in this way.

[0027] In the second clutch state of the clutch device 7, the drive shaft 1 and the output shaft 2 are coupled to each other via the third power path 70. The third power path 70 extends directly from the drive shaft 1 to the output shaft 2 via the clutch device 7. In the second clutch state, that is, via the third power path 70, there is no reversal of the rotational direction between the drive shaft 1 and the output shaft 2.

[0028] exist Figure 1 The clutch device 7 is shown in a third clutch state, in which the power flow between the drive shaft 1 and the output shaft 2 is mechanically interrupted. The clutch device 7 includes a shift sleeve 71, which allows adjustment to different clutch states. The third clutch state can also be referred to as the neutral position and corresponds to the intermediate position of the axially movable shift sleeve 71. If the shift sleeve 71 moves axially from the shown intermediate position toward the output side 20, a first clutch state is activated, in which the driving power of the drive shaft 1 is transmitted to the output shaft 2 via a first power path 30 and simultaneously via a second power path 40. This results in power being distributed to the two power paths 30 and 40.

[0029] Intermediate gears 5 and 6 each have first intermediate gear teeth 51, 61 and second intermediate gear teeth 52, 62 arranged axially offset from each other. The first intermediate gear teeth 51, 61 mesh with drive gear 11, which is arranged anti-rotationally on drive shaft 1, and the second intermediate gear teeth 52, 62 mesh with first intermediate shaft teeth 31, 41, which are arranged anti-rotationally on associated intermediate shafts 3, 4, respectively. The second intermediate shaft teeth 32, 42 on each of the two intermediate shafts 3 and 4 mesh with output gear 21. Output gear 21 is connected anti-rotationally to output shaft 2. In this way, the drive power distributed to the first and second power paths is gathered together or accumulated through the common output gear 21 and guided to output shaft 2. In this embodiment, output gear 21 is supported on output shaft 2 with radial clearance, thereby compensating for geometric deviations and achieving a uniform distribution of drive power to the two power paths 30 and 40. As described in the following description... Figure 4 To elaborate further, this radial clearance is achieved using a floating support spindle.

[0030] Figure 2A cross-sectional view shows a section of the reversing transmission unit 100, with the section plane passing through the central axis 8 and the axis of rotation of the intermediate gear 6. The drive shaft 1 is supported in the housing 9 by means of a drive shaft bearing 12. In this embodiment, the drive shaft bearing 12 comprises two tapered roller bearings. The drive gear 11, anti-rotationally fastened to the drive shaft 1, permanently meshes with the first intermediate gear tooth 61 of the intermediate gear 6. The intermediate gear 6 is rotatably supported on an intermediate gear shaft 60, anti-rotationally supported in the housing 9, by means of an intermediate gear bearing 63 in the form of a double tapered roller bearing.

[0031] The second intermediate gear tooth 62 is axially offset from the first intermediate gear tooth 61 on the intermediate gear 6. The second intermediate gear tooth 62 permanently meshes with the first intermediate shaft tooth 41, which is located in a plane different from the cross-sectional plane and therefore not visible in the figure. In this embodiment, the first and second intermediate gear teeth 61 and 62 are implemented as identical. Thus, the two intermediate gear teeth 61 and 62 transition into each other continuously and without flanges. Therefore, the two intermediate gear teeth 61 and 62 can be advantageously manufactured in only one process.

[0032] In addition, Figure 2 The diagram shows a clutch assembly 7 with a shift sleeve 71, both of which are coaxially arranged on a portion of the output shaft 2 relative to the central axis 8. The multi-part output shaft 2 is rotatably supported in a housing 9 by means of an output shaft bearing 23. Additionally, the drive-side end of the output shaft 2 is supported in a central bore within the drive shaft 1 by means of a needle roller bearing 26. The output gear 21 is supported on the output shaft 2 with radial clearance.

[0033] Figure 3 A cross-sectional view shows another section of the reversing drive unit 100, wherein the cross-sectional plane passes through the axis of rotation of the intermediate gear 6 and the axis of rotation of the intermediate shaft 4. In the current embodiment, the intermediate shaft 4 is configured to be rotatably supported on an intermediate shaft pin 43 fixed relative to the housing by means of an intermediate shaft bearing 44. The intermediate shaft 4 has two intermediate shaft teeth 41 and 42 arranged side by side. The first intermediate shaft tooth 41 permanently meshes with the second intermediate gear tooth 62 of the intermediate gear 6.

[0034] The second intermediate shaft tooth 42 is arranged axially offset from the first intermediate shaft tooth 41 on the intermediate shaft 4. The second intermediate shaft tooth 42 permanently meshes with the output gear 21, which is not shown in the cross-sectional view.

[0035] The intermediate shaft 4 is axially offset from the associated intermediate gear shaft 60 towards the output side 20. This provides a free structural space 13 on the drive side of the intermediate shaft 4. This free structural space 13 is particularly advantageous when the reversing transmission unit 100 is attached as an auxiliary unit to other transmission devices. Improved accessibility is achieved in the area of ​​the free structural space 13, for example in the area of ​​the mounting flange, and in the connection area between the transmission device and the attached reversing transmission unit, allowing for advantageous arrangement and tightening of bolt connections.

[0036] at last, Figure 4 Another section of the reversing drive unit 100 is shown in cross-section, wherein the cross-sectional plane passes through the rotation axis of the intermediate shaft 4 and through the central axis 8.

[0037] Two intermediate shaft teeth 41 and 42, arranged side-by-side on the intermediate shaft 4, are identical and manufactured as continuous teeth in a single process. The first intermediate shaft tooth 41 permanently meshes with the second intermediate gear tooth 62 of the intermediate gear 6, which is not visible in this cross-section. The second intermediate shaft tooth 42 meshes with the output gear 21. The output gear 21 is connected to the output shaft 2 in a rotationally resistant manner. However, the output gear 21 has radial clearance or gap relative to the output shaft 2, thereby achieving a uniform distribution of driving power to the two power paths 30 and 40. The output shaft 2 consists of multiple parts and includes a central shaft 27 and a hollow shaft-shaped main shaft 28 floatingly supported thereon. In the axial direction, the output gear 21 is fixed to the output shaft 2 by means of two thrust washers 24 and 25. A follower tooth 29 with a convex surface is provided, thereby compensating for angular errors between the various parts of the output shaft 2.

[0038] exist Figure 4 The radial overlap 14 or radial bite between the drive gear 11 and the first intermediate shaft tooth 41 can also be seen. As a result, the radial dimension of the first intermediate shaft tooth 41 is not limited by the dimension of the drive gear 11, which in turn provides freedom in the design and implementation of the intermediate gear teeth 61, 62 and the intermediate shaft teeth 41, 42.

[0039] Figure Labels

[0040] 1. Drive shaft

[0041] 2 Output shaft

[0042] 3. Intermediate shaft

[0043] 4. Intermediate shaft

[0044] 5. Intermediate gear

[0045] 6. Intermediate gear

[0046] 7. Clutch assembly

[0047] 8. Central Axis

[0048] 9. Shell

[0049] 10 Drive side

[0050] 11 Drive gear

[0051] 12 Drive shaft bearings

[0052] 13 Structural Space

[0053] 14 Radial overlap

[0054] 20 Output side

[0055] 21 Output gear

[0056] 22 Connecting flange

[0057] 23 Output shaft bearing

[0058] 24 Thrust Washers

[0059] 25 Thrust Washer

[0060] 26 Needle roller bearings

[0061] 27. Central axis

[0062] 28 Spindle

[0063] 29 Follower teeth

[0064] 30 First driving force path

[0065] 31 First intermediate shaft gear section

[0066] 32 Second intermediate shaft tooth section

[0067] 40 Second Power Path

[0068] 41 First intermediate shaft gear section

[0069] 42 Second intermediate shaft tooth section

[0070] 43 Intermediate shaft bolt

[0071] 44 Intermediate Shaft Bearing

[0072] 50 Intermediate Gear Shaft

[0073] 51 First intermediate gear teeth

[0074] 52 Second intermediate gear teeth

[0075] 60 Intermediate gear shaft

[0076] 61 First intermediate gear teeth

[0077] 62 Second intermediate gear teeth

[0078] 63 Intermediate Gear Bearing

[0079] 70 Third Power Path

[0080] 71 Gear Shift Sleeve

[0081] 100 Reversing Drive Unit

Claims

1. A reversing transmission unit (100), the reversing transmission unit comprising a drive shaft (1), an output shaft (2), a first intermediate shaft and a second intermediate shaft (3, 4) and a clutch device (7). in, In the first clutch state of the clutch device (7), the drive shaft (1) and the output shaft (2) are coupled to each other through a first power path (30) extending through the first intermediate shaft (3) and a second power path (40) extending through the second intermediate shaft (4). In the second clutch state of the clutch device (7), the drive shaft (1) and the output shaft (2) are coupled to each other through a third power path (70) extending through the clutch device (7), wherein the third power path (70) does not extend through the intermediate shafts (3, 4). In the first power path and the second power path (30, 40), intermediate gears (5, 6) are respectively arranged between the drive shaft (1) and the corresponding intermediate shafts (3, 4), so that the rotation direction of the output shaft (2) can be switched by switching from the first clutch state to the second clutch state. The intermediate gears (5, 6) each have a first intermediate gear tooth portion (51, 61) and a second intermediate gear tooth portion (52, 62), and the first intermediate gear tooth portions (51, 61) mesh with the drive gear (11) arranged on the drive shaft (1) in a way that resists relative rotation, and the second intermediate gear tooth portions (52, 62) mesh with the first intermediate shaft tooth portions (31, 41) arranged on the corresponding intermediate shafts (3, 4) in a way that resists relative rotation. In this configuration, the second intermediate shaft teeth (32, 42) on each intermediate shaft (3, 4) mesh with the output gear (21), and the output gear (21) is connected to the output shaft (2) in a way that resists relative rotation.

2. The reversing transmission unit (100) according to claim 1, characterized in that, The output gear (21) is supported on the output shaft (2) with radial clearance.

3. The reversing transmission unit (100) according to claim 1 or 2, characterized in that, The first intermediate shaft tooth section and the second intermediate shaft tooth section (31, 32, 41, 42) each have the same number of teeth.

4. The reversing transmission unit (100) according to claim 3, characterized in that, The first intermediate shaft tooth portion and the second intermediate shaft tooth portion (31, 32, 41, 42) and the first intermediate gear tooth portion and the second intermediate gear tooth portion (51, 52, 61, 62) each have the same number of teeth.

5. The reversing transmission unit (100) according to claim 1 or 2, characterized in that, The first intermediate shaft and the second intermediate shaft (3, 4) are axially offset from the intermediate gear shafts (50, 60) respectively and toward the output side (20) of the reversing transmission unit (100), wherein the intermediate gears (5, 6) are arranged on the intermediate gear shafts (50, 60).

6. The reversing transmission unit (100) according to claim 1 or 2, characterized in that, The clutch device (7) is arranged coaxially with the output shaft.

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