DE102023102511A1 - Transmission device with compact bearing structure; and drive device with this transmission device - Google Patents

Abstract

The invention relates to a transmission device (1) for a drive device (15) of a motor vehicle, with three shafts (2, 3, 4) arranged parallel to one another and a housing (5) accommodating the three shafts (2, 3, 4), wherein each shaft (2, 3, 4) is rotatably mounted in the housing (5) by means of a bearing (6, 7, 8, 9, 10), and wherein the bearing (6) of a first shaft (2) radially overlaps the bearing (8) of a second shaft (3) in sections. The invention also relates to an electric drive device (15) with this transmission device (1).

Description

The invention relates to a transmission device for a drive device of a motor vehicle. The transmission device is preferably designed as a transmission device with a fixed gear ratio, but in other embodiments it can alternatively be designed as a manual transmission. The invention also relates to an electric drive device (preferably designed as an electric axle/electric drive axle) having this transmission device, which is preferably used in a purely electrically or hybrid-driven motor vehicle. The motor vehicle can also in turn be designed as a car, truck, bus or other commercial vehicle.

The aim is to provide a transmission device for drive systems that requires a further reduced installation space.

This is achieved according to the invention with the subject matter of claim 1, which claims a transmission device for a drive device of a motor vehicle, which transmission device has three shafts arranged parallel to one another and a housing accommodating the three shafts, wherein each shaft is rotatably mounted in the housing by means of a bearing, and wherein the bearing of a first shaft radially overlaps / superimposes the bearing of a second shaft in sections, that is to say is arranged radially at least in sections at the same height as the bearing of a second shaft.

This clever nesting of the bearings allows the shafts to be placed closer to each other. This requires less installation space and provides a particularly compact transmission device.

Further advantageous embodiments are claimed in the subclaims and explained in more detail below.

The transmission device is made even more compact if the bearing of the first shaft radially overlaps the bearing of a third shaft in sections.

The assembly effort is kept as low as possible by having the bearing of the first shaft fixed to the housing on a first side of a wall of the housing (and preferably closed off from the surroundings of the housing by a cover) and the bearing of the second shaft and/or the bearing of the third shaft fixed to the housing from a second side of the wall.

In this sense, it is also expedient if the first shaft is rotatably mounted in the housing by means of two bearings, wherein on the one hand a first bearing of the first shaft partially overlaps the bearing of the second shaft radially and on the other hand a second bearing of the first shaft partially overlaps another bearing of the second shaft radially.

It is therefore also advantageous if the second bearing of the first shaft partially radially overlaps an additional bearing of the third shaft.

For easy assembly, it is advantageous if the first bearing of the first shaft is accommodated in a first housing component of the housing and the second bearing of the first shaft is accommodated in a second housing component of the housing, which is firmly connected to the first housing component.

Similar advantages in terms of simplifying assembly are achieved if the bearing of the second shaft radially overlapping the first bearing of the first shaft and/or the bearing of the third shaft radially overlapping the first bearing of the first shaft are accommodated in the first housing component of the housing.

For better accessibility during assembly, it is advantageous if at least one bearing of the respective shaft (the first shaft, the second shaft, the third shaft and/or the fourth shaft) is arranged at the end of this shaft.

It has proven to be particularly useful if at least one bearing of the respective shaft is designed as a rolling bearing, particularly preferably a deep groove ball bearing. This results in a clever compromise between efficient bearings and a space-saving bearing arrangement.

It has also proven to be expedient if the third shaft is designed as an input shaft of the transmission device and/or the second shaft is designed as a component of a differential unit of the transmission device and/or the first shaft is designed as an intermediate shaft arranged between the input shaft and the second shaft, viewed along a torque transmission path.

Furthermore, the invention relates to an electric drive device for a motor vehicle, with an electric drive motor and a drive motor according to the invention, connected downstream of the drive motor. Transmission device according to at least one of the previously described embodiments.

The invention will now be explained in more detail with reference to figures, in which context various embodiments are also shown.

• 1 eine Prinzipdarstellung eines Aufbaus einer erfindungsgemäßen Getriebeeinrichtung nach einem ersten Ausführungsbeispiel eingesetzt in einer Antriebsvorrichtung, wobei auf einer linken Seite in der Zeichnungsebene gesehen drei Lager dreier verschiedener Wellen abschnittsweise radial überlappend angeordnet sind, und
• 2 eine Prinzipdarstellung eines Aufbaus einer erfindungsgemäßen Getriebeeinrichtung nach einem zweiten Ausführungsbeispiel, in der sowohl auf er linken Seite als auch auf der rechten Seite in der Zeichnungsebene gesehen drei Lager radial überlappend angeordnet sind.

Show it:

• 1 a schematic representation of a structure of a transmission device according to the invention according to a first embodiment used in a drive device, wherein on a left side in the plane of the drawing, three bearings of three different shafts are arranged in sections radially overlapping, and
• 2 a schematic representation of a structure of a transmission device according to the invention according to a second embodiment, in which three bearings are arranged radially overlapping both on the left side and on the right side in the plane of the drawing.

The figures are merely schematic in nature and serve solely to understand the invention. The same elements are provided with the same reference numerals.

With 1 a first embodiment of the transmission device 1 according to the invention is illustrated. In this regard, the preferred area of application of the transmission device 1 is also made clear. The transmission device 1 is used in an electric drive device 15 serving as the drive train of a motor vehicle. The drive device 15 has, in the usual way, an electric drive machine 16, indicated schematically here. An output of the drive machine 16, preferably realized as a rotor shaft, is directly connected in a rotationally fixed manner to a third shaft 4, described in more detail below, which forms an input shaft of the transmission device 1. Two output shafts 12a, 12b of the transmission device 1 are further rotationally coupled to tires of the motor vehicle.

In this exemplary embodiment, the transmission device 1 is designed as a transmission with a fixed gear ratio. The transmission device 1 is thus implemented as a non-switchable transmission. In other embodiments, however, the transmission device 1 can also be implemented as a manual transmission.

The transmission device 1 has in the embodiment of the 1 several shafts 2, 3, 4. A first shaft 2 is implemented as a so-called intermediate shaft and is inserted/arranged along the torque transmission path between the third shaft 4 as the input shaft and the second shaft 3.

The third shaft 4 is arranged parallel to the first shaft 2. The second shaft 3 (as well as the output shafts 12a, 12b) is (/ are) arranged parallel to the first shaft 2 and the third shaft 4. The two output shafts 12a, 12b are arranged concentrically to each other, but offset from each other in the axial direction (along their axis of rotation).

The two output shafts 12a, 12b are used as outputs of a differential unit 17 of the transmission device 1. An input of the differential unit 17 is formed directly through the second shaft 3. It should be noted that the second shaft 3 thus usually has the shape of a differential cage and therefore has a shape that differs from that of a tube or a rod; nevertheless, due to its rotation about a fixed axis of rotation during operation of the transmission device 1, it is used as a shaft and is referred to as such.

The second shaft 3/the input of the differential unit 17 is rotationally coupled to the first shaft 2. A drive gear 18 of the differential unit 17, which serves as the input and is a component of the second shaft 3, meshes with a (first) gear component 19, which is preferably arranged as a fixed gear on the first shaft 2. The differential unit 17 is thus inserted between the first shaft 2 on the one hand and the two output shafts 12a, 12b on the other hand.

A further (second) gear component 20 (preferably as a fixed gear) of the first shaft 2 is permanently in meshing engagement with a (third) gear component 21 (preferably as a fixed gear) on the third shaft 4. Thus, the third shaft 4 as an input shaft is permanently in rotary connection with the first shaft 2 designed as an intermediate shaft and the first shaft 2 is also permanently in rotary connection with the differential unit 17.

As in the example of the 1 As shown, each shaft 2, 3, 4 with at least one bearing 6, 7, 8, 9, 10, 11 is accommodated in a housing 5.

In this embodiment, the first shaft 2 is rotatably mounted in the housing 5 by means of a first bearing 6 and a second bearing 7. The first bearing 6 is the bearing which is arranged at the end of the first shaft 2 towards a first end region and is oriented in the plane of the drawing towards 1 is positioned on the left side. The second Bearing 7 is the bearing which is arranged at the end of the first shaft 2 to a second end region opposite the first end region and is oriented in the drawing plane according to 1 is positioned on the right side. While the first bearing 6 is accommodated in a first housing component 13 of the housing 5, the second bearing 7 is accommodated in a second housing component 14 of the housing 5, which is formed separately from the first housing component 13 but is firmly connected to the first housing component 13. Consequently, the two gear components 19, 20 of the first shaft 2 are located between the first and second bearings 6, 7 of the first shaft 2 when viewed along the first shaft 2.

In this embodiment, the third shaft 4 is also mounted in the housing 5 by means of a first bearing 9 and a second bearing 10. The first bearing 9 of the third shaft 4 is the bearing which, as seen on the left-hand side in the plane of the drawing, is arranged on a first end region at the end of the third shaft 4. The second bearing 10 of the third shaft 4 is the bearing which, as seen on the right-hand side in the plane of the drawing, is arranged on a second end region at the end of the third shaft 4. The gearing component 21 of the third shaft 4 is therefore arranged between the first bearing 9 and the second bearing 10 of the third shaft 4 when viewed along the third shaft 4.

In this regard, for the sake of completeness, it should be noted that according to further embodiments it can also be advantageous to dispense with the second bearing 10 of the third shaft 4 and, more preferably, to also support the third shaft 4 via the rotor shaft of the drive machine 16 (outside the housing 5). The third shaft 4 can also form the input shaft and the rotor shaft of the drive machine 16 in one piece.

The first bearing 9 of the third shaft 4 is in turn accommodated in the first housing component 13 of the housing 5, while the second bearing 10 of the third shaft 4 is accommodated in the second housing component 14 of the housing 5.

The second shaft 3 is mounted in the housing 5 by means of a first bearing 8 and a second bearing 11. The first bearing 8 of the second shaft 3 is accommodated in the first housing component 13, while the second bearing 11 of the second shaft 3 is accommodated in the second housing component 14. The first bearing 8 of the second shaft 3 and the second bearing 11 of the second shaft 3 are also arranged (axially) at the end of the second shaft 3/the differential cage in the usual way.

The differential unit 17 is in 1 only shown small, but usually fills the entire space between the bearings 8, 11 of the second shaft 3. The first bearing 8 of the second shaft 3 is therefore the bearing which is arranged on the left-hand side in the drawing plane on a first end area at the end of the second shaft 2. The second bearing 11 of the second shaft 3 is the bearing which is arranged on the right-hand side in the drawing plane on a second end area at the end of the second shaft 3.

Further preferably, the output shafts 12a, 12b are designed as plug-in shafts which are inserted into the differential unit 17 via a plug-in toothing.

According to the invention, as in 1 Further shown, in this embodiment, the first bearing 6 of the first shaft 2 is arranged in the radial direction (ie viewed perpendicular to (a rotation axis) of the first shaft 2) overlapping the first bearing 9 of the third shaft 4 and even radially overlapping the first bearing 8 of the second shaft 3. In this regard, for the sake of completeness, it should be noted that in further embodiments it is also possible to arrange the first bearing 6 of the first shaft 2 only radially overlapping the first bearing 8 of the second shaft 3 or the first bearing 9 of the third shaft 4.

The radially overlapping arrangement of at least two bearings is to be understood as meaning that at least individual components of one bearing, for example an outer ring, an inner ring or the rolling elements arranged between the outer ring and the inner ring, overlap/cover in the radial direction with at least individual components of the other bearing, for example an outer ring, an inner ring or the rolling elements arranged between the outer ring and the inner ring.

Due to the design of the respective bearings 6, 8, 9 as rolling bearings, here as deep groove ball bearings, the first bearing 6 of the first shaft 2 is thus also positioned axially (i.e. viewed along the first shaft 2) offset from the first bearing 8 of the second shaft 3 and the first bearing 9 of the third shaft 4.

In this regard, for the sake of completeness, it should be noted that the first bearing 6 of the first shaft 2 can then be arranged/mounted on a side of a wall 22 of the housing 5 that is axially remote from the first bearing 8 of the second shaft 3 and the first bearing 9 of the third shaft 4. The first bearing 6 can be arranged, for example, in a housing extension area 23, which is additionally provided with a separate cover 24. is closed. The first bearing 6 is thus in turn mounted in a receiving space on the housing 5 / of the housing 5, which is separated / sealed from the surroundings of the housing 5.

In further embodiments, the previously explained bearing arrangement is of course also mirror-inverted and thus also provided in the second housing component 14. Then the second bearing 7 of the first shaft 2 would preferably be arranged radially overlapping the second bearing 11 of the second shaft 3 and/or the second bearing 10 of the third shaft 4.

In the embodiment of the 2 , which is essentially based on the embodiment of the 1 which is why only the differences between these two embodiments are described below for the sake of brevity, it can be seen that the second bearing 7 of the first shaft 2 is arranged radially overlapping the second bearing 10 of the third shaft 4 and the second bearing 11 of the second shaft 3.

In 2 a bearing pin 25 is attached to the housing 5, which bearing pin 25 projects into the interior of the transmission device 1, ie from a side wall 26 of the second housing component 14 in the direction of the first housing component 13, and receives the second bearing 7 of the first shaft 2.

It goes without saying that the bearing pin 25 can also be used on the left side.

In other words, according to the invention, the bearing seat is divided into several housing components 13, 14, wherein when mounted from the left and right, the bearings are also nested so that highly efficient bearing concepts can be integrated and the wheelset can be mounted in the housing 5.

The transmission (transmission device 1) consists of several housing parts (housing components 13, 14) which are connected via a flange 27, for example by screwing. The housing 5 can be provided with several flange surfaces. The housing 5 can also house/connect the drive motor 16 or inverter, lubrication channels, oil filter, actuators or other subsystems/components.

The transmission is designed as a spur gear, the drive motor 16 is coupled via the input shaft. There is also an intermediate shaft and an output shaft. The output shaft can be a differential. A parking lock, decoupling device, differential lock or similar can be installed in the wheel set / shaft set.

Shafts 2, 3, 4 are connected to the respective housing parts by bearings (bearings 6 to 11). The gearbox can be actively or passively lubricated.

Preferably, the first bearing 6 of the first shaft 2 is mounted from a different side than the other bearings 8, 9 in the first housing component 13 in order to create a radial overlap with the first bearing 9 of the third shaft 4 and the bearing 8 of the second shaft 3/differential unit 17. In order to seal the transmission in an oil-tight manner, a cover 24 can be provided. This can contain applications for oiling/sealing.

Alternatively, the position of the first bearing 9 of the third shaft 4 and the first bearing 8 of the second shaft 3 / differential unit 17 can be mounted on the outside and the first bearing 6 of the first shaft 2 on the inside. Appropriate covers for the first bearing 9 of the third shaft 4 and the first bearing 8 of the second shaft 3 would have to be provided. If it makes structural sense, this can also be done for the second bearing 7 of the first shaft 2 and the second bearing 11 of the second shaft 3 and optionally for the second bearing 10 of the third shaft 4.

2 shows an extension of the variant of the 1 Here, on the intermediate shaft, in relation to the second bearing 7 of the first shaft 2, it is not the outer ring that is connected to the housing 5, but the inner ring. The outer ring supports the shaft or the gear component (second gear component 20; preferably in one piece with the intermediate shaft or removable). The second bearing 7 of the first shaft 2 is preferably a ball bearing for absorbing axial and radial forces.

List of reference symbols

1

Gearbox device

2

first wave

3

second wave

4

third wave

5

Housing

6

first camp of the first wave

7

second camp of the first wave

8th

first camp of the second wave

9

first camp of the third wave

10

second camp of the third wave

11

second camp of the second wave

12a

first output wave

12b

second output shaft

13

first housing component

14

second housing component

15

Drive device

16

electric drive machine

17

Differential unit

18

drive wheel

19

first gear component

20

second gear component

21

third gear component

22

Wall

23

Housing expansion area

24

Lid

25

Bearing journal

26

Side wall

27

flange

Claims (10)

Gear device (1) for a drive device (15) of a motor vehicle, with three shafts (2, 3, 4) arranged parallel to one another and a housing (5) receiving the three shafts (2, 3, 4), wherein each shaft (2, 3, 4) is rotatably mounted in the housing (5) by means of a bearing (6, 7, 8, 9, 10), and wherein the bearing (6) of a first shaft (2) radially overlaps the bearing (8) of a second shaft (3) in sections. Gearbox (1) according to Claim 1 , characterized in that the bearing (6) of the first shaft (2) partially radially overlaps the bearing (9) of a third shaft (4). Gearbox (1) according to Claim 1 or 2 , characterized in that the bearing (6) of the first shaft (2) is attached to a first side of a wall (22) of the housing (5) so as to be fixed to the housing (and is preferably closed with a cover) and the bearing (8) of the second shaft (3) and/or the bearing (9) of a third shaft (4) are attached to a second side of the wall (22) so as to be fixed to the housing. Transmission device (1) according to one of the Claims 1 until 3 , characterized in that the first shaft (2) is rotatably mounted in the housing (5) by means of two bearings (6, 7), wherein on the one hand a first bearing (6) of the first shaft (2) partially radially overlaps the bearing (8) of the second shaft (3) and on the other hand a second bearing (7) of the first shaft (2) partially radially overlaps another bearing (11) of the second shaft (3). Gearbox (1) according to Claim 4 , characterized in that the second bearing (7) of the first shaft (2) partially radially overlaps an additional bearing (10) of the third shaft (4). Transmission device (1) according to one of the Claims 1 until 5 , characterized in that the first bearing (6) of the first shaft (2) is accommodated in a first housing component (13) of the housing (5) and the second bearing (7) of the first shaft (2) is accommodated in a second housing component (14) of the housing (5), which is firmly connected to the first housing component (13). Gearbox (1) according to Claim 6 , characterized in that the bearing (8) of the second shaft (3) which radially overlaps the first bearing (6) of the first shaft (2) and/or the bearing (9) of the third shaft (4) which radially overlaps the first bearing (6) of the first shaft (2) are/is accommodated in the first housing component (13) of the housing (5). Transmission device (1) according to one of the Claims 1 until 7 , characterized in that the at least one bearing (6, 7, 8, 9, 10, 11) of the respective shaft (2, 3, 4, 12) is designed as a deep groove ball bearing. Transmission device (1) according to one of the Claims 1 until 8th , characterized in that the third shaft (4) is designed as an input shaft of the transmission device (1) and / or the second shaft (3) is designed as a component of a differential unit (17) of the transmission device (1) and / or the first shaft (2) is designed as an intermediate shaft arranged between the input shaft and the second shaft (3), viewed along a torque transmission path. Electric drive device (15) for a motor vehicle, with an electric drive motor (16) and a transmission device (1) connected downstream of the drive motor (16) according to one of the Claims 1 until 9 .

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