DE102022103480A1 - roller bearing arrangement - Google Patents

Abstract

The invention relates to a roller bearing arrangement (1), in particular for supporting a transmission shaft, comprising a roller bearing (2) with an inner ring (3) and an outer ring (4) and between the inner ring (3) and outer ring (4) rolling elements (5 ), wherein the inner ring (3) is arranged on a shaft (6) in a rotationally fixed manner and the outer ring (4) is arranged in a rotationally fixed manner on a housing structure (7), with an annular centering disk (8) being arranged on its outer peripheral surface in the radial direction through the housing structure (7 ) and an annular shim (9) is fixed in the radial direction by the inner peripheral surface of the annular centering disc (8) in the radial direction, the shim (8) bearing axially on the one hand against the outer ring (4) and on the other hand against the housing structure (7). and an arcuate contour (10) is formed on the housing structure (7) between the outer peripheral surface of the adjusting disk (8) and the outer peripheral surface of the centering disk (8).

Description

The present invention relates to a roller bearing arrangement, in particular for supporting a transmission shaft, comprising a roller bearing with an inner ring and an outer ring as well as rolling elements arranged to roll between the inner ring and the outer ring, the inner ring being arranged on a shaft in a rotationally fixed manner and the outer ring being arranged in a rotationally fixed manner on a housing structure.

Electric motors are increasingly being used to drive motor vehicles in order to create alternatives to internal combustion engines that require fossil fuels. Significant efforts have already been made to improve the suitability for everyday use of electric drives and also to be able to offer users the driving comfort they are accustomed to.

A detailed description of an electric drive can be found in an article in the ATZ magazine, volume 113, 05/2011, pages 360-365 by Erik Schneider, Frank Fickl, Bernd Cebulski and Jens Liebold with the title: Highly integrative and flexible electric drive unit for electric Vehicles. This article describes a drive unit for an axle of a vehicle, which includes an electric motor that is arranged concentrically and coaxially with a bevel gear differential, with a switchable 2-speed planetary gear set being arranged in the power train between the electric motor and the bevel gear differential, which is also is positioned coaxially to the electric motor or the bevel gear differential or spur gear differential. The drive unit is very compact and allows a good compromise between climbing ability, acceleration and energy consumption due to the switchable 2-speed planetary gear set. Such drive units are also referred to as e-axles.

From the DE 10 2010 048 837 A1 such a drive device with at least one electric motor and at least one planetary differential that can be driven by a rotor of the electric motor is known, the planetary differential having at least one planetary carrier that is operatively connected to a rotor of the electric motor, first planetary gears and second planetary gears that are rotatably mounted on the planetary carrier, and a first sun gear and a second sun gear, each of which is operatively connected to an output shaft of the planetary differential. The first planetary gears mesh with the first sun gear and each of the second planetary gears meshes with the second sun gear and with one of the first planetary gears. Furthermore, the sun gears are arranged coaxially with an axis of rotation of the rotor.

With the shafts mounted in such transmissions, it is often necessary to adjust the axial shaft play. In addition to the function of the defined axial play, reliable support of the axial forces is also required. Normally, axial play is adjusted by inserting a shim between the end face of the bearing ring and the stop shoulder in a housing bore. The transition in the housing between the bore diameter and the contact face often has to be stress-optimized, e.g. with a radius that is as large as possible or an undercut, as in many cases large axial forces are introduced into the housing. The production, e.g. an undercut is complex here and the size of the radius for stress optimization between the housing bore and the housing shoulder is usually very limited.

It is therefore the object of the invention to provide a roller bearing arrangement, in particular for supporting a transmission shaft, which allows reliable adjustment of the axial play and can provide a high level of axial force absorption. Furthermore, it is the object of the invention to realize a roller bearing arrangement, in particular for supporting a transmission shaft, which is designed to be as cost-effective as possible in terms of manufacture and assembly.

This object is achieved by a roller bearing arrangement, in particular for supporting a transmission shaft, comprising a roller bearing with an inner ring and an outer ring as well as rolling elements arranged to roll between the inner ring and outer ring, the inner ring being arranged in a rotationally fixed manner on a shaft and the outer ring being arranged in a rotationally fixed manner on a housing structure. wherein an annular centering disk is fixed at its outer peripheral surface in the radial direction by the housing structure and an annular shim is fixed in the radial direction by the inner peripheral surface of the annular centering disk in the radial direction, the shim axially abutting on the one hand on the outer ring and on the other hand on the housing structure and of the housing structure between the outer peripheral surface of the adjusting disk and the outer peripheral surface of the centering disk, an arc-shaped contour is formed.

This has the advantage that a solution that is as cost-effective as possible is achieved by separating the “centering” and “stress-optimized transition” functions and fulfilling them with two different components, the adjusting disk and the centering disk. The shim is radially centered by the centering disc, for example to avoid a collision with moving bearing parts (eg cage). The focusing screen must be at their edges opposite the The housing structure must be free so that the axial play is clearly defined.

In contrast to the undercut, the radius of the arcuate contour of the housing structure is a simple contour in terms of production technology and reduces the tool costs and production times for the corresponding housing. In addition to the adjusting disk, the additional component centering disk is required, but the disk contours remain simple, which continue to enable very cost-effective production.

During assembly, only one additional work step is required, namely the initial insertion of the centering disk. The centering disc has a relatively large amount of play in relation to the housing structure on the outside and the adjusting disc on the inside. The axial thickness of the centering disk is dimensioned in such a way that there is clearance between the start of the housing radius and the bearing outer ring. When inserting the shim, you only have to make sure that it is not on but in the centering disc. The outer ring of the bearing is then pressed in (or inserted).

The principle of the additional centering ring can also be applied to the adjustment of a bearing inner ring on a shaft. The object of the invention is therefore also achieved by a roller bearing arrangement, in particular for supporting a transmission shaft, comprising a roller bearing with an inner ring and an outer ring and rolling elements arranged to roll between the inner ring and outer ring, the inner ring being non-rotatably mounted on a shaft and the outer ring being non-rotatably mounted on one housing structure, wherein an annular centering disk is fixed at its inner peripheral surface in the radial direction by the shaft and an annular shim is fixed in the radial direction by the outer peripheral surface of the annular centering disk in the radial direction, the shim being axially fixed on one side to the inner ring and on the other side to a Shoulder of the shaft rests and a circular arc-shaped contour is formed between the shaft and the shoulder between the inner peripheral surface of the shim and the inner peripheral surface of the centering disc.

The housing structure can be designed as a fixed or rotating support structure. For example, the housing structure may be part of a stationary housing or a rotating insert of a planetary gear carrier.

A roller bearing arrangement can be formed from one or more roller bearings. In particular, a roller bearing can be selected from the group of radial roller bearings and/or axial roller bearings.

The roller bearing arrangement is preferably configured as a bearing arrangement that absorbs axial forces. The roller bearing arrangement most preferably absorbs axial forces in both axial directions. The roller bearing arrangement can preferably have a fixed bearing.

First, the individual elements of the claimed subject matter of the invention are explained in the order in which they are mentioned in the set of claims, and particularly preferred configurations of the subject matter of the invention are described below.

A roller bearing can have one or more rows. The roller bearing is preferably configured as a ball bearing.

The inner ring can in particular connect the shaft accommodating the roller bearing to the roller bearing or the roller bodies. In particular, the shaft can be connected to the side of the lateral surface of the inner ring that faces the shaft, with the rolling elements of the roller bearing rolling on the inner ring raceway that is opposite this lateral surface. The inner ring can be made of a metallic and/or ceramic material. In principle, it is conceivable to design the inner ring in one piece or in multiple pieces, in particular in two pieces.

The outer ring can, in particular, connect the bearing arrangement accommodating the roller bearing to the roller bearing or the roller bodies. In particular, the bearing can be connected to the side of the lateral surface of the outer ring facing the bearing, the rolling elements of the roller bearing rolling on the outer ring raceway opposite this lateral surface. The outer ring can be made of a metallic and/or ceramic material. In principle, it is conceivable to design the outer ring in one piece or in multiple pieces, in particular in two pieces.

The rolling elements have the shape of a ball or a roller. They roll on the raceways of the roller bearing and have the task of transferring the force acting on a radial roller bearing from the outer ring to the inner ring and vice versa. In an axial roller bearing, the rolling elements transmit the forces acting on the axial roller bearing between the running disks. Roller-shaped rolling bodies can be selected, for example, from the group of symmetrical spherical rollers, asymmetrical spherical rollers, cylindrical rollers, needle rollers and/or tapered rollers. According to a further preferred further development of the invention, it can also be provided that the rolling elements are made of ceramic.

The rolling bodies are preferably guided in a cage and spaced apart from one another. The cage can be made in one piece or in several pieces.

The rolling bodies can roll within the rolling bearing, in particular on the inner ring raceway of the inner ring. For this purpose, the surface of the inner ring raceway can advantageously be designed to be correspondingly abrasion-resistant, for example also by means of a corresponding surface treatment process and/or by applying a corresponding additional layer of material.

The inner ring raceway can be flat or profiled. A profiled design of the inner ring raceway can be used, for example, to guide the rolling elements on the inner ring raceway. On the other hand, a planar formation of the inner ring raceway can, for example, allow a certain axial displaceability of the rolling elements on the inner ring raceway.

The rolling bodies can roll within the rolling bearing, in particular on the outer ring raceway of the outer ring. For this purpose, the surface of the outer ring raceway can advantageously be designed to be abrasion-resistant, for example by means of a corresponding surface treatment process and/or by applying a corresponding additional layer of material.

The outer ring raceway can be flat or profiled. A profiled design of the outer ring raceway can be used, for example, to guide the rolling elements on the outer ring raceway. On the other hand, a flat shape of the outer ring raceway can, for example, allow a certain axial displaceability of the rolling elements on the outer ring raceway.

A roller bearing may have a seal to prevent lubricant from escaping from the roller bearing or dirt or moisture from entering the roller bearing. For this purpose, the seals used can be provided with one or more sealing lips, which can rest against a component of the roller bearing. These are designed in such a way that on the one hand they seal the bearing for as long as possible over the entire service life, and on the other hand the friction caused by the adjacent seal is not too high. It is particularly preferred that the seal is formed from an elastic, particularly preferably rubber-elastic material. The elastic material can preferably consist entirely or partially of an elastomer, the elastomers in turn preferably being selected from the group of vulcanizates of natural rubber and silicone rubber.

According to a further preferred further development of the invention, it can also be provided that the adjusting disk has a greater axial extent than the centering disk. The centering disk is therefore preferably significantly thinner than the adjusting disk and thus enables a large transition radius of the circular arc-like contour.

Furthermore, according to a likewise advantageous embodiment of the invention, it can be provided that the contour in the form of a circular arc covers an angle of approximately 90°.

According to a further particularly preferred embodiment of the invention, it can be provided that the shaft is a gear shaft. The use of the roller bearing arrangement according to the invention in a planetary gear is particularly preferred. It is very particularly preferred to use a roller bearing arrangement according to the invention for supporting rotating planet gears in a planet carrier. In such applications, particularly high axial forces generally act on a roller bearing arrangement, which requires a particularly stable configuration of the roller bearing arrangement.

The planetary gear is particularly preferably installed in an electric axle drive train of a motor vehicle and is driven by an electric machine. Furthermore, it may be preferable to use the planetary gear in an automatic transmission of a motor vehicle.

Furthermore, the invention can also be further developed such that the shaft is arranged in a drive train of a motor vehicle.

In a likewise preferred embodiment variant of the invention, it can also be provided that the shaft is arranged in an electrically operable final drive train of a motor vehicle.

An electrically operable drive train includes an electric machine and preferably a transmission arrangement coupled to the electric machine. The gear arrangement and the electric machine form a structural unit.

This can be formed, for example, by means of a drive train housing, in which the transmission arrangement and the electric machine are accommodated together.

The electrical machine preferably has a motor housing and/or the transmission has a transmission housing, in which case the structural unit can then be effected by fixing the transmission in relation to the electrical machine. The gearbox housing is a housing for accommodating a gearbox. It has the task of guiding existing shafts via the bearings and giving the wheels (possibly cam disks) the degrees of freedom they require under all loads without impeding their rotational and possible path movement, as well as absorbing bearing forces and supporting torques. A transmission housing can be single-shell or multi-shell, that is, undivided or divided. In particular, the transmission housing should also dampen both noise and vibrations and also be able to safely accommodate hydraulic fluid. The transmission housing is preferably formed from a metallic material, particularly preferably from aluminum, gray cast iron or cast steel, in particular by means of a primary shaping process such as casting or die-casting.

The motor housing encloses the electric machine. A motor housing can also accommodate the control and power electronics. The motor housing can also be part of a cooling system for the electric machine and can be designed in such a way that hydraulic fluid can be supplied to the electric machine via the motor housing and/or the heat can be dissipated to the outside via the housing surfaces. In addition, the motor housing protects the electrical machine and any electronics that may be present from external influences.

A motor housing can be formed in particular from a metallic material. Advantageously, the motor housing can be formed from a metallic cast material, such as die-cast aluminum, die-cast magnesium, cast iron or cast steel.

In particular, the electric machine is dimensioned in such a way that vehicle speeds of more than 50 km/h, preferably more than 80 km/h and in particular more than 100 km/h can be achieved. The electric motor particularly preferably has an output of more than 30 kW, preferably more than 50 kW and in particular more than 70 kW. Furthermore, it is preferred that the electrical machine provides speeds greater than 5,000 rpm, particularly preferably greater than 10,000 rpm, very particularly preferably greater than 12,500 rpm.

For the purposes of this application, motor vehicles are land vehicles that are moved by machine power without being tied to railroad tracks. A motor vehicle can be selected, for example, from the group of passenger cars (cars), trucks (lorries), mopeds, light motor vehicles, motorcycles, buses (COM) or tractors.

In particular, the transmission arrangement can be coupled to the electric machine, which is designed to generate a drive torque for the motor vehicle. The drive torque is particularly preferably a main drive torque, so that the motor vehicle is driven exclusively by the drive torque. The gear arrangement is preferably designed as a planetary gear

It can also be advantageous to further develop the invention in such a way that the shaft is arranged in a gear arrangement of an electrically operable axle drive train. According to a further preferred embodiment of the subject matter of the invention, it can be provided that the housing structure is a housing component of an electrically operable axle drive train.

The invention will be explained in more detail below with reference to figures without restricting the general inventive idea.

• 1 eine erste Ausführungsform einer Wälzlageranordnung in einer schematischen Axialschnittansicht,
• 2 eine zweite Ausführungsform einer Wälzlageranordnung in einer schematischen Axialschnittansicht,
• 3 ein Kraftfahrzeug mit einem elektrisch betreibbaren Achsantriebsstrang in einer schematischen Blockschaltdarstellung.

It shows:

• 1 a first embodiment of a roller bearing arrangement in a schematic axial section view,
• 2 a second embodiment of a roller bearing arrangement in a schematic axial section view,
• 3 a motor vehicle with an electrically operable axle drive train in a schematic block diagram.

The 1 shows a roller bearing arrangement 1 for supporting a transmission shaft, comprising a roller bearing 2 with an inner ring 3 and an outer ring 4 as well as rolling elements 5 arranged to roll between the inner ring 3 and outer ring 4.

The inner ring 3 is arranged in a rotationally fixed manner on a shaft 6 and the outer ring 4 is arranged in a rotationally fixed manner on a pot-like housing structure 7 . Annular centering disk 8 is fixed at its outer peripheral surface in the radial direction by the housing structure 7 and an annular shim 9 in the radial direction by the inner peripheral surface of the annular centering disk 8 in the radial direction. The adjusting disk 8 rests axially on the outer ring 4 on the one hand and on the housing structure 7 on the other hand. On the housing structure 7 is to reduce local stress peaks between the outer peripheral surface of the setting disk 8 and the outer peripheral surface of the centering disk 8 has a contour 10 in the shape of a circular arc.

From the 2 a further embodiment of a roller bearing arrangement 1 according to the invention can be seen. This is in contrast to the Aus der 1 known embodiment, characterized in that the annular centering disk 8 is fixed on its inner peripheral surface in the radial direction by the shaft 6 and an annular shim 9 in the radial direction from the outer peripheral surface of the annular centering disk 8 in the radial direction, with the shim 8 axially on one side the inner ring 3 and on the other hand on a shoulder 11 of the shaft 6 and between the shaft 6 and the shoulder 11 between the inner peripheral surface of the adjusting disk 8 and the inner peripheral surface of the centering disk 8 an arcuate contour 10 is formed.

In all of the exemplary embodiments shown, the adjusting disk 8 has a greater axial extent than the centering disk 8. In the examples shown, the arcuate contour 10 covers an angle of approximately 90°. In the embodiments of 1-2 the shaft 6 is a transmission shaft.

In the 3 it is shown that the shaft 6 is arranged in a drive train 12 of a motor vehicle 13 . The drive train includes an electrically operable final drive train 14. The shaft 6 is arranged in a transmission arrangement 15 of the electrically operable final drive train 14. The housing structure 7 is in the embodiment shown 3 a housing component of the electrically operable final drive train 14.

The invention is not limited to the embodiments shown in the figures. The foregoing description is therefore not to be considered as limiting but as illustrative. The following patent claims are to be understood in such a way that a mentioned feature is present in at least one embodiment of the invention. This does not exclude the presence of other features. If the patent claims and the above description define 'first' and 'second' feature, this designation serves to distinguish between two similar features without establishing a ranking.

Reference List

1

roller bearing arrangement

2

roller bearing

3

inner ring

4

outer ring

5

rolling elements

6

Wave

7

housing structure

8th

centering disc

9

focusing screen

10

contour

11

shoulder

12

powertrain

13

motor vehicle

14

final drive train

15

gear arrangement

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 102010048837 A1 [0004]

Claims (9)

Rolling bearing arrangement (1), in particular for supporting a transmission shaft, comprising a rolling bearing (2) with an inner ring (3) and an outer ring (4) and rolling elements (5) arranged to roll between the inner ring (3) and outer ring (4), the The inner ring (3) is arranged in a rotationally fixed manner on a shaft (6) and the outer ring (4) is arranged in a rotationally fixed manner on a housing structure (7), characterized in that an annular centering disc (8) passes through the housing structure (7) on its outer peripheral surface in the radial direction and an annular shim (9) is fixed in the radial direction by the inner peripheral surface of the annular centering disc (8), the shim (8) abutting axially on the one hand against the outer ring (4) and on the other hand against the housing structure (7) and an arcuate contour (10) is formed on the housing structure (7) between the outer peripheral surface of the adjusting disk (8) and the outer peripheral surface of the centering disk (8). Rolling bearing arrangement (1), in particular for supporting a transmission shaft, comprising a rolling bearing (2) with an inner ring (3) and an outer ring (4) and rolling elements (5) arranged to roll between the inner ring (3) and outer ring (4), the The inner ring (3) is arranged in a rotationally fixed manner on a shaft (6) and the outer ring (4) is arranged in a rotationally fixed manner on a housing structure (7), characterized in that an annular centering disc (8) passes through the shaft (6) on its inner peripheral surface in the radial direction and an annular shim (9) is fixed in the radial direction by the outer peripheral surface of the annular centering disc (8) in the radial direction, the shim (8) axially on the one hand on the inner ring (3) and on the other hand on a shoulder (11) of the shaft (6) and between the shaft (6) and the shoulder (11) between the inner peripheral surface of the adjusting disk (8) and the inner peripheral surface of the centering disk (8) an arcuate contour (10) is formed. Rolling bearing arrangement (1) according to one of the preceding claims, characterized in that the adjusting disk (8) has a greater axial extent than the centering disk. Rolling bearing arrangement (1) according to one of the preceding claims, characterized in that the arcuate contour (10) covers an angle of approximately 90°. Rolling bearing arrangement (1) according to one of the preceding claims, characterized in that the shaft (6) is a gear shaft. Rolling bearing arrangement (1) according to one of the preceding claims, characterized in that the shaft (6) is arranged in a drive train (12) of a motor vehicle (13). Rolling bearing arrangement (1) according to one of the preceding claims, characterized in that the shaft (6) is arranged in an electrically operable axle drive train (14) of a motor vehicle (13). Rolling bearing arrangement (1) according to one of the preceding claims, characterized in that the shaft (6) is arranged in a gear arrangement (15) of an electrically operable axle drive train (14). Rolling bearing arrangement (1) according to one of the preceding claims, characterized in that the housing structure (7) is a housing component of an electrically operable axle drive train (14).

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