WO2008101869A1 - Rolling bearing, in particular for a shift device of a gearwheel change transmission - Google Patents

Abstract

The invention relates to a rolling bearing, in particular for a shift device of a gearwheel change transmission, for the longitudinally movable and pivotable rolling mounting of a shift element, comprising a plurality of rolling bodies which are retained in a cage, characterized in that, as rolling bodies, ball rows (7) and cylindrical rollers (5) are provided in a distributed arrangement, wherein the ball diameter is slightly larger than the roller diameter.

Description

 Name of the invention

Rolling, in particular for a switching device of a gear change transmission

description

Field of the invention

The invention relates to a rolling bearing, in particular for a switching device of a gear change transmission for longitudinally displaceable and pivotable rolling bearing a switching shaft, comprising a plurality of rolling elements held in a cage.

Background of the invention

Such a rolling bearing in use in a switching device for a gear change transmission of a motor vehicle is known for example from DE 43 28 399 A1. The rolling bearing comprises a cage, in which a plurality of rolling elements are accommodated in the form of cylindrical rollers. These are arranged axially offset from one another. About this roller bearing is a switching sleeve which is coupled to a shift lever located in the vehicle and having a shift finger which is engageable with corresponding drivers of shift rails, mounted longitudinally displaceably and rotatably on a shaft journal, wherein two compression springs are further provided on both sides of the Axially engage the shift sleeve and hold it in a neutral position. Another embodiment of such a switching device provides, an axially movable, so longitudinally displaceable and rotatable shift rod or selector shaft in a fixed bearing in which the cage is longitudinally displaceable and pivotable in a, for example, housed in the transmission housing position housing is stored.

When using a cylindrical roller bearing, as is known for example from DE 43 28 399 A1, high load capacities for receiving the radial load of the switching element, so for example, the moving shift sleeve or the moving shift rod or shaft can be achieved. However, the axial mobility of the switching element is unsatisfactory due to friction, the switching is connected to an increased Wählmomentenverlauf.

Summary of the invention

The invention is thus based on the problem of specifying a roller bearing in particular for use in a switching device of a gear change transmission, which allows a bearing of the switching element with high load capacity for receiving high radial loads while allowing a very good axial displacement of the stored switching element.

To solve this problem, ball races and cylindrical rollers are provided in a distributed arrangement according to the invention as rolling elements in a roller bearing of the type mentioned above, wherein the ball diameter is slightly larger than the roller diameter.

The rolling bearing according to the invention is characterized by the use of two different Wälzkörperarten, namely on the one hand cylindrical rollers that provide high load ratings, thus therefore a very good and high radial load receiving radial bearing is achieved, on the other hand of balls arranged in individual rows of balls ensure extremely low axial misalignment. In this case, the ball diameter is somewhat larger than the roller diameter, for example about 1 to 3 μm, preferably about 2 μm. If no or only a small radial load is given, wear the due to the slightly larger diameter, the rows of balls, of course, the balls and the cylinders with their respective centers all on a common radius. As the radial load increases, the ball raceways deform elastically, so that the cylindrical rollers come into play and thus the load capacity of the bearing increases sharply. That is, when selecting the desired shift stage via the manually leading, located in the vehicle shift lever, connected to an axial movement of the shaft, occur low radial forces, so that the cylindrical rolling elements have no contact with the shaft and eg the bearing housing and the bearing can be displaced longitudinally like an ordinary axial ball bearing or the shift rod or shaft mounted therein can easily be displaced axially. This results in a very smooth circuit.

The length of a ball row substantially corresponds to the length of a cylindrical roller, so that the cage with the individual cage pockets can be designed as a simple, symmetrical component. The pocket size is thus constant, it is designed so that on the one hand cylindrical rollers, on the other hand, with a corresponding number of balls ball rows can be recorded. A row of balls may, for example, consist of 3 to 5 balls, it being understood that fewer or more balls may be provided, given a corresponding length of the cylindrical rollers.

Basically, the rows of balls and the cylindrical rollers are expediently provided on the cage in symmetrical distribution in order to ensure both an optimal axial guidance and radial bearing regardless of the actual cage position. In this case, the number of rows of balls and the cylinder rollers may be the same, so that the rows of balls and the cylindrical rollers are arranged, for example, in an alternating arrangement, or, for example, are provided alternately in pairs. Alternatively, it is possible to provide n times as many cylindrical rollers as rows of balls. For example, follow each two adjacent cylindrical rollers a row of balls.

The cage itself can according to a first invention alternative longitudinally displaceable and pivotable in a bearing housing, which is open on both sides of the sleeve or is designed as a one-sided closed pot, be included. This bearing design serves to mount a longitudinally displaceable shift rod or shaft in stationary positioning of the bearing, for example, in a transmission housing. The shift rod or shaft plunges into the roller bearing, while the cage moves in the bearing housing during axial rod or shaft movement. Alternatively, the cage can also be axially stationary and pivotable in a bearing housing, also designed as a bearing sleeve, added. This bearing design serves to support a movable shift sleeve, the rolling bearing is firmly connected to the shift sleeve, so it is moved in total.

In addition to the rolling bearing itself, the invention further relates to a switching device for a gear change transmission comprising a via a rolling bearing according to one of the preceding claims longitudinally displaceable and pivotally mounted th switching element, which can be designed as a switching shaft or rod or as a switching sleeve, depending on the design of the transmission ,

Brief description of the invention

Further advantages, features and details of the invention are described below with reference to embodiments with reference to the figures. The figures are schematic representations and show:

Fig. 1 is a perspective view of a rolling bearing according to the invention, and

2 is a sectional view through the rolling bearing of FIG. 1st

Detailed description of the drawings

Fig. 1 shows an inventive rolling bearing 1, comprising a sleeve-like and in the example shown on both sides open bearing housing 2, in which a cage 3 is received, which holds a plurality of rolling elements. The cage 3 has in a conventional manner a plurality of individual pockets 4, in which the rolling elements are arranged. In the example shown, first rolling elements in the form of cylindrical rollers 5 are provided, as well as second rolling elements in the form of balls 6, which are received in individual rows of balls 7 in the respective pockets 4. As the figures show, the cylindrical rollers 5 and the rows of balls 7 are each arranged alternately. The pockets 4 are each the same length, regardless of whether a cylindrical roller 5 or a row of balls 6 is received. This results in that the length of a cylindrical roller 5 substantially corresponds to the length of a row of balls 7.

The diameter of a ball 6 is slightly larger than the diameter of a cylindrical roller 5. For example, the diameter may be larger by about 2 microns, which is by no means limiting, but ultimately depending on the dimensions of the bearing, the expected load and the used Ball materials is selected. As a result of the slightly larger diameter of the balls 6 carry the rows of balls 7 with no or less radial load of the bearing 1, the cylindrical rollers 5 have no contact in this case to be stored switching element as well as the inner wall of the bearing housing 2. This causes the switching element , In the example shown here, not shown in detail, the rolling bearing 1 axially passing through the switching shaft cylindrical cross-section, is mounted solely on the rows of balls 7, thus therefore low friction relative to the stationary roller bearing 1 can be moved axially. During this axial movement, the entire cage 3 moves axially within the bearing housing 2, the movement path is stop-limited via the peripheral flanges 8.

Only at a sufficiently high radial load during or after the actual switching program, there is an elastic deformation of the ball raceways, that is, the relevant radial diameter of the balls decreases slightly, so that the cylindrical rollers 5, which are arranged on the same radius as the Balls 6, come in contact with the shift shaft and the housing inner wall and wear, so that significantly increases the total load rating of the bearing according to the invention. Instead of the alternating arrangement of a cylindrical roller 5 with a row of balls 7, it is of course also conceivable to arrange the cylindrical rollers 5 as well as the rows of balls 7 in pairs and to change in pairs, this also results in a total symmetrical Wälzkörperanordnung. In addition, it is possible to provide more cylindrical rollers 5 as rows of balls 7, wherein the number of cylindrical rollers 5 must correspond to n times the rows of balls for reasons of symmetry. In such cases, it is then conceivable, for example, to replace one pair of cylindrical rollers with one row of balls. Finally, of course, it is also conceivable to provide a number other than four balls 6 per row of balls 7, that is, the rows of balls 7 may be correspondingly shorter or longer with simultaneous length adjustment of the cylindrical rollers 5.

While Figures 1 and 2 show within the bearing housing 2 axially movable and rotatably received cage 3, which is a fixed arrangement of the rolling bearing 1 via the position housing 2, which is for example pressed in a corresponding bore of a gear cover or a transmission wall, and an axial offset allows a recorded shift shaft, it is also conceivable, the cage 3 fixed in the bearing housing 2, which is correspondingly shorter, to arrange and the rolling bearing directly with the axially movable and pivotable switching element, for example, a shift sleeve with driving fingers, etc. to arrange. The rolling bearing 3 then runs on a stationary bearing shaft.

LIST OF REFERENCE NUMBERS

roller bearing

bearing housing

Cage

Bags

cylindrical rollers

roll

rows of balls

Claims

claims 1. Rolling, in particular for a switching device of a gear change gear for longitudinally displaceable and pivotable rolling bearing a switching element, comprising a plurality of rolling elements held in a cage, characterized in that as rolling elements in a distributed arrangement ball rows (7) and cylindrical rollers (5) are provided, where the ball diameter is slightly larger than the roll diameter. 2. Rolling bearing according to claim 1, characterized in that the length of a row of balls (7) corresponds substantially to the length of a cylindrical roller (5). 3. Rolling bearing according to claim 1 or 2, characterized in that the rows of balls (7) and the cylindrical rollers (5) are provided on the cage (3) in a symmetrical distribution. 4. Rolling bearing according to claim 3, characterized in that the number of rows of balls (7) and the cylindrical rollers (5) is the same. 5. Rolling bearing according to claim 3, characterized in that n times as many cylindrical rollers (5) as rows of balls (7) are provided. 6. Rolling bearing according to one of the preceding claims, characterized in that the cage (3) is longitudinally displaceable and pivotable, or axially stationary and pivotally accommodated in a bearing housing (2). 7. Switching device for a gear change transmission comprising a via a rolling bearing (1) according to one of the preceding claims längsgeschsieblich and pivotally mounted switching element.