FR3106178A1 - Bearing ring integrated in the machining of transmission shafts - Google Patents

Abstract

This transmission shaft (15) for a motor vehicle comprises at each end an inner bearing race (22, 25), one of the bearing rings (25) being integral with said shaft (15). Figure for the abstract: Fig 2

Description

Bearing ring integrated in the machining of transmission shafts

The invention relates to motor vehicle transmission shaft lines, and more specifically to the bearings provided at the ends of the shafts.

Prior techniques

A transmission shaft generally carries one or more pinions of a reducer. These sprockets can be inserted and shrunk onto the shaft.

There is shown in Figure 1 an arrangement according to document FR-A-3072748 in which a pinion 2 is inserted and shrunk on a shaft 1 carried by bearings 3.

These bearings can be conical, ball or cylindrical and conventionally comprise an inner ring 5, an outer ring 6, and a cage 7 enclosing the rolling elements 8. The illustrated bearings are tapered in order to prevent any slippage of the shaft through bearings.

The inner rings 5 are shrunk onto the shaft using a press. Similarly, the outer rings 6 of the bearing are generally shrunk to a casing 10 before enclosing the shaft 1 in the latter.

In order to avoid the appearance of play between the shaft 1 and the casing 10, generating during rotation an uncontrolled movement of the shaft 1 which is detrimental to the proper functioning of the reduction gear and likely to accelerate the wear of mechanics, a shim washer 11 is added between one of the outer rings 6 and the casing 10 before shrinking these two parts. Washer 11 allows more precise control of play in the shaft line.

However, each assembly is different from case to case. The clearance of an assembly varies according to the uncertainty on the dimensions of the parts used, a parameter which itself varies significantly if the number of parts in the assembly is high, according to the shrinking of the parts, according to the swelling of certain hooped components, and according to their wear and possible corrosion due to too little hooping. Each of these parameters contributes to creating a strong dispersion in the clearance values. It is therefore necessary, in order to be able to attenuate the clearance, to have a wide range of different shim washers, around thirty.

However, these washers have a cost, and take up storage space in a workshop.

The object of the present invention is therefore to overcome the aforementioned drawbacks.

The invention therefore relates to a drive shaft for a motor vehicle comprising at each end an inner bearing ring, one of the bearing rings being integral with said shaft.

Thus, the assembly of the shaft in the housing requires one part less, the wear and corrosion due to shrinking between the inner ring and the shaft being eliminated. Finally, the values of the game will be less dispersed and only fifteen to twenty different wedging washers will be necessary, which represents a significant financial and spatial gain.

Advantageously, the inner bearing ring is capable of cooperating with rollers held by an outer bearing ring shrunk to a casing, said casing maintaining the shaft and the bearing stable when the shaft is rotated using a specific shim washer inserted between the casing and the outer ring.

Advantageously, the transmission shaft is made of steel.

The invention also relates, according to another aspect, to a motor vehicle powertrain comprising a transmission shaft as defined above.

Other aims, characteristics and advantages of the invention will appear on reading the following description, given solely by way of non-limiting example, and made with reference to the appended drawings in which:

which has already been mentioned, is a sectional view of a tree cut along its longitudinal axis according to the state of the art;

is a sectional view of a tree cut along its longitudinal axis according to the invention; And

is a sectional view of the transmission shaft in the transmission system of a motor vehicle according to the invention.

Detailed description of at least one embodiment

In Figure 2 is shown schematically a section of a transmission shaft 15 according to the invention cut along its longitudinal axis.

The transmission shaft 15 is machined in the shape of a cylinder and comprises a toothed annular sector 16 integral with the shaft 15 and capable of interacting with a pinion 17 of another transmission shaft (figure 3). In addition, the shaft 15 has a shoulder with an annular constriction, adjacent to the toothed sector 16 and intended to collect a pinion 20 inserted and shrunk on the shaft 15.

A second shoulder 21 adjacent to the first and located at one end of the shaft 15 is machined and is able to receive an inner race 22 of the bearing. The inner ring 22 is inserted and shrunk to the shaft 15 using a press.

At the other end, a progressive annular constriction is machined, thus creating a conical end acting as the inner ring 25 of a bearing, made in one piece with the shaft 15. The inner ring 25 is able and intended to cooperate with the elements rollers 26 of a tapered bearing 27. The slope of the cone is machined according to the characteristics of the bearing 27 supplier.

The same goes for the diameter of the shoulders 18 and 21 which are established according to the characteristics of the pinion 20 and the bearing race 22.

The final assembly of the transmission shaft 15 in the transmission system of a motor vehicle can be seen in figure 3.

The shrinking of the pinion 20 and the inner bearing race 22 are carried out first before the introduction of the shaft 15 and the rolling elements 30 in the housing 31 to which the outer race of the bearing 32 is shrunk.

At the other end of the shaft are placed the conical rolling elements 26, then the casing 33 encloses the shaft 15, casing 33 on which the outer race 34 of the conical bearing 27 is shrunk. A specific shim washer 35 is placed beforehand between the casing 33 and the outer ring 34.

Claims (4)

Transmission shaft (15) for a motor vehicle comprising at each end an inner bearing ring (22, 25), characterized in that one of the bearing rings (25) is integral with said shaft (15). Drive shaft (15) for a motor vehicle according to claim 1, in which the inner bearing ring (25) is able to cooperate with rollers held by an outer bearing ring (34) shrunk to a casing (33), said casing (33) holding the shaft (15) and the bearing (27) stable when the shaft (15) is rotated using a specific shim washer (35) inserted between the casing ( 33) and the outer ring (34). Drive shaft (15) for a motor vehicle according to one of Claims 1 and 2, the composition of which is made of steel. Motor vehicle power unit, characterized in that it comprises a transmission shaft according to any one of Claims 1 to 3.