JPH0596551U - Drive shaft bearing device - Google Patents

Abstract

(57) [Summary] [Purpose] To reduce the axial dimension while creating a structure that prevents preload fluctuations on the bearing without complicated adjustments during assembly. [Structure] A drive shaft 22 is supported by a housing 21 via a double row tapered roller bearing 30. The double row tapered roller bearing 30 includes an outer ring 31 fixed to the housing 21 and having two tapered raceways, two inner rings 32 and 33 each having one tapered raceway, and a plurality of tapered rollers 34 and 35. It has and. One inner ring 32 is the drive shaft 2
3, the other inner ring 33 is in contact with the pinion gear 22a of the drive shaft 22, respectively. When the tightening nut 24 is tightened, the drive shaft 23 and the pinion gear 22
The two inner races 32, 33 are compressed between the two and a, and the force is not transmitted to the tapered rollers 34, 35 more than necessary.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a bearing device for a drive shaft for transmitting power to a differential device such as an automobile.

[0002]

[Prior Art]

 Conventionally, two single-row tapered roller bearings have been used to support this type of drive shaft, as shown in FIG. In the figure, 1 is a housing of a differential device, 2 is a drive shaft, 3 and 4 are single-row tapered roller bearings, 5 is a drive shaft spline-fitted to the drive shaft 2, 6 is a tightening nut, 7 is a sealing device, 8 is a friction plate, 9 is a dustproof cover, and 10 is a collar.

The drive shaft 2 is one in which a pinion gear 2a that meshes with a ring gear of a differential device (not shown) is integrally provided at one end of a stepped shaft portion 2b, and the other end side of the shaft portion 2b is provided at the other end side thereof. A spline 2c and a screw part 2d are formed.

The single-row tapered roller bearings 3 and 4 respectively include inner rings 3a and 4a with flanges, outer rings 3b and 4b, a plurality of tapered rollers 3c and 4c, and cages 3d and 4d. There is. A predetermined preload is applied to these single-row tapered roller bearings 3 and 4 by adjusting the tightening force of the tightening nut 6. The tightening force of the tightening nut 6 is received by the two radially inward flanges 1 a and 1 b of the housing 1 via the tapered roller bearings 3 and 4.

[0005]

[Problems to be solved by the device]

 By the way, in the above-mentioned conventional example, the tightening force of the tightening nut 6 is transmitted from the inner rings 3a, 4a of the two single-row tapered roller bearings 3, 4 to the outer rings 3b, 4b. The preload applied to the roller bearings 3 and 4 changes according to the tightening force. In other words, it is pointed out that the work is troublesome because the tightening force must be finely adjusted during the assembly work. It is also pointed out that the axial dimension around the drive shaft support area is large.

The present invention was devised in view of such circumstances, and has a structure in which the fluctuation of the preload against the bearing does not occur without complicated adjustment at the time of assembly, and the axial dimension is reduced. The purpose is to do.

[0007]

[Means for Solving the Problems]

 In order to achieve such an object, the present invention provides a drive for rotatably supporting a drive shaft having a pinion gear at one end of a shaft and a drive shaft spline-fitted at the other end in a housing. The shaft bearing device has the following structure.

In the drive shaft bearing device of the present invention, an outer ring having two pairs of tapered raceway surfaces whose inner diameter increases from the center side toward both ends in the axial direction, and an outer ring facing each raceway surface in the radial direction. Two inner rings each having a tapered raceway surface that abuts each other in the axial direction, and a plurality of tapered rollers interposed between each raceway surface of both inner rings and each raceway surface of the outer ring, Moreover, the outer ring is fixed to the housing, the one inner ring is in contact with the drive shaft, and the other inner ring is in contact with the pinion gear.

[0009]

[Action]

 Since double-row tapered roller bearings are used, the axial dimension can be smaller than that of the conventional double-row tapered roller bearings. Also, when tightening to connect the drive shaft and the drive shaft, the double row conical roller bearing fixed to the housing when the drive shaft that is spline-fitted to the drive shaft is pressed toward the pinion gear side of the drive shaft. The two inner rings are compressed by the drive shaft and the pinion gear. However, since both inner rings are in contact with each other, the pressing force does not act more than necessary on the tapered roller groups in each row.

[0010]

【Example】

 1 and 2 show an embodiment of a bearing device for a drive shaft according to the present invention. In the figure, 21 is an aluminum housing of a differential device, 22 is a drive shaft, 23 is a drive shaft spline-fitted to the drive shaft 22, 24 is a tightening nut, 25 is a sealing device, 26 is a friction plate, and 27 is a dustproof cover. 28 is a shim, 29 is a bolt, and 30 is a double row tapered roller bearing.

The drive shaft 22 is integrally provided with a pinion gear 22a that meshes with a ring gear of a differential device (not shown) at one end of a stepped shaft portion 22b. A spline 22c and a screw portion 22d are formed on the other end of the shaft portion 22b. The shaft portion 22b has a stepped shape in which the diameter is reduced in four steps. A screw portion 22d is formed in the smallest diameter portion, a spline 22c is formed in the second smallest diameter portion, and a third smallest diameter portion is formed. The double row tapered roller bearing 30 is mounted on the portion and the portion having the largest diameter.

The double-row tapered roller bearing 30 faces the outer races 31 having two pairs of tapered raceways whose inner diameter increases from the center side toward both ends in the axial direction, and radially faces the respective raceways. Two inner rings 32, 33 each having a tapered raceway surface and abutting each other in the axial direction, and a plurality of inner rings 32, 33 interposed between each inner raceway 32, 33 and each outer race 31 raceway surface. It is provided with tapered rollers 34, 35 and cages 36, 37. The outer ring 31 is fixed to the housing 21 by bolts 29, and the inner ring 32 on one side has the friction plate 26 on the end face of the drive shaft 23. And the other inner ring 33 directly contacts the inner surface of the pinion gear 22a of the drive shaft 22.

The outer ring 31 is provided with a radially outward flange portion 31b at one end of a cylindrical portion 31a. The flange portion 31b has bolt insertion holes 31d for inserting the bolts 29 at several circumferential positions. The holes 31c are formed at equal intervals, and oil holes 31c penetrating in the radial direction are formed in the middle of the cylindrical portion 31a in the axial direction at equal intervals at several circumferential positions. The number of the oil holes 31c and the number of the bolt insertion holes 31d are the same, and the center angles formed by the adjacent oil holes 31c and the bolt insertion holes 31d are equal to each other. This is to ensure that the oil hole 31c of the outer ring 31 is always arranged at a predetermined position on the circumference no matter how the bolt insertion hole 31d is aligned with the female screw portion 21a of the housing 21. Is. Further, the cylindrical portion 31a of the outer ring 31 has a two-tiered inner diameter at the bearing mounting portion of the aluminum housing 21, so that the latter half (drive shaft) of the axial direction is more than the first half (pinion gear side). The outer diameter of the side) is set small. Further, the end face corner portion 31e on the rear half side of the cylindrical portion 31a and the corner portion 31f of the central circumferential groove portion are tapered so as not to scrape the inner peripheral surface of the housing 21 when the housing 21 made of aluminum is inserted. It is chamfered. The chamfer angle is preferably 17 ° or less.

The inner rings 32, 33 are set to have different inner diameters in accordance with the stepped shaft portion 22b in order to facilitate the mounting of the drive shaft 22 on the stepped shaft portion 22b. Adjacent rows of tapered rollers 34 and tapered rollers 35 all have the same outer shape and size, and have the same pitch circle diameter (PCD: Pitch Circle Diameter).

Next, a procedure for assembling the drive shaft 22 will be briefly described. First, the flange portion 31b of the outer ring 31 of the double-row tapered roller bearing 30 is fixed to the housing 21 with a plurality of bolts 29, and the drive shaft 22 is press-fitted inside the inner rings 32 and 33. A friction plate 26 is attached to the drive shaft 22 and a seal device 25 is attached to the housing 21, and the drive shaft 23 having a dustproof cover 27 is spline-fitted to the drive shaft 22. After that, the tightening nut 24 is screwed into the threaded portion 22d of the drive shaft 22 and tightened with a predetermined force. When this tightening is performed, the tip of the drive shaft 23 pushes the inner ring 32 on the front side toward the pinion gear 22a side via the friction plate 26, while the pinion gear 22a of the drive shaft 22 is pulled toward the front side. Eventually, both inner rings 32, 33 will be compressed by the drive shaft 23 and the pinion gear 22a. Even if the inner rings 32 and 33 are compressed in this way, the inner rings 32 and 33 are in contact with each other, so that the pressing force due to the tightening from these inner rings 32 and 33 is not transmitted to the tapered rollers 34 and 35 more than necessary. Therefore, the preload of the double-row tapered roller bearing 30 on the double-row tapered roller group does not fluctuate due to the tightening force, and is maintained at a predetermined value.

[0016]

[Effect of the device]

 As described above, in the present invention, since the drive shaft is supported by the housing using the double row tapered roller bearing, the supporting portion of the drive shaft can be made compact, which contributes to the weight reduction and the housing. It is possible to maintain a constant preload on the tapered roller group of the double-row tapered roller bearing without any complicated adjustment when the drive shaft is mounted on the.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an upper half of an embodiment of a drive shaft bearing device of the present invention.

FIG. 2 is a front view of the outer ring of FIG.

FIG. 3 is a vertical cross-sectional view of the upper half of a conventional drive shaft bearing device.

[Explanation of symbols]

 21 Housing 22 Drive Shaft 22a Pinion Gear 22b Shaft 23 Drive Shaft 29 Mounting Bolt 30 Double Row Tapered Roller Bearing 31 Outer Ring 32,33 Inner Ring 34,35 Tapered Roller

Claims (1)

[Scope of utility model registration request] 1. A drive shaft bearing device for rotatably supporting a drive shaft in which a pinion gear is provided at one end of a shaft portion and a drive shaft is spline-fitted at the other end side in a housing so that the drive shaft is rotatable. The outer ring has two pairs of tapered raceway surfaces that increase in size from the center side toward both ends in the axial direction, and the tapered raceway surfaces that individually oppose each of the raceway surfaces in the radial direction are individually provided to contact each other in the axial direction. Two inner rings that are in contact with each other, and a plurality of tapered rollers interposed between each raceway surface of both inner races and each raceway surface of the outer race, and the outer race is fixed to the housing,
The drive shaft bearing device, wherein the one inner ring is in contact with the drive shaft and the other inner ring is in contact with the pinion gear.