JP2001165181A - Constant velocity universal joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a constant speed universal joint capable of increasing torque transmission force while stable tightening force can be obtained. SOLUTION: A bolt 15 inserted in an axial direction through an outer ring 1 is screw engaged with a screw hole 16 formed in a flange 9a of one shaft 9, by tightening of the bolt 15, a flange 8 of an end cap butt to one side face of the outer ring 1 and a flange 11a of a boots adaptor 11 butt to the other side face of the outer ring 1 are integrally tightened. The flange 8a of the end cap 8 and the flange 11a of the boots adaptor 11 are tilted relating to the side face of the outer ring 1, stabilization of tightening force is attained so that it influences to a location in an external diametric side from the periphery of a bolt insertion position when the bolt 15 is tightened, an increase of torque transmission force is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constant velocity universal joint used mainly for transmitting power to a propeller shaft.

[0002]

2. Description of the Related Art FIG. 6 shows a conventional constant velocity universal joint for a propeller shaft. This constant velocity universal joint incorporates a torque transmitting ball 24 between a track groove 21 formed on an inner diameter surface of an outer ring 20 and a track groove 23 formed on an outer diameter surface of an inner ring 22, and one side of the outer ring 20. End cap 25 and outer ring 20 provided on the side
Flanges 2 which abut against the side surface of the outer ring 20 at the outer diameter portions of the cylindrical boot adapters 26 provided on the other side.
7 and 28, which are passed through the flanges 27 and 28 and the outer ring 20 in the axial direction, and are tightened by bolts 31 screwed into the flanges 30 of the first shaft 29.
The end cap 25, the boot adapter 26, and the flange 30 of the first shaft 29 are connected in the axial direction.

A large-diameter end of a boot 32 having a U-shaped cross section is connected to an end of a boot adapter 26, and the boot 3
The second small diameter end is connected to a second shaft 33 connected to the inner ring 22.

In the above constant velocity universal joint, the end cap 25 provided on both sides of the outer race 20 and the boot adapter 26 and the boot 32 prevent the grease filled in the joint from leaking to the outside. The flanges 27 and 28 provided on each of the boot adapters 26 are required to be attached in close contact with the side surfaces of the outer race 20.

Therefore, in the conventional constant velocity universal joint, each of the end caps 25 and the flanges 27 and 28 provided on the outer diameter of the boot adapter 26 is a plane orthogonal to the center axis.

[0006]

When the outer ring 20 and the inner ring 22 take an operating angle to transmit a torque, the end cap 25 and the boot adapter 26 need to be mounted on the ball 2.
In order to prevent the ball 4 from slipping out of the track groove 21 of the outer ring 20, the ball 2
Deformation by the collision of 4. For this reason, the end cap 25 and the boot adapter 26 are subjected to heat treatment after machining to increase the hardness, and the heat treatment causes deformation of the flanges 27 and 28, making it impossible to secure flatness.

In this case, the fastening force of the bolt 31 varies, and in order to suppress the variation, it is necessary to use a high-tensile bolt or a large-sized bolt for tightening, which is disadvantageous in cost. At the same time, there arises a problem that the weight of the constant velocity universal joint increases.

Further, the tightening force of the bolt 31 can be secured only in the vicinity of the bolt bearing surface, and the torque transmitting force when transmitting the torque between the first shaft 29 and the second shaft 33 can be secured. The power point is the distance from the joint center to the fastening position, and a large torque transmission force cannot be obtained.

An object of the present invention is to provide a constant velocity universal joint capable of obtaining a stable tightening force and stabilizing a torque transmitting force.

[0010]

In order to solve the above-mentioned problems, the present invention provides an outer ring having a track groove formed on an inner diameter surface, an inner ring having a track groove formed on an outer diameter surface, and an outer ring track. A ball for torque transmission incorporated between the groove and the inner ring track groove, an end cap having a flange abutting on one side of the outer ring, and a second end having a flange abutting against the flange of the end cap. A first shaft, a second shaft connected to the inner ring, a cylindrical boot adapter having an end having a flange abutting against the other side surface of the outer ring, and a large-diameter end connected to the boot adapter. And
A boot having a small-diameter end connected to the second shaft, the first shaft flange and the first shaft flange being fixed to one side surface of the outer ring by fastening means penetrating the outer ring in the axial direction. A constant velocity universal joint having a flange of a boot adapter fixed to the other side thereof, wherein at least one of the flange of the end cap, the flange provided on the first shaft, and the flange formed on the boot adapter is connected to the side surface of the outer race. Therefore, a configuration inclined with respect to was adopted.

As described above, at least one of the flange of the end cap, the flange provided on the first shaft, and the flange formed on the boot adapter, which is fastened to both side surfaces of the outer ring, is attached to the side surface of the outer ring. By inclining, the inclined flange is elastically deformed at the time of fastening and follows the side surface of the outer ring, and the fastening force extends from the periphery of the fastening position to the outer diameter side, and a stable fastening force can be obtained.

Further, since the center of the tightening range of the inclined flange is deviated to the outer diameter side from the fastening position, the point of force at the time of torque transmission is increased, and the torque transmission force can be increased.

Here, if the inclination angle of the inclined flange with respect to the outer ring side surface becomes unnecessarily large, the deformation of the flange is large, and a strain exceeding the yield point occurs in the flange. Therefore, the inclination angle is set within 2 °. Is good.

The track grooves formed in the outer ring and the track grooves formed in the inner ring are respectively inclined with respect to the center line of the outer ring and the center line of the inner ring, and the track grooves of the outer ring and the inner ring are inclined in opposite directions. Thus, since the torque transmitting ball is always arranged at the intersection of the outer ring track groove and the inner ring track groove, a constant velocity universal joint without play can be obtained.

In the constant velocity universal joint according to the present invention, when the outer ring has a cylindrical portion on the outer diameter portion of the flange of the first shaft, the outer ring and the first shaft are coaxial. The first and second axes can be easily centered with respect to each other.

Here, a small hole for venting air is preferably formed in the end cap. In addition, by providing a cylindrical portion which is press-fitted into one end of the outer diameter surface of the outer ring at the flange outer diameter edge of the end cap, the outer ring and the end cap can be held in an assembled state by press-fitting the cylindrical portion into the outer ring. Therefore, assembly of the constant velocity universal joint can be facilitated. In this case, by forming a fitting surface having a smaller diameter than the outer ring outer diameter surface at one end of the outer ring outer diameter surface, and providing a step corresponding to the thickness of the cylindrical portion between the fitting surface and the outer ring outer diameter surface. Since the cylindrical portion provided on the flange of the first shaft can be fitted with a spigot on the outer diameter surface of the outer race, the first shaft and the outer race can be centered with high accuracy.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a plurality of track grooves 2 reaching both side surfaces are formed on the inner diameter surface of the outer ring 1. As shown in FIG. 4, each track groove 2 is inclined with respect to the center line of the outer race 1, and the adjacent track grooves 2 are inclined in opposite directions.

A plurality of track grooves 4 are formed on the outer diameter surface of the inner ring 3 provided inside the outer ring 1. Each track groove 4 is inclined in the opposite direction to the outer ring track groove 2, and a ball 5 for transmitting torque is incorporated between the inner ring track groove 4 and the outer ring track groove 2. The ball 5 is housed in a pocket 7 of a cage 6 incorporated between the outer ring 1 and the inner ring 3.

An end cap 8 is provided on one side of the outer ring 1,
A first shaft 9 is provided, and on the other side, a second shaft 10 connected to the inner ring 3 and a boot adapter 11 are provided.

The end cap 8 has a flange 8a which abuts on one side surface of the outer race 1, and a cylindrical portion 8b is provided on an outer diameter edge of the flange 8a. The end cap 8 is provided with a small hole 8c for venting air on the axis and a spherical recess 8d at a position facing the outer ring track groove 2 for preventing the ball 5 from coming out of the track groove 2. Have been.

As shown in FIG. 2, the flange 8a of the end cap 8 is inclined with respect to the side surface of the outer race 1. The cylindrical portion 8b of the end cap 8 can be press-fit into a fitting surface 1a provided at one end of the outer diameter surface of the outer race 1.

The fitting surface 1a has a smaller diameter than the outer ring outer diameter surface 1b, and a step slightly larger than the thickness of the cylindrical portion 8b is formed between the outer ring outer diameter surface 1b and the fitting surface 1a.

As shown in FIG. 1, the first shaft 9 has at its end a flange 9a which abuts against a flange 8a of the end cap 8, and a recess 9b in which the end cap 8 is received. And a cylindrical portion 9c in which the outer diameter surface of the outer ring 1 is fitted with a spigot.

The boot adapter 11 has a cylindrical shape, and at one end thereof is provided a flange 11a which abuts on the other side surface of the outer ring 1. The outer diameter edge of the flange 11a is provided at the other end of the outer diameter surface of the outer ring 1. The press-fitted cylindrical portion 11b is provided. The boot adapter 11 has a spherical recess 11c at a position facing the outer ring track groove 2 to prevent the ball 5 from coming off.

A large-diameter end of a boot 12 having a U-shaped cross section is connected to the boot adapter 11, and a small-diameter end of the boot 12 is fixed to the second shaft 10 by tightening a boot band 13. The boot 12 and the end cap 8 prevent the grease filled in the constant velocity universal joint from leaking to the outside.

As shown in FIG. 2, a flange 11a provided on the boot adapter 11 is inclined with respect to the other side surface of the outer race 1. A flange 11a of the boot adapter 11,
A bolt insertion hole 14 is formed in each of the outer ring 1 and the flange 8 a of the end cap 8, and a bolt 15 inserted into the bolt insertion hole 14 is connected to the flange 9 of the first shaft 9.
The outer ring 1, the flange 8 a of the end cap 8, the flange 9 a of the first shaft 9, and the flange 11 a of the boot adapter 11 are integrally fastened by screwing and tightening the screw holes 16 formed in a.

At this time, the flange 8 of the end cap 8
a and the flange 11a of the boot adapter 11 are the outer ring 1
1, the flange 8 a of the end cap 8 and the flange 11 a of the boot adapter 11 are elastically deformed by the tightening of the bolt 15.
As shown in FIG.

As described above, since the flange 8a of the end cap 8 and the flange 11a of the boot adapter 11 are elastically deformed by the tightening of the bolt 15, the bolt 15
As shown by hatching in FIG. 5 (I), the tightening force extends from the periphery of the bolt insertion hole 14 to a portion on the outer diameter side of the bolt insertion hole 14, and each flange 8a, 11a has an outer diameter. Since the parts are fastened, a stable tightening force can be obtained.

In general, the constant velocity universal joint includes the first shaft 9 and the second shaft 9.
When a torque is transmitted between the shafts 10, the torque transmission force T is represented by T = bolt tightening force × bolt number × force point.

Here, the point of force refers to the distance from the center of the constant velocity universal joint to the center by tightening the bolt 15. FIG.
As shown in FIG. 5, when the flanges 27 and 28 are parallel to the side surface of the outer ring 20, the flanges 27 and 28 are tightened in a range corresponding to the bolt head as shown in FIG. Coincides with the center of the bolt 31,
The point of force is 1 of the pitch circle (PCD) passing through the center of the bolt 31.
/ 2.

As in the embodiment, the end caps 8 and
And the flanges 8a, 11a of the boot adapter 11 are removed.
When tilted with respect to the side surface of the wheel 1, as shown in FIG.
Thus, the center O of the tightening range by tightening the bolt 15₁
Is the center O of the bolt insertion hole 14 ₀Only the distance α to the outer diameter side
Due to the offset, the power point becomes large, and as a result, torque transmission
The power can be stabilized.

The flanges 8a and 11a are elastically deformed in the fastened state, and the restoring force acts in the direction in which the bolt 15 is bent, so that the bolt 15 can be prevented from loosening.

Here, the end cap 8 and the boot adapter 11 shown in FIG. 2 are formed by press-forming a steel plate, and after the press-forming, are quenched to increase the hardness. If the inclination angle θ of the flange 8a provided on the end cap 8 and the flange 11a formed on the boot adapter 11 with respect to the side surface of the outer ring 1 becomes unnecessarily large, the flanges 8a and 11a exceed the yield point at the time of fastening by tightening the bolt 15. The inclination angle θ is set within the yield point of the steel, that is, the thickness, the outer diameter, and the thickness of the end cap 8 and the boot adapter 11 in order to stop the deformation within the elastic range.
Alternatively, although it depends on the bolt diameter and the bolt PCD, there is no problem if the proportion is within 2 ° from the current proportion of the propeller shaft.

As in the embodiment, the outer ring 1 is fitted in the cylindrical portion 9c by providing the flange 9a of the first shaft 9 with the cylindrical portion 9c in which one end of the outer ring 1 is fitted with a spigot. By doing so, the outer race 1 and the first shaft 9 are centered, and the first shaft 9 and the second shaft 10 can be precisely centered.

In the embodiment shown in FIG. 2, the flange 8a of the end cap 8 and the flange 11a of the boot adapter 11 are inclined with respect to the side surface of the outer race 1. However, as shown in FIG. 8a and the flange 11a of the boot adapter 11 are parallel surfaces parallel to the side surfaces of the outer race 1, and the flange 9a provided on the first shaft 9
The inner surface 9d of a may be inclined with respect to the side surface of the outer ring 1.

In this case, when the outer ring 1, the flange 8a of the end cap 8, the flange 11a of the boot adapter 11, and the flange 9a of the first shaft 9 are fastened by tightening the bolt 15, the flange 9a of the first shaft 9 becomes elastic. The flange 8a of the end cap 8 is
4 and the outer diameter portion thereof are tightened, and the center of the tightening range is shifted toward the outer diameter side from the center of the bolt insertion hole 14, and as in the constant velocity universal joint shown in FIG. Tightening force can be obtained, and the torque transmission force can be stabilized.

The inclination angle of the inner surface 9d of the flange 9a with respect to the side surface of the outer race is limited to the deformation range within the yield point of steel, that is, in the elastic range.
Depends on outer diameter, bolt diameter, bolt PCD, 2 ° from current propeller shaft proportions
There is no problem if it is within.

[0038]

As described above, according to the present invention, at least one of the end cap flange, the boot adapter flange, and the first shaft flange is inclined with respect to the side surface of the outer race. The fastening force of the fastening means extends to the portion on the outer diameter side of the fastening position, and a stable fastening force can be obtained.

Further, since the center of the tightening range by the tightening of the tightening means is displaced toward the outer diameter side from the tightening position, the power point at the time of torque transmission is increased, and the torque transmitting force can be stabilized.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional front view of a constant velocity universal joint according to the present invention.

FIG. 2 is a longitudinal sectional front view showing a state before fastening the constant velocity universal joint shown in FIG. 1;

FIG. 3 is a longitudinal sectional front view showing another example of the constant velocity universal joint according to the present invention before fastening.

FIG. 4 (I) is a sectional view showing an outer race of a constant velocity universal joint,
(II) is a side view showing a part of the outer ring

FIG. 5 (I) is a schematic view showing the range of the tightening force when the inclined flange is fastened, and (II) is the tightening force when the flange parallel to the side surface of the outer ring is fastened. Schematic showing coverage

FIG. 6 is a sectional view showing a conventional constant velocity universal joint.

[Explanation of symbols]

 Reference Signs List 1 outer ring 1a fitting surface 2 track groove 3 inner ring 4 track groove 5 ball 8 end cap 8a flange 8b cylindrical portion 8c small hole 9 first shaft 9a flange 9c cylindrical portion 9d inner surface 10 second shaft 11 boot adapter 11a flange 11b Cylindrical part 12 Boot 14 Bolt insertion hole 15 Bolt 16 Screw hole

Claims (6)

[Claims] 1. An outer ring having a track groove formed on an inner diameter surface, an inner ring having a track groove formed on an outer diameter surface, a torque transmitting ball incorporated between the outer ring track groove and the inner ring track groove, and an outer ring. An end cap having a flange abutting on one side surface thereof, a first shaft having a flange abutting against the flange of the end cap at an end, a second shaft connected to the inner ring, A cylindrical boot adapter having a flange at its end abutting against the other side surface of the outer ring, and a boot having a large-diameter end connected to the boot adapter and a small-diameter end connected to the second shaft. The first ring is formed on one side surface of the outer ring by fastening means penetrating the outer ring in the axial direction.
In the constant velocity universal joint in which the flange of the shaft and the flange of the first shaft are fixed, and the flange of the boot adapter is fixed to the other side surface, the flange of the end cap, the flange provided on the first shaft, and the boot adapter A constant velocity universal joint wherein at least one of the formed flanges is inclined with respect to the side surface of the outer race. 2. The constant velocity universal joint according to claim 1, wherein the inclination angle of the inclined flange with respect to the outer ring side surface is within 2 °. 3. The constant velocity universal joint according to claim 1, wherein the outer race track groove and the inner race track groove are inclined in opposite directions. 4. The cylinder according to claim 1, wherein an outer diameter of the flange of the first shaft is provided with a cylindrical portion in which one end of the outer ring is fitted with a spigot. Constant velocity universal joint. 5. The end cap according to claim 1, wherein the end cap has a small hole for venting air, and a cylindrical portion fitted to an outer diameter surface of the outer ring is formed at an outer diameter edge. The constant velocity universal joint according to any of the above. 6. The method according to claim 5, wherein a fitting surface having a diameter smaller than the outer diameter surface of the outer ring is formed at one end of the outer diameter surface of the outer ring, and the cylindrical portion of the end cap is press-fitted into the fitting surface. Speed universal joint.