KR20170094861A

KR20170094861A - Cross Groove Constant Velocity Joint

Info

Publication number: KR20170094861A
Application number: KR1020160016106A
Authority: KR
Inventors: 김효진
Original assignee: 서한산업(주); 한국프랜지공업 주식회사
Priority date: 2016-02-12
Filing date: 2016-02-12
Publication date: 2017-08-22
Also published as: KR101874846B1

Abstract

The present invention relates to a cross groove constant velocity joint, comprising: an outer race having a plurality of grooves at the inner surface thereof; an inner race accommodated inside the outer race and having a plurality of inner side grooves at the outer surface thereof; a plurality of balls accommodated in a space within the outer side groove and the inner side groove for moving, and transferring power between the outer race and the inner race; a cage disposed within the outer race and the inner race, and having a window to prevent separation of the balls; a front cover and a rear cover to cover the front of the outer race and a rear wheel respectively; and a stepped protruding portion formed in an outer side groove of the outer race to limit a moving distance of the balls.

Description

Cross Groove Constant Velocity Joint [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cross groove constant velocity joint, and more particularly, to a cross groove constant velocity joint capable of preventing a cage and / or a cover from being damaged or broken by an impact applied to the cage and / .

Generally, a joint is for transmitting rotational power (torque) to a rotation shaft having different angles of rotation axis. In the case of a propulsion shaft having a small power transmission angle, a hook joint or a flexible joint is used. In the case of a drive shaft having a large power transmission angle A constant velocity joint is used.

Since the constant velocity joint can transmit power smoothly at constant speed even when the angle of intersection between the drive shaft and the driven shaft is large, it is mainly used for the drive shaft of the independent suspension type. The transmission side (inboard side) is a tripod type constant velocity joint, Ball type constant velocity joints are mainly used, and wheel type (outboard side) is fixed type ball type constant velocity joint.

A cross groove joint (CGJ), which is a kind of slide type ball type constant velocity joint, is applied only to the transmission side in the case of a drive shaft of a front engine front wheel drive type FF (FF) wheel drive type rear-wheel drive vehicle is applied to both the transmission side and the wheel side.

Generally, a cross groove joint comprises an outer ring having a plurality of grooves formed on an inner surface thereof and an inner ring having a plurality of grooves formed on the outer surface, wherein a ball is formed in a space between a groove of the outer ring and a groove of the inner ring And receives power and transmits the power. An example is United States Patent Publication US 2009/0087250.

That is, a ball is disposed between the groove of the outer ring and the groove of the inner ring to transmit power between the outer ring and the inner ring, and a cage for holding the ball between the outer ring and the inner ring is provided, . Further, a cover is provided on the front and rear of the outer ring.

However, in the case of the cross groove constant velocity joint having the above-described configuration, the ball can repeatedly impact the cage while moving within the window of the cage, and the ball can also impact the inside of the above-described cover . In this case, the strength of the cage may be lowered and the reliability of the durability may be affected. In addition, if an impact is applied to the cover, the cover may be damaged and / or broken, and furthermore, the cover may be detached, resulting in leakage of grease inside the joint.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a cross groove constant velocity joint capable of preventing a shock of a cage or a cover by the ball by restricting the movement distance of the ball between the outer ring and the inner ring have.

It is another object of the present invention to provide a cross groove constant velocity joint which can prevent damage or breakage of a cage or a cover by a ball and further prevent leakage of grease inside the cover.

It is an object of the present invention to provide an outer ring in which a plurality of outer grooves are formed on the inner surface, an inner ring accommodated in the outer ring and having a plurality of inner grooves formed on the outer surface thereof, A plurality of balls for transmitting a force between the outer ring and the inner ring, a cage disposed between the outer ring and the inner ring and having a window for preventing the balls from escaping, and a front cover surrounding the front and rear wheels of the outer ring, And a step portion provided on the outer groove of the outer ring for limiting the moving distance of the ball.

Here, the step is formed at the rear end of the outer groove, and the step is formed perpendicular to the locus of the outer groove.

At this time, in the case of primary machining, heat treatment and secondary machining to form the outer groove of the outer ring, the length of the secondary machining is relatively small compared to the length of the primary machining. For example, the length of the secondary machining corresponds to approximately 70 to 90% of the length of the primary machining.

Further, after the primary machining, the diameter (A) of the locus connecting the center of the balls with the ball in close contact with the outer groove of the outer ring and the diameter (B) of the locus connecting the center of the balls to the diameter

Can be satisfied.

Further, the relationship between the radius of curvature (C) of the outer groove and the radius of curvature (D) of the outer groove after the primary machining is

Can be satisfied.

According to the present invention as described above, the movement distance of the ball between the outer ring and the inner ring is limited, thereby preventing the cage or the cover from being impacted by the ball. Therefore, it is possible to prevent damage or breakage of the cage or the cover by the ball, and further, leakage of the grease inside the cover can be prevented.

1 is a perspective view of a cross groove constant velocity joint according to an embodiment of the present invention,
Fig. 2 is an exploded perspective view showing the internal structure in Fig. 1,
3 is a perspective view showing a state in which a ball and a cage are assembled between an outer ring and an inner ring,
4 is a perspective view of an outer ring having a step portion,
5 is a cross-sectional view of Fig. 4,
6 is a sectional view taken along line VI-VI in FIG. 5,
7 is a perspective view of an outer ring that has undergone primary machining before heat treatment,
8 is a cross-sectional view of Fig. 7,
Fig. 9 is a front view of the outer ring that has undergone the primary machining before the heat treatment,
10 is a front view of the outer ring after the second machining after the heat treatment.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings.

However, it is to be understood that the present invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. It is intended that the disclosure of the present invention be limited only by the terms of the appended claims.

Also, terms used herein are for the purpose of illustrating embodiments and are not intended to limit the invention.

In the present specification, the singular form includes plural forms unless otherwise specified in the specification. &Quot; comprises "and / or" comprising "used in the specification do not exclude the presence or addition of components other than the components mentioned.

Unless defined otherwise, all terms (including technical and scientific terms) used herein may be used in a sense commonly understood by one of ordinary skill in the art to which this invention belongs.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view of a cross groove constant velocity joint according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view showing an internal structure in FIG.

1 and 2, the cross groove constant velocity joint according to the present invention is used for power transmission of a propeller shaft of a four-wheel drive vehicle, and is used for plunging ). In addition, by replacing the universal joint in the state of high angle (more than 3 degrees) and high speed rotation (5000 rpm), noise vibration is prevented and smooth power transmission and constant speed are maintained.

1 and 2, the cross groove constant velocity joint 1 includes an outer ring 10 having a plurality of outer grooves 11 and 12 formed on an inner surface thereof, An inner ring 20 in which inner grooves 21 and 22 of the outer ring 10 are formed and a space between the inner grooves 21 and 22 of the inner ring 20 and the outer grooves 11 and 12 of the outer ring 10 A plurality of balls 30 which move and transmit a force between the outer ring 10 and the inner ring 20 and a plurality of balls 30 which are disposed between the inner ring 20 and the outer ring 10, Cage < / RTI >

The end of the input shaft 100 is connected to the inner ring 20. An insertion hole 23 is formed in the inner ring 20 and a serration part 24 are coupled to the serration portion provided at the end portion of the input shaft 100. In this configuration, when power is transmitted to the input shaft 100, power is transmitted to the output shaft (not shown) via the inner ring 20, the ball 30 and the outer ring 10 to be described later, .

A plurality of inner grooves 21 and 22 are formed on the outer surface of the inner ring 20 and a plurality of outer grooves 11 and 12 are formed on the inner side of the outer ring 10. The inner grooves 21, A plurality of balls 30 are accommodated in a space between the inner grooves 22 and the outer grooves 11, The inner grooves 21 and 22 and the outer grooves 11 and 12 may have various shapes, for example, circular, elliptical, or gothic shapes.

The number of the inner grooves 21 and 22 and the outer grooves 11 and 12 can be appropriately adjusted in accordance with the number of the balls 30 and is not limited to a specific value in the present specification.

3 is a perspective view showing a state where a ball and a cage are assembled between the outer ring and the inner ring.

2 and 3, a cage 40 is disposed between the outer ring 10 and the inner ring 20, and the ball 30 is received in the cage 40, A window 41 is provided. That is, the ball 30 is accommodated in the space between the inner grooves 21 and 22 and the outer grooves 11 and 12 and is further constrained by the window 41 of the cage 40 do.

More specifically, the one outer grooves 11 and 12 and the one inner groove 21 and 22 are arranged to correspond to each other in a radial manner about the input shaft 100, and the outer grooves 11 and 12 Between the outer grooves 11 and 12 and the inner grooves 21 and 22 while the ball 30 is positioned in the window 41 of the cage 40 between the inner grooves 21 and 22, do.

The outer ring 10 is provided with a fastening hole 15 through which a fastening member such as a bolt is inserted. The front cover 110 and the rear cover 120 are formed on the front and rear sides of the outer ring 10 while the inner ring 20, the ball 30 and the cage 40 are accommodated in the outer ring 10, . The front cover 110 on the front side is provided with a boot 130 for preventing leakage of grease.

A first band 141 for fixing the boot 130 to the outer circumferential surface of the input shaft 100 and a second band 142 for fixing the boot 130 to the outer circumferential surface of the tube formed in the front cover 110, . Meanwhile, the rear cover 120 is connected to an output shaft (not shown).

1 to 3, the ball 30 contacts the window 41 of the cage 40 and the rear cover 120 and is restrained in the direction of the input shaft 100. At this time, the ball 30 can repeatedly impact the cage 40 or the rear cover 120 when the cross groove constant velocity joint is driven. The impact applied to the cage 40 may reduce the strength of the cage 40 and affect the reliability of durability. In addition, the impact applied to the rear cover 120 may cause damage and / or breakage of the rear cover 120, and may cause a deviation of the rear cover 120, Leakage can be generated.

Hereinafter, a structure of a cross groove constant velocity joint according to the present invention for solving the above problems will be described in detail.

4 is a perspective view of the outer ring 10 according to the present embodiment.

Referring to FIG. 4, the outer ring 10 may include a step portion 13 formed on the outer groove 11 to limit the moving distance of the ball 30. [0034] Referring to FIG. The ball 30 moves along the outer groove 11 of the outer ring 10 so that when the outer groove 11 is provided with the step portion 13, The movement distance of the ball 30 is limited by the interference of the step portion 13.

At this time, the step portion 13 may be formed at the rear end of the outer groove 11 as shown in the figure. The stepped portion 13 is formed at the rear end of the outer groove 11 so that the ball 30 is prevented from exerting the trajectory of the outer groove 11 and impacting the aforementioned rear cover 120 have.

On the other hand, Fig. 5 is a side sectional view of Fig.

5, the step portion 13 is formed at the rear end of the outer groove 11 (left rear in the drawing), and the outer groove 11 is formed in the axial direction of the input shaft 100 As shown in Fig. At this time, the step portion 13 may be formed to be substantially perpendicular to the locus of the outer groove 11.

It is easy to restrict the movement of the ball 30 moving along the outer groove 11 when the step portion 13 is formed substantially perpendicular to the locus of the outer groove 11. [ In FIG. 5, "F" shows a processing distance of the outer groove 11 for forming the step portion 13, and will be described later.

6 is a cross-sectional view taken along the line VI-VI in FIG. 5. Referring to FIG. 6, at one side of the step portion 13 forming the outer groove 11, at least one rounding corner R1, R2) may be formed.

For example, if the front upper corner V1 and the front lower corner V2 of the step 13 are vertically formed as shown by the hori- zontal lines in the figure, the ball 30 is formed vertically The ball 30 may be damaged or damaged.

Therefore, when forming the step portion 13, at least one rounding corner R1 and R2 may be formed on one side of the step portion 13 forming the outer groove 11. [

Next, a processing procedure of the outer race 10 having the step portion 13 will be described.

In the process of forming and machining the outer groove 11 of the outer ring 10 in the cross groove constant velocity joint according to the present invention, the first machining, the heat treatment and the second machining are performed. Hereinafter, in order to distinguish the outer grooves after the first machining from the outer grooves 11 after the second machining, reference numerals are denoted by 11A.

Fig. 7 shows the outer race 10 in a state where the primary machining is completed, and Fig. 8 shows a sectional view of the above-mentioned Fig. 7 and 8, an outer groove 11A is formed on the inner side of the outer ring 10 by a method such as hard milling or grinding in the inner side of the outer ring 10, as shown in FIGS.

After the above-described primary machining, heat treatment is performed. After the heat treatment, secondary machining is performed on the outer groove 11 by hard milling or grinding. The second machining corresponds to a process of forming the step portion 13 through additional machining on the outer groove 11 after the first machining. The step portion 13 is formed by the above- Lt; / RTI >

Referring to FIGS. 5 and 8, the distance between the first machining and the second machining before and after the heat treatment is as follows. The length F of the secondary machining (see FIG. 5) (E) (see Fig. 8).

That is, in the case of the primary machining, the machining is performed along the trajectory of the outer groove 11A. In the case of the secondary machining, the machining is performed while leaving the step portion 13 at the end of the outer groove 11, The length F of the secondary machining becomes relatively small as compared with the length E of the primary machining. For example, the length F of the secondary machining may correspond to approximately 70 to 90% of the length E of the primary machining.

FIG. 9 is a front view of an outer ring that has undergone a primary machining before heat treatment, and FIG. 10 is a front view of an outer ring that has undergone secondary machining after heat treatment.

9 and 10, the locus connecting the centers of the balls 30 with the balls 30 in close contact with the outer grooves 11 and 11A of the outer ring 10 has a circular shape , And the circular shape has diameters corresponding to 'A' and 'B' in FIGS. 9 and 10, respectively.

9) of the locus connecting the centers of the balls 30 in a state where the balls 30 are in close contact with the outer grooves 11A of the outer ring 10 after the primary machining, The relationship between the diameter B of the locus connecting the center of the balls 30 (see FIG. 10) with the ball 30 in close contact with the outer groove 11 of the outer ring 10 after the secondary machining Can be determined so as to satisfy the following equation (1).

That is, the diameter B of the locus connecting the centers of the balls 30 after the secondary machining is relatively more than the diameter A of the loci connecting the centers of the balls 30 after the primary machining And the relational expression of the diameter may be defined by the above-mentioned equation (1).

9 and 10, that is, the curvature radii of the outer grooves 11 after the first machining and the second machining after the heat treatment are different from each other. For example, when the radius of curvature of the outer groove 11A is defined as 'C' and the radius of curvature of the outer groove 11 after the secondary processing is defined as 'D' The relation between 'C' and 'D' can satisfy the following expression (2).

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be appreciated that one embodiment is possible.

Accordingly, the true scope of the present invention should be determined by the technical idea of the claims.

10 ... Outer ring
11 ... outer groove
13 ... jaw
20 ... inner ring
21 ... inner groove
30 ... balls
40 ... cage
41 ... window
120 ... rear cover
130 ... front cover

Claims

An outer ring having a plurality of outer grooves formed on an inner surface thereof;
An inner ring accommodated in the outer ring and having a plurality of inner grooves formed on an outer surface thereof;
A plurality of balls received and moved in a space between the outer groove and the inner groove and transmitting a force between the outer ring and the inner ring;
A cage disposed between the outer ring and the inner ring, the cage having a window for preventing the balls from escaping; And
And a front cover and a rear cover which respectively surround the front and rear wheels of the outer ring,
And a step portion formed on an outer groove of the outer ring to limit the moving distance of the ball.

The method according to claim 1,
And the step portion is formed at a rear end portion of the outer groove.

The method according to claim 1,
And the step portion is formed perpendicular to the locus of the outer groove.

The method according to claim 1,
Wherein at least one rounding corner is formed on one side of the step portion forming the outer groove.

The method according to claim 1,
Wherein the length of the secondary machining is relatively small in comparison with the length of the primary machining in the case of primary machining, heat treatment and secondary machining to form the outer groove of the outer ring.

6. The method of claim 5,
Wherein the length of the secondary machining corresponds to approximately 70 to 90% of the length of the primary machining.

6. The method of claim 5,
(A) of a locus connecting the centers of the balls in a state in which the balls are in close contact with an outer groove of the outer ring after the primary machining, and a diameter The relationship between the diameter (B) of the locus connecting the centers of the balls

Of the cross groove constant velocity joint.

6. The method of claim 5,
The relationship between the radius of curvature (C) of the outer groove and the radius of curvature (D) of the outer groove after the primary machining is

Of the cross groove constant velocity joint.