JP6711747B2 - Fixed type constant velocity universal joint - Google Patents

Description

The present invention relates to a fixed type constant velocity universal joint.

A constant velocity universal joint that constitutes a power transmission system for automobiles and various industrial machines connects two shafts, a drive side and a driven side, so that torque can be transmitted. can do. Constant velocity universal joints are roughly classified into fixed type constant velocity universal joints that allow only angular displacement and sliding type constant velocity universal joints that allow both angular displacement and axial displacement. For drive shafts that transmit power to the drive wheels, sliding constant velocity universal joints are used on the differential side (inboard side), and fixed type constant velocity universal joints are used on the drive wheel side (outboard side). It

As a fixed type constant velocity universal joint, a Rzeppa type constant velocity universal joint and an undercut free type constant velocity universal joint are known. In recent years, there is also an 8-ball type Rzeppa constant velocity universal joint that is both lightweight and compact, and various fixed type constant velocity universal joints are used according to the purpose.

In order to achieve a higher load capacity than the fixed type constant velocity universal joint described above, a fixed type constant velocity universal joint in which two adjacent paired track grooves are formed on planes parallel to each other has been proposed ( Patent Document 1).

Japanese Patent No. 496758

In order to reduce the weight and size of the fixed type constant velocity universal joint, it is necessary to secure the strength of each component, especially the inner joint member and the cage. For the Rzeppa type constant velocity universal joint and the undercut free type constant velocity universal joint, at the time of assembly, make an angle (installation angle) larger than the operating area to insert the ball into the track groove, and at that angle It is necessary to set the circumferential length of the cage pocket so that the pockets do not interfere with each other. Since the circumferential length of the pocket of the cage does not change even if it is made compact, the pillar portion of the cage becomes thin, and it becomes difficult to secure the strength of the cage. Further, in order to reduce the size, in order to keep the contact surface pressure between the ball and the track groove below a certain value, it is necessary to set the pitch circle diameter PCD of the ball small and set the ball diameter large. As a result, the inner joint member Since the thickness of the end portion of the spherical outer peripheral surface becomes thin, it becomes difficult to secure the strength of the inner joint member.

As a means for solving the problem, in the constant velocity universal joint of Patent Document 1, two adjacent track grooves forming a pair are formed in a plane shape parallel to each other, so that two adjacent balls are placed in one pocket of the cage. The cage can be made thicker by arranging the cage, and the wall thickness of the end portion of the spherical outer peripheral surface of the inner joint member is secured to improve the strength.

However, in the shape in which two adjacent paired track grooves are formed on planes parallel to each other as in the constant velocity universal joint of Patent Document 1, a pair of balls on one side (ball number Since the torque can be transmitted only in half, the contact surface pressure between the ball and the track groove becomes large, and the durability is reduced. The present invention focuses on this problem.

In view of the above problems, it is an object of the present invention to provide a lightweight and compact fixed type constant velocity universal joint that can secure a large load capacity from a normal angle range to a high angle range.

As a result of various studies to achieve the above-mentioned object, the present inventor has arranged the track groove portion on a plane including the axis of the joint in the normal angular range, and the high angular range is parallel to each other at intervals. The present invention was accomplished by arranging a pair of adjacent track groove portions on a plane and smoothly connecting both track groove portions.

As a technical means for achieving the above-mentioned object, the present invention provides an outer joint member having a plurality of track grooves extending in the longitudinal direction on a spherical inner peripheral surface and having an opening side and an inner side separated from each other in the axial direction. An inner joint member formed with a plurality of track grooves extending in the longitudinal direction on the spherical outer peripheral surface so as to face the track grooves of the outer joint member, and a torque transmission ball incorporated between the opposed track grooves, and the torque. A fixed type constant velocity universal joint which holds a transmission ball and comprises a spherical outer peripheral surface of the outer joint member and a cage guided by the spherical outer peripheral surface of the inner joint member, wherein a track groove of the outer joint member (2). (7) is composed of the first two pairs of track grooves (7A ₁ , 7B ₁ , 7A ₃ , 7B ₃ ) and the second two pairs of track grooves (7A ₂ , 7B ₂ , 7A ₄ , 7B ₄ ). The first two pairs of track grooves (7A ₁ , 7B ₁ , 7A ₃ , 7B ₃ ) are spaced on both sides of the first plane (PT1) including the joint axis (NN). And are formed symmetrically with respect to the first plane (PT1), and the second two pairs of track grooves (7A ₂ , 7B ₂ , 7A ₄ , 7B ₄ ) respectively have , A second plane (PT2) that includes the joint axis (NN) and is orthogonal to the first plane (PT1) and is spaced apart from the second plane (PT2). The track grooves (7) are formed symmetrically with respect to each other, and the track grooves (7) respectively include a normal angle range track groove portion (7f), a high angle range track groove portion (7h), and both track groove portions (7f, 7h). And a track center line of the high-angle region track groove portion (7h) of the first two pairs of track grooves (7A ₁ , 7B ₁ , 7A ₃ , 7B ₃ ). Xh)-containing planes (B1, B1′) are formed in parallel to the first plane (PT1), and the second two pairs of track grooves (7A ₂ , 7B ₂ , 7A ₄ , 7B ₄ ), the plane (B2, B2′) including the track centerline (Xh) of the high-angle track groove portion (7h) is formed parallel to the second plane (PT2), and two pairs of the track grooves _{(7A 1, 7B 1, 7A} 3, 7B 3) the common angle region plane including the raceway center line (Xf) of the track groove portions (7f) of the (, A1 A1 ') of the said joint The first plane (PT1) centering on the axis (NN) Is formed at an angle with respect to the track center line (Xf) of the track groove portion (7f) of the common angle zone of the second two pairs of track grooves (7A ₂ , 7B ₂ , 7A ₄ , 7B ₄ ). The including plane (A2, A2') is formed at an angle with respect to the second plane (PT2) about the axis (NN) of the joint, and at least the common angle range of the outer joint member. The track groove portion (7f) has a curved orbital center line (Xf), the center of curvature (O1) of which is axially offset with respect to the joint center (O), and the inner joint member (3) The track center line (Y) of the track groove (9) has the working center of 0°, and includes the joint center (O). It is characterized in that it is formed in mirror image symmetry with the track center line (X) of the track groove (7) forming a pair with the member (2). Here, in the present specification and claims, the track center line of the track groove means the locus of the center of the torque transfer ball when the torque transfer ball moves along the track groove.

With the above configuration, it is possible to realize a lightweight and compact fixed type constant velocity universal joint that can secure a large load capacity from the normal angle range to the high angle range.

Specifically, the high-angle region track groove portion (7h) of the outer joint member (7) also has a curved track center line (Xh), and its center of curvature (O3) is relative to the joint center (O). Preferably axially offset. As a result, the orbital centerlines of the normal angular range track groove portion (7f), the high angular range track groove portion (7h), and the transition track groove portion (7t) have a smooth shape, which is advantageous in terms of processing.

The curvature center (O1) of the track center line (Xf) of the normal angle range track groove portion (7f) and the curvature center (O3) of the track center line (Xh) of the high angle range track groove portion (7h) of the above outer joint member are It is preferable that each is offset to the inner side of the outer joint member with respect to the joint center (O). As a result, the axial force of the ball due to the wedge angle between the track grooves acts on the inner side serving as the base of the outer joint member, so that the strength is stabilized.

The axial offset amount of the center of curvature (O1) of the track centerline (Xf) of the track groove portion (7f) in the normal angle range and the center of curvature (Xh) of the track centerline (Xh) of the track groove portion (7h) of the high angle range ( It is preferable that the axial offset amounts of O3) are equal. In this case, the orbital center lines of the normal angular range track groove portion (7f), the high angular range track groove portion (7h), and the transition track groove portion (7t) have a smoother shape, which is more advantageous in terms of processing.

The angle (β1) between the centers of the paired track grooves (7A ₁ , 7B ₁ , 7A ₂ , 7B ₂ , 7A ₃ , 7B ₃ , 7A ₄ , 7B ₄ ) is the track grooves (7B) adjacent to each other. _{1, 7A 2, 7B 2,} 7A 3, 7B 3, 7A 4, 7B 4, is made smaller than the angle (.beta.2) between the centers of 7A _1), accommodated in the pocket of the cage the two balls Therefore, the configuration is suitable.

The cage (5) described above accommodates two balls assembled in a pair of track grooves (7A ₁ , 7B ₁ , 7A ₂ , 7B ₂ , 7A ₃ , 7B ₃ , 7A ₄ , 7B ₄ ). By having the pocket, the width of the column portion of the cage can be increased and the strength can be improved.

According to the present invention, it is possible to realize a lightweight and compact fixed type constant velocity universal joint that can secure a large load capacity from a normal angle range to a high angle range.

The fixed type constant velocity universal joint which concerns on one Embodiment of this invention is shown, (a) figure is a longitudinal cross-sectional view along the A1-A1 line of FIG. 2(a), (b) figure is FIG. It is sectional drawing which followed the B1-B1 line of a). 1A is a right side view of FIG. 1A, and FIG. 1B is a cross-sectional view taken along the line C-C of FIG. 1A. FIG. 2 is an exploded perspective view of an outer joint member, a cage and an inner joint member of FIG. 1( a ). 1A is a right side view of the outer joint member of FIG. 1A, FIG. 1B is a vertical sectional view taken along line A1-N of FIG. 1A, and FIG. (A) It is sectional drawing which followed the B1-N' line of a figure. It is a front view containing the cross section of the outer joint member which followed the B1-N'-B1 line of Drawing 4 (a). 1A is a right side view of the inner joint member of FIG. 1A, FIG. 1B is a vertical sectional view taken along line A1-N of FIG. 1A, and FIG. (A) It is sectional drawing which followed the B1-N' line of a figure. FIG. 7 is a front view of the inner joint member of FIG. 6A is a sectional view taken along the line DD of FIG. 6B, and FIG. 6B is a sectional view taken along the line EE of FIG. 6C.

A fixed type constant velocity universal joint according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1A shows a fixed type constant velocity universal joint according to the present embodiment, and is a longitudinal sectional view taken along the line A1-A1 of FIG. 2A, and FIG. 3 is a sectional view taken along line B1-B1 of FIG. 2(a) is a right side view of FIG. 1(a), and FIG. 2(b) is a cross-sectional view taken along the line C-C of FIG. 1(a) with the torque transmission balls removed. The state is illustrated.

The fixed type constant velocity universal joint 1 of the present embodiment mainly includes an outer joint member 2, an inner joint member 3, a torque transmission ball (also simply referred to as a ball) 4, and a cage 5. As shown in FIGS. 2A and 2B, four pairs of track grooves 7A ₁ , 7B ₁ , 7A ₂ , 7B ₂ , 7A ₃ , 7B ₃ are formed on the spherical inner peripheral surface 6 of the outer joint member 2. , 7A ₄ and 7B ₄ are formed in the longitudinal direction. The spherical outer peripheral surface 8 of the inner joint member 3 has four pairs of track grooves facing the track grooves 7A ₁ , 7B ₁ , 7A ₂ , 7B ₂ , 7A ₃ , 7B ₃ , 7A ₄ , 7B ₄ of the outer joint member 2. 9A ₁ , 9B ₁ , 9A ₂ , 9B ₂ , 9A ₃ , 9B ₃ , 9A ₄ , 9B ₄ are formed in the longitudinal direction. Eight balls 4 for transmitting torque are incorporated between the track groove 7 of the outer joint member 2 and the track groove 9 of the inner joint member 3 one by one.

In the present specification and claims, the track grooves 7A ₁ of the outer joint member _{2, 7B 1, 7A 2,} 7B 2, 7A 3, 7B 3, 7A 4, the case of collectively 7B ₄ is code 7 When the track grooves 9A ₁ , 9B ₁ , 9A ₂ , 9B ₂ , 9A ₃ , 9B ₃ , 9A ₄ , 9B ₄ of the inner joint member 3 are collectively referred to, the reference numeral 9 is used. In the case of collectively track grooves _{7A 1, 7A 2, 7A 3} , 7A 4 and _{7B 1, 7B 2, 7B 3} , 7B 4 the sign 7A, using 7B. The same procedure is applied to the inner joint member 3. In addition, the same reference numerals are used for reference numerals of the normal angular range track groove part, the high angular range track groove part, and the transition track groove part, which will be described later.

A cage 5 for holding the balls 4 is arranged between the spherical inner peripheral surface 6 of the outer joint member 2 and the spherical outer peripheral surface 8 of the inner joint member 3. The ball 4 is housed in the pocket 5 a of the cage 5. The spherical outer peripheral surface 12 of the retainer 5 is slidably fitted to the spherical inner peripheral surface 6 of the outer joint member 2, and the spherical inner peripheral surface 13 of the retainer 5 slides on the spherical outer peripheral surface 8 of the inner joint member 3. It is freely fitted and guided.

As shown in FIGS. 2A and 2B, the four pairs of track grooves 7A ₁ , 7B ₁ , 7A ₂ , 7B ₂ , 7A ₃ , 7B ₃ , 7A ₄ , 7B ₄ of the outer joint member 2 are , And the second pair of track grooves 7A ₁ , 7B ₁ , 7A ₃ , 7B ₃ and the second pair of track grooves 7A ₂ , 7B ₂ , 7A ₄ , 7B ₄ . Similarly, the four pairs of track grooves 9A ₁ , 9B ₁ , 9A ₂ , 9B ₂ , 9A ₃ , 9B ₃ , 9A ₄ , 9B ₄ of the inner joint member 3 are the first two pairs of track grooves 9A ₁ , 9B. ₁ , 9A ₃ , 9B ₃ and a second pair of track grooves 9A ₂ , 9B ₂ , 9A ₄ , 9B ₄ .

Track grooves 7A ₁ of the first two pairs of the outer joint member 2, 7B _1, 7A _3, 7B ₃ are spaced on opposite sides of the first plane PT1 containing the axis N-N of the joint, the They are formed symmetrically with respect to one plane PT1. Second 2 pairs of the track grooves _{7A 2, 7B 2, 7A 4} , 7B 4 of the outer joint member 2 includes a joint axial line N-N on both sides of the second plane PT2 perpendicular to the first plane PT1 Are arranged at intervals and are formed symmetrically with respect to the second plane PT2.

Similarly, the first track groove 9A ₁ two pairs, 9B _1, 9A _3, 9B ₃ of the inner joint member 2 is spaced on opposite sides of the first plane PT1 containing the axis N-N of the joint arrangement Are formed symmetrically with respect to the first plane PT1. Track grooves 9A ₂ of the second two pairs of the inner joint member 2, 9B _2, 9A _4, 9B ₄ includes a joint axial line N-N on both sides of the second plane PT2 perpendicular to the first plane PT1 Are arranged at intervals and are formed symmetrically with respect to the second plane PT2.

As shown in FIG. 1( a ), a common angle range track groove portion 7 f is formed in the common angle range near the joint center O of the track groove 7 of the outer joint member 2 in the axial direction. The illustrated working angle range track groove portion 7f is specifically the working angle track groove portion of the track groove 7A ₁ , and therefore, is the working angle range track groove portion 7A ₁ f to be precise. The regular angular range track groove portion 7A ₁ f has a curved track center line Xf, and the center of curvature O1 of the track center line Xf is axially offset from the joint center O in the depth direction by an amount f1. As shown in FIG. 2 (a), a plane A1 containing raceway center line Xf conventional angular range track groove portion 7A ₁ f, the angle .beta.1 / 2 relative to the first plane PT1 about an axis N-N of the joint Is formed with.

Here, in the description of the common angular range track groove portion 7f of the outer joint member 2, to ensure accurate alignment with the drawings, but the specific common angular range track groove portion 7A ₁ f has been described as an example, the contents of The same applies to the other normal angular range track groove portions 7f. That is, the track grooves 7A ₁ of 4 pairs of the outer joint member _{2, 7B 1, 7A 2,} 7B 2, 7A 3, 7B 3, 7A 4, among 7B _4, the track grooves _{7A 1, 7A 2, 7A 3} , 7A ₄ have the same shape as each other, and the track grooves 7B ₁ , 7B ₂ , 7B ₃ , 7B ₄ have the same shape. The track grooves 7A ₁ , 7B ₁ and the track grooves 7A ₃ , 7B ₃ are symmetrical with respect to the first plane PT1, and the track grooves 7A ₂ , 7B ₂ and the track grooves 7A ₂ , 7B ₂ with respect to the second plane PT2. 7A ₄ and 7B ₄ are symmetrical. Therefore, the track grooves 7A ₁ , 7A ₂ , 7A ₃ , 7A ₄ and the track grooves 7B ₁ , 7B ₂ , 7B ₃ , 7B ₄ are symmetrical with respect to the first plane PT1 or the second plane PT2. Except for the above relation, the shape of each track groove 7 is the same shape, and the common angle range track groove portion 7f of each track groove 7 is also the same shape. For this reason, the above description of the specific working angle range track groove portion 7A ₁ f can be similarly applied to the other working angle range track groove portion 7f. The above-described relationship of the shapes of the track groove and the track groove portion in the normal angle region is the same for the inner joint member 2. The same applies to the relationship between the shapes of the high-angle region track groove portion and the transition track groove portion described later. Therefore, the following description is the same.

As shown in FIG. 1( a ), a common angle range track groove portion 9A ₁ f is formed in the common angle range near the axial direction of the joint center O of the track groove 9 of the inner joint member 3. The regular angular range track groove portion 9A ₁ f has a curved track center line Yf, and the center of curvature O2 of the track center line Yf is axially offset from the joint center O by f1 toward the opening side. The center of curvature O2 of the track centerline Yf of the track groove portion 9A ₁ f for the common angle range of the inner joint member 3 and the curvature center O1 of the track centerline Xf of the track groove section 7A ₁ f of the common angle range for the outer joint member 2 are the center O of the joint. With respect to the opposite side in the axial direction, the offset is an equal distance f1. As shown in FIG. 2A, the plane A1 including the track center line Yf of the regular angle range track groove portion 9f of the inner joint member 3 is angled with respect to the first plane PT1 about the joint axial line NN. It is formed with β1/2.

As shown in FIG. 1B, a high-angle region track groove portion 7h is formed in the high-angle region on the opening side and the inner side of the joint of the track groove 7 of the outer joint member 2. The high-angle region track groove portion 7A ₁ h has a curved track center line Xh. As shown in FIG. 2A, the plane B1 including the track centerline Xh of the high-angle region track groove portion 7A ₁ h is formed parallel to the first plane PT1. The projection axis N′-N′ and the projection center O′ are the projections of the joint axis NN and the joint center O on the first plane PT1 in the horizontal direction of the drawing on the plane B1. Center of curvature O3 of the curved raceway center line Xh high angle region track groove portion 7A ₁ h is 'to, N'-N projection axis' projection center O are offset by f2 on the far side in the axial direction along the ing.

Similarly, a high-angle region track groove portion 9h is formed in the high-angle region on the opening side and the rear side of the track groove 9 of the inner joint member 3. The high-angle region track groove portion 9h has a curved track center line Yh. The plane B1 shown in FIG. 2A also includes the track centerline Yh of the high-angle region track groove portion 9A ₁ h of the inner joint member 3. Center of curvature O4 of the curved raceway center line Yh high angle region track groove portion 9A ₁ h is 'to, N'-N projection axis' projection center O are offset by f2 on the opening side in the axial direction along the ing. The curvature center O4 of the track centerline Yh of the high-angle track groove 9A ₁ h of the inner joint member 3 and the curvature center O3 of the track centerline Xh of the high-angle track groove 7A ₁ h of the outer joint member 2 are the projection center O Is offset to the opposite side in the axial direction along the projection axis N′-N′ with respect to ′ by an equal distance f2. The plane B1 including the track center line Yh of the high-angle region track groove portion 9A ₁ h of the inner joint member 3 is formed parallel to the first plane PT1.

As shown in FIG. 2A, the first two pairs of track grooves 7A ₁ , 7B ₁ , 7A ₃ , 7B ₃ and the second two pairs of track grooves 7A ₂ , 7B ₂ , 7A of the outer joint member 2 are provided. The angle between the centers of the track grooves 7A ₁ and 7B ₁ which form a pair of ₄ and 7B ₄ , between the centers of 7A ₃ and 7B ₃ , between the centers of 7A ₂ and 7B ₂ , and between the centers of 7A ₄ and 7B ₄ is Is also set to β1. On the other hand, the angles between the centers of the pair of adjacent track grooves 7B ₁ and 7A ₂ , between the centers of 7B ₂ and 7A ₃ , between the centers of 7B ₃ and 7A ₄ , and between the centers of 7B ₄ and 7A ₁ are It is set to β2. In the outer joint member 2 of the present embodiment, the angle β1 between the centers of the paired track grooves is set smaller than the angle β2 between the centers of the adjacent track grooves. The same applies to the angular relationship between the centers of the track grooves 9 of the inner joint member 2.

By reducing the angle β1 between the centers of the pair of track grooves, as shown in FIG. 2(b), the pocket 5a of the cage 5 is incorporated into the pair of track grooves while suppressing the circumferential length. The two balls 4 that have been stored can be accommodated in one pocket 5a. Thereby, the width of the pillar portion 5b of the cage 5 can be increased and the strength can be improved.

Here, the reason why the angle β1 between the centers of the paired track grooves can be reduced will be described. As described above, the track center lines Xh and Yh of the high-angle region track grooves 7h and 9h of the outer joint member 2 and the inner joint member 3 are arranged on the planes B1, B1', B2, and B2', respectively. The planes B1 and B1' are formed parallel to the first plane PT1, and the planes B2 and B2' are formed parallel to the second plane PT2. That is, the track center lines Xh and Yh of the high-angle region track grooves 7h and 9h are formed in parallel with the first plane PT1 or the second plane PT2. Therefore, the thickness of the rib portion 3a [see FIG. 2(a)] between the track grooves 9A and 9B at the end of the inner joint member 3, which is particularly related to securing strength at high angles, does not decrease, and the track groove is not formed. The minimum wall thickness between the inner peripheral hole 9 and the inner peripheral hole (a connecting hole with the intermediate shaft) increases. Therefore, the angle β1 between the centers of the paired track grooves can be reduced.

Between the normal angle range track groove portions 7f and 9f of the track grooves 7 and 9 of the outer joint member 2 and the inner joint member 3 shown in FIGS. 1(a) and 1(b) and the high angle range track groove portions 7h and 9h. The transition track groove portions 7t and 9t (see FIG. 3) allow smooth connection.

FIG. 3 is an exploded perspective view of the fixed type constant velocity universal joint 1 of this embodiment. Of the normal angle range track groove portions 7f and 9f of the track grooves 7 and 9 of the outer joint member 2 and the inner joint member 3, the high angle range track groove portions 7h and 9h, and the transition track groove portions 7t and 9t that smoothly connect them. An overview is shown. In FIG. 3, the two-dot chain line of each track groove 7, 9 indicates the groove bottom. The cage 5 is provided with four pockets 5a (not shown) for accommodating two balls 4 each at equal intervals in the circumferential direction. Thereby, the width of the pillar portion 5b of the cage 5 is increased, and the strength is improved.

Next, details of the track groove 7 of the outer joint member 2 will be described with reference to FIGS. 4 and 5. FIG. 4A is a right side view of the outer joint member of FIG. 1A, and FIG. 4B is a vertical cross-sectional view taken along line A1-N of FIG. 4C is a sectional view taken along the line B1-N′ of FIG. FIG. 5 is a sectional view taken along line B1-N′-B1 of FIG.

As shown in FIG. 4B, the track center line Xf of the track groove portion 7A ₁ f of the track groove 7A ₁ of the outer joint member 2 is formed in a curved shape, and its center of curvature O1 is deeper than the joint center O. It is axially offset at a distance of f1 to the side. The regular angle track groove portion 7A ₁ f is formed in the range of the angle θ1 toward the opening side and the back side around the joint center O.

Here, the angle θ1 that defines the range of the regular angle area track groove portion 7f (7A ₁ f) will be described. When an operating angle θ (not shown) is taken, the ball 4 moves by θ/2 with respect to a plane P including the joint center O of the outer joint member 2 and the inner joint member 3 and perpendicular to the joint axis N-N. To do. Here, the common angle range will be defined. The common angle of the joint refers to an operating angle that occurs in the fixed constant velocity universal joint of the front drive shaft when the steering is in a straight traveling state in an automobile with one passenger on a horizontal and flat road surface. The common angle is usually selected and determined between 2° and 15° according to the design conditions for each vehicle type. Further, the working angle generated in the fixed type constant velocity universal joint in the above-mentioned automobile on a continuously running curved road is also a frequently used working angle. The frequently used operating angle is also determined according to the design condition for each vehicle type, but the frequently used operating angle is set to 20° at the maximum. In the present specification and claims, the normal angle range is used to include the above-mentioned frequently used working angle. In consideration of practicality, the angle θ1 that defines the range of the normal angular range track groove portion 7f (7A ₁ f) is set to 3° to 10°. However, the angle θ1 is not limited to 3° to 10° and can be appropriately set according to the design conditions of the vehicle type. By setting the angle θ1 to 3° to 10°, it can be used for various vehicle types.

As shown in FIG. 4C, the track centerline Xh of the high-angle region track groove portion 7A ₁ h is formed in a curved shape, and the center of curvature O3 thereof is axially extended from the projection center O′ in the depth direction by an amount of f2. Is offset to. The high-angle region track groove portion 7A ₁ h is formed in the range of an angle θ2 or more on the opening side and the back side with the projection center O′ as the center. As described above, the projection axis N′-N′ and the projection center O′ are the projections of the joint axis NN and the joint center O on the first plane PT1 on the plane B1 in the horizontal direction of the drawing.

Here, the angle θ2 that defines the range of the high-angle region track groove portion 7h (7A ₁ h) will be described. The high angle range of the joint refers to a high operating angle of 35° or more that occurs when an automobile turns right or left at an intersection, or when a vehicle is put in a garage, and is selected and determined according to design conditions for each vehicle type. In the present specification and claims, the high angle range has the above meaning. In consideration of practicality, the angle θ2 defining the range of the high angle track groove portion 7A ₁ h is set to 17.5°. However, the angle θ2 is not limited to 17.5° and can be appropriately set according to the design conditions of the vehicle type. By setting the angle θ2 to 17.5°, it can be used for various vehicle types.

In the track groove 7 of the outer joint member 2 in the present embodiment, the offset amount f1 of the curvature center O1 of the curved track center line Xf of the regular angular range track groove portion 7A ₁ f and the curved shape of the high angular range track groove portion 7A ₁ h. The offset amount f2 of the center of curvature O3 of the trajectory center line Xh is set to the same value. However, the present invention is not limited to this, and the offset amounts f1 and f2 may have different values.

The transition track groove portion 7t connecting between the normal angle area track groove portion 7f and the high angle area track groove portion 7h of the track groove 7 of the outer joint member 2 will be described with reference to FIG. In FIG. 5, track grooves 7A ₂ and 7B ₂ are shown at the front positions of the spherical inner peripheral surface 6 of the outer joint member 2. Here, the track groove 7A ₂ will be described as an example. The two-dot chain line illustrated in the track grooves 7A ₂ shows regular angle range track groove portion 7A ₂ f, each groove bottom of the high-angle region track groove portion 7A ₂ h and transition track groove portion 7A ₂ t.

Plane including raceway center line Xf conventional angular range track groove portion 7A ₂ f A1 [FIG. 4 (a), the see FIG. 4 (b)], the angle to the first plane PT1 around the joint axis N-N Since it is formed with β1/2, in FIG. 5, the groove bottom of the normal angle area track groove portion 7A ₂ f is illustrated as being biased upward in the groove width. The regular angle area track groove portion 7A ₂ f is located in the axial range Lfo. The axial range Lfo corresponds to the range of the angle θ1 described above with reference to FIG.

On the other hand, the plane B1 [see FIGS. 4(a) and 4(c)] including the track center line Xh of the high-angle region track groove portion 7A ₂ h is formed parallel to the first plane PT1. In FIG. 5, the groove bottom of the high angle region track groove portion 7A ₂ h is shown at the center position of the groove width. The high-angle region track groove portion 7A ₂ h is located in the axial range Lho. The axial range Lho corresponds to the range equal to or greater than the angle θ2 described above with reference to FIG.

Because of the above-described arrangement relationship, the end of the track centerline Xf of the normal angle range track groove portion 7A ₂ f and the end of the opposite high angle range track groove portion 7A ₂ h of the track centerline Xh are twisted with respect to each other. Is in a closed state.

Between the end of the track centerline Xf of the normal angle range track groove 7A ₂ f and the track centerline Xh of the high angle range track groove 7A ₂ h which are twisted with each other as described above. It is the transition track groove portion 7A ₂ t that has a track center line (not shown) that smoothly connects. The center line of the track of the transition track groove portion 7A ₂ t is formed by a three-dimensionally curved curve. The transition track groove portion 7A ₂ t forms a wedge-shaped track that faces the transition track groove portion of the inner joint member 3 described later and expands toward the inner side of the outer joint member 2. The transition track groove portion 7A ₂ t is located in the axial range Lto.

Next, details of the track groove 9 of the inner joint member 3 will be described with reference to FIGS. 6 to 8. 6(a) is a right side view of the inner joint member of FIG. 1(a), and FIG. 6(b) is a vertical sectional view taken along the line A1-N of FIG. 6(a). 6C is a sectional view taken along the line B1-N′ of FIG. FIG. 7 is a front view of the inner joint member viewed from the upper side of FIG. 8A is a cross-sectional view taken along the line DD of FIG. 6B, and FIG. 8B is a cross-sectional view taken along the line EE of FIG. 6C. ..

The orbital center line Y of the track groove 9 of the inner joint member 3 is defined by the track groove 7 of the outer joint member 2, which is paired with the outer joint member 2 on the basis of a plane P that includes the joint center O and is orthogonal to the joint axis line at an operating angle of 0°. It is formed in mirror image symmetry with the orbital center line X. Specifically, as shown in FIG. 6B, the track center line Yf of the track groove portion 9A ₁ f of the track groove 9A ₁ of the inner joint member 3 is formed in a curved shape, and the center of curvature O2 thereof is It is axially offset from the joint center O toward the opening by an amount of f1. The normal angle track groove portion 9A ₁ f is formed in the range of the angle θ1 toward the opening side and the back side around the joint center O. The definitions of the angle θ1 and the common angle range that define the range of the common angle range track groove portion 9f (9A ₁ f) of the inner joint member 3 are the same as those described above for the outer joint member 2.

As shown in FIG. 6C, the track center line Yh of the high-angle region track groove portion 9A ₁ h is formed in a curved shape, and its curvature center O4 is axially oriented from the projection center O′ toward the opening side in the amount of f2. Is offset to. The high-angle region track groove portion 9A ₁ h is formed in the range of an angle θ2 or more on the opening side and the back side with the projection center O′ as the center. As described above, the projection axis N′-N′ and the projection center O′ are the projections of the joint axis NN and the joint center O on the first plane PT1 on the plane B1 in the horizontal direction of the drawing. The definition of the angle θ2 and the high angle range that define the range of the high-angle range track groove portion 9h (9A ₁ h) of the inner joint member 3 are the same as those described above for the outer joint member 2.

Also in the track groove 9 of the inner joint member 3, the offset amount f1 of the curvature center O2 of the curved track center line Yf of the regular angle track groove 9A ₁ f and the curved track center of the high angle track groove 9A ₁ h The offset amount f2 of the curvature center O4 of the line Yh is set to the same value. However, the present invention is not limited to this, and the offset amounts f1 and f2 may have different values.

The transition track groove portion 9t connecting between the regular angle area track groove portion 9f and the high angle area track groove portion 9h of the track groove 9 of the inner joint member 3 will be described with reference to FIG. In FIG. 7, track grooves 9A ₁ and 9B ₁ are shown at the front positions of the spherical outer peripheral surface 8 of the inner joint member 3. Here, the track groove 9A ₁ will be described as an example. In FIG. 7, two-dot chain line illustrated in the track grooves 9A ₁ shows common angular range track groove portion 9A ₁ f, each groove bottom of the high-angle region track groove portion 9A ₁ h and transition track groove portion 9A ₁ t.

Plane including raceway center line Xf conventional angular range track groove portion 9A ₁ f A1 [FIG. 6 (a), the FIG. 6 (b) see] is an angle with respect to the first plane PT1 around the joint axis N-N Since it is formed with β1/2, in FIG. 7, the groove bottom of the normal angle region track groove portion 9A ₁ f is illustrated as being biased upward in the groove width. The regular angle area track groove portion 9A ₁ f is located in the axial range Lfi. The range Lfi in the axial direction corresponds to the range of the angle θ1 described above with reference to FIG.

On the other hand, the plane B1 containing raceway center line Yh high angle region track groove portion 9A ₁ h [FIG. 6 (a), the FIG. 6 (c) reference], since formed in parallel to the first plane PT1 In FIG. 7, the groove bottom of the high angle area track groove portion 9A ₁ h is shown at the center position of the groove width. The high-angle region track groove portion 9A ₁ h is located in the axial range Lhi. The axial range Lhi corresponds to the range equal to or greater than the angle θ2 described above with reference to FIG.

Due to the above-described arrangement relationship, the end of the track centerline Yf of the regular angle range track groove 9A ₁ f and the end of the track centerline Yh of the opposing high angle range track groove 9A ₁ h are twisted with respect to each other. Is in a closed state.

Between the end of the track centerline Yf of the normal angle range track groove 9A ₁ f and the track centerline Yh of the high angle range track groove 9A ₁ h which are twisted with each other as described above. It is the transition track groove portion 9A ₁ t that has the track center line that smoothly connects. The track centerline of the transition track groove portion 9A ₁ t is formed by a three-dimensionally curved curve. The transition track groove portion 9A ₁ t is located in the axial range Lti.

As described above, the track center line Y of the track groove 9 of the inner joint member 3 is paired with the outer joint member 2 with reference to the plane P that includes the joint center O and is orthogonal to the joint axis line at the operating angle of 0°. Is formed in mirror image with the center line X of the orbit of the track groove 7.

The contact state between the ball 4 and the track groove in the regular angular range track groove portion 9f and the high angular range track groove portion 9h will be described with reference to FIG. FIG. 8A shows a state in which the ball 4 is located in the regular angular range track groove portion 9f, and FIG. 8B shows a state in which the ball 4 is located in the high angular range track groove portion 9h.

As shown in FIG. 8 (a), the ball 4 and the common angle zone track groove portion 9f, as shown on the normal angular range track groove portion 9B ₁ f, the plane A1, A1 'including the axis N-N of the joint Are in contact with each other with a contact angle α. Therefore, in the normal use angular range, torque can be transmitted by the balls on both sides of the pair of normal use angular range track groove portions 9A ₁ f and 9B ₁ f. That is, since the torque of all eight balls can be transmitted, the contact surface pressure between the ball 4 and the normal angle area track groove portion 9f is reduced, and the durability is improved. Although illustration is omitted, the contact state between the ball groove 4 and the normal angular range track groove portion 7f of the outer joint member 2 is the same as above, and the fixed type constant velocity universal joint 1 of the present embodiment has a load capacity in the normal angular range. , Durability can be secured.

As shown in FIG. 8B, the ball 4 and the high-angle region track groove portion 9h are, as shown in the high-angle region track groove portion 9B ₁ h, relative to the planes B1 and B1′ parallel to the first plane PT1. Are in contact with each other with a contact angle α. Therefore, in the high angle range, the ball on one side of the pair of high angle range track groove portions 9A ₁ h and 9B ₁ h transmits most of the torque.

Specifically, in FIG. 8 (b), the in the high angle range track groove portion 9B ₁ h, the inner joint member 3 when loaded with torque is rotated in the direction of the white arrow, the 'ball 4' on the plane B1 The generated torque transmission direction vector f', the ball 4', and the contact direction vector b'of the high-angle region track groove portion 9B ₁ h intersect at a large angle, that is, in a state close to a straight line, whereas they occur on the ball 4 on the plane B1. The torque transmitting direction vector f and the contact direction vector b of the high-angle region track groove portion 9A ₁ h intersect at a small angle, that is, in a bent state. Therefore, the high angle region track groove portion 9A ₁ h pairs of 9B ₁ h, the ball 4 'high angle region track groove portion 9B ₁ h to transmit most of the torque, the ball 4 of the high-angle region track groove portion 9A ₁ h Will hardly transmit torque. As described above, in the high angle range, one side ball (half of the eight balls) of the pair of high angle range track groove portions 9A ₁ h and 9B ₁ h transmits most of the torque. However, in the high angle range, even with the conventional Rzeppa type constant velocity universal joint, since torque can be transmitted only by about half the balls, the contact surface pressure between the balls and the track groove is not disadvantageous. The rib portion 3a [see FIG. 2(a)] between the track grooves 9A and 9B at the end of the inner joint member 3, which is particularly related to securing strength at high angles, does not have a reduced thickness, and The minimum thickness with the inner peripheral hole is increased, and the load capacity can be secured.

Although the contact state between the normal angle track groove portion 7f of the outer joint member 2 and the ball 4 and the contact state between the high angle region track groove portion 7h and the ball 4 are not shown, the contact state of the inner joint member 2 described above is not shown. It is the same.

As described above, in summary, in the fixed type constant velocity universal joint 1 of the present embodiment, the outer joint member 2 and the inner joint member 3 have four pairs of track grooves 7 and 9, respectively. , 9 are common angular range track groove portions 7f and 9f in which track centerlines Xf and Yf are arranged on planes A1, A1′, A2, and A2′ centered on the joint axis NN, and joint axis NN The high angle area track grooves 7h and 9h in which the track center lines Xh and Yh are arranged on the planes B1, B1′, B2 and B2′ parallel to the planes PT1 and PT2 including the track grooves 7f, 7h, 9f and 9h Since the transition track groove portions 7t and 9t are connected smoothly, it is possible to realize the lightweight and compact fixed type constant velocity universal joint 1 capable of ensuring a large load capacity from the normal angle range to the high angle range.

In the present embodiment, the curved track center lines Xh and Yh of the high-angle track grooves 7h and 9h and the curvature centers O3 and O4 are arranged on the projection axis N'-N', but the present invention is not limited to this. Without arranging, the ones radially offset from the projection axis N′-N′ and the curvature centers of the curved orbit centerlines of the high-angle region track groove portions 7h and 9h are arranged on the outer side in the radial direction of the outer joint member 2, The curved track center lines of the high-angle region track grooves 7h and 9h may be S-shaped. Furthermore, the track center lines of the high-angle region track grooves 7h and 9h may be formed in a straight line parallel to the projection axis N'-N'.

The present invention is not limited to the embodiments described above, and it is needless to say that the present invention can be implemented in various forms within the scope not departing from the gist of the present invention. It is indicated by the scope of the claims and further includes equivalent meanings in the claims and all modifications within the scope.

1 Fixed Type Constant Velocity Universal Joint 2 Outer Joint Member 3 Inner Joint Member 4 Torque Transmission Ball 5 Retainer 5a Pocket 6 Spherical Inner Surface 7 Track Groove 7f Normal Angle Range Track Groove 7h High Angle Range Track Groove 7t Transition Track Groove 7A Track Groove 7B Track groove 8 Spherical outer peripheral surface 9 Track groove 9f Normal angle range track groove portion 9h High angle range track groove portion 9t Transition track groove portion 9A Track groove 9B Track groove 12 Spherical outer peripheral surface 13 Spherical inner peripheral surface A1 plane A2 plane B1 plane B2 plane N joint axis O joint center P plane PT1 first plane PT2 second plane X trajectory centerline Xf trajectory centerline Xh trajectory centerline Y trajectory centerline β1 angle β2 angle

Claims (6)

A plurality of track grooves extending in the longitudinal direction are formed on the spherical inner peripheral surface, and an outer joint member having an opening side and a back side that are axially separated from each other, and a plurality of track grooves extending in the longitudinal direction on the spherical outer peripheral surface are the outer joint members. An inner joint member formed so as to face the track groove of the member, a torque transmission ball incorporated between the opposing track grooves, and the torque transmission ball held, and the spherical outer peripheral surface of the outer joint member and the inner side. In a fixed type constant velocity universal joint consisting of a cage guided on the spherical outer peripheral surface of the joint member,
The track groove (7) of the outer joint member (2) includes a first pair of track grooves (7A ₁ , 7B ₁ , 7A ₃ , 7B ₃ ) and a second pair of track grooves (7A ₂ , 7B). ₂ , 7A ₄ , 7B ₄ ),
The first two pairs of the track grooves _{(7A 1, 7B 1, 7A} 3, 7B 3) , respectively, at intervals on both sides of the joint axes the first plane including the (N-N) (PT1) And arranged symmetrically with respect to the first plane (PT1),
The second two pairs of the track grooves _{(7A 2, 7B 2, 7A} 4, 7B 4) each comprise an axis of said fittings (N-N), perpendicular to the first plane (PT1) The two planes (PT2) are arranged on both sides of the second plane (PT2) at intervals, and are formed symmetrically with respect to the second plane (PT2),
Each of the track grooves (7) has a normal angular range track groove part (7f), a high angular range track groove part (7h), and a transition track groove part (7t) smoothly connecting the track groove parts (7f, 7h). And consists of
The plane (B1, B1') including the track centerline (Xh) of the high angle area track groove portion (7h) of the first two pairs of track grooves (7A ₁ , 7B ₁ , 7A ₃ , 7B ₃ ) is Formed parallel to the first plane (PT1),
The plane (B2, B2′) including the orbit center line (Xh) of the high angle area track groove portion (7h) of the second pair of track grooves (7A ₂ , 7B ₂ , 7A ₄ , 7B ₄ ) is Formed parallel to the second plane (PT2),
The first two pairs of the track grooves _{(7A 1, 7B 1, 7A} 3, 7B 3) the common angle region plane including the raceway center line (Xf) of the track groove portions (7f) of the (, A1 A1 ') is It is formed at an angle with respect to the first plane (PT1) about the axis (NN) of the joint,
The second two pairs of the track grooves _{(7A 2, 7B 2, 7A} 4, 7B 4) plane comprising said track center line of the common angular range track groove portions (7f) (Xf) of (A2, A2 ') is It is formed at an angle with respect to the second plane (PT2) about the axis (N-N) of the joint,
At least the normal angular range track groove portion (7f) of the outer joint member (2) has a curved orbit center line (Xf), and the center of curvature (O1) thereof is in the axial direction with respect to the joint center (O). Is offset,
The track center line (Y) of the track groove (9) of the inner joint member (3) is a plane (P) that includes the joint center (O) and is orthogonal to the joint axis (NN) in the state where the operating angle is 0°. ) As a reference, the fixed type constant velocity universal joint is formed so as to have a mirror image symmetry with the track center line (X) of the track groove (7) forming a pair with the outer joint member (2). The high-angle region track groove portion (7h) of the outer joint member (2) also has a curved orbit center line (Xh), and its center of curvature (O3) is axially offset with respect to the joint center (O). The fixed type constant velocity universal joint according to claim 1, wherein the fixed type constant velocity universal joint is provided. The center of curvature (O1) of the track center line (Xf) of the track groove portion (7f) in the normal angle range of the outer joint member (2) and the center of curvature (Xh) of the track center line (Xh) of the track groove portion (7h) in the high angle range. (O3) is offset to the inner side of the outer joint member (2) with respect to the joint center (O), respectively. Fittings. The axial offset amount of the curvature center (O1) of the track center line (Xf) of the track groove portion (7f) in the normal angle range and the curvature center (Xh) of the track center line (Xh) of the track groove portion (7h) of the high angle range ( The fixed type constant velocity universal joint according to any one of claims 1 to 3, wherein the axial offset amounts of O3) are equal. The angle (β1) between the centers of the pair of track grooves (7A ₁ , 7B ₁ , 7A ₂ , 7B ₂ , 7A ₃ , 7B ₃ , 7A ₄ , 7B ₄ ) is the track grooves (7B) adjacent to each other. _It is smaller than the angle (β2) between the centers of ₁ , 7A ₂ , 7B ₂ , 7A ₃ , 7B ₃ , 7A ₄ , 7B ₄ , 7A ₁ ). 5. Fixed type constant velocity universal joint. The retainer (5) accommodates two balls incorporated in the pair of track grooves (7A ₁ , 7B ₁ , 7A ₂ , 7B ₂ , 7A ₃ , 7B ₃ , 7A ₄ , 7B ₄ ). The fixed type constant velocity universal joint according to claim 1, wherein the fixed type constant velocity universal joint has a pocket.

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