JPH04116018U - Constant velocity joint - Google Patents

Abstract

(57) [Summary] [Purpose] To suppress the temperature rise of constant velocity joints and improve rotational balance performance, durability, allowable rotation speed, and NVH performance. [Structure] A plurality of sets of circular contact tracks C ₁ facing the inner surface of the outer ring 1 and the outer surface of the inner ring 2 in the radial direction,
Forms C ₂ . Let at least three sets of circular contact tracks be offset circular contact tracks _C2 . A radial preload is applied to the three sets of offset circular contact tracks _C2 to eliminate radial play in the joint and improve rotational balance performance. In addition, a substantially equal circumferential clearance is formed between each track and the ball 4, and when torque is applied to the joint, each ball 4 is brought into contact with the ball rolling surface at the same time, and a circumferential direction load is applied to each track. This aims to suppress temperature rise and improve durability, allowable rotation speed, and NVH performance.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is used for automobile propeller shafts and drive shafts, etc. It concerns speed joints.

0002

[Conventional technology]

When transmitting the rotational torque of the propeller shaft and drive shaft to the axle, a ball type constant velocity joint is generally used. This ball type constant velocity joint includes those shown in FIGS. 4 to 6. Each joint consists of an outer ring 1, an inner ring 2, a retainer 3, and a plurality of balls 4, and tracks T 1 and T 2 for guiding the movement of the balls 4 are provided on the inner surface of the outer ring ₁ and the outer surface of the inner ring ₂ .

0003 Here, the constant velocity joint shown in Fig. 4 is a cross group joint (LJ). The cage 3 has a spherical inner surface 8 and a spherical inner surface 5 of the outer ring 1. An outer surface 6 is provided.

The constant velocity joint shown in FIG. 5 is called a double offset joint (DOJ), and the cage 3 has a spherical outer surface 10 that is guided in contact with the cylindrical inner surface 9 of the outer ring 1 and a spherical outer surface 11 of the inner ring 2. A spherical inner surface 12 that is guided in contact with the retainer 3 is provided, and the center A ₁ of the spherical outer surface 10 of the retainer 3 and the center B ₁ of the spherical inner surface 12 are offset from the center O ₁ of the joint by an equal distance to the left and right.

Further, the constant velocity joint shown in FIG. 6 is a Zeppa type joint, and the center A ₂ of the track T ₁ formed on the spherical inner surface 13 of the outer ring 1 and the center B of the track T 2 formed on the spherical outer surface 14 of the inner ring ₂ are the same. ₂ is offset equidistantly from the joint center O ₂ to the left and right.

As shown in FIG. 7A, the tracks T ₁ and T ₂ of the outer ring 1 and inner ring 2 of these various ball type constant velocity joints include angular contact tracks (hereinafter referred to as AC tracks) having a fixed contact angle, and There is a circular contact track (hereinafter referred to as a CC track) as shown in FIG.

[0007] Here, if there is a radial gap in the radial direction between the track and the ball, Due to poor rotational balance and vibration, the propeller shaft and drive When used for shafts, apply preload in the radial direction of the joint and It is often used in a clean state.

[0008]

[Problem that the idea aims to solve]

By the way, when a radial preload is applied to a constant velocity joint having an AC track to eliminate radial clearance, the ball 4 and the ball rolling surfaces of tracks T ₁ and T ₂ contact at four points, as shown in FIG. 7B. However, when torque is applied in the direction of the arrow in the figure in the preloaded state, it operates in a four-point contact state with a contact point _P2 due to the preload located at a position away from the contact point _P1 due to the torque load. For this reason, the ball 4 does not roll properly, and slippage occurs between the ball 4 and the outer track T ₁ and between the ball 4 and the inner track T ₂ , and the slippage increases friction and generates heat, which reduces durability. There is a problem of deteriorating the allowable rotation speed and NVH performance.

[0009] On the other hand, CC trucks always transmit torque through two-point contact, so AC trucks This is good compared to the stock. However, in the preloaded state, the ball is trapped between the inner and outer rings. The joint is constrained in both the radial and circumferential directions by the Because it is affected by both directional accuracy, the surface pressure unevenness between each track becomes large. , there is a problem that further worsens the movement of the ball.

0010 This idea eliminates the above disadvantages, suppresses temperature rise, improves rotational balance performance and durability. The technical challenges are to improve durability, allowable rotation speed, and NVH performance.

[0011]

[Means to solve the problem] In order to solve the above problem, in the first invention, the outer ring and the inner ring have circular arcs. A ball-type constant-velocity jig with multiple sets of CC tracks with a ball rolling surface of At the joint, three or more sets of CC tracks are arranged on a first guide surface with a constant facing interval. and a pair of arc-shaped second guide surfaces continuous at both ends to form a ball rolling surface. A offset CC track with approximately equal circumferential clearance between each track and the ball. A radial preload was applied to each of the offset CC tracks. The structure was adopted.

0012 In addition, in the second invention, all of the CC tracks are offset CC tracks. A configuration in which three or more sets of offset CC tracks are preloaded in the radial direction is adopted. I used it.

[0013]

[Effect]

As mentioned above, by applying radial preload to the offset CC track, This eliminates radial play in the joint and improves rotational balance performance. I can do it. Also, when torque is applied between the outer ring and the inner ring, the ball will be tracked. It makes contact with the brake at two points, and transmits torque with each contact point receiving a load.

[0014]

【Example】

An embodiment of this invention will be described below with reference to FIGS. 1 to 3.

[0015] Note that Figure 1 is a cross-sectional view of the constant velocity joint according to this invention, and the overall configuration is as follows. Since it is the same as the constant velocity joint shown in FIGS. 4 to 6, it is omitted.

As shown in FIG. 1, three sets of CC tracks C ₁ and three sets of offset CC tracks C ₂ are formed alternately in the circumferential direction on the inner surface of the outer ring 1 and the outer surface of the inner ring 2. Torque transmission balls 4 incorporated in C ₁ and C ₂ are supported by a retainer 3.

FIG. 2 shows details of the CC track C ₁ and the offset CC track C ₂ . The ball rolling surface 15 of the CC track C ₁ is an arc, and a radial clearance δ ₁ and a circumferential clearance δ ₂ are provided between the ball rolling surface 15 and the balls 4.

On the other hand, the ball rolling surface 16 of the offset CC track C ₂ includes a first guide surface 17 whose facing interval is constant over the entire circumferential direction, and a pair of continuous guide surfaces 17 at both ends of the first guide surface 17 in the circumferential direction. It consists of a circular arc-shaped second guide surface 18. The centers of curvature of the pair of second guide surfaces 18 are offset from the center of the ball 4 by an equal distance to the left and right, and a circumferential gap δ ₃ is formed between the second guide surfaces 18 and the ball 4 . This circumferential clearance δ ₃ is approximately the same size as the circumferential clearance δ ₂ of the CC track C ₁ .

[0019] In the embodiment, the first guide surface 17 is an arcuate surface having a center of curvature at the joint center O. However, it is directly connected to the straight line in the radial direction passing through the joint center O and the track center. It may be a plane that intersects.

A radial preload is applied to the offset CC track C ₂ , and the first guide surface 17 is in pressure contact with the ball 4 due to the preload.

[0021] As described above, by applying a radial preload to the offset CC track _C2 , the radial play of the joint is eliminated, and rotational balance performance can be improved. When torque is applied to the inner ring 2 in the preloaded state, the balls 4 in the CC track C ₁ and the balls 4 in the offset CC track C ₂ move in the circumferential direction.

At this time, since the circumferential clearance δ ₂ provided in the CC track C ₁ and the circumferential clearance δ ₃ provided in the offset CC track C ₂ are approximately the same size, the gap shown in FIG. As _{shown in FIG .} Shares the circumferential load.

Furthermore, since the balls 4 in each track C ₁ and C ₂ contact the corresponding tracks C ₁ and C ₂ at two points, the balls 4 roll correctly and do not generate heat or vibration due to friction. can be suppressed.

[0024] In the case of the example, 3 sets of tracks out of 6 sets are offset CC track. rack, but all tracks are offset CC tracks, with at least 3 A radial preload may be applied to a set of offset CC tracks.

[0025]

[Effect of the idea]

As described above, in the constant velocity joint according to this invention, a plurality of CC trucks are used. Among the tracks, at least three sets are offset CC tracks, and their offset Apply preload to the offset CC track to eliminate radial play in the joint This makes it possible to improve rotational balance performance. Also, the truck Since approximately equal circumferential clearance is provided for each of the tracks, The load in the circumferential direction can be shared, suppressing the temperature rise of the joint, and improving durability. , allowable rotation speed, and NVH performance can be improved.

[Brief explanation of drawings]

[Figure 1] Cross-sectional view of constant velocity joint according to this invention

[Figure 2] Cross-sectional view showing an enlarged part of the same as above

[Figure 3] Cross-sectional view showing the operating state of the same as above

[Figure 4] Cross-sectional view of cross group joint

[Figure 5] Cross-sectional view of double offset joint

[Figure 6] Cross-sectional view of Zeppa-type joint

[Figure 7] A and B are cross-sectional views of angular contacts

[Figure 8] Cross-sectional view of circular contact track

[Explanation of symbols]

1 Outer ring 2 Inner ring 4 Balls 15, 16 Ball raceway 17 First guide surface 18 Second guide surface δ ₂ , δ ₃ Circumferential clearance

Claims (2)

[Scope of utility model registration request] 1. A constant velocity joint in which a plurality of sets of circular contact tracks are formed on the inner surface of an outer ring and an outer surface of an inner ring, the ball rolling surface being a circular arc, and a ball is incorporated in each track, wherein the plurality of sets of tracks are Of these, at least three sets of tracks are offset circular contact tracks in which a ball rolling surface is formed by a first guide surface with a constant facing interval and a pair of arcuate second guide surfaces continuous at both ends thereof, and each track A constant velocity joint characterized in that a substantially equal circumferential clearance is provided between the offset circular contact track and the ball, and a radial preload is applied to each of the offset circular contact tracks. 2. The constant velocity joint according to claim 1, wherein all of the circular contact tracks are offset circular contact tracks, and three or more sets of tracks are preloaded in the radial direction.