JP2000227124A - Tripod type constant velocity universal joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce induced thrust and slide resistance of a tripod type constant velocity universal joint. SOLUTION: A tripod type constant velocity universal joint includes an outside joint member 1 having three truck grooves 2 along axial direction on an inner surface, a tripod member 4 inserted inside of the outside joint member 1 and having three leg shafts 5 projecting toward a radial direction, and a roller 23 carried by each leg shaft 5 of the tripod member 4. The rollers 23 can slide along a roller guide surface 3 formed on both side walls of the truck groove 2 toward the axia direction of the outside joint member 1. A ring 21 and a roller 23 relatively-rotatable are arranged on outer surface sides of the leg shafts 5 rotatably and swingably against the leg shafts 5 through multiple balls 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a tripod type constant velocity universal joint. In general, a constant velocity universal joint is a type of universal joint that connects two shafts on a driving side and a driven side and can transmit rotational force at a constant speed even when there is an angle between the two shafts. In this type, the relative axial displacement between two axes is made possible by plunging a joint, and the tripod type uses a tripod member having three radially protruding leg shafts on one axis. A coupled hollow cylindrical outer joint member having three track grooves extending in the axial direction is coupled to the other shaft, and the torque of the tripod member is engaged by engaging the leg shaft of the tripod member in the track groove of the outer joint member. Is transmitted.

[0002]

2. Description of the Related Art An example of a tripod type constant velocity universal joint is shown in FIG.
In the description, the tripod member (3) is formed by forming three cylindrical track grooves (2) in the axial direction on the inner peripheral surface of the outer joint member (1) and inserting the groove into the outer joint member (1). An annular roller (7) rotatably fitted to the cylindrical outer peripheral surface of the three leg shafts (5) projecting in the radial direction of 4) via a plurality of needle rollers (6) is tracked. It is configured to be inserted into the groove (2). A pair of roller guide surfaces (3) opposed to each other in the circumferential direction of each track groove (2) are concave curved surfaces parallel to the axial direction.
The outer peripheral surface of each roller (7) of the leg shaft (5) is a convex curved surface that matches the roller guide surface (3). Each roller (7)
The track groove (2) engages with the roller guide surface (3) of the corresponding track groove (2) and rotates around the leg shaft (5).
It is movable along.

As shown in FIG. 5 (B), when the outer joint member (1) and the tripod member (4) transmit rotational force in a state where the outer joint member (1) and the tripod member (4) take an operating angle (θ), the rollers (7) and The guide surfaces (3) are oblique to each other as shown in FIG. 5 (C). In this case, while the roller (7) tries to roll in the direction indicated by the arrow t in FIG. 5B, the track groove (2) is cylindrical because it is parallel to the axis of the outer joint member. The roller (7) moves while being restrained by the track groove (2). As a result, slippage occurs between the roller guide surface (3) and the roller (7), causing slide resistance, and furthermore, the slippage generates induced thrust in the axial direction. Such slide resistance and induced thrust cause vibration and noise of the vehicle body, affect the NVH performance of the vehicle, and reduce the degree of freedom in designing the underbody of the vehicle.

FIG. 6 shows a tripod type constant velocity universal joint having reduced induced thrust and slide resistance.
Is known (Japanese Patent No. 2817095). That is, as shown in the figure, the outer peripheral surface of the leg shaft (5) of the tripod member (4) is made a true spherical surface, and the cylindrical inner peripheral surface of the cylindrical ring (11) is slidably fitted into this true spherical surface. An annular roller (7) is rotatably fitted on the cylindrical outer peripheral surface of the ring (11) via a plurality of needle rollers (6). The plurality of needle rollers (6) are used in a state where adjacent rollers are brought into contact with each other and arranged in a single row, and are prevented from falling off by an annular washer (14). The outer peripheral surface of the leg shaft (5) is a true spherical surface having a center of curvature on the axis of the leg shaft (5), and the ring (11) swings around the true spherical surface around the center of curvature of the true spherical surface. Similarly, the roller (7) swings. The roller (7) is accommodated in the track groove (2) of the outer joint member (1), and is movable in the outer ring axial direction while rolling on the roller guide surface (3) of the track groove (2). . In the case where the outer joint member (1) and the tripod member (4) transmit rotational force in a state where the outer joint member (1) has an operating angle, the roller (7) is relatively rotated at the operating angle with respect to the leg shaft (5). The roller (7) is guided by the roller guide surface (3) of the outer joint member (1) so as to maintain a posture parallel to the axis of the outer ring (1).
Roll correctly on top. Therefore, the sliding resistance during the operation angle operation is reduced, and the occurrence of the sliding resistance and the induced thrust is suppressed.

[0005]

It is known to use a tripod-type constant velocity universal joint to transmit rotational force from an automobile engine to wheels at a constant speed. A tripod type constant velocity universal joint has a spherical roller attached to a leg shaft of a tripod member, and needle rollers are used as rolling elements between the outer peripheral surface of the leg shaft and the inner peripheral surface of the spherical roller in a full-roller type without a cage. . When torque is transmitted in an angled state, induced thrust is generated during rotation due to mutual friction between internal components, and slide resistance is generated when the shaft is forcibly expanded and contracted in the axial direction even in a stopped state. . The typical N of automobiles involving these induced thrust and slide resistance
As the VH phenomenon, there is lateral vibration of the running vehicle body in relation to the former, and idling vibration in the D range at the stop of the AT vehicle in relation to the latter.

[0006] The point of solving the NVH problem of automobiles is to reduce the magnitude of the induced thrust and slide resistance of the joint. Generally, the induced thrust and slide resistance of a joint tend to depend on the magnitude of the operating angle. For this reason, when applied to a drive shaft of an automobile, it leads to design restrictions that the operating angle cannot be increased. Therefore, in order to increase the degree of freedom in designing a vehicle underbody, there has been a problem of stabilizing induced thrust and slide resistance at a low level.

However, in the conventional tripod type constant velocity universal joint, since the rolling element is a full-roller type needle roller, an eccentric load such as an edge load tends to act on the rolling element surface due to skew of the rollers during rotation. . Further, the contact state is not stable due to the internal clearance and the relationship of accuracy, and the edge load acts even if the spherical roller is inclined. Also, due to the structure, relative slip occurs between the end of the spherical roller and the leg shaft or washer. It is considered that phenomena such as skew, edge load, and relative slip govern the magnitude of the frictional force inside the joint.

Therefore, an object of the present invention is to reduce and stabilize induced thrust and slide resistance by minimizing these frictional forces as much as possible.

[0009]

A tripod type constant velocity universal joint according to the present invention comprises an outer joint member having three track grooves extending in an axial direction on an inner peripheral surface, and three radially projecting joint members. A roller having a tripod member, which is inserted inside the outer joint member, and a roller rotatably and swingably fitted to each leg axis of the tripod member via a plurality of balls; Are movable in the axial direction of the outer joint member along roller guide surfaces formed on both side walls of the track groove (claim 1). In other words, the present invention uses a ball instead of a conventional needle roller as a rolling element interposed between a leg shaft of a tripod member and a roller, and the ball has a skew like a needle roller. And the problem of edge load, etc., so that the expected problem of minimizing the frictional force when the roller moves along the roller guide surface, further reducing the slide resistance and induced thrust, and stabilizing it. It can be solved.

More specifically, the cylindrical inner peripheral surface of the ring concentrically arranged inside the roller via the ball is externally fitted to the spherical outer peripheral surface of the leg shaft. . Alternatively, the inner peripheral surface of the ring concentrically arranged inside the roller via the ball is gradually reduced in diameter toward the distal end of the leg shaft, and the spherical outer periphery of the leg shaft is provided. Fit outside. Further, as in the invention of claim 4, a sleeve in which the spherical inner peripheral surface of the ring concentrically arranged inside the roller via the ball is slidably fitted to the cylindrical outer peripheral surface of the leg shaft. You may make it engage with a spherical outer peripheral surface. In any case, the roller and the leg shaft can relatively perform relative movement in the axial direction of the leg shaft and swing swinging in a plane including the axis of the leg shaft.

The invention of claim 5 is characterized in that balls are arranged in a double row. The double row means that the number of rolling elements, that is, the number of rows of balls in this case, is two, and the rollers are supported by two ball rows separated in the axial direction of the leg shaft, so that the trunnion member and the outer joint member are supported. This makes it easy to rotate even when a moment load is applied between them. A tripod type constant velocity universal joint with more stable operation is realized.

The invention according to claim 6 is characterized in that the balls are arranged in a full ball state. The total ball means that as many balls as possible are put in without the cage. Therefore, the load capacity increases by arranging it in the full ball state,
For example, it is advantageous when applied to a tripod type constant velocity universal joint for a drive shaft of an automobile.

The invention according to claim 7 is characterized in that a seal member for sealing a space accommodating the ball is provided. By sealing the ball storage space with a sealing member,
Since the ball storage space and the internal space of the outer joint member can be made independent from each other, the same type or different types of lubricating materials can be sealed in these spaces, and higher durability can be exhibited. When a different kind of lubricating material is filled (claim 8), for example, the grease having a smaller coefficient of friction than the grease filled in the inner space of the outer joint member is filled in the ball storage space to thereby reduce the sliding resistance and the like. ,
Induced thrust can be further reduced.

The basic operation of the tripod type constant velocity universal joint of the present invention is the same as that of the conventional one described with reference to FIG. That is, when the outer joint member and the tripod member transmit the rotational force in an angle (operating angle) state, the roller and the leg shaft can relatively swing freely.
The roller rolls on the roller guide surface of the outer joint member while maintaining a posture parallel to the axis of the outer joint member. Therefore, the slip resistance during the operation angle operation is reduced, and the occurrence of the slide resistance and the induced thrust are suppressed.
At this time, the ball also rolls, but since there is no risk of skew or edge load unlike needle rollers, the rotation of the roller is always smooth with little resistance. As a result, the sliding resistance when the roller slides in the track groove in the axial direction of the outer joint member is further reduced, and the induced thrust when the outer joint member and the tripod member operate at the operating angle is further reduced.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

In the embodiment shown in FIG. 1, a ring (21) and a roller which are relatively rotatable on a spherical outer peripheral surface of a leg shaft (5) of a tripod member (4) via double rows of balls (22) are provided. (23) is externally fitted so as to be swingable. The outer peripheral surface of the leg shaft (5) is a spherical surface having a center of curvature on the axis of the leg shaft (5), and the cylindrical inner peripheral surface of the ring (21) is fitted on the spherical surface. Therefore, the ring (21) can swing freely about the leg shaft (5) and can move in the axial direction of the leg shaft (5). In other words,
The ring (21) and the roller (23) are unitized so as to be relatively rotatable via a ball (22).
, The ring (21) and the roller (23) are in a swingable relationship as a unit.

The inner peripheral surface of the ring (21) may have a tapered shape whose diameter gradually decreases toward the tip end of the leg shaft. In this case, the taper angle is, for example, about 0.1 ° to 3 °.
When the inner peripheral surface of the ring (21) has such a tapered shape, the ring (21) is attached to a contact portion between the inner peripheral surface of the ring (21) and the outer peripheral surface of the leg shaft (5) on the tip end side of the leg shaft. A load component force is generated that presses toward. This load component reduces the contact stress generated in the contact portion on the inner diameter side of the roller guide surface (3) on the non-load side of the outer joint member (1), so that the sliding resistance in the axial direction is reduced. It can contribute to reduction of induced thrust.

The roller (23) is housed in the track groove (2) of the outer joint member (1), and its outer peripheral surface is brought into contact with a roller guide surface (3) formed on the side wall surface of the track groove (2). While being guided, it is movable in the axial direction of the outer joint member (1). Here, the outer peripheral surface of the roller (23) is formed by a part of a spherical surface having a center of curvature in the axis of the leg shaft (5). The roller guide surface (3) is constituted by a part of a cylindrical surface whose axis is parallel to the axis of the outer joint member (1).
The cross section of the generatrix of the outer peripheral surface of the roller (23) and the roller guide surface (3) is an arc having substantially the same curvature.

The balls (22) interposed between the ring (21) and the rollers (23) are arranged in multiple rows, and the balls (22) in each row are adjacent to each other as shown in FIG. They are incorporated in a so-called total ball state where they come into contact with each other. The ball (22) is composed of a ring (21) and a roller (23).
Roller (2)
By attaching the washer (24) to the annular groove formed on the inner peripheral surface of 3), it is prevented from coming off. Ring (2
A lubricant (grease) (not shown) is filled between 1) and the roller (23) and inside the outer joint member (1), and the rotation of each component is facilitated.

In the embodiment shown in FIG. 2A, the ball (2) is formed
This is a simplified version of 2). That is, of the multiple rows of outer raceways to be provided on the inner circumference of the roller (23), one outer raceway is formed on the inner circumference of the roller (23), and the other outer raceway is formed on the roller (23). ) Is formed on the bearing ring (25) fitted on the inner peripheral surface. The method of assembling the ball (22) in this case is as follows. First,
The ring (21) is inserted by inserting the ring (21) with the lower row of balls (22) in the double row of balls positioned on the lower outer track surface of the roller (23).
The ball is assembled between the inner raceway surface of the roller and the outer raceway surface of the roller (23). Next, the bearing ring (25) is
Insert the balls (22) in the upper row in the figure with the press-fit partway into 3). Thereafter, the ball (22) is assembled between the inner raceway surface of the ring (21) and the outer raceway surface of the raceway (25) by completely press-fitting the raceway (25). A washer (26) is attached to an annular groove formed on the inner peripheral surface of the upper end portion of the roller (23) to prevent the bearing ring (25) from coming off.

As in the embodiment shown in FIG. 2B, a plurality of rows of balls (22) can be held for each row by a holder (27). In this case, the number of balls in each row is smaller than in the case of all balls, and the load capacity is correspondingly reduced. Therefore, application to a use that does not require a relatively large load capacity can be considered.

In the embodiment shown in FIG. 3A, an annular space (hereinafter, simply referred to as a ball storage space) containing a ball between a ring (21) and a roller (23) is sealed with a seal member. It is. For example, a metal shield (31) such as an iron plate is attached to the opening of the end face of the ring (21) and the roller (23). By sealing the ball storage space, an appropriate lubricant can be sealed in the ball storage space.

The embodiment shown in FIG.
The ball storage space between the ring (21) and the roller (23) is sealed by a rubber seal (32) instead of the metal shield (31) in (A). Rubber seal (3
2) may be a contact type or a non-contact type.

In the embodiment shown in FIG. 4A, a plurality of balls (22) are placed between a ring (21) and a roller (23).
Are arranged in a line. In this case, the stability against moment load is slightly inferior to that of the double row,
Since the number of balls is reduced, it is advantageous in terms of weight reduction and cost reduction.

In the embodiment shown in FIG. 4B, the outer peripheral surface of the leg shaft (5) is cylindrical, and a sleeve (24) is fitted to the cylindrical outer peripheral surface so as to be slidable in the axial direction. is there. The outer peripheral surface of the sleeve (24) is a convex spherical surface having a center of curvature on the axis of the leg shaft (5), and the convex spherical outer peripheral surface is engaged with the concave spherical inner peripheral surface of the ring (21). I have. Ring (2
1) has an inner raceway surface on its outer peripheral surface, and a ring (21)
The ball (22) is interposed between the inner raceway surface of the roller and the outer raceway surface of the roller (23). In addition, in the above-described embodiments of FIGS. 1 to 3, the balls may be arranged in a single row as shown in FIG.

Although the outer peripheral surface of the roller (23) and the roller guide surface (14) are in spherical contact in the embodiment shown in the drawings, they may be in angular contact. For example, by making the cross-sectional shape of the roller guide surface (14) a tapered shape or a Gothic arch shape with respect to the spherical outer peripheral surface of the roller (23), angular contact is realized. The angular contact between the roller and the roller guide surface makes it difficult for the roller to be inclined, so that a posture parallel to the roller guide surface can always be maintained. Further, in the embodiment shown in the drawings, a flange is formed along the upper edge of the roller guide surface (14) to regulate the posture of the roller (23). Is also possible. In particular,
When the roller and the roller guide surface make an angular contact as described above, the posture of the roller is stabilized, and such a flange can be omitted.

[0027]

According to the present invention, the roller interposed between the tripod member and the outer joint member is always supported by the ball which smoothly rotates with low friction without any problem such as skew. When the roller rolls along the roller guide surface in the track groove of the outer joint member, rolling with low friction and low resistance is realized. Therefore, the sliding resistance occurs when the roller slides in the track groove in the axial direction of the outer joint member, and is generated when the outer joint member and the tripod member transmit torque in an operating angle. The induced thrust is further reduced, and a high performance tripod type constant velocity universal joint with less vibration and noise can be provided. Therefore, the tripod-type constant velocity universal joint of the present invention can contribute to the improvement of the NVH performance of a vehicle, in which the slide resistance and the magnitude of the induced thrust are involved, especially when applied to a drive shaft of a vehicle, and the vehicle underbody design can be improved. The degree of freedom also increases.

[Brief description of the drawings]

FIG. 1A is a transverse sectional view of a tripod type constant velocity universal joint according to an embodiment of the present invention, and FIG. 1B is an enlarged sectional view perpendicular to a leg axis.

FIG. 2 is a main part cross-sectional view showing another embodiment.

FIG. 3 is a main part cross-sectional view showing another embodiment.

FIG. 4 is a cross-sectional view showing another embodiment.

5A is a cross-sectional view of a conventional tripod type constant velocity universal joint, FIG. 5B is a longitudinal cross-sectional view of the tripod type constant velocity universal joint of FIG. 5A, and FIG. FIG. 4 is a schematic perspective view illustrating a mutual relationship between a roller guide surface and a roller.

FIG. 6 is a cross-sectional view of another conventional tripod type constant velocity universal joint.

[Explanation of symbols]

 1 outer joint member 2 track groove 3 roller guide surface 4 tripod member 5 leg shaft 21 ring 22 ball 23 roller 24 sleeve

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tatsuro Sugiyama 1578 Higashikaizuka, Iwata City, Shizuoka Prefecture, Japan (72) Inventor Hisaaki Kura 1578 Higashikaizuka, Iwata City, Shizuoka Prefecture, Japan (72) Inventor Masayuki Kuroda 1-3-17 Kyomachibori, Nishi-ku, Osaka City, Osaka Inside NTN Corporation

Claims (8)

[Claims] 1. An outer joint member having three track grooves extending in an axial direction on an inner peripheral surface, and three leg shafts projecting in a radial direction, and are inserted inside the outer joint member. A tripod member, and a roller rotatably and oscillatingly fitted to each leg axis of the tripod member via a plurality of balls, wherein the roller extends along a roller guide surface formed on both side walls of the track groove. A tripod-type constant velocity universal joint which is movable in the axial direction of an outer joint member. 2. An inner peripheral surface of a ring concentrically arranged inside the roller via the ball is formed in a cylindrical shape, and is fitted to a spherical outer peripheral surface of a leg shaft. Tripod type constant velocity universal joint. 3. The inner peripheral surface of a ring concentrically disposed inside the roller via the ball is gradually reduced in diameter toward the tip end of the leg shaft, and is externally fitted to the spherical outer peripheral surface of the leg shaft. The tripod type constant velocity universal joint according to claim 1, wherein 4. A spherical outer peripheral surface of a sleeve slidably fitted on a cylindrical outer peripheral surface of a leg shaft, wherein an inner peripheral surface of a ring disposed concentrically inside the roller via the ball is spherical. 2. The tripod constant velocity universal joint according to claim 1, wherein said joint is engaged with a surface. 5. The tripod type constant velocity universal joint according to claim 1, wherein said balls are arranged in multiple rows. 6. The tripod-type constant velocity universal joint according to claim 1, wherein said balls are arranged in a full ball state. 7. The tripod constant velocity universal joint according to claim 1, further comprising a seal member for sealing a space in which the ball is housed. 8. A tripod constant velocity according to claim 7, wherein the lubricant filled in the space in which the ball is sealed and the lubricant filled in the inner space of the outer joint member are different from each other. Universal joint.