JP2023161283A - Slide type constant velocity universal joint - Google Patents

Abstract

To improve workability when handing a slide type constant velocity universal joint equipped with a slipping-out preventive mechanism locking a retainer ring to a tapered surface.SOLUTION: An annular groove 23 has a tapered surface 27 decreasing a diameter toward an opening side of an outside joint member 11. A tangent line L1 at a contact point α between a ball 13 and a retainer ring 24, and a tangent line L2 at a contact point β between the retainer ring 24 and the tapered surface 27 has a wedge angle θ1 opening from the opening side toward a deep side of the outside joint member 11. A diameter difference ΔD between an outer diameter D1 of the retainer ring 24 installed to the annular groove 23 and an inner diameter D2 of an opening side part (cylindrical surface 22) with respect to the annular groove 23 of the outside joint member 11 is 40% or more of a diameter D of a wire material forming the retainer ring 24.SELECTED DRAWING: Figure 4

Description

The present invention relates to a sliding constant velocity universal joint.

In drive shafts used in automobile power transmission systems, a sliding constant velocity universal joint is connected to the inboard side (the center side in the vehicle width direction) of the intermediate shaft, and the sliding constant velocity universal joint is connected to the outboard side (the end in the vehicle width direction). A fixed constant velocity universal joint is often connected to the side). The sliding type constant velocity universal joint referred to here allows both angular displacement and axial relative movement between two axes, while the fixed type constant velocity universal joint allows angular displacement between two axes. However, relative movement in the axial direction between the two axes is not permitted.

As sliding constant velocity universal joints, double offset type constant velocity universal joints (DOJ) and cross groove type constant velocity universal joints (LJ), which use balls as rolling elements to transmit rotational torque, are known.

When assembling the drive shaft to the vehicle body, first assemble the sliding type constant velocity universal joint mentioned above to the engine side (inboard side), then assemble the fixed type constant velocity universal joint to the wheel side (outboard side). . On the wheel side, wheel bearings are attached to fixed constant velocity universal joints, and then attached to the suspension system of the vehicle body using knuckles.

At the time when the sliding type constant velocity universal joint of the drive shaft is assembled to the engine side of the vehicle body, the fixed type constant velocity universal joint is not assembled to the wheel bearing on the wheel side. Therefore, the sliding constant velocity universal joint may be subjected to a large load in the slide-out direction due to the dead weight of the drive shaft made up of the fixed type constant velocity universal joint and the shaft. In such a state, a slide-over may occur in which the internal components of the sliding constant velocity universal joint (inner joint member, ball, and retainer) protrude from the open end of the outer joint member.

In Patent Document 1 listed below, in order to prevent the internal components of a sliding constant velocity universal joint from sliding over, a retaining mechanism is provided that restricts the amount of axial displacement of the internal components with respect to the outer joint member. Specifically, as shown in FIG. 8, an annular groove 123 is formed on the inner peripheral surface near the open end of the outer joint member 111, and the circlip 124 attached to this annular groove 123 is caused to interfere with the ball 113. This restricts the axial movement of internal components including the ball 113 toward the opening side (right side in the figure).

Furthermore, in Patent Document 2 below, as shown in FIG. 9, a tapered surface 227 is formed in an annular groove 223 into which a circlip 224 is mounted. By causing the circlip 224 in contact with the tapered surface 227 to interfere with the ball 213, internal components including the ball 213 are prevented from coming off. With the ball 213 in contact with the circlip 224, a tangent L1' in the axial cross section at the contact point α' between the circlip 224 and the ball 213 and a contact point β' between the circlip 224 and the tapered surface 227. The tangent L2' in the axial cross section has a wedge angle θ' that opens toward the back side (left side in the figure) of the outer joint member 211. As a result, the axial dimension E1 of the opening side portion of the outer joint member 211 can be made shorter than the annular groove 223 of the outer joint member 211, compared to the outer joint member 111 of FIG. 8 in which the annular groove 123 with a rectangular cross section is formed. E1<E0), the constant velocity universal joint can be made more compact and lighter.

Patent No. 4637723 JP2017-207198A

In the constant velocity universal joint shown in FIG. 9, the circlip 224 is locked in contact with the tapered surface 227. Therefore, in order to make the axial dimension of the outer joint member 211 as short as possible, it is considered preferable to make the axial length of the tapered surface 227 as short as possible within a range that can ensure the contact point β' with the circlip 224. It was getting worse.

However, if the above-mentioned constant velocity universal joint is bumped into something even slightly when it is assembled into a vehicle or transported, the ball 213 will collide with the circlip 224 due to the impact load at this time, and the circlip 224 will move toward the open side. It may move slightly to the right side in the figure. At this time, if the length of the tapered surface 227 is short, the circlip 224 will reach the inner diameter end of the tapered surface 227 and come off the annular groove 223, and as a result, the internal parts including the ball 213 will protrude from the outer joint member 211. There is a fear. Therefore, when handling the sliding type constant velocity universal joint, great care must be taken to avoid the above situation, which reduces work efficiency.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to improve workability when handling a sliding constant velocity universal joint equipped with a retaining mechanism that locks a retaining ring on a tapered surface.

In order to solve the above problems, the present invention provides an outer joint member that is open at one end in the axial direction and has a plurality of linear track grooves formed on the inner circumferential surface, and an outer joint member disposed on the inner circumference of the outer joint member, The inner joint member includes an inner joint member having a plurality of linear track grooves formed on an outer circumferential surface, and a plurality of balls arranged between the track grooves of the outer joint member and the track grooves of the inner joint member. In a sliding constant velocity universal joint that allows axial displacement and angular displacement of a joint member with respect to the outer joint member,
a retaining mechanism including an annular groove formed near the opening side end of the inner circumferential surface of the outer joint member, and a retaining ring attached to the annular groove and with which the ball abuts from the axial direction;
The annular groove has a tapered surface whose diameter decreases toward the opening side of the outer joint member,
With the ball in contact with the retaining ring and the retaining ring in contact with the tapered surface, a tangent in the axial cross section at the contact point between the ball and the retaining ring and the retaining ring A tangent in the axial cross section at the point of contact with the tapered surface has a wedge angle that opens from the opening side of the outer joint member toward the back side,
The difference in diameter between the outer diameter of the retaining ring attached to the annular groove and the inner diameter of a portion of the outer joint member that is closer to the opening than the annular groove is 40% or more of the diameter of the wire forming the retaining ring. characterized by something.

As described above, in the present invention, the diameter difference ΔD between the outer diameter D1 of the retaining ring attached to the annular groove and the inner diameter D2 of the portion of the outer joint member on the opening side of the annular groove is determined by the diameter difference ΔD of the wire forming the retaining ring. The diameter was set to be 40% or more of the diameter D (see FIG. 4). This ensures a sufficient height (diameter difference) of the opening side of the outer joint member relative to the outer diameter of the retaining ring, making it difficult for the retaining ring to come off from the annular groove even when an impact load is applied. .

In the constant velocity universal joint described above, if the inner diameter of the opening side part is too large than the annular groove of the outer joint member, most of the retaining ring attached to the annular groove will be damaged when the outer joint member is viewed from the opening side. It is hidden by the opening side portion of the outer joint member. In this case, it becomes difficult to visually check whether the retaining ring is properly installed in the annular groove from the opening side of the outer joint member.

Therefore, the diameter difference ΔD between the outer diameter D1 of the retaining ring attached to the annular groove and the inner diameter D2 of the opening side portion of the outer joint member should be set to 60% or less of the diameter D of the wire forming the retaining ring. preferable. As a result, the retaining ring installed in the annular groove protrudes sufficiently inward from the opening side of the outer joint member, so that the retaining ring installed in the annular groove can be easily checked from the opening side of the outer joint member. Can be visually observed.

If the angle of inclination of the tapered surface of the annular groove with respect to the axial direction of the outer joint member is 25 degrees or less, the annular groove having the tapered surface can be formed in one turning process. Further, in order to shorten the axial dimension of the outer joint member, it is preferable that the inclination angle of the tapered surface of the annular groove with respect to the axial direction of the outer joint member is 20° or more.

As described above, according to the present invention, the retaining ring is difficult to come off from the annular groove having a tapered surface, so that the workability when handling the sliding type constant velocity universal joint is improved.

FIG. 1 is an axial cross-sectional view of a sliding constant velocity universal joint according to an embodiment of the present invention. FIG. 2 is an axial cross-sectional view showing a state in which internal components of the constant velocity universal joint in FIG. 1 have moved toward the opening side. FIG. 3 is an enlarged sectional view of FIG. 2; FIG. 4 is an enlarged sectional view of section A in FIG. 3; FIG. 2 is a side view of the outer joint member of the constant velocity universal joint shown in FIG. 1, viewed from the opening side thereof. (A) is a side view of the outer joint member as seen from its opening side, and (B) is a sectional view taken along line PP in (A). FIG. 6B is an enlarged sectional view of portion B in FIG. 6(B). FIG. 2 is a sectional view showing a retaining mechanism of a conventional sliding type constant velocity universal joint. FIG. 7 is a cross-sectional view showing a retaining mechanism of another conventional sliding type constant velocity universal joint.

Embodiments of a sliding constant velocity universal joint according to the present invention will be described in detail below based on the drawings.

FIG. 1 shows the overall configuration of a double offset type constant velocity universal joint (hereinafter simply referred to as a constant velocity universal joint), which is one type of sliding constant velocity universal joint assembled to a drive shaft of a vehicle.

The constant velocity universal joint of this embodiment includes a cup-shaped outer joint member 11 with one axial end open, an inner joint member 12, a plurality of balls 13 as rolling elements, and a cage 14. An internal component 15 consisting of an inner joint member 12, a ball 13, and a cage 14 is accommodated on the inner periphery of the outer joint member 11 so as to be axially displaceable. One shaft end of the shaft 17 is connected to the shaft hole 16 of the inner joint member 12 by spline fitting.

In the inner circumferential surface 19 of the outer joint member 11, linear track grooves 18 extending in the axial direction are formed at a plurality of positions at equal intervals in the circumferential direction. On the outer circumferential surface 21 of the inner joint member 12, linear track grooves 20 extending in the axial direction are formed at a plurality of circumferential locations at equal intervals. The ball 13 is disposed between the track groove 18 of the outer joint member 11 and the track groove 20 of the inner joint member 12 that face each other in the radial direction, and transmits rotational torque between the two joint members 11 and 12. The cage 14 has a plurality of pockets 14a arranged at equal intervals in the circumferential direction. Each pocket 14a holds one ball 13.

A spherical surface portion 14b that slides on the inner circumferential surface 19 of the outer joint member 11 is formed on the outer circumferential surface of the cage 14, and a spherical surface portion 14b that slides on the outer circumferential surface 21 of the inner joint member 12 is formed on the inner circumferential surface of the cage 14. A portion 14c is formed. The center of curvature of the spherical portion 14b on the outer peripheral surface of the cage 14 and the center of curvature of the spherical portion 14c on the inner peripheral surface are offset by an equal distance on the opposite side in the axial direction with respect to the joint center. Therefore, when a working angle is given between the outer joint member 11 and the inner joint member 12, the ball 13 held in the pocket 14a of the cage 14 always faces the bisector of the working angle at any working angle. This ensures constant velocity between the outer joint member 11 and the inner joint member 12. Furthermore, the balls 13 held by the cage 14 roll on the track grooves 18 of the outer joint member 11, thereby allowing the internal component 15 to freely slide in the axial direction with respect to the outer joint member 11.

Although not shown in the figures, this constant velocity universal joint is equipped with a retractable resin or rubber joint in order to prevent the leakage of lubricants such as grease sealed inside the joint and to prevent foreign matter from entering from outside the joint. By stretching the bellows-like boot between the outer joint member 11 and the shaft 17, the opening of the outer joint member 11 is closed.

This constant velocity universal joint has a retaining mechanism 25 that prevents the internal component 15 from sliding over from the open end of the outer joint member 11.

As shown in FIGS. 1 and 2, the retaining mechanism 25 includes an annular groove 23 formed near the opening side end of the track groove 18 and the inner circumferential surface 19 of the outer joint member 11, and an annular groove 23 that fits into the annular groove 23. It is composed of a circlip 24 as a retaining ring attached thereto. The circlip 24 is formed by bending a wire rod having a circular cross section into a ring shape, and has an end ring shape that is partially discontinuous in the circumferential direction (see FIG. 5).

3 and 4 show a state in which the ball 13 is brought into contact with the circlip 24 due to the axial displacement of the internal component 15. As shown in FIG. 4, the annular groove 23 of the retaining mechanism 25 has a tapered surface 27 whose diameter decreases toward the opening side of the outer joint member 11. As shown in FIG. The annular groove 23 of this embodiment includes a tapered surface 27, a flat surface 28 extending from the opening side end of the track groove 18 of the outer joint member 11 to the outer diameter side, and a portion between the outer diameter end of the tapered surface 27 and the flat surface 28. It has a cylindrical surface 29 that connects the outer diameter end.

The axial dimension G from the contact point γ between the circlip 24 and the cylindrical surface 29 to the flat surface 28 is longer than the radius R of the wire constituting the circlip 24. Thereby, the circlip 24 can be brought into reliable contact with the cylindrical surface 29 of the annular groove 23. Note that if the axial dimension of the cylindrical surface 29 is too large, the axial dimension of the track groove 18 will be correspondingly shortened, and there is a possibility that the effective sliding length of the ball 13 cannot be ensured. Therefore, it is preferable that the axial dimension of the cylindrical surface 29 be as short as possible within a range that allows the circlip 24 to reliably contact the cylindrical surface 29 as described above.

With the ball 13 in contact with the circlip 24, the circlip 24 contacts the ball 13 at a contact point α and the tapered surface 27 at a contact point β. Between the tangent L1 in the axial cross section at the contact point α between the ball 13 and the circlip 24 and the tangent L2 in the axial cross section at the contact point β between the circlip 24 and the tapered surface 27, there is an outer joint member. A wedge angle θ1 is formed that opens from the opening side of 11 toward the back side. Note that the direction of the tangent line L2 coincides with the direction in which the tapered surface 27 extends.

The wedge angle θ1 is preferably set within a range of 5° to 25°. If the wedge angle θ is smaller than 5°, the force for locking the circlip 24 by the tapered surface 27 will not be sufficient, making it difficult to reliably prevent the internal components from sliding over. On the other hand, when the wedge angle θ is larger than 25°, the direction of the load applied from the circlip 24 to the annular groove 23 of the outer joint member 11 becomes close to the sliding direction, which is disadvantageous in terms of groove strength and makes weight reduction difficult.

In this embodiment, the outer diameter D1 of the circlip 24 attached to the annular groove 23 and the minimum inner diameter of the portion of the outer joint member 11 on the opening side of the annular groove 23 (in the illustrated example, the inner diameter D2 of the cylindrical surface 22 ) is 40% to 60% of the diameter D of the wire forming the circlip 24 over the entire circumference. The diameter difference ΔD between the inner diameter D2 of the cylindrical surface 22 and the outer diameter D1 of the circlip 24, shown by a solid line in FIG. 4, is 40% of the diameter D of the wire forming the circlip 24. The diameter difference ΔD between the inner diameter of the surface 22 and the outer diameter D1 of the circlip 24 is 60% of the diameter D of the wire forming the circlip 24. That is, the cylindrical surface 22 is provided between the radial position shown by the solid line and the radial position shown by the dotted line in FIG.

In the retaining mechanism 25 having the above configuration, when a large load is applied to the internal component 15 in the slide-out direction, the ball 13 of the internal component 15 comes into contact with the circlip 24, thereby reducing the amount of axial displacement of the ball 13. (See Figures 3 and 4).

At this time, the tangent L1 at the contact point α between the ball 13 and the circlip 24 and the tangent L2 at the contact point β between the circlip 24 and the tapered surface 27 of the annular groove 23 are on the opening side of the outer joint member 11. A wedge angle θ1 is formed that expands toward the back side. Thereby, by causing the ball 13 to interfere with the circlip 24 held in the annular groove 23, the amount of axial displacement of the internal component 15 can be reliably regulated.

Further, since the diameter difference ΔD between the outer diameter D1 of the circlip 24 and the inner diameter D2 of the cylindrical surface 22 of the outer joint member 11 is 40% or more of the diameter D of the wire forming the circlip 24, the circlip 24 A sufficient height (diameter difference) of the cylindrical surface 22 with respect to the outer diameter end (that is, the cylindrical surface 29 of the annular groove 23) can be ensured. Further, the axial length of the tapered surface 27 of the annular groove 23 can be ensured sufficiently, for example, the length in the axial cross section of the region of the tapered surface 27 on the opening side from the contact point β with the circlip 24. C can be made longer than the radius R of the wire forming the circlip 24. As a result of the above, even if the circlip 24 moves slightly toward the opening side with respect to the outer joint member 11 due to an impact load or the like, it becomes difficult to get over the tapered surface 27 and therefore difficult to come off from the annular groove 23.

Furthermore, the annular groove 2 A sufficient amount of protrusion (40% or more of the diameter D) of the circlip 24 attached to the outer joint member 11 from the cylindrical surface 22 of the outer joint member 11 can be ensured. As a result, when the outer joint member 11 is viewed from the opening side (right side in FIG. 4), the circlip 24 attached to the annular groove 23 can be easily seen as shown in FIG. The state of attachment to the groove 23 (whether or not it is attached normally) can be easily confirmed from the opening side of the outer joint member 11. In this embodiment, the entire circumference of the circlip 24 fitted in the annular groove 23 protrudes inwardly from the cylindrical surface 22 of the outer joint member 11, so that the state in which the circlip 24 is attached to the annular groove 23 is It becomes easier to check.

If the opening side portion (cylindrical surface 22) of the outer joint member 11 protrudes more radially inward than the annular groove 23 than the track groove 18, the ball 13 will be pushed outward when the internal parts are assembled into the inner periphery of the outer joint member 11. There is a possibility that it may interfere with the opening of the joint member 11 and cannot be assembled. Therefore, the cylindrical surface 22 of the outer joint member 11 is arranged on the extension line of the bottom (outermost diameter part) of the track groove 18 or on the outer diameter side thereof.

As described above, when ensuring the diameter difference ΔD between the outer diameter D1 of the circlip 24 and the inner diameter D2 of the cylindrical surface 22 of the outer joint member 11 to be 40% or more of the diameter D of the wire of the circlip 24, the outer joint member If the inclination angle θ2 of the tapered surface 27 with respect to the axial direction of the outer joint member 11 is too small, the axial dimension of the tapered surface 27 becomes long, and the axial dimension of the outer joint member 11 becomes large. Therefore, it is preferable that the inclination angle θ2 of the tapered surface 27 is 20° or more.

The annular groove 23 can be formed by turning. For example, as shown in FIGS. 6A, 6B and 7, an annular groove 23 is formed by machining the opening side end surface 26 of the outer joint member 11 with a turning tip 30 (see the arrow in FIG. 7). ). Specifically, with the outer joint member 11 rotated around the axis, the turning tip 30 is brought into contact with the end surface 26 of the outer joint member 11 from the opening side, and the cylindrical surface 22, the tapered surface 27, and the cylindrical surface 29 are , and the annular groove 23 can be formed by cutting while continuously moving it along the shape of the flat surface 28 . In the illustrated example, after forming the annular groove 23 with the turning tip 30, the turning tip 30 is moved along the flat surface 28 until it reaches the inner circumferential surface 19, and the annular groove 23 is opened in the inner circumferential surface 19. .

At this time, if the inclination angle θ2 (see FIG. 4) of the tapered surface 27 is too large, there is a possibility that processing cannot be performed in one step with the turning tip 30 as described above. Therefore, it is preferable that the inclination angle θ2 of the tapered surface 27 is 25° or less.

In the above embodiment, the case where the cylindrical surface 29 was provided between the tapered surface 27 and the flat surface 28 of the annular groove 23 was shown, but the present invention is not limited to this, and for example, similar to the conventional product shown in FIG. The tapered surface 27 and the flat surface 28 may be continuous with a curved surface having an arcuate cross section.

In addition, in the above embodiment, the case where the present invention is applied to a double offset type constant velocity universal joint is illustrated, but other ball type sliding type constant velocity universal joints (for example, cross groove type constant velocity universal joint) It is also applicable to

11 Outer joint member 12 Inner joint member 13 Ball 14 Cage 15 Internal component 17 Shaft 18 Track groove 19 Inner circumferential surface 20 Track groove 21 Outer circumferential surface 22 Cylindrical surface (opening side part)
23 Annular groove 24 Circlip (retaining ring)
25 Retaining mechanism 26 Opening side end surface 27 Tapered surface 28 Flat surface 29 Cylindrical surface 30 Turning tip

Claims (3)

an outer joint member that is open at one end in the axial direction and has a plurality of linear track grooves formed on its inner peripheral surface; and an outer joint member that is arranged on the inner periphery of the outer joint member and has a plurality of linear track grooves formed on its outer peripheral surface. and a plurality of balls disposed between track grooves of the outer joint member and track grooves of the inner joint member, the inner joint member has an axial displacement of the inner joint member with respect to the outer joint member and In sliding constant velocity universal joints that allow angular displacement,
a retaining mechanism including an annular groove formed near the opening side end of the inner circumferential surface of the outer joint member, and a retaining ring attached to the annular groove and with which the ball abuts from the axial direction;
The annular groove has a tapered surface whose diameter decreases toward the opening side of the outer joint member,
With the ball in contact with the retaining ring and the retaining ring in contact with the tapered surface, a tangent in the axial cross section at the contact point between the ball and the retaining ring and the retaining ring A tangent in the axial cross section at the point of contact with the tapered surface has a wedge angle that opens from the opening side of the outer joint member toward the back side,
The difference in diameter between the outer diameter of the retaining ring attached to the annular groove and the inner diameter of a portion of the outer joint member that is closer to the opening than the annular groove is 40% or more of the diameter of the wire forming the retaining ring. A sliding type constant velocity universal joint. The sliding constant velocity universal joint according to claim 1, wherein the diameter difference is 60% or less of the diameter of the wire forming the retaining ring. 3. The sliding constant velocity universal joint according to claim 1, wherein the tapered surface has an inclination angle of 20 to 25 degrees with respect to the axial direction of the outer joint member.

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