JP2007040425A - Constant velocity universal joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a constant velocity universal joint comprising a stopper mechanism capable of preventing damage of a cage even when excessive axial force is input with impact, and slide-over occurs. <P>SOLUTION: In this constant velocity universal joint where linear track grooves 26, 27 are axially formed on an outer peripheral face of an inner ring 21 and an inner peripheral face of an outer ring 22 in a state of being inclined in directions opposite to each other, and balls 23 are incorporated in a crossing portion of both track grooves 26, 27, and retained by a cage 24 mounted between the outer peripheral face of the inner ring 21 and the inner peripheral face of the outer ring 22, a projecting step portion 35 as the stopper mechanism for controlling axial displacement by interference with the balls 23, is mounted on the track groove 27 of the outer ring 22. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is a power transmission device used for automobiles, various industrial machines, and the like, and is particularly incorporated in a propeller shaft or the like used in 4WD vehicles, FR vehicles, etc., and has a structure capable of absorbing axial displacement, etc. It relates to a universal joint.

  Propeller shafts used in automobiles such as 4WD vehicles and FR vehicles include a constant velocity universal joint so as to be able to cope with axial displacement and angular displacement due to a relative position change between the transmission and the differential. Usually, from the viewpoint of reducing the weight of the entire vehicle, a sliding type constant velocity universal joint called a Lebro type (or a cross groove type) that is lightweight and has good rotational balance and vibration characteristics is incorporated.

  The Lebro type constant velocity universal joints are roughly classified into two types, that is, the float type shown in FIG. 7 and the non-float type shown in FIG. 8. Both types are characteristic of the vehicle equipped with the propeller shaft (slide amount and load capacity). Etc.).

  Both types of constant velocity universal joints have an inner ring 1, an outer ring 2, a ball 3 and a cage 4 as main components.

  The inner ring 1 has a plurality of track grooves 6 formed on the outer peripheral surface thereof. A stub shaft 8 is inserted into the center hole 5 of the inner ring 1 and is spline-fitted so that torque can be transmitted between the two by the spline fitting. The stub shaft 8 is prevented from coming off from the inner ring 1 by a snap ring 11.

  The outer ring 2 is located on the outer periphery of the inner ring 1, and the same number of track grooves 7 as the track grooves 6 of the inner ring 1 are formed on the inner peripheral surface thereof. The track groove 6 of the inner ring 1 and the track groove 7 of the outer ring 2 form an angle inclined in the opposite direction with respect to the axis (track crossing angle α), and the pair of the track groove 6 of the inner ring 1 and the track groove 7 of the outer ring 2 The ball 3 is incorporated in the crossing portion (see FIG. 9). A cage 4 is disposed between the inner ring 1 and the outer ring 2, and the ball 3 is held in a pocket 9 of the cage 4.

  An end cap 10 for preventing leakage of grease filled in the joint and preventing entry of foreign matters is fixed to one end side in the axial direction of the outer ring 2 by bolting, and the outer ring 2 and the stub on the other end side in the axial direction are fixed. A sealing device is mounted between the shaft 8. This sealing device includes a boot 12 and a metal boot adapter 13. The boot 12 has a small end portion and a large end portion, and is shaped to be folded back into a V shape in the middle. The boot adapter 13 has a cylindrical shape, has a flange fitted to the outer peripheral surface of the outer ring 2 at one end, and is fixed to the outer ring 2 by bolting together with the end cap 10. A small end portion of the boot 12 is attached to the stub shaft 8 and fastened with a boot band 14. The large end portion of the boot 12 is held by crimping the end portion of the boot adapter 13.

  In the Lebro type constant velocity universal joint configured as described above, for example, the axial displacement caused by the relative position change between the transmission and the differential caused by a vehicle collision or the like is detected with respect to the outer ring 2 and the inner ring including the inner ring 1, the ball 3, and the cage 4. The surrounding parts are absorbed by sliding in the axial direction. Thereby, the impact which arises in a vehicle body is reduced significantly, and safety improves.

  As a stopper mechanism for this axial displacement, in the float type constant velocity universal joint, the axial displacement amount is regulated by the interference between the cage 4 and the inner ring 1 as shown in FIG. When an impact is applied (the direction is indicated by a white arrow in the figure), the axial slide width (slide-in) is narrow as shown in FIG.

  On the other hand, in the non-float type constant velocity universal joint, by setting the minimum inner diameter of the cage 4 larger than the maximum outer diameter of the inner ring 1 as shown in FIG. (The direction of which is indicated by a white arrow in the figure), the slide width in the axial direction is only restricted by the interference between the ball 3 and the cage 4 (see FIG. 12). Compared with a constant velocity universal joint, as shown in FIG. 14, a sufficient axial slide width (slide-in) is ensured to absorb a large axial displacement.

As described above, the non-float type constant velocity universal joint cannot restrict the axial displacement in the same manner as the float type. Therefore, as the axial displacement stopper mechanism, the axial displacement amount due to the interference between the ball 3 and the cage 4 can be reduced. Regulation is made (see, for example, Patent Document 1).
US Pat. No. 6,159,103

  By the way, in the non-float type constant velocity universal joint as described above, since the minimum inner diameter of the cage 4 is set larger than the maximum outer diameter of the inner ring 1, when an axial impact at the time of a vehicle collision is applied, When the parts around the inner ring slide in the axial direction with respect to the outer ring 2, a sufficient sliding width in the axial direction can be secured and a large axial displacement can be absorbed. As a stopper mechanism for the axial displacement, the amount of axial displacement is regulated by the interference between the ball 3 and the cage 4.

  However, in the non-float type constant velocity universal joint, when the amount of axial displacement is regulated by the interference between the ball 3 and the cage 4 as an axial displacement stopper mechanism, an excessive axial force is shockedly input to the joint. If a slide-over in which the axial displacement exceeds a specified value occurs, the cage 4 may be damaged.

  Therefore, the present invention has been proposed in view of the above-described problems, and the object of the present invention is to avoid damage to the cage even if an excessive axial force is input impactively and a slide over occurs. An object of the present invention is to provide a constant velocity universal joint having a stopper mechanism.

  As a technical means for achieving the above-described object, the present invention provides a linear track groove on each of the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring that is inclined in directions opposite to each other in the axial direction. In a constant velocity universal joint formed in the axial direction and incorporating balls at the intersections of both track grooves and holding the balls by a cage disposed between the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring, A constant velocity universal joint characterized in that a stopper mechanism is provided in the track groove of the outer ring to restrict axial displacement due to interference of the outer ring.

  In the present invention, in the Lebro type (or cross groove type) constant velocity universal joint, a stopper mechanism for restricting axial displacement by interference with the ball is provided in the track groove of the outer ring. Since the axial displacement is regulated by interference, even if an excessive axial force is input impactively and a slide over occurs, the outer ring receives an axial load, so the impact load on the cage can be suppressed. So there is no possibility of damaging the cage.

  As the stopper mechanism in the above-described configuration, it is possible to use a protruding stepped portion where the ball is locked, or an unprocessed portion left during processing of the track groove of the outer ring. Adopting a protruding step that the ball locks as a stopper mechanism can regulate axial displacement without damaging the cage, and the unprocessed part left when processing the outer ring track groove Even when the stopper mechanism is employed, the axial displacement can be restricted without damaging the cage, as in the case of the projecting stepped portion.

  It is desirable that the stopper mechanism in the above-described configuration is provided in at least two places of the track grooves of the outer ring. If this stopper mechanism is provided only in one place in the track groove of the outer ring, it may be difficult to reliably control the axial displacement due to the interference between the outer ring and the ball. If stopper mechanisms are provided at two or more locations in the track groove, the axial displacement is reliably regulated.

  The present invention is preferably applied to a non-float type Lebro type constant velocity universal joint in which the minimum inner diameter of the cage is set larger than the maximum outer diameter of the inner ring.

  According to the present invention, since the stopper mechanism for restricting axial displacement by interference with the ball is provided in the track groove of the outer ring, the stopper mechanism regulates axial displacement by the interference between the outer ring and the ball. The same amount of axial displacement as the product can be secured, and even if an excessive axial force is input impactively and a slide over occurs, the outer ring receives the axial load, so the impact load on the cage is reduced. Since it can be suppressed, there is no possibility of damaging the cage, the cage strength can be improved, and a highly reliable constant velocity universal joint can be provided.

  FIG. 1 shows a non-float type Lebro type (or cross groove type) constant velocity universal joint in which the minimum inner diameter of the cage is set larger than the maximum outer diameter of the inner ring as an embodiment of the present invention.

  The constant velocity universal joint in this embodiment includes an inner ring 21, an outer ring 22, a ball 23, and a cage 24 as main components.

  The inner ring 21 has a plurality of tracks 26 formed on the outer peripheral surface thereof. A stub shaft 28 is inserted into the center hole 25 of the inner ring 21 and is spline-fitted, and the torque can be transmitted between the two by the spline fitting. The stub shaft 28 is prevented from coming off from the inner ring 21 by a snap ring 31.

  The outer ring 22 is located on the outer periphery of the inner ring 21, and the same number of tracks 27 as the tracks 26 of the inner ring 21 are formed on the inner peripheral surface thereof. As shown in FIG. 2, the track 26 of the inner ring 21 and the track 27 of the outer ring 22 form an angle inclined in the opposite direction to the axis (track crossing angle α), and the pair of the track 26 and the outer ring 22 of the inner ring 21 that make a pair. A ball 23 is incorporated at the intersection with the track 27. A cage 24 is disposed between the inner ring 21 and the outer ring 22, and the ball 23 is held in a pocket 29 of the cage 24.

  On one end side in the axial direction of the outer ring 22, an end cap 30 for preventing leakage of grease filled in the joint and preventing entry of foreign matter is fixed by bolting, and the outer ring 22 and the stub on the other end side in the axial direction are fixed. A sealing device is mounted between the shaft 28. This sealing device includes a boot 32 and a metal boot adapter 33. The boot 32 has a small end portion and a large end portion, and looks like a V-shape in the middle. The boot adapter 33 is cylindrical, has a flange fitted to the outer peripheral surface of the outer ring 22 at one end, and is fixed to the outer ring 22 together with the end cap 30 by bolting. A small end portion of the boot 32 is attached to the stub shaft 28 and fastened by a boot band 34. The large end portion of the boot 32 is held by crimping the end portion of the boot adapter 33.

  In the non-float type Rebro type constant velocity universal joint having the above-described configuration, for example, the axial displacement caused by the relative position change between the transmission and the differential caused by a vehicle collision or the like is caused by the inner ring 21, the ball 23 and the cage with respect to the outer ring 22. 24, the inner ring surrounding parts are absorbed by sliding in the axial direction. However, the minimum inner diameter of the cage 24 is set to the maximum of the inner ring 21 so that the axial sliding width can be sufficiently secured and a large axial displacement can be absorbed. It is set larger than the outer diameter. For this reason, the axial displacement cannot be restricted in the same manner as the float type, and a stopper mechanism for the axial displacement is newly required.

  In the constant velocity universal joint of the embodiment shown in FIG. 1, a stopper mechanism that restricts axial displacement by interference with the ball 23 is provided in the track groove 27 of the outer ring 22. In this embodiment, as the stopper mechanism, as shown in FIGS. 3 and 4, a protruding step portion 35 to which the ball 23 is locked is formed in the vicinity of the end portion of the track groove 27 of the outer ring 22. The protruding step 35 is formed over the entire width of the track groove 27. In FIG. 4, a region where the protruding step portion 35 is formed is indicated by hatching. In the protruding end portion 35, a concave receiving surface 36 with which the ball 23 is engaged has a R-shaped cross section.

  This stopper mechanism needs to be provided in at least two locations of the track groove 27 of the outer ring 22. If the stopper mechanism is provided only at one position of the track groove 27 of the outer ring 22, it may be difficult to reliably control the axial displacement due to the interference between the outer ring 22 and the ball 23. If the stopper mechanisms are provided at two or more locations in the track groove 27 of the outer ring 22, the axial displacement is reliably restricted.

  Here, in assembling the constant velocity universal joint, first, as shown in FIG. 5A, the cage 24 and the inner ring 21 are arranged in a stepped manner with respect to the outer ring 22, and all the balls 23 are placed in the pockets 29 of the cage 24. After the insertion, the assembly around the inner ring 21, the cage 24, and the ball 23 is simultaneously pushed in the axial direction to form an assembly (see FIG. 5B). For this reason, the protruding step portion 35 which is the stopper mechanism described above is formed in the vicinity of the end portion on the opposite side (left side in the drawing) to the insertion side (right side in the drawing) of the parts around the inner ring.

  In this constant velocity universal joint, as shown in FIG. 6, a projecting step 35 is provided in the track groove 27 of the outer ring 22 as a stopper mechanism for restricting axial displacement, so that an axial impact at the time of a vehicle collision is applied. In this case (the direction is indicated by a white arrow in the figure), since the ball 23 is locked to the protruding step 35, the stopper mechanism restricts the axial displacement by the interference between the outer ring 22 and the ball 23. From this, even if an excessive axial force is input impactively and a slide-over occurs, the outer ring 22 receives the axial load, so that the impact load on the cage 24 can be suppressed. There is no possibility of damage.

  In the above-described embodiment, the case where the protruding step portion 35 is formed in the track groove 27 of the outer ring 22 as the stopper mechanism has been described. However, the present invention is not limited to this, and the track groove 27 of the outer ring 22 is not limited thereto. During machining by grinding and hard milling, an unprocessed portion may be left in the vicinity of the end of the track groove 27 (hatched area in FIG. 4).

  By adopting an unmachined portion left during machining of the track groove 27 of the outer ring 22 as a stopper mechanism, as in the case of the projecting step portion 35, an excessive axial impact at the time of a vehicle collision is applied and a slide over is caused. Even if it occurs, this unprocessed portion can regulate the axial displacement due to the interference between the outer ring 22 and the ball 23, and the outer ring 22 receives the axial load, so the impact load on the cage 24 can be suppressed. The possibility of damaging the cage 24 is eliminated. When an unmachined portion is employed as the stopper mechanism, the track groove 27 is not machined to the end surface of the outer ring 22, so that the machining time can be shortened and the tool life can be improved.

In embodiment of this invention, it is sectional drawing which shows the non-float type Lebro type | mold constant velocity universal joint. FIG. 2 is a partial front view for explaining a track crossing angle α in the inner ring and the outer ring of FIG. 1. It is sectional drawing which shows the outer ring | wheel of FIG. FIG. 2 is a partially enlarged view showing a track groove viewed from the inner peripheral surface of the outer ring in FIG. 1. It is for demonstrating the assembly point of the constant velocity universal joint of FIG. 1, (a) is sectional drawing which shows the state before inserting an inner ring, a cage, and a ball | bowl in an outer ring | wheel, (b) is an inner ring, a cage, and a ball | bowl. It is sectional drawing which shows the state after inserting in an outer ring | wheel. It is sectional drawing which shows the state which the outer ring | wheel and the ball interfered in the constant velocity universal joint of FIG. It is sectional drawing which shows the float type lebro type | mold constant velocity universal joint in the prior art example of a constant velocity universal joint. It is sectional drawing which shows the non-float type Lebro type constant velocity universal joint in the conventional example of a constant velocity universal joint. FIG. 9 is a partial front view for explaining a track crossing angle α in the inner ring and the outer ring of FIGS. 7 and 8. It is sectional drawing which shows the state which the inner ring | wheel and the cage interfered with the constant velocity universal joint of FIG. It is sectional drawing which shows the state which the ball | bowl and the cage interfered in the constant velocity universal joint of FIG. It is explanatory drawing which shows the relationship between the pocket of a cage and a ball | bowl with the constant velocity universal joint of FIG. It is a slide diagram in the constant velocity universal joint of FIG. It is a slide diagram in the constant velocity universal joint of FIG.

Explanation of symbols

21 Inner ring 22 Outer ring 23 Ball 24 Cage 26, 27 Track groove 35 Stopper mechanism (protruding step)

Claims (5)

  A straight track groove is formed on each of the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring in the axial direction in a state of being inclined in opposite directions with respect to the axial direction, and balls are incorporated at the intersections of both track grooves, In a constant velocity universal joint in which these balls are held by a cage disposed between the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring, a stopper mechanism for restricting axial displacement by interference with the ball is provided in the track groove of the outer ring. A constant velocity universal joint characterized by being provided.   The constant velocity universal joint according to claim 1, wherein the stopper mechanism is a projecting stepped portion on which a ball is locked.   The constant velocity universal joint according to claim 1, wherein the stopper mechanism is a non-processed portion left during processing of the track groove of the outer ring.   The constant velocity universal joint according to any one of claims 1 to 3, wherein the stopper mechanism is provided in at least two or more of the track grooves of the outer ring.   The constant velocity universal joint according to any one of claims 1 to 4, wherein a minimum inner diameter of the cage is set larger than a maximum outer diameter of the inner ring.

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