JP2009115200A - Boots for constant velocity universal joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide boots for a constant velocity universal joint capable of lengthening the service life by improving rotational expansion performance, without having adverse influence on the other performance except for the rotational expansion performance of its boots. <P>SOLUTION: In a trough part 23 constituting a bellows part 14 of the boots 11, an annular snap ring 26 is embedded as a regulating member in a first trough part 24 and a second trough part 25 on the large diameter end part side. The snap ring 26 is made of metal. In the boots 11, the whole including a first crest part 24 and a second crest part 25 is formed of a resin construction material, and the metal constituting the snap ring 26 uses the one larger in rigidity than resin for constituting the boots 11. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a boot for a constant velocity universal joint that is used in a drive shaft of an automobile or various industrial machines and is mounted on a constant velocity universal joint that transmits high-speed rotational torque.

  The constant velocity universal joint boot has a function to prevent the leakage of lubricating components such as grease and lubricating oil enclosed in the constant velocity universal joint (inside the joint) and the entry of foreign matter from the outside into the joint. Fulfill.

  As a constant velocity universal joint to which such a constant velocity universal joint boot (hereinafter abbreviated as a boot) is attached, FIG. 3 shows a ball fixture type constant velocity universal joint (BJ) which is one of the fixed type constant velocity universal joints. Is illustrated. The fixed type constant velocity universal joint is a constant velocity universal joint that allows only angular displacement, and is used, for example, on the wheel side of a drive shaft in an automobile.

  The constant velocity universal joint 101 includes an outer ring 102, an inner ring 103, a ball 104, and a cage 105 as main parts. Inside the outer ring 102, an internal part 106 including the inner ring 103, the ball 104, and the cage 105 is accommodated. ing.

  The outer ring 102 has an opening at one end, and a plurality of curved track grooves 107 are formed on the inner spherical surface. The inner ring 103 has a plurality of curved track grooves 108 formed on the outer spherical surface, and a shaft 109 is spline-fitted into the center hole 119 and is prevented from coming off by a circlip 110. A ball 104 is interposed between the track groove 107 of the outer ring 102 and the track groove 108 of the inner ring 103, and this ball 104 is held in a pocket 117 of the cage 105 disposed between the outer ring 102 and the inner ring 103. Yes.

Now, the opening of the outer ring 102 is covered with the boot 111 already described. The boot 111 is made of a resin material and has a large diameter end portion 112, a small diameter end portion 113, and a bellows portion 114 that connects the large diameter end portion 112 and the small diameter end portion 113. The bellows portion 114 is formed by alternately forming a plurality of crest portions 122 and trough portions 123, and the crest portion 122 and the trough portion 123 have an inner diameter reduced from the large diameter end portion side toward the small diameter end portion side. ing. The large-diameter end portion 112 is attached to the outer peripheral surface 120 of the open end portion 118 of the outer ring 102, and the small-diameter end portion 113 is attached to the outer peripheral surface 121 of the shaft 109. Each attachment portion adds a boot band (115, 116). It is fastened and fixed (see Patent Document 1).
JP 2001-208215 A

  The constant velocity universal joint described in Patent Document 1 shown in FIG. 3 has excellent bending durability when the joint takes an operating angle because the boot has a bellows shape. However, this type of boot is difficult to cope with the recent increase in the speed of automobiles.

  The reason for this is that, in the boot shown in FIG. 3, when the constant velocity universal joint 101 rotates at a high speed during traveling of an automobile or the like, the first trough and the second trough on the large-diameter end side are caused by the centrifugal force. (124, 125) tends to expand and the inner diameter difference from the peak portion 122 tends to disappear (this is referred to as poor rotational expansion performance). As a result, the boot 111 may not perform its function.

  As means for solving the above problems, there is a method of reducing the size of the boot 111 or increasing the hardness of the boot 111.

  However, in the former case, when the constant velocity universal joint 101 takes an operating angle, there is a problem that the shaft 109 and the valley portion 123 of the boot 111 come into contact with each other to cause early wear of the valley portion 123 due to the interference. In the latter case, when the operating angle is taken, it cannot be easily deformed, and the bending durability of the boot 111 tends to decrease. For this reason, a decrease in durability of the boot 111 has been regarded as a problem, and in particular, there has been a concern about a decrease in durability due to early fatigue of the valley 123.

  The present invention has been made in view of the above circumstances, and has an adverse effect on performances other than the rotational expansion performance of the boots for constant velocity universal joints that can extend the life by improving the rotational expansion performance. The purpose is to provide without giving.

  A boot for a constant velocity universal joint according to the present invention for solving the above problems includes a large-diameter end portion attached to an outer joint member, a small-diameter end portion attached to a shaft member extending from the inner joint member, and the large-diameter end. And a bellows part connecting the small-diameter end part, the bellows part comprising a plurality of crests and a plurality of troughs alternately, the crests and the troughs being large-diameter ends. A constant velocity universal joint boot whose inner diameter is reduced from the portion side toward the small diameter end portion side, characterized in that a regulating member is attached to the valley portion to suppress expansion during high speed rotation of the constant velocity universal joint. And

  As described above, when the regulating member is attached to the valley portion constituting the bellows portion of the boot, the valley portion provided with the regulating member has a high rigidity (hardness to deform), and the constant velocity universal joint with the boot attached thereto. It becomes difficult to be affected by the centrifugal force generated when the high speed (hereinafter referred to as constant velocity universal joint) rotates.

  In the present invention, the regulating member is preferably provided in the first valley portion or the second valley portion on the large diameter end portion side in the valley portion of the boot. The “first valley at the large diameter end” is the first valley from the large diameter end in the valley of the boot, and the “second valley at the large diameter end” "Means the second trough from the large diameter end side in the trough of the boot.

  Since the inner diameter of the valley portion on the large diameter end portion side of the boot is increased, when the constant velocity universal joint rotates at a high speed, it is easily expanded due to the influence of the centrifugal force. Thus, when the valley portion expands, the inner diameter difference between the mountain portion and the valley portion disappears, and the boot does not perform its function. This phenomenon is remarkable in the first valley portion and the second valley portion on the large diameter end side.

  Therefore, as in the present invention, when the regulating member is provided in the first valley portion or the second valley portion on the large diameter end portion side in the valley portion of the boot, the first valley portion or the second valley on the large diameter end portion side. The rigidity of the portion increases, and the expansion of the constant velocity universal joint due to the centrifugal force during high-speed rotation is suppressed, and the rotational expansion performance of the boot is improved. As a result, it is possible to extend the life of the boot. In addition, if the regulating member is attached only to one of the first valley portion and the second valley portion on the large-diameter end portion side, the above-described functions and effects of the present invention can be obtained. It is preferable to attach to both the first trough and the second trough on the radial end side because the above-described functions and effects become remarkable.

  The regulating member is preferably annular, and by making the regulating member annular, the valley of the boot can increase the rigidity over the entire length in the circumferential direction, and the valley is less than when the regulating member is not annular. It is possible to improve the high-speed rotational expansibility of the boot by suppressing the expansion of the portion. For this reason, the lifetime improvement of a boot becomes more reliable. If the restricting member is annular, it is not necessary to locally attach the restricting member to the valley portion, so that the boot can be easily formed and workability related to the formation of the boot can be improved.

  In addition, when the regulating member is attached to the valley, the regulating member can be attached to the valley by integral molding with the boot when the regulating member is embedded in the valley, so that the work related to the molding of the boot is performed. It is preferable because the property can be improved.

  In the above invention, a circlip can be used as the regulating member embedded in the valley. The circlip is easy to follow the movement of the boot when it is bent due to its flexibility, so that it does not adversely affect the operability of the boot and is suitable as a regulating member used in the present invention.

  In addition, it is desirable to use a restriction member made of a material having higher rigidity than the valley portion of the bellows portion of the boot.

  In this case, since the rigidity of the regulating member is higher than that of the trough, even if the constant velocity universal joint rotates at a high speed and is affected by the centrifugal force, the regulating member does not expand following the trough. For this reason, the regulating member can sufficiently exhibit the effect intended by the present invention.

  According to the constant velocity universal joint boot of the present invention, when the constant velocity universal joint equipped with the boot rotates at a high speed, it is possible to suppress expansion of the valley portion of the bellows portion due to the centrifugal force. Therefore, the rotational expansion performance of the boot can be improved. As a result, the boot life can be extended.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 shows a fixed type constant velocity universal joint called a ball fixture type (BJ) equipped with the constant velocity universal joint boot of the present invention.

The constant velocity universal joint 1 has an outer ring 2, an inner ring 3, a ball 4 and a cage 5 as main parts, and an inner part 6 composed of the inner ring 3, the ball 4 and the cage 5 is accommodated inside the outer ring 2. ing.

  The outer ring 2 has an opening at one end, and a plurality of curved track grooves 7 are formed on the inner spherical surface. The inner ring 3 is formed with a plurality of curved track grooves 8 on the outer spherical surface, and a shaft 9 as a shaft member is spline-fitted into the center hole 19 thereof. The shaft 9 is secured by a circlip 10 interposed between a fitting groove 28 formed on the outer peripheral surface of the shaft 9 and a fitting groove 27 formed in the center hole 19 of the inner ring 3. A ball 4 is interposed between the track groove 7 of the outer ring 2 and the track groove 8 of the inner ring 3, and this ball 4 is held in a pocket 17 of the cage 5 disposed between the outer ring 2 and the inner ring 3. Yes.

  Now, the opening of the outer ring 2 is covered with the boot 11 already described. The boot 11 is made of a resin material and has a large diameter end portion 12, a small diameter end portion 13, and a bellows portion 14 that connects the large diameter end portion 12 and the small diameter end portion 13. The bellows portion 14 includes a plurality of ridge portions 22 and valley portions 23 that are alternately continuous. The ridge portions 22 and the valley portions 23 have an inner diameter that decreases from the large-diameter end portion toward the small-diameter end portion. ing. The large-diameter end portion 12 is attached to the outer peripheral surface 20 of the open end portion 18 of the outer ring 2, the small-diameter end portion 13 is attached to the outer peripheral surface 21 of the shaft 9, and each attachment portion adds a boot band (15, 16). Tightened and fixed.

  In this embodiment, in the valley portion 23 of the bellows portion 14 of the boot 11, an annular circlip 26 is embedded as a regulating member in the first valley portion 24 and the second valley portion 25 on the large diameter end side. Here, “the first valley portion 24 and the second valley portion 25 on the large-diameter end portion side” are the first valley portion 23 counted from the large-diameter end portion side in the valley portion 23 of the bellows portion 14, respectively. The second valley 23 is meant. 2 shows an enlarged view of a portion X in FIG.

  As shown in FIG. 2, in the valley portion 23 of the bellows portion 14, the first valley portion 24 and the second valley portion 25 on the large-diameter end portion side have large inner diameters. It tends to expand under the influence of centrifugal force when it rotates. However, since the rigidity of the first trough portion 24 and the second trough portion 25 is increased by embedding the circlip 26 that is a regulating member as in the present embodiment, the influence of the centrifugal force of the constant velocity universal joint 1 is increased. And the expansion of the boot 11 is improved. As a result, the life of the boot 11 can be extended. The circlip 26, which is a restricting member, can obtain the above-described functions and effects of the present invention even when attached to either the first trough 24 or the second trough 25. If it attaches to both the 1st trough part 24 and the 2nd trough part 25 like a form, the effect | action and effect of this invention which were mentioned above can be acquired notably.

  Further, when an annular member such as the circlip 26 of the present embodiment is used as the restricting member, there is no need to locally attach the restricting member to the first trough portion 24 and the second trough portion 25, so that the boot 11 And the workability of the boot 11 is improved.

  Further, in the present embodiment, the circlip 26 that is a restricting member is embedded in the first valley portion 24 and the second valley portion 25, and thus can be integrally formed with the boot 11, thereby forming the boot 11. It is possible to improve workability according to the above.

  Furthermore, since the circlip 26 as a restricting member used in the present embodiment follows the movement of the boot 11 when bent, the operability of the boot 11 is not adversely affected.

  The circlip 26 that is a restricting member is made of a metal having higher rigidity than the boot 11, that is, the first valley portion 24 and the second valley portion 25. For this reason, even if the constant velocity universal joint 1 rotates at a high speed, the circlip 26 that is a restricting member does not expand following the first valley portion 24 and the second end portion 25, so that the rotation of the boot 11 The expansion performance can be improved reliably and the life can be extended.

  The embodiment of the present invention has been described above, but the present invention is not limited to this, and can be appropriately changed within the meaning and content of the claims.

  For example, in the present embodiment, the present invention is applied to a resin boot, but the present invention can also be applied to a boot formed of rubber or silicon.

  Further, the material of the restricting member is not particularly limited as long as it is not made of metal as in the present embodiment and can sufficiently obtain the functions and effects as the restricting member already described. For example, resin can be used as the material of the regulating member.

  In addition, you may make it attach a regulation member by affixing on the internal diameter surface of the trough part of boots.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing a constant velocity universal joint equipped with a constant velocity universal joint boot according to an embodiment of the present invention. It is an enlarged view of the X part shown in FIG. It is sectional drawing which shows the constant velocity universal joint equipped with the boot for conventional constant velocity universal joints.

Explanation of symbols

1 Fixed type constant velocity universal joint (BJ)
2 Outer ring 3 Inner ring 9 Shaft (shaft member)
DESCRIPTION OF SYMBOLS 11 Bellows-shaped boot 12 Large diameter end part 13 Small diameter end part 14 Bellows part 22 Mountain part 23 Valley part 24 First valley part 25 Second valley part 26 Circlip (regulation member)

Claims (7)

A bellows portion having a large-diameter end portion attached to the outer joint member, a small-diameter end portion attached to a shaft member extending from the inner joint member, and a bellows portion connecting the large-diameter end portion and the small-diameter end portion; The constant velocity universal joint has a plurality of crests and a plurality of troughs that are alternately and continuously, and the crests and troughs have an inner diameter that decreases from the large diameter end toward the small diameter end. Boots for
A boot for a constant velocity universal joint, characterized in that a regulating member for suppressing expansion during high speed rotation of the constant velocity universal joint is attached to the valley portion.   The constant velocity universal joint boot according to claim 1, wherein the regulating member is provided in a first trough portion on a large diameter end portion side of the trough portion.   3. The constant velocity universal joint boot according to claim 1, wherein the regulating member is provided in a second trough portion on a large diameter end portion side of the trough portion.   The boot for a constant velocity universal joint according to any one of claims 1 to 3, wherein the regulating member is annular.   The constant velocity universal joint boot according to any one of claims 1 to 4, wherein the regulating member is embedded in the valley.   The constant velocity universal joint boot according to claim 5, wherein the restriction member embedded in the valley portion is a circlip.   The constant velocity universal joint boot according to any one of claims 1 to 6, wherein the restricting member is made of a material having rigidity higher than that of the valley portion.

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