JP2008261395A - Constant velocity universal joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a boot installation structure reduced in cost by reducing an unnecessary sealing amount of grease and also reducing a sealing amount of grease into a joint. <P>SOLUTION: This constant velocity universal joint includes: an outer joint member 2; an inner joint member 1 inserted into the outer joint member 2; and a torque transmitting member 3 interposed between the outer joint member 2 and the inner joint member 1 and transmitting a torque. A shaft 8 is fitted and inserted into the shaft hole 5 of the inner joint member 1, and also the opening portion of the outer joint member 2 on a side where the shaft projects is blocked by a sealing device 10. A separating means 20 is provided for separating a space in the sealing device into a constant velocity universal joint functional section including: the outer joint member 2; inner joint member 1; and torque transmitting member 3, and a non-functional section. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a constant velocity universal joint.

  For example, as shown in FIG. 7, the constant velocity universal joint for a propeller shaft has an inner joint member 101, an outer joint member 102, a torque transmission member (ball) 103, and a cage 104 as main components.

  The inner ring 101 has a plurality of track grooves 106 formed on the outer peripheral surface thereof. A shaft 108 is inserted into the center hole (inner diameter hole) 105 of the inner ring 101 and is spline-fitted, and torque can be transmitted between the two by the spline fitting.

  The outer ring 102 has the same number of track grooves 107 as the track grooves 106 of the inner ring 101 formed on the inner peripheral surface thereof. A plurality of balls 103 that transmit torque are incorporated between the track groove 107 of the outer ring 102 and the track groove 106 of the inner ring 101. A cage 104 is disposed between the inner ring 101 and the outer ring 102, and the ball 103 is held in a pocket 109 of the cage 104.

  A sealing device 110 is mounted between the outer ring 102 and the shaft 108 on the shaft protruding side.

  The constant velocity universal joint for propeller shafts is used at 3 to 4 times higher speed than the constant velocity universal joint for drive shafts, so the boot fixing plate (metal adapter) 113 attached to the outer ring 102 and the shaft In general, a seal structure (sealing device) 110 in which a concave rubber boot 111 is mounted is generally used.

  That is, the sealing device 110 includes a boot 111 made of a flexible material such as a rubber material or a resin material, and a metal adapter 113. The boot 111 includes a large-diameter portion 111a, a small-diameter portion 111b, and a bent portion 111c having a substantially U-shaped cross section that connects the large-diameter portion 111a and the small-diameter portion 111b. The adapter 113 has a substantially cylindrical shape, and one end 113a is press-fitted and crimped to the outer peripheral surface of the end of the outer ring 102 via a seal member such as an O-ring (not shown), and the other end 113b is a large diameter portion 111a of the boot 111. Is held by caulking. The boot 111 has a small-diameter portion 111b fitted on the shaft 108 and is fastened by a boot band 114.

  The bent portion 111c of the boot 111 is inserted in a space between the inner peripheral surface of the adapter 113 and the outer peripheral surface of the shaft 108, and repeats a bending and stretching operation in the radial direction when the joint rotates at an operating angle. Become.

  By the way, grease is sealed inside the constant velocity universal joint, and the lubrication performance of the track grooves 106 and 107 of the inner joint member 101 and the outer joint member 102 and the ball 103 is improved. Improves performance. The sealing device 110 prevents leakage of grease sealed inside the joint to the outside.

However, the boot 111 has a small-diameter portion 111 b that is externally fitted to the shaft 108 and is fastened by the boot band 114. For this reason, there exists a possibility that sealing performance may fall by the internal pressure fluctuation | variation of a boot, etc. Therefore, in order to improve the sealing performance, there has been conventionally a lip portion provided on the inner peripheral surface of the small diameter portion of the boot (Patent Document 1). The thing of this patent document 1 prevents that the grease enclosed inside the joint flows into the small diameter part side of a boot by making a lip part interfere with a shaft.
JP 2006-30875 A

  The grease sealed in the joint exists in the constant velocity universal joint function portion including the outer joint member, the inner joint member, and the ball, and in the boot other than the constant velocity universal joint function portion. For this reason, conventionally, the amount of grease to be filled needs the amount of the non-functional part in the vicinity of the constant velocity universal joint functional part in addition to the quantity necessary for maintaining the function of the constant velocity universal joint, particularly the durability performance. Met. That is, grease is sealed in a space that does not require grease. Therefore, the weight is increased and the cost is increased.

  In addition, as described in Patent Document 1, even if a lip portion is provided on the inner peripheral surface of the small diameter portion of the boot, the sealing of grease into the space S that occupies most of the non-functional portion cannot be suppressed. .

  In view of the above problems, the present invention provides a boot mounting structure that can reduce the amount of unnecessary grease filled, reduce the amount of grease sealed inside the joint, and reduce the cost. To do.

  The constant velocity universal joint of the present invention includes an outer joint member, an inner joint member inserted into the outer joint member, and a torque transmission member that transmits torque by being interposed between the outer joint member and the inner joint member. In the constant velocity universal joint in which the shaft is inserted into the shaft hole of the inner joint member and the opening of the outer joint member on the shaft protruding side is closed by the sealing device, the space in the sealing device is defined as the outer joint member. Separating means for separating the constant velocity universal joint function part including the inner joint member and the torque transmission member into a non-functional part is provided. Here, the constant velocity universal joint function part is a place including an outer joint member, an inner joint member, a torque transmission member, and the like, and is a space in a rotation transmission part that functions as a constant velocity universal joint, and a non-functional part The term “space” refers to a space in a portion other than the functional portion and other than the rotation transmission portion that functions as a constant velocity universal joint.

  According to the constant velocity universal joint of the present invention, by providing a separating means between the boot and the adapter, the space in the sealing device can be used as a constant velocity universal joint function including an outer joint member, an inner joint member, and a torque transmission member. Parts and non-functional parts. As a result, the grease to be sealed inside the joint may be sealed on the functional portion side of the constant velocity universal joint, and it becomes unnecessary to seal the grease in the non-functional portion.

  The sealing device includes a metal cylindrical adapter whose one end is fitted to the outer joint member, a large diameter portion is connected to the other end of the adapter, and a small diameter portion is fitted to the shaft. A boot made of a flexible material, and the separating means may be constituted by an elastic ring-like body disposed between the adapter and the boot. Thereby, when the joint rotates at an operating angle, the elastic ring-shaped body can flexibly follow the behavior of the boot.

  The elastic ring-shaped body can have a cross-sectional shape having a lip shape with a thick outer diameter side and a thin inner diameter side, and the outer diameter portion can be attached to the boot and the inner diameter edge portion can be brought into close contact with the adapter. Thereby, the joining area of the outer diameter side of an elastic ring-shaped body and a boot becomes large, and an elastic ring-shaped body can be firmly attached to a boot. Further, since the elastic ring-shaped body has a lip cross-sectional shape, it can be easily elastically deformed and can follow the boot behavior more flexibly.

  A plurality of the elastic ring-shaped bodies can be provided along the axial direction.

  The present invention can reduce the amount of grease filled in the non-functional portion. As a result, the total amount of grease sealed inside the joint can be reduced, and weight reduction and cost reduction can be achieved. Moreover, leakage of grease from the constant velocity universal joint function part to the non-function part can be prevented, and insufficient grease can be prevented in the function part, and smooth rotation can be provided over a long period of time.

  Since the elastic ring-shaped body can flexibly follow the behavior of the boot, the space in the sealing device can be reliably separated into the constant velocity universal joint functional part and the non-functional part.

  Since the elastic ring-shaped body can be firmly attached to the boot and can follow the boot behavior more flexibly, the durability is excellent.

  By providing a plurality of elastic ring-shaped bodies along the axial direction, the reliability of separation between the functional part and the non-functional part is improved.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  The constant velocity universal joint according to the first embodiment of the present invention is a Lebro type constant velocity universal joint (non-float type), and includes an inner ring 1 as an inner joint member, an outer ring 2 as an outer joint member, a ball 3 and a cage 4. Is the main component.

  The inner ring 1 has a plurality of track grooves 6 formed on its outer peripheral surface (convex spherical outer peripheral surface). A shaft 8 is inserted into the center hole (inner diameter 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 shaft 8 is prevented from coming off from the inner ring 1 by a snap ring 12.

  The outer ring 2 has the same number of track grooves 7 as the track grooves 6 of the inner ring 1 formed on its inner peripheral surface (cylindrical inner peripheral surface). A plurality of torque transmitting members (balls) 3 for transmitting torque are incorporated between the track groove 7 of the outer ring 2 and the track groove 6 of the inner ring 1. 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 15 is fitted on one end side of the outer ring 2 in the axial direction (an opening on the opposite shaft protruding side), and the outer ring opening on the shaft protruding side is closed by a sealing device 10. The end cap 15 and the sealing device 10 prevent leakage of grease filled in the joint and prevent entry of foreign matter.

  This sealing device 10 is the same as the conventional sealing device 10 shown in FIG. 7, and is composed of a metal cylindrical adapter 13 whose one end is fitted to the outer joint member 2, and a rubber material or a resin material. And a boot 11 made of a flexible material. The boot 11 connects (connects) a large-diameter portion 11a fixed to the outer ring 2 via the adapter 13, a small-diameter portion 11b fixed to the shaft 8 with a boot band 14, and the large-diameter portion 11a and the small-diameter portion 11b. And an intermediate portion 11c having a substantially U-shaped cross section. The intermediate portion 11c includes a first tapered portion 11d that decreases in diameter from the large diameter portion 11a toward the inside of the joint, a second tapered portion 11e that increases in diameter from the small diameter portion 11b toward the inside of the joint, and a first tapered portion. 11d and the 2nd taper part 11e consist of the bending part 11f which connects.

  One end portion 13a of the adapter 13 is press-fitted into the outer peripheral surface of the end portion of the outer ring 2 via a seal member such as an O-ring (not shown) in order to secure sealing performance and pull-out strength with respect to the outer ring 2, followed by rolling tightening It is fixed by caulking. The other end portion 13 b of the adapter 13 holds and holds the large diameter portion 11 a of the boot 11. That is, the large-diameter portion 11 a of the boot 11 is surrounded by the other end portion 13 b of the adapter 13.

  An annular recess 17 is formed on the outer peripheral surface of the shaft 8, and the small-diameter portion 11 b of the boot 11 is fitted on the annular recess 17 and fastened with a boot band 14. In addition, a circumferential groove 18 is formed on the outer peripheral surface of the small diameter portion 11b, and the boot band 14 is fitted in the circumferential groove 18.

  As shown in FIG. 1, the separating means 20 is provided in the space in the sealing device. The separating means 20 is constituted by an elastic ring-shaped body 21 disposed between the adapter 13 and the boot 11. The elastic ring-shaped body 21 has a substantially triangular cross-section in a natural state as shown in FIG. 2, and the cross-sectional shape is a lip shape with a thick outer diameter side and a thin inner diameter side. The outer diameter portion 21 a is attached to the inner diameter surface of the boot via, for example, an adhesive, and the inner diameter edge portion 21 b is in close contact with the inner diameter surface of the adapter 13. That is, the boot 11 is folded back from the state shown in FIG. 2, and the large diameter portion 11 a of the boot is crimped and fixed at the other end portion 13 b of the adapter 13, and the small diameter portion 11 b of the boot is attached to the shaft 8 via the boot band 14. Fix it. In this case, as shown in FIG. 1, the inner diameter edge portion 21b is pressed and elastically deformed so as to be convex toward the constant velocity universal joint function portion side. Here, the constant velocity universal joint function part is a place including the outer joint member 2, the inner joint member 1, the ball 3, and the like, and is a space in a rotation transmission portion that functions as a constant velocity universal joint.

  Thus, when the separating means 20 is provided between the adapter 13 and the boot 11, the space in the sealing device by the separating means 20 is a constant velocity universal joint including the outer joint member 2, the inner joint member 1, and the ball 3. It is separated into a functional part S1 and a non-functional part S2. Here, the non-functional portion S2 is a space in a portion other than the functional portion S1 and other than the rotation transmitting portion that functions as a constant velocity universal joint. In the illustrated example, the inner diameter of the cylindrical main body portion 13c of the adapter is shown. A space is formed between the surface and the outer diameter surface of the first tapered portion d of the boot.

  The non-functional portion substantially includes a space S3 formed between the inner diameter surface of the second taper portion 11e of the boot 11 and the outer diameter surface of the shaft 8, but in the embodiment, the space S2 is non-functional. As a part. For this reason, the separating means 20 may be provided so as to come into contact with the inner diameter surface of the second tapered portion 11 e of the boot 11 and the outer diameter surface of the shaft 8. Accordingly, it is possible to prevent the grease from being enclosed in the space formed between the inner diameter surface of the second tapered portion 11e of the boot 11 and the outer diameter surface of the shaft 8, and the grease can be enclosed in a more unnecessary space. Inflow can be eliminated, and further weight reduction and cost reduction can be achieved.

  As described above, in the constant velocity universal joint according to the first embodiment, by providing the separating means 20 between the boot 11 and the adapter 13, the space in the sealing device is reduced to the torque between the outer joint member 2, the inner joint member 1, and the torque. The constant velocity universal joint function part S1 including the transmission member 3 and the non-function part S2 can be separated. As a result, the grease to be sealed inside the joint may be sealed on the functional portion side of the constant velocity universal joint, and there is no need to seal the grease in the non-functional portion S2. For this reason, the total amount of grease to be sealed inside the joint can be reduced, and weight reduction and cost reduction can be achieved. Further, it is possible to prevent grease from leaking from the constant velocity universal joint function part S1 to the non-function part S2, to prevent the function part S1 from running out of grease, and to provide smooth rotation over a long period of time. it can.

  The sealing device 10 includes a metal cylindrical adapter 13 whose one end is fitted to the outer joint member 2, a large diameter portion 11 a is connected to the other end portion 13 b of the adapter, and a small diameter portion 11 b is connected to the shaft 8. And a boot 11 made of a flexible material to be fitted into the boot, and the separating means 20 can be constituted by an elastic ring-shaped body 21 disposed between the adapter 13 and the boot 11. Thereby, when the joint rotates at an operating angle, the elastic ring-shaped body 21 can flexibly follow the behavior of the boot 11. For this reason, the space in the sealing device can be reliably separated into the constant velocity universal joint functional part S1 and the non-functional part S2.

  The elastic ring-shaped body 21 has a lip shape whose outer diameter side is thick and whose inner diameter side is thin, and the outer diameter portion 21 a can be attached to the boot 11 and the inner diameter edge portion 21 b can be in close contact with the adapter 13. Thereby, the joining area of the outer diameter side of the elastic ring-shaped body 21 and the boot 11 becomes large, and the elastic ring-shaped body 21 can be firmly attached to the boot 11. Moreover, since the cross-sectional shape of the elastic ring-shaped body 21 is a lip shape, it can be easily elastically deformed, and can follow the behavior of the boot more flexibly. Thereby, the elastic ring-shaped body 21 is excellent in durability.

  As shown in FIG. 3, the elastic ring-shaped body 21 may be elastically deformed so as to be convex toward the non-functional part S2. Even in this case, the space in the sealing device can be separated into the constant velocity universal joint function part S1 and the non-function part S2.

  Next, a second embodiment of the constant velocity universal joint of the present invention will be described. In this case, the constant velocity universal joint is provided with two elastic ring-like bodies 21 along the axial direction, as shown in FIGS. Thereby, the space in the sealing device by the elastic ring-shaped body 21 is divided into the constant velocity universal joint function part S4 including the outer joint member 2, the inner joint member 1 and the ball 3, and the non-functional part S7 (space S5 and space S6). And separated.

  As described above, the constant velocity universal joint according to the second embodiment has the same effect as that of the first embodiment. In particular, since two elastic ring-shaped bodies 21 are provided along the axial direction, the separation accuracy between the constant velocity universal joint function part S4 and the non-function part S7 is improved in the space in the sealing device. In the constant velocity universal joint shown in FIGS. 4 and 5, the same components as those of the constant velocity universal joint shown in FIGS. .

  Also in the constant velocity universal joint of the second embodiment, as shown in FIG. 6, the elastic ring-shaped body 21 may be elastically deformed so as to be convex toward the non-functional part.

  As described above, the embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the material of the elastic ring-shaped body 21 is elastically deformed. As long as it can follow the behavior of the boot 11, various materials such as rubber and resin can be used, and the same material as the boot 11 or a different material may be used. The attachment method of the elastic ring-shaped body 21 is not limited to the adhesive, but may be welding or the like. Furthermore, the elastic ring-shaped body 21 and the boot 11 are integrally formed. Also good. Also, the number of elastic ring-shaped bodies 21 may be three or more. When a plurality of elastic ring-shaped bodies 21 are provided, all the elastic ring-shaped bodies 21 are not elastically deformed in a convex shape in the same direction, but may be elastically deformed in a convex shape in different directions. The cross-sectional shape of the elastic ring-shaped body 21 is not limited to a triangle, and may be other shapes such as a trapezoidal shape.

  The present invention can be applied to a sliding type constant velocity universal joint other than the Lebro type, and further to a fixed type constant velocity universal joint. That is, as the constant velocity universal joint, various types such as a fixed constant velocity universal joint such as a Rzeppa type and a barfield type, and a sliding constant velocity universal joint such as a double offset type and a tripod type can be used. . Further, the present invention can be applied not only to a propeller shaft of an automobile but also to a constant velocity universal joint for a drive shaft and further for a general industrial machine.

It is sectional drawing of the constant velocity universal joint which shows 1st Embodiment of this invention. It is sectional drawing of the boot of the constant velocity universal joint of the said FIG. It is a principal part expanded sectional view of the modification of the constant velocity universal joint which shows 1st Embodiment of this invention. It is sectional drawing of the constant velocity universal joint which shows 2nd Embodiment of this invention. It is sectional drawing of the boot of the constant velocity universal joint of the said FIG. It is a principal part expanded sectional view of the modification of the constant velocity universal joint which shows 2nd Embodiment of this invention. It is sectional drawing of the conventional constant velocity universal joint.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inner joint member 2 Outer joint member 3 Torque transmission member 5 Shaft hole 8 Shaft 10 Sealing device 20 Separation means 21 Elastic ring-shaped body

Claims (4)

An outer joint member, an inner joint member that is inserted into the outer joint member, and a torque transmission member that transmits torque by being interposed between the outer joint member and the inner joint member. A shaft is provided in the shaft hole of the inner joint member. In the constant velocity universal joint in which the opening of the outer joint member on the shaft protruding side is closed by the sealing device,
A constant velocity universal joint characterized in that a separating means for separating a space in the sealing device into a constant velocity universal joint function part including an outer joint member, an inner joint member and a torque transmission member and a non-functional part is provided.   The sealing device includes a metal cylindrical adapter whose one end is fitted to the outer joint member, a large diameter portion is connected to the other end of the adapter, and a small diameter portion is fitted to the shaft. The constant velocity universal joint according to claim 1, further comprising: a boot made of a flexible material, wherein the separating means is formed of an elastic ring-like body disposed between the adapter and the boot. .   3. The elastic ring-like body has a cross-sectional shape of a lip shape with a thick outer diameter side and a thin inner diameter side, the outer diameter portion being attached to a boot, and the inner diameter edge portion being in close contact with an adapter. The constant velocity universal joint described in 1.   The constant velocity universal joint according to claim 2 or 3, wherein a plurality of the elastic ring-shaped bodies are provided along the axial direction.