JP2018105432A - Constant velocity universal joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a contant velocity universal joint capable of effectively preventing leakage of grease inside of the joint, and intrusion of foreign matters such as water to the inside of the joint, in the constant velocity universal joint capable of enabling relative axial sliding of a shaft to an inner joint member.SOLUTION: A constant velocity universal joint includes an outer joint member, an inner joint member and a torque transmission member disposed between the outer joint member and the inner joint member. A shaft is fitted into the inner joint member in a manner of being relatively axially slidable, and a joint opening portion at a shaft fitting-in side is sealed by a sealing device. The sealing device is composed of a metallic inner diameter-side cylindrical portion in which the shaft is fitted, a metallic outer diameter-side cylindrical portion having an inner diameter dimension larger than an outer diameter dimension of the inner diameter-side cylindrical portion and fixed to the outer joint member, and a bent portion connecting the inner diameter-side cylindrical portion and the outer diameter-side cylindrical portion and composed of a flexible member. A seal member is disposed to seal between the shaft and the inner diameter-side cylindrical portion.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a constant velocity universal joint, and more particularly, to a constant velocity universal joint used for equipment of an industrial machine.

  In general, a constant velocity universal joint (fixed constant velocity universal joint) applied as a power transmission mechanism for automobiles and various industrial machines generally has a seal structure using bellows-shaped boots. That is, in a constant velocity universal joint, a rubber or resin boot is generally attached as a seal member for preventing foreign matter from entering from outside and leakage of grease from inside.

  A metal ring boot (see FIG. 6) advantageous for rotational expansion is applied in the case of low-angle and high-speed rotation such as that used for propeller shafts in automobiles and motors directly connected to industrial machines. By the way, in recent years, in order to improve production efficiency in industrial machine facilities, the speeding up has been accelerated, and it has become necessary to be able to cope with higher speed rotation.

  The constant velocity universal joint shown in FIG. 6 has an outer joint member 3 having a track groove 2 formed on the inner diameter surface 1 and a track groove 5 which forms a pair with the track groove 2 of the outer joint member 3 on the outer diameter surface 4. The inner joint member 6, the ball 7 that is interposed between the track groove 2 of the outer joint member 3 and the track groove 5 of the inner joint member 6, and transmits the torque, the inner diameter surface 1 of the outer joint member 3, and the inner joint A cage 8 is provided between the outer diameter surface 4 of the member 6 and holds the ball 7.

  A female spline 10 is formed on the inner diameter surface of the axial hole of the inner joint member 6, and the male spline 12 at the tip of the stub shaft 11 is fitted into this axial hole. As a result, the female spline 10 and the male spline 12 mesh. Retaining retaining rings 13 and 14 are attached to the distal end portion and the proximal end portion of the male spline 12, respectively. That is, a circumferential groove 12a is formed at the distal end of the male spline 12, a circumferential groove 12b is formed at the proximal end of the male spline 12, and retaining rings 13 and 14 are attached to the circumferential grooves 12a and 12b. .

  At this time, the retaining ring 13 abuts on one end surface 6 a of the inner joint member 6, and the retaining ring 14 is fitted in a notch 15 provided on the inner diameter portion of the other end surface 6 b of the inner joint member 6. For this reason, the shaft 11 is restricted from moving in the axial direction with respect to the inner joint member 6.

  The outer joint member 3 is a disc type, and an adapter (not shown) is attached to one end face 3a via a packing 9a, and a boot fixing plate 20 is attached to the other end face 3b via a packing 9b. The boot fixing plate 20 is formed of a flat ring body, and a fitting recess 20a into which the end of the outer joint member 3 is fitted is provided on the end surface of the joint main body.

  The boot fixing plate 20 and the outer joint member 3 are provided with through holes 22 and 21, and the adapter (not shown) is provided with a screw hole. For this reason, the end of the outer joint member 3 is fitted into the fitting recess 20 a of the boot fixing plate 20. In this state, if a bolt member is fitted into the through hole 22 of the boot fixing plate 20 and the through hole 21 of the outer joint member 3, and the threaded portion of this bolt member is screwed into the screw hole of the adapter (not shown). The boot fixing plate 20, the outer joint member 3, and the adapter are integrated. The packings 9a and 9b are each provided with a through hole through which the bolt member passes.

  The opening on the shaft side of the constant velocity universal joint is sealed with a sealing device 30. The sealing device in this case is a flexible U-shaped cross section that connects the metal inner diameter side cylinder part 30a, the metal outer diameter side cylinder part 30b, and the inner diameter side cylinder part 30a and the outer diameter side cylinder part 30b. It consists of the bending part 30c which consists of a property material.

  The inner diameter side cylindrical portion 30 a is fitted on the shaft 11, and the outer diameter side cylindrical portion 30 b is fixed to the outer joint member 3 via the boot fixing plate 20. That is, a flange portion 26 extending in the outer diameter direction is provided at an end portion on the joint side of the outer diameter side cylindrical portion 30b, and this flange portion 26 is formed on the inner diameter portion of the end surface on the joint side of the boot fixing plate 20. The directional recess 27 is fitted.

  Further, the boot fixing plate 20 is provided with a grease nipple 28 for additionally supplying grease. That is, the grease nipple 28 is in communication with the inside of the joint body.

  Incidentally, a gap C as shown in FIG. 7 is provided between the inner diameter side cylindrical portion 30 a of the sealing device 30 and the outer diameter surface 29 of the shaft 11. For this reason, even if such a sealing device 30 is used, the grease filled in the joint or the sealing device flows out to the outside through the gap, or conversely, the joint inside or the sealing device through the gap. There is a risk that foreign substances such as water may enter the battery.

  In view of this, there has conventionally been a structure in which a seal member that surrounds the end portion of the inner diameter side cylindrical portion of the sealing device is attached to a shaft (Patent Document 1). That is, as shown in FIG. 5, a short cylindrical seal member 31 is attached to the shaft 11. In this case, the inner peripheral surface 32 of the seal member 31 has a large diameter portion 32a and a small diameter portion 32b, the end portion of the inner diameter side cylindrical portion 30a is fitted to the large diameter portion 32a, and the shaft 11 is fitted to the small diameter portion 32b. Is fitted.

JP2015-113875A

  Incidentally, as shown in FIGS. 5 and 6, in the case where the retaining rings 13, 14 are attached to the distal end portion and the proximal end portion of the male spline 12, the inner diameter side cylinders of the shaft 11 and the sealing device 30 are provided. The portion 30a does not slide relatively. For this reason, as shown in FIG. 5, this can be dealt with by attaching a seal member 31 surrounding the end portion of the inner diameter side cylindrical portion 30 a of the sealing device 30 to the shaft 11.

  That is, the sealing member 31 shown in FIG. 5 is based on the premise that the positional relationship between the shaft 11 and the inner diameter side cylindrical portion 30a of the sealing device 30 is constant. Therefore, the seal member 31 as shown in FIG. 5 cannot be applied to a constant velocity universal joint in which the shaft 11 and the inner diameter side cylindrical portion 30a of the sealing device 30 slide relative to each other.

  Accordingly, in view of the above problems, the present invention provides a constant velocity universal joint in which the shaft can slide relative to the inner joint member in the axial direction, such as leakage of grease inside the joint and water inside the joint. The present invention provides a constant velocity universal joint that can effectively prevent the entry of foreign matter.

  The constant velocity universal joint according to the present invention includes an outer joint member, an inner joint member, and a torque transmission member interposed between the outer joint member and the inner joint member, and a shaft relative to the inner joint member. A constant velocity universal joint that is fitted in such a manner that it can be slid in a direction, and a joint opening on a shaft insertion side is sealed with a sealing device, wherein the sealing device is a metal inner diameter side into which the shaft is inserted A cylinder portion, a metal outer diameter side cylinder portion whose inner diameter dimension is larger than the outer diameter dimension of the inner diameter side cylinder portion and fixed to the outer joint member, an inner diameter side cylinder portion and an outer diameter side cylinder portion; A sealing member that seals between the shaft and the inner diameter side cylindrical portion and allows relative sliding between the shaft and the inner diameter side cylindrical portion. It is set.

  According to the constant velocity universal joint of the present invention, the gap between the shaft and the inner diameter side cylindrical portion is sealed with a seal member, so that leakage of grease inside the joint and entry of foreign matters such as water into the joint are prevented. It can be effectively prevented. In addition, this seal member allows relative sliding between the shaft and the inner diameter side cylindrical portion. Even if a fixed type constant velocity universal joint is used as a constant velocity universal joint, the seal member can be placed at a place where the load is stretched. Can respond.

  The seal member can be formed of a ring-shaped seal material fitted on the shaft, for example, an O-ring, or can be a liquid packing disposed between the shaft and the inner diameter side cylindrical portion.

  Further, the seal member includes a first cylindrical portion that is externally fitted to an end portion of the inner diameter side cylindrical portion, a second cylindrical portion that is externally fitted to a boot mounting portion of the shaft protruding from the inner diameter side cylindrical portion, A flexible connecting part that connects the first cylindrical part and the second cylindrical part, and the first cylindrical part is fixed to the boot mounting part at the end of the inner diameter side cylindrical part by tightening the boot band; The two cylindrical portions may be fixed to the boot mounting portion of the shaft by tightening the boot band.

  In the present invention, even if a fixed type constant velocity universal joint is used as a constant velocity universal joint, it can cope with a place where there is load expansion and contraction, is excellent in versatility, and leaks grease inside the joint. Since it is possible to effectively prevent the entry of foreign matter such as water into the water, it has excellent durability. Furthermore, only a seal member is disposed between the shaft and the inner diameter side cylindrical portion, and a compact shape can be maintained without breaking the existing structural design as a constant velocity universal joint.

It is sectional drawing of the 1st constant velocity universal joint of this invention. It is a principal part front view of the constant velocity universal joint shown in FIG. It is sectional drawing of the 2nd constant velocity universal joint of this invention. It is sectional drawing of the 3rd constant velocity universal joint of this invention. It is sectional drawing of the constant velocity universal joint using the conventional sealing member. It is sectional drawing of the conventional constant velocity universal joint. It is the A section enlarged view of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. As shown in FIGS. 1 and 2, the constant velocity universal joint according to the present invention includes an outer joint member 53 having a track groove 52 formed on the inner diameter surface 51, and a track groove 52 of the outer joint member 53 on the outer diameter surface 54. As a torque transmission member that transmits torque by being interposed between the inner joint member 56 in which the track groove 55 that is paired with the inner groove member 56, the track groove 52 of the outer joint member 53, and the track groove 55 of the inner joint member 56 is provided. A ball 57 and a retainer 58 that holds the ball 57 interposed between the inner diameter surface 51 of the outer joint member 53 and the outer diameter surface 54 of the inner joint member 56 are provided.

  A female spline 60 is formed on the inner diameter surface of the axial hole of the inner joint member 56, and the male spline 62 at the tip of the stub shaft 61 is fitted into this axial hole. As a result, the female spline 60 and the male spline 62 are engaged with each other.

  The outer joint member 53 is a disk type, and an adapter (not shown) is attached to one end face 53a via a packing 63a, and a boot fixing plate 70 is attached to the other end face 53b via a packing 63b. The boot fixing plate 70 is formed of a flat ring body, and a fitting recess 70a into which an end portion of the outer joint member 53 is fitted is provided on an end surface of the joint main body side.

  The boot fixing plate 70 and the outer joint member 53 are provided with through holes 72 and 71, and the adapter (not shown) is provided with a screw hole. For this reason, the end of the outer joint member 53 on the side opposite to the adapter is fitted into the fitting recess 70 a of the boot fixing plate 70. In this state, when a bolt member is fitted into the through hole 72 of the boot fixing plate 70 and the through hole 71 of the outer joint member 53, the threaded portion of this bolt member is screwed into the screw hole of the adapter (not shown). The boot fixing plate 70, the outer joint member 53, and the adapter are integrated. The packings 63a and 63b are respectively provided with through holes through which the bolt members pass.

  Further, an opening (joint opening) 79 on the shaft side of the constant velocity universal joint is sealed with a sealing device 80. The sealing device 80 in this case has a U-shaped cross section that connects the metal inner diameter side cylinder part 80a, the metal outer diameter side cylinder part 80b, and the inner diameter side cylinder part 80a and the outer diameter side cylinder part 80b. It consists of the bending part 80c which consists of a flexible material. For example, the bent part 80c is vulcanized and bonded to the metal ring of the inner diameter side cylinder part 80a and the outer diameter side cylinder part 80b. The bent portion 80c is preferably a thermoplastic polyester elastomer excellent in fatigue resistance, wear resistance, heat aging resistance, etc., but is not particularly limited to this, for example, ester-based, olefin-based, urethane-based It may be a thermoplastic elastomer such as amide or styrene, or may be chloroprene rubber, silicone rubber, chlorinated polyethylene rubber, ethylene acrylic rubber or the like.

  The inner diameter side cylinder portion 80 a is fitted on the shaft 51, and the outer diameter side cylinder portion 80 b is fixed to the outer joint member 53 via the boot fixing plate 70. That is, a flange portion 76 extending in the outer diameter direction is provided at the joint-side end portion of the outer-diameter side tubular portion 80 b, and this flange portion 76 is formed on the inner diameter portion of the end surface on the joint side of the boot fixing plate 70. It is fitted in the direction recess 77. The boot fixing plate 70 is provided with a grease nipple 78 for supplementing grease. That is, the grease nipple 78 is in communication with the inside of the joint body.

  Further, a seal member S is disposed between the shaft 61 and the inner diameter side cylinder portion 80a. The sealing member S in this case is configured by a ring-shaped sealing material 81 that is fitted on the shaft 61, for example, an O-ring. That is, a circumferential groove 61a is provided in a corresponding portion of the inner diameter side cylindrical portion 80a of the shaft 61, and the ring-shaped sealing material 81 is fitted into the circumferential groove 61a.

  For this reason, the seal member S can seal between the shaft 61 and the inner diameter side cylinder portion 80a and can allow relative sliding between the shaft 61 and the inner diameter side cylinder portion 80a. Examples of the ring-shaped sealing material (O-ring) 81 include nitrile rubber (NBR), fluorine rubber (FKM), silicon rubber (VMQ), chloroprene rubber (CR), urethane rubber (U), and hydrogenated nitrile rubber (HNBR). ), Existing O-rings such as fluororesin (PTFE) can be used.

  Since the space between the shaft 61 and the inner diameter side cylinder portion 80a is sealed by the seal member S, leakage of grease inside the joint and entry of foreign matters such as water into the joint can be effectively prevented. Moreover, the seal member S allows relative sliding between the shaft 61 and the inner diameter side cylinder portion 80a, and even if a fixed type constant velocity universal joint is used as a constant velocity universal joint, the load can be expanded and contracted. It can correspond to a certain place. In other words, even if a fixed type constant velocity universal joint is used as a constant velocity universal joint, it can cope with a place where the load expands and contracts, and is excellent in versatility. Since the intrusion of foreign matters such as water can be effectively prevented, the durability is excellent. Furthermore, only the seal member S is disposed between the shaft 61 and the inner diameter side cylinder portion 80a, and a compact shape can be maintained without breaking the existing structural design as a constant velocity universal joint.

  Since an O-ring is used as the sealing member S, it is excellent in cost reduction and wearability, and can exhibit a stable sealing effect.

  Next, the flexible member that connects the first cylindrical portion 82a, the second cylindrical portion 82b, and the first cylindrical portion 82a and the second cylindrical portion 82b to the seal member S of the constant velocity universal joint shown in FIG. It comprises a boot 82 provided with a connecting portion 82c. That is, the first cylindrical portion 82 a is fitted on the boot mounting portion 85 at the end of the inner diameter side cylindrical portion 80 a of the sealing device 80 (the end on the anti-joint side), and the inner diameter side cylinder is tightened by tightening the boot band 83. The second cylindrical portion 82 b is fixed to the boot mounting portion 86 of the shaft 61 by fastening the boot band 83.

  In this case, a circumferential concave groove 85a of the boot mounting portion 85 at the outer diameter surface end of the inner diameter side cylindrical portion 80a is formed, and a circumferential bulge portion 87 is formed on the inner diameter surface of the first cylindrical portion 82a. When the one cylindrical portion 82a is fastened by the boot band 83, the circumferential bulge portion 87 is fitted into the circumferential concave groove 85a in a press-fit manner, and the first cylindrical portion 82a is connected to the inner diameter side cylindrical portion 80a. Fixed to. In addition, a circumferential groove 86 a is formed in the boot mounting portion 86 of the shaft 61, a circumferential bulging portion 88 is formed on the inner diameter surface of the second cylindrical portion 82 b, and the second cylindrical portion 82 b is formed by the boot band 83. By tightening, the circumferential bulging portion 88 is fitted into the circumferential concave groove 86 a in a press-fit manner, and the second cylindrical portion 82 b is fixed to the shaft 61.

  Further, the boot 82 is a rubber boot made of chloroprene rubber, silicone rubber, chlorinated polyethylene rubber, ethylene acrylic rubber or the like, even if it is a resin boot made of thermoplastic polyester elastomer or the like, like the bent portion 80c of the sealing device 80. Also good.

  For this reason, even if it is the sealing member S shown in FIG. 3, the effect similar to the sealing member S shown in FIG. 1 mentioned above can be exhibited.

  Further, as shown in FIG. 4, the seal member S may be constituted by a liquid packing 90. A circumferential groove 91a is formed in the boot mounting portion 91 of the shaft 61, and the liquid packing 90 is applied to the circumferential groove 91a. Examples of the liquid packing include liquid silicone rubber (LSR). There are various grades of silicone rubber depending on its form, curing mechanism, etc., and it can be roughly classified into millable silicone rubber and liquid silicone rubber. The millable type is a type that is heated and cured by adding a vulcanizing agent during use. The liquid silicone rubber is a type that is cured by heating at room temperature or by heating.

  For this reason, even if it is the sealing member S shown in FIG. 4, the effect similar to the sealing member S shown in FIG. 1 mentioned above can be exhibited.

  As described above, the embodiments of the present invention have been described. However, the present invention is not limited to the above-described embodiments, and various modifications are possible. In each of the above embodiments, the constant velocity universal joint includes an outer joint member and an inner joint member. Although it was a fixed disc type that only allowed angular displacement with the joint member, it was a sliding disc type that could be angularly displaced and axially displaced between the outer joint member and the inner joint member. May be. Further, the constant velocity universal joint according to the present invention can be used for various industrial machines such as steel, paper making, and testing machines.

  When using a seal ring for the seal member S as shown in FIG. 1, the seal member S is not limited to an O-ring, and an X-ring whose cross-sectional shape is X-shaped, a D-ring whose cross-sectional shape is D-shaped, or the like may be used.

53 Outer joint member 56 Inner joint member 57 Ball (torque transmission member)
80 Sealing device 80a Inner diameter side cylinder part 80b Outer diameter side cylinder part 80c Bending part 81 Ring-shaped sealing material (O-ring)
82 Boot 82a First cylindrical portion 82b Second cylindrical portion 82c Connecting portion 83 Boot bands 85, 86 Boot mounting portion 90 Liquid packing S Seal member

Claims (4)

An outer joint member, an inner joint member, and a torque transmission member interposed between the outer joint member and the inner joint member, and the shaft is allowed to slide relative to the inner joint member in the axial direction. It is a constant velocity universal joint that is inserted and the joint opening on the shaft insertion side is sealed with a sealing device,
The sealing device includes a metal inner diameter side cylinder portion into which a shaft is fitted, and a metal outer diameter side that has an inner diameter dimension larger than the outer diameter dimension of the inner diameter side cylinder portion and is fixed to the outer joint member. A cylindrical portion and a bent portion formed of a flexible member that connects the inner diameter side cylindrical portion and the outer diameter side cylindrical portion; seals between the shaft and the inner diameter side cylindrical portion; and the shaft and the inner diameter side cylinder A constant velocity universal joint characterized in that a seal member allowing relative sliding with respect to the portion is provided. The constant velocity universal joint according to claim 1, wherein the seal member is formed of a ring-shaped seal material fitted on the shaft.   The seal member includes a first cylindrical portion that is externally fitted to an end portion of the inner diameter side cylindrical portion, a second cylindrical portion that is externally fitted to a boot mounting portion of the shaft protruding from the inner diameter side cylindrical portion, and the first cylinder A flexible connecting part for connecting the part and the second cylindrical part, the first cylindrical part is fixed to the boot mounting part at the end of the inner diameter side cylindrical part by fastening the boot band, and the second cylinder The constant velocity universal joint according to claim 1, wherein the portion is fixed to the boot mounting portion of the shaft by tightening the boot band.   The constant velocity universal joint according to claim 1, wherein the seal member is a liquid packing disposed between the shaft and the inner diameter side cylindrical portion.

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