JP2008038928A - Constant velocity universal joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a constant velocity universal joint attachable stably to a vehicle attaching flange, in a short time, and excellent in sealability. <P>SOLUTION: This constant velocity universal joint is formed axially with linear track grooves 26, 27 respectively on an outer circumference of an inner ring 21 and an inner circumference of an outer ring 22, under the condition where the grooves 26, 27 are axially inclined oppositely each other, a ball 23 is assembled in each cross part of both track grooves 26 and 27, and is formed alternately with the first part 31 of long track groove distance and the second part 32 of short track groove distance along a circumferential direction, respectively in both end faces 22a, 22b of an outer ring 22. Bolt holes 3 for attaching to the vehicle attaching flange are provided in the outer ring 22. The two track grooves 27 are arranged between the bolt holes adjacent circumferentially. The bolt holes 37 are opened in the first part 31 of long track groove distance, on an anti-flange side end face of the outer ring 22. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention is a power transmission device used for automobiles, various industrial machines, and the like. For example, it is incorporated in a propeller shaft, a drive shaft, etc. used in 4WD vehicles, FR vehicles, etc., and has a structure capable of absorbing axial displacement. The present invention relates to the provided constant velocity 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 cross groove type) that is lightweight and has good rotational balance and vibration characteristics is incorporated (Patent Document 1). , Patent Document 2, and Patent Document 3).

  The Lebro type constant velocity universal joint is roughly classified into two types, a float type and a non-float type, and both types are properly used according to the characteristics (sliding amount, etc.) of the vehicle equipped with the propeller shaft.

  As shown in FIG. 6, this type of constant velocity universal joint includes an inner ring 1, an outer ring 2, a ball 3, and a cage 4 as main components. FIG. 6 shows a float type in which the minimum inner diameter of the cage 4 is smaller than the maximum outer diameter of the inner ring 1, that is, the inner ring incorporated in the cage does not come out in the axial direction.

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

  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. That is, as shown in FIG. 7, the track groove 6 of the inner ring 1 and the track groove 7 of the outer ring 2 form an angle α inclined in the opposite direction with respect to the axis, and the pair of the track groove 6 of the inner ring 1 and the outer ring 2 A ball 3 is incorporated at the intersection with the track groove 7. 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. For this reason, as shown in FIG. 8, the end surfaces 2a and 2b of the outer ring 2 have a first portion 31 having a large inter-groove distance L (L1) and a second portion 32 having a small inter-groove distance L (L2). Are alternately arranged along the circumferential direction.

  The outer ring 2 is attached to a vehicle attachment flange (companion flange) 16. That is, the bolt member 18 inserted through the insertion hole (bolt hole) 17 of the outer ring 2 is screwed into the screw hole 19 of the vehicle mounting flange 16. Thus, the constant velocity universal joint is fastened to the vehicle mounting flange 16.

  A sealing device 15 is mounted on the opposite side of the outer ring 2 from the flange side. The sealing device 15 includes a boot 12 and a metal boot adapter 13 in order to suppress the rotational expansion of the boot during high-speed rotation. The boot 12 has a small end portion 12b and a large end portion 12a, and is shaped like a V-shape in the middle. The boot adapter 13 includes a large-diameter cylindrical portion 13a, a small-diameter cylindrical main body portion 13b, and a radial wall portion 13c extending in the inner diameter direction from the cylindrical portion 13a toward the cylindrical main body portion 13b. 13a is externally fitted to the outer ring end on the opposite flange side. A through hole 18a through which the bolt member 18 is inserted is provided in the radial wall portion 13c.

  Accordingly, the bolt adapter 18 is used to fasten the boot adapter 13 to the outer ring 2, and the outer ring 2 to which the boot adapter 13 is attached is attached to the vehicle mounting flange 16. At this time, the radial wall portion 13 c of the boot adapter 13 comes into contact with the end surface 2 b of the outer ring 2 on the side opposite to the flange. The small end portion 12b of the boot 12 is attached to the stub shaft 8 and fastened by the boot band 14, and the large end portion 12a of the boot 12 is held by crimping the end portion of the boot adapter 13.

  Such a Lebro type constant velocity universal joint includes an end plate 10. That is, the end plate 10 bulges toward the hollow portion side of the flange portion 16 and the cylindrical portion 10a that is externally fitted to the outer ring end portion on the opposite shaft protruding side, the radial wall portion 10b that extends from the cylindrical portion 10a in the inner diameter direction. A deep dish body 10c. The radial wall portion 10b is provided with a through hole through which the bolt member 18 is inserted, and the bolt member 18 is screwed into the screw hole 19 of the flange 16 through the through hole. For this reason, the radial wall portion 10 b is sandwiched between the end surface 2 a of the outer ring 2 and the outer ring corresponding surface 11 of the flange 16.

By the way, in a general Lebro type constant velocity universal joint, the number of balls and the number of bolt holes are six, and the bolt holes are arranged at an equal pitch of 60 degrees between the track grooves. Patent Document 1 and Patent Document 3 disclose eight balls and six bolts, and Patent Document 2 includes twelve balls and six bolts. Are disclosed.
EP 1541885A1 JP-A-57-129925 DE 10103550A1

  In a Lebro type constant velocity universal joint with 8 or 10 balls, the number of bolt holes that is the same as the number of balls is too many to assemble into the vehicle (the number of bolts), and workability is poor. there were. Therefore, as described in each of Patent Documents 1 to 3, work efficiency can be improved by reducing the number of bolt holes.

  However, it is necessary to increase the diameter of each bolt hole in order to improve the strength of one bolt by reducing the number of bolt holes. If the bolt hole diameter is increased, the strength of the outer ring may be reduced or the sealing performance may be reduced.

  In particular, in Patent Document 1, six bolt holes are arranged at a pitch of 60 degrees along the circumferential direction, but the bolt holes are formed without considering the position of the track grooves. I can't take it big. Moreover, in patent document 2, the protrusion part is provided in the outer diameter surface of the outer ring | wheel at 60 degree pitch along the circumferential direction, and the bolt hole is provided in this protrusion part. In this case, the thickness of the protrusion was thinner than the thickness of the outer ring and was inferior in strength. Further, in Patent Document 3, as in Patent Document 2, a protrusion having a bolt hole is provided, and the thickness of the protrusion is the same as the thickness of the outer ring. However, in the thing of this patent document 3, while being unable to attach to the flange 16 as shown in FIG. 6, the sealing apparatus 15 cannot be mounted | worn.

  In view of the above-described problems, the present invention provides a constant velocity universal joint that can be stably and stably attached to a vehicle mounting flange in a short time and that is excellent in sealing performance.

  In the constant velocity universal joint of the present invention, linear track grooves are formed in 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 where they are inclined in directions opposite to each other in the axial direction. Balls are incorporated into the intersections of the grooves, and 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, and the distance between the first part and the track groove having a large track groove distance is In the constant velocity universal joint formed by alternately forming small second parts on both end faces of the outer ring along the circumferential direction, the outer ring is provided with a bolt hole for mounting on a vehicle mounting flange and adjacent in the circumferential direction. Two track grooves are arranged between the bolt holes, and the bolt holes are opened in the first portion where the distance between the track grooves is large on the end surface of the outer ring on the side opposite to the flange.

  According to the constant velocity universal joint of the present invention, since two track grooves are arranged between the bolt holes adjacent in the circumferential direction, the number of bolt holes is half the number of balls. In addition, since the bolt hole is opened in the first portion having a large distance between the track grooves on the end surface on the side opposite to the flange of the outer ring, insufficient strength can be prevented even if the hole diameter of the bolt hole is increased.

  In other words, since the end surface side on the flange side is attached to the vehicle mounting flange, in the slide-in state in which the internal parts composed of the inner ring, the ball, the cage, and the like have moved to the flange side, the end surface side on the flange side is connected to the vehicle mounting flange. Torque is applied in an enclosed (clamped) state, whereas in a slide-out state in which the internal part has moved to the opposite flange side, torque is applied from a position away from the flange. For this reason, the stress value applied to the bolt hole of the outer ring is different between the slide-in state and the slide-out state. In this case, the stress is high in the slide-out state. Accordingly, even if the diameter of the bolt hole is increased by opening the bolt hole in the first portion having a large distance between the track grooves on the end surface on the side opposite to the flange of the outer ring, the strength decreases on the end surface side on the side opposite to the flange. Can be prevented, and lack of strength can be avoided.

  The number of balls can be set to 10, the number of bolt holes can be set to 5, the number of balls can be set to 8, and the number of bolt holes can be set to 4.

  In the constant velocity universal joint of the present invention, the number of bolt holes is half of the number of balls, so that the number of bolt tightenings to the flange of this constant velocity universal joint can be reduced, and the workability of assembling to the vehicle can be improved. Can do. Moreover, even if the hole diameter of the bolt hole is increased, insufficient strength can be prevented, so that a stable mounting state can be secured.

  Further, since the bolt hole opens in the first portion having the large distance between the track grooves on the end surface on the side opposite to the flange of the outer ring, the dimension between the bolt hole and the track groove can be made sufficiently large. For this reason, a sufficient sealing surface can be secured and the sealing performance is excellent.

  An embodiment of a constant velocity universal joint according to the present invention will be described with reference to FIGS.

  FIG. 3 shows a constant velocity universal joint according to the present invention. This constant velocity universal joint is a float type Lebro type (or cross groove type) constant velocity universal joint in which the minimum inner diameter of the cage is set smaller than the maximum outer diameter of the inner ring. The constant velocity universal joint 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 track grooves 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 the snap ring 20.

  The outer ring 22 is located on the outer periphery of the inner ring 21, and the same number of track grooves 27 as the track grooves 26 of the inner ring 21 are formed on the inner peripheral surface thereof. The track groove 26 of the inner ring 21 and the track groove 27 of the outer ring 22 form an angle inclined in the opposite direction with respect to the axis, and a ball is formed at the intersection of the track groove 26 of the inner ring 21 and the track groove 27 of the outer ring 22 that make a pair. 23 is incorporated. 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.

  Therefore, as shown in FIGS. 1 and 2, in the outer ring 22, the track groove 27 is inclined with respect to the axis, and the end portion 22a, 22b has a large inter-groove distance L (L1). 31 and the second portions 32 having a small inter-groove distance L (L2) are alternately arranged along the circumferential direction. And while providing the bolt hole 37 in the outer ring | wheel 22, the two track grooves 27 and 27 are arrange | positioned between the bolt holes adjacent to the circumferential direction. For this reason, five bolt holes 37 are arranged for ten track grooves 27. In addition, circumferential recesses 33 and 34 are formed on the inner diameter side of both end faces 22a and 22b of the outer ring 22.

  By the way, the outer ring 22 has a companion flange (not shown) attached to one end face 22a side, and a sealing device having a boot or the like attached to the other end face 22b side. Therefore, in the present invention, as shown in FIG. 1, a bolt hole 37 is opened in the first portion 31 having a large distance between the track grooves on the end surface of the outer ring 22 on the side opposite to the flange, that is, the other end surface 22b. . The bolt hole 37 has a larger diameter than that of a conventional constant velocity universal joint of the same type and the same size.

  For this reason, the distance (dimension) L3 between the bolt hole 37 and the track groove 27 can be made relatively large on the end face 22b on the opposite flange side. In the end surface 22a on the flange side, the bolt hole 37 opens in the second portion 32 having a small track groove distance.

  On the other hand, as shown in the comparative example of FIG. 5, it is possible to open the bolt hole 37 in the second portion 32 having a small track groove distance on the end surface 22b on the opposite flange side. However, in this case, the distance (dimension) L3 between the bolt hole 37 and the track groove 27 becomes small.

  Next, the first portion 31 having a large distance between the track grooves on the other end surface 22b (the product of the present invention) in the first portion 31 and the second portion having a small distance between the track grooves on the other end surface 22b. 32 is compared with a bolt hole 37 (comparative product). That is, when the internal parts including the inner ring 21, the cage 24, the ball 23, and the like are slid (slid out) toward the device side, that is, the boot side, a difference in outer ring strength occurs, and the comparative product has lower strength. This is because the damaged portion is generated from a thin bolt hole.

  Further, when the internal part slides (slide in) to the flange side, the product of the present invention has lower strength than the comparative product, but the amount of decrease is small. That is, when the outer ring strength of the product of the present invention is compared with the outer ring strength of the comparative product, the outer ring strength at the time of slide-in of the product of the present invention is larger than the outer ring strength at the time of slide-out of the comparative product. This is because the flange-side end face side is attached to the vehicle mounting flange, so in the slide-in state in which the internal parts composed of the inner ring, ball, cage, etc. have moved to the flange side, Torque is applied in a state where the side is enclosed (pinched), whereas in a slide-out state in which the internal part has moved to the opposite flange side, torque is applied from a position away from the flange. For this reason, the stress value applied to the bolt hole 37 of the outer ring 22 is different between the slide-in state and the slide-out state. In this case, the stress during slide-out is high. Therefore, even if the hole diameter of the bolt hole 37 is increased by opening the bolt hole 37 in the first portion 31 having a large distance between the track grooves on the end face 22b on the side opposite to the flange of the outer ring 22, the end face on the side opposite to the flange. It is possible to prevent a decrease in strength on the 22b side and to avoid a lack of strength. For this reason, as in the product of the present invention, it is advantageous in terms of strength when the bolt holes 37 are opened in the first portion 31 having a large track groove distance when viewed in the entire area where the constant velocity universal joint is used. is there.

  In the constant velocity universal joint of the present invention, two track grooves are arranged between the bolt holes adjacent in the circumferential direction, so the number of bolt holes 37 is half of the number of balls. For this reason, the number of bolt tightening with respect to the flange of this constant velocity universal joint can be reduced, and the workability | assembly workability to a vehicle can be aimed at. Further, since the bolt hole 37 is opened in the first portion 31 having a large track groove distance on the end surface 22b on the side opposite to the flange of the outer ring 22, even if the hole diameter of the bolt hole 37 is increased, the strength is insufficient. Can be prevented, and a stable mounting state can be secured.

  Further, since the bolt hole 37 is opened in the first portion 31 having a large distance between the track grooves on the end surface 22b on the side opposite to the flange of the outer ring 22, the dimension between the bolt hole 37 and the track groove 27 should be sufficiently large. Can do. For this reason, a sufficient sealing surface can be secured and the sealing performance is excellent. By the way, when comparing the boot side and the flange side, lubricant such as grease is more likely to leak on the boot side than on the flange side. For this reason, it is optimal for this type of constant velocity universal joint to improve the sealing performance on the end face 22b side on the anti-flange side which is the boot side.

  Next, FIG. 4 shows an outer ring 22 of another embodiment, in which the number of track grooves 27 (that is, the number of balls 23) is eight and the number of bolt holes 37 is four. Also in this case, two track grooves 27 are arranged between the bolt holes adjacent in the circumferential direction, and the bolt holes 37 are formed in the first portion 31 having a large distance between the track grooves on the end surface 2b on the side opposite to the flange of the outer ring 22. I try to open it.

  Therefore, even the constant velocity universal joint using the outer ring 22 can achieve the same effects as the constant velocity universal joint using the outer ring 22 shown in FIG.

  As described above, the embodiment of the present invention has been described. However, the present invention is not limited to the above embodiment, and various modifications are possible. For example, as a constant velocity universal joint, the number of balls can be increased or decreased arbitrarily. Correspondingly, the number of bolt holes 37 is also arbitrary (in this case, it is half the number of balls). Further, the hole diameter of the bolt hole 37 can be selected so that the mounting strength does not become insufficient and the strength of the outer ring itself does not become insufficient by reducing the number of bolts. The constant velocity universal joint may be a non-float type in which the minimum inner diameter of the cage is larger than the maximum outer diameter of the inner ring.

It is a side view of the outer ring | wheel of the constant velocity universal joint which shows embodiment of this invention. FIG. 3 is a cross-sectional view taken along the line AOB in FIG. 1. It is sectional drawing of the said constant velocity universal joint. It is a side view of the outer ring | wheel of the constant velocity universal joint which shows other embodiment of this invention. It is a side view of the outer ring which shows the comparative example of an outer ring. It is sectional drawing of the conventional constant velocity universal joint. It is a partial front view for demonstrating the track crossing angle in the inner ring | wheel and outer ring | wheel of a constant velocity universal joint. It is a side view of an outer ring for explaining the distance between grooves in the end face of the outer ring of a constant velocity universal joint.

Explanation of symbols

21 Inner ring 22 Outer ring 23 Ball 24 Cage 26 Track groove 27 Track groove 31 First part 32 First part 37 Bolt hole

Claims (3)

A linear 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 where the track grooves are inclined in opposite directions with respect to the axial direction. 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, and a first portion having a large track groove distance and a second portion having a small track groove distance are circumferentially arranged. In the constant velocity universal joint formed on both end faces of the outer ring alternately along
Bolt holes for mounting to the vehicle mounting flange are provided in the outer ring, and two track grooves are disposed between the adjacent bolt holes in the circumferential direction, and the distance between the track grooves is large on the end surface of the outer ring on the side opposite to the flange. A constant velocity universal joint, characterized in that a bolt hole is opened in the first part.   2. The constant velocity universal joint according to claim 1, wherein the number of balls is 10 and the number of bolt holes is 5.   The constant velocity universal joint according to claim 1, wherein the number of balls is eight and the number of bolt holes is four.

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