JP2007071278A - Constant velocity joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture a slide mechanism disposed between an inner ring and a retainer simply at low cost. <P>SOLUTION: A constant velocity joint has a slide mechanism 38 rolling balls 32 retained by a retainer 36 between first guide grooves 26a-26f and second guide groove 28a-28f. The slide mechanism 38 consists of a plurality of tongue pieces 52 divided and arranged along a circumference direction between the inner ring 30 and the retainer 36. A projecting curved surface part 56 touching a recessed curved surface part 40 of the inner ring 30 is formed on an inner surface of the tongue piece 52, and a third spherical surface 54 touching a second spherical surface 46 of the retainer 36 is formed on an outer surface of the tongue piece 52. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a double offset type constant velocity joint for connecting one transmission shaft and the other transmission shaft in, for example, a driving force transmission portion of an automobile.

  Conventionally, in a driving force transmission unit of an automobile, a constant velocity joint that connects one transmission shaft and the other transmission shaft and transmits a rotational force to each axle is used.

  As a constant velocity joint according to this type of prior art, for example, Patent Document 1 discloses a cage having partially spherical inner and outer surfaces having centers of curvature arranged offset on both sides of a ball center plane on a joint axis. A double offset type constant velocity joint is disclosed.

  In the double offset constant velocity joint disclosed in Patent Document 1, axial vibration is applied by providing an axial clearance between the cage and the inner joint member (on both sides of the cylindrical surface of the cage central portion). Even when the inner joint member and the cage are able to move relative to each other by a minute distance along the axial direction, the sliding resistance can be reduced.

  In Patent Document 1, by reducing the sliding resistance in a use state that causes angular displacement and axial displacement while transmitting torque of the drive shaft, such as during idling at the time of running or stopping, from the engine side. This prevents the driver from being transmitted to the vehicle body and causing discomfort to the occupant.

  Similarly, Patent Document 2 discloses a double offset type constant velocity joint. In the double offset type constant velocity joint disclosed in Patent Document 2, the radius of curvature of the partial spherical surface of the cage inner peripheral surface is set to be larger than the radius of curvature of the spherical surface that is the outer peripheral surface of the inner joint member, By disposing the center of curvature of the partial spherical surface of the inner surface of the cage at a position offset in the radial direction from the center of curvature of the spherical surface that is the outer peripheral surface of the inner joint member, a larger axial clearance can be formed. .

  In Patent Document 2, since an axial clearance is formed, even if vibration is applied from the engine side in a state where torque is applied, the relative clearance between the inner joint member and the cage is caused by the axial clearance. It is said that a relatively small movement in the direction is possible and the slide resistance can be reduced.

  However, the double offset type constant velocity joint disclosed in Patent Documents 1 and 2 increases the axial clearance provided between the cage and the inner joint member, so that the cage and the inner joint member are connected to each other. The relative axial movement amount is increased to reduce slide resistance. The moving distance between the cage and the inner joint member, which are relatively moved by the axial gap, is limited to a very small distance, and the axial direction The travel distance due to the gap is limited.

  Therefore, in order to deal with such a problem, Patent Document 3 discloses that an intermediate cage is provided between the inner race and the outer cage. The intermediate cage is formed by integrally forming a plurality of claw portions having a spherical outer diameter surface that engages with the outer cage and an inner diameter surface that engages with the inner race, and an annular body, along the circumferential direction of the annular body. Thus, the plurality of claw portions are configured to protrude at an equal angle.

Japanese Utility Model Publication No. 63-2665 JP-A-11-182570 JP 2001-254754 A

  By the way, the intermediate cage disclosed in Patent Document 3 has a plurality of claw portions that are bent in a direction substantially orthogonal to the periphery of the annular body and project by a predetermined length, and is spherical with respect to the outside of each claw portion. It is necessary to perform a polishing process for forming the outer diameter surface and a polishing process for forming the inner diameter surface with respect to the inside of each claw portion.

  Therefore, when the intermediate cage disclosed in Patent Document 3 is actually manufactured, it is possible to perform high-precision polishing in a state where a member having a complicated shape as described above and having low rigidity is clamped with a cantilever. There is a problem that it is difficult and the manufacturing cost increases.

  The present invention has been made in view of the above points, and an object thereof is to provide a constant velocity joint capable of easily and inexpensively manufacturing a slide mechanism interposed between an inner ring and a retainer. And

  In this section, for ease of understanding, the reference numerals in the accompanying drawings will be described in parentheses. However, the contents described in this section should not be construed as being limited to those given the reference numerals.

In the present invention, a plurality of first guide grooves (26a to 26f) are formed which are connected to one of two intersecting shafts (12, 18), have an inner peripheral surface and extend in the axial direction, and have one end opened. An outer member (16) that
An inner ring (30) connected to the other of the two shafts, extending in the axial direction and having the same number of second guide grooves (28a to 28f) as the first guide grooves (26a to 26f) formed on the outer periphery;
A ball (32) configured to roll between the first guide groove (26a to 26f) and the second guide groove (28a to 28f) and transmitting torque;
A holding window (34) for accommodating the ball is formed, and a first outer surface side having a center of curvature (A, B) offset by an equal distance on both sides of the intersection (C) with the ball center plane on the joint axis. A retainer (36) formed with a spherical surface (44) and a second spherical surface (46) on the inner surface side;
A slide mechanism (38) for rolling the ball (32) held by the retainer (36) between the first guide groove (26a-26f) and the second guide groove (28a-28f);
In constant velocity joints with
On the outer periphery of the inner ring (30), a concave curved surface (40) formed to be depressed toward the center between the adjacent second guide grooves (28a to 28f) is formed,
The slide mechanism (38) is composed of a plurality of tongue pieces (52) divided and arranged along the circumferential direction between the inner ring (30) and the retainer (36). A convex curved surface (56) that contacts the concave curved surface (40) of the inner ring (30) is formed on the inner side, and a second spherical surface (36) of the retainer (36) is formed on the outer side of the tongue piece (52). 46), a third spherical surface (54) is formed.

  According to the present invention, when the two shafts intersect to cause relative displacement in the axial direction, and the inner ring and the outer member relatively move in the axial direction, the concave shape formed on the outer peripheral surface of the inner ring. When the curved surface slides along the convex curved surface formed on the inner surface of the tongue piece, the ball held by the holding window of the retainer becomes in a state where it can roll.

  Therefore, the ball held in the holding window of the retainer rolls smoothly while being guided by the first guide groove and the second guide groove. As a result, in the state where the two-axis constant velocity is ensured, the amount of movement of the inner ring is further increased, and the slide resistance is reduced over a wider range.

  Furthermore, according to the present invention, the concave curved surface formed on the outer peripheral surface of the inner ring and the convex curved surface formed on the inner surface of the tongue piece are brought into surface contact, thereby stabilizing the linear guide function of the tongue piece. In addition, the depth of the second guide groove formed on the outer peripheral surface of the inner ring can be sufficiently secured.

  In this case, by setting the axial width of the holding window formed on the retainer to be larger than the diameter of the ball, an axial gap is generated between the holding window and the ball. Further, the amount of inner ring movement increases.

  Further, a plurality of the balls may be arranged along the inner peripheral surface of the outer member so as to be spaced at equal angles, or a plurality of balls may be arranged along the inner peripheral surface of the outer member so as to be spaced apart at non-equal angles.

  According to the present invention, the following effects can be obtained.

  That is, the slide mechanism interposed between the inner ring and the retainer is configured by a plurality of tongue pieces that are divided and arranged along the circumferential direction between the inner ring and the retainer, so that it is simple and inexpensive. Can be manufactured.

  Preferred embodiments of the constant velocity joint according to the present invention will be described below and described in detail with reference to the accompanying drawings.

  In FIG. 1, reference numeral 10 indicates a constant velocity joint according to an embodiment of the present invention. The constant velocity joint 10 is integrally connected to one end portion of the first shaft 12 and has an opening 14. It is basically composed of a cylindrical outer cup (outer member) 16 and an inner member 22 fixed to one end of the second shaft 18 and housed in the hole 20 of the outer cup 16.

  As shown in FIGS. 2 and 3, the inner wall surface of the outer cup 16 is formed of a cylindrical surface 24. The cylindrical surface 24 extends along the axial direction and is spaced by 60 degrees around the axis. 6 first guide grooves 26a to 26f are formed. The first guide grooves 26a to 26f are each formed in a cross-section arc shape or a cross-section compound curve shape in which a pair of arcs intersect each other in a V-shape.

  The cylindrical surface 24 of the outer cup 16 has a plurality of lubricating oil passages 27a to 27f extending in the axial direction substantially parallel to the adjacent first guide grooves 26a to 26f and spaced apart at equal angles along the circumferential direction. It is formed.

  The lubricating oil passages 27a to 27f are long grooves having an arcuate cross section, and the inner member 22 (the inner ring 30, the ball 32, the retainer 36, and the tongue piece 52) disposed in the hole 20 of the outer cup 16 are integrated. The back side and the near side of the outer cup 16 are communicated with each other, and a smooth lubricating oil supply in the hole 20 of the outer cup 16 is ensured.

  The inner member 22 is formed on an inner ring 30 in which a plurality of second guide grooves 28 a to 28 f having a circular arc cross section corresponding to the first guide grooves 26 a to 26 f are formed on the outer peripheral surface, and an inner wall surface of the outer cup 16. In addition, a plurality of (this embodiment) is provided so as to be able to roll between the first guide grooves 26a to 26f and the second guide grooves 28a to 28f formed on the outer peripheral surface of the inner ring 30 and perform a rotational torque transmission function. In the form, six balls 32 are included.

  The inner member 22 includes a retainer 36 formed between the outer cup 16 and the inner ring 30. The retainer 36 includes a plurality of holding windows 34 that hold the balls 32. And a slide mechanism that rolls the ball 32 held by the retainer 36 between the first guide grooves 26a to 26f and second guide grooves 28a to 28f described later. 38.

  The inner ring 30 is integrated with the end portion of the second shaft 18 through a ring-shaped locking member that is spline-fitted to the end portion of the second shaft 18 or mounted in the annular groove of the second shaft 18. Fixed to. A plurality of second guide grooves 28 a to 28 f are formed on the outer peripheral surface of the inner ring 30 so as to correspond to the first guide grooves 26 a to 26 f of the outer cup 16 and are spaced apart by an equal angle along the circumferential direction. .

  A concave curved surface portion (concave curved surface) is formed between the adjacent second guide grooves 28 a to 28 f so as to extend substantially parallel to the axis of the second shaft 18 and to be recessed toward the center side of the inner ring 30. ) 40 is formed. As shown in FIG. 5, the concave curved surface portion 40 is formed in a circular arc shape whose center of curvature is the outer cup 16 side.

  A chamfered portion 42 that is chamfered is provided at each ridge portion that forms a boundary between the concave curved surface portion 40 and one end surface or the other end surface along the axial direction of the inner ring 30 (see FIG. 1).

  The balls 32 are formed of, for example, steel balls, and are spaced equiangularly along the circumferential direction between the first guide grooves 26 a to 26 f of the outer cup 16 and the second guide grooves 28 a to 28 f of the inner ring 30. One by one is arranged to be able to roll (see FIG. 6).

  The ball 32 transmits the rotational torque of the first shaft 12 to the second shaft 18 via the inner ring 30 and rolls along the first guide grooves 26a to 26f and the second guide grooves 28a to 28f. Thus, the relative displacement in the axial direction between the second shaft 18 (inner ring 30) and the first shaft 12 (outer cup 16) and the relative displacement in the intersecting angular direction are enabled.

  The retainer 36 has a substantially cylindrical shape, and a first spherical surface 44 having a center of curvature at a point A is provided on the outer peripheral surface slidably contacting the inner wall surface (cylindrical surface 24) of the outer cup 16, while the inner peripheral surface has A second spherical surface 46 having a point B as the center of curvature is provided (see FIG. 8). The point A and the point B are respectively arranged on the joint shaft 48, and from the intersection C where the virtual plane (ball center plane) connecting the center point O of the ball 32 and the joint shaft 48 are orthogonal to each other. They are arranged at equally offset positions (line segment AC = line segment BC).

  Further, the retainer 36 is formed with a plurality of holding windows 34 having a substantially rectangular cross section that are spaced by an equal angle along the circumferential direction corresponding to the number of balls 32. The holding window 34 has a first guide groove 26a. The ball 32 disposed between the second guide grooves 28a to 28f and the second guide grooves 28a to 28f is held. In this case, the inner diameter dimension (inner diameter width) along the axial direction of the holding window 34 is set slightly larger than the diameter of the ball 32 (see FIG. 1).

  The slide mechanism 38 is configured by a plurality of tongue pieces 52 that are divided and arranged at equal angular intervals along the circumferential direction between the inner ring 30 and the retainer 36. The plurality of tongue pieces 52 are respectively formed in the same rectangular shape in plan view, extend parallel to the axis of the second shaft 18 (see FIG. 1), and extend along the circumferential direction of the inner ring 30. Are spaced apart by an equal angle (see FIG. 6).

  A third spherical surface 54 having a radius of curvature corresponding to the second spherical surface 46 is provided on the outer surface of the tongue piece 52 so as to be in sliding contact with the second spherical surface 46 of the inner peripheral surface of the retainer 36. Is formed. Further, a convex curved surface portion that is in surface contact with the concave curved surface portion 40 of the outer peripheral surface of the inner ring 30 and allows relative displacement in the axial direction between the inner ring 30 and the inner surface of the tongue piece 52. A (convex curved surface) 56 is formed. As shown in FIG. 5, the convex curved surface portion 56 has a circular arc shape that is convex toward the inner surface side (inner ring 30 side) opposite to the outer surface.

  In other words, the convex curved surface portion 56 of the tongue piece 52 is formed in a circular arc shape convex toward the second shaft 18 in the cross section along the short side direction of the tongue piece 52 having a rectangular shape in plan view ( 5), the tongue piece 52 is linearly formed in a cross section along the long side direction (axial direction) (see FIG. 1).

  In this case, each of the tongue pieces 52 is interposed between the retainer 36 and the inner ring 30, and the ball 32 is disposed between the adjacent tongue pieces 52. Further, after the tongue piece 52 is assembled between the retainer 36 and the inner ring 30, the radius of curvature of the second spherical surface 46 of the retainer 36 and the third spherical surface 54 of the tongue piece 52 which are in surface contact with each other is appropriately set. Accordingly, even when the tongue piece 52 slides as shown in FIG. 7, the retainer 36 and the inner ring 30 are prevented from coming off.

  In this embodiment, as shown in FIGS. 3 and 6, six balls 32 are arranged so as to be spaced apart at equal angles, and tongue pieces 52 are arranged between the adjacent balls 32, respectively. However, the present invention is not limited to this. For example, as shown in the constant velocity joint 50 according to the fourth modification of FIG. By using a retainer 36a that holds an equal angle (two adjacent balls 32 as one set and three sets of balls 32 arranged in three equal parts), a circumferentially wider width between adjacent pairs of balls 32 is achieved. Three tongue pieces 52a can be arranged.

  In this case, by using the three wide tongue pieces 52a, the contact area between the individual tongue pieces 52a and the inner ring 30a can be increased, the surface pressure can be suppressed, and the durability can be improved. By reducing the manufacturing cost, the manufacturing cost can be further reduced.

  The constant velocity joint 10 according to the present embodiment is basically configured as described above. Next, the operation, action, and effect will be described.

  When the first shaft 12 rotates, the rotational torque is transmitted from the outer cup 16 to the inner ring 30 via each ball 32, and the second shaft 18 rotates in a predetermined direction while maintaining constant velocity with the first shaft 12. To do.

  In this case, for example, when the front side of the vehicle is up and the rear side is sunk as when the vehicle suddenly starts, relative displacement in the axial direction occurs between the first shaft 12 and the second shaft 18. Then, the inner ring 30 and the outer cup 16 move relatively in the axial direction. At that time, the concave curved surface portion 40 formed on the outer peripheral surface of the inner ring 30 slides along the convex curved surface portion 56 formed on the inner surface of the tongue piece 52, so that it is held by the holding window 34 of the retainer 36. The ball 32 thus rolled can move. Therefore, the ball 32 held by the holding window 34 of the retainer 36 is guided by the first guide grooves 26a to 26f and the second guide grooves 28a to 28f and rolls smoothly.

  On the other hand, when the crossing angle between the first shaft 12 and the second shaft 18 changes, the ball 32 that rolls between the first guide grooves 26a to 26f and the second guide grooves 28a to 28f is under action. The retainer 36 tilts by a predetermined angle to allow the angular displacement, and the second spherical surface 46 formed on the inner peripheral surface of the retainer 36 and the third spherical surface 54 formed on the outer surface of the tongue piece 52 slide. The tongue 52 is tilted by a predetermined angle with respect to the retainer 36, and the angular displacement is allowed (see FIG. 7).

  Thus, while maintaining the constant velocity of the first shaft 12 and the second shaft 18, their angular displacement and relative displacement in the axial direction are preferably allowed.

  Here, the case where the constant velocity joint 10 according to the present embodiment absorbs the axial displacement will be described with reference to FIG.

  When a relative displacement in the axial direction occurs between the first shaft 12 and the second shaft 18, for example, when the inner ring 30 is about to move in the direction of the arrow X 1, the first guide grooves 26 a to 26 b of the outer cup 16. Assuming that the contact point D between 26f and the ball 32 is 100% rolling contact, the ball 32 moves the contact point D along the arrow X1 while rotating in the direction of arrow E with the center point O as the center of rotation. Is moved along the direction of the arrow X2. 9 simplifies the relationship between the amount of movement of the inner ring 30 and the ball 32 when the first guide grooves 26a to 26f of the outer cup 16 are fixed and the inner ring 30 is movable. It is a representation.

  In this case, the second spherical surface 46 on the inner peripheral surface of the retainer 36 and the third spherical surface 54 on the outer surface of the tongue piece 52 are in spherical contact with each other to restrict the displacement of the tongue piece 52 in the axial direction. As the concave curved surface portion 40 on the outer peripheral surface of the inner ring 30 slides along the convex curved surface portion 56 on the inner surface of the piece 52, displacement of the inner ring 30 in the axial direction is allowed.

  Therefore, as shown in FIG. 8, the contact point F between the ball 32 and the second guide grooves 28a to 28f of the inner ring 30 is movable along the axial direction, and is in 100% rolling contact. As a result, even when a large axial displacement occurs between the first shaft 12 and the second shaft 18, the convex curved surface portion 56 on the inner surface of the tongue piece 52 and the outer periphery of the inner ring 30. The amount of displacement of the inner ring 30 in the axial direction can be further increased under the sliding action with the concave curved surface portion 40 of the surface, and the slide resistance can be reduced over a wide range.

  In the present embodiment, a slide mechanism 38 interposed between the inner ring 30 and the retainer 36 is provided with a plurality of tongue pieces that are divided and arranged along the circumferential direction between the inner ring 30 and the retainer 36. By comprising 52, it can manufacture simply and cheaply.

  That is, by configuring the slide mechanism 38 with a plurality of tongue pieces 52, the outer surface of the tongue piece 52 is held by the retainer 36 while the tongue piece 52 is clamped in a cantilever manner via a clamping mechanism (not shown). The third spherical surface having a radius of curvature corresponding to the second spherical surface 46 can be polished with high accuracy, and the inner surface of the tongue piece 52 is a convex curved surface corresponding to the concave curved surface portion 40 of the inner ring 30. The portion 56 can be polished with high accuracy.

  In other words, in this embodiment, the slide mechanism 38 is configured by a plurality of tongue pieces 52 having a simple shape made of a rectangular claw member in plan view and having a relatively high rigidity. A member according to the prior art in which the claw portion is integrally formed can be easily and inexpensively manufactured.

  Furthermore, in the present embodiment, the convex curved surface portion 56 formed on the inner surface of the tongue piece 52 is brought into surface contact with the concave curved surface portion 40 formed on the outer peripheral surface of the inner ring 30 and is slid. As shown in FIG. 4, the linear guide function along the axial direction (see arrow S) of the tongue piece 52 is stabilized, and the circumferential rotation of the tongue piece 52 (see arrow T) is prevented. it can.

  Furthermore, in the present embodiment, the concave curved surface portion 40 formed on the outer peripheral surface of the inner ring 30 and the convex curved surface portion 56 formed on the inner surface of the tongue piece 52 are brought into surface contact with each other in FIG. As shown, the groove depths of the second guide grooves 28a to 28f on which the ball 32 rolls can be sufficiently taken.

  That is, if the outer peripheral surface of the inner ring 30 is a convex curved surface portion (see the two-dot chain line in FIG. 5), the concave curved surface portion is formed on the outer peripheral surface of the inner ring 30 in this embodiment. By forming 40, the groove depth of the second guide grooves 28a to 28f can be increased by the dimension δ shown in FIG. As a result, it becomes easier for the ball 32 to roll along the second guide grooves 28a to 28f, and the slide resistance can be reduced.

  Furthermore, in the present embodiment, when the tongue piece 52 is assembled to the retainer 36, escape to the inner diameter side is unnecessary, and the ball 32 is in a point contact with the holding window 34 of the retainer 36. The tongue piece 52 can be easily assembled.

  Next, the constant velocity joint 10 according to the present embodiment and the constant velocity joint (refer to Japanese Patent Laid-Open No. 3-277822) 101 according to the comparative example will be described in detail below.

  As shown in FIG. 16, the constant velocity joint 101 according to this comparative example includes an outer joint member 103 in which a first guide groove 102 is formed, and an inner joint member 105 in which a second guide groove 104 is formed. A ball 106 rotatably disposed between the first guide groove 102 and the second guide groove 104, and interposed between the outer joint member 103 and the inner joint member 105, A cage 108 formed with a ball holding window 107 for holding the ball 106.

  The constant velocity joint 101 according to the comparative example includes a sliding ring 109 interposed between the inner joint member 105 and the cage 108, and an axial end of the sliding ring 109 and the cage 108. And a pair of elastically deformable elastic members 110a and 110b disposed between the two.

  The sliding ring 109 includes a right cylindrical outer peripheral surface 111 that contacts the inner peripheral surface of the cage 108, a concave spherical inner peripheral surface 112 that contacts the outer peripheral surface of the inner joint member 105, and a ball holding window. An accommodation window which is provided at a position corresponding to 107 and is slightly larger than the ball holding window 107 is formed.

  In the constant velocity joint 101 according to the comparative example, a relative displacement in the axial direction occurs between the drive shaft 114 and the driven shaft 115, and the inner joint member 105 and the outer joint member 103 move in the axial direction. When moved relatively along, the sliding ring 109 moves together with the inner joint member 105 and slides in the axial direction with respect to the cage 108. The displacement of the sliding ring 109 is absorbed by a pair of elastic members 110a and 110b disposed at both ends thereof.

  When there is no large axial relative movement between the inner joint member 105 and the outer joint member 103, the pair of elastic members 110 a and 110 b are elastically restored, and the cage 108 is inward via the sliding ring 109. The joint member 105 is returned to the initial setting position and centered.

  For this reason, in the constant velocity joint 101 according to the comparative example, the ball 106 is always held in a state in which it can roll, and even if a large relative displacement in the axial direction occurs between the drive shaft 114 and the driven shaft 115, the ball 106 slides. The resistance can be kept small.

  Next, a comparative study will be made on the configuration and operational effects of the constant velocity joint 10 according to the present embodiment and the constant velocity joint 101 according to the comparative example.

  In the constant velocity joint 10 according to the present embodiment, the third spherical surface 54 of the outer surface of the tongue piece 52 contacts the second spherical surface 46 of the inner peripheral surface of the retainer 36 and the convex curved surface of the inner surface of the tongue piece 52. Whereas the portion 56 is formed so as to come into contact with the concave curved surface portion 40 of the inner ring 30, in the constant velocity joint 101 according to the comparative example, the right cylindrical outer peripheral surface 111 of the sliding ring 109 is The configuration is different in that the inner circumferential surface 112 of the concave spherical surface of the sliding ring 109 is formed so as to contact the outer circumferential surface of the inner joint member 105 while being in contact with the inner circumferential surface.

  In other words, in the tongue piece 52 of the constant velocity joint 10 according to the present embodiment and the sliding ring 109 of the constant velocity joint 101 according to the comparative example, the relationship between the spherical surface and the cylindrical surface on the outer peripheral surface and the inner peripheral surface. Are different in that they are reversed.

  Regarding the point of action, in the constant velocity joint 10 according to the present embodiment, the inner ring 30 is provided so as to be displaced in the axial direction along the tongue piece 52 alone, whereas according to the comparative example, etc. The speed joint 101 is different in that the inner joint member 105 is displaced in the axial direction integrally with the sliding ring 109.

  Regarding the effect, in the constant velocity joint 10 according to the present embodiment, under the sliding action between the convex curved surface portion 56 of the inner surface of the tongue piece 52 and the concave curved surface portion 40 of the outer peripheral surface of the inner ring 30, While it is possible to set a large amount of displacement of the inner ring 30 in the axial direction, the constant velocity joint 101 according to the comparative example includes a pair of elastic members 110a and 110b that absorb the displacement of the sliding ring 109. Since it is disposed between the sliding ring 109 and the axial end of the cage 108, the inner joint member 105 can move by a minute distance.

  In this case, in the constant velocity joint 101 according to the comparative example, when the movement amount of the inner joint member 105 is increased, the cage 108 and the ball 106 are separated from the bisector, and the drive shaft 114 and the covered shaft are separated. It may be difficult to ensure constant speed with the drive shaft 115.

  On the other hand, in the constant velocity joint 10 according to the present embodiment, in a state where the configuration of the double offset type constant velocity joint 10 that ensures constant velocity between the first shaft 12 and the second shaft 18 is maintained, the inner joint is maintained. It has a remarkable effect different from the constant velocity joint 101 according to the comparative example in that the amount of displacement of the ring 30 in the axial direction is further increased.

  Here, the constant velocity property of the double offset type constant velocity joint 10 according to the present embodiment will be described with reference to FIG.

  In FIG. 10, the ball 32 is disposed between the first guide grooves 26 a to 26 f of the outer cup 16 and the second guide grooves 28 a to 28 f of the inner ring 30 so as to freely roll. The first guide grooves 26a to 26f and the axis G of the first shaft 12 serving as the input shaft are provided in parallel, and the second guide grooves 28a to 28f and the axis H of the second shaft 18 serving as the output shaft are provided. Are parallel to each other. The axis I indicates the axis of the retainer 36.

  Further, the input shaft angular velocity is ω1, the output shaft angular velocity is ω2, and a contact point when a perpendicular is drawn from the center point O of the ball 32 to the first guide grooves 26a to 26f of the outer cup 16 is defined as a. Let b be the contact point when the perpendicular line is lowered from the center point O to the second guide grooves 28 a to 28 f of the inner ring 30.

In this case, the tangential velocity V1 of the ball 32 viewed from the first shaft 12 as the input shaft is
V1 = vector ao · ω1 (1)
On the other hand, the tangential velocity V2 of the ball 32 viewed from the second shaft 18 that is the output shaft is
V2 = vector bo · ω2 (2)
It becomes. Here, from V1 = V2, vector ao · ω1 = vector bo · ω2 (3)
Holds.

  In this case, since vector ao = vector bo, ω1 = ω2, and constant velocity between the first shaft 12 as the input shaft and the second shaft 18 as the output shaft is ensured.

  As described above, in the present embodiment, the inner curved surface 56 and the concave curved surface 40 on the outer peripheral surface of the inner ring 30 are slidably acted on by the inner surface of the plurality of divided tongue pieces 52. Even when the displacement amount of the ring 30 with respect to the axial direction is set to be large, a ball 32 (ball center plane connecting a plurality of ball centers) having a torque transmission function is intersected with the first shaft 12 and the second shaft 18. Is held on a bisecting surface that bisects the bisect. Therefore, equal velocity is ensured.

  Further, in the present embodiment, the convex curved surface portion 56 on the inner surface of the tongue piece 52 and the concave curved surface portion 40 on the outer peripheral surface of the inner ring 30 slide in contact with each other. A slight relative displacement (about 1 mm) with respect to the circumferential direction of the piece 52 is allowed.

  For example, when the crossing angle (operating angle) between the first shaft 12 and the second shaft 18 is 0 degree, the positions of the six balls 32 viewed from the second shaft 18 side are the first guide grooves 26a to 26a of the outer cup 16. Although it appears to be spaced apart by an equal angle in the circumferential direction along 26f (see FIG. 6), the two axes are angularly displaced and the first axis 12 and the second axis 18 intersect each other (see FIG. 6). When viewed from the second shaft 18 side, the apparent position of the ball 32 is not equiangular along the circumferential direction (the state is not equidistant from the center).

  Accordingly, when the balls 32 appear to be in an apparent position that does not appear to be equally spaced, the convex curved surface portion 56 on the inner surface of the tongue piece 52 and the concave curved surface portion 40 on the outer peripheral surface of the inner ring 30 are in surface contact. By allowing the ball 32 to slide along the circumferential direction, the ball 32 having a degree of freedom with respect to the circumferential direction of the ball 32 and having a torque transmission function (a ball center plane connecting a plurality of ball centers) is provided on the first shaft 12. And the crossing angle of the second axis 18 can be stably held on a bisector.

  Furthermore, in the present embodiment, the convex curved surface portion 56 on the inner surface of the tongue piece 52 and the concave curved surface portion 40 on the outer peripheral surface of the inner ring 30 have a surface contact structure, thereby reducing the surface pressure, Good grease intervention (lubricity) can be obtained and durability can be improved.

  As shown in FIG. 5, the width dimension M along the circumferential direction (short side direction) of the tongue piece 52 and the width dimension N along the circumferential direction of the concave curved surface portion 40 of the inner ring 30 are: <N is set. Accordingly, a pair of circumferential clearances 59a and 59b is formed between the tongue piece 52 and the adjacent balls 32 and 32, and the tongue piece 52 and the inner ring 30 are convex on the inner surface of the tongue piece 52. The curved surface portion 56 and the concave curved surface portion 40 on the outer peripheral surface of the inner ring 30 are provided so as to be relatively displaceable along the circumferential direction by the sum of the pair of circumferential clearances 59a and 59b. Further, the separation distance along the circumferential direction of the adjacent tongue pieces 52 is set to be slightly larger than the diameter of the ball 32.

  Next, FIG. 11 shows a state in which the constant velocity joint 10 according to the present embodiment is applied to the drive shaft 58. In the drive shaft 58, a constant velocity joint 10 according to the present embodiment is assembled on a differential gear (not shown), and a known Barfield type constant velocity joint 60 is assembled on the opposite wheel side.

  By applying the constant velocity joint 10 according to the present embodiment to the end of the drive shaft 58 connected to the differential gear side, when the driving force from the differential gear is transmitted to a tire (not shown), angular displacement or Axial relative displacement can be suitably absorbed.

  Next, constant velocity joints 10a to 10c according to modifications of the present invention are shown in FIGS.

  In the constant velocity joint 10a according to the first modification shown in FIG. 12, the inner diameter dimension (inner diameter width) of the holding window 34 of the retainer 36 is set larger than the diameter of the ball 32, and the inner wall surface of the holding window 34 and the ball By forming the axial gap 62 between the inner ring 30 and the inner ring 30, the axial displacement of the inner ring 30 can be further increased.

  Further, in the constant velocity joint 10b according to the second modification shown in FIG. 13, one end portion of the second guide grooves 28a to 28f of the inner ring 30 is bulged to restrict the displacement amount of the ball 32. A stopper portion 64 is formed.

  Furthermore, in the constant velocity joint 10 c according to the third modification shown in FIG. 14, the buffer member 68 is attached to the stopper portion 64 to suppress interference noise. The buffer member 68 may be formed of, for example, a resin material, but is not limited thereto, and other materials such as a rubber material may be used to suppress interference noise.

It is a longitudinal cross-sectional view along the axial direction of the constant velocity joint which concerns on embodiment of this invention. It is the perspective view notched in the axial direction of the constant velocity joint shown in FIG. It is a disassembled perspective view of the constant velocity joint shown in FIG. It is a partial expansion perspective view which shows the surface contact state of the concave curved surface part of the inner ring which comprises the constant velocity joint shown in FIG. 1, and the convex curved surface of a tongue piece. FIG. 2 is a partially enlarged longitudinal sectional view in a direction orthogonal to the axial direction of the constant velocity joint shown in FIG. 1. It is a longitudinal cross-sectional view along the VI-VI line of the constant velocity joint shown in FIG. It is a longitudinal cross-sectional view of the state in which the 2nd axis | shaft of the constant velocity joint shown in FIG. 1 tilted. It is a fragmentary longitudinal cross-sectional view explaining operation | movement of the constant velocity joint shown in FIG. It is explanatory drawing which simplified the relationship of the moving amount | distance of the ball | bowl and inner ring shown in FIG. It is explanatory drawing of the constant velocity property of the constant velocity joint shown in FIG. It is a partial longitudinal cross-section block diagram of the state which applied the constant velocity joint shown in FIG. 1 to the drive shaft. It is a partial longitudinal cross-sectional view of the constant velocity joint which concerns on the 1st modification of this invention. It is a partial longitudinal cross-sectional view of the constant velocity joint which concerns on the 2nd modification of this invention. It is a partial longitudinal cross-sectional view of the constant velocity joint which concerns on the 3rd modification of this invention. It is a longitudinal cross-sectional view of the direction orthogonal to the axis of the constant velocity joint which concerns on the 4th modification of this invention. It is a longitudinal cross-sectional view of the constant velocity joint which concerns on a comparative example.

Explanation of symbols

10, 10a to 10c, 50 ... constant velocity joint 12 ... first shaft 16 ... outer cup 18 ... second shaft 26a-26f ... first guide groove 28a-28f ... second guide groove 30, 30a ... inner ring 32 ... ball 34 ... holding window 36, 36a ... retainer 38 ... slide mechanism 40 ... concave curved surface portion 44 ... first spherical surface 46 ... second spherical surface 48 ... joint shaft 52, 52a ... tongue piece 54 ... third spherical surface 56 ... convex curved surface portion 58 ... Drive shaft 59a, 59b ... circumferential clearance 68 ... cushioning member

Claims (3)

An outer member connected to one of two intersecting shafts, having an inner peripheral surface and extending in the axial direction, a plurality of first guide grooves formed at one end;
An inner ring connected to the other of the two shafts, extending in the axial direction and having the same number of second guide grooves as the first guide grooves formed on the outer periphery;
A ball that is configured to roll between the first guide groove and the second guide groove and transmits torque;
A holding window for receiving the ball is formed, and a first spherical surface on the outer surface side and a second spherical surface on the inner surface side having a center of curvature offset by an equal distance on both sides of the intersection with the ball center plane on the joint axis. A formed retainer;
A slide mechanism for rolling the ball held by the retainer between the first guide groove and the second guide groove;
In constant velocity joints with
On the outer periphery of the inner ring, a concave curved surface is formed that is recessed toward the center between the adjacent second guide grooves,
The slide mechanism includes a plurality of tongue pieces arranged in a circumferential direction between the inner ring and the retainer, and a convex shape that contacts a concave curved surface of the inner ring on the inner side of the tongue piece. A constant velocity joint, wherein a curved surface is formed, and a third spherical surface that contacts the second spherical surface of the retainer is formed outside the tongue piece. The constant velocity joint according to claim 1,
The constant velocity joint according to claim 1, wherein an axial width of the holding window formed in the retainer is set larger than a diameter of the ball. The constant velocity joint according to claim 1,
A plurality of the balls are arranged at equal angular intervals along the inner peripheral surface of the outer member, or a plurality of balls are arranged at non-equal angular intervals along the inner peripheral surface of the outer member. Constant velocity joint.

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