JP2016008660A - Constant velocity joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a constant velocity joint which stably suppresses rotational wobbling while employing a simple constitution.SOLUTION: A constant velocity joint has: a cylindrically-formed outer ring 24 in which three pieces of roller guide grooves 26 are formed at an internal peripheral face in an axial direction; a tripod 34 in which a torque transmission angle is formed so as to be changeable with respect to an axial line of the outer ring 24, and which comprises three pieces of tripod shaft parts 38 which extend to the outside of a radial direction; three pieces of rollers 40 which are rotatably supported to the respective tripod shaft parts 38, and rollingly arranged in groove extension directions of the respective roller guide grooves 26; and an elastic torus-shaped member 60 which is arranged between the roller guide grooves 26 and upper parts of external peripheries of the rollers 40.

Description

  The present invention relates to a constant velocity joint.

  Conventionally, for example, Patent Document 1 is known as a constant velocity joint that suppresses the occurrence of rotational play. In Patent Document 1, in order to suppress the occurrence of rotation play, a metal plate is fitted to both surfaces of a concave groove in an outer ring formed in a cylindrical shape via elastic bodies, and the roller is used as a metal plate. The structure which transfers the surface of this to the axial direction of an outer ring | wheel is disclosed.

JP 2008-240811 A

  However, in the technique in Patent Document 1, it is necessary to provide a metal plate and an elastic body on both sides in the radial direction of the roller in the outer ring. Therefore, the configuration of the outer ring increases, which may increase the material cost and increase the assembly work. Moreover, when elastic deformation of both elastic bodies becomes non-uniform | heterogenous, there exists a possibility that suppression of rotation backlash may not be performed stably.

  The present invention was devised in view of such a point, and the problem to be solved by the present invention is a constant velocity joint that stably suppresses rotational play while adopting a simple configuration. There is.

  In order to solve the above problems, the constant velocity joint of the present invention takes the following means. First, a constant velocity joint according to a first aspect of the present invention is a constant velocity joint, which is formed in a cylindrical shape and has an outer ring formed with three roller guide grooves in the axial direction of the inner peripheral surface thereof, and the outer ring A torque transmission angle with respect to the axis can be changed, a tripod having three tripod shafts extending radially outward, and rotatably supported by each of the tripod shafts, and a groove of each of the roller guide grooves Three rollers arranged so as to be able to roll in the extending direction, and an elastically deformable torus-like member disposed between the roller guide groove and the outer periphery of the roller.

  According to the first invention, the elastically deformable torus-like member is disposed between the roller guide groove and the outer periphery of the roller. Therefore, it becomes a structure which has one elastically deformable member with respect to a roller, and can be simplified. Moreover, since the torus-like member is annularly disposed on the outer periphery of the roller, the torus-like member is configured to be elastically deformed as the roller rolls. Therefore, it is possible to stably suppress the rotation play. Thereby, a rapid torque fluctuation can be suppressed.

  Next, the constant velocity joint according to a second aspect of the present invention is the first aspect of the present invention, wherein the roller guide groove rolls the roller with the arcuate surfaces facing each other when viewed in the radial cross section of the outer ring. The roller has a roller guide surface that can be guided, and the roller has an arcuate rolling surface whose outer peripheral surface can come into contact with the roller guide surface when viewed in a radial section of the outer ring, and the torus The shaped member is disposed at the outermost peripheral position of the rolling surface of the roller.

  According to the second aspect of the invention, the torus-like member is disposed at the position of the outermost periphery of the rolling surface of the roller, so that the rotation backlash can be more smoothly suppressed.

  Next, the constant velocity joint according to a third aspect of the present invention is the first aspect or the second aspect, wherein the rolling surface of the roller has an annular groove in which the torus-shaped member is accommodated.

  According to the third aspect of the invention, the rolling surface of the roller has the annular groove in which the torus-like member is accommodated, so that the torus-like member can be prevented from falling off.

  Next, in the constant velocity joint according to the fourth aspect of the present invention, in any one of the first aspect to the third aspect, one of the opposite surfaces of the roller guide surfaces transmits torque when torque transmission acts. The torque transmitting surface is a non-torque transmitting surface that does not transmit torque, and the torus-shaped member is configured such that the torque transmitting surface and the rolling surface of the roller are in contact with each other when torque transmission is applied. As a result of being compressed and deformed, the non-torque transmission surface is not in contact with each other, and when the torque transmission direction is reversed and the torque transmission surface and the non-torque transmission surface are switched. It becomes the structure which contacts both surfaces of the said roller guide surface which opposes.

  According to the fourth aspect of the present invention, when torque transmission acts, the forcing force of the induced thrust force can be reduced by providing a non-contact configuration between the torus-like member and the non-torque transmission surface. Further, when the torque transmission direction is reversed, since the state is in contact with both surfaces of the roller guide surface facing the torus-like member, it is possible to suppress rotational backlash and abrupt torque fluctuation. Thereby, coexistence of reduction of the forced force of induced thrust force and suppression of rotation backlash can be aimed at.

  Next, the constant velocity joint according to a fifth aspect of the present invention is the constant velocity joint according to any one of the first to fourth aspects, wherein the roller includes two rollers between the roller guide groove and the tripod shaft portion. Double roller type.

  According to the fifth aspect of the present invention, the double roller type has a configuration in which the two rollers move relative to each other, and rotation backlash is likely to occur due to a gap between the components. Further, since the double roller type roller is so-called swingable that tilts with respect to the axis of the tripod shaft, rotation backlash tends to occur. Therefore, a torus-like member can be suitable for a double roller type roller.

  According to the present invention, by adopting the means of each of the inventions described above, a constant velocity joint that stably suppresses the rotation play can be obtained while adopting a simple configuration.

It is a disassembled perspective view which shows the whole structure of the double roller type tripod type | mold constant velocity joint of embodiment of this invention. It is an axial sectional view of the same embodiment. It is the III-III sectional view taken on the line of FIG. It is sectional drawing which showed the torque transmission state of the state which the roller contacted the roller guide groove of the outer ring | wheel. It is the VV sectional view taken on the line of FIG. It is sectional drawing which showed the state which a torque transmission direction reverses and a torque transmission surface and a non-torque transmission surface interchange. It is the VII-VII sectional view taken on the line of FIG. It is the graph which showed the relationship of the torque transmitted to a driven shaft with respect to the rotational phase of a drive shaft.

  Hereinafter, embodiments of the constant velocity joint of the present invention will be described with reference to FIGS. In FIG. 1, illustration of the boot 12 shown in FIG. 2 is omitted. A double roller type tripod type constant velocity joint will be described as an example of the constant velocity joint in the present embodiment. The tripod type constant velocity joint 10 (constant velocity joint) is a case where the drive shaft that transmits the rotational driving force of the vehicle to the wheels is provided, and is provided between the differential device and the driven shaft (intermediate shaft) 32. . Accordingly, the tripod constant velocity joint 10 is disposed on both sides of the differential device.

  As shown in FIG. 1, the tripod constant velocity joint 10 mainly includes a drive unit 20 that is an input side of a rotational driving force and a passive unit 30 that is an output side of the rotational driving force. Even if the axis 30X of the driven shaft 32 of the passive unit 30 does not coincide with the axis 20X of the driving shaft 22 and is inclined at a predetermined angle, the driving shaft 22 and the driven shaft 32 are always rotated at a constant speed. Thus, the rotational driving force (torque) can be transmitted. In this case, in this embodiment, the drive shaft 22 is connected to the output shaft (not shown) of the side gear of the differential device. One of the driven shafts 32 is connected to a tripod 34 and the other is connected to an outboard constant velocity joint (not shown).

  As shown in FIG. 1, the drive unit 20 mainly includes an outer ring 24 and a drive shaft 22 fixed to the outer ring 24. The outer ring 24 is formed in a substantially cylindrical shape with a bottom that is open at one end. The drive shaft 22 is fixed to the bottomed portion, and the tripod 34 is fitted and inserted from the opening side. The cylindrical inner cylinder shape (inner peripheral surface) of the outer ring 24 is formed with three roller guide grooves 26 arranged in parallel with the axis 20X. As shown in FIG. 3, the three roller guide grooves 26 are arranged at equal intervals in the circumferential direction. The roller guide groove 26 is disposed between the roller guide surfaces 26A and 26B and the roller guide surfaces 26A and 26B. A bottom surface 26C is formed. The roller guide surfaces 26 </ b> A and 26 </ b> B are formed in an arc shape that is convex outward when viewed in the radial cross section of the outer ring 24. The arcuate shapes of the roller guide surfaces 26A and 26B may be one arc shape, or may be a so-called gothic shape having a pointed arch shape by intersecting a plurality of arc shapes. Further, as shown in FIG. 2, a boot 12 is attached to the opening of the outer ring 24 to prevent intrusion of foreign matter, muddy water, and the like, and to keep grease inside.

  As shown in FIG. 1, the passive unit 30 is mainly composed of a driven shaft 32 and a tripod 34 fixed to one end of the driven shaft 32. The tripod 34 is integrally provided with an annular base member 36 and three tripod shafts 38 extending radially outward from the outer periphery of the base member 36. The inner surface of the base member 36 is fixed to one end of the driven shaft 32 by spline fitting or the like. The tripod shaft portion 38 is formed by radially projecting three shaft portions from three locations on the circumference of the base member 36. The arrangement relationship of the tripod shaft portion 38 is configured to protrude toward the three roller guide grooves 26 formed on the inner peripheral surface of the outer ring 24 (corresponding to the roller guide grooves 26). Yes, like the roller guide grooves 26, they are arranged at equal intervals on the circumference.

  Each of the tripod shaft portions 38 is fitted with a roller 40 so as to be rotatably supported with respect to the tripod shaft portion 38. As a result, each roller 40 is disposed in the roller guide groove 26, and rolls along the roller guide surfaces 26A and 26B on both sides of the roller guide groove 26 while extending the roller guide groove 26 (in the direction of the axis 20X). Can be moved to.

  As shown in FIG. 4, the roller 40 includes an outer roller 42, an inner roller 44, and a plurality of needle rollers 46, which are assembled by two snap rings 48, 48 arranged one above the other. The outer roller 42 has a substantially cylindrical inner peripheral surface 50. A substantially cylindrical inner roller 44 is disposed inside the inner circumferential surface 50 of the outer roller 42. A plurality of needle rollers 46 are rollably disposed between the inner peripheral surface 50 of the outer roller 42 and the outer peripheral surface 58 of the inner roller 44. Thus, the outer roller 42 and the inner roller 44 are assembled so as to be freely rotatable relative to each other. The inner peripheral surface 56 of the inner roller 44 is formed in a cylindrical surface, and the spherical portion at the tip of the tripod shaft portion 38 of the tripod 34 is configured to be slidable on the inner peripheral surface 56 of the inner roller 44. Yes. The inner peripheral surface 50 of the outer roller 42 is formed in a cylindrical shape, and the needle roller 46 is disposed along the inner peripheral surface 50. Further, fitting grooves 52 and 52 into which the snap rings 48 and 48 are fitted are formed at the upper and lower end positions where the needle roller 46 is disposed, and the snap rings 48 and 48 are fitted into the fitting grooves 52 and 52. As a result, the needle roller 46 and the inner roller 44 are held inside the outer roller 42 and are assembled. The basic shape of the rolling surface 54 on the outer periphery of the outer roller 42 is formed in an arc shape that comes into contact with the roller guide surfaces 26 </ b> A and 26 </ b> B that form the roller guide groove 26.

  As shown in FIG. 2, the tip portion of the tripod shaft portion 38 (engagement portion that engages with the inner peripheral surface 56 of the inner roller 44 of the roller 40) is formed in a spherical shape. When the tripod 34 side driven shaft 32 takes a joint angle with respect to the drive shaft 22 on the outer ring 24 side (a relationship where the axis 30X intersects the axis 20X), the tripod shaft portion 38 has the outer roller 42 connected to the outer ring 24. 2 is allowed to move relative to the tripod 34 of the outer roller 42 when moving along the roller guide groove 26. As a result, the roller 40 can move in the vertical direction in FIG. 2 with respect to the tripod shaft portion 38. The roller 40 can rotate with respect to the tripod shaft portion 38 and can swing. As a result, when a rotational driving force is input from the drive shaft 22, the tripod constant velocity joint 10 is brought into contact with the roller guide surface 26 </ b> A that is disposed so as to face the rotational direction so that the tripod 34 and the driven body are driven. A rotational driving force is output (transmitted) to the shaft 32.

  FIG. 4 is a cross-sectional view showing a state where torque is transmitted from the outer ring 24 to the roller 40. The illustrated state of FIG. 4 shows one portion of the three roller guide grooves 26. In the tripod constant velocity joint 10, torque transmission from the drive shaft 22 to the driven shaft 32 is transmitted from the outer ring 24 to the roller 40 as shown in FIG. As described above, the inner ring-shaped roller guide groove 26 is formed in the outer ring 24. As shown in FIG. 4, the roller guide groove 26 is formed by roller guide surfaces 26A, 26B and a bottom surface 26C on both sides as viewed in the radial cross section. Here, the direction of torque transmission of the present embodiment is shown as an example in which the outer ring 24 rotates in the direction of the white arrow and is transmitted to the roller 40 as seen in FIG. Therefore, the left roller guide surface 26A as viewed in FIG. 4 is a torque transmission surface that transmits torque, and the right roller guide surface 26B is a non-torque transmission surface that does not transmit torque. Accordingly, the left roller guide surface 26A that transmits torque is in contact with a rolling surface 54 of an outer roller 42 of a roller 40 described later. Further, the right roller guide surface 26B that does not transmit torque on the opposite side is in a non-contact state with a clearance S between it and the rolling surface 54 of the outer roller 42.

  This is because when the outer roller 42 of the roller 40 is pushed and rolled by the roller guide surface 26A of the torque transmission surface of the outer ring 24 in the torque transmission state of the tripod type constant velocity joint 10, the outer roller of the roller 40 is rolled. This is to prevent 42 from coming into contact with the roller guide surface 26B of the non-torque transmission surface. This is because the state where the outer roller 42 is in contact with the roller guide surface 26B of the non-torque transmission surface is a factor that causes vibration during torque transmission due to the forced force of the induced thrust force in the rolling of the roller 40.

  However, in the configuration having the gap interval S between the roller guide surface 26B of the non-torque transmission surface and the rolling surface 54 of the outer roller 42, there is a concern about sudden torque fluctuation due to so-called rotational play. Here, in the illustrations shown in FIGS. 4 and 6, it is assumed that the torus-like member 60 described later is not configured. As shown in FIGS. 4 and 6, it is assumed that the torque transmission direction of the tripod constant velocity joint 10 is reversed and the torque transmission surface and the non-torque transmission surface are switched. When the torque transmission direction is reversed, the roller guide surface 26B shifts from a non-contact state having a clearance S to the contact surface with the rolling surface 54 of the outer roller 42 to a contact state. Here, torque is not transmitted until the roller guide surface 26B and the rolling surface 54 come into contact with each other. On the other hand, the torque is transmitted at the moment when the roller guide surface 26B and the rolling surface 54 come into contact with each other. As a result, the tripod constant velocity joint 10 is assumed to have a rotational backlash as shown by 110T in FIG.

  Therefore, in the present embodiment, the torus-like member 60 is configured on the roller 40 in order to achieve both the reduction of the forced force of the induced thrust force and the suppression of the rotation play. The torus-like member 60 is disposed between the roller guide surfaces 26 </ b> A and 26 </ b> B that form the roller guide groove 26 and the outer periphery of the roller 40. The torus-like member 60 is disposed at the outermost peripheral position of the rolling surface 54 of the outer roller 42.

  The torus-like member 60 is made of synthetic resin, synthetic rubber, natural rubber, or the like, thereby enabling elastic deformation. Since the torus-like member 60 can be elastically deformed, the shape changes between a free state in which no force is applied from the outside and a pressurized state in which a force is applied from the outside. The toroidal member 60 has a circular cross section in the radial direction when in a free state, but a portion that is pressurized when in a pressurized state is noncircular. When the torus-like member 60 is viewed from the central axis direction, the inner peripheral side shape and the outer peripheral side shape in the free state are concentric circular shapes. When the torus-like member 60 is viewed from the central axis direction, the inner peripheral side shape and the outer peripheral side shape do not maintain the circular shape when in a pressurized state, and the center is shifted. This is because a compressive load is generated in the circumferential direction from the pressurized portion.

  Here, as shown in FIGS. 4 to 7, the torus-like member 60 is compressed and deformed by contact between the roller guide surface 26 </ b> A of the torque transmission surface and the rolling surface 54 of the roller 40 when torque transmission is applied. Accordingly, the non-torque transmission surface is not in contact with the roller guide surface 26B. Further, when the torque transmission direction is reversed and the torque transmission surface and the non-torque transmission surface are switched, the roller guide surfaces 26A and 26B that face each other are in contact with each other.

  Further, the rolling surface 54 of the outer roller 42 has an annular groove 70 that accommodates the torus-like member 60. The annular groove 70 is configured to suppress the torus-like member 60 from falling off the rolling surface 54. Here, the width 72 of the annular groove 70 is larger than the diameter 60D (see FIG. 6) of the radial section in the free state, and is compressed by the roller guide surface 26A and the rolling surface 54 being in contact with each other. Even if it is deformed to have a flat cross-sectional shape (an elliptical shape as shown in FIG. 4), it needs to have a width that can be accommodated. The depth 74 of the annular groove 70 is smaller than the diameter 60D of the radial cross section in the free state, and when the torque transmission direction is reversed and the torque transmission surface and the non-torque transmission surface are switched. The depth must be such that the torus-shaped member 60 comes into contact with both surfaces of the opposing roller guide surfaces 26A and 26B.

  Next, the operation of the torus-like member 60 when torque transmission is acting in the tripod type constant velocity joint 10 of the embodiment and when the torque transmission direction is reversed will be described. As shown in FIG. 5, when the torus member 60 is viewed from the central axis direction when torque transmission is applied, the inner peripheral shape 62P and the outer peripheral shape 64P are different in shape. As shown in FIG. 4, the torus-like member 60 has an elliptical flat shape at a portion compressed by the proximity of the roller guide surface 26 </ b> A and the annular groove 70. Then, as shown in FIG. 5, in the torus-like member 60, the inner peripheral side shape 62 </ b> P maintains a circular shape along the annular groove 70. On the other hand, a compressive load is generated in the circumferential direction from the compression portion in accordance with the compressive deformation of the torus-like member 60, the portions orthogonal to the roller guide surfaces 26A and 26B swell, and the outer peripheral side shape 64P becomes elliptical. As shown in FIG. 4, the portion of the torus-shaped member 60 that faces the roller guide surface 26 </ b> B also has an elliptical flat shape similar to the compression portion due to the compression load. For this reason, the torus-like member 60 and the non-torque transmission surface roller guide surface 26B have a non-contact configuration. Therefore, the tripod type constant velocity joint 10 can reduce the forcing force of the induced thrust force when the torque transmission acts by configuring the torus-like member 60.

  As shown in FIGS. 6 and 7, at the moment when the torque transmission direction is reversed and the torque transmission surface and the non-torque transmission surface are switched, the torque is not transmitted. That is, the torus-like member 60 is in a free state where it is not pressurized from either of the roller guide surfaces 26A and 26B. Therefore, the radial cross section of the torus-shaped member 60 has a circular shape with a diameter of 60D in a free state. Further, when the torus-like member 60 is viewed from the central axis direction, the inner peripheral side shape 62F and the outer peripheral side shape 64F in a free state are concentric circular shapes. At this time, the torus portion 60 and the roller guide surfaces 26A and 26B are in contact with each other at the same distance. Therefore, the tripod type constant velocity joint 10 constitutes the torus-like member 60 as shown in 10T of FIG. 8 to suppress the rotation backlash when the torque transmission direction is reversed, thereby suppressing a rapid torque fluctuation.

  As described above, according to the tripod type constant velocity joint 10 of the present embodiment, the elastically deformable torus-like member 60 is disposed between the roller guide groove 26 and the outer periphery of the roller 40. Therefore, it becomes a structure which has one elastically deformable member with respect to a roller, and can be simplified. Further, since the torus-like member 60 is annularly arranged on the outer periphery of the roller 40, the torus-like member 60 is configured to be elastically deformed as the roller 40 rolls. Therefore, it is possible to stably suppress the rotation play. Thereby, a rapid torque fluctuation can be suppressed.

  Moreover, since the torus-like member 60 is disposed at the outermost peripheral position of the rolling surface 54 of the roller 40, the rotation backlash can be more smoothly suppressed. Moreover, since the rolling surface 54 of the roller 40 has an annular groove in which the torus-like member 60 is accommodated, the torus-like member 60 can be prevented from falling off.

  Further, when torque transmission acts, the forced force of the induced thrust force can be reduced by having a non-contact configuration between the torus-like member 60 and the roller guide surface 26B of the non-torque transmission surface. Further, when the torque transmission direction is reversed, the roller guide surfaces 26A and 26B opposed to the torus-like member 60 are in contact with each other, so that rotation backlash can be suppressed and rapid torque fluctuation can be suppressed. Thereby, coexistence of reduction of the forced force of induced thrust force and suppression of rotation backlash can be aimed at.

  Further, the double roller type tripod type constant velocity joint 10 has a configuration in which the two rollers move relative to each other, and rotation backlash is likely to occur due to a gap between the components. The double roller type roller 40 has a so-called swingable configuration that is inclined with respect to the axis of the tripod shaft portion 38, so that rotation backlash tends to occur. Therefore, the torus-like member 60 can be suitable for the double roller type roller 40.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to embodiment, It can implement in other various embodiment. In the above embodiment, the double roller type tripod type constant velocity joint is described as an example of the constant velocity joint. However, the present invention can also be applied to a single roller type tripod type constant velocity joint.

10 Tripod type constant velocity joint (constant velocity joint)
12 Boot 20 Drive unit 20X Axis 22 Drive shaft 24 Outer ring 26 Roller guide groove 26A Roller guide surface (torque transmission surface)
26B Roller guide surface (non-torque transmission surface)
26C Bottom surface 30 Passive portion 30X Axis 32 Driven shaft 34 Tripod 36 Base member 38 Tripod shaft portion 40 Roller 42 Outer roller 44 Inner roller 46 Needle roller 48 Snap ring 50 Inner surface 58 of outer roller Outer surface 56 of inner roller Inner roller Inner circumferential surface 52 Fitting groove 54 Rolling surface 60 Torus-like member 60D Diameter 62P of torus-like member in the radial cross section Torus-like member inner circumferential side shape 62F when torque transmission is applied The torque transmission direction is reversed. Inner peripheral side shape 64P of the torus-like member in the free state Outer peripheral side shape 64F of the torus-like member when torque transmission acts The outer peripheral side shape 70 of the torus-like member in the free state by reversing the torque transmission direction Annular groove 72 Annular groove Width 74 annular groove depth S clearance gap

Claims (5)

A constant velocity joint,
An outer ring formed in a cylindrical shape and formed with three roller guide grooves in the axial direction of its inner peripheral surface;
A tripod provided with three tripod shafts that are arranged such that a torque transmission angle can be changed with respect to the axis of the outer ring and extends radially outward;
Three rollers rotatably supported by each of the tripod shafts and arranged to roll in the groove extending direction of each of the roller guide grooves;
A constant velocity joint having an elastically deformable torus-like member disposed between the roller guide groove and the outer periphery of the roller. The constant velocity joint according to claim 1,
The roller guide groove has a roller guide surface that is disposed so that arc-shaped surfaces are opposed to each other when viewed in a radial cross section of the outer ring, and guides the roller in a rollable manner.
The roller has an arcuate rolling surface whose outer peripheral surface can be in contact with the roller guide surface as seen in the radial cross section of the outer ring,
The torus-like member is a constant velocity joint disposed at an outermost peripheral position of the rolling surface of the roller. The constant velocity joint according to claim 1 or 2,
The rolling surface of the roller is a constant velocity joint having an annular groove in which the torus-like member is accommodated. The constant velocity joint according to any one of claims 1 to 3,
Both the roller guide surfaces facing each other are
When torque transmission acts, one is a torque transmission surface that transmits torque and the other is a non-torque transmission surface that does not perform torque transmission.
The torus-shaped member is
When the torque transmission is applied, the torque transmission surface and the rolling surface of the roller come into contact with each other and are compressed and deformed so that the non-torque transmission surface is not in contact with each other. And
A constant velocity joint configured to come into contact with both surfaces of the roller guide surfaces facing each other when the torque transmission direction is reversed and the torque transmission surface and the non-torque transmission surface are switched. The constant velocity joint according to any one of claims 1 to 4,
The roller is a constant velocity joint of a double roller type in which two rollers are formed between the roller guide groove and the tripod shaft portion.

Images