JP2002295503A - Constant velocity joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify fitting work of an inside roller to a trunnion. SOLUTION: Corresponding to a trunnion guide portion formed into an approximately elliptic shape, a pair of curved portions 54a, 54b indicating a direction for fitting the inside roller 40 to the trunnion 28a (28b, 28c) is provided on an end face of the above inside roller 40.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constant velocity joint for connecting a first shaft as one transmission shaft and a second shaft as another transmission shaft, for example, in a driving force transmitting portion of an automobile.

[0002]

2. Description of the Related Art Conventionally, in a driving force transmitting section of an automobile,
A constant velocity joint that connects a first shaft, which is one transmission shaft, and a second shaft, which is the other transmission shaft, and transmits torque to each axle is used (see Japanese Patent Application Laid-Open No. 7-103251). .

As shown in FIG. 19 and FIG. 20, this constant velocity joint 1 has guide paths 2a,
2b is formed on the inner wall surface of the outer joint 3, and a spherical report journal 4 is disposed between the guide tracks 2a and 2b. An inner roller 5 is externally fitted to the report journal 4, and an outer roller 7 is supported on an outer peripheral surface of the inner roller 5 via a plurality of needle bearings 6.

[0004] In this case, on the peripheral surfaces of the trip journal 4 and the outer roller 7, surfaces 8 a, 8 b extending substantially parallel to the axis of the trip journal 4 are provided on opposite sides of the joint in both rotational directions. 9a and 9b are formed respectively. By these surfaces 8a, 8b, 9a, 9b, a circumferentially effective force applied to the trip journal 4 is 2
It is said that the components are decomposed by two component forces, and this configuration achieves an improved distribution of the contact pressure under a torque load.

However, in the constant velocity joint 1 according to the prior art, for example, the component forces F ₁ and F _{2 applied} to the inner roller 5 by the surface 8b formed on the peripheral surface of the trip journal 4 are provided. Because of the relatively high load,
There is a disadvantage that the contact pressure in the direction of the arrow between the trip journal 4 and the inner roller 5 is increased as compared with the contact pressure on the other peripheral surface, which leads to a problem that the durability is deteriorated.

Further, in the constant velocity joint 1 according to the prior art, the inner roller 5 and the outer roller 7 are held on the guide tracks 2a, 2b via the needle bearing 6, and the guide track 2
The trip journal 4 is provided so as to be displaced in the vertical direction along the inner wall surface of the inner roller 5 held by a and 2b. For this reason, in the constant velocity joint 1 according to the prior art, the report journal 4 and the inner roller 5
There is an inconvenience that the sliding resistance of the sliding surface between the two cannot be reduced.

[0007] In order to overcome the above-mentioned various disadvantages, the present applicant has reduced the sliding resistance generated when one of the transmission shafts is tilted and the trunnion is displaced along the guide track. A constant velocity joint capable of further improving the thrust performance and improving the durability has been proposed (JP-A-2000-192).
No. 984).

[0008]

SUMMARY OF THE INVENTION The present invention has been made in connection with the above proposal, and has a trunnion having a spherical surface formed along a circumferential direction, and a spherical surface corresponding to the spherical surface on an inner peripheral surface. When assembling with the inner roller with the recess formed,
It is an object of the present invention to provide a constant velocity joint that can be easily assembled by providing a display unit that displays the direction of assembly on the inner roller.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a plurality of guide tracks which are provided at predetermined intervals and extend in the axial direction on an inner peripheral surface, and one of the transmission shafts is provided. In a constant velocity joint having a cylindrical outer member to be connected, and an inner member to be inserted into the open space of the outer member and connected to the other transmission shaft, the joint swells toward the guide track, A plurality of trunnions each having a first curved surface and a second curved surface facing each other and a spherical surface orbiting between the first curved surface and the second curved surface; and an inner peripheral surface in surface contact corresponding to the spherical surface. A first recess formed with a spherical recess and a trunnion guide continuing from the spherical recess;
An annular member, a second annular member externally fitted to the first annular member via a bearing member, and provided to be relatively displaceable with respect to the first annular member along the axial direction of the trunnion;
Wherein the first annular member is provided with a display unit for displaying a direction when the first annular member is assembled to the trunnion.

In this case, the display section is constituted by an outer shape formed corresponding to a trunnion guide section comprising a non-circular opening including a substantially elliptical shape or a pair of arc-shaped recesses facing each other. Good.

Further, the display section is constituted by a set of curved portions formed on the end face of the second annular member, and a virtual line connecting the set of curved portions is a substantially elliptical opening serving as a trunnion guide portion. It may be formed substantially parallel to a long axis of the portion or an imaginary line connecting a pair of arc-shaped concave portions facing each other. Alternatively, the display section is constituted by a set of cutouts having a rectangular cross section formed on the end face of the second annular member, and a virtual line connecting the set of cutouts has a substantially elliptical shape as a trunnion guide. The opening may be formed substantially parallel to a long axis of the opening or an imaginary line connecting a pair of arcuate concave portions facing each other.

According to the present invention, the first trunnion is
By providing the first annular member with a display portion for displaying the directionality when assembling the annular member, it is possible to easily attach the annular member after confirming the direction when assembling by the display portion.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a constant velocity joint according to the present invention will be described in detail with reference to the accompanying drawings.

In FIG. 1 and FIG.
1 shows a constant velocity joint according to the embodiment of the present invention.

The constant velocity joint 10 has an opening integrally connected to one end of a first shaft 12 (one part of which is omitted in FIG. 2) which is one transmission shaft. It comprises a cylindrical outer cup (outer member) 14 and an inner member 18 fixed to one end of a second shaft 16 serving as the other transmission shaft and housed in a hole of the outer cup 14.

FIG. 1 shows the inner wall surface of the outer cup 14.
As shown in (3), three guide grooves (guide tracks) 20a to 20c are formed extending along the axial direction and spaced at intervals of about 120 degrees around the axis. The guide grooves 20a to 20c are respectively provided with a ceiling portion 22 having a concave portion formed in an arc-shaped cross section along the outer peripheral surface, and arc-shaped side surfaces formed opposite to each other on both sides of the ceiling portion 22. And 24b and 24b.

As shown in FIG. 1, a ring-shaped spider boss 26 is externally fitted to the second shaft 16, and guide grooves 20a to 20 are formed on the outer peripheral surface of the spider boss 26, respectively.
The three trunnions 28a to 28c are integrally formed at an interval of about 120 degrees around the axis that bulges toward c.

As shown in FIG. 3, each of the trunnions 28a to 28c has a neck 30 bulging radially outward from a ring-shaped spider boss 26, and a head formed integrally with the neck 30. 32. In addition,
As shown in FIG. 4, the columnar trunnions 29a (2
9b, 29c), the ring body 31 may be press-fitted to the outer peripheral surface.

The upper surface of the head 32 is formed in an arc shape having a predetermined curvature when viewed from the axial direction of the outer cup 14 (see FIGS. 1 and 3).
When viewed from a direction substantially orthogonal to the axis of No. 4, a first curved surface 33 formed linearly is provided (see FIG. 2). In this case, the shape of the first curved surface 33 is not limited to a straight line when viewed from a direction substantially perpendicular to the axis of the outer cup 14, but may be formed in an arc shape having a predetermined curvature.

A second curved surface 34 similar to the first curved surface 33 is formed on the lower surface of the head 32 so as to be continuous with the neck 30. Further, the head 32 has a spherical surface 3 formed on an outer peripheral surface between the first curved surface 33 and the second curved surface 34.
5 In each of the trunnions 28a to 28c, a not-shown chamfered section having a curved cross section may be provided at the boundary between the first curved surface 33 and the spherical surface 35 and at the boundary between the second curved surface 34 and the spherical surface 35.

The trunnions 28a to 28c and the side portions 24
As shown in FIG. 1, the trunnion 2 is formed of a ring body over substantially the entire inner peripheral surface thereof as shown in FIG.
An inner roller (first annular member) 40 in which a spherical concave portion 38 corresponding to the spherical surface 35 of 8a to 28c is formed (see FIGS. 5 to 9), and a plurality of needle bearings (bearing members)
And an outer roller (second annular member) 44 which is fitted to the inner roller 40 via the outer roller 42. The outer roller 4
4 has side surfaces 24a of the guide grooves 20a to 20c,
24b, the outer peripheral surface of the outer roller 44 and the side surfaces 24a of the guide grooves 20a to 20c are formed.
24b are provided so as to be in surface contact with each other.

The cross-sectional shapes of the outer peripheral surface of the outer roller 44 and the side portions 24a, 24b of the guide grooves 20a, 20b are not limited to the arc shapes, respectively.
The cross section may be formed in a plane so as to be linear.

The plurality of needle bearings 42 are rotatably mounted in an annular recess 46 formed on the inner peripheral surface of the outer roller 44. In addition, the plurality of needle bearings 42 are connected to the concave portions 46 by the keystone effect.
It may be incorporated so that it does not fall off from.

As shown in FIG.
The trunnion 28a (28) is formed at the boundary between the annular flat portion 48 of the
In order to easily incorporate b, 28c), a trunnion guide 52 having a substantially elliptical shape is formed. As shown in FIG. 5, a pair of curved portions 54a formed in a concave shape toward the annular flat surface portion 48 is provided on the end surface on the opposite side of the inner roller 40 on which the annular flat surface portion 48 is formed. , 54b are formed so as to face each other.

The pair of curved portions 54a and 54b are provided on the inner roller 4 with respect to the trunnions 28a (28b and 28c).
It functions as a display unit that displays an assembling direction when assembling 0, so that an imaginary line connecting a pair of curved portions 54a and 54b and a long axis of the substantially elliptical trunnion guide 52 are substantially parallel to each other. Is formed.

The columnar trunnion 29a (29)
b, 29c), when the ring body 31 is press-fitted to the outer peripheral surface thereof, instead of the inner roller 40, as shown in FIGS. An inner roller 40a formed by cutting out a pair of arcuate trunnion guides 52a and 52b facing each other at the boundary between the hole 50 and the inner wall surface may be used.

In this case, as shown in FIG. 3, the spherical surface 35 of the trunnions 28a to 28c and the concave portion 38 of the inner roller 40 are provided so as to be in surface contact with each other. Therefore, the trunnions 28a to 28c are provided rotatably in the direction of arrow A about the point O with respect to the inner roller 40, and the circumferential direction along the spherical surface 35 around the axis of the trunnions 28a to 28c as the rotation center. (In the direction of arrow B).

The trunnions 28a to 28c and the inner roller 40 are provided integrally with the needle bearing 42 held by the outer roller 44 so as to be displaceable in the vertical direction (the direction of arrow C).

Further, the trunnions 28a to 28c are slidably provided in the axial direction of the outer cup 4 (direction of arrow D) along the guide grooves 20a to 20c via the outer rollers 44.

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

When the first shaft 12 functioning as one of the transmission shafts rotates, the rotational force is transmitted to the inner member 18 via the outer cup 14, and the trunnions 28a to 28c
, The second shaft 16 rotates in a predetermined direction.

That is, the rotational force of the outer cup 14 is
The power is transmitted to the inner roller 40 via the outer roller 44 and the needle bearing 42 which contact the guide grooves 20a to 20c, and further transmitted to the trunnions 28a to 28c via the spherical surface 35 which comes into surface contact with the concave portion 38 of the inner roller 40. Accordingly, the second shaft 16 engaged with the trunnions 28a to 28c rotates.

In this case, when the second shaft 16 is inclined by a predetermined angle with respect to the outer cup 14 having the first shaft 12, the spherical surface 35 of the trunnions 28a to 28c is formed with respect to the spherical concave portion 38 formed in the inner roller 40. While maintaining the surface contact state, the trunnions 28a to 28c are slid and displaced in the direction of arrow A around the point O as shown in FIG. 3, or the trunnions 28a to 28c are And slides in the circumferential direction (the direction of arrow B) along the spherical concave portion 38.

The trunnions 28a to 28c are
The trunnions 28a to 28c are displaced along the axial direction (the direction of arrow C) integrally with the inner roller 40 that slides with respect to the needle bearing 42 held by the outer roller 44.

Further, the trunnions 28a to 28c
Is in a direction substantially perpendicular to the axis of the trunnions 28a to 28c via the outer rollers 44 sliding along the guide grooves 20a to 20c, that is, along the longitudinal direction (the direction of arrow D) of the guide grooves 20a to 20c. Displaced (see FIG. 2).

In this manner, the rotational motion of the first shaft 12 is smoothly transmitted to the second shaft 16 without being affected by the inclination angle of the second shaft 16 with respect to the outer cup 14.

Next, the method of assembling the constant velocity joint 10 according to the present embodiment will be described with reference to the hole 5 of the inner roller 40.
The following describes an example in which the trunnions 28a (28b, 28c) are mounted in the area 0.

First, as shown in FIG. 14, the operator operates a pair of curved portions 5 formed on the end face of the inner roller 40.
4a, 54b while applying a finger along the inner roller 40.
By grasping, the assembling direction of the inner roller 40 with respect to the trunnion 28a can be confirmed.

Because the imaginary line connecting the pair of curved portions 54a and 54b is formed substantially parallel so as to correspond to the long axis of the trunnion guide portion 52 formed in a substantially elliptical shape, This is because it is not necessary to turn the inner roller 40 upside down and check the long axis direction of the trunnion guide portion 52, and the set direction of the inner roller 40 can be visually recognized at a glance by the pair of curved portions 54a and 54b.

Further, the operator can use a set of bending portions 54a,
While holding the finger on the inner roller 40b,
Is displaced along the arrow direction, whereby the inner roller 40 can be mounted on the trunnion 28a. As a result, the inner roller 40 can be easily assembled to the trunnions 28a (28b, 28c) based on the pair of curved portions 54a, 54b indicating the direction of assembly of the inner roller 40. Can be improved.

That is, in the inner roller 40 provided with the substantially elliptical trunnion guide portion 52 (see FIG. 6), the trunnions 28a (28b, 28c) are attached to the inner roller 40 as shown in FIG. By inserting the trunnions 28a (28b, 28c) along the substantially elliptical trunnion guides 52 at an angle θ, the inner rollers 40 are mounted on the trunnions 28a (28b, 28c). In this case, the second shaft 16 corresponds to FIG.
It extends in a direction substantially perpendicular to the paper surface.

In FIG. 15, θ is the mounting angle, R is the radius of the spherical surface 35 of the trunnion 28a (28b, 28c), H is the spherical width of the trunnion 28a (28b, 28c), and r is the trunnion guide of the inner roller 40. The short radius of the portion 52, h is the width of the inner roller 40, d is the trunnion 28a
(28b, 28c), the radius of the neck 30 and X are the trunnions 28a (28b, 2b,
8c) represents the projected length of the spherical surface 35, and Y represents the projected short width of the spherical surface 35 of the trunnion 28a (28b, 28c) when the mounting angle is inclined by θ.

In this case, the trunnions 28a (28b,
The condition for the projection short width Y of the spherical surface 35 of 8c) to be smaller than 2R (diameter of the spherical surface 35) (securing the spherical surface 35 within the width h of the inner roller 40) is expressed by the following equation (1). Is done.

[0044]

(Equation 1)

A condition for satisfying Y <X is expressed by the following equation (2).

[0046]

(Equation 2)

Further, the trunnions 28a (28b, 28
The condition for preventing c) from interfering with the inner roller 40 is expressed by the following equation (3).

[0048]

(Equation 3)

The trunnions 28a (28b, 28c) are set so as to satisfy the above equations (1), (2) and (3).
And the shape of the trunnion guide 52 of the inner roller 40 is set. The assembling angle θ is the operating angle of the constant velocity joint 10 (the first shaft 12) on the paper surface (the surface including the axes of the three trunnions 28a to 28c) in FIG.
The axis of the inner roller 40 and the trunnion 28 a (2
8b, 28c) are set to be larger than the angle formed by the axis.

When the above equations (1) to (3) are satisfied and the trunnions 28a (28b, 28c) are assembled into the trunnion guide portion 52 of the inner roller 40 without press fitting, the following equation (4) is satisfied. It is good to satisfy.

[0051]

(Equation 4)

On the other hand, the above expressions (1) to (3) are satisfied,
Further, when the trunnions 28a (28b, 28c) are press-fitted into the trunnion guide portions 52 of the inner rollers 40 and assembled, the following formula (5) may be satisfied.

[0053]

(Equation 5)

On the other hand, cylindrical trunnions 29a (29b, 29c) in which the ring body 31 is pressed into the inner roller 40a (see FIG. 10) provided with a pair of trunnion guides 52a, 52b facing each other. (See FIG. 4), the annular flat portion 4 of the inner roller 40a is mounted.
8 and the upper surface of the trunnion 29a (29b, 29c) are substantially perpendicular to each other,
Along the trunnions 29a (29b, 29b)
c) is inserted into the concave portion 38 of the inner roller 40a, and the trunnions 29a (29b, 29c) are so arranged that the axis of the trunnion 29a (29b, 29c) is substantially perpendicular to the annular flat portion 48 of the inner roller 40a. The inner roller 40a is mounted on the trunnion 29a (29b, 29c) by tilting the inner roller 40a.

The ring 3 is attached to the inner roller 40a.
1 is press-fitted into a cylindrical trunnion 29a (29b, 2b).
9c), a set of trunnion guides 52a,
The direction of assembly can be confirmed by a pair of curved portions 54a and 54b formed substantially parallel to the imaginary line connecting 52b.

As described above, in this embodiment, the trunnions 28a (28b, 28b) of the inner rollers 40, 40a are formed.
c), 29a (29b, 29c)
A pair of curved portions 54a, 54b allow the inner roller 40,
By giving directionality to the outer shape of the 40a, an operator can visually confirm it, and the assembling work can be simplified by shortening the assembling time.

It should be noted that a display for displaying the direction of assembly of the inner rollers 40, 40a is a set of curved portions 54a, 5a.
The inner roller 40b is not limited to the inner roller 40b (see FIG. 16). For example, a pair of notches 58a and 58b having a rectangular cross section are formed on a flat annular surface 56 so as to face each other.
), Or a pair of notches 60a, 60
b inside roller 40c formed so as to face each other
(See FIG. 17) Alternatively, the inner roller 40d (see FIG. 18) in which a pair of small projections 62a and 62b slightly projecting from the flat annular surface 56 may be formed.

In this case, the pair of notches 58a, 58
By attaching a positioning jig (not shown) to b, not only manual assembly but also an automatic assembling apparatus (not shown) can be used.

[0059]

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

That is, when assembling the first annular member having the spherical concave portion corresponding to the spherical surface to the trunnion having the spherical surface, the assembling direction of the first annular member to the trunnion may be, for example, By giving the direction by the display portion having the outer shape of one annular member, the operator can visually confirm the direction, and the assembling work can be simplified by shortening the assembling time.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a constant velocity joint according to an embodiment of the present invention, taken in a direction substantially orthogonal to an axis.

FIG. 2 is a longitudinal sectional view taken along line II-II of FIG.

FIG. 3 is an enlarged vertical cross-sectional view of a part of FIG.

FIG. 4 is a partial longitudinal sectional front view according to a modification of the trunnion.

FIG. 5 is a perspective view of an inner roller mounted on the trunnion.

FIG. 6 is a perspective view seen from a direction of an arrow E in FIG. 5;

FIG. 7 is a plan view of the inner roller shown in FIG. 6;

8 is a vertical sectional view taken along the line VIII-VIII in FIG.

FIG. 9 is a longitudinal sectional view taken along line IX-IX in FIG. 7;

FIG. 10 is a perspective view of an inner roller according to a first modification.

FIG. 11 is a plan view of the inner roller shown in FIG. 10;

FIG. 12 is a longitudinal sectional view taken along line XII-XII in FIG. 11;

FIG. 13 is a longitudinal sectional view taken along line XIII-XIII in FIG. 11;

FIG. 14 is a perspective view showing a state in which an inner roller is mounted on the trunnion.

FIG. 15 is an explanatory diagram provided for setting conditions for attaching the inner roller to the trunnion.

FIG. 16 is a perspective view of an inner roller according to a second modification.

FIG. 17 is a perspective view of an inner roller according to a third modification.

FIG. 18 is a perspective view of an inner roller according to a fourth modification.

FIG. 19 is a partially omitted longitudinal sectional view of a constant velocity joint according to the related art.

FIG. 20 is a partially omitted transverse sectional view of a constant velocity joint according to the related art.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Constant velocity joint 12, 16 ... Shaft 14 ... Outer cup 18 ... Inner member 20a-20c ... Guide groove 26 ... Spider boss part 28a-28c, 29a-29c ... Trunnion 35 ... Spherical surface 38 ... Recess 40, 40a-40d ... Inner roller 42 needle needle 44 outer roller 48 annular flat surface 50 hole 52, 52a, 52b trunnion guide 54a, 54b curved portion 58a, 58b
Notch

Claims (4)

[Claims] 1. A cylindrical outer member provided on an inner peripheral surface of a plurality of guide tracks extending along an axial direction at a predetermined interval, and a cylindrical outer member connected to one of transmission shafts; A constant velocity joint having an inner member inserted into the hollow portion and connected to the other transmission shaft, wherein the first curved surface and the second curved surface bulge toward the guide track and face each other; A plurality of trunnions formed with a spherical surface orbiting between the second curved surface, a spherical concave portion that is in surface contact with the inner peripheral surface corresponding to the spherical surface, and a trunnion guide portion continuous with the spherical concave portion; And a second annular member which is externally fitted to the first annular member via a bearing member and is relatively displaceable with respect to the first annular member along the axial direction of the trunnion. An annular member, wherein the first ring A constant velocity joint, wherein the shape member is provided with a display unit for displaying a direction when the first annular member is assembled to the trunnion. 2. The constant velocity joint according to claim 1, wherein the display section corresponds to a trunnion guide section comprising a non-circular opening including a substantially elliptical shape or a pair of arc-shaped recesses facing each other. A constant velocity joint characterized by having an outer shape formed by forming. 3. The constant velocity joint according to claim 2, wherein the display unit includes a pair of curved portions formed on an end surface of the second annular member, and a virtual line connecting the pair of curved portions is a trunnion. A constant velocity joint formed substantially parallel to a long axis of a substantially elliptical opening serving as a guide portion or an imaginary line connecting a pair of arcuate concave portions facing each other. 4. The constant velocity joint according to claim 2, wherein the display section comprises a pair of cutouts having a rectangular cross section formed on an end face of the second annular member, and connects the pair of cutouts. A constant velocity joint, wherein the line is formed substantially parallel to a long axis of the substantially elliptical opening serving as the trunnion guide or an imaginary line connecting a pair of arcuate concave portions facing each other.