JPH03282011A - Uniform motion joint - Google Patents

Abstract

PURPOSE:To reduce slide resistance by providing a spherical part to be guided and an energizing member in a cup-shaped cage which holds a ball arranged and installed between the grooves of an outer joint member and an inner joint member, and slidably energizing and holding the ball by the inner joint member. CONSTITUTION:A uniform motion joint is formed by an outer joint member 1 with a first guide groove 15, an inner joint member with a second guide groove 24, a ball 3 arranged-installed between the guide grooves 15,24, and a cage 4. A cage body 42 has a ball holding window 48, and a rod 44 to be guided having a spherical part 445 to be guided is slidably inserted and fitted into a guide hole 425. The spherical part 445 being guided is slidably installed in a guide part 26, and held against a holding surface 261 by a second energizing member 28. Further, the cage body 42 is abutted against a stopper part 443 by a first energizing member 46. Thus, since the cage 4 is centered on the inner joint member 2, the ball smoothly rolls to reduce its slide resistance.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a constant velocity joint used in a driving force transmission shaft portion of an automobile, etc., and more specifically, the present invention relates to a constant velocity joint used in a driving force transmission shaft portion of an automobile, etc. This invention relates to a constant velocity joint that allows angular displacement of both axes and relative displacement in the axial direction.

[Prior Art] As such a constant velocity joint, the one shown in FIG. 2 is conventionally known. This constant velocity joint is connected to the drive shaft 7
an outer joint member 1a which is connected to the driven shaft 8a and has a right cylindrical inner peripheral surface 13a on the inner periphery and has a plurality of first guide grooves 15a extending in the axial direction and is open at one end; An inner joint member 2a having a convex spherical outer peripheral surface 22a and second guide grooves 248 extending in the axial direction and having the same number of first guide grooves 15a, and first and second guide grooves 15a124.
A ball 3a that is rotatably arranged between a and transmits torque.
The ball 3a is held by a ball holding window 48a, and the cage 4a is interposed between the inner and outer universal joint members 1a and 28 and is movable relative to the inner joint member 2a in the axial direction. . In this constant velocity joint, as shown in FIG. 3, a gap A1 is formed between the ball 3a and the ball holding window 48a, and a gap A1 is formed between the inner joint member 2a and the cage 4.
A gap B1 is also formed on both sides in the axial direction between the inner joint member 2a and the cage 4a, thereby allowing relative movement in the axial direction between the inner joint member 2a and the cage 4a within a relatively narrow range, and reducing sliding resistance. ing.

Further, as a constant velocity joint designed to reduce sliding resistance, the one shown in FIG. 4 is known.

This constant velocity joint is a guide rod 21b extending in the axial direction.
a spherical guide member 5b which is slidably fitted into the kite rod 21b and has a convex spherical sliding surface on its outer periphery, and a cup-shaped guide member whose bottom is spherical. a cage 4b that is slidably attached to the sliding surface of the kite rod 5b; first and second biasing members 46b that are fitted into the guide rod 21b and center the spherical guide member 5b at a predetermined position on the kite rod 21b; 28b.

Note that point 0 in FIG. 4 is the rotation center of the joint passing through the center of the ball 3b, and a predetermined distance 111 from this point 0
Point P1 on the axis of i1 is the center of swing of the inner joint member 2b with respect to the gauge 4b, and point P2 is the center of swing of the inner joint member 2b with respect to the gauge 4b.
This is a point on the axis arranged in the opposite direction to point P1 so that 0P1=OP2, and is the rotation center of the cage 4b.

The former constant velocity joint can absorb relatively small vibrations transmitted from the automobile engine to the drive shaft 8a in a range where sliding resistance is low due to the presence of the gap At, 81. However, the gap B1 between the cage 4a and the inner joint member 2a
If a large vibration exceeding the range of is input in the axial direction, the gap A1 between the ball 3a and the ball holding window 48a may become clogged, and the ball 3a may slip. In this state, the ball 3a rolls and becomes female, which causes a problem of increased sliding resistance.

Further, the latter constant velocity joint requires a certain amount of space between the spherical guide member 5b and the inner joint member 2b so that they do not interfere with each other when the joint angle changes. Therefore, since the amount of eccentricity (offset amount) of the center of curvature P1 forming the spherical surface of the spherical guide member 5b from the point O has to be increased, when the joint angle becomes large, the ball 3b is removed from the ball holding window 48b. There is a problem in that the amount of protrusion increases and the maximum joint angle cannot be set large. Further, when the amount of offset increases, the thickness of the cage 4b is increased, and the first guide groove 1 of the outer joint member 1b is increased.
There is also the problem that the depth of 5b must be made shallow, which is disadvantageous in terms of durability.

The present invention has been devised in view of the above-mentioned problems, and its technical problem is to solve the problem when the inner and outer universal joint members move relative to each other in the axial direction without being disadvantageous in the allowable range of the maximum joint angle or the durability. The object of the present invention is to provide a constant velocity joint that can always keep the sliding resistance small over a wide range.

[Means for Solving the Problems] The constant velocity joint of the present invention has a plurality of first guide grooves that are connected to one of two intersecting shafts, have a right cylindrical inner peripheral surface, and extend in the axial direction. an outer joint member with an open end at one end; and an inner joint member connected to the other of the two shafts and having a convex spherical surface on the outer periphery and extending in the axial direction and having second guide grooves having the same number as the first guide grooves. , a ball that is rotatably disposed between the first and second guide grooves and transmits torque; and the inner joint member that is held between the inner and outer joint members by holding the ball in a ball holding window and interposed between the inner and outer joint members. and a cage provided so as to be relatively movable in the axial direction.The cage is a cup-shaped joint having a cylindrical inner circumferential surface with one end open and a guide hole penetrating in the axial direction at the bottom. a cage main body, a guided rod whose rear end is slidably inserted into the guide hole and has a spherical curved portion at the tip;
and an E1 biasing member that biases the cage to hold the cage in a predetermined position. a guide portion having a guard surface that is formed continuously with the surface and slidably guides the spherical guided portion in the axial direction; and a second biasing member that biases the spherical guided portion against the holding surface. It is characterized by having the following.

[Operation] In the constant velocity joint of the present invention, when a relative displacement in the axial direction occurs between the cage and the inner joint member due to an input such as vibration [ζ], the relative displacement between the inner joint member and the guided H Displacement is the second
This is absorbed by the biasing member, and the relative displacement between the guided rod and the cage body is also absorbed by the first biasing member.

This causes the cage to be returned to its initial position and centered relative to the inner joint member. As a result, the ball held in the ball holding window of the cage is maintained in a state where it can roll and move at a predetermined position in the ball holding window.

Therefore, the sliding resistance when the inner and outer universal joint members move relative to each other in the axial direction is always kept small, and vibrations are reduced.

Moreover, since the inner circumferential surface of the cage is formed into a right cylindrical shape, relative movement between the cage and the inner joint member that is in sliding contact with the cage is possible over a wide range in the axial direction, and the degree of freedom is large. Therefore, even when large vibrations are input in the axial direction, the first and second biasing members can absorb the relative displacement between the cage and the inner joint member, and the sliding resistance is always kept small over a wide range. maintained.

[Example code] Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows a sectional view of a constant velocity joint according to this embodiment. The constant velocity joint of this embodiment includes an outer joint member 1 having a first guide groove 15 and connected to a drive shaft 7, and a second guide groove 2.
4 and connected to the driven shaft 8;
The ball 3 that is rotatably disposed in the second guide groove 15.24 and the cage 4 that holds the ball 3 and is interposed between the outer joint member 1 and the inner joint member 2 are mainly used. It is composed as an element.

The outer joint member 1 is cup-shaped with one end open, and its bottom 11 side is integrally fixed to one end of the drive shaft 7. The inner circumference of the outer joint member 1 has a cylindrical inner circumferential surface 13 formed on the same axis as the drive shaft 7, and the inner circumferential surface 13 has a first guide groove 15 extending linearly in the axial direction. are formed at equal angular intervals.

The inner joint member 2 has a bottomed cylindrical shape with one end open, and is formed into a convex spherical shape with its axis centered on its outer periphery and the center of curvature at a point P eccentrically located a certain distance from the joint center plane C. It has an outer circumferential surface 22. A second guide groove 24 that corresponds to the first guide groove 15 and extends in the axial direction is formed on the outer circumferential surface 22 .

Further, the point P becomes the center of swing of the inner joint member 2 with respect to the gauge 4. At the center of the inner circumference of the inner joint member 2, there is a guide portion 26 that guides a spherical guided portion 445, which will be described later.
is formed. This guide portion 26 includes a holding surface 261 formed in a concave spherical shape having a center of curvature at the same position as the center of curvature P of the outer circumferential surface 22 of the inner joint member 2, and a holding surface 261
The guide surface 263 is formed to be continuous with the guide surface 263 and to be inclined so that the diameter becomes larger toward the bottom side. Further, on the bottom side of the guide surface 263, a biasing member holding chamber 27 formed in a cylindrical shape with a diameter smaller than that of the guide surface 263 is provided at a stepped portion 272.
It is provided through. A second biasing member 28 that biases a spherical kited portion 445, which will be described later, is disposed in the biasing member holding chamber 27. Note that the inner circumferential surface 29 that is continuous with the opening side of the holding surface 261 is formed to be inclined so that the diameter becomes larger toward the opening side (the opening side).

The balls 3 are made of steel and have a perfect spherical shape.
One each is rotatably disposed between the guide groove 15 and each second guide groove 24 corresponding thereto. This ball 3 transfers the rotational torque of the drive shaft 7 to the inner and outer universal joint member 1.
2 to the driven shaft 8, and the first and second
Relative movement of the inner and outer universal joint members 1.2 is made possible by rolling in the guide grooves 15.24.

The cage 4 includes a cage body 42, a guided rod 44, and a first biasing member 46.

The cage body 42 is cup-shaped with one end open, and has a right cylindrical inner peripheral surface 421 and a convex spherical outer peripheral surface 423.
has. The convex spherical outer circumferential surface 423 is formed with its center of curvature at a point Q, which is equidistantly eccentric from the joint center plane C to the opposite side of the point P on the axis. A guide hole 425 passing through in the axial direction is formed in the center of the bottom of the cage body 42 . This cage main body 42 has ball holding windows 48 formed at equal angular intervals along the circumferential direction, and holds the balls 3 in the ball holding windows 48 so that the balls 3 can be held on the inner circumferential surface 13 of the outer joint member 1 and inwardly. It is interposed between the outer circumferential surface 22 of the joint member 2 and in sliding contact therewith. A gap A is formed between the ball holding window 48 and the ball 3.

The guided rod 44 includes a flange portion 441 protruding in the centrifugal direction at the rear end edge, a stopper portion 443 formed by attaching a ring member to the outer peripheral surface of the central portion, and a spherical guided rod formed at the tip portion. 445. The guided rod 44 has a portion between the flange portion 441 and the stopper portion 443 slidably inserted into the guide hole 425 of the cage body 42, and a spherical guided portion 445 that is connected to the inner joint member 425. It is slidably disposed on the guide portion 26 of. The spherical guided portion 445 is attached to the holding surface 26 of the guide portion 26.
1, and is constantly urged against the holding surface 261 by the second urging member 28.

The first biasing member 46 is fitted onto the outer circumferential surface of the guided rod 44 on the rear end side and is disposed between the flange portion 441 and the cage body 42 . The first biasing member 46 constantly biases the cage body 42 so that it comes into contact with the stopper portion 443.

In the constant velocity joint configured as described above, when the drive shaft 7 rotates, the rotational torque is transmitted from the outer joint member 1 to the inner joint member 2 via each ball 4, and the driven shaft 8 rotates at a constant speed. When a relative displacement in the axial direction occurs between the drive shaft 7 and the driven wheel 8 due to an input such as vibration, the gauge 4 moves to the first and second positions with respect to the inner joint member 2 that moves together with the driven shaft 8. It is returned to the initial setting position and centered by the two biasing members 46 and 28.

That is, when the inner joint member 2 moves in a direction away from the drive shaft 7, the guided rod 44 moves together with the inner joint member 2 with the spherical guided portion 445 held by the holding surface 261 of the guide portion 26. do. At this time, the cage body 4
2 is constantly urged by the first biasing member 46 so as to contact the stopper portion 443 of the guided rod 44, the cage body 42 follows the guided rod 44. Note that when a large input acts between the guided rod 44 and the cage body 42, the guided rod 44 is guided by the guide hole 425 of the cage body 42 and slides, but the relative displacement between the two is the first.
It is absorbed by the biasing member 46.

On the other hand, when the inner joint member 2 moves in a direction approaching the drive shaft 7, the spherical guided portion 445 moves toward the second biasing member 28.
The guided rod 44 follows the inner joint member 2 because it is urged toward the holding surface 261 of the guide portion 26 . Also, at this time, if a large input acts between the inner joint member 2 and the guided rod 44, the relative displacement between the two will be the second
It is absorbed by the biasing member 28. In addition, the inner joint member 2
The relative movement between the cage body 42 and the inner peripheral surface 4 of the cage 4
4 is formed into a right cylindrical shape, it can be used over a wide range even when large vibrations are input.

In this way, the cage 4 is centered with respect to the inner joint member 2, so that the ball 3 held in the ball holding window 46 of the cage 4 is placed at a position with a gap A between it and the ball holding window 46. is maintained. Therefore, the ball 3 is always in a state where it can roll, and is guided by the first and second guide grooves 15, 24 and rolls smoothly. As a result, the sliding resistance is always kept small and vibrations are reduced.

When the joint angles of the driving shaft 7 and the driven shaft 8 change, the ball 3 is inserted into the first and second guide grooves 15 and 24.
The upper part rolls toward both ends, and the outer circumferential surface 22 of the inner joint member 2 and the inner circumferential surface 44 of the cage 4 slide, and the guided rod 44 slides against the holding surface 261 of the inner joint member 2. The spherical guided portion 445 swings to allow its angular displacement. Note that the holding surface 261 of the inner joint member 2 and the spherical guided portion 4
Since the sliding surface with 45 is formed of the same spherical surface, it swings smoothly. Further, the outer circumferential surface 22 of the inner joint member 2 is formed into a convex spherical shape with a constant radius of curvature, and the inner circumferential surface 22 of the cage 4
4 is formed in a right cylindrical shape, so that no matter where in the axial direction they are in sliding contact, they slide smoothly as the joint angle changes.

In this state, when a relative displacement occurs in the axial direction between the drive shaft 7 and the driven shaft 8, the relative displacement between the inner joint member 2 and the cage 4 causes the first and second biasing members 46, 28 is absorbed in the same manner as above.

Therefore, in this case as well, the sliding resistance is always maintained in a small state.

As described above, in the constant velocity joint of this embodiment, when the inner joint member 2 and the cage 4 move relative to each other in the axial direction, the cage 4 is moved toward the inner joint member by the first and second biasing members 46.2B. Since the ball 3 is centered with respect to the ball 2, the ball 3 is always in a state where it can roll and move, and the sliding resistance can always be kept small.

Since the inner circumferential surface 421 of the cage body 42 is formed into a cylindrical shape, relative movement in the axial direction between the inner joint member 2 and the cage 4 is possible over a wide range, thereby constantly reducing sliding resistance. The range that can be maintained can be expanded. Further, since the inner circumferential surface 421 of the cage body 42 can be formed more easily and accurately than when forming a spherical surface, it is also advantageous in terms of manufacturing.

Furthermore, in the constant velocity joint of this embodiment, the center of curvature (swing center) P of the inner joint member 2 and the center of curvature (swing center) of the cage 4 (
Since there is no need to increase the amount of offset of the rotation center (center of rotation) Q, there is no disadvantage in terms of maximum joint angle tolerance or durability. Therefore, there is no need to make changes such as increasing the thickness of the cage body 42 or making the first guide groove 15 shallower.

[Effects of the Invention] The constant velocity joint of the present invention has a cage having a cup-shaped cage main body having a cylindrical inner circumferential surface with an open end and a guide hole passing through the bottom in the axial direction, and A guided rod whose rear end is slidably inserted and has a spherical guided portion at its tip, and a first biasing member that biases the guided rod to hold the guided rod in a predetermined position with respect to the cage. The inner joint member includes a concave spherical holding surface that swingably holds the spherical guided portion, and a concave spherical holding surface that is formed continuously with the holding surface and guides the spherical guided portion slidably in the axial direction. Since it has a guide part having a guide surface to hold the spherical guided part and a second biasing member that biases the spherical guided part to the holding surface, there is no disadvantage in the maximum joint angle tolerance range or durability. Slide resistance when the universal joint members move relative to each other in the axial direction can always be kept small over a wide range.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a constant velocity joint according to an embodiment of the present invention. 2 to 4 relate to a conventional constant velocity joint, FIG. 2 is a cross-sectional view thereof, FIG. 3 is a cross-sectional view of the main part thereof, and FIG. 4 is a cross-sectional view of Haku's constant velocity joint. 1... Outer joint member 3... Ball 15... First guide groove 26... Guide portion 42... Cage body 46... First biasing member 261... Holding surface 425... ... Guide hole 2 ... Inner joint member 4 ... Cage 24 ... Second guide groove 28 ... Second biasing member 44 ... Guided rod 48 ... Ball holding window 263 ... ... Guide surface 445 ... Spherical guided part

Claims (1)

[Claims] (1) An outer joint member that is connected to one of two intersecting shafts and has a right cylindrical inner peripheral surface on its inner periphery, has a plurality of first guide grooves extending in the axial direction, and is open at one end; an inner joint member that is connected to the other of the inner joint members and has a convex spherical surface on the outer periphery and extends in the axial direction and has second guide grooves of the same number as the first guide grooves, and is rollable between the first and second guide grooves. a ball disposed in the inner joint member for transmitting torque; and a cage that holds the ball in a ball holding window, is interposed between the inner and outer joint members, and is movable relative to the inner joint member in the axial direction. In the constant velocity joint, the cage includes a cup-shaped cage main body having a cylindrical inner peripheral surface with one end open and a guide hole penetrating in the axial direction at the bottom, and a rear end slidable in the guide hole. The inner joint comprises a guided rod that is fitted into the guided rod and has a spherical guided portion at its tip, and a first biasing member that urges the guided rod so as to hold the cage in a predetermined position. The member includes a concave spherical holding surface that swingably holds the spherical guided portion, and a guide surface that is formed continuously with the holding surface and slidably guides the spherical guided portion in the axial direction. 1. A constant velocity joint comprising: a guide portion having a guide portion; and a second biasing member biasing the spherical guided portion toward the holding surface.