JP2000205288A - Drive shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drive shaft having an enhanced operating stability in high speed rotation. SOLUTION: A drive shaft includes a cylindrical shaft 1 and a convex shaft 2 which are coupled together in such a way as capable of relative displacement in the axial direction and also torque transmission in the circumferential direction, and a plurality of balls 15 are installed in the confronting spaces of spline grooves 1b and 2a formed on the two shafts 1 and 2 in their regions midway in the axial direction, and rings 8 and 9 to make slide contact with the regions on the cylindrical inner peripheral surfaces at the two ends in axial direction of the spline groove 1b for hindering the two shafts 1 and 2 from inclining are fitted fast on the regions on the cylindrical outer peripheral surfaces at the two ends in axial direction of the spline groove 2a, and a group of balls 15 are located in the spline groove 2a by locating means (6, 7, 9, 10, 11) in such a way as not capable of moving in the axial direction. In this configuration, the contacting area of the rings 8 and 9 with the cylindrical shaft 1 is greater than in the conventional arrangement, which allows increasing the resisting force against the moment load generated in association with high speed rotation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive shaft in which a cylindrical shaft and a convex shaft are connected so as to be relatively displaceable in the axial direction and to transmit torque in the same direction.

[0002]

2. Description of the Related Art As a conventional drive shaft of this type, the present applicant has proposed, for example, one shown in FIG.

In the figure, reference numeral 71 denotes a cylindrical shaft, and 72 denotes a convex shaft. A plurality of balls 73 and a plurality of coil springs 74 are interposed in a space facing each spline groove of the cylindrical shaft 71 and each spline groove of the convex shaft 72.

Further, at the outer end positions of the coil springs 74, 75 disposed at both ends in the axial direction within one spline groove, washers 76, 77 and rings 78, 79 are slightly loosely fitted inside. Fitted and mounted.

The ball 73 group, the coil springs 74, 7
5. The washers 76, 77 and the ring bodies 78, 79 are provided with a retaining ring 8 which is engaged with a peripheral groove provided on the inner peripheral surface of the cylindrical shaft 71.
0 and 81, it is positioned almost immovably in the axial direction on the spline groove side of the cylindrical shaft 71.

The above-described coil springs 74 and 75 are for applying axial tension to both shafts 71 and 72 to eliminate axial play.

The annular bodies 78 and 79 are adapted to be in sliding contact with the outer diameter surfaces of the spline teeth of the convex shaft 72.
While eliminating the radial play between 1 and the convex shaft 72,
This is to prevent the axes of both shafts 71 and 72 from being inclined so as to intersect.

[0008]

By the way, in the above conventional example, a pair of rings 78, 79 are mounted on the cylinder shaft 71 side,
Since the inner peripheral surface is configured to receive the outer diameter surface of the spline teeth of the convex shaft 72, it has been found that it is disadvantageous in use at high speed rotation where the rotational centrifugal force becomes strong.

That is, since the inner peripheral surfaces of the annular bodies 78 and 79 are in contact with the outer peripheral surface of the convex shaft 72 where the spline teeth are cut at several places, the contact area is reduced. The moment load generated during the high-speed rotation acts locally on the rings 78 and 79. For this reason, local wear and depressed deformation of the annular bodies 78 and 79 are likely to occur with the lapse of use, so that the effect of preventing the cylinder shaft 71 and the convex shaft 72 from inclining is weakened, and the rotational runout is increased. There is a risk.

Accordingly, an object of the present invention is to provide a drive shaft having a structure advantageous for use at high speed rotation.

[0011]

According to a first aspect of the present invention, there is provided a drive shaft in which a cylindrical shaft and a convex shaft are connected so as to be relatively displaceable in the axial direction and to transmit torque in the same direction. A plurality of balls are interposed in the opposing space of each spline groove provided in the axially intermediate region of both shafts, and in the region of the cylindrical outer peripheral surface at both axial ends of the spline groove of the convex shaft,
Rings for slidingly contacting the regions of the cylindrical inner peripheral surface at both axial ends of the spline grooves of the cylindrical shaft to prevent the inclination of both shafts are respectively fitted and fixed, and the ball group is projected by positioning means. It is positioned substantially immovably in the axial direction within the spline groove of the shaft.

According to a second aspect of the present invention, a drive shaft is formed by connecting a cylindrical shaft and a convex shaft so as to be relatively displaceable in the axial direction and to transmit torque in the circumferential direction. A plurality of balls are interposed in the opposing space of each spline groove provided in the region, and the cylinder at the axial both ends of the spline groove of the cylindrical shaft is formed in the region of the cylindrical outer peripheral surface at both axial ends of the spline groove of the convex shaft. Rings for slidingly contacting the region of the inner peripheral surface of the shaft to prevent inclination of both shafts are fitted and fixed respectively, and both ends of the ball group in the spline groove of the convex shaft are axially attached to the two shafts. Coil springs for applying an axial tension force are respectively provided between the outer ends of the coil springs in the axial direction and the annular bodies. Each coil spring and Spacer for positioning immobile if ho the ball groups in the axial direction to the spline groove of the male shaft is fitted attachment.

According to a third aspect of the present invention, in the drive shaft according to the first or second aspect, there is provided a strip-shaped retainer for retaining the ball groups in a state where they are not in contact with each other.

According to a fourth aspect of the present invention, in the drive shaft according to the second aspect of the present invention, the outer end of the coil spring in the axial direction is fitted to several places on the inner side in the axial direction of the spacer. It has a pin-like projection.

As described above, in the present invention, in short, an annular body for preventing inclination of the cylindrical shaft and the convex shaft is externally fitted and fixed to the cylindrical outer peripheral surface of the convex shaft, and is attached to the cylindrical inner peripheral surface of the cylindrical shaft. The contact is made with the surface.

As a result, the contact area of the ring body with the cylinder shaft becomes larger than that of the conventional example, so that the resistance to the moment load generated by the high-speed rotation increases. Therefore, even at the time of high-speed rotation in which the centrifugal force is strong, the cylindrical shaft and the convex can be held concentrically, and the occurrence of rotational runout can be suppressed.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described based on embodiments shown in FIGS.

1 to 7 relate to an embodiment of the present invention. FIG. 1 is a partial sectional view of a drive shaft, and FIG.
1 is a sectional view taken along the line (2)-(2) of FIG. 1, FIG. 3 is a sectional view taken along the line (3)-(3) of FIG. 1, and FIG. 4 is a view of the drive shaft of FIG. FIG. 5 is an enlarged view of a main part, FIG. 5 is a perspective view of a retainer of a linear motion ball bearing, FIG. 6 is a perspective view of a first spring receiver, and FIG. 7 is a perspective view of a second spring receiver.

In the figure, A indicates the entire drive shaft, and the drive shaft A allows the cylindrical shaft 1 and the convex shaft 2 to be relatively displaceable in the axial direction via a linear motion ball bearing 3. The structure is connected so that power can be transmitted in the circumferential direction.

A pair of coil springs 4 and 5 are provided at both ends in the axial direction of the direct acting ball bearing 3 in relation to the cylindrical shaft 1 and the convex shaft 2.
A pair of spring receivers 6,7, a pair of rings 8,9, a seal ring 10, and a snap ring 11 are provided.

The outer ends of the cylindrical shaft 1 and the convex shaft 2 are
Cross joints 12 and 13 are attached, and a seal ring 14 is attached to the free end of the cylindrical shaft 1 so as to be in contact with the cylindrical outer peripheral surface in the axial direction of the convex shaft 2.

Hereinafter, each of the above-mentioned components will be specifically described.

The cylindrical shaft 1 is provided with an annular bulging portion 1a which bulges inward in the axial direction in a region in the axial direction other than the region on the free end side and the region on the base end side on the inner peripheral surface. A spline groove 1b is provided at several places around the circumference of the annular bulging portion 1a. In the cylindrical shaft 1, the region on the free end side and the region on the base end side of the inner peripheral surface are cylindrical surfaces.

The convex shaft 2 is provided with spline grooves 2a on the outer peripheral surface thereof at several locations along the axial direction corresponding to the annular bulging portion 1a of the cylindrical shaft 1 and has a small-diameter region on the free end side. It is formed on a cylindrical surface. In the convex shaft 2, the region on the free end side and the region on the base end side in the outer peripheral surface are cylindrical surfaces.

Each spline groove 1 of the cylindrical shaft 1 and the convex shaft 2
In the configurations of b and 2a, oil sump grooves (reference numerals are omitted) are provided along the axial direction.

The linear motion ball bearing 3 is interposed in a space between each spline groove 1b of the cylindrical shaft 1 and each spline groove 2a of the convex shaft 2, and comprises a plurality of balls 15 and a group of balls 15 And a strip-shaped retainer 16 for rotatably holding the retainers in a non-contact state with each other. As shown in FIG. 5, the retainer 16 has a pocket 16b that rotatably holds the ball 15 at equal intervals in the longitudinal direction of the main body 16a of the strip-shaped thin plate.
Bulges 1 are formed on both upper and lower surfaces of each pocket 16b to prevent the ball 15 from coming out.
6c and 16d are provided.

A pair of coil springs 4 and 5 are disposed at both ends in the axial direction of the linear bearing 3 in the spline grooves 2 a of the convex shaft 2, and are axially stretched against both shafts 1 and 2. This is for applying a force to eliminate play in the axial direction.

The pair of spring receivers 6 and 7 correspond to the spacers described in the claims, and are disposed at the axially outer ends of the pair of coil springs 4 and 5. The first spring receiver 6 is shown in FIG.
As shown in FIG. 5, a plurality of pin-shaped projections 6b are protruded at several locations on one end in the axial direction of a cylindrical main body 6a.
A cap 6c into which the outer end of the first coil spring 4 is fitted is fitted into each pin-shaped projection 6b by press fitting. The main body 6a of the first spring receiver 6 is externally fitted and fixed to the cylindrical outer peripheral surface on the base end side of the convex shaft 2 by press-fitting. As shown in FIG. 7, the second spring receiver 7 has pin-shaped projections at which the outer end of the second coil spring 5 is fitted at several circumferential positions on one axial end of the cylindrical main body 7 a. 7b has a protruding shape. The main body 7a of the second spring receiver 7 is loosely fitted to the cylindrical outer peripheral surface on the free end side of the convex shaft 2 in a loose-fit state.

The pair of annular bodies 8 and 9 eliminate radial play between the cylindrical shaft 1 and the convex body 2 and also prevent the shafts 1 and 2 from tilting so that the axes thereof intersect. Things. First
The ring body 8 is externally fitted and fixed to the cylindrical outer peripheral surface on the base end side of the convex shaft 2 by press-fitting, and the outer peripheral surface thereof contacts the cylindrical inner peripheral surface on the free end side of the cylindrical shaft 1. Have been allowed. Further, the second annular body 9 is externally fitted and fixed to the cylindrical outer peripheral surface on the free end side of the convex shaft 2 by press-fitting, and the outer peripheral surface thereof is the cylindrical inner peripheral surface on the base end side of the cylindrical shaft 1. Is in contact with These rings 8 and 9 are, for example, S4 of JIS standard.
It is made of carbon steel such as 3C, S45C, and SCM440.

The seal ring 10 is made of, for example, JIS S43C, and has an O-ring 17 on its inner diameter side.
The shaft seals 18 are respectively incorporated on the outer diameter side, and interference is provided between the O-ring 17 and the cylindrical outer peripheral surface of the convex shaft 2 and between the shaft seal 18 and the cylindrical inner peripheral surface of the convex shaft 2. Is kept.

The snap ring 11 is engaged with a circumferential groove formed on the cylindrical outer peripheral surface on the free end side of the convex shaft 2.

The above-described direct acting ball bearing 3 and a pair of coil springs 4 and 5 have a first spring bearing 6, a second spring bearing 7, a second ring 9, a seal ring 10 and a snap ring 11. , And is positioned substantially immovably in the axial direction within the spline groove 2 a of the convex shaft 2. That is, the outer end of the first coil spring 4 arranged on the base end side of the convex shaft 2 is received by the first spring receiver 6 fixed to the convex shaft 2, and the free end of the convex shaft 2 The outer end of the second coil spring 5 arranged on the side is formed with a snap ring 11 via a second spring receiver 7, a second ring body 9 and a seal ring 10.
It is received by.

As described above, in this embodiment, the cylindrical shaft 1 and the convex shaft 2
Of the rings 8 and 9 for preventing the inclination with the convex shaft 2
Side, and the entire outer peripheral surface is brought into surface contact with the cylindrical inner peripheral surface of the cylindrical shaft 1, so that the contact area is significantly larger than that of the conventional example. The resistance to the moment load generated with the high-speed rotation increases. Therefore, even at the time of high-speed rotation in which the centrifugal force is strong, the cylindrical shaft 1 and the convex shaft 2 can be held concentrically, and the wear and deformation of the annular bodies 8 and 9 can be suppressed. Can be prevented from rotating.

In addition, as described above, the direct acting ball bearing 3 and the coil springs 4 and 5 are connected to the spline grooves 2 of the convex shaft 2.
a is positioned so as to be substantially immovable in the axial direction so as not to come out. In operation, the phenomenon that the coil springs 4 and 5 are bent and caught on the edges of the spline grooves 1b and 2a between the cylindrical shaft 1 and the convex shaft 2 does not occur. Therefore, the expansion and contraction operation of the drive shaft A is smoothed.

It should be noted that the present invention is not limited to only the above embodiment, and various applications and modifications are conceivable.

(1) In the above embodiment, for example, the shape of the spring receivers 6, 7 is changed is also included in the present invention. Further, as shown in FIG. 8, a structure without using the spring supports 6 and 7 may be adopted.

(2) In the above embodiment, the retainer 16
May be used.

[0038]

According to the first to fourth aspects of the present invention, the annular body for preventing the inclination between the cylindrical shaft and the convex shaft is fixed to the convex shaft side, and the entire outer peripheral surface is formed in the cylindrical shape of the cylindrical shaft. Since the surface is brought into contact with the inner peripheral surface, the contact area becomes much larger than that of the conventional example, thereby increasing the resistance to the moment load generated by the high-speed rotation. Therefore, even at the time of high-speed rotation where the centrifugal force becomes strong, the cylindrical shaft and the convex shaft can be held concentrically, and wear and deformation of the ring body can be suppressed, so that the rotational vibration of the drive shaft can be prevented for a long time. Can be prevented.

In addition, as described above, since the direct acting ball bearing and the coil spring are positioned substantially immovably in the axial direction within the spline groove of the convex shaft so as not to come off, for example, the cylindrical shaft and the convex When the shaft is temporarily displaced in the axial direction in the direction away from the shaft, and then expands and contracts to return to the original state, the phenomenon that the coil spring bends and gets caught on the edge of the spline groove between the cylindrical shaft and the convex shaft This eliminates the occurrence of the problem, and allows the user to contribute to the smooth expansion and contraction of the drive shaft.

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of a drive shaft according to the present invention, partially cut away.

FIG. 2 is a sectional view taken along line (2)-(2) of FIG.

FIG. 3 is a sectional view taken along line (3)-(3) of FIG. 1;

FIG. 4 is an enlarged view of a main part of the drive shaft of FIG. 1;

FIG. 5 is a perspective view of a retainer of the linear motion ball bearing in FIG. 1;

FIG. 6 is a perspective view showing a first spring receiver in FIG. 1 with a part cut away.

FIG. 7 is a perspective view showing a second spring receiver in FIG. 1 with a part cut away.

FIG. 8 shows another embodiment of the drive shaft of the present invention.
Enlarged view of main parts

FIG. 9 is an enlarged view of a main part of a conventional drive shaft.

[Description of Signs] A Drive shaft 1 Cylindrical shaft 1b Spline groove of cylindrical shaft 2 Convex shaft 2a Spline groove of convex shaft 3 Direct acting ball bearing 4,5 Coil spring 6,7 Spring receiver 8,9 Ring 11 Snap ring 15 Balls of direct acting ball bearings 16 Ball bearings of direct acting ball bearings

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shunichi Usui 1-4-1 Meieki Station, Nakamura-ku, Nagoya Tokai Passenger Railway Co., Ltd. F-term (reference) 3J033 AA01 BA09 BA20 BC02

Claims (4)

[Claims] 1. A drive shaft comprising a cylindrical shaft and a convex shaft connected to each other so as to be relatively displaceable in an axial direction and to be able to transmit torque in a circumferential direction, wherein each spline is provided in a halfway area in the axial direction of the two shafts. In the space facing the groove, a plurality of balls are interposed, and in the region of the cylindrical outer peripheral surface at both axial ends of the spline groove of the convex shaft, the cylindrical inner peripheral surface at both axial ends of the spline groove of the cylindrical shaft is provided. Rings for slidingly contacting the region and preventing the inclination of both shafts are fitted and fixed to the outside, respectively, and the ball group is positioned substantially immovably in the axial direction within the spline groove of the convex shaft by the positioning means. Drive shaft characterized by: 2. A drive shaft comprising a cylindrical shaft and a convex shaft connected to each other so as to be relatively displaceable in the axial direction and to be able to transmit torque in the circumferential direction, wherein each spline is provided in an axially intermediate region between the two shafts. A number of balls are interposed in the space facing the groove, and in the region of the cylindrical outer peripheral surface at both axial ends of the spline groove of the convex shaft, the cylindrical inner peripheral surfaces of both axial ends of the spline groove of the cylindrical shaft are provided. Rings for slidingly contacting and preventing the inclination of both axes are respectively fitted and fixed to the area of the ball group, and are axially opposite to the two ends of the ball group in the spline grooves of the convex shaft. Coil springs are provided respectively for applying the tension force to eliminate the axial play, and between the outer ends of the coil springs in the axial direction and the rings, the axial direction of the spline grooves of the convex shaft is provided. Each coil spring is attached to the cylindrical outer end at both ends. And a spacer for externally mounting a spacer for positioning the ball group in the spline groove of the convex shaft in the axial direction substantially immovably. 3. The drive shaft according to claim 1, further comprising: a band-shaped retainer for retaining the group of balls in a non-contact state. shaft. 4. The drive shaft according to claim 2, wherein said spacer has a plurality of pin-shaped projections on which axially outer end portions of said coil springs are fitted at a plurality of circumferential positions on the inner side in the axial direction. A drive shaft characterized by having: