JPS5928776B2 - Ball spline with support bearing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a ball spline with a support bearing used for rolling and guiding rotational motion, reciprocating motion, and their combined motion.

In this way, a bearing for rolling and guiding rotational motion, reciprocating motion, and their combined motion incorporates a retainer and balls inside a cylindrical outer cylinder, so that the load can be applied evenly by each ball. It is known what has been done. However, in such conventional bearings, the stroke length of the axial reciprocating motion is limited to twice the length that the cage can move within the outer cylinder, and a large stroke length is required. Sometimes it becomes necessary to increase the length of the outer cylinder in accordance with the length of the outer cylinder, and to increase the distance over which the retainer can move within this outer cylinder. This makes it difficult to install bearings with long outer cylinders in machines where it would be difficult to install them, and the use of such bearings also makes the machinery larger than necessary. There was a problem. This invention is
It was invented in view of this point of view, and uses a ball spline whose stroke length is not limited by the outer cylinder of the bearing, and is capable of rotary motion, reciprocating motion, and a combination of these motions, and is compact at the same time. To provide a ball spline with a support bearing that can

Hereinafter, the content of the present invention will be described in detail based on embodiments shown in the accompanying drawings.

1 and 2, a ball spline with a support bearing according to a first embodiment of the present invention is shown.

This ball spline with support bearing includes a ball spline 1 consisting of a spline bearing 3 and a spline shaft 4 that is slidably supported in the axial direction by a ball 16 incorporated in the spline bearing 3, and an outer part of the spline bearing 3. A pair of angular contact bearings 2a and 2b attached to the outer wall of the cylinder 5
It is made up of. The angular contact bearings 2a and 2b each include an outer ring 6, a large number of balls 8 disposed in ball rolling grooves 7 formed along the circumferential direction on the inner wall of the outer ring 6, and a plurality of balls 8. many balls 8
The balls 8 are held by the cage 9 and can freely rotate within the ball rolling grooves 7 of the outer ring 6.

Further, one of the angular contact bearings 2a is formed with a flange 13 along the outer periphery of the outer wall of the outer ring 6, and this flange 13 has an insertion hole through which a mounting fixture (not shown) such as a bolt is inserted. A hole 17 is bored.

The spline bearing 3 constituting the ball spline 1 has a pair of circumferential grooves 10 with a generally concave cross section formed along the circumferential direction near the center of the outer wall, and has a pair of circumferential grooves 10 with a substantially concave cross section on the inner wall thereof. A loaded ball groove 23 and an unloaded ball groove 24 that extend in the axial direction and each of these grooves 2
an outer cylinder 5 having a circumferential guide groove 25 that communicates both ends of the balls 3 and 24; , a ball holder 18 having concave grooves 27 corresponding to the non-load ball groove 24 and the circumferential guide groove 25, the outer cylinder 5, the ball holder 18, the loaded ball groove 23, and the non-load ball groove. 24, a large number of balls 1 fitted in an endless track 19 formed by a guide groove 25, a long hole 26, and a groove 27 so as to be able to roll freely;
It consists of 6.

Furthermore, the spline shaft 4 constituting the ball spline 1 is located on the load ball groove 23 of the outer cylinder 5 and is partially exposed from the elongated hole 26 of the ball holder 18 so that the balls 16 that load the ball roll. It has a substantially arc-shaped rolling groove 20, and is supported by a ball 16 so as to be freely slidable in the axial direction.

In this embodiment, the outer cylinder 5 of the spline bearing 3
A pair of circumferential grooves 10 formed in the outer wall have the angular contact bearings 2a, 2 at mutually adjacent corners.
Rolling surface 1 with a radius of curvature approximately equal to the radius of curvature of ball 8 in b
1 is formed, and the outer cylinder 5 of the spline bearing 3
When each angular contact bearing 2a, 2b is assembled to
The directions of the loads acting on each raceway surface 11 from the balls 8 of 2b are directed in directions that converge with each other.

In addition, each angular contact bearing 2a, 2b
When assembled into the outer cylinder 5 of the spline bearing 1, a gap is formed between each end face of each angular contact bearing 2a, 2b with a predetermined spacing dimension, and within this gap. A ring-shaped spacer 14 having a width D slightly smaller than the distance between the two is interposed. Therefore, when installing the ball spline with support bearing of this embodiment, one angular contact bearing 2b is fitted into the mounting recess 21 formed in the housing 12, and the other angular contact bearing 2a is inserted into the mounting recess 21 formed in the housing 12. When the outer ring 6 is fixed to the housing 12 with a fixture via the flange 13, the raceway surface 11 and the balls 8 are separated by the difference between the width d1 of the spacer 14 and the distance between each angular contact bearing 2a, 2b. Tightening is applied to the ball rolling groove 7 on the inner wall of the outer ring 6, and preload is applied to each angular contact bearing 2a, 2b.

Next, the ball spline with a support bearing of the second embodiment shown in FIG. A circumferential groove 10 is formed, and raceway surfaces 11 are formed at both left and right corners of the circumferential groove 10. Each of these rolling surfaces 1
1 is such that when the angular contact bearings 2a, 2b are assembled to the outer cylinder 5 of the spline bearing 3, the directions of the loads acting on the raceway surfaces 11 from the balls 8 are oriented in directions that are separated from each other. Further, between each end face of each angular contact bearing 2a, 2b, a spacer 1 having a width D2 slightly larger than the spacing dimension thereof is provided.
4 is interposed, so that a preload is applied to each angular contact bearing 2a, 2b. Therefore, according to the ball spline with support bearing of the second embodiment, even if there is no mounting recess on the housing 12 side with which one end surface of one angular contact bearing 2b can come into contact, the spacer 14 This allows preload to be applied to each angular contact bearing 2a, 2b. Next, FIGS. 4 and 5 show a modification of the first embodiment, in which the outer wall of the outer cylinder 5 of the spline bearing 3 has a flange 13 on the outside of the angular contact bearing 2a. A gear 28 is formed along the circumferential direction.

This gear 28 is adapted to mesh with a power gear 15 such as a gear directly connected to a motor 29 for imparting rotation to the subline bearing 3 or an idle gear that meshes with this gear to transmit power. Further, FIG. 6 shows a modification of the second embodiment, in which a gear 28 is formed at the outer wall end of the outer cylinder 5 of the spline bearing 3, as in the case of FIGS. 4 and 5. be. In each of these modified examples, the spline bearing 3 of the ball spline 1 is formed with three pairs of load ball rows extending in the axial direction on the inner wall of its outer cylinder 5, and the spline shaft 4 is provided with three pairs of load balls. An axial protrusion 30 is formed to be fitted into the recess formed by the load ball rows, and the spline shaft 4 slides in the axial direction with each protrusion 30 supported by each pair of load ball rows. At the same time, torque is transmitted in the rotational direction. Support for each of these variations 1
- According to the ball spline with a bearing, the spline bearing 3 can be directly rotated by the gear 28 formed on the outer wall end of the outer cylinder 5, and thereby the spline bearing 3 or this spline bearing 3
It is no longer necessary to attach special parts to give rotational motion to the spline shaft 4, which is fitted so as to be slidable in the axial direction, and the ball spline with support bearing can be formed compactly. It can be easily attached.

Note that the gear 16 formed on the outer cylinder 5 of the spline bearing 3 can be formed not only at one end of the outer wall of the outer cylinder 5 as in each of the above-mentioned modifications, but also at both ends thereof. Moreover, it is also possible to form it separately from the outer cylinder 5 and to attach it thereto.

Further, the gear 16 is not limited to a spur gear, but may be formed into a worm gear, for example, so that power is transmitted by the worm. Furthermore, the ball spline 1 is not limited to the type shown in FIGS. 1 and 3, and may include a ball spline 1 having an endless track 19 of balls 16 on a spline bearing 3 and supporting the axis of the spline shaft 4. It may be of any type as long as it allows linear movement in the direction and transmits torque in the rotational direction.

As described above, the present invention provides a ball spline with a support bearing in which each angular contact bearing is composed of an outer ring, a large number of balls, and a retainer, and the outer cylinder of the spline bearing has a circumference having a rolling surface. Since the grooves are formed so that the bobbin of each angular contact bearing rolls in direct contact with the raceway surface formed on the outer cylinder of the spline bearing, the inner ring of each angular contact bearing can be omitted. It can be made more compact. In addition, in this way, a pair of angular contact bearings are integrally assembled to the spline bearing of the ball spline, so the linear movement in the axial direction of the spline shaft is borne by the spline bearing, and the spline bearing or the spline shaft The rotational motion of each angular contact bearing is negative, so that it can be used as a bearing that rolls and guides rotational motion, reciprocating motion, and their combined motion, which are independent of the stroke length. Furthermore, according to the present invention, a spacer is interposed between each angular contact bearing, and the width of the spacer can be adjusted so that an appropriate preload acts on each bearing. In addition to being able to reduce the crush of each angular contact bearing to zero,
If the ball rolling groove of each angular contact bearing or the raceway surface formed on the outer cylinder of a spline bearing wears out and cracks occur, simply replace the spacer with one of the appropriate width. Appropriate preload can be applied again.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view showing a ball spline with a support bearing according to a first embodiment of the present invention, and FIG.
Figure 3 is a partial sectional view showing a part of the ball spline with support bearing of the seventh embodiment;
The figure is a sectional view showing a modification of the first embodiment with the spline shaft omitted, FIG. 5 is a sectional view taken along the line V-v in FIG.
The figure is a partial sectional view similar to FIG. 2 showing a modification of the second embodiment. Code explanation, 1...Ball spline, 2a, 2
b... Angular contact bearing, 3
... Spline bearing, 4 ... Spline shaft, 5 ... Outer cylinder, 6 ...
・Outer ring, 7...Ball rolling groove, 8...
Ball, 9...Cage, 10...Circumferential groove, 11...Race surface, 12...Housing, 13... Flange, 14... Spacer, Dl, d,... Width dimension, 15...
...Power gear, 28...Gear.

Claims (1)

[Scope of Claims] 1. A support consisting of a ball spline 1 composed of a spline bearing 3 and a spline shaft 4, and a pair of angular contact bearings 2a and 2b attached to the outer wall of an outer cylinder 5 of the spline bearing 3. In the ball spline with a bearing, each of the angular contact bearings 2a and 2b has an outer ring 6, a large number of balls 8 disposed in a ball rolling groove 7 formed on the inner wall of the outer ring 6, and a large number of balls 8. The outer cylinder 5 of the spline bearing 3 is formed with a circumferential groove 10 along its circumferential direction, and the corners of the circumferential groove 10 are located at symmetrical positions. Each of the angular contact bearings 2a, 2
A substantially arc-shaped raceway surface 11 is formed on which each ball 8 of b rolls, and the angular contact bearings 2a, 2b
A housing 12 is provided on the outer wall of the outer ring 6 on either one of the
A support bearing characterized in that a flange 13 is provided for attachment to the angular contact bearings 2a and 2b, and a spacer 14 is interposed between each angular contact bearing 2a and 2b to adjust the preload applied to each angular contact bearing 2a and 2b. Comes with a ball spline. 2 Each raceway surface 11 formed on the outer cylinder 5 of the spline bearing 3 is connected to each angular contact bearing 2a, 2.
The directions of the loads received from each ball 8 of b are convergent to each other, and the width dimension d_1 of the spacer 14 is
is formed smaller than the distance between the end faces of each angular contact bearing 2a, 2b, and by fixing to the housing 12 via the flange 13 of one angular contact bearing 2a, each angular contact bearing 2a, 2b A ball spline with a support bearing according to claim 1, wherein a preload is applied to the ball spline. 3 Each raceway surface 11 formed on the outer cylinder 5 of the spline bearing 3 is connected to each angular contact bearing 2a, 2.
The directions of the loads received from each ball 8 of b are in directions that are separated from each other, and the width dimension d_2 of the spacer 14 is
is formed larger than the distance between the end faces of each angular contact bearing 2a, 2b, and a spacer 14 is provided between each angular contact bearing 2a, 2b.
Claim 1: A preload is applied to each angular contact bearing 2a, 2b by interposing a
Ball spline with support bearing as described in section. 4 The outer cylinder 5 of the spline bearing 3 has a pair of angular contact bearings 2a approximately at the center of its outer wall.
2b, and a gear 28 is formed at the end of the outer wall of the outer cylinder 5, in which a power gear 15 that rotates the spline bearing 3 meshes with the gear 28. A ball spline with a support bearing according to any one of Item 3.