JP2504812Y2 - Ball bearing for linear bearing - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ball retainer for holding and aligning a ball sandwiched between a bearing outer cylinder and a bearing shaft in a linear bearing such as a ball spline and a ball bush. Relates to improvement of the shape of a ball retainer for smoothly circulating the ball.

[0002]

2. Description of the Related Art Conventionally, as a ball cage of this type,
For example, a ball spline ball retainer shown in FIG. 9 is generally known.

Speaking of its specific structure, it is formed into a thin cylindrical shape in which a spline shaft (not shown) is loosely fitted in the hollow portion a, and a spline outer cylinder c is formed on the outer peripheral surface thereof. An elongated ball-shaped load ball guide groove e in which a load ball d sandwiched between a spline shaft rolls, an unloaded ball guide groove g in which an unloaded ball f rolls, and the above-mentioned loaded ball guide groove e and no load. A plurality of endless ball guide grooves are formed, each of which is composed of a ball turning groove h that communicates with the ball guide groove f, and the balls d,
It is used by aligning f and fitting it into the hollow portion of the spline outer cylinder c. The ball retainer configured and used as described above is integrally formed by injection molding of synthetic resin or the like from the consideration of the assembly efficiency of the ball spline, and the hollow cage is formed from one opening of the spline outer cylinder c. It is assembled to the spline outer cylinder c by being inserted into.

[0004]

By the way, on the inner peripheral surface of the spline outer cylinder c, a plurality of ridges i for sandwiching the load ball d together with the spline shaft have a predetermined length along the axial direction. The formed load ball area and a pair of ball scooping areas j adjacent to both sides of the load ball area for releasing the load ball d from between the ridge i and the spline shaft.

Therefore, in order to fit the above-mentioned integrally formed ball cage into the hollow portion of the spline outer cylinder c, the shape of the outer peripheral surface of the ball cage is the cross section of the load ball area in which the ridge i is formed. It is necessary to match the shape, and for this reason, the conventional ball cage has a uniform cross-sectional shape along the axial direction, as can be seen from FIG.

However, this causes the following inconveniences. That is, since the ball turning groove h corresponds to the ball scooping area j on the outer cylinder c side, if the cross-sectional shape of the ball cage is made to match the cross-sectional shape of the load ball area, a part of the ball turning groove h (Fig. 9 in the section A) is extremely shallow, and a gap is formed between the inner peripheral surface of the outer cylinder and the ball cage in the ball scooping area j, and the unloaded ball d rolls in the section A. Is likely to be unstable.

Therefore, during high speed movement or vertical movement of the spline outer cylinder, the balls d are likely to be eccentric from the turning groove h, and the balls d interfere with each other as shown in FIG. There is a problem that the groove is clogged and the ball cannot be circulated.

The present invention has been made in view of the above problems, and an object thereof is to have an endless ball guide groove which can smoothly guide a ball on a predetermined trajectory, and (EN) It is an object to provide a ball bearing of a linear bearing which can be easily mounted on a bearing outer cylinder.

In order to achieve the above object, the ball retainer of the linear bearing of the present invention comprises a hollow bearing outer cylinder.
Retainer body that is inserted into one part from one of its openings
And an annular piece inserted through the other opening.
The cage body has a ridge on which the loaded ball rolls.
Load bearings on the outer side of the bearing
Has a small diameter part that fits in the roll area
At one end of the bearing, fit the ball scooping area on the side of the bearing outer cylinder.
The large diameter part that fits in is smaller than the small diameter part at the other end of the small diameter part.
Is formed with a diameter of
Each has a tip portion to be formed, and the outer peripheral surface of the small diameter portion has a base.
Loaded ball rolling surface and inner surface of the outer ring
Loaded ball guide groove corresponding to the unloaded ball groove
While the ball guide groove is formed, on the outer peripheral surface of the large diameter part
Connects the loaded ball guide groove and the unloaded ball guide groove.
A ball turning groove is formed on the ring piece.
Shape the ball swivel groove on the outer peripheral surface of the tip of the cage body.
A semi-circular notch for forming the
The cage body inserted in the hollow part of the outer ring
The diameter is locked in the axial direction by the ridge of the bearing outer cylinder.
On the other hand, the annular piece is barely attached to the tip of the cage body.
Of the cage to fill the space between the inner surface of the outer casing and
It is characterized in that it is fixed to the outer peripheral surface of the tip portion of the body .

A linear bearing to which such technical means can be applied is a relative linear movement between a cylindrical bearing outer cylinder and a bearing shaft, in which a plurality of infinitely circulating balls are sandwiched. As shown in FIG. 11, for example, the balls d are in point contact with the loaded ball rolling surface k formed on the inner peripheral surface of the bearing outer cylinder c and the outer peripheral surface of the bearing shaft 1, respectively, as shown in FIG. As shown in FIG. 12, the ball bushes that apply load by contacting the bearing surface with the ball d that is a shallow groove formed on the bearing outer cylinder c and the bearing shaft l respectively come into surface contact with the load. This includes a ball spline capable of transmitting the rotational torque acting between the two members as well as the load.

[0011]

According to the above-mentioned technical means, the ball cage is assembled by fitting the retainer main body into the hollow portion of the bearing outer cylinder through one opening and the annular piece through the other opening. The shape of the cage can be made to match the shape of the hollow part of the bearing outer cylinder, and the entire length of the ball turning groove that connects the loaded ball guide groove and the unloaded ball guide groove is formed in a deep groove shape. The inside is lined up in a line and it will roll smoothly.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A ball bearing for a linear bearing according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is an exploded perspective view showing a ball retainer of a ball spline to which the present invention is applied, and a retainer main body 1 fitted into a hollow portion of one opening of a spline outer cylinder 3 (hereinafter, outer cylinder). And an annular piece 2 fitted into the hollow portion from the other opening of the outer cylinder 3.

First, the cage body 1 has a load ball 4
The small diameter portion 11 fitted into the load ball area of the outer cylinder 3 in which the convex strip 32 on which a rolls is formed, and the small diameter portion 11 which is continuously provided at one end of the small diameter portion 11 and is fitted into the ball scooping area of the outer cylinder 3. The small diameter portion 11 and the large diameter portion 12 axially locked by the projection 32 and the small diameter portion 11 are continuously provided at the other end of the small diameter portion 11 and are located in the ball scooping region 31 of the outer cylinder 3. The outer cylinder 3 and the tip 10 have a slightly smaller diameter, and are formed to have substantially the same length as the outer cylinder 3 by injection molding of synthetic resin.

As shown in the cross section of FIG. 5, the small-diameter portion 11 has a long window-shaped load for guiding a load ball 4a for applying a load between the outer cylinder 3 and a spline shaft (not shown). A ball guide groove 5 and an unloaded ball guide groove 6 along which the unloaded ball 4b rolls are formed. An island 7 is provided between the guide grooves 5 and 6 so as to partition the guide grooves 5 and 6, and on one side of the unloaded ball guide groove 6, a jetty 8 facing the island 7 and continuing from the large diameter portion 12 is formed. Is provided to guide the unloaded ball 4b rolling in the unloaded ball guide groove 6 so as to wrap it. Then, as shown in FIG. 2, the island 7 and the jetty 8 are fitted into the unloaded ball grooves 33 formed between the plurality of ridges 32 of the outer cylinder 3. Further, at both ends of the load ball guide groove 5, tongue pieces 14 for picking up the load ball 4a rolling on the groove 5 into the ball turning grooves 9 and 13 are provided.

Further, as shown in FIG. 6, the large-diameter portion 12 is provided with a deep groove-shaped ball turning groove 9 for guiding the ball 4 so as to surround the ball 4, similarly to the unloaded ball guide groove 6. One end of the loaded ball guide groove 5 and the unloaded ball guide groove 6
Is connected to one end of.

Further, the tip portion 10 is the annular piece 2
Is a seat for fitting into the outer peripheral surface, and a ball swivel groove 13 is engraved on the tip portion 10 for connecting the loaded ball guide groove 5 and the unloaded ball guide groove 6 to each other.

On the other hand, the annular piece 2 is a ring-shaped member whose inner diameter is fitted to the outer peripheral surface of the tip portion 10.
As shown in FIG. 5, a semicircular cut portion 21 corresponding to the ball turning groove 13 formed in the tip portion 10 of the cage body 1.
Are formed at equal intervals by the number of balls.

In the ball retainer of this embodiment having such a structure, the retainer body is fitted into the hollow portion through one opening of the outer cylinder, and the annular piece 2 is inserted through the other opening into the hollow portion. It is fitted into the outer cylinder by fitting and fixing the annular piece to the tip portion 10 of the retainer body 1.

At this time, the ball turning groove 13 formed in the tip portion 10 has the cage body 1 as shown in FIGS. 4 and 7.
The groove 7 is surrounded by the island 7 and the notch 21 of the annular piece 2 to have a deep groove shape, and has the same groove shape as the ball turning groove 9 (see FIG. 6) formed in the large diameter portion 12.

Therefore, in the ball cage according to this embodiment, by fixing the annular piece 2 to the cage body, the deep groove-shaped ball circulation path for connecting both ends of the loaded ball guide groove 5 is formed. 9 and 13 and the unloaded ball guide groove 6 are continuously formed, so that the ball 4 scooped from the loaded ball guide groove 5 can be accurately guided to a predetermined orbit and smoothly circulated. It is possible.

Next, FIG. 8 shows a second embodiment of the present invention.

This embodiment has substantially the same construction as that of the first embodiment, but since the small diameter portion 11 of the retainer body 1'is machined by lathing, the central portion of the island 7 and the jetty. 8 has been scraped off.

Therefore, the unloaded ball guide groove 6 is formed in a shallow groove shape, but the ball turning grooves 9, 13 are formed in a deep groove shape in the same manner as in the first embodiment, and the ball 4 is formed in a predetermined shape. The ball guide groove 5 can be smoothly guided to the unloaded ball guide groove 6 by aligning with the track.

In FIG. 8, the same components as those shown in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

Further, in the above-mentioned first and second embodiments, an example in which the present invention is applied to a ball spline having three ball threads has been described, but the present invention is applicable to any ball regardless of the number of ball threads. It can also be applied to splines.

[0027]

As described above, according to the ball bearing of the linear bearing of the present invention, the loaded ball guide groove and the unloaded ball guide groove are formed by combining the cage body and the annular piece. Since the entire length of the ball turning groove to be connected can be formed in a deep groove shape, the ball does not get out of a predetermined orbit in the ball turning groove and is blocked, and the ball circulation is made smoother and the bearing outer cylinder is It is possible to achieve a smooth sliding motion.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an assembled state of a ball cage according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing an assembled state of the ball cage according to the first embodiment.

FIG. 3 is a side view of the ball cage according to the first embodiment.

FIG. 4 is a sectional view taken along the line IV-IV in FIG.

5 is a sectional view taken along line VV of FIG.

FIG. 6 is a cross-sectional view showing a ball turning groove in a large diameter portion of the cage main body.

FIG. 7 is a cross-sectional view showing a ball turning groove in the seat of the cage main body.

FIG. 8 is an exploded perspective view showing an assembled state of the ball cage according to the second embodiment of the present invention.

FIG. 9 is an exploded perspective view showing an assembled state of a conventional ball cage.

FIG. 10 is an enlarged view of a main part for explaining a problem in the conventional ball cage.

FIG. 11 is a cross-sectional view showing a ball contact state in a ball bush to which the ball retainer of the present invention can be applied.

FIG. 12 is a sectional view showing a ball contact state in a ball spline to which the ball retainer of the present invention can be applied.

[Description of sign]

 1 Cage main body 2 Annular piece 3 Spline outer cylinder 4 Ball 5 Loaded ball guide groove 6 Unloaded ball guide groove 9 Ball swivel groove 10 Tip part 11 Small diameter part 12 Large diameter part 32 Convex ridge

Claims (1)

(57) [Scope of utility model registration request] 1. A ball retainer for a linear bearing, which is fitted in a hollow portion of a bearing outer cylinder that linearly moves around a bearing shaft and holds and aligns balls sandwiched between the bearing outer cylinder and the bearing shaft. That is, for the hollow part of the above-mentioned bearing outer cylinder,
The cage body inserted from one opening and the other
It is composed of an annular piece that is inserted from the cage.
Load balls on the side of the outer cylinder of the bearing
It has a small diameter part that fits in the area and
At the end, it fits in the ball scooping area on the bearing outer cylinder side.
The diameter of the large diameter part is smaller than the small diameter part at the other end of the small diameter part.
Is formed on the inner surface of the bearing outer cylinder to form a gap
Each of the small diameter parts, and the bearing on the outer peripheral surface of the small diameter part.
Bearing ball rolling surface formed on the inner peripheral surface of the outer casing
Load ball guide groove corresponding to the load ball groove, no load bow
Guide groove is formed on the outer peripheral surface of the large diameter portion.
Connecting the load ball guide groove and the unloaded ball guide groove
A ball turning groove is formed, and the annular piece has
Form the ball turning groove on the outer peripheral surface of the tip of the cage body.
A semi-circular notch for forming the cage is inserted into the hollow part of the bearing outer cylinder.
The large diameter part is axially engaged by the ridge of the bearing outer cylinder.
On the other hand, the annular piece is
In order to fill the space between the inner surface of the bearing outer cylinder and
A ball bearing for a linear bearing, which is fixed to the outer peripheral surface of the tip of the holder body .