JPH0333506A - Linear bearing - Google Patents

Abstract

PURPOSE: To increase loading force and to prolong life by positioning non- operative sectors of a ball chain on both sides of the edge of a cassette and positioning an operative sector near a center line of a wall of the cassette. CONSTITUTION: Continuos two-track groove 8 is machined to a wall 7 of a cassette 2. A ball chain 19 is positioned at the same level in the wall 7 of the cassette 2. Non-operative sectors 22 of the ball chain 19 are positioned on both sides of the edge 10 of the cassette 2. While, an operative sector 21 is positioned near a center line 13 of the wall 7 of the cassette 2. The outer surface 24 of a cassette is surrounded with the inner surface 23 having the same shape in a sleeve 1. Therefore, in a linear bearing, loading force can be increased, and the life can be prolonged.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a linear bearing having a ball chain;
In particular, it relates to a bearing for linear movement along an axis having a circular cross section. This is used in machines, instruments, robots, etc.

Linear bearings consisting of ball chains, outer cylindrical sleeves and polyhedral cassettes are known.

The cassette and sleeve each have a continuous two-way groove filled with balls forming a ball chain. In such a construction, the operating sectors of the bearing ball chain are machined into the walls of the polyhedral cassette, so that the grooves in the sectors have a depth corresponding to the ball size. The inactive sectors of the ball chain are at the edges of the cassette, so the depth of the grooves is shallow. This reduction in depth is compensated for by a V-shaped slot machined in the inner surface of the sleeve at a location corresponding to the edge of the cassette. Thus, nineteen branches of the continuous two-way groove are disposed entirely in the wall of the cassette, while the other branch is disposed partly in the wall of the cassette and partly in the surrounding sleeve, in which the V-shaped slot is located. processed,
It is located in Both branches of the groove are therefore differently shaped.

Moreover, transitions are machined where the ball chain passes from one branch of the groove to the other, ie from the working sector to the non-working sector and vice versa. Therefore, when the ball passes through the V-shaped slot in the sleeve,
make a special move.

As mentioned above, the ball chain is placed at two different levels, with working sectors and non-working sectors.

A disadvantage of the above-described structure is that it reduces the loading force.

And the unreasonable placement of the groove in the ball chain, and therefore the pole itself, shortens the life of the bearing.

Another drawback is the need for machining of the two-way groove transitions, ie, where the ball goes from active to inactive and vice versa.

Furthermore, with the above-described construction, there is no guarantee that the cassette will not over-rotate or slip relative to the sleeve. If it turns too much or slips, apply the force to the sleeve.
It must be completely covered by the ball in the shaped slot. This is a fatal flaw.

Also, a disadvantage of the above-mentioned bearings is that they require various machining equipment. In particular, the geometric shapes formed on the outer surface of the cassette and the inner surface of the sleeve are different. This increases the opening and increases the overall size of the bearing.

An object of the present invention is to provide a linear bearing that eliminates the above-mentioned drawbacks and provides the following effects.

Same size, large load force, and long life. Also, the cassette and sleeve should not rotate too much or slip. Also, it has a simple structure and is easy to manufacture.

The above object is achieved by a linear bearing having the following configuration.

It consists of an outer cylindrical sleeve and a polyhedral cassette inserted into this sleeve, into which a continuous two-track groove containing the balls forming the ball chain is machined, the depth of the groove in both branches being , such that the ball chain contained within the groove lies at the same level within the wall of the cassette. In the working sector of the ball chain, the groove is perforated so that the ball touches the shaft. The non-active sectors of the ball chain are located along the edges of the cassette on both sides and adjacent to the edges, while the active sectors are located near the centerline of the cassette wall.

Furthermore, the inner surface of the outer cylindrical sleeve has the same geometry as the outer surface of the polyhedral cassette, so that the ball chain is covered by the polyhedral inner surface within the sleeve.

If necessary, one or more ball chains can be provided on the base wall of the cassette. Alternatively, sharp edges of the polyhedron may be cut off. This allows the overall size of the bearing to be reduced.

The linear bearing of the present invention can increase the load force by providing one or more ball chains on the base wall of the polyhedron. Further, by making the outer surface of the cassette and the inner surface of the sleeve the same in geometry, the polyhedral edges can prevent the sleeve and the cassette from rotating too much or slipping relative to each other. Furthermore, by tightly contacting surfaces of the same shape, the overall size of the bearing can be reduced.

Machining is easy because the full shape and depth of both branches of the ball chain groove are the same.

Furthermore, since the movement of the ball chain is made on the same plane of the cassette wall 19, a transition where the balls go from an active state to a non-active state can be eliminated.

Furthermore, the linear bearing of the present invention has a simple structure, is easy to manufacture, and is easy to assemble and disassemble.

[Example 1] As shown in FIG. 1, a linear bearing is composed of an outer cylindrical sleeve 1 and a cassette 2 coaxially inserted into the sleeve 1 when assembling the bearing.

The bearing is laterally reinforced by a disc 3 and a lock ring 4. In order to position the bearing, grooves 5 are provided on the outer peripheral surface of both ends of the sleeve 1.

The cassette 2 has a polyhedral shape. In FIG. 1, the cassette h2 has a hexahedron shape, but it may also have a 3-, 4-, or 5-hedron structure. The preferable number of surfaces 7 of the cassette 2 is 2 to 12, and is appropriately selected depending on the diameter of the circular shaft. Diameter is 20m
For axes with a diameter of m or less, a tri- to hexahedron is appropriate, and for an axle with a diameter of 20 mm or more, a penta- to dodecahedron is appropriate.

The cassette 2 has a shaft with a circular cross section (not shown).
A center hole 6 is bored. By compressing the shaft into the hole 6, a bearing is obtained. Each wall 7 of the cassette 2 has at least nineteen consecutive two-track grooves 8 machined longitudinally into the wall 7 of the cassette 2.

The continuous two-track groove 8 has 19 linear sectors 9.
(FIG. 2.3) is provided adjacent to the edge 10 of the cassette 2. The position of the second linear sector 2 of the two-track groove 8 is determined by the number eight on the wall 7.

If there are only nineteen consecutive track grooves 8 in each wall 7 of the cassette 2, the second linear sector 2 is provided on the centerline 13 of the wall 7, as shown in FIG.

However, when each wall 7 has two full 8's, the second linear sector 2 is provided symmetrically on both sides adjacent to the center line of the wall 7, as shown in FIG. Both linear sectors 9 and 12 are connected at their ends by a circular sector 14 and separated by an insulator 15 . This insulation portion forms the inner wall 16 of the two-track groove 8, and the outer wall 17 is formed by the thickness of the wall 7 of the cassette 2. The height of the insulation part 15 is the same as the thickness of the wall 7.

Each successive two-track groove 8 is filled with a ball 18, as shown in FIG. The balls 18 are placed in contact with each other in the groove to form a ball chain 19. The size of the ball and thus the groove is determined by the standard size of the bearing and the diameter of the circular shaft to which it is applied. This linear bearing has a shaft diameter of 5 to 150 +
Applicable to nm.

A continuous two-track groove can also be considered to be composed of two branches. The No. 19 branch 25 is an idle portion of the ball chain 19, and the second branch 26 is an operating portion. The bottom of the branch 25 of the idle part is closed, while the bottom of the branch 26 of the operating part is a through hole 20.

In the working branch 26 of the ball chain 19, the ball chain 19 contacts the circular shaft via the hole 20.

In this way, the operating sector 21 (first
In FIG. 1B, the ball 18 passes through the hole 20, while in the non-active sector 22 the ball 18 is in another position, i.e. in a position other than the hole 20.

The working sector 21 and the non-working sector 22 of the ball chain 19 are on the same level, and the difference in the required distance of these sectors from the circular axis is due to the difference between the ball chain 19 and the two consecutive sectors.
The position of the track grooves 8 is obtained by approaching the edges of the cassette 2 respectively. Each edge of the cassette 2 is thus sandwiched from both sides by a non-working sector of the ball chain.

In a preferred example of the cassette 2 (FIG. 4), the corners of the edges 10 are cut out to form flat portions 11. In this way, the size of the cassette and therefore the overall size of the bearing can be reduced.

Furthermore, in this invention, the inner surface 23 of the cylindrical cylinder 1 is the same as the outer surface 24 of the cassette 2. In this way, both surfaces 23 and 24 are brought into contact with each other, and the non-operating sectors of the ball chain are covered by the opposite flat parts of the sleeve 1. Moreover, the surfaces 23 and 24 are
To prevent the sleeve 1 and the cassette 2 from rotating too much and slipping.

In the above example, the cylinder 1 and the cassette 2 have an integral structure, but they may be divided into two parts where the groove 8 is not provided.

The linear bearing according to the present invention described above is assembled as follows.

The continuous two-track groove 8 is filled with balls 18.

Then, the cassette 2 in which the balls are arranged and the ball chain is formed is pushed into the cylindrical sleeve 1.

The inner surface of this sleeve is previously made the same as the outer surface of the cassette. Then, attach the disks 3 to both ends of the cassette 2.
And install Rock Song 4. The bearing is now ready to be mounted on the circular shaft. When the bearing is mounted on the lees, the shaft contacts the working sector 21 of the ball chain 19, which is obstructed by the hole 20. The shaft thus slides along the ball 18.

[Brief explanation of drawings]

Figure 1 shows 4 arc minutes of linear bearing, Figure 2 shows 1
FIG. 3 is a front view of a cassette wall with two ball chains; FIG. 4 is a cross-sectional view of a variant with a cut-off corner of the cassette edge of the bearing; FIG. be.

Claims (1)

[Claims] 1) A linear bearing, particularly a bearing for linear motion along an axis having a circular cross section, comprising an outer cylindrical sleeve;
Consisting of a polyhedral cassette inserted into this sleeve and a ball chain disposed in a continuous two-track groove, the continuous two-track groove (8) is formed in the wall (7) of the cassette (2) by said groove. is machined to the same depth over the entire length of the ball chain (1
9) is located at the same level in the wall (7) of the cassette (2) and in the non-working sector (19) of said ball chain (19).
22) are located on both sides of the edge (10) of said cassette (2), close to said edge and along the edge, while working sectors (21) are located along the center line (1) of the wall (7) of the cassette (2).
3) and further located near the outer surface (24) of the cassette.
) is the inner surface (23) of the same shape within the sleeve (1).
A linear bearing characterized by being surrounded by. 2) Linear bearing according to claim 1, characterized in that the ball chain (19) is covered by the inner plane (23) of the sleeve (1). 3) Each wall (7) of the cassette (2) comprises at least one ball chain (19) and the edges (10) of the cassette (2) have rounded corners. linear bearing.