JPH05126149A - Double row ball chain - Google Patents

Abstract

PURPOSE:To improve strength of a connection part, smoothness of ball circulation, and alignment motion of the balls by arranging a flexible connecting member between rows of the balls parallelly arranged with a specified distance, and providing spacer parts to be inserted into the balls, on both side of the connecting member. CONSTITUTION:A double row ball chain is provided with a connection plate 2 and spacers 4. The spacers 4 are provided on the bilateral sides of the connection plate 2 all with distances relevant to the diameter of balls over its length, for forming a small-diameter flat cylindrical member. Recessions 5 are formed on both ends for slidably holding balls 3. The connection plate 2 is a thin plate member extending along cenral axes 0, 0 of ball rows parallelly extended. The spacers 4 are connected to both edges thereof, for forming a flexible member. Connection strength between the spacers is thus improved. Position, distances in respect to the balls are held and reinforced so that alignment motion of the balls is effectively done. The balls of two rows are simultaneously shifted from a load area to an unload area, so that circulation of the balls are smoothly done.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ball chain used in a linear motion guide device utilizing rolling of a ball, and more particularly to a double row ball chain which holds two rows of balls and enables infinite circulation.

[0002]

2. Description of the Related Art In a conventional linear motion guide device of infinite slide type, an infinite circulation path for infinitely circulating a large number of balls interposed between a raceway base and a slide base is constructed. For the purpose of eliminating mutual friction between balls rolling and moving in the infinite circulation path, the applicant has proposed a ball chain for holding each ball so as not to contact each other over the entire area of the infinite circulation path. See Japanese Patent Application No. 3-141481).

[0003]

However, the above-mentioned ball chain of the prior application has a single-row structure, and it is necessary to mount one ball chain on each infinite circulation path of the linear motion guide device.

Further, since such a ball chain repeats bending when the ball is infinitely circulated, it is required to further increase the strength of the connecting portion of the chain.

Further, it is required to further improve the alignment of the balls.

The present invention has been made to solve the above-mentioned problems of the prior art. The object of the present invention is to improve the strength of the connecting portion, improve the smoothness of ball circulation, and align the balls. It is to provide a double-row ball chain capable of improving exercise.

[0007]

In order to achieve the above object, according to the present invention, a flexible connecting member is provided between two rows of balls arranged in parallel with each other with a predetermined interval. Spacers that are arranged and that are inserted between the balls of each ball row are provided on both sides of the connecting member.

It is effective that the two rows of balls are arranged in parallel.

[0009]

In the double-row ball chain having the above structure, the spacers provided on the left and right sides of the connecting member are inserted between the balls of the two rows of balls, and the two rows of balls are formed by one ball chain. Rows of balls are retained.

By mounting the linear motion guide device in the two infinite circulation paths, the two ball rows can be assembled at once.

By integrating the two-row chain,
It is possible to increase the area of the contact portion where the ball loads and rolls.

By arranging the connecting member between the two rows of balls, the connecting strength between the spacers can be improved.

Further, the spacer portion is reinforced and maintained in posture and interval by the connecting member, which is effective for the alignment movement of the balls.

Furthermore, if two rows of balls are arranged in parallel, the two rows of balls will simultaneously escape from the load range to the non-load range. The stress amplitude of the ball when it comes out of the slide balances out and there is no change in the movement posture of the slide table, and the ball can be smoothly circulated by the circulating movement of the connecting member. The accuracy can be improved.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to illustrated embodiments. 1 and 2 showing a double-row ball chain according to an embodiment of the present invention, reference numeral 1 denotes the entire double-row ball chain, and the double-row ball chain 1 is a generally flexible connecting member. The connecting plate 2 and spacers 4 provided on both left and right sides of the connecting plate 2 and interposed between the balls 3 of the two ball rows B1 and B2.

The spacer portions 4 are provided along the left and right sides of the connecting plate 2 at intervals of the ball diameter over the entire length. The spacer portion 4 is a small-diameter flat cylindrical member, and holding recesses 5 for slidably holding the balls 3 are provided on both end surfaces thereof. The holding recess 5 is formed in a spherical shape into which the ball crown portion of the ball 3 is inserted. Therefore, the cross-sectional shape is a drum shape, and the width of the root portion fixed to the connecting plate 2 is wide,
The spacer portion 4 has a structure that does not easily collapse.

On the other hand, the connecting plate 2 is a thin plate-shaped member extending along the central axes O, O of the left and right ball rows extending in parallel with each other, and the spacer portions 4 are connected to both side edges thereof. The connecting plate 3 is formed of a flexible member, but in this embodiment, it can be deformed only in the direction orthogonal to the plate surface. The shape between the spacer portions 4 on the side edge of the connecting plate 2 is an arc shape following the outer peripheral shape of the ball 3.

The spacer portions 4 provided on the left and right sides of the connecting plate 2 can be arbitrarily arranged, for example, in parallel with the two rows of balls 3 having the same phase, or in a staggered arrangement having different phases.

Further, although the mounting angle of the spacer portion 4 is arranged on the width direction line Y which is orthogonal to the longitudinal direction of the connecting plate 2, as shown in FIG. Alternatively, the projection may be provided at a predetermined angle α.

In this example, the spacer portions 4 are independent of each other only by being fixed to the connecting plate 2, but as shown in FIG. 1 (f), the free ends of the spacer portions 4 are flexible. You may make it connect by the connecting piece 6 of.

The double-row ball chain 1 can be formed into an endless shape by bending the connecting plate 2 as shown in FIG. 2 (a).

Here, as shown in FIGS. 1E and 1F, in the case where the mounting angle of the spacer portion 4 is inclined by a predetermined angle with respect to the width direction line Y, it is endless. Then, as shown in FIGS. 2B and 2C. That is, FIG.
When the spacer portion 4 is bent so as to be located outside the connecting plate 2 as indicated by an arrow A in FIG. 4B, the spacing of the spacer portion 4 changes so as to open from the glue side to the tip side. Therefore, when it is made endless as shown in FIG. 2C, a gap g is formed between the ball 3 and the spacer portion 4 in the direction changing portion. If a gap is formed in this way, the ball 3 will come off in the free space, but the ball will not fall off even if there is a gap when rolling in the direction change path. There is no support when assembling.

On the other hand, when the spacer portion 4 is bent so as to be positioned inside the connecting plate 2 as shown by an arrow B in FIG. 2B, the spacer is bent as shown in FIG. 2C. Since the distance between the portions 4 changes so as to close from the joint side of the spacer portion 4 toward the tip side, the ball 3 and the spacer portion 4 interfere with each other at a portion where the distance is narrow, and it tends to be clogged. However, in this case, for example, when the direction is changed, the spacer portion 4 is bent at a base portion in a direction perpendicular to the connecting plate 2 so that the interference can be escaped and the ball pitch can be changed. It is possible to change the direction by holding it a little large so as not to support it.

The spacer portion 4 is inserted between the balls 3 for the purpose of eliminating mutual friction between the balls 3. The shape and structure of the spacer portion 4 is a circle slightly smaller than the above-mentioned ball diameter. However, the spacer 3 may have an elliptical shape as shown in FIG. 3A, and the balls 3 are held on both the left and right sides of the spacer 42 as the spacer 42 having the same thickness as the connecting plate 2. The tongue piece 7 for this purpose may be provided, and in short, any structure that does not interfere with other members may be used.

4 to 6 show an example of a linear motion guide device using the double-row ball chain 1 described above.

This linear motion guide device includes a rail 20 and
The track stand 20 is composed of a slide stand 21 slidably mounted on the track stand 20 via a large number of balls 3.

The linear motion guide device of the illustrated example has a rail 20.
It is a four-way equal load type in which four rows of balls are arranged symmetrically in the vertical and horizontal directions, two rows each on the left and right, and four infinite circulation paths 22, ... Are provided. There is. The left and right upper and lower two infinite circulation paths 22 are parallel to each other, and the two rows of balls held by the double row ball chain 1 of the present invention are incorporated therein.

As shown in FIG. 5, the infinite circulation path 22 connects a straight load ball passage 23 and a non-load ball passage 24 extending in parallel with each other and both ends of the load ball passage 23 and the non-load ball passage 24. It is composed of an arc-shaped turning path 25.

That is, jetty walls 27, 27 extending in the longitudinal direction are provided on the left and right side surfaces of the track 20, and ball rolling grooves 28 are provided at both upper and lower corners of the jetty walls 27, 27.
On the other hand, a ball rolling groove 29 corresponding to the ball rolling groove 28 is provided on the inner surface of the slide base 21.
A ball 3 held by a double-row ball chain 1 is rotatably interposed between 8 and 29 to support a load. The ball rolling grooves 28 and 29 are circular arc grooves in this embodiment, and the ball 3 rolls by contacting at two points.

Of course, the present invention is not limited to the circular arc groove, but can be used in the case of a Gothic arch groove as shown in FIG.

In consideration of the shapes of the inner surface of the jetty 27 of the raceway and the sliding base 21 and the arrangement of the balls, the ball chain 1 has a clearance between the tip of the jetty 27 and the internal surface in order to maximize the space efficiency. The type shown in FIG. 1 (e) is used in which the connecting plate 2 is arranged and extends obliquely between the ball rolling grooves 28, 29 on both sides thereof. Then, in the direction changing path 25, the spacer portion 4 is bent so as to be located outside the connecting plate 2, and as shown in FIG. A small gap g is formed between the ball 3 and the spacer portion 4 so as to widen. This turning path is 25
Is a side lid 21 attached to both end surfaces of the slide base body 21a.
b, 21b.

This ball 3 and each ball rolling groove 28, 29
The contact angle with the ball, that is, the horizontal direction of the rolling groove is drawn in the normal direction of the contact portion with the ball rolling grooves 28, 29 of the ball 3 with respect to the horizontal lines H, H passing through the centers of the left and right jetty 27, 27 The angle formed by the broken line, that is, the contact angle line X is approximately 45
It is taken near the degree. Further, the illustrated example has a so-called DF structure in which the left and right contact angle lines X, X, ...

However, the direction of the contact angle line of the ball is a so-called DB in which the contact angle line X'of each ball is gradually closed to the left and right as shown in FIG.
It can also be a structure. The same components as those of the DF structure shown in FIG. 4 are designated by the same reference numerals and the description thereof will be omitted.

In the case of this DB structure, it is preferable in terms of space that the spacer portion 4 is tilted inward of the ball circulation path, but if this is done, the balls will become clogged when the direction is changed. Therefore, as shown in FIGS. 8 (c) and 8 (d), the trajectory at the time of changing the direction of the ball by elastically deforming the spacer portion 4 is escaped by expanding from the H position to the H'position. Further, the space between the ball pitches may be increased by π ( _{RD- RS} ) / (2 × the number of balls) as shown in FIG. 8 (b).

Next, the movement of the ball 8 when the slide base 21 moves will be described.

When the slide base 21 moves with respect to the track base 20, the slide base 21 of the load ball passage 23 of the infinite circulation path 22 is moved.
The balls 3, ... Roll while supporting a load between the ball rolling grooves 28 and 29 of the track 20 and move in the moving direction of the slide 21.

By the movement of the balls 3 in this load range, each ball holding member 2 moves in the moving direction of the slide base 21 together with the balls 3, and the double row ball chain 1 circulates in the endless circulation path 22 infinitely. By the movement of the double-row ball chain 1, the balls 3 are sequentially supplied from the unloaded ball passage 24 into the loaded ball passage 23 from the rear end of the sliding base 21 in the moving direction through the ball direction changing passage 25.

The balls 3 are held between the spacers 4 during the entire course of the loaded ball passage 23, the direction changing passages 25, 26 and the unloaded ball passage 24 of the endless circulation passage 22, so that the balls 3 are separated from each other. Align and move without interfering with each other.

In this way, the connecting plate 2 is provided between the two rows of balls.
By arranging, the strength of the connecting portion can be improved.

The spacer portion 4 is reinforced by the connecting plate 2 so as to maintain its posture and its interval, and is effective for the alignment movement of the balls 3.

Further, by integrating the two rows of chains in this way, it is possible to increase the area of the contact portion where the balls 3 roll under a load.

Further, if the two rows of balls 3 are arranged in parallel at a predetermined pitch P, the two rows of balls 3 are placed in the load range L, as schematically shown in FIGS. 6 (a) and 6 (b). Since the ball 3 simultaneously exits to the no-load area M, the stress amplitude (waving) of the ball 3 is balanced, the movement posture of the slide base 20 does not change, and the circulation of the connecting plate 2 allows the ball 3 to circulate smoothly. Therefore, it is possible to improve the accuracy of rolling, pitching, etc. when the sliding table 20 is running.

In the illustrated example, although there is a gap g between the spacer portion 4 and the ball 3 in the direction change path of the load area, the spacing of the spacer portion 4 becomes equal to the ball diameter immediately before entering the load area. There are no gaps, and the two rows of balls 3 and 3 are simultaneously removed from the load region L.

The linear motion guide device to which the double-row ball chain of the present invention is applied is not limited to the infinite circulation type in which the double-row ball chain is made endless as shown in the drawing, but is used as it is. It can also be used for a finite sliding type.

[0045]

According to the present invention having the above-described structure and operation, the spacer portion provided on the connecting member is inserted between each ball of the two rows of balls, and one row of two balls is provided with one ball chain. The balls in the row of balls are held and mounted in the two infinite circulation paths of the linear motion guide device, so that the rows of two balls can be assembled at once.

By integrating the two ball chains, it is possible to increase the area of the contact part where the ball rolls under a load.

By arranging the connecting member between the two rows of balls, it is possible to improve the connecting strength of each spacer portion, and it is possible to hold and reinforce the posture and spacing of the spacer portions, and to improve the alignment movement of the balls. It is effective.

Further, if the two rows of balls are arranged in parallel, the two rows of balls are simultaneously withdrawn from the loaded area to the unloaded area, so that the stress amplitudes of the balls are balanced and the movement posture change of the slide table is changed. Instead, the ball can be smoothly circulated by the circulation motion of the connecting member, and the accuracy of rolling, pitching, etc., can be improved when the slide table of the linear motion guide mechanism travels.

[Brief description of drawings]

FIG. 1 shows a double-row ball chain according to an embodiment of the present invention. FIG. 1 (a) is a partial perspective view, FIG. 1 (b) is a partially cutaway front view, and FIG. ) Is a plan view, (d) is a side sectional view, and (e) and (f) are side sectional views when the spacer portion is provided with an angle.

2 (a) to 2 (c) are explanatory views of a state in which the double-row ball chain of FIG. 1 is bent.

3 shows another embodiment of the spacer portion of the double-row ball chain shown in FIG. 1, where FIG. 3 (a) is a side view of the elliptical spacer portion, and FIG. 3 (b) is a spacer portion. FIG. 13C is a side view showing still another embodiment of the above, and FIG. 16C is a front view of FIG.

4 (a) is a vertical sectional view showing an example of a linear motion guide device incorporating the double-row ball chain of FIG. 1, and FIG. 4 (b) is a schematic perspective view of the device of FIG. 4 (a). Is.

5 is a partial cross-sectional view of an endless circuit of the device of FIG.

FIG. 6 is a diagram for explaining the movement of the device of FIG. 4 from a ball-loaded region to an unloaded region, and FIG. 6 (a) is the same diagram.
(b) is a schematic cross-sectional view taken along the line A-O-A, and (b) is a partial cross-sectional view schematically showing the device of FIG. 4 to show the cross-sectional position of (a). ..

FIG. 7 is a partial cross-sectional view of the double-row ball chain shown in FIG. 1 incorporated into a double Gothic arch groove type linear motion guide device.

FIG. 8 (a) is a partially broken semi-longitudinal sectional view showing an example of a linear motion guide device having a DB structure, FIG. 8 (b) is a schematic view of a ball circulation path, and FIG. 8 (c) is the same figure. (b) CC line sectional drawing, the same figure
(d) is a sectional view taken along line D-D of FIG.

[Explanation of symbols]

 1 double-row ball chain 2 connecting member (connecting plate) 3 ball 4 spacer part 5 holding recess 6 connecting piece 20 raceway base 21 sliding base 22 infinite circulation path 23 loaded ball path 24 unloaded ball path 25 ball direction change path

Claims (2)

[Claims] 1. A flexible connecting member is arranged between two rows of balls arranged in parallel with each other at a predetermined interval, and is inserted between the balls of each row of balls on both sides of the connecting member. A double-row ball chain characterized in that it is provided with a spacer portion. 2. The double row ball chain according to claim 1, wherein the two rows of balls are arranged in parallel.