JP2004125171A - Bearing unit equipped with double row capped ball bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase the life time and reduce the cost coping with two guiding actions in the rotational direction and vertical direction without producing wear and unevenness in rotation, etc. <P>SOLUTION: A bearing unit 10 equipped with a double row capped ball bearing 20 is coaxially arranged on a shaft 11 in parallel in a state where a pair of right and left ball bearings 21 and 22 in the figure are sandwiched between inner rings 23 and 24 via an inner ring spacer 25. Outer rings 26 and 27 in each of ball bearings 21 and 22 are formed to roll independently and respectively. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a bearing unit having a double-row sealed ball bearing suitably used for machine tools and general assembly machines, and more particularly to a double-row sealed ball bearing having two types of guide mechanisms in a rotating direction and a vertical direction. Bearing unit structure.

Conventionally, as a rolling bearing unit 50 applied to machine tools and general assembling machines, as shown in FIG. 5, two types of guides along a rotational direction and a vertical direction of a head are provided by using a needle roller bearing 51. There are cam followers to do.

The needle roller bearing 51 includes a needle roller 52 sandwiched between a shaft flange 61 provided on a shaft 60 and a bearing fixing ring 62, and an outer ring 53 having a length substantially equal to the length of the needle roller in the axial direction. It is configured. The needle roller 52 does not include a retainer.

The rolling bearing unit 50 to which the above-described conventional needle roller bearing 51 is applied can perform two kinds of guiding operations in the rotation direction and the vertical direction by the rotation of the outer ring 53 having a length substantially equal to the length of the needle roller 52 in the axial direction. Yes, it is. For this reason, there is a problem in that the sliding portion of the outer ring 53 slips, wears, and uneven rotation occurs, thereby shortening the bearing life and increasing the cost.

The present invention provides a double row sealed ball bearing which can cope with two kinds of guiding operations in the rotating direction and the vertical direction without causing wear, uneven rotation, etc., and can achieve a long life and low cost. It is an object of the present invention to provide a bearing unit having the same.

An object of the present invention is to provide an inner race having an inner raceway on an outer peripheral surface, an outer race having an outer raceway on an inner peripheral surface, a plurality of balls rollingably interposed between the inner raceway and the outer raceway, Respectively, and a seal member that is disposed at least on one side in the axial direction with respect to the ball, and that separates an internal space filled with a lubricant from the outside, and a pair of the inner rings. A double-row sealed ball bearing having an inner ring spacer, wherein a pair of the ball bearings are arranged in parallel via the inner ring spacer over at least half of the entire shaft length having a flange, and the arrangement of the ball bearings on the shaft. The present invention can be achieved by a bearing unit having a double-row sealed ball bearing, in which a fixing screw portion is formed in a portion not provided.

According to the bearing unit having the double-row sealed ball bearing having the above configuration, the pair of ball bearings are arranged in parallel via the inner ring spacer over half or more of the entire length of the shaft having the flange, and the ball bearing of the shaft is arranged. A screw portion for fixing is formed in a portion which is not provided.

Therefore, the respective outer races of the respective ball bearings that independently roll and rotate can perform two types of rotational movements necessary for a mechanism that moves, for example, along a guide surface, and perform two types of guide operations in a rotational direction and a vertical direction. It is possible to cope without abrasion and rotation unevenness.

に は It is preferable that an enlarged diameter portion is provided at the end of the shaft on the side where the pair of ball bearings is arranged with the flange interposed therebetween, the diameter being enlarged from other parts of the shaft. The enlarged diameter portion surely prevents the ball bearings from coming off from the shaft along the axial direction without having to manage the inner diameter tolerance of each ball bearing.

径 It is preferable that the enlarged diameter portion is formed in a tapered shape so that a dimensional difference in a radial direction from another portion of the shaft gradually increases toward the shaft end. The tapered enlarged diameter portion surely prevents the ball bearings from coming off from the shaft along the axial direction without requiring the inner diameter tolerance management of each ball bearing.

最大 It is preferable that a maximum dimensional difference in a radial direction between the enlarged diameter portion and another portion of the shaft is about 40 μm in radius. The diameter-expanded portion expanded in the radial direction by up to about 40 μm surely prevents the ball bearings from coming off from the shaft along the axial direction without requiring the inner diameter tolerance management of each ball bearing.

As described above, according to the bearing unit having the double-row sealed ball bearing of the present invention, the pair of ball bearings are arranged in parallel via the inner ring spacer over half or more of the entire shaft length having the flange, A fixing screw portion is formed on a portion of the shaft where the ball bearing is not disposed. Therefore, the two types of guiding operations in the rotating direction and the vertical direction can be performed without causing wear, uneven rotation, and the like, and the life of the bearing unit can be extended and the cost can be reduced.

Hereinafter, a first embodiment of a bearing unit having a double-row sealed ball bearing of the present invention will be described in detail with reference to FIGS. FIG. 1 is a sectional view showing a first embodiment of a bearing unit provided with a double-row sealed ball bearing of the present invention, and FIG. 2 is a perspective view of a main part showing a component insertion device to which the bearing unit in FIG. 1 is applied.

As shown in FIG. 1, in a bearing unit 10 including a double-row sealed ball bearing of the first embodiment, a shaft 11 having a shaft flange 11 a protruding substantially at the center in the axial direction is rotated by a double-row sealed ball bearing 20. It is freely supported. The double-row sealed ball bearing 20 is disposed on the shaft 11 on the left side of the shaft flange 11a in the drawing. At the right end in the figure of the shaft 11 from the shaft flange 11a, a shaft screw portion 11b made of a fixing male screw is provided.

The double row sealed ball bearing 20 is arranged on the shaft 11 in parallel with a pair of left and right ball bearings 21 and 22 in FIG. 1 with an inner ring spacer 25 interposed between inner rings 23 and 24 of the ball bearings 21 and 22. , And the outer races 26 and 27 of the ball bearings 21 and 22 respectively roll and rotate independently.

That is, the ball bearings 21 and 22 include inner races 23 and 24 having inner races 23a and 24a on the outer peripheral surface, outer races 26 and 27 having outer races 26a and 27a on the inner peripheral surface, and inner races 23a and 24a and the outer race A plurality of balls 28 rotatably interposed between the tracks 26a and 27a, a retainer 29 for rotatably holding the balls 28, and a seal member 30 for partitioning an internal space filled with grease from the outside. ing.

The sealing member 30 is disposed axially outside of each ball 28, that is, on the left side of the ball 28 in the ball bearing 21 on the left side in FIG. 1 and on the right side of the ball 28 in the ball bearing 22 on the right side in FIG. , Respectively.

The above-described bearing unit 10 is applied to, for example, a component insertion device 40 of a general assembly machine as shown in FIG. 2, and rotates the supply cup 42 relative to the cam cylinder 41 (in the direction of arrow A) and moves up and down (in the direction of arrow B). Is possible. That is, in the bearing unit 10, the ball bearing 21 on the near side in FIG. 2 rotates according to the uneven surface 41 a of the cam cylinder 41, and the ball bearing 22 on the other side in FIG. It functions as a guide roller for guiding up and down movement along 42a.

作用 The operation of the present embodiment will be described.

The double row sealed ball bearing 20 of the bearing unit 10 has the ball bearings 21 and 22 combined in parallel on the shaft 11, and the outer races 26 and 27 that roll and rotate independently of each of the ball bearings 21 and 22. For example, two kinds of rotational movements required for a mechanism moving along a guide surface are enabled.

Therefore, it is possible to eliminate the problems of the conventional rolling bearing unit using the needle roller bearing, such as slippage, wear, increased torque, and uneven rotation. In addition, since the rolling element is the ball 28, it is possible to secure a lubricating grease pool space, which is difficult with a conventional needle roller bearing, and it is possible to extend the life of the rolling function. Furthermore, the respective outer races 26.27 of the respective ball bearings 21 and 22 independently have alignment properties, which is advantageous for lowering the torque and extending the life.

FIG. 3 is a sectional view showing a second embodiment of the bearing unit provided with the double-row sealed ball bearing of the present invention, and FIG. 4 is an enlarged sectional view of a main part of the bearing unit of FIG.

As shown in FIGS. 3 and 4, in the bearing unit 70 including the double-row sealed ball bearing according to the second embodiment, the side on which the pair of ball bearings 21 and 22 is arranged with the flange 11 a of the shaft 71 interposed therebetween (see FIG. 3 and FIG. 4). At the shaft end of the shaft 71 (left side in FIG. 3), there is provided an enlarged diameter portion 72 which is larger in diameter than the other portion on the left side of the flange 11a of the shaft 71 in FIG. Can be The enlarged diameter portion 72 is formed so as to gradually increase the dimensional difference in the radial direction from other portions of the shaft 71 toward the shaft end. The maximum dimensional difference L in the radial direction between the enlarged diameter portion 72 and other portions of the shaft 71 is about 40 μm in radius.

The enlarged diameter portion 72 is formed by applying, for example, a tapered tool punch 100 to a hexagonal hole 73 formed on the end face of the shaft end, and applying a load of about 50 kgf in the direction of the arrow in FIG. The hexagonal hole 73 is a hole for inserting a tool wrench when the bearing unit 70 is screwed to a mechanical device or the like.

Other configurations and operations are the same as those in the first embodiment.

In the first embodiment, the axial interference of the ball bearings 21 and 22 from the shaft 11 is prevented by the interference between the inner rings 23 and 24 of the ball bearings 21 and 22 and the shaft 11. It is set based on the tolerance of the inner diameter of the ball bearings 21 and 22 and the outer diameter of the shaft 11 so that the radial gap in the ball bearings 21 and 22 does not become negative.

In contrast, in the second embodiment, the ball bearings 21 and 22 are prevented from coming off from the shaft 71 along the axial direction by the enlarged diameter portion 72 provided at the shaft end of the shaft 71. Therefore, it is not necessary to manage the inner diameter tolerance of the respective ball bearings 21 and 22, and the likelihood of occurrence of variation in interference during bearing assembly is eliminated.

As described above, according to the first and second embodiments, in the double-row sealed ball bearing 20 of the bearing units 10 and 70, the pair of left and right ball bearings 21 and 22 in FIGS. The shafts 11 and 71 are coaxially arranged in parallel with the inner ring spacer 25 interposed therebetween, and the outer rings 26 and 27 of the ball bearings 21 and 22 independently roll and rotate. Therefore, the two kinds of guiding operations in the rotating direction and the vertical direction can be performed smoothly without causing wear, uneven rotation, and the like. As a result, it is possible to extend the life of the bearing units 10 and 70 and reduce the cost.

Further, according to the second embodiment, in the double-row sealed ball bearing 20 of the bearing unit 70, each ball bearing 21 from the shaft 71 can be moved without the need to manage the inner diameter tolerance of the ball bearings 21 and 22. 22 can reliably be prevented from coming off along the axial direction.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows 1st Embodiment of the bearing unit provided with the double row sealing ball bearing of this invention. FIG. 2 is a perspective view of a main part showing a component insertion device to which the bearing unit in FIG. 1 is applied. It is sectional drawing which shows 2nd Embodiment of the bearing unit provided with the double row sealed ball bearing of this invention. FIG. 4 is an enlarged sectional view of a main part of the bearing unit of FIG. 3. It is sectional drawing which shows the rolling bearing unit which applied the conventional needle roller bearing.

Explanation of reference numerals

Reference Signs List 10 bearing unit 11 shaft 11a shaft flange 11b shaft screw portion 20 double row sealed ball bearing 21,22 ball bearing 23,24 inner ring 23a, 24a inner ring track 25 inner ring spacer 26,27 outer ring 26a, 27a outer ring track 28 ball 29 retainer 30 Seal member 40 Component insertion device 41 Cam cylinder 42 Supply cup

Claims (4)

An inner ring having an inner raceway on the outer peripheral surface, an outer race having an outer raceway on the inner peripheral surface, a plurality of balls rollingly interposed between the inner raceway and the outer raceway, and each of the balls being rollably held. A double row seal including a retainer, a seal member disposed at least on one side in the axial direction with respect to the ball, and separating an internal space filled with a lubricant from the outside, and an inner ring spacer between a pair of the inner rings. A ball bearing,
A pair of the ball bearings are arranged in parallel via the inner ring spacer over half or more of the entire length of the shaft having the flange, and a fixing screw portion is formed in a portion of the shaft where the ball bearing is not arranged. A bearing unit comprising a double-row sealed ball bearing. 2. The shaft according to claim 1, wherein the shaft end on the side of the shaft on which the pair of ball bearings is arranged with the flange interposed therebetween is provided with an enlarged diameter portion that is enlarged in diameter from other parts of the shaft. Bearing unit with row sealed ball bearings. 3. The multi-layered structure according to claim 2, wherein the enlarged diameter portion is formed in a tapered shape so that a dimensional difference in a radial direction from another portion of the shaft gradually increases toward a shaft end. Bearing unit with row sealed ball bearings. The bearing unit provided with a double row sealed ball bearing according to claim 2 or 3, wherein a maximum dimensional difference in a radial direction between the enlarged portion and another portion of the shaft is about 40 µm in radius. .

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