JP2008002673A - Ball roller rolling element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ball roller rolling element that can prevent the slip of a fitting part of a spherical recess by a simple structure and can precisely grind a rolling spherical portion. <P>SOLUTION: This ball roller rolling element comprises the rolling spherical portion 2 and left and right end face spherical portions 3, 4 formed at both ends of the rolling spherical portion 2 and swelling in a spherical shape, wherein the circular arc radius of the rolling spherical portion 2 is made larger than the radius of curvature R1 of each of the end face spherical portions 3, 4, and the end face spherical portion on one side has a spherical recess 5 of the same radius of curvature R1 as the end face spherical portion. A circular flat face 6 perpendicular to a rotation center line is formed on a vertex of the end face spherical portion 4 on the opposite side from the end face spherical portion 3 having the spherical face recess 5. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a ball roller rolling element used as a rolling element for a rotary bearing or a rolling guide device.

The inventor has already obtained a patent for a rolling element having both the self-aligning property of “ball” and the high rigidity of “roller” (Patent Document 1). “Tamako” is a coined word of the present applicant, and is a rolling element having a large load capacity equivalent to “roller” and at the same time being easy to handle as “ball”. The rolling spherical surface portion is located above and has a circular arc shape with a larger radius of curvature than the end surface spherical surface portion.
In order to make it easy to perform stable conveyance such as alignment and separation of the rolling elements, separation between right and left during lapping, and configuration of a work row during polishing, the present applicant has a spherical surface on one end surface spherical portion. A ball-rolling element provided with a cylindrical recess has been proposed (see Patent Document 2). That is, as shown in FIG. 5 (A), this rolling element 200 includes a rolling spherical surface portion 201 and left and right end surface spherical surface portions 202 and 203 that swell into spherical shapes at both ends of the rolling spherical surface portion 201. In addition, a spherical concave portion 204 having the same radius of curvature as that of the other end surface spherical surface portion 203 is provided in one end surface spherical surface portion 202.

As shown in FIG. 5 (B), the rolling element provided with the spherical recess 204 uses a raw ball, which is a raw ball before quenching for a ball bearing, as the work 210, and has the same diameter as the work 210. The workpiece 210 is compressed by a pressing tool 212 having a hardened steel ball 211 and a spherical recess 204 having a predetermined depth is formed. After that, as shown in FIG. 6A, the workpieces 210 are arranged in a row to form a rod-like workpiece row 213, and the rolling spherical surface portion is ground together by a centerless grinding machine or the like.
In the workpiece row 213, the spherical concave portion 204 of the adjacent one workpiece 210 is fitted with the spherical concave portion 204 of the other workpiece and the end surface spherical portion 203 located on the opposite side to the spherical center, and both ends of the workpiece row are arranged. The workpieces 213 are sandwiched between the poles 214 and 215 of the N and S poles and magnetically attracted to form a rod shape, and the contact portion between the workpieces 210 is made to be a surface contact so that the contact portion does not slip. When the workpiece 210 slips, the rolling spherical surface portion 201 is not accurately processed, and it is necessary to prevent slipping.
However, as a result of repeated trial production, it was found that slipping occurred between the workpieces 210 even though the workpiece 210 was fitted into the spherical concave portion 204.
Examining the cause, the spherical concave portion 204 is plastically deformed using a spherical pressing tool having the same diameter as the workpiece. As shown in FIG. 6B, the amount of springback after plastic deformation is spherical. The spring back amount δ2 at the center portion is larger than the spring back amount δ1 at the peripheral portion of the concave portion 204, and the end surface spherical portion 203 of the work 210 that fits into the spherical concave portion 204 is in point contact with the central portion 204a of the spherical concave portion 204. It was found that the spherical surface of the end face was swung so as to make a slidable movement.
JP 2001-140895 A JP 2005-188737 A

  The present invention has been made to solve the above-described problems of the prior art, and the object of the present invention is to prevent the fitting portion of the spherical concave portion from slipping and to increase the rolling spherical surface portion with a simple configuration. An object of the present invention is to provide a rolling element that can be ground accurately.

In order to achieve the above object, the present invention includes a rolling spherical surface portion and left and right end surface spherical portions that swell in a spherical shape at both ends of the rolling spherical surface portion, and an arc radius of the rolling spherical surface portion. Is set larger than the radius of curvature of the end surface spherical portion, and a spherical concave portion having the same radius of curvature as the end surface spherical surface is provided on the one end surface spherical surface, and the outer edge portion of the spherical concave portion is made larger than the maximum diameter of the rolling spherical surface portion. In the roller rolling element in which the length between the end surface spherical portion which is the length between the passing surface and the vertex of the other end surface spherical portion is shortened,
A circular flat surface orthogonal to the rotation center line is provided at the top of the end surface spherical portion opposite to the end surface spherical portion provided with the spherical concave portion.

When grinding the rolling spherical surface portion, when the work row of the roller rolling elements is configured, the spherical concave portion of one adjacent roller rolling element and the spherical concave portion of the next rolling contact roller are opposite to each other. Since the fitting portion with the end surface spherical portion is provided with a flat surface at the top of the end surface spherical portion, the spring back of the central portion of the spherical concave portion is absorbed by the flat surface, and the peripheral portion reliably faces the spherical concave portion. It is possible to prevent contact and slip of the fitting portion during grinding, and the rolling spherical surface portion can be accurately ground.
Further, since the flat surface is a surface parallel to the center line, the diameter and axial length of the ball roller can be accurately and easily managed on the basis of this flat surface. The rolling elements can be selected with high accuracy.

The present invention will be described below based on the illustrated embodiments.
1 and 2 show a rolling element according to an embodiment of the present invention.
The rolling element 1 includes a rolling spherical surface portion 2 and left and right end spherical surface portions 3 and 4 swelled in a spherical shape at both ends of the rolling spherical surface portion 2, and an arc radius R 0 of the rolling spherical surface portion 2. Is set to be larger than the arc radius of the end surface spherical surface portions 3 and 4.

  The curvature radii R1 of the end surface spherical portions 3 and 4 are substantially the same, the center of curvature O is located on the central axis X of the rolling spherical surface portion 2, and each of the end surface spherical portions 3 and 4 is on one substantially phantom spherical surface B. Is located. However, the center of curvature of each of the end surface spherical portions 3 and 4 may be shifted, and the radius of curvature of each of the end surface spherical portions 3 and 4 may be different. The direction in which the center of curvature deviates is preferably shifted in a direction in which the end surface spherical surface portions 3 and 4 approach the axial direction. Depending on the case, it may shift | deviate in the direction away.

Then, the spherical surface recess 5 having the same radius of curvature R1 as that of the spherical surface portion 4 on the other side is provided in the spherical surface portion 3 on one side. The spherical concave portion 5 is obtained by partially denting the apex portion of the end surface spherical portion 3 into a concave shape, and the center of curvature O3 of the spherical concave portion 5 is also located on the central axis X.
The outer edge 51 of the spherical recess 5 is circular and is set according to the size of the ball roller 1. Relative to the diameter D ₀ of the diameter d1 of the outer edge of the spherical recess 5 is a virtual sphere B, 70 ± 5% approximately in the range, preferably preferably set to a size of about 70%. For example, the diameter D ₀ of the virtual spherical surface B is set to be about 7.8 to 8 mm with respect to φ11.15 mm.
On the other hand, a circular flat surface 6 orthogonal to the central axis X is provided on the top of the end surface spherical portion 4 opposite to the end surface spherical portion 3 provided with the spherical concave portion 5.
Diameter d2 of the flat surface 6 is in the range of about 25 ± 5% relative to the diameter D ₀ of the virtual sphere B, and preferably suitably be on the order of about 1/4. For example, the diameter D ₀ of the virtual spherical surface B may be set to be about 3 mm with respect to φ11.15 mm.
The axial length W between the end surface spherical portions 3 and 4 is the length between the surface passing through the outer edge portion 51 of the spherical concave portion 5 of one end surface spherical portion 3 and the flat surface of the other end surface spherical portion 4.

  The ball rolling element 1 is manufactured from, for example, a workpiece 10 made of a raw ball that is a raw ball before quenching for a ball bearing. The size of the workpiece 10 corresponds to the virtual spherical surface B described above. The manufacturing process includes a plastic deformation process for manufacturing the spherical recess 5 in the workpiece 10 and a grinding process for the rolling spherical surface portion 2.

In the plastic deformation step, for example, a plastic forming jig 100 as shown in FIG.
The plastic forming jig 100 includes a cylindrical ring jig 101 that holds the outer periphery of the workpiece 10, and an upper mold 103 and a lower mold 102 that are arranged above and below the ring jig 101. The ring jig 101 has a cylindrical shape and is assembled to the lower mold 102. A punch 104 is inserted into the ring jig 101, and a recess 104 a having a predetermined depth on which a part of the workpiece 10 is seated is provided on the end surface of the punch 104. The recess 104a has a spherical shape with the same radius of curvature as that of the workpiece 10, and a flat flat surface forming portion 104b corresponding to the flat surface 6 of the ball rolling element 1 is formed at the center of the recess 104a. Is provided.
A spherical pressing tool 105 made of a hardened steel ball having the same diameter as the workpiece 10 is attached to the upper mold 103, and the workpiece 10 inserted into the ring jig 101 is compressed by the pressing tool 105, A spherical recess 5 is formed.

  As shown in FIG. 3 (B), the workpiece 10 has a spherical recess 5 at the steel ball abutting portion of the pressing tool 105, and is compressed in the axial direction of the ring jig 101 as a whole. Inflates. The periphery of the center of the work 10 is pressed against the inner periphery of the ring jig 101 and plastically deformed linearly, and the portions 10b and 10c on both sides of the deformed center straight part 10a are also more circular than the initial contour surface of the work 10 Swells in an arc. The intermediate shape of the workpiece 10 thus swollen is shown by a dotted line in FIG. As described above, the shape of the final rolling spherical surface portion is closer to that of the original spherical surface and the polishing allowance can be reduced.

With respect to the plastically deformed workpiece 10, as shown by a two-dot chain line in FIG. 3B, a predetermined range g including the central cylindrical portion 10a is ground, and the cross-sectional arc shape has a larger radius of curvature than the end surface spherical portions 3 and 4. The rolling spherical surface portion 2 is ground.
In the grinding, as shown in FIG. 4A, a plurality of workpieces 10 having the same dimensions are joined to each other in a non-moving state to form a rod-like workpiece row 11, and a virtual axis X that passes straight through the center of each workpiece 10 is formed. Formed and fed between the grinding wheel 151 and the adjustment wheel 152 of the centerless grinding machine, the outer periphery of each workpiece 10 is simultaneously ground to process the rolling spherical surface portion 2 having a predetermined size and shape.

The workpiece row 11 is formed by fitting the spherical surface 5 of the other workpiece 10 into the spherical concave portion 5 of the adjacent workpiece 10 and connecting both ends of the workpiece row 11 connected in a rod shape to the N pole and S pole. The workpieces 10 are sandwiched between the tools 121 and 122, and each workpiece 10 is magnetically adsorbed into a bar shape.
Since the flat surface 6 is provided on the top of the end spherical surface portion 3 that fits into the spherical concave portion 5 of each workpiece 10, even if the spring back amount at the center of the spherical concave portion 5 is large, the spherical concave portion 5. Is absorbed by the gap between the flat surface 6 and the central portion of the end surface, and the peripheral area of the flat surface 6 of the end surface spherical surface portion 3 contacts. The peripheral area of the flat surface 6 has a small amount of springback, and comes into close contact with the end surface spherical portion 3 up to the outer edge portion of the spherical concave portion 5 in a surface contact state.
Thus, since the contact portion of the end surface spherical surface portion 3 of the workpiece 10 fitted into the spherical concave portion 5 is in surface contact, the contact portion is not slipped and the rolling spherical surface portion 2 is accurately ground. Can do. In particular, if the diameter is set to about 70% of the diameter of the phantom spherical surface B, the friction torque is large and the search can be performed accurately.

  Also, when measuring the dimensions of the ball roller 1, the width and height can be measured accurately with reference to the spherical recess 5 and the flat surface 6. Obtainable. In addition, it is important that the rolling elements 1 have uniform dimensions, and according to the rolling elements 1 of the present invention, the dimensions can be selected with high accuracy.

FIG. 1 shows a rolling element according to an embodiment of the present invention. FIG. 1 (A) is a front view, FIG. 1 (B) is a left side view, and FIG. 1 (C) is a right side view. . 2 is an enlarged front sectional view of the rolling element of FIG. FIG. 3A is an enlarged cross-sectional view of the main part of the pressing process of the rolling element of FIG. 1, and FIG. 3B is a view showing the shape of the workpiece after pressing. 4A is a view showing a state in which the pressed workpiece of FIG. 3B is connected in a rod shape for grinding, and FIG. 4B is an enlarged view of the fitting state between the workpieces of FIG. 4A. FIG. FIG. 5A is a partially broken front view of a conventional ball roller rolling element, and FIG. 5B is an enlarged cross-sectional view of a main part of a conventional pressing process. 6A is a diagram showing a state in which the pressed workpiece of 5B is connected in a rod shape for grinding, and FIG. 6B is a schematic diagram of the shape of the spherical concave portion of the workpiece after B pressing. FIG. 6C is a partially enlarged sectional view schematically showing a fitting state between the workpieces of FIG. 6A.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rolling roller body, 2 Rolling spherical surface part, 3, 4 End surface spherical surface part 5 Spherical recessed part, 51 Outer edge part 6 Flat surface R0 Arc radius R1, R2 End surface spherical surface curvature radius D Rolling spherical surface Part maximum diameter W Length between spherical surfaces of end face d1 Diameter of outer edge of spherical concave portion d2 Diameter of flat surface 10 Workpiece 100 Plastic forming jig, 101 Ring jig, 103 Upper die, 102 Lower die 104 Punch, 104a Recessed portion 104b Flat surface forming part 105 Pressing tool

Claims (1)

A rolling spherical surface portion, and left and right end surface spherical portions swelled in a spherical shape at both ends of the rolling spherical surface portion, and the arc radius of the rolling spherical surface portion is set larger than the curvature radius of the end surface spherical surface portion, A spherical concave portion having the same radius of curvature as the end spherical surface is provided on one end spherical surface, and the length between the surface passing through the outer edge of the spherical concave portion and the vertex of the other spherical surface portion is larger than the maximum diameter of the rolling spherical portion. In the rolling element with a shortened length between the spherical surfaces of the end face,
A ball rolling element characterized in that a circular flat surface perpendicular to the rotation center line is provided at the top of the end surface spherical portion opposite to the end surface spherical portion provided with the spherical concave portion.

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