JP2010038289A - Resin retainer for rolling bearing and manufacturing method of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin retainer for a rolling bearing with a structure capable of preventing a burr on a surface of the resin retainer caused by welding. <P>SOLUTION: The resin retainer for the rolling bearing is provided with a first annular part 21 and a second annular part 22, and a plurality of columnar parts 23 in intervals along a circumferential direction. A region surrounded by the first annular part 21, the second annular part 22 and the columnar parts 23 adjacent with each other in the circumferential direction is a pocket 7 where a ball 3 is rotatably held. The columnar part 23 comprises a first division part 24 and a second division part 25 divided into two and joined with each other. A recessed part 15 is formed on a joint surface 24a of the first division part 24, and a protruded part 16 fitted in the recessed part 15 is formed on a joint surface 25a of the second division part 25. A bottom part 15a of the recessed part 15 and a distal end part 16a of the protruded part 16 are welded with each other. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a resin cage for a rolling bearing and a method for manufacturing the same, and particularly to a rolling bearing suitable for use in various automotive accessories such as an alternator and used in a high-temperature / high-speed rotating environment. The present invention relates to a resin cage and a method for manufacturing the same.

As a general ball bearing, an outer ring, an inner ring, a plurality of balls that roll on the outer ring raceway surface and the inner ring raceway surface, and a synthetic resin cage that holds the plurality of balls rotatably. There is something to prepare. As the retainer, a crown retainer (for example, FIG. 21 of Patent Document 1) and a machined retainer (FIG. 2 of Patent Document 1) are known.
The crown-shaped cage has a plurality of pockets opened in one axial direction in the circumferential direction, and has a pair of claw portions on the opening side of the pocket. It prevents it from coming out.
A plurality of machined cages are provided with a plurality of circumferentially spaced first annular portions (rim portions) and second annular portions (rim portions) provided concentrically with an interval in the axial direction. And a column part connecting the first annular part and the second annular part. A region surrounded by the first annular portion, the second annular portion, and the column portion adjacent in the circumferential direction is formed as a pocket for holding the ball rotatably.

When the ball bearing rotates, the retainer also rotates with this, so that centrifugal force acts on the retainer. In particular, when ball bearings are used in high-speed and high-temperature environments, the opening side (claw side) has a low rigidity in the case of a crown type cage. It may be deformed to the outside and the nail part may contact the ball locally. In this case, the oil film (lubricating oil) formed on the balls is scraped off, the lubrication state of the ball bearings is deteriorated, and the ball bearings may be seized.
On the other hand, in the machined cage, the first annular portion and the second annular portion function as a stiffening ring. It does not occur, and a part of the pocket does not contact the ball locally, so that the oil film formed on the ball can be prevented from being scraped off. Thus, the machined cage may be more advantageous when used at high speeds.

  The machined cage of Patent Document 1 is divided into two parts, a first annular part side and a second annular part side, and these are assembled and integrated. One column portion connecting the first annular portion side and the second annular portion side is constituted by two column portion elements being overlapped in the circumferential direction. In addition, a claw is provided at the tip of each column part element, a through hole penetrating in the axial direction is provided in the first annular part and the second annular part, and the claw engages with the through hole, The one annular part side and the second annular part side are integrated. Patent Document 1 discloses that the column part element and the first and second annular parts are welded by ultrasonic waves.

JP 2007-113592 A (refer to FIG. 2 and FIG. 21)

As in Patent Document 1, when the claw at the tip of the column part element is inserted into the through-hole of the annular portion and the portion where the claw is inserted is welded by ultrasonic waves, the welded resin protrudes from the through-hole and becomes a burr when solidified Remain. That is, burrs appear on the surface of the cage. For this reason, a step of removing burrs is required, which increases the manufacturing cost of the cage.
Accordingly, the present invention provides a resin-made cage for a rolling bearing having a configuration capable of preventing burrs generated by welding from appearing on the surface of the resin-made cage, and a rolling bearing for preventing this from occurring. It aims at providing the manufacturing method of a resin cage.

  The resin cage for a rolling bearing according to the present invention includes a plurality of annular first annular portions and second annular portions provided concentrically with an interval in the axial direction, and a plurality of the annular retainers spaced in the circumferential direction. A first annular part and a pillar part connecting the second annular part, and a region surrounded by the first annular part, the second annular part and the pillar part adjacent in the circumferential direction is a rolling element. A resin cage for a rolling bearing formed as a pocket for rotatably holding the first and second divided portions, which are divided into two and joined to each other. A concave portion is formed on one joining surface of the first divided portion and the second divided portion, and a convex portion that fits into the concave portion is formed on the other joining surface, and a bottom portion of the concave portion, The tip of the convex portion is welded.

  According to this invention, the 1st division part and the 2nd division part are joined by welding, one pillar part is formed, and the 1st annular part and the 2nd annular part are united. And since the bottom part of a recessed part and the front part of a convex part are welded, the burr | flash produced by welding arises between the bottom part of a recessed part, and the front part of a convex part. Therefore, burrs generated by welding can be prevented from occurring inside the resin cage (column portion) and appearing on the surface of the resin cage.

  In addition, the manufacturing method of the present invention includes a first half member having an annular first annular portion, and a plurality of first divided portions protruding in the axial direction from the first annular portion and spaced apart in the circumferential direction. And an annular second annular part, a second half member having a plurality of second divided parts protruding in the axial direction from the second annular part and provided at the same pitch in the circumferential direction as the first divided part. Provided concentrically, the bottom of the recess formed on one joining surface of the first divided part and the second divided part, and the tip of the projecting part formed on the other joining surface and fitted with the recessed part And the first half member and the second half member are integrated.

  According to the present invention, in order to integrate the first half member and the second half member, the bottom portion of the recess formed on one joint surface of the first divided portion and the second divided portion, Since the front part of the convex part which is formed on the other joint surface and fits with the concave part is welded, a burr generated by the welding occurs between the bottom part of the concave part and the front part of the convex part. Therefore, burrs generated by welding can be prevented from occurring inside the resin cage (column portion) and appearing on the surface of the resin cage.

  According to the present invention, it is possible to prevent burrs generated by welding from occurring on the surface of the resin cage and appearing on the surface of the resin cage. Cost can be reduced.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view of a ball bearing in a state where a resin cage 4 of the present invention is attached. This ball bearing includes an outer ring 1, an inner ring 2 provided concentrically with the outer ring 1, a plurality of balls (rolling elements) 3 provided between the outer ring 1 and the inner ring 2, and the plurality of balls 3. Are held at equal intervals, and a resin cage 4 (hereinafter referred to as cage 4) is provided.
An outer ring raceway surface 11 is formed on the inner peripheral surface of the outer ring 1, and an inner ring raceway surface 12 is formed on the outer peripheral surface of the inner ring 2. The centers of the plurality of balls 3 are arranged on one pitch circle centered on the axis C of the ball bearing, and these balls 3 roll on the outer ring raceway surface 11 and the inner ring raceway surface 12. And the holder | retainer 4 hold | maintains these some balls 3 on a pitch circle as rolling freely. The balls 3 are all the same.

  FIG. 2 is a perspective view of the cage 4. As shown in FIGS. 1 and 2, the retainer 4 connects the annular first annular portion 21 and the annular second annular portion 22, and the first annular portion 21 and the second annular portion 22. The column part 23 is provided. The first annular portion 21 and the second annular portion 22 are provided on the same axis C with an axial interval therebetween, and the column portion 23 is spaced apart in the circumferential direction with the first annular portion. A plurality are provided so as to connect 21 and the second annular portion 22. The cage 4 includes a first half member 5 and a second half member 6 that are divided in the axial direction. The first half member 5 and the second half member 6 are joined to each other. All together.

  The first half member 5 includes the first annular portion 21 and a plurality of first divided portions 24 provided in the circumferential direction, and the second half member 6 includes the second annular portion 22. And a plurality of second divided portions 25 provided in the circumferential direction. And one said pillar part 23 is comprised by joining one 1st division part 24 and one 2nd division part 25, and the holder | retainer 4 is united. A region surrounded by the first annular portion 21, the second annular portion 22 and the column portions 23, 23 adjacent in the circumferential direction is formed as a pocket 7 that holds the ball 3 rotatably.

The first annular portion 21 and the second annular portion 22 are annular portions having the same diameter and thickness, and constitute portions on both sides in the axial direction of the cage 4.
Each of the pillar portions 23 is configured by joining a first divided portion 24 and a second divided portion 25 that are divided in two in the axial direction. The first divided portion 24 is a portion that protrudes in the axial direction from the first annular portion 21 and is provided at equal intervals in the circumferential direction. The plurality of first divided portions 24 and the first annular portion 21 are integrally formed of the same resin material. The second divided portion 25 is a portion that protrudes in the axial direction from the second annular portion 22 and is provided at the same pitch as the first divided portion 24 in the circumferential direction. The plurality of second divided portions 25 and the second annular portion 22 are integrally formed of the same resin material.

  A side surface 24b facing the circumferential direction of the first divided portion 24 has an arc shape and forms a spherical surface. A side surface 21b facing the axial direction of the first annular portion 21 between the first divided portions 24, 24 adjacent in the circumferential direction is also arc-shaped and forms a spherical surface. These side surfaces 24b, 24b, and 21b constitute half of the inner surface of the pocket 7. Similarly, the side surface 25b facing the circumferential direction of the second divided portion 25 is entirely arc-shaped and forms a spherical surface. A side surface 22b facing the axial direction of the second annular portion 22 between the second divided portions 25, 25 adjacent in the circumferential direction is also arc-shaped and forms a spherical surface. These side surfaces 25b, 25b, and 22b constitute the remaining half of the inner surface of the pocket 7. The inner surface of the pocket 7 is formed along a spherical surface that is concentric with the ball 3 and has a diameter slightly larger than the diameter of the ball 3.

  FIG. 3 is an enlarged cross-sectional view of the pillar portion 23, where (a) shows a state where the first divided portion 24 and the second divided portion 25 are separated, and (b) shows the first divided portion 24 and the second divided portion 25. The state which the two division | segmentation part 25 was joined is shown. Note that each of the plurality of column portions 23 has the same configuration. The first divided portion 24 has a distal end surface 24a facing the second divided portion 25 side on the distal end side in the axial direction, and the second divided portion 25 is a distal end facing the first annular portion 24 side on the distal end side in the axial direction. It has a surface 25a. And the column part 23 is comprised by joining in the state in which the front end surface 24a of the 1st division part 24 and the front end surface 25a of the 2nd division part 25 were faced | matched (refer FIG.3 (b)). . That is, the front end surface 24a and the front end surface 25a serve as a joint surface between the first divided unit 24 and the second divided unit 25. Specifically, the front end surface 24a and the front end surface 25a serve as a butting surface.

And the recessed part 15 is formed in the front end surface 24a (one joining surface) of the 1st division part 24, and it fits into the recessed part 15 in the front end surface 25a (the other joining surface) of the 2nd division part 25. A convex portion 16 is formed. The recess 15 is formed to be recessed in the axial direction parallel to the axis C (see FIG. 2), and the protrusion 16 is formed to protrude in the axial direction parallel to the axis C. The concave portion 15 and the convex portion 16 have a shape that fits in close contact.
The recess 15 is initially reduced in cross section from the opening toward the back 15a, but the cross section is enlarged on the back 15a side. On the other hand, the convex section 16 is initially reduced in cross section from the base portion toward the front portion 16a, but the cross section is enlarged on the front portion 16a side. That is, a raised portion 41 that is curved and raised toward the opposite side wall is formed on the side wall of the concave portion 15, and a concave portion 42 that is curved and depressed is formed on the side wall of the convex portion 16. Has been. According to this configuration, since the raised portion 41 of the concave portion 15 is fitted into the recessed portion 42 of the convex portion 16, the convex portion 16 is difficult to come out of the concave portion 15. That is, physical (mechanical) engagement is performed between the convex portion 16 and the concave portion 15. Moreover, since the recessed part 15 and the convex part 16 are extended and formed in the axial direction parallel to the axial center C, since the mutual fitting is carried out, the 1st half member 5 and the 2nd half member 6 are the circumferential direction. Can be prevented from being displaced. By preventing this position shift, it is possible to prevent the generation of abnormal noise and vibration in the cage 4 during rotation.

  Furthermore, as shown in FIG. 3B, the pillar portion 23 is formed with a welded portion 17 in which the bottom portion 15 a of the concave portion 15 and the tip portion 16 a of the convex portion 16 are welded. That is, the 1st division part 24 and the 2nd division part 25 are welded. Although this welding may be performed by ultrasonic waves, it is preferable that welding is performed by laser light in order to prevent the molten resin from protruding. In order to weld and bond the first divided portion 24 and the second divided portion 25 by laser light, the first half member 5 having the first divided portion 24 and the second half member 6 having the second divided portion 25; One of them is made of a transmissive resin that transmits laser light, and the other is made of an absorptive resin that absorbs laser light. Thus, when the laser beam is irradiated on the transparent resin side, the laser beam that has passed through the transparent resin is absorbed by the absorbent resin, and heat is generated at that portion. That is, heat is generated at the interface between the bottom 15 a of the recess 15 and the tip 16 a of the protrusion 16. The heat-absorbing resin and the permeable resin including the interface are melted and welded by the heat to form the welded portion 17.

  In the embodiment of FIG. 3, the first half member 5 is a permeable member made of a permeable resin, and the second half member 6 is an absorptive member made of an absorbent resin. To further explain the materials, the permeable member and the absorbent member are crystalline thermoplastic resins or polymer alloys, such as PA6, PA66, PA46, PA6T, PA9T, PPS, PPS / PI, PPS / PAI or PEEK. can do. The transparent member (the first half member 5) is preferably made of a material having a high laser beam transmittance from the viewpoint of ensuring the welding strength. For this reason, it is preferable that the thickness t (axial dimension) in the portion to be welded of the permeable member is 4 mm or less.

  The absorptive member (second half member 6) has a performance of absorbing laser light by adding, for example, carbon black to the resin. The carbon black is preferably 0.005 wt% or more, and preferably 3 wt% or less with respect to the amount of resin to be added. If it is less than 0.005 wt%, the laser beam absorption performance is poor, and if it exceeds 3 wt%, the impact strength of the material is lowered. Further, since the cage 4 is used in a high-speed rotation and high-temperature environment, it is necessary to increase the rigidity and strength of the first half member 5 and the second half member 6. Fiber) is added to strengthen. The glass fiber content of the absorbent member and the transmissive member is preferably 10 wt% or more, and preferably 50 wt% or less, based on the amount of resin added. In particular, in the case of a transmissive member, it is preferable that the amount of fiber is large (10 wt% or more) from the viewpoint of securing strength, but if it is too large (exceeding 50 wt%), the laser transmittance decreases.

  In addition, the cage 4 is configured such that welding can be performed on all the column portions 23 by irradiating laser light only from one side in the axial direction. That is, in all the column parts 23, since the bottom part 15a (bottom surface) of the recessed part 15 and the front part 16a (tip surface) of the convex part 16 are formed as a surface which faces in an axial direction, If laser light is irradiated to the interface) from one side in the axial direction, welding is performed in all the column parts 23.

  Next, a method for manufacturing the cage 4 of the embodiment will be described. A first half member 5 having a first annular portion 21 and a plurality of first divided portions 24 provided in the circumferential direction is formed by a transparent resin that transmits laser light, and is different from the first half member 5. As a body, the second half member 6 having the second annular portion 22 and a plurality of second divided portions 25 provided in the circumferential direction is formed by an absorbent resin that absorbs laser light.

  Then, as shown in FIG. 4, in a state where a plurality of balls 3 are interposed between the outer ring 1 and the inner ring 2 (see FIG. 1), the balls 3 are sandwiched from both sides in the axial direction, and the first half The split member 5 and the second half member 6 are joined by laser welding. In other words, the ball 3 is interposed between the axial directions, the first half member 5 and the second half member 6 are provided concentrically (axis C), and the concave portion formed on the joint surface of the first divided portion 24. 15, the bottom portion 15 a and the tip portion 16 a of the convex portion 16 formed on the joint surface of the second divided portion 25 are welded, and the first half member 5 and the second half member 6 are integrated.

  This manufacturing method will be described in more detail. Before welding the bottom portion 15a of the concave portion 15 and the tip portion 16a of the convex portion 16, the convex portion 16 is inserted into the concave portion 15, and the concave portion 15 and the convex portion 16 are brought into close contact with each other. State. Then, from the axially outer side of the first half member 5 (upper side in FIG. 4) toward the first half member 5 (downward side in FIG. 4), the laser beam is axially centered C (see FIG. 2). ) In the axial direction parallel to. The portion irradiated with the laser light is an interface between the tip portion 16 a of the convex portion 16 and the back portion 15 a of the concave portion 15. Moreover, as shown in FIG. 4, when irradiating a laser beam, the 1st half member 5 and the 2nd half member 6 in the state which fitted the recessed part 15 and the convex part 16 are clamp members. 30 is held in a state of being sandwiched from both sides in the axial direction.

  According to the above manufacturing method, the 1st division | segmentation part 24 and the 2nd division | segmentation part 25 are joined by welding, the one pillar part 23 is formed, and the 1st half member 5 and the 2nd half member 6 are comprised. Become one. And since the welding part 17 is formed by welding with the bottom part 15a of the recessed part 15, and the front part 16a of the convex part 16, the burr | flash produced by welding is the bottom part 15a of the recessed part 15, and the front part 16a of the convex part 16. Occurs between. That is, it is possible to prevent burrs from occurring inside the pillar portion 23 and appearing on the surface of the cage 4. For this reason, the process of removing burrs is not necessary, and the manufacturing cost can be reduced. Further, in addition to the physical fitting between the convex portion 16 and the concave portion 15, the retainer 4 is integrated by welding of the resins, so that the bonding strength between the first half member 5 and the second half member 6 is Can be high.

  Further, as shown in FIG. 3B, since the raised portion 41 of the concave portion 15 is fitted into the recessed portion 42 of the convex portion 16, the physical relationship between the concave portion 15 and the convex portion 16 is obtained. Further, in addition to this engagement, the concave portion 15 and the convex portion 16 are joined by welding, so that the first half member 5 and the second half member 6 are joined. The retainer 4 can have a strength sufficient to be used at high speed rotation (for example, 15000 rpm or more). In addition, when used in a high-temperature environment (for example, 150 ° C.), the crown-shaped resin cage needs to use a material having high creep resistance at a high temperature, which increases the manufacturing cost. However, according to the structure of the machined mold retainer 4 as in the present invention, it is possible to use an inexpensive material, and to reduce the manufacturing cost.

Further, by executing the laser beam irradiation from the axial direction, the first half member 5 and the second half member 6 can be quickly joined. That is, one side (first half member 5) in the axial direction of the cage 4 to be manufactured is made of the transparent resin, and the other side (second half member 6) is made of the absorbent resin and is welded by laser light. Since the interface on which the surface is formed is a surface facing in the axial direction, welding can be performed by irradiating laser light only from one outer side in the axial direction. That is, it is not necessary to irradiate laser light from both sides in the axial direction.
Furthermore, the pillar part 23 is provided in multiple places in the circumferential direction, and the concave part 15 and the convex part 16 are provided in each of the pillar parts 23. And the said welding part 17 is formed in each of these pillar parts 23 with a laser beam. For this purpose, as shown by a two-dot chain line in FIG. 4, a mask member 31 is provided on the side surface in the axial direction on the laser irradiation side of the cage 4, that is, the side surface on the outer side in the axial direction of the first half member 5. May be. Although the mask member 31 is a member that does not transmit laser light, the mask member 31 is provided with a plurality of through holes 32 penetrating in the thickness direction. The through hole 32 is formed at a position overlapping the position where the concave portion 15 and the convex portion 16 are present in the axial direction. As a result, if the entire holder 4 is irradiated with laser light, the laser light passes through the through hole 32 and reaches the interface between the bottom 15a of the recess 15 and the tip 16a of the protrusion 16. Can do. Thereby, the some recessed part 15 and the convex part 16 can be welded simultaneously, and the joining of the 1st half member 5 and the 2nd half member 6 can be performed rapidly.

  Moreover, the resin cage for a rolling bearing according to the present invention is not limited to the illustrated form, and may be in another form within the scope of the present invention. In the above embodiment, the rolling bearing has been described as a ball bearing. That is, the rolling element has been described as a ball, but the rolling element may be a (cylindrical) roller. In the case of a cage that holds cylindrical rollers, the cage is provided with a roller retaining portion. Conventionally, at the time of forming a cage, the roller retaining portion has a forcible shape, so that the thickness of the retaining portion needs to be a dimension that can be forcibly removed. That is, conventionally, it is difficult to increase the size. However, according to the method of joining the pair of halved members by welding as in the present invention, the forcibly punched portion does not occur, and the thickness of the retaining portion can be increased. For this reason, the holder | retainer which has the rigidity which can endure this in the environment which rotates at high speed can be obtained.

It is sectional drawing of the ball bearing in the state to which the resin cage of this invention was attached. It is a perspective view of a holder | retainer. It is an expanded sectional view of a pillar part, (a) shows the state where the 1st division part and the 2nd division part separated, (b) shows the state where the 1st division part and the 2nd division part were joined. Show. It is explanatory drawing explaining the manufacturing method of a holder | retainer.

Explanation of symbols

3 balls (rolling elements)
4 Resin cage 5 First half member 6 Second half member 7 Pocket 15 Concave portion 15a Depth portion 16 Protruding portion 16a Tip portion 17 Welding portion 21 First annular portion 22 Second annular portion 23 Column portion 24 First division Part 24a Tip surface (joint surface)
25 Second division 25a Tip surface (joint surface)
C axis

Claims (2)

Annular first annular part and second annular part provided concentrically at intervals in the axial direction, and a plurality of annular parts provided at intervals in the circumferential direction are connected to the first annular part and the second annular part. And a pillar portion,
A resin cage for a rolling bearing in which a region surrounded by the first annular portion, the second annular portion and the column portion adjacent in the circumferential direction is formed as a pocket for rotatably holding a rolling element. ,
The column part is composed of a first divided part and a second divided part which are divided into two and joined together,
A concave portion is formed on one joint surface of the first divided portion and the second divided portion, and a convex portion that fits into the concave portion is formed on the other joint surface, and the bottom portion of the concave portion and the convex portion A resin cage for a rolling bearing, characterized by being welded to the tip of the roller. An annular first annular portion, a first half member having a plurality of first divided portions protruding in the axial direction from the first annular portion and spaced apart in the circumferential direction;
An annular second annular portion, a second half member having a plurality of second divided portions protruding in the axial direction from the second annular portion and provided at the same pitch in the circumferential direction as the first divided portion;
Concentrically,
Welding the bottom part of the concave part formed on one joining surface of the first divided part and the second divided part and the tip part of the convex part formed on the other joining surface and fitted with the concave part,
A method for producing a resin cage for a rolling bearing, wherein the first half member and the second half member are integrated.

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