WO2016125855A1 - Rolling bearing retainer, rolling bearing, and method for manufacturing rolling bearing retainer - Google Patents

Abstract

This rolling bearing retainer is a synthetic resin retainer disposed between the inner ring and the outer ring of a rolling bearing, wherein a plurality of sections to be guided are provided along the circumferential direction to protrude radially outward from the outer diameter surface. Each of the sections to be guided is provided with a guide surface which can be in sliding contact with the outer ring, a chamfered section formed on an edge portion of the guide surface, and a groove section formed in a portion of the guide surface in the axial direction. The guide surface 27 and the chamfered section have surface properties in which the arithmetic average roughness Ra is 1.0-9.8 µm and the maximum height Rt is 10.1-102.9 µm. A parting line PL is provided radially inside the guide surface.

Description

Roller bearing cage, rolling bearing, and method for manufacturing rolling bearing cage

The present invention relates to a rolling bearing cage, a rolling bearing, and a method for manufacturing a rolling bearing cage.

At present, angular contact ball bearings and the like are widely used as spindle bearings for machine tools. For angular contact ball bearings for machine tools, phenol resin cages are used particularly when the use conditions are severe. Phenol resin cages have high sliding wear resistance and exhibit excellent durability when used in bearings. However, since it has a low strength and a large amount of water expansion, there is a disadvantage that the dimensional stability is low and the design is limited. Generally, a cage made of phenol resin cannot reduce dimensional tolerances and guide clearances, and may cause generation of cage noise and non-repeatable run-out (NRRO). Moreover, since a phenol resin is a thermosetting resin, it is difficult to make it into a complicated shape having a plurality of pockets. Therefore, there is a problem that cutting is necessary after molding, productivity is low, and it is not suitable for mass production.
On the other hand, a cage made of synthetic resin produced by injection molding has high productivity. However, when the usage conditions of the bearing are severe, the lubricity of the sliding portion is lowered, and the life may be reduced due to wear.
As means for improving the durability of the cage, there is a technique of forming a fine uneven shape on the surface of the cage and controlling the surface shape as in Patent Document 1. According to this technique, the lubricity and durability of the sliding portion can be improved by adjusting the fine uneven shape.

Japanese Unexamined Patent Publication No. 2014-95469 Japanese Unexamined Patent Publication No. 2002-144380

As a typical cage injection molding method, there are a radial draw method in which a movable mold is slid in a radial direction and an axial draw method in which a movable mold is slid in an axial direction. However, in a general shape of a cage and a mold for molding the cage, burrs are formed on the surface of the molded product corresponding to the mold matching portion of the mold member. In the radial draw type, burrs are generated on the outer diameter side surface of the cage, and in the axial draw type, burrs are generated in the connection portion with the chamfered portion. If burrs are generated in the guided portion of the cage (in the case of a cage for outer ring guidance, the outer diameter surface of the cage corresponds to the guided portion), the generated burrs may damage the sliding counterpart member. Further, the progress of wear may be promoted starting from the burr generated on the cage side. The generated burrs can be removed by barrel processing or the like, but the fine irregularities transferred and formed on the cage are also removed together, and the above-described effects of improving lubricity and durability cannot be obtained.

Patent Document 2 describes a technique that eliminates the need for burr removal processing by providing a parting line in a recess on the outer diameter surface of the cage. However, no consideration is given to a cage that transfers a specific surface shape. Further, it cannot be applied to a rolling bearing used in a severe environment such as a rolling bearing for supporting a spindle of a machine tool. For this reason, the wear resistance of the cage is insufficient and the life of the bearing is reduced. Even if this problem is changed to a resin material having high slidability, this problem is not necessarily improved.

Furthermore, neither of Patent Documents 1 and 2 considers the presence of a chamfered portion at the edge of the guided portion. Usually, since the cage is supported with a clearance in the bearing, the cage itself may be inclined and the chamfered portion may slide with other members such as an outer ring. For this reason, if burrs are generated in the chamfered portion, the wear of the cage proceeds as described above, and the life of the bearing may be reduced by the generated wear powder.

The fine uneven shape on the surface of the cage can be obtained by processing the mold surface of the molding die into a fine uneven shape in advance and transferring the fine uneven shape on the mold surface to the molded product. However, since the pocket of the cage is formed by the slide core, when the slide core is pulled out, the fine irregular shape on the inner peripheral surface of the pocket may be scraped off by shearing with the mold.

The present invention has been made in view of the above matters, a cage having a specific surface shape formed on the surface thereof, a cage for a rolling bearing having further improved durability without impairing productivity, and a rolling bearing, A first object is to provide a method for manufacturing a rolling bearing cage.
In addition, it is possible to suppress the damage of the fine irregularities on the inner peripheral surface of the pocket of the cage, and to provide a highly durable and productive rolling bearing cage, a rolling bearing provided with the rolling bearing cage, and a rolling bearing cage. A second object is to provide a manufacturing method.

The present invention has the following configuration.
(1) A synthetic resin rolling bearing cage disposed between an inner ring and an outer ring of a rolling bearing,
A plurality of guided portions protruding radially outward from the outer diameter surface are provided along the circumferential direction of the outer diameter surface,
The guided portion is formed along the axial direction on a guide surface formed so as to be slidably contacted with the outer ring, a chamfered portion formed on an edge of the guide surface, and a part of the guide surface. A groove portion,
The guide surface and the chamfered portion have a surface property with an arithmetic average roughness Ra of 1.0 to 9.8 μm and a maximum height Rt of 10.1 to 102.9 μm.
A rolling bearing retainer, wherein a parting line is provided radially inward from the guide surface.
(2) The rolling bearing retainer according to (1), wherein the parting line is provided on either the groove or the end face of the retainer.
(3) The cage for a rolling bearing according to (1) or (2), wherein the chamfered portion has a curved surface connected in a tangential direction to the edge portion of the guide surface.
(4) The chamfered portion is connected to the edge portion of the guide surface, and has an inclined surface formed with the guide surface and having an angle of 20 ° or less. (1) or (2) Roller bearing cage.
(5) A relief groove recessed radially inward is formed in a region facing a raceway surface edge that is a boundary between an outer ring inner peripheral surface of the outer ring and an outer ring raceway surface. 4) The rolling bearing retainer according to any one of 4).
(6) The surface layer of the cage is formed with an amorphous layer having a thickness from the surface of the cage of 0.1 to 30 μm and containing no reinforcing fiber, (1) to (5) The cage for rolling bearings as described in any one.
(7) A method for manufacturing a rolling bearing cage, wherein the rolling bearing cage according to any one of (1) to (6) is molded using a molding die,
A method for manufacturing a rolling bearing retainer, wherein the shape of a processed surface provided on a mold surface of the molding die is transferred to at least one of the guide surface and the chamfered portion.
(8) A rolling bearing retainer in which a pocket for holding a plurality of rolling elements disposed between an inner ring raceway and an outer ring raceway of a rolling bearing is formed.
The inner peripheral surface of the pocket has a surface property with an arithmetic average roughness Ra of 1.0 to 9.8 μm and a maximum height Rt of 10.1 to 102.9 μm.
The inner circumferential surface of the pocket is a cylindrical surface along the radial direction of the cage, and the thickness of the cylindrical surface in the radial direction of the cage is 3.5 mm or less.
(9) A rolling bearing retainer in which a pocket for holding a plurality of rolling elements arranged between an inner ring raceway and an outer ring raceway of a rolling bearing is formed.
The inner peripheral surface of the pocket has a surface property with an arithmetic average roughness Ra of 1.0 to 9.8 μm and a maximum height Rt of 10.1 to 102.9 μm, from the inner peripheral side toward the outer peripheral side. A cage for a rolling bearing, characterized by a tapered surface that expands in diameter.
(10) In (8) or (9), an amorphous layer not containing reinforcing fibers having a thickness from the surface of the cage of 0.1 to 30 μm is formed on the cage surface layer. The cage for rolling bearings as described.
(11) The cage for a rolling bearing according to any one of (8) to (10), wherein a stepped portion that expands or contracts the inner diameter of the pocket is provided on at least one of the cage inner diameter side or the cage outer diameter side. .
(12) A method for manufacturing a rolling bearing cage, wherein the rolling bearing cage according to any one of (8) to (11) is injection-molded using a molding die,
A method for manufacturing a rolling bearing cage, wherein the pocket is formed by a slide core of the molding die.
(13) The method for manufacturing a rolling bearing cage according to (12), wherein the shape of the processed surface provided on the mold surface of the molding die is transferred to the inner diameter surface of the pocket.
(14) The surface of the slide core that forms the inner peripheral surface of the pocket is formed by any one of shot peening, electric discharge machining, and etching, for the rolling bearing according to (12) or (13) A method for manufacturing a cage.
(15) A rolling bearing comprising the rolling bearing cage according to any one of (1) to (6) and (8) to (11).

According to the present invention, by forming a parting line by a molding die in at least one of the groove portion on the radially inner side of the guided surface and the end face of the cage, the protruding part (burr) of the parting line is There is no wear on the cage or other members. As a result, the progress of wear of the cage due to the rubbing of the convex portion is suppressed, and it is possible to prevent the occurrence of abnormalities such as a decrease in life and vibration. In addition, since the chamfered portion of the cage has a specific surface property that provides high dynamic sliding properties, wear of the chamfered portion and the outer ring can be suppressed even when the cage is tilted and contacts the outer ring in the rolling bearing. Therefore, smooth guidance can be performed even during high-speed rotation. Furthermore, the durability of the rolling bearing can be improved by using this cage for the rolling bearing.
In addition, according to the present invention, the pocket inner surface has an arithmetic mean roughness Ra of 1.0 to 9.8 μm and a maximum height Rt of 10.1 to 102.9 μm. The thickness in the radial direction is 3.5 mm or less. Therefore, even when the pocket is formed with the slide core, it is possible to suppress damage to the fine unevenness on the inner peripheral surface of the pocket. Thereby, durability of a holder | retainer can be improved, without impairing productivity.

It is a figure for demonstrating embodiment of this invention, and is a partial cross section figure of a rolling bearing. It is an external appearance perspective view of a holder | retainer. FIG. 3 is a partially enlarged perspective view of the cage shown in FIG. 2. FIG. 4 is an enlarged sectional view taken along line P1-P1 of the cage shown in FIG. (A)-(C) are enlarged sectional views showing the shape of the chamfered portion. (A) is explanatory drawing which shows typically an example of the metal mold | die for shaping | molding, (B) is explanatory drawing which shows the P2-P2 line cross section of (A). It is explanatory drawing which shows typically the other structural example of the metal mold | die for shaping | molding. It is a partially expanded perspective view of a cage. It is a graph which shows the relationship between the ratio of the sum total of the outer-diameter groove length with respect to a holder | retainer circumferential length, and break-in time. (A) is an enlarged view of the outer diameter surface of the cage, and (B) is a cross-sectional view schematically showing a molding die for P3-P3 line in (A). (A) to (C) are partially enlarged views showing outer diameter surfaces of other cages. (A) to (H) are enlarged sectional views showing various pocket shapes of the cage. It is a partial cross section figure of the angular ball bearing provided with the cage of other composition. It is an external appearance perspective view of the holder | retainer shown in FIG. It is a partial cross section figure of the angular ball bearing provided with the cage of other composition. It is an external appearance perspective view of the holder | retainer of another structure. It is an external appearance perspective view of the holder | retainer of another structure. It is a partial expanded sectional view of a rolling element guide type holder.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a view for explaining an embodiment of the present invention and is a partial sectional view of a rolling bearing. Here, an angular ball bearing used in a device that rotates at high speed, such as a spindle of a machine tool, will be described as an example of the rolling bearing.

An angular ball bearing 100 (hereinafter also abbreviated as “bearing”) includes an outer ring 13 having an outer ring raceway surface 11 on an inner peripheral surface, an inner ring 17 having an inner ring raceway surface 15 on an outer peripheral surface, and a plurality of balls ( Rolling element) 19 and a cage (roller bearing cage) 23 having a plurality of pockets 21.

The balls 19 are arranged so as to roll freely with a contact angle α between the outer ring raceway surface 11 and the inner ring raceway surface 15. The holder | retainer 23 hold | maintains the some ball 19 within the pocket 21 so that rolling is possible.

The retainer 23 is formed with a plurality of guided portions 25A and 25B protruding outward in the radial direction at both axial ends of the outer diameter surface of the retainer. The guided portions 25A and 25B are arranged at equal intervals along the circumferential direction, and both are arranged at the same circumferential position.

In the angular ball bearing 100 of this configuration, the guide surface 27 of the guided portion 25A on one end side in the axial direction (left side in FIG. 1) is the outer ring inner peripheral surface on the counter-bore side with respect to the outer ring raceway surface 11 of the outer ring 13. 29 is an outer ring guide method guided by 29.

<Basic shape of cage>
The guided portions 25 </ b> A and 25 </ b> B of the cage 23 have a surface shape with a predetermined surface roughness, as will be described in detail later. Grease, which is a lubricant, is held in the minute recesses that form the surface shape, and the sliding performance between the cage 23 and the outer ring 13 is improved.

The cage 23 is an injection molded product using a material containing synthetic resin. Examples of the synthetic resin that can be used for the cage 23 include PPS (polyphenylene sulfide), PPS-CF (carbon fiber reinforced polyphenylene sulfide), and the like. In addition, PA (polyamide), PAI (polyamideimide), thermoplastic polyimide, PEEK (polyetheretherketone) can be used as the base material, and organic fibers such as carbon fiber, glass fiber, and aramid fiber can be used as the reinforcing fiber. Fiber is available.

2 is an external perspective view of the cage 23, and FIG. 3 is a partially enlarged perspective view of the cage shown in FIG. Each of the guided portions 25A and 25B includes a guide surface 27 that protrudes radially outward and is slidably contactable with the inner peripheral surface 29 of the outer ring (see FIG. 1), and a chamfered portion that is formed at the edge of the guide surface 27 31. The chamfered portion 31 of this configuration is provided over the entire circumference of the peripheral edge, which is the axial and circumferential edge of the guide surface 27.

A groove portion 33 </ b> A is formed in the circumferential central portion of the guide surface 27 of the guided portion 25 </ b> A so as to be recessed from the radial height of the guide surface 27 and along the axial direction of the cage 23. Similarly, a groove 33 </ b> B is formed in the central portion in the circumferential direction of the guide surface 27 of the guided portion 25 </ b> B so as to be recessed from the radial height of the guide surface 27 and along the axial direction of the cage 23. The cross-sectional shape in the circumferential direction of the grooves 33A and 33B may be a triangular shape, a rectangular shape, a trapezoidal shape or the like in addition to the circular arc shape in the illustrated example.

In the set of guided portions 25A and 25B arranged at the same circumferential position, the respective groove portions 33A and 33B are arranged on a single straight line parallel to the axial direction. On the outer diameter surface of the cage 23, a plurality of sets of groove portions 33A and 33B having the same phase in the circumferential direction are arranged along the circumferential direction.

Further, outer diameter grooves 35A and 35B having a radial height lower than that of the guide surface 27 are formed between the guided portions 25A and 25A adjacent to each other in the circumferential direction and between the guided portions 25B and 25B. . Each outer diameter groove 35A, 35B functions as a lubricant discharge groove.

FIG. 4 is an enlarged cross-sectional view taken along line P1-P1 of the cage 23 shown in FIG. The chamfered portion 31 formed at the edge in the axial direction of the guide surface 27 has a curved surface with a curvature radius of 0.2 mm or more.

Generally, as shown in FIG. 1, the cage 23 disposed in the bearing is movable within a range of a guide clearance ΔG / 2 between the guide surface 27 and the outer ring inner peripheral surface 29 and a pocket clearance. . For this reason, the cage 23 may be inclined from the axis and the peripheral edge of the guide surface 27 may be biased against the outer ring 13. When uneven contact occurs, the cage 23 is worn, and abnormalities such as a decrease in life and deterioration of vibration occur. In this case, the wear of the cage 23 mostly proceeds from the peripheral edge of the guide surface 27. However, according to the cage 23 of this configuration, the peripheral edge of the guide surface 27 is made into the chamfered portion 31 with smooth corners, so that the wear does not easily progress.

In general, in the outer ring guide type angular contact ball bearing 100, the cage 23 may come into contact with the raceway surface edge 11a at the boundary between the outer race inner circumferential surface 29 of the outer race 13 and the outer raceway raceway surface 11 shown in FIG. is there. When the cage 23 comes into contact with the track surface edge 11a, the wear of the cage 23 proceeds from the contact portion with the track surface edge 11a as described above. Therefore, as shown in FIGS. 1 and 4, the cage 23 of this configuration is in contact with the raceway surface edge 11 a which is an axial edge of the outer ring raceway surface 11 of the outer ring 13 so as not to contact the raceway surface edge 11 a. An edge relief 37 that is recessed radially inward is provided in the facing region.

The edge relief portion 37 corresponds to a region between the guided portions 25A and 25B shown in FIG. 3, and is formed one step lower than the radial height of the guide surface 27. Even if the cage 23 is tilted by this step, the raceway edge 11a does not contact the cage 23, and wear of the cage 23 due to contact with the raceway edge 11a can be prevented.

In addition, the guide surface 27 and the chamfered portion 31 are formed with surface characteristics of minute irregularities. Since the lubricant such as the grease described above accumulates in the minute concave and convex portions, the contact resistance at the time of contact with the outer ring 13 is reduced, and the progress of wear is suppressed. In order to form this surface property, it is necessary to connect the guide surface 27 and the chamfered portion 31 smoothly.

5A to 5C are enlarged sectional views showing the shape of the chamfered portion 31. FIG. The chamfered portion 31 shown in FIG. 5A is configured by a curved surface having a curvature radius r of 0.2 mm or more. Thereby, the surrounding edge of the guide surface 27 does not stand, and the guide surface 27 and the curved surface are smoothly connected.

Further, as shown in FIG. 5B, the chamfered portion 31 intersects the guide surface 27 with the tangential direction of the curved surface of the chamfered portion 31 by bringing the center of the curvature radius r of the chamfered portion 31 closer to the guide surface 27. The chamfered portion 31 may be connected to the edge portion 27a of the guide surface 27 in the tangential direction. The angle θ formed by the tangential direction of the curved surface connected at the edge 27a and the guide surface 27 is preferably 20 ° or less (0 ° <θ ≦ 20 °).

Further, as shown in FIG. 5C, the chamfered portion 31 is an inclined surface having an angle θ formed with the guide surface 27 of 20 ° or less (0 ° <θ ≦ 20 °) in the axial cross section of the cage 23. There may be. In this case, the surface pressure applied to the cage 23 can be reduced, the occurrence of dents can be prevented, and the progress of wear can be suppressed.

The shape of the chamfered portion 31 described above is an example, and is not limited to these, and can be an arbitrary shape. Desirably, the chamfered portion 31 has a curved surface shape (R shape), and the curved surface tangent and the guide surface 27 are smoothly connected.

Further, as shown in FIG. 1, the radial guide clearance ΔG / 2 between the outer ring inner circumferential surface 29 of the outer ring 13 and the guide surface 27 of the cage 23 generates the cage noise during asynchronous rotation, and is asynchronous. Greatly affects runout NRRO, dynamic torque, etc. By setting the guide clearance ΔG / 2 to 0.2% to 0.8% of the guide diameter φG of the inner peripheral surface 29 of the outer ring, the NRRO and dynamic torque of the bearing during high speed rotation can be reduced.

In the case of an outer ring guide cage, the guide diameter φG changes due to centrifugal force and thermal expansion acting during rotation. If the initial guide clearance is small, the guide clearance during rotation becomes zero, and there is a risk of increased torque, temperature rise, breakage, and abnormal noise. Therefore, it is preferable that the guide clearance ΔG / 2 is 0.2% or more of the guide diameter φG.

In addition, since the rotation diameter of the cage 23 when the bearing rotates is determined by the guide clearance ΔG / 2, the contact load on the guide surface increases in proportion to the guide clearance ΔG / 2. Furthermore, when the guide clearance ΔG / 2 is excessive, the cage 23 vibrates inside the bearing and causes cage noise. For these reasons, the guide clearance ΔG / 2 is preferably smaller than 0.8% of the guide diameter φG.

When the cage 23 in which the guide clearance ΔG / 2 is set to 0.8% or less of the guide diameter φG is incorporated in a bearing and used for grease lubrication, the grease discharge is prevented. Such a cage 23 becomes a defective product because it takes a long time for the break-in operation. This break-in operation time is obtained by including the pocket 21 of the cage 23 in the region of the outer diameter grooves 35A and 35B, in other words, by providing the outer diameter grooves 35A and 35B on the side of the pocket 21 in the bearing axial direction. Can be shortened.

<Mold for molding cage>
Next, a molding die for injection molding the cage 23 having the above configuration will be described.
The above-described cage 23 made of synthetic resin is molded using a molding die. 6A and 6B schematically show an example of a molding die. FIG. 6A shows an outer mold 41 that molds the outer diameter surface of the cage 23 and a slide core 43 that molds the pocket 21 of the cage 23. FIG. 6B is a cross-sectional view taken along line P2-P2 of FIG. The molding die includes an inner die that forms the inner diameter surface of the cage 23 in addition to these die members, but the description thereof is omitted here.

6 (A) and 6 (B) are axial draw molds. A plurality of outer molds 41 are arranged along the circumferential direction of the cage 23, and the guided portions 25A and 25B of the cage 23 are formed. The outer molds 41 are each movable in the radial direction. The circumferential position of the groove portion 33A (33B) of the guided portions 25A, 25A (25B, 25B) is a parting line with the adjacent outer mold.

In the illustrated example, one outer mold 41 is configured to mold the circumferential half of a pair of adjacent guided portions 25A, 25A (25B, 25B). It is good also as a structure shape | molded with a mold member.

<Surface properties of cage>
In the molding die described above, the mold surfaces corresponding to the guide surfaces 27 and the chamfered portions 31 in the guided portions 25A and 25B of the cage 23 are processed surfaces having a predetermined surface roughness larger than usual. . The surface shape of the processed surface of the mold surface is transferred to the surfaces of the guide surface 27 and the chamfered portion 31 of the cage 23 to be injection-molded.

The shape of the guide surface 27 of the cage 23 and the shape transfer surface of the chamfered portion 31 to which the shape of the processing surface of the mold surface is transferred are given an arithmetic average roughness Ra defined by JIS B0601 of 1. 0.0 to 9.8 μm and the maximum height Rt is set to 10.1 to 102.9 μm (For numerical values of Ra and Rt, refer to Japanese Unexamined Patent Publication No. 2014-95469 as necessary. ).

As a result, grease as a lubricant is held in the concave portion forming a predetermined surface roughness, and the contact interface between the guide surface 27 of the cage 23 and the outer ring inner peripheral surface 29 (see FIG. 1) of the outer ring 13 from the concave portion. Is supplied with grease. Therefore, even if the lubrication conditions become severe due to the high-speed rotation of the bearing, the oil film does not break at the contact interface. For this reason, rapid temperature rise and seizure of the bearing can be suppressed over a long period of time.

The retainer 23 may be reinforced by mixing a filler such as glass fiber or carbon fiber with a resin material in order to improve wear resistance and mechanical strength. In that case, wear powder containing a filler may be generated at the contact interface between the guide surface 27 of the cage 23 and the outer ring inner peripheral surface 29 of the outer ring 13. This wear powder acts as a foreign object during rotation of the bearing, and there is a risk that cutting wear will increase. However, according to this structure, the unevenness | corrugation of predetermined surface roughness is formed along the direction parallel to the direction where the holder | retainer 23 and the ball | bowl 19 are guided, ie, the circumferential direction of the holder | retainer 23. FIG. By forming the unevenness, the generated wear powder is easily removed from the contact interface. Therefore, the wear resistance of the cage 23 is improved. In addition, the wear resistance of the cage 23 can be further improved by setting the surface roughness in the direction orthogonal to the guided direction and the surface texture of the irregularities in the same range as described above.

In addition, when the arithmetic average roughness Ra in the guide surface 27 and the chamfered portion 31 is less than 1.0 μm, the amount of grease retained in the concave portion forming the surface roughness decreases, and the guide surface 27 of the cage 23 and the outer ring 13 The amount of grease supplied to the contact interface with the inner peripheral surface 29 of the outer ring becomes insufficient. Further, when the arithmetic average roughness Ra exceeds 9.8 μm, the roughness itself may adversely affect the rotational accuracy of the spindle bearing for machine tools that require high-precision high-speed rotation.

The surface roughness given to the guide surface 27 and the chamfered portion 31 has a maximum height Rt in the range of 10.1 to 102.9 μm. By setting the maximum height Rt within the above range, the generation of specifically high peaks and low valleys can be suppressed, and vibration during sliding can be suppressed to improve bearing performance.

As described above, the surface properties of the guide surface 27 and the chamfered portion 31 of the cage 23 are imparted by shape transfer of the mold surface during the injection molding of the cage 23. For this reason, a surface layer (shape transfer layer) is formed on the guide surface 27 and the chamfered portion 31 in a uniform and highly reproducible state, which can be improved more reliably than the wear resistance of the cage 23.

The processed surface (textured surface) having a predetermined surface roughness provided in the molding die can be formed by any one of shot processing such as shot peening, electric discharge processing, etching, water jet, and laser processing. In addition, the said processed surface may be formed by the processing which combined the said processing method individually or in combination, and may be formed by processing methods other than the above. The surface shape of the processed surface may be a concave shape such as a dimple or a surface shape composed of fine grooves.

Further, if at least the guide surface 27 and the chamfered portion 31 of the cage 23 are provided with the shape transfer surface having the above-described surface roughness, the shape is formed on the outer circumferential surface, the inner circumferential surface, or the entire surface of the cage. A transfer surface may be formed.

When the burrs generated on the surface of the cage 23 are removed by barreling or the like, the shape transfer surface is removed from the cage 23 provided with the shape transfer surface, and the grease cannot be retained. Therefore, in this configuration, the parting lines that cause burrs are not removed by post-processing, and the parting lines are arranged at positions that do not affect the burrs. Thereby, productivity can be improved, without making the processing process of the holder | retainer 23 complicated.

According to the cage 23 of this configuration, a specific surface shape is formed on the surface of the cage, and the convex portion due to the parting line is not arranged at the sliding portion. Will improve. Further, the cage 23 can be easily mass-produced by an injection molding method that does not require post-processing such as cutting. Therefore, both the durability and productivity of the cage 23 can be improved.

<Configuration of other molds>
Next, another mold for molding will be described.
FIG. 7 schematically shows another configuration example of the molding die. The mold for molding includes an outer mold 45 for molding the outer diameter surface side of the cage 23 and a slide core 47 for molding the pocket 21 of the cage 23. In addition to these mold members, the molding mold includes an inner mold or the like that forms the inner diameter surface side of the cage 23, but the description thereof is omitted here. In the following description, the same members as those shown in FIG. 1 are denoted by the same reference numerals, and the description of the members is omitted or simplified.

In this molding die, the slide core 47 slides in the radial direction to form the pocket 21. Further, the outer mold 45 is a radial draw method, and is slid in the P1 direction in the drawing with the slide core 47 being removed from the pocket 21. Thereby, the outer diameter surface of the cage 23 is formed.

When the cage 23 is molded using the molding die having the above-described configuration, the parting line PL of the cage 23 is generated on the end surface of the cage 23 as shown in FIG. 8, and guided portions 25A and 25B and chamfers are formed. It does not occur in the part 31. Even if burrs exist on the end face of the cage, the burrs do not contact the outer ring 13 or the inner ring 17 of the angular ball bearing 100 shown in FIG. 1, and the burrs do not affect the bearing performance.

Therefore, by forming the cage 23 using the molding die of this configuration, the wear of the cage 23 described above is suppressed, and the durability of the rolling bearing can be enhanced.

Figure 9 is the angular contact ball bearing having an inner diameter is 70 mm (NSK Ltd. 70BNR10H), rotation speed 4000 min ^-1, the time and the outer diameter groove to break operation is completed when rotating in axial load 150N size ( It is a graph which shows the relationship with the ratio of the sum total of the outer-diameter groove | channel length with respect to a holder | retainer circumference.

¡If the ratio of the sum of the outer diameter grooves to the cage circumference is 35% or less, it takes 1 minute or more to finish the break-in operation of grease lubrication. When the ratio is around 30%, the slope of the graph is gentle, and in the region beyond that, the change in the running-in time is small even if the ratio of the outer diameter groove is increased.

Although not shown, when the ratio is 70% or more, the area in contact with the inner peripheral surface 29 of the outer ring becomes too small, the contact surface pressure is increased, the cage 23 is worn, and the life of the bearing is reduced. Therefore, it is preferable that the outer diameter grooves 35A and 35B have a total groove of 35% to 70% of the circumferential length of the cage. Further, it is more preferably 40% to 70%.

The same applies to oil / air lubrication, and if the guide clearance is too small, the oil drainage will deteriorate, causing abnormal temperature rise and seizure. When the guide clearance is large, the grease discharge is not hindered and the outer diameter groove does not have to be provided.

Further, as shown in FIG. 4, the torque of the rotational resistance of the cage 23 can be reduced by reducing the guide width L of the guide surface 27 (the width of the straight portion excluding the chamfered portion 31). However, when the guide width L is less than 0.5 mm, the contact surface pressure with the inner peripheral surface 29 of the outer ring increases. In that case, wear progresses and the durability of the bearing decreases. For this reason, the guide width L of the guide surface 27 needs to be 0.5 mm or more.

Further, when the axial width of the outer ring 13 is B (see FIG. 1), the width H (see FIG. 4) of the cage 23 is H / B ≦ 0.95 from the viewpoint of securing the space volume and reducing the weight. Furthermore, in order to secure a minimum thickness t (see FIG. 10B described later) in a pocket opening portion described later of the cage 23, it is desirable that 0.4 ≦ H / B (0 .4 ≦ H / B ≦ 0.95).

Next, a mold for securing a minimum thickness t at the pocket opening of the cage 23 will be described.
FIG. 10A is an enlarged view of the outer diameter surface of the cage. FIG. 10B is a cross-sectional view taken along the line P3-P3 in FIG. 10A, schematically showing the molding die. FIG. 10B shows an outer mold 41 that molds the outer diameter portion of the cage 23 and a slide core 43 that molds the pocket 21 of the cage 23. The molding die in the illustrated example includes an inner die that forms the inner diameter surface of the cage 23 in addition to these die members, but the description thereof is also omitted here.

The mold for molding shown in FIG. 10B is an axial draw mold. A plurality of outer molds 41 and slide cores 43 are arranged along the circumferential direction of the cage 23 and are movable in the radial direction. The circumferential position of the groove portion 33A (33B) of the guided portions 25A, 25A (25B, 25B) is a parting line with the adjacent outer mold.

As shown in FIGS. 10A and 10B, the retainer 23 has an outer diameter surface including guided portions 25 </ b> A and 25 </ b> B, outer diameter grooves 35 </ b> A and 35 </ b> B, and edge relief portions 37 from the outer mold 41. Molded. Further, the pocket 21 is formed by the slide core 43. As will be described later, predetermined surface properties formed on the surface of the slide core 43 are transferred to the inner peripheral surface of the pocket 21 of the cage 23.

The processed surface (textured surface) having a predetermined surface property provided on the slide core 43 can be formed by any one of shot processing such as shot peening, electric discharge processing, etching, water jet, and laser processing. In addition, the said processed surface may be formed by the processing which combined the said processing method individually or in combination, and may be formed by processing methods other than the above.

By the way, since the corner | angular part K of the guided parts 25A and 25B and the pocket 21 (inner peripheral surface) are approaching, the minimum thickness t of the convex part 41a of the outer side metal mold | die 41 which shape | molds this connection part becomes thin. . As described above, if the mold has a thin portion having the minimum thickness t, the mold strength may be insufficient, and the mold may be deformed or cracked.

Therefore, as shown in FIG. 10A, the circumferential phase of the corner portion K of the guided portions 25A, 25B is set to the circumferential position Pk1 that is the maximum axial diameter of the pocket 21 and the circumferential end of the pocket 21. It is provided in a region C between the circumferential position Pk2. And the minimum distance (minimum thickness t) between the corner | angular part K of the to- be-guided parts 25A and 25B and the inner peripheral surface of the pocket 21 shall be 0.5 mm or more. As a result, the part where the mold is particularly thin is eliminated, and the failure due to insufficient mold strength is prevented.

FIGS. 11A to 11C are partially enlarged views showing the outer diameter surfaces of other cages formed by a mold in which a thin portion is corrected. In the cage shown in FIG. 11A, the minimum thickness t of the mold is increased by making the corner portion K of the guided portions 25A and 25B into a curved chamfered shape.

In the cage shown in FIG. 11 (B), the minimum thickness t of the mold is increased by obliquely cutting the corners K of the guided portions 25A and 25B.

Further, the cage shown in FIG. 11C has a guide clearance ΔG / 2 of a normal size (for example, 0.8% or more of the guide diameter φG of the inner peripheral surface 29 of the outer ring), and the outer diameter groove 35A. , 35B need not be provided (see FIG. 16 described later). This cage 23 is provided with guided portions 26A, 26B spaced apart from the pocket 21 in the axial direction, so that the minimum distance (minimum thickness t) between the guided portions 26A, 26B and the pocket 21 is 0.5 mm or more. It is said.

Any of the cages shown above can prevent a failure due to insufficient strength of the mold.

<Surface properties of pocket inner peripheral surface>
Next, a description will be given of a cage in which minute irregularities are formed on the inner peripheral surface of the pocket.
The pocket 21 of the cage 23 is a cylindrical surface whose inner circumferential surface is along the radial direction of the cage, and the cylindrical inner circumferential surface has a predetermined surface property. Grease, which is a lubricant, is held in the minute recesses that form this surface property, and the sliding performance with the balls 19 of the pocket 21 is improved.

In order to mold the cage 23 having the above-described configuration, a molding die in which the surface of the mold (slide core 43) for forming the pocket 21 in the cage 23 has a predetermined surface property is used. That is, the mold surface of the slide core 43 is a processed surface having a predetermined surface roughness larger than usual. The surface shape of the processed surface is transferred to the inner peripheral surface of the pocket 21 of the cage 23 to be injection molded. Thereby, the pocket inner peripheral surface becomes a shape transfer surface (for example, a textured surface) corresponding to the shape of the processed surface.

The surface roughness of the shape transfer surface obtained by transferring the shape of the processed surface of the mold surface to the inner peripheral surface of the pocket 21 of the cage 23 is 1.0 to the arithmetic average roughness Ra specified in JIS B0601. The maximum height Rt is set to 9.8 μm and 10.1 to 102.9 μm (refer to Japanese Laid-Open Patent Publication No. 2014-95469 as necessary for the numerical values of Ra and Rt).

Thereby, the grease as the lubricant is held in the concave portion forming a predetermined surface roughness, and the grease is supplied from the concave portion to the contact interface (see FIG. 1) between the inner peripheral surface of the pocket 21 and the ball 19. Therefore, even if the lubrication conditions become severe due to the high-speed rotation of the bearing, the oil film does not break at the contact interface. For this reason, rapid temperature rise and image sticking can be suppressed over a long period of time.

Further, the surface shape of the processed surface may be a concave shape such as a dimple or a fine groove in addition to a random fine uneven shape.

When the arithmetic average roughness Ra is less than 1.0 μm, the amount of grease retained in the recesses that form the surface roughness decreases, and the grease is supplied to the contact interface between the inner peripheral surface of the pocket 21 of the cage 23 and the ball 19. It becomes insufficient. Further, when the arithmetic average roughness Ra exceeds 9.8 μm, the roughness itself may adversely affect the rotational accuracy of the spindle bearing for machine tools that require high-precision high-speed rotation.

The surface roughness applied to the inner peripheral surface of the pocket 21 has a maximum height Rt in the range of 10.1 to 102.9 μm. Thus, by setting the maximum height Rt within the above range, the generation of specifically high peaks and low valleys can be suppressed, vibration during sliding can be suppressed, and bearing performance can be improved.

As described above, the surface property of the inner peripheral surface of the pocket 21 is imparted by transferring the shape of the surface of the slide core 43 during the injection molding of the cage 23. For this reason, a surface layer (shape transfer layer) is formed on the inner peripheral surface of the pocket 21 in a uniform and highly reproducible state, and the wear resistance of the cage 23 can be improved more reliably.

Moreover, the cage 23 having the above-described configuration may have both the above-described guide surface 27 and the chamfered portion 31 having a micro uneven surface property. In that case, due to the synergistic effect of the surface properties of the guide surface 27, the chamfered portion 31, and the inner peripheral surface of the pocket 21, the wear of the cage 23 is more reliably suppressed, and the guidance during high-speed rotation becomes smoother.

<Pocket molding>
The pocket 21 of the outer ring guide type cage 23 is generally cylindrical in the radial direction. For this reason, when extracting the slide core 43 provided with the surface shape which becomes the above-mentioned surface property to the outside in the radial direction, the surface shape applied to the inner peripheral surface of the pocket 21 may be broken by shearing.

Table 1 shows that a retainer 23 was formed by using a die obtained by processing a cylindrical portion having a diameter of 95 mm into an arithmetic average roughness Ra of 3 μm by a shot method, and a distance of 16 mm in length was drawn parallel to the surface shape transfer surface. The result of having observed the state of the surface shape of PPS-CF resin at the time with a microscope is shown.

When the drawing length is 3.5 mm or less, the surface shape transferred from the mold remains without abnormality. When the drawing distance is 3.5 to 4.5 mm, 80% or more of the surface shape transferred from the mold remains. However, when the drawing distance is 4.5 mm or more, the surface is scraped off by shearing with the mold, and the surface shape having a predetermined surface roughness transferred from the mold is destroyed. Therefore, the length D (see FIG. 12) of the inner peripheral surface of the pocket 21 corresponding to the drawing distance in the shearing direction of the mold, that is, the thickness of the cylindrical surface of the pocket 21 in the cage radial direction is 4.5 mm. Hereinafter, it is more preferable that the thickness is 3.5 mm or less.

 

In the cage, when the radial length D of the inner peripheral surface of the pocket 21 is large and the above drawing distance is large, or the surface shape to be applied is large, the surface shape of the inner peripheral surface of the pocket 21 is damaged by the pulling. The mold may be worn out and the life may be shortened. In such a case, instead of the above-described shape shown in FIG. 12A, as shown in FIG. 12B, the pocket diameter d1 on the radially inner side of the cage 23 that does not contact the ball 19 is reduced. That's fine. Alternatively, as shown in FIG. 12C, the pocket diameter d2 on the radially outer side of the cage 23 that does not contact the ball 19 may be increased.

By providing the stepped portion 22 that expands and contracts the inner diameter of the pocket 21 on the inner diameter side of the cage and the outer diameter side of the cage, a substantial pulling distance (a distance that slides while contacting) can be shortened. Damage to the transferred surface shape can be suppressed.

Further, as shown in FIG. 12D, the pocket diameter d1 on the radially inner side of the cage 23 may be reduced and the pocket diameter d2 on the radially outer side may be increased. In this case, the drawing distance can be further shortened.

Further, as shown in FIG. 12 (E), the entire inner peripheral surface of the pocket 21 may be a tapered surface with a taper angle of θ = 0.5 ° or more and the diameter is increased from the inner peripheral side toward the outer peripheral side. . In that case, when the slide core 43 is pulled out, shearing does not occur, and the surface shape of the pocket can be protected. In addition, the life of the slide core can be improved.

In FIG. 12 (F), the pocket diameter d1 on the radially inner side is reduced and a tapered surface 21a is formed. In FIG. 12G, the radially outer pocket diameter d2 is increased and a tapered surface 21a is formed. In FIG. 12H, the radially inner pocket diameter d1 is reduced, the radially outer pocket diameter d2 is increased, and the tapered surface 21a is formed. Thus, by making the shape of the inner peripheral surface of the pocket 21 into a shape in which the drawing distance is substantially shortened, damage to the resin when the slide core 43 is drawn can be suppressed, and the mold life can be extended. It becomes possible.

As described above, a shearing force is generated in the pocket portion when the slide core 43 is pulled out. Therefore, it is conceivable that the lifetime of the outer mold 41 that molds the outer diameter portion of the cage 23 and the lifetime of the slide core 43 that molds the pocket 21 of the cage 23 are greatly different. However, according to the present mold configuration, the outer mold 41 having a complicated shape and expensive is continuously used as it is, and the slide core 43 is configured separately from the outer mold 41. Therefore, only the inexpensive pin-shaped slide core 43 can be replaced, and the running cost of the mold can be reduced.

Note that the minute uneven shapes of the guide surface 27 and the chamfered portion 31 are the same as the inner peripheral surface of the pocket 21, and the arithmetic average roughness Ra = 1.0 to 9.8 μm and the maximum height Rt = 10.1 to You may make it the range of 102.9 micrometers. Further, this minute uneven shape can be obtained by applying to the mold surface in the same manner as the surface processing method of the slide core 43.

<Skin layer on cage surface>
When the cage 23 is molded by injection molding, the high temperature resin comes into contact with a low temperature mold and is rapidly cooled. Therefore, an amorphous layer called a skin layer is formed on the surface portion of the cage 23 in the vicinity of the mold. In addition, since the resin during molding flows in parallel to the resin surface, reinforcing fibers (CF (carbon fiber), GF (glass fiber), AF (aramid fiber), etc.) in the surface layer inside the resin after molding are also parallel to the surface. Arranged.

When the resin material is PPS (polyphenylene sulfide resin), PEEK (polyether ether ketone resin), etc., the amorphous layer crystallizes to the vicinity of the surface, so that it has a very thin thickness of about 0.1 to 10 μm. It becomes. When the resin material is a polyamide resin such as nylon, an amorphous layer is easily formed and has a thickness of about 10 to 30 μm.

Reinforcing fibers are highly aggressive against the outer ring, inner ring, and rolling element steel that slide with the cage. In particular, when the surface subjected to barrel processing or cutting for deburring a resin material containing reinforcing fibers is used as a sliding surface, the reinforcing fibers are deposited in a direction intersecting the resin surface. Therefore, the end of the reinforcing fiber has an acute angle, which damages the outer ring, the inner ring, and the rolling element, or causes wear. Furthermore, since the reinforcing fibers appear on the surface of the cage, the reinforcing fibers may fall off, leading to a reduction in bearing life.

Therefore, by having a skin layer on the surface layer of the cage, it is possible to suppress the dropping of the reinforcing fibers and the attack on the mating member by the precipitated reinforcing fibers.

Furthermore, since the reinforcing fibers are arranged in parallel on the cage surface, the ends of the reinforcing fibers do not hit the outer ring, the inner ring, and the rolling element even after the skin layer is removed by wear or the like. Thereby, wear of the mating member can be suppressed.

This skin layer is desirably present at 30 μm or less from the surface as disclosed in JP-A-2001-227548. Further, as described above, since it is necessary for the skin layer to be present in the surface layer portion, the cage surface layer has an amorphous thickness of 0.1 to 30 μm from the cage surface and does not contain reinforcing fibers. It is desirable that a layer is formed.

<Other configuration examples>
Next, another configuration example of the above-described cage 23 will be described.
(First modification)
FIG. 13 is a partial sectional view of an angular ball bearing 110 provided with a cage 23A having another configuration, and FIG. 14 is an external perspective view of the cage 23A. In the following description, the same members as those shown in FIG. 1 are given the same reference numerals, and the description of the members is omitted or simplified.

The cage 23A of this modification is provided with a guided portion 25A only on one end side in the axial direction, and the guided portion on the other end side is omitted. In the cage 23 </ b> A, the guided portion 25 </ b> A is guided to the outer ring inner peripheral surface 29 of the outer ring 13. At that time, since the edge escape portion 37 is provided in the cage 23A, the raceway surface edge 11a of the outer ring does not contact the cage 23A. Further, a parting line (not shown) at the time of injection molding of the cage 23A is provided along the axial direction in the groove 33A formed in the guided portion 25A, as described above.

According to this modification, the cage 23A can have a simpler structure, and the bearings are not affected by burrs by arranging the parting lines to be convex portions (burrs) in the groove portions 33A. Therefore, both durability and productivity of the cage 23A can be improved.

Further, the inner peripheral surface of the pocket 21 of the cage 23A has the predetermined surface properties described above. This surface shape is formed by transferring the processed surface of the mold (slide core 43).
According to this modified example, the cage 23A can have a simpler structure. Further, grease as a lubricant is held in a minute recess of the pocket 21 forming a predetermined surface roughness, and grease is supplied from this recess to the contact interface between the inner peripheral surface of the pocket 21 and the rolling element 19. The Therefore, the durability of the cage 23A is improved.

Note that the above-described surface properties of the guide surface 27 and the chamfered portion 31 of the cage 23A and the inner peripheral surface of the pocket 21 may be formed on at least one of them, or may be formed on both. .
When formed on both sides, the wear resistance and durability of the cage 23A can be further improved by a synergistic effect.

(Second modification)
FIG. 15 shows a partial cross-sectional view of an angular ball bearing 120 provided with a cage 23B having another configuration. The cage 23B of this modified example does not include any of the guided portions 25A and 25B, and the predetermined surface properties described above are transferred from the mold to the inner peripheral surface of the pocket 21 of the cage 23B. Is formed. Other than that, it is the same as the cage 23A of the first modified example described above.

According to this modification, the cage 23B can have a simpler structure. In addition, grease, which is a lubricant, is held in a minute recess that forms a predetermined surface property, and grease is supplied from this recess to the contact interface between the inner peripheral surface of the pocket 21 and the ball 19. Therefore, the durability of the cage 23B is improved.

(Third Modification)
FIG. 16 shows an external perspective view of a cage 23C having another configuration. The cage 23C has guided portions 26A and 26B projecting radially outward at both axial ends of the cage outer diameter surface. A plurality of groove portions 33A, 33B that are recessed from the radial height of the guide surface 27 along the axial direction are formed in each guided portion 26A, 26B.

In the cage 23C of the present modification, a set of groove portions 33A and 33B are arranged at the same circumferential position as in the case of the cage 23 shown in FIG. Further, chamfered portions 31, 31 are formed at the axial edges of the guided portions 26 </ b> A, 26 </ b> B of the guide surface 27. However, the aforementioned outer diameter grooves 35A and 35B (see FIG. 3) do not exist, and the guide surface 27 is continuously arranged in the circumferential direction.

Further, the parting line (not shown) is provided along the axial direction in the groove portions 33A and 33B formed in the guided portions 26A and 26B, as described above.

According to the cage 23C of this modified example, the peripheral edge of the guide surface 27 is made into the chamfered portion 31, and the wear is less likely to proceed. In addition, the edge relief portion 37 recessed radially inward prevents the raceway surface edge 11a (see FIG. 1) from coming into contact with the cage 23, thereby preventing wear due to contact. Furthermore, since the guide surface 27 and the chamfered portion 31 become a shape transfer surface having a predetermined surface roughness, the wear resistance can be improved. And by providing the parting line used as a convex part (burr) in groove part 33A, 33B, a bearing will not receive the influence of a burr | flash and it can improve both durability and productivity of the holder | retainer 23B.

Further, the cage 23C is formed in the pocket 21 in which the surface shape having the predetermined surface roughness described above is transferred from the slide core 43.

According to the cage 23C of this modified example, the inner peripheral surface of the pocket 21 becomes a shape transfer surface having a predetermined surface property, so that the wear resistance can be improved and the durability of the cage 23C is enhanced.

Note that the above-described surface properties of the guide surface 27 and the chamfered portion 31 of the cage 23C and the inner peripheral surface of the pocket 21 may be formed on at least one of them, or may be formed on both. . When formed on both sides, the wear resistance and durability of the cage 23C can be further improved by a synergistic effect.

(Fourth modification)
FIG. 17 shows an external perspective view of a cage 23D having another configuration. The cage 23D is the same as the cage 23C of the third modified example described above except that it has a guided portion 26A that protrudes radially outward only at one axial end of the cage outer diameter portion.

According to the cage 23D of the present modified example, the cage 23D can have a simple structure, and the bearing can be affected by burrs by disposing the parting line serving as a convex portion (burr) in the groove portion 33A. Disappear. Therefore, both durability and productivity of the cage 23C can be improved.

Further, according to the cage 23D of the present modification, the cage 23D can be made simple, and the surface shape having the predetermined surface properties described above is transferred from the mold to the inner peripheral surface of the pocket 21. As a result, grease is supplied to the contact interface between the inner peripheral surface of the pocket 21 and the rolling element 19. Therefore, the durability of the cage 23D can be increased.

Note that the above-described surface properties of the guide surface 27 and the chamfered portion 31 of the cage 23D and the inner peripheral surface of the pocket 21 may be formed in at least one of them, or may be formed in both. . When formed on both sides, the wear resistance and durability of the cage 23D can be further improved by a synergistic effect.

Note that the rolling bearing of this configuration is not limited to an angular ball bearing, and may be another type of rolling bearing such as a cylindrical roller bearing, or may be a rolling element guide type rolling bearing. . For example, as shown in FIG. 18, the cage 23E is a ball 19 that is rotatably arranged in a tapered hole 21b formed in the pocket 21, or a rolling element guide type rolling bearing guided by rollers. May be.

As described above, the present invention is not limited to the above-described embodiments, and those skilled in the art can make changes and applications based on combinations of the configurations of the embodiments, descriptions in the specification, and well-known techniques. This is also the scope of the present invention, and is included in the scope for which protection is sought.

This application is a Japanese patent application filed on February 4, 2015 (Japanese Patent Application No. 2015-020736), a Japanese patent application filed on February 4, 2015 (Japanese Patent Application No. 2015-020737), and an application filed on February 2, 2016 Japanese Patent Application (Japanese Patent Application No. 2016-017836) and Japanese Patent Application (Japanese Patent Application No. 2016-017837) filed on Feb. 2, 2016, the contents of which are incorporated herein by reference.

11 outer ring raceway surface 13 outer ring 15 inner ring raceway surface 17 inner ring 19 ball (rolling element)
21 pocket 21a taper surface 22 stepped portion 23, 23A, 23B, 23C, 23D, 23E cage (roller bearing cage)
25A, 25B Guided portion 26A, 26B Guided portion 27 Guide surface 31 Chamfered portion 33A, 33B Groove portion 37 Edge relief portion 41 Outer mold 43 Slide core 100, 110, 120 Angular ball bearing (rolling bearing)
D Radial length of inner peripheral surface (radial thickness of cylindrical surface)

Claims (15)

1. A rolling bearing cage made of synthetic resin disposed between an inner ring and an outer ring of a rolling bearing,
   A plurality of guided portions protruding radially outward from the outer diameter surface are provided along the circumferential direction of the outer diameter surface,
   The guided portion is formed along the axial direction on a guide surface formed so as to be slidably contacted with the outer ring, a chamfered portion formed on an edge of the guide surface, and a part of the guide surface. A groove portion,
   The guide surface and the chamfered portion have a surface property with an arithmetic average roughness Ra of 1.0 to 9.8 μm and a maximum height Rt of 10.1 to 102.9 μm.
   A rolling bearing retainer, wherein a parting line is provided radially inward from the guide surface.
2. The rolling bearing retainer according to claim 1, wherein the parting line is provided on either the groove or the end face of the retainer.
3. The rolling bearing retainer according to claim 1 or 2, wherein the chamfered portion has a curved surface connected in a tangential direction to the edge portion of the guide surface.
4. 3. The rolling bearing according to claim 1, wherein the chamfered portion is connected to the edge portion of the guide surface and has an inclined surface having an angle of 20 ° or less with the guide surface. Cage.
5. 5. A relief groove recessed radially inward is formed in a region facing a raceway surface edge that is a boundary between an outer ring inner peripheral surface of the outer ring and an outer ring raceway surface. The rolling bearing retainer according to any one of the above.
6. 6. The amorphous layer which does not contain reinforcing fibers and has a thickness of 0.1 to 30 μm from the surface of the cage is formed on the surface layer of the cage. The rolling bearing retainer according to item.
7. A method for manufacturing a rolling bearing cage, wherein the rolling bearing cage according to any one of claims 1 to 6 is molded using a molding die.
   A method for manufacturing a rolling bearing retainer, wherein the shape of a processed surface provided on a mold surface of the molding die is transferred to at least one of the guide surface and the chamfered portion.
8. A rolling bearing retainer in which a pocket for freely rolling a plurality of rolling elements arranged between an inner ring raceway and an outer ring raceway of a rolling bearing is formed,
   The inner peripheral surface of the pocket has a surface property with an arithmetic average roughness Ra of 1.0 to 9.8 μm and a maximum height Rt of 10.1 to 102.9 μm.
   The inner circumferential surface of the pocket is a cylindrical surface along the radial direction of the cage, and the thickness of the cylindrical surface in the radial direction of the cage is 3.5 mm or less.
9. A rolling bearing retainer in which a pocket for freely rolling a plurality of rolling elements arranged between an inner ring raceway and an outer ring raceway of a rolling bearing is formed,
   The inner peripheral surface of the pocket has a surface property with an arithmetic average roughness Ra of 1.0 to 9.8 μm and a maximum height Rt of 10.1 to 102.9 μm, from the inner peripheral side toward the outer peripheral side. A cage for a rolling bearing, characterized by a tapered surface that expands in diameter.
10. The rolling according to claim 8 or 9, wherein an amorphous layer containing no reinforcing fibers and having a thickness from the surface of the cage of 0.1 to 30 µm is formed on the surface of the cage. Bearing cage.
11. The rolling bearing cage according to any one of claims 8 to 10, further comprising a stepped portion that expands or contracts the inner diameter of the pocket on at least one of the cage inner diameter side and the cage outer diameter side.
12. A method for manufacturing a rolling bearing cage, wherein the rolling bearing cage according to any one of claims 8 to 11 is injection-molded using a molding die.
    A method for manufacturing a rolling bearing cage, wherein the pocket is formed by a slide core of the molding die.
13. The method for manufacturing a rolling bearing cage according to claim 12, wherein the shape of the processed surface provided on the mold surface of the molding die is transferred to the inner diameter surface of the pocket.
14. 14. The rolling bearing cage according to claim 12, wherein the surface of the slide core that forms the inner peripheral surface of the pocket is formed by any one of shot peening, electric discharge machining, and etching. Production method.
15. A rolling bearing comprising the rolling bearing cage according to any one of claims 1 to 6 and claims 8 to 11.

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