JP7155601B2 - Rolling bearing resin retainer, manufacturing method thereof, and rolling bearing - Google Patents

Description

TECHNICAL FIELD The present invention relates to a resin retainer for a rolling bearing and a method of manufacturing the retainer by injection molding. The present invention also relates to a rolling bearing including the resin retainer.

Resin cages are generally manufactured by injection molding. As a retainer, for example, a crown-shaped retainer 100 as shown in FIG. 13 is known. A plurality of pillars 120 protruding in the axial direction at predetermined intervals in the base 110 , and a pocket 130 is formed by the surfaces 122 , 122 of the pair of adjacent pillars 120 , 120 facing each other and the side surface 112 at one axial end of the base 110 . to form In order to manufacture this crown-shaped retainer 100 by injection molding, as shown in FIG. 13, a mold is used in which a cavity 140 having a shape corresponding to the base portion 110, the column portion 120 and the pocket 130 is formed. , a gate 150 is provided at a position corresponding to the column portion 120, and the molten resin composition is allowed to flow in and solidify by cooling.

In such injection molding, the molten resin composition supplied from the gate 150 flows horizontally in the cavity 140 as indicated by the arrows in FIG. A joint surface (hereinafter referred to as a "weld line W") is formed when they meet and solidify. It is known that the strength decreases at this weld line W, and when reinforcing fibers such as carbon fibers and glass fibers are blended into the molten resin composition, the reinforcing fibers at this meeting part cause the molten resin composition to flow. It is oriented perpendicular to the direction, and the reinforcing effect is not sufficiently exhibited. Moreover, in portions other than the weld line W, the reinforcing fibers are oriented parallel to the flow direction of the molten resin composition, resulting in a large difference in strength from the weld line W.

As described above, a resin retainer manufactured by injection molding is often damaged from the weld line W. Therefore, a resin pool is provided at or near the meeting part of the molten resin composition, and the resin is melted in the resin pool. A clear weld line W is prevented from being formed by allowing the resin composition to flow in to disturb the flow of the molten resin composition.

In addition, the present applicant also disclosed in Patent Documents 1 and 2 that the cross-sectional area of the communicating portion between the resin reservoir and the cavity is set to 1/4 or less of the cross-sectional area of the gate, thereby further reducing the strength reduction at the weld line W. I suggest reducing it.

JP 2016-50616 A JP 2016-75295 A

In Patent Documents 1 and 2, the ratio between the cross-sectional area of the communicating portion of the resin reservoir and the cross-sectional area of the gate is defined. becomes smaller, the cross-sectional area of the communicating portion of the resin reservoir becomes excessively small, and the molten resin composition solidifies at the opening of the communicating portion before the molten resin composition flows. As a result, sufficient turbulence cannot be caused in the flow of the molten resin composition, and the effect of suppressing the occurrence of weld lines may not be obtained sufficiently.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of manufacturing a resin retainer by injection molding, which can further suppress the occurrence of weld lines even when the retainer has a small diameter. and Another object of the present invention is to provide a high-strength resin cage capable of suppressing damage to the cage due to a decrease in strength at the weld position. Another object of the present invention is to provide a rolling bearing having a high-strength resin retainer and excellent durability.

In order to achieve the above objects, the present invention provides the following resin retainer for rolling bearing, method for manufacturing the same, and rolling bearing.
(1) A substantially annular base, a plurality of pillars protruding in the axial direction at predetermined intervals in the circumferential direction from one axial end side surface of the base, and surfaces of a pair of adjacent pillars facing each other. A resin retainer having the same number of pockets as the pillars formed by one axial end side surface of the base,
A first cut mark and a second cut mark are formed on the circumferential surfaces of the pillars on both sides of the weld line in the circumferential direction,
Further, the resin retainer is characterized in that the cut surface of the first cut marks and the cut surface of the second cut marks have different areas on the circumferential surface of the retainer.
(2) The resin cage according to (1) above, wherein the weld line is located below the pocket of the base portion and away from the deepest position of the pocket.
(3) The resin retainer according to (1) or (2) above, which has a third cut mark in the vicinity of a position radially opposite to the weld line.
(4) A rolling bearing in which a plurality of rolling elements are rotatably held by a retainer between an inner ring and an outer ring,
A rolling bearing, wherein the retainer is the resin retainer according to any one of (1) to (3) above.
(5) A substantially annular base, a plurality of pillars protruding in the axial direction at predetermined intervals in the circumferential direction from one axial end side surface of the base, and surfaces of a pair of adjacent pillars facing each other. In the method of manufacturing a resin retainer having a pocket formed by one axial end side surface of the base by injection molding a molten resin composition containing a resin and reinforcing fibers,
A cavity having a base-corresponding portion having a shape corresponding to the base, a column-corresponding portion having a shape corresponding to the column, and a pocket-corresponding portion having a shape corresponding to the pocket is formed, and the single gate Provided in contact with the column equivalent part,
On both sides in the circumferential direction of an imaginary line connecting the gate and a position diametrically opposed to the gate, a first resin reservoir is provided in one of the column-corresponding portions, and a second resin is provided in the other column-corresponding portion. The reservoirs are respectively attached, and the opening area of the communicating portion of the first resin reservoir with the column-corresponding portion of the retainer peripheral surface and the column-corresponding portion of the second resin reservoir. using a molding die in which the opening area of the communicating portion of the cage is different from
A method of manufacturing a resin retainer for a rolling bearing, characterized in that the molten resin composition is injected from the gate toward the portion corresponding to the column portion of contact.
(6) The resin retainer for a rolling bearing according to (5) above, characterized in that both the first resin reservoir and the second resin reservoir are provided radially outside the portion corresponding to the base portion. The method of making the vessel.
(7) The resin retainer for a rolling bearing according to (5) above, wherein both the first resin reservoir and the second resin reservoir are provided radially inside the portion corresponding to the base portion. The method of making the vessel.
(8) The first resin reservoirs are provided to face each other across the portion corresponding to the column, and the second resin reservoirs are provided to face each other across the portion corresponding to the column. A method for manufacturing a resin retainer for a rolling bearing according to (5) above, characterized in that:
(9) The difference between the diameter of the equivalent circle corresponding to the opening area of the first resin pool and the diameter of the equivalent circle corresponding to the opening area of the second resin pool is 0.5 mm or more. A method for manufacturing a resin retainer for a rolling bearing according to any one of (5) to (8) above, characterized in that:

According to the present invention, at the meeting position (weld position) of the molten resin composition, the orientation of the reinforcing fibers in the molten resin composition is mainly horizontally oriented reinforcing fibers, and at the meeting position of the molten resin composition A decrease in strength can be suppressed, and a high-strength resin cage can be obtained. Further, according to the present invention, since the high-strength resin retainer is provided, a rolling bearing having excellent durability can be obtained.

It is a schematic diagram which shows the cavity of the molding die used by the manufacturing method of this invention, and its peripheral member. It is the figure which looked at the cavity and the resin pool from the base equivalent part side of the cavity. FIG. 3 is a schematic diagram for explaining the flow state (fountain flow) of the molten resin composition in the cavity. 4(a) and 4(b) are schematic diagrams for explaining the orientation state of reinforcing fibers. FIG. FIG. 4 is a schematic diagram for explaining the flow state of the molten resin composition around the communicating portion of the large-opening resin reservoir. FIG. 4 is a diagram for explaining the flow state of the molten resin composition around the meeting position; It is a schematic diagram which shows the periphery of a resin pool about 2nd Embodiment of the manufacturing method of this invention. It is a schematic diagram which shows the periphery of a resin pool about 3rd Embodiment of the manufacturing method of this invention. (A) is a perspective view showing a first embodiment of the resin cage of the present invention, and (B) is an enlarged view around a weld line. (A) is a perspective view showing a second embodiment of the resin retainer of the present invention, and (B) is an enlarged view around the weld line. FIG. 10 is a diagram showing a third embodiment of the resin retainer of the present invention, showing the periphery of the weld line. It is a figure which shows the result of having simulated the flow of molten resin composition, and it flows in order of (A) -> (B) -> (C). It is a perspective view which shows an example of a crown-type holder|retainer. FIG. 14 is a schematic diagram for explaining a conventional method of manufacturing the crown-shaped retainer shown in FIG. 13 by injection molding;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings, and description will be given by exemplifying the crown-shaped retainer shown in FIG. 13 as a retainer. First, the manufacturing method will be described.

(First embodiment)
As shown in FIGS. 1 and 2, the cavity 100A corresponds to a base portion 110A corresponding to the base portion 110 of the crown retainer 100 shown in FIG. 130A corresponding to the pocket.

A gate 10 is connected to the inner peripheral side of one column portion 120A of the cavity 100A. It is supplied to cavity 100A. Then, as indicated by the arrows in the figure, the molten resin composition 30 splits into two directions from the gate 10 to form a molten resin composition 30a and a molten resin composition 30b, which fill the left and right halves of the cavity 100A. They flow respectively and meet in the vicinity of the position opposite to the gate 10 in the circumferential direction.

The molten resin composition 30 contains resin and reinforcing fibers. As the resin, a thermoplastic resin can be used, but since the strength of the resin itself is excellent, polyamide resin, polybutylene terephthalate, polyphenylene sulfide (PPS), polyether ether ketone (PEEK), polyether nitrile (PEN ), etc., and appropriate amounts of antioxidants, lubricants, antistatic agents, plasticizers, curing agents, curing aids, and the like may be added.

There is no restriction on the reinforcing fiber, and glass fiber, carbon fiber, metal fiber, etc. can be blended in the range of 50% by mass or less of the total amount with the resin. If the content exceeds 50% by mass, there is a concern that the fluidity of the molten resin composition will decrease. Further, the fiber diameter is preferably 5 to 13 μm from the viewpoint of the strength of the obtained resin cage. Furthermore, considering the adhesiveness to the resin, it is preferable that the surface is treated with a coupling agent, a sizing agent, or the like.

In addition, various compounds contained in the resin cage may be added.

As shown in FIG. 2, assuming that a line passing through the gate 10 and a position diametrically opposed to the gate 10 is a virtual line X, adjacent column-corresponding portions 120A1 and 120A2 on both sides of the virtual line X in the circumferential direction Resin reservoirs 15 and 16 are provided respectively. The resin reservoirs 15 and 16 are connected to the column-like portions 120A1 and 120A2 facing each other through the communication portions 17 and 18, respectively. Communicating portions 17 and 18 are connected to central portions of widths of column portions 120A1 and 120A2 facing each other in the circumferential direction. Moreover, the capacities of the resin reservoirs 15 and 16 may be the same or different.

Further, the communication portion 17 of the resin reservoir 15 on one side and the communication portion 18 of the resin reservoir 16 on the other side have different opening sizes on the side corresponding to the column portion. In the example of FIG. 2, the opening area of the communicating portion 17 of the resin pool 15 on the peripheral surface of the retainer is large. 15 is referred to as a "large opening resin reservoir 15", and the resin reservoir 16 having a smaller opening area on the peripheral surface of the retainer of the communicating portion is referred to as a "small opening resin reservoir 16".

The difference in size between the opening 19 of the large-opening resin pool 15 and the opening 20 of the small-opening resin pool 16 is defined by D1 being the diameter of an equivalent circle corresponding to the opening area of the communicating portion 17 on the retainer peripheral surface, and D1 being the diameter of the communicating portion 18. Assuming that the diameter of an equivalent circle corresponding to the opening area on the retainer peripheral surface is D2, the difference between D1 and D2 is preferably 0.5 mm or more.

By the way, it is known that a molten resin composition flowing in a flow path becomes "fountain flow". As shown in FIG. 3, in this fountain flow, the molten resin composition 30 has the highest flow velocity in the center of the cavity 100A and has a flow velocity distribution in which the flow velocity gradually decreases toward the wall surface of the cavity 100A. In addition, as indicated by symbol F in the drawing, the molten resin composition 30 is in a flowing state in which it flows from the center of the tip toward the wall surface of the cavity 100A in the direction opposite to the flow direction. In injection molding, the mold is cooled to solidify the molten resin composition 30. At this time, the wall surface of the cavity 100A is solidified to form a solidified layer 33 called a "skin layer." Gradually grow thicker.

In addition, as shown in FIG. 4A, the reinforcing fibers 35 mixed in the molten resin composition 30 have a high flow velocity at the center of the flow, so the reinforcing fibers 35 located at the center of the cavity 100A It is oriented almost parallel to the wall surface. However, the closer the molten resin composition 30 is to the wall surface of the cavity 100A, the slower the flow velocity is, and the flow velocity is slower in the portion where the solidified layer 33 is not formed because the flow path is wider than the portion where the solidified layer 33 is formed. Furthermore, since the flow is opposite to the flow direction near the tip, the closer the reinforcing fiber 35 is to the tip of the molten resin composition 30, the greater the inclination from the horizontal. Further, the reinforcing fibers 35 with a large inclination act as resistance to the flow, further slowing down the flow velocity. As a result, as shown in FIG. 4(b), in the vicinity of the tip of the molten resin composition 30, the reinforced fibers 35 (indicated by reference numeral 35A) with a large inclination and the slow reinforced fibers 35 from the upstream side (left side in the figure) The reinforcing fibers 35 collide one after another, and the reinforcing fibers 35 are bent and sometimes broken at the bent portion. In the following description, the reinforcing fibers 35 that are greatly bent or broken are referred to as "broken reinforcing fibers 35".

Further, when the resin pool is arranged closer to the gate 10 than the imaginary line X, a part of the molten resin composition 30 near the opening of the resin pool flows into the resin pool. In addition, since the flow velocity of the molten resin composition 30 increases near the opening of the resin pool, it becomes difficult to form the solidified layer 33 and the molten resin composition 30 flows more easily. Also, the larger the opening of the resin reservoir, the easier it is for the molten resin composition 30 to flow.

The molten resin composition 30 containing the reinforcing fibers 35 is in such a fluid state. In the present invention, since the large-opening resin pool 15 and the small-opening resin pool 16 are provided, as shown in FIG. A part of 30 a flows into the large opening resin pool 15 . Along with this, part of the molten resin composition 30b flowing in the cavity 100A on the left half circumference side in the figure where the small-opening resin pool 16 is arranged flows up to the opening 19 of the large-opening resin pool 15, and reaches the center of the opening 19. In the vicinity Y, it associates with the molten resin composition 30a. In both the molten resin compositions 30a and 30b, there are many reinforcing fibers 35 with a large inclination angle and many broken reinforcing fibers 35 in the vicinity of each tip, and many of these reinforcing fibers 35 flow into the large-opening resin pool 15. do. In addition, when the molten resin composition 30a and the molten resin composition 30b are associated, the reinforcing fibers 35 collide with each other, break, and flow into the large-opening resin pool 15. As shown in FIG. In this way, most of the broken reinforcing resin 35 flows into the large-opening resin pool 15, and the large-opening resin pool 15 functions as a collection section for the broken reinforcing fibers 35. As shown in FIG.

When the large-opening resin pool 15 is filled with the molten resin composition 30, the molten resin composition 30a flows toward the small-opening resin pool 16 as shown in FIG. As a result, the molten resin composition 30 ceases to flow in the vicinity of the opening 19 of the large-opening resin pool 15, so that the solidified layer 33 is formed to close the opening 19, and the solidified layer 33 grows thicker. Therefore, the flow path from the opening 19 of the large-opening resin reservoir 15 to the small-opening resin reservoir 16 becomes narrower, the flow velocity of the molten resin composition 30a increases, and the inclination of the reinforcing fibers 35 becomes small and almost horizontal.

A solidified layer 33 is also formed between the large-opening resin pool 15 and the small-opening resin pool 16, and the flow path is narrowed. A molten resin composition 30a in which many reinforcing fibers 35 are present flows. Therefore, in the small-opening resin pool 16, compared with the large-opening resin pool 15, the number of broken reinforcing fibers 35 is greatly reduced. The opening 20 of the small opening resin reservoir 16 is closed with the solidified layer 33 after being filled.

Since the large-opening resin pool 15 and the small-opening resin pool 16 are equidistant from the virtual line X, after both the resin pools 15 and 16 are filled, the molten resin composition 30a and the molten resin composition 30b meet near the imaginary line X to keep the balance. As described above, in both the molten resin compositions 30a and 30b flowing around the imaginary line X, the reinforcing fibers 35 have a small inclination and are mainly horizontal, and even if they are associated, the reinforcing fibers may collide with each other. less and less breakage. Therefore, at the meeting position (weld position), the horizontally oriented reinforcing fibers 35 are the main component, and it is possible to suppress the decrease in strength at the position where the molten resin compositions 30a and 30b meet, and a high-strength resin cage can be obtained. can get.

Since the size of the opening of the gate 10 is not limited in the present invention, it is also effective in manufacturing a small-diameter resin cage.

(Second embodiment)
In the first embodiment, both the large-opening resin pool 15 and the small-opening resin pool 16 are arranged on the radially outer peripheral side of the base-corresponding portion 110A, but are arranged on the radially inner peripheral side as shown in FIG. You can also In this case also, the diameter D1 of the equivalent circle of the opening 19 of the large opening resin reservoir 15 and the diameter D2 of the equivalent circle of the opening 20 of the small opening resin reservoir 16 are different, preferably 0.5 mm or more.

(Third Embodiment)
As shown in FIG. 8, the large-opening resin pool 15 and the small-opening resin pool 16 are arranged to face both the radially inner peripheral side and the radially outer peripheral side with the base-corresponding portion 110A interposed therebetween. can also With such a facing arrangement, the recovery rate of the broken reinforcing fibers 35 can be increased, and the inclination of the reinforcing fibers 35 can be made smaller, so that the reduction in strength at the meeting position can be further suppressed.

According to the manufacturing methods of Embodiments 1 and 2 described above, for example, a crown-shaped retainer as shown below is obtained. In addition, as shown in FIG. 1, the case where the gate 10 is installed on the inner peripheral side of the base portion corresponding portion 100A and the large opening resin pool 15 and the small opening resin pool 16 are installed on the outer peripheral side of the column portion corresponding portion 120A will be described. .

In the crown-shaped retainer 100 shown in FIG. 9, the same number of odd-numbered pockets and odd-numbered pillars are provided. A cut trace 160 derived from the large-opening resin pool 15 is formed on one of the columns 120a and 120b, and a cut trace 170 derived from the small-opening resin pool 16 is formed on the other column 120b. The areas of the two cut marks 160, 170 on the circumferential surface of the retainer are different.

In addition, as shown in the figure, the crown-shaped retainer 100 is also formed with a cut mark 180 originating from the gate 10 .

Incidentally, FIG. 9B is an enlarged view of the periphery (encircled portion) of the weld line W in FIG. It has a convex curved shape.

The position of the weld line W can be changed according to the position of the gate 10 and the flow conditions (flow velocity, viscosity, etc.) of the molten resin composition 30 . In the crown-shaped retainer 100 shown in FIG. 9, the weld line W is formed in the center of the width of the pocket 130a of the base 110, that is, in the vicinity of the deepest position. 15 can be displaced to the side of the column portion 120a on which the cut mark 160 derived from 15 is formed. The thicker the base portion 110, the higher the strength. Therefore, the closer to the pillars 120a and 120b than the deepest position of the pocket 130a, the higher the strength. Therefore, by bringing the weld line W closer to the column portion 120a, the crown-type retainer 100 with higher strength can be obtained. The same effect can be obtained by displacing the weld line W toward the column portion 120b where the cut marks 170 originating from the small opening resin reservoir 16 are formed.

Incidentally, in the crown-shaped retainer 100 shown in FIG. 10, the same number of odd-numbered pockets and the same number of odd-numbered pillars are provided. FIG. 10(B) is an enlarged view of the periphery (encircled portion) of the weld line W in FIG. 10(A). It has a curved shape.

For the same reason, forming the weld line W in the column portion 120 can further increase the strength. In this case, if the number of pillars and pockets is the same and even, and the gate is provided at an arbitrary position of the pillar, the position facing the gate becomes the pillar. A weld line W is formed in the pillar facing the gate in the obtained crown-shaped retainer.

Specifically, FIG. 11 shows the peripheral portion of the weld line W, and the weld line W is formed in the pillar portion 120c facing the gate. With this pillar 120c interposed therebetween, a cut mark 160 derived from a large opening resin pool is formed on one adjacent pillar 120a, and a cut mark 170 derived from a small opening resin pool is formed on the other adjacent pillar 120b. It is formed. That is, the large-opening resin pool and the small-opening resin pool are provided symmetrically with respect to the imaginary line connecting the gate and the position facing the gate. In addition, the weld line W has a curved shape that protrudes toward the cut mark 160 originating from the large-opening resin pool.

(simulation)
Also, a simulation was conducted on the method for manufacturing the retainer of the present invention. In addition, the mold cavity has an annular shape with only a portion corresponding to the base portion 110A without the portion corresponding to the column portion 120A and the portion corresponding to the pocket 130A. provided at intervals. The large-opening resin pool 15 and the small-opening resin pool 16 have the same capacity, D1 is 1.5 mm, and D2 is 0.5 mm. The molten resin composition was assumed to be a polyamide resin composition containing 25% by mass of glass fiber, and the amount supplied from the gate 10 was set at 10 cc/s. "3D TIMON" was used as analysis software.

The results are shown in FIG. 12. As shown in FIG. 12A, the molten resin composition 30 supplied from the gate 10 flows toward the position facing the gate 10 in the radial direction. Then, it first flows into the large-opening resin pool 15 as shown in FIG. 1B, and then flows into the small-opening resin pool 16 when the large-opening resin pool 15 is filled as shown in FIG. 1C.

As described above, the resin cage and the manufacturing method thereof according to the present invention have been described by exemplifying the crown type cage 100 as shown in FIG. It can also be applied to manufacture of various cages.

The present invention also relates to a rolling bearing provided with such a high-strength resin cage. That is, although illustration is omitted, a rolling bearing can be formed in which a plurality of rolling elements are rotatably held by, for example, the crown-shaped resin cage 100 between the inner ring and the outer ring. Further, since the crown-type retainer 100 has high strength as described above, the rolling bearing of the present invention is excellent in durability.

10 gate 11 sprue 12 liner 15 large-opening resin reservoir 16 small-opening resin reservoirs 17, 18 communicating parts 19, 20 openings 30, 30a, 30b molten resin composition 33 solidified layers 35, 35A reinforcing fiber 100 crown-shaped retainer 110 base 120 , 120a, 120b, 120c Columns 130, 130a Pockets 160, 170 Cut marks 100A Cavity 110A Base equivalents 120A, 120A1, 120A2 Columns equivalent 130A Pockets equivalent

Claims (9)

A substantially annular base, a plurality of pillars protruding in the axial direction at predetermined intervals in the circumferential direction from one axial end side surface of the base, surfaces of a pair of adjacent pillars facing each other, and the base. A resin retainer having the same number of pockets as the column portions formed by one axial end side surface and containing reinforcing fibers ,
A first cut mark and a second cut mark are formed on the peripheral surface of the pillar on both sides of the weld line in the circumferential direction and closest to the weld line,
Further, the resin retainer is characterized in that the cut surface of the first cut marks and the cut surface of the second cut marks have different areas on the circumferential surface of the retainer. 2. The resin retainer according to claim 1, wherein the weld line is located below the pocket of the base and away from the deepest position of the pocket. 3. The resin cage according to claim 1, further comprising a third cut mark in the vicinity of a position radially facing the weld line. A rolling bearing in which a plurality of rolling elements are held between an inner ring and an outer ring so as to be free to roll by a retainer,
A rolling bearing, wherein the retainer is the resin retainer according to any one of claims 1 to 3. A substantially annular base, a plurality of pillars protruding in the axial direction at predetermined intervals in the circumferential direction from one axial end side surface of the base, surfaces of a pair of adjacent pillars facing each other, and the base. A method for manufacturing a resin retainer having a pocket formed by one axial end side surface by injection molding a molten resin composition containing a resin and reinforcing fibers,
A cavity having a base-corresponding portion having a shape corresponding to the base, a column-corresponding portion having a shape corresponding to the column, and a pocket-corresponding portion having a shape corresponding to the pocket is formed, and the single gate Provided in contact with the column equivalent part,
One of the pair of column-corresponding portions closest to the imaginary line on both sides in the circumferential direction of the imaginary line connecting the gate and the position diametrically opposed to the gate has a first A resin reservoir and a second resin reservoir are attached to the other column-corresponding part, respectively, and the open area of the portion of the first resin reservoir communicating with the column-corresponding part on the peripheral surface of the retainer. and a molding die having a different opening area on the peripheral surface of the retainer at a portion communicating with the column-corresponding portion of the second resin reservoir,
A method of manufacturing a resin retainer for a rolling bearing, characterized in that the molten resin composition is injected from the gate toward the portion corresponding to the column portion of contact. 6. The manufacturing of a resin retainer for a rolling bearing according to claim 5, wherein both the first resin pool and the second resin pool are provided radially outside the portion corresponding to the column portion. Method. 6. The manufacturing of a resin retainer for a rolling bearing according to claim 5, wherein both the first resin pool and the second resin pool are provided radially inside the portion corresponding to the column portion. Method. The first resin reservoir is provided oppositely across the portion corresponding to the column, and the second resin reservoir is provided oppositely across the portion corresponding to the column. The manufacturing method of the resin cage for rolling bearings according to claim 5. A difference between a diameter of an equivalent circle corresponding to the opening area of the first resin pool and a diameter of an equivalent circle corresponding to the opening area of the second resin pool is 0.5 mm or more. The method for manufacturing a resin cage for a rolling bearing according to any one of claims 5 to 8.

Images