JPH08296652A - Resin cage for ball bearing - Google Patents

Abstract

PURPOSE: To reduce the oscillation of a cage by reducing the pushing force of a roller into a pocket. CONSTITUTION: A cage 1 is provided with a narrow part 5a whose section is smaller than that of other parts in one part in the longitudinal direction of a column 5 between pockets 3, 3. The side of each column 5 is formed of cylindrical surface shape along the outer diameter surface of a roller 2, and the width W1 of an opening of the pocket 3 is smaller than the outer diameter D of the roller 2. The narrow part 5a is made by reducing the width of the column of the part corresponding to an opening edge of the pocket 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called push-in type resin cage for roller bearings, in which the pushing force when assembling rollers is reduced.

[0002]

2. Description of the Related Art Conventionally, a window type shown in FIG. 6 has been generally used as a resin retainer for a cylindrical roller bearing. The cage 51 is formed in a cylindrical shape, and is formed by arranging a plurality of pockets 53 formed of through holes for holding the rollers 52. The side surface of each pillar 54 between the pockets 53, 53 is
The roller 52 is formed into a cylindrical surface shape along the outer diameter surface of the roller 52.
Does not fall from the opening of the pocket 53. Therefore, the width dimension C of the opening of the pocket 53, which serves as the roller inlet, is smaller than the outer diameter dimension D of the roller 52. At the time of assembly, the roller 52, as shown by the white arrow,
The cage 51 is pushed from the inner diameter side of the cage 51 into the pocket 53, and the elasticity of the resin of the cage 51 causes the column 54 to bend so that the rollers 52
It is possible to enter.

[0003]

As described above, the roller 52
Is pushed into the pocket 53, and when the difference between the width C of the opening and the roller outer diameter D becomes large, the roller 5
2 is difficult to enter the cage 51. The tendency becomes stronger for large products. When the opening width dimension C is increased, the rollers 52 are easily inserted, but the radial deflection of the cage 51 when incorporated in the bearing is increased, which causes problems of vibration and noise. Therefore, it is not preferable to widen the opening width dimension C.

The present invention solves the above-mentioned problems and reduces the roller pushing force into the pocket to facilitate the pushing operation, while reducing the play of the roller in the pocket, thereby retaining the cage. An object of the present invention is to provide a resin retainer for roller bearings that can reduce runout of the roller bearing.

[0005]

In the resin retainer for roller bearings according to the present invention, a plurality of pockets each having a through hole for holding the roller are provided side by side, and the width of the pocket opening is smaller than the outer diameter of the roller. In the cage described above, a narrow portion having a cross section smaller than that of the other portion is provided in a part of the column between the pockets in the longitudinal direction. The side surface of each pillar is generally formed in a cylindrical surface shape along the outer diameter surface of the roller, but in that case, the narrow portion should be a narrow pillar width of the portion corresponding to the opening edge of the pocket. Is preferred. Further, it is preferable that the narrow portion is provided at the center of the column in the longitudinal direction. The narrow portion may be formed by narrowing only the opening edge on one side of the pocket. This roller bearing resin retainer may be applied to a cylindrical retainer or the like used in a cylindrical roller bearing.

[0006]

According to this structure, since the column between the pockets is provided with the narrow portion and is partially thinned, the pushing force for inserting the roller into the pocket is reduced. Therefore, if the pushing force is the same, the difference between the pocket opening width and the outer diameter can be made larger than that of a conventional cage that does not have a narrow portion, and the cage due to the play of the rollers in the pocket can be increased. It is possible to reduce the fluctuation of the. Since the narrow portion provided in the pillar is only a part in the longitudinal direction, the function of holding the rollers in the pocket is not deteriorated in practical use. When the side surface of each pillar is formed in a cylindrical surface shape along the outer diameter surface of the roller, the narrow width portion has a narrowed pillar width only in the portion corresponding to the opening edge of the pocket in the pillar thickness. It is preferable that As a result, the decrease in column strength is suppressed. In this case, in the narrow portion, the portions corresponding to the opening edges on both sides of the pocket may be formed narrow, but since the pushing direction of the roller is fixed, only the portion corresponding to the opening edge on one side is formed. By forming the width narrow, the pushing force can be reduced, and the strength of the column can be maintained by reducing the extent to which the cross section of the column becomes small as much as possible.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIGS. This embodiment is applied to a window type cage for guiding rolling elements in a cylindrical roller bearing. The cage 1 is a resin-made cylindrical body integrally formed by injection molding, and a plurality of pockets 3 formed of through holes for holding the rollers 2 are formed at equal intervals on a peripheral wall portion.
By forming these pockets 3, the cage 1 is constituted by the ring portions 4 and 4 on both sides and the pillars 5 between the pockets 3. The side surface of each pillar 5 is formed in a cylindrical surface shape along the outer diameter surface of the roller 2, and the width dimensions W1 and W2 of the opening inside and outside the pocket 3 are both smaller than the outer diameter dimension D of the roller 2. Has become.

In this cage 1, a narrow portion 5a having a smaller cross section than the other portions is provided at the center of the pillar 5 between the pockets 3 in the longitudinal direction. The length of the narrow portion 5a is about 1/3 of the length of the pillar 5. This narrow portion 5a is
The column width of the portion corresponding to the opening edge of the pocket 3 is narrowed. That is, the normal width portion of the pillar 5 has a cross-sectional shape in which both side surfaces are cylindrical and the central portion of the plate thickness (the portion on the pitch circle PCD) has the narrowest width, and the inner and outer sides gradually expand. However, the narrow portion 5a has a shape in which the portion corresponding to the pocket opening edge of the pillar 5 is cut out so that the side surface of the pillar 5 is a flat surface. In the narrow portion 5a, the side surfaces of the columns 5 and 5 on both sides of the pocket 3 are parallel to each other.

According to the cage 1 having this structure, the roller 2 is pushed from the inner diameter surface to be housed in the pocket 3 as shown in FIG. 1 (C), but the narrow width portion 5a is provided on the column 5 to partially thin it. The column 5 is easily bent as shown in the figure, and the pushing force of the roller 2 is small. Therefore, if the pushing force is the same, compared to a conventional cage that does not have the narrow portion 5a,
The difference between the opening width dimension W1 of the pocket 3 and the outer diameter dimension D of the pocket 2 can be increased, and the deflection of the cage 1 due to the play of the roller 2 in the pocket 3 can be reduced. That is,
The radial movement amount F of the cage 1 is the distance from the position where the roller 2 is in the center of the pocket to the radial direction until it hits the inner surface of the pocket, and is the difference between the outer diameter D of the roller 2 and the inner diameter of the pocket. Although proportional to each other, as described above, since the difference between the opening width dimension W1 and the outer diameter dimension D can be increased, the movement amount F decreases. Since the narrow portion 5a provided on the pillar 5 is only a part in the longitudinal direction, there is practically no problem with the decrease in the function of holding the roller 2 in the pocket 3 and the decrease in the strength of the pillar 5. The effect of reducing the pushing force is particularly effective in the case of a large bearing. For example, it is effective in the case of a bearing having a diameter of 100 mm or more, preferably 150 mm or more.

In the above embodiment, the narrow portion 5a of the pillar 5 is used.
1A, the width dimension is narrowed at the opening edges on both the inside and outside of the pocket 3 as shown in FIG. 1A. However, the narrow portion 5a has only the opening edge outside the pocket 3 as shown in FIG. The width may be narrow, or the width may be narrow only at the opening edge inside the pocket 3 as shown in FIG. Figure 2
When the outer diameter side is formed to be narrow as in the example of Fig. 3, the roller 2 is pushed in from the outer diameter side, and when the inner diameter side is formed to be narrow as in the example of Fig. 3, the roller 2 is inserted from the inner diameter side. Try to push it in. The examples of FIGS. 2 and 3 are the same as the example of FIG. 1 except that the cross-sectional shape of the narrow portion 5a is different.

Further, although the above-mentioned respective embodiments have been described in the case of being applied to the cage of the cylindrical roller bearing, the present invention will be described with reference to FIG.
The cage 1A in the needle roller bearing shown in FIG.
Cage 1B for the tapered roller bearing of (B) and FIG. 4 (C)
It is also applicable to the cage 1C for thrust roller bearings. Furthermore, the present invention can also be applied to a cage 1D for holding rollers in a linear motion bearing as shown in FIG. 4 and 5, parts corresponding to those in the example of FIG. 1 are designated by the same reference numerals, and description thereof will be omitted.

Next, the cage 1 in these examples
1D material examples will be described. The resin used for the cages 1 to 1D in each of the above-described examples may be any resin that can be injection-molded, and if the composition is such that it can be injection-molded even when fibers and other fillers are mixed. good. For example, the following materials can be used as the material of the cage. That is, as the fluororesin, polytetrafluoroethylene (PTF
E), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-ethylene copolymer (ETFE), etc. are used, and polyamide (nylon 66 (PA66), nylon 6 (PA6), Nylon 46 (PA46)), cloth-containing phenol resin, etc. can also be used. Polyamide is preferable because it is easily elastically deformed when the roller is pushed. In addition, a composition obtained by adding an organopolysiloxane elastomer and a fibrous reinforcing material to a polyphenylene sulfide resin, or a polycyanoaryl ether resin such as polyether nitrile as a main component, tetrafluoroethylene resin, graphite, glass A material to which an appropriate amount of filler such as fiber is added can be used.

Further, a perfluoroalkoxy resin containing heat resistant fibers is also preferable, and the heat resistant fibers are contained in an amount of 5 to 40% by weight.
And 30 to 90% by weight of perfluoroalkoxy resin,
One or more powder additive materials 5 to 3 selected from molybdenum powder, molybdenum compound powder and calcium compound powder
A composition containing 0% by weight is also preferable. Specific examples of the heat-resistant fiber in this case, glass fiber, carbon fiber, graphite fiber, wollastonite, potassium titanate whiskers, silicon carbide whiskers, inorganic fibers and whiskers such as sapphire whiskers, steel wire, copper wire Examples include metal fibers such as stainless wires, tungsten fibers or carbon fibers, so-called boron fibers obtained by vapor deposition of polon, silicon carbide, etc., composite fibers such as silicon carbide fibers, and heat-resistant organic fibers such as aromatic polyimide fibers. I can. From the viewpoint of ease of injection molding, the fiber is preferably a fibrous powder having a length of 10 mm or less, preferably 6 mm or less, and a diameter of 2 to 15 μm. It is also desirable to treat the fibers with a treating agent such as a silane coupling agent for the purpose of increasing the affinity between the fibers and the resin.

The molybdenum compound powder in this composition is a variety of molybdenum divalent to hexavalent compounds such as molybdenum disulfide and molybdenum trioxide. Examples of the calcium compound powder include calcium fluoride, calcium carbonate, calcium oxide and the like. The particle size of the above powder and molybdenum powder is preferably 50 μm or less in order to improve the mechanical durability and lubricity of the cage. Here, the amount of the heat-resistant fiber added to the perfluoroalkoxy resin is 50 to 95 perfluoroalkoxy resin, with the total weight of the components being 100.
The heat-resistant fibers are preferably 5% to 50% by weight, and more preferably the perfluoroalkoxy resin is 60 to 90% by weight and the heat-resistant fibers are 10 to 40% by weight. This is because when the amount of the heat-resistant fiber added is less than 5% by weight, improvement in mechanical properties and abrasion resistance of the composition can hardly be expected, and when it is more than 50% by weight, moldability deteriorates. This is because it is not preferable because it causes deterioration of mechanical properties. Furthermore, when one or more powder fillers selected from molybdenum powder, molybdenum compound powder and calcium compound powder are added to the above two components, the compounding ratio is 5 to 40% by weight of heat resistant fiber, 30 to 90% of perfluoroalkoxy resin. Powder filler 5 to weight%
It is 30% by weight. Because the addition amount of powder filler is 5
If the amount is less than 30% by weight, the lubricity is not improved, and if the amount exceeds 30% by weight, the mechanical durability of the cage is unfavorably deteriorated.

Further, various fillers other than the above may be added. Generally, the amount added is preferably 10% or less of the total amount. As such fillers, aromatic polyetherketone resins, polyetherimide resins, polyethersulfone resins, polyamideimide resins, polyphenylene sulfide resins, heat resistant polyamide resins, phenolic resins, aromatic polyester resins, heat Starting with organic heat-resistant polymer materials such as plastic polyimide resin, silicone resin, fluorine-based resin, graphite or zinc, aluminum, inorganic powder for improving heat conduction such as metal or oxide such as magnesium, glass beads, silica balloon, Omiaceous earth, asbestos, inorganic powder such as magnesium carbonate, graphite, carbon, mica, inorganic powder for improving lubricity such as talc, and iron oxide, cadmium sulfide, cadmium selenide, inorganic pigments such as carbon black, silicone oil, S Ruoiru, fluorine oil, polyphenylene ether oils, waxes, can be exemplified a number of things such as internal lubricant additives, such as zinc stearate. The mixing method of the above-mentioned perfluoroalkoxy resin, fibrous reinforcing material and other additives is not particularly limited, and after heat-mixing with a mixer such as a Henschel mixer, a ball mill or a tumbler mixer, heat For example, pellets may be formed as a molding material by melt-mixing with a roll, a kneader, a Banbury mixer, a melt extruder or the like, and this may be melt-molded into a predetermined shape as a rolling bearing cage by an injection molding machine or the like. Molding conditions are not particularly limited, and may be carried out under normal molding conditions of perfluoroalkoxy resin.

As a molding method in the case of this composition, the respective materials are dry blended at a predetermined ratio and then fed to a twin-screw melt extruder at 360 ° C. and a screw rotation speed of 150 rp.
While extruding from a strand die having 5 holes with a diameter of 3 mm while melt-kneading at m, pellets are produced by continuously cutting the extruded strands, and the obtained pellets are injection-molded (barrel temperature 320 to 380 ° C., A method of molding into a cage shape determined by applying a mold temperature of 210 ° C. and an injection pressure of 800 kg / cm ² ) can be adopted.

[0017]

The roller cage resin retainer of the present invention is a cage in which a plurality of pockets each having a through hole are arranged side by side, and the width dimension of the pocket opening is smaller than the outer diameter dimension of the roller. Since a narrow part with a smaller cross section than the other part is provided in a part of the column in the longitudinal direction, the pushing force of the roller into the pocket is reduced and the play of the roller in the pocket is reduced. It is possible to reduce the swing of the cage. In the case of the invention of claim 2, since the narrow portion has a narrowed portion corresponding to the opening edge of the pocket, the pushing force of the roller can be reduced while maintaining the column strength. In addition, since the narrow portion is provided at the central portion in the longitudinal direction of the column, the pushing force can be effectively reduced. In the case of the third aspect of the invention, since the narrow portion is narrowed only in the portion corresponding to the opening edge on one side, the column strength can be maintained more reliably against the formation of the narrow portion. In the case of the invention of claim 4, in the cage for the cylindrical roller bearing in which the reduction of the roller pushing force is strongly desired, the reduction of the roller pushing force and the runout prevention of the cage can be achieved.

[Brief description of drawings]

FIG. 1A is a partial cross-sectional view of a resin cage for roller bearings according to an embodiment of the present invention, and FIG. 1B is a partial plan view thereof.
(C) is an explanatory view of a process of inserting a roller into the cage, (D)
[Fig. 3] is an enlarged cross-sectional view showing a state where rollers are inserted in the cage.

FIG. 2 is a partial sectional view of another embodiment of the present invention.

FIG. 3 is a partial cross-sectional view of still another embodiment of the present invention.

4A to 4C are a partial perspective view, an overall perspective view and a partial plan view, respectively, of yet another embodiment of the present invention.

5A and 5B are a partial plan view and a partial cross-sectional view, respectively, of yet another embodiment of the present invention.

FIG. 6A is a partial sectional view showing a roller pushing process of a conventional cage, and FIG. 6B is a partial plan view of the cage.

[Explanation of symbols]

1 ... Retainer, 2 ... Roller, 3 ... Pocket, 5 ... Pillar, 5a ...
Narrow part

Claims (4)

[Claims] 1. A roller bearing resin retainer in which a plurality of pockets each having a through hole for holding a roller are provided side by side, and a width dimension of an opening portion of the pocket is smaller than an outer diameter dimension of the roller. A resin retainer for a roller bearing, characterized in that a narrow portion having a smaller cross section than that of the other portion is provided in a part of the longitudinal direction of the. 2. The side surface of each pillar is formed in a cylindrical surface shape along the outer diameter surface of the roller, and the narrow portion narrows the pillar width of the portion corresponding to the opening edge of the pocket, 2. The roller bearing resin retainer according to claim 1, wherein the narrow portion is provided at the center of the column in the longitudinal direction. 3. The roller bearing resin retainer according to claim 2, wherein the narrow portion is formed by narrowing a portion corresponding to an opening edge on one side of the pocket. 4. A retainer for a cylindrical roller bearing.
Alternatively, the resin retainer for the roller bearing according to claim 2.