JPH11325081A - Holder for rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a holder for a rolling bearing to reduce a manufacturing cost, easily ensure a shape advantageous to lubricity and assembly properties, besides hardly generate a sound and vibration, increase load capacity by increasing the number of pockets (the number of rollers), and further ensure sufficient strength and heat resistance. SOLUTION: In an annular holder 1 for a rolling bearing wherein a plurality of pocket parts 5 to rollingly hold a roller 4 are arranged in a plurality of spots, this holder comprises a core part 2; and a plastic part 3 disposed in a part where the core 2 is fleshed by insert-molding and at least the pocket part 5 makes contact with a roller 4. The core part 2 is formed of a metallic material having strength higher than that of the plastic part 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an annular rolling bearing retainer having a plurality of circumferentially provided pockets for rotatably holding rolling elements.

[0002]

2. Description of the Related Art As a cage of this type, a ring with a flange is manufactured by pressing an iron plate, and a pocket portion is provided on an outer peripheral surface of the ring by punching, and a side portion of the pocket portion facing in a circumferential direction is bent. Press cage with roller contact parts bent to the inner ring side by processing, the whole is manufactured by plastic injection molding, and the contact surface with the roller outer diameter surface of the pocket part (the pillar part between the roller parts) is A plastic retainer having a cylindrical surface having an R dimension slightly larger than the roller radius and having a roller falling-off prevention convex portion provided on the outer surface of the cylindrical surface, and the entire machine including the pocket portion, which is constituted by two parts, is machined, 2. Description of the Related Art An extruded cage for riveting both parts after assembly is known.

[0003]

The above three types of conventional cages have the following advantages and disadvantages, respectively.

[0004] In the press cage, the production cost is low, and the strength and weight are well balanced, but the processing accuracy (roller contact surface) is poor due to the sheet metal processing, and the damping of the cage itself is small, so that the acoustic pressure is low. (Squeaking noise, etc.)-Vibration is likely to occur. Furthermore, since complicated shapes are difficult to machine, it is necessary to ensure sufficient lubrication between the pockets, and the assemblability is poor due to falling off rollers, and the pockets face the circumferential direction. Since the roller contact portions are provided by bending the side portions, there is a problem that the number of pocket portions (the number of rollers) cannot be increased.

[0005] In the plastic cage, the production cost is the lowest, a complicated shape is possible, and a shape advantageous for lubricity and assemblability between pocket portions can be easily secured. Due to the large damping, sound and vibration hardly occur, and the column between the roller and the roller has a simple shape, so the number of pockets (number of rollers) can be increased, but the material itself Since the strength is relatively small compared to metal, even if the design is thickened, the total strength is limited and the operating conditions cannot be widened, resulting in a limited use range. Since it is inevitable, there is a limit in the use temperature, and there is a problem that the use is not expanded in this respect.

In the machined cage, the machining accuracy (the guide surfaces of the outer and inner races of the cage, the roller contact surface) is the best, and the roller contact surface of the pocket portion can be formed in an R shape, and the lubrication is good. Since the manufacturing cost is highest due to the machining cost due to machining and the assembly cost due to the rivet caulking structure, furthermore, the dimensions of the column are limited by the rivet holes,
There is a problem that the number of pockets (the number of rollers) cannot be increased.

The present invention has been made in view of such technical background, and by integrating only the advantages of the above three types of cages, it is possible to easily form a shape which is low in manufacturing cost and advantageous in lubricity and assemblability. It is possible to increase the number of pockets (the number of rollers) and to increase the load capacity.
Still another object of the present invention is to provide a rolling bearing retainer capable of securing sufficient strength and heat resistance.

[0008]

In order to achieve the above object, a rolling bearing retainer according to the present invention has an annular shape in which a plurality of pockets for rollingly holding a rolling element are provided in a circumferential direction. A cage for a rolling bearing, comprising: a core portion; and a plastic portion which is thickened by insert molding on the core portion and which is disposed at least at a portion of the pocket portion where the rolling element contacts. It is characterized by being made of a material having higher strength than the part.

Examples of the material for the core include metal and plastics having strength and rigidity equal to or higher than metal. When the core is made of a metal material, a metal casting can be used in addition to a press-formed product.

As the shape of the core portion, a flat annular ring having a plurality of holes corresponding to the pocket portions formed in the circumferential direction, and a flange portion protruding toward the inner ring at one end of the annular ring are provided. And the like.

On the other hand, the plastic part may be a composite material by mixing reinforcing fibers, or the plastic part may be made of an elastomer. Further, a preload may be applied in the circumferential direction of the retainer by elastically holding the rolling element in the pocket portion by using the elasticity of the plastic portion.

Further, when the rolling element is inserted into the pocket part by elastically expanding the plastic part, the rolling part guide surface may be provided on the plastic part, and furthermore, the center part of the pillar part in the width direction may be provided. A concave portion may be provided in the groove to serve as a relief portion for elastically expanding the plastic portion.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a state in which a retainer for a rolling bearing as an example of an embodiment of the present invention is incorporated in a cylindrical roller outer ring flanged bearing, and FIG. 2 is II-II in FIG.
FIG. 3 is a perspective view for explaining a head contact portion,
4 is a perspective view of the core, FIG. 5 is an explanatory view for explaining the geometrical shape of the plastic part, FIG. 6 is a sectional view showing a state where the core is set in an insert mold, and FIG. 7 is a core. FIG. 8 is a perspective view showing a modified example of FIG. 8, FIG. 8 is a sectional view showing a modified example of the core portion,
FIG. 9 is a cross-sectional view for explaining another embodiment of the present invention.

The rolling bearing retainer 1 includes a core 2 made of a metal press-formed product, and a plastic portion 3 formed by inserting the core 2 with insert molding. As shown in FIG. 4, the core portion 2 has a flat ring shape, and a hole 6 corresponding to a pocket portion 5 for rollingably holding the roller 4 is provided on the outer peripheral surface according to the number of rollers. A plurality of portions are formed in the circumferential direction. One end of the annular ring is provided with a flange portion 7 protruding toward the inner ring, and an outer peripheral surface of the annular ring is provided with an anchor hole for firmly connecting the core portion 2 and the plastic portion 3. 8 are formed.

The plastic portion 3 includes a cylindrical surface 9 in contact with the outer diameter surface of the roller 4, a roller falling-off preventing convex portion 10 provided on the inner ring side of the cylindrical surface 9, and a head contact portion 11 in contact with an end surface of the roller 4. These portions are fleshed to the core portion 2 to form the rolling bearing retainer 1.

The material of the plastic part 3 is not particularly limited as long as it can be insert-molded, and various materials can be used in consideration of strength, temperature characteristics, lubricity, and the like. An engineering plastic such as nylon having excellent lubricating properties, an elastomer having elasticity, or a combination of these two materials can be used. Also, compatibility with the material of the core part 2 of the plastic part 3,
In this embodiment, compatibility with metal is also important. For example, the plastic part 3 can be made of a composite material in which reinforcing fibers are mixed in order to approach a linear expansion coefficient close to that of metal. In this case, as the reinforcing fiber, a carbon fiber having a linear expansion coefficient having a negative value is preferable.

Next, the geometrical shape of the plastic part 3 will be described with reference to FIG. The contact surface of the plastic portion 3 with the roller 4 (the surface of the pillar portion 3a facing in the circumferential direction) is a cylindrical surface 9 having a radius R slightly larger than the radius d / 2 of the roller 4;
Of which the clearance Δ / 2 is secured. In order to prevent the rollers 4 from coming off, the width B of the plastic part 3 on the inner ring side is made larger than the distance b between the rollers 4 and 4 so that the inner surface of the cylindrical surface 9 can be removed. A roller falling-off prevention convex portion 10 is provided. The width B of the plastic part 3 on the inner ring side is set to a range where the elasticity of the plastic part 3 expands the roller falling-off prevention convex part 10 so that the rollers 4 can be inserted from the inner ring side.

In this embodiment, the preload is applied in the circumferential direction so that the elastic deformation amount δ of the roller falling-off preventing projection 10 remains after the roller 4 is inserted. In order to more smoothly insert the roller 4, the roller guide slope 10 is provided on the roller falling-off preventing convex portion 10, and a concave elastic escape portion Y is provided at the center of the plastic portion 3 in the width direction on the inner ring side.

FIG. 6 shows a state in which the core 2 is set in the insert molding die. The insert molding die has a pocket molding convex portion 21 which is loosely inserted into the hole 6 of the core 2 on its outer peripheral portion. It has a middle mold 22 inserted into the inner diameter part of the part 2, and a contact part 23 fitted on the end of the middle mold 22 on the flange part 7 side of the core part 2 and abutting on the flange part 7, and the outside of the core part 2. An outer insertion portion 24 is inserted outside with a predetermined gap between the inner surface of the outer insertion portion 24 and the inner peripheral surface of the outer insertion portion 24 is in contact with the distal end surface of the pocket forming protrusion 21. Outer mold 2 having a contact portion 25 that contacts the outer diameter surface of the core portion 2 on the flange portion 7 side of the outer mold 2
6 and a side mold 27 which is disposed on the end of the core 2 on the side away from the flange 7 and is extrapolated to the middle mold 22. The contact portions 23 and 25 serve as reference surfaces. The flange 7 is formed by the outer mold 26 by resin pressure during insert molding.
The contact portion 23 is reliably pressed against the contact portion 23.

As is apparent from the above description, in the present embodiment, the core 2 is made of a metal material having higher strength and rigidity than the plastic portion 3, so that the core 2 has a sufficient strength as a retainer. Since the plastic part 3 is insert-molded, the plastic part 3 can be formed into a complicated shape, and a shape advantageous for lubricity and assemblability of the roller contact part can be easily secured.

Further, since the core portion 2 can have the strength as a retainer, the degree of freedom in selecting the material of the plastic portion 3 can be increased, and the operating temperature range can be widened. Can be expanded.

Further, a plastic part 3 is attached to the metal core 2.
Is formed by insert molding, so that the manufacturing cost can be kept low. Further, the rigidity of the retainer against deformation of the cage is increased by the metal core portion 2 and the damping is increased and the weight is relatively reduced by the plastic portion 3, so that sound and vibration can be hardly generated.

Further, since the column portion 3a between the rollers 4 and 4 has a simple shape, the number of the pocket portions 5 (the number of rollers) can be increased and the load capacity can be increased. In this case, by making the core 2 a relatively thick plate, the circumferential dimension of the column 3a (possible because of the simple shape) can be shortened, and as a result, the number of pockets 5 (the number of rollers)
And the load capacity can be further increased.

Further, the elasticity of the plastic portion 3 is used to apply a preload in the circumferential direction so that the amount of elastic deformation δ of the roller falling-off preventing convex portion 10 remains after the roller 4 is inserted. And skew control, in particular, attitude control in a non-load zone.

Further, when the rollers 4 are inserted into the pockets 5 by pushing and expanding the roller stoppers 10, the deformation of the stoppers 10 can be easily removed, so that the rollers 4 are less likely to be scratched. be able to.

Furthermore, by setting the clearance C between the inner diameter of the outer ring collar and the outer diameter of the retainer 1 to an appropriate value, the outer ring of the retainer 1 can be guided. The contact of No. 3 can improve the wear resistance.

In the above-described embodiment, a metal is used as the material of the core 2. However, the material is not limited to this, and a plastic material having strength and rigidity equal to or higher than that of the metal is used as the material of the core 2. May be used.

Further, in the above embodiment, the core 2 having the flange 7 provided at one end of the ring is taken as an example.
However, the present invention is not limited to this, and a core 28 without the flange 7 may be used as shown in FIG.

Further, in the above embodiment, the hole 6 of the core 2 is
8 is simply punched out, but as shown in FIG. 8, the side facing the circumferential direction of the hole 6 is bent toward the inner ring side to form a substantially U-shape, so that the connection with the plastic part 3 is further strengthened. It can be.

Further, in the above-described embodiment, the case where the cage 1 according to the present invention is applied to the bearing with the outer ring flange of the cylindrical roller is taken as an example. However, the present invention is not limited to this, and as shown in FIG.
The retainer 30 according to the present invention may be applied to a bearing with an inner ring flange on a cylindrical roller. In this case, the inner ring side and the outer ring side of the cage 30 may be reversed from the cage 1 described above.

Further, in the above embodiment, the case where the cage for a rolling bearing according to the present invention is applied to a cylindrical roller bearing is taken as an example. However, the present invention is not limited to this. The present invention may be applied to a ball bearing other than the roller bearing. In this case, these bearings can be applied to a thrust bearing.

Further, in the above-described embodiment, the case where a hole corresponding to the pocket portion 5 is formed in the annular ring by press working is taken as an example. A corresponding hole 6 is formed by press working,
This may be rounded into an annular shape and the butted portion may be welded.

Further, in the above embodiment, the metal core 2 is a press-formed product, but the metal core 2 may be constituted by a metal casting. In this case, the strength and rigidity of the cage can be further increased.

[0034]

As is apparent from the above description, according to the present invention, the manufacturing cost is low, a shape advantageous for lubricity and assemblability can be easily secured, and furthermore, sound and vibration are generated. In addition, the load capacity can be increased by increasing the number of pocket portions (the number of rollers), and furthermore, the effect of securing sufficient strength and heat resistance can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state in which a cage for a rolling bearing, which is an example of an embodiment of the present invention, is incorporated in a cylindrical roller outer ring flanged bearing.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a perspective view for explaining a head contact portion.

FIG. 4 is a perspective view of a core.

FIG. 5 is an explanatory diagram for explaining a geometric shape of a plastic part.

FIG. 6 is a cross-sectional view showing a state where a core is set in an insert mold.

FIG. 7 is a perspective view showing a modification of the core.

FIG. 8 is a cross-sectional view showing a modification of the core.

FIG. 9 is a cross-sectional view for explaining another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Retainer for rolling bearings 2 ... Core part 3 ... Plastic part 4 ... Roller (rolling element) 5 ... Pocket part

Claims (1)

[Claims] An annular rolling bearing retainer provided with a plurality of circumferentially provided pockets for rollingly holding a rolling element, wherein the core is formed by insert molding the core and the core is filled with at least the pocket. A plastic part provided in a portion of the pocket part in contact with the rolling element, wherein the core part is made of a material having higher strength than the plastic part.