JP2003083334A - Antifriction bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antifriction bearing capable of reducing the number of working process of a metallic bearing cage, saving production cost and enhancing productivity. SOLUTION: For the antifriction bearing equipped with metallic bearing cage 21 that regulates the interval of a plurality of rolling elements arranged between inner and outer rings, the ball bearing cage 21 consists of a pair of ring structure bodies 23 and 25 connected to butt each other in the axial direction. The pair of ring structure bodies 23 and 25 are formed by hot forging to make outer shell form have concave parts 23b and 25b for pockets on the butted face 23a and 25a and rivet seats 23e and 25e on the outer faces 23c and 25c so that grinding work that requires a great deal of man-power can be minimized.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a metal retainer between inner and outer wheels for regulating the distance between a plurality of rolling elements provided between the inner and outer wheels. More specifically, the present invention relates to an improvement for realizing reduction in manufacturing cost and improvement in productivity of a metal cage. 2. Description of the Related Art In a rolling bearing, a retainer is used to maintain a space between a plurality of rolling elements provided between inner and outer rings. The cage has a structure in which a pocket for accommodating a rolling element is formed in an annular structure orbiting between inner and outer rings, and a cage made of resin and a cage made of metal have been developed. A cage made of resin is formed into a desired shape by injection molding, and it is relatively easy to make the inner surface of the pocket a curved surface structure corresponding to the outer surface of the rolling element. It is difficult to secure and improve durability. For this reason, it is common to employ a metal cage for a high-load or high-speed rolling bearing. [0004] As a metal cage suitable for high load and high-speed rotation, there is a machined-type cage in which a pocket for accommodating a rolling element is formed in a relatively thick annular structure by grinding or the like. Widespread. FIG. 5 and FIG. 6 show a method of manufacturing such a machined-type cage. [0005] The machined-type cage 1 shown in FIG.
For a split-type deep groove ball bearing, pockets 4 for accommodating balls as rolling elements are formed through metal annular structure 2 at regular intervals in the circumferential direction. As shown in FIG. 5, the pocket 4 is formed by temporarily assembling a two-piece type retainer and then moving the rotation axis L in the direction of the center axis C of the annular structure 2.
The cutting is performed by a cutting tool 5 such as a drill bit set in a direction perpendicular to the direction of the cutting. In the case of such a machined retainer 1, the pocket 4 is usually a straight hole. In addition, as shown in FIG. 6, there is also a case in which the pocket shape is not a straight hole but a cylindrical shape on the outer diameter side of the cage and a conical shape on the inner diameter side of the cage. In this case, cutting by a drill is formed up to the center of the cage. FIG. 7 shows one of a pair of annular structures constituting another two-piece type cage. The annular structure 6 shown here becomes a retainer for a deep groove ball bearing by being joined to another annular structure having a similar structure in the direction of the center axis of the bearing. In the annular structure 6 constituting such a two-piece type retainer, a rivet hole 8 for rivet-connecting a pair of annular structures is formed along the width direction (central axis direction) of the annular structure. And a substantially hemispherical concave portion 9 for a pocket is formed in the mating surface 6a. Further, although not shown, a caulking portion of a rivet is formed on an outer surface opposite to the mating surface. A rivet seat is formed to prevent the protrusion of the rivet. The recess 9 is formed by a cutting tool 11 in which the direction of the rotation axis Z is set parallel to the central axis C1 of the annular structure 6, as shown in FIG. Such 2
In the case of the split type cage, the concave portion 9 is formed into a spherical surface corresponding to the curved state of the outer surface of the rolling element to be accommodated. [0008] However, each of the cages 1 and 6 of the above-mentioned machined type has a pocket 4 and a concave portion 9.
Since they are formed one by one by a cutting tool or a grinding tool, there are problems that the number of processing steps is large, a large amount of time is required for processing, and productivity is poor. There is also a problem that the processing cost is increased and the production cost is increased. The present invention has been made in view of the above circumstances,
An object of the present invention is to provide a rolling bearing capable of reducing the number of processing steps of a metal cage and improving productivity and reducing manufacturing costs. [0010] In order to achieve the above object, a rolling bearing according to the present invention is a metal for regulating the distance between a plurality of rolling elements provided between inner and outer rings and between inner and outer rings. In a rolling bearing provided with a cage made of a non-ferrous metal material, the cage is formed of a pair of annular structures that are joined while being joined in the central axis direction of the bearing. It is formed by hot forging, and a plurality of recesses provided on the mating surfaces of the respective annular structures for pockets for accommodating the rolling elements, and a plurality of annular structures for connecting the pair of annular structures to each other. Various irregularities on the annular structure such as a plurality of rivet seats formed on the outer side surface are formed by hot forging, and hot forging is performed only at locations where dimensional accuracy higher than the working accuracy of hot forging is required. Machine with higher processing accuracy than It is characterized by performing finishing by mechanical processing. According to the above construction, in the pair of annular structures constituting the metal cage, a large number of concave and convex portions such as pocket concave portions provided on the mating surface and rivet seats provided on the outer side surface. Are collectively formed by hot forging. Therefore, when compared with a conventional machined-type cage in which a plurality of uneven portions are sequentially formed one by one by a time-consuming machining process such as grinding, the number of processing steps when manufacturing a metal cage is reduced. It can be greatly reduced. In addition, complicated machining can be minimized only in a portion where the required dimensional accuracy cannot be ensured by hot forging, so that productivity can be improved and manufacturing cost can be reduced. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a rolling bearing according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a perspective view of an embodiment of a metal cage used in a rolling bearing according to the present invention, FIG. 2 is an exploded perspective view of the cage shown in FIG. 1, and FIG. 3 is each annular structure shown in FIG. FIG. 4 is a schematic cross-sectional view of a hot forging die for forming the non-ferrous metal base material shown in FIG. 3 when the body is hot forged. The metal cage 21 of this embodiment is provided between the inner and outer rings of the deep groove ball bearing, and adjusts the interval between a plurality of rolling elements (balls) provided between the inner and outer rings of the deep groove ball bearing. As shown in FIG. 1, a pair of annular structures 23 and 25 joined together in a direction of the center axis C <b> 2 of the bearing.
It consists of. Each of the annular structures 23 and 25 includes a ring-shaped base material 30 made of a non-ferrous metal material as shown in FIG. 3 placed in a hot forging die 40 shown in FIG. 4 and pressed under a predetermined heating environment. It is formed by hot forging. In each of the annular structures 23 and 25, a plurality of pocket recesses 23b and 25b for accommodating rolling elements are formed to face each other, and a pair of annular structures 23 and 2 are formed.
5. A plurality of rivet insertion holes 23 for connecting each other
d and 25d are formed through the butting surfaces 23a and 25a. In addition, seats for avoiding the protrusion of the caulked portion of the rivet mounted in each of the rivet insertion holes 23d, 25d are provided on the outer side surfaces 23c, 25c located on the opposite side of the butting surfaces of the respective annular structures 23, 25. Rivet seat 23
e, 25e are formed. Recess 23 for pocket
The inner surfaces of b and 25b are formed into spherical surfaces having a diameter slightly larger than the outer diameter of the ball as the rolling element. As shown in FIG. 4, the hot forging die 40 includes a lower die 41 for forming butting surfaces 23a, 25a and recesses 23b, 25b of the annular structures 23, 25, and an outer surface 23.
c, 25c and the upper mold 42 for molding the rivet seats 23e, 25e, and the intermediate mold 43 sandwiched between the upper and lower molds 41, 42.
It is composed of And the intermediate mold 43 further
Outer die 43a for forming the outer peripheral surfaces of the annular structures 23 and 25
And an inner mold 43 for forming the inner peripheral surfaces of the annular structures 23 and 25.
b. Each of the annular structures 23, 25 such as the plurality of recesses 23b, 25b and the rivet seats 23e, 25e described above.
The upper various uneven portions are formed by hot forging using a hot forging die 40. Then, each of the annular structures 23, 25
Is performed only at a place where a dimensional accuracy higher than the working accuracy of hot forging is required by a machining process having a higher working accuracy than the hot forging to finish to a desired dimensional accuracy. In the rolling bearing using the cage 21 described above, a pair of annular structures 2 constituting the metal cage 21 are provided.
3 and 25, the pocket recesses 23 provided on the butting surfaces 23a and 25a of the annular structures 23 and 25, respectively.
A large number of uneven portions such as b, 25b and rivet seats 23e, 25e provided on the outer side surfaces 23c, 25c are collectively formed by hot forging. Therefore, when manufacturing the metal cage 21 as compared with the case of manufacturing the conventional machined-type cage in which a plurality of uneven portions are formed one by one in order by machining such as laborious grinding, etc. Can greatly reduce the number of processing steps. In addition, complicated machining can be minimized only in a portion where the required dimensional accuracy cannot be ensured by hot forging, so that productivity can be improved and manufacturing cost can be reduced. It is needless to say that the cage according to the present invention can be applied not only to the deep groove ball bearing but also to various rolling bearings by changing the shape of the pocket recesses 23b and 25b. Also, pocket recesses 23b, 25b
The shape of the inner surface is not limited to the spherical surface described in the above embodiment. A cylindrical straight hole may be formed between the concave portions 23b and 25b. According to the rolling bearing of the present invention, in a pair of annular structures constituting a metal cage, a pocket recess provided on a mating surface and a rivet seat provided on an outer surface. Are formed at once by hot forging. Therefore, when compared with a conventional machined-type cage in which a plurality of uneven portions are sequentially formed one by one by a time-consuming machining process such as grinding, the number of processing steps when manufacturing a metal cage is reduced. It can be greatly reduced. In addition, complicated machining can be minimized only in a portion where the required dimensional accuracy cannot be ensured by hot forging, so that productivity can be improved and manufacturing cost can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of one embodiment of a metal cage used in a rolling bearing according to the present invention. FIG. 2 is an exploded perspective view of the retainer shown in FIG. FIG. 3 is a longitudinal sectional view of a non-ferrous metal base material put into a forging die when hot forging each annular structure shown in FIG. 2; 4 is a schematic configuration diagram of a hot forging die for forming the non-ferrous metal base material shown in FIG. FIG. 5 is a perspective view showing a method of manufacturing a conventional two-piece metal cage. FIG. 6 is a cross-sectional view of a conventional two-piece metal cage having different pocket shapes. FIG. 7 is a perspective view showing a method for manufacturing another conventional two-piece metal cage. [Description of Signs] 21 Cages 23, 25 Annular structures 23a, 25a Butt surfaces 23b, 25b Recesses 23c, 25c Outer side surfaces 23d, 25d Rivet insertion holes 23e, 25e Rivet seat 30 Base material 40 Hot forging die

Continuation of front page    (72) Inventor Tatsuo Egawa             1-50-50 Kugenuma Shinmei, Fujisawa City, Kanagawa Prefecture             Nippon Seiko Co., Ltd. F term (reference) 3J101 AA01 AA02 AA12 AA32 AA62                       BA21 BA22 BA34 BA45 DA09                       DA11 EA01 FA44                 4E087 AA10 CB01 HA43

Claims (1)

Claims: 1. A rolling bearing comprising a metal retainer between inner and outer rings for regulating the interval between a plurality of rolling elements provided between the inner and outer rings, wherein the retainer is a bearing. And a pair of annular structures formed by hot forging of a ring-shaped non-ferrous metal material, and for a pocket for accommodating rolling elements. A plurality of recesses provided on the mating surface of each annular structure, and a plurality of rivet seats formed on the outer surface of each annular structure for coupling a pair of annular structures to each other. The upper and lower irregularities are formed by hot forging, and only in places where dimensional accuracy higher than the processing accuracy of hot forging is required, finish processing by machining with higher processing accuracy than hot forging Rolling bearings characterized .