JP2001304269A - Holder for rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extend longevity of a rolling element and a holder by protecting them from small metal pieces such as abrased powder, chips, etc. SOLUTION: A holder 5 is formed of a resin material and is constituted by providing a hard metal layer 8 made of a hard metal material to cover an outer peripheral surface 6A, an inner peripheral surface 6B, each of end surfaces 6C of a ring body 6 and an inner surface 7A of each of pockets 7. Consequently, it is possible to eliminate breakage of a ball 4 and the holder 5 by these small metal pieces by the hard metal layer 8 having hardness of more than the same as the small metal pieces such as the abrased powder, the chips, etc., mixed in lubricating oil even in the case when a lubricating method in an oil bathing state is adopted. Additionally, it is possible to protect the whole of the holder 5 from lubricating oil and metal pieces as the hard metal layer 8 is formed to cover the whole of the holder 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling bearing using a plurality of rolling elements comprising balls and rollers, and more particularly to a rolling bearing retainer for rotatably holding the plurality of rolling elements.

[0002]

2. Description of the Related Art In general, when a shaft is rotatably supported, a rolling bearing is used. The rolling bearing includes a cylindrical retainer and a rolling element rotatably held by the retainer. This is roughly configured. Here, the rolling bearing includes a ball bearing using a ball as a rolling element and a roller bearing using a roller as a rolling element. Some rolling bearings have their retainers formed of a resin material, and are known, for example, from Japanese Patent Application Laid-Open No. 56-10818.

[0003] The prior art cage disclosed in Japanese Patent Application Laid-Open No. 56-10818 discloses an annular body formed of a resin material in an annular shape, and a radially penetrating radially spaced apart annular body. And a plurality of pockets rotatably supporting the rolling elements. In this conventional technique, a hardened layer having high wear resistance is formed on the surface of the cage by applying heat to the cage.

On the other hand, rolling bearings include, for example, Japanese Utility Model Laid-Open No.
As disclosed in Japanese Patent No. 56518, etc., a cage is formed using a metal material, and a film made of a fluororesin or the like is formed on the surface of the cage to prevent rust due to corrosion.

[0005] Rolling bearings provided with these conventional cages are used in, for example, a planetary gear reduction device constituting a crawler belt driving device of a construction machine or the like. in this case,
Lubricating oil is supplied to the rolling bearings to make the operation of the rolling elements smooth.

[0006]

Incidentally, in the above-mentioned planetary gear reduction device, lubrication in a so-called oil bath state is performed as a method of lubricating a bearing or the like while lubricating oil is sealed in a casing. For this reason, if the reduction gear is used for a long time, small metal pieces such as abrasion powder and debris will be generated at gear meshing parts, sliding parts between parts, etc., and these fine metal pieces gradually mix into the lubricating oil. become.

[0007] Therefore, when the speed reducer is in operation, a small metal piece floats in the lubricating oil, and a part thereof enters between the pocket of the retainer and the rolling element, and is interposed between the rolling element and the pocket. It will be sandwiched. At this time, the minute metal pieces are embedded in the inner surface of the pocket made of the resin material.

As a result, the small metal pieces embedded in the inner surface of the pocket come into contact with the rolling elements during operation of the reduction gear transmission, so that the rolling elements are damaged by the small metal pieces,
There is a risk of early damage.

The conventional cage disclosed in Japanese Patent Application Laid-Open No. Sho 56-10818 has a configuration in which a hardened layer is provided on the surface of a resin cage. However, the hardened layer is also made of a resin material. Absent. For this reason, when a fine metal piece harder than the hardened layer is floating, the fine metal piece sometimes enters the hardened layer. Then, there is a problem that once the minute metal pieces enter the hardened layer, the metal pieces damage the resin portion of the cage.

On the other hand, the cage disclosed in Japanese Utility Model Application Laid-Open No. 6-56518 has a body portion formed of a metal material, but is subjected to a surface treatment such as a fluororesin to prevent rusting due to corrosion. It has a configuration. For this reason, when a fine metal piece harder than the film enters the film made of the fluororesin, the film is damaged and the metal material as the base material is corroded.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to prevent a rolling element, a retainer, and the like from being damaged by minute metal pieces such as abrasion powder and debris. An object of the present invention is to provide a rolling bearing retainer capable of extending its life.

[0012]

According to a first aspect of the present invention, there is provided an annular member formed of a resin material in an annular shape, and the annular member is radially penetrated at intervals in a circumferential direction of the annular member. And a plurality of pockets rotatably supporting the rolling elements, wherein the pockets are provided with a hard metal layer made of a hard metal material covering an inner surface thereof. It is characterized by:

[0013] With this configuration, even if small metal pieces such as abrasion powder and debris mixed in the lubricating oil are interposed between the rolling element and the pocket, the inner surface of the pocket is equivalent to the small metal piece. Since the hard metal layer is harder than the above, the fine metal pieces cannot enter the cage. Therefore, the hard metal layer can protect the resin cage from the fine metal pieces, and can prolong the life of the rolling elements.

According to the second aspect of the present invention, the hard metal layer is
It is provided on the entire surface of the annular body including the inner surface of the pocket. Thereby, the hard metal layer can protect the annular body made of the resin material from the lubricating oil and the minute metal pieces.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a cage for a rolling bearing according to an embodiment of the present invention.

FIG. 1 to FIG. 3 show a first embodiment of the present invention. Reference numeral 1 denotes a ball bearing as a rolling bearing, and the ball bearing 1 is used in a planetary gear reduction device (both not shown) constituting a crawler belt driving device of a construction machine, for example. The ball bearing 1 is provided on the outer surface side with an inner race 2 in which an arc-shaped raceway groove 2A on which an after-mentioned ball 4 rolls is formed over the entire circumference, and on the outer periphery side of the inner race 2, and on the inner surface side. Track groove 2
A outer race 3 having an arc-shaped raceway groove 3A in which the ball 4 rolls facing A and a rolling element provided between the raceway groove 2A of the inner race 2 and the raceway groove 3A of the outer race 3 are formed. Are constituted by a plurality of balls 4, 4,... And a retainer 5 described later for holding each of the balls 4.

Reference numeral 5 denotes a retainer according to the present embodiment used for the ball bearing 1. The retainer 5 includes a plurality of balls 4, 4,. They are arranged at intervals. The retainer 5 includes an annular body 6, a pocket 7, and a hard metal layer 8, which will be described later.

Reference numeral 6 denotes an annular body constituting the main body of the retainer 5. The annular body 6 is made of a resin material, and is located in the outer peripheral surface 6A, the inner peripheral surface 6B and the axial direction as shown in FIG. It is formed in a cylindrical shape having left and right end surfaces 6C, 6C. The outer peripheral surface 6A, the inner peripheral surface 6B, and the end surface 6C of the annular body 6 are covered with a hard metal layer 8 described later.

Reference numerals 7, 7,... Denote a plurality of pockets formed in the annular body 6. The pockets 7 are arranged at equal intervals in the circumferential direction of the annular body 6, and penetrate in the radial direction of the annular body 6. It is provided. Each pocket 7 rotatably holds the spherical ball 4 and is formed as a circular hole into which the ball 4 is fitted with a gap. The inner surface 7 </ b> A of the pocket 7 is a concave arc surface corresponding to the shape of the ball 4.

Reference numeral 8 denotes a hard metal layer provided so as to cover the annular body 6 and each pocket 7. The hard metal layer 8 is composed of abrasion powder and debris generated at a gear meshing portion, a sliding portion between parts, and the like. It is formed into a thin film by performing a plating process or a coating process using a metal material harder than or equal to the minute metal piece such as chromium, nickel, cobalt or the like. Then, the hard metal layer 8 is provided in each pocket 7.
The entire surface of the annular body 6 including the inner surface 7A is covered. Here, in the case of chrome plating, for example, hard chrome plating is used, and in the case of nickel plating, for example, nickel-phosphorus (Ni-P plating, Ni-P-SiC plating, etc.) is used, and cobalt plating is used. In the case, cobalt-chromium (Co-Cr3 C3 plating, Co-Cr2
O3 plating) is used.

The ball bearing 1 according to the present embodiment has the above-described configuration, and can be rotatably supported on a shaft portion and the like of the planetary gear reduction device by being used in a rotating portion of the planetary gear reduction device. . Also, in the planetary gear reducer,
As a method of lubricating the ball bearing 1, a lubrication method in a so-called oil bath state in which lubricating oil is sealed in a casing is employed.

As described above, according to the present embodiment, the outer peripheral surface 6A, the inner peripheral surface 6B, the end surfaces 6C, 6C of the annular body 6 and the inner surface 7A of each pocket 7 are covered with the hard metal layer 8. Therefore, even when the cage 5 made of a resin material is used in a state of being immersed in lubricating oil, the cage 5 can be prevented from being deteriorated by the lubricating oil or damaged by minute metal pieces. 5 can be extended.

Further, even when minute metal pieces such as abrasion powder and debris are mixed in the lubricating oil, the hard metal layer 8 made of chromium plating, nickel plating, and cobalt plating has a metal equivalent to or more than the fine metal pieces. It is formed by the body.
For this reason, the surface of the hard metal layer 8 is damaged by the minute metal pieces, and the situation where the metal pieces enter is eliminated, so that the long life of the balls 4 and the retainer 5 can be secured, and the reliability is improved. Can be.

Next, FIGS. 4 to 6 show a second embodiment of the present invention. The feature of the present embodiment is that the cage for a rolling bearing is applied to a roller bearing using a roller as a rolling element.

Reference numeral 11 denotes a roller bearing that forms a rolling bearing according to the present embodiment. The roller bearing 11 includes a roller 12 and a retainer 13, which will be described later.

Reference numeral 12 denotes rollers serving as a plurality of rolling elements constituting the roller bearing 11, and each of the rollers 12 is formed in a small cylindrical shape as shown in FIGS.
Are arranged in parallel at equal intervals in the circumferential direction.

Reference numeral 13 denotes a cage according to the present embodiment. The cage 13 has a plurality of rollers 12 arranged at equal intervals in the circumferential direction. The retainer 13 is made of a resin material, and includes an annular body 14, a pocket 15, and a hard metal layer 16, which will be described later.

Numeral 14 denotes an annular body constituting the main body of the retainer 13. The annular body 14 is arranged at equal intervals in the circumferential direction with a pair of ring portions 14A, 14A spaced apart in the axial direction. And a plurality of columns 14 connecting the respective ring portions 14A.
B, 14B,... Also,
The ring-shaped body 14 includes the ring portions 14A,
B outer peripheral surface 14C, inner peripheral surface 14D and each ring portion 14
Left and right end faces 14E, 14E located axially outside of A
And is formed in a cylindrical shape having:

Are a plurality of pockets formed in the annular body 14, and each pocket 15 is formed as an opening surrounded by each ring portion 14A and support 14B. As a result, each pocket 15 is
4 are arranged at equal intervals in the circumferential direction, and are provided so as to penetrate in the radial direction of the annular body 14. In addition, each pocket 15
The cylindrical roller 12 is rotatably held, and the roller 12 is formed as a rectangular hole (a long groove) that fits with a gap. Further, the inner surface of the pocket 15 is a pair of side surfaces 15B, 15B extending in parallel between the longitudinal end surfaces 15A, 15A and the respective end surfaces 15A.

Reference numeral 16 denotes a hard metal layer provided so as to cover the annular body 6 and the pockets 7. The hard metal layer 16 is formed of a hard metal layer similar to the hard metal layer 8 described in the first embodiment. It is formed in a thin film shape from a suitable metal material. The hard metal layer 16 covers the entire surface of the annular body 14 including the end surface 15A and the side surface 15B of each pocket 15, as shown in FIGS.

Thus, according to the present embodiment configured as described above, the same hard metal layer as that of the first embodiment is provided on the surface of the cage 13 for holding the rollers 12 each having a small diameter cylindrical body. 16, the roller 12, the cage 1
3 can be protected from minute metal pieces, and their life can be extended.

In the first embodiment, the hard metal layer 8 has been described as covering the entire surface of the annular body 6 including the inner surface 7A of each pocket 7, but the present invention is not limited to this. 7 and 8, the hard metal layers 21, 21,... May be provided so as to cover only the inner surface 7A of each pocket 7 facing the ball 4. This configuration can be similarly applied to the second embodiment.

In the second embodiment, a roller bearing 11 comprising a roller 12 and a retainer 13 is used as a rolling bearing.
However, the present invention is not limited to this, and may be applied to a roller bearing having an inner ring, an outer ring, and the like.

Further, in each of the embodiments, the ball bearing 1 and the roller bearing 11 forming a radial bearing are exemplified as rolling bearings. Instead, the hard metal layers 8 and 16 according to the present embodiment are used as thrust bearings. May be applied.

Further, in the embodiment, the case where the ball bearing 1 and the roller bearing 11 are used in a planetary gear reduction device has been described as an example. However, the present invention is not limited to this, and for example, a rotating shaft, a support pin, The present invention can be widely applied to rolling bearings that rotatably support a rotating body such as a rotating rod.

[0036]

As described above in detail, according to the first aspect of the present invention, since the pocket is provided with the hard metal layer made of the hard metal material covering the inner surface thereof, the wear powder mixed in the lubricating oil is provided. Even if a small metal piece such as a fragment is sandwiched between the rolling element and the pocket, the inner surface of the pocket is covered with a hard metal layer harder than the fine metal piece, so the small metal piece is retained. You can't get into the bowl. Therefore, the resin cage can be protected from the minute metal pieces by the hard metal layer, and the life of the rolling elements can be extended,
The reliability of the rolling bearing can be improved.

According to the second aspect of the present invention, the hard metal layer is
Because it is provided on the entire surface of the annular body including the inner surface of the pocket,
The hard metal layer can protect the annular body made of the resin material from lubricating oil and minute metal pieces, thereby also extending the life of the cage.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of a main part showing a ball bearing using a cage according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of the ball bearing as seen from the direction of arrows II-II in FIG.

FIG. 3 is an external perspective view showing a cage alone.

FIG. 4 is an enlarged sectional view of a main part showing a roller bearing using a cage according to a second embodiment of the present invention.

FIG. 5 is a cross-sectional view of the roller bearing as viewed from a direction indicated by arrows VV in FIG. 4;

FIG. 6 is an external perspective view showing the cage alone.

FIG. 7 is an enlarged sectional view of a main part showing a ball bearing using a cage according to a modification of the present invention.

FIG. 8 is a sectional view of the ball bearing as viewed from the direction of arrows VIII-VIII in FIG. 7;

[Explanation of symbols]

 Reference Signs List 1 ball bearing (rolling bearing) 4 ball (rolling element) 5,13 cage 6,14 annular body 6A, 14C outer peripheral surface 6B, 14D inner peripheral surface 6C, 14E end surface 7,15 pocket 7A inner surface 15A end surface (inner surface) 15B Side surface (inner surface) 8, 16, 21 Hard metal layer

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Yuji Igawa 650, Kandamachi, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Co., Ltd. Inside the Tsuchiura Plant of Shikisha (72) Inventor Takeshi Shibukawa 650, Kandamachi, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Co., Ltd.

Claims (2)

[Claims] 1. An annular body formed of a resin material in an annular shape, and a plurality of pockets provided radially through the annular body at intervals in a circumferential direction and rotatably supporting a rolling element. The cage for a rolling bearing according to claim 1, wherein the pocket is provided with a hard metal layer made of a hard metal material covering an inner surface of the pocket. 2. The cage for a rolling bearing according to claim 1, wherein the hard metal layer is provided on an entire surface of the annular body including an inner surface of the pocket.