JP3874617B2 - Manufacturing method of rolling bearing - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of manufacturing a rolling bearing, and more particularly to a manufacturing method improved so that a yellow chromate layer on a side end surface of a bearing ring is not peeled off.
[0002]
[Prior art]
When manufacturing rolling bearings in which the rust-preventive galvanized layer and yellow chromate layer are laminated on the surface of the inner and outer races (inner and outer races that form the raceway), the inner and outer races are manufactured as follows. A rolling element, its retainer, a seal and the like are incorporated between the inner and outer races.
[0003]
To manufacture the inner and outer races, first, the inner and outer races are formed by turning from a metal base material, heat-treated, and then the race (width side surface) is ground. After the galvanizing and yellow chromate treatments are applied sequentially to the inner and outer race rings, the finish surfaces are finished and superfinished, and the inner ring inner surface and outer ring outer surface are ground. The inner and outer races are manufactured.
[0004]
[Problems to be solved by the invention]
However, when the surface of the raceway is subjected to galvanization and yellow chromate treatment as described above, the side surface of the raceway is magnetically attached to the backing plate of the grinding machine, and the finish grinding of the raceway surface is performed. Due to the relative sliding between the backing plate and the side end face of the race, the thin and relatively soft yellow chromate layer on the end face of the race is worn away, and the galvanized layer is exposed.
[0005]
The present invention has been made to address the above problems, and its object is to provide a method of manufacturing a rolling bearing with an improved bearing ring manufacturing process so that the yellow chromate layer on the side end face of the bearing ring is not worn away. There is to do.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a rolling bearing manufacturing method according to the present invention includes a rolling step for forming a bearing ring of a rolling bearing by turning the bearing ring from a metal base material, and a side end surface of the formed bearing ring. A grinding process for grinding the surface, a galvanizing process for galvanizing the ground raceway, a finishing process for finishing the raceway surface of the galvanized raceway and removing the galvanized layer on the raceway surface, And a yellow chromate process in which the finished raceway ring is immersed in a chromate solution to perform yellow chromate treatment .
[0007]
In this way, when the order of the yellow chromate treatment process and the finish machining process is switched and the finish machining process is incorporated between the galvanization treatment process and the yellow chromate treatment process, a galvanized layer is formed on the surface of the raceway in the finish machining process. As a result, the yellow chromate layer cannot be worn by the relative slip between the grinding machine backing plate and the side end face of the race, and the relatively hard galvanized layer is also worn by the relative slip. There is nothing. Then, after removing the galvanized layer on the surface such as the raceway surface that does not need to be plated in the finishing process, the raceway ring is subjected to yellow chromate treatment in the yellow chromate treatment step. The yellow chromate layer is not formed, and the yellow chromate layer is formed only on the surface that needs to be plated, such as the side end face from which the zinc plating layer is not removed. Therefore, the conventional problem that the galvanized layer is exposed by the abrasion of the yellow chromate layer on the end surface of the raceway ring can be reliably solved.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.
[0009]
1 to 4 illustrate a bearing ring manufacturing process in the rolling bearing manufacturing method of the present invention. FIG. 1 is a half sectional view showing inner and outer bearing rings formed in a turning process, and FIG. 2 is a galvanizing process. 3 is a half sectional view showing the inner and outer race rings galvanized in the process, FIG. 3 is a half sectional view showing the inner and outer race rings finished in the finishing process, and FIG. 4 is yellow chromate treated in the yellow chromate treatment process. It is a half sectional view showing the inner and outer races. FIG. 5 is a half sectional view showing the rolling bearing assembled in the final assembly process.
[0010]
According to the rolling bearing manufacturing method of the present invention, by turning the metal base material in the first turning process of the bearing ring manufacturing process, the inner and outer bearing rings 1, 2 as shown in FIG. An inner ring 1 having a raceway surface 1c at the center in the axial direction of the surface 1a and an outer ring 2 having a raceway surface 2c at the center in the axial direction of the inner diameter surface 2b are formed. In this embodiment, not only the raceway surfaces 1c and 2c are formed on the inner ring outer diameter surface 1a and the outer ring inner diameter surface 2b by turning, but the step portions 1d and 1d are formed at both axial ends of the inner ring outer diameter surface 1a and the outer ring inner diameter surface 2b. 2d is formed, and a groove 2e is formed in the step portion of the inner surface 2b of the outer ring.
[0011]
The inner ring 1 and the outer ring 2 obtained in the above-described turning process improve strength, toughness, and other mechanical properties by performing normal quenching generally performed in the next heat treatment process.
[0012]
Then, the heat-treated inner ring 1 and outer ring 2 perform so-called width grinding on the side end faces 1f and 2f on both sides in the axial direction in the next grinding step. In this grinding step, rough grinding of the outer ring outer diameter surface 2a may be performed as necessary.
[0013]
The inner ring 1 and the outer ring 2 that have been subjected to width grinding are subjected to a galvanizing process on the entire surface in the following galvanizing process, thereby forming a galvanized layer 3 on the entire surface of the inner ring 1 and the outer ring 2 as shown in FIG. To do. In this galvanizing process, the inner ring 1 and the outer ring 2 are immersed in a plating bath using a zinc plate as an anode and dissolving zinc cyanide, sodium cyanide, sodium hydroxide, zinc oxide, etc., as in the past. Then, it may be performed by connecting to the cathode and energizing. The galvanized layer 3 is preferably formed to a thickness of about 5 to 15 μm. With this thickness, the inner ring 1 and the outer ring 2 can be sufficiently covered and protected.
[0014]
The galvanized inner ring 1 and outer ring 2 are baked at a temperature of about 120 ° C. to 150 ° C. in order to stabilize the galvanized layer 3 in the next baking step.
[0015]
The baked inner ring 1 and outer ring 2 are subjected to finish grinding or superfinish polishing in the next finishing process. That is, for the inner ring 1, the raceway surface 1c and the inner ring inner surface 1b are finish-ground, and the raceway surface 1c is superfinish polished. As for the outer ring 2, the outer ring outer diameter surface 2a and the raceway surface 2c are finish-ground, and the raceway surface 2c is superfinished. When finishing is performed in this manner, the galvanized layer 3 in that portion is removed, and as shown in FIG. 3, the raceways 1c and 2c of the inner ring 1 and the outer ring 2 that do not require plating, the inner ring inner surface 1b, the outer ring The outer diameter surface 2a is exposed.
[0016]
Since this finishing process is performed by magnetically attaching the side end faces 1f, 2f of the inner ring 1 and the outer ring 2 to the backing plate of the grinding machine as in the prior art, there is a relative slip between the side end faces 1f, 2f and the backing plate. appear. However, in this finishing process, only the galvanized layer 3 is formed, and the yellow chromate layer has not yet been laminated. Therefore, the yellow chromate layer cannot be worn by relative sliding as in the past, Also, the relatively hard galvanized layer 3 is not worn away by relative sliding.
[0017]
The finished inner ring 1 and outer ring 2 are subjected to yellow chromate treatment in the next yellow chromate treatment step, so that as shown in FIG. 4, the side end surfaces of the inner ring 1 and outer ring 2, the inner ring outer diameter surface, and the outer ring inner diameter surface. A yellow chromate layer 4 is formed on the galvanized layer 3 covering the substrate. This yellow chromate treatment may be performed by immersing the inner ring 1 and the outer ring 2 for several seconds to several tens of seconds in a chromate solution containing chromic acid, sulfuric acid, and nitric acid, as in the prior art. When immersed in this manner, the surface layer portion of the galvanized layer 3 is dissolved, and a thin layer of chromium chromate containing zinc chromate having a thickness of 1 μm or less, that is, a yellow chromate layer 4 is rapidly formed on the surface of the galvanized layer 3. Is done.
[0018]
As described above, in the manufacturing method of the present invention, since the yellow chromate treatment is performed after the finishing process, the yellow chromate layer is not worn and the zinc plating is not exposed as in the conventional case.
[0019]
When the yellow chromate treatment of the inner ring 1 and the outer ring 2 is completed, a rolling element (ball) 5, its retainer 6, a seal 7, etc. are assembled between the inner ring 1 and the outer ring 2 as shown in FIG. 5 in the final assembly process. Further, grease (not shown) is further sealed to complete a desired rolling bearing (ball bearing). The seal 7 of this rolling bearing is obtained by integrally fixing a rubber material 7b to the inner periphery of an annular cored bar 7a by insert molding. The outer peripheral part of the tubular cored bar 7a is fitted into the step 2d of the outer ring 2, and the outer ring 2 is fixed so as not to drop off by a fixing ring 8 fitted in the groove 2e. The rubber material 7b of the seal 7 is formed with a lip so as to be in sliding contact with the stepped surface of the stepped portion 1d and exhibit excellent sealing performance.
[0020]
The manufacturing method of the present invention has been described above by taking the case of manufacturing a ball bearing as an example, but the present invention is naturally applicable to the case of manufacturing other rolling bearings using rollers or the like as rolling elements. .
[0021]
【The invention's effect】
The manufacturing method of the rolling bearing of the present invention simply replaces the order of the yellow chromate treatment process and the finish machining process in the bearing ring manufacturing process, and incorporates the finish machining process between the galvanization treatment process and the yellow chromate treatment process. There is a remarkable effect that the conventional problem that the yellow chromate layer on the side end face of the bearing ring is worn away and the galvanized layer is exposed can be surely solved.
[Brief description of the drawings]
FIG. 1 is a half sectional view showing inner and outer races formed in a turning process in a manufacturing method of the present invention.
FIG. 2 is a half sectional view showing inner and outer races that have been galvanized in the galvanizing step in the manufacturing method of the present invention.
FIG. 3 is a half sectional view showing inner and outer races finished in the finishing step in the manufacturing method of the present invention.
FIG. 4 is a half sectional view showing inner and outer race rings that have been subjected to yellow chromate treatment in the yellow chromate treatment step of the production method of the present invention.
FIG. 5 is a half sectional view showing the rolling bearing assembled in the final assembly step in the manufacturing method of the present invention.
[Explanation of symbols]
1, 2 Inner and outer races (1 inner ring, 2 outer ring)
1a inner ring outer diameter surface 1b inner ring inner diameter surface 2a outer ring outer diameter surface 2b outer ring inner diameter surface 1c, 2c raceway surface 1f, 2f side end surface 3 galvanized layer 4 yellow chromate layer 5 rolling element 6 cage 7 seal

Claims (1)

As rolling ring bearing ring manufacturing processes, a turning process in which the bearing ring is formed by turning from a metal base material, a grinding process in which the side end surface of the formed bearing ring is ground, and a galvanization in which the ground bearing ring is galvanized. Treatment process, finishing process to finish the raceway surface of the galvanized raceway ring to remove the galvanized layer on the raceway surface, and yellow chromate treatment by immersing the finished raceway ring in chromate solution A method of manufacturing a rolling bearing, comprising: a yellow chromate process.

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