JPS6224956A - Superfinishing method for raceway groove of ball bearing - Google Patents

Abstract

PURPOSE:To have efficient processing by performing lapping by the use of a tape coated with abrasive grains consisting of boron nitride of cubic crystal type, thereby providing uniform striation due to processing in a raceway groove and lessening the frequency of tape replacement. CONSTITUTION:The foremost surface 5 of a tape pressing member 3 is given the same curvature as that of a raceway ring 1, and a lapping tape 10 consisting of a base tape 11 coated one one of the sides with abrasive grains 13' of cubic crystalline boron nitride (CBN) with the aid of adhesives 12, is pressed to the raceway groove 2 in the raceway ring 1. Then the tape 10 is run in the longitudinal direction (as shown by arrow), and the above-mentioned tape pressing member 3 is swung oscillatively in the direction along the curvature, and now processing is performed with the raceway ring 1 revolved at a high speed. These abrasive grains 13' which are harder than diamond cause less crush and eventual crush should produces a flat and smooth plane of cleavage, so that uniform and continuous striations 4' are left on the raceway groove 2, and thus noise generation is less when a ball bearing is formed. Sharpness in cutting should require less frequency of tape 10 replacement to accomplish effective processing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method of superfinishing the pole raceway grooves of a ball bearing using a wrapping tape.

[Conventional technology and its problems]

The present applicant has already proposed a superfinishing device for polishing raceway grooves of ball bearings using lapping tape in Japanese Patent Application No. 59-1043.

The super-finishing device shown in the above specification is explained by taking as an example the case where the raceway groove provided on the inner diameter surface of the outer ring is polished, but it is also possible to polish the raceway groove on the outer diameter surface of the inner ring in the same way. can. The superfinishing method in this case is as shown in FIG. The abrasive coated surface of the lapping tape 10 drawn out along the tip surface of the tape pressing member 3 is pressed against the raceway groove 2 by the pressing member 3, and in this state, the lapping tape is pressed against the raceway groove 2. 10 is moved in the length direction, the tape pressing member 3 is swung around the center of curvature of the raceway groove 2 as the center of oscillation, and the raceway ring 1 is further rotated in one direction.

Here, as shown in FIG. 3, the lapping tape 10 is made by uniformly coating abrasive grains 13 on one side of a thin film 11 made of polyester or the like through an adhesive layer 12, and has the above-mentioned raceway grooves. Conventionally, alumina abrasive grains or silicon carbide abrasive grains were used as polishing abrasive grains 13 for super finishing in step 2.
The polishing work was performed using a wrapping tape 10 having the following properties.

By the way, in the superfinishing method using lapping tape as described above, alumina abrasive grains and silicon carbide abrasive grains often break and fall off during polishing, and as a result, the
As shown in the figure, uneven circumferential streaks 4 remain in the raceway groove 2 of the raceway ring 1, which causes an inconvenience in that abnormal noise is generated when a ball bearing is constructed.

In addition, unlike polishing with a grindstone, the lapping tape 10 described above has a limited abrasive layer, so it is easily clogged.
It is necessary to process the tape by changing it several times, and if the tape pressing force is increased, there are problems such as tape breakage.

[Purpose of the invention]

The object of the present invention is to provide a superfinishing method that eliminates the above-mentioned disadvantages, makes the processing streaks on the processed surface uniform, and reduces the frequency of tape replacement.

[Structure of the invention]

In order to achieve the above object, the present invention employs a lapping tape coated with cubic boron nitride abrasive grains, and the abrasive grain surface of the lapping tape is pressed into the raceway groove of the raceway ring by the pressing action of a tape pressing member. The tape pressing member is oscillated around the center of curvature of the raceway groove as the center of oscillation while moving the wrapping tape in the length direction, and the raceway ring is rotated in one direction to super finish the raceway groove. It is processed.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in Fig. 2, a bearing ring 1 that is rotationally driven in one direction.
The tip surface 5 of the tape pressing member 3 that presses the wrapping tape 10 against the raceway groove 2 is formed to have the same curvature as the curvature of the raceway ring 1. On the other hand, the wrapping tape 10 is
As shown in FIG.
2 through cubic boron nitride (CBN) abrasive grains 13'
is evenly coated.

When superfinishing the raceway groove 2, as in the past, with the abrasive grain surface of the lapping tape 1o pressed against the raceway groove 2, the lapping tape 10 is moved in the length direction to align the center of curvature of the raceway groove 2. The tape pressurizing member 3 is oscillated about the oscillation center, and the bearing ring 1 is rotated at high speed in one direction.

Here, the cubic boron nitride abrasive grains 13' coated on the lapping tape 10 are harder than diamond, so they are less likely to be crushed, and if they are crushed,
A smooth surface that is cracked or peeled off parallel to a specific surface,
In other words, in order to create the inter-fold surface, the raceway groove 2 is
A machining line 41 that continues in the circumferential direction of the raceway groove 2 as shown in FIG. 2 remains, which is effective in making the machining line 4 uniform.

〔effect〕

As described above, according to the present invention, the raceway grooves of the raceway ring are superfinished using a lapping tape coated with low grains of cubic boron nitride, which is harder than diamond and has inter-fold properties. Since it is machined, the superfinishing process leaves uniform machining lines in the raceway groove, which is advantageous for reducing noise generated from the ball bearing when a ball bearing is constructed.

In addition, since the abrasive grains are less crushed, the frequency of tape replacement is reduced, and the sharpness is good, so there is no problem of tape breakage during processing, and superfinishing can be performed extremely efficiently.

[Brief explanation of the drawing]

Fig. 1 is an enlarged cross-sectional view of the wrapping tape used in the method according to the present invention, Fig. 2 is a schematic diagram showing how a raceway groove is processed using the same tape, and Fig. 3 is an enlarged view showing a conventional wrapping tape. A cross-sectional view, FIG. 4 is a front view of a bearing ring processed using the wrapping tape, and FIG. 5 is a perspective view showing a schematic view of a processing device using the wrapping tape. 1... Raceway ring, 2... Raceway groove, 3... Pressure member,
10... Lapping tape, 13'... Cubic boron nitride abrasive grains. Patent Applicant NCH NTO Bearing Co., Ltd. Agent Kama 1) Text 2 Figure 2

Claims (1)

[Claims] The tip surface of a tape pressing member that can be pressed against and separated from the arcuate raceway groove formed in the raceway ring is an arcuate surface with a curvature that fits into the raceway groove, and the tape pressing member is applied to the raceway groove. In the method of superfinishing the raceway groove by moving the pressed wrapping tape in the length direction, swinging the tape pressing member, and rotating the raceway ring in one direction, the wrapping tape is made of cubic nitride. A superfinishing method for raceway grooves in ball bearings, characterized by using a lapping tape coated with boron abrasive grains.