JPS6148010B2 - - Google Patents

Abstract

PURPOSE:To eliminate risk of hot crack during heat treatment and provide possibility of dividing with light load by furnishing a slit in the R'ed part at the tip of a notch, formed in the end face during turning process, after heat treatment, and by dividing after final grinding process. CONSTITUTION:A notch 5 is formed in the end face of a bearing ring 4 during turning process. After heat treatment a wheel 7 with small wall thickness shall make a slit 6 in the R'ed part at the tip of said notch 5. After final grinding process, a wedge type crushing means 8 having a tip with larger angle than the notch 5 shall apply a wedge stress to the notch 5 so as to split the bearing ring 4.

Description

[Detailed description of the invention]

B. Field of Industrial Application This invention relates to bearing rings (inner ring, outer ring) used in locations where assembly from the shaft end is impossible, locations where there are obstacles on the shaft, locations where the shaft is extremely long, etc. The present invention relates to a method of manufacturing a split bearing in which a cage is split. B. Prior art Generally, when dividing the bearing ring of the above-mentioned split bearing, a substantially V-shaped notch 2 is provided in advance in the end face of the bearing ring 1 as shown in FIG. 1 in the turning process, and after heat treatment and grinding, as shown in FIG. As shown in FIG. 2, a wedge-type crushing means 3 having a tip having a larger angle than the notch 2 is used to apply a wedge stress to the notch 2, and the bearing ring 1 is
was naturally divided in the axial direction. By the way, in the above bearing ring 1, if the tip radius of the notch 2 is small or if the notch 2 is deep, quench cracking is likely to occur during heat treatment, and if the tip radius of the notch 2 is large. Also, if the depth of the notch 2 is shallow, there is a problem that cracking is difficult to occur during the splitting operation after grinding, and chipping of the fracture surface is likely to occur. C. Purpose of the Invention The present invention provides a method for manufacturing a split bearing that has no risk of quench cracking during heat treatment, can be split with a relatively small load after grinding, and exhibits a normal fracture surface. The purpose is to D. Structure of the Invention In the method for manufacturing a split bearing according to the present invention, a notch with a large tip radius is formed on the end face of the bearing ring in the turning process, and after heat treatment, a slit is formed with thin foil in the tip radius of the notch, and the final grinding process is performed. The bearing ring was later separated. E. Embodiment Figures 3 and 4 are invention drawings for inventing a method for manufacturing a split bearing according to the present invention, and 4 is an inner ring or an outer ring (hereinafter referred to as (referred to as bearing ring), 5 is the concentrated stress rate α≦ of the tip radiused portion on the end face of bearing ring 4.
3.0 is a substantially V-shaped notch 6, which is a slit formed at the rounded end of the notch 4 to a depth where the concentrated stress factor α≧4.0. In this invention, the bearing ring 4 is divided by forming a notch 5 on the end face of the bearing ring 4 as shown in FIG. 3 in the turning process, and after heat treatment or grinding, as shown in FIG. A slit 6 is formed in the rounded end of the notch 5, and after the final grinding process, a wedge is formed in the notch 5 using a wedge-type crushing means 8 having a tip with a larger angle than the notch 5, as shown in FIG. The bearing ring 4 is divided by applying stress. FIG. 6 shows that when a specimen 10 of finite width B with a notch 9 on one side shown in FIG. 7 is subjected to tensile force P, the horizontal axis represents the depth α/B of the notch 9, and the vertical axis represents the maximum stress,
That is, it is a relational diagram in which the stress concentration force α of σx occurring at the notch bottom point A is taken and the radius of curvature ρ/B is plotted as a parameter. Table 1 shows the number of quench cracks and the number of defective splits after grinding when the α value was varied. That is,

[Table] N = 10 rings of φ650 x φ570 x 170 (outer diameter x inner diameter x width dimensions) with various notches of α = 2.0, 3.0, 5.0, and 6.5 made with SUJ-3,
It was quenched in oil at 810°C to 60°C and tempered at 180°C. According to this, when α≧5.0, there is a risk of quench cracking, and when α≦3.0, there is a risk of poor division after grinding. On the other hand, another n = 20 rings of the same size with a notch of α = 2.0, which has no risk of quench cracking, are heat treated under the same conditions as above, and after heat treatment, α = 4.0 and 6.5 for foils with a thickness of 0.5 mm. 10 pieces each to the depth
After cutting at a cutting speed of 2.0 mm/min, division was performed. According to this, there is no occurrence of splitting defects, and the cracking load is the same as in the case of having notches of α=4.0 and 6.5 before quenching. F. Effect of the Invention The method for manufacturing a split bearing according to the present invention includes forming a notch with a large tip radius on the end face of the bearing ring in the turning process, and after heat treatment, forming a slit with a thin foil in the tip radius of the notch, and then performing the final grinding process. Since the purpose is to split the bearing later, there is no risk of quench cracking of the bearing ring during heat treatment, and it is also possible to split the bearing ring with a relatively small load to obtain a normal split surface. It is something to do.

[Brief explanation of the drawing]

1 and 2 are drawings showing a conventional method for manufacturing a split bearing, FIGS. 3 to 5 are drawings showing a method for manufacturing a split bearing according to the present invention, and FIG. 6 is a curvature of the tip radius of the notch. FIG. 7 is a relationship diagram in which the radius is plotted as a parameter, and is a drawing showing the specimen. 4... Bearing ring, 5... Notch, 6... Slit, 7... Thin foil, 8... Wedge type crushing means.

Claims (1)

[Claims] 1 After the final grinding process, in a split bearing where the bearing ring is naturally split in the axial direction, a notch with a stress concentration rate of α≦3.0 at the tip radius is provided on the end face of the split ring in the turning process, and after heat treatment, the tip radius of the notch is A method for manufacturing a split ring, characterized in that a slit with α≧4.0 is provided in the portion using thin foil, and the bearing ring is split after final grinding.