JP2022055108A - Manufacturing method of bearing ring - Google Patents

Abstract

To provide a manufacturing method of a bearing ring in which deformation due to a heat treatment is suppressed.SOLUTION: A manufacturing method of a bearing ring includes an annular member arrangement step of arranging a plurality of annular members 1 to be a bearing ring on a basket 10, a basket arrangement step of arranging the basket 10 inside a heating furnace 20, and a heat treatment step of heat-treating the plurality of annular members 1 arranged on the basket 10. In the annular member arranging step, the plurality of annular members 1 are arranged on the basket 10 so as not to contact each other. In the heat treatment step, the plurality of annular members 1 are quenched by performing heating and cooling while maintaining the arrangement of the plurality of annular members 1 on the basket 10.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for manufacturing a bearing raceway ring.

The bearing raceway ring, which is an annular member, requires the desired mechanical strength as a required function. In order to impart mechanical strength to the bearing raceway ring, in the process of manufacturing the bearing raceway ring, for example, a heat treatment including a quenching treatment is performed on an annular member formed of bearing steel (SUJ2).

For example, Patent Document 1 discloses a continuous heat treatment furnace that heat-treats an object to be heated by carburizing, sintering, or the like.

Japanese Unexamined Patent Publication No. 2009-228116

The bearing raceway ring has low rigidity against elliptical deformation, and the round shape material obtained by turning the material may undergo elliptical deformation due to the thermal influence of the quenching process and the influence of the phase transformation. As described above, the elliptical deformation indicates a phenomenon in which a perfect circular steel component is distorted into an elliptical shape.

The elliptical deformation of the bearing raceway ring is evaluated by measuring the roundness of the bearing raceway ring raceway surface after quenching. The elliptical deformation caused by such heat treatment is removed by the subsequent grinding process, but if the elliptical deformation of the bearing raceway ring is large and the roundness is poor, the grinding amount must be increased, and the bearing raceway ring must be ground. It caused an increase in cost in the manufacturing process.

When heat-treating the annular member to be the bearing raceway ring, for example, continuous heat treatment or batch heat treatment may be performed. The continuous type is a mass production method in which an annular member is placed on a belt conveyor or the like and the annular member is heated while passing through the furnace. The batch type is a method in which an annular member is placed in a basket and the basket is placed in a fixed furnace (batch type heating furnace) to perform heat treatment (heating and cooling). The batch type heating furnace has a feature that the temperature and time can be freely adjusted each time according to the type of the bearing rolling element and the heating conditions.

However, when the annular member is heat-treated using a batch type heating furnace, there has been a problem in the past that the annular member is deformed into an ellipse and the roundness is deteriorated. However, it was not clear what caused this elliptical deformation and deterioration of roundness.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for manufacturing a bearing raceway ring capable of suppressing deformation due to heat treatment.

The above object of the present invention is achieved by the following configuration.
(1) A method for manufacturing a bearing raceway ring.
An annular member arranging process for arranging a plurality of annular members to be bearing raceway rings on a basket,
A basket arranging step of arranging the basket inside the heating furnace, and
A heat treatment step of heat-treating the plurality of annular members arranged on the basket,
Including
In the annular member arranging step, the plurality of annular members are arranged on the basket so as not to come into contact with each other.
In the heat treatment step, the plurality of annular members are quenched by heating and cooling while maintaining the arrangement of the plurality of annular members on the basket.
How to manufacture bearing raceway rings.
(2) At the time of the quenching in the heat treatment step, the basket is immersed in the cooling liquid stored in the liquid tank, and the cooling liquid is allowed to flow in the vertical direction to come into contact with the plurality of annular members, whereby the plurality of annular members are brought into contact with the plurality of annular members. The method for manufacturing a bearing raceway ring according to (1) for cooling a member.
(3) The method for manufacturing a bearing raceway ring according to (1) or (2), wherein the plurality of annular members are installed at predetermined positions in the basket by a positioning member.
(4) The method for manufacturing a bearing raceway ring according to any one of (1) to (3), wherein the heating furnace is a batch type heating furnace.
(5) The method for manufacturing a bearing raceway ring according to any one of (1) to (4), wherein the plurality of annular members are arranged in a houndstooth pattern in the annular member arranging step.
(6) The method for manufacturing a bearing raceway ring according to any one of (1) to (5), wherein the plurality of annular members are carburized in the heat treatment step.
(7) The method for manufacturing a bearing raceway ring according to any one of (1) to (5), wherein the plurality of annular members are nitrided in the heat treatment step.
(8) The method for manufacturing a bearing raceway ring according to any one of (1) to (5), wherein the plurality of annular members are carburized and nitrided in the heat treatment step.
(9) The method for manufacturing a bearing raceway ring according to any one of (1) to (5), wherein the plurality of annular members are quenched in the heat treatment step.
(10) In the heat treatment step, after the plurality of annular members are quenched, the plurality of annular members are further tempered.
The method for manufacturing a bearing raceway ring according to any one of (1) to (9).
(11) Further including a grinding step of grinding the annular member after the heat treatment step.
The method for manufacturing a bearing raceway ring according to any one of (1) to (10).

According to the method for manufacturing a bearing raceway ring of the present invention, it is possible to suppress deformation of the annular member due to heat treatment.

It is a figure which shows the state in which a plurality of annular members are arranged on a basket in an embodiment (Embodiment 1). In the comparative example, it is a figure which shows the state which a plurality of annular members are arranged on a basket. It is a schematic sectional drawing of a heating furnace. It is sectional drawing of the cooling part. It is a figure which shows the state which a plurality of annular members are arranged on a basket in an embodiment (the second embodiment). (A) to (c) are diagrams showing the roundness measurement results of a plurality of annular members after carburizing and nitriding treatment, and (a) to (c) are in Comparative Example, Example 1 and Example 2, respectively. It is a roundness measurement result. (A) to (c) are diagrams showing the roundness measurement results of a plurality of annular members after secondary quenching, and (a) to (c) are in Comparative Example, Example 1 and Example 2, respectively. It is a roundness measurement result.

Hereinafter, a method for manufacturing a bearing raceway ring according to an embodiment of the present invention will be described. In the following description, the bearing raceway ring is also simply referred to as a "raceway ring".

The method for manufacturing the raceway ring includes an annular member preparing step of preparing an annular member 1 to be a raceway ring, an annular member arranging step of arranging a plurality of annular member 1s on the basket 10, and the basket 10 inside the heating furnace 20. It includes a basket arranging step of arranging the annular member 1, a heat treatment step of heat-treating a plurality of annular members 1 arranged on the basket 10, and a grinding step of grinding the annular member 1 after the heat treatment step.

(Circular member preparation process)
In the step of preparing the annular member 1 to be the raceway ring (inner ring or outer ring), the annular member 1 made of the material to be the raceway ring is prepared. As the material of the annular member 1, skin-baked steel is preferable so that a surface-hardened layer can be easily formed by carburizing treatment, nitriding treatment, carburizing nitriding treatment, or the like. Further, in order to improve the hardenability, it is also preferable to add Cr, Mn or the like as an alloy component to the annular member 1.

(Annular member placement process)
After preparing the annular member 1, a plurality of annular members 1 are arranged on the basket 10 in the annular member arranging step as shown in FIG. The basket 10 has a flat bottom surface 11 and a flange portion 13 that stands up from the peripheral edge of the bottom surface 11. Therefore, the basket 10 has a tray-like shape without an upper surface.

Although not shown, since the bottom surface 11 and the flange portion 13 of the basket 10 are mesh-like, the annular member 1 is prevented from falling from the basket 10, and the heat treatment (heating, cooling) for the annular member 1 is efficient. Can be done.

Here, in the present invention, the plurality of annular members 1 are arranged on the bottom surface 11 of the basket 10 so as not to come into contact with each other. That is, the minimum horizontal distance L between adjacent annular members 1 is set to be larger than 0 (L> 0).

Further, as shown in FIG. 1, it is preferable that the plurality of annular members 1 are arranged in a houndstooth pattern. A positioning member may be used in order to accurately install the plurality of annular members 1 at predetermined positions in the basket. By adopting the houndstooth arrangement, it is possible to secure a gap between the adjacent annular members 1 while arranging more annular members 1 on the basket 10.

The arrangement of the plurality of annular members 1 is not particularly limited to a houndstooth shape as long as a gap between adjacent annular members 1 can be secured (L> 0), and for example, a grid pattern (lattice shape) is adopted. It doesn't matter.

When arranging the plurality of annular members 1 on the basket 10 so as to have a gap between them, the plurality of annular members 1 may be positioned by using a jig separate from or integrated with the basket 10. The basket 10 may be provided with irregularities or the like to position the plurality of annular members 1, and the positioning method is not particularly limited.

As shown in FIG. 2, in the prior art, a plurality of annular members 1 are packed tightly on the basket 10. It is normal in consideration of productivity to pack the adjacent annular members 1 so as to be in contact with each other without a gap. That is, when a plurality of annular members 1 are packed without gaps, the number of raceway rings that can be produced at one time can be increased, and the work of arranging them is very simple. In such a conventional technique, elliptical deformation occurs in the annular member 1 after the heat treatment, but the roundness of the annular member 1 is ensured in the subsequent grinding process by increasing the removal allowance. Therefore, in the past, there was no tendency to worry about the elliptical deformation of the annular member 1. However, in reality, it takes a lot of time and cost to secure the roundness of the annular member 1 in the grinding process.

The inventor of the present application has focused on the fact that when the annular member 1 is heat-treated using a batch-type heating furnace, the annular member 1 is elliptical deformed and the roundness is deteriorated by the method of the above-mentioned prior art. Further, it was found that the deterioration of the roundness was caused by the heat treatment (particularly cooling at the time of quenching) while the adjacent annular members 1 were in contact with each other. Therefore, as described above, I came up with the idea of arranging the plurality of annular members 1 so as not to come into contact with each other.

(Basket placement process)
Next, a basket arranging step of arranging the basket 10 in which the plurality of annular members 1 are arranged on the bottom surface 11 inside the heating furnace 20 will be described.

As shown in FIG. 3, the heating furnace 20 is a batch type heating furnace, and is a carry-in unit 30 into which the basket 10 is carried, a heating unit 40 for heating a plurality of annular members 1, and a plurality of annular members. A cooling unit 50 for cooling 1 and a transport unit 60 for transporting the basket 10 between the carry-in unit 30 and the heating unit 40 and between the carry-in unit 30 and the cooling unit 50 are provided. In FIG. 3, the circulation device 55 provided in the cooling unit 50 is not shown. The circulation device 55 will be described later with reference to FIG.

Each of the carry-in section 30, the heating section 40, the cooling section 50, and the transport section 60 supports a plurality of rollers 31, 41, 51, 61 for moving the basket 10 and rollers 31, 41, 51, 61. It has bases 33, 43, 53, 63 and.

A first door 71 that can be opened and closed is provided between the carry-in unit 30 and the transport unit 60, and a second door 73 that can be opened and closed is provided between the transport unit 60 and the heating unit 40.

The heating unit 40 includes a burner 45 for heating the inside of the heating unit 40 and a fan 47 for stirring the atmosphere inside the heating unit 40.

The base 53 of the cooling unit 50 and the base 63 of the transport unit 60 are connected to each other, and are integrally movable in the vertical direction by a cylinder 65 provided above.

The cooling unit 50 is a liquid tank in which the cooling liquid is stored, and in this example, it is an oil tank in which the cooling oil O is stored. The cooling liquid is not limited to the cooling oil, and may be water, an aqueous solution, or the like. The height of the liquid level of the cooling oil O is set so that all of the plurality of baskets 10 arranged in the cooling unit 50 are immersed in the cooling oil O.

As shown in FIG. 4, the cooling unit 50 includes a circulation device 55 that circulates the cooling oil in the oil tank. FIG. 4 is a view of the cooling unit 50 seen from the left-right direction in FIG.
The circulation device 55 is arranged on both sides of the base 53, surrounds a pair of screws 56 that generate a flow of cooling oil O in the vertical direction and a pair of screws 56 from the outside, and a cooling liquid by the pair of screws 56. It is provided with a pair of guide members 57 for guiding the flow of the above.

Therefore, when a downward flow of the cooling oil O is generated in the vicinity of the pair of screws 56, the cooling oil O passes upward through the basket 10 placed on the base 53 (broken line in FIG. 4). See the arrow). On the other hand, when an upward flow of the cooling oil O is generated in the vicinity of the pair of screws 56, the cooling oil O passes downward through the basket 10 placed on the base 53.

When arranging the basket 10 inside such a heating furnace 20, first, a plurality of baskets 10 accommodating a plurality of annular members 1 are vertically arranged on a base 33 (roller 31) of a carrying-in portion 30. Stacked in. In the illustrated example, ten baskets 10 are stacked and arranged in two rows on the base 33.

Next, the first door 71 is opened, the basket 10 is moved onto the base 63 of the transport unit 60, and the first door 71 is closed. Then, the second door 73 is opened, the basket 10 is moved onto the base 43 of the heating unit 40, and the second door 73 is closed. In this way, a plurality of baskets 10 each containing the plurality of annular members 1 are arranged in the heating unit 40.

(Heat treatment process)
In the heat treatment step of heat-treating a plurality of annular members 1 housed in each basket 10, quenching (heating and cooling) is performed, and then tempering (heating and cooling) heat treatment is performed.

It is preferable to form a surface-hardened layer on the annular member 1 by a carburizing treatment, a nitriding treatment, or a carburizing nitriding treatment. This is because when the elliptical deformation is suppressed as in the annular member 1 of the present embodiment, the surface hardened layer can be uniformly ground in the circumferential direction, so that a hardened layer with less unevenness can be formed on the surface of the annular member 1. .. The carburizing treatment, the nitriding treatment, or the carburizing nitriding treatment is performed by holding the carburized nitriding treatment at 900 to 1000 ° C. in a gas atmosphere of carbon or nitrogen for several hours to several tens of hours. Thereby, a desired surface-hardened layer can be obtained.

The plurality of annular members 1 arranged in the heating unit 40 are hardened (heated). It is preferable that the plurality of annular members 1 are subjected to quenching. The condition for quenching is oil cooling at a quenching temperature of 800 to 850 ° C.

Next, by driving the cylinder 65, the base 53 of the cooling unit 50 and the integrated base 63 are raised, and are positioned at the same height as the base 33 of the carry-in unit 30 and the base 43 of the heating unit 40. Let me. Then, after the quenching (heating) of the plurality of annular members 1 is completed, the second door 73 is opened and the basket 10 is moved to the base 53 of the cooling unit 50. Then, the base 53 of the cooling unit 50 is lowered so that all the baskets 10 are immersed in the cooling oil O.

As described above, the pair of screws 56 allows the cooling oil O to pass upward or downward through the mesh-like basket 10 placed on the base 53. Quenching (cooling) is performed by stirring the cooling oil O at 60 to 100 ° C.

Here, since the heating furnace 20 is a batch type heating furnace and has the above-mentioned configuration, quenching (heating) and quenching (cooling) are performed while the arrangement of the plurality of annular members 1 on the basket 10 is maintained. That is, as shown in FIG. 1, the plurality of annular members 1 are arranged on the basket 10 in a houndstooth pattern so as not to come into contact with each other, and the arrangement is maintained (the plurality of annular members 1). 1 does not move), and moves between the carry-in unit 30, the heating unit 40, the cooling unit 50, and the transport unit 60.

Therefore, in the cooling unit 50, even when the plurality of annular members 1 are quenched (cooled), the plurality of annular members 1 are arranged on the basket 10 so as not to come into contact with each other. As a result, the cooling oil O flows in the vertical direction between the adjacent annular members 1, so that the cooling of the annular members 1 becomes uniform. On the other hand, when the cooling oil O flows in the left-right direction (both sides, one side), the cooling can be different due to the difference in the flow velocity of the cooling oil depending on the place where the annular member 1 is arranged, and all the annular members in the same basket are uniform. The annular member 1 is not cooled and the deformation of the annular member 1 becomes large. When the cooling oil O flows in the vertical direction as in the present embodiment, there is no problem that only a part of the annular member 1 is cooled and the other parts are not cooled, and the entire annular member 1 is uniformly cooled. Will be done.

The inventor of the present application has found that whether or not the annular member 1 can be uniformly cooled during this quenching (cooling) is related to the elliptical deformation (deterioration of roundness) of the annular member after the heat treatment. That is, during quenching (cooling), the portion where the annular members 1 are in contact with each other is not sufficiently cooled, while the portion where the annular members 1 are not in contact with each other is cooled. It was discovered that it was the cause of the elliptical deformation of the annular member 1 of. Then, in order to uniformly cool the annular member 1, we came up with a configuration in which the plurality of annular members 1 are arranged on the basket 10 so as not to come into contact with each other.

The arrangement of the plurality of annular members 1 as described above is when quenching (heating) and quenching (cooling) are performed while the arrangement of the plurality of annular members 1 on the basket 10 is maintained, that is, batch heating. It is particularly suitable when the furnace 20 is used. In the batch type heating furnace 20, the arrangement of the plurality of annular members 1 on the basket 10 is maintained from the annular member arranging step before the annular member 1 is carried into the heating furnace 20 to the basket arranging step and the heat treatment step. Therefore, the arrangement of the plurality of annular members 1 during the annular member arrangement process is very important.

On the other hand, in the continuous heating furnace, the arrangement of the plurality of annular members 1 may differ between quenching (heating) and quenching (cooling). That is, during quenching (during cooling), the plurality of annular members 1 are individually charged into the oil tank in which the cooling oil is stored. In this case, the arrangement of the plurality of annular members 1 is not maintained. In such a case, even if a plurality of annular members 1 are arranged side by side so as not to contact each other and quenched (heated), the annular members 1 may come into contact with each other during quenching (during cooling), and the annular member 1 may be deformed in an elliptical shape. be.

After quenching (cooling), the basket 10 is moved to the base 33 of the carry-in section 30 again, and further moved to a tempering furnace (not shown), and the plurality of annular members 1 are tempered (heated and cooled). It will be. Tempering is performed at 150 to 300 ° C. for 1 to 2 hours.

(Grinding process)
After the heat treatment step, a grinding step of grinding the annular member 1 is performed. In the grinding process, the inner diameter surface and the outer diameter surface of the annular member 1 are ground to manufacture a bearing raceway ring. According to the manufacturing method of the present application, the elliptical deformation of the annular member 1 due to heat treatment is suppressed, and the roundness of the annular member 1 is also good, so that the amount of grinding required in the grinding process can be reduced and the number of grinding steps is reduced. can.

Then, the bearing raceway ring completed by the above method can be assembled together with the rolling element and the cage to form a bearing.

(Example)
Next, the influence of the arrangement of the plurality of annular members 1 on the basket 10 on the elliptical deformation (roundness) of the annular member 1 after the heat treatment was investigated.

In the first embodiment, as shown in FIG. 1, the plurality of annular members 1 are housed in the basket 10 so as not to come into contact with each other. The number of annular members 1 arranged in one basket 10 is 42, and the baskets 10 stacked in 16 stages are arranged in two rows as shown in FIG. 3 to perform heat treatment. Therefore, 1344 (42 × 16 × 2) annular members 1 are heat treated at the same time.

In the second embodiment, as shown in FIG. 5, the plurality of annular members 1 are housed in the basket 10 so as not to come into contact with each other. In the second embodiment, the number of the annular members 1 arranged on the basket 10 is reduced in order to further widen the distance between the adjacent annular members 1 as compared with the first embodiment. The number of annular members 1 arranged in one basket 10 is 9, and the baskets 10 stacked in 12 stages are arranged in two rows as shown in FIG. 3 to perform heat treatment. Therefore, 216 (9 × 12 × 2) annular members 1 are heat-treated at the same time.

In the comparative example (L = 0), as shown in FIG. 2, a plurality of annular members 1 are packed on the basket 10 without gaps. The number of annular members 1 arranged in one basket 10 is 54, and the baskets 10 stacked in 12 stages are arranged in two rows as shown in FIG. 3 to perform heat treatment. Therefore, 1296 (54 × 12 × 2) annular members 1 are heat treated at the same time.

The material of the annular member 1 used in Example 1, Example 2, and Comparative Example is steel having a carbon concentration of 0.4 wt%, and an alloy such as Cr or Mn is used to ensure hardenability in oil cooling. An appropriate amount of element is added. Using this steel as a material, it was molded to a predetermined size by machining and various effects were evaluated. It was confirmed that when the annular member manufactured from the above material was quenched under the heat treatment conditions described in the present application, the annular member 1 was sufficiently cured under any heat treatment conditions.

The outer diameter of the annular member 1 was about φ75 mm. In the heat treatment step, the annular member 1 is carburized and nitrided for 3.5 hours in a batch heating furnace, then secondarily heated, and then quenched in oil at about 100 ° C. (secondary quenching). Then, it was tempered. The roundness of the plurality of annular members 1 for which the heat treatment was completed was measured in this way.

The roundness measurement results of the plurality of annular members 1 after the carburizing and nitriding treatment are shown in FIGS. 6A to 6C. In FIGS. 6A to 6C, the horizontal axis is the roundness (μm), and the vertical axis is the number of annular members 1 having the roundness in the corresponding range. 6 (a) to 6 (c) are roundness measurement results in Comparative Example, Example 1, and Example 2, respectively. The results of FIGS. 6 (a) to 6 (c) are summarized in Table 1 below.

In the comparative example, among the plurality of annular members 1, the maximum value of roundness was 200 μm, the minimum value of roundness was 20 μm, and the average value of roundness was 85 μm. In Example 1, among the plurality of annular members 1, the maximum value of roundness was 160 μm, the minimum value of roundness was 10 μm, and the average value of roundness was 58 μm. In Example 2, the maximum value of roundness was 120 μm, the minimum value of roundness was 10 μm, and the average value of roundness was 43 μm. As described above, it can be seen that Examples 1 and 2 have better roundness than Comparative Examples. In particular, Example 2 in which the gap between the adjacent annular members 1 was set to be large had a better roundness than that in Example 1.

The roundness measurement results of the plurality of annular members 1 after the secondary quenching are shown in FIGS. 7 (a) to 7 (c). In FIGS. 7A to 7C, the horizontal axis is the roundness (μm), and the vertical axis is the number of annular members 1 having the roundness in the corresponding range. 7 (a) to 7 (c) are roundness measurement results in Comparative Example, Example 1, and Example 2, respectively. The results of FIGS. 7 (a) to 7 (c) are summarized in Table 2 below.

In the comparative example, among the plurality of annular members 1, the maximum value of roundness was 260 μm, the minimum value of roundness was 20 μm, and the average value of roundness was 108 μm. In Example 1, the maximum value of roundness was 220 μm, the minimum value of roundness was 10 μm, and the average value of roundness was 68 μm. In Example 2, the maximum value of roundness was 140 μm, the minimum value of roundness was 10 μm, and the average value of roundness was 52 μm. Similar to the roundness measurement after carburizing and nitriding, it can be seen that the roundness of Examples 1 and 2 is better than that of the comparative example in the roundness measurement after the secondary quenching. In particular, Example 2 in which the gap between the adjacent annular members 1 was set to be large had a better roundness than that in Example 1.

As described above, it has been clarified that the elliptical deformation can be suppressed when the annular members 1 are heat-treated in a state where they are arranged at regular intervals. In Examples 1 and 2, since the elliptical deformation of the annular member 1 after the heat treatment is suppressed and the roundness is good, the grinding amount can be reduced in the grinding step after the heat treatment, and there is a great cost reduction effect. ..

1 Circular member 10 Basket 11 Bottom surface 13 Flange part 20 Heating furnace (batch type heating furnace)
30 Carry-in part 31 Roller 33 Base 40 Heating part 41 Roller 43 Base 45 Burner 47 Fan 50 Cooling part 51 Roller 53 Base 55 Circulation device 56 Screw 57 Guide member 60 Transport part 61 Roller 63 Base 65 Cylinder 71 First door 73 Second door O Cooling oil (cooling liquid)

Claims (11)

It is a method of manufacturing bearing raceway rings.
An annular member arranging process for arranging a plurality of annular members to be bearing raceway rings on a basket,
A basket arranging step of arranging the basket inside the heating furnace, and
A heat treatment step of heat-treating the plurality of annular members arranged on the basket,
Including
In the annular member arranging step, the plurality of annular members are arranged on the basket so as not to come into contact with each other.
In the heat treatment step, the plurality of annular members are quenched by heating and cooling while maintaining the arrangement of the plurality of annular members on the basket.
How to manufacture bearing raceway rings. At the time of the quenching in the heat treatment step, the basket is immersed in the cooling liquid stored in the liquid tank, and the cooling liquid is allowed to flow in the vertical direction to come into contact with the plurality of annular members, thereby cooling the plurality of annular members. The method for manufacturing a bearing raceway ring according to claim 1. The method for manufacturing a bearing raceway ring according to claim 1 or 2, wherein the plurality of annular members are installed at predetermined positions in the basket by a positioning member. The method for manufacturing a bearing raceway ring according to any one of claims 1 to 3, wherein the heating furnace is a batch type heating furnace. The method for manufacturing a bearing raceway ring according to any one of claims 1 to 4, wherein the plurality of annular members are arranged in a houndstooth pattern in the annular member arranging step. The method for manufacturing a bearing raceway ring according to any one of claims 1 to 5, wherein the plurality of annular members are carburized in the heat treatment step. The method for manufacturing a bearing raceway ring according to any one of claims 1 to 5, wherein in the heat treatment step, the plurality of annular members are nitrided. The method for manufacturing a bearing raceway ring according to any one of claims 1 to 5, wherein the plurality of annular members are carburized and nitrided in the heat treatment step. The method for manufacturing a bearing raceway ring according to any one of claims 1 to 5, wherein in the heat treatment step, the plurality of annular members are quenched. In the heat treatment step, after the plurality of annular members are quenched, the plurality of annular members are further tempered.
The method for manufacturing a bearing raceway ring according to any one of claims 1 to 9. After the heat treatment step, the grinding step of grinding the annular member is further included.
The method for manufacturing a bearing raceway ring according to any one of claims 1 to 10.

Images