Bearing device production method and bearing device

Abstract

In order to make an operation to press-fit a holder (21) of a sensor unit (20) into a fixed ring (11) of a rolling bearing (10) easier and to suppress deformations of the holder (21) and the fixed ring (11), several samples are extracted from holders (21) constituting one processed lot when press-forming the holders (21). The sizes in the radial direction of press-fit surfaces (25) of the samples are measured, and a representative size of the holders (21) is set for each lot on the basis of the measurement result. Then, a reference size and a dimensional tolerance of the size in the radial direction of a notch part (16) of the fixed ring (11) are set so that the tightening allowance between the notch part (16) and the press-fit surface (25) falls within a range which has been set in advance with respect to the representative size. Subsequently, notch parts (16) for one lot are processed.

Description

Bearing device manufacturing method and bearing device

[0001] The present invention relates to a method for manufacturing a bearing device in which a sensor unit is attached to a rolling bearing, and to a bearing device manufactured by this manufacturing method.

[0002] 2. Description of the Related Art Conventionally, there is known a bearing device in which a sensor unit for detecting the state of a rolling bearing is attached to the rolling bearing.

[0003] In such bearing devices, a sensor unit incorporating a sensor is generally fixed to the fixed raceway (hereinafter also referred to as the "fixed raceway") of the outer and inner rings of the rolling bearing, and power is supplied to the sensor unit from a generator located between the fixed raceway (hereinafter also referred to as the "rotating raceway") of the outer and inner rings and the fixed raceway.

[0004] For example, Patent Document 1 discloses a bearing device in which an extension part that protrudes annularly from the outer periphery of the outer ring outward in the axial direction is provided at one axial end of a deep groove ball bearing in which balls are arranged as rolling elements between an outer ring that is a fixed ring and an inner ring that is a rotating ring, and a sensor unit is provided on the inner periphery of this extension part, so that rotational speed, etc. can be detected by power supplied to the sensor unit from a generator provided between the outer ring and the inner ring.

[0005] In this bearing device, an annular holder with an L-shaped cross section (which also serves as a yoke member that constitutes the generator) to which the sensor of the sensor unit is attached is fitted and fixed to the inner side of the extension of the outer ring (the annular cutout portion at one axial end).

[0006] Japanese Patent Application Laid-Open No. 2003-307435

[0007] In bearing devices in which a sensor unit is attached to a rolling bearing as in Patent Document 1, the metal holder of the sensor unit is formed by pressing into an L-shaped cross section, i.e., a shape in which a fitting portion protrudes annularly in the axial direction from the outer or inner periphery of an annular disc portion, and the fitting portion of the holder is often press-fitted into an annular cutout portion formed on the surface of the fixed ring facing the rotating ring.

[0008] When the sensor unit holder is formed by press working, the tolerances listed on the production drawings are set relatively large (e.g., 0.2 mm) to take into account wear of the press die. On the other hand, the notch in the fixing ring into which the holder is fitted and fixed is formed by cutting or grinding, so the tolerance can be relatively small (e.g., 0.03 mm or less).

[0009] The radial tolerance of the notch in the fixed ring is set based on the radial tolerance of the press-fit surface (outer or inner peripheral surface) of the fitting portion of the holder into the notch, but because the dimensional tolerance of the holder is large, when actually press-fitting the fitting portion of the holder into the notch in the fixed ring, the interference between the notch and the press-fit surface of the fitting portion becomes large, which can make the press-fitting operation difficult. In that case, there is also the concern that the areas around the notch in the holder and fixed ring may be deformed.

[0010] Therefore, an object of this invention is to provide a bearing device in which a sensor unit is attached to a rolling bearing, in which the sensor unit holder can be easily pressed into the fixed ring of the rolling bearing, and deformation of the holder and fixed ring can be suppressed.

[0011] To solve the above problem, the inventors of this invention studied the variation in the interference between the press-fit surface of the sensor unit holder and the notch in the fixed ring, and noticed that while the radial dimension of the press-fit surface of the holder formed by press working varies greatly over the entire life of the press die used due to the progression of die wear, the variation is quite small (the difference between the maximum and minimum values ​​is about 0.01 mm) within a single press working lot (e.g., 500 holders continuously processed with a single die). They then came up with the idea that, for holders whose press-fit surfaces are formed with small variation within a single press working lot, by setting the reference dimension and dimensional tolerance of the radial dimension of the notch in the fixed ring based on the dimensional measurement results of the press-fit surface and then processing the notch in the fixed ring for one lot, the interference between the notch in the fixed ring and the press-fit surface of the holder can be kept within an appropriate range.

[0012] Specifically, the present invention relates to a method for manufacturing a bearing device comprising: a rolling bearing having an outer ring, an inner ring arranged radially inside the outer ring, and a plurality of rolling elements arranged to be rollable between the outer ring and the inner ring; and a sensor unit fixed to a raceway ring which is one of the outer ring and the inner ring and which is a fixed side, wherein the raceway ring on the fixed side has an annular notch formed at one axial end of the opposing surface between the outer ring and the raceway ring on the rotating side of the inner ring; and the sensor unit has a holder to which a sensor is attached having an annular disc portion and a fitting portion which protrudes annularly in the axial direction from an outer circumferential portion or an inner circumferential portion of the disc portion, and the fitting portion of the holder of the sensor unit is press-fitted into the notch portion of the raceway ring on the fixed side, When the holder of the sensor unit is formed by press working, one or more samples are extracted from a plurality of holders that make up one lot in the press working, and the radial dimensions of the press-fit surfaces of the outer and inner surfaces of the fitting portion of the sampled holder that fit into the notch of the fixed side raceway are measured. After that, a representative dimension for each lot is set based on the measurement results of the radial dimensions of the press-fit surfaces, and a reference dimension and dimensional tolerance for the radial dimension of the notch of the fixed side raceway are set based on the representative dimension of the press-fit surfaces for each lot, and then the notch of the fixed side raceway is machined (Configuration 1).

[0013] According to the manufacturing method of the bearing device of this configuration 1, the interference between the notch of the fixed ring and the press-fit surface of the holder is within an appropriate range, making it easier to press-fit the holder and suppressing deformation of the holder and fixed ring.

[0014] In the above-mentioned configuration 1, the representative dimension of the press-fit surface of the holder for each lot can be determined by extracting multiple samples, and using an estimated maximum dimension obtained by adding a predetermined estimated error to the maximum value of the dimensional measurement results of the samples, and an estimated minimum dimension obtained by subtracting the estimated error from the minimum value of the dimensional measurement results of the samples, and the reference dimension and dimensional tolerance of the radial dimension of the notch portion can be set so that the interference between the notch portion of the fixed side raceway ring and the press-fit surface of the holder falls within a predetermined range for both the estimated maximum dimension and the estimated minimum dimension of the press-fit surface (configuration 2).

[0015] Alternatively, the representative dimension of each lot of the press-fit surface of the holder can be determined by extracting multiple samples, calculating the average value and standard deviation of the dimensional measurement results of the samples, and using the estimated maximum and minimum dimensions obtained by adding or subtracting an integer multiple of the standard deviation to or from the average value as an estimated error, and setting the reference dimension and dimensional tolerance of the radial dimension of the notch portion so that the interference between the notch portion of the fixed side raceway ring and the press-fit surface of the holder falls within a predetermined range for both the estimated maximum and estimated minimum dimensions of the press-fit surface (Configuration 3).

[0016] Furthermore, in any of the above configurations 1 to 3, the radial dimension of the press-fit surface of the holder is measured at multiple locations in the axial direction, and if the press-fit surface is a tapered surface that increases in diameter as it moves away from the disc portion, the notch portion of the fixed side raceway has a step halfway in the axial direction so that it expands radially on the axial outside, and the fitting portion of the holder is press-fitted axially inside the step of the notch, and the representative dimension of the press-fit surface of the holder for each lot is set based on the dimensional measurement results of the portion of the fitting portion that is press-fitted axially inside the step of the notch, and after setting the reference dimension and dimensional tolerance of the radial dimension axially inside the step of the notch based on the representative dimension of the press-fit surface for each lot, the notch can be machined (configuration 4).

[0017] The present invention also provides a bearing device manufactured by the above-mentioned manufacturing method, which has the following configuration: a rolling bearing having an outer ring, an inner ring arranged radially inside the outer ring, and a plurality of rolling elements arranged to be rollable between the outer ring and the inner ring, and a sensor unit fixed to a raceway which is one of the outer ring and the inner ring and which is a fixed raceway, the fixed raceway having an annular notch formed at one axial end of the opposing surface between the outer ring and the rotating raceway of the inner ring, the sensor unit having a holder to which a sensor is attached having an annular disc portion and a fitting portion which annularly protrudes in the axial direction from the outer circumferential portion or the inner circumferential portion of the disc portion, the fitting portion of the sensor unit holder being press-fitted into the notch of the fixed raceway, When the holder of the sensor unit is formed by press working, one or more samples are extracted from a plurality of holders that make up one lot in the press working, and the radial dimensions of the press-fit surfaces of the outer and inner peripheral surfaces of the fitting portion of the sampled holder that fit into the notch of the fixed side raceway are measured. After that, a representative dimension for each lot is set based on the measurement results of the radial dimensions of the press-fit surfaces, and a reference dimension and dimensional tolerance for the radial dimension of the notch of the fixed side raceway are set based on the representative dimension of the press-fit surfaces for each lot. The notch of the fixed side raceway is then machined, and the fitting portion of the holder is press-fitted into the notch, thereby providing a bearing device in which the interference between the notch and the press-fit surface of the holder is controlled.

[0018] As described above, in the manufacturing method of the bearing device of this invention, when the holder of the sensor unit of the bearing device is formed by press processing, a representative dimension for each lot is set based on the measurement results of the radial dimension of the press-fit surface of a sample extracted from a lot of holders, and the reference dimension and dimensional tolerance of the radial dimension of the notch portion of the fixed ring into which the holder is press-fit are set based on the representative dimension of the press-fit surface for each lot, and then the notch portion of the fixed ring is processed.This means that the interference between the notch portion of the fixed ring and the press-fit surface of the holder can be kept within an appropriate range, making it easier to press the holder into the fixed ring and suppressing deformation of the holder and fixed ring.

[0019] Furthermore, since the bearing device of the present invention is manufactured by the above manufacturing method, there is little deformation of the holder and fixed ring, and the device can be used stably.

[0020] 4 is an explanatory diagram of a method for setting the representative dimension of the holder used in the setting procedure of FIG. 4; FIG. 5 is an explanatory diagram of another method for setting the representative dimension of the holder used in the setting procedure of FIG. 4; FIG. 6 is a longitudinal front view of the main part showing a modified shape of the fitting portion of the holder of FIG. 1;

[0021] An embodiment of the present invention will now be described with reference to the drawings. As shown in Figures 1 and 2, the bearing device according to this embodiment comprises a rolling bearing 10 having a sensor unit 20 and a generator 30 attached to one axial end thereof.

[0022] In the following, the circumferential direction around the central axis of the rolling bearing 10 (bearing central axis) will be referred to as the circumferential direction, the direction along the bearing central axis will be referred to as the axial direction, and the direction perpendicular to the bearing central axis will be referred to as the radial direction. One axial side is the right side in Figure 2, and the other axial side is the left side in Figure 2.

[0023] The rolling bearing 10 is a deep groove ball bearing comprising an outer ring 11 having a raceway groove 11a on its inner circumference, an inner ring 12 having a raceway groove 12a on its outer circumference, a plurality of balls 13 as rolling elements arranged to roll freely between the raceway groove 11a of the outer ring 11 and the raceway groove 12a of the inner ring 12, a retainer 14 that holds the plurality of balls 13 so that they can roll freely at equal intervals, and a sealing member 15 that seals the other axial side of the bearing space between the outer ring 11 and the inner ring 12, with the outer ring 11 being a fixed ring fixed to a housing or the like (not shown), and the inner ring 12 being a rotating ring attached to a rotating shaft (not shown) so as to rotate integrally with it.

[0024] Annular cutouts 16 and 17 are formed at one axial end of the inner surface of the outer ring 11 and the outer surface of the inner ring 12 (the opposing surfaces of the outer ring 11 and the inner ring 12), respectively, and the sensor unit 20 and the generator 30 are arranged between the cutouts 16 and 17.

[0025] The sensor unit 20 has a holder 21 that forms part of the generator 30, as described below, a board 22 attached to the holder 21, a sensor 23 mounted on the board 22, and a cover 24 that covers the board 22 and the sensor 23.

[0026] The holder 21 is formed by pressing a single metal plate and has an annular disk portion 21a that expands in the radial and circumferential directions, and a fitting portion 21b that annularly protrudes from the outer periphery of the disk portion 21a to one axial side. The fitting portion 21b is press-fitted into the notch 16 of the outer ring 11, thereby fixing the holder 21 to the outer ring 11. That is, in this holder 21, the outer circumferential surface of the fitting portion 21b forms a press-fit surface 25 for the notch 16 of the outer ring 11 (see FIG. 3).

[0027] The substrate 22 is formed in the shape of an arcuate plate, and is attached by screws or adhesive to one axial surface of the disk portion 21 a of the holder 21. In addition to the sensor 23, a wireless communication module, a power supply circuit, and the like (not shown) are also mounted on this substrate 22.

[0028] The generator 30 is a claw-pole type consisting of a magnetic ring 31 arranged so as to be rotatable integrally with the inner ring 12 of the rolling bearing 10, and an annular stator 32 fixed to the outer ring 11 in a state facing the magnetic ring 31 radially across an air gap.

[0029] The magnetic ring 31 is a rotor that generates a rotating magnetic field for the stator 32, and is made of magnetic rubber magnets 31a that are magnetized with alternating north and south poles in the circumferential direction and adhered to a core metal 31b around its entire circumference. The magnetic ring 31 is formed in a shape that has a flange at one end of a cylindrical portion, and the other end of the cylindrical portion is press-fitted or adhered to the outer periphery of the inner ring 12, thereby fixing it to the inner ring 12.

[0030] The stator 32 is a stator that guides the magnetic flux emitted from the magnetic ring 31 using a yoke structure and induces an AC voltage in a coil 34 wound around a bobbin 33 within the yoke structure. The yoke structure is composed of a main stator 35 formed from the inner periphery of the holder 21 of the sensor unit 20, and a sub-stator 36 attached to the main stator 35. The main stator 35 and the sub-stator 36 are combined so that claw-shaped claw poles extending axially at regular intervals from their respective inner peripheries are arranged alternately in the circumferential direction. The cover 24 of the sensor unit 20 is fitted between the outer periphery of the sub-stator 36 and the inner periphery of the fitting portion 21b of the holder 21.

[0031] When the inner ring 12 of the rolling bearing 10 rotates integrally with the rotating shaft, an AC voltage is generated at both ends of the coil 34 in response to the rotation, and the generated AC power is supplied to the sensor unit 20.

[0032] The bearing device of this embodiment has the above-mentioned configuration, and the features of the manufacturing method thereof will be described below.

[0033] What makes this manufacturing method of a bearing device different from ordinary methods is that after one lot of holders 21 of sensor units 20 are press-formed, the radial dimension of press-fit surface 25 of the processed holder 21 (outer diameter D of fitting portion 21b in Figure 3) is measured and the radial dimension of cutout portion 16 of outer ring 11 (inner diameter d of cutout portion 16 in Figure 3) is set in consideration of the measurement results, and cutout portion 16 of outer ring 11 is machined in accordance with the set radial dimension.

[0034] Specifically, as shown in FIG. 4, first, when the holder 21 is formed by press processing, several samples are extracted from the holders 21 that make up one processed lot, and the radial dimension (outer diameter D) of the press-fit surface (outer peripheral surface) 25 of the fitting portion 21b of the holder 21 selected as the sample is measured.

[0035] Here, the number of holders 21 in one press-processing lot can be, for example, about 500. Furthermore, samples of holders 21 can be selected from, for example, the first few molded in one lot, the middle few molded, and the last few molded in one lot, with the number of samples at each timing being about three. The number of samples and the timing of sampling are not limited to this, and, for example, sampling in the middle of a lot may be omitted, or sampling may be performed at only one of the first, middle, and last timings.

[0036] Next, the representative dimensions for each lot are set based on the measurement results of the sampled holders 21. Here, an example will be described in which three samples are extracted at the beginning, middle, and end of each lot, and the representative dimensions are set based on the measurement results.

[0037] A method for setting the typical dimensions for each lot is shown in Figure 5. In Figure 5, the tolerance of the press-fit surface 25 of the fitting portion 21b shown in the production drawing of the holder 21 is the range between two chain double-dashed lines. Note that the tolerance of the radial dimension of the press-fit surface 25 of the fitting portion 21b is set only on the positive side of the reference dimension, so the minimum allowable dimension is equal to the reference dimension.

[0038] Then, the maximum value (maximum measurement value) and minimum value (minimum measurement value) of the measured dimensions of nine samples of holder 21 pressed according to the production drawings are extracted, and the estimated maximum dimension obtained by adding a predetermined estimated error to the maximum measurement value and the estimated minimum dimension obtained by subtracting the same estimated error from the minimum measurement value are used as representative dimensions for each lot.

[0039] Here, the estimated error is set by conducting an experiment in advance to measure the dimensions of all the pieces in one lot, so that the measured values ​​of all the pieces fall between the estimated maximum dimension and the estimated minimum dimension.

[0040] After setting the representative dimension for each lot as described above, the reference dimension and dimensional tolerance of the radial dimension of the notch 16 are set so that the interference between the notch 16 of the outer ring 11 and the press-fit surface 25 of the holder 21 falls within a preset range for both the estimated maximum and minimum dimensions of the representative dimension for each lot, i.e., the press-fit surface 25 (for example, so that the minimum interference is 0.02 mm and the maximum interference is 0.06 mm). One lot of outer rings 11 are then machined in accordance with the set radial dimension of the notch 16.

[0041] Therefore, each time the press-processing lot of the holder 21 changes, the press-fit surface 25 of the sample is measured to set the representative dimensions for each lot, and the radial dimensions of the cutout portion 16 of the outer ring 11 are set based on this, and then the cutout portion 16 of the outer ring 11 is processed.

[0042] In the manufacturing method of the bearing device of the embodiment described above, when holder 21 of sensor unit 20 is press-formed, attention is paid to the fact that the radial dimension of press-fit surface 25 is formed with small variation within a single lot, and a representative dimension for each lot is set based on the dimensional measurement results of press-fit surface 25 of samples within that lot, and the radial dimension of notch 16 in outer ring 11 is set based on that representative dimension of press-fit surface 25 before machining the outer ring 11. This makes it possible to keep the interference between notch 16 in outer ring 11 and press-fit surface 25 of holder 21 within an appropriate range more reliably than when the notch in the outer ring is machined according to the radial dimensions (reference dimensions and dimensional tolerances) specified in the production drawings. As a result, the operation of press-fitting holder 21 into outer ring 11 is facilitated, and deformation of holder 21 and outer ring 11 is suppressed.

[0043] Therefore, in a bearing device set, which is an assembly of bearing devices manufactured by this manufacturing method, if the bearing devices manufactured using one lot of holders 21 are considered to be one product lot, the range of the radial dimension of the press-fit surface 25 of the holder 21 will be different for at least two product lots, and it is possible for the interference between the notch 16 of the outer ring 11 and the press-fit surface 25 of the holder 21 for all the bearing devices to fall within a predetermined range common to each product lot. In other words, even if the radial dimensions of the notch 16 of the outer ring 11 and the press-fit surface 25 of the holder 21 differ for the bearing devices that make up this bearing device set, there is little deformation of the holder 21 and outer ring 11, and they can be used stably.

[0044] FIG. 6 illustrates another example of a method for determining the representative dimension for each lot when press-forming the holder 21. In this example, as in the example of FIG. 5, the average (measurement average) and standard deviation (measurement standard deviation) of the measurement results of nine samples extracted from one lot are calculated. The estimated maximum dimension is calculated by adding an integer multiple of the measurement standard deviation to the measurement average as an estimated error, and the estimated minimum dimension is calculated by subtracting the same estimated error from the measurement average. In this case, if the radial dimensions of the holders 21 in one lot are normally distributed, setting the estimated error to three times the measurement standard deviation will result in a 99.73% probability that the radial dimension of each holder 21 in one lot will fall between the estimated maximum dimension and the estimated minimum dimension. Furthermore, after determining the representative dimension for each lot using this method, the radial dimension of the notched portion 16 of the outer ring 11 can be set and processed in the same manner as in the example of FIG. 5.

[0045] In the above-described embodiment, the fitting portion 21b of the holder 21 extends parallel to the axial direction, but the shape of the holder 21 may be changed by providing a draft angle to the press mold, so that the fitting portion 21b opens on one axial side and the press-fit surface 25 has a tapered surface, as shown in Fig. 7. In this case, the radial dimension varies depending on the axial position of the fitting portion 21b, so it is necessary to determine a method for measuring the sample in advance.

[0046] For example, in the holder 21 of Figure 7, if three points (P1, P2, P3) in the axial direction of the fitting portion 21b are considered to be the measurement targets, the measurement value at position P1, which is closest to the disc portion 21a, can be used as the measurement result, or the average value of the measurement values ​​at the three points can be used as the measurement result.

[0047] Furthermore, when the fitting portion 21b of the holder 21 is open on one axial side as shown in FIG. 7 , the notch 16 of the outer ring 11 may have a stepped shape as shown in FIG. 8 to shorten the fitting length between the notch 16 and the holder 21. The notch 16 of the outer ring 11 shown in FIG. 8 has a step formed midway in the axial direction so as to expand radially on the axially outer side, and the fitting portion 21b of the holder 21 is press-fitted axially inward of the step. Therefore, in this case, the representative dimension of the press-fit surface 25 of the holder 21 for each lot may be set based on the dimensional measurement results of a portion of the fitting portion 21b that is press-fitted axially inward of the step of the notch 16 (e.g., position P1 in FIG. 7 ). This allows the holder 21 to be press-fitted into the outer ring 11 with an appropriate interference.

[0048] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0049] For example, the holder of the sensor unit in the embodiment is fitted and fixed to the outer ring, which is the fixed ring, with the fitting portion facing outward in the axial direction, but the holder may also be fitted and fixed to the outer ring in the opposite manner, with the fitting portion facing inward in the axial direction.

[0050] In addition, although the outer ring of the rolling bearing is the fixed ring and the inner ring is the rotating ring in the embodiment, it is also possible to use the inner ring as the fixed ring and the outer ring as the rotating ring. In this case, the sensor unit holder is fitted and fixed into a notch formed in the shaft end of the inner ring, and the press-fit surface of the holder becomes the inner peripheral surface of the fitting portion.

[0051] Of course, the present invention can also be applied to a bearing device in which a sensor unit is attached to a rolling bearing other than a deep groove ball bearing as in the embodiment.

[0052] REFERENCE SIGNS LIST 10 deep groove ball bearing (rolling bearing) 11 outer ring (fixed ring) 12 inner ring (rotating ring) 13 ball (rolling element) 16 notch portion 20 sensor unit 21 holder 21a disc portion 21b fitting portion 23 sensor 25 press-fit surface 30 generator

Claims

1. A rolling bearing (10) having an outer ring (11), an inner ring (12) disposed radially inside the outer ring, and a plurality of rolling elements (13) disposed between the outer ring (11) and the inner ring (12) so as to be freely rollable; and a sensor unit (20) fixed to a raceway of the outer ring (11) and the inner ring (12) on the fixed side, the raceway of the outer ring (11) having an annular notch (16) formed at one axial end of the opposing surface between the outer ring (11) and the raceway of the inner ring (12) on the rotating side; the sensor unit (20) has a holder (21) to which a sensor (23) is attached, the holder having an annular disc portion (21a) and a fitting portion (21b) protruding annularly in the axial direction from the outer circumferential portion or the inner circumferential portion of the disc portion (21a); a manufacturing method for a bearing device in which a fitting portion (21b) of a holder (21) of the sensor unit (20) is pressed into a notch portion (16) of the fixed-side raceway, the manufacturing method for a bearing device being characterized in that, when forming the holder (21) of the sensor unit (20) by press working, one or more samples are extracted from a plurality of holders (21) constituting one lot in the press working, a radial dimension of a press-fit surface (25) of an outer circumferential surface and an inner circumferential surface of the fitting portion (21b) of the holder (21) selected as the sample, which surface fits into the notch portion (16) of the fixed-side raceway, is measured, a representative dimension for each lot is set based on the measurement result of the radial dimension of the press-fit surface (25), a reference dimension and a dimensional tolerance of the radial dimension of the notch portion (16) of the fixed-side raceway are set based on the representative dimension of the press-fit surface (25) for each lot, and then the notch portion (16) of the fixed-side raceway is machined.

2. A method for manufacturing a bearing device as described in claim 1, wherein the representative dimension for each lot of the press-fit surface (25) of the holder (21) is determined by extracting a plurality of samples, and using an estimated maximum dimension obtained by adding a predetermined estimated error to the maximum value of the dimensional measurement results of the samples, and an estimated minimum dimension obtained by subtracting the estimated error from the minimum value of the dimensional measurement results of the samples, and the reference dimension and dimensional tolerance of the radial dimension of the cutout portion (16) are set so that the interference between the cutout portion (16) of the fixed side raceway ring and the press-fit surface (25) of the holder (21) falls within a preset range for both the estimated maximum dimension and the estimated minimum dimension of the press-fit surface (25).

3. A method for manufacturing a bearing device as described in claim 1, wherein the representative dimension of the press-fit surface (25) of the holder (21) for each lot is determined by extracting a plurality of samples, calculating the average value and standard deviation of the dimensional measurement results of the samples, and using the estimated maximum dimension and estimated minimum dimension obtained by adding / subtracting an integer multiple of the standard deviation to / from the average value as an estimated error, and setting the reference dimension and dimensional tolerance of the radial dimension of the cutout portion (16) so that the interference between the cutout portion (16) of the fixed side raceway and the press-fit surface (25) of the holder (21) falls within a preset range for both the estimated maximum dimension and the estimated minimum dimension of the press-fit surface (25).

4. When the radial dimension of the press-fit surface (25) of the holder (21) is measured at a plurality of axial positions and the press-fit surface (25) is found to be a tapered surface whose diameter increases with increasing distance from the disc portion (21a), the notch portion (16) of the fixed-side raceway has a step in the axial direction so as to expand radially on the axially outer side, and the fitting portion (21b) of the holder (21) is press-fitted axially inward of the step of the notch portion (16), and the representative dimension of the press-fit surface (25) of the holder (21) for each lot is set based on the dimensional measurement results of the portion of the fitting portion (21b) that is press-fitted axially inward of the step of the notch portion (16), 4. A method for manufacturing a bearing device as claimed in any one of claims 1 to 3, wherein a reference dimension and a dimensional tolerance of a radial dimension axially inward from a step of the cutout portion (16) are set based on a typical dimension of the press-fit surface (25) for each lot, and then the cutout portion (16) is machined.

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