WO2018092433A1 - Bearing structure and manufacturing method for bearing structures - Google Patents

Abstract

A bearing structure comprises an outer ring (141) and an outer ring fitting portion (12). The outer ring constitutes a portion of a bearing (14) and is provided on the outside in the radial direction with respect to an inner ring (142) of the bearing with a rolling element (143, 144) of the bearing therebetween. The outer ring is fit into the outer ring fitting portion, and the outer ring fitting portion presses the outer ring radially inward. In addition, the outer ring has an outer ring raceway face (141a, 141b) that faces the rolling element and is concave to the outside in the radial direction of the outer ring. The outer ring fitting portion generates an outer ring compressive stress (Pcp) on the outer ring by pressing the outer ring radially inward. In the stress distribution of the outer ring compressive stress, a site at which the generated outer ring compressive stress is greater than the outer ring compressive stress at a central position (W1c, W2c) of the outer ring raceway face in the axial direction (DRa) of the outer ring is in a location separated from a raceway face region (W1, W2) that is occupied by the outer ring raceway face in the axial direction.

Description

Bearing structure and method for manufacturing the bearing structure Cross-reference to related applications

This application is based on Japanese Patent Application No. 2016-222543 filed on November 15, 2016, the description of which is incorporated herein by reference.

The present disclosure relates to a bearing structure including a bearing and a method for manufacturing the bearing structure.

As an apparatus including this type of bearing structure, for example, an electromagnetic clutch described in Patent Document 1 is conventionally known. The electromagnetic clutch described in Patent Document 1 is an electromagnetic clutch for an air conditioner refrigerant compressor.

Specifically, the electromagnetic clutch of Patent Document 1 includes a bearing and a rotor that is rotatably supported via the bearing. The rotor has an inner cylindrical portion that also functions as a bearing housing, and an outer ring of the bearing is fitted into the inner cylindrical portion by press-fitting. Due to the configuration of such an electromagnetic clutch, the bearing structure includes an inner cylindrical portion and a bearing.

JP 2016-121760 A

Conventionally, a bearing used for a power transmission device such as an electromagnetic clutch or a rotating device is press-fitted and held in a housing. In recent years, there has been a strong demand for weight reduction and cost reduction of the power transmission device and the rotating device.

For example, for an electromagnetic clutch as described in Patent Document 1, in order to expand the coil space of a stator that generates electromagnetic force in a limited physique, the housing that press-fits and holds the bearing is thinned. Is required. When the housing is simply thinned in this way, it is assumed that the bearing holding force for holding the press-fitted bearing is reduced due to a reduction in the rigidity of the housing. In order to prevent this decrease in bearing holding force, a general technique is to increase the tightening margin (in other words, press-fit margin) between the outer diameter of the bearing outer ring and the inner diameter of the housing.

However, when the press-fitting allowance is simply increased, the accuracy of the inner peripheral surface of the housing into which the bearing outer ring is fitted is reflected on the outer ring rolling surface of the bearing after press-fitting, so the accuracy of the outer ring rolling surface is deteriorated. . As a result, the life of the bearing is greatly reduced. As a result of detailed studies by the inventor, the above has been found.

In view of the above points, it is an object of the present disclosure to provide a bearing structure capable of sufficiently securing a bearing holding force while suppressing deterioration in accuracy of the outer ring rolling surface and a method for manufacturing the bearing structure. To do.

In order to achieve the above object, according to one aspect of the present disclosure, a bearing structure includes:
An outer ring that forms a part of the bearing and is provided radially outside the inner ring of the bearing via the rolling elements of the bearing;
An outer ring is fitted, and an outer ring insertion portion that presses the outer ring radially inward,
The outer ring has an outer ring rolling surface that faces the rolling elements and is recessed radially outward of the outer ring,
The outer ring insertion portion generates an outer ring compressive stress on the outer ring by pressing the outer ring radially inward,
In the stress distribution of the outer ring compressive stress, the part where the outer ring compressive stress is larger than the outer ring compressive stress at the center position of the outer ring rolling surface in the axial direction of the outer ring is occupied by the outer ring rolling surface in the axial direction. The position is out of the surface range.

According to another aspect of the present disclosure, the bearing structure is
An outer ring that forms a part of the bearing and is provided radially outside the inner ring of the bearing via the rolling elements of the bearing;
An outer ring is fitted, and an outer ring insertion portion that presses the outer ring radially inward,
The outer ring has an outer ring rolling surface that faces the rolling elements and is recessed radially outward of the outer ring,
The outer ring insertion portion generates an outer ring compressive stress on the outer ring by pressing the outer ring radially inward,
The portion where the outer ring compressive stress is minimum in the stress distribution of the outer ring is within the rolling surface range occupied by the outer ring rolling surface in the axial direction of the outer ring, and the outer ring compressive stress is maximized. The part which exists is in the position out of the rolling surface range.

According to still another aspect of the present disclosure, a method for manufacturing a bearing structure includes:
An outer ring that forms a part of the bearing and that is provided on the radially outer side of the inner ring of the bearing via the rolling element of the bearing, and has an outer ring rolling surface that is recessed radially outward facing the rolling element;
A method for manufacturing a bearing structure including an outer ring insertion portion into which an outer ring is fitted,
Preparing an outer ring and an outer ring insertion part;
Pressing the outer ring into the outer ring fitting portion in the axial direction of the outer ring,
In the outer ring press-fitting, the outer ring press-fitting allowance for the outer ring fitting part is out of the rolling surface range occupied by the outer ring rolling surface in the axial direction, and more than the press-fitting allowance at the center position of the outer ring rolling surface in the axial direction. Increased.

The position where the coupling force between the outer ring insertion portion and the outer ring is out of the rolling surface range while suppressing distortion of the outer ring rolling surface due to the outer ring fitting into the outer ring insertion portion according to any of the above viewpoints. Can be enlarged. Therefore, it is possible to sufficiently secure the bearing holding force while suppressing deterioration in accuracy of the outer ring rolling surface.

It is sectional drawing which shows the structure of the electromagnetic clutch in 1st Embodiment. It is the enlarged view which expanded and showed the area | region II of FIG. In 1st Embodiment, it is a flowchart which shows the manufacturing process which press-fits the outer ring | wheel of a bearing to the inner cylindrical part of a rotor. It is sectional drawing which extracted and showed the outer ring | wheel of the bearing and the inner cylindrical part of the rotor from FIG. FIG. 5 is a schematic cross-sectional view showing the inner cylindrical portion of the rotor before the outer ring of the bearing is press-fitted in the first embodiment in the same direction as in FIG. 4. In 1st Embodiment, it is the figure which showed the distribution image of the outer ring | wheel compressive stress which has arisen in the outer ring | wheel by the press injection to the inner cylindrical part of a rotor. In a comparative example, it is the figure which showed the relationship between the press-fitting allowance in the press injection of the outer ring with respect to an inner cylindrical part, and the roundness of the outer ring rolling surface after press injection. FIG. 6 is a schematic cross-sectional view showing the inner cylindrical portion of the rotor before the outer ring of the bearing is press-fitted in the second embodiment, corresponding to FIG. 5 of the first embodiment. FIG. 6 is a schematic cross-sectional view showing the inner cylindrical portion of the rotor before the outer ring of the bearing is press-fitted in the third embodiment, corresponding to FIG. 5 of the first embodiment.

Hereinafter, each embodiment will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals in the drawings.

(First embodiment)
An electromagnetic clutch 1 according to this embodiment shown in FIG. 1 is a power transmission device that transmits a rotational driving force from an engine as a drive source for vehicle travel. Specifically, the electromagnetic clutch 1 is provided in a power transmission path between the engine and the compressor 2 that rotationally drives the compression mechanism, and connects and disconnects the power transmission path. Therefore, in the present embodiment, the engine is a drive source, and the compressor 2 is a driven device.

Compressor 2 is a device that sucks and compresses refrigerant. The compressor 2 exhibits a heat absorbing effect by radiating heat discharged from the compressor 2, an expansion valve for decompressing and expanding the refrigerant flowing out from the radiator, and evaporating the refrigerant decompressed by the expansion valve. The refrigeration cycle apparatus of the vehicle air conditioner is configured together with the evaporator.

The electromagnetic clutch 1 includes a rotor 10 constituting a driving side rotating body that rotates around a rotation center line CLc when receiving a rotational driving force from an engine, and a driven side rotation connected to a rotating shaft 2a of the compressor 2. And an armature 20 constituting the body. When the rotor 10 and the armature 20 are connected to each other or disconnected, the transmission of the rotational driving force from the engine to the compressor 2 is interrupted. 1 shows a state where the rotor 10 and the armature 20 are separated from each other, and FIG. 2 shows a state where the rotor 10 and the armature 20 are connected to each other.

That is, when the rotor 10 and the armature 20 are connected to each other by the electromagnetic clutch 1, the rotational driving force of the engine is transmitted to the compressor 2 and the refrigeration cycle apparatus is operated. On the other hand, when the rotor 10 and the armature 20 are separated from each other by the electromagnetic clutch 1, the rotational driving force of the engine is not transmitted to the compressor 2 and the refrigeration cycle apparatus does not operate. The operation of the electromagnetic clutch 1 is controlled by a control signal output from an air conditioning control device that controls the operation of various components of the refrigeration cycle apparatus.

Hereinafter, a specific configuration of the electromagnetic clutch 1 will be described. As shown in FIG. 1, the electromagnetic clutch 1 includes a rotor 10, an armature 20, and a stator 30.

The rotor 10 has a double-cylindrical structure having a U-shaped cross section with an opening on the side opposite to the armature 20 (specifically, the right side in FIG. 1). That is, the rotor 10 includes an outer cylindrical portion 11, an inner cylindrical portion 12, and a wall portion 13. The outer cylindrical portion 11 and the inner cylindrical portion 12 both have a cylindrical shape centered on the rotation center line CLc of the rotor 10, and the inner cylindrical portion 12 is disposed on the inner peripheral side of the outer cylindrical portion 11. Furthermore, the wall portion 13 extends in the radial direction DRr of the rotation center line CLc so as to connect the end portions on the armature 20 side of the outer cylindrical portion 11 and the inner cylindrical portion 12.

Further, the wall portion 13 is a portion located between the outer cylindrical portion 11 and the inner cylindrical portion 12 in the radial direction DRr of the rotation center line CLc. The outer cylindrical portion 11, the inner cylindrical portion 12, and the wall portion 13 are made of a magnetic material such as iron.

The outer cylindrical portion 11 and the inner cylindrical portion 12 are arranged coaxially with respect to the rotating shaft 2a of the compressor 2. That is, the rotation center line CLc shown in FIG. 1 is a rotation center line of the outer cylindrical portion 11 and the inner cylindrical portion 12, and also a rotation center line of the rotation shaft 2a. On the outer peripheral side of the outer cylindrical portion 11, a V groove 11a on which a V belt is hung is formed.

The outer ring 141 of the bearing 14 is fixed to the inner peripheral side of the inner cylindrical portion 12 by press-fitting. Accordingly, the inner cylindrical portion 12 is an outer ring insertion portion into which the outer ring 141 is inserted.

Further, the outer ring 141 has an outer ring outer peripheral surface 141c formed on the outer peripheral side of the outer ring 141. The inner cylindrical portion 12 has a cylindrical inner peripheral surface 122 as an insertion portion inner peripheral surface formed on the inner peripheral side of the inner cylindrical portion 12. Since the outer ring 141 is press-fitted into the inner cylindrical portion 12, the inner peripheral surface 122 of the cylindrical portion is in contact with the outer peripheral surface 141c of the outer ring. Specifically, the cylindrical portion inner peripheral surface 122 is in close contact with the outer ring outer peripheral surface 141c.

The bearing 14 is a double row rolling bearing, specifically, a ball bearing having two rows of rolling elements. The bearing 14 includes an outer ring 141, an inner ring 142, and balls 143 and 144 that are rolling elements arranged in two rows. The bearing 14 and the inner cylindrical portion 12 to which the bearing 14 is fixed constitute a bearing structure as a whole. In this bearing structure, the inner cylindrical portion 12 functions as a bearing housing that surrounds the radially outer side of the bearing 14.

The bearing 14 rotatably supports the rotor 10 with respect to a compressor case as a non-rotating member that forms the outer shell of the compressor 2. Therefore, a case boss portion 2b as a non-rotating portion provided in the compressor case of the compressor 2 is fitted in the inner ring 142 of the bearing 14, and thereby the inner ring 142 is fixed to the case boss portion 2b. .

In the bearing 14, the outer ring 141 is provided on the radially outer side of the bearing 14 with respect to the inner ring 142 via a plurality of rows of balls 143 and 144. Therefore, the outer ring 141 is rotatable with respect to the inner ring 142.

Further, since the outer ring 141 and the inner ring 142 are arranged coaxially with the rotor 10, the rotation center line CLc of the rotor 10 is both the center axis of the outer ring 141 and the center axis of the inner ring 142. Therefore, the axial direction of the rotation center line CLc, that is, the rotor axial direction DRa is both the axial direction DRa of the outer ring 141 and the axial direction DRa of the inner ring 142. The radial direction of the rotation center line CLc, that is, the rotor radial direction DRr is also the radial direction DRr of the outer ring 141 and the radial direction DRr of the inner ring 142.

As shown in FIGS. 1 and 2, the outer ring 141 of the bearing 14 has a plurality of outer ring rolling surfaces 141a and 141b that face the balls 143 and 144 and are recessed outward in the radial direction of the outer ring 141. Further, the inner ring 142 has a plurality of inner ring rolling surfaces 142 a and 142 b that face the balls 143 and 144 and are recessed inward in the radial direction of the inner ring 142. A plurality of rows of balls 143 and 144, that is, a first ball 143 and a second ball 144 are accommodated between the outer ring rolling surfaces 141a and 141b and the inner ring rolling surfaces 142a and 142b so as to roll freely.

Outer ring rolling surfaces 141a and 141b are included in the outer ring inner peripheral surface on the radially inner side of the outer ring 141, and inner ring rolling surfaces 142a and 142b are included in the inner ring 142 on the outer peripheral surface of the inner ring in the radial direction. Specifically, two outer ring rolling surfaces 141a and 141b and two inner ring rolling surfaces 142a and 142b are provided. The first outer ring rolling surface 141a that is one of the two outer ring rolling surfaces 141a and 141b and the first inner ring rolling surface 142a that is one of the two inner ring rolling surfaces 142a and 142b are each in two rows. 1 corresponds to the first ball 143. That is, the first outer ring rolling surface 141a and the first inner ring rolling surface 142a face the first ball 143, respectively.

Similarly, a second outer ring rolling surface 141b that is the other of the two outer ring rolling surfaces 141a and 141b and a second inner ring rolling surface 142b that is the other of the two inner ring rolling surfaces 142a and 142b are respectively provided. It corresponds to the second ball 144 which is the other of the two rows. That is, the second outer ring rolling surface 141b and the second inner ring rolling surface 142b face the second ball 144, respectively.

Therefore, the first outer ring rolling surface 141a is arranged side by side on the one side in the rotor axial direction DRa with an axial interval Ca from the second outer ring rolling surface 141b. The same applies to the inner ring rolling surfaces 142a and 142b. That is, the first inner ring rolling surface 142a is arranged side by side on the one side in the rotor axial direction DRa with an axial interval from the second inner ring rolling surface 142b.

The wall 13 of the rotor 10 has one end face 13a on one side in the rotor axial direction DRa. And the wall part 13 has the other end surface 13b in the other side in rotor axial direction DRa. The end faces 13a and 13b are located apart from each other in the rotor axial direction DRa and also extend in the rotor radial direction DRr.

The wall 13 is formed with a plurality of arc-shaped demagnetization slits 13c and 13d arranged in two rows in the rotor radial direction DRr when viewed from the rotor axial direction DRa. The demagnetization slits 13c and 13d extend through the wall 13 in the rotor axial direction DRa. One end surface 13a of the wall portion 13 faces the armature 20 and serves as a friction surface of the rotor 10 that contacts the armature 20 when the rotor 10 and the armature 20 are connected. Therefore, hereinafter, one end surface 13a of the wall portion 13 is also referred to as a friction surface 13a.

In this embodiment, a friction member 15 for increasing the friction coefficient of the wall portion 13 is disposed on a part of the friction surface 13a of the wall portion 13. The friction member 15 is made of a non-magnetic material. Specifically, as the constituent material of the friction member 15, a material obtained by solidifying alumina with a resin or a sintered material of metal powder such as aluminum powder is adopted. Is done.

The armature 20 is made of a magnetic material such as iron. The armature 20 is a disk-shaped member that extends in the rotor radial direction DRr and has a through-hole formed in the center thereof that penetrates the front and back in the rotor axial direction DRa. The armature 20 has one end face 20a on one side in the rotor axial direction DRa. The armature 20 has the other end face 20b on the other side in the rotor axial direction DRa. The rotation center of the armature 20 is disposed coaxially with the rotation shaft 2 a of the compressor 2. That is, the rotation center line of the armature 20 coincides with the rotation center line CLc.

The armature 20 is formed with a plurality of arc-shaped demagnetization slits 20c when viewed from the rotor axial direction DRa, like the wall portion 13 of the rotor 10. The demagnetization slit 20c passes through one end surface 20a and the other end surface 20b of the armature 20. The demagnetization slit 20 c is positioned between the demagnetization slit 13 c on the inner side in the radial direction of the wall portion 13 and the demagnetization slit 13 d on the outer side in the radial direction of the wall portion 13.

Further, the other end surface 20b of the armature 20 faces the friction surface 13a of the rotor 10, and forms a friction surface that comes into contact with the rotor 10 when the rotor 10 and the armature 20 are connected. Therefore, hereinafter, the other end surface 20 b of the armature 20 is also referred to as a friction surface 20 b of the armature 20. Furthermore, a substantially disc-shaped outer hub 21 is fixed to one end face 20 a of the armature 20.

The outer hub 21 constitutes a connecting member for connecting the armature 20 and the rotating shaft 2a of the compressor 2 together with an inner hub 22 described later. The outer hub 21 and the inner hub 22 have cylindrical portions 21a and 22a that extend in the rotor axial direction DRa, respectively. Cylindrical rubber 23, which is an elastic member made of an elastic material (in other words, elastomer), is vulcanized and bonded to the inner peripheral surface of the cylindrical portion 21a of the outer hub 21 and the outer peripheral surface of the cylindrical portion 22a of the inner hub 22. ing.

Further, the inner hub 22 is fixed to the rotary shaft 2a by being fastened to a bolt 24 that is screwed into a screw hole provided in the rotary shaft 2a of the compressor 2. Thereby, the armature 20, the outer hub 21, the rubber 23, the inner hub 22, and the rotating shaft 2a of the compressor 2 are connected to each other. When the rotor 10 and the armature 20 are connected, the armature 20, the outer hub 21, the rubber 23, the inner hub 22, and the rotation shaft 2a of the compressor 2 rotate around the rotation center line CLc together with the rotor 10. .

Further, the rubber 23 applies an elastic force to the outer hub 21 in a direction away from the rotor 10. In a state where the rotor 10 and the armature 20 are separated by this elastic force, a shaft having a predetermined interval between the friction surface 20b of the armature 20 connected to the outer hub 21 and the friction surface 13a of the rotor 10 is used. A directional gap is formed.

The stator 30 is fixed to the compressor 2 in this embodiment. Therefore, the stator 30 is a non-rotating part that does not rotate.

1 and 2, the stator 30 is disposed in an internal space 600 of the rotor 10 surrounded by the outer cylindrical portion 11, the inner cylindrical portion 12 and the wall portion 13 of the rotor 10. For this reason, the stator 30 faces the other end surface 13 b of the wall portion 13, and an axial gap is formed between the stator 30 and the other end surface 13 b of the wall portion 13. The stator 30 is made of a magnetic material such as iron and houses an electromagnetic coil 36.

The stator 30 has a U-shaped double cylindrical structure having an opening 30a on one side in the rotor axial direction DRa, that is, on the armature 20 side. Specifically, the stator 30 has an outer cylindrical portion 31, an inner cylindrical portion 32, and a wall portion 33. The outer cylindrical portion 31 and the inner cylindrical portion 32 both have a cylindrical shape centered on the rotation center line CLc of the rotor 10, and the inner cylindrical portion 32 is disposed on the inner peripheral side of the outer cylindrical portion 31. Furthermore, the wall portion 33 extends in the rotor radial direction DRr so as to connect ends of the outer cylindrical portion 31 and the inner cylindrical portion 32 on the side opposite to the armature. The wall portion 33 is a portion located between the outer cylindrical portion 31 and the inner cylindrical portion 32 in the rotor radial direction DRr.

As shown in FIG. 2, the outer cylindrical portion 31 and the inner cylindrical portion 32 of the stator 30 are arranged in the internal space 600 of the rotor 10. The outer peripheral surface 311 of the outer cylindrical portion 31 of the stator 30 is opposed to the inner peripheral surface 111 of the outer cylindrical portion 11 of the rotor 10 with a gap G1. The inner peripheral surface 321 of the inner cylindrical portion 32 of the stator 30 is opposed to the outer peripheral surface 121 of the inner cylindrical portion 12 of the rotor 10 with a gap G2. The gaps G1 and G2 are set to a minimum distance so as to minimize the magnetic resistance and are uniform.

The electromagnetic coil 36 is disposed in the internal space 300 surrounded by the outer cylindrical portion 31, the inner cylindrical portion 32 and the wall portion 33 of the stator 30. Specifically, an annular coil spool 34 is accommodated in the internal space 300 of the stator 30. The coil spool 34 is made of a resin material such as polyamide resin. An electromagnetic coil 36 is wound on the coil spool 34. The entire wound electromagnetic coil 36 has a substantially rectangular cross-sectional shape (that is, a right-angled quadrilateral shape).

Furthermore, a resin member 37 that seals the electromagnetic coil 36 is provided on the opening 30 a side of the stator 30. As a result, the opening 30 a of the stator 30 is blocked by the resin member 37. The resin member 37 is made of polyamide resin or the like.

Further, as shown in FIG. 1, a stator plate 38 is fixed to the outside (specifically, the right side in FIG. 1) of the wall portion 33 of the stator 30. The stator 30 is fixed to the compressor case of the compressor 2 through the stator plate 38.

Next, the operation of the electromagnetic clutch 1 having the above configuration will be described. When the electromagnetic coil 36 is energized, the armature 20 is attracted to the friction surface 13a of the rotor 10 by the electromagnetic attractive force generated by the electromagnetic coil 36, and the rotor 10 and the armature 20 are connected. Thereby, the rotational power from the engine is transmitted to the compressor 2.

On the other hand, when the energization of the electromagnetic coil 36 is interrupted, that is, when the electromagnetic coil 36 is not energized, the armature 20 is separated from the friction surface 13a of the rotor 10 by the elastic force of the rubber 23. Thereby, the rotational power from the engine is not transmitted to the compressor 2.

Next, a manufacturing process for press-fitting the outer ring 141 of the bearing 14 to the inner cylindrical portion 12 of the rotor 10 will be described. In the manufacturing process, as shown in FIG. 3, first, in step S01 corresponding to the preparation process, the outer ring 141 and the inner cylindrical part 12 as the outer ring fitting part are prepared. In short, the bearing 14 including the outer ring 141 and the rotor 10 including the inner cylindrical portion 12 are prepared. After step S01, the process proceeds to step S02.

In step S02 corresponding to the press-fitting process, the outer ring 141 of the bearing 14 is fitted into the inner cylindrical portion 12 with an interference fit. Specifically, the outer ring 141 of the bearing 14 is pressed into the inner cylindrical portion 12 in the rotor axial direction DRa. This press-fitting is performed by inserting the outer ring 141 into the inner cylindrical portion 12 from the other side in the rotor axial direction DRa to one side. In the press-fitting of the outer ring 141, the press-fitting allowance of the outer ring 141 with respect to the inner cylindrical portion 12, that is, the tightening allowance in the interference fit, is not uniform in the rotor axial direction DRa, and depends on the position of the rotor axial direction DRa. It is a different size.

Here, as shown in FIG. 4, the range occupied by the first outer ring rolling surface 141a in the rotor axial direction DRa is referred to as a first rolling surface range W1, and the second outer ring rolling surface 141b in the rotor axial direction DRa The occupied range is referred to as a second rolling surface range W2.

Further, a range of the outer ring 141 located on one side of the rotor axial direction DRa with respect to the first outer ring rolling surface 141a is referred to as a one-side range Xa. That is, the one side range Xa is a range located on one side in the rotor axial direction DRa with respect to the entirety of the plurality of outer ring rolling surfaces 141a and 141b of the outer ring 141. Further, a range of the outer ring 141 that is located on the other side of the rotor axial direction DRa with respect to the second outer ring rolling surface 141b is referred to as the other side range Xb. That is, the other side range Xb is a range located on the other side in the rotor axial direction DRa with respect to the entire outer ring rolling surfaces 141a and 141b of the outer ring 141. Further, a range occupied by the axial interval Ca between the first outer ring rolling surface 141a and the second outer ring rolling surface 141b is referred to as an intermediate range Xc. That is, the intermediate range Xc is a range located between the plurality of outer ring rolling surfaces 141a and 141b in the rotor axial direction DRa in the outer ring 141.

Further, the allowance for press-fitting the outer ring 141 to the inner cylindrical portion 12 is based on the outer diameter φDr of the bearing outer ring that is the diameter of the outer peripheral surface 141c before press-fitting and the inner diameter φDh of the bearing housing that is the diameter of the inner peripheral surface 122 of the cylindrical portion before press-fitting. , “Press-fit allowance = φDr−φDh”.

As described above, the press-fitting allowance in the press-fitting of the outer ring 141 is not uniform in the rotor axial direction DRa, and more specifically, the press-fitting in the rolling contact surface exclusion range Xabc deviating from any of the rolling contact surface ranges W1 and W2. The allowance is made larger than the press-fit allowance in the rolling surface ranges W1 and W2. Therefore, in the press-fitting of the outer ring 141 in this step S02, each outer ring rolling surface 141a in the rotor axial direction DRa is at a position where the press-fitting allowance deviates from any rolling surface range W1, W2 in the rotor axial direction DRa. , 141b at the center positions W1c, W2c, which is larger than any press-fitting allowance.

The rolling surface exclusion range Xabc is specifically composed of one side range Xa, the other side range Xb, and an intermediate range Xc. And the position which remove | deviated from the rolling surface range W1 and W2 in the rotor axial direction DRa enters in the rolling surface exclusion range Xabc. The center position W1c is the center position of the first outer ring rolling surface 141a in the rotor axial direction DRa, and the center position W2c is the center position of the second outer ring rolling surface 141b in the rotor axial direction DRa. .

For example, as shown in FIG. 5, a plurality of steps B1, B2, B3, and B4 are provided on the inner peripheral surface 122 of the cylindrical portion in the inner cylindrical portion 12 before press-fitting. The plurality of steps B1, B2, B3, and B4 are each formed in an annular shape around the rotation center line CLc, and are arranged side by side in the rotor axial direction DRa. Then, the bearing housing inner diameter φDh changes with each step B1, B2, B3, B4 as a boundary.

Therefore, by providing such a plurality of steps B1, B2, B3, B4, in the distribution of the press-fitting allowance of the outer ring 141 with respect to the inner cylindrical portion 12, the press-fitting allowance is the respective steps B1, B2, B3, It is changed at the position B4. That is, as described above, there is a press-in allowance distribution in which the press-fit allowance in the rolling contact surface exclusion range Xabc in FIG. 4 is larger than the press-fit allowance in the rolling contact surface ranges W1 and W2.

In this embodiment, the steps B1, B2, B3, and B4 for changing the press-fitting allowance are provided in the cylindrical portion inner peripheral surface 122 as shown in FIG. It may be provided on one or both of the cylindrical portion inner peripheral surface 122.

Further, in FIG. 5, a part of the outer ring 141 after press-fitting is indicated by a two-dot chain line in order to show the relative positional relationship between the outer ring 141 after press-fitting and the inner cylindrical portion 12 in an easily understandable manner. The steps B1, B2, B3, and B4 are actually very small, but are exaggerated in FIG. 5 for easy understanding. The illustrated method is the same in FIGS. 8 and 9 described later.

In step S02, after the outer ring 141 is press-fitted into the inner cylindrical portion 12, a plurality of protrusions 123 projecting radially inward on the other side of the rotor axial direction DRa with respect to the outer ring 141, as shown in FIG. It is formed on the inner peripheral side of the inner cylindrical portion 12. For example, the plurality of protrusions 123 are formed by caulking work or the like, and are provided so as to leave a predetermined circumferential interval therebetween.

Since the outer ring 141 of the bearing 14 is press-fitted into the inner cylindrical part 12 of the rotor 10 as described above, the inner cylindrical part 12 presses the outer ring 141 radially inward in the press-fitted state where the outer ring 141 is press-fitted. ing. That is, the inner cylindrical portion 12 as the outer ring insertion portion presses the outer ring 141 radially inward to generate a compressive stress Pcp in the outer ring 141. The compressive stress Pcp of the outer ring 141 is referred to as outer ring compressive stress Pcp.

Since the press-fitting allowance of the outer ring 141 to the inner cylindrical portion 12 has different magnitudes depending on the position in the rotor axial direction DRa, the outer ring compressive stress Pcp resulting from the press-fitting also differs depending on the position in the rotor axial direction DRa. It has become. This is shown in FIG.

As shown in FIG. 6, the outer ring compression stress Pcp is large at the portion where the press-fitting allowance is large in the rotor axial direction DRa, and the outer ring compressive stress Pcp is also small at the portion where the press-fit allowance is small. That is, the outer ring compression stress Pcp in the rolling surface exclusion range Xabc is larger than the outer ring compression stress Pcp in the rolling surface ranges W1 and W2.

Specifically, the outer ring compression stress Pcp of the rolling surface exclusion range Xabc is PH except for the boundary portion between the rolling surface exclusion range Xabc and the rolling surface ranges W1 and W2. The outer ring compression stress PH is the maximum value in the stress distribution of the outer ring compression stress Pcp.

On the other hand, the size of the outer ring compressive stress Pcp in the rolling surface ranges W1 and W2 is PL. Therefore, the magnitude of the first compression stress P1, which is the outer ring compression stress Pcp, at the center position W1c of the first outer ring rolling surface 141a in the rotor axial direction DRa is PL. The magnitude of the second compression stress P2, which is the outer ring compression stress Pcp at the center position W2c of the second outer ring rolling surface 141b in the rotor axial direction DRa, is also PL. The outer ring compression stress PL is the minimum value in the stress distribution of the outer ring compression stress Pcp.

For this reason, the minimum stress portion where the outer ring compressive stress Pcp is minimized in the stress distribution of the outer ring compressive stress Pcp is within at least one of the first and second rolling contact surface ranges W1 and W2. It can be said that there is. The maximum stress portion where the outer ring compressive stress Pcp is maximized in the stress distribution of the outer ring compressive stress Pcp is at a position deviating from any of the rolling contact surface ranges W1 and W2 in the rotor axial direction DRa. In short, the maximum stress portion is located within the rolling surface exclusion range Xabc.

Furthermore, it can be said that in the stress distribution of the outer ring compressive stress Pcp, the high stress portion of the outer ring 141 is located at a position outside any of the rolling surface ranges W1 and W2. The high-stress part of the outer ring 141 means that the outer ring compressive stress Pcp larger than any outer ring compressive stress Pcp at the center positions W1c and W2c of the outer ring rolling surfaces 141a and 141b in the rotor axial direction DRa is the stress distribution. It is the site | part which has arisen in. In short, the high stress portion of the outer ring 141 is also located within the rolling surface exclusion range Xabc.

In other words, the outer ring 141 has a large outer ring compressive stress Pcp in the rolling surface exclusion range Xabc with respect to both the first compressive stress P1 and the second compressive stress P2.

As described above, according to the present embodiment, the outer ring 141 of the bearing 14 is press-fitted in the rotor axial direction DRa into the inner cylindrical portion 12 in step S02 of FIG. The press-fitting allowance in the press-fitting is a position deviating from any rolling surface range W1, W2 in the rotor axial direction DRa, and the center positions W1c, W2c of the outer ring rolling surfaces 141a, 141b in the rotor axial direction DRa. It is made larger than any press-fitting allowance. In the outer ring 141 after press-fitting, a stress distribution of the outer ring compressive stress Pcp corresponding to the size of the press-fitting allowance is generated. Specifically, as shown in FIG. 6, the minimum stress portion where the outer ring compressive stress Pcp is minimum in the stress distribution of the outer ring compressive stress Pcp after press-fitting is within the rolling surface ranges W1 and W2. On the other hand, the maximum stress portion where the outer ring compressive stress Pcp is maximum is at a position deviating from any rolling surface range W1, W2 in the rotor axial direction DRa. In other words, in the stress distribution of the outer ring compressive stress Pcp after the press-fitting, the high-stress part of the outer ring 141 is at a position deviating from any rolling surface range W1, W2.

Therefore, while suppressing the distortion of the outer ring rolling surfaces 141a and 141b caused by fitting the outer ring 141 into the inner cylindrical part 12, the coupling force between the inner cylindrical part 12 and the outer ring 141 due to the press-fitting can be any rolling. It is possible to enlarge it at a position outside the surface ranges W1 and W2. Therefore, it is possible to sufficiently secure a bearing holding force for holding the press-fitted bearing 14 while suppressing deterioration in accuracy of the outer ring rolling surfaces 141a and 141b.

Here, for comparison with the present embodiment, a comparative example is assumed in which the press-fitting allowance of the outer ring 141 to the inner cylindrical portion 12 is uniform in the rotor axial direction DRa. In the press-fitting in the comparative example, as shown in FIG. 7, the roundness of the outer ring rolling surface after press-fitting, that is, the rolling surface accuracy deteriorates as the press-fitting allowance increases. On the other hand, in the bearing structure of the present embodiment, since the accuracy deterioration of the outer ring rolling surfaces 141a and 141b can be suppressed as described above, the bearing 14 of the bearing 14 caused by the accuracy deterioration of the outer ring rolling surfaces 141a and 141b can be suppressed. It is possible to avoid a decrease in life.

Further, according to the present embodiment, as shown in FIG. 6, within the rolling surface exclusion range Xabc that deviates from the first and second rolling surface ranges W1 and W2 of the outer ring 141 in the rotor axial direction DRa. The outer ring compressive stress Pcp is larger than the first compressive stress P1 and the second compressive stress P2. Therefore, in the double row bearing such as the bearing 14 of the present embodiment, it is possible to sufficiently secure the bearing holding force while suppressing deterioration in accuracy of the two outer ring rolling surfaces 141a and 141b. That is, it is possible to ensure both the required holding force of the bearing 14 and the required life.

Further, according to the present embodiment, as shown in FIG. 5, a plurality of steps B <b> 1, B <b> 2, B <b> 3, and B <b> 4 are provided on the inner peripheral surface 122 of the cylindrical portion in the inner cylindrical portion 12 before press fitting. Thereby, in the distribution of the press-fitting allowance of the outer ring 141 with respect to the inner cylindrical portion 12, the press-fitting allowance is changed at each of the steps B1, B2, B3, and B4. Therefore, by forming a simple shape on the inner peripheral surface 122 of the cylindrical portion, it is possible to provide the size of the press-fitting allowance in the distribution of the press-fit allowance.

(Second Embodiment)
Next, a second embodiment will be described. In the present embodiment, differences from the first embodiment will be mainly described. Further, the same or equivalent parts as those of the above-described embodiment will be described by omitting or simplifying them. The same applies to the third and later embodiments described later.

In this embodiment, as shown in FIG. 8, a plurality of tapered surfaces T1, T2, T3, and T4 are provided on the inner peripheral surface 122 of the cylindrical portion in the inner cylindrical portion 12 before press-fitting. The plurality of tapered surfaces T1, T2, T3, and T4 are provided in place of the steps B1, B2, B3, and B4 of the first embodiment shown in FIG. In this respect, the present embodiment is different from the first embodiment.

Specifically, as shown in FIG. 8, the plurality of tapered surfaces T1, T2, T3, and T4 are each formed in an annular shape around the rotation center line CLc, and are arranged side by side in the rotor axial direction DRa. Then, the bearing housing inner diameter φDh changes with the taper surfaces T1, T2, T3, and T4 as boundaries.

Therefore, since the cylindrical inner peripheral surface 122 before press-fitting includes such a plurality of tapered surfaces T1, T2, T3, T4, the press-fitting allowance in the distribution of the press-fitting allowance of the outer ring 141 with respect to the inner cylindrical portion 12 is: It is changed at each tapered surface T1, T2, T3, T4.

In this embodiment, the tapered surfaces T1, T2, T3, and T4 for changing the press-fitting allowance are provided in the cylindrical portion inner peripheral surface 122 as shown in FIG. 8, but not limited thereto, the outer ring outer peripheral surface 141c is not limited thereto. And one or both of the inner peripheral surface 122 and the cylindrical portion may be provided.

Except as described above, this embodiment is the same as the first embodiment. And in this embodiment, the effect show | played from the structure common to the above-mentioned 1st Embodiment can be acquired similarly to 1st Embodiment.

Further, according to the present embodiment, as shown in FIG. 8, the cylindrical portion inner peripheral surface 122 before press-fitting includes a plurality of tapered surfaces T1, T2, T3, and T4. Thereby, in the distribution of the press-fitting allowance of the outer ring 141 with respect to the inner cylindrical portion 12, the press-fitting allowance is changed at each of the tapered surfaces T1, T2, T3, and T4. Therefore, similarly to the first embodiment, by forming a simple shape on the inner peripheral surface 122 of the cylindrical portion, it is possible to provide the size of the press-fitting allowance in the distribution of the press-fitting allowance.

(Third embodiment)
Next, a third embodiment will be described. In the present embodiment, differences from the first embodiment will be mainly described.

In this embodiment, the steps B1, B2, B3, and B4 of the first embodiment shown in FIG. 5 are not provided. Instead, as shown in FIG. 9, a plurality of separate members 40, 41, 42 configured as separate parts from the inner cylindrical portion 12 and the outer ring 141 are provided. In this respect, the present embodiment is different from the first embodiment.

Specifically, each of the plurality of separate members 40, 41, and 42 shown in FIG. 9 has a cylindrical shape centered on the rotation center line CLc and has a thin thickness in the rotor radial direction DRr. The plurality of separate members 40, 41, and 42 are arranged side by side in the rotor axial direction DRa.

Specifically, each of the plurality of separate members 40, 41, and 42 is sandwiched between the outer ring 141 and the inner cylindrical portion 12 in the rotor radial direction DRr, and any rolling surface range W1 in the rotor axial direction DRa, It is arranged at a position deviating from W2. Specifically, as shown in FIGS. 4 and 9, the first separate member 40 is disposed in the one side range Xa, the second separate member 41 is disposed in the intermediate range Xc, and the other range Xb is disposed in the other range Xb. A third separate member 42 is arranged.

In the manufacturing process of the bearing structure including the bearing 14 and the inner cylindrical portion 12 according to the present embodiment, a plurality of separate members 40, 41, and 42 are also prepared together with the bearing 14 and the rotor 10 in step S01 of FIG. .

In step S02 of FIG. 3, the outer ring 141 of the bearing 14 is press-fitted in the rotor axial direction DRa with respect to the inner cylindrical portion 12 with a plurality of separate members 40, 41, 42 sandwiched between the inner cylindrical portion 12. The Therefore, in the press-fitting of the outer ring 141, the press-fitting allowance of the separate member arrangement place where each separate member 40, 41, 42 is arranged is compared with the press-fitting allowance of the place removed from any of the separate member arrangement places. Increased. That is, in this embodiment, it is possible to obtain a press-fit allowance distribution similar to the press-fit allowance distribution due to the provision of the plurality of steps B1, B2, B3, and B4 in FIG. Each of the separate members 40, 41, 42 is elastically deformed together with the outer ring 141 and the inner cylindrical portion 12 by press-fitting, and exhibits a bearing holding force together with the outer ring 141 and the inner cylindrical portion 12.

Except as described above, this embodiment is the same as the first embodiment. And in this embodiment, the effect show | played from the structure common to the above-mentioned 1st Embodiment can be acquired similarly to 1st Embodiment.

Further, according to the present embodiment, as shown in FIG. 9, in the press-fitting of the outer ring 141, the press-fitting allowance of the different member arrangement locations where the different members 40, 41, 42 are arranged is any of the different member arrangement locations. It is made larger than the press-fitting allowance of the part that has been removed. Therefore, the size of the press-fit allowance can be provided in the distribution of the press-fit allowance by adding the separate members 40, 41, and 42.

(Other embodiments)
(1) In each of the above-described embodiments, as shown in FIG. 1, the bearing structure including the bearing 14 and the inner cylindrical portion 12 as the bearing housing is applied to the electromagnetic clutch 1, but this is an example. . For example, the bearing structure may be applied to a rotating device such as an idle pulley or another pulley or a power transmission device in addition to the electromagnetic clutch 1.

(2) In each of the above-described embodiments, as shown in FIG. 1, the bearing 14 is a double-row ball bearing, but the bearing type of the bearing 14 constituting the bearing structure is not limited. For example, depending on the device to which the bearing structure is applied, the bearing type of the bearing 14 may be a single row bearing, a roller bearing, a needle bearing, or the like. If the bearing 14 is a single-row bearing, there is no intermediate range Xc in FIG. 6, and therefore the rolling surface exclusion range Xabc is composed of one side range Xa and the other side range Xb.

(3) In each of the above-described embodiments, as shown in FIG. 6, the high-stress part of the outer ring 141 exists in each of the one-side range Xa, the other-side range Xb, and the intermediate range Xc, and therefore there are a plurality. However, this is an example, and the high stress portion may be one. When the number of the high stress portions is one, the high stress portion is in any one of the one side range Xa, the other side range Xb, and the intermediate range Xc.

(4) In each of the embodiments described above, as shown in FIG. 6, the outer ring compression stress Pcp of the rolling surface ranges W1 and W2 is greater than zero, but the outer ring compression stress Pcp of the rolling surface ranges W1 and W2 is zero. Or it can be considered to be substantially zero. In order to make the outer ring compression stress Pcp in the rolling surface ranges W1 and W2 zero or substantially zero as described above, the press-fitting allowance in the rolling surface ranges W1 and W2 is set to zero or substantially zero.

(5) In each embodiment described above. The outer ring 141 of the bearing 14 is fixed to the inner peripheral side of the inner cylindrical portion 12 by press fitting, but this is an example. If the outer ring 141 is fitted into the inner cylindrical portion 12 by an interference fit, the outer ring 141 may be fixed to the inner cylindrical portion 12 by a method other than press fitting.

In addition, this indication is not limited to the above-mentioned embodiment, It can implement by changing variously. In each of the above-described embodiments, it is needless to say that elements constituting the embodiment are not necessarily essential unless explicitly stated as essential and clearly considered essential in principle. Yes.

Further, in each of the above embodiments, when numerical values such as the number, numerical value, quantity, range, etc. of the constituent elements of the embodiment are mentioned, it is clearly limited to a specific number when clearly indicated as essential and in principle. The number is not limited to the specific number except for the case. In each of the above embodiments, when referring to the material, shape, positional relationship, etc. of the constituent elements, etc., unless otherwise specified, or in principle limited to a specific material, shape, positional relationship, etc. The material, shape, positional relationship, etc. are not limited.

(Summary)
According to the 1st viewpoint shown by one part or all part of said each embodiment, the outer ring | wheel insertion part is producing the outer ring | wheel compressive stress in the outer ring | wheel by pressing an outer ring | wheel to radial direction inner side. And in the stress distribution of the outer ring compressive stress, the outer ring rolling surface occupies a portion where the outer ring compressive stress is larger than the outer ring compressive stress at the center position of the outer ring rolling surface in the axial direction of the outer ring in the axial direction. It is in a position outside the rolling surface range.

According to the second aspect, the portion where the outer ring compressive stress is minimized in the stress distribution is within the rolling surface range occupied by the outer ring rolling surface, and the outer ring compressive stress is maximized. The part which exists is in the position out of the rolling surface range. The same applies to the third viewpoint.

Further, according to the fourth aspect, the outer ring of the bearing has a plurality of outer ring rolling surfaces. The first outer ring rolling surface of the plurality of outer ring rolling surfaces is arranged on one side in the axial direction with an axial interval with respect to the second outer ring rolling surface of the plurality of outer ring rolling surfaces. Be placed. Moreover, the said rolling surface range is comprised from the range which a 1st outer ring rolling surface occupies in the axial direction, and the range which a 2nd outer ring rolling surface occupies. Further, within the rolling surface exclusion range of the outer ring that is axially deviated from the rolling surface range, the outer ring compressive stress at the center position of the first outer ring rolling surface in the axial direction and the second outer surface in the axial direction. A large outer ring compressive stress is generated with respect to any of the outer ring compressive stresses at the center position of the rolling contact surface. Therefore, in the double row bearing having two outer ring rolling surfaces, it is possible to sufficiently secure the bearing holding force while suppressing deterioration in accuracy of the two outer ring rolling surfaces.

Further, according to the fifth aspect, the position outside the rolling surface range is within the rolling surface exclusion range in the axial direction. And the rolling surface exclusion range is a range located on one side in the axial direction from the whole of the plurality of outer ring rolling surfaces and the other side in the axial direction from the whole of the plurality of outer ring rolling surfaces. It is comprised from the range located, and the range located between several outer ring rolling surfaces in an axial direction.

Further, according to the sixth aspect, the outer ring has a plurality of outer ring rolling surfaces arranged side by side in the axial direction. The position out of the rolling surface range is in the rolling surface exclusion range in the axial direction. And the rolling surface exclusion range is a range located on one side in the axial direction from the whole of the plurality of outer ring rolling surfaces and the other side in the axial direction from the whole of the plurality of outer ring rolling surfaces. It is comprised from the range located, and the range located between several outer ring rolling surfaces in an axial direction.

Further, according to the seventh aspect, the position outside the rolling surface range is within the rolling surface exclusion range in the axial direction. And the rolling surface exclusion range is comprised from the range located in the one side of an axial direction rather than an outer ring rolling surface among outer rings, and the range located in the other side of an axial direction from an outer ring rolling surface. .

According to the eighth aspect, in the outer ring press-fitting, the outer ring press-fitting allowance of the outer ring with respect to the outer ring fitting portion is out of the rolling surface range occupied by the outer ring rolling surface in the axial direction. It is larger than the press-fitting allowance at the center position of the running surface.

Further, according to the ninth aspect, by providing a step on one or both of the outer peripheral surface of the outer ring and the inner peripheral surface of the fitting portion, the press-fitting allowance varies in the portion of the step in the distribution of the press-fitting allowance. It has been made. Therefore, by forming a simple shape on one or both of the outer peripheral surface of the outer ring and the inner peripheral surface of the fitting portion, the size of the press-fitting allowance can be provided in the distribution of the press-fitting allowance.

Further, according to the tenth aspect, since one or both of the outer peripheral surface of the outer ring and the inner peripheral surface of the fitting portion include a tapered surface, the press-fitting allowance varies in the portion of the tapered surface in the distribution of the press-fitting allowance. It has been made. Therefore, even in this case, the size of the press-fitting allowance can be provided in the distribution of the press-fitting allowance by forming a simple shape on one or both of the outer peripheral surface of the outer ring and the inner peripheral surface of the fitting portion.

Further, according to the eleventh aspect, in the press-fitting of the outer ring, the press-fitting allowance of the different member arrangement place where the different member is arranged is made larger than the press-fitting allowance of the part removed from the different member arrangement place. Therefore, the size of the press-fit allowance can be provided in the distribution of the press-fit allowance by adding another member.

Further, according to the twelfth aspect, the outer ring has a plurality of outer ring rolling surfaces arranged side by side in the axial direction. The position out of the rolling surface range is in the rolling surface exclusion range in the axial direction. And the rolling surface exclusion range is a range located on one side in the axial direction from the whole of the plurality of outer ring rolling surfaces and the other side in the axial direction from the whole of the plurality of outer ring rolling surfaces. It is comprised from the range located, and the range located between several outer ring rolling surfaces in an axial direction.

Further, according to the thirteenth aspect, the position outside the rolling surface range is in the rolling surface exclusion range in the axial direction. And the rolling surface exclusion range is comprised from the range located in the one side of an axial direction rather than an outer ring rolling surface among outer rings, and the range located in the other side of an axial direction from an outer ring rolling surface. .

Claims (13)

1. A bearing structure,
   An outer ring (141) which forms a part of the bearing (14) and is provided radially outside the inner ring (142) of the bearing via the rolling elements (143, 144) of the bearing;
   The outer ring is fitted, and an outer ring insertion portion (12) for pressing the outer ring radially inward,
   The outer ring has outer ring rolling surfaces (141a, 141b) that are recessed radially outward of the outer ring, facing the rolling elements,
   The outer ring insertion portion generates an outer ring compressive stress (Pcp) in the outer ring by pressing the outer ring radially inward.
   In the stress distribution of the outer ring compressive stress, a portion where the outer ring compressive stress is larger than the outer ring compressive stress at the center position (W1c, W2c) of the outer ring rolling surface in the axial direction (DRa) of the outer ring. The bearing structure which exists in the position which remove | deviated from the rolling surface range (W1, W2) which the said outer ring rolling surface occupies in the said axial direction.
2. The portion where the outer ring compressive stress is minimum in the stress distribution is in the rolling surface range, and the portion where the outer ring compressive stress is maximum is at a position outside the rolling surface range. The bearing structure according to claim 1.
3. A bearing structure,
   An outer ring (141) which forms a part of the bearing (14) and is provided radially outside the inner ring (142) of the bearing via the rolling elements (143, 144) of the bearing;
   The outer ring is fitted, and an outer ring insertion portion (12) for pressing the outer ring radially inward,
   The outer ring has outer ring rolling surfaces (141a, 141b) that are recessed radially outward of the outer ring, facing the rolling elements,
   The outer ring insertion portion generates an outer ring compressive stress (Pcp) in the outer ring by pressing the outer ring radially inward.
   The portion where the outer ring compressive stress is minimum in the stress distribution of the outer ring compressive stress is in the rolling surface range (W1, W2) occupied by the outer ring rolling surface in the axial direction (DRa) of the outer ring, And the site | part where the said outer ring | wheel compressive stress becomes the maximum is a bearing structure in the position which remove | deviated from the said rolling-plane surface range.
4. The outer ring has a plurality of outer ring rolling surfaces,
   The first outer ring rolling surface (141a) of the plurality of outer ring rolling surfaces is spaced apart in the axial direction (Ca) from the second outer ring rolling surface (141b) of the plurality of outer ring rolling surfaces. Are arranged side by side on the one side in the axial direction,
   The rolling surface range is composed of a range (W1) occupied by the first outer ring rolling surface and a range (W2) occupied by the second outer ring rolling surface in the axial direction,
   The outer ring compression at the center position (W1c) of the first outer ring rolling surface in the axial direction is within the rolling surface exclusion range (Xabc) out of the rolling surface range of the outer ring in the axial direction. 4. The outer ring compressive stress is large with respect to both the stress and the outer ring compressive stress at the center position (W2c) of the second outer ring rolling surface in the axial direction. Bearing structure described in 1.
5. The position outside the rolling surface range is within the rolling surface exclusion range in the axial direction,
   The rolling surface exclusion range is a range (Xa) located on one side in the axial direction with respect to the entire outer ring rolling surface of the outer ring, and a plurality of the outer ring rolling surfaces. The bearing structure according to claim 4, comprising a range (Xb) located on the other side in the axial direction and a range (Xc) located between the plurality of outer ring rolling surfaces in the axial direction. .
6. The outer ring has a plurality of outer ring rolling surfaces arranged side by side in the axial direction,
   The position outside the rolling surface range is within the rolling surface exclusion range (Xabc) in the axial direction,
   The rolling surface exclusion range is a range (Xa) located on one side in the axial direction with respect to the entire outer ring rolling surface of the outer ring, and a plurality of the outer ring rolling surfaces. Any one of Claims 1 thru | or 3 comprised from the range (Xb) located in the other side of the said axial direction, and the range (Xc) located between the said some outer ring rolling surfaces in the said axial direction. Bearing structure described in 1.
7. The position outside the rolling surface range is within the rolling surface exclusion range (Xabc) in the axial direction,
   The rolling surface exclusion range is a range (Xa) located on one side in the axial direction with respect to the outer ring rolling surface and a position on the other side in the axial direction with respect to the outer ring rolling surface. The bearing structure according to any one of claims 1 to 3, comprising a range (Xb).
8. A part of the bearing (14) is formed, and is provided on the radially outer side through the rolling elements (143, 144) of the bearing with respect to the inner ring (142) of the bearing. An outer ring (141) having a recessed outer ring rolling surface (141a, 141b);
   A method for manufacturing a bearing structure including an outer ring fitting portion (12) into which the outer ring is fitted,
   Preparing the outer ring and the outer ring fitting portion (S01);
   Pressing the outer ring into the outer ring fitting portion in the axial direction (DRa) of the outer ring (S02),
   In the outer ring press-fitting, the outer ring press-fitting allowance with respect to the outer ring fitting portion is out of the rolling surface range (W1, W2) occupied by the outer ring rolling surface in the axial direction, and the axial direction The manufacturing method of the bearing structure made larger than the said press fitting allowance in the center position (W1c, W2c) of an outer ring rolling surface.
9. The outer ring has an outer ring outer peripheral surface (141c) formed on the outer peripheral side of the outer ring,
   The outer ring insertion portion has an insertion portion inner peripheral surface (122) formed on the inner peripheral side of the outer ring insertion portion and in contact with the outer ring outer peripheral surface.
   By providing a step (B1, B2, B3, B4) on one or both of the outer peripheral surface of the outer ring and the inner peripheral surface of the fitting portion, the press-fitting allowance is at the position of the step in the distribution of the press-fitting allowance. The method for manufacturing a bearing structure according to claim 8, wherein the bearing structure is changed.
10. The outer ring has an outer ring outer peripheral surface (141c) formed on the outer peripheral side of the outer ring,
    The outer ring insertion portion has an insertion portion inner peripheral surface (122) formed on the inner peripheral side of the outer ring insertion portion and in contact with the outer ring outer peripheral surface.
    One or both of the outer peripheral surface of the outer ring and the inner peripheral surface of the fitting portion includes a tapered surface (T1, T2, T3, T4), so that in the distribution of the press-fitting allowance, the press-fitting allowance is a portion of the tapered surface. The method for manufacturing a bearing structure according to claim 8, wherein
11. Another member (40, 41, 42) that is sandwiched between the outer ring and the outer ring fitting portion in the radial direction (DRr) of the outer ring and is disposed at a position outside the rolling surface range in the axial direction. Including preparing,
    The bearing according to claim 8, wherein, in the press-fitting of the outer ring, the press-fitting allowance of a separate member arrangement place where the separate member is arranged is made larger than the press-fitting allowance of a part removed from the separate member arrangement place. Manufacturing method of structure.
12. The outer ring has a plurality of outer ring rolling surfaces arranged side by side in the axial direction,
    The position outside the rolling surface range is within the rolling surface exclusion range (Xabc) in the axial direction,
    The rolling surface exclusion range is a range (Xa) located on one side in the axial direction with respect to the entire outer ring rolling surface of the outer ring, and a plurality of the outer ring rolling surfaces. Any one of Claims 8 thru | or 11 comprised from the range (Xb) located in the other side of the said axial direction, and the range (Xc) located between the said some outer ring rolling surfaces in the said axial direction. The manufacturing method of the bearing structure as described in one.
13. The position outside the rolling surface range is within the rolling surface exclusion range (Xabc) in the axial direction,
    The rolling surface exclusion range is a range (Xa) located on one side in the axial direction with respect to the outer ring rolling surface and a position on the other side in the axial direction with respect to the outer ring rolling surface. The manufacturing method of the bearing structure according to any one of claims 8 to 11, comprising a range (Xb) to be operated.

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