Shell-shaped roller bearing

Abstract

To provide a shell type roller bearing for actualizing easy bending work for a flange part while developing excellent corrosion resistance.SOLUTION: A shell type roller bearing includes a shell outer ring including a cylindrical part 12, and a flange part 13 expanding from one axial end of the cylindrical part to the inner diameter side and formed of austenitic stainless material. On one axial end of an inner diameter face 16 of the cylindrical part 12 is made as an inclined face 16b, the inner diameter of the inclined face 16b is larger than the inner diameter of an axial center region of the inner diameter face 16, and the hardness of the flange part 13 is included in a range of 300-450 HV.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a rolling bearing that bears a radial load.

Background Art

[0002] Conventionally, as a shell-shaped rolling bearing, a bearing described in Japanese Patent No. 3212880 (Patent Document 1) is known. The bearing described in Patent Document 1 is assembled by the elements constituting the bearing, then subjected to carbonitriding treatment, and then quenched and tempered. Such a shell outer ring is formed of carburized steel. Specifically, the roller and the cage are incorporated from one end in the axial direction of the shell outer ring, and such one end in the axial direction is bent inward in the diameter direction to form a flange portion and a theft groove of the shell outer ring.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, a throttle valve for adjusting the air supply amount supplied to an automobile engine or the like is known. A bearing for a throttle valve is required to have an air leakage prevention function. Therefore, in the above-described conventional shell-shaped bearing, it is conceivable to provide a ring-shaped seal member at one end in the axial direction of the shell outer ring.

[0005] The seal member has, for example, a lip, and such a lip projects inward in the diameter direction and contacts the outer peripheral surface of the throttle valve shaft to close the annular gap of the shell-shaped bearing. In this case, one region in the axial direction of the seal member covers the theft groove of the shell outer ring, and the remaining other region fits on the inner diameter surface of the shell outer ring. Then, the larger the groove width of the theft groove is, the smaller the axial fitting dimension becomes and the radial tightening margin of the seal member decreases, and as a result, the sealing performance of the seal member deteriorates.

[0006] Here, it may be considered to reduce the groove width of the theft groove and increase the axial fitting dimension. However, when the groove width of the theft groove becomes small, it is likely that a bulge will occur on the inner diameter surface of the outer ring of the shell when the flange portion is bent and formed. From this, there is a concern that the bearing clearance will be partially reduced and the service life will be shortened.

[0007] In recent years, an exhaust gas recirculation mechanism (EGR: Exhaust Gas Recirculation) has been adopted for the purpose of improving the fuel efficiency of engines. The bearings for throttle valves described above may also be exposed to exhaust gas, and bearings with corrosion resistance are required. Since the above-described conventional shell-type roller bearings use normalized steel, there is room for improvement in terms of corrosion resistance.

[0008] In view of the above circumstances, an object of the present invention is to provide a shell-type roller bearing with improved sealing performance. Another object is to provide a shell-type roller bearing with improved corrosion resistance.

Means for Solving the Problems

[0009] For this purpose, the shell-type roller bearing according to the present invention includes a cylindrical portion, and flange portions that extend from one axial end and the other axial end of the cylindrical portion toward the inner diameter side, a shell outer ring made of an austenitic stainless steel material, a seal member provided at one axial end portion of the shell outer ring, rollers that rollingly contact the inner diameter surface of the cylindrical portion, and a cage that is disposed on the inner diameter side of the shell outer ring and holds the rollers. The inner diameter of one axial end portion of the inner diameter surface is the same as or larger than the inner diameter of the axial center region of the inner diameter surface, and the hardness of at least one flange portion is included in the range of 300 to 450 HV.

[0010] According to the present invention, corrosion resistance is ensured by an austenitic stainless steel material. Further, since the hardness of the flange portion is set in the range of 300 to 450 HV, when the flange portion is formed by bending, bulging is less likely to occur on the inner diameter surface of the shell outer ring, or the bulging occurring on the inner diameter surface of the shell outer ring can be suppressed to such an extent that it does not affect the bearing function. And the concern that the bearing clearance of the shell-shaped roller bearing becomes partially small and the life becomes short is suppressed. When the hardness of the flange portion is less than 300 HV, there is a concern about a decrease in the press-fitting force (load resistance) when the bearing is incorporated into the housing of the bearing clearance. Further, when the hardness of the flange portion exceeds 450 HV, there is a concern that the bulging occurring on the inner diameter surface of the shell outer ring described above becomes large. As a preferred aspect of the present invention, the hardness of the flange portion on the thinner side of the flange portions at both ends in the axial direction is 300 to 450 HV. This facilitates the formation of the flange portion by bending in the stainless steel outer ring formed of stainless steel.

[0011] In the case of a shell-shaped roller bearing alone, the required accuracy and shape cannot be obtained. Therefore, it is necessary to press-fit it into a housing with correct dimensional accuracy. Here, the housing refers to one having an inner diameter dimension that is 0.020 mm smaller than the nominal outer diameter dimension D (an integer without a decimal point) of the outer ring and a wall thickness of 20 mm or more. As one aspect of the present invention, on the inner peripheral side of the shell outer ring, a pilferage groove extending in the circumferential direction is formed between the inner diameter surface and the flange portion. The inner axial portion of the seal member is press-fitted and fixed to the inner diameter surface, and the outer axial portion of the seal member contacts the flange portion and covers the pilferage groove from the inner diameter side. And it has an inner diameter dimension that is smaller by a predetermined value included in the range of 0.015 to 0.025 mm than the outer diameter of the shell outer ring before press-fitting, a wall thickness of 20 mm or more, and a correct accuracy of IT4 or a higher rank (IT3, or IT2, or IT1) in terms of roundness and / or cylindricity maximum value. In the state where the shell outer ring is press-fitted into a housing, the groove width of the pilferage groove with respect to the overall axial dimension of the seal member is 49% or less. According to such an aspect, there is no concern that the inner diameter surface bulges inward during bending due to the pilferage groove, and moreover, the sealing performance of the seal member can be ensured. Also, the bearing of the present invention can be press-fitted into the hole of the housing to ensure correct accuracy and dimensions. As a preferable aspect, among both flange portions, the hardness of the flange portion where the pilferage groove is provided is included in the range of 300 to 450 HV. According to such an aspect, when the flange portion is produced by bending for providing the pilferage groove, it becomes difficult for the inner diameter surface of the shell outer ring to bulge.

[0012] As a preferable aspect of the present invention, the plate thickness of the cylindrical portion on the inner diameter surface is 0.4 to 0.6 [mm]. As a preferable aspect of the present invention, regarding the flange portion with the thinner plate thickness among the flange portions at both axial ends, the portion with the minimum hardness in the flange portion is 300 to 400 HV. This makes it easier to bend and form the flange portion, and the quality of the shell outer ring is stabilized. As a preferable aspect of the present invention, the roller has a roller length that is 2.1 to 5.4 times the roller diameter. As a preferable aspect of the present invention, the seal member is made of fluororubber, and the hardness of the seal member is HS65 to 85. According to such an aspect, the corrosion resistance and sealing performance of the seal member can be confirmed.

[0013] In a more preferred aspect of the present invention, the roughness of the portion of the inner diameter surface of the cylindrical portion that is in surface contact with the inner portion in the axial direction of the seal member is Ra 0.6 [μm] or less. As a result, the equal magnification portion becomes smooth, and air leakage is prevented.

[0014] In a more preferred aspect of the present invention, the shell-shaped roller bearing rotatably supports the shaft body of the throttle valve or the shaft body of the EGR valve. According to such an aspect, the life of the shell-shaped roller bearing can be extended in an atmosphere of high-temperature gas and / or corrosive gas.

Advantages of the Invention

[0015] As described above, according to the present invention, with respect to the shell-shaped roller bearing, the sealing performance and corrosion resistance are improved as compared with the prior art. The shell-shaped roller bearing of the present invention is suitably used in a high-temperature location, a location where airtightness is required, or a location where corrosion resistance is required.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Modes for Carrying Out the Invention

[0017] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a throttle valve structure in which the bearing of the present invention is used. FIG. 2 is a diagram showing an EGR valve structure in which the bearing of the present invention is used. FIG. 3 is a longitudinal sectional view showing a shell-shaped roller bearing according to an embodiment of the present invention. The structure shown in FIG. 1 includes a shell-shaped roller bearing 10, a valve body 101, a throttle valve shaft 102, an elastic member 103, a drive transmission mechanism 104, a drive source 105, an air pipe 106, and a case 107. One end (not shown) of the air pipe 106 is connected to an engine (not shown), and supplies air for combustion to the engine as an internal combustion engine.

[0018] The valve body 101 is a metal disk and is installed inside a middle portion of the air pipe 106. The throttle valve shaft 102 extends so as to intersect the air pipe 106, and the valve body 101 is fixed to the central portion of the throttle valve shaft 102. Both ends of the throttle valve shaft 102 penetrate through the metal pipe wall of the air pipe 106 respectively. Both ends of the throttle valve shaft 102 are rotatably supported by the shell-shaped roller bearing 10. The shell outer ring 11 of the shell-shaped roller bearing 10 is press-fitted into a hole of a metal case 107 (housing) that is integrally formed with and supports the air pipe 106, thereby being fixedly attached.

[0019] An elastic member 103 is provided at one end of the throttle valve shaft 102. The elastic member 103 is, for example, a coil spring. One end of the elastic member 103 is fixed to the case 107 to urge the throttle valve shaft 102 in the closing direction. Thereby, the valve body 101 closes the air pipe 106 (opening degree 0) in a state where it is not driven at all.

[0020] The shell-shaped roller bearing 10 has a sealing performance and seals the air pipe 106. Thereby, it is possible to prevent the air flowing through the air pipe 106 from leaking out of the pipe through the shell-shaped roller bearing 10. Details will be described later.

[0021] Case 107 is further provided with a drive transmission mechanism 104 and a drive source 105. One end of the throttle valve shaft 102 is connected to the drive transmission mechanism 104. The drive transmission mechanism 104 is connected to the drive source 105. The drive source 105 is, for example, an electric motor, and rotates the throttle valve shaft 102 in the opening direction via the drive transmission mechanism 104. Thereby, the valve body 101 is opened to an arbitrary opening degree against the biasing force of the elastic member 103 in the air pipe 106.

[0022] The structure shown in FIG. 2 includes a shell-shaped roller bearing 10, a ball bearing 60, a valve body 101, a valve shaft 202, an elastic member 103, a drive transmission mechanism 104, an air pipe 106, and a case 107. The same members as those in the above-described structure are denoted by the same reference numerals and the description thereof is omitted. The tip of the valve shaft 202 reaches the inside of the air pipe 106 and is coupled to the valve body 101. The loose end of the valve shaft 202 is coaxially coupled to the gear of the drive transmission mechanism 104. The central portion of the valve shaft 202 is installed outside the air pipe 106 and is supported by the case 107 via the shell-shaped roller bearing 10 and the ball bearing 60.

[0023] As shown in FIG. 2, the shell-shaped roller bearing 10 is installed on the tip side (valve body 101 side) of the valve shaft 202, and the ball bearing 60 is installed on the end side of the valve shaft 202.

[0024] The shell-shaped roller bearing 10 has a sealing performance and seals the air pipe 106. Thereby, it is possible to prevent the gas flowing through the air pipe 106, particularly the high-temperature and high-pressure exhaust gas, from leaking out of the pipe through the shell-shaped roller bearing 10.

[0025] As shown in FIG. 3, the shell-shaped roller bearing 10 includes a shell outer ring 11, rollers 21, a retainer 31, and a seal member 41. In the following description, the circumferential direction refers to the circumferential direction of the shell-shaped roller bearing 10, the axial direction or the axis O direction refers to the extending direction of the axis O representing the center of the shell-shaped roller bearing 10, the inner side in the axis O direction refers to the side from the bearing O direction end of the shell-shaped roller bearing 10 toward the bearing O direction center, and the outer side in the axis O direction refers to the side from the bearing O direction center of the shell-shaped roller bearing 10 toward the bearing O direction end.

[0026] The shell outer ring 11 has a cylindrical portion 12, flange portions 13, 14, and a pilferage groove 15, and is a stainless steel outer ring formed of stainless steel, specifically, formed of austenitic stainless steel such as SUS304. Such a shell outer ring 11 has corrosion resistance.

[0027] The inner diameter surface 16 of the cylindrical portion 12 constitutes the outer raceway surface of the roller 21. The flange portions 13, 14 are inward flange shapes respectively formed at the end portions of the cylindrical portion 12 in the direction of the axis O, and restrict the movement of the roller 21, the cage 31, and the seal member 41 in the direction of the axis O. Note that the thickness of the flange portion 13 in the direction of the axis O of the present embodiment is smaller than the thickness of the flange portion 14 in the direction of the axis O. The reason for this is that in the manufacturing process of the shell-type roller bearing 10, the material portion that becomes the flange portion 13 is further protruded outward in the direction of the axis O from the cylindrical portion 12, a step is provided on the inner circumference and it is formed thinly, and after the roller 21 and the cage 31 are incorporated into the cylindrical portion 12, the above-mentioned material portion is bent and formed inward in diameter. This is for the convenience of the bending formation. At the time of this bending formation, a pilferage groove 15 is formed at one end portion of the cylindrical portion 12 in the direction of the axis O. The pilferage groove 15 is a circumferential groove extending over the entire circumference between the inner diameter surface 16 and the flange portion 13. The shell outer ring 11 of the present embodiment is manufactured by deep drawing processing starting from a flat disk. The flange portion 14 is composed of the original flat disk. A pilferage groove adjacent to the flange portion 14 is not provided.

[0028] A plurality of rollers 21 are arranged at intervals in the circumferential direction and roll on the inner diameter surface of the shell outer ring 11. The cage 31 is arranged between the flange portions 13, 14 on both sides in the axial direction and holds the circumferential interval of the rollers 21. The roller 21 of the present embodiment is a needle roller. Specifically, the roller length is 2.1 to 5.4 times the roller diameter.

[0029] The seal member 41 is a ring made of a polymer material, and is disposed between one flange portion 13 and the retainer 31, and between the other flange portion 14 and the retainer 31, respectively. The material of the seal member 41 in this embodiment is fluororubber, which has corrosion resistance. The hardness of the fluororubber is desirably set in the range of HS65 to 85. As can be understood from the longitudinal sectional shape shown in FIG. 3, the seal member 41 has an annular base portion 42 whose axial dimension is larger than the circumferential dimension, and an annular lip portion 43 that branches radially from the base portion 42. The lip portion 43 of this embodiment protrudes from the base portion 42 toward the inner diameter side and extends outward in the direction of the axis O.

[0030] FIG. 4 is an enlarged cross-sectional view of one end portion of the shell outer ring 11 in the direction of the axis O, and represents the circular enclosure in FIG. 3. The inner diameter surface 16 has a uniform inner diameter from the center in the direction of the axis O toward the outside in the direction of the axis O. However, a gently sloped inclined surface 16b is provided at the end of the inner diameter surface 16, and the inclined surface 16b gradually increases in diameter toward the outside in the direction of the axis O like a tapered hole.

[0031] The inclined surface 16b smoothly connects to the sneak groove 15. A position that is larger than the inner diameter of the inner diameter surface 16 by a diameter dimension Br is defined as the boundary between the inclined surface 16b and the sneak groove 15. The diameter dimension Br is a predetermined value of, for example, 20 [μm] or less.

[0032] The sneak groove 15 smoothly connects to the inner surface of the flange portion 13. A position at the base of the flange portion 13 that is the same as the inner diameter of the inner diameter surface 16 is defined as the boundary between the sneak groove 15 and the flange portion 13. In the axial direction, the distance between these two boundaries is defined as the groove width Cl of the sneak groove 15. The groove width Cl is set to a sufficient dimension so that the inner diameter surface 16 does not bulge toward the inner diameter side due to the bending formation of the flange portion 13.

[0033] Note that the shell outer ring 11 is made of stainless steel and has a higher hardness than ordinary steel materials, so there is a potential risk of the above-mentioned bulging. The inclined surface 16b absorbs the bulging even if the above-mentioned bulging occurs. As a modification not shown, the sneak groove 15 may be connected to the inner diameter surface 16 with a constant inner diameter without providing the inclined surface 16b.

[0034] In this embodiment, by appropriately selecting the hardness, the risk of bulging described above is avoided. Specifically, the hardness of the curved portion 13r of the flange portion 13 is set in the range of 300 to 450 HV. Thereby, the flange portion 13 can be formed while suppressing bulging on the inner diameter surface 16 of the shell outer ring 11, so that it is possible to prevent the bearing clearance of the shell type roller bearing 10 from becoming partially small. Preferably, in order to make it easier to bend and stabilize the quality, the hardness of the portions 16f to 13p of the flange portion 13 shown in FIG. 5 is made smaller (softer) within the range of 300 to 450 HV. Specifically, it is desirable that the hardness of the smallest (softest) point among the eight points assigned to the portions 16f to 13p in FIG. 5 is included in the range of 300 to 400 HV.

[0035] The hardness was measured for the examples of this embodiment.

[0036] It is an enlarged cross-sectional view showing the shell outer ring of an example of the present invention, and the measurement locations of the hardness are represented by black circles and black rhombuses. As shown in FIG. 5, the region from the cylindrical portion 12 to the flange portion 13 sequentially includes the connection portion 16f, the curved portion 13r, the axial end portion 13q, and the inner diameter edge portion 13p. The region of the series of connection portion 16f, curved portion 13r, axial end portion 13q, and flange inner diameter edge portion 13p is formed by bending the edge of a circumferential-shaped material, and is also referred to as an edge bending portion.

[0037] In the actual product, the hardness of the portions 16f to 13p is 300 to 450 HV.

[0038] According to this embodiment, by using an austenitic stainless steel as the material of the shell outer ring 11 and setting the hardness of the flange portion 13 to 300 to 450 HV, it is possible to achieve both corrosion resistance and ease of bending.

[0039] FIG. 6 is an enlarged cross-sectional view showing a state in which the seal member 41 is fitted to the outer ring 11 of the shell. The inner region in the axial direction of the seal member 41 is press-fitted into the inner diameter surface 16. Regarding the fitting dimension Bl (also referred to as the tightening allowance range) in the axial direction of such a fitting portion, the end portion of the inner diameter surface 16 is preferably formed smoothly so as to have a width of at least Bl or more and a surface roughness Ra of 0.6 [μm] or less. This is because there is a concern about air leakage when the surface roughness of the fitting portion between the inner diameter surface 16 and the seal member 41 is large.

[0040] The outer region in the axial direction of the seal member 41 covers the stealing groove 15 from the inner diameter side. The inner surface 13c of the flange portion 13 contacts the base portion 42. The inner diameter of the base portion 42 is larger than the inner diameter of the flange portion 13, and the base portion 42 does not come out axially outward beyond the flange portion 13. The inner diameter of the lip portion 43 is smaller than the inner diameter of the flange portion 13, and slidably contacts the outer peripheral surface (not shown) of the valve shaft passed through the central opening of the seal member 41.

[0041] FIG. 7 is a longitudinal sectional view showing the seal member 41 taken out, and represents the overall dimension Sl in the axial direction of the seal member 41. The relationship between the overall dimension Sl and the above-described fitting dimension Bl is shown in Table 1. In the present embodiment, the overall dimension Sl is equal to the axial dimension of the base portion 42. The base portion 42 may have a chamfer 44. The chamfer 44 is provided, for example, at the corner of the outer peripheral surface and the outer end surface.

[0042]

Table 1

[0043] In Table 1, based on the case where the fitting dimension Bl of the seal member 41 is 100% of the overall dimension Sl of the seal member 41, if the ratio Bl / Sl is larger than half, the reduction ratio can be suppressed to 7%. On the other hand, when the ratio Bl / Sl is less than half, the reduction ratio becomes 20% or more, and there is a concern about a decrease in seal performance. Therefore, a ratio Bl / Sl ≧ 50% is recommended. Thereby, the pressing force of the lip portion 43 is ensured.

[0044] The shell-shaped roller bearing 10 of the present embodiment includes a cylindrical portion 12 and flange portions 13 and 14 that extend from one end and the other end in the axial direction of the cylindrical portion 12 toward the inner diameter side. It includes a shell outer ring 11 made of an austenitic stainless steel material, a seal member 41 provided at one end portion of the shell outer ring 11 in the axial direction, a roller 21 that rolls in contact with the inner diameter surface 16 of the cylindrical portion 12, and a cage 31 that is disposed on the inner diameter side of the shell outer ring 11 and holds the roller 21. The inner diameter of the inclined surface 16b at one end portion of the inner diameter surface 16 in the axial direction is larger than the inner diameter of the central region of the inner diameter surface 16 in the axial direction, and the hardness of at least one of the flange portions 13 is included in the range of 300 to 450 HV. Thereby, corrosion resistance, ease of forming the flange portion 13 by bending, and sealing performance by the seal member 41 are ensured. As a modification not shown, the inner diameter of one end portion of the inner diameter surface 16 in the axial direction may be made equal to the inner diameter of the central region of the inner diameter surface 16 in the axial direction without providing the inclined surface 16b at one end portion of the inner diameter surface 16 in the axial direction.

[0045] Also, on the inner circumferential side of the shell outer ring 11, a stealing groove 15 that extends in the circumferential direction is formed between the inner diameter surface 16 and the flange portion 13. The inner axial portion of the seal member 41 is press-fitted and fixed to the inner diameter surface 16, and the outer axial portion of the seal member 41 contacts the flange portion 13 and covers the stealing groove 15 from the inner diameter side. The groove width Cl of the stealing groove 15 with respect to the overall dimension of the seal member 41 in the axial direction O is 49% or less. Thereby, the sealing performance by the seal member 41 is sufficiently ensured. Also, the plate thickness of the cylindrical portion 12 on the inner diameter surface 16 is 0.4 to 0.6 [mm].

[0046] Regarding this point, for supplementary explanation, the shell outer ring 11 of the shell-shaped roller bearing 10 of the present embodiment is press-fitted into the hole of the case 107 (housing) shown in FIG. 1 or FIG. 2. Thus, the shell outer ring 11 of the shell-shaped roller bearing 10 is attached and fixed to the case 107 (housing). The inner diameter dimension (before press-fitting) of the housing hole on the press-fitting side is smaller by a predetermined value included in the range of 0.015 to 0.025 mm than the outer diameter (before press-fitting) of the shell outer ring 11. Further, the case 107 constituting the housing hole has a wall thickness of 20 mm or more and is made to have a correct accuracy with a maximum value of roundness and / or cylindricity of IT4 or a more stringent tolerance (IT3 or less). The accuracy refers to the accuracy of the inner diameter dimension (before press-fitting) of the hole on the pressed side. In a state where the shell outer ring 11 is press-fitted into the housing hole of the case 107, the groove width Cl (FIG. 6) of the theft prevention groove with respect to the entire axial dimension Sl (FIG. 7) of the seal member 41 is 49% or less.

[0047] The roller 21 of the present embodiment has a roller length that is 2.1 to 5.4 times the roller diameter. The seal member 41 is made of fluororubber, and the hardness of the seal member 41 is HS65 to 85. Thereby, the corrosion resistance and the sealing performance of the seal member 41 are ensured. Since the roughness of the portion of the inner diameter surface 16 that is in surface contact with the inner axial portion of the seal member 41 is Ra0.6 [μm] or less, concerns about air leakage are eliminated. The shell-shaped roller bearing 10 rotatably supports the valve shaft 101 of the throttle valve or the valve shaft 202 of the EGR valve.

[0048] Next, a modified example of the present invention will be described. FIG. 8 is a longitudinal sectional view showing a modified example of the present invention. Regarding this modified example, for the configurations common to the above-described embodiment, the same reference numerals are given and the description is omitted, and the different configurations will be described below. In the shell-shaped roller bearing 20 of the modified example, the seal member 41 is provided at one axial end portion of the shell outer ring 11, but not provided at the other end portion. The shell-shaped roller bearing 20 is used in place of the shell-shaped roller bearing 10 in FIGS. 1 and 2. In this case, it is installed so that the axial end portion having the seal member 41 is close to the air pipe 106.

[0049] The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the illustrated embodiments. Various modifications and variations can be made to the illustrated embodiments within the same scope or an equivalent scope of the present invention.

Industrial Applicability

[0050] The present invention is advantageously used in mechanical elements.

Explanation of Reference Numerals

[0051] 10 Shell-type roller bearing, 11 Shell outer ring, 12 Cylindrical portion, 13, 14 Flange portions, 13c Inner surface, 13p Inner diameter edge portion, 13q Axial end portion, 13r Curved portion, 15 Pilferage groove, 16 Inner diameter surface, 16b Inclined surface, 16f Connection portion, 31 Retainer, 41 Seal member, 42 Base portion, 43 Lip portion, 60 Ball bearing, 101 Valve body, 102 Throttle valve shaft, 103 Elastic member, 104 Drive transmission mechanism, 105 Drive source, 106 Air pipe, 107 Case, 202 Valve shaft.

Claims

1. A shell outer ring made of an austenitic stainless steel material, including a cylindrical portion and flange portions that extend from one end and the other end in the axial direction of the cylindrical portion toward the inner diameter side, a seal member provided at one end portion of the shell outer ring in the axial direction, a roller that rolls in contact with the inner diameter surface of the cylindrical portion, and a cage that is disposed on the inner diameter side of the shell outer ring and holds the roller. The inner diameter of one end portion of the inner diameter surface in the axial direction is the same as or larger than the inner diameter of the central region of the inner diameter surface in the axial direction. Among the flange portions at both axial ends, the hardness of the thinner flange portion is 300 to 450 HV. On the inner peripheral side of the shell outer ring, a theft groove extending in the circumferential direction is formed between the inner diameter surface and the thinner flange portion. An inclined surface that gradually expands in diameter toward the outer side in the axial direction of the shell outer ring is provided at the end of the inner diameter surface. The inclined surface is smoothly connected to the theft groove, and the boundary between the inclined surface and the theft groove is at a position larger by a predetermined diameter dimension than the inner diameter of the inner diameter surface. The diameter dimension is 20 μm or less. A shell-type roller bearing.

2. The shell-type roller bearing according to claim 1, wherein the plate thickness of the cylindrical portion on the inner diameter surface is 0.4 to 0.6 [mm].

3. Regarding the thinner flange portion among the flange portions at both axial ends, the portion with the minimum hardness in the flange portion is 300 to 400 HV. The shell-type roller bearing according to claim 1 or 2.

4. The roller has a roller length that is 2.1 to 5.4 times the roller diameter. The shell-type roller bearing according to any one of claims 1 to 3.

5. The seal member is made of fluororubber, and the hardness of the seal member is HS65 to 85. The shell-type roller bearing according to any one of claims 1 to 4.

6. The roughness of the portion of the inner diameter surface that is in surface contact with the inner axial portion of the seal member is Ra 0.6 [μm] or less. The shell-type roller bearing according to any one of claims 1 to 5.

7. The shell-type roller bearing according to any one of claims 1 to 6, which rotatably supports the shaft body of a throttle valve or the shaft body of an EGR valve.

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