JP6074966B2 - Bearing device - Google Patents

Description

  The present invention relates to a bearing device used in, for example, a turbocharger.

  As shown in FIG. 4, a cylindrical outer ring housing 91 provided in the casing 90 and both axial sides of the outer ring housing 91 as a bearing device for a turbocharger that supports a rotating shaft that rotates at a high speed in the casing. There are rolling bearings 92 and 92 attached to the respective parts, and these rolling bearings 92 and 92 rotatably support a rotating shaft 99 on the radially inner side of the outer ring housing 91 (see Patent Document 1). ).

  In the turbocharger shown in FIG. 4, an oil supply hole 96 is provided in the casing 90, and oil is supplied from the oil supply hole 96 to the outer peripheral surface 91 a of the outer ring housing 91. With this oil, an oil film (oil film) is formed between the inner peripheral surface 90 a of the casing 90 and the outer peripheral surface 91 a of the outer ring housing 91, and the vibration of the bearing device 97 can be hardly transmitted to the casing 90.

  The oil supplied between the inner peripheral surface 90 a of the casing 90 and the outer peripheral surface 91 a of the outer ring housing 91 passes between the end surface 98 in the axial direction of the outer ring housing 91 and the side wall surface 90 b in the casing 90. The oil is supplied into the rolling bearing 92, and the oil can lubricate and cool the rolling bearing 92 with this oil.

JP 2010-133266 A

  As described above, the oil supplied from the casing 90 side of the turbocharger functions to lubricate and cool the rolling bearing 92. However, the oil exceeding the amount of oil required for this lubrication and cooling is in the rolling bearing 92. The oil that has passed through the rolling bearing 92 stays in the annular space 100 between the spacer 99a attached to the outer peripheral side of the rotating shaft 99 and the outer ring housing 91, and rotates at high speed. The oil stirring resistance at 92 is increased. As a result, the rotational resistance of the rotating shaft 99 increases, and the function as a turbocharger may not be fully exhibited.

  In addition, an oil discharge hole 89 is formed in a part of the axial center of the outer ring housing 91, and excess oil in the annular space 100 formed between the rolling bearings 92 on both sides in the axial direction is discharged. Although the oil can be discharged out of the bearing device 97 through the hole 89, if the amount of oil discharged is not sufficient compared to the amount of oil supplied, the oil stays in the annular space 100, and the oil stirring resistance in the rolling bearing 92 increases. .

  Therefore, the present invention can make the oil that has passed through the rolling bearing easily flow in the annular space in order to prevent the oil from staying in the annular space and increasing the stirring resistance of the oil in the rolling bearing. It is an object of the present invention to provide a bearing device that can be discharged well.

  The present invention includes a cylindrical outer ring housing provided in a casing and having an oil discharge hole formed in a part of an axial center thereof, and attached to both sides in the axial direction of the outer ring housing. A rolling bearing that includes a moving body and rotatably supports a rotating shaft radially inward of the outer ring housing, and the oil supplied between the inner peripheral surface of the casing and the outer peripheral surface of the outer ring housing, The oil supplied to the rolling bearing through an axial end surface of the outer ring housing and the side wall surface in the casing is formed between the rolling bearings on both axial sides. A bearing device that is discharged from an annular space through the discharge hole, and an inner peripheral surface of the outer ring housing is provided with annular holders provided on both axial sides for mounting the outer ring. And a cylindrical surface that is provided between the mounting surfaces and that constitutes the outer peripheral surface of the annular space, and the cylindrical surfaces are on both axial sides having an inner diameter larger than the inner diameter of the outer ring. A first inner peripheral surface, and an axially central second inner peripheral surface having an inner diameter larger than the inner diameter of the first inner peripheral surface and expanding the annular space radially outward. And

  According to the present invention, since the first inner peripheral surface has an inner diameter larger than the inner diameter of the outer ring, the annular space is expanded radially outwardly than the bearing space between the inner ring and the outer ring of the rolling bearing. Furthermore, the second inner peripheral surface has an inner diameter larger than the inner diameter of the first inner peripheral surface, and further expands the annular space radially outward. In this way, by gradually expanding the annular space radially outward, the oil flow passage cross section in the annular space can be enlarged, and the oil that has passed through the rolling bearing can be easily flowed in the annular space. Can be efficiently discharged from the discharge hole.

The second inner peripheral surface is located at the center in the axial direction and connects the cylindrical bottom surface where the discharge hole is opened to the cylindrical bottom surface and the first inner peripheral surface on both axial sides. It preferably has a tapered surface.
In this case, the oil that has flowed into the annular space from the inside of the rolling bearing is guided from the first inner peripheral surface side to the cylindrical bottom surface along the tapered surface, and further to the discharge hole that is open at the cylindrical bottom surface. The oil can be easily taken from the intake port of the discharge hole. For this reason, it becomes easy to discharge | emit oil from a discharge port, and it becomes possible to make oil hard to stay in annular space.

The inner diameter of the first inner peripheral surface is preferably smaller than the inner diameter of the mounting surface.
In this case, the radial position of the first inner peripheral surface can be set between the inner peripheral surface of the outer ring of the rolling bearing and the mounting surface, and the oil in the rolling bearing gradually increases in the annular space. It is possible to guide the oil to the region (region on the second inner peripheral surface side) and flow the oil in the annular space.

Further, it is preferable that the first inner peripheral surface and the second inner peripheral surface face an outer peripheral surface of the rotating shaft or an outer peripheral surface of a cylindrical body provided radially outside the rotating shaft.
In this case, there is no portion that obstructs the oil flow between the outer peripheral surface of the rotating shaft or the outer peripheral surface of the cylindrical body and the first inner peripheral surface, and the outer peripheral surface of the rotating shaft or the outer peripheral surface of the cylindrical body. There is no portion that obstructs the flow of oil between the surface and the second inner peripheral surface, and oil can be prevented from staying in a part of the annular space.

  According to the present invention, the annular space formed between the rolling bearings on both axial sides is enlarged stepwise outward in the radial direction, so that the oil flow passage cross section in the annular space is enlarged and passed through the rolling bearing. It is possible to facilitate the flow of the oil in the annular space, and the oil can be efficiently discharged from the discharge hole. As a result, it is possible to prevent the oil agitation resistance in the rolling bearing from increasing, and it is possible to improve the rotational performance of the rotating shaft.

It is a longitudinal cross-sectional view of the turbocharger in which the bearing apparatus of this invention is integrated. It is a longitudinal cross-sectional view of a bearing apparatus. It is sectional drawing to which some bearing devices were expanded. It is a longitudinal cross-sectional view of the conventional bearing device.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view of a turbocharger T in which a bearing device 1 of the present invention is incorporated. The turbocharger T includes a casing 2 and a rotating shaft 3 that rotates at high speed in the casing 2. The rotating shaft 3 has a turbine 53 provided at an end portion on one axial side (right side in FIG. 1) and an impeller 54 provided at an end portion on the other axial side (left side in FIG. 1). doing.

  An exhaust passage 51 is provided on one side of the casing 2 in the axial direction, and an air supply passage 55 is provided on the other side in the axial direction. When the turbine 53 is rotated by the exhaust gas flowing through the exhaust passage 51, the rotating shaft 3 rotates at a high speed, and the impeller 54 rotates in the air supply passage 55 by the rotational force of the rotating shaft 3. Then, the air sucked from the opening of the air supply passage 55 is compressed by the impeller 54, and this compressed air is sent into a cylinder chamber of an engine (not shown) together with fuel such as gasoline and light oil.

  The rotating shaft 3 of such a turbocharger T rotates at a high speed of several tens of thousands to several tens of thousands (times / minute), and the rotation speed frequently changes according to the operating state (the number of rotations) of the engine. Therefore, it is preferable to reduce the rotation loss of the rotating shaft 3 as much as possible. Therefore, the bearing device 1 provided in the casing 2 supports the rotary shaft 3 so as to have a small rotational resistance.

  FIG. 2 is a longitudinal sectional view of the bearing device 1. The bearing device 1 includes a cylindrical outer ring housing 10 provided in a casing 2, and rolling bearings 20 and 20 attached to both axial side portions 11 and 11 of the outer ring housing 10. By these rolling bearings 20, 20, the rotary shaft 3 on the radially inner side of the outer ring housing 10 is rotatably supported.

  The casing 2 of the turbocharger T is formed with a housing chamber 4 for housing the bearing device 1 at the center. That is, in the casing 2, an inner peripheral surface 5 and annular side wall surfaces 6 and 6 extending radially inward from both axial sides of the inner peripheral surface 5 are formed. The region surrounded by the side wall surfaces 6 and 6 is the storage chamber 4.

  Further, the casing 2 is formed with oil supply holes 7 and 7 and an oil discharge hole 8 which are opened on the inner peripheral surface 5. The oil supply hole 7 is formed in the upper part of the casing 2, and oil (lubricating oil) is supplied between the outer peripheral surface 16 of the outer ring housing 10 and the inner peripheral surface 5 of the casing 2 through the oil supply hole 7. The oil drain hole 8 is formed in the lower part of the casing 2, and the oil that has passed through the bearing device 1 provided in the storage chamber 4 is discharged to the outside through the oil drain hole 8.

The outer ring housing 10 is a cylindrical member that includes both axial side portions 11 and 11 having a cylindrical shape and a main body portion 19 therebetween, and these are integrally formed. An oil discharge hole 15 is formed in a part (lower part) of the axial center of the outer ring housing 10. The discharge hole 15 is arranged continuously with the oil discharge hole 8 of the casing 2.
The axial dimension of the outer ring housing 10 is slightly smaller than the axial dimension between the side wall surfaces 6 and 6 of the casing 2, and the outer ring housing 10 is limited in rotation in the circumferential direction within the casing 2. The one side and the other side of the direction can be moved by a minute dimension.

  Further, the end faces 17, 17 on both sides in the axial direction of the outer ring housing 10 are opposed faces facing the side wall surfaces 6, 6 provided on both sides in the axial direction in the casing 2 with a gap. A minute gap is formed between the end surface 17 in the axial direction of the outer ring housing 10 and the side wall surface 6 of the casing 2. In FIG. expressing.

Further, when the outer ring housing 10 moves in the casing 2 to one side in the axial direction (right side in FIG. 2), the end surface 17 on one side in the axial direction of the outer ring housing 10 is the side wall surface 6 (see FIG. 2). Then, the right side wall surface 6) may be contacted from the axial direction. This end surface 17 is located on the axially outer side (right side in FIG. 2) than the axially outer side surface 25 of the outer ring 22.
Similarly, when the outer ring housing 10 moves in the casing 2 to the other side in the axial direction (left side in FIG. 2), the end surface 17 on the other side in the axial direction of the outer ring housing 10 is the side in the casing 2. The wall surface 6 (left side wall surface 6 in FIG. 2) may come into contact in the axial direction. The end surface 17 is located on the axially outer side (the left side in FIG. 2) than the axially outer side surface 25 of the outer ring 22.

The rolling bearings 20 and 20 on both axial sides have the same structure, and the rolling bearing 20 of this embodiment is an angular ball bearing. Each of the rolling bearings 20 includes an outer ring 22, an inner ring 23, and balls 24 as rolling elements. The ball 24 is made of ceramic.
The outer ring 22 is fitted in each of the axial side portions 11, 11 of the outer ring housing 10, and the inner ring 23 is fitted on the rotary shaft 3. A cylindrical spacer 9 is provided between the inner rings 23 on both sides in the axial direction, and the rotary shaft 3 is inserted through the spacer 9. The left and right inner rings 23 are positioned in the axial direction by the spacer 9. An annular space 50 is formed between the outer ring housing 10 and the spacer 9 (rotating shaft 3) and between the rolling bearings 20 and 20 on both axial sides.

In the present embodiment, an oil film (oil film) is formed between the inner peripheral surface 5 of the casing 2 and the outer peripheral surface 16 of the outer ring housing 10 by the oil supplied from the oil supply holes 7, 7. 1 is difficult to be transmitted to the casing 2.
The oil supplied between the inner peripheral surface 5 and the outer peripheral surface 16 passes between the axial end surface 17 of the outer ring housing 10 and the side wall surface 6 in the casing 2 on both axial sides. It is supplied into the rolling bearing 20. That is, the oil is supplied to the annular bearing space Q between the outer ring 22 and the inner ring 23. The oil that has passed through each of the rolling bearings 20 and 20 (oil that has passed through the bearing space Q) flows through the annular space 50, and is further discharged to the outside from the annular space 50 through the discharge holes 15 and the oil discharge holes 8. The

  The inner peripheral surface shape of the outer ring housing 10 will be described. The inner peripheral surface 12 of the outer ring housing 10 has annular mounting surfaces 31, 31 provided on both axial sides 11, 11 and a cylindrical surface 32 provided between these mounting surfaces 31, 31. doing. The attachment surface 31 is a portion for attaching the outer ring 22, and the outer ring 22 is attached to the attachment surface 31 by press-fitting.

  FIG. 3 is an enlarged cross-sectional view of a part of the bearing device 1. The cylindrical surface 32 is a surface constituting the outer peripheral surface of the annular space 50, and the cylindrical surface 32 includes first inner peripheral surfaces 33, 33 on both sides in the axial direction and a second inner peripheral surface 34 on the central side in the axial direction. have. The first inner peripheral surface 33 is a linear cylindrical surface centered on the center line L of the outer ring housing 10 and has an inner diameter A larger than the inner diameter B of the outer ring 22 (A> B). The inner diameter B of the outer ring 22 is the inner diameter of the shoulder 22a of the outer ring 22. Thus, the first inner peripheral surface 33 has an inner diameter A larger than the inner diameter B of the outer ring 22, and the annular space 50 is more radially outward than the bearing space Q between the inner ring 23 and the outer ring 22. It is expanding.

  The inner diameter A of the first inner peripheral surface 33 is smaller than the inner diameter D of the mounting surface 31. With this configuration, a surface 28 that abuts the outer ring 22 in the axial direction is formed between the attachment surface 31 and the first inner peripheral surface 33, and the axial positioning of the outer ring 22 is performed by this surface 28. .

  The second inner peripheral surface 34 is a surface having an inner diameter (C) larger than the inner diameter A of the first inner peripheral surface 33, and the second inner peripheral surface 34 allows the annular space 50 to have a diameter. It is further expanded outward in the direction. In the present embodiment, the second inner peripheral surface 34 has a cylindrical bottom surface 35 positioned at the center in the axial direction, and tapered surfaces 36, 36 provided on both axial sides of the cylindrical bottom surface 35. ing.

The cylindrical bottom surface 35 is a linear cylindrical surface centered on the center line L of the outer ring housing 10, and the inner diameter C of the cylindrical bottom surface 35 is larger than the diameter A of the first inner peripheral surface 33 (C> A). This is the portion where the inner diameter is maximum in the range of the cylindrical surface 32.
As shown in FIG. 2, the discharge hole 15 is opened in a part (lower part) of the cylindrical bottom surface 35. The discharge hole 15 has a circular cross section, and the diameter at the opening (intake port) and the axial dimension of the cylindrical bottom surface 35 are the same.

  In FIG. 3, each of the tapered surfaces 36 on both axial sides is an inclined surface whose diameter decreases from the axial center to the both axial sides of the outer ring housing 10, and the cylindrical bottom surface 35 and the first inner circumferences on both axial sides. This is a surface connecting the surfaces 33 and 33. For this reason, the diameter of the small diameter portion of the tapered surface 36 is the same as the diameter A of the first inner peripheral surface 33, and the diameter of the large diameter portion of the tapered surface 36 is the same as the diameter C of the cylindrical bottom surface 35.

  As described above, according to the bearing device 1 according to the present embodiment, as described above, the oil supplied between the inner peripheral surface 5 of the casing 2 and the outer peripheral surface 16 of the outer ring housing 10 It is supplied into the rolling bearing 20 through the space between the axial end surface 17 of the housing 10 and the side wall surface 6 in the casing 2. The oil that has passed through each of the rolling bearings 20 and 20 flows through the annular space 50, and is further discharged from the annular space 50 to the outside through the discharge hole 15 and the oil discharge hole 8.

  Therefore, description will be made by paying attention to the annular space 50 formed between the rolling bearings 20 and 20 between the outer ring housing 10 and the spacer 9 and on both axial sides. According to the bearing device 1 according to the present embodiment, among the inner peripheral surfaces of the outer ring housing 10, the first inner peripheral surface 33 has an inner diameter A larger than the inner diameter B of the outer ring 22. The annular space 50 can be expanded radially outward than the bearing space Q between the outer ring 22 and the outer ring 22. Furthermore, since the second inner peripheral surface 34 has an inner diameter (C) larger than the inner diameter A of the first inner peripheral surface 33, the annular space 50 can be further expanded radially outward.

  Thus, by expanding the annular space 50 in stages, the oil flow passage cross section in the annular space 50 can be gradually increased. For this reason, the oil that has passed through the rolling bearing 20 can be easily flown in the annular space 50, and this oil can be efficiently discharged from the discharge hole 15. As a result, it is possible to prevent oil from staying in the annular space 50 and prevent the oil stirring resistance in the rolling bearing 20 from increasing. Therefore, it is possible to prevent the rotational resistance of the rotary shaft 3 from increasing, and it is possible to fully exhibit the function as a turbocharger.

In addition, as shown in FIG. 2, the first inner peripheral surface 33 faces the outer peripheral surface of the spacer 9, and the second inner peripheral surface 34 also faces the outer peripheral surface of the spacer 9. That is, between the outer peripheral surface of the spacer 9 and the first inner peripheral surface 33, there is no portion that obstructs the oil flow, and a hollow space that does not obstruct the oil flow is formed. Further, between the outer peripheral surface of the spacer 9 and the second inner peripheral surface 34, there is no portion that obstructs the oil flow, and a hollow space that does not obstruct the oil flow is formed. For this reason, oil can be prevented from staying in a part of the annular space 50.
Although the spacer 9 is provided in the present embodiment, when the spacer 9 is omitted, the first inner peripheral surface 33 and the second inner peripheral surface 34 face the outer peripheral surface of the rotating shaft 3.

  Further, as shown in FIG. 3, the second inner peripheral surface 34 includes a cylindrical bottom surface 35 at the center in the axial direction having the maximum inner diameter, and the cylindrical bottom surface 35 and the first inner peripheral surfaces 33 and 33 on both sides in the axial direction. And tapered surfaces 36, 36 connecting the two. For this reason, the oil that has flowed from the rolling bearing 20 into the annular space 50 can be guided from the first inner peripheral surface 33 side along the tapered surface 36 to the cylindrical bottom surface 35 side.

  A discharge hole 15 (see FIG. 2) for discharging oil to the outside is formed in the cylindrical bottom surface 35. When viewed from the opening (intake port) of the discharge hole 15, this opening is tapered. It is continuous with the surface 36. For this reason, the oil that has flowed to the cylindrical bottom surface 35 side is guided to the discharge hole 15, and the oil can be easily taken from the intake port of the discharge hole 15. That is, it is possible to make it difficult for oil to stay in the annular space 50.

  In the present embodiment, the inner diameter A of the first inner peripheral surface 33 is smaller than the inner diameter D of the mounting surface 31. For this reason, the radial position of the first inner peripheral surface 33 can be set between the inner peripheral surface 26 of the outer ring 22 of the rolling bearing 20 and the mounting surface 31, and the oil in the rolling bearing 20 is stepped. It is possible to guide the oil into the region where the annular space 50 becomes wider (region on the second inner peripheral surface 34 side) and to make the oil flow easily in the annular space 50.

  In the present embodiment, a spacer 9 made of a cylindrical body is provided on the radially outer side of the rotating shaft 3. The inner peripheral surface of the spacer 9 is a cylindrical surface whose diameter (inner diameter) is constant along the axial direction, but the outer peripheral surface is a cylindrical surface whose diameter (outer diameter) varies along the axial direction. That is, as shown in FIG. 3, the outer peripheral surface includes a first annular surface 45 on both axial sides, a second annular surface 46 on the axially central side having a diameter larger than that of the first annular surface 45, and a second annular surface. A tapered outer peripheral surface 47 connecting the surface 46 and the first annular surface 45 is provided.

  The outer diameter of the first annular surface 45 is set to be the same as or slightly smaller than the outer diameter E of the outer peripheral surface in the small diameter side portion of the inner ring 23. On the other hand, the outer diameter F of the second annular surface 46 is set to be larger than the outer diameter E of the outer peripheral surface in the small diameter side portion of the inner ring 23. The strength of the spacer 9 is ensured by increasing the outer diameter F of the second annular surface 46. The first annular surface 45 and the tapered outer peripheral surface 47 set as described above are formed so that the oil that has passed through the rolling bearing 20 flows smoothly along the outer peripheral surface of the spacer 9.

  Further, when the outer diameter E of the outer peripheral surface in the portion on the small diameter side of the inner ring 23 is larger than the diameter of the outer peripheral surface of the spacer 9 or when these diameters are the same, the tapered outer peripheral surface as described above is not formed. Thus, the spacer can be a linear spacer having the same outer diameter along the axial direction.

  Further, the bearing device of the present invention is not limited to the illustrated form, and may be of another form within the scope of the present invention. For example, in the above-described embodiment, the case where the inner diameter A of the first inner peripheral surface 33 is smaller than the inner diameter D of the attachment surface 31 has been described, but the inner diameter D may be the same as the inner diameter A (not shown).

  DESCRIPTION OF SYMBOLS 1: Bearing apparatus 2: Casing 3: Rotating shaft 5: Inner peripheral surface 6: Side wall surface 10: Outer ring housing 11: Axial side part of outer ring housing 12: Inner peripheral surface 15: Discharge hole 16: Outer peripheral surface 17: End surface 20 : Rolling bearing 22: Outer ring 23: Inner ring 24: Ball (rolling element) 26: Inner circumferential surface of outer ring 31: Mounting surface 32: Cylindrical surface 33: First inner circumferential surface 34: Second inner circumferential surface 35: Cylindrical bottom surface 36 : Tapered surface 50: Annular space A: Inner diameter of first inner peripheral surface B: Inner diameter of outer ring C: Inner diameter of second inner peripheral surface D: Inner diameter of mounting surface Q Bearing space

Claims (4)

A cylindrical outer ring housing provided in the casing and having an oil discharge hole formed in a part of the axial center;
A rolling bearing mounted on each of both axial sides of the outer ring housing, and provided with an outer ring, an inner ring and a rolling element, and rotatably supporting a rotating shaft radially inside the outer ring housing;
Have
The oil supplied between the inner peripheral surface of the casing and the outer peripheral surface of the outer ring housing passes between the axial end surface of the outer ring housing and the side wall surface in the casing and the outer ring of the rolling bearing. Oil supplied to the bearing space between the inner ring and oil passing through the bearing space is discharged from the annular space formed between the rolling bearings on both axial sides through the discharge hole,
An inner peripheral surface of the outer ring housing includes an annular mounting surface provided on both sides in the axial direction for mounting the outer ring, and a cylindrical surface that is provided between the mounting surfaces and constitutes an outer peripheral surface of the annular space. Have
The cylindrical surface has an inner diameter larger than the inner diameter of the outer ring, and has a first inner peripheral surface on both sides in the axial direction that expands the annular space radially outward from the bearing space, and one axial direction side An axially central side having an inner diameter larger than the inner diameter of the first inner peripheral surface and larger than the inner diameter of the first inner peripheral surface on the other axial side, further expanding the annular space radially outward. And a second inner peripheral surface of the bearing device. A cylindrical outer ring housing provided in the casing and having an oil discharge hole formed in a part of the axial center;
A rolling bearing mounted on each of both axial sides of the outer ring housing, and provided with an outer ring, an inner ring and a rolling element, and rotatably supporting a rotating shaft radially inside the outer ring housing;
Have
Oil supplied between the inner peripheral surface of the casing and the outer peripheral surface of the outer ring housing is supplied into the rolling bearing through an axial end surface of the outer ring housing and a side wall surface in the casing. The oil that has passed through the rolling bearing is discharged from the annular space formed between the rolling bearings on both sides in the axial direction through the discharge hole.
An inner peripheral surface of the outer ring housing includes an annular mounting surface provided on both sides in the axial direction for mounting the outer ring, and a cylindrical surface that is provided between the mounting surfaces and constitutes an outer peripheral surface of the annular space. Have
The cylindrical surface has a first inner peripheral surface on both axial sides having an inner diameter larger than an inner diameter of the outer ring, and an inner diameter larger than the inner diameter of the first inner peripheral surface, and the annular space is radially directed. A second inner peripheral surface on the axially central side that is expanded outward, and
The second inner peripheral surface is a tapered surface that is located at the center in the axial direction and that connects the cylindrical bottom surface to which the discharge hole is open and the first inner peripheral surface on both sides in the axial direction. And a bearing device.   The bearing device according to claim 1, wherein an inner diameter of the first inner peripheral surface on one axial side and an inner diameter of the first inner peripheral surface on the other axial side are smaller than an inner diameter of the mounting surface.   The said 1st inner peripheral surface and said 2nd inner peripheral surface are facing the outer peripheral surface of the cylindrical body provided in the outer peripheral surface of the said rotating shaft or the radial direction outer side of the said rotating shaft. The bearing device according to any one of the above.

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