Squeeze film damper, bearing unit, and turbine

A squeeze film damper includes a bearing housing as an inner ring disposed around a radially outer side of a bearing which rotatably supports a rotary shaft, an outer ring disposed around a radially outer side of the bearing housing, a squeeze film formed by circulating a viscous fluid through a clearance in a radial direction between the bearing housing and the outer ring, and a coupling pin which couples the bearing housing and the outer ring to each other and is deformable in response to relative displacement in the radial direction between the outer ring and the bearing housing. The coupling pin has stiffness that is higher in a vertical direction than in a horizontal direction in a cross section perpendicular to an axial direction of the rotary shaft.

FIELD

The present invention relates to a squeeze film damper that includes a squeeze film formed in a clearance between an inner ring and an outer ring, a bearing unit, and a turbine.

BACKGROUND

There has been conventionally known a bearing support structure that forms an elastic vibration control structure around a bearing (refer to Patent Literature 1, for example). The bearing support structure is provided with an outer housing which surrounds a bearing support body and includes a squeeze film ring formed in a clearance between the radially outer face of the bearing support body and the radially inner face of the outer housing.

CITATION LIST

Patent Literature

SUMMARY

Technical Problem

When a rotary shaft rotates, vibration caused by the rotation and natural vibration of a rotary component including the rotary shaft and the bearing are generated around the rotary shaft. The rotational vibration has a frequency (rotational frequency) corresponding to the number of rotations of the rotary shaft. On the other hand, the natural vibration is a low-frequency vibration whose frequency (natural frequency) is lower than the rotational frequency. A squeeze film damper is disposed around the bearing of the rotary shaft to reduce these vibrations.

In this case, the self-weight of the rotary component including the rotary shaft and the bearing and a static load caused by steam are applied mainly to the lower side in the vertical direction of the squeeze film damper. Accordingly, the outer housing which serves as an outer ring and the bearing support body which serves as an inner ring may be brought into contact with each other due to a narrowed clearance therebetween. In order to prevent such a situation, the outer ring and the inner ring are coupled to each other with a rod-like coupling member to maintain the clearance between the outer ring and the inner ring. On the other hand, the size of the clearance between the outer ring and the inner ring is required to vary in response to a dynamic load so as to function as a damper. Thus, the coupling member has stiffness that allows deformation of the clearance between the outer ring and the inner ring while maintaining the clearance so as to prevent contact between the outer ring and the inner ring in response to a static load.

However, with increases in the length and the size of a shaft system and in output in recent years, the self-weight and a steam power increase. Thus, it is necessary to design a coupling member having a higher stiffness. However, the higher stiffness makes it difficult for the clearance to vary in response to a dynamic load and difficult to obtain a damper effect by the squeeze film. As a result, it is difficult to reduce the vibrations generated around the rotary shaft.

In view of the above, it is an object of the present invention to provide a squeeze film damper, a bearing unit, and a turbine that enable a clearance between an inner ring and an outer ring to be appropriately maintained to reduce a deterioration in a damper performance by a squeeze film.

Solution to Problem

A squeeze film damper according to the present invention comprises an inner ring disposed around a radially outer side of a bearing, the bearing rotatably supporting a rotary shaft; an outer ring disposed around a radially outer side of the inner ring; a squeeze film formed by circulating a viscous fluid through a clearance in a radial direction between the inner ring and the outer ring; and a coupling member configured to couple the inner ring and the outer ring to each other, the coupling member being deformable in response to relative displacement in the radial direction between the outer ring and the inner ring, wherein the coupling member has stiffness that is higher in a load direction than in a perpendicular direction perpendicular to the load direction in a cross section perpendicular to an axial direction.

This configuration enables the stiffness of the coupling member to be increased in the load direction even when the coupling member is long. Thus, since the clearance between the inner ring and the outer ring can be appropriately maintained in the load direction, it is possible to reduce a deterioration in a damper effect by the squeeze film that may be caused by a narrowed clearance. On the other hand, the stiffness of the coupling member can be made lower in the perpendicular direction than in the load direction. In this case, in the perpendicular direction, since the clearance between the inner ring and the outer ring is not narrowed by a load, the clearance between the inner ring and the outer ring can be appropriately maintained. Further, the clearance between the inner ring and the outer ring can be more easily deformed in the perpendicular direction than in the load direction. Thus, the damper effect by the squeeze film can be appropriately exhibited in the perpendicular direction. The bearing is not particularly limited to any bearing, and may be a tilting pad bearing, a slide bearing, or a rolling bearing. The viscous fluid is not particularly limited to any fluid, and may be air or a lubricating oil. The load direction is not particularly limited to any direction, and may be the vertical direction. The perpendicular direction is not particularly limited to any direction, and may be the horizontal direction.

In this case, preferably, the inner ring and the outer ring each have overlap parts overlapping each other in the axial direction, the coupling member is disposed along the axial direction and couples the overlap part of the inner ring and the overlap part of the outer ring to each other, a part of the coupling member serves as a deformable damper part deformable in response to the displacement, and the deformable damper part has stiffness that is higher in a load direction than in a perpendicular direction perpendicular to the load direction in a cross section perpendicular to an axial direction.

This configuration enables the stiffness of the deformable damper part of the coupling member to be higher in the load direction than in the perpendicular direction in the cross section perpendicular to the axial direction when the coupling member is arranged in the axial direction. Thus, appropriate stiffness corresponding to the arrangement of the coupling member can be obtained.

In this case, preferably, the deformable damper part has a cross-sectional shape that is long in the load direction and short in the perpendicular direction in the cross section.

This configuration enables the stiffness of the deformable damper part of the coupling member to be higher in the load direction than in the perpendicular direction with the cross-sectional shape of the deformable damper part that is long in the load direction and short in the perpendicular direction. The cross-sectional shape that is long in the load direction and short in the perpendicular direction is not particularly limited to any shape, and may be, for example, a rectangular shape, an elliptical shape, or an oval shape.

In this case, preferably, the overlap part of the inner ring includes an inner coupling hole into which the coupling member is inserted, the overlap part of the outer ring includes an outer coupling hole into which the coupling member is inserted, the coupling member includes an inner fitting part fitted with the inner coupling hole, an outer fitting part fitted with the outer coupling hole, and the deformable damper part formed between the inner fitting part and the outer fitting part and housed in the outer coupling hole, and the deformable damper part abuts against an inner face of the outer coupling hole at a side in the load direction.

This configuration enables the deformation in the load direction of the deformable damper part to be restricted by the abutment of the deformable damper part of the coupling member against the inner face in the load direction of the outer coupling hole. Thus, it is possible to restrict the deformation of the clearance between the inner ring and the outer ring caused by a load and more appropriately maintain the clearance.

In this case, preferably, the inner ring and the outer ring each have overlap parts overlapping each other in a load direction, the coupling member is disposed along the load direction and couples the overlap part of the inner ring and the overlap part of the outer ring to each other, and a part of the coupling member serves as a deformable damper part deformable in response to the displacement.

This configuration enables the length of the coupling member to be increased in the load direction by arranging the coupling member along the load direction. Accordingly, the stiffness of the deformable damper part of the coupling member can be made higher in the load direction than in the perpendicular direction. Thus, appropriate stiffness corresponding to the arrangement of the coupling member can be obtained merely by changing the arrangement of the coupling member without changing the shape of the coupling member.

In this case, preferably, a plurality of the coupling members are disposed along an axial direction at predetermined intervals in a circumferential direction of the rotary shaft, and the intervals in the circumferential direction of the plurality of coupling members are short on both sides in the load direction and long on both sides in the perpendicular direction.

With this configuration, since the intervals between the coupling members are narrowed on both sides in the load direction, and, on the other hand, expanded on both sides in the perpendicular direction, the stiffness of the plurality of coupling members can be made higher in the load direction than in the perpendicular direction. Thus, appropriate stiffness can be obtained by the arrangement of the plurality of coupling members.

Another squeeze film damper according to the present invention comprises an inner ring disposed around a radially outer side of a bearing, the bearing rotatably supporting a rotary shaft; an outer ring disposed around a radially outer side of the inner ring; a squeeze film formed by circulating a viscous fluid through a clearance in a radial direction between the inner ring and the outer ring; and a coupling member configured to couple the inner ring and the outer ring to each other, the coupling member being deformable in response to relative displacement in the radial direction between the outer ring and the inner ring, wherein the inner ring and the outer ring are arranged in contact with each other at a load direction side in a cross section perpendicular to an axial direction.

With this configuration, even when the coupling member is long, the contact between the inner ring and the outer ring makes it possible to restrict the deformation in the load direction and increase the stiffness in the load direction. On the other hand, the stiffness is lower in the perpendicular direction than in the load direction. In this case, in the perpendicular direction, since the clearance between the inner ring and the outer ring is not narrowed by a load, the clearance between the inner ring and the outer ring can be appropriately maintained. Thus, the damper effect by the squeeze film can be appropriately exhibited in the perpendicular direction.

In this case, preferably, the outer ring has an inner peripheral face facing the inner ring, the inner peripheral face being in contact with an outer peripheral face of the inner ring at the load direction side, and the inner peripheral face of the outer ring has a curvature radius that is larger in a region located at the load direction side than in a region other than the load direction side in a cross section perpendicular to an axial direction.

This configuration enables contact between the outer ring and the inner ring by increasing the curvature radius of the inner peripheral face of the outer ring in the region on the load direction side. When the outer ring and the inner ring relatively move in the perpendicular direction, the inner ring moves along the inner peripheral face of the outer ring. Thus, it is possible to vary the clearance between the inner ring and the outer ring in the perpendicular direction and appropriately exhibit the damper effect.

Another squeeze film damper according to the present invention comprises an inner ring disposed around a radially outer side of a bearing, the bearing rotatably supporting a rotary shaft; an outer ring disposed around a radially outer side of the inner ring; a squeeze film formed by circulating a viscous fluid through a clearance in a radial direction between the inner ring and the outer ring; a coupling member configured to couple the inner ring and the outer ring to each other, the coupling member being deformable in response to relative displacement in the radial direction between the outer ring and the inner ring; and a spacer disposed between the inner ring and the outer ring at a load direction side, the spacer being in contact with the outer ring and the outer ring.

With this configuration, even when the coupling member is long, the contact between the inner ring and the outer ring with the spacer interposed therebetween makes it possible to restrict the deformation in the load direction of the coupling member and increase the stiffness in the load direction. On the other hand, the stiffness is lower in the perpendicular direction than in the load direction. In this case, in the perpendicular direction, since the clearance between the inner ring and the outer ring is not narrowed by a load, the clearance between the inner ring and the outer ring can be appropriately maintained. Thus, the damper effect by the squeeze film can be appropriately exhibited in the perpendicular direction.

In this case, preferably, the spacer is laid on an inner peripheral face of the outer ring, the inner peripheral face facing the inner ring.

This configuration enables easy installation of the spacer by laying the spacer on the inner peripheral face of the outer ring. Thus, the processing cost can be reduced.

In this case, preferably, the spacer penetrates the outer ring from a radially outer side through a radially inner side.

This configuration enables easy installation of the spacer by disposing the spacer in a manner to penetrate the outer ring. Thus, the processing cost can be reduced.

In this case, preferably, a plurality of the coupling members are disposed along the axial direction at predetermined intervals in a circumferential direction of the rotary shaft, and the number of the plurality of coupling members is smaller at the load direction side than at an opposite side of the load direction side.

With this configuration, since the inner ring and the outer ring are in contact with each other at the load direction side, the load of the inner ring is supported by the outer ring. Thus, since the stiffness at the load direction side can be increased, the number of coupling members disposed at the load direction side can be reduced. Thus, since the number of coupling members can be reduced, the processing cost can be reduced.

Another squeeze film damper according to the present invention comprises an inner ring disposed around a radially outer side of a bearing, the bearing rotatably supporting a rotary shaft; an outer ring disposed around a radially outer side of the inner ring; a squeeze film formed by circulating a viscous fluid through a clearance in a radial direction between the inner ring and the outer ring; and a coupling member configured to couple the inner ring and the outer ring to each other, the coupling member being deformable in response to relative displacement in the radial direction between the outer ring and the inner ring, wherein the clearance between the inner ring and the outer ring is larger in a load direction than in a perpendicular direction perpendicular to the load direction in a cross section perpendicular to an axial direction.

With this configuration, even when the coupling member is long, the clearance between the inner ring and the outer ring in the load direction is not narrowed. Thus, the clearance between the inner ring and the outer ring can be appropriately maintained in the load direction, and a deterioration the damper effect by the squeeze film can be reduced. On the other hand, in the perpendicular direction, since the clearance between the inner ring and the outer ring is not narrowed by a load, the clearance between the inner ring and the outer ring can be appropriately maintained. Thus, the damper effect by the squeeze film can be appropriately exhibited in the perpendicular direction.

In this case, preferably, the outer ring includes grooves formed in a recessed form on an inner peripheral face facing the inner ring, and the grooves are formed on both sides in the load direction in the cross section perpendicular to the axial direction.

With this configuration, forming the grooves makes it possible to easily ensure the clearance between the inner ring and the outer ring in the load direction and reduce the processing cost.

Another squeeze film damper according to the present invention comprises an inner ring disposed around a radially outer side of a bearing, the bearing rotatably supporting a rotary shaft; an outer ring disposed around a radially outer side of the inner ring; a squeeze film formed by circulating a viscous fluid through a clearance in a radial direction between the inner ring and the outer ring; and a coupling member configured to couple the inner ring and the outer ring to each other, the coupling member being deformable in response to relative displacement in the radial direction between the outer ring and the inner ring, wherein the inner ring has stiffness that is higher in a load direction than in a perpendicular direction perpendicular to the load direction in a cross section perpendicular to an axial direction.

With this configuration, the inner ring is more resistant to deformation in the load direction than in the perpendicular direction. Thus, in the load direction, since the clearance between the inner ring and the outer ring can be appropriately maintained, a deterioration in the damper effect by the squeeze film can be reduced. Further, in the perpendicular direction, since the clearance between the inner ring and the outer ring is not narrowed by a load, the clearance between the inner ring and the outer ring can be appropriately maintained. Thus, the damper effect by the squeeze film can be appropriately exhibited in the perpendicular direction.

In this case, preferably, the inner ring includes cut-away parts formed on both sides in the load direction.

With this configuration, forming the cut-away parts on both sides in the load direction of the inner ring makes it possible to easily reduce the stiffness of the inner ring in the perpendicular direction and relatively increase the stiffness of the inner ring in the load direction. Thus, the processing cost can be reduced.

In this case, preferably, the bearing is a tilting pad bearing including a plurality of pads disposed around the rotary shaft at predetermined intervals, and a bearing housing configured to hold the plurality of pads, the bearing housing being disposed around radially outer sides of the plurality of pads, and the bearing housing and the inner ring are integrated with each other.

With this configuration, since the bearing housing and the inner ring can be integrated with each other, it is possible to reduce the number of components and reduce the manufacturing cost.

A bearing unit according to the present invention comprises a bearing configured to rotatably support a rotary shaft; and the squeeze film damper described above and disposed around a radially outer side of the bearing.

With this configuration, even when a load is applied to the squeeze film damper, the vibrations of the rotary shaft and the bearing can be appropriately reduced by the damper effect of the squeeze film.

A turbine according to the present invention comprises the bearing unit described above; and the rotary shaft rotatably supported by the bearing unit.

With this configuration, it is possible to appropriately rotate the rotary shaft while reducing the vibration of the rotary shaft by the bearing unit.

DESCRIPTION OF EMBODIMENTS

Hereinbelow, embodiments according to the present invention will be described in detail with reference to the drawings. It is to be noted that the present invention is not limited by the embodiments. Elements in the embodiments described below include elements easily replaceable by those skilled in the art or substantially the same elements.

First Embodiment

FIG. 1is a sectional view of a bearing unit provided with a squeeze film damper according to a first embodiment, the view being taken along an axial direction.FIG. 2is a sectional view of the bearing unit provided with the squeeze film damper according to the first embodiment, the view being taken along a plane perpendicular to the axial direction, specifically, taken along line A-A ofFIG. 1.FIG. 3is a perspective view schematically illustrating a coupling pin of the squeeze film damper according to the first embodiment.FIG. 4is a sectional view of the coupling pin of the squeeze film damper according to the first embodiment, the view being taken along a plane perpendicular to an axial direction.FIG. 5is a sectional view of a coupling pin of a squeeze film damper according to a first modification, the view being taken along a plane perpendicular to an axial direction.

As illustrated inFIG. 1, a squeeze film damper11according to the first embodiment is disposed on a bearing unit1and integrated with a bearing10which rotatably supports a rotary shaft5. That is, the bearing unit1includes the bearing10which rotatably supports the rotary shaft5and the squeeze film damper11which supports the bearing10, the bearing10and the squeeze film damper11being integrated with each other.

The rotary shaft5is a turbine rotor which is disposed on a turbine6and arranged with an axial direction thereof aligned with the horizontal direction. When the rotary shaft5rotates, vibration caused by the rotation and natural vibration of a rotary component including the rotary shaft5and the bearing10are generated around the rotary shaft5. In this case, the natural vibration is a low-frequency vibration whose frequency (natural frequency) is lower than the frequency of the rotational vibration (rotational frequency). The bearing10rotatably supports the rotary shaft5, and the squeeze film damper11controls the vibration of the rotary shaft5. The turbine6is not particularly limited to any turbine, and may be a steam turbine or a gas turbine.

The bearing10is, for example, a tilting pad bearing, and includes a plurality of pads21disposed around the rotary shaft5and a bearing housing22disposed around the pads21.

The plurality of pads21are disposed on the outer periphery of the rotary shaft5at predetermined intervals in the circumferential direction. In the first embodiment, for example, four pads21are provided. Each of the pads21is formed in a circular arc shape, and the inner peripheral face thereof forms a curved plane facing the outer peripheral face of the rotary shaft5.

The housing22is annularly disposed on the outer peripheries of the pads21which are arranged in the circumferential direction. As illustrated inFIG. 1, the housing22includes an annular part22awhich is located on the outer peripheral sides of the pads21, a pair of inner peripheral flanges22bwhich are formed on both axial sides of the annular part22a, and a pair of outer peripheral flanges22cwhich are formed on both axial sides of the annular part22a.

The pair of inner peripheral flanges22bare formed on both axial sides of the annular part22aand project inward in the radial direction. The pads21are disposed between the pair of inner peripheral flanges22bin the axial direction, and the pair of inner peripheral flanges22brestrict axial movement of the pads21to the axial direction.

The pair of outer peripheral flanges22care formed on both axial sides of the annular part22aand project outward in the radial direction so that an outer ring31of the squeeze film damper11(described below) can be housed inside thereof. That is, the pair of outer peripheral flanges22cconstitute an overlap part which overlaps the outer ring31of the squeeze film damper11(described below) in the axial direction.

The annular part22aincludes a first oil passage24which is formed for supplying a lubricating oil from the radially outer side toward the pads21located on the radially inner side. Thus, the lubricating oil flows into the first oil passage24from the outer peripheral face of the annular part22a, then flows toward the inner peripheral face of the annular part22a, and then flows out to the inner peripheral side of the annular part22a. Since the pads21are disposed on the inner peripheral side of the annular part22a, the lubricating oil is filled around the pads21and also filled between the rotary shaft5and the pads21.

As illustrated inFIG. 2, a plurality of pivots25for positioning the respective pads21are formed on the inner peripheral face of the annular part22a, and the number of the pivots25is the same as the number of the pads21to be provided. The pivots25are projections which project inward in the radial direction from the inner peripheral face of the annular part22a. On the other hand, an engagement hole26which is engaged with the corresponding pivot25is formed in a recessed form on the outer peripheral face located on the radially outer side of each of the pads21. Thus, each of the pads21is positioned with respect to the bearing housing22by the engagement of the engagement hole26of the pad21with the corresponding pivot25of the annular part22a.

The bearing10configured in this manner rotatably supports the rotary shaft5with a lubricating oil existing between the rotary shaft5and the pads21.

The squeeze film damper11which is disposed around the radially outer side of the bearing10includes an inner ring, the outer ring31, and a coupling pin (coupling member)32which couples the inner ring and the outer ring31to each other. Since the inner ring is integrated with the bearing housing22, a part of the bearing housing22functions as the inner ring.

The outer ring31is disposed between the pair of outer peripheral flanges22cwhich are formed on both axial sides of the annular part22a, and axial movement of the outer ring31is restricted. The outer ring31is formed in an annular shape and overlaps the pair of outer peripheral flanges22cin the axial direction. The outer peripheral face of the outer ring31is supported by a fixation member38.

The inner peripheral face of the outer ring31faces the outer peripheral face of the annular part22aof the bearing housing22. The outer ring31includes a second oil passage33which is formed for supplying a lubricating oil from the radially outer side toward the annular part22aof the bearing housing22located on the radially inner side. Thus, the lubricating oil flows into the second oil passage33from the outer peripheral face of the outer ring31, then flows toward the inner peripheral face of the outer ring31, and then flows out to the outer peripheral side of the annular part22a. Thus, the lubricating oil as a viscous fluid existing between the outer ring31and the annular part22aforms an annular squeeze film35. The lubricating oil flowing on the outer peripheral side of the annular part22aflows into the first oil passage24.

The squeeze film35formed in an annular shape exhibits a damper effect with respect to relative displacement in the radial direction between the outer ring31and the bearing housing22to reduce the vibration generated around the rotary shaft5.

The coupling pin32is a member that couples the bearing housing22and the outer ring31to each other while forming a clearance for circulating a lubricating material between the outer ring31and the annular part22a. The coupling pin32is formed in a rod-like shape elongated in a longitudinal direction and arranged with the longitudinal direction aligned with the axial direction of the rotary shaft5.

An inner coupling hole41for inserting the coupling pin32axially penetrates each of the outer peripheral flanges22cof the bearing housing22. An outer coupling hole42for inserting the coupling pin32axially penetrates the outer ring31. The inner coupling hole41and the outer coupling hole42axially overlap each other, and have circular cross sections. The inner coupling hole41and the outer coupling hole42have the same inside diameter.

As illustrated inFIG. 2, a plurality of inner coupling holes41, for example, twelve inner coupling holes41in the first embodiment are formed at predetermined intervals along the circumferential direction of the outer ring31, and a plurality of outer coupling holes42, for example, twelve outer coupling holes42in the first embodiment are formed at predetermined intervals along the circumferential direction of the outer ring31.

Again referring toFIG. 1, the rod-like coupling pin32is inserted into the inner coupling hole41of one of the outer peripheral flanges22c, then inserted into the outer coupling hole42of the outer ring31, and then inserted into the inner coupling hole41of the other outer peripheral flange22c. The coupling pin32includes a pair of inner fitting parts51which are formed on both longitudinal ends, an outer fitting part52which is formed between the pair of inner fitting parts51, and a pair of deformable damper parts53each of which is formed between the corresponding inner fitting part51and the outer fitting part52.

As illustrated inFIGS. 1 and 3, the pair of inner fitting parts51are fitted with the pair of inner coupling holes41. Thus, each of the inner fitting parts51is formed in a cylindrical shape having a diameter substantially equal to the inside diameter of each of the inner coupling holes41so as to be fitted with each of the inner coupling holes41having a circular cross section.

The outer fitting part52is fitted with the outer coupling hole42. Thus, the outer fitting part52is formed in a cylindrical shape having a diameter substantially equal to the inside diameter of the outer coupling hole42so as to be fitted with the outer coupling hole42having a circular cross section similarly to the inner fitting parts51. The axial length of the outer fitting part52is shorter than the axial length of the outer coupling hole42, and the outer fitting part52is located on the axial center of the outer coupling hole42.

The pair of deformable damper parts53are formed between one of the inner fitting parts51and the outer fitting part52and between the other inner fitting part51and the outer fitting part52, and inserted into the outer coupling hole42. Each of the deformable damper parts53is deformable in response to relative deformation in the radial direction between the outer ring31and the bearing housing22.

As illustrated inFIGS. 3 and 4, in each of the deformable damper parts53, a cross section taken along a plane perpendicular to the longitudinal direction (axial direction) has a rectangular shape. The cross section of the deformable damper part53is smaller than the cross section of the inner fitting part51and the cross section of the outer fitting part52, and has a size that can fit within the cross section of the inner fitting part51and the cross section of the outer fitting part52. In this case, the long side of the rectangular cross section of the deformable damper part53is aligned with the vertical direction, and the short side of the rectangular cross section is aligned with the horizontal direction. Since the deformable damper part53has such a rectangular cross-sectional shape, the stiffness thereof is higher in the vertical direction than in the horizontal direction. Thus, the coupling pin32is resistant to warping even when a load is applied to the coupling pin32in the vertical direction.

As described above, the configuration of the first embodiment enables the stiffness of the coupling pin32to be increased in the vertical direction even when the coupling pin32is long. Thus, since the clearance between the outer ring31and the annular part22aof the bearing housing22can be appropriately maintained in the vertical direction as a load direction, it is possible to reduce a deterioration in a damper effect by the squeeze film35that may be caused by a narrowed clearance. On the other hand, the stiffness of the coupling pin32can be made lower in the horizontal direction than in the vertical direction. In this case, in the horizontal direction, since the clearance between the outer ring31and the annular part22aof the bearing housing22is not narrowed by a load, the clearance between the outer ring31and the annular part22aof the bearing housing22can be appropriately maintained. Further, the clearance between the outer ring31and the annular part22aof the bearing housing22can be more easily deformed in the horizontal direction than in the vertical direction. Thus, the damper effect by the squeeze film35can be appropriately exhibited in the horizontal direction.

The configuration of the first embodiment enables the stiffness of the deformable damper part53of the coupling pin32to be higher in the vertical direction than in the horizontal direction in the cross section perpendicular to the axial direction when the coupling pin32is arranged with the longitudinal direction aligned with the axial direction. Thus, appropriate stiffness corresponding to the arrangement of the coupling pin32can be obtained.

The configuration of the first embodiment enables the stiffness to be higher in the vertical direction than in the horizontal direction with the simple structure of the rectangular cross sectional shape of the deformable damper part53.

The configuration of the first embodiment enables integration between the bearing housing22and the inner ring. Thus, it is possible to reduce the number of components and reduce the manufacturing cost of the bearing unit1.

The configuration of the first embodiment enables the damper effect of the squeeze film35to be exhibited even when a load in the vertical direction is applied to the squeeze film damper11. Thus, it is possible to appropriately rotate the rotary shaft5while appropriately reducing the vibration of the rotary shaft5by the bearing unit1.

Although, in the first embodiment, the bearing10is a tilting pad bearing, the bearing10is not particularly limited to any bearing and may be a slide bearing or a rolling bearing. Although, in the first embodiment, a lubricating oil is used as a viscous fluid, the viscous fluid is not particularly limited to any fluid and may be air.

Although, in the first embodiment, the cross section of the deformable damper part53of the coupling pin32has a rectangular shape, the cross section of the deformable damper part53may have a shape illustrated inFIG. 5.FIG. 5is a sectional view of a coupling pin of a squeeze film damper according to a first modification, the view being taken along a plane perpendicular to an axial direction. As illustrated inFIG. 5, in the cross-sectional shape of the coupling pin32of the first modification, upper and lower sides in the vertical direction are formed in circular arcs, and right and left sides in the horizontal direction are formed in straight lines extending in the vertical direction. In this case, the coupling pin32has a cross-sectional shape that is long in the vertical direction and short in the horizontal direction similarly to the first embodiment. Thus, when the coupling pin32is arranged with the longitudinal direction aligned with the axial direction, the stiffness of the deformable damper part53of the coupling pin32can be made higher in the vertical direction than in the horizontal direction in the cross section perpendicular to the axial direction. Thus, appropriate stiffness corresponding to the arrangement of the coupling pin32can be obtained.

The cross-sectional shape of the deformable damper part53is not limited to the cross-sectional shapes of the first embodiment and the first modification, and may be any shape that is long in the vertical direction (load direction) and short in the horizontal direction, for example, an elliptical shape or an oval shape.

Second Embodiment

Next, a bearing unit according to a second embodiment will be described with reference toFIGS. 6 and 7.FIG. 6is a perspective view schematically illustrating a coupling pin of a squeeze film damper according to the second embodiment.FIG. 7is a sectional view of the coupling pin of the squeeze film damper according to the second embodiment, the view being taken along a plane perpendicular to an axial direction. In the second embodiment, parts different from the first embodiment will be described and parts having the same configuration as the first embodiment will be designated by the same reference signs to avoid overlapping description.

As illustrated inFIGS. 6 and 7, in the bearing unit according to the second embodiment, the position of each deformable damper part73of a coupling pin71differs from the position of the deformable damper part53of the coupling pin32in the bearing unit1of the first embodiment.

Specifically, in the deformable damper part73, a cross section taken along a plane perpendicular to the longitudinal direction (axial direction) has a rectangular shape similarly to the first embodiment. In this case, the deformable damper part73is arranged in such a manner that a lower part in the vertical direction, more specifically, a lower corner thereof abuts against the lower face of the outer coupling hole42into which the deformable damper part73is inserted. That is, the deformable damper part73of the second embodiment is located at a side that is lower, in the vertical direction, than the deformable damper part53of the first embodiment.

As described above, the configuration of the second embodiment enables deformation in a load direction (a vertically downward direction) of the deformable damper part73to be restricted by the abutment of the deformable damper part73of the coupling pin71against the lower face (the inner face on the lower side in the vertical direction) of the outer coupling hole42. Thus, it is possible to restrict deformation of a clearance between the outer ring31and the annular part22aof the bearing housing22caused by a load and more appropriately maintain the clearance.

Although, in the second embodiment, the cross section of the deformable damper part73of the coupling pin71has a rectangular shape, the cross section of the deformable damper part73may have a shape illustrated inFIG. 8.FIG. 8is a sectional view of a coupling pin of a squeeze film damper according to a second modification, the view being taken along a plane perpendicular to an axial direction. As illustrated inFIG. 8, in the cross-sectional shape of a deformable damper part73in the coupling pin71of the second modification, the lower short side of the deformable damper part73of the second embodiment having a rectangular cross-sectional shape is formed in a circular arc curved along the inner face of the outer coupling hole42. Thus, it is possible to allow the deformable damper part73of the coupling pin71to abut against the lower face (the inner face on the lower side in the vertical direction) of the outer coupling hole42with a larger contact area. Thus, it is possible to more firmly restrict the deformation in the load direction (the vertically downward direction) of the deformable damper part73.

The cross-sectional shape of the deformable damper part73is not limited to the cross-sectional shapes of the second embodiment and the second modification. The cross-sectional shape of the deformable damper part73is not particularly limited to any shape, and may be any shape that enables the deformable damper part73of the coupling pin71to abut against the lower face of the outer coupling hole42.

Third Embodiment

Next, a bearing unit101according to a third embodiment will be described with reference toFIGS. 9 to 11.FIG. 9is a sectional view of the bearing unit provided with a squeeze film damper according to the third embodiment, the view being taken along a plane perpendicular to an axial direction.FIG. 10is a sectional view of the bearing unit provided with the squeeze film damper according to the third embodiment, the view being taken along the axial direction, specifically, taken along line B-B ofFIG. 9.FIG. 11is a sectional view of the bearing unit provided with the squeeze film damper according to the third embodiment, the view being taken along the axial direction, specifically, taken along line C-C ofFIG. 9. Also in the third embodiment, parts different from the first and second embodiments will be described and parts having the same configuration as the first and second embodiments will be designated by the same reference signs to avoid overlapping description. Although, in the first and second embodiments, the longitudinal direction of the coupling pins32,71is the same as the axial direction of the rotary shaft5, the longitudinal direction of a coupling pin121is the same as the vertical direction in the third embodiment.

As illustrated inFIG. 9, the coupling pin121is a member which couples the bearing housing22and the outer ring31to each other while forming a clearance for circulating a lubricating oil between the outer ring31and the annular part22a. The coupling pin121is formed in a rod-like shape elongated in the longitudinal direction and arranged with the longitudinal direction aligned with the vertical direction.

An inner coupling hole111for inserting the coupling pin121vertically penetrates the bearing housing22. The inner coupling hole111penetrates the bearing housing22from the outer peripheral face to the outer peripheral face through the inside thereof. A pair of inner coupling holes111are formed on both horizontal sides of the bearing housing22having an annular shape across the rotary shaft5. Thus, the pair of inner coupling holes111are arranged in parallel to each other.

An outer coupling hole112for inserting the coupling pin121vertically penetrates the outer ring31. The outer coupling hole112penetrates the outer ring31from the outer peripheral face to the inner peripheral face as well as from the inner peripheral face to the outer peripheral face. That is, two outer coupling holes112are formed continuously in the vertical direction. When the two outer coupling holes112continuous in the vertical direction are defined as one set, a pair of two sets of outer coupling holes112are formed on both horizontal sides of the outer ring31having an annular shape across the rotary shaft5. Thus, the pair of outer coupling holes112are arranged in parallel to each other.

The one set of outer coupling holes112and the inner coupling hole111vertically overlap each other and have circular cross sections. The inner coupling hole111and the outer coupling hole112have the same inside diameter. In this case, the inner coupling hole111is arranged between the one set of outer coupling holes112in the vertical direction.

The outer ring31includes a housing part113which is formed on the radially outer side of the outer coupling hole112and houses a longitudinal end of the coupling pin121. A stopper member128(described below) abuts against the housing part113to restrict the position of the coupling pin121.

As illustrated inFIGS. 10 and 11, a plurality of inner coupling holes111are formed at predetermined intervals along the axial direction of the rotary shaft5, and a plurality of sets of outer coupling holes112are formed at predetermined intervals along the axial direction of the rotary shaft5. InFIGS. 10 and 11, the pad21and the rotary shaft disposed inside the bearing housing22are not illustrated.

Again referring toFIG. 9, the rod-like coupling pin121is inserted into one of the outer coupling holes112of the outer ring31, then inserted into the inner coupling hole111of the bearing housing22, and then inserted into the other outer coupling hole112of the outer ring31. The coupling pin121includes a pair of outer fitting parts126which are formed on both longitudinal ends, an inner fitting part125which is formed between the pair of outer fitting parts126, and a pair of deformable damper parts127each of which is formed between the corresponding outer fitting part126and the inner fitting part125.

As illustrated inFIG. 10, the pair of outer fitting parts126are fitted with the pair of outer coupling holes112. Thus, each of the outer fitting parts126is formed in a cylindrical shape having a diameter substantially equal to the inside diameter of each of the outer coupling holes112so as to be fitted with each of the outer coupling holes112having a circular cross-sectional shape. As illustrated inFIG. 9, a longitudinal end of each of the outer fitting parts126projects from the outer coupling hole112. The stopper member128for restricting the position of the coupling pin121is disposed on the projecting end of the outer fitting part126. The stopper member128is inserted into a through hole which penetrates the outer fitting part126in the radial direction and abuts against the housing part113in this state to prevent the coupling pin121from coming off.

As illustrated inFIG. 11, the inner fitting part125is fitted with the inner coupling hole111. Thus, the inner fitting part125is formed in a cylindrical shape having a diameter substantially equal to the inside diameter of the inner coupling hole111so as to be fitted with the inner coupling hole111having a circular cross-sectional shape.

As illustrated inFIG. 9, the pair of deformable damper parts127are formed between one of the outer fitting parts126and the inner fitting part125and between the other outer fitting part126and the inner fitting part125, and inserted throughout the inner coupling hole111and the outer coupling holes112. Each of the deformable damper parts127is deformable in response to relative deformation in the radial direction between the outer ring31and the bearing housing22. The deformable damper part127is formed in a cylindrical shape having a diameter smaller than the inside diameter of the inner coupling hole111and the inside diameter of the outer coupling hole112.

As described above, the configuration of the third embodiment enables the length of the coupling pin121to be increased in the vertical direction by arranging the coupling pin121along the vertical direction (load direction). Accordingly, the stiffness of the deformable damper part127of the coupling pin121can be made higher in the vertical direction than in the horizontal direction. Thus, the stiffness of the coupling pin121can be made lower in the horizontal direction than in the vertical direction merely by changing the arrangement of the coupling pin121without changing the shape of the coupling pin121.

Fourth Embodiment

Next, a bearing unit131according to a fourth embodiment will be described with reference toFIG. 12.FIG. 12is a sectional view of the bearing unit provided with a squeeze film damper according to the fourth embodiment, the view being taken along a plane perpendicular to an axial direction. Also in the fourth embodiment, parts different from the first to third embodiments will be described and parts having the same configuration as the first to third embodiments will be designated by the same reference signs to avoid overlapping description. In the bearing unit131of the fourth embodiment, a bearing housing22and an outer ring31are brought into contact with each other at the lower side in the vertical direction.

As illustrated inFIG. 12, in the bearing unit131of the fourth embodiment, the inner peripheral face of a region31alocated on the lower side in the vertical direction of the outer ring31and the inner peripheral face of a region31bother than the lower side in the vertical direction have different curvature radii. Specifically, the inner peripheral face of the lower side region31ahas a larger curvature radius than the inner peripheral face of the region31bother than the lower side. The lower side region31ais formed on the lower side in the vertical direction within a range extending over a predetermined angle around the rotary shaft5. The lower side region31aformed in this manner projects toward the bearing housing22so that the inner peripheral face on the lower side of the outer ring31comes into contact with the outer peripheral face on the lower side of the bearing housing22.

A coupling pin32which couples the bearing housing22and the outer ring31to each other is formed in a rod-like shape elongated in the longitudinal direction and arranged with the longitudinal direction aligned with the axial direction of the rotary shaft5. A plurality of coupling pins32are disposed at predetermined intervals along the circumferential direction of the outer ring31. In this case, the number of coupling pins32located on the lower side in the vertical direction is smaller than the number of coupling pins32located on the upper side in the vertical direction. Specifically, no coupling pin32is disposed on the lower half part in the vertical direction of the outer ring31, and, on the other hand, the plurality of coupling pins32are disposed on the upper half part in the vertical direction of the outer ring31.

As described above, in the fourth embodiment, even when the coupling pin32is long, the contact between the bearing housing22and the outer ring31at the lower side in the vertical direction makes it possible to restrict the deformation of the squeeze film damper11at the lower side in the vertical direction and increase the stiffness at the lower side in the vertical direction. On the other hand, the stiffness of the squeeze film damper11is lower in the horizontal direction than in the vertical direction. In this case, in the horizontal direction, since a clearance between the bearing housing22and the outer ring31is not narrowed by a load, the clearance between the bearing housing22and the outer ring31can be appropriately maintained. Thus, the damper effect by the squeeze film35can be appropriately exhibited in the horizontal direction.

In the fourth embodiment, since the bearing housing22and the outer ring31are in contact with each other at the lower side in the vertical direction, the load of the bearing housing22is supported by the outer ring31. Thus, since the stiffness at the lower side in the vertical direction can be increased, the number of coupling pins32disposed on the lower side in the vertical direction can be reduced. Thus, the number of coupling pins32can be reduced, which enables a reduction in the processing cost.

Although, in the fourth embodiment, the inner peripheral face of the outer ring31projects toward the bearing housing22so as to come into contact with the bearing housing22, the present invention is not limited to this configuration. For example, the outer peripheral face of the bearing housing22may project toward the outer ring31so as to come into contact with the inner peripheral face of the outer ring31.

Fifth Embodiment

Next, a bearing unit141according to a fifth embodiment will be described with reference toFIG. 13.FIG. 13is a sectional view of the bearing unit provided with a squeeze film damper according to the fifth embodiment, the view being taken along a plane perpendicular to an axial direction. Also in the fifth embodiment, parts different from the first to fourth embodiments will be described and parts having the same configuration as the first to fourth embodiments will be designated by the same reference signs to avoid overlapping description. In the bearing unit141of the fifth embodiment, a spacer145is disposed between a bearing housing22and an outer ring31.

As illustrated inFIG. 13, in the bearing unit141of the fifth embodiment, the spacer145is disposed between the bearing housing22and the outer ring31at the lower side in the vertical direction. Specifically, the spacer145is laid on the inner peripheral face of the outer ring31at the lower side in the vertical direction so as to be attached to the inner peripheral face of the outer ring31. The lower side in the vertical direction of the spacer145is in contact with the inner peripheral face of the outer ring31, and the upper side in the vertical direction thereof is in contact with the outer peripheral face of the bearing housing22. Thus, the bearing housing22and the outer ring31are in contact with each other with the spacer145interposed therebetween.

A coupling pin32which couples the bearing housing22and the outer ring31to each other is formed in a rod-like shape elongated in the longitudinal direction and arranged with the longitudinal direction aligned with the axial direction of the rotary shaft5. A plurality of coupling pins32are disposed at predetermined intervals along the circumferential direction of the outer ring31. In this case, the number of coupling pins32located at the lower side in the vertical direction is smaller than the number of coupling pins32located on the upper side in the vertical direction. Specifically, no coupling pin32is disposed on the lower half part in the vertical direction of the outer ring31, and, on the other hand, the plurality of coupling pins32are disposed on the upper half part in the vertical direction of the outer ring31.

As described above, in the fifth embodiment, even when the coupling pin32is long, the contact between the bearing housing22and the outer ring31with the spacer145interposed therebetween at the lower side in the vertical direction makes it possible to restrict the deformation of the squeeze film damper11at the lower side in the vertical direction and increase the stiffness at the lower side in the vertical direction. On the other hand, the stiffness of the squeeze film damper11is lower in the horizontal direction than in the vertical direction. In this case, in the horizontal direction, since a clearance between the bearing housing22and the outer ring31is not narrowed by a load, the clearance between the bearing housing22and the outer ring31can be appropriately maintained. Thus, the damper effect by the squeeze film35can be appropriately exhibited in the horizontal direction.

In the fifth embodiment, since the bearing housing22and the outer ring31are in contact with each other with the spacer145interposed therebetween at the lower side in the vertical direction, the load of the bearing housing22is supported by the outer ring31. Thus, since the stiffness at the lower side in the vertical direction can be increased, the number of coupling pins32disposed on the lower side in the vertical direction can be reduced. Accordingly, the number of coupling pins32can be reduced, which enables a reduction in the processing cost.

In the fifth embodiment, laying the spacer145on the inner peripheral face of the outer ring31enables easy installation of the spacer145. Thus, the processing cost can be reduced.

Although, in the fifth embodiment, the spacer145is attached to the inner peripheral face of the outer ring31, the present invention is not limited to this configuration. The spacer145may be attached to the outer peripheral face of the bearing housing22.

Although, in the fifth embodiment, the spacer145is laid on the inner peripheral face of the outer ring31at the lower side in the vertical direction between the bearing housing22and the outer ring31, a configuration of a third modification illustrated inFIG. 14may be employed.FIG. 14is a sectional view of a bearing unit provided with a squeeze film damper according to the third modification, the view being taken along a plane perpendicular to an axial direction. In the third modification illustrated inFIG. 14, a spacer145is disposed in a manner to penetrate the outer ring31from the radially outer side through the radially inner side thereof.

As illustrated inFIG. 14, in the bearing unit141of the third modification, the spacer145is disposed between the bearing housing22and the outer ring31at the lower side in the vertical direction. The spacer145includes a spacer body145aand a fixation part145b. The spacer body145aextends from the outer peripheral face through the inner peripheral face of the outer ring31. A spacer through hole penetrates the outer ring31, and the spacer body145ais inserted into the spacer through hole.

The fixation part145bis disposed on the spacer body145aat a side corresponding to the outer ring31(the lower side in the vertical direction) and attached to the outer peripheral face of the outer ring31. The fixation part145bis attached to the outer peripheral face of the outer ring31to fix the spacer body145a. The fixed spacer body145aprojects from the inner peripheral face of the outer ring31and comes into contact with the outer peripheral face of the bearing housing22.

As described above, in the third modification, the spacer145can be disposed in a manner to penetrate the outer ring31. Thus, it is possible to easily install the spacer145and reduce the processing cost.

Sixth Embodiment

Next, a bearing unit151according to a sixth embodiment will be described with reference toFIG. 15.FIG. 15is a sectional view of the bearing unit provided with a squeeze film damper according to the sixth embodiment, the view being taken along a plane perpendicular to an axial direction. Also in the sixth embodiment, parts different from the first to fifth embodiments will be described and parts having the same configuration as the first to fifth embodiments will be designated by the same reference signs to avoid overlapping description. In the bearing unit151of the sixth embodiment, a plurality of coupling pins32are arranged on both vertical sides.

As illustrated inFIG. 15, in the bearing unit151of the sixth embodiment, a coupling pin32which couples the bearing housing22and the outer ring31to each other is formed in a rod-like shape elongated in the longitudinal direction and arranged with the longitudinal direction aligned with the axial direction of the rotary shaft5. A plurality of coupling pins32are disposed at predetermined intervals along the circumferential direction of the outer ring31. The intervals between the plurality of coupling pins32in the circumferential direction are shorter on both vertical sides (the upper side and the lower side) and longer on both horizontal sides (the left side and the right side). Thus, the plurality of coupling pins32are arranged with small intervals on the upper side and the lower side in the vertical direction and, on the other hand, with large intervals on the left side and the right side in the horizontal direction.

As described above, in the sixth embodiment, since the intervals between the coupling pins32are reduced on both vertical sides and, on the other hand, the intervals between the coupling pins32are expanded on both horizontal sides, the stiffness of the plurality of coupling pins32can be made higher in the vertical direction than in the horizontal direction. Thus, the arrangement of the plurality of coupling pins32enables the squeeze film damper11to have appropriate stiffness.

Seventh Embodiment

Next, a bearing unit161according to a seventh embodiment will be described with reference toFIG. 16.FIG. 16is a sectional view of the bearing unit provided with a squeeze film damper according to the seventh embodiment, the view being taken along a plane perpendicular to an axial direction. Also in the seventh embodiment, parts different from the first to sixth embodiments will be described and parts having the same configuration as the first to sixth embodiments will be designated by the same reference signs to avoid overlapping description. In the bearing unit161of the seventh embodiment, a groove165is formed on the inner peripheral face of an outer ring31.

As illustrated inFIG. 16, in the bearing unit161of the seventh embodiment, the groove165is formed on the inner peripheral face of the outer ring31at the lower side in the vertical direction. The groove165is recessed from the inner peripheral face of the outer ring31. The groove165is formed along the inner peripheral face of the outer ring31with a predetermined depth. The groove165is formed within a range extending over a predetermined angle around the rotary shaft5at either side in the vertical direction. Grooves165are formed on both vertical sides (the upper side and the lower side). Thus, a clearance between the bearing housing22and the outer ring31is larger on both vertical sides than on both horizontal sides.

As described above, in the seventh embodiment, even when the coupling pin32is long, the clearance between the bearing housing22and the outer ring31is not narrowed on both vertical sides. Thus, the clearance between the bearing housing22and the outer ring31can be appropriately maintained on both vertical sides, which enables a deterioration in the damper effect by the squeeze film35to be reduced. On the other hand, in the horizontal direction, since the clearance between the bearing housing22and the outer ring31is not narrowed by a load, the clearance between the bearing housing22and the outer ring31can be appropriately maintained. Thus, the damper effect by the squeeze film can be appropriately exhibited in the horizontal direction.

In the seventh embodiment, forming the grooves165makes it possible to easily ensure the clearance between the bearing housing22and the outer ring31on both vertical sides and reduce the processing cost.

Although, in the seventh embodiment, the grooves165are formed on the inner peripheral face of the outer ring31, the position of the grooves165is not particularly limited to any position. The grooves165may be formed on the outer peripheral face of the bearing housing22, or may be formed on both the inner peripheral face of the outer ring31and the outer peripheral face of the bearing housing22.

Eighth Embodiment

Next, a bearing unit171according to an eighth embodiment will be described with reference toFIG. 17.FIG. 17is a sectional view of the bearing unit provided with a squeeze film damper according to the eighth embodiment, the view being taken along a plane perpendicular to an axial direction. Also in the eighth embodiment, parts different from the first to seventh embodiments will be described and parts having the same configuration as the first to seventh embodiments will be designated by the same reference signs to avoid overlapping description. In the bearing unit171of the eighth embodiment, a cut-away part175is formed on the inner peripheral face of a bearing housing22.

As illustrated inFIG. 17, in the bearing unit171of the eighth embodiment, the cut-away part175is formed on the inner peripheral face of the bearing housing22at the lower side in the vertical direction. The cut-away part175is recessed from the inner peripheral face of the bearing housing22. The cut-away part175is formed on the bearing housing22in a cut-away manner with a predetermined depth. The cut-away parts175are formed on both vertical sides (the upper side and the lower side). Thus, the stiffness of the bearing housing22is higher in the vertical direction than in the horizontal direction.

As described above, in the eighth embodiment, the bearing housing22is more resistant to deformation in the vertical direction than in the horizontal direction. Thus, in the vertical direction, since a clearance between the bearing housing22and the outer ring31can be appropriately maintained, a deterioration in the damper effect by the squeeze film35can be reduced. Further, in the horizontal direction, since the clearance between the bearing housing22and the outer ring31is not narrowed by a load, the clearance between the bearing housing22and the outer ring31can be appropriately maintained. Thus, the damper effect by the squeeze film35can be appropriately exhibited in the horizontal direction.

In the eighth embodiment, forming the cut-away parts175on both vertical sides of the bearing housing22makes it possible to easily reduce the stiffness of the bearing housing22in the horizontal direction and relatively increase the stiffness of the bearing housing22in the vertical direction. Thus, the processing cost can be reduced.

Although, in the eighth embodiment, the cut-away parts175are formed on the inner peripheral face of the bearing housing22, the position of the cut-away parts175is not particularly limited to any position. The cut-away parts175may be formed on the outer peripheral face of the bearing housing22, or may be formed on both the inner peripheral face and the outer peripheral face of the bearing housing22.

REFERENCE SIGNS LIST

51INNER FITTING PART

52OUTER FITTING PART