What is claimed is:
1. A leveling plate, comprising:
a main body including a surface extending in first and second directions orthogonal to each other;
an end protrusion which is provided respectively at both ends of the main body in the first direction, and protrudes from the main body in a third direction perpendicular to the surface, the end protrusion having an end circumferential surface whose central axis extends in the second direction of the main body; and
an intermediate protrusion which is provided between the end protrusions of the main body in the first direction, and protrudes from the main body to an opposite side of the end protrusions in the third direction, the intermediate protrusion having an intermediate circumferential surface whose central axis extends in the second direction of the main body;
wherein letting an imaginary line connecting a central axis of the intermediate circumferential surface with a central axis of the end circumferential surface be a line L 1 , and an imaginary line which is tangent to each tip end of the end protrusions be a line L 2 in a section perpendicular to the central axis of the end protrusion, an angle α formed by the line L 1 and the line L 2 is a≤55°.
2. A thrust bearing device, comprising:
a first leveling plate and a second leveling plate, the first and second leveling plates comprising the leveling plate according to claim 1 ;
the second leveling plate being disposed so as to be inverted about the third direction with respect to the first leveling plate and to alternate with the first leveling plate;
a first member having a first surface which comes into contact with an area on an opposite side of the end protrusion in the third direction of the first leveling plate; and
a second member having a second surface which is provided in parallel with the first surface and comes into contact with an area on an opposite side of the end protrusion in the third direction of the second leveling plate, the second member holding the first leveling plate and the second leveling plate, which are provided in an alternating manner, between the second member and the first member.
3. The thrust bearing device according to claim 2 , wherein
the first leveling plate and the second leveling plate are in contact in a state that central axes of the end protrusions of the first leveling plate are non-parallel with central axes of the end protrusions of the second leveling plate.
4. A rotary mechanical device, comprising:
a rotary body which rotates about a center of a shaft member; and
the thrust bearing device according to claim 2 , which supports the rotary body in an axial direction.
5. The leveling plate according to claim 1 , wherein
the end protrusions are provided symmetrically across the intermediate protrusion, and extend in parallel with the intermediate protrusion.
6. A thrust bearing device, comprising:
a first leveling plate and a second leveling plate, the first and second leveling plates comprising the leveling plate according to claim 5 ;
the second leveling plate being disposed so as to be inverted about the third direction with respect to the first leveling plate and to alternate with the first leveling plate;
a first member having a first surface which comes into contact with an area on an opposite side of the end protrusion in the third direction of the first leveling plate; and
a second member having a second surface which is provided in parallel with the first surface and comes into contact with an area on an opposite side of the end protrusion in the third direction of the second leveling plate, the second member holding the first leveling plate and the second leveling plate, which are provided in an alternating manner, between the second member and the first member.
7. The thrust bearing device according to claim 6 , wherein
the first leveling plate and the second leveling plate are in contact in a state that central axes of the end protrusions of the first leveling plate are non-parallel with central axes of the end protrusions of the second leveling plate.
8. A rotary mechanical device, comprising:
a rotary body which rotates about a center of a shaft member; and
the thrust bearing device according to claim 6 , which supports the rotary body in an axial direction.
9. A leveling plate, comprising:
a main body including a surface extending in first and second directions orthogonal to each other;
an end protrusion which is provided respectively at both ends of the main body in the first direction, and protrudes from the main body in a third direction perpendicular to the surface, the end protrusion having an end circumferential surface whose central axis extends in the second direction of the main body; and
an intermediate protrusion which is provided between the end protrusions of the main body in the first direction, and protrudes from the main body to an opposite side of the end protrusions in the third direction, the intermediate protrusion having an intermediate circumferential surface whose central axis extends in the second direction of the main body;
wherein letting a radius of the intermediate circumferential surface be R 1 , a radius of the end circumferential surface be R 2 , and a distance from a tip end of the intermediate protrusion to a tip end of the end protrusion be H in a section perpendicular to the central axis of the end protrusion, the following relationship is set:
R 1+ R 2= H.
10. The leveling plate according to claim 9 , wherein
the end protrusions are provided symmetrically across the intermediate protrusion, and extend in parallel with the intermediate protrusion.
11. A thrust bearing device, comprising:
a first leveling plate and a second leveling plate, the first and second leveling plates comprising the leveling plate according to claim 10 ;
the second leveling plate being disposed so as to be inverted about the third direction with respect to the first leveling plate and to alternate with the first leveling plate;
a first member having a first surface which comes into contact with an area on an opposite side of the end protrusion in the third direction of the first leveling plate; and
a second member having a second surface which is provided in parallel with the first surface and comes into contact with an area on an opposite side of the end protrusion in the third direction of the second leveling plate, the second member holding the first leveling plate and the second leveling plate, which are provided in an alternating manner, between the second member and the first member.
12. The thrust bearing device according to claim 11 , wherein
the first leveling plate and the second leveling plate are in contact in a state that central axes of the end protrusions of the first leveling plate are non-parallel with central axes of the end protrusions of the second leveling plate.
13. A rotary mechanical device, comprising:
a rotary body which rotates about a center of a shaft member; and
the thrust bearing device according to claim 11 , which supports the rotary body in an axial direction.
14. A thrust bearing device, comprising:
a first leveling plate and a second leveling plate, the first and second leveling plates comprising the leveling plate according to claim 9 ;
the second leveling plate being disposed so as to be inverted about the third direction with respect to the first leveling plate and to alternate with the first leveling plate;
a first member having a first surface which comes into contact with an area on an opposite side of the end protrusion in the third direction of the first leveli