| 摘要 |
PURPOSE:To form the superior oil film in a bearing gap by allowing the magnetic fluid which serves as lubricating agent to exist between an annular permanent magnet, nonmagnetic cylindrical part, and a shaft body. CONSTITUTION:A plain bearing 34 is equipped with an annular permanent magnet 38 and a magnetic pole piece 41 which contacts with the magnetic pole of the permanent magnet 38, and the inner peripheral surface 54 of the permanent magnet and the inner peripheral edges 58 and 61 of the pole piece are opposed to a nonmagnetic cylindrical part 52 installed onto the outer peripheral part of a shaft body 36, and the magnetic fluid 43 which serves as lubricating agent exists between the plain bearing 34 and the shaft body 36. Magnetic fluid is attracted and retained along the lines of magnetic force in a bearing gap 58 and sealing gaps 63 and 65, and a sufficient amount of magnetic fluid exists in the beating gap 56, when a plain bearing apparatus is in operation and in standstill state, and therefore an oil film is favourably formed in the bearing gap 56. Therefore, starting torque can be reduced, and abrasion is reduced, and the high loading capacity and the superior lubrication performance can be obtained, and sealing performance and maintenance performance can be improved. |
