| 摘要 |
PROBLEM TO BE SOLVED: To reduce the occurrence of noise, prevent seizure and abrasion and improve durability by making the diameter at one end of the outer peripheral portion of a rotary shaft facing the inner periphery of a radial bearing in the radial direction smaller than the diameter at the other end. SOLUTION: The diameterϕD1 at one end of the outer peripheral portion of a rotary shaft 7 facing the inner periphery of a sliding radial bearing 9 is made smaller than the diameterϕD2 at the other end, a taper made more slender toward one end from the other end of the outer peripheral portion is formed on the rotary shaft 7, and the taper has a linear shape, a curved shape or a combined shape of them. The differenceϕD2-ϕD1 is about severalμm. When the rotary shaft 7 is rotated, lubricating oil is fed to the bearing 9 by a trochoid pump and enters the gap S1 between the outer periphery of the rotary shaft 7 and the inner periphery of the bearing 9, the lubricating oil is pulled from one end to the other end by a capillary phenomenon, and an oil film is formed between the outer periphery of the rotary shaft 7 and the inner periphery of the bearing 9. A gap S2 is very small and can reduce noise, the oil film is not exhausted at the gap S2, heating, abrasion or seizure rarely occurs, and durability is improved.
|
