| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent the seizure of a crank shaft due to its one-sided contact by surely lubricating the sliding surface of the crank shaft while suppressing a lubrication failure of the sliding surface.SOLUTION: A crank shaft (20) is formed with a main passage hole (21) where oil sucked from an oil reservoir part (17) distributes, an oil supply hole (22), and a gas drainage hole (23). The upstream end of the oil supply hole (22) opens to the middle of the passage of the main passage hole (21), and the downstream end thereof opens to a sliding surface (28) with respect to a main bearing (34). The upstream end of the gas drainage hole (23) opens to a further upward position of the main passage hole (21) than the upstream end of the oil supply hole (22), and the downstream end thereof opens to a space between the main bearing (34) and a rotor (14) of a motor (12). The gas drainage hole (23) and the oil supply hole (22) open to positions apart from each other in the peripheral direction, respectively.</p> |
