Hydraulic pump

摘要

A hydraulic pump unit is encased between a pump body and a pump cover. A bearing hole passes through the pump body and is formed in the pump body. A drive shaft and a bearing bush are inserted into the bearing hole. The drive shaft drives the hydraulic pump unit and the bearing bush supports the drive shaft. At an end portion of the bearing hole, a seal chamber is formed. The seal chamber encases a seal member. An oil groove is formed inside the bearing hole. The oil groove connects the hydraulic pump unit side with the seal chamber and carries hydraulic oil for lubrication. The oil groove is formed in such a manner that a sectional area in the seal chamber side is greater than a sectional area in the hydraulic pump unit side. The bearing bush comprises a plurality of bush pieces arranged at a predetermined interval in an axial direction of the bearing hole.