Patent ID: 8591203
Filing Date: 2013-11-26
Classification: F04B,F04C

Abstract:
1. A pump apparatus, comprising: a housing; a pump section and a reduction chamber within the housing; a first discharge channel within the housing, the pump section connected to the reduction chamber by the first discharge channel so that hydraulic fluid pressurized in the pump section is supplied to the reduction chamber; a second discharge channel within the housing, the reduction chamber connected to an outlet provided in an outer surface of the housing by the second discharge channel; and a remaining fluid inflow prevention pipe disposed vertically within the housing and having a first and second end, the first end disposed in the reduction chamber, the second end fitted into the second discharge channel, wherein the second end has an integrally formed seal end part having an outer diameter larger than an inner diameter of the second discharge channel, the seal end part elastically deformed to form a seal while maintaining the inner diameter of the second discharge channel when installed within the second discharge channel, the seal end part having a first end and a second end at the second end of the remaining fluid inflow prevention pipe, wherein the second end of the seal end part is closer to the remaining fluid inflow prevention pipe second end than the first end of the seal end part in an axial direction of the inflow prevention pipe, the seal end part second end having a greater diameter than the seal end part first end; said remaining fluid inflow prevention pipe is configured to prevent hydraulic oil remaining in the reduction chamber from flowing into the outlet provided in an outer surface of the housing from a space between the outer diameter of the second end and an inner wall of the second discharge channel, and wherein the remaining fluid inflow prevention pipe is made of a synthetic resin, wherein the second discharge channel has a stepped portion, and the stepped portion of the second discharge channel contacts two faces of the seal end part, for sealing, and wherein the second end of the remaining fluid inflow prevention pipe has a thin portion with a larger inside diameter and a smaller thickness than another portion over a predetermined length.