GEAR PUMP AND METHOD OF PRODUCING THE SAME

摘要

A gear pump where, when sealing is made by deformation of ribs, the maximum value of a load required to obtain a desired deformation amount is reduced to facilitate processing. The gear pump has a pump assembly, a housing (10), and ribs (500, 600). The pump assembly is constructed from a drive gear (130) supported by a drive shaft (110), a driven gear (140) meshing with the drive gear and supported by a driven shaft (120), a pair of side plates (150, 160) arranged axially on both sides of the drive gear and driven gear, and a seal block (200) for sealing the tooth tips of the gears and forming a first oil chamber (Din) by its engagement with the side plates. The housing (10) receives the pump assembly and defines a second oil chamber (Dout). The ribs (500, 600) are arranged at least either on the pair of side plates or on the seal block. The ribs are elastically deformed when they cause the pair of side plates and the seal block to be pressed against each other, defining the first oil chamber and second oil chamber in a liquid tight manner, and are constructed from a first rib section (621in) on one end side, extending in parallel with the side plates, a second rib section (621out) on the other end side, and a third rib formed contiguous to the first rib section and second rib section and extending substantially in parallel with the axis of the drive shaft. After the ribs are elastically deformed, the hardness or density of the second rib section (621out) is higher than the hardness or density of the first rib section (621in).