| 摘要 |
A hydraulic pump for liquids of the type comprising a body, a cylinder rotor surrounded by and mounted in an external support, the body having an inlet port and an outlet port for the liquid to be pumped and the rotor carrying a plurality of equiangularly spaced cylinders which are disposed parallel to or radially extending from the rotor axis, pistons in the cylinders being caused to reciprocate as the rotor is rotating, by cam means such as a surface inclined to the rotor axis or by inclining the rotor axis itself in order to pump liquid. As the rotor rotates the cylinders are moved sequentially past the inlet port as the liquid is drawn into the cylinders and sequentially past the outlet port as the liquid is forced out of the cylinders by the actions of the pistons. As each cylinder passes from the inlet port to the outlet port a precompression zone is provided in which there is a hole communicating with the high pressure outlet port, the hole being closed by a valve which opens when the pressure in the cylinder reaches the pressure in the outlet port. The invention is characterized by the provision of a flat spring valve to control the opening and closing of the hole, the flat spring valve being preferably of a stiffness such that it substantially closes under its own resilience in the absence of a pressure differential across it and consists preferably of a central portion from which two or three arms extend radially, the arms being clamped at their extremities between faces and parts of the hydraulic pump. |
