HYDRAULIC PUMP EXCLUSIVELY USABLE AS HYDRAULIC MOTOR

摘要

PURPOSE: A hydraulic pump is provided to simplify the structure of the pump and allow the pumping capacity of the pump to be increased in an easy manner. CONSTITUTION: A hydraulic pump(10) comprises a cylinder(12); an end member(14) arranged at both ends of the pump; a fluid passage plate(16) arranged adjacent to the end member; a first pump member(18) installed inside of the cylinder; a second pump member(20) installed inside of the cylinder and arranged adjacent to the first pump member; a third pump member(22) and a fourth pump member(24); valve plates(260,262) interposed between the fluid passage plate and the first pump member, and between the fluid passage plate and the fourth pump member; and a compensation spring(28) interposed between the second pump member and the third pump member. The space between the first pump member and the second pump member changes between minimum and maximum sizes, during rotation of the second pump member, whereby an oil is sucked into or discharged from the space formed between the first pump member and the second pump member.