CONSTANT POWER HYDRAULIC PUMP

摘要

The invention relates to a constant power hydraulic pump with several rows of radial pistons which may be used in oil actuation hydraulic installations. According to the invention, the pump comprises a housing (1) provided with a central rectangular recess wherein there are introduced fives races, one fixed race (2) and four mobile races (3), whereon there may roll, by means of some bearing balls, five rows of radial pistons (4), each row containing three equally spaced pistons, all mounted in a rotor (5), which may be rotated by a disk (6) having an outer driving shaft, the radial pistons (4) being aligned by five on three generatrices of the rotor (5), in order to use only three inlet valves (7) and three discharge valves (8), the sliding recesses of five pistons having a common connection groove, and the four mobile races (3) have inner eccentric identical circular grooves and they are kept on the maximal eccentricity position by four springs (9), each having another pre-compression, against some control pistons (10.1, 10.2, 10.3 and 10.4) which, under the action of the discharge pressure of the pump installed in a discharge cover (11) may move said pistons transversally and successively in order to vary the flow rate in an inverse ratio, depending on pressure, thereby achieving a functioning characteristic as closed as possible to the constant power curve, the pump also comprising a central valve (13) which limits the maximal functioning pressure, and an input cover (12) through which the working fluid may be taken in.