PUMP HYDRAULIC DRIVE Russian patent published in 1999 - IPC

FIELD: transport engineering; control system mechanisms of different vehicles, ships, test machinery, etc. SUBSTANCE: cut-in hydraulic valve and external load feedback device are installed in high-pressure pump suction hydraulic line. Control chamber of cut-in hydraulic valve is connected with low-pressure pump feed hydraulic line. External load feedback device is made in form of spring-loaded cylinder with control chamber connected with high-pressure pump feed hydraulic line and provided with working ports in form of triangles whose bases are pointed to port closing side and summary area of which is equal to value providing flow rate not exceeding value of geometrical delivery of high pressure pump at minimum speed of drive shaft. Spring of external feedback device is installed without preloading, and spring of displacer is installed with preloading providing required increment of setting force in proportion to increment of temperature of working liquid in hydraulic tank. EFFECT: increased stability of speed and load characteristics within wide range of working liquid temperature variations in hydraulic tank, and considerable rise in drive shaft speed, increased service life of hydraulic drive. 1 dwg