HYDRAULIC DRIVE OF SELF-PROPELLED VEHICLE Russian patent published in 1995 - IPC

FIELD: agricultural engineering. SUBSTANCE: hydraulic drive of self-propelled vehicle has pump 1 with drive motor 2, spool-type one-section, three-position hydraulic control valve unit 3 whose working channels are intended for connection of hydraulic motor, direction and speed control lever 9 and oil tank 10. Introduced additionally into hydraulic drive are two sets 11, 12 of hydraulic motors for front and rear axles of self-propelled vehicle, respectively. Hydraulic control valve unit 3 has additional four-position spool-valve section 17. Main section 4 is made up by fourth position. Working channels of main and additional spool-valve sections of hydraulic control valve unit are connected by pipelines, respectively, with sets of hydraulic motors of front and rear axles of self-propelled vehicle. Direct connection of sets of hydraulic motors with driving wheels of both driving axles simplifies design and enhances efficiency of hydraulic drive, thus increasing tractive and coupling capabilities of vehicle. Hydraulic control valve unit with two four-position sections provides possibility of forward and reverse motion, braking and coasting of each driving axle of vehicle. Owing to the fact that working volumes of hydraulic motors of front and rear axles differ in value and third four-position spool-valve section is introduced into hydraulic control valve unit, additional possibilities in speed control and position control of mounted implement hydraulic cylinder are provided. EFFECT: simplified design, higher efficiency, and performance of vehicle. 6 cl, 2 dwg