Chmuzh Y. Substantiation of the parameters of low-speed high-torque hydraulic motors based on cylinders.

The study deals with a solution to the theoretical and practical problem of parameter substantiation for low-speed high-torque (LSHT) hydraulic motors based on cylinders. Working processes running in the mechanisms of building, track, loading and unloading machines require a low rotation frequency of over 0-1 rev/min for the working equipment. Standard motors require drive units, and sometimes braking units. But the use of such hydraulic motors in machine mechanisms is not effective; it is confirmed by a low performance ratio of these mechanisms. The analysis of serial LSHT motors demonstrated complexity of realization of low-frequency rotation due to an unstable working mode through considerable losses of the operating fluid in standard hydraulic motors. The use of LSHT motors based on power cylinders allows realizing an output shaft frequency of over 0-1 rev/min and rejecting reduction, and sometimes braking units. An analytical review of LSHT motors based on cylinders showed that the motors are not used. The problem is solved with the physical modelling of LSHT models based on electric, pneumatic and hydraulic cylinders. The experimental research into the model based on electric cylinders made it possible to reveal interference of the cylinders supplied from a single power supply source. The use of individual supply sources excluded cylinder interference, and therefore the power supplied was decreased by 20%. And motor models on pneumatic and hydraulic cylinders were designed on the basis of the results obtained in experiments with electric cylinders. The models designed confirmed the preconceived hypothesis and proposed schematic solutions for effective operation of LSHT hydraulic motors. Research into the LSHT model based on the hydraulic cylinders in a load lifting mechanism made it possible to define its total efficiency and the efficiency of the model motor designed. Due to the results obtained, the recommendations on implementation of LSHT motors were developed.