Steady-state performance investigation of open-circuit hydrostatic drives used in the rotary head of drill machine

Abstract

This paper highlights the steady-state performance of open-circuit hydrostatic drives for the rotary head of drill machine through modeling and experiment. In this respect, two alternative drive systems are considered. A drive system that consists of a variable displacement pump and two high-speed low-torque hydro-motors with a gear reducer unit and the other one consists of an identical pump and a low-speed high-torque hydro-motor. The steady-state model of the proposed drive arrangements is made by bondgraph simulation technique, where the relationship of the various losses of the components are obtained as a function of operating parameters and are identified experimentally. Using them, the slip and torque loss along with the overall efficiency of the drives are characterized. The performances of the hydrostatic drives are compared for the usual operating speed range of the drill machine used in mining operation. The studies made also identify the operating range of the proposed hydrostatic drives with reasonable efficiency. Keywords Hydrostatic drive, bondgraph modeling, continuously variable transmission, pump, high-speed low-torque hydro-motor, low-speed high-torque hydro-motor, loss coefficients Date

Determination of the optimum steady-state performance of an open-loop and a closed-loop valve-controlled hydro-motor drive: a design approach

“…To study the steady-state performance of the HSLT and the LSHT hydro-motor drives discussed above, at the onset, the losses of the hydro-motors were identified. On understanding the flow and the torque losses, a number of studies are made [10][11][12] The test data were collected for the operating parameters P s , P 1 , P 2 , Q 1 , Q 2 , T l and N m , and using them in Eqs. 30 through 32, the actual characteristics of the speed, power transfer and efficiencies of the drives were determined.…”

Design and justification of hydrostatic transmission parameters for special transport vehicles

“…Due to the complexity of the closed-loop system, there is interest in organising the operation of the HST in open-loop mode [6]. This simplifies the system somewhat in terms of cooling and filtration, but does not reduce the complexity of the HST.…”