Based on composite control of large scale gear variable speed device

the control system of displacement of scoop tube

inlet oil of working chamber and outlet oil of scoop tube are studied

the formula of the working oil capacity is deduced.The working oil capacities needed for different speed ratio are calculated

the relation curve between oil passing area of the inletoil control valve and speed ratio is obtained

a computational formula of the inner diameter of scoop tube is provided

the positions of scoop tube orifice in different volume ratio are computed.An important basis for the over all design of oil circuit control system for large-scale gear valiablespeed device is provided.