液压卷（Hydraulic coil）.docVIP

液压卷（Hydraulic coil） Taiyuan University of Science and Technology Hydraulic drive course examination paper A roll Item numbertotal score Fraction A choice. (each of 2 points, the four option is 20 points in each item listed in only one is in line with the requirements of the subject, please fill in the code in question after the brackets. The wrong choice or not, choose no points) 1. displacement of hydraulic or hydraulic motors is determined by []. A. flow change, B. pressure change, C. speed change, D. geometry size. 2. if the valve core of a three bit directional valve is in the middle position, the pressure oil is connected with the two cavity of the oil cylinder and is closed back to oil, and then the valve of the valve is []. Type B., A.P, Y, C.K, D., C 3. compared with the throttle valve, the remarkable characteristic of the speed regulating valve is [.]. B. has large range of adjustment, simple structure and low cost of A. C. traffic stability is good, D. minimum pressure difference is less limited 4., the most direct cause of the gear pumps oil leakage is: [ The axial clearance between the two sides of the A. gear and the two ends of the B. gear; the overlap coefficient at the gear engagement is greater than 1 C the dead volume is changed from large to small, the oil is squeezed, and the oil in the D. alveolus is gradually compressed to high pressure by low pressure 5. when a single piston hydraulic cylinder is differentially connected, the ratio of the diameter of the screw to the piston shall be as follows: [v3=v2] A.1:2 B.:1 C. 1:D.2:1 6., in the external feedback variable pressure variable vane pump Q - P characteristic curve, to determine the curve inflection point C at the maximum working pressure value of Pmax: [] A. change the work pressure, B. adjust the flow adjustment screw C. adjust the spring pre compression spring stiffness of different D. replacement 7., double acting telescopic hydraulic cylinder, when retracting, thrust and speed a