超星 - Chapter_7_Basic Circuit

单选题

In order to make the working mechanism can stay at any position reliably, for instance payload of a hydraulic crane, and the working mechanism will not slip under the condition of force, what circuitis usually used? ()

A. unloading loop
B. pressure regulation circuit;
C. pressure counter-balance circuit;
D. back pressure circuit.

查看答案

单选题

The speed regulating valve (installed between the hydraulic pump and the actuator) regulates ____ to control the speed of the actuator. ()

A. hydraulic pump flow
B. oil discharged from actuator
C. actuator supply pressure
D. the area of its opening

查看答案

单选题

which fast speed circuit is most suitable for the situation where the system needs large flow in a short time? ()

A. Hydraulic cylinder differential connection fast speed circuit
B. Double pump oil supply fast speed circuit
C. Speed increasing cylinder fast speed circuit
D. Fast speed circuit with accumulator

查看答案

单选题

The unloading circuit is used for ().

A. reducing flow loss
B. reducing pressure loss
C. reduce power loss
D. increase system heating

查看答案

单选题

The volumetric speed control circuit with constant power output is ( ).

A. variable displacementpump--variable displacement motor circuit
B. fixed displacement pump--variable displacement motorcircuit
C. variable displacement pump--fixed displacement motorcircuit
D. fixed displacement pump--fixed displacement motorcircuit

查看答案

单选题

The function of the relief valve is to cooperate with the oil pump to overflow the surplus oil in the system, so as to keep the system__________ stable.()

A. pressure
B. flow rate
C. flow direction
D. cleanliness

查看答案

单选题

Pressure control circuit includes ().

A. locking circuit
B. pressure regulating, pressure reducing and unloading circuit
C. pressure regulating and directional control circuit
D. throttling and volume speed regulating circuit

查看答案

单选题

Why is pilot operated check valve used in clamping operation?

A. to reduce leakage in spool valve
B. to avoid decrease in pressure during clamping
C. both a and b
D. none of the above

查看答案

单选题

Which of the following statements is true, for two pumps used in circuit when initially fast operation is performed to reach a workpiece and feeding operation is done at a slow speed?

A. initially to reach a workpiece, a tool must be connected to a pump of high discharge and low pressure
B. initially to reach a workpiece, a tool must be connected to a pump of low discharge and high pressure
C. for feeding operation low discharge low pressure pump is required
D. none of the above

查看答案

单选题

Which of the following pump system saves more power?

A. single pump
B. double pump
C. single and double pump use same amount of power
D. none of the above

查看答案