hyd pumps and actuators

Question 1

cavitation can be a result of

Answer 1

running the pump at too high a speed

Question 2

an example of a dynamic pump is a/an

Answer 2

impeller

Question 3

a cylinder which is extended by hydraulic force and retracted by a spring or gravity is known as

Answer 3

single acting

Question 4

at what pressure is the flow produced by a pressure compensated pump during cylinder extension ( without the use of flow control)

Answer 4

load psi

Question 5

what flow is produced by a pressure compensated pump when the cylinder is at the end of the stroke and deadheading is ?

Answer 5

no flow

Question 6

what is the purpose of a cylinder cushion?

Answer 6

reduce mechanical shock

Question 7

unbalanced vane pumps control fluid by?

Answer 7

shifting the eccentric cam ring

Question 8

the vanes of a vane pump are kept in contact with the cam ring by:

Answer 8

centrifugal force / fluid pressure

Question 9

a pump in a hydraulic system produces?

Answer 9

fluid flow

Question 10

a balanced vane pump would have:

Answer 10

sets of inlet and outlet ports opposing eachother

Question 11

what is the volumetric efficiency of a pump with an inlet flow measured at 15gpm and an outlet at 12gpm?

Answer 11

80%

Question 12

how is the flow changed in a bent axis piston pump?

Answer 12

vary the angle of the cylinder block

Question 13

what is the effect on the system if a 10gpm pump has its case drain flow increase from 0 gpm to 2 gpm

Answer 13

decrease speed of actuator

Question 14

what factors determine the amount of torque in a hydraulic motor?

Answer 14

inlet pressure, surface area, radius of rotation

Question 15

what would be effected by internal leakage over the piston seals on a hydraulic cylinder

Answer 15

speed

Question 16

which cylinder component prevents oil from leaving a cylinder?

Answer 16

rod seal

Question 17

which type of cylinder accelerated during extension?

Answer 17

telescopic

Question 18

what is the pressure of the flow created by a load sensing pump while moving a load?

Answer 18

load and standby pressure

Question 19

what do balance vane motors require in order to begin motor rotation?

Answer 19

springs under vanes

Question 20

if you witness a cylinder displaying jerky movement , squealing or rattling these are symptoms of ?

Answer 20

aeration

Question 21

in an in-line axial piston motor , speed can be increased by:

Answer 21

decreasing the swash plate angle

Question 22

what is the purpose of a stop tube in a cylinder?

Answer 22

reduce side load on bushings when extended

Question 23

what cylinder component prevents outside contamination from entering the cylinder?

Answer 23

rod wiper

Question 24

in a rotary piston pump the fluid is ported in and out of the pistons through the

Answer 24

PINTLE

Question 25

balanced vane motors maintain vane tip contact by?

Answer 25

low speed/high torque