hyd pumps and actuators Flashcards
cavitation can be a result of
running the pump at too high a speed
an example of a dynamic pump is a/an
impeller
a cylinder which is extended by hydraulic force and retracted by a spring or gravity is known as
single acting
at what pressure is the flow produced by a pressure compensated pump during cylinder extension ( without the use of flow control)
load psi
what flow is produced by a pressure compensated pump when the cylinder is at the end of the stroke and deadheading is ?
no flow
what is the purpose of a cylinder cushion?
reduce mechanical shock
unbalanced vane pumps control fluid by?
shifting the eccentric cam ring
the vanes of a vane pump are kept in contact with the cam ring by:
centrifugal force / fluid pressure
a pump in a hydraulic system produces?
fluid flow
a balanced vane pump would have:
sets of inlet and outlet ports opposing eachother
what is the volumetric efficiency of a pump with an inlet flow measured at 15gpm and an outlet at 12gpm?
80%
how is the flow changed in a bent axis piston pump?
vary the angle of the cylinder block
what is the effect on the system if a 10gpm pump has its case drain flow increase from 0 gpm to 2 gpm
decrease speed of actuator
what factors determine the amount of torque in a hydraulic motor?
inlet pressure, surface area, radius of rotation
what would be effected by internal leakage over the piston seals on a hydraulic cylinder
speed
which cylinder component prevents oil from leaving a cylinder?
rod seal
which type of cylinder accelerated during extension?
telescopic
what is the pressure of the flow created by a load sensing pump while moving a load?
load and standby pressure
what do balance vane motors require in order to begin motor rotation?
springs under vanes
if you witness a cylinder displaying jerky movement , squealing or rattling these are symptoms of ?
aeration
in an in-line axial piston motor , speed can be increased by:
decreasing the swash plate angle
what is the purpose of a stop tube in a cylinder?
reduce side load on bushings when extended
what cylinder component prevents outside contamination from entering the cylinder?
rod wiper
in a rotary piston pump the fluid is ported in and out of the pistons through the
PINTLE
