1
to achieve maximum lifespan, hydraulic fluids must resist ______.
Undesirable changes
What type of device keeps the hydraulic fluid pressurized with a compressed gas
Gas charged accumulator or a hydropneumatic accumulator
Screw pumps move hydraulic fluid with _____screw shaped rotors
3
What are the four Control devices (valves) that manage hydraulic fluid?
flow control valves
Check Valves
Pressure control valves
Directional control valves
What does an HPU stand for?
Hydraulic Power Unit
water and oil form an _____?
Emulsion
the amount of fluid that a pump ejects per shaft rotation is called ____?
Displacement
The ______ has an off center rotor that spins inside the pump housing
Vane Pump
a hydraulic cylinder is a ________?
Linear actuator
Internal friction between a liquids layers determines its _______
viscosity
Most Hydraulic fluids contain ____?
Additives
a pumps capacity is measured in _____?
GPM (Gallons Per Minute)
a ________ rotor is centered within an elliptical housing
Balanced vane pump
Manufacturers rate hydraulic cylinders by their maximum force and ______
Stroke distance
a Hydraulic fluids ___ _____ is closely related to its _____
Viscosity
hydraulic tanks hold _________ as much fluid as the pump can deliver per minute
3 to 5 times
two types of positive displacement pump are____?
variable and fixed displacement
_____ numbers identify pipe sizes
Schedule
What is the formula to figure out a cylinders surface area?
3.14x(.5x bore diameter)2
a ___________ contains a coil spring pressing against the piston
Spring Loaded accumulator
hydraulic systems hold extra energy in a ____?
accumulator
a hydraulic pump that has two identical gears turning side by side is called a _____?
External Gear Pump
JIC fittings have sealing surfaces that form a ____ degree angle
37 degree
hydraulic piston motors are internally identical to their piston pump counterparts, they come in both ____ and ___________? versions
Axial and radial
a ___________ are in a circular block attached to a shaft, The block rotates off center on the shaft,
rotating shaft radial piston pump