302 D - Actuator & Motor Fundamentals Flashcards
What is regeneration in hydraulic terms?
Supplementing base cylinder oil supply with oil from the rod side to extend quicker.
Why are piston rods on cylinders chrome plated?
To extend seal life, reduce corrosion and contamination.
When a telescoping cylinder extends, how are pressure and speed affected?
Pressure is reduced, and speed is increased as extensions occur.
What are some materials that piston seals can be made of?
Leather, Polyurethane, Nitrile Rubber or Viton
Is a Gerotor motor a High Speed Low Torque or Low Speed High Torque
Low Speed High Torque
What is the normal position of a variable displacement pressure compensated Motor?
Minimum swash plate angle, as there is not enough load to build pressure to overcome the compensator spring and increase torque.
What is the difference between a Piston and Ram style single acting Cylinder?
Piston Style use piston seals to centre Ram style uses a guide ring to centre
What is the best way to check for blown piston seals?
Check for pressures at the base end of the cylinder and
What is the benefit of a telescoping cylinder?
Long reach in a compact size
What is the difference between differential and non differential cylinders?
Non Differential Cylinders are designed to have the same surface area above and below the piston, so no pressure or speed changes occur.
What can leaking piston seals cause?
Longer cycle times Drifting in the extension direction Pressure intensification when holding
Why are double acting cylinders sometimes called differential cylinders?
Due to the speed and pressure difference between extension and retraction
What is the purpose of the piston relief circuit?
To prevent heat generation due to the piston being at the end of its stroke.
What is pressure intensification within a cylinder?
Leaking piston seals, causing pressure nullification of the piston area, and only allowing fluid to act on the rod end surface area. Drastically increasing pressure within the cylinder.
What is the reason behind cylinder cushions and how are they designed?
Prevents shock loading cylinder at end of travel and easing actuator use. This is accomplished by either having spiral drillings back to tank or a way to back pressure the piston and slow it.
