1. Hydraulic Power
basics

2. Pascal’s Law Pressure exerted at any point on
a confined liquid is transmitted
undiminished in all directions.

3. Hydraulic Terms Hydraulic Piston Shaft PSI Pneumatic Stroke
Check valve
Spool valve
Pump
Seal
Rockshaft
Cylinder
Hydraulic motor
Single-acting
Double-acting
Input / Output

4. Hydraulic
Tool or equipment powered by the movement of fluid under pressure. Examples are brakes, jacks & tractor lifts.

5. Pneumatic
Tool or equipment powered or supported by the movement of compressed air.

6. PSI GPM Pounds per Square Inch determines amount of force
Gallons per Minute
determines speed of action

7. Basic principle
Pressure applied to piston “A” is transferred equally to a piston of the same size “B” because PSI is the same throughout the system.

8. hydraulic advantage
If the surface area of piston “B” is 10 times the surface area of piston “A”, then the force applied to piston “A” is multiplied 10 times as the force exerted on piston “B”. PSI is equal throughout the system.

9. Input / Output
Force input on a hydraulic system or component results in transfer of power to output of force by the system or component.

10. Pump
Functions in a hydraulic system by pressurizing and moving fluid from one part of the system to another.

11. Hydraulic pumps are usually one of four types: PISTON GEAR VANE INTERNAL ROTOR

12. Piston Pumps Work well at PSI’s of 2000 or more
Single piston pump used in bottle jacks
Require several pistons working together to generate enough volume for tractor applications
Necessarily involve many moving parts

13. Gear Pumps Work well at 1500 PSI and below
Work with a minimum of moving parts
Less expensive to manufacture than piston type pumps

14. Gear Pump
driven gear
idler gear

15. Hydraulic Motor
Receives power from moving fluid to transfer hydraulic power to mechanical rotating force.

16. Cylinder
Piece of equipment that transfers hydraulic power into mechanical movement in one or two directions only.

17. Hydraulic Cylinder

18. Single-acting Double-acting
Refers to a hydraulic cylinder that works in one direction only.
Double-acting
Refers to a hydraulic cylinder that pushes and pulls.

19. Single-acting cylinder

20. Double-acting Cylinder

21. Piston
Internal component of a hydraulic cylinder that is moved in a linear motion by the action of fluid introduced into the cylinder.

22. Shaft
The polished round bar that is extended from and retracted into a hydraulic cylinder.

23. Stroke
The length of movement that a hydraulic cylinder is capable of producing.

24. Seal
Found in hydraulic components; function is to keep fluid from leaking between moving and non-moving parts

25. Check Valve
Restricts flow of fluid to only one direction; allows pressure to build up or be maintained.

26. Spool Valve
Controls direction of flow of fluid in a hydraulic system to cause the different parts of the system to function.

29. The first hydraulic power lift for a tractor was introduced in 1935 by John Deere. This unit only had two positions, up and down, but the hydraulic action cushioned the lowering of the implement.

30. Rockshaft
Rotating shaft on a modern tractor powered by an internal hydraulic cylinder; used to transfer power to the implement lift.