1. Advanced Hydraulics Don Gilliland
Hydraulic Components
Advanced Hydraulics
Don Gilliland

2. Hydraulic Components Reservoirs Accumulators Pumps Valves Actuators
Conductors

3. Hydraulic Components Reservoir Functions Fluid Cooling
Contaminates to settle
Air to escape
Volumetric variance during Actuator operation
Heat Expansion

4. Reservoir Considerations
Atmospheric Venting
In many fluid power systems, the only force acting on the hydraulic fluid to move fluid to the pump is the force of atmospheric air pressure. The vent in most fluid power reservoirs is thus critical. The fluid cannot flow out if the air cannot flow in. It is through the reservoir vent that atmospheric air pressure is applied on the hydraulic fluid.
Volumetric variance during Actuator operation
Single and two way single rod cylinders both require different fluid volumes during system operation. The reservoir volume must allow for this variance.

5. Reservoir Considerations
Volumetric variance during 1 way Actuator operation
During advancing a controlled distance to the right
More fluid volume into cylinder from reservoir
Air only is forced out through a breather (Reservoir must lower)
breather

6. Reservoir Considerations
Volumetric variance during 1 – way Actuator operation
During retracting to the left under load down force
More volume out back to reservoir
Air must go in breather (Reservoir level Raises)
breather

7. Reservoir Considerations
Volumetric variance during 1 – way Actuator operation
Breather must have filtration
Keeps contaminates out of cylinder chamber and away from piston seals
Reservoir level change can be quite large
breather

8. Reservoir Considerations
Volumetric variance during 2 way Actuator operation
During advancing a controlled distance to the right
More volume in than volume out
Due to Rod volume on right side

9. Reservoir Considerations
Volumetric variance during 2 way Actuator operation
During retracting same controlled distance to the left
More volume out than in
Due to Rod volume on right side

10. Reservoir Considerations
Fluid Cooling
Heat is generated in hydraulic fluid from component motion and friction and when pressure forces molecules of fluid together. These molecules begin to rub on components and one another, generating friction and heat. The reservoir should be made of a heat dissipating material and be large enough to allow some motion slowing time to allow heat dissipation.
Contaminate Settling
The reservoir should be large enough to allow some motion slowing time to allow contaminate settling during the fluid cooling process.

11. Reservoir Considerations
Fluid Cooling 

12. Reservoir Considerations
Contaminate Settling

13. Reservoir Considerations
Fill cap may be filtered breather and need periodic cleaning

14. Reservoir Leaks

15. Reservoir Leaks
A leaky or overrunning reservoir can spill hydraulic fluid.
The mess
DOT or EPA ramifications
Hydraulic fluid may be caustic with other vehicle system materials
Tires, brake linings, drive belts, wiring, insulation, and even Wheels or Battery Cases can be damaged by some hydraulic fluids.

16. Hydraulic Components
Reservoirs
Review
Next Accumulators
THE END