Hydraulic Systems Vocabulary

Flashcards for vocabulary related to hydraulic systems, covering components like actuators, pumps, valves, and accessories.

Hydraulic Reservoir/Tank

Storage for hydraulic fluid, providing a steady supply to the system.

Hydraulic Pump

Converts mechanical energy into fluid power to drive system components.

Electric Motor (in hydraulic diagram)

An electric motor that operates the pump

Check Valve

Ensures fluid flows in only one direction, preventing back pressure on the pump.

Relief Valve

Controls pressure by releasing excess fluid to maintain a preset system pressure.

Secondary Relief Valve

Serves as a safety backup in case of primary relief valve failure; typically set 20-30% higher.

Hydraulic Actuator/Cylinder

Converts fluid power into linear motion.

Single Acting Hydraulic Actuator

Moves in one direction using hydraulic pressure and returns with a spring or gravity.

Double Ended Actuator

Has a piston rod on both sides, allowing equal force in both directions.

Telescopic Actuator

Composed of multiple stages that extend outward, providing long reach and saving space.

Double Acting Hydraulic Actuator

Uses hydraulic pressure on both sides of the piston for back and forth movement.

Valve Body

Main structure of the valve, housing internal components and designed for spool movement and fluid flow.

Ports

Points of entry and exit for fluid in the directional valve.

Spool

The component inside the directional valve that moves to control the direction of fluid flow.

Directional Flow Control Valve

Controls the flow of fluid to change the speed of the actuator; regulates flow in one direction.

Tandem Center Valve

Pump port connects to the tank port, work ports are blocked; saves energy but is limited to a single circuit.

Open Center Hydraulic Valve (H-center)

Work ports open to the tank, fluid flows freely from pump to tank; reduces strain but limited to single circuit.

Float Center Hydraulic Valve

Work ports connect to the tank, allowing free actuator movement; pump can operate multiple circuits.

Four-way Solenoid Operated Spring Return Valve

Reverses actuator direction via a spring mechanism when power is turned off.

Hydraulic Accumulators

Store pressurized fluid and release it when needed, maintaining system pressure and absorbing shocks.

Piston Accumulators

Separates gas and hydraulic fluid with a piston; durable and handles high pressures.

Bladder Accumulators

Uses a flexible bladder to separate gas and fluid; quick response to pressure changes.

Pilot Operated/Solenoid Operated Check Valve

Keeps loads securely locked in place; used with counterbalance valves.

Pilot Lines

Dashed lines in hydraulic diagrams, showing connections for control signals.

Pressure Filter

Filters oil on the pressure side of the system, but can cause pressure drops; least preferred method.

Return Filter

Filters oil as it returns to the tank; cost-effective due to low return line pressure.

Kidney Loop Filtration

Uses a separate pump and filter to continuously cycle oil back to the tank; for large systems.

Air Cooled Heat Exchanger

Cools hydraulic oil by flowing it through tubes while air passes over fins.

Water Cooled Heat Exchanger

Cools hydraulic oil by flowing it through tubes while water circulates around them.