actuatorshydraulic

A hydraulic actuator is a device that uses pressurized hydraulic fluid to create linear or rotary motion. Based on Pascal's law, pressure applied to a confined incompressible fluid is transmitted equally, allowing a small input force to generate a large output force. In hydraulic actuators, energy stored in a hydraulic fluid under pressure is converted into mechanical work.

The most common form is the hydraulic cylinder which provides linear motion. Cylinders can be single-acting (one fluid port, one direction force) or double-acting (both directions). Rotary hydraulic actuators include hydraulic motors and vane motors that convert fluid energy into rotation. Performance: output force equals pressure times piston area; speed depends on fluid flow rate, with system pressure and friction reducing efficiency. Acceleration is controlled by valve opening and pump rate.

Key components: hydraulic pump, reservoir, directional control valves, actuators (cylinders or motors), piping, seals, fluid, filters. Systems may include accumulators for energy storage, heat exchangers for temperature control, and sensors for feedback in closed-loop control. Fluids are typically mineral oil-based, but water-glycol and synthetic fluids exist for specific environments. Maintenance focuses on leak prevention, cleanliness, and periodic fluid replacement.

Applications include manufacturing presses, mobile hydraulics (construction equipment), aerospace actuators, robotics, and automotive braking or suspension systems. Advantages: high force in compact size, good controllability, overload tolerance. Disadvantages: potential leaks, fluid hazards, lower energy efficiency than electric actuators, and sensitivity to temperature. Safety and environmental considerations emphasize containment and proper disposal of hydraulic fluid.