Aktuatormedel

Aktuatormedel, or actuator medium, is the working substance or energy carrier used by an actuator to produce motion. Actuators convert energy into mechanical work, and the medium defines how power is transmitted and controlled. The most common actuator media are hydraulic fluids and compressed gases. Hydraulic actuators use incompressible liquids such as mineral oil or synthetic fluids, which enable high force and precise positioning, good loadholding, and smooth motion, but require seals, reservoirs, pumps, and leak containment, and pose fire and environmental risks with some fluids. Pneumatic actuators use compressed air (often dried and filtered) or other gases; they are simple, fast, and intrinsically safe in many environments, but their compressibility reduces position accuracy and force at load, and they store limited energy.

Electric actuators rely on electrical energy as the actuation medium; they do not use a fluid medium but instead convert electricity via motors or piezoelectrics, offering high controllability and precise positioning, with different trade-offs in speed, torque, and efficiency. Hybrid systems combine media, such as electro-hydraulic actuators.

Selection of the medium depends on required force, speed, precision, environment, maintenance, and safety. Hydraulic systems are favored for high power and smooth control; pneumatics for simple, clean, and low-cost setups; electric actuators for precise control and complex integration without fluids. Design considerations include fluid compatibility, temperature range, filtration, seals, and energy efficiency. See also actuator, hydraulic system, and pneumatic system for related topics.