Plungerdriven

Plunger-driven refers to devices or systems in which a plunger—a cylindrical rod that slides inside a bore—acts as the primary actuator to convert energy into linear motion or pressure. The term is used in hydraulics, pneumatics, and mechanical design to describe mechanisms that displace fluid or material by moving a plunger.

Mechanism: A plunger is moved by a driving element such as a cam, crank, electric motor, or hydraulic/pneumatic actuator. The plunger's reciprocating motion creates suction on one stroke and pressure on the next, with seals preventing backflow and leakage.

Applications and variants: Plunger pumps are positive-displacement devices used for high-pressure liquids in industry and laboratory settings. Medical syringes are common examples of plunger-driven devices. In diesel engines, plunger-type injection pumps use cam-driven plungers to pressurize fuel for injection.

Advantages and limitations: The design offers simple construction, reliable sealing, and precise displacement per stroke, enabling high pressures. Drawbacks include wear of seals, pulsating flow, and limited speed due to mechanical inertia.

Design considerations: Bore and stroke determine volume per stroke; plunger material and seals must resist wear and chemical attack; alignment, lubrication, and backflow control affect efficiency and longevity.