Diaphragmspring

Diaphragmspring, also called a diaphragm spring, is a flat, circular metal spring designed to act as a flexible membrane. It is formed from a single sheet of spring metal that is shaped with folds or a domed contour so that deflection produces axial force along the circumference. This configuration provides a compact means of generating relatively high clamping or actuation force in a small space.

Mechanism and operation lie at the core of its utility. When an axial load is applied, typically by a release lever, hydraulic actuator, or similar mechanism, the central region of the diaphragm deflects while the outer rim remains in contact with a mating surface. The bending of the metal disk converts the applied load into an axial force, allowing precise control of clamping pressure or actuation force with a relatively short travel.

Construction and materials commonly involve stamped or formed spring steel, often stainless or coated carbon steel, tempered to an appropriate hardness for long-term cycle life. The disk may be designed with concentric folds, radial fingers, or a central boss to interact with other components. Manufacturing processes include stamping, forming, finishing, and heat treatment to optimize stiffness, fatigue resistance, and corrosion resistance.

Applications are widespread in mechanical systems requiring high force in a compact form. The most well-known use is in automotive clutch release diaphragms, where the diaphragm spring applies pressure to the clutch pressure plate. Diaphragmsprings also appear in valve actuators, hydraulic regulators, and other precision actuators where smooth, rapid response and a compact footprint are advantageous.

Compared with coil springs, diaphragmsprings offer a higher force per diameter and a favorable stiffness-to-stroke ratio, but they typically provide limited travel and can be more sensitive to edge defects or uneven loading.