A Belleville washer, also known as a coned-disc spring,[1] conical spring washer,[2] disc spring, Belleville spring or cupped spring washer, is a conical shell which can be loaded along its axis either statically or dynamically. A Belleville washer is a type of spring shaped like a washer. It is the frusto-conical shape that gives the washer its characteristic spring.

The "Belleville" name comes from the inventor Julien Belleville who in Dunkerque, France, in 1867 patented a spring design which already contained the principle of the disc spring.[1][3] The real inventor of Belleville washers is unknown. //

n the different fields, if they are used as springs or to apply a flexible pre-load to a bolted joint or bearing, Belleville washers can be used as a single spring or as a stack. In a spring-stack, disc springs can be stacked in the same or in an alternating orientation and of course it is possible to stack packets of multiple springs stacked in the same direction.

Disc springs have a number of advantageous properties compared to other types of springs:[4]

Very large loads can be supported with a small installation space,
Due to the nearly unlimited number of possible combinations of individual disc springs, the characteristic curve and the column length can be further varied within additional limits,
High service life under dynamic load if the spring is properly dimensioned,
Provided the permissible stress is not exceeded, no impermissible relaxation occurs,
With suitable arrangement, a large damping (high hysteresis) effect may be achieved,
Because the springs are of an annular shape, force transmission is absolutely concentric.