A Belleville washer, also known as a coned-disc spring, conical spring, washer disc spring, Belleville spring or cupped spring washer, which is a conical shell and be loaded along with axis either statically or dynamically. A Belleville washer is a type of spring shaped like a washer.
It is the frusto-conical shape which gives the washer its characteristic spring. 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.Belleville washers have been used as return springs.