Borrelly ROB™
Rondelle Optimisée Belleville

Borrelly introduces its new patented product: ROB™ (Rondelle Optimisée Belleville)

This patented design, using jointly traction and compression stresses, is a reliable solution for saving considerable weight in comparison to Belleville disc springs.

Our analytic or numerical calculation methods enable to propose in a very short time a reliable solution in the appropriate spring material.

Borrelly Rondelle Optimisée Belleville: ROB™

ROB™ principle

La ROB™ has the following geometry

  • Outside gear (couronne extérieure)
  • Inside gear (couronne intérieure)
  • Radius (rayons) linking the inside gear to the outside gear

Rondelle Optimisée Belleville


The global geometry is generally a conical shape. The axial compression of the spring tends to get the spring flat, which causes the expansion of the outer ring and the compression of the inner ring and radiuses.

Recesses in radiuses give to the spring a pliability ensuring a very low flexion. The stressed areas are almost pure traction or compression.

A proper design provides a traction stress limit in the outer ring equal to the inner compression stress limit. This design permits the storage of optimal spring energy.

Rondelle Optimisée Belleville

The possible evolution of the product is to replace the outer ring by rectilinear segments, allowing the possible compression of the appropriate zone if numbers of radiuses are low.

Rondelle Optimisée Belleville

This patented design enables to jointly use traction and compression stresses, and icomparison to Belleville disc spring, ROB™ is a reliable solution for saving considerable weight.