Magnetic device for pivoting an arbor of a rotating member in a timepiece movement

摘要

The device for pivoting an arbor of a rotating member, on a determined pivot axis, inside a timepiece movement includes at least one magnetic bearing including a magnet which exerts a force of attraction on a pivot made of magnetic material, of the arbor, and an endstone arranged between the magnet and the pivot, the endstone being formed of a material having a hardness greater than 500 HV and a friction coefficient less than or substantially equal to 0.1 with the material of which the pivot is made. The material forming the endstone has a high magnetic permeability and the endstone has, in cross-section to the pivot axis, smaller dimensions than those of the magnet, said endstone being arranged in the timepiece movement to be centred on the determined pivot axis.

主权项

1. A timepiece assembly including the arbor of a rotating member and a device for pivoting said arbor about a determined pivot axis inside a timepiece movement, the pivoting device including at least one magnetic bearing including a magnet, which exerts a force of attraction on a pivot made of magnetic material, of the arbor, and an endstone arranged between the magnet and the pivot, the endstone being formed of a material having a hardness greater than 500 HV and a friction coefficient less than or equal to 0.1 with the material of which the pivot is made; wherein the material forming the endstone has a high magnetic permeability, wherein said endstone has, in cross-section to the pivot axis, smaller dimensions than those of the magnet, and wherein the endstone is arranged in the timepiece movement to be centred on the determined pivot axis.