The Torrington Company

Francis Travostino

A John Santos

Mark E LaCroix

Alain Bochet

Stephen J Lyle

The invention relates to a digital sensor of relative position, which has a circular multipolar magnetic ring which is mobile in rotation opposite a stationary magnetic sensor comprised of at least two sensitive elements, respectively positioned facing a main track and a &ldquo;revolution tick&rdquo; reference track, and a device for processing of the output signals, such that on the magnetic ring, a magnetic pattern is produced from a pair of north and south poles whose transition is different from the transition between the other north and south poles of the magnetic ring, and of which the angular width of the north pole is different at the site of the &ldquo;revolution tick&rdquo; reference track. The sensitive elements can be three in number, the first of which faces reference track and of which the other two face the main track, or they can be produced in the form of two parallel bars.

Digital sensor of relative position

A moving target opposite a stationary analog sensor has two sensitive elements delivering two sinusoidal output signals, of equal maximum amplitudes, centered on the same average value, in quadrature and with a period equal to one revolution of the target. A device for processing the two output signals, generates n output signals in-parallel, where n is a positive whole number greater than or equal to 2, for providing the position of a rotating component, connected to the moving target, with a resolution equal to 2,. The processing device includes a generator device, a detection device, a multiplexing device and an interpolation device.

Digital position sensor for sensing position of a moving target

A multipolar magnetic ring that generates a sinusoidal magnetic field has a cylindrical shape and two magnetic poles, north (N) and south (S), which are imbricated one in the other in such a manner that their widths (L.sub.p) are equal and constant. Two magnetic transitions between each of the two poles each follow a continuous curve that moves by one half pole width for each quarter of a turn of the magnetic ring, with the two curves being shifted by 180.degree. so that the magnetic field has a single period per turn of the magnetic ring. The magnetic field is implemented either along two spirals (s.sub.1 and s.sub.2) on one of the flat faces, or along two helixes (h.sub.1 and h.sub.2) on its cylindrical side. The magnetic ring may be used in absolute-position sensors, notably in bearings.

Growing community of inventors

Annecy-le-Vieux, France

Francis Travostino