Magnetic rotational detecting arrangement for sensing the speed of a railway vehicle

摘要

A magnetic speed detecting arrangement for a railway vehicle including a number of permanent magnets fixed on the outer circumference of an axle of the railway vehicle at fixed intervals in which the distance between two adjacent permanent magnets is larger than the width of the permanent magnets. A detector holder is fixed to the sprung portion of the body of the railway vehicle. A number of magnetic sensing elements are mounted to the detector holder and face the outer circumference of the axle. The number of permanent magnets may vary between 7 and 17 and the number of magnetic sensing elements may vary between 4 and 9 so that the product of the permanent magnets and magnetic sensing elements causes the detector to produce at least 60 pulses per revolution of the axle.