Patent ID: 7394242

Claim:
A tachometer for an aircraft wheel mounted on an axle to rotate about an axis of rotation, the tachometer comprising: a stationary part to be secured to the axle and an independent rotary part to be secured to the wheel, wherein the stationary part and the rotary part are mountable independently on the axle and on the wheel, respectively, said stationary part and said rotary part having portions facing each other in a radial direction, one of said portions carrying a sensor and another one of said portions carrying a target element, so that said sensor and said target element are in register in a radial direction and cooperate for generating a signal indicative of a rotation speed of the rotary part, and wherein the portion of the rotary part extends inside the axle when the rotary part is mounted on the wheel so that the target and the sensor extend at least partially inside the axle.