Patent ID: 7540095

Claim:
Rotary position transducer comprising a housing, a rotor, which is connected to a drive shaft to be measured and projects into the housing so as to rotate with it and the angular position of which within one revolution is measured, and a multi-turn unit, which is mounted in the housing and measures the number of revolutions of the rotor, wherein the multi-turn unit is coupled to the rotor by way of a gear wheel gear mechanism, which has a driving spur wheel ( 10 ) connected to the rotor and a driven spur wheel ( 12 ) of the multi-turn unit, characterized in that in the case of one of the spur wheels ( 10 ), the head of every second tooth ( 16 ) is shortened up to the reference circle, that in the case of the other spur wheel ( 12 ), the base of every second gap ( 18 ) between teeth is filled up to the reference circle, and that the spur wheels ( 10 , 12 ) are helical-geared, wherein the modulus and the helix angle (α) of the helical gearing ( 14 ) are determined in such a manner that at least one tooth ( 16 ) is always in engagement.