Engine shaft revolution rate and rotation angle measurement - using hall generator segmented control wheel with distinguishing projecting tooth

摘要

A device for contactless measurement of the revolution rate and/or the position of a point marked on a shaft is esp. for combustion engine crankshaft or camshafts. A transducer wheel fixed on the shaft has two or more projecting segments and is used to generate electronic ignition pulses. Each segment is associated electronically with its corresp. engine cylinder and teh revolution rate is measured down to zero using very simple components. Two fixed Hall chambers directed towards the segments each have a Hall generator in a magnetic circuit controlled by the segments. The Hall chambers are radially offset by an angle (beta) slightly larger than the angle (alpha-o) subtended by the segments (2, 3). A radially projecting tooth (5) is separated from each segment (2, 3) by a different size gap (6, 7).