Sensor unit for stepless speed change unit with cone pulleys and belt

摘要

The sensor unit has a structure (5), which is fitted on the periphery of a transmitter wheel (1), which is connected with a movable cone pulley (2) and is arranged coaxially to this, or the structure is mounted on the pulley itself. The structure is scanned by two sensors (3,4), which are fitted close together on the transmitter wheel, at an axial distance, greater than the axial movability of the cone pulley and spaced relative to this. The direction of rotation and the transmission ratio of the speed change unit are determined based on measured rpm and taking account of alteration of structure in axial direction. The structure in region (5.1) of first sensor (3) consists of axial running lines. In region (5.2) of second sensor (4) these lines continue in spiral form. A rotation of the transmitter wheel, produces in sensors a signal of line passages with a frequency proportional to rotational frequency. The phase of signals is shifted due to helical line structure in region of second sensor. The phase shift gives direction of rotation. Axial position of the cone pulley determines transmission ratio of speed change unit.