Shearbar clearance detector

摘要

A forage harvester includes four multiple-bladed rotary cutting segments positioned near a shearbar. Four proximity sensors are mounted in shearbar bores near each of the cutting segments, each including a permanent magnet and a sensing coil. Blade motion near the sensors produces an electrical signal in the sensing coils. The signals from each sensing coil are integrated, sampled and averaged. The largest average signal is conditioned and applied to an analog meter for display to a vehicle operator. Switch and logic circuits permit the operator to monitor only selected one or ones of the cutting segments.