Fabrication of a rotating shaft torque sensor for power data determination of rotary farm implements

Abstract

A rotating shaft torque sensor so-called a torque transducer for power data determination of rotary farm implements was developed, fabricated, and calibrated. It built according to the working theory of the commercial power take-off (PTO) torque meter model of Lebow Model 1228-20k, Eaton Advanced Electronics, Troy, Michigan, USA using local materials. For a typical torque measuring design, resistance type strain gages were glued to a spline shaft surface similar to a PTO shaft and integrated into a Wheatstone bridge circuitry. A slip ring was used to interface the bridge circuitry on either side of the transducer to a data logger named Daytronic data PAC model 10k4. For a torque range of 0 to 5 kN.m, the fabricated torque transducer has been constructed. A 60 teeth gear was installed on the torque transducer to measure the rotational velocity. Laboratory static and dynamic calibration tests were conducted. The dynamic tests were accomplished during the full load varying speed tests using a hydraulic PTO dynamometer type AW NEB 400. In both dynamic and static calibration tests, the fabricated torque transducer confirmed high accuracy measurement with linear relationship addressed by determination coefficient (R2) in the range of 0.992 to 0.9994. The fabricated PTO torque transducer is less expensive considering the typical commercially available PTO torque transducer. For acquiring PTO torque data during field operations, particularly when using a rotary plow or similar implements, the fabricated PTO torque transducer can be installed on the tractor's PTO shaft easily.