Abstract
In order to know the force, stress and displacement appearing at every power transmission system of a power tiller, one of the widely used models in Japan, new measuring devices have been made. All transitorized mobile part of these devices which were attached to a power tiller operated in the farm field, was designed and constructed without making any change or destruction of the power tiller's own construction.
Torque at the rotating tilling axis and the right and left wheel axes was measured using wire resistance strain gages attached to the principal strain directions of them. Connections between the rotating axis and frame of the tiller were made with noiseless silver to silver contact slip rings and brushes.
Three accelerometers of the type of wire strain gage were attached around the gravity center of the tiller for three independent directions, one for the direction of movement and the others for perpendicular to the first. Distance and velocity were obtained by integrating the accerelation with electronic analog computer under real time operation. Tension at the link plate of the moving roller chain was also measured using wire resistance strain gages.
Non-touching pitch counters of the roller chain sprockets were constructed for observing their angular displacement, angular velocity, angular acceleration and ununiformity of their rotation.
All signals obtained from the mobile parts were preamplified and transmitted through the cables about 45 meters long to the laboratory where amplification, discrimination and recording were made. Every power supply for these purposes was fed from precisely regulated electronic voltage stabilizer.
Recording was made using electro-magnetic oscillograph of 12 elements, direct writing recorder of 6 elements and 2 channels of magnetic tape recorder. This simultaneous recording made it possible to display the phase relation among these signals.
Experimental results and analyses will be reported successively.
