Abstract
The purpose of this paper is to describe the results of the fundamental studies to make a threepoint linkage dynamometer for mounted implements at free float linkage position of hydraulic system. Their results obtained and further investigations are as follows:
1) It was imposible to keep a load distribution uniformly on a link pin dynamometer, in case that conventional plain bail joint of tractor link was used at the link pin dynamometer. For this reason, such a ball joint was not fitted for the purpose of transducer elements.
2) Adaptation of a self-aligning ball bearing in place of the plain ball joint, showed linearity in relation between load and strain at each pin dynamometer. On account of this, deviation of non-linearity at each pin dynamometer was obtafined at the ±5% level within the limits of 500-1500kg.
3) It is likely that right side lower link pin dynamometer curved upward at 0-300kg load was an effect of mechanical failure at strain beam. Then a reinvestigation to resolve this problem is called for.
4) Presently, the calibration curve adapted for the three-point linkage dynamometer was assumed to be true, taking a hypothesis that working depth of mounted implements was constant. Therefore, this work calls for fresh experiments to develop calibrating apparatus and method, and to investigate measuring accuracies of this three-point linkage dynamometer, since invariable calibration curve for this dynamometer should be secured without such a hypothesis.
