Abstract
To study the characteristics of the sensing device of torque on a hydraulic driving system, some experiments and analyses have been done.
(1) The torque sensing device has a coil-spring by which oil pressure is transformed to spring displacement.
(2) Steady state characteristic of sensing system has a relationship of linearity between oil preesure and spring displacement.
(3) Transient response of the spring displacement to the oil pressure is very good and its time lag is very short.
(4) Steadily, the number of revolution of a hydraulic motor is almost constant under a setting pressure of a relief valve.
(5) A system of velocity of rotation of hydraulic motor to torque constitutes a disturbance control system. Its transient variation is little and becomes smaller rapidly.
(6) The dynamic characteristic of this system is under great influence of the inertia momentum of load and the capacity of actuator. To get a good responsability for the system, it is important to use the hydraulic motor which has a capacity suited to a value of inertia momentum of load.
(7) The gain of the system is low on high frequency and the response is relieved from the impactional input. This is a merit of the hydraulic driving system.
(8) It is easy to find the value of torque on hydraulic system by a spring and the signal is transmitted easily by the pilot pressure. This sensing system is very simple and has little inertia force. And so, the response characteristic is good and stable.
