| 摘要 |
PROBLEM TO BE SOLVED: To save energy, by reducing worthless heat generation in a spring-return type valve, and to elongate the lifetime.SOLUTION: A reactance element 11 is connected to between an alternator 13 and an induction motor 10 driving a valve in a direction opening the valve against a spring via a switch means 12. When the valve is opened, the alternator 13 is connected with the induction motor 10 to open the valve and thereby to compress the spring. After the valve is opened, the reactance element 11 is connected to between the alternator 13 and the motor 10 through the switch means 12 to decrease voltage applied to the motor 10 and thereby to decrease torque of the motor 10. The electric power is not consumed since a phase difference between a current flowing in the reactance element 11 and the voltage becomes π/2, so that the heat generation is suppressed to save energy. |
