Somfy

Nippon Gear Co., Ltd.

Bailey Japan Co., Ltd.

Yutaka Utsumi

Jean-Michel Orsat

Takeshi Saito

Toshio Endo

Takeshi Suguro

Device for indicating the state of a single-phase asynchronous motor (MO) with a phase-shift capacitor, including an automatic stop switch (FC1, FC2) on each live conductor and a thermal switch (TH) on the return conductor, and the direction of rotation of which can be reversed by means of a changeover switch (CM). The indicator device consists of a current detector (DC), of a voltage detector (DT) and of processing logic (LT) respectively delivering information on the direction of rotation of the motor, the state of the live conductor switches and of the thermal switch.

Device for indicating the state of a single-phase asynchronous motor

An electric actuator for a control valve for fluids utilizes an induction motor to control the degree of opening of the valve and is provided with a control system which determines the deviation of the actual opening degree from the demand opening degree, generates a valve opening or closing speed command in accordance with the opening deviation, determines the deviation of the actual opening or closing speed from the command speed, generates a torque command in accordance with the speed deviation, and computes by means of the vector computing method the primary current to be supplied to the induction motor to enable the induction motor to output the required torque. When the valve is in the fully closed position, the control system stops the supply current to the induction motor and activates a braking device which locks the motor shaft to prevent reverse rotation of the motor shaft due to load reaction. The actuator has a means for re-starting the induction motor to optimize the thrust load should any change occur in the level of thrust acting on the valve rod. The actuator is furthermore provided with a means for diagnosing whether any abnormal performance is due to wear and/or deterioration of the induction motor, of the torque transmitting system or of the valve body.

Electric actuator for a control valve

Growing community of inventors

Hiratsuka, Japan

Yutaka Utsumi