| 摘要 |
<p>An electrically operated valve assembly has a valve element moved by an actuator (10, fig 3). The actuator (10) has a stepper motor 20 connected to an output 18 via a gear train 30. The output 18 is connected to valve element (64, fig 5) such as a spindle element of a throttle valve in an internal combustion engine or a butterfly valve or a ball valve. The gear train 30 has a gear ratio which is variable depending on the actuation angle of the output shaft 18. A return spring 54 is arranged to resiliently return the output shaft 18 to an initial actuation angle when the motor 20 is not active. Motor 20 may be connected to PCB having a control circuit for controlling the motor 20 in response to control signals. The valve may be a liquid control valve or a water supply valve or a control valve of a heat exchanger system for the engine.</p> |
