| In order to transform from manual operation to electric operation, multi.turnvalve actuator often needs to add auxiliary switch device to make the tooth clutchcombination or separation, which causes much more trouble to the transformation.The main transmission mechanism of the electric actuator used to adopt a wormgearing. As the structure is complicated, the overall mechanical efficiency is verylow. The output shaft of the actuator is not stable, which often causes a larger impactforce, breaks the stem, causes out of control and operation, and arises thephenomenon of the oil and gas leakage. In order to solve the problems, the paper digdeep research on the design of electric actuator.To improve the transmission structure, achieve fully automatic transformationoperation between manual and electric, and increase the overall mechanicalefficiency, the author has done the main jobs as follows:Firstly, compare and analyze the existing actuators. The main transmissionmechanism, which includes spur gear, bevel gear and planetary gear, is moredelicate and efficient. The designed double.action roller brake installed it on thebevel gear agencies, When the whole system is driven by the motor, it can transmittorque and power. And when the whole system is driven by manual operation,it canachieve double.action brake. So we can achieve arbitrary switching between manualand electric. Hand.operated equipment uses the worm gear. When the whole systemis driven by the motor, the self.locking protective device can be made full use of,and the equipment can be braked completely.Secondly, we can establish parameterized model of the electric actuator andaccomplish assembly and interference inspection by CATIA software, and thesimplified model can be import into ADAMS to build the virtual prototype modelFinally, in order to verify the correctness of the transmission ratio, kinematicsanalysis was carried out on the virtual prototype model, so as to provide a basis for dynamic analysis. The dynamic analysis is carried out in view of the motor positiveinput and manual reverse input. In this process, the author analyzes the dynamicchange of the output shaft, two.way dynamic check mechanism and meshing gears.The above research verifies whether the designed actuator and non.returninstitutions can achieve desired effect. Besides, comparing mechanical efficiency ofthe physical prototype and simulation model through simple experiment examinesthe efficiency and correctness of the established model, and provides reliable datasfor further study and product design. |
