Electro Mechanical Actuator Case Study
A Rotary Electromechanical Actuation system with an Electric Motor, a gear box & an elastic spring to absorb peak torque loads experienced during operational life. The Schematic below describes the system.
Fig. 1.1 Rotary Electro-mechanical Actuator
The Gear Box at the Motor Output is intended to amplify the torque output of the Motor with reduction in speed. The tentative ratio is set at 10:1.
Functional Requirements of the Gear Box
1. Nominal continuous input Torque 3.2 Nm
2. Peak Torque Input 7 Nm
3. Nominal continuous input speed 2200 rpm
4. Maximum No Load input speed 4500 rpm
5. Nominal continuous output Torque 35 Nm
6. Maximum bidirectional backlash 0.25 Degree
7. Peak output torque (20% duty cycle) 70 Nm
8. Limit Torque from the Output side 125 Nm
9. Torsional Stiffness of the Gear Box 3830 Nm/rad or 100 Nm/ 1.5 Deg
10. …show more content…
With the help of nine piezoelectric stacks and flexure hinges, the designed actuator can realize stepping rotary movement with high accuracy. The flexure hinges are designed to realize the needed force and can also reduce the number of components and the assembly effort. The experimental results suggest that this actuator has a large motion range and high position accuracy. This novel actuator has some reference significance for the application of the inchworm principle and flexure hinges in the design of the piezoelectric-driven actuators. Due to its advantages: small size, high resolution, rapid response and low energy consumption, the piezoelectric-driven actuator is suitable for the precise positioning system. So far, the piezoelectric-driven actuator can be mainly classified into ultrasonic actuators , Inertial stepping actuators , inchworm actuators [8-12] and so