Fatigue Life Calculation Method and Experimental Study of the Multiple Corrugated Diaphragm Coupling

The multiple corrugated diaphragm (MCD) coupling is a new flexible coupling developed based on the diaphragm and diaphragm disc coupling. Compared to traditional couplings, the MCD coupling has the advantages of high torque diameter, high torque weight, and high compensation capability. It is more suitable for high power speed and high power density working conditions. The MCD coupling is subjected to axial, angular, torque, and centrifugal force loads. The fatigue failure caused by alternating stress is the primary failure mode of the coupling. The fatigue life of the MCD coupling cannot be accurately calculated because of the complexity of the force in operation. Some theoretical simplifications can only obtain the approximate result. In this paper, a parameterized finite element model of the MCDs is established. A method for calculating the fatigue safety factor of the MCD coupling is proposed based on a modified Goodman curve to know the design of the MCD coupling. The feasibility of this method is verified by the fatigue life test of the coupling.

Corrugated Diaphragm Actuator for Soft Robotic Applications

Soft robotics is projected to have a significant impact on healthcare, industry, and the military to deliver assistance in rehabilitation, daily living activities, repetitive motion tasks, and human performance augmentation. Many attempts have been made for application-specific robotic joints, robots, and exoskeletons using various actuator types, materials, and designs. The progress of creating soft robotic systems can be accelerated if a set of actuators with defined characteristics were developed, similar to conventional robotic actuators, which can be assembled to create desired systems including exoskeletons and end effectors. This work presents the design methodology of such a modular actuator, created with a novel corrugated diaphragm that can apply linear displacement, angular displacement, and force. This modular actuator approach allows for creating various robotic joints by arranging them into different configurations. The modular corrugated diaphragm actuator concept was validated through numerical simulation, fabrication, and testing. Linear displacement, angular displacement, and force characteristics were shown for a single module and in multi-module assemblies. Actuator assemblies that are configured in a serial and parallel manner were investigated to demonstrate the applicability and versatility of the concept of the modular corrugated diaphragm actuator for creating single and multi-DOF joints.

Corrugated Diaphragm Actuator for Soft Robotic and Exoskeleton Applications

Soft robotics is projected to have a significant impact on healthcare, industry, and the military to deliver assistance in rehabilitation, daily living activities, repetitive motion tasks, and human performance augmentation. Many attempts have been made for application-specific robotic joints, robots, and exoskeletons using various actuator types, materials, and designs. The progress of creating soft robotic systems can be accelerated if a set of actuators with defined characteristics were developed, similar to conventional robotic actuators, which can be assembled to create desired systems including exoskeletons and end effectors. This work presents such an attempt by designing a modular corrugated diaphragm actuator that can apply linear displacement, force, and bending motion. This modular actuator approach allows for creating various robotic joints by arranging them into different configurations. Numerical simulation, fabrication, and testing were carried out to evaluate the displacement, force, and bending characteristics of the corrugated diaphragm actuator as a single unit and in multi-unit arrays to understand their applicability for different scenarios. Actuator arrays that are configured in a serial and parallel manner were investigated. The results will be presented in terms of using this modular actuator concept to create single and multi-DOF joints, which will demonstrate the versatility of this modular actuator approach.

Analytical and experimental study on the axial stiffness of multiple corrugated diaphragm coupling based on the corrugated circular plate theory

Compared to traditional couplings, the multiple corrugated diaphragm (MCD) coupling has the advantages of high torque diameter and weight ratios, and high compensation capability. Due to the irregularity of the MCD, it is difficult to analyze and study it through traditional methods. In this paper, an analytical method for calculating the axial stiffness of MCDs is derived based on the mechanical theory of corrugated circular plates, and the results of the analytical method, finite element method, and stiffness tests are compared. The results indicate that the analytical solution of the MCD axial stiffness is consistent with the finite element analysis and experimental results. This proves the feasibility of analyzing the MCDs using the theory of corrugated annular plates. This study provides a theoretical basis for the design of MCD coupling and can guide the rapid design of MCD coupling.