Mechanical Design of Variable Stiffness Joint Based on Planetary Gear Train and Modular Elastic Element

Title:Mechanical Design of Variable Stiffness Joint Based on Planetary Gear Train and Modular Elastic Element

Volume: 17

Author(s): Jishu Guo*

Affiliation:

• School of Information and Automation Engineering, Qilu University of Technology (Shandong Academy of Sciences), No. 3501, Daxue Road, Changqing District, Jinan, Shandong Province, PR China

Abstract: Background: The variable stiffness joint (VSJ) is a kind of inherent flexible actuator with independent controllable position and stiffness. Among various types of VSJs, the VSJs based on equivalent lever mechanisms and relying on changing the position of the lever pivot to adjust the transmission rate between input and output have the characteristic of low energy consumption for stiffness adjustment. Therefore, many patents have been applied for this type of VSJ. As the structural design of VSJs is an open research field, it is necessary and meaningful to explore novel structural designs of VSJs based on equivalent lever mechanisms.

Objective: The purpose of this article is to design a variable stiffness joint that changes the joint stiffness by adjusting the position of the lever pivot.

Methods: By referring and combining existing mechanical design ideas of some series configuration VSJs with good stiffness adjustment mechanism schemes, a novel series configuration VSJ based on an equivalent lever mechanism and relying on adjusting the position of the lever pivot to change joint stiffness has been implemented through CAD drawing, 3D printing, and assembly.

Results: Due to the wide movable range of the lever pivot, the designed VSJ has a wide adjustable range of stiffness. Moreover, assembly design and modular design have been achieved in terms of elastic output and power transmission, for easy installation and maintenance. The movability and stiffness adjustability of the designed VSJ were preliminarily verified through manual adjustment.

Conclusion: The assembly model of the VSJ demonstrates the feasibility of structural design. The stiffness adjustment experiment showed the variable stiffness ability of the designed VSJ.

Cite this article as:

Guo Jishu*, Mechanical Design of Variable Stiffness Joint Based on Planetary Gear Train and Modular Elastic Element, Recent Patents on Mechanical Engineering 2024; 17 () . https://dx.doi.org/10.2174/0122127976287776240426105333