Case Study: Performance Evaluation of Strain Wave Gearing Using Virtual Simulation

Abstract

Strain wave gearing, also known as harmonic gearing, offers high reduction ratios in compact and lightweight designs, making it essential for precision robotics. This study evaluates the performance of strain wave gearing through virtual simulation using RecurDyn’s MFBD (Multi Flexible Body Dynamics) technology. By analyzing gear deformation, contact forces, and dynamic interactions, the study identifies optimal design parameters, predicts performance, and reduces development time and costs.

Strain Wave Gearing

Understanding Gear Mesh Vibration in Speed Reducers

Strain Wave GearingStructure

Strain wave gearing relies on the deformation of a flexible gear (Flex Spline) by a rotating Wave Generator to engage with a rigid Circular Spline. Its unique mechanism presents challenges for traditional FEA tools due to rapid deformation, high contact forces, and inertial effects. RecurDyn’s MFBD technology enables precise simulation of these dynamics, offering insights into stress distribution, vibration, and transmission error under various operational conditions.

Advanced Order Tracking Techniques for Gear Vibration Analysis

Simulation Process:

  1. Modeling Components:

    • Circular Spline and Wave Generator modeled as rigid bodies.
    • Flex Spline modeled as a flexible body, prestressed in its initial state using FullFlex.

  2. Contact Algorithms:

    • High-accuracy Geo Contact for interactions between Flex Spline teeth and Circular Spline.
    • Optimized Geo Cylinder contact for the interface between the Flex Spline and Wave Generator.

  3. Dynamic Simulation:

    • Simulated high-speed motion and large deformations of the Flex Spline.
    • Visualized contact force distribution and pressure between gear teeth.

Outcomes of Gear Mesh Vibration Analysis in Speed Reducers

Performance Insights:


  • Quantified the effects of design tolerances, such as dimensional differences and twist angle variations, on vibration and transmission error.
  • Evaluated stresses and deformation in the Flex Spline under different load and speed conditions.
  • Predicted reaction forces on the Wave Generator and their impact on overall system behavior.

Optimization:


  • Identified an optimal tooth profile for improved efficiency and reduced transmission error.
  • Suggested design adjustments based on quantitative performance predictions.

Cost and Time Savings:

  • Accelerated the design process through virtual testing, reducing reliance on physical prototypes.
Strain Wave Gearing Contact

Insights into Gear Vibration Challenges and Solutions

The study highlights the importance of RecurDyn’s MFBD technology in analyzing complex gear systems like strain wave gearing. Advanced contact algorithms ensured accurate simulations of gear interactions, while visualization tools provided valuable insights into force distributions and stresses. These capabilities enabled precise performance predictions and facilitated design optimization for high-precision applications.

Enhancing Speed Reducer Reliability through Expert Vibration Analysis

This case study demonstrates the effectiveness of virtual simulation for evaluating strain wave gearing performance. RecurDyn enabled accurate modeling of gear deformation and contact dynamics, providing critical insights into design parameters and operational efficiency. The approach reduced development time and costs, ensuring optimal performance for robotics and other precision applications.