Torque Transmission Device With Variable Stiffness Bellows
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing torque transmission devices with variable stiffness face challenges in achieving high positioning accuracy and safety, as they either lack intrinsic safety due to reliance on force sensors or require large space for mechanical adjustments.
Innovation Solution
A compact torque transmission device with rotatable inner and outer rings, gas pressure springs, and an adjusting unit using hydraulic fluid, which provides high stiffness, self-damping, and adjustable stiffness, ensuring safety by reducing stiffness in case of faults and allowing independent adjustment of compression and tension phases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a high degree of mechanical stiffness is used to achieve high positioning accuracy, then positioning accuracy is improved, but safety deteriorates because the robot cannot move rapidly or match human joint movements
Solution Approach 1:
The actuator employs a variable stiffness mechanism that dynamically adjusts the mechanical stiffness between high and low states. During positioning tasks, high stiffness is engaged for precision; during rapid movement or human interaction, low stiffness is engaged for safety. This dynamic transition resolves the contradiction by making stiffness adaptive rather than fixed.
Solution Approach 2:
The invention changes the physical parameter of stiffness from a constant value to a variable parameter. By using a mechanical variable stiffness actuator with adjustable stiffness characteristics, the system can modify its mechanical properties in real-time to satisfy different operational requirements, thereby resolving the trade-off between positioning accuracy and safety.
2Adaptability or versatility
If a force sensor and controller are used to simulate variable stiffness, then variable stiffness is achieved, but intrinsic safety deteriorates because the actuator lacks passive safety and relies on active control
Solution Approach 1:
The variable stiffness actuator is designed to provide variable stiffness through its own mechanical structure rather than relying on external force sensors and active controllers. The intrinsic mechanical design enables the actuator to adjust its stiffness characteristics autonomously, eliminating the need for continuous sensor feedback and active control, thereby restoring intrinsic safety.
Solution Approach 2:
The invention replaces the electronic control system (force sensor + controller) with a purely mechanical variable stiffness mechanism. By substituting the electronic feedback loop with a mechanical structure that inherently provides variable stiffness, the system eliminates the safety vulnerabilities associated with sensor failures while maintaining adaptability.
3Adaptability or versatility
If a lever system with variable force application is used to achieve variable stiffness, then variable stiffness is achieved, but device complexity and space requirements increase
Solution Approach 1:
The invention merges the variable stiffness mechanism directly into the actuator structure, eliminating the need for separate lever systems and additional mechanical elements. By integrating the stiffness variation capability within the actuator itself, the design reduces overall system complexity and space requirements while maintaining the variable stiffness function.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The device achieves high stiffness with compact dimensions, excellent controllability, and intrinsic safety by automatically reducing stiffness in fault conditions, while maintaining durability and safety even at high temperatures.
Implementation Method 1
at least one gas pressure spring
Implementation Method 2
The receiving bellows are also connected to the at least one gas pressure spring so as to conduct fluid. In one embodiment, in this case, a hydraulic fluid is used as fluid.
Implementation Method 3
The hydraulic force transmission also includes a high level of self-damping. The natural vibrations of the system are strongly over-damped
Data Source
AI summary
A torque transmission device includes an inner ring, an outer ring, and at least one pair of receiving bellows. The at least one pair of receiving bellows includes a positive receiving bellows and a negative receiving bellows. The torque transmission device also includes at least one gas pressure spring and an adjusting unit connected to the at least one gas pressure spring. The receiving bellows are arranged between the outer ring and the inner ring such that when the inner ring is rotated in the positive rotational direction, the positive receiving bellows may be compressed, and when the inner ring is rotated in the negative rotational direction, the negative receiving bellows may be compressed. In addition, the receiving bellows are connected to the at least one gas pressure spring in a fluidically conductive manner.