Planar Torsion Spring for Compact Robot Joints
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Solution Overview
Problem
Conventional robot joint designs are prone to damage from external impacts due to a lack of flexibility, and existing flexible joint solutions, such as those using force/torque transducers or serial elastic driving joints, face challenges in achieving a compact and lightweight structure.
Innovation Solution
A planar torsion spring for a robot joint is introduced, comprising a torsion spring outer ring, inner ring, and elastic bodies with symmetrical units, connecting beams, and strategically placed holes, allowing for wide-angle deformation and enhanced elasticity through elastic body distribution and structural modifications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional spiral springs are used in flexible joints, then the joint possesses flexibility and anti-impact performance, but the joint occupies large space and has a loose structure
Solution Approach 1:
The patent transforms the conventional three-dimensional spiral spring into a two-dimensional planar torsion spring. This dimensional reduction allows the elastic element to achieve the required flexibility and energy storage capacity while occupying significantly less space, directly resolving the contradiction between anti-impact performance and joint size.
Solution Approach 2:
The planar torsion spring is segmented into multiple elastic body units distributed around the circumference, with each unit containing inner and outer circular hole slots connected by connecting beams. This segmentation allows the deformation to be distributed across multiple elements, achieving wide-angle deformation in a compact configuration while maintaining flexibility.
2Reliability
If conventional spiral springs are used in flexible joints, then the joint possesses flexibility, but the structure becomes loose and less compact
Solution Approach 1:
The patent merges the inner and outer circular hole slots with the connecting beams into integrated elastic body units, eliminating the need for separate components. This merging creates a compact, unified structure that maintains flexibility while reducing overall device complexity and improving structural integrity.
Solution Approach 2:
The inner circular hole slot is nested within the outer circular hole slot, with both slots and connecting beams forming a concentric, nested configuration. This nesting approach maximizes the use of available space, achieving wide-angle deformation capability in a compact footprint while maintaining structural rigidity.
3Reliability
If the elasticity of the torsion spring is increased by thickening walls and widening connecting beams, then the anti-impact performance improves, but the device complexity increases
Solution Approach 1:
The patent applies local quality by selectively thickening the walls of the circular hole slots and widening the connecting beams only in the regions where elastic deformation is needed. This localized reinforcement increases the overall elasticity and energy storage capacity of the spring without unnecessarily increasing the complexity of the entire structure.
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 planar torsion spring enhances the robot joint's flexibility and compactness, enabling safer interaction with humans and environments while improving the robot's operational resilience and design efficiency.
Implementation Method 1
when the torsion spring inner ring of the planar torsion spring rotates, the inner circular hole slot is drove to elastically deform through the connecting beam, the inner circular hole slot then drives the outer circular hole slot to elastically deform through the connecting beam
Data Source
AI summary
The present invention discloses a planar torsion spring for a robot joint, including a torsion spring outer ring, a torsion spring inner ring and a plurality of elastic bodies; the elastic bodies are uniformly distributed around the circumference and connected with the torsion spring outer ring and the torsion spring inner ring respectively at their two ends; each elastic body is composed of two symmetrical elastic body units, each elastic body unit includes an outer circular hole slot, an inner circular hole slot and a connecting beam; the connecting beam connects respectively between the torsion spring inner ring and the inner circular hole slot, the inner circular hole slot and the outer circular hole slot, the outer circular hole slot and the torsion spring outer ring; a wide-angle deformation of the torsion spring is achieved through a series of elastic deformation of the inner and outer circular hole slot.