Collaborative Robot Joint CVT With Spherical Bidirectional Transmission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current continuously variable transmission systems in human-robot interfaces face challenges such as inability to independently control outlet torque and position, high inertias leading to poor back driving performance, and unidirectional transmission, which limits bidirectional interaction and fails to effectively damp sudden physical crashes.
Innovation Solution
A collaborative robot joint using two spheres that contact conical variators, allowing for independent control of outlet location and stiffness through adjustable normal forces and friction, enabling bidirectional transmission and safer force handling by minimizing frictional effects during stage changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a wheel is used for power transmission in SDA systems, then the structure is simple, but holonomic motion cannot be achieved and stage change is impossible without rotating conical variators
Solution Approach 1:
The patent replaces the traditional wheel with a sphere that has point contact with the conical variators. This spherical geometry enables holonomic motion capability because the sphere can rotate about any axis passing through its center, allowing stage change in multiple directions without requiring complex rotating conical variator mechanisms.
2Reliability
If planet gear systems are used for power transmission, then transmission ratio can be changed, but sudden physical forces cannot be damped mechanically
Solution Approach 1:
The patent introduces a spring element as an intermediary component between the sphere and the housing. This spring mechanically damps sudden physical forces by absorbing and releasing energy, protecting the transmission system from shock loads while maintaining the overall structural simplicity.
3Adaptability or versatility
If a single sphere is used for transmission, then the structure is simple, but unidirectional transmission is enabled only
Solution Approach 1:
The patent divides the single sphere into two separate spheres, each responsible for one direction of transmission. The first sphere handles transmission in one direction while the second sphere handles the opposite direction, enabling bidirectional transmission capability without requiring a complex single-sphere mechanism.
4Productivity
If the outlet location is kept constant, then the joint structure is simple, but transmission ratio cannot be changed
Solution Approach 1:
The patent makes the outlet location dynamic by allowing it to move along the axis of the joint. This dynamic positioning of the outlet, combined with the spring-loaded sphere mechanism, enables continuous variation of the transmission ratio while keeping the overall joint structure relatively simple.
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 solution enables independent control of outlet torque and position in both directions, improves damping of sudden crashes, and facilitates safer bidirectional interaction by minimizing frictional resistance, enhancing the performance of continuously variable transmission systems in human-robot interfaces.
Implementation Method 1
The transmission between the variators is enabled by means of a belt, chain or dry friction
Implementation Method 2
A compression spring is located on the supportive connecting piece in order to make a normal force on the sphere
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
The invention is a collaborative robot joint with continuously variable transmission, is related to two spheres (1, 2) which are located on the housings (81) on the carrying structure (8) for providing transmission between the input/output conical variators (10), a changed transmission ratio by means of changing the locations of these spheres (1, 2) on the conical variators (10) in a linear manner, the compression springs (6) with adjustable compression value in order to guarantee these spheres (1, 2) providing the transmission in both directions by means of friction, the adjusting screw (7) which provides changing the compression amount of the compression springs (6) for adjusting the highest transmittable torque value, the spherical bearings (3) which would allow the spheres (1, 2) to rotate with least amount of friction in both transmission directions and in the direction of progress for changing the transmission amount, not requiring the rotation of the inlet/outlet conical variations (10) during the transmission ratio change by means of the rotation of the spheres (1, 2) in two directions.