Counterbalance Mechanism with Variable Drive Ratio
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Solution Overview
Problem
Conventional counterbalance mechanisms struggle to effectively balance periodic gravitational torque in mechanical arms due to packaging constraints and discrete spring selections, limiting their viability in various applications.
Innovation Solution
The implementation of a counterbalance mechanism that includes a force transformation mechanism providing a drive ratio, which modifies the force provided by a spring to balance gravitational forces on a load, allowing for increased design flexibility and adaptability to different applications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional counterbalance mechanisms use discrete spring selections and standard pulley configurations, then the mechanism structure is simple, but the adaptability to different packaging constraints and spring rates is limited
Solution Approach 1:
The patent introduces a variable drive ratio mechanism that can dynamically adjust the force transformation ratio between the spring and load. This allows the same basic mechanism structure to adapt to different spring rates and packaging constraints by changing the drive ratio, rather than requiring multiple fixed-configuration mechanisms.
Solution Approach 2:
The patent changes the key parameter of the drive ratio to enable adaptation. By allowing the drive ratio to vary, the mechanism can accommodate different spring rates, extension lengths, and packaging constraints while maintaining a relatively simple overall structure, thus resolving the contradiction between adaptability and complexity.
2Reliability
If the spring force is directly applied to the load without force transformation, then the mechanism is simple, but the effectiveness in balancing periodic gravitational torque is insufficient
Solution Approach 1:
The patent introduces a force transformation mechanism as an intermediary between the spring and the load. This intermediary component transforms the spring force through a variable drive ratio to better match the periodic gravitational torque requirements, improving balancing effectiveness without requiring direct complex coupling between spring and load.
Solution Approach 2:
The force transformation mechanism utilizes variable drive ratio as a controllable parameter to optimize the force transmission. By adjusting the drive ratio parameter, the system can effectively balance gravitational torque across different operating conditions while maintaining reasonable mechanical complexity.
3Volume of moving object
If springs with specific extension lengths are selected to match packaging constraints, then the packaging efficiency is improved, but the selection range of suitable springs is limited
Solution Approach 1:
The variable drive ratio mechanism dynamically compensates for mismatches between spring extension length and packaging constraints. This allows a broader range of springs to be used, as the drive ratio can be adjusted to accommodate different spring characteristics while maintaining proper force balance and fitting within packaging limits.
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
This solution enables more efficient use of springs with varying spring rates and extension lengths, accommodating specific packaging constraints and enhancing the range of suitable springs for counterbalance mechanisms, thereby improving the mechanism's effectiveness and versatility.
Implementation Method 1
a force provided by the spring is modified in magnitude by the force transformation mechanism
Implementation Method 2
a force provided by the spring is modified in magnitude by the force transformation mechanism and is applied to the load via the second tension element. The force transformation mechanism includes a plurality of elements and the modification of the force is based on a drive ratio of the elements of the force transformation mechanism
Implementation Method 3
a plurality of counterbalance pulleys coupled to the second tension element. At least one of the counterbalance pulleys is coupled to a load that is moveable with reference to a mechanical ground
Implementation Method 4
a first tension element, a second tension element, a force transformation mechanism coupled to the spring by the first tension element and coupled to the second tension element
Data Source
AI summary
Implementations relate to a counterbalance mechanism including a force transformation mechanism that provides a drive ratio. In some implementations, a counterbalance apparatus includes a spring, a first tension element, a second tension element, a force transformation mechanism coupled to the spring by the first tension element and coupled to the second tension element, and a plurality of counterbalance pulleys coupled to the second tension element. At least one of the counterbalance pulleys is coupled to a load that is moveable with reference to a mechanical ground, and a force provided by the spring is modified in magnitude by the force transformation mechanism and is applied to the load via the second tension element. The force transformation mechanism includes a plurality of elements and the modification of the force is based on a drive ratio of the elements of the force transformation mechanism.