Speed Change Operation Apparatus Dual Spring Mechanism
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Solution Overview
Problem
Existing speed change operation apparatuses for stepless speed changer devices experience variation in operational resistance due to changes in urging force as the trunnion shaft moves from the neutral to the highest speed position, leading to inconsistent performance.
Innovation Solution
A speed change operation apparatus with a main urging mechanism and an auxiliary urging mechanism, where the returning urging force at the neutral position is stronger than at the operational position, and the auxiliary urging force is weaker at the neutral position but stronger at the operational position, optimizing the force application to maintain consistent operational resistance throughout the range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single spring mechanism is used to urge the positioning body, then the structure is simple, but the urging force varies significantly as the trunnion shaft moves from neutral to operational position, causing variation in operational resistance
Solution Approach 1:
The single spring mechanism is divided into two separate spring mechanisms: a first spring mechanism that provides urging force when the trunnion shaft is at or near the neutral position, and a second spring mechanism that provides urging force when the trunnion shaft is at an operational position. This segmentation allows each spring to be optimized for its specific operational range, maintaining consistent operational resistance throughout the full range of motion.
Solution Approach 2:
Different spring mechanisms are applied to different operational regions of the trunnion shaft. The first spring mechanism is configured with specific urging force characteristics for the neutral position area, while the second spring mechanism is configured with different urging force characteristics for the operational position area. This local quality approach ensures that each region receives the appropriate urging force characteristics for its specific function.
2Reliability
If the urging force is increased to ensure the trunnion shaft returns to neutral position, then the returning reliability is improved, but the operational resistance becomes excessively high during speed change operations
Solution Approach 1:
The urging force is made dynamic by switching between two different spring mechanisms based on the trunnion shaft's position. The first spring mechanism provides stronger urging force when the trunnion shaft is near the neutral position to ensure reliable returning, while the second spring mechanism provides reduced urging force when the trunnion shaft is at an operational position to maintain smooth speed change operations. This dynamic adjustment of urging force resolves the contradiction between returning reliability and operational smoothness.
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 configuration reduces variation in operational force and progressively increases force as the device approaches maximum speed, allowing for stable operation with minimal resistance change, enabling precise and smooth speed change operations.
Implementation Method 1
a first spring mechanism operably coupled with the positioning body to vary a returning urging force in response to a movement of the positioning body from the operational position to the neutral position
Implementation Method 2
a second spring mechanism operably coupled with the positioning body to vary an urging force in response to a movement of the positioning body from the neutral position to the operational position
Data Source
AI summary
A speed change operation apparatus includes a pivotal body operatively connected to a trunnion shaft to be pivotally displaced in response to an operational displacement by an operational tool, a positioning body operatively coupled with the pivotal body so as to be pivotally displaced in response to a pivotal displacement of the pivotal body, a main urging mechanism for applying an urging force to the pivotal body via the positioning body for returning the pivotal body from an operational position to the neutral position, and an auxiliary urging mechanism for applying an auxiliary urging force to the pivotal body for returning the pivotal body from the operational position to the neutral position.