Rotary Input Mechanism With Split Projections for Lower Wear
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Solution Overview
Problem
Conventional input devices for vehicles suffer from alternating loads on projections, leading to reduced durability due to the way they engage with the rotating member and mover, causing wear and tear during operation.
Innovation Solution
The input device incorporates a rotating member with first and second projections and an inclined protrusion on the mover, where only one projection is subjected to a load based on the rotation direction, reducing wear and allowing for parallel movement of the mover, thus enhancing durability and reducing friction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single projection is used in the conventional input device, then the structure is simple, but the projection is subjected to alternating loads in both rotation directions which reduces durability
Solution Approach 1:
The single projection is segmented into two separate projections (first projection and second projection) that are positioned at different angular locations on the rotating member. This segmentation allows each projection to handle loads in specific rotation directions, preventing alternating loads on a single projection and thereby improving durability while maintaining structural simplicity.
Solution Approach 2:
Different regions of the rotating member are given different functions through the first and second projections. The first projection is optimized for one rotation direction while the second projection is optimized for the opposite direction. This local quality differentiation ensures that each projection experiences unidirectional loads, enhancing overall reliability without complicating the overall structure.
2Ease of operation
If the groove is formed to be inclined with respect to the rotation axis, then the projection can be engaged, but alternating loads are applied to the projection causing wear and tear
Solution Approach 1:
The engagement mechanism is segmented into two separate projection-groove interfaces instead of one. The first projection engages with the groove during rotation in one direction, while the second projection engages during rotation in the opposite direction. This segmentation eliminates alternating loads on a single engagement interface, reducing wear and improving durability while maintaining ease of operation.
3Device complexity
If both projections are subjected to loads in both rotation directions, then the structure is symmetric and simple, but friction and wear increase reducing movable range
Solution Approach 1:
The loading pattern is made asymmetric by designing the first and second projections to be loaded in opposite rotation directions rather than both directions. This asymmetric load distribution reduces cumulative friction and wear on each projection, extending the movable range and duration of action. The structural symmetry is maintained in the overall arrangement, but the functional loading is asymmetric, optimizing performance.
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 design improves the durability of the rotating member by ensuring only one projection is loaded at a time, increasing the movable range and reducing friction, resulting in a more stable and efficient operation.
Implementation Method 1
The protrusion of the mover is inclined with respect to the predetermined rotation axis and disposed between the first projection and the second projection
Data Source
AI summary
An input device includes: a rotating member that rotates about a predetermined rotation axis; and a mover that includes a protrusion protruding toward an inner peripheral surface of the rotating member and moves in a direction different from a rotation direction of the rotating member along with rotation of the rotating member. The protrusion protrudes toward an inner peripheral surface of the rotating member. The rotating member includes a first projection and a second projection that project from the inner peripheral surface toward the mover. The protrusion of the mover is inclined with respect to the predetermined rotation axis and disposed between the first projection and the second projection.