Switch Contact Reliability via Grease Zone Avoidance
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Solution Overview
Problem
In switches, grease accumulation at the contact points leads to increased viscosity and impaired contact reliability due to abrasion powder and wettability, causing the movable contact member to ride on a thick grease layer, which affects contact reliability.
Innovation Solution
A switch design that includes a base, fixed and movable contact members, an elastic body, and an operation body to move the movable contact member to specific positions, allowing it to return from the contact position to a position away from grease accumulation, ensuring contact reliability even with grease accumulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If grease is applied between the movable contact member and fixed contact member to enable smooth movement, then the movable contact member can move smoothly, but grease accumulates at the movement final end and spreads to form a thick grease layer that impairs contact reliability
Solution Approach 1:
The movement range of the movable contact member is segmented into multiple positions (initial position, first position at movement final end, second position intermediate between initial and first positions). By limiting the movable contact member to operate only within this segmented range and preventing it from reaching the extreme first position, the patent segments the grease accumulation problem into manageable zones, ensuring contacts occur in grease-free zones while still enabling smooth movement through the permitted range.
Solution Approach 2:
The patent applies preliminary anti-action by pre-defining and restricting the movement range of the movable contact member to prevent it from reaching the position where grease accumulation occurs. The operation body is designed with a physical stop or limiting structure that prevents the movable contact member from moving beyond the second position, thereby preemptively avoiding the grease accumulation zone before it can impair contact reliability.
2Productivity
If the movable contact member moves to the position where contacts come into contact and then moves in the opposite direction, then contact switching is achieved, but grease adheres to the movable contact member and spreads on the fixed contact member due to wettability
Solution Approach 1:
The patent applies local quality by creating different functional zones within the movement range. The zone between the initial position and the second position (intermediate position) is designated as the safe operation zone where contact switching occurs without grease contamination. The zone beyond the second position toward the first position is designated as the grease accumulation zone that is physically avoided. This spatial differentiation of quality ensures that contact switching functionality is maintained in the safe zone while the harmful grease accumulation zone is excluded.
Solution Approach 2:
The patent implements preliminary action by pre-positioning the movable contact member to return to the second position (intermediate position) after contact closing, before grease accumulation can occur. The operation body is designed to automatically reverse direction at the second position, preemptively preventing the movable contact member from reaching the grease accumulation zone. This preliminary reversal action ensures that grease never has the opportunity to adhere and spread.
3Ease of operation
If the movable contact member rides on the thick grease layer, then movement is maintained, but contact reliability is impaired
Solution Approach 1:
The patent applies the taking out principle by extracting the movable contact member from the grease accumulation zone through restricted movement. By designing the operation body and contact structure so that the movable contact member operates only within the range from the initial position to the second position (intermediate position), the patent effectively removes or extracts the movable contact member from the harmful environment of thick grease accumulation, thereby maintaining movement capability while eliminating contact reliability impairment.
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 switch maintains contact reliability by moving the movable contact member to a position away from grease accumulation, preventing impairment from increased viscosity and wettability, thus ensuring consistent contact performance.
Implementation Method 1
an elastic body configured to energize the movable contact member in the second direction
Data Source
AI summary
A switch includes a base, a fixed contact member having fixed contact, and a movable contact member having a movable contact. The movable contact member moves in a first direction to bring the movable contact into contact with the fixed contact, and moves in a second direction opposite to the first direction to separate the movable contact from the fixed contact. The switch further includes a cover, an elastic body that energizes the movable contact member in the second direction, and an operation body configured to move the movable contact member sequentially to a first position, a second position, and a third position.