Relay Contact Layout With External Spring to Limit Abrasion Powder
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Solution Overview
Problem
In relays with internal space partitioned by a contact case, abrasion powder generated from sliding movable parts tends to adhere to contacts, increasing contact resistance and hindering energization capacity.
Innovation Solution
The contact spring is arranged outside the contact case, preventing abrasion powder from adhering to the movable or fixed contacts by positioning it outside the contact case, and the drive shaft is immovably fixed to the movable contact piece to minimize abrasion, with additional configurations allowing compact arrangement of springs and iron cores outside the case.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If movable parts are arranged inside the contact case together with contacts, then device compactness is improved, but contact resistance increases due to abrasion powder adhesion
Solution Approach 1:
The relay is divided into two separate spaces: the contact case housing the contacts, and the coil case housing the movable parts (drive shaft, contact spring, movable iron core). This spatial segmentation prevents abrasion powder from moving parts from reaching the contacts, resolving the contradiction between compactness and contact reliability.
Solution Approach 2:
The contact spring and movable iron core are extracted from the contact case and relocated to the coil case. This extraction removes the source of abrasion powder generation away from the contacts, eliminating the harmful effect while maintaining device functionality.
2Volume of moving object
If contact spring is arranged inside the contact case, then device compactness is improved, but abrasion powder generation increases causing contact resistance increase
Solution Approach 1:
The contact spring is extracted from the contact case and positioned in the coil case, removing it from the environment where it would generate abrasion powder near the contacts. This eliminates the harmful factor while preserving the spring's mechanical function.
Solution Approach 2:
The relay structure is segmented into distinct functional zones: the contact case for electrical contacts and the coil case for mechanical actuation components. This segmentation isolates the contact spring in a separate zone where its abrasion does not affect the contacts.
3Ease of operation
If drive shaft slides against movable contact piece, then movable portion mobility is improved, but abrasion powder is generated that adheres to contacts
Solution Approach 1:
The drive shaft is extracted from the contact case and extended into the coil case, removing the sliding interface away from the contacts. The mobility function is preserved through the extended drive shaft configuration, while abrasion powder generation is isolated from the contact area.
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 effectively suppresses the increase in contact resistance due to abrasion powder, ensuring reliable contact performance and compact design by preventing abrasion powder from adhering to contacts, thus maintaining or improving energization capacity.
Implementation Method 1
The coil generates a magnetic force that moves the movable iron core in a moving direction of the movable portion
Implementation Method 2
The return spring urges the movable portion in the direction in which the movable contact is separated from the fixed contact
Implementation Method 3
The contact spring urges the drive shaft in the direction in which the movable contact contacts the fixed contact
Data Source
AI summary
A relay includes a fixed contact, a movable contact piece including a movable contact, a movable portion, a coil, a return spring, and a contact spring. The movable portion includes a drive shaft and a movable iron core. The drive shaft is fixed to the movable contact piece in a contact case and extends from an inside of the contact case to an outside of the contact case. The movable iron core is connected to the drive shaft outside the contact case. The return spring urges the movable portion in an open direction in which the movable contact is separated from the fixed contact. The contact spring urges the drive shaft in a contact direction in which the movable contact contacts the fixed contact. The contact spring is arranged outside the contact case.