Separately Excited Synchronous Motor Slip Ring Brush Guide
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electric motor designs, particularly separately excited synchronous motors, face issues with contact element vibration and wobbling due to manufacturing and assembly tolerances, leading to intermittent electrical contact and increased wear, which are not adequately addressed by complex spring systems that require precise design for axial and lateral tensioning.
Innovation Solution
The use of two separate spring elements, a constant force spring for axial tensioning and a coil spring for lateral tensioning, allows for optimized contact pressure in both directions, preventing vibration and wear by ensuring neither excessive nor insufficient contact pressure, and simplifies the design by eliminating the need for complex spiral springs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single spiral spring is used for both axial and lateral tensioning, then the contact element can be spring-loaded in both directions, but the device complexity increases and the spring design becomes very specific and difficult to manufacture
Solution Approach 1:
The single spiral spring is divided into two separate spring elements: a first spring element for axial tensioning and a second spring element for lateral tensioning. This segmentation allows each spring to be independently designed and optimized for its specific function, reducing overall system complexity while maintaining contact stability.
Solution Approach 2:
The lateral tensioning function is extracted from the axial spring system. The second spring element is specifically added to provide lateral tensioning, separating this function from the first spring element that handles axial tensioning. This extraction simplifies the design requirements for each individual spring.
2Reliability
If axial spring-loading is increased to prevent vibration, then contact stability improves, but wear increases due to excessive contact pressure
Solution Approach 1:
The spring-loading function is segmented into axial and lateral components with different spring elements. The first spring element provides axial tensioning to prevent vibration, while the second spring element provides lateral tensioning to optimize contact pressure distribution. This segmentation allows independent optimization of each tensioning direction to prevent excessive wear.
Solution Approach 2:
The spring elements are designed with specific force characteristics that change based on displacement. The springs are configured to provide appropriate contact pressure within an optimal range, increasing tension when needed to prevent vibration and decreasing tension when optimal contact is achieved, thereby reducing wear.
3Reliability
If lateral tensioning is increased to prevent tilting, then contact element guidance improves, but friction increases due to excessive surface pressure against the guide wall
Solution Approach 1:
The second spring element is designed with specific force characteristics that adjust lateral tensioning based on operating conditions. The spring provides sufficient lateral tensioning to prevent tilting and ensure proper guidance, but the force is optimized to maintain surface pressure within a range that prevents excessive friction against the guide wall.
Solution Approach 2:
The lateral tensioning is applied locally through the second spring element at specific contact points. This localized application ensures that the contact element is properly guided without applying excessive force across the entire contact surface, thereby minimizing friction while maintaining guidance stability.
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 ensures stable and efficient electrical contact by maintaining optimal contact pressure, reducing vibrations and wear, and simplifying the spring system design, thereby enhancing the reliability and longevity of the motor's contact element arrangement.
Implementation Method 1
a contact element (6), in particular a carbon brush, which bears against the slip ring (4) and is accommodated in a channel-like guide (8) formed in a housing (2), wherein the contact element (6) is radially tensioned against the slip ring (4) by means of a spring element (10)
Implementation Method 2
a roller (22) is provided which is tensioned laterally against the contact element (6) by means of a further spring element (20) and by means of which the contact element (6) is tensioned against a wall of the guide (8)
Data Source
AI summary
An electric motor, in particular a separately excited synchronous motor, has a rotor shaft with at least one slip ring and at least one electrically conductive contact element, in particular a carbon brush, which bears against the slip ring and is accommodated in a channel-like guide formed in a housing and extending radially with respect to the rotor shaft and which carbon brush is radially tensioned against the slip ring by means of a spring element, wherein a roller is provided which is tensioned laterally against the contact element via a further spring element and via which the contact element is tensioned against a wall of the guide.