Stator Pole Clamping via Metallic Ring Prestress
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Solution Overview
Problem
Existing stators for electronically commutated DC motors require complex and labor-intensive assembly methods, as known holding parts, such as plastic pins or clamping rings, do not adequately secure the stator poles together without relying on the motor housing for support.
Innovation Solution
A metallic clamping ring is placed under prestress around the hollow-cylindrical yoke to securely clamp the stator poles together, allowing for easier assembly and providing design freedom for housing tightness and weight optimization, with integral screw-on eyelets for additional support and alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If plastic holding parts with axially projecting pins are used to connect stator poles, then the stator poles can be assembled together, but they cannot brace the poles sufficiently and require additional pressing into the motor housing with great effort
Solution Approach 1:
The holding part is changed from plastic to metallic material, fundamentally altering the mechanical properties. The metallic clamping ring can be elastically deformed during assembly and then springs back to provide continuous prestress, enabling sufficient bracing of stator poles without requiring additional pressing into the motor housing.
Solution Approach 2:
The metallic clamping ring is designed to be elastically deformable during assembly, allowing it to be compressed onto the stator poles and then spring back to provide continuous dynamic prestress. This dynamic characteristic enables the holding part to actively maintain the bracing of stator poles throughout operation.
2Reliability
If stator poles are pressed into the motor housing or housing is shrunk onto stator poles to brace them, then sufficient bracing is achieved, but the assembly process requires great effort
Solution Approach 1:
The metallic clamping ring is pre-formed with elastic deformation capabilities before assembly. During assembly, the ring is temporarily compressed and then springs back to apply prestress to the stator poles, achieving sufficient bracing without requiring additional pressing operations into the motor housing.
Solution Approach 2:
The metallic clamping ring serves its own bracing function through its elastic prestress mechanism, eliminating the need for the motor housing to provide bracing support. The holding part becomes self-sufficient in providing the necessary mechanical support for stator poles.
3Device complexity
If the holding part serves as both a clamping element and a motor housing element, then structural integration is achieved, but design freedom for housing tightness and weight is reduced
Solution Approach 1:
The clamping function is extracted from the motor housing structure and assigned to a separate metallic holding part. This separation allows the motor housing to be optimized independently for tightness and weight, while the metallic holding part is专门 optimized for the clamping function with integral screw-on eyelets for additional support and alignment.
Solution Approach 2:
The stator assembly is segmented into distinct functional components: the hollow-cylindrical yoke formed by yoke sections, the metallic holding part for clamping, and the motor housing. This segmentation allows each component to be independently optimized for its specific function, enhancing overall design freedom.
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 enables reliable and efficient assembly of the stator within the motor housing, reducing assembly effort and offering greater design flexibility for housing tightness and weight optimization, while the clamping ring serves its primary function without being a yoke or motor housing element.
Implementation Method 1
the holding part is a metallic clamping ring, which is placed under prestress around the entire circumference of the hollow-cylindrical yoke and clamps the stator poles together
Data Source
Figure 1~5
Figure 6~7
Figure 8~9
AI summary
The stator has several individual stator poles (1) having return sections (27) including concave and convex profiles (28,29) which are intermeshed with each other, so as to form hollow cylinder portion. A pole core (25) connected with return section, is directed radially along inward direction. A retaining portion having metal clamping ring, is positioned around periphery of hollow cylinder portion so as to tighten stator poles relative to each other.