Low-noise rotary pump split-core ribs press-fit stator
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Solution Overview
Problem
Existing rotary pumps with plastic components face issues of play and resonance due to low rigidity, leading to noise, vibrations, and potential resonances, especially under varying temperature conditions.
Innovation Solution
A rotary pump design featuring a plastic split core with axial-parallel ribs and a press-fit connection between the claw pole stator and split core, along with a welded return ring, ensures a stable and resonance-free structure without additional damping measures, utilizing injection molding for production efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a tab connection is used to join the return ring with the claw pole stator, then the connection can be assembled easily, but the low rigidity of the tab causes play and resonance under temperature variations
Solution Approach 1:
The connection structure is segmented into multiple functional elements: the return ring with end sections, the claw pole stator, and intermediate connection elements. This segmentation allows each component to be optimized independently while maintaining overall connection stability through the distributed rib structure.
Solution Approach 2:
The connection design employs asymmetric features including the non-uniform distribution of ribs around the periphery of the split core and the asymmetric welding arrangement of the return ring end sections. This asymmetry prevents uniform resonance patterns and enhances connection rigidity under varying thermal conditions.
2Object-affected harmful factors
If additional noise damping devices are installed to suppress vibrations and resonances, then noise and vibrations are reduced, but the device complexity and manufacturing cost increase
Solution Approach 1:
The design converts potentially harmful vibrations and resonances into beneficial structural reinforcement. The ribs and welded connections are positioned and dimensioned to create natural vibration damping through the structural geometry itself, eliminating the need for separate damping materials or devices while actually enhancing connection rigidity.
Solution Approach 2:
The invention changes key structural parameters including the number, distribution, and dimensions of the ribs, as well as the welding configuration of the return ring. These parameter optimizations enable the structure to inherently suppress resonances at critical frequencies without requiring additional damping components.
3Reliability
If a firm connection is achieved through rigid joining methods, then play is eliminated, but the assembly process becomes more complex and costly
Solution Approach 1:
The invention merges multiple functions into integrated components: the return ring serves both as a structural support element and as a welding substrate; the ribs provide both mechanical reinforcement and alignment features; the press-fit and welding processes are combined in a sequential operation that achieves firm connection while maintaining manufacturing efficiency.
Solution Approach 2:
The design incorporates preliminary action through the press-fit process that pre-positions the claw pole stator and return ring assembly onto the split core ribs before final welding. This preliminary mechanical interference fit ensures proper alignment and eliminates play before the permanent welding connection is established, simplifying the overall manufacturing process.
Data Source
AI summary
A rotary pump with a plastic pump housing, that can be processed by injection molding, with a first housing part defining a pump space, which is connected to a second intermediate housing part accommodating an electric motor with a wound core stator. The rotary pump includes a plastic split core, the wound claw pole stator being mounted on the split core and a permanent magnetic rotor being mounted to rotate within the split core. A plastic motor housing part defines a motor space, wherein at least three axial and parallel split core ribs are provided between the split core and the claw pole stator, the ribs being distributed about the periphery of the split core at predetermined angles relative to each other. A return ring has first and second end sections, the return ring being connected to the wound claw pole stator, so that the first and second end sections are welded to each other. The stator is press-fit onto the split core via the ribs. At least three axial-parallel housing ribs protrude radially inward and are formed with the motor housing part, the axial-parallel housing ribs being distributed on the inside periphery of the motor housing part. Finally, the stator is press-fit into the motor housing part via the housing ribs.