Pump Assembly Rotor Can Flange Axial Biasing
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Solution Overview
Problem
Existing wet rotor pumps in the 5W to 3kW power range for house heating systems face challenges in achieving a compact design while maintaining precise coaxial alignment of the rotor axis with the pump housing, leading to inefficiencies in fluid handling and increased fluid loss.
Innovation Solution
The pump assembly features a rotor can flange that is axially biased away from the impeller by a resiliently spring-loaded bearing retainer, allowing for a compact design and precise alignment, with the bearing retainer acting as a spring to secure the rotor can in place without additional springs, and utilizing a bayonet ring for stator housing alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a large rotor can flange is used for rotation prevention and axial alignment, then the components are securely aligned, but the pump requires significant lateral space
Solution Approach 1:
The alignment function is segmented into multiple independent elements: the bearing retainer with its flange provides axial positioning, while the locking ring with its radial protrusions provides rotational positioning. This segmentation allows each element to be optimized for its specific function without requiring a large overall flange diameter.
Solution Approach 2:
The bearing retainer acts as an intermediary component between the rotor can flange and the pump housing. It provides a dedicated axial positioning interface through its flange that rests on the pump housing, eliminating the need for the rotor can flange itself to be large for alignment purposes.
2Reliability
If the rotor can flange is axially biased towards the impeller against the pump housing, then the components are securely positioned, but the design cannot be made compact
Solution Approach 1:
Instead of biasing the rotor can flange towards the impeller (conventional approach), the invention inverts the approach by using a resilient bearing retainer that biases the flange away from the impeller. This inversion allows the flange to be smaller while maintaining positioning stability through the spring-loaded bearing retainer mechanism.
Solution Approach 2:
The bearing retainer is resiliently spring-loaded, providing dynamic positioning capability. The spring mechanism allows the bearing retainer to adapt to manufacturing tolerances and maintain reliable contact between the rotor can flange and pump housing, enabling compact dimensions while preserving positioning reliability.
3Reliability
If additional springs are used to provide spring loading, then the bearing retainer can be resiliently loaded, but the device complexity increases
Solution Approach 1:
The spring loading function is merged into the bearing retainer itself. The bearing retainer flange is designed with resilient properties, combining the bearing support function with the spring loading function in a single component, thereby eliminating the need for separate springs and reducing overall device complexity.
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 results in a more compact and efficient pump design with reduced fluid loss, improved alignment, and enhanced pumping efficiency by minimizing manufacturing tolerances and fluid leakage.
Implementation Method 1
the bearing retainer is resiliently spring-loaded for biasing the stop surface of the rotor can flange axially away from the impeller against a locking ring
Data Source
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AI summary
The present disclosure is directed to a pump assembly (1) comprising - a rotor axle (45) extending along a rotor axis (R), - an impeller (12) fixed to the rotor axle (45), - a pump housing (11) accommodating the impeller (12), - a drive motor comprising a stator (17) and a rotor (51), wherein the rotor (51) is fixed to the rotor axle (45) for driving the impeller (12), - a rotor can (57) accommodating the rotor (51), wherein the rotor can (57) comprises a rotor can flange (63), - a stator housing (13) accommodating the stator (17), - a first radial bearing ring (47) being in sliding contact with the rotor axle (45), and - a bearing retainer (41) comprising a bearing retainer flange (43) and embracing the first radial bearing ring (47). The rotor can flange (63) comprises a stop surface (79) facing away from the impeller (12), wherein the bearing retainer (41) is resiliently springloaded for biasing the stop surface (79) of the rotor can flange (63) axially away from the impeller (12) against a locking ring (85).