Electric Pump Housing Layout for Shaft-Stator Coaxiality
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge of reducing the concentricity tolerance between the pump shaft and the stator winding in electric pumps during multiple injection molding processes is addressed.
Innovation Solution
The electric pump design includes a housing formed in two stages, with the stator winding and pump shaft used as inserts, ensuring coplanar parting surfaces to minimize positioning errors and improve concentricity by maintaining a consistent positioning reference throughout the molding process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If multiple injection molding processes are used to form the housing with stator winding and pump shaft as inserts, then the housing can be manufactured with integrated components, but positioning errors accumulate and concentricity tolerance deteriorates
Solution Approach 1:
The housing is divided into a first housing and a second housing that are formed in separate injection molding processes. The first housing contains the stator winding while the second housing contains the pump shaft. By segmenting the housing into multiple parts with coplanar parting surfaces, each component can be positioned independently with high precision, avoiding the accumulation of positioning errors that would occur if all components were integrated in a single molding process.
Solution Approach 2:
The coplanar parting surfaces between the first and second housings serve as an intermediary reference plane that ensures accurate alignment during assembly. This common reference surface acts as a mediator that maintains consistent positioning for both the stator winding and pump shaft, thereby preserving concentricity tolerance across multiple manufacturing stages.
2Productivity
If the first assembly is demolded and repositioned for the next molding step, then the molding process can proceed in stages, but positioning errors increase due to repeated loading
Solution Approach 1:
The first housing is formed as a preliminary structure with the stator winding insert positioned on a coplanar parting surface. This preliminary action creates a stable reference platform that remains in place for the subsequent molding of the second housing, eliminating the need to demold and reposition the first assembly and thereby preventing positioning errors from accumulating.
Solution Approach 2:
The manufacturing process merges the first and second housing formation operations by maintaining the first assembly in the mold during the second injection molding step. This combining of operations around a common coplanar reference surface ensures that both housings are positioned accurately relative to each other without the positioning errors that would result from separate demolding and reloading cycles.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
An electric pump (100), comprising a stator winding (131), a housing (134), and a pump shaft (133). The housing (134) comprises a first housing (1341) and a second housing (1342); at least part of the first housing (1341) is formed by injection molding with the stator winding (131) as an insert; a first assembly (136) is defined, and the first assembly (136) comprises the first housing (1341) and the stator winding (131); at least part of the second housing (1342) is formed by injection molding with the first assembly (136) and the pump shaft (133) as inserts; the first housing (1341) comprises a first parting surface (A); the second housing (1342) comprises a second parting surface (B); and the first parting surface (A) and the second parting surface (B) are coplanar. By means of the structure, the coaxiality tolerance of the pump shaft and the stator winding can be reduced.