Molded Stator Lead-Out Component Design for Fluid Ingress Prevention
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Solution Overview
Problem
Conventional molded electric motors face issues with fluid ingress through gaps between the stator and wire lead-out components, leading to pattern corrosion and potential motor inoperability, and have environmental resistance concerns due to elastic bushing degradation in severe conditions.
Innovation Solution
The solution involves increasing molding pressure on the lead-out component to ensure it contacts the molding die radially, using thermoplastic resin for the lead-wire wiring component, and employing a lead-out unit with a power-supply and sensor-lead wire holding components to maintain positional stability and prevent fluid ingress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a wire lead-out component is integrally molded with the stator from mold resin, then the manufacturing process is simplified and production efficiency is improved, but gaps or interfaces between the outer frame and wire lead-out component or between the wire lead-out component and lead wire create paths for fluid ingress
Solution Approach 1:
The wire lead-out component is divided into multiple separate parts: the outer frame, the wire lead-out component itself, and sealing components. This segmentation allows each part to be optimized independently - the outer frame provides structural support, the wire lead-out component enables wire passage, and sealing components prevent fluid ingress, thereby resolving the contradiction between manufacturing simplicity and waterproof performance.
Solution Approach 2:
A sealing component acts as an intermediary element between the outer frame and the wire lead-out component. This sealing component fills and seals the gap or interface between these parts, preventing fluid ingress while maintaining the integral molding structure. The sealing component mediates between the need for a simple molded structure and the requirement for waterproof performance.
2Reliability
If a conventional elastic body bushing is used as the lead-out unit, then fluid ingress is reduced through compression by the outer frame, but the bushing material degrades under severe environmental conditions
Solution Approach 1:
The sealing component uses composite material construction, combining materials with different properties to achieve both sealing performance and environmental resistance. The composite structure provides the necessary elasticity for sealing while incorporating materials that resist degradation under severe environmental conditions, thereby resolving the contradiction between fluid sealing and environmental durability.
Solution Approach 2:
The sealing component is designed with optimized geometric parameters and material properties that allow it to maintain effective sealing pressure without relying solely on elastic compression. By changing the structural parameters (such as cross-sectional shape, thickness distribution) and material parameters (temperature resistance, chemical stability), the sealing component achieves both fluid ingress prevention and environmental resistance.
3Ease of manufacture
If the wire lead-out unit is placed on the outer periphery side of the stator core, then it can be easily integrated with the lead-wire wiring component, but the connection part creates additional interfaces that become paths for fluid ingress
Solution Approach 1:
The sealing component is merged with the wire lead-out component through integral molding, creating a unified structure that eliminates separate connection interfaces. This merging maintains the ease of manufacture by keeping the components as a single molded piece while simultaneously improving fluid sealing by removing the additional interfaces that would otherwise create fluid ingress paths.
Data Source
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AI summary
The present invention is a molded stator including a stator and a substrate having a position detection circuit of a rotor mounted thereon, and an outer frame thereof being formed in mold resin. The molded stator includes a donut-shaped lead-wire wiring component 1 that is attached to an end of the stator in the axial direction, wires power-supply lead wires to a winding wire of the stator, and wires sensor lead wires to the position detection circuit, a lead-out component 6 that is provided on a radially outer side of the lead-wire wiring component 1 and leads out the power-supply lead wires and the sensor lead wires to outside of the molded stator, a power-supply lead-wire holding component that is assembled to the lead-out component 6 and holds the power-supply lead wires, and a sensor-lead-wire holding component that is assembled to the lead-out component 6 and holds the sensor lead wires, where the lead-out component 6 is connected to a latching part 26b that latches the sensor-lead-wire holding component, and includes projections 17 as plane parts that are substantially perpendicular to a radial direction of the stator on the radially outer side.