Resin-Molded Sensor Protection in Brushless Motor
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Solution Overview
Problem
Existing electric work machines with air compressors lack effective protection and space utilization for sensor boards, which can lead to inefficiencies and potential damage due to inadequate resin-molded portions.
Innovation Solution
The design incorporates a resin-molded portion that covers the sensor board, featuring recesses and protrusions to enhance bonding strength and protect the sensor board, while also optimizing space usage by allowing the stator to be closer to the sensor board, thus improving the motor's compactness and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the resin-molded portion is designed to cover the sensor board, then the protection of the sensor board is improved, but the space utilization and compactness are worsened
Solution Approach 1:
The sensor board is nested within the resin-molded portion, with the resin material forming a protective cavity that accommodates the sensor board. This nesting approach allows the sensor board to be protected while minimizing the overall volume occupied, as the protective structure is integrated rather than additive.
Solution Approach 2:
The resin-molded portion provides localized protection only where the sensor board is positioned, rather than protecting the entire motor assembly. The recess is formed specifically at the sensor board location, providing targeted protection while leaving other areas with standard spacing, thus optimizing space utilization.
2Strength
If the resin-molded portion is designed to cover the sensor board, then the bonding strength is improved, but the device complexity is worsened
Solution Approach 1:
The resin-molded portion is segmented into distinct functional regions: a recess area that directly contacts and bonds to the sensor board, and an outer protective shell. This segmentation allows the bonding surface to be optimized for adhesion while the outer structure provides protection, simplifying the overall design by separating functional requirements.
Solution Approach 2:
The protective function and bonding function are merged into a single resin-molded portion. The same resin material that provides mechanical protection also forms the bonding interface with the sensor board, eliminating the need for separate protective housing and bonding structures.
3Volume of moving object
If the stator is positioned closer to the sensor board, then the motor compactness is improved, but the protection of the sensor board is worsened
Solution Approach 1:
The sensor board is nested within a recess of the resin-molded portion, which itself is positioned adjacent to the stator. This nested arrangement allows the stator to be placed as close as possible to the sensor board for compactness, while the recess provides a protective buffer zone that shields the sensor board from direct contact with the stator and other components.
Data Source
AI summary
An electric work machine includes a resin-molded portion that is designed appropriately. An electric work machine includes a brushless motor, a sensor board, a resin-molded portion, and an output unit. The brushless motor includes a stator and a rotor rotatable relative to the stator. The sensor board faces the rotor and the stator in an axial direction along a rotation axis of the rotor and includes a sensor on an opposing surface of the sensor board opposing the rotor and the stator. The sensor detects a position of the rotor in a rotation direction. The resin-molded portion covers the opposing surface of the sensor board and has a recess at a position corresponding to the stator. The output unit is directly or indirectly drivable by the rotor.