Vehicle Motor Detector Radial Nesting for Axial Miniaturization
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Solution Overview
Problem
Conventional vehicle motors face challenges in miniaturization due to the axial extension of components like the resolver rotor, stator, and bearing, making it difficult to reduce the motor's size while maintaining high output capability.
Innovation Solution
The motor design includes a detector positioned between the stator coil end and the bearing, overlapping radially with the stator coil end and bearing, and uses a cage rotor with an end ring, allowing for reduced axial length and eliminating the need for a noise shield, along with a retainer plate to minimize electromagnetic noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the resolver rotor, stator, and bearing are disposed extended in the axial direction, then the motor can accommodate all necessary components, but the motor size in the axial direction cannot be reduced
Solution Approach 1:
The patent transitions from a conventional axial arrangement of components to a radial arrangement. The detector is positioned radially between the stator coil end and the bearing, utilizing the radial dimension instead of extending axially. This dimensional change allows the motor to achieve compact axial length while accommodating all necessary components.
Solution Approach 2:
The detector is nested within the radial space between the stator coil end and the bearing, effectively utilizing the existing radial dimension. This nesting approach allows the detector to be integrated without requiring additional axial space, thereby reducing the overall motor size while maintaining functional integrity.
2Reliability
If a noise shield is added to protect the detector, then electromagnetic noise interference is reduced, but the number of components and cost increase
Solution Approach 1:
The patent introduces a retainer plate as an intermediary component that serves multiple functions: it holds the detector in position and simultaneously acts as a magnetic shield to block electromagnetic noise from reaching the detector. This intermediary structure provides noise protection without requiring a separate noise shield, thereby reducing component count while maintaining detection accuracy.
3Volume of moving object
If the detector is positioned to overlap radially with the stator coil end and bearing, then the motor can be shrunk in size, but the detector must be precisely positioned to avoid interference
Solution Approach 1:
The retainer plate serves as a precise positioning intermediary that accurately locates the detector radially between the stator coil end and the bearing. This intermediary structure provides mechanical guidance and stable positioning, reducing the need for high-precision direct installation while enabling the compact radial arrangement that shrinks motor size.
Solution Approach 2:
The patent utilizes magnetic field distribution changes (analogous to color changes in optical detection) to detect the rotational speed of the rotor. The detector leverages the magnetic field variations generated by the rotating rotor to determine speed, enabling precise measurement without requiring complex positioning mechanisms.
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 enables the motor to be shrunk in size, reduces component count and material costs, and enhances controllability by minimizing detection errors and electromagnetic noise interference.
Implementation Method 1
a detector that detects a rotational speed of the rotor
Data Source
AI summary
A motor mounted on a vehicle includes a housing; a shaft rotatably supported by the housing via a bearing; a rotor fixed to the shaft; a stator; and a detector that detects a rotational speed of the rotor. The stator includes: a stator core disposed at an outer circumferential side of the rotor to face the rotor in the radial direction along which the rotor and the stator are arranged to be adjacent each other; and a stator coil being wound around the stator core, the stator coil having a stator coil end formed at one end side of the stator coil in the axial direction. The detector is disposed between the stator coil end and the bearing that supports both ends of the shaft, and at least a part of detector is disposed to be overlapped in the radial direction with the stator coil end and the bearing.