Electric Motor Axial Sensor Module for Radial Space Reduction
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Solution Overview
Problem
Existing electric motors with angle detection systems require significant radial installation space, making them bulky and prone to damage during transport or collision, and the relative position of pulse generators can only be determined through the fan cover, leading to errors and increased costs.
Innovation Solution
A compact electric motor design featuring a fan wheel connected to a rotor shaft with a signal disk that interacts with sensors on the fan cover, where the sensors are integrated into a detachable module on the fan cover, reducing protrusion and eliminating radial errors, and allowing for various angular resolutions with interchangeable signal disks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If sensors are arranged on the circumference with protruding pulse generators, then angular position detection is achieved, but radial installation space increases and damage risk occurs during transport or collision
Solution Approach 1:
The patent moves the sensors from a radial arrangement on the circumference to an axial arrangement behind the signal disk. This dimensional change from radial to axial placement eliminates the need for protruding pulse generators and reduces radial installation space while maintaining angular position detection capability through the signal disk's interaction with axially positioned sensors
2Measurement precision
If sensors are arranged on the circumference, then angular position detection is achieved, but the system becomes prone to damage during transport or collision
Solution Approach 1:
By repositioning sensors from a radial circumference arrangement to an axial position behind the signal disk, the invention protects sensors from radial collisions and transport damage while maintaining detection functionality through the signal disk's axial interaction with the sensor array
Solution Approach 2:
The invention integrates the sensors directly into the fan cover structure, merging the sensor housing with the existing fan cover component. This integration eliminates separate protective housings and reduces the number of parts while maintaining sensor protection and structural integrity
3Ease of manufacture
If the relative position of pulse generators is determined via the fan cover, then assembly is simplified, but measurement errors increase
Solution Approach 1:
The invention uses a signal disk with radial slots that creates a precise geometric copy of angular position information. The signal disk's slot pattern serves as a reference that the sensors read to determine angular position, eliminating the need for mechanical determination through the fan cover and providing higher measurement precision through optical or electromagnetic detection of the slot pattern
4Weight of moving object
If a metallic signal disk is used, then the moment of inertia is reduced, but manufacturing complexity increases
Solution Approach 1:
The invention changes the material parameter of the signal disk from traditional non-metastic materials to metallic materials, thereby reducing the moment of inertia and improving dynamic response. The metallic signal disk can be manufactured using conventional metal forming processes such as stamping or machining, making the manufacturing complexity manageable despite the material change
Data Source
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AI summary
The invention relates to an electric motor comprising a fan with a fan wheel that is at least partially surround by a fan cover. The fan wheel, at its one axial end area, is connected to a signal disc that interacts with sensors of a module provided on the fan cover. The sensors are axially placed behind the signal disc.