Electric Motor Angle Sensor Mounting via Floating Bearing
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Solution Overview
Problem
Existing electric motors with integrated angle sensors face challenges in achieving a compact and cost-effective design while maintaining precise angle determination and accommodating thermal and axial displacements, often requiring specialized housings and complex alignments.
Innovation Solution
The electric motor incorporates a displaceable bearing system with a transmitter stator and rotor connected to the shaft, where the encoder stator is directly or indirectly connected to the bearing, allowing for a constant distance between the encoder rotor and stator, and utilizing a form-fitting connection to ensure precise angle measurement without additional housing needs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an angle sensor is connected to the rotor shaft by means of an expanded shaft connection, then the angle sensor can detect the angular position, but the device complexity increases and the motor becomes less compact
Solution Approach 1:
The patent combines the angle sensor mounting function with the floating bearing structure. The encoder stator is directly connected to the bearing outer ring, eliminating the need for separate shaft expansion connections. This merging of functions reduces device complexity while maintaining angle detection precision.
Solution Approach 2:
The floating bearing serves multiple functions: it supports the rotor shaft mechanically and simultaneously provides the mounting structure for the angle sensor. The bearing outer ring acts as both a mechanical support element and a sensor mounting base, reducing the need for additional components.
2Measurement precision
If a fixed housing is used for the angle sensor, then the sensor position is stable, but the motor cannot accommodate thermal and axial displacements
Solution Approach 1:
The patent employs a floating bearing design that allows dynamic adjustment of the bearing outer ring position in the axial direction. This dynamic capability enables the system to accommodate thermal expansions and contractions while the encoder stator remains securely mounted on the bearing outer ring, maintaining relative position stability for accurate angle measurement.
3Manufacturing precision
If the bearing outer ring is machined to provide form-fitting connection, then the connection is precise, but the bearing cannot be easily replaced and standard bearings cannot be used
Solution Approach 1:
The patent introduces an adapter ring as a separate component that provides the form-fitting connection to the housing. The bearing outer ring itself remains unmodified and can be a standard bearing. The adapter ring acts as an intermediary that achieves precise positioning without requiring machining of the bearing, enabling easy bearing replacement while maintaining connection precision.
4Measurement precision
If the encoder stator is connected to the housing part, then the sensor is stable, but additional housing structure is required increasing device complexity
Solution Approach 1:
The bearing outer ring serves dual purposes: it provides mechanical support for the rotor shaft through the floating bearing function and simultaneously serves as the mounting structure for the encoder stator. This eliminates the need for separate housing structures for sensor mounting, reducing device complexity while ensuring sensor stability.
Data Source
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AI summary
The invention relates to a system or electric motor having an angle sensor for detecting the angular position of a shaft, said angle sensor including a transducer stator and a transducer rotor connected to the shaft, said shaft being supported displaceably in a housing part by means of at least one bearing disposed in an axially displaceable fashion relative to the housing part, wherein the transducer stator is directly or indirectly connected to the bearing.