Impulse Ring Centering for Accurate Bearing Rotor Position Sensing
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Solution Overview
Problem
Magnetic sensors used in motor control, such as belt starter generators, face inaccuracies in sensor output due to misalignment of components in the bearing unit, leading to a non-perfect alignment of the impulse ring with detection means, which affects the accuracy of rotor position measurement.
Innovation Solution
A method for centering the magnetic center of the impulse ring on the center of rotation of the bearing unit involves using a first and second ring capable of rotating concentrically, with a target and fixing sleeve configuration, recording an angular signal, determining a total pitch deviation vector, shifting the impulse ring radially based on this vector, and securing it relative to the first ring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manufacturing accuracy of bearing unit components is improved to reduce misalignment, then sensor output accuracy is improved, but manufacturing cycle time increases and production costs increase
Solution Approach 1:
The patent applies preliminary action by measuring the angular signal and determining pitch deviation vectors before final assembly, then using shims to pre-compensate for misalignment. This allows the impulse ring to be pre-adjusted to the correct position relative to detection means, achieving accurate sensor output without requiring high-precision manufacturing of all components.
Solution Approach 2:
The patent changes the parameter of radial positioning by introducing variable thickness shims between the impulse ring and bearing component. By adjusting the shim thickness, the radial position of the impulse ring is modified to compensate for manufacturing tolerances, thereby aligning the magnetic center with the detection means without improving manufacturing precision.
2Measurement precision
If manufacturing accuracy of bearing unit components is improved to reduce misalignment, then sensor output accuracy is improved, but production costs increase
Solution Approach 1:
The patent changes the parameter of radial positioning by introducing variable thickness shims between the impulse ring and bearing component. By adjusting the shim thickness, the radial position of the impulse ring is modified to compensate for manufacturing tolerances, thereby aligning the magnetic center with the detection means without improving manufacturing precision.
Solution Approach 2:
The patent uses shims as an intermediary element between the impulse ring and the bearing component. These shims act as a mediator that absorbs manufacturing tolerances and enables positional adjustment, avoiding the need for expensive high-precision manufacturing while still achieving accurate alignment.
3Ease of operation
If the impulse ring is rigidly fixed without adjustment capability, then assembly is simplified, but misalignment cannot be compensated and sensor accuracy deteriorates
Solution Approach 1:
The patent applies dynamics by making the impulse ring position adjustable during assembly through the use of shims. The impulse ring can be positioned at different radial locations by changing shim thickness, allowing optimization of alignment between the magnetic center and detection means while maintaining simple assembly procedures.
Solution Approach 2:
The patent changes the parameter of radial positioning by introducing variable thickness shims between the impulse ring and bearing component. By adjusting the shim thickness, the radial position of the impulse ring is modified to compensate for manufacturing tolerances, thereby aligning the magnetic center with the detection means.
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 method effectively reduces misalignment without improving manufacturing accuracy, enhancing the precision of rotor position detection and improving sensor output accuracy by ensuring the magnetic center aligns with the mechanical center, thereby improving the control of machine torque and reducing noise in sensor signals.
Implementation Method 1
a rotor formed out of an impulse ring fitted with magnetic poles and a stator fitted with detection means, able to detect the magnetic field of each magnetic pole
Implementation Method 2
When rotation is applied to the rotor, the magnetic poles pass successively in front of the detections means. A current is induced within the detections means based on its distance to the magnetic poles.
Data Source
AI summary
A method for centering an impulse ring of a bearing unit on the center of rotation of the bearing unit including a first ring and a second ring. The impulse ring provided with a target having pairs of magnetic poles, and with a fixing sleeve. The method provides a) inserting the impulse ring between the first ring and the fixing sleeve, the first ring and the fixing sleeve being configured to maintain the impulse ring in an axial direction of the bearing; b) recording an angular signal over one mechanical turn of the impulse ring, the angular signal being generated by detection configured to cooperate with the pairs of magnetic poles; c) determining a total pitch deviation vector of the impulse ring based on the angular signal; d) shifting the impulse ring in a radial direction of the bearing, and e) securing the impulse ring relative to the first ring.