Shaft Angular Position Detection Using Integrated PCB and Pole Disk
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Solution Overview
Problem
Existing electric motor designs face challenges in determining the angular position of a shaft compactly and efficiently, with a need for improved angular resolution and reduced additional components, while also requiring effective transmission of multiple sensor values to a control unit.
Innovation Solution
The solution involves a compact design where a shaft is mounted in a housing part with a non-rotatably connected fan wheel, a circuit board aligned parallel to the shaft axis, and magnetized pole disks on the fan wheel detected by sensors on the circuit board, allowing for high angular resolution and transmission of angle, revolution, and acceleration values via a single digital interface, with a Ferraris sensor for rotational acceleration and energy storage for mains-independent operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an angle sensor is arranged on the B side of the rotor shaft via a coupling, then the angular position can be detected, but the device complexity and space requirements increase
Solution Approach 1:
The patent combines multiple sensor functions (angle detection, number of revolutions detection, rotational acceleration detection) onto a single printed circuit board that is integrated into the motor housing. This eliminates the need for separate sensors and couplings on the B side, reducing device complexity while maintaining detection precision through the magnetized pole disk and Hall effect sensors
2Measurement precision
If multiple sensors are used for angle, number of revolutions, and rotational acceleration detection, then measurement precision improves, but the quantity of components and device complexity increase
Solution Approach 1:
The printed circuit board serves multiple functions: it detects angular position through Hall effect sensors, counts revolutions through a revolution counter, and measures rotational acceleration through a Ferraris sensor. The magnetized pole disk provides reference signals for all three measurement types, allowing a single component assembly to perform what would traditionally require multiple separate sensors and processing units
Solution Approach 2:
The patent merges three separate detection systems into one integrated printed circuit board assembly. The angle sensor, revolution counter, and rotational acceleration sensor all share the same mounting location and reference the same magnetized pole disk, reducing the total quantity of components while maintaining high measurement precision for all parameters
3Measurement precision
If multiple sensor values are transmitted to the control unit, then control accuracy improves, but the data transmission complexity and communication interface requirements increase
Solution Approach 1:
The patent combines multiple data transmission functions into a single digital communication interface. The printed circuit board transmits angle values, number of revolutions, and rotational acceleration values simultaneously through one interface to the control unit or converter, eliminating the need for multiple separate communication channels and reducing interface complexity while maintaining high control accuracy
4Volume of moving object
If the printed circuit board is aligned parallel to the shaft axis, then the device becomes more compact, but the sensor arrangement becomes more challenging
Solution Approach 1:
The patent orients the printed circuit board parallel to the shaft axis rather than perpendicular to it, utilizing the axial dimension for sensor placement. The Hall effect sensors are positioned to detect the magnetized pole disk as it rotates past, with the circuit board extending axially along the motor housing. This dimensional reorientation achieves compactness while the radial magnetic field from the pole disk simplifies sensor alignment
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 approach enables a compact, high-resolution angular position determination with minimal additional parts, improved control behavior, and efficient data transmission, supporting precise motor control and reliability through the integration of sensors and evaluation electronics on a single printed circuit board.
Implementation Method 1
magnetized areas, in particular a pole disk, being provided on the side of the fan wheel arranged towards the printed circuit board, which can be detected by sensors arranged on the printed circuit board
Implementation Method 2
a rotational acceleration sensor, in particular a Ferraris sensor, is connected to the printed circuit board, which comprises an electrically conductive ring which is non-rotatably connected to the fan wheel
Data Source
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AI summary
Arrangement for determining the angular position of a shaft which is mounted in a housing part with at least one bearing, wherein an impeller wheel is connected in a rotationally fixed fashion to the shaft, wherein a printed circuit board is attached to the housing part, in particular wherein the normal direction of the printed circuit board is oriented parallel to the shaft axis, wherein magnetized regions, in particular a pole disc are provided on the side of the impeller wheel arranged towards the printed circuit board and can be detected by sensors arranged on the printed circuit board, wherein the magnetized regions form three concentric tracks and each track is assigned at least one sensor on the printed circuit board, wherein the axially embodied magnetization direction is embodied in an alternating fashion in the circumferential direction in each track, in particular that is to say a north pole region which is magnetized in the axial direction is followed by a south pole region.