Electric Actuator Control Board Layout for Stable Rotor Sensing
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Solution Overview
Problem
Existing electric actuators face challenges in stabilizing rotor rotation, placing control board components close to the rotor, and controlling size and cost, due to deviations in rotor and stator lengths and complex structures.
Innovation Solution
The electric actuator design separates the control board into a main board and a smaller board with electric components, such as a magnetic sensor, positioned closer to the rotor, allowing precise detection and stable rotation while maintaining a compact size by using a connecting member and screws for alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the rotor is made longer than the stator in the rotation axis direction to bring the rotor close to the control board, then some electrical components mounted on the control board can be brought close to the rotor, but a deviation occurs between the center position of the rotor and the center position of the stator in the rotation axis direction, causing increased rotational inertia and vibration (backlash) that may reduce the durability of the electric motor
Solution Approach 1:
The control board is divided into a main board and a sub-board, with the sub-board positioned closer to the rotor. This segmentation allows electrical components on the sub-board to be near the rotor for compact design while the main board remains at a safe distance from the stator, avoiding the need to extend the rotor length and preventing center position deviation between rotor and stator.
2Reliability
If the length of the rotor in the rotation axis direction is extended to bring the rotor close to the control board, then some electrical components can be placed close to the rotor, but the electric actuator becomes larger and more expensive
Solution Approach 1:
Instead of extending the rotor length in the rotation axis direction, the solution positions the sub-board closer to the rotor by utilizing the radial dimension and arranging the control board components in a multi-dimensional layout. This allows electrical components to be placed close to the rotor without increasing the actuator's overall size in the rotation axis direction.
3Reliability
If a portion of the resin part is extended in the direction approaching the magnetic sensor and the sensor magnet is attached to this extending part, then the sensor magnet and magnetic sensor can be placed close to each other, but the structure becomes more complicated and manufacturing becomes cumbersome
Solution Approach 1:
The control board is segmented into a main board and a sub-board, with the sub-board positioned closer to the rotor to accommodate the magnetic sensor. This segmentation allows the sensor magnet and magnetic sensor to be placed close to each other on the sub-board without requiring complex extensions of the resin part, thereby simplifying the overall structure and manufacturing process.
4Reliability
If a portion of the resin part is extended in the direction approaching the magnetic sensor and the sensor magnet is attached to this extending part, then the sensor magnet and magnetic sensor can be placed close to each other, but the electric actuator becomes larger and more expensive
Solution Approach 1:
The magnetic sensor is placed close to the sensor magnet by utilizing the radial dimension and positioning the sub-board closer to the rotor, rather than extending the resin part in the axial direction. This dimensional approach allows close placement of the sensor components without increasing the overall size of the electric actuator.
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 stable rotor rotation, precise component placement, and cost-effective manufacturing by reducing the actuator's size and complexity, while maintaining efficient space usage and durability.
Implementation Method 1
a magnetic sensor (Hall IC) for detecting the position and rotational state of the rotor
Data Source
AI summary
The electric actuator comprises an electric brushless motor having a rotor and a stator, and the control board has a plurality of electric components and controls operation of the brushless motor. The control board comprises a main board and a small board that has a smaller planar shape than the main board and that is connected to the main board via a connecting member. The small board has one or more electric components, faces the rotor, and is arranged at a position closer to the rotor than is the main board in the rotation axis direction of the rotor.