Pneumatic Actuator Magnet Guide for Sensor Alignment and Lower Cost
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Solution Overview
Problem
Existing pneumatic actuators for automatic transmission systems in commercial vehicles are costly due to the use of large, expensive magnets, and they require precise angular orientation during assembly, which increases complexity and potential for errors.
Innovation Solution
A pneumatic actuator design where the magnet is fixed axially to the piston head and partially rotatable about the central axis, utilizing a magnet guide with primary and secondary guide elements to ensure alignment with the magnetic position sensor, allowing for flexible piston orientation and reduced magnet size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If large magnets are used to allow partial rotation of the piston while ensuring close proximity to the magnetic position sensor, then the adaptability and ease of operation are improved, but the cost increases due to expensive rare metals and/or rare earths
Solution Approach 1:
The magnet is divided into two independent functional aspects: axial positioning (fixed to piston head) and angular orientation (rotatable via magnet guide). This segmentation allows the magnet to be smaller while still providing the necessary flexibility through the guide mechanism rather than requiring a large magnet to cover all orientations simultaneously.
Solution Approach 2:
The magnet guide acts as an intermediary mechanism between the magnet and the piston head, enabling rotational alignment without requiring the magnet itself to be large. The guide elements (guide groove and guide projection) mediate the rotational movement, allowing the magnet to achieve proper orientation with a smaller size.
2Measurement precision
If the magnet and piston are exactly positioned relative to the magnetic position sensor, then the measurement precision and reliability are improved, but the device complexity and assembly difficulty increase
Solution Approach 1:
The magnet guide elements (guide groove and guide projection) enable the magnet to self-align with the magnetic position sensor during assembly. The geometric constraint of the guide automatically positions the magnet at the correct angular orientation without requiring external alignment tools or complex adjustment procedures, reducing assembly complexity while maintaining precision.
Solution Approach 2:
The mechanical guide elements replace complex alignment mechanisms or precision machining requirements. Instead of relying on precise mechanical positioning through complex fixtures or multiple adjustment steps, the guide groove and projection provide a simple mechanical constraint that automatically achieves the required angular alignment.
3Ease of manufacture
If the magnet is fixed axially and partially rotatable about the central axis, then the ease of manufacture and adaptability are improved, but the device complexity increases due to the magnet guide mechanism
Solution Approach 1:
The magnet guide mechanism is implemented locally at the magnet-piston interface rather than as a system-wide complex mechanism. The guide groove in the piston head and guide projection on the magnet create a localized constraint that provides rotational alignment only where needed, minimizing overall device complexity while achieving the desired functionality.
Solution Approach 2:
The magnet guide enables dynamic rotational adjustment of the magnet relative to the piston head during assembly and operation. The guide groove allows the magnet to rotate freely within a limited angular range while maintaining axial positioning, providing the necessary adaptability without requiring a fully complex mechanical linkage system.
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 design reduces the overall cost of the pneumatic actuator by using smaller, less expensive magnets, simplifies the assembly process by allowing for multiple angular orientations of the piston, and enhances the reliability and accuracy of position sensing.
Implementation Method 1
a magnetic position sensor for detecting a relative position of the pneumatic piston to the pneumatic cylinder; and a magnet cooperating with the magnetic position sensor
Data Source
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AI summary
The invention relates to a pneumatic actuator (1) including a pneumatic cylinder (4) comprising a pneumatic chamber (10) having a central axis (A), a pneumatic piston (6) slidably received in the pneumatic chamber (10), a magnetic position sensor (56) for detecting a relative position of the pneumatic piston (6) to the pneumatic cylinder (4); and a magnet (58) cooperating with the magnetic position sensor (56). The magnet (58) is relatively fixed to the piston head (16) at least in an axial direction (R4) along the central axis (A) and at least partially rotatable relative to the piston head (16) about the central axis (A), wherein the pneumatic actuator (1) further comprises a magnet guide (64) for rotationally aligning the magnet with the magnetic position sensor (56). The invention further relates to an assembly method (100) for a pneumatic actuator (1), a gearbox (200) and a commercial vehicle (300).