Integrated Rotor-Screw Actuator for Linear Motion Conversion
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Solution Overview
Problem
Existing actuators face challenges in efficiently converting rotational motion to linear motion while minimizing complexity and magnetic interference, and require multiple motors and components, leading to increased size, cost, and reduced accuracy.
Innovation Solution
The actuator design includes a stator with a magnetizing coil and core, a first rotor, a screw shaft with a threaded surface, a nut for linear motion, and a second rotor, allowing for independent rotation and preload mechanisms to stabilize the system, reducing the need for multiple motors and components, and minimizing magnetic interference through a circular back yoke with slits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a ball screw mechanism is used to convert rotational motion to linear motion, then linear motion output is achieved, but an additional electric motor is required increasing device complexity
Solution Approach 1:
The patent combines the rotational-to-linear motion conversion function with the motor function by integrating a screw shaft directly into the rotor structure. The rotor itself becomes the driving element that converts electromagnetic rotational force into linear motion through the screw mechanism, eliminating the need for a separate motor and reducing overall system complexity.
Solution Approach 2:
The rotor is designed to serve multiple functions: it generates rotational force through electromagnetic interaction and simultaneously acts as a screw shaft for linear motion conversion. This multi-functional design allows a single component to perform what previously required separate components, reducing the number of motors needed.
2Ease of manufacture
If outer teeth and inner teeth are both provided on the same back yoke, then manufacturing is simplified, but magnetic interference occurs reducing rotational accuracy
Solution Approach 1:
The patent divides the back yoke into two separate structures: an inner back yoke for the inner teeth and an outer back yoke for the outer teeth. This segmentation prevents magnetic interference between the two sets of teeth by providing separate magnetic paths, thereby maintaining rotational accuracy while still allowing both tooth structures to be manufactured efficiently.
Solution Approach 2:
The patent introduces a magnetic shield or flux barrier between the inner and outer teeth to prevent magnetic interference. This intermediary element acts as a mediator that allows both tooth structures to coexist on the same back yoke without compromising rotational accuracy, as the shield directs and separates the magnetic flux paths.
3Ease of operation
If a hydraulic piston is used for rotational and linear operation, then smooth motion along a given path is achieved, but the structure becomes complex and difficult to disassemble
Solution Approach 1:
The patent replaces the hydraulic piston mechanism with a direct electromagnetic-driven screw mechanism. The rotor itself drives the screw shaft, eliminating the need for complex hydraulic systems while maintaining smooth rotational and linear motion through the inherent mechanics of the screw drive.
Solution Approach 2:
The rotor serves its own dual purpose by simultaneously generating rotational force and driving the linear motion through the integrated screw shaft. This self-service design eliminates the need for separate hydraulic pistons and complex transmission mechanisms, simplifying the overall structure while maintaining operational smoothness.
4Productivity
If multiple components are used for rotational-to-linear motion conversion, then motion conversion is achieved, but component count increases leading to increased size and cost
Solution Approach 1:
The patent merges the motor rotor and screw shaft into a single integrated structure. The rotor core directly forms the screw shaft, combining what were previously separate components into one unified element. This reduces the component count while maintaining effective rotational-to-linear motion conversion.
Solution Approach 2:
The integrated rotor-screw structure performs multiple functions simultaneously: it generates electromagnetic force, converts rotational motion to linear motion, and provides the mechanical drive. This multi-functional design eliminates the need for separate motors, gearboxes, and lead screws, reducing both component count and overall system size.
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 enables efficient conversion of rotational to linear motion, improves rotational accuracy, reduces component count and size, and lowers costs by eliminating the need for separate motors and components, while maintaining high reliability and accuracy.
Implementation Method 1
a stator including a magnetizing coil and a stator core; a first rotor that is positioned radially internal to the stator and is rotated relatively to the stator
Implementation Method 2
a screw shaft that is a rod-like member positioned at rotational center of the first rotor, at least a part of a surface of the screw shaft having a thread; a nut that is screwed onto the thread of the screw shaft and rotates with the first rotor to move the screw shaft in a linear motion direction
Data Source
AI summary
An actuator, a stator, a motor, a rotational-to-linear motion conversion mechanism, and a linear actuator are provided. The motor, the actuator, and the linear actuator at least include a screw shaft and a nut. The screw shaft is a rod-like member, and at least a part of the surface of the screw shaft has a thread. The nut is screwed onto the thread on the screw shaft, and moves the screw shaft in a linear motion direction that is a direction in parallel with a rotational center. The stator, the motor, the actuator, and the linear actuator can at least convert a rotational motion into a linear motion.