Electromechanical Actuator Structure for High Load and Dust Sealing
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Solution Overview
Problem
Existing electromechanical actuators face limitations in withstanding high loads and harsh conditions, such as buckling and reduced lifespan due to dust ingress, with complex designs that are costly and difficult to maintain.
Innovation Solution
A design featuring a spindle, planetary roller nut, irreversibility system, and sealed bearings within a cylindrical tube, utilizing C-shaped springs and load-distributing pads to enhance rigidity, reduce buckling, and minimize dust ingress, with servo motors for torque distribution and easy maintenance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If four rods are arranged circumferentially with a single locking element, then the device can withstand heavy loads, but the structure allows dust and particles to enter through openings, reducing bearing life
Solution Approach 1:
The locking element is divided into multiple separate locking elements, each with its own sealing capability. This segmentation allows each locking element to independently seal against dust and particles while maintaining the load-bearing structure, thus resolving the contradiction between load capacity and bearing protection
Solution Approach 2:
Sealing elements are introduced as intermediary components between the locking elements and the external environment. These sealing elements act as mediators that prevent dust and particles from entering the bearing areas while allowing the locking elements to maintain their load-bearing function
2Force
If angular ball bearings are arranged in line and connected back to back, then the device can handle axial loads, but the bearing life is limited and load capacity is reduced
Solution Approach 1:
The bearing arrangement is changed from angular ball bearings connected back to back to a different configuration that improves both load handling and lifespan. This parameter change in the bearing type and arrangement allows for extended bearing life while maintaining or improving axial load capacity
3Length of moving object
If rods are arranged circumferentially with increased buckling length, then the device can accommodate larger movements, but the maximum loads withstood are reduced
Solution Approach 1:
The rod structure utilizes composite construction or optimized material properties to achieve high strength-to-weight ratio. This allows the rods to maintain high load-bearing capacity despite increased length, enabling larger stroke while withstanding maximum loads
4Reliability
If a helical spring is used for irreversibility system, then the system can prevent reverse movement, but the volume is large and installation is complex
Solution Approach 1:
The helical spring is extracted and replaced with a more compact irreversibility mechanism. This extraction of the problematic component and its replacement with a simpler alternative reduces both volume and installation complexity while maintaining the irreversibility function
Solution Approach 2:
The irreversibility system uses simple, easily replaceable components rather than complex spring mechanisms. This approach allows for simpler installation and maintenance, reducing overall device complexity while achieving the same functional result
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
The actuator achieves high load capacity and extended lifespan with reduced costs and maintenance, while maintaining structural integrity and efficiency in harsh environments.
Implementation Method 1
a planetary roller nut, an irreversibility system, one or more servo motors coupled directly to the spindle or through a mechanical transmission
Implementation Method 2
utilizing C-shaped springs and load-distributing pads to enhance rigidity, reduce buckling, and minimize dust ingress
Implementation Method 3
sealed bearings within a cylindrical tube
Implementation Method 4
sealed bearings within a cylindrical tube
Implementation Method 5
utilizing C-shaped springs and load-distributing pads to enhance rigidity, reduce buckling
Data Source
AI summary
A device formed by a spindle is connected to a nut and to one or more servo motors where the transmitted torque will be the sum of the separate torques of the servo motors. The device has a set of two or more rods arranged around the spindle. The spindle is supported in two bearing housings that restrict axial movement in both directions, including an anti-reverse system that only allows a drive shaft to rotate, all inside an inner sleeve. An outer sleeve moves along the outside of the inner sleeve under a fixed metal structure for securing to a machine, keeping all particle entry units closed. Four screwed elements allow the spindle to be put into a parked position to facilitating replacement of wear units.