Belt-Driven Linear Actuator for Compact Motion Simulator Platforms
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Solution Overview
Problem
Existing linear actuators used in motion simulators face limitations in producing low to medium amplitude outputs at low or medium frequencies while supporting platform weight, and are often elongated, restricting seat or platform design, and are costly due to high-precision ball screw technology.
Innovation Solution
A linear actuator design featuring a base, output, and tensioning member routed through idlers to convert winding/unwinding into translation, with idlers on both the base and output, and a sensor to monitor tension, allowing for efficient displacement of platforms relative to the ground.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high-precision ball screw technology is used, then manufacturing precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces the traditional ball screw mechanical transmission system with a direct-drive motor system. The motor shaft is directly coupled to the positioning mechanism, eliminating the ball screw component entirely. This substitution maintains positioning precision while significantly reducing device complexity and cost, as the direct-drive system has fewer moving parts and no mechanical transmission elements.
2Length of moving object
If elongated linear actuators are used, then stroke length is improved, but adaptability to different seat or platform designs deteriorates
Solution Approach 1:
The patent divides the actuator system into modular components: a compact motor unit, a transmission mechanism, and a positioning platform. The transmission mechanism uses a belt-driven system with pulleys that can be configured in different arrangements, allowing the same basic actuator design to achieve various effective stroke lengths while maintaining a compact form factor. This modularity enables adaptation to different seat or platform designs without requiring elongated actuator bodies.
Solution Approach 2:
The patent employs a belt-driven transmission system where the belt wraps around pulleys in a multi-dimensional path. This allows the actuator to achieve extended effective stroke length through the spatial arrangement of the belt path rather than through a proportionally longer actuator body. The belt can wrap around pulleys multiple times or follow complex paths, effectively multiplying the displacement output from a compact motor unit, thereby maintaining compactness while providing long stroke capability for various platform designs.
3Measurement precision
If electro-mechanical linear actuators with ball screw technology are used, then positioning precision is improved, but noise generation increases
Solution Approach 1:
The patent eliminates the ball screw mechanism and replaces it with a direct-drive motor system using belt-driven transmission. The direct-drive configuration removes the mechanical contact and friction between ball screws and nut components that generate noise during operation. The belt-driven system operates with minimal mechanical contact noise, providing smooth and quiet positioning while maintaining precision through the motor's controlled rotation and the belt's tensioned transmission path.
4Adaptability or versatility
If compact actuator design is used, then adaptability to platform designs is improved, but load capacity deteriorates
Solution Approach 1:
The patent employs a belt-driven transmission system where the belt tension and pulley configuration can be dynamically adjusted to optimize load capacity. The tensioned belt acts as a flexible structural element that can transmit high forces from the motor to the positioning platform. By adjusting belt tension, pulley diameters, and wrap angles, the system can be tuned to handle various load requirements while maintaining a compact actuator form factor that adapts to different platform designs.
Solution Approach 2:
The patent utilizes high-strength materials for the belt and pulley components to achieve high load capacity in a compact design. The belt is constructed from reinforced materials that provide both flexibility for compact routing and high tensile strength for load bearing. The pulleys are made from materials with high surface hardness and wear resistance to handle the contact stresses. This composite material approach allows the compact actuator to withstand high loads that would typically require larger, more robust mechanical transmission systems.
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 solution enables efficient, low-profile, and cost-effective displacement of motion platforms with high bandwidth (0-100 Hz) and high load capacity, supporting various platform designs without the need for complex gear reduction, while maintaining precision and reducing noise.
Implementation Method 1
a tensioning member having a first end connected to the rotational output of the actuator unit, and at least one idler rotatably mounted on at least one of the output and the base, wherein a second end of the tensioning member is connected to an anchor point on one of the output and the base, the tensioning member being routed from the rotational output, through the at least one idler and to the anchor point for converting a winding/unwinding of the tensioning member into a translation of the output
Data Source
AI summary
A linear actuator is configured to be connected between a platform and a structure or ground for displacement of the platform relative to the structure or the ground. The actuator comprises a base, and an output displaceable linearly relative to the base. A first plurality of idlers are on the base, and a second plurality of idlers are on the output. An actuator unit has a reciprocating rotational output. A tensioning member has a first end connected to the rotational output of the actuator unit, and a second end connected to an anchor point on one of the output and the base, the tensioning member being routed from the rotational output, through the first plurality of idlers and the second plurality of idlers and to the anchor point for converting a winding/unwinding of the tensioning member into a translation of the output.