Parallel Link Hub Gear Layout for Compact Wide-Range Posture Control
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Solution Overview
Problem
Existing link actuating devices for medical and industrial equipment face challenges in achieving high-speed, high-accuracy operation over a wide range while maintaining a compact size, as they often result in large dimensions and limited weight capacity due to the configuration of parallel link mechanisms and the placement of motors and speed reduction mechanisms.
Innovation Solution
A link actuating device with a proximal and distal end side link hub connected via three or more quadric chain link mechanisms, incorporating a bent proximal side end link member with a rotation shaft mounting portion and a gear mechanism that allows for posture control actuation, enabling compact size and wide operating range without limiting the operating range, and includes a speed reduction mechanism integrated within the gear mechanism to reduce the size of the device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the parallel link mechanism is configured with motors and speed reduction mechanisms disposed radially outward, then the posture control capability is improved, but the radial size of the device becomes large
Solution Approach 1:
The patent merges the motor, speed reduction mechanism, and link mechanism into a single integrated structure. The motor is disposed inside the link mechanism, and the speed reduction mechanism is integrated with the link mechanism, eliminating the need for separate radial components. This combining of functions into one compact unit achieves posture control capability while maintaining a small radial size.
Solution Approach 2:
The patent implements a nested configuration where the motor is disposed inside the link mechanism, and the speed reduction mechanism is integrated within the same space. This nesting arrangement allows multiple functional components to occupy the same spatial envelope, achieving comprehensive posture control without increasing the radial dimensions of the device.
2Measurement precision
If the speed reduction mechanism or motor is added to control posture, then the posture control accuracy is improved, but the operating range is limited due to interference
Solution Approach 1:
By merging the motor and speed reduction mechanism with the link mechanism into a single integrated unit, the patent eliminates spatial interference between components. The integrated design allows the mechanism to operate freely throughout its full range of motion while maintaining precise posture control through the speed reduction mechanism.
Solution Approach 2:
The patent changes the spatial arrangement by disposing the motor inside the link mechanism rather than radially outward. This dimensional reorganization eliminates interference with the operating range while preserving posture control accuracy through the integrated speed reduction mechanism.
3Device complexity
If the parallel link mechanism uses simple configuration, then the device complexity is reduced, but the operating angle of each link becomes small
Solution Approach 1:
The patent combines the motor directly with the link mechanism in an integrated configuration, which maintains relative simplicity while enabling larger operating angles. The integration allows the link to rotate through a wider range without requiring complex additional mechanisms.
4Adaptability or versatility
If the link length is increased to achieve large operating range, then the operating range is improved, but the dimensions of the entire mechanism become large
Solution Approach 1:
The patent achieves a compact mechanism with large operating range by changing the spatial arrangement. The motor is disposed inside the link mechanism rather than radially outward, and the speed reduction mechanism is integrated, creating a compact radial profile while maintaining full operating range through the integrated design.
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 device achieves high-speed, high-accuracy operation over a wide range while maintaining a compact radial size, improving rigidity and reducing the size of the link actuating device by integrating the gear mechanism and speed reduction within the rotation shaft mounting portion, allowing for efficient assembly and reduced interference.
Implementation Method 1
at least a part of a gear mechanism configured to transmit rotary motion by the posture control actuator to the proximal side end link member is mounted on the rotation shaft mounting portion
Implementation Method 2
the proximal side end link member has a bent portion that is bent at an arbitrary angle and a rotation shaft mounting portion that is fixed to one end of the bent portion
Data Source
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AI summary
A distal end side link hub (3) is coupled to a proximal end side link hub (2) via three or more link mechanisms (4). Each link mechanism (4) has a proximal side end link member (5), a distal side end link member (6), and an intermediate link member (7). The proximal side end link member (5) has a bent portion (30) and rotation shaft mounting portions (31A, 31B). A rotation shaft (12) is mounted to the rotation shaft mounting portion (31A). A bevel gear (54), forming a part of a gear mechanism (52) for transmitting rotary motion of a posture control actuator (50) to the proximal side end link member (5), is mounted on the rotation shaft mounting portion (31A) and disposed in a space (S) between two virtual planes obtained by extending a radially inner edge and a radially outer edge of one end of the bent portion (30) in a longitudinal direction of the rotation shaft mounting portion (31A).