Two-Stage Valve Actuator for Quiet High-Ratio Reduction
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Solution Overview
Problem
Conventional actuators lack consideration for quietness during operation, which is essential for applications like submarine robots, camera lenses, and ship valves, where noise and vibrations can disrupt precise work or disturb sensitive environments.
Innovation Solution
The actuator design incorporates a motor, a friction-drive-type first speed reducer, and a gear-type second speed reducer, along with a final shaft, to achieve a high reduction ratio, minimizing drive sound and allowing for accurate control, with a drive sound level of 30 dB or less and position accuracy of ±0.0125 degrees, using a brushless motor and an absolute encoder.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a single gear reducer with high reduction ratio is used, then the device size can be reduced, but the drive sound increases due to gear meshing noise
Solution Approach 1:
The patent divides the single high-ratio gear reducer into two separate speed reducers with different reduction ratios (first speed reducer: 1/10 to 1/50, second speed reducer: 1/2 to 1/10). This segmentation allows the first speed reducer to operate at lower speeds with reduced noise, while the second speed reducer handles the final reduction, achieving overall quiet operation without increasing device volume excessively.
Solution Approach 2:
The patent applies different gear characteristics to different stages of reduction. The first speed reducer uses specific gear parameters optimized for low-noise operation at higher speeds, while the second speed reducer uses different parameters optimized for final torque multiplication. This local differentiation of gear qualities enables noise reduction while maintaining compact dimensions.
2Object-generated harmful factors
If a friction-drive-type speed reducer is used, then the drive sound is reduced, but the power transmission efficiency decreases
Solution Approach 1:
The patent merges a friction-drive-type speed reducer (first speed reducer) with a gear reducer (second speed reducer) in series. The friction-drive stage provides noise reduction through controlled slipping and lower meshing frequencies, while the gear reducer stage compensates for efficiency losses by providing high-ratio reduction with better mechanical efficiency. This combination achieves both quiet operation and acceptable power transmission.
3Force
If the reduction ratio is increased to obtain high torque, then the device size increases, but the drive sound increases due to larger gear meshing
Solution Approach 1:
The patent segments the total reduction ratio (1/2 to 1/500) into two stages, allowing each stage to operate within optimal noise and torque ranges. The first stage handles the majority of speed reduction at lower torque, while the second stage provides final torque multiplication at lower speeds, minimizing gear meshing noise while achieving high output torque in a compact configuration.
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 sufficient quietness, compact size, excellent power transmission performance, and precise control, making it suitable for noise-sensitive applications while maintaining high torque and accuracy.
Implementation Method 1
a friction-drive-type first speed reducer that is connected to the motor
Data Source
AI summary
An actuator that is capable of securing sufficient quietness when driven, that is small in size, that has excellent power transmission performance because of a high reduction ratio, and that is capable of performing highly accurate control. The actuator functions as a valve actuator that opens or closes a valve. The actuator includes a drive transmission gear, a motor, a friction drive speed reducer, a wave gear reducer, and an absolute encoder.