Mechanical Valve Actuator Gear Cutoff for Over-Torque Prevention
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Solution Overview
Problem
Existing valve actuators for air conditioners face issues with sensor instability in harsh environments and require separate PCBs for motor stop signals, leading to potential damage from over-torque and inaccurate RPM control.
Innovation Solution
A valve actuator design that uses a mechanical power transmission unit with a lift member or friction member to interrupt gear rotation after a predetermined angle, eliminating the need for electronic sensors and separate PCBs, thereby preventing over-torque and ensuring durable, stable operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electronic sensors and PCBs are used for motor stop control, then valve actuation control is achieved, but sensor instability occurs in harsh environments
Solution Approach 1:
The patent replaces electronic sensors and PCB-based motor stop control with a purely mechanical power transmission interruption mechanism. The gear assembly mechanically interrupts power transmission to the output shaft after a predetermined rotation angle, eliminating electronic components and their associated instability issues in harsh environments.
Solution Approach 2:
The patent extracts and removes electronic sensors and separate PCB components from the valve actuator system. By eliminating these electronic elements, the design achieves harsh environment reliability while reducing device complexity and potential failure points.
2Ease of operation
If separate PCB for motor stop signal is used, then motor control is achieved, but device complexity increases
Solution Approach 1:
The patent merges the motor stop control function directly into the mechanical power transmission system through the gear assembly. The interruption of power transmission is achieved through the mechanical interaction of gears rather than through a separate PCB and electronic control circuit, thereby maintaining motor control capability while eliminating electronic complexity.
Solution Approach 2:
The patent extracts the motor stop control function from the electronic domain and implements it purely mechanically. This removes the need for separate PCB and electronic circuits, reducing device complexity while preserving the essential motor control capability needed for valve actuation.
3Device complexity
If continuous power transmission is used, then motor rotation control is simple, but over-torque damage occurs to gear assembly
Solution Approach 1:
The patent introduces dynamic characteristics to the power transmission system by enabling the gear assembly to mechanically interrupt power transmission after a predetermined rotation angle. This dynamic interruption prevents continuous power transmission and the associated over-torque damage, while the mechanical design maintains relative simplicity without requiring complex electronic control systems.
4Measurement precision
If electronic limit switch is used for motor stop, then valve position control is achieved, but sensor instability in harsh environment occurs
Solution Approach 1:
The patent replaces electronic limit switches and sensors with a mechanical power transmission interruption mechanism. The gear assembly mechanically determines and executes the stop position based on predetermined rotation angle, providing precise valve position control through mechanical geometry rather than electronic sensing, thereby achieving reliability in harsh environments.
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 design enhances durability and stability by preventing gear and motor damage, reduces complexity and material costs, and maintains accurate valve control without electronic sensors.
Implementation Method 1
a friction member provided at the output gear so as to brake the rotation of the first gear by contacting the first gear after the output gear is rotated at a predetermined angle
Data Source
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AI summary
Disclosed is a valve actuator including: a motor (120); a gear assembly including an input gear (131) rotated by the motor, an output gear (132) receiving rotational force of the input gear (131), and at least one power transmission gear (133, 134, 135) transmitting the rotational force of the input gear to the output gear; a valve output shaft (140) coupled to the output gear and actuated to close a path of a valve; and a selective power transmission unit interrupting rotation of the output gear after the output gear is rotated at a predetermined angle by the input gear, the selective power transmission unit including a lift member (150) releasing meshing of the first gear (133) and the second gear (134) by moving the first gear to an upper side after the output gear is rotated at the predetermined angle or a friction member provided in the output gear so as to brake the rotation of the first gear by contacting the first gear after the output gear is rotated at the predetermined angle. Accordingly, after the valve is actuated to close the path, the driving force of the motor is not transmitted to the valve output shaft.