Electronic Expansion Valve Planetary Gear for Precise Flow Range
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Solution Overview
Problem
Conventional electronic expansion valves face challenges in achieving high precision and miniaturization while increasing the adjusting range of the flow rate, as traditional spur gear deceleration mechanisms require increased volume and complexity, leading to reduced transmission efficiency and stability.
Innovation Solution
The implementation of a planetary gear deceleration mechanism with a gearbox that includes a planetary carrier, planetary gear, and a gearbox with internal meshing gears, allowing for a higher deceleration ratio within a smaller space, enabling precise control of the valve needle and increasing the flow rate adjusting range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the deceleration ratio of the gear at each stage is increased to increase the output torque and control range, then the flow rate adjusting range is improved, but the outer diameter of the large gear increases, resulting in increased volume of the gear decelerator
Solution Approach 1:
The patent employs a planetary gear mechanism where planetary gears are nested within the central sun gear and surrounded by the inner gear ring. This nested configuration allows multiple gear elements to occupy the same radial space, achieving high deceleration ratios without increasing the outer diameter of the decelerator, thus resolving the contradiction between flow rate adjusting range and volume.
Solution Approach 2:
The patent transitions from a traditional multi-stage spur gear arrangement (linear dimensionality) to a planetary gear system that utilizes radial and axial dimensions simultaneously. By arranging gears in a three-dimensional planetary configuration rather than a linear train, the system achieves high deceleration ratios within a compact volume, addressing both the adjusting range requirement and volume constraint.
2Force
If the number of stages of the gear decelerator is increased to increase the deceleration ratio, then the output torque is improved, but the number of gears increases, resulting in increased volume of the gear decelerator
Solution Approach 1:
The planetary gear mechanism nests multiple functional elements (sun gear, planetary gears, inner gear ring) within a single compact stage. This nested structure provides high deceleration ratios and output torque without requiring multiple sequential stages, thereby avoiding the volume increase that would result from adding more gear stages.
Solution Approach 2:
The patent merges multiple gear functions into a single integrated planetary gear stage. Instead of using separate spur gear stages that would require multiple discrete gear sets, the planetary mechanism combines sun gear, planetary gears, and ring gear into one unified deceleration stage, achieving high torque output within a smaller volume.
3Measurement precision
If the number of stages of the gear decelerator is increased to increase the deceleration ratio, then the control precision is improved, but the transmission efficiency and stability of the overall system are reduced
Solution Approach 1:
The planetary gear mechanism provides high deceleration ratios in a single stage, eliminating the need for multiple sequential gear stages. This reduces the number of meshing interfaces and potential failure points, thereby maintaining high transmission efficiency and system stability while achieving the required control precision through the inherent mechanical advantage of the planetary 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
This solution enhances the precision and miniaturization of the electronic expansion valve, achieving a larger deceleration ratio than traditional spur gear mechanisms, thereby improving the control accuracy and meeting the requirements of high precision and miniaturization.
Implementation Method 1
The planetary gear deceleration mechanism includes a planetary carrier, a planetary gear and a gearbox, the gearbox includes a box body, a fixed inner gear ring and an output inner gear ring which is movably arranged in the box body
Implementation Method 2
the output inner gear ring is fixedly connected to a screw rod of the transmission mechanism to enable the screw rod to rotate, the screw rod is in threaded connection with a nut, to convert a rotation motion of the screw rod into a linear motion
Data Source
AI summary
An electronic expansion valve and a refrigeration system including the electronic expansion valve are provided. The electronic expansion valve includes a valve seat, a valve needle, a drive mechanism, a planetary gear deceleration mechanism. The drive mechanism serves as an input end of the planetary gear deceleration mechanism, the planetary gear deceleration mechanism has the output inner gear ring, the output inner gear ring is fixedly connected to a screw rod of the transmission mechanism to enable the screw rod to rotate, the screw rod is in threaded connection with a nut, to convert a rotation motion of the screw rod into a linear motion.