Motor-Operated Valve Gear and Thread Tuning for Faster Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing motor-operated valves used in automotive air conditioners require a longer time to switch states due to reduced force exerted by the driving shaft when a lower speed-reduction ratio is applied, limiting the Cv value and valve port size.
Innovation Solution
A motor-operated valve design utilizing multiple combinations of gear mechanism speed-reduction ratios and driving shaft thread pitches to achieve both a shorter switching time and sufficient axial force, with specific lead and speed-reduction ratio ranges (0.04 ≤ L ≤ 0.1, 30 ≤ K ≤ 100) and thread diameter constraints.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If a lower speed-reduction ratio is applied to the gear mechanism, then the moving speed of the valve member increases and the switching time decreases, but the force exerted by the driving shaft to move the valve member decreases
Solution Approach 1:
The patent applies parameter changes by optimizing the speed-reduction ratio K and lead L within specific ranges (0.04 ≤ L ≤ 0.1, 30 ≤ K ≤ 100) to achieve the desired balance between switching time and axial force. This quantitative adjustment of key parameters resolves the contradiction between speed and force requirements.
2Speed
If a lower speed-reduction ratio is applied to the gear mechanism, then the moving speed of the valve member increases, but the size of the valve port is reduced and the Cv value decreases
Solution Approach 1:
The patent resolves this contradiction by changing the parameters of the screw mechanism (lead L and speed-reduction ratio K) to optimize the relationship between valve member speed and valve port size, enabling faster switching without sacrificing flow capacity.
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 ensures a shorter switching time while maintaining the necessary force to move the valve member, optimizing the motor-operated valve's performance for rapid state changes.
Implementation Method 1
The driving shaft has an external thread. The guide member has an internal thread into which the external thread of the driving shaft is screwed. When the driving shaft rotates, the driving shaft moves in the axial direction by a screw-feed action.
Data Source
AI summary
A motor-operated valve includes a driving shaft that has an external thread, a guide member that has an internal thread into which the external thread is screwed, and a planetary gear mechanism that reduces the rotational speed of a rotor and transmits rotation of the rotor to the driving shaft. Where L represents the lead of the external thread, and K represents the speed-reduction ratio of the planetary gear mechanism, the motor-operated valve 1 satisfies expressions [1] and [2] below:0.04K≤L≤0.1K and[1]30≤K≤100.[2]