Motor-Driven Control Valve for Compressor Crankcase Pressure Control
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Solution Overview
Problem
Existing electrical control valves for air conditioning compressors suffer from imprecise control and high energy consumption due to mechanical and magnetic interactions, leading to hysteresis and the need for constant current flow to maintain position.
Innovation Solution
An electrical control valve with a control piston moved by an electric motor, featuring a Hall sensor and control unit to precisely position the piston between high-pressure and crankcase pressure areas, and crankcase pressure and low-pressure areas, reducing hysteresis and energy usage by converting rotational motor movement into translational piston movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If an electromagnetic annular coil is used to move the control piston, then the control valve can be actuated electrically, but mechanical and magnetic interactions cause hysteresis and require constant current flow to maintain position, leading to high energy consumption and imprecise control
Solution Approach 1:
The patent replaces the electromagnetic annular coil with a DC motor to actuate the control piston. The DC motor provides precise positional control through electrical signal processing without the hysteresis and constant holding current requirements of electromagnetic coils, thereby reducing energy consumption while improving control precision.
Solution Approach 2:
The patent implements feedback control by processing the electrical signal based on the actual position of the control piston. This closed-loop control system adjusts the motor actuation to achieve precise positioning and eliminates the need for constant holding current, resolving the contradiction between control precision and energy consumption.
2Ease of operation
If an electromagnetic annular coil is used to maintain control piston position, then electrical actuation is achieved, but constant current flow is required to maintain position, leading to high energy consumption
Solution Approach 1:
The patent substitutes the electromagnetic annular coil with a DC motor system that provides electrical actuation capability without requiring constant current flow to maintain position. The motor achieves positioning through controlled actuation followed by mechanical holding, dramatically reducing energy consumption while preserving ease of electrical operation.
Solution Approach 2:
The patent uses periodic or pulsed electrical signals to actuate the DC motor to the desired position, rather than requiring continuous current flow. The system maintains position through the mechanical structure after the actuation pulse, eliminating continuous energy consumption while preserving electrical actuation capability.
3Extent of automation
If mechanical and magnetic interactions are used in the control valve, then electrical actuation is achieved, but hysteresis occurs leading to imprecise control
Solution Approach 1:
The patent replaces the electromagnetic annular coil with a DC motor to eliminate the magnetic interactions that cause hysteresis. The DC motor provides electrical control capability through electromagnetic fields optimized for motor operation, combined with mechanical transmission to the control piston, achieving both automation and precision without the hysteresis problems of coil-based actuation.
Solution Approach 2:
The patent implements feedback control by processing electrical signals based on the actual control piston position. This closed-loop system compensates for any remaining mechanical play and achieves precise control, eliminating the hysteresis effects that plague open-loop electromagnetic coil systems while maintaining full electrical automation.
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 solution enables precise control with reduced hysteresis, improved energy efficiency, and cost-effectiveness by eliminating the need for constant holding current, allowing for precise refrigerant flow management between pressure areas.
Implementation Method 1
the sensor is designed as a Hall sensor and the movement of the control piston is ascertained as a change in a magnatic field
Implementation Method 2
An electrical control valve with a control piston moved by an electric motor
Data Source
Figure 1~2a
Figure 2b~2c
AI summary
The present invention relates to an electrical control valve, particularly designed for use in an air conditioning compressor, to control a refrigerant flow from a high-pressure area into a crankcase pressure area, and from the crankcase pressure area into a low-pressure area. The control valve comprises a control piston which in two different positions connects the high-pressure area to the crankcase pressure area, and the crankcase pressure area to the low-pressure area. Further, the control valve comprises an electric motor which moves the control piston back and forth between the two positions. The control valve comprises a sensor which ascertains the position of the control piston moved by the electric motor. In addition, the control valve comprises a control unit which, depending on the position of the control piston ascertained by the sensor, controls the refrigerant flow by means of movement of the control piston by the electric motor.