Rotating Ice Tray Ejection for Low-Cost Refrigerator Ice Makers
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Solution Overview
Problem
Existing refrigerator designs for ice making in refrigerators are costly due to the need for pumps, electronic valves, and high-torque motors, and they often result in inefficient power consumption and risk of fire from heaters operating without proper control.
Innovation Solution
A refrigerator design featuring an ice making tray that rotates at an angle to supply and separate ice, using a cheap AC motor and eliminating the need for pumps and electronic valves by allowing water to freely fall from a valve-controlled water tank, with a heater that only operates when water is present to prevent freezing and minimize power usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a pump and electronic valve are installed to forcibly supply water to the ice maker, then water supply control is improved, but manufacturing cost increases
Solution Approach 1:
The patent removes the pump and electronic valve from the system by utilizing gravity-based water supply. The water tank is positioned above the ice making tray, allowing water to flow naturally through gravity without requiring mechanical pumping or electronic flow control, thereby eliminating costly components while maintaining water supply functionality.
Solution Approach 2:
The water tank is positioned at a higher elevation than the ice making tray, creating a gravitational potential difference that enables water to flow automatically from the tank to the tray. This gravitational equipotential approach replaces the need for active pumping mechanisms, reducing system complexity and manufacturing cost.
2Ease of operation
If a heater is installed to separate ice pieces from the metal ice making tray, then ice separation is improved, but power consumption increases
Solution Approach 1:
The patent replaces the thermal field approach (heater) with a mechanical field approach. The ice making tray is designed with an ejector mechanism that mechanically pushes ice pieces out of the mold cavities. This mechanical ejection system eliminates the need for continuous heater operation, significantly reducing power consumption while achieving effective ice separation.
Solution Approach 2:
The ejector operates periodically only when ice pieces need to be removed, rather than continuously heating the tray. This periodic mechanical action provides ice separation on demand, reducing energy consumption compared to continuous thermal processing.
3Ease of operation
If a bidirectional DC motor is used to rotate and twist the ice maker for separation, then ice separation is achieved, but motor cost increases due to high torque requirement
Solution Approach 1:
Instead of rotating the entire ice making assembly bidirectionally, the patent inverts the approach by keeping the ice making tray stationary and using a fixed ejector to push ice pieces out. This eliminates the need for bidirectional motor rotation and high-torque requirements, allowing the use of simpler, lower-cost single-direction motors or even manual ejection mechanisms.
Solution Approach 2:
The ice making tray is segmented into multiple cavities with individual ejectors or a centralized ejector system that can target specific cavities. This segmentation allows for selective ice ejection without requiring rotation of the entire assembly, reducing the mechanical complexity and motor torque requirements.
4Reliability
If the heater operates continuously to prevent water freezing in the tank, then water supply reliability is improved, but power consumption increases and fire risk increases
Solution Approach 1:
The patent implements a feedback control system with a temperature sensor that monitors the water tank temperature and a control unit that activates the heater only when the temperature drops below a predetermined threshold. This feedback mechanism ensures water supply reliability by preventing freezing only when necessary, reducing power consumption and eliminating fire risks associated with continuous heater operation.
Solution Approach 2:
The heater operates periodically based on temperature conditions rather than continuously. The control unit activates the heater only when freezing conditions are detected, providing reliable water supply protection while minimizing energy consumption and safety risks.
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 design reduces manufacturing costs, improves energy efficiency, prevents overheating, and enhances safety by eliminating the need for costly components and ensuring the heater only operates when necessary, thus minimizing power consumption and preventing potential malfunctions.
Implementation Method 1
allowing water to freely fall from a valve-controlled water tank
Implementation Method 2
with a heater that only operates when water is present to prevent freezing
Data Source
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AI summary
A refrigerator (1) includes a main body (10) including a storage compartment (11, 12), a door (13, 14) opening and closing the storage compartment (11, 12), an ice making device disposed in the storage compartment (11, 12) or on a back surface of the door (13, 14), a water tank (40) disposed above the ice making device (20) to supply water for making ice pieces into the ice making device (20), and an ice bin () disposed under the ice making device (20) to store ice pieces manufactured in the ice making device (20). The ice making device (20) includes an ice making tray (210) including a plurality of ice making chambers (212) in which the water for making the ice pieces is filled, and an ejector (260) extending from an upper central portion of the ice making tray (210) in a longitudinal direction of the ice making tray (210) to pass through both ends of the ice making tray (210). The ejector (260) is maintained in a fixed state during the water supply, ice making, and ice separation, and the ice making tray (210) rotates at an angle of about 360° in one direction with respect to the ejector (260).