Ice Maker Cam Gear Structure for Stable Magnet Lever Detection

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Solution Overview

Problem

Existing ice makers face issues with ice detection arm collisions and assembly tolerance, leading to detection failures due to space constraints and force imbalances, causing distortion and shaking of the magnet lever.

Innovation Solution

The ice maker design enhances the cam gear's cam surface by increasing its thickness and adding protrusions towards the center, reducing the force transferred to the magnet lever, and integrates a shaft support to firmly secure the magnet lever, preventing distortion and ensuring correct-position signal detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the ice detection arm is lowered to enter the ice storage container, then the ice amount can be detected, but the ice detection arm rubs against or collides with surrounding structures causing detection failure

Engineering Contradiction:

Improveice amount detectionVSAvoiddetection reliability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

A guide groove is introduced as an intermediary structure to constrain the ice detection arm's movement path. The guide groove is formed on the inner wall of the ice storage container, providing a predefined trajectory that prevents the detection arm from colliding with surrounding structures while maintaining its detection function.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If the ice detection arm rotates with part located in the ice storage container, then ice separation and transfer is enabled, but ice may be stuck between the detection arm and ice making plate

Engineering Contradiction:

Improveice transfer efficiencyVSAvoidice transfer reliability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The ice storage container is divided into a first storage container and a second storage container positioned at different locations. This segmentation allows the ice detection arm to rotate and transfer ice between separate storage spaces, preventing ice from becoming stuck between the detection arm and ice making plate while maintaining efficient ice transfer capability.

Inventive Principle:

Principle #1Segmentation

3Ease of operation

If force is transferred from cam surface to lever, then the lever moves along the cam surface, but the lever shaft becomes distorted due to unbalanced force

Engineering Contradiction:

Improvelever movementVSAvoidlever shaft stability

Core Design Contradiction:

Ease of operationVSStability of the object's composition

Solution Approach 1:

A counterweight structure is added to balance the force transferred from the cam surface to the lever. The counterweight is positioned to create an opposing moment that counteracts the unbalanced force causing lever shaft distortion, enabling smooth lever movement while maintaining structural stability.

Inventive Principle:

Principle #8Anti-weight (Counterweight)

4Ease of manufacture

If assembly tolerance occurs between ice detection arm and DC motor, then the ice detection arm rubs against surrounding structure, but no compensation mechanism exists

Engineering Contradiction:

Improveassembly toleranceVSAvoiddetection reliability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

A buffer structure is introduced to compensate for assembly tolerance between the ice detection arm and DC motor. The buffer provides a cushioning effect that absorbs minor misalignments and prevents the detection arm from rubbing against surrounding structures, ensuring reliable detection operation despite manufacturing variations.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentUS11788782B2Ice maker and a refrigerator including the same

Publication Date: 2023.10.17 LG ELECTRONICS INC

AI summary

In a refrigerator, a cam of a cam gear rotating by a driving motor is provided with a structure protruding from an edge portion of a cam gear to a center, thereby increasing the thickness of a cam surface. Therefore, it is possible to reduce the magnitude of force directly transferred from the cam gear to a magnet lever.