Washing Machine Motor Rotor Venting for Cooling and Low Height
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Solution Overview
Problem
Conventional washing machine motors face issues with heat efficiency and noise due to high driving forces required for washing and high-speed rotation during dewatering, leading to vibration and noise, and are limited in height reduction due to cooling fin placement.
Innovation Solution
A motor design for a washing machine featuring a rotor with a disk-shaped base and vertical wall, including a second ring portion with air inlet channels that guide outside air to the stator coil for enhanced cooling, allowing for reduced height and improved cooling efficiency without the need for speed reducers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If cooling fins are located directly below the coil of the stator, then cooling efficiency is improved, but the height of the motor cannot be reduced
Solution Approach 1:
The patent transitions from radial cooling fins to axial air inlet holes in the rotor base portion, changing the cooling air flow direction from radial to axial. This dimensional change allows cooling without increasing motor height, as the air inlet holes are formed in the axial direction within the existing rotor structure.
Solution Approach 2:
The rotor base portion is designed with multiple air inlet holes formed directly in it, creating a porous structure that allows cooling air to pass through. This eliminates the need for separate cooling fins while maintaining effective cooling, and the holes can be formed without increasing the overall motor height.
2Temperature
If ventilation holes are provided on the bottom surface of the rotor, then cooling is improved, but air cannot be effectively drawn outside the rotor into the inside
Solution Approach 1:
The air inlet holes are pre-formed in the rotor base portion at strategic locations to guide cooling air from the external environment directly into the motor's internal cooling passages. This preliminary positioning of air inlets ensures efficient air draw-in and distribution before the air reaches the heating components.
3Force
If high driving force is applied for washing, then washing performance is improved, but motor temperature increases and efficiency deteriorates
Solution Approach 1:
The patent employs a pneumatic cooling system where cooling air is supplied to the motor's internal passages to remove heat generated during high-force washing operations. The air flow through the rotor base holes and stator cooling passages effectively dissipates heat, allowing the motor to maintain efficiency even under high driving force conditions.
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 effectively cools the motor, reduces noise, and allows for a lower motor height, enhancing the capacity of the washing tub while maintaining the outer shape of the washing machine.
Implementation Method 1
a second ring portion with air inlet channels that guide outside air to the stator coil for enhanced cooling
Data Source
AI summary
A motor for a washing machine includes a stator and a rotor. The rotor includes a rotor casing including a base portion formed in a disk shape and a vertical wall extending substantially perpendicularly from an outer periphery of the base portion, a permanent magnet provided on an inner surface of the vertical wall of the rotor casing, and a connecting member provided at a center of the base portion of the rotor casing and connected to a shaft. The base portion of the rotor casing includes a first ring portion facing a coil portion of the stator and a second ring portion, provided with a plurality of air inlet holes, that is positioned between the first ring portion and the connecting member and does not face the coil portion of the stator.