Drain Pump Motor Speed Ripple Control to Reduce Laundry Machine Noise
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Laundry treatment machines generate noise during drainage due to the constant speed operation of drain pumps, which is not effectively mitigated by existing technologies.
Innovation Solution
A drain pump driving apparatus that includes a motor, an inverter to convert DC power to AC power, an output current detector, and a controller to calculate and adjust the motor speed based on detected speed ripple, reducing noise by varying the motor speed during drainage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the drain pump operates at constant speed, then the drainage function is simple and reliable, but noise is generated during drainage
Solution Approach 1:
The patent applies dynamics by transitioning from constant speed operation to variable speed operation. The motor speed is dynamically adjusted based on detected speed ripple to reduce noise during drainage, while maintaining the necessary drainage function. This resolves the contradiction by making the speed a dynamic parameter rather than a fixed one.
Solution Approach 2:
The patent implements feedback by detecting the speed ripple of the motor during operation and using this information to control the inverter for adjusting the motor speed. This closed-loop feedback mechanism enables noise reduction through speed adjustment without requiring complex additional sensors, thus resolving the contradiction between noise reduction and control system complexity.
2Object-generated harmful factors
If additional sensors are added to control motor speed, then noise can be reduced, but manufacturing costs increase
Solution Approach 1:
The patent applies self-service by using the motor's own speed ripple as the feedback signal for control. Instead of requiring external sensors to detect operating conditions, the system utilizes the inherent speed ripple of the motor itself to adjust the motor speed and reduce noise. This eliminates the need for additional sensors and reduces manufacturing costs while achieving noise reduction.
Solution Approach 2:
The patent changes the operating parameter of the motor from fixed speed to variable speed based on detected speed ripple. By adjusting the motor speed parameter dynamically during drainage operation, noise is reduced without requiring additional hardware sensors, thereby maintaining ease of manufacture and lowering costs.
3Object-generated harmful factors
If the motor speed is adjusted during drainage, then noise is reduced, but the control system becomes more complex
Solution Approach 1:
The patent applies universality by making the existing inverter serve multiple functions: it not only controls the motor to operate but also detects speed ripple and adjusts speed for noise reduction. By enabling the inverter to perform both motor control and noise reduction functions, the patent avoids adding separate control systems, thus reducing overall system complexity while achieving noise reduction through speed adjustment.
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 reduces noise and improves drainage efficiency by smoothly controlling the motor speed based on calculated speed ripple, reducing power consumption and manufacturing costs without requiring additional sensors.
Implementation Method 1
an inverter to convert a direct current (DC) power to an alternating current (AC) power by a switching operation and output the converted AC power to the motor
Implementation Method 2
the controller may calculate a speed ripple of the motor based on the output current and performs a control operation based on the calculated speed ripple of the motor to change a speed of the motor
Data Source
AI summary
Disclosed herein is a drain pump driving apparatus and a laundry treatment machine including the same. The drain pump driving apparatus and the laundry treatment machine including the same according to an embodiment of the present invention include a motor to operate the drain pump, an inverter to convert a direct current (DC) power to an alternating current (AC) power by a switching operation and output the converted AC power to the motor, an output current detector to detect an output current flowing to the motor, and a controller to control the inverter, wherein the controller may calculate a speed ripple of the motor based on the output current and performs a control operation based on the calculated speed ripple of the motor to change a speed of the motor.