Dual-Function Drain Pump Design to Prevent Backflow and Cavitation
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Solution Overview
Problem
Existing drain pumps in laundry treating apparatuses require separate motors for circulation and drainage, leading to space constraints, increased costs, and issues with backflow and cavitation, which affect efficiency and noise levels.
Innovation Solution
A drain pump design utilizing a single motor and impeller that switches between circulation and drainage functions by controlling the impeller's rotational direction and speed, with a ribbed housing to guide water flow and prevent backflow, and an optimized impeller structure to reduce cavitation and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate motors are used for circulation pump and drain pump, then each pump can function independently, but the installation space is restricted and cost increases
Solution Approach 1:
The patent combines the circulation pump and drain pump into a single integrated pump unit with one motor and one impeller. The pump chamber is designed with multiple ports (inlet port, first discharge port, second discharge port) that allow the single impeller to perform both circulation and drainage functions by directing water flow to different outlets, thereby reducing installation space and component count while maintaining independent functionality.
Solution Approach 2:
The single pump unit is designed to perform multiple functions - it can operate as a circulation pump to move water to the first discharge port, and as a drain pump to move water to the second discharge port. The pump chamber and impeller are configured to handle different flow directions and destinations, enabling one device to replace what traditionally required two separate devices.
2Volume of moving object
If one motor and impeller are used for both circulation and drainage, then installation space is reduced, but water flows backward through undesired flow paths
Solution Approach 1:
The pump chamber is segmented into different flow paths with distinct ports - an inlet port, a first discharge port for circulation, and a second discharge port for drainage. The impeller is positioned and configured to direct water flow selectively to different discharge ports based on operational mode, preventing backflow by providing dedicated exit paths for each function.
Solution Approach 2:
The pump chamber acts as an intermediary structure that receives water from the impeller and directs it to appropriate discharge ports. The chamber's geometry and port positioning serve as a flow mediator that prevents direct backflow between circulation and drainage paths, ensuring water is routed to the intended destination.
3Reliability
If water inflow pressure is reduced to prevent backflow, then backflow is minimized, but cavitation occurs increasing noise
Solution Approach 1:
The system dynamically adjusts impeller rotational speed based on operational mode (circulation or drainage). By optimizing the rotational speed, the pump maintains appropriate water inflow pressure that prevents backflow while avoiding conditions that would cause cavitation. This dynamic control allows the system to prevent backflow without excessively reducing pressure to the point of causing cavitation and noise.
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 efficient dual-functionality without space constraints, reduces noise, and prevents backflow, enhancing the overall performance and cost-effectiveness of the drain pump.
Implementation Method 1
a water flow portion provided with an impeller forming the flow of the water or wash water
Implementation Method 2
the rib guides the movement of water or wash water to the circulation port or the drain port by the rotation of the impeller in one direction
Implementation Method 3
a drain pump chamber formed on an inner circumferential surface of the housing to receive or store the water or wash water before the water or wash water flows into the water flow portion
Data Source
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AI summary
The present disclosure relates to a drain pump (100) for a laundry treating apparatus, including a housing (110) configured to accommodate water; a water flow portion (420) provided with an impeller (125) forming a flow of water or wash water, and formed on an inner circumferential surface of the housing (110) to circulate the accommodated water or wash water to a tub or drain the accommodated water or wash water out of a washing machine; a drain pump chamber (19) formed on an inner circumferential surface of the housing (110) to receive or store the water or wash water before the water or wash water flows into the water flow portion (420); and an inlet port (113) formed to protrude toward the water flow portion (420) between the water flow portion (420) and the drain pump chamber (19).