Single-Motor Dishwasher Pump Assembly with Sealed Filter Aperture
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Solution Overview
Problem
Conventional dishwasher appliances require two separate motors for the wash pump and drain pump, increasing space, cost, and the likelihood of leaks, while single-motor designs with a common drive shaft face issues with food soil passing through filters in 100% filtration systems.
Innovation Solution
A dishwasher appliance uses a single motor with a common drive shaft to rotate both the wash pump and drain pump impellers, with the impellers separated by a filter, and an inlet guide assembly that includes an upper and lower inlet guide forming a clearance bore and washer chamber to prevent food soil from passing through the filter aperture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single motor and common drive shaft are used to operate both wash pump and drain pump, then device complexity and cost are reduced, but the likelihood of leaks increases due to additional seals required
Solution Approach 1:
The patent combines two separate motors into a single motor that drives both the wash pump and drain pump through a common drive shaft. This merging reduces device complexity and eliminates the need for multiple motor seals, thereby reducing leak paths while maintaining functional separation of the pumps.
Solution Approach 2:
The single motor is designed to perform multiple functions by sequentially driving both the wash pump impeller and drain pump impeller through the common drive shaft. This multi-functionality allows one motor to replace two separate motors, reducing overall system complexity and seal requirements.
2Object-generated harmful factors
If a filter is used to separate wash pump impeller and drain pump impeller in a 100% filtration system, then food soil is prevented from circulating, but the common drive shaft must pass through the filter creating a leak path
Solution Approach 1:
The patent introduces an inlet guide assembly as an intermediary component that seals around the common drive shaft where it passes through the filter. This assembly includes an inlet guide and washer that create a food-tight seal, preventing food soil from passing through the drive shaft penetration while allowing the drive shaft to rotate freely.
Solution Approach 2:
The inlet guide assembly uses a flexible washer or sealing element that can deform to accommodate the rotating drive shaft while maintaining a continuous seal. This flexible sealing mechanism prevents food soil from passing through the filter aperture without interfering with the drive shaft's rotational motion.
3Reliability
If two separate motors are used for wash pump and drain pump, then reliability is improved by eliminating shared components, but space, cost, and seal requirements increase
Solution Approach 1:
The patent merges two separate motor assemblies into a single motor unit with a common drive shaft that can sequentially drive both pumps. This consolidation reduces the total number of seals and moving parts, thereby reducing potential leak paths while maintaining the functional independence of each pump through controlled operation sequences.
Data Source
AI summary
A dishwasher appliance is provided having a fluid circulation assembly that uses a single motor and a common drive shaft to rotate both a wash pump impeller and a drain pump impeller. The wash pump impeller and the drain pump impeller are separated by a filter to prevent food soil from being circulated by the wash pump impeller. The common drive shaft passes through an aperture in the filter, the aperture being sealed to prevent the passing of food soil by an inlet guide assembly. The inlet guide assembly includes an upper inlet guide and a lower inlet guide that define a clearance bore and a washer chamber. A washer is positioned in the washer chamber to prevent the flow of food soil through the clearance bore.