Dishwasher Pump Assembly With Elastic Damping for Torque Ripple
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional pumps in dishwasher appliances experience torque ripple during operation, leading to undesirable movement, noise, and inefficiency, with existing solutions either inaccurately positioning the shaft or increasing pump size and reducing efficiency.
Innovation Solution
A pump assembly with an elastic damper coupled to the stator, allowing the stator to rotate relative to the rotor and housing, reducing torque ripple transmission and maintaining accurate shaft placement while minimizing size and improving efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the entire motor is isolated from other components of the pump to reduce torque ripple effects, then torque ripple transmission is reduced, but shaft positioning accuracy deteriorates
Solution Approach 1:
The motor assembly is divided into two separate damping systems: a first damper between the rotor and housing, and a second damper between the stator and housing. This segmentation allows independent optimization of rotor and stator damping, reducing torque ripple transmission while maintaining shaft positioning accuracy through the combined effect of both dampers.
Solution Approach 2:
The first and second dampers act as intermediary elements between the rotating components (rotor and stator) and the housing. These dampers serve as mediators that absorb and dissipate torque ripple vibrations, preventing direct transmission to the housing while allowing the shaft to maintain accurate positioning through the dampers' vibration isolation properties.
2Object-generated harmful factors
If the entire pump including motor assembly is isolated to reduce torque ripple effects, then torque ripple transmission is reduced, but pump size increases and efficiency decreases
Solution Approach 1:
The damping system is segmented into two independent dampers rather than using a single comprehensive isolation system. This allows targeted damping of torque ripple at specific locations (rotor-housing interface and stator-housing interface) without requiring isolation of the entire pump assembly, thereby maintaining compact size and high efficiency.
Solution Approach 2:
Damping properties are applied locally at critical interfaces where torque ripple is generated and transmitted (between rotor-housing and stator-housing). This localized approach provides effective torque ripple reduction only where needed, avoiding the penalties of global isolation while maintaining pump efficiency and compact dimensions.
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 effectively reduces torque ripple, enhances shaft accuracy, and improves pump efficiency without the need for full motor or pump isolation, resulting in a more compact and efficient fluid circulation system.
Implementation Method 1
an elastic damper coupled to the stator for reducing stator torque ripple transmissions to the housing
Implementation Method 2
an elastic damper coupled to the stator for reducing stator torque ripple transmissions to the housing
Data Source
AI summary
Pump assemblies and fluid circulation systems for dishwasher appliances are provided. A pump assembly includes a housing defining an interior, and a pump. The pump includes an impeller disposed within the interior, and a motor connected to the impeller and comprising a stator and a rotor. The rotor is rotatable about a central axis. The stator is rotatable about the central axis relative to the rotor and the housing. The pump further includes an elastic damper coupled to the stator for reducing stator torque ripple transmissions to the housing.