Dishwasher Pumping With Brushless Motors and Shared Control
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Solution Overview
Problem
Dishwashing machines using shaded-pole motors require costly sealing measures due to 'dry-running' operation, while synchronous motors have undefined impeller direction leading to low pumping rates and inefficient flow dynamics.
Innovation Solution
Employing two pumps with brushless permanent magnet motors and a shared electronic controller, allowing for adjustable speed and direction control, eliminating the need for costly sealing and optimizing pump housing design for higher pumping rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If shaded-pole motors are used for pumping, then a high pumping rate and defined running direction are achieved, but costly sealing measures are required due to dry-running operation
Solution Approach 1:
The patent changes the operating parameter of the motor from dry-running (shaded-pole) to wet-running (brushless permanent magnet), allowing the pump to operate with the impeller submerged in liquid. This eliminates the need for costly sealing measures while maintaining high pumping rates through electronic speed control of the brushless motor.
2Ease of manufacture
If synchronous motors are used for pumping, then simpler mechanical design without costly sealing is achieved, but the running direction cannot be defined leading to low pumping rate
Solution Approach 1:
The patent replaces the mechanical commutator and brushes of traditional synchronous motors with an electronic control system for the brushless permanent magnet motor. This allows precise electronic control of the impeller's running direction while maintaining the wet-running advantage, thereby achieving both simple mechanical design and high pumping rate.
Solution Approach 2:
The patent introduces dynamic control of the impeller rotation direction through electronic commutation of the brushless motor. The direction can be changed on-demand to optimize flow dynamics and pumping rate, transforming the static limitation of conventional synchronous motors into a dynamic advantage.
3Ease of manufacture
If a single pump with brushless permanent magnet motor is used, then wet-running operation without costly sealing is achieved, but blockage clearance capability is limited due to fixed running direction
Solution Approach 1:
The patent implements periodic reversal of the impeller rotation direction through electronic control of the brushless motor. When blockage is detected or periodically, the rotation direction is reversed to dislodge and clear blockages, then returns to normal operation. This periodic action provides blockage clearance capability while maintaining the wet-running advantage.
4Productivity
If multiple pumps with separate electronic controllers are used, then adjustable speed and direction control is achieved, but manufacturing costs increase
Solution Approach 1:
The patent merges multiple electronic controllers into a single integrated controller that manages both pumps (or the single pump with multiple functions). This single controller provides adjustable speed and direction control through electronic commutation, reducing manufacturing costs while maintaining full controllability of the pumping system.
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
This configuration achieves higher and adjustable pumping rates, improved flow dynamics, and reduced energy consumption by enabling systematic operation and blockage clearance, enhancing cleaning efficiency and manufacturing economics.
Implementation Method 1
The rotor of a brushless permanent magnet motor comprises one or more permanent magnets; the stator comprises a plurality of electromagnets
Implementation Method 2
the electromagnets in the stator are commutated via an electronic controller
Data Source
AI summary
A dishwashing machine having a pumping device to pump a dishwashing solution. The pumping device has a first pump and a second pump, wherein each of the first pump and the second pump has a brushless permanent magnet motor. A shared electronic controller is shared by the first pump and the second pump.