Magnetic Water Pump Drive Unit Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing water pumps face issues with water ingress into the drive unit, leading to failure and reduced motor efficiency due to the lack of effective sealing and inefficient magnetic gap maintenance in canned pump designs.
Innovation Solution
A water pump design that mechanically partitions the pump and drive units, utilizing a magnetic power transmission unit and an outer rotor type with ferrite-based magnets, and features a fixed shaft integrally formed on the lower casing to prevent water ingress, while supporting the rotor and impeller for axial alignment and easy assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a canned cover structure is used to seal the stator, then water ingress into the drive unit is prevented, but the rotor becomes sunk in water which adversely affects bearing durability and motor efficiency
Solution Approach 1:
The pump is divided into two separate units: a drive unit containing the motor (stator and rotor) and a pump unit containing the impeller. The drive unit is sealed with a drive unit cover to prevent water ingress, while the pump unit is separately sealed. This segmentation allows the rotor to remain dry while the impeller operates in water, resolving the contradiction between protecting the drive unit and preventing rotor submersion.
Solution Approach 2:
A magnetic coupling mechanism acts as an intermediary between the drive unit and pump unit. The rotor in the drive unit generates a magnetic field that couples with a magnetic component in the pump unit, transmitting rotational force without mechanical connection. This allows the rotor to remain isolated from water while still driving the impeller, maintaining both drive unit protection and rotor dryness.
2Reliability
If a canned cover is disposed between the rotor and stator, then sealing is achieved, but the magnetic gap cannot be optimally maintained causing efficiency to drop
Solution Approach 1:
The motor is segmented into a stator in the drive unit and a magnetic coupling component in the pump unit, separated by a magnetic gap. This segmentation allows optimal maintenance of the magnetic gap for efficiency while the drive unit cover provides sealing. The magnetic coupling component transmits rotational force across the gap without requiring the rotor to be in direct contact with water.
3Temperature
If the rotor is sunk into water, then water cooling is achieved, but the rotation of the rotor is affected and motor efficiency is lowered
Solution Approach 1:
The drive unit is segmented and sealed separately from the pump unit, allowing the rotor to remain in a dry environment while the impeller operates in water. This eliminates the need to submerge the rotor for cooling, as the sealed drive unit maintains optimal operating conditions for the motor while the pump unit handles water cooling of the impeller separately.
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 design effectively prevents water from entering the drive unit, enhances motor efficiency, and simplifies assembly by ensuring the axial alignment of the rotor and impeller, while using cost-effective ferrite-based magnets to improve performance.
Implementation Method 1
a power transmission unit that is installed between the impeller and the rotor and transmits the rotational force of the rotor to the impeller by a magnetic force
Implementation Method 2
a fixed shaft fixed to the center of the lower casing... an outer rotor that is arranged at a predetermined gap to the outer circumferential surface of the stator and is rotatably supported on the fixed shaft; an impeller that is disposed in the upper casing and that is rotatably supported on the fixed shaft
Data Source
AI summary
A water pump includes: a lower casing; a shaft fixed to the center of the lower casing; a stator disposed in the lower casing; an outer rotor that is arranged at a predetermined gap to the outer circumferential surface of the stator and is rotatably supported on the fixed shaft; an upper casing that is sealably mounted on an upper side of the lower casing in which an inlet and an outlet are formed; an impeller that is disposed in the upper casing and that is rotatably supported on the fixed shaft; and a power transmission unit that is installed between the impeller and the rotor and transmits the rotational force of the rotor to the impeller by a magnetic force, to prevent water from being introduced into the lower casing, and to allow the fixed shaft to rotatably support the rotor, as well as to rotatably support the impeller.