Ribbed Resin Rotor Assembly for Stable Pump Magnet Fit
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Solution Overview
Problem
Conventional pump devices with a gap space for sealing material between the rotor and drive magnet are prone to eccentricity and wobbling, leading to potential cracking of the drive magnet due to thermal expansion differences and applied stress.
Innovation Solution
A pump device design where the rotor is made of resin with a cylindrical tube part and a ribbed outer peripheral face, allowing the drive magnet to be press-fitted and securely contacted with ribs, reducing eccentricity and stress on the drive magnet, and incorporating a gap space for fluid flow and cooling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a gap space with sealing material is provided between the rotor and drive magnet, then the drive magnet is protected from thermal stress, but eccentricity and wobbling occur during rotation
Solution Approach 1:
The outer peripheral face of the cylindrical tube part is divided into multiple rib structures spaced circumferentially. These segmented ribs provide discrete contact points with the drive magnet, maintaining positional stability while allowing thermal expansion. The segmentation transforms the continuous contact problem into discrete support points, resolving the contradiction between gap provision and rotational stability.
Solution Approach 2:
The rib structures create localized contact regions on the outer peripheral face of the cylindrical tube part. Instead of uniform contact, the drive magnet contacts specific localized rib surfaces, which provides stable positioning while accommodating thermal expansion in non-contact areas. This local quality approach maintains rotational stability while preventing thermal stress damage.
2Weight of moving object
If the rotor is made of resin to reduce weight, then manufacturing complexity increases and structural strength decreases
Solution Approach 1:
The resin rotor incorporates rib structures on its outer peripheral face, segmenting the contact interface. These ribs are formed as integral parts of the resin rotor through molding, providing precise geometric features that compensate for resin material limitations. The segmented rib design enables accurate positioning of the drive magnet while maintaining the lightweight resin construction.
Solution Approach 2:
The rotor combines resin material with integrated rib structures that provide enhanced local stiffness and precision. The rib geometry is optimized to compensate for the lower inherent strength of resin, creating a composite-like structure where the resin matrix provides lightweight construction while the rib features provide precise dimensional control and structural reinforcement at critical interfaces.
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 design effectively suppresses eccentricity and stress on the drive magnet, preventing cracking and ensuring stable operation even with rapid temperature changes, while allowing efficient fluid flow and heat dissipation.
Implementation Method 1
the drive magnet is press-fitted to the cylindrical tube part so as to contact with the rib from an outer side in a radial direction
Implementation Method 2
incorporating a gap space for fluid flow and cooling
Data Source
AI summary
A pump device includes a motor and an impeller which is disposed in a pump chamber provided on one side in a rotation center axial line with respect to the motor and is connected with a rotor of the motor. The rotor is made of resin and includes a seat part which supports an end part on one side of a drive magnet and a cylindrical tube part which is extended from the seat part along the rotation center axial line and is fitted to an inner side of the drive magnet. An outer peripheral face of the cylindrical tube part is provided with a rib extended along the rotation center axial line at a plurality of positions in a circumferential direction, and the drive magnet is press-fitted to the cylindrical tube part so as to contact with the rib from an outer side in a radial direction.