Miniature Pump Motor Shaft Axial Play Stabilization
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Solution Overview
Problem
Miniature pumps, particularly those with axially movably mounted motor shafts, experience vibrations and noise due to axial shaft play, which is challenging to mitigate effectively while maintaining performance and cost-effectiveness, especially in medical applications where noise and vibration are undesirable.
Innovation Solution
A stabilizing element is used outside the motor housing to apply axial compressive or tensile forces to the motor shaft, reducing or eliminating axial shaft play, thereby minimizing vibrations and noise without altering the motor's design or size, using a mechanical or magnetic coupling to maintain the motor shaft's position and reduce friction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If electric motors with axially movably mounted motor shafts are used in miniature pumps, then cost-effectiveness and small size are improved, but vibrations and noise increase due to axial shaft play
Solution Approach 1:
The stabilizing element is implemented as a separate, independent component that can be added to existing motor designs without modifying the motor itself. This segmentation allows the noise reduction function to be isolated from the motor design, maintaining cost-effectiveness while eliminating vibrations and noise through a dedicated stabilizing component
Solution Approach 2:
The stabilizing element acts as an intermediary component between the motor shaft and the pump housing. It mediates the axial shaft play by providing a stabilizing force that prevents excessive movement, thereby reducing vibrations and noise without requiring direct modification of the motor shaft or housing
2Object-generated harmful factors
If the motor shaft is stabilized to reduce axial shaft play, then vibrations and noise are reduced, but the motor design and size may be altered
Solution Approach 1:
The stabilization function is extracted from the motor design itself and implemented as a separate stabilizing element. This extraction allows the motor to remain unchanged in terms of design and size, while the independent stabilizing element provides the necessary axial play compensation without adding complexity to the motor structure
Solution Approach 2:
The stabilizing element is designed as a universal component that can be applied to various motor designs without requiring custom modifications. It performs multiple functions including reducing axial shaft play, minimizing vibrations, and maintaining compatibility with existing motor sizes and configurations
3Object-generated harmful factors
If prestressing of the connecting rod is used to reduce vibrations, then noise and vibration are reduced, but long-term stability deteriorates
Solution Approach 1:
The stabilizing element applies preliminary stabilizing forces to the motor shaft before axial loads are applied during operation. This preliminary action prevents excessive axial shaft play from the beginning, ensuring consistent performance and long-term stability without the degradation issues associated with prestressed connecting rods
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 solution effectively reduces or eliminates axial shaft play and associated noise and vibrations in miniature pumps, ensuring low-vibration and low-noise operation across various installation and operating positions without compromising the pump's size or performance.
Implementation Method 1
A stabilizing element is used outside the motor housing to apply axial compressive or tensile forces to the motor shaft, reducing or eliminating axial shaft play
Implementation Method 2
using a mechanical or magnetic coupling to maintain the motor shaft's position and reduce friction
Data Source
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AI summary
A pump assembly (1) for a pump, in particular for a miniature pump, comprising an electric motor (2) and a housing unit (3) is shown and described. The electric motor (2) has a motor shaft (5) that is freestanding through a motor housing of the electric motor (2), and the motor housing is connected to the housing unit (3). The motor shaft (5) is mounted in the motor housing with axial play. According to the invention, at least one stabilizing element (6, 13, 14, 16) arranged outside the motor housing is provided to reduce or eliminate the axial play of the motor shaft (5). The stabilizing element (6, 13, 14, 16) applies an axial compressive or tensile force to the motor shaft (5).