Centrifugal Pump Shaft Seal for Liquid Infiltration Prevention
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Solution Overview
Problem
Centrifugal electric pumps for aeriform fluids suffer from liquid infiltration issues due to pressure differentials, causing damage to the drive shaft bearing, leading to premature wear, noise, and increased maintenance costs, with existing sealing solutions being inefficient and difficult to reproduce.
Innovation Solution
A centrifugal electric pump design incorporating a V-Ring type gasket with a cylindrical main body and truncated-cone shaped sealing lip made of elastic material, cooperating with a flat face of a metal ring for a watertight closure, which is easy to mount and adaptable to various shaft diameters, reducing wear and maintenance needs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a ring shaped gasket is used to seal around the shaft, then liquid infiltration is prevented, but the contact point is very small and performances deteriorate rapidly with wear
Solution Approach 1:
The invention transitions from a simple ring gasket sealing at a single point to a shoe-shaped gasket that seals along a linear dimension (the length of the shaft portion). This dimensional expansion from point contact to line contact increases the sealing surface area, distributing wear and improving both initial sealing performance and durability throughout the gasket's service life.
2Reliability
If a ring shaped gasket is compressed to seal, then liquid leakage is prevented, but the deformability must be precisely calculated and calibrated, making design delicate and reproduction difficult
Solution Approach 1:
The invention changes the geometric parameters of the gasket from a simple ring to a shoe-shaped form with specific dimensions (length along the shaft, width, thickness). This parameter modification allows the gasket to achieve effective sealing through its extended contact length rather than relying on precisely calibrated compression deformability, simplifying manufacturing and improving reproducibility across pump series.
3Reliability
If the gasket surface on the drive shaft is reduced in roughness to improve sealing, then seal quality increases, but the surface treatment becomes complicated and onerous to produce on curved surfaces
Solution Approach 1:
The shoe-shaped gasket extends the sealing interface from a circumferential ring to a linear surface along the shaft length. This dimensional change allows sealing to be achieved through the extended contact area rather than requiring high-precision surface roughness control on the curved shaft surface, thereby reducing manufacturing complexity while maintaining or improving seal quality.
4Device complexity
If a simple ring gasket is used, then the structure is simple, but no compensation takes place when the gasket becomes worn, necessitating replacement
Solution Approach 1:
The shoe-shaped gasket is designed to utilize the internal pressure of the aeriform fluid it handles to automatically compensate for wear. As the gasket wears during service, the pressurized fluid maintains contact pressure across the extended sealing surface, self-adjusting to maintain effective sealing without requiring external compensation mechanisms or frequent manual intervention.
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 provides an effective liquid seal with low friction and high durability, compensating for wear through internal pressure, eliminating leaks and protecting the bearing from damage, thus reducing maintenance and manufacturing costs.
Implementation Method 1
a gasket (11) comprising a cylindrical main body (13) with a truncated-cone shaped sealing lip (14), wherein the main body (13) and the sealing lip (14) are made of elastic material
Implementation Method 2
said sealing lip cooperates with a flat face of a metal ring (12) to produce watertight closure of said box
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
A centrifugal electric pump (1) for suction of aeriform fluids with liquids anti-infiltration device, comprising: an electric motor (2) equipped with a shaft (3); a cylindrical suction box (4) associated with said motor (2), provided with an intake (5) for aeriform fluid, with at least one exhaust port (6) and with a closing cover (7) also arranged for acting as base for said motor (2); at least one fan (8), fitted onto said shaft (3) and driven in movement by said motor (2); a bearing (9) interposed between said shaft and said base of said suction box; a liquids anti-infiltration device (10) arranged between said electric motor (2) and said suction box (4), provided with a gasket (11), wherein said gasket (11) rotates with said drive shaft (3) and comprises a cylindrical main body (13) associated with said shaft, and a truncated-cone shaped sealing lip that cooperates with the flat face of a metal ring (12), provided between the bearing and the cover (7) of said suction box (4) to produce watertight closure of said box.