Multi-stage Centrifugal Pump Mechanical Seal Axial Length Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multi-stage centrifugal pumps require a significant axial length for mechanical seals, which increases the overall size and cost, while maintaining hydraulic performance and cost-effectiveness in large-scale production is a challenge.
Innovation Solution
The mechanical seal is optimized by using the transition region between the cylindrical and splined shaft sections for the stop ring, incorporating form-fitting means for rotational movement, and arranging the spring means to overlap the stop and rotating slide rings, reducing the axial length and using a helical compression spring for efficient force application.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional mechanical seal with spring holders and stop ring is used, then the seal function is reliable, but the axial length of the pump increases
Solution Approach 1:
The stop ring is integrated into the transition area of the shaft between cylindrical and splined sections, merging the stop ring function with the shaft structure itself. This eliminates the need for separate axial space for the stop ring, reducing overall axial length while maintaining seal reliability
Solution Approach 2:
The spring holders are designed with form-fitting means that engage with the splined shaft section, utilizing the radial dimension of the shaft to provide axial positioning. This dimensional transition allows the spring holders to be positioned more compactly along the axial direction
2Ease of manufacture
If the mechanical seal components are arranged in a conventional manner, then the assembly is simple, but the axial length and manufacturing cost increase
Solution Approach 1:
The transition area of the shaft is given multiple functions: it serves as both the structural transition between cylindrical and splined sections and as the mounting location for the stop ring. This multi-functionality reduces the number of separate components and simplifies manufacturing while reducing axial length
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 significantly reduces the axial length of the pump, making it more compact and cost-effective while maintaining hydraulic performance, and allows for easier assembly and operation with automatic release of prestressed components.
Implementation Method 1
compression spring means (23) are held between the two spring holders (24, 25)
Implementation Method 2
a helical compression spring as the spring means
Data Source
Figure 1
Figure 2~3
AI summary
The pump (2) having a shaft (12) rotatably mounted in a housing (3). A set of impellers (8) is clamped between an abutment ring and a free end of the shaft, where the abutment ring is arranged in a transition region of the shaft. A stationary axial face seal ring is arranged in the housing. A rotating axial face seal ring is arranged on the shaft. Positive-fit unit and helical compression spring are arranged between a motor-side spring holder and an impeller-side spring holder, where the motor-side spring holder is provided in engagement with the stationary ring.