Reciprocating Pump Bellows Mounting on Segmented Rod
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Solution Overview
Problem
Existing reciprocating pumps with bellows seals face challenges in mounting and replacing the bellows due to the need for longer bellows with increased pump stroke, which complicates the assembly and maintenance, especially when the pump rod is designed as two pieces.
Innovation Solution
A reciprocating pump design featuring a single-piece rod with a lobed sleeve and bearings within the bellows, allowing for easier assembly and maintenance by preventing rotation and providing a secure seal, thus simplifying the replacement of the bellows without disassembling the entire pump.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the pump stroke is increased, then the pumping capacity is improved, but the bellows length increases making mounting and replacement difficult
Solution Approach 1:
The pump rod is divided into two separate pieces: a lower pump rod and an upper pump rod. The bellows is mounted only on the upper pump rod, which can be independently removed. This segmentation allows the bellows to be accessed and replaced without requiring disassembly of the entire pump or removal of the lower pump rod, thus maintaining ease of operation despite increased pump stroke and bellows length.
2Ease of operation
If the pump rod is made as two pieces, then access to both ends is improved, but the assembly complexity increases
Solution Approach 1:
A connecting mechanism serves as an intermediary between the lower and upper pump rods. This connector allows the two rod pieces to be easily assembled and disassembled without complex procedures. The intermediary component simplifies the joining process, offsetting the inherent complexity of having a two-piece rod design and enabling straightforward maintenance access.
3Strength
If a single-piece rod is used, then the structural strength is improved, but the bellows replacement requires complete pump disassembly
Solution Approach 1:
The pump rod is segmented into replaceable sections (lower and upper rods), prioritizing ease of repair over maximum structural strength. This segmentation allows the upper rod with the mounted bellows to be independently removed and replaced without complete pump disassembly, directly addressing the ease of repair requirement.
4Reliability
If the bellows is made longer, then the seal coverage is improved, but the mounting difficulty increases
Solution Approach 1:
The pump rod segmentation enables the bellows to be mounted on a separate, removable upper rod section. This allows long bellows to be pre-assembled and tested separately, then easily installed into the pump by removing only the upper rod, significantly reducing mounting difficulty despite the increased bellows length required for adequate seal coverage.
Data Source
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AI summary
A reciprocating pump includes a housing, a rod, a sleeve, a bellows, and a nut. The housing includes a bellows chamber and a working chamber. The rod extends into the reciprocating pump such that the rod extends through the bellows chamber and partly into the working chamber. The rod includes a shoulder. The sleeve is connected to the rod such that the sleeve surrounds a portion of the rod. The bellows is connected to the sleeve such that the bellows surrounds a portion of the sleeve. The nut is attached to a bottom end of the sleeve such that the nut clamps an end of the bellows to the bottom end of the sleeve.