Fastener-Free Fluid Pump Cover Retention via Spring Bias
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Solution Overview
Problem
Conventional fluid pumps rely on external fasteners for attaching internal components to the pump housing, which can lead to manufacturing complexities and inefficiencies due to thermal expansion and manufacturing tolerances, particularly in cartridge-style pumps used within fluid-handling mechanisms.
Innovation Solution
A fastener-free fluid pump design utilizing a spring assembly and retaining ring within a perimeter retaining channel of the pump housing to secure the pump cover, rotor, and stator, allowing for axial and rotational alignment without external fasteners, and absorbing thermal expansion and manufacturing tolerances through a pre-load spring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If external fasteners are used to attach internal components to the pump housing, then the components can be securely fixed, but manufacturing complexity increases and thermal expansion causes assembly issues
Solution Approach 1:
The patent removes external fasteners from the assembly, extracting the problematic element that caused manufacturing complexity and thermal expansion issues. The pump cover and internal components are retained without fasteners, using instead an interference fit and snap-fit mechanism that eliminates the need for separate fastening elements.
Solution Approach 2:
The pump cover and internal components perform their own fastening function through the interference fit between the pump cover flange and housing, combined with the snap-fit of the pump cover into the retaining channel. This self-service mechanism eliminates the need for external fasteners and reduces assembly complexity.
2Reliability
If external fasteners are used to attach internal components, then components can be securely fixed, but manufacturing time and efficiency decrease
Solution Approach 1:
By removing external fasteners from the design, the patent eliminates the time-consuming steps of fastener installation and adjustment. The snap-fit and interference fit mechanism allows for rapid assembly and disassembly, significantly improving manufacturing efficiency while maintaining secure component fixation.
Solution Approach 2:
The pump cover and internal components are designed with pre-formed flanges and retaining channels that enable snap-fit assembly. This preliminary design of the retention mechanism allows components to be quickly attached without requiring separate fastening operations, thereby improving manufacturing productivity.
3Reliability
If rigid fastening is used to attach components, then components are securely fixed, but thermal expansion causes internal stresses and assembly difficulties
Solution Approach 1:
The patent transitions from a rigid fastening system to a dynamic retention system where the pump cover can move axially within the retaining channel. This dynamic capability allows the assembly to accommodate thermal expansion and contraction of components without generating harmful internal stresses, while the interference fit maintains secure fixation during normal operation.
Solution Approach 2:
The interference fit between the pump cover flange and housing provides a friction-based retention that can accommodate dimensional changes due to thermal expansion. The fit parameters are designed to maintain secure fixation at operating temperatures while allowing for thermal growth, thereby preventing internal stresses.
4Reliability
If fasteners are used to attach the pump cover, then the pump cover is securely retained, but manufacturing waste increases
Solution Approach 1:
By eliminating external fasteners from the design, the patent removes the material waste associated with fastener production, handling, and disposal. The snap-fit and interference fit mechanism uses the existing pump cover and housing materials for retention, eliminating additional material consumption and reducing manufacturing waste.
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 simplifies manufacturing, reduces waste, and minimizes internal stresses by allowing components to expand and contract freely, while ensuring consistent assembly and operation of the fluid pump without the need for external fasteners.
Implementation Method 1
A spring assembly, retained within a retaining channel of the pump housing, serves to bias the pump cover in a generally axial direction toward the pump assembly and to absorb thermal expansion and manufacturing tolerances
Implementation Method 2
The pump cover and the pump assembly are retained within a perimeter retaining channel of the pump housing without the use of fasteners
Data Source
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AI summary
A fluid pump includes a stator. A rotor is rotationally operable with respect to the stator. A drive shaft extends from the rotor to a pump assembly that delivers a fluid from an inlet to an outlet. A pump housing includes an interior cavity that contains the stator, the rotor and the pump assembly. A pump cover is disposed at an end of the pump housing. The pump cover defines an end of the interior cavity. A spring assembly biases the pump cover in an axial direction toward the pump assembly.