Parallel Pump Slider-Crank Layout for Long Stroke Capacity
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Solution Overview
Problem
Conventional reciprocating fluid pumps face limitations in increasing stroke length without escalating crankshaft size, leading to higher manufacturing costs, increased pump height and weight, and reduced service life due to increased pump speed, which also results in higher valve replacement costs and wear and tear.
Innovation Solution
A long stroke parallel pump design featuring a switch-back configuration with a slider-crank mechanism that allows for increased stroke length without raising the pump's height, utilizing a gearbox to reduce prime mover rpm and increase torque, enabling longer strokes at slower speeds to reduce wear and tear on components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If stroke length is increased using a crankshaft mechanism, then fluid flow capacity is improved, but crankshaft diameter increases proportionally leading to higher manufacturing cost and increased pump height and weight
Solution Approach 1:
The patent repositions the slider-crank mechanism from a vertical arrangement (above the driveshaft) to a horizontal arrangement (parallel to the driveshaft). This dimensional change allows the stroke length to extend horizontally rather than vertically, achieving long stroke without increasing pump height. The mechanism is arranged in a 'switch-back' configuration that fits within the pump's horizontal footprint while maintaining the required stroke length for increased fluid flow capacity.
Solution Approach 2:
The patent employs a gearbox to dynamically adjust the relationship between crankshaft rotation and plunger stroke. By reducing the prime mover rpm and increasing torque through gear reduction, the system achieves longer effective stroke length at slower speeds without requiring a proportionally larger crankshaft. This dynamic speed-torque conversion allows the same crankshaft size to produce longer strokes at reduced speeds, maintaining fluid flow capacity while avoiding increased pump dimensions.
2Productivity
If pump speed is increased to change stroke length, then fluid flow capacity is improved, but valve wear increases resulting in reduced service life and higher replacement costs
Solution Approach 1:
The patent changes the operational parameters by using a gearbox to reduce the prime mover's rotational speed while increasing torque. This parameter transformation allows the pump to achieve the required fluid flow capacity through longer strokes at slower speeds rather than shorter strokes at high speeds. The slower operating speed reduces the frequency of valve cycles, thereby decreasing wear on valves and seats and extending the service life of the fluid end components.
3Ease of manufacture
If stroke length is increased without using a larger crankshaft, then manufacturing cost is reduced, but achieving long stroke while maintaining pump compactness becomes difficult
Solution Approach 1:
The patent resolves the space constraint by reorienting the slider-crank mechanism from a vertical to a horizontal arrangement. This allows the mechanism to achieve long stroke length while fitting within the pump's horizontal footprint rather than extending vertically. The 'switch-back' configuration efficiently utilizes the available horizontal space, maintaining pump compactness while enabling long stroke without requiring a larger crankshaft or increasing manufacturing cost.
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 enhances fluid flow capacity by allowing longer strokes at slower speeds, reducing wear on pump components and extending service life while maintaining similar fluid flow rates, thus lowering maintenance costs and improving operational efficiency.
Implementation Method 1
This can be achieved by a slider-crank mechanism that converts rotational motion of a crankshaft to lateral reciprocation movement of a plunger or piston
Implementation Method 2
This reciprocation motion can create a suction phenomenon in a cylinder while traveling on one direction, and a discharge phenomenon while traveling in an opposing direction
Data Source
AI summary
A pump system may include a drive shaft extending along a longitudinal axis and supplying rotation about the longitudinal axis, a gear system operably coupled to the shaft for changing the orientation of the rotation, and a slider-crank mechanism. The slider crank mechanism may include a rotating member assembly mechanically coupled to and driven by the gear system. The rotating member assembly may include a plurality of rotating members having respective rotational axes offset laterally from one another and generally orthogonal to the longitudinal axis. The slider crank mechanism may also include a sliding member assembly mechanically coupled to the rotating member assembly. The rotating member assembly may be configured to drive reciprocating motion of the sliding member to alternately draw fluid in and discharge fluid. The slider crank mechanism may also include a connecting rod assembly mechanically coupling the rotating member assembly to the sliding member assembly.