Screw Pump Double-Start Threads Mass Balance
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Solution Overview
Problem
Conventional screw pumps have limited suction power due to uneven mass distribution causing imbalance at high speeds, restricting their operational speed and efficiency.
Innovation Solution
Designing screws with two threads that form a double helix structure, ensuring symmetrical mass distribution and allowing higher operational speeds, along with a housing design that includes a large suction gap and strategically positioned inlet opening to enhance gas entry and compression.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If conventional single-start threads are used in screw pumps, then the structure is simple, but the mass distribution is uneven causing imbalance at high speeds
Solution Approach 1:
The patent applies asymmetry by transitioning from single-start threads to double-start threads. The double-start thread configuration creates a symmetrical mass distribution around the screw axis, balancing the rotating mass and enabling high-speed operation without excessive vibration. This resolves the contradiction by introducing a more complex thread structure that achieves operational symmetry.
2Productivity
If screw pumps operate at high speeds to increase suction capacity, then productivity improves, but imbalance from uneven mass distribution becomes difficult to control
Solution Approach 1:
The double-start thread design creates radial symmetry in mass distribution, which balances the centrifugal forces during high-speed rotation. This symmetry ensures that the center of mass remains on the rotation axis, preventing vibrations and maintaining reliability at high operational speeds while maximizing suction capacity.
3Productivity
If the housing is designed with a large suction gap to enhance gas entry, then suction power increases, but the leakage gap between housing and thread increases
Solution Approach 1:
The patent applies local quality by differentiating the housing design into two distinct sections: a first housing section with a larger suction gap to facilitate gas entry and improve suction performance, and a second housing section with a minimal leakage gap to prevent gas escape. This localized differentiation allows the system to optimize both suction power and sealing efficiency in different functional zones.
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 significantly increases suction power, enabling the pump to handle larger volumes and higher pressures, making it suitable for applications where conventional screw pumps are inadequate, such as in booster pump assemblies and liquid ring vacuum systems.
Implementation Method 1
The threads are designed to be symmetrical with respect to the screw axis, so that for each outwardly projecting element of one thread, there is a corresponding element of the other thread, located radially opposite it with respect to the screw axis. This symmetrical design balances the mass distribution and reduces vibration at high speeds.
Implementation Method 2
The volume of the working chambers decreases from the suction side to the pressure side. The gas is compressed within the pump and released at a higher pressure on the pressure side.
Implementation Method 3
In the first housing section, there is a suction gap between the housing and the thread. The inlet opening is positioned to allow gas to be drawn into the working chambers through this gap by the pressure differential created during screw rotation.
Data Source
Figure 1
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Figure 4~5
AI summary
Screw pump with two screws (14), each screw (14) having a first thread (19) and a second thread (19). The threads (19) extend from a suction side (20) to a pressure side (21) and are in mesh with each other, so that the threads (19) are divided into a plurality of working chambers, the volume of which decreases from the suction side (20) to the pressure side (21). The threads (19) have two threads, and the housing (15) is provided with an inlet opening (24) that is larger than 60% of the cross-sectional area of the thread (19).