Rotary Lobe Blower SIDF Flow Synchronization for Lower NVH
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Solution Overview
Problem
Traditional rotary lobe blowers experience significant flow pulsations and induced noise, vibration, and harshness (NVH) due to out-of-phase flow paths, leading to inefficiencies and increased complexity at high speeds and pressures.
Innovation Solution
Implementing a synchronized induction and discharge flow (SIDF) mechanism by angularly shifting the suction and discharge ports to synchronize the flow paths, reducing flow velocity swings and enhancing blower efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If traditional out-of-phase flow paths are used in rotary lobe blowers, then the blower can operate at high speeds, but flow pulsations and NVH increase significantly
Solution Approach 1:
The patent implements synchronized periodic action by adjusting the angular positions of suction and discharge ports so that both rotors induce and discharge flows simultaneously at regular intervals, converting the traditional out-of-phase periodic action into in-phase periodic action. This synchronization eliminates the alternating flow pulsations that occur with out-of-phase operation, reducing NVH while maintaining high-speed capability
Solution Approach 2:
The patent merges the flow induction and discharge timing of the two rotors by angularly positioning the ports so that both rotors perform the same flow operation simultaneously. This merging of previously separate out-of-phase operations into a unified in-phase operation reduces flow velocity swings and associated harmful effects while preserving high-speed performance
2Device complexity
If out-of-phase flow paths are used, then the blower design is simpler, but blower efficiency decreases at high pressures
Solution Approach 1:
The patent changes the angular position parameters of the suction and discharge ports relative to the rotor lobes. By adjusting these angular parameters, the flow induction and discharge timing is optimized to occur simultaneously for both rotors, improving volumetric efficiency and pressure handling capability without adding mechanical complexity to the flow path configuration
3Volume of moving object
If traditional aligned inlet and outlet ports are used, then the structure is more compact, but flow velocity directional swing is large
Solution Approach 1:
The patent introduces asymmetric angular positioning of the suction and discharge ports relative to the rotor axis and lobe positions. Instead of symmetric alignment, the ports are positioned at specific asymmetric angles that synchronize the flow operations of both rotors, reducing flow velocity directional swing while maintaining a compact overall blower structure
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 SIDF mechanism effectively reduces flow pulsations and NVH, improves blower efficiency, and maintains a compact, lightweight design suitable for high-speed and high-pressure applications.
Implementation Method 1
The two rotors counter-rotate and are synchronized non-contact by a set of timing gears inside the casing wall
Data Source
AI summary
Synchronized Induction & Discharge Flows (SIDF) for a rotary lobe blower (pump) or vacuum pump reduce flow pulsations, noise, vibration, harshness (NVH) and improve blower efficiency. Generally, a rotary lobe blower (pump) or vacuum pump with a SIDF has a pair of mechanically synchronized multi-lobe rotors with the same number of lobes housed in a well of a casing wall with an off-center suction port and discharge port. The fluid being trapped by adjacent lobes of each of the rotors and the walls along two flanks of the walls of the well are synchronized wherein the suction port and the discharge port have each an axis that are parallel with each other; the suction port axis and the discharge port axis being offset with each other; wherein the offset provides simultaneous fluid inducting for the two flanks at the suction port and simultaneous fluid back filling and discharging for the two flanks at the discharge port respectively.