Internal Gear Pump Relief Channel Design for Noise Reduction
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Solution Overview
Problem
Internal gear pumps, such as trochoid pumps, face challenges in achieving high fluid-mechanical efficiency while minimizing noise emissions, as the generation of squeezing flows and pressure surges leads to noise pollution and efficiency losses, particularly in applications where noise reduction is critical, like in vehicles.
Innovation Solution
The design incorporates relief and additional channels that form flow connections between the tooth engagement and pressure chambers, allowing squeezed fluid to escape into the pressure chamber, minimizing crushing losses and noise generation without fluid-mechanical losses, and optimizing psychoacoustic parameters by reducing specific loudness and roughness in specific frequency groups.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the tooth shapes are selected so that the rolling tooth surfaces lie closely together, then pump efficiency is improved, but noise emissions increase due to squish flows and pressure surges
Solution Approach 1:
The patent introduces relief channels as intermediary flow paths between the tooth engagement region and the pressure chamber. These channels mediate the discharge of squish flows, allowing them to escape gradually into the pressure chamber rather than being forced through tight tooth clearances, thereby reducing both noise and fluid-mechanical losses simultaneously
2Object-generated harmful factors
If the gap between the tooth tips of the inner and outer rotors is enlarged, then noise pollution is reduced, but pump efficiency decreases due to fluid circulation between chambers
Solution Approach 1:
The relief channels serve as controlled intermediary pathways that allow squish flows to be discharged into the pressure chamber in a managed manner. This eliminates the need to enlarge the gap between tooth tips, as the channels provide an alternative route for fluid discharge that reduces noise without creating the harmful circulation loops that would reduce efficiency
3Productivity
If standard trochoidal pump design is used, then high pump efficiency is achieved, but psychoacoustic parameters become unpleasant due to high sound pressure and noise
Solution Approach 1:
The relief channels act as intermediary discharge paths that capture and redirect squish flows away from the noisy tooth engagement region. By providing this intermediate flow path, the system maintains the efficient tooth meshing geometry while redirecting the harmful high-energy flows into the pressure chamber, thereby preserving pump efficiency while significantly reducing psychoacoustic noise
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 effectively reduces psychoacoustic noise and maintains high fluid-mechanical efficiency by diverting squeezing flows into the pressure chamber, minimizing noise emissions and pressure surges, thus enhancing the pump's operational performance and compatibility in noise-sensitive environments.
Implementation Method 1
at least one relief channel is provided, which forms a flow connection between the tooth engagement region and the pressure chamber, so that a fluid or a squeeze flow can flow from or away from the tooth engagement region to the pressure chamber
Data Source
Figure 1~2
AI summary
The invention relates to an internal gear pump, in particular a trochoidal pump, for a vehicle, with a pump housing (3) having a rotor chamber (4) in which a toothed ring (6) having internal teeth (7a-7g) is received, which can be engaged with a gear (11) mounted eccentrically to the toothed ring (6) and having external teeth (12a-12f) in such a way that at least one of the external teeth (12a) is engaged in a tooth engagement area (13a) between two internal teeth (7a;7g) lies in the inner interdental space, wherein the volumes forming the pump chambers (16) between the inner teeth (7a-7g) and the outer teeth (12a-12f) increase in a rotor chamber area associated with a suction chamber (17), starting from the tooth engagement area (13a) to a tooth boundary area (14a), in which at least one outer tooth (12d) abuts or rests against an inner tooth (7d) at its head side, and decrease again in a rotor chamber area associated with a pressure chamber (18), starting from the tooth boundary area (14a) to the tooth engagement area (13a). According to the invention, at least one relief channel (19) is provided, which forms a flow connection between the tooth engagement area (13a) and the pressure chamber (18).