The rotor profile of the internally meshing crescent pump, enclosed by crescent plates, forms a series of sealed chambers. During the meshing operation, it conveys fluid from the low-pressure zone to the high-pressure zone, creating suction and discharge. The sealing characteristics of the rotor profile affect the pump's internal leakage and volumetric efficiency; the change rate in the volume of the enclosed chamber impact the pump's volumetric efficiency, cavitation, hydraulic vibration, etc; the meshing characteristics of the rotor profile determine the transmission characteristics of torque and motion, subsequently influencing related factors such as tooth contact stress, friction wear life, mechanical vibration and noise, and mechanical efficiency.
Considering the convenient manufacturing processes and design algorithms, the involute tooth profile has been widely adopted in the industry. However, its notable drawbacks include low space efficiency (smaller displacement for the same size) and limited effective sealing width, challenges that involute profiles find difficult to overcome.
The Composite Integral Algorithm (Cotegral® Algorithm) developed by APT, breaks through the constraints of traditional profile solutions. It allows the use of more complex curves and segmented curves as base functions for solving rotor pair profiles. Compared to traditional involute rotor profiles, the new series of rotor profiles based on the Composite Integral Algorithm can be highly flexible in multi-parameter optimization. Depending on actual working conditions and technical requirements, optimization of volumetric efficiency, sealing range, pressure pulsation, cavitation characteristics, etc., can be done on-demand, making the crescent pump achieve better hydraulic performance, transmission performance, and reliability.
The crescent pump rotor profile types developed by APT are showcased in the images above, with various profile types already maturely applied in the automotive and aviation industries. APT can also customize new specialized profiles according to customer-specific requirements or specific technical requirements.