Vane pump for AIrbus

grabcad

The pump weighs 76 grams, with a topology-optimized version at 62 grams (excluding motor). It has a flow rate of 7-10 l/min, which can be controlled by adjusting the motor speed. The working height is 47 meters, or about 5 bar. The pump can be modified to produce 10 bar by increasing the rotor and encloser radius by 2 and reducing the motor speed by 2. Centrifugal, gear, screw, and rotary vane pumps were considered for this application due to high pressure requirements and low flow with low pulsation. However, centrifugal pumps require multiple stages, making them bulkier and more expensive. Gear and screw pumps have higher pulsation rates and lower efficiency, while also being difficult and costly to manufacture and maintain. Thus, a rotary vane pump was chosen for its low pulsation (allowing for a 5% flow variation), small size/low weight, ease of repair, and affordable manufacturing cost. Replaceable vanes can be easily replaced when needed. A single-action pump design was selected due to the pressure being less than 105 kg/cm³, preventing excessive pressure on bearings and the need for a second action pressure compensation. The hollow steel shaft helps reduce weight, with titanium as an alternative but at higher cost. Calculations and FEA are available for review (safety factor is 2). PEEK (Polyether ether ketone) was chosen for its material properties, including lower manufacturing costs, increased hardness, better wear and friction resistance, improved chemical resistance, and lower density compared to aluminum and steel. M5 PEEK bolts reinforced with fiberglass are recommended for assembly, with a proof load of 2160 N per bolt. Alternatively, aluminum or stainless steel bolts can be used but will increase weight. The rotor and pump body can be injection-molded, with machining to specification for low-cost production (both parts can be made from aluminum as an option). Vane gaps must have at least 0.01mm clearance, and the shaft should be press-fitted onto the rotor using A/X fit. A splined connecting type is suggested for evenly distributing load on the shaft/rotor connection (modeled with key connection due to limited time). A 28V, 1080 RPM motor with a power output of 0.149 kW is required for control. Two flow control options are available: using a simple controller like Atmel ATmega8 and an ESC to adjust the motor's RPM based on flow meter and pressure meter readings, or testing pressure and flow changes at different altitudes and adjusting the RPM using an altimeter feed. The BOM/materials include seals, pump vanes, rotors, enclosures, a steel shaft, bearings, springs, and screws made of PEEK or steel. Injection molding can reduce material costs to approximately $3 per piece. The design is still in need of refinement and testing.