Vane pump for AIrbus

grabcad

Pump spec :Weight = 76 grams (topology optimized version 62 grams ) without a motor Q=7-10l/min (can be controlled with speed of the motor)H=47m (about 5 bar) It can be modified to produce 10 bar by increasing radius of rotor and enloser by 2 and decreasing the speed of motor by 2. Design process:The most applicable pumps to use for this application are centrifugal type, gear, screw pumps and rotary vane pumps due to high pressure requirements and low flow with low pulsation.Centrifugal pump will require multiple stages to get that small flow with high pressure which will make the assembly bulkier and more expensive to manufacture Gear and screw pumps have higher pulsation rate than rotary vane as well as slightly lower efficiency. Also they are difficult and expensive to manufacture and maintain. So I decided that rotary vane pump type is the most suitable in this application due to low pulsation (so we can achieve +-5% of the specified flow) , small size/ low weight , being easy to repair and cheap to manufacture. Replaceable vanes can be really easily replaced when needed I decided to design one action pump since the pressure is less 105kg/cm3 which doesn't create excessive pressure on the bearings and doesn't need to be compensated from the opposite side with the second 2nd action pressure.I decided to use hollow steel shaft to decrease the weight. The shaft can be made from titanium as well to save some weight but it will increase the cost. See attached picture for calculations proving design (if you need detailed calculations please ask) and FEA.Safety factor is 2. The weight turned out to be very small and I was able to decrease it even more using topology optimization Material choice: I picked PEEK (Polyether ether ketone) due to PEEK has cheaper manufacturing cost , harder , has better wear and friction , chemical resistance, lower density than aluminum and has cheaper manufacturing cost, has fewer leachables , has better dry wear properties, has better chemical resistance, has lower density than steel. Bolts :The force in one pump opening is about 1774 NI recommend using M5 PEEK bolts reinforced with fiberglass (2160 N proof load per bolt, fiber glass almost triples the strength of peek bolts ). Also there is an option using Aluminum 6061-T6 (2480 N proof load per bolt ) bolts and Stainless steel bolts (3200 N proof load per bolt ) however it will add some weight.Manufacturing tips/ Assembly:Rotor and the body of the pump can be injection molded and then diameters can be machined to spec to allow low cost. (Both parts can be made from aluminum as an option)Vane gaps must have at least 0.01mm clearance Press fit the shaft onto the rotor with A/X fitI also suggest using splined connecting type for shaft / rotor to evenly distribute the load. I modeled it with key connection (still passed fea) due to very limited time. Motor: 28v ,1080 rpm and 0.149 kWtsControl : 1 Option- Flow can be controlled with simple controller like Atmel ATmega8 and ESC (electronic speed controller)Put flow meter and pressure meter on the outlet of the pump and feed that information to the controller to make the adjust of the rpm of the motor. 2 Option - to test pressure and flow changes depending on the altitude and then use altimeter feed to adjust the RPM using the same controller. (Let me know if you need more info on that) BOM/Materials: Seal 1mm x 7mm (Silicone rubber) x2Seal 1mm x 62mm (Silicone rubber)Pump vane (PEEK) X 3Pump rotor (PEEK)Pump encloser (PEEK)Pump encloser upper (PEEK)Shaft (Carbon steel)Key (Carbon steel)Bearing 608RS *2Socket button head cap screw (PEEK reinforced with fiberglass or use regular steel) x 6Spring 3m force 0.07 kg x 3Hex flange nut with thread locker (PEEK reinforced with fiberglass or use regular steelCost :Using injection molding technology the total cost of material can be about $3 a piece The model is pretty rough and will need more tweaks and tests .