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Roberts Engineering
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795 Kuykendall Road, Albertville, AL 35951
Telephone 256-891-1613
High Volume Engine Lube Scavenge Pumps
Pump with single inlet and outlet provides 20 gpm of suction at 3500 rpm for single stream systems. The tandem pump provides 10 gpm at 3500 rpm each pump with two inlets and outlets for double stream suction. Spline connection and mounting for Lycoming IO360 engine shown. Pumps can be equipped to be pulley driven. Black hard coat anodized finish for high wear characteristics. Connections are AN-10 (7/8-14 thread with o-ring seat) for high flow in and out of the pump. Tandem pump can be supplied to provide 20 gpm suction each module. We can help you design your system for a modest fee. Call for pricing.
Tandem Pump Single Pump
In Pursuit of the Perfect Propeller
See the test (thrust, volts, amps, torque oz/in, HP, rpm) information under propellers.
After conducting the tests on the propellers shown in the following photos I machined another 8 x 6 twisted propeller and added the Hoerner wing tip modification. This propeller produced slightly more thrust with a noticeable reduction in noise. I expect this is due to a reduction in vortex generation at the tip. I will remount the two twisted blades and get an actual decibel reading to confirm the noise reduction. Also, the insight gained here has resulted in a new tip design that is an improvement of the Hoerner tip I will machine another 8 x 6 twisted blade propeller with my modification to the Hoerner tip and re-run the thrust and noise test. to confirm the design.
So much for the human ear. The decibel readings are as follows. All readings taken at 6540rpm. Twisted with Hoerner tip 95 decibels. Twisted not tipped 91 decibels. Not twisted and not tipped 94 decibels. For all practical purposes there is no difference in sound level.
Note:- the power requires to reach 6540 rpm is 148 watts for the straight as opposed to 324 watts for the twisted.
Upper propeller is twisted to maintain the proper pitch from tip to root. The lower propeller is straight from tip to root.
The above three pictures show the various configurations of an eight inch diameter by six inch pitch. The airfoil is a modified NACA 8405. One propeller is straight and the other is twisted. The airfoil is consistent from tip to root but increased in size slightly to take care of centrifugal forces. Test results show the straight configuration produces more thrust at less torque than the twisted version. The results are 42 oz/in torque for 18 oz of thrust for the straight configuration and 59 oz/in torque for 16 oz of thrust for the twisted version. I was unhappy about this because I had postulated that the twisted blade would be the better performer. Some pills are hard to swallow!
Here it is... the 15 inch fan ducted and ready to test. 120 lb thrust at 12000 rpm.
3 Inch 18 blade turbofan with E471 airfoil properly twisted blades.
Automotive Pumps 3 Lobe Gerotor Animation Engine Oil Pump Display
Transmission Oil Pump Display Radial Aircraft Engine Animation
| Revised 05/23/09 |
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