WarP ™Motors for electric vehicles - when power and quality matter!
Our motors are manufactured and warranted by Warfield Electric Co. in Frankfort, Illinois USA. Warfield is the nation's largest re-builder of series wound DC motors. Warfield also manufactures new motors to our specifications. From their years of experience repairing "all the other brands of motors" they know the common failure points. From that starting point it was a matter of Warfield working with us to help design motors that are intended for the unusual stresses encountered in electric and hybrid electric vehicles. ™Motors. Why buy a WarP ™Motor ? Read Here!
EVers are always looking for information that is not normally provided by motor manufacturers. Industry wide, motors are rated by operating temperature. All our motors utilize better
than Class "H" insulation. Class "H" insulation is rated at 180 degrees Celsius. Beginning in August, 2010, our motors will be produced using 1/2" terminal studs rather than the wimpy 3/8"
or 5/16" (or smaller) used by some manufacturers.
Beginning with motors produced after August 2010, we will also be using a new internal fan capable of moving as much as 50% more air thru the motor (9" motors). We've also nearly doubled the spring pressure to reduce the chances of spring bounce (which also creates arcing). And, we have even had special brushes custom made for our motors. This new "split" brush design is better able to carry the high voltages and currents used by today's EVers.
All our motors are equipped with an internal "Temperature Snap Switch." This is a normally open (effective August, 2010) temperature switch, set at 120 degrees C on 9" and smaller
motors, and 150 degrees C on 11" and larger motors. This switch will close if the motor starts to overheat. This switch can be connected to a diagnostic system or an emergency shut off
switch ... or not connected to anything. All of our motors now include temperature sensors as well, so you can even connect a motor temperature gauge.
NOTE: The hottest point on the exterior of a motor should never exceed 180 degrees Celsius, although our motors are stress tested to 205 degrees C. The maximum brush temperature should not exceed 205 degrees Celsius.
For vehicles intended solely for use on the drag strip, motor cooling is not required. The motors do not run long enough to build any substantial amounts of heat. HOWEVER -- either an external "blower" or the internal fan should still be used to help remove carbon dust. When a brushed, series wound DC motor runs -- it grinds down the brushes. As a result, a cloud of carbon dust is circulated inside the motor. If this dust accumulates, it is possible to have an arc flash over inside the motor -- causing serious damage. The carbon dust must be blown out of the motor. If the motor is being used for racing purposes we recommend the carbon dust be blown out after each pass or event using an air compressor.
Some customers have asked for motor ratings while cooling the motors. We do not have a horse power rating for a motor with forced air cooling. There are some obvious limitations to forced air testing, such as ambient temperature, fan type, fan efficiency, motor intake & exhaust ports and CFM (cubic feet of air per minute) moved by the fan.
We have performed some testing with forced air ... and cooling with exotic gases, such as CO2, helium and argon. What we have found is interesting. For EVers, ambient temperature is the key. As a motor gets hot, the HP is lower than the initial HP generated by a cool motor. By blowing enough air to maintain, or approximate, ambient temperature ... the motor's one hour HP rating can be maintained to near its initial HP output. This is not something normally tested or rated by motor manufacturers ... but typically you can expect a 10 - 15 % increase in HP, with 20% possible on some motor designs.
One of the problems in determining motor ratings (for EVers) is finding a dynamometer capable of handling the unusual voltage and current used in racing EV's and the torque developed in testing these motors. So far, we have been unable to locate such a dyno ... but we are still looking and have recently developed some good prospects. To date, most of the high voltage ratings seen on web site haves been calculated using standard industry formulas and practices.
WarP ™Motors do not have interpoles, (with the exception of the WarP 11HV ™Motors). The interior size limitations of the motor case prevent interpoles from fitting inside the 8 and 9 inch motors. That is why no motor (of these HP ratings) is available with interpoles in a 9" or smaller configuration. Our 11", and 13" motors, and potentially larger motors, may be equipped with interpoles. The exact configuration of the interpoles may be specified. Interpoles that are incorrectly engineered may cause substantial performance problems. There are additional costs associated with the addition of interpoles. We have also strived to improve the performance of our motors by incorporating series/parallel field switching as a standard item on our 13" motors. We intend to consider this an option on our other motors as well.
We have had numerous requests to provide the torsional strength ratings for the shafts used on our motors. These ratings become critical when linking multiple motors together end-to-end. It should be apparent why we have increased the diameter of our TransWarP Motor shafts. Additionally, we have included the 1.750” diameter shaft calculations for a motor that is currently in development.
Based upon alloy steel shafts, using a conservative torsional shear strength of 50,000 PSI, but NOT considering fatigue (duty cycles are unknown),
the allowable shaft torque that will not exceed the noted shear strengths are:
DOWNLOAD CAD DRAWINGS
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