15-20kw Brushless Motor Differences?

Electric Motors and Controllers
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socalfusions   10 mW

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15-20kw Brushless Motor Differences?

Post by socalfusions » Apr 30 2012 10:58pm

What are the features that really set apart the brushless motors in the 15-20kw range such as the Hacker A200, Predator 37, Joby Motors, etc. Is it the Kv that makes a large difference? The Predator has a unique design that allows better cooling from spaces in the center of it, other than that I don't have enough understanding of these high watt brushless motors to really discern them from eachother.

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ion   1 µW

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Re: 15-20kw Brushless Motor Differences?

Post by ion » May 12 2012 11:59pm

Motor quality depends on the grade of magnets, wire, bearings and its ability to dissipate heat. The wattage that the manufacture places on the label may be over rated or under rated by independent testing. The KV is the RPM for every volt your battery pack puts out. A 110 Kv motor at 48v will spin the shaft at 5,280 RPM. The Kv of your motor matched with your battery pack output volts along with your gear ratio may help govern your design for let’s say a flat environment or a hilly environment.

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Miles   100 GW

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Re: 15-20kw Brushless Motor Differences?

Post by Miles » May 13 2012 9:55am

socalfusions wrote:Is it the Kv that makes a large difference?
With regard to performance, the velocity constant is only significant in relation to the terminal resistance (Rm).

A good way to compare motors is to use the motor constant (Km), expressed as torque per root Watt.
Km = Kt / √[Rm]

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