What are the symbols in thesew electric motor equations?

Im revising for an exam and i've come across these equations in my lecture notes.
Has anyone seen these equations before, and can tell me what the symbols represent?

T = k1 ᶲ Ia

Ea = k1ᶲ2πN = k2ᶲN

Ea = Va-IaRa

N = (Va-IaRa) / (2πk1ᶲ)

Im guessing T is torque, Ea is the volatge across the motor, and Va is the source voltage. Im not sure though.

Thanks

These are equations for DC motors - usually based on the DC Shunt motor but can be applied to all types.

Ea is the voltage produced by the armature is oppostion to the applied voltage E (your Va) so re-writing your eq
Ea = E - (Ia* Ra) Ra is the armature resistance

N is speed in RPM

So N = 60*Ea / (Z*60) most assume that at rated load E and Ea are essentially the same but they are not as Ea and E can never but equal. Assuming they are though will give you the max speed possible with a given flux (k)

Z is a constant due to motor construction - active number of conductors in the armature - I like to call it the fudge factor

Torque is proportinal to flux and armature current

T=Z*K/ 6.28


in general
Torque goes up ( load increases) current goes up, speed goes down

If flux goes up - speed goes down

by the way Power P = Ea * Ia

which is also P= nT/ 9.55

Good book to look at for all these equations
Electrical Machines, Drives and Power Systems by Theodore Wildi

also google " DC motor equations"

here are few links to look at
http://zone.ni.com/devzone/cda/ph/p/id/46
http://coep.vlab.co.in/?sub=33&brch=95&sim=1040&cnt=1