MySpec! Login
Glossary of Terms
- DC
- Duty Cylcle
- The part of the time in % of the total time in which the workpoint is active
- Pelec
- Electrical dissipation
- Pfric
- Dissipation due to mechanical friction
- Rth1
- Thermal resistance between windings and motor house
- Rth2
- Thermal resistance between motor house and surrounding
- Rhs
- Thermal resistance between motor house and surrounding of additional mounted heatsink
- Cth1
- Thermal capacity between windings and surrounding
- Cth2
- Thermal capacity between motor house and surrounding
- Θwinding
- Temperature of the windings
- Θhouse
- Temperature of the motor house
- Θamb
- Ambient temperature
- Θmax
- Maxium temperature of the motor (usually determined by the allowed temperature of the magnet at which demagnetisation is avoided)
- p
- amount of pole pairs (so half the amount of poles)
- Umax
- Maximum terminal voltage
- Unom
- Nominal terminal voltage
- Pin
- Input output
- input power of motor is electrical power U·I
- Prated
- Power output as rated by the manufacturer
- Pmax,comm
- Maximum allowed power due to commutation limit
- Pmax
- Maximum power
- Imax,thermal
- Maximum continously allowed current for which the motor reaches its maxium temperature (usually determined by the maximum temperature of the magnets)
- Imax
- Maximum allowed current (usually determined for a short period). Where AC current is applicable this indicates the RMS value.
- Ilimit
- Current for which the magnets reach their maximum allowed temperature for a given speed and duty cycle
- ω
- omega - symbol for rotational speed
- ωmax
- maximum motor speed (usually determined by inbalance of the rotor)
- ω0
- motor speed at no load (so also no friction of the motor itself) for the nominal terminal voltage
- Tstall
- Stall torque
- Tfric
- Friction torque
- Tmotor
- Total torque that the motor has to provide
- η
- eta - symbol for efficiency
- ηred
- Efficiency of the reduction
- ηmotor
- Efficiency of the motor
- ηtotal
- Total efficiency (usually associated with efficiency of motor plus reduction)
- Jrotor
- Inertia of the rotor as experienced on the motor axis
- k
- Motor constant
- Torque constant
- Voltage constant
- kref
- Motor constant at the magnet reference temperature of 22 oC
- kend
- Motor constant at the end temperature for a given workpoint at equilibrium (no temperature changes occur)
- S
- steepness of the motor
- Determined by k and R according to k2/R
- L
- self-inductance of the motor
- R
- resistance of the motor (windings)
- resistance is dependant on winding temperature
- Rref
- resistance of the windings at the winding reference temperature of 22 oC
- α
- rate at which resistance increases with winding temperature
- material constant, for copper: 0.00393
- TKBr
- rate at which field strength changes with increasing magnet temperature
Units
- rpm
- revolutions per minute - rotationspeed
- N
- Newton - force