Supplement : Thermal effects on four performance-characters of motor

• N0 : No-load speed
  The magnetic force of magnets becomes weaker and N0 rises in inverse proportion.
• I0 : No-load current
  The current changes in inverse proportion to the magnetic force of magnets, but is affected even more than that due to the loss in bearing oil viscosity. In our approximation of I0, calculation is made without considering thermal changes.
• Is : Stall current
  Because the current changes in inverse proportion to the winding resistance, as the temperature rises, Is falls.
• Ts : Stall torque
  Because the magnetic force of magnets becomes weaker with decreasing current, as the temperature rises, Ts falls greatly.