Selection Of The Spindle Motor - HEIDENHAIN TNC 410 M Technical Manual

Maximum torque of
a drive

3.3 Selection of the Spindle Motor

Procedure
April 2007
If the power module is not powerful enough, the maximum torque of the
motor cannot be reached because the required current is being limited by the
power module. The maximum torque M
calculated.
Synchronous motors:
M
Nmot
⋅
----------------- -
M I
=
max Ndrv
I
Nmot
Asynchronous motors:
⋅
60
P
max
=
M -------------------------- -
⋅ π ⋅
2
max
n
I
qmax
⋅ ---------------- -
P = P
max Nmot
I
qN
2
I = I – I
0mot
qmax max
2
I I I
= –
0mot
qN Ndrv
M : Rated torque of the motor in Nm
Nmot
I : Rated current of the motor in A
Nmot
I : Rated current of the power module in A
Ndrv
n: Motor speed in rpm
P : Power rating of the motor in W
Nmot
I : Lesser value between the maximum current of the motor and the
max
maximum current of the power module in A
I : No-load current of the motor
0mot
Selection of the spindle motor for required torque and speed
Selection of the Spindle Motor
achievable by the drive can be
max
2
2
3 – 9