
B–65160E/02
2. FUNCTION EXPLANATION
FANUC AC SPINDLE MOTOR a series
57
The time required for orientation differs between the first orientation
(before the position coder one–rotation signal has first been detected) and
the second and subsequent orientations (once the one–rotation signal has
been detected).
(1) Before the one–rotation signal has first been detected (first
orientation)
The time, from the input of an orientation command until orientation
stops, is divided into four periods.
In the following figure, A indicates that the motor in the stop state
starts rotating and is accelerated to the orientation speed. B indicates
that the already rotating motor is decelerated to the orientation speed.
t
1
t
2
t
3
t
4
A
B
Nori
Motor speed
Time
t
1
: Time required to achieve orientation speed Nori [sec]
t
2
: Time from the detection of a one–rotation signal (0 to 1
rotation) after Nori is achieved, until the number of
pulses output before the next one–rotation signal has been
checked [sec]
t
3
: Time from the completion of the checking of the number of
pulses until deceleration starts [sec]
t
4
: Time from the start of deceleration until orientation is
completed [sec]
(a) Normally, t
1
is measured on the actual machine.
Orientation speed Nori [min
–1
] is calculated from position gain
PG [sec
–1
] and the motor speed limit ratio for orientation Rori.
Nori + PG 60 Rori
(b) t
2
is the time required for the motor to rotate one to two turns at
orientation speed Nori [min
–1
].
1 60 Nori x t
2
x 2 60 Nori
N
1
PG Rori
x t
2
x
2
PG Rori
2.1.7
Calculating the
Orientation Time