
FANUC AC SPINDLE MOTOR a series
2. FUNCTION EXPLANATION
B–65160E/02
76
(1) Calculating the orientation time
In the following explanation, the time, from the input of an
orientation command until orientation stops, is divided into five
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
t
5
Nms
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
t
2
: rotation) after Nori is achieved, until deceleration starts (1 –
t
2
: Rori rotation) [sec]
t
3
: Time from the start of deceleration until speed Nms is
t
2
: achieved [sec]
t
4
: Time from reaching Nms until the LS signal is detected [sec]
t
5
: Time from detection of the LS signal until orientation is
t
2
: completed [sec]
(a) 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 to rotate (1 – Rori) to (2 – Rori) turns at
orientation speed Nori [min
–1
].
(1 * Rori) 60 Nori x t
2
x (2 * Rori) 60 Nori
N
1
PG Rori
*
1
PG
x t
2
x
2
PG Rori
*
1
PG
(c) For simplicity, t
3
will be calculated later, together with t
5
.