Rockwell Automation 8520 9/Series CNC Integration Maintenance Manual Documentation Set User Manual
Page 658
Section 13A
Connecting 8520 Digital Drive Systems
13A-24
The 8500 digital servo motors are used to drive the axes of the 8520 digital
servo drive system. The 8500 digital servo motors have a feedback device
mounted on them that provides position and velocity data to the servo
module. A second feedback device can be mounted directly on the axis
(such as a linear slide) to provide greater precision for positioning
feedback. On these systems with multiple feedback devices, the motor
mounted encoder is used for motor commutation and velocity feedback.
The control uses a digital velocity command scheme to improve motor
performance and efficiency. This requires the use of servo motors
designed for 8520 digital drive application.
The 8520 digital servo drive system can be configured to handle various
8500 digital servo motors. Table 13A.N lists the 1000/2000 RPM servo
motor options and their specifications.
Table 13A.N
1000/2000 RPM 8500 Digital Servo Motor Options and Specifications
Specifications
1000/2000 RPM 8500 Digital Servo Motor Options
8500-A1C
8500-A2C
8500-B1C
8500-B2C
8500-B3C
Rated Output/Axis
kW (HP)
0.3 (0.4)
0.6 (0.8)
1.2 (1.6)
2.0 (2.7)
3.0 (4.1)
Rated Torque
kg
.
cm (lb
.
in)
29 (25)
58 (50)
117 (102)
195 (169)
290 (252)
1
Continuous Max. Torque
kg
.
cm (lb
.
in)
30 (26)
60 (52)
120 (104)
220 (191)
330 (286)
Instantaneous Max. Torque
kg
.
cm (lb
.
in)
87 (76)
2
174 (151)
2
351 (305)
2
390 (339)
2
703 (610)
2
Rated Current
Arms
3.0
5.8
11.7
18.8
26
1
Rated Revolution
rpm
1000
Maximum Rated Revolution
rpm
2000
Torque Constant
kg
.
cm/A (lb
.
in/A)
10.3 (8.9)
10.6 (9.2)
10.4 (9.0)
10.9 (9.5)
11.8 (10.2)
Rotor Inertia
(J)
g
.
cm
.
s
2
(lb
.
in s
2
x10
-3
)
13.8 (12.0)
24.8 (21.5)
68.2 (59.2)
112 (97.2)
146 (126.7)
(GD
2
/4) kg
.
cm
2
(lb
.
in
2
)
13.5 (4.61)
24.3 (8.31)
66.8 (22.8)
110 (37.6)
143 (48.9)
Power Rate
kW/s
6.1
13.3
19.7
33.2
57.0
Mechanical Time Constant
ms
8.3
5.9
6.9
5.2
4.1
Electrical Time Constant
ms
4.2
5.4
10.4
12.9
15.3
Number of Pole
poles
8
Weight
kg (lb)
10 (15)
15 (33)
24 (53)
32 (71)
43 (95)
1
The rated current available for the 8500-B3C digital servo motor is limited to 21 amps (rms) by the amplifiers maximum output rating.
This limits the available rated torque to 232 kg.cm (203 lb.in).
2
These values will vary depending on the amplifier selected to operate these motors. You may need to recalculate these values based
on your amplifier selection.
Important: 8500 digital servo motor mounting dimensions start on page 13B-1.
13A.8
8500 Digital Servo Motors
13A.8.1
8500 Digital Servo Motor
Options