| When you must select a servomotor for initial installation or for a replacement, you will need to consider the following data, which are shown in the table in Fig. 11-95. The first point to consider is whether the motor will be used for continuous duty or intermittent duty. The table shows the amount of continuous stall torque each motor can produce. The second rating from the table is the amount of peak torque. Both the continuous torque and the peak torque are listed in ounce-inches (oz-in.), pound-inches (Ib-in.), or inch-pound (in-lb.), and in newton-meters (N-m).
The conversion of ounce-inches, pound-inches, and newton-meters follows:
The rated power for each motor is listed in horsepower (hp) and kilowatts (kW). The calculation for determining horsepower and the conversion from horsepower to watts follows.
The horsepower calculation uses the torque available at the specified speed.
The rated speed is listed on the data table as rpm (revolutions per minute). The rated current is listed in A rms. The peak current and the maximum continuous AC input power are listed in A rms. The rotor inertia is rated in oz-in.2 (mass). The model numbers for each motor are listed across the top of this table.
| Technical |
Data |
Z-605
ZX-605
ZXF-605 |
Z-606
ZX-606
ZXF-606 |
Z-610
ZX-610
ZXF-610 |
Z-620
ZX-620
ZXF-620 |
Z-630
2X-630
ZXF-630 |
Z-635
ZX-635
ZXF-635 |
Z-640
ZX-640
ZXF-640 |
Z-910
ZX-910
ZXF-910 |
Z-920
ZX-920
ZXF-920 |
Z-930
ZX-930
ZXF-930 |
Z-940
ZX-940
ZXF-940 |
Continuous stall torque
oz-in Ib-in Nm |
346
22
2.44 |
633
40
4.47 |
867
54
6.12 |
1,743
109
12.31 |
2,475
155
17.48 |
2,475
155
17.48 |
4,114
257
29,05 |
2,407
150
17.0 |
4,263
266
30.1 |
5,990
374
42.3 |
9,021
564
63.7 |
|
| Peak torque |
oz-in
Ib-in
Nm |
1,083
68
7.65 |
1,954
122
13.80 |
1,733
108
12.24 |
3,486
218
24.62 |
4,951
309
34.96 |
4,951
309
34.96 |
8,228
514
58.10 |
5,205
325
35.4 |
8,525
533
61.5 |
11,980
749 84.6 |
18,041
1,128
127.5 |
| Rated power |
hp
k Watts |
2
1.49 |
2.1
1.57 |
4.2
3.13 |
5.6
4.18 |
5.4
4.03 |
6.1
4.5 |
5.9
4.40 |
9.6
7.2 |
10.4
7.8 |
11.0
8.2 |
11.1
8.3 |
| Rated speed |
rpm
rps |
6,200
103 |
3,600
60 |
7,000
117 |
3,700
62 |
2,500
42 |
3,000
50 |
1,600
27 |
5,000
83.3 |
3,150
52.5 |
2,300
38.3 |
1.500
25.0 |
Rated current
[line) |
A (rms) |
5 |
5.3 |
14.1 |
14.1 |
14.1 |
14.1 |
14.1 |
27.2 |
27.7 |
28.3 |
28.3 |
| Peak current (3.3 sec max) |
A (rms) |
16.6 |
17.2 |
28.2 |
28.2 |
28.2 |
28.2 |
28.2 |
56.6 |
56.6 |
56.6 |
56.6 |
| Max cont AC A (rms) input power (3 phase 240 VAC) |
6 |
6 |
15 |
15 |
15 |
15 |
15 |
30 |
30 |
30 |
30 |
|
| Rotor inertia |
oz-in2 (mass)
oz-in-sec2
kgm‘xlO6 |
5.45
0.01
99.6 |
9.45
0.02
172,9 |
13.73
0.04
251.2 |
35.87
0.09
656 |
50.79
0.13
929 |
56.21
0.15
1,028 |
111.21
0.29
2,034 |
50.79
0.132
929 |
111.21
0.288
2,034 |
166.21
0.431
3,040 |
459.48
1.190
8,404 |
| Motor weight |
Ibs
kg |
10.0
4.5 |
14.0
6.4 |
17.0
7.7 |
29.0
13.2 |
32.0
14.5 |
37
16.8 |
51.0
23.2 |
32.0
15.0 |
57.0
26.0 |
65.0
29.0 |
112.0
51.0 |
| Shipping weight |
Ibs
kg |
52.0
23.6 |
55.0
25.0 |
56.0
26.4 |
71.0
32.3 |
74.0
33.6 |
79.0
35.9 |
93.0
42.3 |
89.0
40.0 |
114.0
52.0 |
122.0
55.0 |
169.0
77.0 |
FIGURE 11-95 Technical data table for selecting servomotors. The motors are listed across the top of the table and the data are listed down the side. (Courtesy ofParker Compumotor Division.)
Problem 11-9
Select the proper motor from the table shown in Fig. 11-95. The load for the motor is 6 hp, the rated speed is 3000 rpm, and the rated torque required for the load is at least 4500 oz-in.
Solution
Since the load requires a minimum of 6 hp and requires at least 4500 oz-in. of torque, the Z-635, ZX-635, or ZFX-635 should be the smallest motor selected. The motor could be the next larger size, but it is not advisable to select too large a motor. |
