01 |
Characteristic of Speed Control Motor |
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02 |
Selection of the motor |
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i = |
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Use the nearest approximated value of the gearhead (gear ratio=i) |
① Selection of motor and controller
③ Highest number of rotations and lowest number of rotations of the motor shaft When the highest number of rotations is NH and the lowest number of rotations is NL, they are as follows.
④ Required torque of the motor
TM : Required torque of the motor [g·㎝] TL : Torque necessary to operate actual load [g·㎝] i : Reduction ratio η : Efficiency of the gearhead ⑤ Selection of the motor
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03 |
Sample Calculation for Selection (Fig. 2) |
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Number of rotations = |
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Speed of belt conveyor |
Outer diameter of drum |
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= |
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≒ 3.18 [rpm] |
Number of rotations = |
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Speed of belt conveyor |
Outer diameter of drum |
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= |
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≒ 6.37 [rpm] |
Number of rotations = |
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Speed of belt conveyor |
Outer diameter of drum |
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= |
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≒ 12.74 [rpm] |
Number of rotations of the motor |
Number of rotations of the gearhead |
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≒ 102 |
With single direction rotation of the belt conveyor, change the speed of the item being transported to 1m/minute, 2m/minute, and 4m/minute.
Instantaneous braking in emergencies, but no holing power. ① MOTOR and CONTROLLER
② Revolutions of output shaft of gearhead
③ Gear ratio The gear ratio is calculated using the higher number of rotations of the gearhead. Using 102, since there is no such reduction ratio as 1/102, 1/100 is selected. ④ Number of rotations of motor shaft
3.18 × 100 = 318 [rpm] 6.37 × 100 = 637 [rpm] 12.74 × 100 = 1274 [rpm] ⑤ Required torque of motor
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Drum diameter : 10㎝
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Operating torque : 30㎏ · ㎝
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Power : Single phase 110V 60㎐
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Rotation is in one direction and there is no holding power. Therefore, the induction motor is selected.
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The number of rotations of the gearhead shaft when the belt conveyor speed is 1m/minute.
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Number of rotations of the gearhead shaft when the belt conveyor speed is 2m/minute.
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Number of rotations of the gearhead shaft when the belt conveyor speed is 4m/minute.
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The number of rotations of the motor shaft is calculated by the number of rotations of the gearhead shaft x reduction ratio for each speed of the belt conveyor to get the following.
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The transfer efficiency of a gearhead with gear ratio 100 is 66%, so the required torque of the motor is
Operating torque |
Gear ratio × Efficiency |
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= |
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≒ 0.45 [kg·cm] |
⑥ Selection of motor
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From the N-T curve of the induction motor, it can be seen that the K8IG25NC-S motor and the K8G100B gearhead can be combined to use. However, in such a case, make sure that the inertia load should fall within the specification of the selected motor.
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04 |
The Principle of Speed Control |
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① The principle of speed control
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05 |
Limit of Use |
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① Limit curve
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