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Which of the following drive is used for metal-cutting machines tools, rolling mills etc
Group Drive
Individual drive
Multimotor drive
All of the above
Multimotor drive
Quick Summary: Multimotor drives are used in heavy industrial applications like rolling mills and complex machine tools where different parts of a machine require separate, coordinated motor control. This allows independent control over speed, torque, and positional accuracy for various sections of the process.
Multimotor drives are used in heavy industrial applications like rolling mills and complex machine tools where different parts of a machine require separate, coordinated motor control. This allows independent control over speed, torque, and positional accuracy for various sections of the process.
PtotalтАЛ=тИСi=1nтАЛPiтАЛ тАФ Total power delivered by individual motors
╧Й1тАЛ=╧Й2тАЛ тАФ Synchronized angular velocity in coordinated sections
In a multimotor drive, separate motors are assigned to specific functional components of the machine, such as the main spindle, feed mechanism, and auxiliary cooling pumps. These motors are controlled via a centralized control system (like a PLC or VFD network) to ensure synchronization and precise mechanical coordination, which is impossible with a single motor or group drive.
Used when independent speed/torque control is required for different load points.
Essential in rolling mills for tension control between successive roll stands.
Reduces mechanical transmission complexity compared to group drives.
Provides high reliability as the entire machine doesn't stop if one motor fails.
Independent control of different machine components.
High efficiency due to eliminated line-shaft losses.
Easy to automate with advanced electronic controllers.
High initial investment and complex control circuitry.
Requires skilled maintenance for electronic drive systems.
Steel Rolling Mills
Paper Mills
Automated CNC Machine Tools
Conveyor Systems
| Feature | Group Drive | Multimotor Drive |
|---|---|---|
Flexibility | Low | High |
Transmission | Mechanical (Shafts/Belts) | Electrical (Cables/Signals) |
Group drives are now mostly obsolete due to inherent energy losses in mechanical transmission.
Individual drive uses one motor per machine, whereas multimotor drive uses multiple motors for a single complex process.
C is correct тАФ Multimotor drives are essential for complex machinery where various parts require independent speed, torque, or synchronous motion control.
Always remember that in electrical machine exams, 'Multimotor' implies coordinated control, while 'Individual' is for simple single-operation machines.