Several Driving Methods of Belt Conveyors Comparison and Advantages and Disadvantages Analysis

With the development of the national economy, belt conveyors are showing new trends such as large transport capacity, high belt speed, long transport distance, strong adaptability of the operating line, intelligence, informatization, large size, smartness, environmental friendliness, etc. This inevitably requires the belt conveyor to have a large power, and with the large-sized driving power, there will be many factors affecting safe operation. Therefore, how to reasonably choose the driving device of the belt conveyor is one of the key considerations in the design process, and it is also the key to ensuring whether the design of the belt conveyor is reasonable, whether the operation is normal, and whether the maintenance cost and maintenance quantity are relatively small.

1. **Electric Drum Motor**

Electric drum motors are divided into **internal drum motors and external drum motors**. The main difference between them is that the internal drum motor has the electric motor installed inside the drum, while the external drum motor has the electric motor installed outside the drum and is rigidly connected to the drum.

The internal drum motor, due to the electric motor being installed inside the drum, has poor heat dissipation and is generally used on belt conveyors with a power of less than 30kw and an installation machine length of less than 150m.

The external drum motor, due to the electric motor being installed outside the drum, has better heat dissipation and is generally used on belt conveyors with a power of less than 45kw and an installation machine length of less than 150m. **In actual use, the power is greater.**

**Advantages:**

The biggest advantage is its compact structure. Low maintenance costs. High reliability, the driving device and transmission drum are combined into one.

**Disadvantages:**

The disadvantage is poor soft-starting performance. When the electric motor starts, it has a large impact on the power grid. The reliability is worse than the Y-type motor + coupling + reducer driving method.

2. **Y-type Motor + Coupling + Reducer**

**Advantages:**

Simple structure, small maintenance workload, low maintenance costs, high reliability.

**Disadvantages:**

Poor soft-starting performance, large impact on the power grid when the electric motor starts. Generally used on belt conveyors with a power of less than 45kw and an installation machine length of less than 150m.

3. **Y-type Motor + Limited Torque Fluid Coupling + Reducer**

The Y-type motor + limited torque fluid coupling + reducer is a widely used driving device on belt conveyors.

There are two types of limited torque fluid couplings: one with an auxiliary chamber and one without. The limited torque fluid coupling with an auxiliary chamber has better starting performance because the hydraulic oil slowly enters the working chamber of the fluid coupling through the throttle hole during the motor start. However, due to the long starting time and large heat generation, when selecting the limited torque fluid coupling, if there are two models that can meet the transmission power, the larger model should be preferred due to its longer starting time and larger heat generation; if there are two models that can meet the transmission power, the smaller model should be preferred due to its shorter starting time and smaller heat generation. For belt conveyors with multiple motors, if the Y-type motor + limited torque fluid coupling + reducer driving method is chosen, it is recommended to use the limited torque fluid coupling with an auxiliary chamber. Therefore, the Y-type motor + limited torque fluid coupling + reducer driving method is generally used on belt conveyors with a single machine power of less than 630KW and an installation machine length of less than 1500m.

**Advantages:**

High cost-performance ratio, simple and compact structure, small maintenance workload, low maintenance costs, protect the motor from overload, when multiple motors drive, they can balance the motor power, start in stages, reduce the impact on the power grid when the belt conveyor starts, high reliability. Low price, it is the preferred driving method for belt conveyors with a machine length of less than 1500m.

**Disadvantages:**

Poor soft-starting performance, not suitable for downhill belt conveyors and belt conveyors requiring speed control.

4. **Y-type Motor + Adjustable Speed Fluid Coupling + Reducer**

The Y-type motor + adjustable speed fluid coupling + reducer is a commonly used driving method for large belt conveyors and is generally used on long-distance large belt conveyors with a machine length greater than 800m.

**Advantages:**

Simple structure, small maintenance workload, the motor starts under no load, protects the motor from overload, when multiple motors drive, they can start in stages, reducing the impact on the power grid when the belt conveyor starts, high reliability, good soft-starting performance, controllable start, that is, the start time is controllable, the start speed curve is controllable, the price is relatively low.

**Disadvantages:**

When the fluid coupling starts, due to the nonlinear relationship and lag between the change of oil quantity and speed in the working chamber of the fluid coupling, the controllability dynamic response is slow, and it is difficult to do closed-loop control. Sometimes there is oil leakage. Not suitable for downhill belt conveyors and belt conveyors requiring speed control.

5. **Y-type Motor + CST Drive Device**

The Y-type motor + CST drive device is a highly reliable mechatronics integrated drive device designed by Dodge specifically for belt conveyors and is generally used on long-distance large belt conveyors with a machine length greater than 1000m.

**Advantages:**

Good soft-starting performance, controllable start speed curve, controllable parking speed curve, the motor starts under no load, simple structure, small maintenance workload, when multiple motors drive, they can start in stages, reducing the impact on the power grid when the belt conveyor starts.

**Disadvantages:**

High maintenance requirements for maintenance workers and lubricating oil, high equipment price. Not suitable for downhill belt conveyors and belt conveyors requiring speed control.

6. **Wound Rotor Motor + Reducer**

There are three control methods for wound rotor motors + reducers:

The first control method is wound rotor motors with frequency-sensitive resistors or water resistors. This control method has no speed control function, and the motor cannot start frequently, generally used on belt conveyors with a machine length greater than 500m and motors that do not start frequently;

The second control method is wound rotor motors with metal resistors. This control method has no speed control function, but the motor can start frequently. With a controllable silicon power brake, it is a commonly used drive method for downhill belt conveyors;

The third control method is wound rotor motor cascade speed control. This control method has speed control function and can do closed-loop control, generally used on long-distance large belt conveyors with a machine length greater than 1000m and speed control requirements.

**Advantages:**

The first and second control methods have simple structure, small maintenance workload, good soft-starting performance, low price, small impact on the power grid when starting, high reliability, and good controllability; the third control method has excellent dynamic braking performance.

**Disadvantages:**

The first and second control methods have large energy consumption during starting and stopping; the third control method has a complex system and is being replaced by AC-DC-AC or AC-AC variable frequency drives.

7. **High-Speed DC Motor + Reducer**

The high-speed DC motor + reducer drive method is a variable speed drive method, generally used on large belt conveyors requiring variable speed.

**Advantages:**

Good soft-starting performance, controllable start speed curve, controllable parking speed curve, good electrical braking performance, variable speed, closed-loop control, good controllability, high reliability.

**Disadvantages:**

Very expensive, complex silicon controlled rectifier system, large area required for electrical control equipment, low power factor, DC motors have commutators, brush wear is large, large maintenance workload, currently no explosion-proof type, cannot be used in coal mines.

8. **Low-Speed DC Motor Direct Drive Belt Conveyor Drum (Permanent Magnet Motor + Transmission Drum)**

The low-speed DC motor direct drive belt conveyor drum drive method is a variable speed drive method. It is generally used on large belt conveyors requiring variable speed, and belt conveyors with motor unit power greater than 1000kw.

**Advantages:**

Excellent soft-starting performance, controllable start speed curve, controllable parking speed curve, good electrical braking performance, variable speed, closed-loop control, good controllability. No reducer, high reliability.

**Disadvantages:**

Very expensive, complex silicon controlled rectifier system, large area required for electrical control equipment, low power factor, DC motors have commutators, brush wear is large, large maintenance workload, currently no explosion-proof type for large power, cannot be used in coal mines.

9. **Variable Frequency Speed Motor + Reducer**

There are two control methods for variable frequency speed motors + reducers, the first control method is AC-AC frequency conversion, and the second control method is AC-DC-AC frequency conversion. The AC-AC frequency conversion system has a low power factor, and a large number of high-order harmonics will be generated during startup and operation, causing pollution to the power grid. The frequent startup of the motor will also cause a large reactive impact on the power grid,