The transmission system of a cold roll forming machine must meet requirements such as high synchronization, stable torque output, and adaptability to continuous production. The commonly used transmission methods are mainly as follows, each with its applicable scenarios:
I. Gear Transmission (Core and Most Commonly Used)
Gear transmission is the mainstream transmission method for cold roll forming machines due to its precise transmission ratio, high efficiency, and strong load-carrying capacity. The specific forms include:
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Spur Gear Transmission
- Application: Mostly used for the transmission of horizontal roll groups (such as the main shaft transmission of roll-type cold roll forming machines).
- Characteristics: Power is transmitted from the motor/reducer to each roll through the meshing of multiple sets of gears, ensuring the synchronous rotation of multiple rolls (consistent speed to ensure the accuracy of sheet forming).
- Advantages: Compact structure, transmission efficiency of 90%-98%, suitable for medium and high-speed, high-torque scenarios (such as thick plate forming).
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Bevel Gear Transmission
- Application: Used in parts that need to change the transmission direction (such as the power transmission between the roll group and the vertical guide wheel).
- Characteristics: It can realize power transmission between vertical or intersecting shafts, adapting to the complex roll system layout of the cold roll forming machine.
II. Chain Transmission (Auxiliary and Distributed Transmission)
Chain transmission transmits power through the meshing of chains and sprockets, suitable for non-parallel shafts and medium-to-long distance transmission, and is mostly used as auxiliary transmission in cold roll forming machines:
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Application Scenarios:
- Used to drive auxiliary equipment (such as feeding rolls, straightening rolls), forming a shunt power output with the main gear transmission;
- In small cold roll forming machines, it replaces part of the gear transmission to reduce costs (such as thin-wall profile forming machines).
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Characteristics:
- Allows a large center distance between two shafts (no need for close meshing of gears), but the transmission ratio accuracy is slightly lower than that of gears (with slight elastic sliding);
- Simple maintenance (regular lubrication is sufficient), but it is prone to vibration and noise at high speeds.
III. Gear-Chain Combined Transmission (Balancing Precision and Flexibility)
In complex cold roll forming lines (such as multi-stage forming equipment with multiple sets of independent rolls), a “gear + chain” combined transmission is often used:
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Working Logic:
- The main power is uniformly adjusted through a gearbox (high-precision gear set) to ensure the synchronization of core rolls;
- The branch power is transmitted to auxiliary rolls or feeding mechanisms through chains to adapt to the installation distance requirements of different components.
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Advantages: Balances the synchronization of gears and the layout flexibility of chains, suitable for large cold roll forming units (such as H-beam forming machines).
IV. Worm and Worm Gear Transmission (Special Low-Speed Scenarios)
- Application: Mainly used in non-main transmission parts of cold roll forming machines, such as deviation adjustment mechanisms and pressing devices (occasions requiring low speed and large reduction ratio).
- Characteristics:
- Large reduction ratio (up to 10-80 for a single stage), which can convert the high-speed rotation of the motor into the low-speed movement of the roll for fine adjustment;
- It has a self-locking property (no reverse rotation due to load when stopped), ensuring the stability of the position after deviation adjustment.
- Limitations: Low efficiency (60%-80%), not suitable for main transmission (prone to heat generation and large power loss).
Summary of Selection
The transmission mode of cold roll forming machines is centered on gear transmission (to ensure forming accuracy and power efficiency), supplemented by chain transmission (to meet layout requirements) and worm and worm gear transmission (to satisfy special fine adjustment functions). The selection should be based on:
- Roll synchronization accuracy requirements (gears are necessary for high precision);
- Transmission distance and spatial layout (chains can be selected for long distances);
- Load size and speed (gears are preferred for high torque and high speed, and worm and worm gears can be selected for low-speed fine adjustment).
For example, cold roll forming machines for automobile door frames (thin-walled, high-precision) mainly use gear transmission; large steel structure cold roll forming machines (thick plate, multi-roll group) mostly adopt gear-chain combined transmission.