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V-belt and synchronous belt are two major types of power transmission drive belts. But they are different in belt construction, working principle and applications.
Construction & Working Principle
Traditional V-belt is made of elastomer, its cross section is V-shaped. V-belt is a friction-based device that operates on the wedge principle. The belt is designed to dig into the sheave of the wheel, transmits power by creating friction on the sidewalls of the sheave. In some drive design, slippage is both intended and beneficial. When overloaded, the V-belt slips on the sheave to prevent damage to the wearing parts and plays a function of protection.
Timing belt is a positive engagement device.The inner side of the timing belt has a tooth, which can be accurately embedded in the tooth groove of the synchronous sprocket. The synchronous belt achieves accurate power transmission through the meshing of belt teeth with sprocket teeth, which does not depend on friction. This structure makes the timing belt more stable and accurate during transmission.
Material
Traditional V-belt is made of rubber material with fabric or steel reinforced. Now also have V-belt made of TPU material, like power twist link v belt.
Synchronous belt is usually made of polyurethane or rubber with wire, Kevlar or fiberglass core.
Features Comparison
- Transmission Efficiency
The transmission efficiency of synchronous belt is usually higher than that of V-belt, because timing belt transmits power by meshing of belt teeth with pulley teeth. V-belt has a certain energy loss during transmission, because it relies on friction to transmit power. - Transmission Accuracy
Synchronous belt has good transmission accuracy compared with V-belt, which can ensure the synchronous movement of each component on the synchronous shaft. For V-belt, slippage is desired in some case. Timing belt not allow slippage, as certain drives require precise synchronization and any slippage could lead to damage. - Maintenance and Life Service
Timing belt needs less maintenance for tensioning compared to V-belt. Unlike V-belt, which requires regular checks to maintain proper tension, toothed belts generally stay correctly tensioned well after their initial installation. Timing belt does not wear due to friction, so its life is usually longer than that of V belt. V-belt will gradually wear out due to friction during operation and needs to be replaced regularly to maintain transmission efficiency.
Application
V-belt is suitable for low cost, medium and low power transmission needs. Simple installation and maintenance, suitable for general mechanical equipment. For occasions where transmission accuracy is not required, such as household appliances, fans, pumps, belt-drive type blower and compressors and etc.
Synchronous belt is more used for industrial applications requiring high transmission accuracy ans stability and high-power and high-speed transmission system, such as CNC machine tools, laser cutting machines, automated production lines, etc.
Summarization
V-belt is used for general power transmission, medium load and slippage is desirable occasions.
Synchronous belt is suitable for high-speed, high accuracy and no slippage occasions.
