What are the specifications of various models of pulleys?
2 Answers
Pulley models are divided into the following 6 categories: flat surface plain bearing pulleys; concave surface plain bearing pulleys; flat surface ball bearing pulleys; concave surface ball bearing pulleys; flat surface needle bearing pulleys; concave surface needle bearing pulleys. Each category is further divided into 02, 04, 06, 08, 10, and 13 specifications based on load capacity. Characteristics of pulley shapes: Small-sized pulleys with relatively low load-bearing capacity are solid pulleys, made of 15 steel, Q235, or cast iron. Pulleys bearing heavy loads are made of ductile iron or cast steel, cast into structures with ribs and holes or spokes. Pulleys are categorized into "fixed pulleys" and "movable pulleys": Fixed pulley: The position of the axle remains stationary during use; essentially an equal-arm lever that can change the direction of the applied force. Movable pulley: The position of the axle moves along with the object being pulled; saves half the force but doubles the distance.
As a seasoned auto mechanic who frequently deals with pulley issues, I've observed that specifications vary significantly by vehicle model. For compact cars, pulley diameters typically range from 50-80mm, with some Japanese models using a standard 60mm size. Mid-sized vehicles like SUVs may have pulleys measuring 80-120mm. Common materials include wear-resistant cast iron or lightweight aluminum alloy, with hole patterns (e.g., 6-8 holes) matched to engine displacement. A typical 1.5L engine pulley measures 60-65mm in diameter, but exact specifications should be verified against OEM part numbers from manufacturers like Bosch or Gates in their code libraries. I've seen cases where incorrect specifications led to belt slippage, abnormal noise, or even system failure. When replacing, it's best to measure the old part or consult the service manual. Using wrong specifications can accelerate wear - I recommend checking pulley balance and tightness every two years to prevent sudden failures.
