What is the pulley size ratio?
3 Answers
The ratio of the driving pulley diameter to the driven pulley = reduction ratio = 80/240 = 3, at which point the speed of the driven shaft is approximately 80r/min. If you want to reduce the speed of the driven shaft to 60r/min, the reduction ratio needs to reach 24. However, the speed ratio of V-belts is generally less than 10; otherwise, the wrap angle of the belt around the small pulley will be too small, reducing friction and causing the belt to slip easily. This not only affects the power transmission but also leads to rapid belt wear. Situations requiring a wheel alignment include: 1. Damage to the chassis and suspension due to an accident; 2. Replacement of the steering system and components; 3. Uneven wear on one side of the front or rear tires; 4. Replacement or adjustment of the suspension system. Wheel alignment involves adjusting the geometric angles of the tires, steering, and suspension components to ensure tight contact between the tires and the ground. The benefits of wheel alignment include: 1. Enhanced driving safety; 2. Reduced tire wear; 3. Maintaining a straight steering wheel when driving straight; 4. Automatic return of the steering wheel after turning, improved driving control, reduced fuel consumption, and minimized wear on suspension components.
I've seen many examples of pulley systems, where the ratio mainly depends on the speed requirements. Simply put, it's the diameter ratio between the driving pulley (smaller pulley) and the driven pulley (larger pulley). The ratio determines the speed change. For instance, when a small pulley drives a large one, the larger pulley slows down but torque increases, which is crucial for air conditioning compressors. Common ratios are around 1:1.5 or similar. In practical applications, material strength must be considered; otherwise, the belt may slip and overheat, affecting efficiency. In my experience, when modifying cars, we often use a formula to calculate the ratio—dividing the small pulley's diameter by the large pulley's diameter. A ratio below 1 means speed reduction, while above 1 means speed increase. Engine heat and ambient temperature also influence this, so factories conduct multiple tests to optimize the design during production. Regular maintenance checks for belt wear can also indicate ratio issues. Don’t just focus on the numbers—adjust based on the vehicle's condition to ensure system stability.
Previously, my car's AC suddenly became very noisy. After inspection, it turned out the pulley ratio was misaligned. The small pulley was too large, causing excessive speed when driving the large pulley, which led to belt misalignment and overheating. The ratio refers to the size proportion between small and large pulleys - for example, 1:1.2 means the small pulley drives the large one with 20% speed reduction. Common values range from 0.8 to 1.5 depending on component type. When repairing, I always measure diameters with calipers to calculate ratios accurately. Too large a ratio causes premature belt wear, while too small may result in insufficient power. Regular groove cleaning and tension checks are recommended - proper ratios extend service life. Remember not to modify factory designs without professional support, as improper changes can lead to costly repairs.
