Do Gear Shafts with Multi-tooth and Few-tooth Have Differences

If we liken a mechanical system to a ‘logistics distribution centre’, then the gear shaft acts as the ‘conveyor belt’ responsible for transferring goods—its teeth function like the slats on a conveyor belt, precisely engaging with other components to deliver power from the “warehouse” to its ‘destination’. Do not mistake the gear shaft for merely a ‘toothed shaft’. The number of teeth varies considerably, with differences as pronounced as the ‘light gear’ and ‘heavy gear’ on a bicycle.

A multi-tooth gear shaft resembles a ‘quick trot’, while a few-tooth gear shaft resembles a ‘slow amble’. Take the bicycle, the most familiar example to all: the gear shaft beneath the handlebars exemplifies the stark difference between many teeth and few teeth. When you shift to a ‘low gear’, the chain engages with the sprocket featuring more teeth. At this point, the sprocket resembles a ‘delivery courier tiptoeing along’, moving the chain ‘a short distance’ with each rotation. Though slower, it requires considerably less effort. Conversely, shifting to a ‘high gear’ moves the chain to a sprocket with fewer teeth. Here, the sprocket resembles an ‘athlete striding with long steps’. Each rotation propels the chain ‘in great leaps’, achieving speed at the cost of considerable effort.

The “subtlety” of transmitting power

Multi-toothed shafts resemble ‘pouring water from a narrow-spouted teapot,’ while fewer-toothed shafts resemble ‘scooping water with a wide bowl.’ Take household blenders, for instance: the shafts in their mixing cups are mostly multi-toothed, featuring small, densely packed teeth—often twenty or thirty per circumference—much like the spout of a narrow-spouted teapot, ensuring exceptionally even power transmission. Swapping to a low-tooth shaft is akin to scooping water with a coarse bowl, where power transmission becomes jerky and erratic, causing the blades to spin erratically.

Conversely, construction site mixers typically employ low-tooth shafts on their mixing shafts. These feature coarse, sparse teeth—often no more than a dozen per circumference—resembling the rim of a coarse bowl. This design enables them to withstand greater impact forces. When mixing concrete, the heavy mixture of gravel and cement requires the strong ‘gripping force’ of the few, thick teeth to steadily drive the mixing blades without getting “jammed” by the weight. A shaft with many fine teeth, however, would be like ‘thin plastic sheets’ easily worn down or even broken by the gravel, causing the mixer to stall.

Tailored for specific scenarios

Multi-tooth gear shafts are suited to “meticulous precision”, while fewer-tooth shafts cater to “bold, sweeping motions”. Take a car's gearbox, for instance: the shafts corresponding to lower gears are mostly multi-tooth, much like “using an embroidery needle to sew clothes” – requiring “steady” and “gentle” power. When pulling away, the vehicle requires gradual acceleration. A multi-tooth gear shaft enables power to be transmitted ‘gently’ to the wheels, preventing sudden surges that could cause the body to jerk. Using a low-tooth gear shaft for starting would be like ‘cutting cloth with an axe’ – the abrupt power delivery risks causing the engine to ‘choke’ or even stall.

Multi-tooth gear shafts resemble ‘meticulous craftsmen who take their time,’ exerting gentle force at a measured pace yet delivering power with steadiness and precision. They excel in scenarios demanding smooth exertion and exact control. Fewer-tooth gear shafts resemble ‘swift and decisive workhorses,’ generating substantial force at high speeds yet transmitting power directly and robustly. They thrive in contexts requiring vigorous momentum and efficient operation. There is no question of ‘which is better’; only ‘which is more suitable’. Choosing the right gear allows machinery to ‘work without strain, doubling efficiency’.