A roller chain is a sequence of alternating inner and outer links whose rollers engage toothed sprockets. In the ideal pitch-line model used here, one driver revolution advances the chain by the selected chain pitch multiplied by the driver's tooth count.
Roller Chain Interactive Calculator
Explore ideal mean pitch-line travel and speed for a selected roller-chain driver.
Equation Used
- Chain pitch and driver tooth count define ideal pitch-line travel per revolution.
- Driver speed is constant and the chain remains engaged without slip or elastic extension.
- The displayed chain speed is a mean value; polygonal speed variation is excluded.
- Load, power, lubrication selection, alignment, wear, life and ratings are excluded.
The secondary figure uses the same selected pitch, driver tooth count and mean chain speed; the return sprocket is illustrative and equal in size.
How a roller-chain drive works
Inner-link bushings carry rollers, outer-link pins pass through the bushings, and the alternating links form a flexible tension member. As the driving sprocket turns, successive tooth spaces engage the rollers and advance the chain by one pitch per passing tooth.
The visual identifies the driving sprocket, an illustrative equal-size return sprocket, discrete rollers and the pitch dimension. It is a topology and pitch-line schematic rather than a generated tooth profile or a selected commercial drive.
What this calculator demonstrates
Select chain pitch, driver tooth count and driver speed. The calculator returns ideal mean pitch-line travel per driver revolution and the corresponding mean chain speed in metres per second, metres per minute and feet per second.
It does not select a chain, sprocket or lubrication method and does not calculate power, tension, polygonal speed variation, impact, bearing load, wear, temperature, life or rating.
Ideal mean pitch-line kinematics
For chain pitch p, driver tooth count N and driver speed n, ideal travel per driver revolution is s = pN. Mean chain speed is v = pNn/60 when p is in metres and n is in revolutions per minute.
The result is a mean pitch-line speed. A real roller chain engages a polygon of discrete pitches, so instantaneous chain speed and articulation are not represented by this constant-speed model.
Default selected example
With 0.500 in pitch, 19 driver teeth and 1,500 rpm, ideal travel per driver revolution is 0.2413 m. Mean pitch-line speed is 6.0325 m/s, 361.95 m/min or about 19.79 ft/s.
Those kinematic values do not establish allowable speed, power capacity, lubrication method or service life for a real chain drive.
Scope and lubrication boundary
The removed calculator assigned a lubrication level from chain speed alone. Manufacturer guidance instead selects lubrication using chain size, speed, ambient temperature, duty and the actual application, so the unsupported level output is replaced by travel per revolution.
Detailed selection also requires transmitted power or chain pull, sprocket sizes, centre distance, shock and service factors, alignment, environment, lubrication delivery, installation and maintenance data for an identified chain system.
Questions
Why is travel per revolution pitch times tooth count?
Each tooth passage advances the chain by one pitch in the ideal pitch-line model, and one full driver revolution passes every driver tooth.
Is the displayed speed instantaneous?
No. It is the ideal mean pitch-line speed. Discrete sprocket engagement produces polygonal or chordal speed variation that this model excludes.
Does speed determine the lubrication method?
Not by itself. Manufacturer selection guidance also considers chain size, temperature, load, duty, environment and the lubrication system.
Can the calculator size a chain drive?
No. It supplies kinematics only; chain and sprocket selection requires the actual load, geometry, service and manufacturer ratings.
Manufacturer technical references
- U.S. Tsubaki, RS Roller Chain Lubrication Systems — lubrication method depends on chain size, chain speed, ambient temperature and system conditions.
- Renold, Transmission Chain Installation and Maintenance — lubrication-method charts, application conditions, inspection and maintenance context.
- U.S. Tsubaki, Roller Chain Selection — chain-drive selection requires power, speed, sprocket and service information beyond pitch-line kinematics.
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