English (UK) 
简体中文 Hello! Do the brothers who work on the production line always get driven crazy by these two questions."Why does a multiplier chain run three times faster than a roller line?"or"When calculating the acceleration torque, the motor is selected too small to carry and too large to waste money?"Don't worry, let's break it down today!
I. Principle of acceleration: one relies on "cheating" and the other relies on "carrying hard".
doubled speed chainIt's like a bike with gears! It'sThe secret weapon is a combination of small and large rollers: While the small rollers follow the chain and climb slowly, the big rollers swish around with the pallet. The formula is simple:
Pallet speed ≈ 2.5 times chain speed
Why is it 2.5? Because the diameter of the large roller (R) is about 1.5 times that of the small roller (r).V tray = (R/r + 1) × V chainOnce you do the maths, you'll understand. But in practice it will be discounted a bit - it may only be 2.2x when the track is uneven!
platenBut there's no such thing as a fancy job, it's purely motor stiffness!Acceleration force = total mass × acceleration(F=ma). But don't miss the maths!The rotational inertia of the roller itself is the hidden boss.-- For example, the moment of inertia of 20 rollers adds up to 0.072 kg-m², which is heavier than the cargo!
👉A chestnut comparison::
| sports event | doubled speed chain | platen |
|---|---|---|
| Acceleration Principle | Roller Diameter Differential Amplification Speed | Direct motor-driven rollers |
| speed relation | Pallet speed = 2.5 x chain speed | Roller speed = conveyor speed |
| coefficient of friction | Transmission segment approx. 0.08 (rolling friction) | Retention section up to 0.3 (including sliding friction) |
| inertia trap | Neglect chain weight error ±15% | Double the roller inertia error by omission |
Second, acceleration force calculation: three steps to avoid those pits!
Step 1: Figure out "who's dragging their feet" - total inertia Jt
- doubled speed chain: Focus onEquivalent mass of pallets + goods! Because the velocity is amplified, the equivalent mass has to be discounted:
m equivalent = m actual × (chain speed/pallet speed)²
For example, if the pallet actually weighs 100kg, the chain speed is 0.1m/s and the pallet speed is 0.25m/s → m-equivalent = 100 x (0.1/0.25)² =16kg! - platen:.Every roller is an "inertia assassin".! A 76mm diameter, 5kg drum with inertia J=0.0036kg-m². 20 of them? Directly 0.072kg-m² crushes the motor!
Step 2: Don't apply the wrong acceleration torque formula!
- universal formula:.Acceleration moment T = total inertia Jt × angular acceleration α
Angular acceleration α = linear acceleration a / drum radius r - The radius trap of the multiplier chain:.The radius is based on the drive sprocket!Sprocket diameter 100 mm, radius r = 0.05 m. Can not be used with pallet sizes!
- Acceleration of the roller line: If you are required to accelerate from 0 to 15m/min (0.25m/s) in 0.5 seconds, the acceleration a = 0.5m/s².
Step 3: Select motor - torque + inertia double insurance
- doubled speed chain:.Inertia ratio (load inertia/motor inertia) ≤10! Above that the motor starts shaking like a sieve.
- platen:.Total torque = (static friction torque + acceleration torque) / efficiency(The worm gear efficiency is taken as 0.8).
Don't estimate static torque blindly! Teach you a trick.No-load torque measurement by pulling a drum with a spring scaleThe measured ratio manual quasi 30%!
Thirdly, optimisation tips: save electricity, save money, save maintenance!
▶ Three axes for multiplier chain optimisation
- Roller diameter ratio D/d dislike to upper limit: Although limited by chain pitch, try 1.6x if 1.5x isn't enough! For every 10% of increase in speed, the motor power drops by 8%.
- Self-lubricating chain + enclosed track: The coefficient of friction was reduced from 0.1 to 0.08, and the maintenance rate dropped by 68% straight away.
- Dynamic Sleep Sensor: Automatic speed reduction when no load, energy consumption cut 22% - an electronics factory rely on this trick to save 17 million annual electricity costs!
▶ The violent aesthetics of the roller line
- Heavy-duty rollers carry large loads: Heavy-duty drums with a diameter of 80mm, carrying 2 tonnes of steel coils without bending! But watch out.Acceleration time of 0.1 seconds more, motor cost halved.
- Inverter motor + gearbox golden combination: The worm gear efficiency is only 0.8, but it has a high overload capacity and is preferred for heavy loads.
- Anti-freeze coating to resist the cold: Cold Chain Logistics with Bexcel Chain? Lubricants freeze to popsicles! Roller lines brushed with anti-freeze coating, -20°C as high as ever.
IV. Selection guide: copy the work without turning over!
Q: Which one is used for the mobile phone case assembly line?
Answer.Close your eyes and pick the multiplier chain!0.01mm level precision stops, patch yields skyrocket 15%.
Q: What about shipping steel coils?
Answer.The roller line is a solid win!Diameter 100mm heavy duty roller + anti-slip coating, 2 tonnes of cargo accelerate without shaking.
Q: What can I do with a limited budget?
Remember the formula:
(Cargo weight x 0.3 + process complexity x 2 - budget x 0.5)
Score >80 for speed chain, <30 for roller line
On a personal note: I'm stomping on these potholes for you!
- Don't believe in "theoretical speed doubling."! The speed chain is labelled as 2.5x speed, but actually presses the2.2 to 2.3 timesMore stable - the slightest unevenness in the track drops the speed.
- Coefficient of Friction Field MeasurementThe manual says 0.08! The manual says 0.08, but in reality it may be 0.1! After loading the deviceFeel the motor temperatureWhat's the matter? Hurry up and check the friction!
- Number of drum line stacksThe inertia of 20 rollers can be heavier than the cargo.Replacing multiple rollers with wide rollersThe inertia is cut straight in half!
- Don't get stuck on acceleration time.! Multiple 0.5 second buffers and the motor goes from 1.5kW to 0.75kW with a three year payback on the electric bill.
One last rant.The formula is dead, the production line is alive.The design is not as good as the teacher touching a guide rail. Calculation is not as accurate as the actual measurement of the current is accurate, the design is not as good as the teacher touches a guide rail! Mechanics.You can't know what you're doing until you have oil on your hands.Ah!
(concluded)
