English (UK) 
简体中文 Are you curious as to why a seemingly ordinary chain can make a work plate run 3 times its own speed?This is not magic, but the mechanical design of a sophisticated "trick" - so that the roller and the roller of the pair of partners, through the diameter difference between the performance of a speed superposition of a good show. Today we will dismantle this trick, to see how the triple speed in the end "cheat" out!
First, the core theatre: roller and roller "height difference" director speed superposition
The key is in a design trap.Let the roller (diameter D) against the work plate be one turn larger than the roller (diameter d) on the chain. When the chain is yanked forward by the motor, two things happen:
- Rollers forced to roll: It is pressed against the guide, and when the chain goes 1 metre, it rolls 1 metre honestly, at a speed recorded as V₁;
- The rollers rotate on their own.: When the roller turns, so does the roller on top of it. But the roller is big! When it turns round, the edge travels a lot further than the roller - and that extra speed is V₂.
Mathematical showdown: V₂ = (D/d) × V₁
The actual speed of the work plate, is the speed at which the chain drags it (V₁) plus the speed at which the rollers transfer it forward (V₂), so:
Total velocity V = V₁ + V₂ = V₁ + (D/d) × V₁ = V₁ × (1 + D/d)
When the roller diameter is 2 times that of the roller (D = 2d), V = V₁ × (1+2) = 3V₁--Three times the speed, and it's a done deal!
Let's take a brown example.: It's like when you push your bike along (V₁ = your walking speed) and the wheels scuff the ground and turn themselves (V₂ = wheel-edge speed), with the result that the parcel in the basket is actually travelling forwards much faster than if you were walking!
II. Structure dismantling: what is hidden in the "sandwich" of the multiplier chain?
It's not enough to have a formula, you have to see it in the flesh! Take apart a triple speed chain with six layers of structure looping together:
| parts | material (that sth is made of) | Functional truth |
|---|---|---|
| track roller | Engineering plastics/alloy steel | Directly on top of the work plate, the larger the diameter D, the more rapid the speed |
| rollers | Engineering plastics/alloy steel | The "foot" of the chain, the smaller the diameter d, the faster it accelerates. |
| a tube for wrapping | hardened steel | Protecting the pin reduces friction and internal wear |
| Internal and external chain plates | manganese steel | It's like a spine, with all the parts in series to carry the tension. |
| a pin | carburised steel | Putting up the chain plate, load-bearing key |
Deadly details.: Rollers and rollers mustrigid occlusion--Imagine a two-person, three-legged race where you can't tie it tight enough to fall, and the speed stack goes right out the window.
Third, the reality of the face: the theory of 3 times the speed, why the actual only 2.7?
"I bought a triplex chain and it's only 2.7x in real life!" --Don't be quick to call out the crooks.Friction and sliding are sneaking up on you and eating your speed.::
- friction loss: The rollers roll against the rail, like a tyre rubbing against the road, there is always energy to heat;
- sliding error: The rollers may slip under heavy loads, as if the car was idling in the snow;
- manufacturing errorInferior chains have a roller diameter error of more than ±0.1mm, and the speed is immediately unstable.
Want to force 3x speed? Three remedial moves::
- The guideways are polished + lubricated with synthetic grease, and the coefficient of friction is pressed to below 0.15;
- Lightweight work plates (e.g. aluminium) to reduce rolling resistance;
- Buy the chain dead on the quality inspection report, the diameter tolerance should be within ± 0.05mm!
Fourth, the application rollover: triple speed is not something you can play if you want to
Many factories are superstitious about "the higher the speed, the better", and the result is a disastrous overturning scene:
- Electronic factory strong on 3x speedMobile phone motherboard patch line open to 20 m / min, precision capacitors all vibration fly, yield rate fell 20% a week;
- Car factory using the wrong material: Nylon roller pulling 500kg engine, overloaded 30% after roller crushed, fault stopping increase 50%.
What scene would you dare to use a true-triple?
✅ Light load (<50kg): e.g. mobile phone cases, box sorting
✅ Short distance straight line conveying: avoiding centrifugal flinging of workpieces around bends.
✅ Dry and clean environment: dust and oil can exacerbate slippage
Heavy loads are slowing down.: Engine assembly line with 2.5x steel chain, speed pressed to 8m/min, instead total capacity rises 35%-"Slow and steady" is the way to last.
V. Design practice: get the right three parameters, three times the speed of not fooling around
Want to really squeeze out 3x speed? Three parameters must be locked:
- Diameter ratio D/d=2: The roller is selected as a 38.1 mm pitch chain (d ≈ 12 mm) and the roller diameter D must be ≥ 24 mm;
- Track straightness ≤0.5mm/mThe guides are skewed by more than 1mm, and they immediately stall and lose speed! Don't save money on laser calibration;
- Load factor ≤80%: Don't let the work plate be fully loaded to the limit! Leave 20% margin to prevent slippage, for example, a chain labelled 1 tonne will only pull 800kg.
A personal view of stepping on the pits
After ten years of designing production lines, I've seen too many people fall prey to three illusions:
- Blindly chasing high multipliers--Speed up ≠ efficiency! Shocks, shifts, and maintenance downtime are all waiting for you in the shadows;
- Ignoring no-load losses--Motor power don't just count the weight of the goods! Chain running empty friction accounted for 30% load, a factory motor burned out to understand this reasoning;
- Cheap to buy poor quality chain--Save $20,000? The result was erratic speeds, frequent repairs, and an extra $100,000 in repairs over three months.
Remember: tripling is the art of precision mechanics, not a numbers game on a parameter list. Dare your supplier to make a 1.2x load test video? A chain that turns up is more honest than a contract!
