GENERAL ENGINEERING INFORMATION - ATTACHMENT CHAIN SELECTION GUIDE
3. Calculate the required power Calculate the required power to drive the conveyor from the following formula.
4. Verify chain selection
Multiply the chain tension (T) by the chain coefficient (K 1 ) listed in Table 3 and verify the following formula. T●• K 1 ≤ Max. Allowable load of the chain................(14)
Environmental Temperatures and Points of Concern Temperatures
Chain Selection
Caution
● Under (-20°F) or lower, ANSI 304 stainless, super stainless and 600 stainless chains are suggested
1- Low-temperature embrittlement may occur on link plates of carbon chain. 2- Freezing of lubricant 3 - Rust due to condensation. 4 - Seizure due to freezing.
(-60°F) to (-20°F)
● Carbon chains are not suggested
Table 3: Chain Speed Coefficient (K 1 ) Chain Speed (Ft/Min)
Speed Factor (K 1 )
(-20°F) to 15°F
The chain should be selected on the basis of the corrected working load below.
0 - 50
1.0 1.2 1.4 1.6 2.2 2.8
Where: T= Chain Tension (lbs)
50 - 100 100 - 160 160 - 230 230 - 300 300 - 360 360 - 400
140°F to 300°F
Special lube required
w = Weight of chain and attachments per foot (lbs/ft) M = Weight of material conveyed per foot (lbs/ft) V = Vertical center distance of conveyor (ft.) H = Horizontal center distance of conveyor (ft.) C = Center distance between sprockets (ft.)
1 - Excessive wear due to decrease of hardness of pin and bushing. 2 - Poor Lubrication due to deterioration of lube.
The chain should be selected on the basis of the corrected working load below. Selection of the next larger pitch chain over the originally selected chain is suggested.
300°F to 480°F
3.2 When the design chain tension (T •●K 1 ) is over the allowable load or much less than it, try the same steps agagin for the next bigger or smaller chain size to select a more suitable chain.
480° F and Greater
ANSI 304, 316 and 600 stainless steel chains are suggested.
Table 5: Corrected Working Load Temperature
f 1 = Coefficient of rolling friction between chain and guide rail (Table 1) f 2 = Coefficient of sliding friction between chain and guide rail (Table 2) ƞ = Transmission efficiency
Corrected Working Load
(-20° F - -4° F) (-4° F - 15° F) (15° F - 300° F) (300° F - 390° F) (390° F - 480° F)
(Max. allowable load in catalog) (Max. allowable load in catalog) (Max. allowable load in catalog) (Max. allowable load in catalog) (Max. allowable load in catalog)
x 0.25 x 0.30 x 1.00 x 0.75 x 0.50
5. Verify the allowable roller load
When the load is carried on the rollers, the total weight of the chain and load per roller should not exceed the allowable roller load shown in Table 4.
S = Speed =
P x N x
= (ft/min)
12
P= Chain pitch N = Number of teeth n = Sprocket speed (rpm)
2 - Wet Conditions: When the chain is exposed to water in a sterilizer or in a water screen, excessive wear due to insufficient lubrication and rust may shorten life. In these cases, a larger chain size provides less bearing pressure and stainless steel or coated chains will provide rust prevention. 3 - Corrosive Environments: When the chain is exposed to acidic or alkaline solution or operates in a corrosive atmosphere, excessive wear may occur due to chemical corrosion on the chain parts in addition to mechanical wear. Hydrogen embrittlement may also occur in an acidic atmosphere. Roller chain is more easily affected by acid than alkali. In special cases, electro-checmical corrosion may occur on the chain due to sea or mine water. Refer to the “Corrosion Resistance” guide on page 270 for the proper chain selection. 4 - Dusty conditions: When conveyor chain operates in dusty conditions, (in coke, foundary’s, sand, metal powder) the chain wears very quickly because foreign material penetrates the pin and bushing area. In such cases, consult Tsubaki engineering for the best roller chain option. Options include, Titan ® , Lambda ® and, potentially, larger pitch chains for higher wear resistance.
Table 4: Allowable Roller Load
Table 1: Coefficient of Rolling Friction (f 1 ) Type of Roller Dry
Allowable Roller Load lbs/roller Oversized Roller Plastic Oversized Roller Standard Roller
Lubricated
Chain No.
Oversized “R” roller type
0.12
0.08
C2040 C2050
40 50 60 80
143 220 350 590 880
44 66
33 44 66
Standard “S” roller type
0.21
0.14
Top roller type
0.09
0.06
C2060H C2080H C2100H C2120H C214OH C2160H
110 198 286
120 180 260 300 430
100 120 140 160
Table 2: Coefficient of Sliding Friction (f 2 ) Dry Lubricated 0.3 0.2
1,320
2,160
Note - Oversized rollers available only for double pitch chains.
261
262
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