Page 1681 - MiSUMi 2025

[Technical Data]
Selection of Conveyor Timing Belts

■Conveyor belt selection guidelines [Step 4] Determine belt length (no. of teeth) and center distance.
The following steps for selection is based on the case that sizes of head pulley and tail pulley are same. (1) Obtain approximate belt length from tentative center dimension (C') and approximate pulley diameter (Dp').
(Follow the steps 1 -3 even when sizes of head pulley and tail pulley are different) Lp' (mm) Approx. belt length

Use a head pulley as a driving pulley. Lp’＝2·C’＋Q·Dp’ C' (mm) Tentative center dimension
For belt installation and tension control, make the structure of the driven side to be Dp'(mm) Approx. pulley diameter
adjustable of alignment and center distance with set screws.
※ Head Pulley: The front of the pulley against traveling direction (2) Determine the number of teeth required from the approximate belt length (Lp') and pitch (P).
Tail Pulley: The rear end of the pulley against traveling direction Round down the obtained number of teeth (N) to the nearest whole number.
[Step 1] Calculate effective tension (Te). N＝Lp’/P N No. of belt teeth
P (mm)

Pitch
*Check the minimum teeth of belt which is available.
Traveling Direction Head pulley (Driving Pulley) (3) Obtain the proper belt length from the number of teeth (N) and pitch (P).
Te= 9.8(μ·G+G·H/C)
Lp＝ P·N
Lp (mm)
Belt length
H (4) Determine proper center distance with the following formula:
Te (N) Effective tension
G (Kg) Net weight of load placed on the belt surface C＝ P·(N－Dz)/2 C (mm) Center Distance
O Friction coefficient of belt vs. table (Table 1) Dz No. of teeth of pulley
C H (mm) Lift
Tail pulley C (mm) Tentative center dimension (conveyor length) [Step 5] Confirm the ajustment margin for the center distance is larger than figures in Table7-a and 7-b.
Table 1. Typical Friction Coefficient of Belt versus Table
Table Material Steel Stainless Aluminium UHMW Teflon
Friction coefficient: O 0.65 0.68 0.42 0.31 0.21
[Step 2] Calculate design tension (Td). Center Distance
Td＝K·Te Td (N) Design Tension Inner Adjustment Allowance Outer Adjustment Allowance
K
Overload Coefficient

Te (N) Effective Tension Table 7-a: Inner Adjustment Allowance (Attachment Allowance) Table 7-b: Outer Adjustment Allowance (Tension Allowance)
K＝K1＋K2＋K3 K1 Correction factors for daily operation hours Belt Type Inner Adjustment Allowance Distance between shafts (mm) Outer Adjustment Allowance
More than 5mm
~ 500
More than 5mm
XL
Belt length correction coefficient

K2
K3 Belt speed correction coefficient L More than 10mm 501~1000 More than 10mm
H
Table 2. K1 Correction Factors for Daily Operation Hours Unit: hour S3M More than 15mm 1001~1500 More than 15mm
More than 20mm
1501~2000
More than 5mm
～5 5～8 8～12 12～16 16～24 S5M More than 10mm 2001~2500 More than 25mm
1.0 1.1 1.2 1.3 1.4 S8M More than 15mm 2501~ 1% of center distance
T5
More than 5mm
Table 3. K2 Belt Length Correction Factors Unit : mm T10 More than 10mm
～1500 1501～3000 3001～4500 4501～ H3M More than 5mm
0.3 0.2 0.1 0.0 H5M More than 10mm
H8M More than 15mm
Table 4. K3 Belt Speed Correction Factors Unit : m/min
～60 61～90 91～120
0.0 0.1 0.2 [Step 6] Install timing belt.
[Step 3] Select belt type, belt width and pulley dimension. Install the belt with the installation tension in Table 8.
Axis weight at this time is twice as the installation tension.
➀Select from Table 5 a belt type and a width which have a greater allowable tension than the design tension. Fs＝2·Ti Fs (N) Shaft load
Table 5. Allowable Tension of Joint Belts Unit : N Ti (N) Fixing Tension (Table 8)
Belt Belt Width(mm)
Type 6 9 10 12 15 20 25 30 40 50 Table 8. Installation Tension for Joint Belts Unit : N
S3M 70 － 80 － 110 － － － － － Belt Type Belt Width(mm)
S5M － － 165 － 230 － 400 － － － 6 9 10 12 15 20 25 30 40 50
S8M － － － － 240 － 450 530 650 － S3M 35 － 40 － 55 － － － － －
T5 － － 150 － 200 270 350 － － － S5M － － 83 － 115 － 200 － － －
T10 － － － － 320 440 640 720 960 1280 S8M 120 225 265 325
H3M 70 80 － 90 － － － － － － － － － － － －
H5M － 165 － － 230 － 400 － － － T5 － － 75 － 100 135 175 － － －
H8M － － － － － 360 450 530 650 － T10 － － － － 160 220 320 360 480 640
Unit: N H3M 35 40 － 45 － － － － － －
Belt Nominal Width H5M － 83 － － 115 － 200 － － －
Belt Type H8M － － － － － 180 225 265 325 －
025 037 050 075 100 150 200
XL 70 80 110 － － － － Unit: N
L － － 200 300 400 600 － Belt Type Belt Nominal Width
H － － － 300 400 600 800 025 037 050 075 100 150 200
➁Select a pulley with a larger number of teeth than the minimum allowable number in Table 6 for both of driving and driven pulley. XL 35 40 55 － － － －
Table 6. Number of Minimum Allowable Number of Teeth for Pulleys L － － 100 150 200 300 －
Belt Type XL L H S3M S5M S8M T5 T10 H3M H5M H8M H － － － 150 200 300 400
Pitch (mm) 5.08 9.525 12.7 3 5 8 5 10 3 5 8
Min. No. of Pulley Teeth 12 14 14 14 14 24 12 14 14 14 24
Pulley Diameter (mm) 19.40 42.45 56.60 13.37 22.28 61.12 19.10 44.56 13.37 22.28 61.12
Reference: Open End Belt Allowable Tension Table Unit : N Unit : N
Belt Belt Width(mm) Belt Nominal Width
Type Material 6 9 10 12 15 20 25 30 40 50 Belt Type Body Material 025 037 050 075 100 150 200
S3M Urethane 127 － 145 － 159 － － － － － XL Urethane 127 145 159 － － － －
S5M Urethane － － 215 － 323 － 539 － － － L Urethane － － 270 404 539 809 －
S8M Urethane － － － － 647 － 1176 1412 1882 － H Urethane － － － 404 539 809 1078
T5 Urethane － － 196 － 291 394 497 － － － When using belts for other purpose than conveyance (e.g. transmission),
T10 Urethane － － － － 523 695 926 1097 1509 1862 for polyurethane belt S3M/H3M; design with 1/2 of the allowable tension
H3M Urethane 127 145 － 150 159 － － － － － in the table; for XL, L, H, S5M, S8M, T5, T10, H5M and H8M, design with
H5M Urethane － 215 － － 323 － 539 － － － approx. 2/3 of the allowable tension in the table.
H8M Urethane － － － － － 941 1176 1412 1882 －
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