Open Belt Length
Compute open-belt pitch length from pulley diameters D1/D2 and centre distance C.
Inputs
Formula
L = 2C + π(D1+D2)/2 + (D2−D1)²/(4C)
Round to the nearest standard belt length.
Fundamentals
Compute open-belt pitch length from pulley diameters D1/D2 and centre distance C.
This tool computes Open Belt Length from the formula: L = 2C + π(D1+D2)/2 + (D2−D1)²/(4C)
History
Classical mechanics founded by Newton; kinematics formulas remain the basis of mechanical and vehicle design.
Engineering applications
Used for mechanism kinematics, energy calculations and balancing.
Glossary
| Small pulley D1 | Input parameter |
| Large pulley D2 | Input parameter |
| Centre distance C | Input parameter |
| Belt length L | Output result |
How to use
- Fill in Small pulley D1, Large pulley D2, Centre distance C in the Inputs section (watch the unit on each field).
- Click Calculate; the tool evaluates the formula shown above.
- Read Belt length L in the results area.
Formula · Worked Example · Knowledge
Formula
核心计算关系：L = 2C + π(D1+D2)/2 + (D2−D1)²/(4C)
输入变量：
- Small pulley D1
D1— mm - Large pulley D2
D2— mm - Centre distance C
C— mm
输出结果：
- Belt length L
L— mm
假设/适用：Kinematic formulas assume rigid bodies, ignoring friction & elasticity; add losses for dynamics.
Worked Example
根据公式 L = 2C + π(D1+D2)/2 + (D2−D1)²/(4C)，取 Small pulley D1 = 100 mm；Large pulley D2 = 200 mm；Centre distance C = 500 mm。
代入计算得：Belt length L = 1,476 mm。
Key Points
- Kinematic formulas assume rigid bodies, ignoring friction & elasticity; add losses for dynamics.
- Use SI units (kg, m, s, rad) to avoid conversion errors.
- Angular and linear quantities relate by radius r: v = ω·r, a = α·r.
Parameters
Inputs
| Parameter | Symbol | Unit | Default |
|---|---|---|---|
| Small pulley D1 (mm) | D1 | mm | 100 |
| Large pulley D2 (mm) | D2 | mm | 200 |
| Centre distance C (mm) | C | mm | 500 |
Outputs
| Result | Symbol | Unit |
|---|---|---|
| Belt length L | L | mm |
Applications
- Linkage and cam kinematics design
- Pulley mechanical-advantage study
- Engine valve-train and crank analysis
FAQ
What formula does this tool use?
This tool computes per ISO / AGMA / ASME standard formulas: L = 2C + π(D1+D2)/2 + (D2−D1)²/(4C)
How accurate are the results?
Results match input precision, based on SI units and common engineering approximations; for critical duty re-check with a safety factor.
Where is it used?
Linkage and cam kinematics design