Belts, Timing Belts, Variable Speed Timing BeltVariable Speed Belts
Variable speed belts or Adjustable Speed Belts are a specialized type of power transmission belt designed for variable-speed drives, where the speed of the driven shaft changes depending on the position of an adjustable pulley. These belts are commonly used in machines requiring controlled speed variations, such as industrial machinery, agricultural equipment, and automotive applications. They contain a wider cross-section which provides greater surface area for improved power transmission. They are flexible and strong with reinforced with aramid (Kevlar), polyester, or fiberglass cords to handle high dynamic loads and speed changes. They are resistant to wear and heat since they are made from specialized rubber compounds (e.g., neoprene, EPDM, or polyurethane) for increased oil, heat, and abrasion resistance. They are designed for variable pulley systems what work in expanding and contracting pulleys, allowing for continuous speed adjustments.
Variable speed belts are wider than classical V-belts and are available in several standard widths and angles.
| Belt Section |
Top Width (mm) |
Height (mm) |
Angle (°) |
Common Applications |
| 22x |
22 mm |
8 mm |
26° |
Light-duty industrial machines |
| 28x |
28 mm |
10 mm |
26° |
Textile machinery, compressors |
| 32x |
32 mm |
10 mm |
26° |
Printing presses, HVAC systems |
| 37x |
37 mm |
13 mm |
26° |
Heavy-duty equipment, agricultural machines |
| 47x |
47 mm |
15 mm |
26° |
Industrial conveyors, drilling rigs |
| 55x |
55 mm |
17 mm |
26° |
Mining, crushers, large generators |
- The “x” in the belt designation represents a variable-speed design.
- Example: 32×1250 means:
- 32 mm wide belt
- 1250 mm outer circumference
