This revision shows a connected endless flat belt and a separately dimensioned symmetric double-taper pulley section. The worksheet reports declared geometry only and does not turn a crown ratio into a universal recommendation or tracking guarantee.
Declared Flat-Pulley Crown Geometry Explorer
Enter face width, edge diameter and radial centre rise for an ideal symmetric double-taper crown. The worksheet returns exact centre diameter, half-face taper angle, one-side slant length and relative diameter rise.
Equation Used
- The crown is symmetric about the face centreline.
- Each half-face is an ideal straight taper from edge radius to centre radius.
- Edge diameter is equal at both ends.
- The belt path animation is prescribed and both pulleys rotate consistently with that path.
- Belt construction, tension, stiffness, width, wrap, friction, load, shaft alignment and support geometry are not modeled.
- No crown recommendation, tracking guarantee, allowable speed, transmitted power, bearing load, wear or service result is made.
Replaces a universal recommended-crown calculator and unsupported tracking and performance advice with exact declared double-taper geometry only.
A flat belt wraps connected rotating pulleys
Flat-belt systems use an endless flexible belt around rotating pulleys. Patents document crowned pulleys whose diameter is larger at the centre than at the ends, with tapered, trapezoidal or curved profiles used in different systems.
The animation keeps one continuous belt path connected to both pulleys. Its lower axial section isolates the declared double-taper geometry.
Crown selection belongs to the complete belt system
Habasit's engineering guide gives application-specific crown guidance tied to pulley diameter, belt and width recommendations. Patents also note that belt construction, alignment, contact area and system arrangement affect tracking. This page therefore does not prescribe one universal crown percentage.
Resolve the declared double-taper section
A radial centre rise c adds c to radius and therefore 2c to diameter. On each half-face, rise c over axial run W/2 gives the exact taper angle and slant length.
A declared geometry example
For a 200 mm face, 300 mm edge diameter and 1.50 mm radial centre rise, centre diameter is 303.00 mm, half-face taper angle is 0.859 degrees, one-side slant length is 100.01 mm and diameter rise is 1.000%.
Profile geometry is not tracking or drive performance
Crowned pulleys can influence flat-belt tracking, but the result depends on belt construction and stiffness, length-to-width relationship, tension, wrap, alignment, pulley arrangement and load. No generic geometry alone proves stable tracking.
Unsupported universal crown limits, speed and efficiency comparisons, friction values, bearing-load conclusions, wear timelines, maintenance instructions, brand installations, operating fixes and fabricated sawmill examples are removed.
Flat-pulley crown questions
Is centre diameter edge diameter plus c?
No. A radial rise c increases diameter by 2c.
Is the entered crown recommended?
No. It is declared geometry.
Does a crown guarantee tracking?
No.
Does this calculate belt tension or power?
No.
Flat-belt crown references
- US 5,281,189, Crowned pulley for a belt conveyor: tapered and trapezoidal crowned-pulley profiles and belt-tracking context.
- US 7,416,073, Diverting flat belt support system: crowned-pulley definition and limits of tracking behavior across complete systems.
- Habasit Fabric Conveyor Belts Engineering Guide: pulley design, crown guidance and dependency on width recommendations.
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