Spur gears

i = z₂/z₁ = n₁/n₂

d = mz

a = (d₁+d₂)/2

p = πm

dᵦ = d cos α

Open belt

n₁D₁ ≈ n₂D₂

v = πDn/60 with D in metres

L ≈ 2C + π(D₁+D₂)/2 + (D₂−D₁)²/(4C)

Geometry is not rating

• Gear tooth root/contact strength must be rated.
• Belt power capacity depends on belt series and wrap.
• Use pitch geometry from the selected system.
• Check shaft and bearing reaction loads.

Packaging prompts

• Center distance adjustable?
• Tensioning method?
• Guard and service access?
• Backlash/synchronization requirement?