Mechanical Technical Information

Mechanical Technical Information

 Torque, Horsepower and other Calculations:

HP & Torque

Horsepower = (Torque Ft*lbs)(RPM)

Torque Ft*lbs = (5252)(Horsepower)

At 1800 RPM a motor develops 3 ft-lb per HP
At 1200 RPM a motor develops 4.5 ft-lb per HP

Conveyor Speed

Feet Per Minute = (0.262)(Head Pulley Dia in Inches)(RPM)

RPM =                Feet Per Minute                            
……….. (0.262)(Head Pulley Dia in Inches)

Dia in Inches  =    Feet Per Minute       
…………………………. (0.262)(RPM)


Do Not use Grey Cast Iron Sheaves with a Rim Speed in Excess of 6,500 Feet Per Minute

Maximum Cast Iron Sheave Diameter at RPMs
1200 RPM => 20.7″ Max Diameter
  1750 RPM => 14.2″ Max Diameter
3600 RPM => 6.9″ Max Diameter

Heat Required to Make the Interference Bore Fits 

▲D = D x ▲t x Le
Change in Distance in inches = ▲D
Distance across the bore in inches = D
Change in Temperature in Fahrenheit= ▲t
Linear Coefficient of Expansion = Le
Le for steel = 0.000 0063 in/in/°F
Le for steel = 0.063 in growth / 10,000 °F in

D of a 6320 Bearing is 100 mm = 3.9362 inches
If heating a bearing from 70°F to 250°F
▲D = (3.9362) x (250°F – 70°F) x 0.000 0063
▲D = (3.9362) x (250°F – 70°F) x (0.063 / 10,000)
▲D = 0.0044″


Tapered Bushings

QD Bushings

Split Tapered Bushings

Scaling Laws
[W’/(rN3D5)]2 = [W’/(rN3D5)]1

W = Power
r = fluid density
N = rotational speed
D = impeller diameter


Timken Bearing Search Tool 

  • Identifies all of the cups related to a cone and all of the cones related to a cup.
  • Also searches from dimension ranges

SKF Bearing Handbook for Electric Motors

  • Speed Ratings and
  • Shaft & Housing Diameters
  • Grease Relube Recommendations

EDT Selection

  • Plane Bearing design checklist


Belt Drive Data Collection Worksheet

Helpful Videos:

How do SKF Shaker Bearings Work

How to install an Input Coupling on Rexnord Planetgear

SKF Bearing Installation Video

Posi Lock Pullers

How a Ball Bearing is Made

Simatec lubrication

SKF Marathon Food Line bearing

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