Mechanical Technical Information
Torque, Horsepower and other Calculations:
HP & Torque
Horsepower = (Torque Ft*lbs)(RPM)
5252
Torque Ft*lbs = (5252)(Horsepower)
…………………………RPM
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)
Sheaves
Do Not use Grey Cast Iron Sheaves with a Rim Speed in Excess of 6,500 Feet Per Minute
Sheave RPM | Max Diameter |
---|---|
1200 RPM | 20.7″ Max |
1750 RPM | 14.2″ Max |
3600 RPM | 6.9″ Max |
Maximum Cast Iron Sheave Diameter at RPMs
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
Example:
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″
Bushings
Scaling Laws
[W’/(rN3D5)]2 = [W’/(rN3D5)]1
W = Power
r = fluid density
N = rotational speed
D = impeller diameter
Bearings:
- 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
- Plane Bearing design checklist
Belts:
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