Journals (plain bearing) Calculator v1

Price: £25.41 (£25.41 Inc. VAT)
Plain bearing calculator


Plain bearings (Journals) are used in the power transmission industry for very large, very small, highly loaded and long-life applications.

Unlike low-friction bearings, plain bearings ...

... easily accommodate unrestricted longitudinal movement of the shaft within the bearing with little or no effect on performance or additional design requirements

... could, in theory, last indefinitely. Whilst it is unlikely that you will ever get plains bearing to last forever, if designed, manufactured, installed, operated and maintained correctly, there is no reason why they shouldn’t last more than 10 or 20 times the life of equivalent low-friction bearings, making them very cost efficient

... fail gradually giving plenty of notice for corrective action before total collapse

The most obvious applications for Journal bearings are internal combustion engine crankshafts and Calender rollers.


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Journals determines performance characteristics based upon theories proposed by Michell and Cardullo.

The plain bearings calculator is applicable to all grooved and non-grooved bearings except those with ‘through’ longitudinal slots minimising back pressure in the lubricating oil.

In addition to the minimum basic design criteria for your plain bearing (e.g. power loss, oil pressure and oil flow), Journals also provides a considerable amount of additional information to assist with its specification; i.e. Sommerfeld, load and capacity numbers, friction coefficient, etc. (see output data below)

Journals may be used in conjunction with CalQlata’s Limits and Fits, Shafts and Beams calculators

For help on using this calculator see Technical Help

You enter: and the Journals calculator will provide:
  • Shaft diameter
  • Bearing diameter
  • Bearing length
  • Revs per second
  • Dynamic viscosity
  • Mass density
  • Angle
  • Distance in 'z' direction
  • Minimum film thickness
  • Power loss
  • Total load
  • Load in 'x' direction
  • Load in 'y' direction
  • Film thickness @ 'Angle'
  • Radial clearance
  • Eccentricity
  • Eccentricity ratio
  • Friction force
  • Friction coefficient
  • Petroff friction force
  • Petroff friction coefficient
  • Friction ratio
  • Friction factor
  • Minimum oil flow rate
  • Minimum oil flow factor
  • Oil pressure @ 'Angle'
  • Unit pressure
  • Peak pressure
  • Peak pressure ratio
  • Peak pressure angle
  • Angle to peak pressure
  • Application angle
  • Sommerfeld number
  • Reynold's number
  • Capacity number
  • Load number
  • Length:diameter ratio
  • Surface speed

Check minimum system requirements

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