Hiscox's lenticular bearing is a pressure-oil-fed step bearing for a vertical shaft. Alternating hard-bronze concave discs and steel convex discs carry axial thrust; a central hole distributes oil from below, and a chamber in the cast-iron step circulates cooling water.
Lenticular Bearing Interactive Calculator
Vary vertical thrust, disc diameter, central oil-bore diameter and the number of stacked disc elements. The result is nominal projected pressure F/A on each annular contact, not a load rating or oil-film design.
Equation Used
- The stated thrust is centered and shared uniformly over the projected annular face.
- The disc outer diameter D and central oil-bore diameter d describe every loaded interface.
- Elastic deformation, edge loading, oil-film hydrodynamics and thermal effects are excluded.
The viewer shows the documented vertical-shaft step-bearing arrangement and a limited F/A geometry check; it does not calculate rolling-bearing life or allowable capacity.
How the pressure-fed step bearing works
The historical section shows a vertical shaft terminating in a steel toe above a stack of alternating curved discs. Hiscox identifies the concave discs as hard bronze and the convex discs as steel. Pressure oil enters from beneath through the central hole and reaches each section of the stack.
This is a thrust or step bearing: the vertical load passes successively through every contact interface into the cast-iron step. The disc count therefore does not create parallel load paths. A water-circulation chamber in the step is a separate cooling feature.
Elements established by the source
- Vertical shaft and steel toe: transmit the axial load into the disc stack.
- Hard-bronze concave discs: alternate with the steel members.
- Steel convex discs: form the mating lenticular surfaces.
- Central pressure-oil feed: supplies lubricant upward from beneath.
- Cast-iron step with water chamber: supports the stack and provides a cooling passage.
What this reconstruction is for
The calculator is an interpretation aid for the vertical-shaft step bearing shown in Hiscox item 1284. It lets you compare annular face geometry and nominal projected pressure while preserving the source's oil-feed and water-chamber arrangement.
It is not evidence that this exact construction was used in a particular mill or machine. Selecting or rebuilding a real thrust bearing requires the original drawings or a complete bearing analysis, including speed, lubricant viscosity and supply pressure, heat rejection, surface geometry, materials, clearances and shaft alignment.
Nominal projected-pressure calculation
For outer disc diameter D and central oil-hole diameter d, one annular projected face has area:
Dividing the vertical thrust F by that area gives a first-order nominal pressure:
With force in newtons and area in square millimetres, the result is N/mm², numerically equal to MPa. This is only a screening quantity. The real pressure distribution over curved, lubricated faces is not uniform and requires the surface geometry, oil-film conditions and deformation.
Worked geometry example
For a 50 kN vertical thrust, 200 mm disc outer diameter and 30 mm central oil hole, the projected annular area is π(200²−30²)/4 = 30,709 mm². The nominal projected pressure is therefore 50,000/30,709 = 1.628 MPa.
A stack of five disc elements has four contacts. Each contact still transmits the full 50 kN thrust. Four contacts do not reduce the result to one quarter. They change the construction and lubrication path, not the series load carried by each face.
Limits of the model
Nominal F/A pressure is useful for checking input scale and comparing geometry, but it is not an allowable bearing pressure. This reconstruction does not calculate the pressure-oil supply, hydrodynamic lift, minimum film thickness, friction, starting torque, heat generation, cooling-water duty, wear, shaft stability or material stress.
The engraving establishes the arrangement and materials in broad terms, not dimensions, tolerances, curvature radii or operating limits. The rendered thicknesses and curvatures are explanatory choices rather than manufacturing data.
Lenticular-bearing questions
Is this a rolling-element bearing?
No. Hiscox item 1284 shows a vertical-shaft step bearing made from stacked concave bronze and convex steel discs, with pressure oil supplied through a central hole.
Why is there no L10-life result?
L10 equations require a catalogued rolling-bearing dynamic load rating. The source does not describe rolling elements or provide such a rating, so applying that equation here would be unsupported.
Does adding more discs divide the thrust?
No. The contacts are stacked in series and every interface carries the same axial thrust. The count is shown to explain the construction, not to multiply capacity.
Does the calculator size the oil system?
No. Supply pressure, flow, viscosity, temperature, film thickness and leakage need a separate lubrication analysis.
Primary reference
- Gardner D. Hiscox, Mechanical Movements, Powers, Devices and Appliances, item 1284, printed page 317: vertical shaft, pressure-oil feed, hard-bronze concave discs, steel convex discs, steel toe and water-chambered cast-iron step.
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