Bearing Equivalent Dynamic Load Calculator mechanism

Model scope

The arithmetic formula is standard, but the instrument specification is underspecified for a reliable lookup-table implementation. It must identify the bearing manufacturer or table convention, bearing type and geometry, the e-ratio selection rule, valid input ranges, and pure-axial-load behavior. The honest label should state that the result is an equivalent dynamic load only, not bearing life or bearing-selection approval.

• P = XFr + YFa is the standard equivalent dynamic bearing-load equation only after the bearing type, contact angle, load ratio Fa/Fr, and applicable factor table have been selected.
• The specification does not define how X and Y are selected from bearing type/e-ratio tables. X and Y are not universal constants; they vary by bearing construction, contact angle, row arrangement, and manufacturer table.
• The specification omits the usual branch condition comparing Fa/Fr with e. For example, a commonly tabulated single-row deep-groove ball-bearing convention uses X=1, Y=0 when Fa/Fr <= e, and different factors when Fa/Fr > e.
• The specification does not state constraints that Fr and Fa must be nonnegative loads expressed in compatible units.
• The specification does not define handling for pure axial loading Fr=0, for which Fa/Fr is undefined and the applicable bearing calculation may require a separate manufacturer rule.

Units and conventions

• Fr and Fa must use the same force unit; P has that same force unit.
• The test vectors use newtons unless explicitly marked kN.
• X and Y are dimensionless.
• The e values and X/Y factors are dimensionless and apply only to the stated bearing-table convention.
• The table fragments use a widely tabulated ISO 281-based bearing-factor convention for single-row deep-groove ball bearings; the exact bearing manufacturer's catalog must take precedence for a production calculator.

Inspectable vector

One of 4 source-bound review vectors:

{
  "inputs": {
    "bearing_type": "single-row deep-groove ball bearing, 15-degree contact-angle table",
    "Fr": 1000,
    "Fa": 0,
    "Fr_unit": "N",
    "Fa_unit": "N",
    "e": 0.22,
    "X": 1,
    "Y": 0
  },
  "expected_outputs": {
    "P": 1000,
    "P_unit": "N"
  },
  "reference_data": {
    "bearing_table": "single-row deep-groove ball bearing, 15-degree contact-angle factor table",
    "condition": "Fa/Fr <= e",
    "e": 0.22,
    "X": 1,
    "Y": 0,
    "source_convention": "widely tabulated standard value, ISO 281-based bearing-factor convention"
  },
  "working": "Fa/Fr = 0/1000 = 0. Since 0 <= e = 0.22, use X = 1 and Y = 0. P = XFr + YFa = (1)(1000 N) + (0)(0 N) = 1000 N."
}

Failure boundary

BREAK_CLAIMED · SELF_FLAGGED

The calculator cannot determine the formula branch without the missing bearing type/e-ratio factor tables, and an extreme but representable input combination overflows a typical floating-point implementation. Signed axial input also produces a physically invalid negative result unless the magnitude convention is enforced.

Other records

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json
• evidence-tranche7/tranche7-results.json
• BOUNDARY_HAZARD_CATALOG.json