Vacuum-preloaded air bearing, simple orifice feed — fixed reference geometry

Reference-geometry calculator (76mm outer diameter, 5µm film, 0.28MPa supply — fixed, matching the original) for a vacuum-preloaded aerostatic thrust collar bearing fed through discrete simple orifices. Vary the remaining diameters and pressures.

✓ gevalideerd tegen origineelorigineel: /calculators/c12_6b.htm

Vacuum-preloaded air bearing, simple orifice feed — fixed reference geometry — original diagram from /calculators/c12_6b.htm

Buitendiameter smoorgatring, 2R₁10⁻³ mBinnendiameter smoorgatring, 2R₂10⁻³ mBinnendiameter kraaglager, 2R₃10⁻³ mBuitendiameter vacuümvoorspanning, 2R₄10⁻³ mBinnendiameter vacuümvoorspanning, 2R₅10⁻³ mGroefdiepte, h₂10⁻⁶ mOmgevingsdruk, pₐ10⁶ PaVacuümniveau, p_V10⁶ PaRestrictordruk, p_R10⁶ Pa

Massastroom kraaglager, ṁ_b3.266 10⁻⁶ kg/s

Volumestroom kraaglager, Q_b164.8 10⁻³ l/min

Massastroom vacuümsysteem, ṁ_V0.466 10⁻⁶ kg/s

Volumestroom vacuümsysteem, Q_V23.5 10⁻³ l/min

Draagvermogen kraaglager, F_b70.4 N

Trekkracht vacuümvoorspanning, F_V-38.4 N

Uitwendige belasting, vacuümvoorgespannen lager, F32 N

Axiale stijfheid, S = −dF/dh36.5 10⁶ N/m

The legacy "please login" demo lock froze D0/H0/pS to these exact values. Per docs/phase6/OWNER-DECISIONS-BACKLOG.md K4, this fixed geometry is kept exactly as in the original and only the inputs that were already free under the lock are exposed. Generalizing it is a deliberate future decision for Anton, not made here. Restrictor pressure pR is clamped to 0.53·pₛ if entered lower (choked flow); solve iteratively (adjust pR) until the external load F matches the intended operating point.

Methode & referenties

The pressure ratio in orifice restrictors is limited at the lower end by choked flow: for air, pR/pS>0.53.
The homogeneous-pressure-over-groove assumption requires a relatively large groove depth (h₂/h₀>40); shallow grooves need finite element analysis.
FIXED GEOMETRY: outer diameter 76 mm, film thickness 5 µm, supply pressure 0.28 MPa — the original demo lock froze these three together.

De berekening is een letterlijke overzetting van de originele client-side JavaScript van /calculators/c12_6b.htm. Resultaten zijn geverifieerd gelijk aan het origineel via een geautomatiseerde golden-master-test. Geen enkele formule is opnieuw afgeleid of “verbeterd”.

Vacuum-preloaded air bearing, simple orifice feed — fixed reference geometry — Engineering ABC