4. 3. Collar
2. Fluid
1. Pad
Lubrication Regimes
NO CONTACTCONTACT
DRY WET FULL FILM LUBRICATION
5. 3. Collar
2. Fluid
1. Pad
Lubrication Regimes
NO CONTACTCONTACT
DRY WET FULL FILM LUBRICATION
6. 3. Collar
2. Fluid
1. Pad
Lubrication Regimes
NO CONTACTCONTACT
DRY WET FULL FILM LUBRICATION
Gap Height
No Contact ModelContact Model
Asperities
Reynolds PDE
Modified Reynolds
+ Homogenization
+ Starvation
No
Reynolds
Fluid Film
11. 3. Collar
2. Fluid
1. Pad
COLLAR
PAD SUPPORT
SHAFT WEIGHT
Pressure
distribution
p Fluid Velocity
Field
U
Gap Height h
Spring-supported Thrust Bearings
𝜕
𝜕𝑥
𝜌ℎ3
12𝜂
𝜕𝑝
𝜕𝑥
=
𝑈
2
𝜕
𝜕𝑥
(𝜌ℎ)
gap height
velocity
density
viscosity
pressure
12. 3. Collar
2. Fluid
1. Pad
Spring-supported Thrust Bearings
Pressure on the Gap Pad TemperatureFluid Film Thickness
PAD
COLLAR
FLUID
14. 3. Collar
2. Fluid
Stern Tube Seals: Rotary Seals
Pgas
Pambient
A) No pressure build-up is expected between rod due to the rod rotation.
B) Any axial displacement will easily cause a leakage.
C) The negative pressure gradient towards ambient will hamper leakage into the
machine.