TOWER-MBS Hydrodynamic bearings andsliders in commercial ... · TOWER-MBS Hydrodynamic bearings andsliders in commercial MKS programs ... ØUniversal tool for sleeve bearing calculations

1SIMPACK User Meeting, TOWER-MKS, November 2004

IST GmbH, Aachen

TOWER-MBSHydrodynamic bearings and sliders

in commercial MKS programs

Summary of Content:

0. IST-Company Profile

1. Introduction into TOWER-MKS- Overall Concept- User-Interface SIMPACK- Demonstration Application

2. Hydrodynamics Theory - Methods- Mixed Friction- Elasto-Hydrodynamics (EHD)

3. Application of Hydrodynamics- Hydrodynamics Input Parameters- Evaluation with XPost

positioning

slider

2

SIMPACK User Meeting, TOWER-MKS, November 2004

Program System Overview

IST Ingenieurgesellschaft für Strukturanalyse und Tribologie mbH

.

TOWER

COMO3D

FIRST

MKS -HYDRO

Program Systems FIRST, PIMO3D, COMO3D und TOWERStructure DynamicsTribologie

Load

Deformations, velocities, accelerationsHydrodynamic lubricant film pressure, solid body contact, friction losses, Gap course, shifting course, bearing deformationBearing loads, stress of components•

••

PIMO3DThe ‘IST GmbH’ was found in 1997 as spin-off of the ‘RWTH Aachen’and of the ‘Universität Kassel’ headed by Prof. Knoll. The IST is an engineering association with core competences in the development of computer-assisted simulation software as well as its application on structure dynamics/elastohydrodynamics coupled engine components. Areas of application are dimensioning, weak point analysis and system optimisation of tribological, structure dynamical and acoustical problems. An extensive cooperation exists at present with enginemanufactures and their suppliers. Furthermore, the IST is responsible for the maintenance of software that was developed as part of the FVV research projects of the ‘Institut für Maschinenelemente und Konstruktionstechnik’ of the University of Kassel.

3


Ø Universal tool for sleeve bearingcalculations

Ø Calculation method- Characteristic diagram-method- Quasi-static EHD-method- Full-dynamic EHD-method

Ø Solution of the Reynolds differential equation for rough surfaces in each period

Ø Optional bearing geometriesØ Consideration of the oil supplyØ Mixed friction (flow factors, contact pressure)

Sleeve Bearing Calculation

TOWER

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Ø Solution of the complete Reynolds equation in each period

Ø Piston- and bold hydrodynamicsØ Multi body system for illustration of large rigid

body motionsØ Complex production- and contour in operationØ Contour coverØ Partial filling status in the piston flow clearance Ø Mixed friction model based on flow simulations

(flow factors, contact pressure)

PIMO3D

Piston-Cylinder-Dynamics

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Ø Structure dynamic multiple body simulationØ Integration in the period (non-linear)Ø Complex FEM structures (~1.e6 FHG)

static/modal reduction (~150 FHG)Ø Rigid body dynamic (big motions)Ø Open model generation

systems, drives, FD elements, loads, ...Ø Hydrodynamics: integrated TOWER-module

mixed friction, cavitation, grooves, ...Ø EHD with substructure technique (engine

compound)

FIRST

Dynamic of the Engine Compound


Summary of Content:


1. Introduction into TOWER-MBS- Overall Concept- User-Interface SIMPACK- Demonstration Application



7


TOWER-MBS Overview

8


MBS – Hydrodynamics Module TOWER_MBSTime Integration t

Input ParameterPosition / Velocity(Shaft, Bearing)

Output ParameterBearing ForcesMinimum GapMaximum Pressure

10.5

0-0.5

-1 -1 -0.5 0 0.51

Interpolation Impedance Charts

Hydrodynamic Forces

Gap Function and Derivative with Respect to time

So So= ( , )ε ϑ

Calculation Procedure: Example Impedance Method

Hyd

rody

nam

ics

Mod

ule

TOW

ER M

BS

• kinematics• kinetics• elasticity

External Loads

IntegrationS

truct

ure

MK

S-Pr

ogra

mWidth

Diameter

Bearing Clearance

Viscosity

Number of RevolutionsCouple NodeTi

me

Inva

riant

Inpu

t Par

amet

er

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MBS – Hydrodynamics Module TOWER_MBSTime Integration t

Input ParameterPosition / Velocity(Shaft, Bearing)

Output ParameterBearing ForcesMinimum GapMaximum Pressure

Calculation Procedure: Example Online-FEM-Procedure

Hyd

rody

nam

ics

Mod

ule

TOW

ER M

BS

• kinematics• kinetics• elasticity

External Loads

IntegrationS

truct

ure

MK

S-Pr

ogra

mWidth

Diameter

Bearing Clearance

Viscosity

Number of RevolutionsCouple NodeTi

me

Inva

riant

Inpu

t Par

amet

er Solution of the Reynolds differential equation to each period

Hydrodynamic Forces

Gap Function and Derivative with Respect to time

( ) ( )

3 3

1 2

12 121 ( )2

+ =

+ +

h p h px x z z

u u h hx t

∂ ρ ∂ ∂ ρ ∂∂ η ∂ ∂ η ∂

∂ ∂ρ ρ

∂ ∂


Summary of Content :


1. Introduction into TOWER-MBS - Overall Concept- User-Interface SIMPACK- Demonstration Application

2. Hydrodynamics Theory - Reynolds differential equation- Mixed Friction- Impedance Method- Online-FE-Method- Summary of all Methods


11


Hydrodynamic Methods Overview

Glo

bal E

last

icity

Loca

le E

last

icity

(EH

D)

Online-EHD with substructure technique- complex engine compound with bearingsn- substructures with main axis reduction- interface modes with SVD (boundary modes)- high locale precision in each bearing bore

Impedance Method (characteristics diagram solution)- interpolation in characteristic diagrams (very quick)- limited model generation(only cylindrical, no tilting, grooves, ...)

Online FEM-Method- solution of the Reynolds equation in each period- optional shell geometry (oil grooves, holes, etc)- variable gap in axial direction (tilting )

Offline-EHD (TOWER)- Input: shaft tilting and force from MBS- rear EHD-analysis (without reaction)

Online-EHD- compact single body (e.g. connection rod ) - main axis reduction for bores

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Mixed Friction Theory – Micro-Hydrodynamics

p 1

p 2

u 1

u 2

Micro hydrodynamics or rough surfaces

Hydrodynamic Lubricant Film Reaction

16 122 1 1r

W Wz

ht

p ps∂

∂ϕ η∂∂ϕ

∂∂ η

∂∂

∂∂

σ∂∂

∂∂

Φ ΦΦ∆h p

zh p

z6

hz

3 3

+

= + +

Reynoldssche Dgl.

Druckflußfaktor PΦ

/h σ

3P rauh

glatt

q hq h

Φ = ∗

Scherflußfaktor

/h σ

SΦS rauhq

u σΦ =

∗

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Umfangsfräsen

Läppen

Drehen

Schleifen

Honen

Funkenerosion

Stirnfräsen

0

0.2

0.4

0.6

0.8

1

0 2 4 6 8 10

Φ P

[-]

Spaltweite hd [µm]

Druckflußsimulation- transversal

ideal glatte Oberfläche

Tragkraft-steigerung

ISO-Rauheitskennzahl N6R = 0.8 µma

Micro Hydrodynamics on different Editing

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Mixed Friction Theory – Solid Body Contact

Hydrodynamische Schmierfilmreaktion

16 122 1 1r

W Wz

ht

p ps∂

∂ϕ η∂∂ϕ

∂∂ η

∂∂

∂∂

σ∂∂

∂∂

Φ ΦΦ∆h p

zh p

z6

hz

3 3

+

= + +

Reynoldssche Dgl.

Festkörperkontakt

F F FHyd c= +

F f F µ Fr Hyd c c= +

Normalkraft

ReibungKontaktmodellIMK

Spaltweite h

p c Kontaktdruck integralStreubereich Greenwood/Tripp

3D-Oberfläche Kontaktdruck lokal

Gesamtdruckpges = p + pC

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pc[GPa]

Contact Pressure Characteristic Diagram pc(h*)

0

1

0 1 2 3 4

Ra=0,75[µm]

Ra=0,61[µm]

Ra=0,54[µm]

h* [µm]

New ConditionLow wearHigh wear

Test block experimentdragged:- F = 50N/mm2- n = 1500 1/min- T = 90 ° C

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1. Bearing coupling (gap function h)

2. Force coupling

Cone: • coupling node on the rotation axis• interpolated spline)

Shell:• coupling node in the bore• "least square fit" of a rigid cylinder (bore)

Cone:• local pressure forces on adjacent coupling nodes

Shell:• optimal force distribution (singular-value

decomposition)

Exact resulting loads Approximation of the pressure distribution

Hydrodynamic Coupling: Online-FEM

rigidcylinder

h

p

Fres

coupling nodes

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x

y

z

Fhyd

h

Coupling with rigid body Coupling with flexible body

localegap course

localeforces

x

y

z

Fhyd

hydM

Coupling with MBS-Body


Summary Of Content:


1. Introduction Into TOWER-MBS - Overall Concept- User-Interface SIMPACK- Demonstration Application


3. Application Of Hydrodynamics- Hydrodynamics Input Parameters- Evaluation with XPost

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SIMPACK-Input Mask / Impedance

*bearing, name = impedancebearing definition = standard-bearing

*bearing def., name = standard-bearingimpedance file = /home/reynolds.impbearing segment = seghydrodynamics data = standard

*bearing segment, name = segshell clearance = 1.d-3

*hydrodynamic data, name = standardbearing diameter = 30.0d-3bearing width = 20.0d-3reference viscosity = 0.0057

Hydrodynamic-Input File (complete)bearing namehydrodynamics

marker

reference rotation speed

shell-coupling

shaft-coupling

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SIMPACK-Input Mask / FEM-Online

*bearing, name = online-fembearing definition = standard-lager

*bearing definition,name = standard-bearingbearing segment = seghydrodynamic data = standardpressure boundary condition = rbd-1pressure boundary condition = rbd-2

*bearing segment, name = segshell clearance = 1.d-3

*pressure boundary condition, name = rbd-1width-start = 1.width-end = 1.

*pressure boundary condition, name = rbd-2width-start = -1.width-end = -1.

*hydrodynamic data, name = standardhydrodynamic method= fem-internx-subdivisions = 36y-subdivisions = 10bearing diameter = 7.0d-3bearing width = 44.d-3reference viscosity = 0.0057

Hydrodynamic-Input File (complete)bearing namehydrodynamics

marker

reference rotation speed

shell-coupling

shaft-coupling

FEM

FEM

FEM

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Input File Structure

Input File:- chart orientated- hierarchic- super positioned

*Bearing

*Bearing Definition

*Hydrodynamic Data

*Bearing Segment

*Crush Relief

*Pressure Boundary Conditions

*Oil Supply

*Roughness Chart

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Half-Shell Tilting

b zb,e

ϕzb,a

ϕzb,e

b zb,a

Oil Supply

ϕf3,a

ϕf3,e

tf3

lf3

Crush Relief

vo

Segment Shifting

ϕa

360°−ϕe

ϕm

α

r

Multi-Segment Bearing

Elliptic Clearance

rsrb

ϕm

γ

Basic Bearing Geometries

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*bearing segment, name=upphi-start = 0 phi-end = 180 phi-m = 90shell clearance = 2.e-3minimum clearance = 1.e-3

*bearing segment, name=downphi-start = 180phi-end = 360phi-m = 270shell clearance = 2.e-3

*bearing segment,name=cylindrphi-start = 0 phi-end = 360 shell clearance = 2.e-3

Sleeve bearing withelliptical clearance

Sleeve bearing withcylindrical clearance

RSRB

ϕm

ψSS W

W

R RR

=−

ψBB W

W

R RR

=−

RB

shell clearance minimum clearance

Basic Bearing Geometries Specification

*Bearing

*Bearing Definition

*Hydrodynamic Data

*Bearing Segment

*Crush Relief


*Oil Supply*Roughness Chart

minimum clearance = 1.e-3

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Crush relief

Depth

Width

Width-end

Groove in the top-shell

Phi-endPhi-start

Unwound bearing shell

ϕ

z

Phi-start

Phi-end

Width-start

*crush relief, name = crush-rightangle = 0 # [°]width = 10.e-3 # [m]depth = 20.e-6 # [m]

*crush relief, name = crush-leftangle = 180 # [°]width = 10.e-3 # [m]depth = 20.e-6 # [m]

Unwound bearing shell

ϕ

z

Angle (r.)=0Angle (l.)=180

* crush relief, name = groovephi-start = 45 # [°]phi-end = 135 # [°]width-start = -2.e-3 # [m]width-end = 2.e-3 # [m]depth = 1.5e-3 # [m]

Basic Bearing Geometries Specification

*Bearing

*Bearing Definition

*Hydrodynamic Data

*Bearing Segment

*Crush Relief



Angle

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Lagermitte LagerrandBreitenrichtung

0°90°

180°270°

360°Lagermitte

Lagerrand

Umfangsrichtung Breiten

richtung

3-d Contour File <prefix>-.gap-3d / <prefix>-.gap-3de

set view 90, 90

0° 180° 270°90° 360°Umfangsrichtung

2-d Contour File<prefix>.gap-mid <prefix>.gap-mid-seg<prefix>.gap-negative <prefix>.gap-positive

.000 -9.2e-3 -4.6e-3 0.0e-3 4.6e-3 9.2e-3 .000 .022873e-3 .023873e-3 .024873e-3 .025873e-3 .026873e-3 10.000 .022873e-3 .023873e-3 .024873e-3 .025873e-3 .026873e-3 20.000 .023445e-3 .023445e-3 .023445e-3 .023445e-3 .023445e-3 . . . . . . . . . . . . . . . . . .170.000 .059954e-3 .058954e-3 .057954e-3 .056954e-3 .055954e-3 180.000 .060540e-3 .060540e-3 .060540e-3 .060540e-3 .060540e-3 . . . . . .

Umfangsrichtung [°]

Breitenrichtung [m]Input – Contour File

Output

Basic Bearing Geometrie Specification

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Pressure Boundary Conditions

*pressure boundary condition, name=rbd-1width-start = -1width-end = -1pressure = 5.e5

Pressure boundary conditions on bearing boundaries

0° 90° 180° 270° 360°

0

Pressure

0° 90° 180° 270° 360°

0

* pressure boundary condition, name =rbd-1width-start = 1width-end = 1pressure = 0.e0

Hydrodynamic pressure on asymmetric

Pressure boundary condition

* pressure boundary condition, name =rbd-1width-start = -1width-end = -1pressure = 0.e0

* pressure boundary condition, name =rbd-1width-start = 1width-end = 1pressure = 0.e0

*Bearing

*Bearing Definition

*Hydrodynamic Data

*Bearing Segment

*Crush Relief



Hydrodynamic pressure on symmetric

Pressure boundary condition

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Oil Supply (Pressure Boundary Conditions)

*oil supply, name = zbphi-start = 0phi-end = 180width-start = -5.d-3width-end = 5.d-3pressure = 5.d5

Oil supply groove in the bearing shell

Axial section in the bearing shell

Unwound bearing oil supply

ϕ

z

ϕ start ϕend

bend

b start

*Bearing

*Bearing Definition

*Hydrodynamic Data

*Bearing Segment

*Crush Relief



28


Consideration of Roughness per Measurements

( ) ( ) ( )31 2 12 ; 3

12 2 2

si i ijp

i j

i iij

ji

h hh p v v ix x x t

v vx

ρ ρρσσ

ρη

∂ ∂ Φ−Φ −

∂

∂ ∂ ∂ += + ≠ ∂ ∂ ∂ ∂

V

Modified Reynolds differential equation

Pressure flow factor Shear flow factorΦp Φs

h / σ

γ

h / σ

γ

ΦP rauh

glatt

qq

hh

= ∗

3

p1

p2

u1

u2

Micro hydrodynamics

ΦS rauhqu

=*σ

Flow simulation

Influence of micro hydrodynamics ∼ h/σ < 10

→ Flow tensors→ Integral roughness effect

*Bearing

*Bearing Definition

*Hydrodynamic Data

*Bearing Segment

*Crush Relief



29


Surface

-404

xy

δ

2,

1Ω

= ΩΩ ∫∫q x yR dδ

σ Standard deviation (=Rq) h* nominal gap widthK Factor

(common size 1*10-3)

E here: Steel on both bodies

6.804* *54.4086 10 4 ; 4− ′= ⋅ ⋅ ⋅ ⋅ − <

c

h hp K Eσ σ

*hydrodynamic data, name = contactcontact pressure factor = 2.1e9 # calculate on contact pressurestandard deviation shell = 1.e-6 # [m] according to Rqstandard deviation shaft = 1.e-6 # [m] according to Rqfriction value = 0.05 # friction value according to

Coulomb

Geometric roughness average value

Contact Pressure

1 22 2

1 2 2 1

2(1 ) (1 )

⋅′ =− + −

E EEE Eν ν

Replacement-E-Module for both Contact Bodies

δ Profile deviationsΩ Roughness reference area

Consideration of Roughness according to Greenwood and Tripp

*Bearing

*Bearing Definition

*Hydrodynamic Data

*Bearing Segment

*Crush Relief



30


XPost V6.0

Program XPost

31


XPost V6.0

and local result dimensions :- Pressure distribution- Gap function- Oil output (hole def.)

Program XPost

Graphic interactive evaluation

of integral result dimensions:- Shifting course- Min. gap- Max. pressure- Friction capacity

curve operations:- Scaling- Integration/Differentiation- Addition/Subtraction- FFT-Analysis

2D-animation of the hydrodynamicpressure distribution

programmable serial-evaluation

32


XPost: Curves Creation and Plot-Windows

33


XPost: Curve Index and Curve Operations

34


XPost: FEM-Data Export

35


XPost: Animations Creation, Animator3 Interface

36


XPost: Automated Evaluation In TCL

XPOST- Evaluation Script (TCL)# XPOST Demonstration-Scriptxp_reaprj first.prj

xp_setkw 720 1440

xp_makkur shaft:kw_v2:1 shaft:kw shaft:v2:1

for each k 1 2 3 4 5 xp_makkur shaft:fa2:$k shaft:kw shaft:fa2:$kxp_makkur shaft:fa3:$k shaft:kw shaft:fa3:$k

for each k 1 2 39 40 xp_makkur block:kw_x1:$k block:kw:$k block:x1:$k xp_makkur Block:kw_x2:$k Block:kw:$k Block:x2:$k xp_makkur block:kw_x3:$k block:kw:$k block:x3:$k

for each l bear-1 bear-2 bear-3 bear-4 bear-5 xp_makkur $l:epsx_epsy $l:epsx $l:epsyforeach var hmin pmax prei

xp_makkur $l:kw_$var $l:kw $l:$var

xp_makkur bearing-1:kw_k2z_p:bearing centre\bearing-1:kw bearing-1:k2z:bearing centre \bearing-1:p:bearing centre

exit

forces on crank shaft FHG evaluation

velocity on crank shaft FHG evaluation

comment

project file importation

output period specification

integral hydrodynamics-results ofBasic bearings (Hmin , Pmax, friction)

Waterfall diagram generation for thehydr. pressure in the bearing centre

shifting course of basic bearings

deflection of engine block FHG evaluation

37


Summary

Perspective

> Hydrodynamic Slider- Online-FEM Solution

> Hydrodynamic Bearing- Impedance-Solution (fast)- Online-FEM Solution- Offline-EHD Solution (TOWER)

> Enhanced Model Generation- Valve Steam Direction- Camshaft positioning- Basic Bearing- Connecting-rod Bearing

> Online-EHD (without Substructure Technique)

Summary and Perspective

Documents

TOWER-MBS Hydrodynamic bearings andsliders in commercial ... · TOWER-MBS Hydrodynamic bearings andsliders in commercial MKS programs ... ØUniversal tool for sleeve bearing calculations