mbs roller bearing modeling - simpack · 1 2014-10-08 dtgs2, mbs roller bearing modeling, public ©...

© ZF Friedrichshafen AG, 2014 1 2014-10-08 DTGS2, MBS Roller Bearing Modeling, Public

ZF Friedrichshafen AG

DTGS2

Carsten Stamm

MBS Roller Bearing Modeling


Agenda

1.

2.

3.

4.

5.

6.

7.

8.

Options in Simpack

Ball Bearings

Needle Roller Bearings

Tapered Roller Bearings

Thrust Bearings

Introduction

Performance

Conclusion


Agenda

1.

2.

3.

4.

5.

6.

7.

8.

Options in Simpack

Ball Bearings



Thrust Bearings

Introduction

Performance

Conclusion


Roller Bearings in Transmissions

Roller bearing function:

• Keep shafts in place

• Interface between shafts and housing

(transfer of static and dynamic forces)

Influence of bearings:

• Noise

• Stiffness of whole system

Role of bearings in noise prediction:

• Lower frequencies (unbalance):

Bearing clearance

• Higher frequencies (gear meshing frequencies):

Misalignment of shafts (stiffness, clearance)


Motivation

Requested function of roller bearing force elements:

• Interaction between radial, axial forces, tilting moments and stiffnesses

• Fast

• Accurate

• Stable

Expected improvements in MBS models:

• Correct misalignments

• Correct gear excitation

• Correct transfer path to housing

• Correct stiffnesses, Eigenmodes


Roller Bearing Stiffness

Bearing stiffness calculation according to ISO/TS 16281 includes:

• Rollers: numbers, dimensions, shape, position

• Clearance

• Load


Tested Bearing Types

Stiffness maps:

3 dim 4 dim 5 dim

Fax, ß, g Fy, Fz, ß, g Fax, Fy, Fz, ß, g

x

y

d = 65

D = 120

Nof Rollers= 10

d = 100

D = 130

Nof Rollers= 37

d = 43

D = 59

Nof Rollers= 48

d = 51

D = 95

Nof Rollers= 16

Bearinx map files include correct geometry. Other methods with approximated geometry.


Testmodels and Result check

static + sweep 2) freefall with thrust bearing 1) Symmetric shaft bending

Static result check with ZF-Tool (deflections, torques, stiffnesses)

Dynamic check of Eigenmodes and resonance

g


Agenda

1.

2.

3.

4.

5.

6.

7.

8.

Options in Simpack

Ball Bearings



Thrust Bearings

Introduction

Performance

Conclusion


Third Party Options in Simpack (Tested Force Elements)

FE Name radial axial bending clearance nonlinear comment usable

49 INA Bearinx

Roller Bearing

x x x x x Large map files (>200 MB)

No information about content

x

89 KissSoft

Roller Bearing

x x x x *) x Pre release x

UF25 Radial/Axial

Spring/Damper

x x x x ZF x

UF27 Stiffness map x x x x x ZF, modified FVA x

UF27 Hertzian Formula x x x ZF, modified FVA x

UF28 LAMBDA x x x x x FVA, at present only ball bearings x

*) clearance not available for needle roller bearing


Simpack Roller Bearing User Forces

ZF-UF25: linear stiffness, clearance, thrust forces with possible contact radius

ZF-UF27 Hertz: nonlinear stiffness with Hertz formula. No clearance, no tilting stiffness.

Based on FVA project DrespToSimpack

ZF-UF27 Map file: stiffnesses according to map file, created with ISO/TS 16281

Based on FVA project DrespToSimpack

FVA Lambda: modeling of inner bearing geometry and contact calculation.

Calculation of roller dynamic and cage possible

c


Agenda

1.

2.

3.

4.

5.

6.

7.

8.

Options in Simpack

Ball Bearings



Thrust Bearings

Introduction

Performance

Conclusion


Ball Bearings dynamic

Load

10 µm (10%)

0.5 * clearance


Agenda

1.

2.

3.

4.

5.

6.

7.

8.

Options in Simpack

Ball Bearings



Thrust Bearings

Introduction

Performance

Conclusion


Needle Roller Bearings dynamic

800 Hz

330 Hz

Load

?


Agenda

1.

2.

3.

4.

5.

6.

7.

8.

Options in Simpack

Ball Bearings



Thrust Bearings

Introduction

Performance

Conclusion


Tapered Roller Bearings, static load

No clearance in bearing definition

Axial clearance in system

0.5 mm 0.5 mm

right side centered

left side displaced


Tapered Roller Bearings, dynamic load


Agenda

1.

2.

3.

4.

5.

6.

7.

8.

Options in Simpack

Ball Bearings



Thrust Bearings

Introduction

Performance

Conclusion


Thrust Bearings

Testmodel: Tilted 3mm free fall

Bearinx failed! Worked only for distance<50µm

Clearance is not a property of thrust bearing (Unilateral springs) !

UF25 + KissSoft: Alignment perfect

UF27 Mapfile: Misalignment 5 mrad


Agenda

1.

2.

3.

4.

5.

6.

7.

8.

Options in Simpack

Ball Bearings



Thrust Bearings

Introduction

Performance

Conclusion


Performance

Model description:

2 Bearings

1 Flexbody

Simulation time 2 s

Simpack V9.7

min

min

min


Agenda

1.

2.

3.

4.

5.

6.

7.

8.

Options in Simpack

Ball Bearings



Thrust Bearings

Introduction

Performance

Conclusion


Conclusion

Stiffness calculation in every time step (KissSoft):

Good results but slow (complete gearbox > 10 bearings, DoE)

Differences in needle roller bearing results are examined.

Map files (Bearinx, UF27):

Bearinx: Good performance but sometimes large map files. Correct geometry for INA bearings

UF27: More flexible than Bearinx, but not always accurate yet. Some improvements required.

Modeling of inner geometry (Lambda):

Not mandatory for stiffness calculation. Good for examination of bearing inner dynamics

Hertz Formula (UF27 Hertz):

Too fast and slick to ignore. Good for shafts without bending and pure radial load

Linear stiffness (UF25):

Fast. Good for shafts without bending.

Correct results require correct bearing geometry!


Bei Bedarf können

Platzhalter für ein

persönliches Bild und

Referenteninfos über

den Menüpunkt

„Einfügen-Elemente-

Standard“ eingefügt

werden.

-------------------------------

Upon need,

placeholders for a

personal picture and

information about the

consultant can be

added in via the "Insert-

Elements-Standard"

menu item

ZF Friedrichshafen AG behält sich sämtliche Rechte an den gezeigten technischen Informationen einschließlich der Rechte zur Hinterlegung von Schutzrechtsanmeldungen und an daraus entstehenden Schutzrechten im In- und Ausland vor.

ZF Friedrichshafen AG reserves all rights regarding the shown technical information including the right to file industrial property right applications and the industrial property rights resulting from these in Germany and abroad.

Thank you for your attention

mbs roller bearing modeling - simpack · 1 2014-10-08 dtgs2, mbs roller bearing modeling, public ©...

Documents