KISSsoft AG •Rosengartenstr. 4•8608 Bubikon

Contact analysis of

planetary gearboxe

The contact analysis calculates for helical gear

pairs and planetary gears the

actual path of contact under load,

error, flank stress distribution, f

specific sliding, power loss, heat

lubrication film thickness, safety against micropi

ting, wear and other characteristics

meshing cycle. The simulation consid

tual bearing and shaft deforma

the micro geometry of each flank in contact

deformation of the planet carrier

culated in a separate FEM analysis and

be considered in KISSsoft by

tional misalignment of the planet shaft.

Planetary systems The contact analysis for planetary systems

improved in KISSsoft release

calculation takes into account the system

rium in all meshes. In addition, the face load

KHβ, the load distribution factor K

transmission errorin the entire wheel set

lated. The interaction of load distri

planet and tilting of the planet bearings having

clearance is resolved iteratively

The simultaneous presentation

either on three neighbouring

tooth is especially useful. This

proves the understanding of the

system and the comparison between calculation

and experimental results.

8608 Bubikon•Switzerland• Tel: +41 55 254 20 50• info@KISSsoft.AG

Contact analysis of

ary gearboxes

contact analysis calculates for helical gear

gears the normal force, the

under load, transmission

, flash temperature,

, heat development,

safety against micropit-

, wear and other characteristics during the

. The simulation considers the ac-

tual bearing and shaft deformation and of course

each flank in contact. The

carrier may first be cal-

culated in a separate FEM analysis and can then

by defining an addi-

misalignment of the planet shaft.

The contact analysis for planetary systems is

03/2013. Now, the

calculation takes into account the system equilib-

tion, the face load factor

, the load distribution factor Kγ and the static

in the entire wheel set is calcu-

of load distribution on the

planet bearings having

clearance is resolved iteratively.

presentation of all contacts,

teeth or a single

ful. This illustration im-

the understanding of the behaviour of the

system and the comparison between calculation

Calculation of Kγ

At planetary systems with more t

(see below a helicopter gearbox with five planets)

the calculation of the load distribution between the

planets is interesting. Here,

position error of the planet bolts are taken into

account.

info@KISSsoft.AG• www.KISSsoft.AG

with more than three planets

a helicopter gearbox with five planets)

the calculation of the load distribution between the

planets is interesting. Here, a radial and tangential

position error of the planet bolts are taken into

The load per planet is then displayed through a

meshing cycleand Kγis calculated:

Link to the shaft calculation Shaft files can be specified also in the contact

analysis for planetary systems. In these KISSsoft

shaft calculations the orientation of the gears is

determined taking the following deformations into

account:

• Tilting of the sun, planet carrier and internal

gear

• Twist of the planet carrier as a tilting of the

planet pin

• Tilt of the planet on the planet bearings

• Torsion of the sun shaft and the internal gear

If the housing and bearing stiffness in the shaft

calculation is defined, these effects may be con-

sidered in the contact analysis. A shaft calculation

with multiple coaxial shafts (such as shaft of sun,

planet carrier and housing with integrated internal

gear) can be used.

Alternatively deviations and inclinations of the

shafts or the planets can be pre-set in the contact

analysis manually, or the shaft files may be linked

automatically throughKISSsys. Using KISSsys the

behaviour of the entire system may be considered

with little additional effort.

Calculation of KHβ The face load factor KHβ is taking into account the

misalignment and the flank and profile corrections

of both gears in a mesh. The calculation is per-

formed separately for all meshes between the sun

and the planets as well as the planet and the in-

ternal gear. For increased precision of the load

distribution, the shaft deformation is iteratively

calculated until the load distribution between the

gears no longer changes. This calculation method

is according to ISO 6336-1, Appendix E. In addi-

tion, manufacturing deviations can be included in

the calculation of KHβ.

Sizing and optimization of profile

and flank line modifications For the sizing of the profile and flank line modifica-

tions, two wizards are available. The wizard for

the tooth trace correction and for the tip and root

relief was redesigned and takes now into account

parallel or conical helix angle corrections. The

necessary correction is calculated for the loaded

flank and can be applied by the user as sug-

gested.

The search algorithm for an optimized modifica-

tion is available now for planetary systems too.

This algorithm iterates in a parameter range pro-

vided by the user through all possible combina-

tions of profile and tooth modifications. Thus, a full

contact analysis is performed for each variant,

where even the load can be varied. The results for

all load and geometry combinations are listed in

various reports and can be individually imported to

the main calculation.

The user can then select the optimal variant

based on the calculated transmission error, the

face load factor KHβ, safety againstmicropitting,

etc., see [2]. It is supported by various radar-

charts, multiple results for multiple load levels can

be represented at the same time.

Additional calculations In addition, the software performs a Fourier analy-

sis of the transmission error and stiffness. Also,

the acceleration of the transmission error is calcu-

lated − a criterion for assessing noise.

Graphical display of the results The orientation of the axis is displayed graphically

and allows for a check of the applied gear mis-

alignments in the 3D geometry graphics.

The normal load, root stress, Hertzian pressure

and safety against micropitting are shown on the

flanks of 3D models. This allows a very easy vis-

ual assessment of the contact field. Innovations

are found in KISSsoft release 03/2013 including

the graphical representation of the tooth modifica-

tions, the single tooth stiffness of the gear pair and

the contact lines on the tooth flank.

In the KISSsoft release 03/2013, thegear data

including modificationsare represented in amanu-

facturer drawing, which can be stored directly as

an image file or DXF.

These new functions are available with the new

release of KISSsoft, available from April 2013. To

use this calculation, prior versions need to be

updated.

Literature The following publications provide in-depth insight

into selected topics

[1] I. Kalliakatsos, U. Kissling, H. Dinner,

Tragbildberechnung in Planetensätzen,

Antriebstechnik (Publicationpending)

[2] J. Langhart, M. Erjavec, Building Reliable

Wind Energy Gears without Micropitting,

KISSsoft AG, 2012

[3] H. Dinner, U. Kissling, An algorithm for

robust gear modifications design, Gear

Solutions, July 2012

[4] B. Mahr, U. Kissling, Comparison be-

tween different commercial gear tooth

contact analysis software packages,

SMK2012

If you want to know the new highlights of our

software and are interested in further information

or a trial license, send us please an email to

info@KISSsoft.AG