KISSsys 03/2014 – Tutorial 3

Gear transmission with planetary differential

KISSsoft AG

Rosengartenstrasse 4

8608 Bubikon

Switzerland

Tel: +41 55 254 20 50

Fax: +41 55 254 20 51

info@KISSsoft.AG

www.KISSsoft.AG

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Foreword

The tutorial has two parts to be studied in this order.

Part I Introduction,

explains the most important points for this modeling task and introduces how to start KISSsys.

Part II Modelling,

shows techniques how to build a KISSsys model of a complex gearbox with several power path

possibilities.

During the study of this tutorial, questions may arise or problems may occur. The KISSsoft customer support

can be reached through the address and phone number given above.

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Contents

1 Introduction .............................................................................................................................................. 4 1.1 Summary of the most important points ........................................................................................... 4 1.2 Systematic procedure ..................................................................................................................... 4 1.3 Errata and remarks ......................................................................................................................... 4 1.4 Modelling task ................................................................................................................................. 5 1.5 Starting KISSsys ............................................................................................................................. 6 1.6 Selection of the project directory .................................................................................................... 6 1.7 Use KISSsys in the administrator mode ......................................................................................... 7 1.8 Loading the templates .................................................................................................................... 7

2 Building a model....................................................................................................................................... 8 2.1 Tree structure ................................................................................................................................. 8

2.1.1 Shafts and shaft groups ............................................................................................................. 8 2.1.2 Machine elements ...................................................................................................................... 9 2.1.3 Connection of coaxial shafts .................................................................................................... 11 2.1.4 Connections of the gears ......................................................................................................... 12

2.1.4.1 Helical gearpair connections ............................................................................................ 12

2.1.4.2 Connection Planet/Sun, Sun/Ring ................................................................................... 13

2.1.5 Definition of the boundary conditions ....................................................................................... 14 2.1.6 Adding KISSsoft calculation elements ...................................................................................... 15

2.2 Input of Gear, shaft, and bearing data .......................................................................................... 17 2.2.1 Gear data ................................................................................................................................. 17 2.2.2 Definition of shafts and bearings .............................................................................................. 19

3 3D View .................................................................................................................................................. 20 3.1 Adding 3D view in the tree structure ............................................................................................. 20 3.2 Location of the shafts ................................................................................................................... 21

3.2.1 Positioning of the shafts group “Middle” ................................................................................... 21 3.2.2 Positioning of the shaft group “Main” ........................................................................................ 21 3.2.3 Positioning of the group „Planet“ .............................................................................................. 22

3.3 Work with the 3D Viewer .............................................................................................................. 22 3.3.1 Inside diameters of the gear wheels ......................................................................................... 22 3.3.2 Color and transparency ............................................................................................................ 23

3.4 Insert data from CAD system ....................................................................................................... 24 4 Changing of gears .................................................................................................................................. 25

4.1 Background Information about clutch elements ........................................................................... 25 4.2 Application in the current example ............................................................................................... 25 4.3 Call the function ............................................................................................................................ 26 4.4 Table approach ............................................................................................................................. 27

5 User Interface......................................................................................................................................... 28 5.1 Input of the power ......................................................................................................................... 28 5.2 Execute buttons for function in the User Interface ........................................................................ 30

6 Completing the model ............................................................................................................................ 31 6.1 Input of the speed ratio for front and rear drive ............................................................................ 31 6.2 Input of efficiency .......................................................................................................................... 33 6.3 Settings to calculation methodology ............................................................................................. 33

7 Annex ..................................................................................................................................................... 34 7.1 Code [line numbers are not part of the code] ............................................................................... 34

7.1.1 Clarification ............................................................................................................................... 34 7.2 Code to set the internal diameter „di“ of the gears ....................................................................... 35

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1 Introduction

1.1 Summary of the most important points

1. Where two or more shafts overlap (e.g. loose gear, ring and sun of the planetary stage), the shafts

(element “kSysCoaxialShaft”) must be positioned under the same element “kSysGroup”.

2. The calculation of a connection with three helical gears is calculated with KISSsoft calculation

“kSoft3HelicalGears”.

3. The speed at the two output shafts (front and rear axle) are placed with one to another in reference.

Therefore the speed at one output shaft has to be set as "Constraint=Yes" and an expression is set

to compute one speed (those of the front axle) from the other (the rear axle). In addition, an iteration

is necessary for the calculation of the relative speed.

4. "Iteration for torques” and “speed with damping" must be set to execute the iteration.

1.2 Systematic procedure

The following steps are involved when building a KISSsys model:

1. Planning: Naming, range and goals of the model

2. Insert mechanical component in the tree structure (grey Icons)

3. Connect mechanical component to each other (grey Icons)

4. Define sources of power flow

5. Add KISSsoft calculation elements to the mechanical components (blue Icons)

6. Add 3D graphic, and position elements in the graphic

7. Add tables / User Interfaces

8. Program own functions

9. Tests, debugging

1.3 Errata and remarks

1. If questions or difficulties arise during the tutorial, KISSsoft Hotline can be used for assistance (e-

mail address, phone no.etc. are written on the front page).

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2. The planetary differential used for this example in practice would be a double planet planetary where

the sun and the planet carrier have the same sense of rotation. However, to prevent the example

becoming too complex, a simple planetary train is used. Therefore both outputs rotate contrary to

each other.

3. The original idea for this tutorial had planned a differential lock between the annulus and the planet

carrier. This clutch is called c3. In reality it will be not used although in the tutorial it is described. It

is recommended to proceed exactly according to the tutorial instructions (i.e. the clutch c3 is to be

modeled although this is not used).

1.4 Modelling task

A transfer gearbox for a 4x4 off-highway vehicle is to be modeled. The transmission possesses an on- and

off -road gear as well as a lockable epicyclic differential acting as a longitudinal differential. A part of the power

is continually taken off over a PTO. The bevel gear differentials in the axles are not modeled. The unlocked

gears z1 and z3 on the input shaft clutches can be switched on or off.

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Figure 1. Diagram of the gearbox to be modelled

1.5 Starting KISSsys

First, a project folder has to be created. Then, KISSsys has to be started and the intended folder is chosen

as project folder.

Using “Options”, activate the administrator mode. Then, the templates should be opened using “File/Open

templates…”.

Make sure the latest Patch version is installed on your computer. (Download from www.KISSsoft.ch)

1.6 Selection of the project directory

KISSsys uses projects to manage the files. Project folder simply defines where KISSsys models and the

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respective KISSsoft files are saved. Before a KISSsys model can be opened or created, the project / folder

where the model will be saved has to be defined.

File Open project folder, the project folder will be defined.

If there is no Project folder defined everything will be saved in the default folder. E.g. Users KISSsoft.

In the following figure it is shown the project folder for this tutorial. In this case the folder is

C:\Programme\KISSsoft 03-2014\KISSsys\Tutorial. After the selection, this is confirmed and KISSsys opens.

Figure 2. Opening the project folder

1.7 Use KISSsys in the administrator mode

KISSsys starts now with an empty model. As a first step, the "administrator" mode must be activated under

the main menu "Extras".

Figure 3. Activating the administrator mode

If the option "Administrator" can not be selected, then the KISSsys license is missing. In this case contact

KISSsoft AG.

1.8 Loading the templates

As a first step when creating a new KISSsys model, the templates have to be imported through the menu “File”

“Open templates…” “templates.ks”. In the templates, all elements are now listed which can be used in

KISSsys:

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Figure 4. Element library after loading the templates

After having imported the templates, it can be started with building the model.

2 Building a model

It is up to the user which method is used to build the model. It is recommended to use the Elements box

method for this tutorial.

2.1 Tree structure

In a first step the shaft groups (element “kSysGroup”) “Input”, “Middle” and “Main” must be defined in a tree

structure under the element “GB” (also element “kSysGroup”). Now all the coaxial shafts must be placed

under each shaft group. It is highly recommended to name gears, shafts, bearings and couplings in such a

way as shown in the illustration down. User can define first shaft (e.g. “s1” with bearings “b1 and “b2”) and

then copy it to avoid adding all bearings one by one.

2.1.1 Shafts and shaft groups

Figure 5. Adding the groups Input, Middle and Main

The shaft group “planet” is placed under the shaft “s5”. This group characterizes the planet of the differential

Figure 6. The coaxial shafts “pin” and “planet” are copied into “Planet”. The shaft ”pin” (Planet pin) is fixed

with the planet carrier “s5” by a coupling.

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Figure 6. Adding the Shaft group “Planet”

2.1.2 Machine elements

The same names can be used several times for different mechanical components, as long as the mechanical

components are in a different path of the tree. Please note all bearings are called "b". The bearing on the left

hand side is "b1", the one on the right hand side is "b2".

The following is important when modeling an epicycle gear train:

1) The planet stage is a configuration of coaxial shafts: sun shaft “s4”, ring “s3” and planet carrier “s5”.

2) The planet is supported by two bearings of the planet pin (shaft “pin”). The pin is fixed with

supports “support1”and “support2” and will be connected with the planet carrier through the

coupling constraint “carrier_pin” (element “kSysCouplingConstraint”).

3) The planet carrier needs a special coupling: ”kSysPlanetCarrierCoupling“. Do not mix up this

element with „kSysCoupling“. This special coupling should be named as „carriercoup“ and will be

positioned on the shaft s5. This element is necessary to rotate the planet in the world coordinate

system.

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Figure 7. Model with the machine elements

The settings for the connection „carrier_pin“ between the carrier and the planet pin are as followed:

Figure 8. Settings for the connection between carrier and planet pin

The connection of two coaxial shafts with clutches and bearings will be described in the next chapter.

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2.1.3 Connection of coaxial shafts

The coaxial shafts are connected with connection roller bearing elements “kSysconnectionRollerBearing”. In all of the groups it is necessary to define the inner and the outer race. In the example, in group “Input” is added a connection roller bearing between shaft “s1” and “s1a”.

Figure 9. Selection of the inner and outer race for the connecting roller bearings

All of the other coaxial shafts can be mounted in the same way together.

Figure 10. Model tree after adding the connection roller bearings

The clutches “c1”, ”c2” and “c3”are elements of the type “kSysConnectionBearing”. These can be used for a connection between two coaxial shafts (synchronizers in gearboxes). The elements must be inserted under each shaft group. In the following dialog the inner race (for “c1” use shaft s1) and outer race (for “c1” use shaft ”s1a”) must be selected. In chapter 4 it will be explained how to activate or deactivate the clutches through a function automatically. For getting a correct power flow it is necessary switching the clutch c1 first manually. So select the coupling “c1” and set under properties the variable “stateRy” to “fixed”. The same setting can also be done by clicking with the right mouse button on the element and selecting “Dialog”. As it

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is given in the information in section 1.3, the clutch c3 is modelled but not used in the Tutorial. Therefore the rotation around the y-axis has to be free.

Figure 11. Condition for the clutch c3

In the next step, the gear elements can be added to the Model tree.

Figure 12. Model tree after adding the connection bearings and gears

2.1.4 Connections of the gears

2.1.4.1 Helical gearpair connections

In the next step the gears are connected. For the spur gears, the type "kSysGearPairConstraint" is

necessary. The following connections need to be defined:

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Connection Element1 Element2

gp1 z1 z2

gp2 z3 z4

gp3 z4 z5

gp4 z6 z7

Figure 13. Table for the gearpair connections

2.1.4.2 Connection Planet/Sun, Sun/Ring

The planets need the type “kSysPlanetaryGearPairConstraint" two times. One where the sun wheel

meshes with the planet, the other for the mesh between planet and ring. The connections are copied from the

templates into the tree structure, below the group of "GB":

Figure 14. Left: Definiton of the connection “ps” Planet/Sun; right: Definition of the connection “pr” Planet/Ring.

The tree structure with the connections defined in the KISSsys sketch should look now as follows:

Figure 15. Model Tree after adding the connections

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2.1.5 Definition of the boundary conditions

The definition of the power flow in the gearbox is through the element „kSysSpeedOrForce“ . This element

has to be copied from the templates and pasted four times into the root directory (not under „GB“). According

to the Diagram in Figure 1, the following boundary conditions have to be defined:

Name Element Speed contraint Speed[1/min] Torque constraint Power/Torque input Torque [Nm]

Input CIn Yes 2000 Yes Torque with sign 100

PTO cPTO No Yes Torque with sign 10

OutR crOut No No

OutF cfOut Yes No

Figure 16. Table for the boundary conditons

During the power input "Input" speed and the torque are given. Both values are signed sizes. If the product

of the two signs is positive, then the power is positive, i.e. it concerns a positive input power.

The PTO torque is set to 10Nm (acceptance for this example). The direction of rotation is counter clockwise.

The number of revolutions is therefore negative. The torque has to be entered positively thereby the power

output becomes negative.

The condition for the front wheel drive (OutF) is defined as follows:

Front axle and rear axle turn with the same speed, but contrary. This condition will be still specified in section

6.2. Thus the number of revolutions at this output (the front axle) is the same as from the number of revolutions

of the output “OutR", therefore "speed of constrained=yes" must be set.

With the right mouse-click on the power output "OutF" and the choice in "Properties" of "speed", an expression

for the speed can be defined at this output. Enter in the field "Expression":

"-OutR.speed". This guarantees that the speed at the output is equal to the speed of the shaft s5, but in

opposite direction of rotation.

Figure 17. Additional definition of the output speed for “OutF”.

Now the kinematic calculation can be performed by clicking on . After a Refresh, the sketch looks as

follows:

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Figure 18. Diagram after the definition of the boundary conditions and the kinematic calculation

2.1.6 Adding KISSsoft calculation elements

Next step is to introduce the KISSsoft analysis modules. These are copied from the templates. KISSsoft

analysis modules for coaxial shafts, bearings (included in the shaft calculation in the new release) and gears

are needed. The gear pair calculations “GP1” (gears z1 and z2) and “GP4” (gears z6 and z7) are directly

placed under the appropriate gear pair connection. For the connections gp2 and gp3 the KISSsoft analysis

module “kSoft3HelicalGears” is copied on the same level like the connections. This regards the

connection of gear z4 with two gears and the therefore reduced lifetime.

Figure 19. Settings for the three geair train calculation element

The planetary gear analyses are arranged directly below the appropriate connection with the same name.

It is necessary to select the “Planetary gear pair constraint” option which was used for the planetary stage

connections as well.

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Figure 20. Settings for the planetary stage calculation element

The shaft calculation elements have to be placed in the corresponding shaft group. Since only coaxial shafts

are used in this Tutorial, the coaxial shaft calculation element has to be added.

Figure 21. Model tree after adding the calculation elements

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2.2 Input of Gear, shaft, and bearing data

2.2.1 Gear data

The following teeth data is used in this example. To switch to the KISSsoft interface double-click on the

computations (blue Icons) in the tree structure. After entering the design data, the input in each case has to

be confirmed with "calculation F5". Afterwards, close the KISSsoft window with "exit" (cross in the right upper

corner).

Figure 22. Input values for the gearpair calculation GP1 in KISSsoft

Figure 23. Input values for the gearpair calculation GP4 in KISSsoft

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Figure 24. Input data for the three gear train GP2_3 in KISSsoft

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Figure 25. Input data for the planetary stage in KISSsoft

2.2.2 Definition of shafts and bearings

All shafts of a shaft group will be built up in the appropriate shaft calculation module. There are used very

simple structure for shaft modeling. The effective diameter of the couplings should be entered in the shaft

editor, so that the clutch is visible in the 3D-view.

position couplings:

cIn: y = 5mm

c1: y = 50mm

c2: y = 120mm

position shafts s1a,s1b:

y = 40 mm

y = 110 mm

position bearings b1,b2:

y = 15 mm

y = 170 mm

position gears z1,z3 (resp. s1a,s1b):

y = 10mm

y = 10mm

position z6:

y = 190 mm

Figure 26. Input data for the shaft group “INPUT”

position gears:

z2 y = 50 mm

z4 y = 120 mm

position shaft s6:

y = 180 mm

position bearings b1,b2:

y = 15 mm

y = 170 mm position z7, cPTO (resp. s6): y = 10mm y = 22.5mm

Figure 27. Input data for the shaft group “MIDDLE”

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position shaft planet:

y = 2.5mm

position zp:

y = 5 mm

Be careful! The displacement in x- and z- direction is set to

„fixed“ for support1 in the element editor.

Figure 28. Input data for the shaft group “PLANET”

position of the coup.

(resp. appropriate shaft):

cfOut: y = 10mm

crOut: y = 165mm

carriercoup,coupling: both y = 0

c3: y = 238 mm

position shafts:

s4 y = 0 mm

s3 y = 170 mm

s5 y = 195 mm

position bearings:

s4: b1 y = 30 mm

b2 y = 150 mm

s3: b1 y = 30 mm

b2 y = 58 mm

s5: b1 y = 10,5 mm

b2 y = 136 mm

position gears: zs(resp.s4)y=190mm zr(resp.s3) y=20mm z5(resp.s3) y=10mm

Figure 29. Input data for the shaft group “MAIN”

3 3D View

3.1 Adding 3D view in the tree structure

From the templates or from the element box, the 3D view "kSys3Dview" is inserted into the highest level

of the tree structure. Select “show" after clicking with the right mouse button on the element. All mechanical

components are still in the same position because their position in the working sheet is not defined. Therefore,

the next step will be to arrange the positions of the shafts in the coordinate system.

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Figure 30. View of the model in 3D before positioning the shafts

3.2 Location of the shafts

3.2.1 Positioning of the shafts group “Middle”

The shaft group “Middle” is positioned over center distance a between z1 to z2 relative to shaft group “Input”.

For this select “Middle”, right mouse click and “Dialog”.

Figure 31. Positioning of the shaft group “Middle”

3.2.2 Positioning of the shaft group “Main”

The shaft group “main” is positioned in r-direction over center distance from z4 to z5 relative to shaft group

“Middle”. The angle phi is set to –90. The position in y- direction must be chosen so that z4 and z5 are in

correct engagement. This is realized through the calculation: “position gear 4 - (position shaft 3 + position

gear 5)”. The input is: “GB.Middle.s2.z4.position-GB.Main.s3.position-GB.Main.s3.z5.position“.

Figure 32. Positioning of the shaft group “main”

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3.2.3 Positioning of the group „Planet“

The shaft group “Planet”, which characterizes the planet pin, is positioned in r-direction over center distance

sun-planet (center distance of epicyclic stage “PGS”) relative to shaft group “Main”. The angle phi is set to

–90. The position in y- direction must be chosen so that sun ”zs” and planet “zp” are in correct engagement.

This is realized through the calculation: “position sun - (position shaft planet + position planet)”. The input is:

„GB.Main.s4.zs.position-GB.Main.s5.Planet.planet.position-GB.Main.s5.Planet.planet.zp.position“.

Figure 33. Positioning of the group “Planet”

Press “Refresh” button on menu to see all components places correctly in the space.

3.3 Work with the 3D Viewer

3.3.1 Inside diameters of the gear wheels

The inside diameters of the gear wheels should be set equal to the outside diameter of the respective shaft.

For all gear wheels, except the internal gear, the variable “di” should have the following text inserted in the

field “expression”:

Figure 34. Expression for the variable “di”, which has to be defined for the gears

This supplies the outside diameter of the shaft at the place where the gear part is located, checking that the

input value is not superior to the root diameter.

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3.3.2 Color and transparency

By clicking on the user can change the color and transparency of the “3D-view” for gears, shafts,

bearings and couplings. Further all elements can be shown more detailed. For this it must be chosen “Solid

Elements” under “Representation mode”. For transparency: 0 means not transparent and 1 full transparent

(invisible).

Figure 35. Representation settings of the 3D view

Figure 36. 3D View after changing the settings

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3.4 Insert data from CAD system

Depending upon version of KISSsys *.sat, *.iges or *.step data from any CAD system can be imported. In

addition, "kSysCasing" has to be copied from the templates into the tree structure. In this example, four

individual CAD data records are read in, and four KISSsys elements of type "kSysCasing" are created. They

are called in this example "Wheel1" to "Wheel4": The file attached in this example is called “tut-003-CAD-

data.igs”.

By clicking with the right mouse button on the Housing-element and selecting “Dialog” and changing “Type”

to ” Read file”, it can be defined that a file should be imported. In the field "file name" the complete file name

inclusive path has to be indicated if file is not located in the project folder.

Figure 37. Settings to import the CAD data to de 3D view

There is always a refresh needed to see the graphical changes. Positioning of the wheels can be done

manually entering in the Properties and changing position values.

Figure 38. Positioning of the housing element

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Figure 39. 3D view after importing and positioning the CAD data

4 Changing of gears

4.1 Background Information about clutch elements

The variable “stateRy” of the clutches c1 and c2 is necessary for switching the gears. This variable can

be “free” (disconnected) or “fixed” (connected). The same can also be done by clicking with the right mouse

button on the element and selecting “Dialog”.

4.2 Application in the current example

The function for changing gears should be contained in a table "Settings". First from the templates the table

"UserInterface" must be copied into the highest level of the tree structure. The table has to be named

"Settings". Using the right mouse button, the size of the table can be defined under "dialog". The table can

be visualized by selecting "show". Using the right mouse-click under "Settings" in the tree structure, on

selection of "new variable" a further variable with the name "SetGear" of the type "function" can be inserted.

With the right mouse-click on "Settings" and the selection of „Properties", the following window opens. Now

the function editor can be called by the right mouse-click on "SetGear" and the selection of "Edit".

Further, a variable "OnOffRoad" of the type "real" has to be added. This will describe the momentarily selected

gear. If it is 0, the on-road gear is active, if 1 then the off-road gear is engaged.

Figure 40. Edit the function SetGear

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Figure 41. Expression to be written in the function SetGear

The function "CADH_VarDialog" generates a dialogue in which can be defined whether the on- or off- road

gear is selected. The dialogue supplies an array of "res" as result. Zero elements into "res" is 1 (or TRUE) if

the dialogue is confirmed using "OK", 0 (or FALSE) if the dialogue is closed with "CANCEL". The first element

of the array corresponds to the selection made. If "on-Road" is selected then 0 is returned, otherwise "off

Road" is selected and 1 is set.

The first “IF” condition examines if the dialogue was closed with "OK". After this the selection is put into the

variable “Settings.OnOffRoad”. If "on-Road" was selected, the clutch “c1” is closed, “c2” is open. If "off Road"

was selected, the clutch “c2” is closed, and “c1” is open. Next, the kinematic calculation is called to calculate

new power flow. To see the clutches in 3D-view, the outer diameter “D”, the inner diameter “d” and the

thickness must be set under properties. The function can still be extended so that the open clutch in the 3D

diagram is translucently represented, the closed clutch obscurely:

4.3 Call the function

With a right mouse-click on the desired cell in the user interface, the selection of "Insert function" has to be

done and it has to be defined:

Figure 42. Implementing a function into a cell

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Figure 43. Input to call the function SetGear through the function SetSpeed

Through a double-click on the grey button "SetSpeed" the following dialogue is called:

Figure 44. Change of the power flow by changing the speed

Depending upon selection, either the on- or off road gear is activated and the current power flow is computed.

The path over which the power flows is marked red marked in the pattern.

4.4 Table approach

There is also another type of approach available in KISSsys. This is reprogrammed “Speed-table” to select

different speeds in the model without own programming. For more details, please see “ins-305-

SpeedTable.pdf”.

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5 User Interface

The user interface table can be created in different ways. The method with copying the values to the right cell

was used in the previous tutorials. As an alternative, the method with inserting the values directly to the cell

is shown in this tutorial.

5.1 Input of the power

In principle the following operations are used in the "UserInterface". There are more available, however, those

noted here are the most frequently used.

Input of text As a comment Clarifying text can be typed directly into a cell.

This text appears in black writing with white background.

Input of

numbers

Display of

values of

variable

Right mouse-click on the desired cell, select "Real insert". An input mask

appears. Into “expression” the path of the variable has to be written, their

value should be displayed.

The value appears in black writing with white background.

See Figure 46.

Reference on

numbers

For display

and input of

values of

variables

Right mouse-click on the desired cell, select "Real insert". An input mask

appears left down "reference" must be pressed. After this, "reference up"

the path of the variable has to be written their value should be displayed

Note: the path must be located in quotation marks. The values are

indicated in red writing with white background. See Figure 48.

Insert execute

buttons for

functions

Execute

functions

through

double click

Right mouse-click on the desired cell, select "function insert". An input

mask appears. Under "name" the name can be inserted, where the

function in the user interface has to be indicated with. In the field

"expression" are called those variable in those the functions is located

which will be required. The function is locked with an empty argument

called () and closed with a semicolon.

Functions are indicated with black writing on light blue background. See

Section 5.2

Figure 45. User Interface after inserting the values

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The path of the variable has to be written into

“expression”, then their value is displayed. In

the example shown, this variable is the power

input calculated from the speed and torque.

(See below).

For the display of speed, torque and power at

the front- and rear axle the following variables

have to be used:

OutF.speed

OutF.torque

OutF.power

OutR.speed

OutR.torque

OutR.power

Figure 46. Inserting the variable directly into the cell

The User Interface looks then as follows:

Figure 47. UserInterface with the variable values

Now for the definition of the input torque and speed, a reference can be inserted for each:

Figure 48. Inserting a variable directly as reference

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After “Reference” is selected, the “reference to” field is switch on to insert a text. The path of the desired

variable must be inserted now. (put it between the two semicolons “ “)

Here the example for Input.speed as the Input speed is shown.

For the input of the torque at the input shaft the following expression has to be insert accordantly:

„Input.torque“

5.2 Execute buttons for function in the User Interface

The following function should be executed from the User Interface:

1) Selection of the gear (already accomplished in section 4)

2) Calculation of kinematics as speed, torque and power flow

3) Performing all of the KISSsoft calculations

4) Show the whole calculation report for the entire gearbox

The functions which can be inserted are defined as follows:

In a first step, the dialogue for the selection of the gear is

called (as defined above).

Next the kinematics computation is called. After conclusion

of the kinematics computation, a refresh takes place.

Figure 49. Implementing the function “Kinematics” into the UserInterface table

The KISSsoft calculations are called with the function

kSoftCalculate, these are defined under “System”. After

termination of the computations, a refresh takes place.

Figure 50. Implementing the function “Strenght” into the UserInterface table

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With this instruction, a general report is generated in which

all individual KISSsoft reports are summarized.

Figure 51. Definition of the function “Report” to generate the KISSsoft calculation report

The User Interface looks now as follows:

Figure 52. UserInterface after inserting the functions

If user doesn’t want to create functions for “Kinematics”, “Strength” and “Report” it is possible to use buttons

for the same from the menu.

6 Completing the model

6.1 Input of the speed ratio for front and rear drive

The number of revolutions at the front axle is still opposite and equal to that of the rear axle. It should be

possible however for any number of revolution relationships.

The value of the speed ratio should be defined via a variable "FrontRearRatio" under "Settings". To create

such a variable in the tree structure the right mouse-click must be pressed the on "Settings" and "new variable"

selected. Then a variable "FrontRearRatio" can be added of the type "Real":

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Figure 53. Creation of the variable “FrontRearRatio” in settings

The speed at the front axle is now equal to the number of revolutions at the rear axle multiplied by this ratio.

Also, under the element "OutF" (output at the front axle) in the tree structure the expression for "speed" is

extended as follows:

Figure 54. Expression for the output speed “OutF”

In the same dialogue where the gear is selected, the speed ratio can also be entered. For this purpose the

dialogue must be extended (input of a value, delivery of this value into the variable provided above). This is

possible through “edit", with a right mouse-click on "SetSpeed" in the characteristics of "Settings“. Again the

function editor appears:

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Figure 55. Update of the function “SetGear”

The dialogue now looks as follows. For instance, when the value 1.5 is entered for "Front to Rear”, the

numbers of revolutions result is as shown:

Figure 56. Definition of ratio between front and rear axis

6.2 Input of efficiency

The efficiencies can be put in the connections either through the dialogue boxes or directly into the variable

"eta". Only the teeth efficiencies are to be entered.

6.3 Settings to calculation methodology

The kinematic analysis contains conditions for the torques and speeds, which are to be solved only by iterative

computation. Therefore, select "iteration for speed and torques with damping" under system

"kSysKinematicMode".

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Figure 57. Setting for the kinematic calculation

7 Annex

7.1 Code [line numbers are not part of the code]

1 VAR res; 2 res=CADH_VarDialog( ["SetSpeed",250,250,0.4,1], 3 [[C:VDLG_StrCom],"Speed:",["On-Road","Off-Road"],[OnOffRoad],1], 4 [[C:VDLG_Real],"Front to Rear:",Settings.FrontRearRatio,Settings.FrontRearRatio] 5 ); 6 IF res[0] THEN 7 OnOffRoad=res[1]; 8 Settings.FrontRearRatio=res[2]; 9 IF res[1]=0 THEN 10 GB.Input.c1.stateRy=1; 11 GB.Input.c2.stateRy=0; 12 GB.Input.c1.kSys_3DTransparency=0; 13 GB.Input.c2.kSys_3DTransparency=0.7; 14 ELSE 15 GB.Input.c1.stateRy=1; 16 GB.Input.c2.stateRy=0; 17 GB.Input.c1.kSys_3DTransparency=0; 18 GB.Input.c2.kSys_3DTransparency=0.7; 19 ENDIF 20 System.calcKinematic(); 21 ENDIF

7.1.1 Clarification

VAR res;

A local variable of "res" is defined. The type of the variable does not have to be defined for the time being.

The type is equal to the type on the right side of the equal sign being located in the line 2. Since the instruction

“CADH_VarDialog” returns an array, "res" is likewise an array.

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CADH_VarDialog

"Set speed" is the name of the dialogue, 250 is the width (in pixels), 250 is the height (in pixels). Value 0.4

defines that 40% of the width is in the left part of the window, 60% in the right. The following expressions in

square brackets define in each case an input field. The square brackets are separate by comma. In the first

expression a selection list is generated, called "speed". Between "on Road" and "off Road" are selected. The

second line permits the input of a value. The pre-emption of the input mask becomes defined through [

Settings.OnOffRoad ] and Settings.FrontRearRatio.

The outside IF loop examines whether the dialogue with "ok" was locked or not. If this applies, then the zero

element is alike 1 in the array of "res". Thus returns res[0] 1 or TRUE and the IF condition is fulfilled.

Line 7: Into the variable "OnOffRoad" is written 1 or 0. 0 means on road gear is selected, 1 means off road

gear is selected.

Line 8: The entered ratio is written into the variable "FrontRearRatio".

Second IF loop: if the selection is zero, whether on-road or off-road gear is selected (res [1]), then the on-

road gear is set. The clutch c1 is closed and c2 open. In the ELSE loop (will be execute if the on-road gear is

selected) c2 is closed and c1 opened.

In line 20 the kinematics calculation will be executed.

7.2 Code to set the internal diameter „di“ of the gears

# IF df > kSoft_RotCADDiameter(^.OBJ_GetMember("outerGeometry"),position) THEN

RETURN kSoft_RotCADDiameter(^.OBJ_GetMember("outerGeometry"),position); ELSE

CADH_Message("The defined diameter in the shaft calculation is too big" + "\n" + "(" + CADH_ValToStr(kSoft_RotCADDiameter(^.OBJ_GetMember("outerGeometry"),position)) + "mm) following value will be set (" + CADH_ValToStr(CADH_Round(df - 2 * 3.5 * d / z, 3)) + "mm)"); RETURN df - 2 * 3.5 * d / z;

ENDIF