CylGear
Application for calculation of Cylindrical Involute Gears
CylGear calculates
 executable gear domain and its boundary lines
 dimensioning of a gear pair
 gear geometry according to standard DIN 3960
 gear measurements: chordal thickness, span width and dimension over pins or balls
 contact path and diameters of profile points needed for profile grinding with profile correction
 the tooth forces in mesh point and the reaction forces in the bearings
 determination of the dynamic model
 load capacity according to standard ISO 6336
 dimensioning and verification of geometry and calculation of load capacity of a planetary gear train
Topics covered in this site
User Interface
CylGear is an application running under Microsoft Windows operating system.
The user can select a language for the user interface and output among:
 Dutch
 English
 French
 German
The user interface is very user friendly: the application guides the user through each calculation sequence.
Identification of a Calculation Project
At the start of a new calculation project, a dialog box opens for input of data for the identification of the calculation project.
Gear Definition
A gear pair is defined by a standard theoretical basic rack and by seven independent geometric parameters. The calculation
is being done for a pinion and gear pair.
Theoretical Basic Rack
The theoretical basic rack is defined by the following proportions:

pressure angle 
α_{P} 
20.00 ° 

addendum coefficient 
k_{haP} 
1.00 

dedendum coefficient 
k_{hfP} 
1.25 

toothroot radius coefficient 
k_{ρfP} 
0.30 
The proportions can be changed, input is to do with following dialog:
The basic rack propotions are stored as default values in the registry with a simple
mouse click on the command button Default.
The basic gear rules, the theoretical basic rack and two coefficients for the minimal normal crest width for external gear,
respectively minimal normal root space width for internal gear, are defining the executable gear domain. The application
calculates the boundary lines. Required input are the following proportions:
External gear 
Gear boundary line G_{1} 
k_{san} 
0.20 
Internal gear 
Gear boundary line G_{5} 
k_{efn} 
0.20 
This two proportions are stored in the system registry and are used as default values for a next calculation.
The boundary lines are calculated for the given basic rack data as pressure angle α_{P}, addendum and
dedendum coefficients. The boundary lines enclosing the executable gear domain are drawn in red color in the diagram in the dialog below:
The gear boundary diagram can be printed on paper by a click with the mouse on the command button Print.
For a pressure angle 20 ° and a virtual number of teeth in normal section one should particularly in the range z_{n} = 9 ... 60 teeth
pay attention to respect the gear boundary lines. That's exactly what the application is doing for you:
if a gear boundary condition is not satisfied a message box will warn you.
Definition of gear boundary lines:
External gear:

Boundary line G_{1} 
x_{G1} 
maximum profile shift coefficient applicable from the condition to respect a minimum normal crest width of
s_{an} = k_{san} m_{n}

Boundary line G_{2} 
x_{G2} 
minimum profile shift coefficient to apply in order to avoid undercutting of the toothroot 
Boundary line G_{3} 
x_{G3} 
minimum profile shift coefficient to apply from the condition d_{a} >= d_{b} + 2 m_{n} 
Internal gear:

Boundary line G_{4} 
x_{G4} 
maximum profile shift coefficient to apply from the condition d_{a} <= d_{b} 
Boundary line G_{5} 
x_{G5} 
minimum profile shift coefficient from the condition minimum normal toothroot space width
e_{fn} = k_{efn} m_{n} 