TBK News: Version 32.2

Dear Sir or Madam,
We hereby would like to inform you about the latest news relating to our calculation software TBK and about some further news from our company.

Our Customers can find the new version in their download area here. The new version 07/2020 of SystemManager is available for download.

TBK-News 09/2020 Content:
1. Cylindrical Gear Pair: New Functions
2. Cylindrical Gear Pair: Load Capacity of Plastic Gears According to VDI 2736
3. Planetary Gear Train: New Dimensioning Functions for Profile Shift
4. Worm Gears: Direct Input of Power Losses
5. New Module: Mass Moment of Inertia
6. Shaft Strength According to DIN 743: Switch Between 2000 and 2012 Edition
7. New Versions of the 3D CAD Plugins
8. New Functions in SystemManager Software
9. New Video Tutorials
10. GWJ Attends Bevel Gear Seminar „Innovations in Bevel Gears“
1. Cylindrical Gear Pair: New Functions
In addition to various dimensioning functionalities for the distribution of the profile shift, a new function for disconnecting the centre distance from the profile shift was added. By using the function „Fixed working centre distance (recalculation)“, the profile shift coefficients can be defined independently from the centre distance. This enables, for example, the calculation of existing gear pairs that are to be installed in the housing with the „wrong“ centre distance. Transverse contact ratio, backlash and load capacity are also calculated correctly in this case.

Now the factor for the minimum tooth tip thickness can be defined individually by using the „Options“ menu item.

The functionality of tools with shifted profile reference line has been extended. Additionally to the addendum coefficient haMP0* of the shifted profile, the dedendum coefficient hfMP0* is displayed and visible in the calculation report. The dedendum coefficient hfMP0* can also be defined by clicking the „Lock“ button so that the dedendum coefficient hfP0* of the converted, non-shifted basic rack profile is always 1.0 according to DIN 867.

Furthermore, new basic rack profiles for plastic gears were added according to ANSI/AGMA 1106-A97.

The option „Full radius“ for the tip form of gear shaper cutters has now also been added to hobs.

For the definition of load spectra, the user can specify the face coefficient KHbeta and the temperature for each load case. This enables the automatic transfer of values directly from the system extension „SystemManager“ to the „Cylindrical gear pair“ module in the background. The user can see directly the effects of flank modifications on the root and flank safeties of the gear in the system.

In addition to the nominal tooth depth, the calculation report now also includes the effective tooth depth (min./max.). The minimum and maximum values for circular normal space widths were integrated as well.
2. Cylindrical Gear Pair: Load Capacity of Plastic Gears According to VDI 2736
In addition to the common calculation methods for the load capacity DIN 3990, ISO 6336 and ANSI/AGMA 2101, the calculation method VDI 2736 for plastic gears was added to the cylindrical gear pair module. The first plastic materials were added to the general material database. For this, the temperature-dependent material properties, such as fatigue strength and E-module, were approximated in detail from available diagrams in VDI 2736 and stored accordingly. Pairings of plastic/plastic as well as plastic/metal are supported. The calculation of load spectra is also possible for the load capacity calculation according to VDI 2736. In addition, „Dry run“ was added to the lubrication types for VDI 2736.
3. Planetary Gear Train: New Dimensioning Functions for Profile Shift
Now there are several new options for the profile shift sum as well as for the distribution of the profile shift coefficients. Another new feature is that the profile shift coefficients or profile shift sum can be specified and used to determine the center distance, similarly to the functionality in the eAssistant cylindrical gear module. A function for disconnecting the center distance and the sum of the profile shift coefficients was added. This allows a calculation with a „wrong“ center distance. In addition to „Own Input“ and balanced specific sliding, new options for the distribution of the profile shift were also integrated:

– Minimum sliding speed,
– Maximum root safety,
– Maximum flank safety and
– Maximum scuffing safety (integral).

The user can choose to dimension either sun/planet or planet/annulus pairing.
4. Worm Gears: Direct Input of Power Losses
In the load capacity calculation of worm pairings, the calculated power losses can be overwritten or specified individually:

– Total power loss P_V
– Idle running power loss P_V0
– Bearing power loss P_VLP
– Sealing power loss P_VD
– Meshing power loss P_VZ

This means that the load capacity calculation can be better adapted to the results of test bench trials.
5. New Module: Mass Moment of Inertia
The new module enables the calculation of the mass moments of inertia of individual shafts and gear bodies as well as shaft systems. The results obtained are the masses and mass moments of inertia of the individual shafts as well as the mass moment of inertia of the shaft system related to the input shaft and output shaft.

Calculation data, that were created with module of the same name of the old and discontinued TBK software generation up to V22, can be read in and used.
6. Shaft Strength According to DIN 743: Switch Between 2000 and 2012 Edition
Both versions of DIN 743 (version 2000 and 2012) are now available for calculating the fatigue strength and safety against permanent deformation of shafts. The desired version can be selected in the settings menu. The default standard is now the version DIN 743: 2012.
7. New Versions of the 3D CAD Plugins
The new 3D CAD Plugin versions support the following CAD versions:

– Solid Edge up to Solid Edge 2020
– Autodesk Inventor up to Autodesk Inventor 2021
– Siemens NX up to NX 1926

In addition, the generation of gear racks in SOLIDWORKS, Solid Edge and Autodesk Inventor has been improved. In certain cases, a surface could remain on the tooth tips of rectangular racks and generation could fail with round racks. This could now be solved in the new versions.
8. New Functions in SystemManager Software
The database format was not changed compared to the previous version, so your own bearings can be transferred to the new database by using the update function. The bearing databases (catalogue data) from Schaeffler and SKF are updated. In addition, a database from HQW Precision GmbH and The Barden Corporation (UK) Limited and CSC were added. These sub-databases are encrypted and contain the internal geometry of the bearings. Additional encrypted databases containing internal geometry are available from GMN and IBC, but have to be requested from the manufacturer.

A possibility to add rules is added to the optimization step in the parameter variation.

A curve for the current result can now be inserted into frozen diagrams.

The additional language Turkish has been added. The help can be opened via an .exe file, so it can be used over a network path, where CHM files are blocked. On calculations with load spectra on addition to a progress bar, a cancellation button is shown. This allows to cancel a running calculation.

For the thermal permissible speed now the temperature and frictional moments are shown for all load spectrum elements in the main report.

The mesh stiffness for cylindrical gear pairs can now be calculated also as c_gamma_ß. Before c_gamma_a was used only.

Bevel gears are now shown including teeth in the 3D views. There is also an interface to Klingelnberg´s KIMoS software.

REXS interface has been updated to version 1.2. to exchange multi-shaft systems with other software solutions, for example FVA Workbench.

The option „Add System“ is added to the context menu for groups in the system tree. It allows to generate a multi-stage cylindrical gearbox or a simple planetary gear set. With just a few specification, for the multi-stage cylindrical gearbox for example the number of stages, the total ratio, the input torque and the input speed, a proposal for a multi-stage gearbox can be created with a simple mouse click. Shaft diameter and dimensions of the cylindrical gears are suggested for each stage and automatically set up as a system. The shaft geometries can be refined afterwards and the bearings for example can be changed into rolling bearings. The software makes it easy to get a first draft of a multi-stage cylindrical gearbox. This also saves time when building the system.

If a geometry is imported as mesh (Nastran or FEMAP mesh, not as STEP), then multiple materials can be assigned for 3D elastic parts (meshed FEM parts). A new connection type „elastic contact“ is added for 3D elastic parts.

Evaluation of surface stresses is a new functionality. Optionally, surface stresses fields can be calculated on reduction for a 3D elastic part. As the meshed are not refined on corners, these stresses cannot include stress concentrations, they just give an estimate for the load inside of the part. Graphics for stresses are added in graphics menu.

Results for condensed nodes can be determined, that means displacements, rotations and forces are now shown for reduction points.

Harmonic response for 3D elastic parts are now shown as animation. Imbalance and dynamic forces can be defined on 3D elastic shafts and results for harmonic results are available as result for supports and forces of 3D elastic parts.

For geometry import from CAD, a preview dialog is shown. This dialog shows the number of parts available in the file and allows to delete parts and merge the remaining parts. The part can be remeshed with different settings to evaluate the mesh quality. Only the currently selected part is meshed and imported. To combine parts, the „Merge“ function has to be used and a reasonable merge tolerance has to be set. After meshing, the number of surface nodes is shown in the window to get an idea about mesh complexity.
9. New Video Tutorials
Over the last few months, we have added lots of new video tutorials to our YouTube channel. These video tutorials cover many different topics, such as an overview of the functions in the cylindrical gear module, the 3D CAD integrations or the development of gearboxes in the SystemManager software including working with 3D elastic parts in the system calculation. If you are interested, we can provide the used models and generated calculation files of the system calculations. Please do not hesitate to contact us.

The videos come with language support, i.e. the explanations during the videos are usually in German or English (there are two language versions of each video). The following video tutorials are currently available:

* Creation of shaft geometries using background graphics in SystemManager:

* TBK gear pair calculation short introduction:

*  TBK gear pair calculation tutorial:

* Introduction TBK plugin for SOLIDWORKS:

* Introduction TBK plugin for Solid Edge:

* Introduction TBK plugin for Autodesk Inventor:

* Configuration of a two-stage gear box with SystemManager:

* Configuration of the planetary gear train with fixed bolts for the planets:

* Configuration of the planetary gear train with mounted planet shaft:

* Draft dimensioning of a planetary gear train:

* 3D elastic planet carrier in SystemManager:

* Single stage gearbox with housing in SystemManager:
10. GWJ Attends Bevel Gear Seminar „Innovations in Bevel Gears
GWJ will, once again, attend the bevel gear seminar „Innovations in Bevel Gears“ on October 7th & 8th, 2020 at the RWTH Aachen. Together with the company Zeiss, we will give a lecture, the topic is „The Digital Twin in the First-Part-Right Production Chain“. Our Mr. Gunther Weser will be happy to answer any questions and provide you with further information.

Please feel free to contact us if you have any questions.

All the best,
Your GWJ team