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Please login with your user name and your password. Select the module through the tree structure of the Project Manager by double-clicking on the module or clicking on the button ‘New calculation’.
The calculation module is opened in a new window.
Define here any number of bearings.
The following listbox ‘Current view’ allows you to select between the several bearings.
You can add a description or a short comment to the bearing.
If you would like to delete an already added bearing, please enter the new number of bearings and confirm your input with ‘ENTER’.
A new window is opened.
Now select a bearing which you would like to delete and click on the button ‘Delete the selected bearings!’.
The corresponding bearing is deleted.
The clearly arranged database provides about 20.000 bearings.
There are the following manufacturers to choose from:
Here you get the information how many bearings of a certain manufacturer are available in the database.
The following bearing types are available for your calculation:
Please note: For every bearing type you will get a graphical representation.
Here you can define the radial force, the axial force and speed.
Please note: If you right-click in an input field, then you have the possibility to change the unit of measurement. Now all units are displayed in a context menu. The two arrows mark the current setting.
Select the unit of measurement. The current field value will be converted automatically into the chosen
unit.
A calculation with load collectives is also possible. To use the load collectives, activate the option ‘Use load collective’.
A new window is opened.
You can define any number of loading cases.
For every loading case a specification for time slice, speed, radial force, axial force, temperature and cleanness is possible. A listbox shows you the degree of impurities.
You can differentiate between:
.
The load collectives can be opened and saved independently of the underlying bearing calculation. For that purpose use the button ‘Open’ and ‘Save’.
Please note: The entries for the expanded modified rating theory will be specified with the definition of the
several loading cases.
When you start the calculation module, the expanded modified rating theory is automatically activated. When there are no defined load collectives, then enter you individual specifications for the requisite reliability, operating temperature or cleanness. You can enter your own cleanness factor for the degree of impurities. Select ‘User-defined’ from the listbox. The calculated value for the expanded modified rating theory is displayed immediately in the result panel of the module.
For the calculation of the expanded modified rating theory you can choose different oils and greases from the lubricant database or you can create your own lubricant.
About 150 products of the following manufacturer are available:
Select different lubricants directly from a listbox.
Click on the button ‘Lubricant’.
The lubricant selection is opened. Here you get all information to the selected lubricant.
Please note: The two arrow keys ‘Up’ and ‘Down’ of your keyboard allows you to search through the lubricant database, so you can compare the different values with each other.
In case you cannot find a special lubricant, then click on the entry ‘User-defined’ in the listbox.
Afterwards you can define your individual inputs as well as add a short comment. In order to confirm these
inputs, click on the button ‘OK’. If you now click on the button ‘Lubricant’, your user-defined inputs
open.
Please note: In case you decide for another lubricant, your user-defined inputs will be deleted.
When you selected a manufacturer and a bearing type, you can choose the bearing directly from a list or you can identify the bearing from the ‘Bearing selection search’ by using the button ‘Bearing selection’.
The button ‘Bearing selection’ opens the bearing database where you can find a wide range of bearings.
The bearing database opens.
For the bearing search the different parameters
can be entered for a certain range. So it is easy to refine the search to get precisely the results you want.
Please enter your values.
You can navigate around the input fields by using the ‘Tab’ key on your keyboard. All inputs will be confirmed automatically.
Please note: You can enter your data into all input fields to reduce the number of bearings. Then you have
to decide between only a few bearings. In case you have already entered values into the input
fields and now you would like to have any inner or outer diameter of the bearing again, then delete
your own value and click into another input field or use the ‘Tab’ key on your keyboard. The option
‘Any’ is use again in the appropriate input fields. Thereby the number of bearings will be increased
again.
If you have entered the according values, click on the button ‘Search’.
The bearing search is accomplished and all found bearings will be displayed.
Please note: With the display of the found bearings you can re-sort the list by clicking on the column headings.
If the bearings are to be sorted in reverse order, then click on the column heading again.
Receive here also additional details on the selected bearing.
Now select one of the bearings and confirm your choice with the button ‘OK’.
The bearing is taken over to the main mask of the calculation module.
In addition to the selection of bearings directly from the database, you can also enter and calculate bearings individually. Activate the option ‘User-defined’, then you have the possibility to enter your own values into the appropriate input fields.
Please confirm your inputs with the button ‘OK’.
The inputs will be taken over to the main mask.
The calculation module contains a message window. Here you get all information, warnings and hints. You will find all information, which are displayed in the message window, in the calculation report later. The button ‘Report’ allows you to generate a calculation report upon completion of your calculation (see also section 6.10 ‘The documentation: The calculation report’).
When you define a bearing, the calculation will be accomplished automatically and the results will be displayed immediately in the result panel. This means that after every input of your data your results will be calculated again. The rating life, the expanded modified rating life as well as the static identification number will be displayed.
For a further illustration the following diagrams are available:
The listbox shows the diagrams and you can decide which diagram should be displayed.
Choose the diagram and click on the button ‘Diagram’ next to the listbox.
The diagram with the values for the rating life and for the expanded modified rating life is displayed immediately.
Finally you can generate a calculation report. Click on the button ‘Report’.
The calculation report is generated.
The calculation report contains a table of contents. You can navigate through the report via the table of contents that provides links to the input values, results and figures. The report is available in HTML and PDF format. Calculation reports, saved in HTML format, can be opened in a web browser or in Word for Windows.
‘Save as’ from your browser menu
bar. Select the file type ‘Webpage complete’, then just click on the button ‘Save’.
After accomplishment of your calculation, you can save the calculation. There you have the possibility to save either on the eAssistant server or on your own workstation locally. Click on the button ‘Save’.
If you have activated the option ‘Enable file save local’ in the Project Manager and the option ‘Local’ in the
calculation module, a standard Windows dialog for saving the file on your workstation appears.
Please note: You must not forget that the calculation module has to be closed to activate the option ‘Enable file save local.’
In case you have not activated this option, a new window is opened and you can save the calculation on the eAssistant server (find further information in the chapter ‘The general functions’ 4.2).
Please enter a name into the input field ‘Filename’ and click on the button ‘Save’. Then click on the button ‘Refresh’ in the Project Manager. Your saved calculation file is displayed in the window ‘File’.
The button ‘Undo’ allows you to reset your input to an older state. The button ‘Redo’ reverses the undo.
Here you can specify which diagrams are to be displayed in the calculation report. Click on the button ‘Options’.
A new window opens. Now you can define which diagrams are to be integrated later into the calculation report.
Please login with your user name and your password. Select the module through the tree structure of the Project Manager by double-clicking on the module or clicking on the button ‘New calculation’.
The calculation module is opened in a new window.
The arc of contact of the rope is 180∘ for the sheaves of hook blocks. Therefore, a double tensile load is acting on the bearing. The axial forces and the torque are small. When there is a diagonal tension of 5∘ , then axial forces have to be considered for the calculation of the rating life. Two rows of idler bearing units in one bearing or two bearings next to each other form the supporting base for taking up the torque. In the following example the rating life and expanded modified rating life are to be calculated.
We have taken this example from: J. Brändlein: Die Wälzlagerpraxis: Handbuch zur Berechnung und Gestaltung von Wälzlagern (1995, p. 466-470). (The following figure: J. Brändlein: Die Wälzlagerpraxis, p.467).
Please enter the following input values:
| Bearing load | 65 kN |
| Type of bearing | Tapered roller bearing (single row) |
| Speed n | 30 min |
| Built-in bearing | A pair of tapered roller bearing (100 x 150 x 67) |
| For-life lubrication | Grease with EP-additive |
In this example we would like to calculate one bearing of a tapered roller bearing pair. When you open the calculation module, usually one bearing is shown. So you need not to change the number of the bearings. Enter a description into the comment field, for example ‘bearing of the sheave’.
In the database about 20.000 bearings of different manufacturer are available. For our example please select the manufacturer ‘SKF’.
Select the bearing type ‘Tapered roller bearing (single row)’.
Now enter the values for the bearing load. Please pay attention that the values will be entered in ‘kN’. Change the unit of measurement by right-clicking.
Please note: The expanded modified rating life is deactivated.
To get into the bearing database, click on the button ‘Bearing selection’.
The bearing database is opened.
Right now there are ‘472’ bearings in the database. But it is easy to refine the selection to get precisely the results you want, because you can use the value for the inner and outer diameter of the bearing.
| Inner diameter of bearing | = 100 mm |
| Outer diameter of bearing | = 150 mm |
Enter the values for the inner and outer diameter of the bearing and click on the button ‘Search’.
Finally the number of bearings reduces from 472 to two bearings.
Select the bearing ‘32020 X/Q’ and confirm with the button ‘OK’.
The bearing is taken over to the main mask of the calculation module.
When you define the bearing, the calculation will be accomplished automatically and the results will be displayed immediately in the result panel. At first you get the result for the rating life as well as the static identification number.
The result of the rating life is 
= 14.237,9 h
For sheaves a rating life from 5.000 to 20.000 hours is required. The bearing is sufficiently dimensioned. For this
example you will find a note in the message window.
In this case you can ignore this message. When the pair is clamped, then the correct axial clearance and the
necessary axial force for the tapered roller bearing occur.
After you get the result for the rating life, please have a look at the expanded modified rating life 
in regard
to the operating conditions (lubrication, clearance).
When you open the calculation module, the option ‘Use expanded modified rating theory’ is automatically activated.
Now you an define the requisite reliability and the cleanness as well as a lubricant.
Please select the grease ‘Klüber Klübersynth BMQ 72-162 (094073)’. Select this lubricant directly from the listbox. If you need detailed information, please click on the button ‘Lubricant’.
The lubricant database opens.
Now you can see that this grease contains active EP additive.
Click on the button ‘OK’.
The lubricant ‘Klübersynth’ is taken over to the main mask.
Next you have to estimate the influence of possible impurities by using the cleanness factor. Actually it is assumed that the ‘highest cleanness’ is used for sealed and greased bearings (for-life-lubrication). But during the entire operating time, a certain wear of the seals could occur which can let light impurities into the bearing. In this case you can assume light impurities. Therefore, choose ‘Light impurities’ from the listbox.
Now you get immediately the result for the expanded modified rating life.
Please note: The two arrow keys ‘Up’ and ‘Down’ of your keyboard allows you to search through the lubricant
database, so you can compare the different values with each other.
The result of the expanded modified rating life is 
= 9.657,8 h.
Finally the expanded modified rating life 
is in the range of the rating life 
.
For a further illustration the following diagrams are available:
Click on the button ‘Diagram’ next to the listbox.
The selected diagram opens. The diagram including the values for the rating life and for the expanded modified rating life is displayed immediately.
The button ‘Options’ allows you to define which diagrams are to be represented in the calculation report later. Afterwards click on the button ‘Report’.
The calculation report is generated.
The calculation report contains a table of contents. You can navigate through the report via the table of contents
that provides links to the input values, results and figures. The report is available in HTML and PDF
format. Calculation reports, saved in HTML format, can be opened in a web browser or in Word for
Windows.
After accomplishment of your calculation, you can save the calculation. There you have the possibility to save either on the eAssistant server or on your own workstation locally. Click on the button ‘Save’.
Please note: You must not forget that the calculation module has to be closed to activate the option ‘Enable file
save local.’
In case you have not activated this option, a new window is opened and you can save the calculation on the eAssistant server.
Please enter a name into the input field ‘Filename’ and click on the button ‘Save’. Then click on the button ‘Refresh’ in the Project Manager. Your saved calculation file is displayed in the window ‘File’.
For the ventilator the impeller can be placed either centrically between two bearings or in an overhung position to the both bearing points. For small or medium ventilators the overhung bearing of the impeller is usual. Here a support for the fan drive shaft in two separated pillow block housings is possible.
The unit (figure 6.63) contains a cylindrical roller bearing A and a deep groove ball bearing B in a shared casing (figure 6.64). The bearing diameter is 70 mm.
This calculation example we have taken from: J. Brändlein: Die Wälzlagerpraxis: Handbuch zur Berechnung und Gestaltung von Wälzlagern (1995, p. 516-520). (The following figure: J. Brändlein: Die Wälzlagerpraxis, p.517)
The input values for bearing A (Cylindrical roller bearing NU 314 ECP)
| Loading case no. 1 | Loading case no. 2 |
Time slice  | = 50% | Time slice  | = 50% |
Speed  | = 3.000 min-1 | Speed  | = 4.500 min-1 |
Radial force  | = 8.500 N | Radial force  | = 11.000 N |
Axial force  | = 0 N | Axial force  | = 0 N |
Temperature  | = 70 ∘C | Temperature  | = 70 ∘C |
All input values for bearing B (deep groove ball bearing 6314)
| Loading case no. 1 | Loading case no. 2 |
Time slice  | = 50% | Time slice  | = 50% |
Speed  | = 3.000 min-1 | Speed  | = 4.500 min-1 |
Radial force  | = 2.000 N | Radial force  | = 5.000 N |
Axial force  | = 5.000 N | Axial force  | = 5.000 N |
Temperature  | = 70 ∘C | Temperature  | = 70 ∘C |
In this example we would like to calculate the rating life of the cylindrical roller bearing and the deep groove ball bearing. Here you find two bearings, that is why you have to change the number of bearings. So enter ‘2’ into the input field ‘Number of bearings to calculate’.
Please note: Please calculate the bearings one after another separately. The listbox ‘Current view’ allows you
to switch between the two bearings
Add a comment for the first bearing.
Now select the manufacturer ‘SKF’.
Choose the cylindrical roller bearing.
Define the load collective for the first bearing. Activate the option ‘Use load collective’. The input options for the radial and axial force as well as for the speed will be deactivated.
A new window is opened.
Define two loading cases for the bearing. For each individual loading case enter the time slice, the radial force, axial force, the temperature, and cleanness. When you have defined all inputs, then confirm with the button ‘OK’.
Click on the button ‘Bearing selection’.
The bearing database opens.
It is easy to filter the search to get precisely the results you want, because you can use the value for the inner diameter of the bearing. So please enter into the input field ‘Inner diameter of bearing’ the value ‘70 mm’ and click on the button ‘Search’. Finally 52 bearings remain. Please look for the cylindrical roller bearing ‘NU 314 ECP’ and confirm your input with the button ‘OK’. The bearing is taken over to the main mask of the calculation module.
When you define a bearing, the calculation will be accomplished automatically and the results will be displayed immediately in the result panel. This means that after every input of your data your results will be calculated again. At first, you get the result for the rating life.
The result for the rating life is 
= 99.134,4 h
With this the rating life is sufficiently dimensioned.
Calculate now the rating life for the deep groove ball bearing. Please pay attention that you select ‘Bearing No. 2’ from the listbox ‘Current view’.
Select the manufacturer ‘SKF’ and the bearing type ‘deep groove ball bearing (single row)’. Then activate the option ‘Use load collective’.
Define the separate loading cases.
Click on the button ‘Bearing selection’ and choose the bearing ‘6314’ from the listbox. Filter your search and enter into the input field ‘Inner diameter of bearing’ the value ‘70 mm’ and click on the button ‘Search’. Then you can select the bearing ‘6314’ from the list.
The result for the rating life is 
= 4.869,6 h
The rating life for the deep groove ball bearing B is lower than the rating life for the cylindrical roller
bearing. This means that the load for bearing B is higher than for bearing A. At least 22.000 hours are
required for the rating life of the deep groove ball bearing. With this the rating life is not sufficiently
dimensioned. Next take a closer look at the expanded modified rating life 
for the bearing
B.
The next step is to calculate the expanded modified rating life for the deep groove ball bearing. Generally the expanded modified rating theory is activated.
Select the grease ‘Lubcon Turmograse Highspeed L 252 (K HC P 2/3 K-50)’ directly from the listbox or click on the button ‘Lubricant’ to open the lubricant selection. Accept the lubricant and confirm with the button ‘OK’.
The lubricant is taken over to the main mask of the calculation module. The result for the expanded modified rating life is displayed automatically.
The result of the expanded modified rating life is 
= 34.092,4 h.
Because at least 22.000 hours are required, the bearing is sufficiently dimensioned.
The button ‘Options’ allows you to define which diagrams are to be represented in the calculation report later.
Afterwards click on the button ‘Report’.
Please note: If you calculate the bearing with load collective, then not all diagrams can be displayed.
The calculation report is generated.
The calculation report contains a table of contents. You can navigate through the report via the table of contents
that provides links to the input values, results and figures. The report is available in HTML and PDF
format. Calculation reports, saved in HTML format, can be opened in a web browser or in Word for
Windows.
After accomplishment of your calculation, you can save the calculation. There you have the possibility to save
either on the eAssistant server or on your own workstation locally. Click on the button ‘Save’. If you have
activated the option ‘Enable file save local’ in the Project Manager and the option ‘Local’ in the calculation
module, a standard Windows dialog for saving the file on your workstation appears.
Please note: You must not forget that the calculation module has to be closed to activate the option ‘Enable file
save local.’
In case you have not activated this option, a new window is opened and you can save the calculation on the eAssistant server.
Please enter a name into the input field ‘Filename’ and click on the button ‘Save’. Then click on the button ‘Refresh’ in the Project Manager. Your saved calculation file is displayed in the window ‘File’.
Our manual is improved continually. Of course we are always interested in your opinion, so we would like to know what you think. We appreciate your feedback and we are looking for ideas, suggestions or criticism. If you have anything to say or if you have any questions, please let us know via telephone +49 (0) 531 129 399-0 or email eAssistant@gwj.de.
