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Please login with your user name and your password. Open the calculation module from the listing window ‘Calculation type’ in the Project Manager.
The calculation module is started.
The arc of contact of the rope is 180∘ for the pulleys 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 a rope 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 measurement unit by right-clicking.
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 filter 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 rope 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 appear. (Das richtige Axialspiel und damit die notwendige Axialkraft für das Kegelrollenlagerpaar ergibt sich, wenn das Innenringpaar zusammengespannt wird.)
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 for sealed and greased bearings (for-life-lubrication) the ‘highest cleanness’ is used. But during the entire operating time a certain wear of the seals could appear which can let light impurities into the bearing. In this case you can assume the light impurities. Therefore choose ‘Light impurities’ from the listbox.
Now you get immediately the result for the expanded modified rating life.
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 with 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 report includes a table of contents. Through this all results can be called very fast. All input data as well as all results are listed. The calculation report is available in HTML and PDF format. You can save the report in a HTML format. Later you can open the generated report in a web browser or open it in Microsoft Word.
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’.
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 ventilator the impeller (Laufrad) can be placed either centrically between two bearings or in an overhung position to the both bearing points. (Bei Ventilatoren kann das Laufrad entweder mittig zwischen zwei Lagern oder fliegend zu den beiden Lagerstellen angeordnet werden.) For small or medium ventilators the overhung bearing of the impeller is usual. (Bei kleinen und mittleren Ventilatoren ist die fliegende Lagerung des Laufrades üblich.) Here a support for the fan drive shaft in two separated pillow block housings is possible. (Hierbei ist eine Abstützung der Lüfterwelle in zwei getrennten Stehlagergehäusen möglich.)
The unit (figure 1.22) contains a cylindrical roller bearing A and a deep groove ball bearing B in a shared casing (figure 1.23). 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’.
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 clindrical 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’.
Note: If you calculate the bearing with load collective, then not all diagrams can be displayed.
Afterwards click on the button ‘Report’.
The calculation report is generated.
The report contains a table of contents. Through this all results can be called very fast. All input data as well as all results are listed. The calculation report is available in HTML and PDF format. You can save the report in a HTML format. Later you can open the generated report in a web browser or open it in Microsoft Word.
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.
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’.
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