Bearing Generator dialog box - Calculation tab

This tab extends the Design tab. Calculates generator data based on selections in the Design tab.

If you selected a bearing in the Design tab, the bearing data taken from the manufacturer are transferred to the Calculation Tab. The edit fields with such data are displayed with a gray background. If data is missing, modify values in the edit fields with a white background.

Access:

Ribbon: Design tab Power Transmission panel Bearing and switch to the Calculation tab.

Type of Strength Calculation

Bearing Design	Designs a bearing for the required life. Selects the bearing from the bearing list that matches all criteria specified in the Design and Calculation tabs and its calculated Adjusted Bearing Life (L na ) value is equal or close to Bearing Required Life (L reg ) value.
Check Calculation	Strength check of selected bearing.

Loads

The Loads area is used to input loads and shaft rotation.
Specifies the radial and axial components of external loads of the bearing.
Click the diagrammatic picture to display Various Load Conditions dialog box where you can insert additional loads.
Required Static Safety Factor	Enter the safety at static loading of the bearing.

Lubrication

The reason for lubricating rolling bearings is to create a carrying lubrication film on contacts between rolling bodies with orbital paths of the rings. In addition, the lubricant protects the bearing from corrosion, improves its sealing, exhibits cooling effects and lubricates the surfaces of the bearing with sliding friction. Rolling bearings can be lubricated by plastic or liquid lubricants. Selection of a suitable lubricant is determined, above all, by the speed, operational temperature, position of the shafts, general concept of seating and economy of operation. If permitted by operational conditions, greases are preferred with rolling bearings.
Grease lubrication	Grease lubrication is preferred because of ease of operation, economy, and sealing of bearings against dirt and moisture. It enables a simple arrangement of seating and is better suited for high and surge loading. Greases must show good lubrication capability and high chemical, thermal, and mechanical stability. The market offers a wide range of suitable greases. In addition, most producers of rolling bearings offer their own ranges of lubricants.
Oil Lubrication	Lubrication of rolling bearings by oil is not so good and is usually used only in the following cases:
	Speed of the bearing is so high that refilling intervals for lubrication by grease would be too short. Operational temperature is higher than the permissible temperature for greases. The adjacent parts are lubricated by oil. Lubrication by oil flow is required for intensive cooling of the bearing. Lubrication of spherical roller bearings.

Bearing Properties

Basic static load rating

Specifies the external load that causes a permanent deformation of 0.0001 of the diameter of the rolling body at the contact point of the most loaded rolling body. This permanent deformation usually has no adverse effects on the bearing function. Values of static load ratings are given for each bearing in the respective catalogs.

Bearing Life Calculation

Options displayed are dependent on the selected bearing life method.
Specifies the type of calculation you select from a list of 2: Calculation according to ANSI/AFBMA 9-1990 (ISO 281 - 1990), or Calculation according to SKF AG.
Required Life	Value must be defined. Enter the appropriate life of the bearing. Click the arrow next to the edit field to display Desired Service Life dialog box where guide values are presented.
Required Reliability	Value must be defined. Click the arrow next to the edit field to select the reliability in the selection list.

List of Bearings

In the lower part of the Calculation tab, there is the list of bearings that matches the specify criteria from the Design tab. If you select one bearing, only that bearing values are transferred to the Calculation tab.

When you select the Bearing Design option in the type of Strength Calculation area, a new column, Adjusted rating life, is added to the list.

Click the bearing to select it. The generator then uses the manufacturer data of the selected bearing. Such data are entered into the edit fields with gray background. If data is missing, modify values yourself in the edit fields with a white background.

Results

To display the Results area on the right side of the Calculation tab, double-click the double line on the right or click the chevron.

The area displays the calculated values and the bearing strength check. Values are calculated when the Calculate command is pressed.

The units of the results values can be changed. Double-click the specified value you want to change.

Summary of Messages

Displays the reports about calculation. To open the Summary of Messages areas at the bottom of the tab, double-click the double line at the bottom of the tabs or click the chevron.

Design tab

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