Parallel Key Connection Generator dialog box - Calculation tab

Use this tab to calculate the generator data based on selections in the Design tab.

Access:

Ribbon: Design tab Power Transmission panel Key and click the Calculation tab.

Type of Strength Calculation

Design Key Length

Designs optimum key dimensions for the specified load, dimensions, and joint properties.

Check Calculation

Performs a strength check for the specified load, dimensions, and joint properties.

Simplified calculation

Calculates force from torque in the distance d/2, no chamfer, and the depth of groove is considered h/2.

Loads

Enters loading through power, speed, or torque according to the method selected in the list.

Power, Speed Torque

Calculates the torque according to the power and speed.

Torque, Speed Power

Calculates the power according to the torque and speed.

Power, Torque Speed

Calculates the speed according to the power and torque.

Dimensions

Shaft Diameter

Chooses a diameter of the shaft sufficient so that the diameter of a solid shaft d1, not weakened by a key groove, is larger than the minimum required diameter d1min.

 

Warning: The diameter of the shaft should be within the standard specified range.

 

Recommendations: If shafts are exposed to additional loading from external radial forces (for example, with gears), choose a diameter for the shaft so that the diameter d1 is approx. 20% - 30% larger than the minimum diameter d1min.

Hollow Shaft Inner Diameter

If you use a hollow shaft in the coupling, enter the inner diameter of the shaft. This parameter affects the size of loading of the shaft in torsion and considerably affects the determination of the minimum permitted diameter of the shaft.

Key Size

Specifies the width and height of the key.

Key Length

Specifies key length. Choose a length of key within the standard specified range so that it is larger than the minimum length. When determining the length, keep in mind that the chosen length of the key influences the length of the hub.

Keyway Length

Specifies the length of the keyway.

Key Material

The Material database is not connected to Autodesk Inventor Material Library.

Note: The values in the edit field that are not satisfactory turn red when you click Calculate.

Warning: Determines the strength parameters of material empirically and reflects the minimum values applicable for a group of materials. Although these values are close to the values obtained using measurement of particular materials, we recommend that you use parameters of material according to the material sheet or specifications of the producer in cases of final calculations.

Specifies the material values you enter, or selects a material from the Material Database. If a material is selected from the Material Database, the values are inserted automatically into the following edit field, and the edit field is locked. To unlock the field, clear the check box.

Allowable Pressure

Specifies the allowable pressure of the key material with the least quality in the Joint Properties group. The key is checked for pressure during the strength check.

Shaft Material

Specifies the material values you enter, or selects a material from the Material Database. If a material is selected from Material Database, the values are inserted automatically into the following edit field, and the edit field is locked. To unlock the field, clear the check box.

Allowable Pressure

Specifies the allowable pressure of the key material with the least quality in the Joint Properties group. The key is checked for pressure during the strength check.

Allowable Shear Stress

Specifies the allowable pressure of the key material with the least quality in the Joint Properties group. This value is used in designing the minimum shaft diameter.

Hub Material

Specifies material values you enter, or selects a material from the Material Database. If a material is selected from the Material Database, values are inserted automatically into the following edit field, and the edit field is locked. To unlock the field, clear the check box.

Allowable Pressure

Specifies the allowable pressure of the key material with the least quality in the Joint Properties group. The key is checked for pressure during the strength check.

Joint Properties

Key Number

For transfer of higher torsional moments, it is possible to use two keys in the coupling. The keys are arranged symmetrically on the shaft (in opposite positions). A non-symmetrical arrangement is also used for transfer of cyclical moments (at 120° spacing). Although the loading capacity of a coupling with two keys should be theoretically doubled, it is in fact lower due to production inaccuracies. In practice, the loading capacity is considered 1.5 times higher than with one key.

Desired Safety

With regards to accuracy and credibility of the input information, the importance of the coupling, the quality of production and accuracy of the calculation, chosen within a range from 1.5 to 3.

 

Orientation values for choice of safety:

 
  • 1.3 to 1.5 - Very accurate input information, perfect knowledge of material characteristics, high quality, and exact accuracy in production technology. Includes insignificant couplings, damage to which does not cause any serious consequences.
  • 1.5 to 1.8 - Less accurate calculation without any experimental verification, lower accuracy in production technology, couplings of lower importance.
  • 1.8 to 2.5 - Decreased accuracy of calculations, approximate determination of material characteristics, inaccurate knowledge of actual effects of external loading. Large diameters of shafts, important couplings, damage to which could jeopardize human life or bring about high material losses.
  • Note: Even higher levels of safety are used if of couplings are working in a corrosive environment or at high temperatures.

Results

Displays the calculated values and the key strength check. Values are calculated when you click Calculate. The units of the results values can be changed. Double-click the specified value you want to change.

Following output parameters are displayed in the Results pane:

Note: For further description of the calculated parameters in metric or English units, see Engineer's Handbook.
  • Results
    • Min. Shaft Diameter (d min )
    • Min. Functional Key Length (l min )
    • Functional Length (l f )
  • Key Deformation
    • Safety (S)
    • Calculated Pressure (P Ac )
  • Shaft Key Groove Deformation
    • Safety (S)
    • Calculated Pressure (P Ac )
  • Hub Key Groove Deformation
    • Safety (S)
    • Calculated Pressure (P Ac )

Summary of Messages area

Displays the reports about calculation. To open the Summary of Messages area at the bottom of the tab, double-click the double line at the bottom of the window or click the chevron at the bottom of the window. It displays the reports about calculation.

Design tab

Loading Conditions

Toolbar commands

Parent topic: Parallel Key Connection Generator
Related Information
Design keys