Spur Gears Component Generator dialog box

Sets parameters for design of a spur gear.

Note: Curve used in a tooth shape is simplified.

Access:

Ribbon: Design tab

Power Transmission panel

Spur Gear

Common

Defines the spur gear.
Design Guide
Selects the type of geometry calculation. Depending on your selected design guide, edit fields in the Design tab enables.
If you know all spur gears parameters and you want to insert spur gears model, we recommend you select Center Distance or Total Unit Correction. These options enable you to insert many entry parameters.
Module and Number of Teeth	Calculates the module and number of teeth according to the center distance and other input parameters.
Number of Teeth	Calculates the number of teeth according to the center distance and other input parameters.
Center Distance	Calculates the center distance according to all other input parameters.
Total Unit Correction	Calculates the unit summary correction according to the center distance and all other input parameters. Note: This type is sensitive to other inputs and we recommend that you select this option to for final design corrections.
Module	Calculates the module according to the center distance and all other input parameters.
Desired Gear Ratio	Gear ratio is the ratio between the number of teeth in mating gears.
Internal	Switch to internal gears transmission. Note: Spur Gear with higher number of teeth is automatically considered as an internal gear.
Module	Module is the ratio of the pitch diameter to the number of teeth. Not available if you select Module and Number of Teeth or Module options in the Design Guide drop-down menu. If not available, calculate module based on other parameters. Note: This option is enabled if you select Module in the Size Type area of More options.
Diametral Pitch	Diametral Pitch is the ratio of the number of teeth to the number of inches in the pitch diameter in the plane of rotation, or the number of gear teeth to each inch of pitch diameter. Normal diametral pitch is the diametral pitch as calculated in the normal plane, or the diametral pitch divided by the cosine of the helix angle. Note: This option is enabled if you select Diametral Pitch in the Size Type area of More options.
Center Distance	Specifies the shortest distance between centers of gears. This option is disabled when you select Center Distance in the Design Guide drop-down menu - you want to calculate center distance based on other input parameters.
Pressure Angle	Pressure angle is the angle between a tooth profile and a radial line at its pitch point. In involute teeth, the pressure angle is often described as the angle between the line of action and the line tangent to the pitch circled.
Helix Angle	Helix angle is the angle that a helical gear tooth makes with the gear axis at the pitch circle. You can insert only positive values from 0 to 55. to change direction you must click Flip next to the edit field.
Helix Angle Flip	Switches the helix direction.
Unit Correction Guide	Specifies the method to use for calculation of the teeth correction.
Total Unit Correction	Specifies the sum of the gear unit corrections. Not available if you select Total Unit Correction option in the Design Guide drop-down menu. If not available, calculate total unit correction based on other parameters.
Preview	Click to display the Preview dialog box with a schematic image of spur gears dimensions.

Gear 1, Gear 2

Specifies the type of gear (Component, feature, no model) and placement of the gear.
There are three methods to insert the spur gear. According to your selection, commands for placement are enabled in the Gear 1 and Gear 2 boxes. Component - creates a component. Feature - creates a feature. No Model - inserts only calculation.
Cylindrical Face	Selects a cylindrical face.
Start plane	Selects a planar face or work plane. Use Flip to flit the orientation of planar face or work plane.
Number of Teeth	Number of teeth contained in a gear. Not available if you select Module and Number of Teeth or Number of Teeth options in the Design Guide drop-down menu. If not available, calculate number of teeth based on other parameters.
Facewidth	Facewidth is the dimensional width of a gear blank. It can exceed the effective facewidth, as with a double-helical gear where the total face width includes any distance separating the right-hand and left-hand helical gear teeth.

(More)

Displays additional options for spur gear design. To display the More Options area, click More in the right lower corner of the Design Tab.
Input Type
Gear ratio	Select to calculate number of teeth of the second gear according to gear ratio.
Number of Teeth	Select to calculate the gear ratio according to number of teeth.
Size Type
Module	Select to calculate the diametral pitch. Typically, select this option if using metric units.
Diametral Pitch	Select to calculate the module. Typically, select this option if using English units.
Reaching Center Distance
Options are enabled if you select Module and Number of Teeth option from the drop-down list in the Common area.
Teeth Correction	Select to calculate the unit summary correction according to the center distance and other input parameters.
Helix Angle	Select to calculate the helix angle according to the center distance and other input parameters. It is recommended that you replace the calculated real value with an integer value.
Unit Tooth Sizes
Check the Gear 2 box to enter values for Gear 2.

Results

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

The area 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.

Note: In the Results area, the results for calculation of the appropriate dimensions of the spur gears connections display. For information about used formulas for spur gears calculation, see Engineer's Handbook.

Following output parameters are displayed in the Results pane:

Corrected Endurance Limit (σ_e)
Virtual Mean Stress (S_e / Ψ) (σ_F)
Mean Fatigue Stress of the Joint (σ_M)
Amplitude of Joint Fatigue Joint Stress (σ_A)
Mean Cycle Stress of the Joint (σ_m)
Cycle Stress Amplitude (σ_a)
Calculated Safety Degree (n_c)

Summary of Messages

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

Graphical Preview

When you specify the spur gear placement, select a cylindrical face and start plane. A Graphical preview of the designed spur gear displays in the Autodesk Inventor window. The preview changes according to changes made in Spur Gears Generator.

Calculation tab