PartDesign InvoluteGear

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Arrow-left.svg Předchozí: WizardShaft.svg Shaft design wizard
Další: Set tip PartDesign MoveTip.svg Arrow-right.svg

PartDesign InvoluteGear.svg PartDesign InvoluteGear

Umístění Menu
Part Design → Involute gear...
Pracovní stoly
PartDesign
Výchozí zástupce
Nikdo
Představen ve verzi
-
Viz také
Nikdo

Description

This tool allows you to create a 2D profile of an involute gear. This 2D profile is fully parametric, and can be padded with the PartDesign Pad or PartDesign AdditiveHelix feature.

For more detailed information see Wikipedia's entries for: Gear and Involute Gear

PartDesign Involute Gear 01.png

Usage

Create the profile

  1. Optionally activate the correct body.
  2. Go to the menu Part Design → PartDesign InternalExternalGear.svg Involute gear....
  3. Set the Involute parameters.
  4. Click OK.
  5. If there was no active body: drag and drop the gear into a body for the application of further features like padding.

Create a spur gear

  1. Select the gear profile in the tree.
  2. Press the PartDesign Pad.svg PartDesign Pad button.
  3. Set the pad's ÚdajeLength to the desired face width of the gear.
  4. Click OK

Create a helical gear

introduced in version 0.19

  1. Select the gear profile in the tree.
  2. Press the PartDesign AdditiveHelix.svg PartDesign AdditiveHelix button.
  3. Choose as Axis the normal of the gear profile, that is Normal sketch axis introduced in version 0.20. (In earlier versions the Base Z axis can be used as long as the profile's plane has not been altered.)
  4. Choose a Height-Turns mode.
  5. Set the ÚdajeHeight to the desired face width of the gear.
  6. To set the desired helical angle an Expressions for the ÚdajeTurns is required.
    1. Click the blue Bound-expression.svg icon at the right of the input field.
    2. Enter the following formula: Height * tan(25°) / (InvoluteGear.NumberOfTeeth * InvoluteGear.Modules * pi), where 25° is an example for the desired helical angle (also known as beta-value) and InvoluteGear is the ÚdajeName of the profile.
    3. Click OK to close the formula editor.
  7. Click OK to close the task panel.

Hint: To make the helical angle an accessible parameter, use a dynamic property:

  1. Select the profile.
  2. In the Property editor activate the Show all option in the context menu.
  3. Again in the context menu, select Add Property. Note: this entry is only available when Show all is active.
  4. In the Add Property dialog:
    1. Choose App::PropertyAngle as Type.
    2. Set Gear as Group.
    3. Set HelicalAngle as Name (without a space).
    4. Click OK
  5. Now a new property ÚdajeHelical Angle (space added automatically), with an initial value of 0.0°, becomes available.
  6. Assign the desired helical angle to the new property.
  7. In the formula of the ÚdajeTurns property of the AdditiveHelix, you can now reference InvoluteGear.HelicalAngle instead of the hard coded value of e.g. 25°; again assuming InvoluteGear is the ÚdajeName of the profile.

Properties

  • ÚdajeExternal Gear: True or false
  • ÚdajeHigh Precision: True or false
  • ÚdajeModules: Pitch diameter divided by the number of teeth.
  • ÚdajeNumber Of Teeth: Sets the number of teeth.
  • ÚdajePressure Angle: Acute angle between the line of action and a normal to the line connecting the gear centers. Default is 20 degrees. (More info)

Tutorials

How to make gears in FreeCAD

Related


Arrow-left.svg Předchozí: WizardShaft.svg Shaft design wizard
Další: Set tip PartDesign MoveTip.svg Arrow-right.svg