PartDesign InvoluteGear/de: Difference between revisions

From FreeCAD Documentation
(Updating to match new version of source page)
(Updating to match new version of source page)
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=== Create a spur gear ===
=== Create a spur gear ===


# Select the gear profile in the tree.
# Select the gear profile in the [[Tree_view|Tree view]].
# Press the {{Button|[[Image:PartDesign_Pad.svg|16px]] PartDesign Pad}} button.
# Press the {{Button|[[Image:PartDesign_Pad.svg|16px]] [[PartDesign_Pad|PartDesign Pad]]}} button.
# Set the pad's {{PropertyData|Length}} to the desired face width of the gear.
# Set the pad's {{PropertyData|Length}} to the desired face width of the gear.
# Click {{Button|OK}}
# Click {{Button|OK}}
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{{Version|0.19}}
{{Version|0.19}}


# Select the gear profile in the tree.
# Select the gear profile in the [[Tree_view|Tree view]].
# Press the {{Button|[[Image:PartDesign_AdditiveHelix.svg|16px]] [[PartDesign_AdditiveHelix|PartDesign AdditiveHelix]]}} button.
# Press the {{Button|[[Image:PartDesign_AdditiveHelix.svg|16px]] [[PartDesign_AdditiveHelix|PartDesign AdditiveHelix]]}} button.
# Choose as Axis the normal of the gear profile, that is {{MenuCommand|Normal sketch axis}} {{Version|0.20}}. (In earlier versions the {{MenuCommand|Base Z axis}} can be used as long as the profile's plane has not been altered.)
# Choose as Axis the normal of the gear profile, that is {{MenuCommand|Normal sketch axis}} {{Version|0.20}}. (In earlier versions the {{MenuCommand|Base Z axis}} can be used as long as the profile's plane has not been altered.)
# Choose a {{MenuCommand|Height-Turns}} mode.
# Choose a {{MenuCommand|Height-Turns}} mode.
# Set the {{PropertyData|Height}} to the desired face width of the gear.
# Set the {{PropertyData|Height}} to the desired face width of the gear.
# To set the desired helical angle an [[Expressions]] for the {{PropertyData|Turns}} is required.
# To set the desired helical angle an [[Expressions|Expression]] for the {{PropertyData|Turns}} is required.
## Click the blue [[Image:Bound-expression.svg|16px]] icon at the right of the input field.
## Click the blue [[Image:Bound-expression.svg|16px]] icon at the right of the input field.
## Enter the following formula: {{incode|Height * tan(25°) / (InvoluteGear.NumberOfTeeth * InvoluteGear.Modules * pi)}}, where {{incode|25°}} is an example for the desired helical angle (also known as beta-value) and {{incode|InvoluteGear}} is the {{PropertyData|Name}} of the profile.
## Enter the following formula: {{incode|Height * tan(25°) / (InvoluteGear.NumberOfTeeth * InvoluteGear.Modules * pi)}}, where {{incode|25°}} is an example for the desired helical angle (also known as beta-value) and {{incode|InvoluteGear}} is the {{PropertyData|Name}} of the profile.
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* Eingriffswinkel: Winkel zwischen der Wirkungslinie und einer Normalen zu der Linie, die die Zahnradzentren verbindet. Standard ist 20 Grad. ([https://de.wikipedia.org/wiki/Evolventenverzahnung Weitere Informationen])
* Eingriffswinkel: Winkel zwischen der Wirkungslinie und einer Normalen zu der Linie, die die Zahnradzentren verbindet. Standard ist 20 Grad. ([https://de.wikipedia.org/wiki/Evolventenverzahnung Weitere Informationen])
</div>
</div>


==Limitations==

* It is currently not possible to adjust the tooth thickness. Tooth and tooth space are distributed equally on the pitch circle. Thus the only way to control backlash is to adjust the center distance in a gear paring.
* There is currently no [https://www.tec-science.com/mechanical-power-transmission/involute-gear/undercut/ undercut] in the generated gear profile. That means gears with a low number of teeth can interfere with the teeth of the mating gear. The lower limit depends on the {{PropertyData|Pressure Angle}} and is around 17 teeth for 20° and 32 for 14.5°. Most practical applications tolerate a missing undercut for gears a little smaller than this theoretical limit though.


==Tutorials==
==Tutorials==

Revision as of 20:04, 27 January 2022

PartDesign Evolventenverzahnung

Menüeintrag
Part Design → Evolventenverzahnung...
Arbeitsbereich
PartDesign
Standardtastenkürzel
Keiner
Eingeführt in Version
-
Siehe auch
Keiner

Description

Beschreibung

Dieses Werkzeug erlaubt dir ein 2D Profil eines Evolventenzahnrades zu erstellen. Dieses 2D Profil ist vollständig parametrisch und kann mit dem Grundelement PartDesign Polster aufgefüllt werden.
Für ausführlichere Informationen siehe die Wikipedia Einträge zu: Zahnrad und Evolventenverzahnung

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

Usage

Create the profile

Anwendung

  1. Gehe zum Menü Part Design → Evolventenverzahnung....
  2. Setze die Parameter für die Evolvente.
  3. Klicke auf OK.
  4. Das Evolventenzahnrad wird außerhalb des aktiven Körpers erzeugt. Ziehe und Legen es für die Anwendung von weiteren Funktionen wie z.B. Polsterung, in einen Körper.

Create a spur gear

  1. Select the gear profile in the Tree view.
  2. Press the PartDesign Pad button.
  3. Set the pad's DatenLength 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 view.
  2. Press the 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 DatenHeight to the desired face width of the gear.
  6. To set the desired helical angle an Expression for the DatenTurns is required.
    1. Click the blue 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 DatenName 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 DatenHelical 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 DatenTurns 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 DatenName of the profile.

Properties

  • Außenrad: Wahr oder Falsch
  • Hohe Präzision: Wahr oder Falsch
  • Module: Zahnabstand dividiert durch die Anzahl der Zähne.
  • Anzahl Zähne: Setzt die Anzahl der Zähne.
  • Eingriffswinkel: Winkel zwischen der Wirkungslinie und einer Normalen zu der Linie, die die Zahnradzentren verbindet. Standard ist 20 Grad. (Weitere Informationen)


Limitations

  • It is currently not possible to adjust the tooth thickness. Tooth and tooth space are distributed equally on the pitch circle. Thus the only way to control backlash is to adjust the center distance in a gear paring.
  • There is currently no undercut in the generated gear profile. That means gears with a low number of teeth can interfere with the teeth of the mating gear. The lower limit depends on the DatenPressure Angle and is around 17 teeth for 20° and 32 for 14.5°. Most practical applications tolerate a missing undercut for gears a little smaller than this theoretical limit though.

Tutorials

How to make gears in FreeCAD

Verwandt