FCGear InvoluteRack/pl: Difference between revisions

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{{Properties_Title|base}}
{{Properties_Title|base}}


* {{PropertyData|add_endings|Bool}}: If {{Emphasis|True}}, then the total length of the rack is teeth * pitch, otherwise the rack starts with a tooth-flank.
* {{PropertyData|add_endings|Bool}}: If {{True}} (default) the total length of the rack is teeth * pitch, if {{False}} the rack starts with a tooth-flank.
* {{PropertyData|height|Length}}: Value of the gear width.
* {{PropertyData|height|Length}}: Default is {{Value|5,00 mm}}. Value of the gear width.
* {{PropertyData|module|Length}}: Module is the ratio of the reference diameter of the gear divided by the number of teeth (see [[#Notes|Notes]]).
* {{PropertyData|module|Length}}: Default is {{Value|1,00 mm}}. Module is the ratio of the reference diameter of the gear divided by the number of teeth (see [[#Notes|Notes]]).
* {{PropertyData|teeth|Integer}}: Number of teeth.
* {{PropertyData|teeth|Integer}}: Default is {{Value|15}}. Number of teeth.
* {{PropertyData|thickness|Length}}: Height from the tooth root to the lower side of the rod.
* {{PropertyData|thickness|Length}}: Default is {{Value|5}}. Height from the tooth root to the lower side of the rod.


{{Properties_Title|computed}}
{{Properties_Title|computed}}
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{{Properties_Title|fillets}}
{{Properties_Title|fillets}}


* {{PropertyData|head_fillet|Float}}:
* {{PropertyData|head_fillet|Float}}: Default is {{Value|0,00 mm}}.
* {{PropertyData|root_fillet|Float}}:
* {{PropertyData|root_fillet|Float}}: Default is {{Value|0,00 mm}}.


{{Properties_Title|helical}}
{{Properties_Title|helical}}


* {{PropertyData|beta|Angle}}: With the helix angle β a helical gear is created (positive value → rotation direction right, negative value → rotation direction left).
* {{PropertyData|beta|Angle}}: Default is {{Value|0,00°}}. With the helix angle β a helical gear is created positive value → rotation direction right, negative value → rotation direction left.
* {{PropertyData|double_helix|Bool}}: {{Emphasis|True}} creates a double helix gear (see [[#Notes|Notes]])
* {{PropertyData|double_helix|Bool}}: Default is {{False}}, {{True}} creates a double helix gear (see [[#Notes|Notes]]).
* {{PropertyData|properties_from_tool|Bool}}: If helix angle β is given and {{Emphasis|properties_from-tool}} is enabled, gear parameters are internally recomputed for the rotated gear.
* {{PropertyData|properties_from_tool|Bool}}: Default is {{False}}. If {{True}} and {{PropertyData|beta}} is not zero, gear parameters are recomputed internally for the rotated gear.


{{Properties_Title|involute}}
{{Properties_Title|involute}}


* {{PropertyData|pressure_angle|Angle}}: Default is 20° (see [[#Notes|Notes]]).
* {{PropertyData|pressure_angle|Angle}}: Default is {{Value|20°}} (see [[#Notes|Notes]]).


{{Properties_Title|precision}}
{{Properties_Title|precision}}


* {{PropertyData|simplified|Bool}}: {{Emphasis|True}} generates a simplified display (without teeth).
* {{PropertyData|simplified|Bool}}: Default is {{False}}, {{True}} generates a simplified display (without teeth).


{{Properties_Title|tolerance}}
{{Properties_Title|tolerance}}


* {{PropertyData|clearance|Float}}: Default is 0,25 (see [[#Notes|Notes]]).
* {{PropertyData|clearance|Float}}: Default is {{Value|0,25}} (see [[#Notes|Notes]]).
* {{PropertyData|head|Float}}: Default is 0,00. This value is used to change the tooth height.
* {{PropertyData|head|Float}}: Default is {{Value|0,00}}. This value is used to change the tooth height.


{{Properties_Title|version}}
{{Properties_Title|version}}

Revision as of 14:40, 5 October 2022

FCGear InvoluteRack

Menu location
Gear → Involute Rack
Workbenches
FCGear
Default shortcut
None
Introduced in version
v0.16
See also
FCGear InvoluteGear

Opis

Gear racks are used to convert a rotary motion into a linear motion or vice versa. The following examples show the different applications:

  • A rack with gear on at a retaining weir.
  • Various rack systems of rack-and-pinion railways.
  • Rack and pinion steering in a vehicle.
  • Rack and pinion winch as mechanical hoist (e.g. car jack).
  • Pneumatic rack and pinion drives used to control valves in pipeline transport.

From left to right: Spur gearing, helical gearing, double helical gearing

Usage

  1. Switch to the FCGear Workbench.
  2. There are several ways to invoke the command:
    • Press the Involute Rack button in the toolbar.
    • Select the Gear → Involute Rack option from the menu.
  3. Change the gear parameter to the required conditions (see Properties).

Properties

An FCGear InvoluteRack object is derived from a Part Feature object and inherits all its properties. It also has the following additional properties:

Data

base

  • DANEadd_endings (Bool): If true (default) the total length of the rack is teeth * pitch, if false the rack starts with a tooth-flank.
  • DANEheight (Length): Default is 5,00 mm. Value of the gear width.
  • DANEmodule (Length): Default is 1,00 mm. Module is the ratio of the reference diameter of the gear divided by the number of teeth (see Notes).
  • DANEteeth (Integer): Default is 15. Number of teeth.
  • DANEthickness (Length): Default is 5. Height from the tooth root to the lower side of the rod.

computed

  • DANEtransverse_pitch (Length): (read-only) Pitch in the transverse plane (see Notes).

fillets

  • DANEhead_fillet (Float): Default is 0,00 mm.
  • DANEroot_fillet (Float): Default is 0,00 mm.

helical

  • DANEbeta (Angle): Default is 0,00°. With the helix angle β a helical gear is created – positive value → rotation direction right, negative value → rotation direction left.
  • DANEdouble_helix (Bool): Default is false, true creates a double helix gear (see Notes).
  • DANEproperties_from_tool (Bool): Default is false. If true and DANEbeta is not zero, gear parameters are recomputed internally for the rotated gear.

involute

  • DANEpressure_angle (Angle): Default is 20° (see Notes).

precision

  • DANEsimplified (Bool): Default is false, true generates a simplified display (without teeth).

tolerance

  • DANEclearance (Float): Default is 0,25 (see Notes).
  • DANEhead (Float): Default is 0,00. This value is used to change the tooth height.

version

  • DANEversion (String):

Notes

  • transverse_pitch: The value is the result of multiplication of module * pi. This means for the standard involute rack of FCGear: 15 (teeth) * 3,14 (transverse_pitch) is 47.12 mm. See also module further below.
  • clearance: At a gear pair, clearance is the distance between the tooth tip of the first gear and the tooth root of the second gear.
  • double_helix: To use the double helical gearing the helix angle β (beta) for the helical gearing must first be entered.
  • module: Using ISO (International Organization for Standardization) guidelines, Module size is designated as the unit representing gear tooth-sizes. Module (m): m = 1 (p = 3.1416), m = 2 (p = 6.2832), m = 4 (p = 12.566). If you multiply Module by Pi, you can obtain Pitch (p). Pitch is the distance between corresponding points on adjacent teeth. The result of the multiplication is displayed in transverse_pitch
  • pressure_parameter: Only change the parameter, if sufficient knowledge of the gear geometry is available.

Useful formulas

See FCGear InvoluteGear.

Scripting

Use the power of python to automate your gear modeling:

import FreeCAD as App
import freecad.gears.commands
gear = freecad.gears.commands.CreateInvoluteRack.create()
gear.teeth = 20
gear.beta = 20
gear.height = 10
gear.double_helix = True
App.ActiveDocument.recompute()
Gui.SendMsgToActiveView("ViewFit")