FCGear CrownGear

From FreeCAD Documentation
Revision as of 13:32, 9 April 2020 by BavariaSHAPE (talk | contribs)
Other languages:

FCGear CrownGear

Menu location
FCGear → Create an Crown gear
Workbenches
FCGear
Default shortcut
None
Introduced in version
v0.16
See also
FCGear InvoluteGear

Description

The crown wheel resembles a ring-shaped curved rack. The pressure angle decreases continuously from the outer to the inner diameter. Thus, the variable peripheral speed at the crown wheel is compensated against the constant peripheral speed of the pinion. The pointed outer teeth and the steep tooth flanks on the inner diameter limit the usable tooth width. Crown gears achieve similar efficiencies as spur gears. One crown gear can drive several pinions.

Known field of application of crown gears:

  • Rear axle drives for cars and motorcycles
  • Swivel mechanism for operating tables
  • Angular milling heads
  • Powered tool systems with multiple pinions and a crown gear

Above: Crown gear

Usage

  1. Switch to the FCGear Workbench.
  2. Invoke the command several way:
  3. Change the gear parameter to the required conditions (see Properties → Data below).

Properties

Data

Base

  • DataPlacement: Placement is the location and orientation of an object in space.
  • DataLabel: User name of the object in the Tree view.

accuracy

  • Dataconstruct: Default is True. Change to False and the construction component disappears.
  • Datanum_profiles: Number of profiles used for loft.

gear_parameter

  • Dataheight: Value for the gear width.
  • Datamodule: Module is the ratio of the reference diameter of the gear divided by the number of teeth (see also the information in Note).
  • Dataother_teeth: Number of teeth of the other gear (pinion). See also the information in Note.
  • Datateeth: Number of teeth
  • Datathickness: Height from the tip of tooth to the lower side of the crown wheel.

involute_parameter

  • Datapressure_parameter: Default is 20 (see also the information in Note).

View

The parameter descriptions of the View tab will be found in Property editor, further below at Example of the properties of a PartDesign object.

Notes

  • 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.
  • other_teeth: Several pinions with the same number of teeth only can be used on one crown wheel.

Limitations

No limitations are known.