A gear generator in python.
Py-gearworks is built on build123d CAD package. It focuses on accurate geometric representation of gears, gear-pairs. Design calculations related to strength, pitting, efficiency may be implemented in the future - but currently not supported.
Currently the recommended way for most users to install py_gearworks is to install from github directly (git is required on the user's system for this):
python -m pip install git+https://github.com/GarryBGoode/py_gearworks
Alternatively, one can clone or download this repository and install via this command from the repository root directory:
python -m pip install .
py_gearworks CAD model creation uses build123d package: build123d github
It is highly recommended, though not strictly necessary to use a python-CAD gui solution. See OCP VSCode and CadQuery Editor.
Docs hosted on readthedocs
| Gear Types | Profile Mods | Position & Alignment |
|---|---|---|
| Spur | Undercut | Std. position |
| Helical | Profile shift | Backlash-controlled position* |
| Bevel | Root/tip fillet | Axis alignment (bevels and helicals) |
| Cycloid | Crowning | Geartooth alignment to mesh |
| Inside-ring |
It is a development goal that all (sensible) combination of supported features should be combined. Profile shifted cycloids don't exist, but inside-ring-bevel cycloids can be made. Undercut and profile shift is available for bevels - but positioning of profile shifted bevels is lacking. Please use complementary profile shifts for bevels.
* Positioning and backlash design is a bit of work-in-progress. Spur gears and parallel-axis helical gears can be placed with accurate backlash (inc. 0 backlash). This matters for profile shifted gears. Cross-axis helicals and bevel gears can only be positioned via nominal formula (can't adjust backlash via axial distance).
Work in progress / partially supported:
- Racks
- Backlash control
- Contact ratio calculation
Not yet supported:
- Hypoid gears
- Worm gears
- Face / crown gears
Planned upcoming other features
- Planetary drive design
- Backlash, contact ratio and profile shift optimization
The example is built on VSCode with OCP VScode plugin.
See examples.py for more.
from py_gearworks import *
from ocp_vscode import show
# create 2 spur gears
gear1 = SpurGear(
number_of_teeth=12,
module=2,
height=4,
profile_shift=0.3,
)
gear2 = SpurGear(
number_of_teeth=23,
module=2,
height=4,
)
# move and align gear 1 next to gear 2 in the Y direction
# backlash can be optionally specified
# angle_bias conrtols location within backlash range (-1 to 1)
# backlash is a coefficient of module
# there will be 0.2 mm distance between inactive tooth sides in this example
gear1.mesh_to(gear2, target_dir=UP, backlash=0.1, angle_bias=1)
# generate build123d Part objects
gear_part_1 = gear1.build_part()
gear_part_2 = gear2.build_part()
# center-bores are recommended to be added separately via build123d workflow
# center_location_top is a build123d location object
# multiplying with a location means placement at that location
hole_obj_1 = gear1.center_location_top * Hole(radius=2, depth=4)
gear_part_1 = gear_part_1.cut(hole_obj_1)
hole_obj_2 = gear2.center_location_top * Hole(radius=2, depth=4)
gear_part_2 = gear_part_2.cut(hole_obj_2)
# visualize parts
show(gear_part_1, gear_part_2)
This project was originally named gggears - a poor choice, since it was already taken by another, similar project. I've renamed the project, but some references, URLs might still point to gggears.
Project is licensed under Apache 2.0, see license file for details.