freecad-cam/Mod/PartDesign/Scripts/Gear.py
2026-02-01 01:59:24 +01:00

305 lines
10 KiB
Python

# Involute Gears Generation Script
# by Marcin Wanczyk (dj_who)
# (c) 2011 LGPL
import FreeCAD
import FreeCADGui
import Part
import Draft
import MeshPart
import Mesh
import math
from PySide import QtGui, QtCore
App = FreeCAD
Gui = FreeCADGui
def proceed():
try:
compute()
except Exception:
hide()
QtGui.QApplication.restoreOverrideCursor()
def compute():
QtGui.QApplication.setOverrideCursor(QtCore.Qt.WaitCursor)
if FreeCAD.ActiveDocument is None:
FreeCAD.newDocument("Gear")
oldDocumentObjects = App.ActiveDocument.Objects
try:
N = int(l1.text())
p = float(l2.text())
alfa = int(l3.text())
y = float(l4.text()) # standard value y<1 for gear drives y>1 for Gear pumps
m = p/math.pi # standard value 0.06, 0.12, 0.25, 0.5, 1, 2, 4, 8, 16, 32, 60 (polish norm)
c = float(l5.text())*m # standard value 0,1*m - 0,3*m
j = float(l6.text())*m # standard value 0,015 - 0,04*m
width = float(l7.text()) # gear width
except ValueError:
FreeCAD.Console.PrintError("Wrong input! Only numbers allowed...\n")
# tooth height
h = 2*y*m+c
# pitch diameter
d = N*m
# root diameter
df = d - 2*y*m - 2*c # df=d-2hf where and hf=y*m+c
# addendum diameter
da = d + 2*y*m # da=d+2ha where ha=y*m
# base diameter for involute
db = d * math.cos(math.radians(alfa))
#Base circle
baseCircle = FreeCAD.ActiveDocument.addObject("Part::FeaturePython", "BaseCircle")
Draft._Circle(baseCircle)
Draft._ViewProviderDraft(baseCircle.ViewObject)
baseCircle.Radius = db/2
baseCircle.FirstAngle = 0.0
baseCircle.LastAngle = 0.0
# Root circle
rootCircle = FreeCAD.ActiveDocument.addObject("Part::FeaturePython", "RootCircle")
Draft._Circle(rootCircle)
Draft._ViewProviderDraft(rootCircle.ViewObject)
rootCircle.Radius = df/2
rootCircle.FirstAngle = 0.0
rootCircle.LastAngle = 0.0
# Addendum circle
addendumCircle = FreeCAD.ActiveDocument.addObject("Part::FeaturePython", "AddendumCircle")
Draft._Circle(addendumCircle)
Draft._ViewProviderDraft(addendumCircle.ViewObject)
addendumCircle.Radius = da/2
addendumCircle.FirstAngle = 0.0
addendumCircle.LastAngle = 0.0
# Pitch circle
pitchCircle = FreeCAD.ActiveDocument.addObject("Part::FeaturePython", "PitchCircle")
Draft._Circle(pitchCircle)
Draft._ViewProviderDraft(pitchCircle.ViewObject)
pitchCircle.Radius = d/2
pitchCircle.FirstAngle = 0.0
pitchCircle.LastAngle = 0.0
#************ Calculating right sides of teeth
# Involute of base circle
involute = []
involutee = []
involutesav = []
for t in range(0, 60, 1):
x = db/2*(math.cos(math.radians(t))+math.radians(t)*math.sin(math.radians(t)))
y = db/2*(math.sin(math.radians(t))-math.radians(t)*math.cos(math.radians(t)))
involute.append(Part.Vertex(x, y, 0).Point)
#************ Drawing right sides of teeth
involutesav.extend(involute)
involutee.extend(involute)
for angle in range(1, N+1, 1):
involuteobj = FreeCAD.ActiveDocument.addObject("Part::Feature", "InvoluteL" + str(angle))
involutee.insert(0, (0, 0, 0))
involuteshape = Part.makePolygon(involutee)
involuteobj.Shape=involuteshape
involutee = []
for num in range(0, 60, 1):
point = involute.pop()
pointt = Part.Vertex(point.x*math.cos(math.radians(angle*360/N)) - point.y*math.sin(math.radians(angle*360/N)),point.x*math.sin(math.radians(angle*360/N)) + point.y*math.cos(math.radians(angle*360/N)),0).Point
involutee.insert(0,pointt)
involute.extend(involutesav)
involutee = []
#************ Calculating difference between tooth spacing on BaseCircle and PitchCircle
pc = App.ActiveDocument.getObject("PitchCircle")
inv = App.ActiveDocument.getObject("InvoluteL1")
cut = inv.Shape.cut(pc.Shape)
# FreeCAD.ActiveDocument.addObject("Part::Feature","CutInv").Shape=cut
invPoint = cut.Vertexes[0].Point
diff = invPoint.y*2 # instead of making axial symmetry and calculating point distance.
anglediff = 2*math.asin(diff/d)
#************ Calculating left sides of teeth
#************ Inversing Involute
for num in range(0, 60, 1):
point = involute.pop()
pointt = Part.Vertex(point.x, point.y*-1, 0).Point
involutee.insert(0, pointt)
involute.extend(involutee)
involutee = []
#Normal tooth size calculated as: 0,5* p - j j = m * 0,1 below are calculations
# 0,5* p - m * 0,1
# 0,5* p - p /pi * 0,1
# 0,5*360/N - ((360/N)/pi)* 0,1
# 0,5*360/N - (360/N)*((1/pi)*0,1) j = (p/pi)*0,1
# 0,5*360/N - (360/N)*((p/pi)*0,1)/p
# 0,5*360/N - (360/N)*( j )/p
for num in range(0, 60, 1):
point = involute.pop()
pointt = Part.Vertex(point.x*math.cos(math.radians(180/N-(360/N)*(j/p))+anglediff) - point.y*math.sin(math.radians(180/N-(360/N)*(j/p))+anglediff),point.x*math.sin(math.radians(180/N-(360/N)*(j/p))+anglediff) + point.y*math.cos(math.radians(180/N-(360/N)*(j/p))+anglediff),0).Point
involutee.insert(0, pointt)
involute.extend(involutee)
involutesav = []
involutesav.extend(involute)
#************ Drawing left sides of teeth
for angle in range(1, N+1, 1):
involuteobj = FreeCAD.ActiveDocument.addObject("Part::Feature", "InvoluteR" + str(angle))
involutee.insert(0, (0, 0, 0))
involuteshape = Part.makePolygon(involutee)
involuteobj.Shape = involuteshape
involutee = []
for num in range(0,60,1):
point = involute.pop()
pointt = Part.Vertex(point.x*math.cos(math.radians(angle*360/N)) - point.y*math.sin(math.radians(angle*360/N)),point.x*math.sin(math.radians(angle*360/N)) + point.y*math.cos(math.radians(angle*360/N)),0).Point
involutee.insert(0,pointt)
involute.extend(involutesav)
Gui.SendMsgToActiveView("ViewFit")
#************ Forming teeth
cutCircle = FreeCAD.ActiveDocument.addObject("Part::FeaturePython", "CutCircle")
Draft._Circle(cutCircle)
Draft._ViewProviderDraft(cutCircle.ViewObject)
cutCircle.Radius = da # da because must be bigger than addendumCircle and bigger than whole construction da is right for this but it not has to be.
cutCircle.FirstAngle = 0.0
cutCircle.LastAngle = 0.0
cutTool = cutCircle.Shape.cut(addendumCircle.Shape)
# cutshape = Part.show(cutTool)
gearShape = rootCircle.Shape
for invNum in range(1, N+1, 1):
invL = App.ActiveDocument.getObject("InvoluteL" + str(invNum))
invR = App.ActiveDocument.getObject("InvoluteR" + str(invNum))
cutL = invL.Shape.cut(cutTool)
cutR = invR.Shape.cut(cutTool)
pointL = cutL.Vertexes.pop().Point
pointR = cutR.Vertexes.pop().Point
faceEdge = Part.makeLine(pointL, pointR)
toothWhole = cutL.fuse(cutR)
toothWhole = toothWhole.fuse(faceEdge)
toothWire = Part.Wire(toothWhole.Edges)
toothShape = Part.Face(toothWire)
# tooth = App.ActiveDocument.addObject("Part::Feature", "Tooth" +str(invNum))
# tooth.Shape=toothShape
gearShape = gearShape.fuse(toothShape)
for o in App.ActiveDocument.Objects:
if oldDocumentObjects.count(o) == 0:
App.ActiveDocument.removeObject(o.Name)
gearFlat = App.ActiveDocument.addObject("Part::Feature", "GearFlat")
gearFlat.Shape = gearShape
Gui.ActiveDocument.getObject(gearFlat.Name).Visibility = False
gear = App.ActiveDocument.addObject("Part::Extrusion", "Gear3D")
gear.Base = gearFlat
gear.Dir = (0, 0, width)
App.ActiveDocument.recompute()
if c1.isChecked():
gearMesh = App.ActiveDocument.addObject("Mesh::Feature", "Gear3D-mesh")
faces = []
triangles = gear.Shape.tessellate(1) # the number represents the precision of the tessellation)
for tri in triangles[1]:
face = []
for i in range(3):
vindex = tri[i]
face.append(triangles[0][vindex])
faces.append(face)
mesh = Mesh.Mesh(faces)
gearMesh.Mesh = mesh
App.ActiveDocument.removeObject(gear.Name)
App.ActiveDocument.removeObject(gearFlat.Name)
App.ActiveDocument.recompute()
Gui.SendMsgToActiveView("ViewFit")
QtGui.QApplication.restoreOverrideCursor()
hide()
def hide():
dialog.hide()
dialog = QtGui.QDialog()
dialog.resize(200,450)
dialog.setWindowTitle("Gear")
la = QtGui.QVBoxLayout(dialog)
t1 = QtGui.QLabel("Number of teeth (N)")
la.addWidget(t1)
l1 = QtGui.QLineEdit()
l1.setText("16")
la.addWidget(l1)
t2 = QtGui.QLabel("Circular pitch (p)")
la.addWidget(t2)
l2 = QtGui.QLineEdit()
l2.setText("1.65")
la.addWidget(l2)
t3 = QtGui.QLabel("Pressure angle (alfa)")
la.addWidget(t3)
l3 = QtGui.QLineEdit()
l3.setText("20")
la.addWidget(l3)
t4 = QtGui.QLabel("Tooth height factor (y)")
la.addWidget(t4)
l4 = QtGui.QLineEdit()
l4.setText("1.0")
la.addWidget(l4)
t5 = QtGui.QLabel("Tooth clearance (c)")
la.addWidget(t5)
l5 = QtGui.QLineEdit()
l5.setText("0.1")
la.addWidget(l5)
t6 = QtGui.QLabel("Tooth lateral clearance (j)")
la.addWidget(t6)
l6 = QtGui.QLineEdit()
l6.setText("0.04")
la.addWidget(l6)
t7 = QtGui.QLabel("Gear width")
la.addWidget(t7)
l7 = QtGui.QLineEdit()
l7.setText("6.0")
la.addWidget(l7)
c1 = QtGui.QCheckBox("Create as a Mesh")
la.addWidget(c1)
e1 = QtGui.QLabel("(for faster rendering)")
commentFont = QtGui.QFont("Times", 8, True)
e1.setFont(commentFont)
la.addWidget(e1)
okbox = QtGui.QDialogButtonBox(dialog)
okbox.setOrientation(QtCore.Qt.Horizontal)
okbox.setStandardButtons(QtGui.QDialogButtonBox.Cancel|QtGui.QDialogButtonBox.Ok)
la.addWidget(okbox)
QtCore.QObject.connect(okbox, QtCore.SIGNAL("accepted()"), proceed)
QtCore.QObject.connect(okbox, QtCore.SIGNAL("rejected()"), hide)
QtCore.QMetaObject.connectSlotsByName(dialog)
dialog.show()