118 lines
4.6 KiB
Python
118 lines
4.6 KiB
Python
# -*- coding: utf-8 -*-
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#***************************************************************************
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#* *
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#* This program is free software; you can redistribute it and/or modify *
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#* it under the terms of the GNU Lesser General Public License (LGPL) *
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#* as published by the Free Software Foundation; either version 2 of *
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#* the License, or (at your option) any later version. *
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#* for detail see the LICENCE text file. *
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#* *
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#* This program is distributed in the hope that it will be useful, *
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#* but WITHOUT ANY WARRANTY; without even the implied warranty of *
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#* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
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#* GNU Library General Public License for more details. *
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#* *
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#* You should have received a copy of the GNU Library General Public *
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#* License along with this program; if not, write to the Free Software *
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#* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 *
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#* USA *
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#* *
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#***************************************************************************
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from __future__ import division
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from numpy import cos, sin, arccos, pi, array, linspace, transpose, vstack
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from ._functions import rotation, reflection
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class cycloide_tooth():
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def __init__(self, z1 = 5, z2 = 5, z = 14, m = 5, clearance = 0.12, backlash = 0.00):
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self.m = m
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self.z = z
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self.clearance = clearance
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self.backlash = backlash
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self.z1 = z1
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self.z2 = z2
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self._calc_gear_factors()
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def _calc_gear_factors(self):
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self.d1 = self.z1 * self.m
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self.d2 = self.z2 * self.m
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self.phi = self.m * pi
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self.d = self.z * self.m
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self.da = self.d + 2*self.m
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self.di = self.d - 2*self.m - self.clearance * self.m
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self.phipart = 2 * pi / self.z
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def epicycloide_x(self):
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def func(t):
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return(((self.d2 + self.d) * cos(t))/2. - (self.d2 * cos((1 + self.d / self.d2) * t))/2.)
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return(func)
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def epicycloide_y(self):
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def func(t):
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return(((self.d2 + self.d) * sin(t))/2. - (self.d2 * sin((1 + self.d / self.d2) * t))/2.)
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return(func)
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def hypocycloide_x(self):
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def func(t):
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return((self.d - self.d1)*cos(t)/2 + self.d1/2 * cos((self.d / self.d1 - 1) * t))
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return(func)
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def hypocycloide_y(self):
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def func(t):
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return((self.d - self.d1)*sin(t)/2 - self.d1/2 *sin((self.d/self.d1 - 1)*t))
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return(func)
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def inner_end(self):
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return(
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-((self.d1*arccos((2*self.d1**2 - self.di**2 -
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2*self.d1*self.d + self.d**2)/(2.*self.d1*
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(self.d1 - self.d))))/self.d)
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)
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def outer_end(self):
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return(
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(self.d2*arccos((2*self.d2**2 - self.da**2 +
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2*self.d2*self.d + self.d**2)/
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(2.*self.d2*(self.d2 + self.d))))/self.d
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)
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def points(self, num = 10):
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inner_x = self.hypocycloide_x()
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inner_y = self.hypocycloide_y()
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outer_x = self.epicycloide_x()
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outer_y = self.epicycloide_y()
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t_inner_end = self.inner_end()
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t_outer_end = self.outer_end()
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t_vals_outer = linspace(0, t_outer_end, num)
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t_vals_inner = linspace(t_inner_end,0,num)
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pts_outer_x = map(outer_x, t_vals_outer)
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pts_outer_y = map(outer_y, t_vals_outer)
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pts_inner_x = map(inner_x, t_vals_inner)
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pts_inner_y = map(inner_y, t_vals_inner)
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pts_outer = transpose([pts_outer_x, pts_outer_y])
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pts_inner = transpose([pts_inner_x, pts_inner_y])
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pts1 = vstack([pts_inner[:-2],pts_outer])
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rot =rotation(self.phipart / 4 - self.backlash)
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pts1 = rot(pts1)
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ref = reflection(0.)
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pts2 = ref(pts1)[::-1]
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one_tooth = [pts1,array([pts1[-1],pts2[0]]), pts2]
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return(one_tooth)
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def _update(self):
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self.__init__(m = self.m, z = self.z, z1 = self.z1, z2 = self.z2,
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clearance = self.clearance, backlash = self.backlash)
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if __name__ == "__main__":
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from matplotlib import pyplot
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gear = cycloide_tooth()
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x = []
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y = []
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for i in gear.points(30):
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for j in i:
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x.append(j[0])
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y.append(j[1])
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pyplot.plot(x[-60:],y[-60:])
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pyplot.show()
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