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PRODUCTION AUTOMATION

PROGRAM OF GEOMETRY CALCULATION OF CYLINDRICAL GEARS
OF EXTERNAL AND INTERNAL CLUTING

The program is designed to calculate program can determine 147 geometrical
the geometry of cylindrical gears of external transmission parameters: according to
and internal gearing with a constant GOST 16532-70 for external gearing,
gear ratio, the gear and wheel of which according to GOST 19274-73 for internal
correspond to the normal initial contour with gearing. In total, in the process, the program
equal dividing nominal tooth thickness and can calculate 158 parameters. In addition
trough width, with a pitch line, dividing the to the geometric calculation, the program
approach depth in half, without modification calculates the dimensional tolerances for
and with profile modification of the head controlling the relative position of opposite
of the tooth, if the line of modification is tooth profiles according to GOST 9178-
straight or the involute of a circle, without 81 or GOST 1643-81, in accordance with
blunting and with blunting the longitudinal the degree of accuracy specified by these
edge of the tooth. GOSTs. The range of acceptable values
The calculation of the transmission (RAV) of the source data:
geometry is carried out depending on the ● module 0.05 <= m <= 100 mm;
processing tool, which can be of the rack ● the number of gear teeth, wheels
type (gear cutting combs, hobbing cutters, 4 <= z <= 9999 (for internal gears z1 <=
hobbing abrasive grinding wheels) or gear z2);
cutting cutter with an involute tooth profile. ● the angle of inclination of the tooth
A rack-type tool can have a rounding helical gear 0º <β <= 60º;
along the radius of the circle at the corner ● Normal source circuit (SC).
of the tooth apex, which is taken into For a standard SC according to GOST
account by the coefficient ρf * of the normal 9578-81 (0.1 <= m <1 mm) and according
initial contour. If ρf * = 0, then there is no to GOST 13755-81 (1 <= m <= 100 mm),
rounding. the program determines the composition of
The top of the gearwheel cutter tooth the SC parameters in accordance with these
is considered to be non-rounded. For the standards.
admissibility of such a provision, see [18] If the value of any SC parameters
p. 117. (except for the case when the coefficient of
The presence or absence of rounding radius of curvature of the transition curve ρf
at the corner of the top of the tooth of * = 0) does not meet the specified standards,
the cutting tool affects the value of the the IR is considered non-standard.
minimum displacement coefficient xmin RAV for any SC:
for the external tooth and the position of ● profile angle 5º <= α <= 30º;
the boundary point of the involute tooth ● head height coefficient 0.8 <= ha *
profile. In the presence of rounding, the <= 1.1;
negative value of the coefficient xmin in ● coefficient of radial clearance in the
absolute value is larger and the boundary transmission 0.25 <= s * <= 0.40;
point of the involute tooth profile is on a ● leg height factor hf * = ha * + c *
larger diameter, since the rectilinear part of ● boundary height coefficient hl *
the cutting edge of the rack-type tool or the = 2ha * (for SC GOST 9587-81, the ratio
involute part of the tooth of the gearwheel specified in the note to clause 3 of this
cutter, forming the involute part of the cut GOST is allowed);
tooth, shorter and leave the line of machine ● coefficient of approach depth in a
engagement earlier. pair of initial contours hw * = 2 ha *;
Depending on the input data, the ● coefficient of radius of curvature of

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