SU1739179A1 - Method to examine gear teeth shape - Google Patents

Abstract

This invention relates to mechanical engineering, in particular to methods for controlling the accuracy of gear wheels. The purpose of the invention is to improve the control accuracy by taking into account the chamfer on the top of the teeth of the wheel. The control is carried out by changing the number of teeth covered by the general normal, in the range from 2Min to ZMSKC, the values of which are determined by the mathematical expressions given in the description of the invention. 2 Il.

Description

The invention relates to mechanical engineering, in particular to methods and means of controlling gears.

A known method for monitoring tooth profiles of gear wheels, in which chords are measured at different tooth heights between the unlike tooth profiles and compared with the corresponding nominal chord values. An edge tooth gauge is used to measure chords.

The disadvantage of the known method is the necessity to base the measuring tool on the auxiliary base — the circumference of the tooth peaks, which reduces the accuracy of control.

A known method for monitoring tooth profiles of gears, which consists in measuring the values of the general normals to the unlike profiles of the teeth and comparing them with the corresponding nominal values of the general normals, changes the number of teeth covered by the general normal, ranging from

ZMHH to ZMSKC. The values of ZMHH and ZMSKC are defined by mathematical expressions.

The disadvantage of this method is that the choice of 2Max does not take into account the effect of chamfer on the top of the tooth, and this reduces the accuracy of control.

The purpose of the invention is to improve the control accuracy by taking into account the effect of the chamfer on the top of the teeth on the choice of ZMBKC.

The purpose of the invention is achieved in that according to the method the chamfer is measured, and the maximum number of teeth ZMaKc covered by the general normal is determined by the mathematical gain

(L

with

VJ with about

l

da Sin "a

, 71

+ 2

n cos a cosySb, -2-x-tga-Z-inVat) -Q-gL.

Figure 1 shows a sector of a controlled gear with the arrangement of general normals; FIG. 2 shows one tooth of a wheel with points of control and chamfer on its profile.

The gears are monitored by measuring with a normal gauge the values of the general normals W to the unlike profile of m 2 teeth 3 and compare them with the corresponding nominal values of the general normals determined by the mathematical expression

W (l 2p 0.5) + 2 x tg a +

+ Z in v «t) m cos a, where Zn is the number of teeth covered by a common normal. In this case, the chamfer f is measured, and the maximum number 2 Max and the minimum number 2 Min teeth, covered by the general normal, is determined by mathematical expressions

j

l

da Sin Oa

m cos a

f

+ I- + 2

0)

-2 -x-tga-Z- inv "t) -Q-g-: m

ZMHH 2max 2,

where imax is round to the nearest lower integer;

da is the circumference of the tops of the teeth of the wheel;

m is a normal module;

  the main angle of inclination of the teeth; “A is the angle of the profile on the circle of vertices;

“T is the profile angle (for indirect wheels), inv Ut tg a - (i;

“-An angle of the tooth profile of the original contour;

x is the displacement factor of the initial contour;

Z is the number of teeth of the controlled gear;

f is the chamfer value.

A change in the number of teeth covered by a common normal in the range from 7 Min to ZMaKc causes the control point to move along the profile 1 of the tooth 2, which allows controlling the profile 1 at different points of it and thereby increasing the accuracy of the control.

In expression (1), the presence of a chamfer at the top of the tooth 2 is taken into account

member -.

0.6 m

So, for a gear with 35 teeth, after appropriate calculations we get

: 6.1 f

0.6 m ®

Then, with a gear without chamfer, a general normal can span a maximum of 6

5 teeth, while the control point lies at a distance of 0.053 m from the top of the tooth. If this gear has chamfers on the tops of the teeth, the size of which is f 0.08 m, then the chamfers cut the control points

10 at the top of the teeth. Then a general normal can span a maximum of 5 teeth, which is confirmed by calculations using expression (2) after rounding the result to the nearest smaller integer

15 „„ 0.08 m

-Max

 6.1 5.97.

0.6 m

Claims (1)

Claims The method of monitoring tooth profiles of gear wheels, which consists in that: 20 values of common normals to unlike profiles of teeth are measured and compared with the corresponding nominal values of general normals, thus changing the number of teeth covered 25 in general, in the range from ZMHH to ZMHH, characterized in that, in order to increase accuracy by taking into account the effect of the chamfer on the top of the teeth on the choice of 2max, the chamfer is measured, and the maximum 30 the number of teeth ZM3Kc covered by the general normal is determined by the mathematical expression five five 0 one -Max da Sin "a + JI t cos a cos / Зь 2 -2 х tg «-Z in v« t) 0, 6 m where ZMBKC is rounded to the nearest lower whole number; 0 da - diameter of a circle of vertices m is a normal module;   the main angle of inclination of the teeth; “And the angle of the tooth profile on the circumference of the vertices; “-An angle of the tooth profile of the original body; "T is the angle of the profile (for non-spur wheels), inv "t tg a-fXt; x is the offset of the original contour; Z is the number of teeth of the gear; f is the chamfer value. W5 wf IA 1 L FIG I