RU1776221C - Method for cutting circular-arc teeth - Google Patents

Abstract

Usage: mechanical engineering, cutting of circular teeth of bevel wheels. The essence of the invention lies in the fact that the cutting of the concave and convex sides of the circular teeth is performed simultaneously, while using a tool consisting of external and internal parts, the cutting elements of which are located on the same forming radius. The rotation axes of the tool parts are offset relative to each other by an amount whose value is determined by the dependence of Itm A / Rm, where Itm is the average circumferential width of the tooth cavity of the machined wheel; A is the calculated radius of rotation of the axis of the cutting head; Rm is the mean cone distance. 3 ill.

Description

The invention relates to mechanical engineering and may find application in cutting circular teeth of bevel wheels.

The purpose of the invention is to improve machining accuracy by shaping the concave and convex sides of the teeth with the same radius of curvature.

The essence of the method of cutting circular teeth consists in cutting the concave and convex sides of a circular tooth at the same time, using a tool consisting of two parts with cutters that process the concave and convex sides of the tooth along the radius of the same curvature, which allows to obtain the exact tooth geometry and proper contact in the gear pair.

In FIG. 1 shows a diagram of a cutting head; in FIG. 2 is a diagram of forming trajectories of movement of cutting edges of a cutting head; in FIG. 3 is a diagram for calculating the positions of the axes of rotation of the cutting heads relative to the cut wheel The tool is made in the form of a cutting head, consisting of two parts concentrically spaced relative to each other. The first part of the cutting head 1 contains cutters 2 for processing the concave side of a circular tooth located on the inside of the cutting head

The second part of the cutting head 3 comprises cutters 4 for machining the concave side of the tooth located on the outside of the cutting head. In the initial position, both parts of the tool are arranged concentrically, with the coincidence of their axes Ci and Ca, while the cutting edges of the two parts are located on the same radius R.

To treat an equirependicular circular tooth of the bevel wheel, the cutter heads are offset relative to each other to form a tool from the cutters 2 and 4 of the tooth that cut through the tapering tooth cavity of the wheel offset

(L

WITH

H

-h

Oh hO

Yu

W

the axes Ci and C2 of the cutting heads are produced by the calculated value a.

The machining of the equally tapering circular teeth of the wheels is carried out by two rotating cutting heads with the coordinated movement of the tool axes Ci and C2 along the radius A with rotation of the bevel gear being cut under rolling conditions. Moreover, the axis of rotation of the radius A of the location of the two parts of the cutting heads 1 and 3 intersects the top of the wheel pitch cone with the average conical distance Rm.

The radius of the axes Ci and C2 of the parts of the cutting head is determined in accordance with the angle of inclination of the circular tooth according to known dependencies:

And V «2 + Rm - 2 R Rm Sin Дп j where R is the radius of the generatrix of the conical surface of the tooth of the wheel;

Rm is the average conical distance of the wheel;

DP - the angle of inclination of the circular tooth.

The displacement a of the axes Ci and C2 of the parts of the tool is determined by the average tooth cavity width Itm calculated by the dividing cone. The angle of convergence V of the width of the depression (Fig. 3) is determined from the triangle OEIV2 and is equal to

V ltm / Rm

In accordance with the angle of convergence 1 /}, the displacement a of the axes Ci and C2 from the triangle OCiC2 is determined

a ltm A / Rm

An example of a specific implementation. The initial data obtained previously by calculation, taking into account

geometrical parameters of the cut and producing wheels:

Itm 6 mm - medium flange width of tooth cavities

Rm 300 mm - average cone distance

And 250 mm is the radius of rotation of the axis of the cutting head, then the necessary displacement of the axes Ci and C2 of the spindles a along the arc

the circumference of radius A will be a 6,250 / 300 5 mm. The use of this method of cutting circular teeth of the wheels allows you to accurately process the sides of the circular with one

radius of curvature on each side, which gives the correct contact between the teeth and pa- Rbi.

Claims (1)

SUMMARY OF THE INVENTION A method for cutting circular teeth of bevel wheels by a double-sided method, comprising coordinated rotations of a machined wheel about its axis and the axis of the cutting head along a calculated radius, characterized in that in order to increase the accuracy of processing by shaping the concave and convex sides of the teeth of the same radius of curvature, use a cutting head consisting of external and internal parts, the cutting elements of which are located on the same forming radius, while the axis of rotation of the parts of the head are displaced one relative to the other by a km A / Rm, where Itm is mid tooth cavity width of the machined wheel; A is the calculated radius of rotation of the axis of the cutting head; Rm is the average conical distance of the machined wheel, Fig 3