SU946831A1 - Method of finishing toothed gears - Google Patents

Description

(54) METHOD A. M. SABLINA FINISHING GEAR WHEELS

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This invention relates to metal working, in particular to the manufacture of gear wheels.

A known method of rolling gear wheels is aimed at reducing unevenness and finishing with several tools, S made with different displacement of the initial contour, which ensures a different position of the initial circle when the processed wheel is sequentially engaged with tools I.

The purpose of the invention is to increase the uniformity of the finish along the tooth profile due to the periodic movement of the pole of engagement along the engagement line.

This goal is achieved by the fact that 5 one of the elements of the tool-part pair is informed by additional rotation about an axis located eccentrically with respect to the geometrical axis of the gear wheel.

FIG. Figure 1 shows the kinematic diagram of the engagement of a tool-part pair; in fig. 2 is a diagram of the movement of an engagement pole in a coordinate system with a fixed intercenter axis; pas figs. 3 is a graphical depiction of the effective eccentricity and angular velocities of the gear and eccentric mandrel; on phpg. 4 - an example of the implementation of the method of finishing gear Ko.iec. According to the kinematic scheme of engagement of a pair of instrumental part (fig. 1), the gear wheel 1 has a fixed axis of rotation O. The tool 2 made in the form of a gear wheel is mounted on a cylindrical mandrel 3, the axis of rotation of which is shifted from its geometric center O2 on the value of the e-eccentricity of the mandrel. The C axis of rotation of the mandrel 3 is installed in the slider 4 and is capable of being moved along the center line. During joint rolling, the gear wheel I rotates relative to the fixed axis Oi with an angular velocity u / i, and the tool 2 mounted on the mandrel 3. which rotates at a speed of h / o around the axis C, offset from its geometric center, rotates from the angular speed C. The tool 2 also rotates relative to the mandrel 3 with an angular velocity Uj. The distance between the geometric centers of the tool-part pair is kept constant in machining. An increase in the degree of finish along the tooth profile is achieved as a result of moving the engagement pole along the engagement line. In the coordinate system with the fixed center line Oi02 (Fig. 2), the position of the rotation axis C of the eccentric mounted gear wheel moves around the radius of the radius, adopting a number of consecutive positions C, € 2, Cj, € 4, and the position of the engagement line (tangent to main cogwheel circumference) is unchanged. At the same time, the intersection point of the engagement line with the center line O, C (engagement pole) moves along the engagement line due to the displacement (relative to the line of the centers CjOj) of the rotation axis C. At the points GI and Cj, the position of the pole of engagement coincides with the usual position of the pole on the line of O) O2 centers at the point P. In the C2 and C positions, as a result of the center line OiC deviating from the O, O2 line of centers, the pole of the engagement shifts the position of the PH and RK. By selecting the magnitude of the eccentricity of the mandrel, it is possible to ensure the required movement of the pole along the engagement line, the corresponding displacement of the initial line along the entire working tooth profile and even beyond its limits with a constant depth of teeth entry. The additional rotation of the wheel relative to the eccentric mandrel displaces the position of the instantaneous center of rotation of the gear C (Fig. 3), thereby changing the effective eccentricity of the gear wheel E, which refers to the distance from the center of the gear O2 to the instantaneous center of rotation where the linear speeds of the mandrel Vo and gears (tools) with respect to the mandrel Vj are equal and directed in opposite directions (, €) -Vo (C). V., in this case, the relationship of the effective eccentricity with the eccentricity of the mandrel and the angular velocity of the mandrel and gear on the mandrel is determined by the dependence E 54- (where E is the effective eccentricity (distance between the geometric center of the gear and its instantaneous center of rotation); e is the eccentricity of the mandrel; and / o is the angular velocity of the mandrel; o /, is the angular velocity of the gear relative to the mandrel. Example: The parameters of the gear: the number of teeth Z 23; modulus m 6 mm; the offset coefficient of the initial contour X 0.45, and travel contour according to GOST 13755-68; angular velocity cj, 12 rad / s. Parameters of the tool mounted on an eccentric mandrel; number of teeth Zp, 25; modulus m 6 mm; displacement coefficient of the initial contour Chi -0.45. Eccentricity of the mandrel E 2mm The angular velocity of an instrument mounted on an eccentric mandrel, made in the form of a gear wheel, is determined., 00,,, 0– g 11.0 rad / s. To ensure uniformity, the ™ section of the tooth profile must be made to move the pole during processing along the entire active line. gearing as. The effective eccentricity E required for this is determined from rb 4 2 (fig.). E sinUr, where aw is the center distance Oi O2; ip is the larger knot of the Ur-tip angles and the Ur a- W and the engagement angle; otp-angle of the profile at the lower point of the active part of the tooth profile; ci-o.- angle of the tooth profile on the circumference of the vertices. From the geometric calculation carried out in accordance with GOST 16532-70, it follows that the axial distance in the transmission tool-part a 144 mm, the engagement angle o (.w 20 °; radius of the tops of the wheel being machined Gd., 77.64 mm; radius the tips of the tool Ha, 78.36 mm; the angle of the tooth profile at the lower point of the machined wheel сАр 13.024 °, the angle of the tooth profile of the machined wheel on the diameter of the apex and 33.372 °., 20 °, 0-13.024 ° 6.9Т6 ° -.w 33.372 ° -20 °, O 13.372 °. For the calculation of the effective eccentricity, the following is assumed: sp Er aw-sin 1fp l44 - sin n, 572 ° -33.4 mm To ensure such a magnitude of the effect I .1 I l CPU fl l (LJV-L / lrt-lrili LJi 1 rl and eccentricity E to the tool mate) need to communicate the angular velocity relative to the (bE) level, equal to 1 g where iJo 2 is the angular velocity or ojo) .., 4I 7.37 rad / s In general, the eccentricity value is not essential for the implementation of the proposed method, since the effective eccentricity, the value of which is chosen experimentally from the condition of ensuring the least slip of the tooth profile during finishing, is provided any eccentricity value The torus can be either larger or smaller than the effective eccentricity.

Changing the eccentricity during rotation of the wheel relative to the eccentric mandrel expands the technological capabilities of the proposed method, allowing you to vary the limits of movement of the initial line along the side surface of the tooth while maintaining the eccentricity of the mandrel.

Claims (3)

1. The method of finishing the gear wheels by running the workpiece together with a tool made in the form of a gear with a constant center distance, characterized in that, in order to improve the uniformity of the finish over the tooth profile due to periodic the displacement of the engagement pole along the engagement line, one of the elements of the tool-part pair is informed by additional rotation around an axis eccentrically with respect to a geometrical axis located eccentrically with respect to the geometrical axis of the gear. 2. A method according to claim 1, characterized in that the additional rotation about an axis located eccentrically with respect to the geometric axis of the gear wheel coincides in direction with the rotation around the latter. 3. The method according to claim 1, characterized in that the additional rotation about an axis located eccentrically with respect to the geometric axis of the gear wheel does not coincide in direction with the rotation around the latter. Sources of information taken into account during the examination 1. Kokichev V. N. Sudupromgiz tee-cutting machines, 1960, p. 46-48. Ufj. / . J