SU1583269A2 - Spindle for metal-cutting machine - Google Patents

Abstract

The invention relates to a machine tool industry and can be used in precision machine tools. The purpose of the invention is to improve the quality of the treated surfaces. The spindle of the metal-cutting machine tool contains a shaft mounted in a housing on supports. The supports are made in the form of rolling bearings, one of which, for example, a radial bearing. In the front support there is a mechanism for creating a radial tension in the direction of the cutting force in a plane perpendicular to the spindle axis. The radial bearing 6 is made with an even number of rolling elements, and its outer ring is mounted on two pairs of rollers 11. The rollers are placed in a sleeve 13 made of a material with a temperature coefficient of linear expansion, greater than the temperature coefficient of linear expansion of the material of the outer ring of the bearing. The rollers 11 are located at an angle to the direction of creation of a preliminary radial tension of the bearing. The initial value of the angle of installation of the rollers is determined from the mathematical expression, taking into account the design of the bearing and the required value of the radial tension. When the spindle is working, the sleeve 13 is heated in which the rollers 11 are mounted. The installation angle of the rollers increases in proportion to the temperature increase, retaining the original shape of the deformed bearing outer ring. 4 il.

Description

The invention relates to the field of Machine Tool Building, can be used in precision machine tools and is an improvement of the known

invention of auth. St. No. 986610.

The purpose of the invention is to improve the quality of processing.

Figure 1 shows the spindle of the metal-cutting machine, general view; Fig. 2 is a diagram for calculating the angle of installation of the rollers; on fig.Z - section aa in figure 1; figure 4 - sleeve without installing rollers.

The spindle of the metal-cutting machine contains a housing 1 (fig, 1) in which the stator winding 2 is fixed, the shaft-rotor 3 carrying a grinding wheel 5 on the mandrel 4, a radial thrust bearing 6 of the front bearing fixed on the shaft 3 axially rigidly with a nut 8, Val-rotor 3 has 9 drills for supplying oil mist to the supports. Radial roller bearing 6 is installed in the cover 10 on two pairs of rollers 11, which are inserted without a gap in the grooves 12 of the sleeve 13.

Installing the rollers at an optimal angle reduces the dynamic displacement of the spindle due to the fact that when the rolling body enters the wedge-shaped zone, the force of interaction of the rolling body with the outer ring passes through the point of contact of the roller with the outer ring (Fig. 2), the result is an increase in the rigidity of the support in the direction of the forces of contact interaction and,

reduction of the amplitude of dynamic displacements when the rolling bodies pass wedge-shaped zones. In addition, the installation of rollers in the additionally inserted sleeve, made of material with TCLE large TKJIP material of the outer ring of the bearing, makes it possible to control the installation angle of the rollers when the rolling bearing temperature rises, which allows to stabilize the radial tension in the bearing. provides stabilization of geometrical parameters of wedge-shaped zones and makes it possible to increase the accuracy of spindle rotation due to compensation of dynamic loads arising in two wedges. s areas. The angle of its installation of each roller 11 is determined from 4 00., E (Fig. 1), where 00, R - b; R - GM Taking into account the trigonometric relations we get

c / 2 arcsin

 & - ± -b) lP -L ± rW)

1P | (R - b) (R - gsh)

Substituted P values

2R -4-b + g & c ag

. n - semi-perimeter, R g

the radius of curvature along the bottom of the groove track. The rolling of the deformed outer ring, and - R n + Ј, + the big semi-axis along the bottom of the groove of the raceway of the deformed outer ring, b RH - cf will get

d 2 arcsin

c / de RH is the radius at the bottom of the groove of the raceway of the undeformed outer ring; half of the radial clearance in the bearing;

half the value of radial tension ha;

the radius of the rolling bearing body;

the radius at the bottom of the groove of the raceway of the inner ring,

L, u

 Vn

d 00,

.).

RH LA Angular contact ball bearing 7 (FIG. 1) is installed directly in the cover 10. The outer rings of the bearings of the front support are fixed rigidly in the axial direction with the help of flanges 14 and 15. The cover 10 has two diametrically opposite holes 16 and 17 (FIG. ), each of which has an elastic element 18 and 19, located between two balls 20, 21 and 22, 23 and an emphasis 24, 25, installed with the possibility of moving and interacting with the outer ring of the radial bearing during rotation of the adjusting washer 26, in which inner hole is made o in the form of an ellipse. The adjusting washer 26 is fixed in the radial direction by means of a centering shoulder, which is made directly on the adjusting washer. In the axial direction, the adjusting washer is fixed by a ring 27, which has holes around the circumference of the ball retainer 28, which is equipped with an adjusting washer. The ring 27 is fastened to the cover 10 with screws 29. The sleeve 13 (Fig. 4) is made of an alloy with a high temperature coefficient of linear expansion as compared with the temperature coefficient of linear expansion of material 2 arcsin

Rk

i-Au 4

J and

Iv.

The rial of the outer ring of the radial bearing 6 and the rollers 11.

On the sleeve 13 is made grooves 30 and the centering grooves 31, which are inserted into the locking pins 32.

The grooves 30 ensure the stability of the geometric shape of the sleeve 13 when it is heated.

0

five

0

five

0

five

0

The preliminary radial tension of the radial bearing 6 is created by rotating the adjusting washer 26, in which the internal opening is made in the form of an ellipse (FIG. 3). The radial tension of the bearing 6 is created only in the direction coinciding with the direction of action of the cutting force.

When grinding, the spindle bearings are heated, while the dimensions of the outer ring of the bearing 6, the rollers 11 increase, the radial tension r d1 increases, which leads to the displacement of the position of the simultaneous contact of the rolling body with the surfaces of the inner and outer rings of the bearing 6, at the same time the sleeve 13 is heated, its the size increases and the rollers 11 are moved circumferentially to both sides of the line of action of the cutting force, as a result of which the required angle of the rollers 11 is established with respect to the changed conditions and m operation.

Claims (1)

Invention Formula Spindle metal cutting machine for auth. St. No. 986610, which is designed to improve the quality of processing, it is equipped with an additional sleeve installed between the cover and the outer ring of the bearing with rollers at an angle about to the plane passing through the axes radial through holes, selected according to the formula L) i rJRH -t, - A de RH is the radius at the bottom of the groove of the raceway of the undeformed outer ring of the bearing; , o1 - half of the radial gap in the bearing; o ,, is half the radial tension value; d is the radius at the bottom of the groove of the road — fO ki rolling of the inner ring; gsh is the radius of the rolling bearing body, when e, the sleeve is made of a material with a temperature coefficient of linear expansion, a large temperature coefficient of linear expansion of the material of the bearing outer collar, the number of rolling bodies of which is even, and the apex of the angle oi is offset relative to the center of the spindle in the direction opposite to the position of the roller according to the formula l LH (J + "m RH - 1 Figure 2 // 31 32