CN217413620U

CN217413620U - High-stability live center

Info

Publication number: CN217413620U
Application number: CN202123175565.8U
Authority: CN
Inventors: 周一波; 彭日阳
Original assignee: Jiangsu Weize Intelligent Technology Co ltd
Current assignee: Jiangsu Weize Intelligent Technology Co ltd
Priority date: 2021-12-16
Filing date: 2021-12-16
Publication date: 2022-09-13
Anticipated expiration: 2031-12-16

Abstract

The utility model provides a high-stability live center, which comprises a center body; the front end of the rotating shaft is provided with a clamping groove for clamping the tip body; the shaft sleeve is used for supporting the rotating shaft, and the rotating shaft can rotate in the shaft sleeve; the angular contact bearings are arranged between the rotating shaft and the shaft sleeve and support the tail of the rotating shaft, and the two rows of angular contact bearings are arranged back to back; and the combined bearing is used for rotatably supporting the abdomen of the rotating shaft and is a bearing formed by combining a needle bearing and a thrust cylindrical bearing. The utility model discloses angular contact bearing replaces the single-row ball bearing commonly used, can bear radial and axial load steadily, and pivot operation rotation accuracy is high, and radial run-out can be controlled steadily in several microns, is applicable to the processing of high accuracy cutter.

Description

High-stability live center

Technical Field

The utility model belongs to the technical field of the machine tooling, concretely relates to high stability type live center.

Background

The live center is used for tightly pushing the workpiece in the machining process of the grinding machine, and the live center is flexibly matched with the main shaft to rotate, so that the workpiece is prevented from being abraded and abraded, and the machining precision is improved. The live center usually adopts a rolling bearing, the radial runout of the live center is increased due to the play of the rolling bearing, the severe runout can be as large as 10 microns, and the rotation precision is difficult to meet the requirement of processing precision. And adopt o type glan sealing washer sealed between axis body and the axle sleeve, long-term back of using, the annular mill groove of o type sealing washer can grind out on the axle sleeve inner wall, has shortened the life of axle sleeve, has influenced oil blanket performance. In addition, the common tip steel material uses T10A carbon tool steel, although the wear resistance is high and the price is low, the bearing capacity is poor and the deformation amount is large after extrusion.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a high stability type live center to it is big to solve the runout volume in the live center working process, the poor problem of gyration precision.

A high stability live center comprising:

the center comprises a center body, wherein the center body is made of 9CrWMn, and the front end of the center body is provided with a vertical jacking surface;

the front end of the rotating shaft is provided with a clamping groove for clamping the tip body;

the shaft sleeve is used for supporting the rotating shaft, and the rotating shaft can rotate in the shaft sleeve;

the angular contact bearings are arranged between the rotating shaft and the shaft sleeve and support the tail of the rotating shaft, and the two rows of angular contact bearings are arranged back to back;

and the combined bearing is used for movably supporting the belly of the rotating shaft, and is a bearing formed by combining a needle bearing and a thrust cylindrical bearing.

Preferably, the inner wall of the shaft sleeve is provided with a convex ring for separating and positioning the angular contact bearing and the combined bearing.

Furthermore, the shoulder part of the rotating shaft is retracted into the shaft sleeve, a sealing gap is arranged between the shoulder part of the rotating shaft and the inner wall of the shaft sleeve, the sealing gap is sealed by a rotating oil seal, and the rotating oil seal is positioned at an opening at the front end of the shaft sleeve.

Preferably, the lip of the rotary oil seal comprises a dust lip and a sealing lip, the dust lip is tightly attached to the inner wall of the shaft sleeve, and the sealing lip is obliquely pressed on the shoulder of the rotating shaft.

Preferably, an end cover is installed at the tail part of the rotating shaft, and the end cover positions the angular contact bearing on the rotating shaft.

The utility model has the advantages that:

the back-to-back angular contact bearing between the rotating shaft and the shaft sleeve of the utility model replaces a common single-row ball bearing, can stably bear radial and axial loads, has high rotating precision of the rotating shaft operation, can stably control the jumping within 1-3 microns, and is suitable for processing high-precision cutters; and should two angular contact bearing back-to-back installation, for two structures that the bearing concatenated, the utility model discloses a load point of action span is great, and when the pivot was heated, the bearing play grow was difficult to the card and is died.

The utility model discloses install rotatory oil blanket between the shoulder of pivot and the inner wall of axle sleeve, replace current o type glan sealing washer, the dust lip of rotatory oil blanket is big with the area of contact of axle sleeve to and be the mode of movive seal between the axle sleeve, avoided the problem of long-term back glan circle and the easy wearing and tearing of axle sleeve of using.

Drawings

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and together with the description serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic view of the internal structure of the present invention;

fig. 2 is a schematic view of the installation structure of the rotary oil seal of the present invention.

Labeled in the figure as: 1. a tip body; 2. a rotating shaft; 3. a shaft sleeve; 4. an angular contact bearing; 5. rotating the oil seal; 6. pressing the surface; 7. a clamping part; 8. a clamping groove; 9. a shaft cavity; 10. a combination bearing; 11. a convex ring; 12. an end cap; 13. a dust lip; 14. a sealing lip; 15. a screw; 16. a main shaft; 17. a tail axle box.

Detailed Description

As shown in fig. 1 to 2, a high stability live center includes: the center comprises a center body 1, a rotating shaft 2, a shaft sleeve 3, an angular contact bearing 4 and a rotating oil seal 5.

The main body part of the centre body is a long cylindrical rod part, and the front end of the rod part is provided with a vertical jacking surface 6 for tightly propping against a workpiece; the rear end of the rod part is provided with a clamping part 7 which is fixedly connected with the rotating shaft 2. The tip body is made of 9CrWMn, the material is high in hardness, and deformation after extrusion is small, so that the processing precision is improved.

The front end of the rotating shaft 2 is provided with a clamping groove 8 for clamping a clamping part 7 of the tip body, and the clamping part 7 and the clamping groove 8 are locked and fixed by a pin along the radial direction.

The shaft sleeve 3 is used for supporting the rotating shaft 2, the shaft sleeve 3 is fixed in a tail shaft box 17 of a machine tool, a shaft cavity 9 is arranged in the shaft sleeve 3, the rotating shaft 2 is assembled in the shaft cavity 9, and the rotating shaft 2 can rotate in the shaft cavity 9, so that the center body 1 and the rotating shaft 2 rotate synchronously.

The angular contact bearings 4 are arranged between the rotating shaft 2 and the shaft sleeve 3 and movably support the tail of the rotating shaft 2, the model of the angular contact bearings 4 can be SKF 71802, the two columns of angular contact bearings 4 are arranged back to back, radial and axial loads can be stably borne, the rotating shaft 2 is high in running and rotating precision and small in radial runout, the radial runout can be stably controlled within about 3 microns, and high-precision cutter machining can be met.

The utility model discloses still include combination bearing 10 for the belly of pivot 2 is supported in the activity, and combination bearing 10 is the bearing of bearing and the combination of thrust cylinder bearing, and NKXR20 can be chooseed for use to the model. The combination bearing 10 provides smooth and reliable rotational support for the main body portion of the shaft 2.

The inner wall of the shaft sleeve 3 is provided with a convex ring 11 for separating and positioning the angular contact bearing 4 and the combined bearing 10, when the center body and a main shaft 16 of a machine tool jointly push against a workpiece, the main shaft 16 extrudes the rotating shaft 2 into the shaft sleeve 3, so that the rotating shaft 2 and the combined bearing are abutted against the convex ring 11 and are limited by the convex ring 11. An end cover 12 is installed at the tail part of the rotating shaft 2, the end cover 12 is installed on the rotating shaft 2 through a screw 15, the end cover 12 is matched with the convex ring 11, and the two rows of angular contact bearings 4 are positioned between the rotating shaft 2 and the shaft sleeve 3.

The shoulder of the rotating shaft 2 is retracted into the shaft sleeve 3, a sealing gap is arranged between the shoulder of the rotating shaft 2 and the inner wall of the shaft sleeve 3, and the sealing gap is sealed by a rotary oil seal 5. The rotary oil seal 5 is positioned at the opening at the front end of the shaft sleeve 3, so that the rotary oil seal is convenient to replace.

The model of the rotary oil seal 5 is VCW 28X 40X 4, and other specifications can be selected adaptively according to the size specification of the rotating shaft. As shown in fig. 2, the lip of the rotary oil seal 5 includes a dust lip 13 and a seal lip 14, the dust lip 13 has a smooth surface, the dust lip 13 is tightly attached to the inner wall of the shaft sleeve 3, when the rotary oil seal 5 rotates, the contact area with the shaft sleeve 3 is large, the pressure is small, the shaft sleeve is not easily abraded, and the sealing effect is ensured. The sealing lip 14 is pressed on the shoulder part of the rotating shaft 2 in an inclined way, the sealing lip 14 is made of flexible elastomer materials, the stable sealing effect can be still kept under the influence of mechanical vibration and pressure variation of sealing fluid, and the lip part is in stable contact with the surface of the rotating shaft.

The utility model discloses can be used to press from both sides tightly the work piece in the lathe such as grinding machine, milling machine, top body 1 presss from both sides tight work piece with the 16 cooperations of main shaft of lathe jointly, drives top body 1 and 2 synchronous rotations of pivot during 16 rotatory work pieces of main shaft, and pivot 2 is supported by two angular contact bearing 4 and a set of combination bearing 10 back to back reliably in axle sleeve 3, has reduced the radial run-out volume of pivot 2, has satisfied the demand of carrying out the high accuracy processing to the work piece. The rotary oil seal 5 arranged at the front end of the rotating shaft 2 performs rotary sealing on the rotating shaft 2, reduces the abrasion of a shaft sleeve and prolongs the service life.

Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described in the foregoing embodiments, or equivalents may be substituted for elements thereof. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A high stability live center, comprising:

a tip body;

and the combined bearing is used for rotatably supporting the belly of the rotating shaft and is a bearing formed by combining a needle bearing and a thrust cylindrical bearing.

2. The high stability live center according to claim 1, wherein a protruding ring for separating and positioning the angular contact bearing and the combination bearing is provided on an inner wall of the bushing.

3. The high stability live center according to claim 1, wherein the shoulder of the rotating shaft is retracted into the shaft sleeve, a sealing gap is provided between the shoulder of the rotating shaft and the inner wall of the shaft sleeve, the sealing gap is sealed by a rotary oil seal, and the rotary oil seal is located at an opening at the front end of the shaft sleeve.

4. The high stability live center according to claim 3, wherein the lip portion of the rotary oil seal comprises a dust lip and a sealing lip, the dust lip is tightly attached to the inner wall of the shaft sleeve, and the sealing lip is obliquely pressed on the shoulder portion of the rotating shaft.

5. The high stability live center according to claim 1, wherein the center body is made of 9CrWMn, a rod portion of the center body extends out of the rotating shaft, and a vertical jacking surface is arranged at the front end of the rod portion.

6. The high stability live center according to claim 2, wherein an end cap is mounted to the rear portion of the rotating shaft, and the end cap cooperates with the protruding ring to position the angular contact bearing on the rotating shaft.