KR20190001140A - Rotary table assembly of a machine tool - Google Patents

Abstract

A rotary table assembly of a machine tool can comprise a table and a labyrinth ring. The table can be rotationally connected to a bed. The labyrinth ring can have an air line for injecting air for preventing foreign matters from penetrating into a gap between the bed and the table. Therefore, the penetration of foreign matters can be effectively prevented in both a milling process and a turning process.

Description

Technical Field [0001] The present invention relates to a rotary table assembly for a machine tool,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary table assembly of a machine tool, and more particularly, to a rotary table assembly of a multi-axis processing machine capable of performing milling and turning.

In general, a five-axis machine can be used to machine parts of complex shapes. The 5-axis machine can perform milling and turning. A 5-axis machining unit can have 3 linear axes and 2 rotation axes. The two rotational axes may include a first axis for rotating the bed, and a second axis for rotating the table substantially orthogonal to the first axis. As the table rotates about the second axis, the table can rotate about the second axis on the fixed bed.

According to the related art, a sealing ring for preventing foreign matter penetration can be interposed between the table and the bed. The sealing ring can make frictional contact with the table. Since the number of revolutions of the rotary shaft for rotating the table during milling is only a few tens of RPM, the contact type sealing ring can prevent foreign matter from penetrating. However, since the number of revolutions of the rotary shaft during turning is several hundreds to several thousands of RPM, the contact type sealing ring can be excessively rubbed against the table rotating at a high speed. Therefore, the contact type sealing ring can not be applied due to technical reasons such as the lifetime of the sealing and the change due to the frictional heat.

To solve this problem, a noncontact sealing ring which does not contact the table can be used. However, the noncontact sealing ring exhibits a foreign matter penetration preventing function at high speed rotation, but can not exhibit the foreign matter penetration preventing function at low speed rotation.

The present invention provides a rotary table assembly of a machine tool capable of preventing the penetration of foreign matter in both milling and preheating.

A rotary table assembly of a machine tool according to one aspect of the present invention may include a table and a labyrinth ring. The table may be rotatably connected to the bed. The labyrinth ring may have an air line for injecting air for preventing foreign matter penetration into a gap between the bed and the table.

In exemplary embodiments, the airline may extend through the interior of the bed.

In exemplary embodiments, the bed may be rotated about a first direction. The table may be rotated about a second direction orthogonal to the first direction.

In exemplary embodiments, the rotary table assembly may further include a rotation axis disposed between the bed and the table, for rotating the table about the second direction.

In exemplary embodiments, the rotary table assembly may further include a clamping mechanism for restricting rotation of the rotation shaft.

In the exemplary embodiments, the clamping mechanism may include a cylinder disposed between the bed and the rotary shaft and having a hydraulic line, a piston lifted by hydraulic pressure provided between the cylinder and the rotary shaft via the hydraulic line, And a brake ring which is fixed to the piston and interrupts the rotation of the rotation shaft by contact with the piston.

In exemplary embodiments, the air line may extend along the interior of the cylinder.

In exemplary embodiments, the labyrinth ring may be disposed between the outer circumferential surface of the rotating shaft and the inner circumferential surfaces of the bed and the table.

In exemplary embodiments, the rotary table assembly may further include at least one sealing ring interposed between an outer circumferential surface of the labyrinth ring and an inner circumferential surface of the table.

In exemplary embodiments, the sealing ring may comprise Teflon.

In exemplary embodiments, the rotary table assembly may further include a cover attached to an outer circumferential surface of the table and covering the clearance.

In exemplary embodiments, the labyrinth ring may include at least one labyrinth formed on the upper surface of the labyrinth ring facing the table.

In exemplary embodiments, the labyrinth ring may have a drain line connected to the labyrinth for draining a foreign object that has penetrated into the labyrinth.

In exemplary embodiments, the drain line may extend along the interior of the bed.

In exemplary embodiments, the machine tool may include a multi-axis processing machine.

According to the present invention described above, the foreign matter can be primarily blocked by the cover covering the gap between the bed and the table. The foreign matter can be cut off secondarily by the air injected through the gap between the bed and the table through the air line. The foreign matter can be thirdly blocked by a sealing ring disposed between the table and the labyrinth ring. The foreign matter can be quadratically blocked by the labyrinth of the labyrinth ring. The foreign matter may be discharged through the drain line connected to the labyrinth and shut off in a fifth order. Therefore, the penetration of foreign matter can be effectively prevented in both milling processing in which the rotary shaft rotates at low speed and turning processing in which the rotary shaft rotates at high speed.

1 is a perspective view of a rotary table assembly of a machine tool according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing an air line in the connection structure of the bed and the table shown in FIG. 1;
3 is a cross-sectional view illustrating a drain line in the connection structure of the bed and the table shown in FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The present invention is capable of various modifications and various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Like reference numerals are used for like elements in describing each drawing.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the terms "comprises", "having", and the like are used to specify that a feature, a number, a step, an operation, an element, a part or a combination thereof is described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

FIG. 1 is a perspective view showing a rotary table assembly of a machine tool according to an embodiment of the present invention, FIG. 2 is a cross-sectional view showing an air line in the connection structure between the bed and the table shown in FIG. 1, Sectional view showing a drain line in a connection structure of a bed and a table.

1 to 3, the rotary table assembly of the machine tool according to the present embodiment includes a bed 110, a table 120, a first rotary shaft 130, a second rotary shaft 140, a clamping mechanism, a labyrinth ring A cover 150, a cover 180, and at least one sealing ring 190.

In the present embodiment, the machine tool may include a multi-axis machining apparatus, for example, a five-axis machining apparatus. The 5-axis machine can perform milling and turning. For this purpose, a 5-axis machining unit can be rotated about 5 axes. The five axes may include three linear axes and two rotational axes. The three linear axes may correspond to the centers of the milling tool and the turning tool. The two rotating shafts may correspond to the shafts serving as rotation centers of the bed 110 and the table 120. In another embodiment, the rotary table assembly of the machine tool may have a structure that is rotated only about a single axis.

The first rotary shaft 130 may be connected to the bed 110 along the horizontal direction. The first rotation shaft 130 may be rotated about the first direction. The first direction may be a horizontal direction. The first rotating shaft 130 may be a tilting shaft that tilts the bed 110 about the first direction.

The motor 132 can rotate the first rotation shaft 130 about the first direction. Accordingly, the bed 110 can also be rotated about the first direction.

The second rotary shaft 140 may be connected to the central portion of the bed 110 along a vertical direction. The second rotation shaft 140 may be rotated about a second direction substantially perpendicular to the first direction. Since the first direction is the horizontal direction, the second direction may be vertical. The rotation of the second rotation shaft 140 can be supported by the main bearing 142.

The table 120 may be fixed to the upper surface of the second rotation shaft 140. [ Thus, the table 120 can be rotated about the second direction together with the second rotation shaft 140. [ The lower surface of the table 120 may be disposed adjacent the upper surface of the bed 110. A gap may be formed between the upper surface of the bed 110 and the lower surface of the table 120 because the table 120 is rotated around the second direction in a state where the bed 110 is fixed.

The clamping mechanism can interrupt the rotation of the second rotation shaft 140. [ The clamping mechanism may include a cylinder 160, a piston 170 and a brake ring 175.

The cylinder 160 may be disposed in a space between the bed 110 and the second rotation shaft 140. The cylinder 160 includes an upper surface spaced from the lower surface of the table 120, a lower surface closely contacting the upper surface of the bed 110, an outer circumferential surface facing the inner surface of the bed 110, And may have an inner peripheral surface spaced apart from the outer peripheral surface. Thus, the cylinder 160 may rotate with the bed 110 but not with the table 120. Spaces may be formed between the upper surface of the cylinder 160 and the lower surface of the table 120 and between the inner circumferential surface of the cylinder 160 and the outer circumferential surface of the second rotary shaft 140, respectively.

The piston 170 can be vertically received in a space between the inner circumferential surface of the cylinder 160 and the outer circumferential surface of the second rotation shaft 140 along the second direction. The hydraulic line 114 may be connected to the upper surface of the piston 170. The hydraulic line 114 may be formed along the inside of the bed 110 and the cylinder 170 and may be connected to the upper surface of the piston 170. Accordingly, the hydraulic pressure provided through the hydraulic line 114 is applied to the upper surface of the piston 170, so that the piston 170 can be lowered along the second direction.

The brake ring 175 may be fixed to the second rotation shaft 140. Accordingly, the brake ring 175 can be rotated together with the second rotation shaft 140. The brake ring 175 may be located below the piston 170. Therefore, by the strong frictional contact of the lowered piston 170 with the brake ring 175, the rotation of the brake ring 175 can be prevented. As a result, the rotation of the second rotation shaft 140 and the table 120 connected to the brake ring 175 can also be interrupted.

The spring 172 is connected to the lower end of the piston 170 to elastically support the piston 170 upward. When the hydraulic pressure supply to the piston 170 is interrupted, the restoring force of the spring 172 can return the piston 170 to its original position.

The labyrinth ring 150 can be disposed within a space between the top surface of the cylinder 160, the bottom surface of the table 120, the inner circumferential surfaces of the bed 110 and the table 120 and the outer circumferential surface of the second rotational shaft 140 have. The labyrinth ring 150 may include at least one labyrinth 152 to prevent penetration of foreign matter. The labyrinth 152 may be formed on the upper surface of the labyrinth ring 150 facing the lower surface of the table 120.

An air line 112 may be formed in the interior of the labyrinth ring 150. The air line 112 can blow air toward the gap between the bed 110 and the table 120. [ Therefore, an air curtain for preventing foreign matter from penetrating into the gap between the bed 110 and the table 120 can be formed.

In this embodiment, the air line 112 may extend along the second direction from the lower surface of the labyrinth ring 150 and then extend along the horizontal direction toward the clearance. The air line 112 may be connected to the outside through the cylinder 160 and the bed 110 along the second direction from the lower surface of the labyrinth ring 150. In another embodiment, the airline 112 may have a structure that is directly connected to the exterior from the labyrinth ring 150.

The cover 180 may be attached to the outer circumferential surface of the table 120 to cover the gap. That is, the cover 180 may have a shape extending along the second direction from the outer circumferential surface of the table 120 to the extent that it covers the gap. Therefore, the penetration of the foreign matter can be prevented primarily by the cover 180. [ The infiltration of the foreign matter passing through the cover 180 can then be prevented secondarily by the air curtain formed by the air line 112.

The sealing ring 190 may be attached to the outer peripheral surface of the labyrinth ring 150. The sealing ring 190 may be in frictional contact with the inner circumferential surface of the rotating table 120. The sealing ring 190 may include a material capable of preventing a gap between the outer circumferential surface of the labyrinth ring 150 and the inner circumferential surface of the table 120 from being formed without causing friction with the inner circumferential surface of the rotating table 120 have. For example, the sealing ring 190 may comprise Teflon. Such a sealing ring 190 can prevent the penetration of the foreign material having passed through the cover 180 and the air curtain. Penetration of foreign matter through the cover 180, the air curtain, and the sealing ring 190 can be prevented by the labyrinth 152 in a quadratic manner.

A drain line 116 may be formed in the labyrinth ring 150. The drain line 116 may be connected to the labyrinth 152. Drain pressure may be provided to the labyrinth 152 via drain line 116. [ Accordingly, the foreign matter in the labyrinth 152 is discharged to the outside through the drain line 116, so that the penetration of foreign matter can be prevented by the drain line 116 in a fifth order.

In this embodiment, the drain line 116 may be connected to the outside through the cylinder 160 and the bed 110 along the second direction from the labyrinth ring 150. In another embodiment, the drain line 116 may have a structure directly connected from the labyrinth ring 150 to the exterior.

As described above, according to the embodiments, the foreign matter can be primarily blocked by the cover covering the gap between the bed and the table. The foreign matter can be cut off secondarily by the air injected through the gap between the bed and the table through the air line. The foreign matter can be thirdly blocked by a sealing ring disposed between the table and the labyrinth ring. The foreign matter can be quadratically blocked by the labyrinth of the labyrinth ring. The foreign matter may be discharged through the drain line connected to the labyrinth and shut off in a fifth order. Therefore, the penetration of foreign matter can be effectively prevented in both milling processing in which the rotary shaft rotates at low speed and turning processing in which the rotary shaft rotates at high speed.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. And changes may be made without departing from the spirit and scope of the invention.

110; Bed 112; Airline
114; Hydraulic line 116; Drain line
120; Table 130; The first rotating shaft
140; A second rotating shaft 150; Labyrinth ring
152; Labyrinth 160; cylinder
170; Piston 172; spring
175; Brake ring 180; cover
190; Sealing ring

Claims (15)

A table rotatably connected to the bed; And
And a labyrinth ring having an air line for injecting air for preventing foreign matter penetration into a gap between the bed and the table. 2. The rotary table assembly of claim 1, wherein the air line extends through the interior of the bed. 2. The rotary table assembly of claim 1, wherein the bed is rotated about a first direction and the table is rotated about a second direction orthogonal to the first direction. 4. The rotary table assembly of claim 3, further comprising a rotating shaft disposed between the bed and the table for rotating the table about the second direction. 5. The rotary table assembly of a machine tool according to claim 4, further comprising a clamping mechanism for restricting rotation of the rotary shaft. 6. The apparatus of claim 5, wherein the clamping mechanism
A cylinder disposed between the bed and the rotating shaft, the cylinder having a hydraulic line;
A piston lifted and lowered by the hydraulic pressure provided through the hydraulic line between the cylinder and the rotary shaft; And
And a brake ring fixed to the rotating shaft and interrupting rotation of the rotating shaft by contact with the piston. 7. The rotary table assembly of claim 6, wherein the air line extends along an interior of the cylinder. 5. The rotary table assembly of claim 4, wherein the labyrinth ring is disposed between an outer circumferential surface of the rotating shaft and inner circumferential surfaces of the bed and the table. The rotary table assembly of a machine tool according to claim 1, further comprising at least one sealing ring interposed between an outer circumferential surface of the labyrinth ring and an inner circumferential surface of the table. 10. The rotary table assembly of a machine tool according to claim 9, wherein the sealing ring comprises Teflon. The rotary table assembly of a machine tool according to claim 1, further comprising a cover attached to an outer circumferential surface of the table and covering the gap. 2. The rotary table assembly of claim 1, wherein the labyrinth ring comprises at least one labyrinth formed on an upper surface of the labyrinth ring facing the table. 13. The rotary table assembly of a machine tool according to claim 12, wherein the labyrinth ring has a drain line connected to the labyrinth for discharging impurities that have penetrated into the labyrinth. 14. The rotary table assembly of claim 13, wherein the drain line extends along the interior of the bed. The rotary table assembly of a machine tool according to claim 1, wherein the machine tool comprises a multi-axis processing machine.

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