KR20170116525A - The rotary joint - Google Patents

Abstract

[0001] The present invention relates to a live center which alleviates vibrations and loads transmitted during machining of a workpiece and has enhanced durability, and includes a hollow portion 120 opened to one side, A center housing 110 fixed to the base 110; A center body 210 having one end inserted into the hollow portion 120 and rotatably supported by the bearings 222, 224, 226 and including a cylinder chamber 230 opened to one side; A center shaft 310 which is inserted into the cylinder chamber 230 at one end, is rotatable together with the center body 210, is reciprocable in an axial direction, and supports one end of the workpiece during processing of the workpiece; And elastic supporting means 320 provided in the cylinder chamber 230 for elastically supporting the center shaft 310 in the axial direction.
According to the present invention, vibrations and loads transmitted through the center shaft at the time of machining the workpiece are alleviated, and there is an advantage that damage to the accessories such as the bearings mounted in the live center and the end of the center shaft can be prevented.

Description

Rotary joint {THE ROTARY JOINT}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary joint, and more particularly, to a rotary joint that improves airtightness of a shaft and a housing to minimize leakage and improves durability.

In general, a rotary joint is a connection device that connects or disconnects fixed piping and a rotating rotating body to supply or discharge fluid such as cooling water or cutting fluid to the rotating body. For example, in a machine tool using a rotating shaft such as a lathe or a milling grinder, a rotating shaft is cooled by passing a fluid such as cooling water or cutting oil through the rotating shaft, or the rotating shaft is used as a fluid moving path. Thus, in order to allow the fluid to pass through the rotating shaft, a rotary joint having a structure in which the fixed pipe and the rotating body are connected and the fluid is not leaked is required.

Conventionally, various rotary joints have been developed which are connected to a fixed body so as to allow various rotators to rotate, and at the same time to allow fluid to flow. Although various structures have been developed and employed for the rotary joints, it has not been easy to develop a structure in which no leakage of fluid occurs because the rotating body is rotatably connected to the stationary body.

Particularly, when the high speed rotating body is connected to the fixed body, it is often difficult to use due to a large flow rate of the fluid. The conventionally developed structure prevents the leakage of the fluid itself in the high- It was not appropriate for the structure.

In addition, the conventional rotary joint is provided with a separate spacer between the sealing members arranged at equal intervals in order to prevent the axial movement of the sealing member and to reinforce the side surface of the sealing member, thereby increasing the number of parts, There has been a problem of becoming complicated.

Further, in the conventional rotary joint, there is a problem that the durability of the sealing member is weak due to excessive wear of the sealing member when friction occurs between a shaft made of a metal material and a sealing member made of an elastic material.

Korea Registered Utility Model No. 0462850 Korean Registered Patent No. 1081893

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a rotary joint in which leakage can be minimized by improving the airtight structure of the shaft and the housing.

Another object of the present invention is to provide a rotary joint in which wear resistance of the airtightness maintaining member can be minimized by applying an anti-wear coating treatment to the outer surface of the shaft, thereby improving durability.

According to an aspect of the present invention, there is provided a rotary joint comprising: a hollow housing having at least one fluid port formed from a hollow interior to an outer periphery; A shaft rotatably coupled through the housing and having at least one flow path communicating with the fluid port; An airtight pocket cut into a ring-shaped groove along the inner periphery of the housing and disposed at regular intervals along the axial direction of the housing; And a hermetic retaining member inserted in the airtight pocket and surrounding an outer periphery of the shaft; The hermetic retaining member may include a first seal member surrounding the outer periphery of the shaft and a second seal member surrounding the outer periphery of the first seal member and pressing the first seal member.

The shaft is provided with a fluid pocket that is cut into a ring-shaped groove along the outer circumference so as to be disposed between the airtight pockets.

The first seal member may have a band shape having a rectangular cross section, a cut groove may be formed on a surface contacting the shaft, and the second seal member may have a ring shape having a circular cross section.

Wherein the shaft is a nanocomposite material having graphene and copper on its outer surface and is subjected to an abrasion coating treatment.

The rotary joint according to the present invention has the following effects.

In the present invention, airtight pockets are formed in the housing, and airtight holding members surrounding the shaft are inserted into the airtight pockets.

In addition to the provision of the airtight pockets, the airtightness maintaining member is tightly attached to the outer surface of the shaft by improving the structure of the airtightness maintaining member, and the inner surfaces of the airtight pockets can be brought into close contact with each other.

Further, in the present invention, the fluid pockets are provided in the shaft so that even if leakage ports and airtightness maintaining members are formed when the fluid port of the housing and the outflow port of the flow path formed in the shaft are disconnected, Leakage that can occur can be accommodated, thereby improving airtightness.

Since the outer surface of the shaft is made of a nanocomposite material and subjected to an abrasion-resistant coating process, the lubrication can be smoothly performed, the airtightness can be improved, the wear of the airtightness maintaining member can be prevented, and the durability can be improved.

1 is a cross-sectional view showing a configuration of a rotary joint according to an embodiment of the present invention;
FIG. 2 is an enlarged view of a portion of FIG. 1 'A'. FIG.
3 is a partially enlarged view showing an action of a hermetic member constituting an embodiment of the present invention.

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

1 is a cross-sectional view of a rotary joint according to an embodiment of the present invention.

1, a rotary joint 10 according to the present invention includes a hollow housing 100, a shaft 200 coupled to the housing 100, and a shaft 200 coupled between the housing 100 and the shaft 200. [ And the airtightness maintaining member 300 may be included.

The housing 100 is formed in a cylindrical shape having an axial hollow.

The housing 100 is provided with a plurality of fluid ports 110 communicating with the hollow and the outside of the housing 100. The fluid port (110) penetrates in a direction perpendicular to the hollow axis of the housing (100).

The fluid port 110 communicates with the fluid passage 210 provided in the shaft 200 to transmit the fluid, and at least one fluid port may be provided.

A shaft (200) is rotatably coupled to the inside of the housing (100). The shaft 200 is installed through the housing 100 in a direction coaxial with the hollow shaft of the housing 100 and is coupled to the housing 100 at both ends thereof through a bearing 102 to be rotatable.

In the shaft 200, a fluid passage 210 communicating with the fluid port 110 is formed. Preferably, the fluid passage 110 is provided to correspond to the number of the fluid ports 110, and is configured to transfer fluid supplied or discharged through the fluid port 110.

A sealing member 300 is provided between the housing 100 and the shaft 200 to prevent oil leakage.

First, the housing 100 is provided with a gas-tight pocket 120 for receiving the gas-tightness holding member 300.

The airtight pockets 120 are cut into ring-shaped grooves along the inner periphery of the housing 100. That is, the airtight pockets 120 are formed into a round groove along the inner surface of the housing 100.

The airtight pockets 120 are arranged at regular intervals along the axial direction of the housing 100.

Here, the airtight pockets 120 are preferably disposed on both sides of the fluid port 110. That is, it is preferable that the fluid port 110 is positioned between the airtight pockets 120 disposed along the hollow axis direction of the housing 100.

An airtightness maintaining member (300) is inserted into the airtight pocket (120).

The airtightness maintaining member 300 is installed to surround the outer circumference of the shaft 200 and is accommodated in the airtight pocket 120. That is, the airtightness maintaining member 300 has a shape protruding to the outside of the shaft 200 while surrounding the outer circumference of the shaft 200, and the protruded airtightness maintaining member 300 is formed in the airtight pocket 120, respectively.

The hermetic sealing member 300 includes a first seal member 310 that surrounds the outer circumference of the shaft 200 and a second seal member 320 that surrounds the outer circumference of the first seal member 310, .

The first seal member 310 directly surrounds the outer circumference of the shaft 200 and the second seal member 320 is fixed to the shaft 200 so that the first seal member 310 is in close contact with the shaft 200. [ (310).

FIG. 2 is an enlarged view of the airtight pocket 120 and the airtightness maintaining member 300 ('A' portion in FIG. 1).

2, the first seal member 310 of the hermetic retaining member 300 is of a band-like shape having a rectangular cross section, and the second seal member 320 is an O- (O-rings).

A cutout groove 312 is formed in a surface of the first seal member 310 in contact with the shaft 200. The cutout groove 312 is opened by the urging of the second seal member 320, thereby adding flexibility to the first seal member 310.

Meanwhile, the shaft 200 is provided with a fluid pocket 220.

The fluid pockets 220 are cut into ring-shaped grooves along the outer periphery of the shaft 200. That is, the fluid pockets 220 are formed into a round groove along the outer surface of the shaft 200.

The fluid pockets (220) are disposed at equal intervals along the axial direction of the shaft (200), and are disposed between the airtight pockets (120). In other words, the fluid pocket 220 is provided between the airtightness maintaining member 300 and the airtightness maintaining member 300.

Also, since the fluid port 110 is disposed between the airtight pockets 120, the fluid pockets 220 are disposed corresponding to the positions of the fluid ports 110.

In the fluid pocket 220, an outflow inlet 212 of the flow path 210 formed in the shaft 200 is formed.

The fluid pockets 220 serve to receive leakage generated when the fluid port 110 is disconnected from the outflow inlet 212 of the flow path 210.

On the other hand, the shaft 200 is provided with an anti-wear coating layer on its outer surface.

The abrasion resistant coating layer is formed by heat treatment with a nanocomposite material including graphene or copper nano.

Wherein the nanocomposite material is characterized in that the graphene is homogeneously dispersed in the copper matrix through a molecular level mixing process and forms a strong interfacial bond with the copper matrix, wherein the particle size is about 50 μm to 1 μm, It has a relative density of 99% or more through sintering of the nanocomposite powder because it forms a chemical bond with the copper particles.

In addition, in order to improve the lubricity of the rotary joint, it is preferable that the bearing (102) and the housing (100) have the abrasion-resistant coating layer in addition to the shaft (200).

Hereinafter, the operation of the rotary joint according to the present invention will be described in detail with reference to the accompanying drawings.

1, a rotary joint 10 according to the present invention includes a shaft 200 installed inside a housing 100, and a rotary shaft 200 connected to the rotary joint 10 through a fluid port 110 provided in the housing. The fluid is supplied to the fluid passage.

When the housing 100 and the shaft 200 are coupled with each other, the hermetic sealing member 300 is pressurized to form a hermetic seal in the hollow of the housing 100 as shown in FIG.

Fig. 3 is a partially enlarged view showing the operation of the hermetic member constituting one embodiment of the present invention.

As shown in FIG. 3, the hermetic sealing member 300 is formed by coupling the first seal member 310 and the second seal member 320.

The airtightness maintaining member 300 is in contact with the inner surface of the shaft 200 and the airtight pocket 120 by being compressed in the airtight pocket 120.

The inner surface of the second seal member 320 presses the outer surface of the first seal member 310 by pressing the first seal member 310 and the second seal member 320, Since the seal member 320 is formed in a circular shape, the force is concentrated at the center of the outer surface of the first seal member 310.

The strength of the central portion of the first seal member 310 is relatively weakened by the inner cutout groove 312 and the force is concentrated on the center portion of the first seal member 310 so that the first seal member 310 Is closely contacted with both inner side surfaces of the airtight pockets (120).

Further, flexibility is improved in the first seal member (310) by the cutout groove (312), and the first seal member (310) can be deformed with less force.

In addition, since the fluid pockets 220 are provided between the airtightness maintaining members 300 disposed at even intervals in the axial direction of the shaft 200, the leakage can be minimized by minimizing leakage.

Specifically, the fluid pockets 220 serve to receive the oil leakage generated in the front and back processes in which the fluid port 110 and the outflow inlet 212 of the flow path 210 are completely connected to each other.

That is, since the oil pocket is received in the fluid pocket 220 and then flows out along the oil passage 210, leakage is hardly generated outside the shaft 200.

Further, depending on the operation of the shaft or the load of the fluid, the fluid may exceed the capacity of any one of the fluid pockets 220, so that even if a fluid exiting the airtightness holding member 300 is generated, It can accommodate leakage.

Meanwhile, the shaft 200 is provided with an abrasion-resistant coating layer formed by heat-treating the nanocomposite material including graphene or copper nano on the outer surface thereof.

The abrasion-resistant coating layer maintains airtightness and is excellent in lubrication, thereby preventing abrasion of the airtightness maintaining member 300, which slips due to rotation of the shaft 200, and enhances durability of the rotary joint as a whole.

It is to be understood that the invention is not limited to the disclosed embodiment, but is capable of many modifications and variations within the scope of the appended claims. It is self-evident.

100. Housing 110. Fluid port
120. Air tight pocket 200. Shaft
300. Airtightness maintaining member 310. First chamber member
320. Second chamber member

Claims (3)

A hollow housing (100) having at least one fluid port (110) formed from a hollow interior to an outer peripheral side thereof;
A shaft 200 rotatably coupled through the housing 100 and having at least one flow path 210 formed therein to communicate with the fluid port 110;
An airtight pocket 120 cut into a ring-shaped groove along the inner periphery of the housing 100 and disposed at regular intervals along the axial direction of the housing 100; And
And a sealing member (300) inserted in the airtight pocket (120) and surrounding the outer periphery of the shaft (200);
On the outer surface of the shaft 200,
Characterized in that a coating layer composed of a nanocomposite material containing graphene or copper nano is provided. The airtight container according to claim 1, wherein the airtightness maintaining member (300)
A first seal member 310 that surrounds the outer circumference of the shaft 200 and a second seal member 320 that surrounds the outer circumference of the first seal member 310 and presses the first seal member 310 And a rotary joint. 3. The method of claim 2,
The first seal member 310 has a band shape having a rectangular cross section. A cutout groove 312 is formed in a surface of the first seal member 310 in contact with the shaft 200,
Wherein the second seal member (320) comprises an O-ring having a circular cross section.

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