Patent Description:
In general, a sealing apparatus capable of linear and rotational motion for vacuum pressure equipment is provided on the outer circumferential surface of a shaft that faces a high pressure region and a low pressure region and is capable of linear and rotational motion therebetween such that the high pressure region and the low pressure region are sealed with each other.

<FIG> is a cross-sectional view showing a conventional sealing apparatus for vacuum pressure equipment. As shown in the figure, the conventional sealing apparatus <NUM> for vacuum pressure equipment may include a housing <NUM> and a shaft <NUM> penetrating and coupled to the housing <NUM>. The shaft <NUM> faces a high pressure region and a low pressure region, and the housing <NUM> is located on the interface between these, that is, the high pressure region and the low pressure region. In addition, a bushing <NUM> and a seal <NUM> for sealing are provided between the housing <NUM> and the shaft <NUM>. The bushing <NUM> is for reducing friction generated between the housing <NUM> and the shaft <NUM>, and the seal <NUM> is for sealing between the housing <NUM> and the shaft <NUM>. At this time, friction is generated between the shaft <NUM> and the seal <NUM>, and a ceramic layer is coated on the surface of the shaft <NUM> to minimize the friction generated at this time. In addition, a plurality of seals <NUM> are provided to increase the sealing effect and are located on the upper and lower portions of the housing <NUM>, respectively.

The shaft <NUM> is installed to be capable of rotational motion with respect to the housing <NUM>. At this time, as the bushing <NUM> for reducing friction generated during the rotational motion of the shaft <NUM>, a ball bushing provided with a plurality of balls therein, or a slide bushing provided with a solid lubricant therein is used.

However, the conventional sealing apparatus <NUM> for vacuum pressure equipment having the above-described configuration has the disadvantage that only rotational motion or linear motion is possible, and when rotational motion and linear motion are performed simultaneously, the seal <NUM> also performs sealing with respect to rotational motion and sealing with respect to linear motion in parallel. When rotational motion and linear motion are performed simultaneously, the seal <NUM> is easily damaged, which has the disadvantage of a short life and frequent replacement.

Meanwhile, the shaft <NUM> is installed to be capable of rotational motion with respect to the housing <NUM>. At this time, as the bushing <NUM> for reducing friction generated during the rotational motion of the shaft <NUM>, a ball bushing provided with a plurality of balls therein, or a slide bushing provided with a solid lubricant therein is used.

However, the conventional sealing apparatus <NUM> for vacuum pressure equipment having the above-described configuration has the disadvantage that the seal <NUM> is easily damaged and has a short life which causes frequent replacement. In addition, there is a problem that the shaft <NUM> separates from the housing <NUM>.

<CIT> discloses a sealing apparatus according to the preamble of claims <NUM> and <NUM>, and <CIT> is an example of another similar sealing apparatus.

Provided are a sealing apparatus capable of rotational motion for vacuum pressure equipment, which may prevent a fluid from leaking between a shaft and a housing that is a fixed body while the shaft performs the rotational motion.

Provided also is a sealing apparatus capable of linear and rotational motion for vacuum pressure equipment, which may prevent a fluid from leaking between a shaft and a housing that is a fixed body while the shaft performs the linear and rotational motion simultaneously.

Provided also is a sealing apparatus capable of linear and rotational motion, which may replace a sealing member with another newly prepared preparatory sealing member by moving a shaft in the axial direction when the sealing member for sealing the rotational motion is damaged.

Provided also is a sealing apparatus capable of rotational motion, which may prevent a shaft that transfers the rotational motion from separating from a housing.

According to an aspect of the present disclosure, a sealing apparatus capable of linear and rotational motion includes a housing; a hollow first shaft penetrating and coupled to the housing; a first sealing member provided between the housing and the first shaft to seal therebetween; a second shaft of which at least a part is inserted into the first shaft; a second sealing member provided between the first shaft and the second shaft to seal therebetween; and a third sealing member provided on either an inner circumferential surface of the first shaft or an outer circumferential surface of the second shaft, wherein the first shaft is installed to be capable of only linear motion in an axial direction with respect to the housing, and the second shaft is installed to be capable of both rotational motion and linear motion with respect to the first shaft, and wherein the third sealing member does not perform sealing between the first shaft and the second shaft when the second shaft is in a first position in the first shaft, and performs sealing between the first shaft and the second shaft when the second shaft moves to and is in a second position in the first shaft, characterized by the fact that the third sealing member is provided on the inner circumferential surface of the first shaft, and a groove portion is provided in the second shaft to form a predetermined gap with the inner circumferential surface of the third sealing member, wherein a ring-shaped coupling ring provided separately on the second shaft is mounted on the groove portion, such that in the first position, the third sealing member does not seal between the first shaft and the second shaft, and in the second position, the third sealing member seals between the first shaft and the second shaft by contacting the coupling ring on the second shaft.

The first sealing member may be a linear seal for linear motion, the second sealing member may be a rotational seal for rotational motion, and the third sealing member may be a rotational seal for rotational motion.

A projection extending in the axial direction may be formed on any one of the inner circumferential surface of the housing and the outer circumferential surface of the first shaft, and a groove into which the projection is inserted may be formed in the other one.

A bushing may be provided between the housing and the first shaft, and a bushing or a radial bearing may be provided between the first shaft and the second shaft.

The first shaft may be formed in a multistep in which an inner diameter increases toward one end portion or the second shaft may be formed in a multistep in which an outer diameter decreases toward one end portion, and the bushing or the radial bearing may be provided between the one end portion of the first shaft and the one end portion of the second shaft.

Locking protrusions may be spaced apart from each other by a predetermined distance in the axial direction and respectively formed on the inner circumferential surface of the housing and the outer circumferential surface of the first shaft such that linear motion therebetween in the axial direction is restricted by a predetermined distance.

According to an aspect of the present disclosure, a sealing apparatus capable of linear and rotational motion includes a housing; a hollow first shaft penetrating and coupled to the housing; a first sealing member provided between the housing and the first shaft to seal therebetween; a second shaft of which at least a part is inserted into the first shaft; a second sealing member provided between the first shaft and the second shaft to seal therebetween; and a third sealing member provided on either an inner circumferential surface of the housing or an outer circumferential surface of the first shaft, wherein the first shaft is installed to be capable of rotational motion with respect to the housing, and the second shaft is installed to be capable of linear motion in an axial direction with respect to the first shaft, and wherein the third sealing member does not perform sealing between the first shaft and the housing when the first shaft is in a first position in the housing, and performs sealing between the first shaft and the housing when the first shaft moves to and is in a second position in the housing, characterized by the fact that the third sealing member is provided on the inner circumferential surface of the housing, and a groove portion is provided in the first shaft to form a predetermined gap with the inner circumferential surface of the third sealing member, wherein a ring-shaped coupling ring provided separately on the first shaft is mounted on the groove portion such that in the first position, the third sealing member does not seal between the housing and the first shaft, and in the second position, the third sealing member seals between the housing and the first shaft.

The first sealing member may be a rotational seal for rotational motion, the second sealing member may be a linear seal for linear motion, and the third sealing member may be a rotational seal for rotational motion.

A projection extending in the axial direction may be formed on any one of the inner circumferential surface of the first shaft and the outer circumferential surface of the second shaft, and a groove into which the projection is inserted may be formed in the other one.

A bushing or a radial bearing may be provided between the housing and the first shaft, and a bushing may be provided between the first shaft and the second shaft.

Locking protrusions may be spaced apart from each other by a predetermined distance in the axial direction and respectively formed on the inner circumferential surface of the first shaft and the outer circumferential surface of the second shaft such that linear motion therebetween in the axial direction is restricted by a predetermined distance.

The sealing apparatus capable of linear and rotational motion according to the present disclosure may include a pair of shafts to respectively perform linear and rotational motion and sealing members between a housing and a first shaft and between the first shaft and a second shaft to prevent a fluid from leaking therebetween.

In addition, the sealing apparatus capable of linear and rotational motion may replace a sealing member with another newly prepared preparatory sealing member by moving a shaft in the axial direction when the sealing member for sealing the rotational motion is damaged.

In addition, the sealing apparatus capable of rotational motion according to the present disclosure may include a pair of shafts to perform the rotational motion and sealing members between a housing and a first shaft and between the first shaft and a second shaft to prevent a fluid from leaking therebetween.

In addition, the sealing apparatus capable of rotational motion may replace a sealing member with another newly prepared preparatory sealing member by moving a shaft in the axial direction when the sealing member for sealing the rotational motion is damaged, which has the effect of increasing the life of the sealing apparatus capable of rotational motion.

In addition, it is possible to prevent the shaft that transfers the rotational motion from separating from the housing through a separation preventing member.

The disclosure will now be described more fully with reference to the accompanying drawings, in which embodiments of the disclosure are shown. The disclosure may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the disclosure to those of skill in the art. For clarity, portions that are not relevant to the description of the disclosure are omitted.

The terms used in the present specification are merely used to describe particular embodiments of the disclosure, and are not intended to limit the disclosure.

In the present specification, it is to be understood that the terms such as "including", "having," and "comprising" are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof disclosed in the specification, and are not intended to preclude the possibility that one or more other features, numbers, steps, actions, components, parts, or combinations thereof may exist or may be added.

In addition, the components shown in the embodiments of the present disclosure are shown independently to represent different characteristic functions, and do not mean that each component may include separate hardware or one software unit. That is, each component is described by listing each component for convenience of description, and at least two of the components may be combined to form one component, or one component may be divided into a plurality of components to perform a function.

In addition, embodiments below are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the disclosure to those skilled in the art. In the drawings, sizes and thicknesses of components may be exaggerated for clarity.

Hereinafter, the disclosure will be described in detail with reference to the attached drawings.

<FIG> is a perspective view showing a first embodiment of a sealing apparatus capable of linear and rotational motion according to the first embodiment of the present disclosure, <FIG> is an exploded perspective view showing the sealing apparatus capable of linear and rotational motion of <FIG>. <FIG> is a partial cross-sectional perspective view showing the sealing apparatus capable of linear and rotational motion of <FIG>, and <FIG> is a cross-sectional view showing the sealing apparatus capable of linear and rotational motion of <FIG>. <FIG> is a cross-sectional view showing a state in which a second shaft is moved in the axial direction in the embodiment of <FIG>.

Referring to <FIG>, a sealing apparatus capable of linear and rotational motion according to an embodiment of the present disclosure may include a housing, a hollow first shaft penetrating and coupled to the housing, a first sealing member provided between the housing and the first shaft to seal therebetween, a second shaft of which at least a part is inserted into the first shaft, a second sealing member provided between the first shaft and the second shaft to seal therebetween, and a third sealing member provided on either the inner circumferential surface of the first shaft or the outer circumferential surface of the second shaft.

Here, the first shaft is installed to be capable of only linear motion in the axial direction, or to be capable of both rotational motion and linear motion in the axial direction with respect to the housing. Meanwhile, the second shaft may be installed to be capable of both rotational motion and linear motion in the axial direction, or to be capable of only linear motion in the axial direction with respect to the first shaft.

Of these, a case where the first shaft performs linear motion in the axial direction and the second shaft performs rotational motion and moves in the axial direction will be described as a first embodiment, and a case where the first shaft performs rotational motion and moves in the axial direction and the second shaft performs linear motion in the axial direction will be described as a second embodiment.

The illustrated first embodiment includes a housing <NUM>, a hollow first shaft <NUM> penetrating and coupled to the housing <NUM>, a first sealing member <NUM> provided between the housing <NUM> and the first shaft <NUM> to seal therebetween, a second shaft <NUM> of which at least a part is inserted into the first shaft <NUM>, and a second sealing member <NUM> provided between the first shaft <NUM> and the second shaft <NUM> to seal therebetween.

The first shaft <NUM> is installed to be capable of linear motion in the axial direction with respect to the housing <NUM>, and the second shaft <NUM> is installed to be capable of rotational motion and moves in the axial direction with respect to the first shaft <NUM>.

The first embodiment will be described in more detail as follows.

The housing <NUM> is formed in a cylindrical shape having a flange <NUM> so as to be fixed to a boundary surface between a high pressure region and a low pressure region, and a locking protrusion <NUM> protruding inward is formed on one side of the inner circumferential surface of the housing <NUM>. A plurality of screw holes <NUM> are formed in the flange <NUM> so as to be fixed to the boundary surface. In addition, a bushing <NUM> in a cylindrical shape may be provided inside the housing <NUM>, and a housing cover <NUM> fixing the bushing <NUM> together with the locking protrusion <NUM> may be provided on the other end of the housing <NUM>. The housing cover <NUM> is screwed to the other end of the housing <NUM>. At this time, the bushing <NUM> is positioned such that both ends are in contact with the locking protrusion <NUM> and the housing cover <NUM>, respectively, and is fixed by the housing cover <NUM> that is screwed. Further, the bushing <NUM> is for reducing friction between the housing <NUM> and the first shaft <NUM>, and various types of bushings may be used, and a slide bushing provided with a solid lubricant therein may be used.

Meanwhile, one surface of the locking protrusion <NUM> may be formed in the multistep, and a first sealing member <NUM> may be provided on a step protrusion <NUM> of the multistep. A washer <NUM> that is inserted into the housing <NUM> and fixes the first sealing member <NUM> may be provided outside the locking protrusion <NUM>. A step protrusion <NUM> of the multistep may be formed on one surface of the washer <NUM> and another first sealing member <NUM>' may be provided on the step protrusion <NUM>. In addition, a washer cover <NUM> for fixing the washer <NUM> and the other first sealing member <NUM>' may be provided outside the washer <NUM>.

The first sealing members <NUM> and <NUM>' are for sealing between the housing <NUM> and the first shaft <NUM> and may be a linear seal for linear motion that exhibits excellent sealing performance for linear motion so as to be applicable to the first shaft <NUM> performing linear motion in the axial direction. In the present embodiment, an O-ring is used, but this is only an example, and the present disclosure is not limited thereto, and various types of linear seals such as a lip seal may be applied.

The first shaft <NUM> has a hollow shape and is formed in the multistep in which the outer diameter and the inner diameter increase from one end portion to the other portion. That is, the outer circumferential surface of the first shaft <NUM> may be formed in three steps including a small outer diameter portion <NUM>, a middle outer diameter portion <NUM>, and a large outer diameter portion <NUM> from one end portion. The inner circumferential surface of the first shaft <NUM> may be formed in two steps including a small inner diameter portion <NUM> and a large inner diameter portion <NUM> from one end portion.

The small outer diameter portion <NUM> of the first shaft <NUM> penetrates the locking protrusion <NUM>, the washer <NUM>, and the washer cover <NUM> and protrudes to one side, and the middle outer diameter portion <NUM> is located in contact with the bushing <NUM> provided to reduce friction with the housing <NUM> during linear motion of the first shaft <NUM>. Meanwhile, the end portion of the large outer diameter portion <NUM>, that is, the other end portion of the first shaft <NUM>, is connected to the other end portion of the housing <NUM> by a flexible cover <NUM>.

The first shaft <NUM> may perform linear motion in the axial direction along the bushing <NUM>. When the first shaft <NUM> moves to one side, movement may be restricted because a step protrusion <NUM> formed between the small outer diameter portion <NUM> and the middle outer diameter portion <NUM> is locked on the locking protrusion <NUM>. In addition, when the first shaft <NUM> moves to the other side, the movement may be restricted by the flexible cover <NUM>.

The flexible cover <NUM> is for preventing foreign matters from being introduced between the housing and the other end portion of the first shaft <NUM>, and may be expanded or contracted as the first shaft <NUM> moves in the axial direction. As the flexible cover, bellows of a synthetic resin material having elasticity such as rubber is most often used, and a flexible cover made of Teflon or stainless steel may be used according to the purpose of machine equipped with the sealing apparatus capable of linear and rotational motion for vacuum pressure equipment.

Meanwhile, since the first sealing member <NUM> provided between the housing <NUM> and the first shaft <NUM> is a linear seal for linear motion, when rotation occurs in the first shaft <NUM>, the first sealing member <NUM> is undesirable because of loss of a function as the linear seal for linear motion.

Therefore, although not shown in the drawing, it is desirable that a projection extending in the axial direction is formed on any one of the inner circumferential surface of the housing <NUM> and the outer circumferential surface of the first shaft <NUM>, and a groove into which the projection is inserted is formed in the other one such that the first shaft <NUM> does not rotate.

The second shaft <NUM> is formed in the multistep in which the outer diameter decreases from one end portion to the other portion. That is, the outer circumferential surface of the second shaft <NUM> is formed in four steps including a large outer diameter portion <NUM>, a middle outer diameter portion <NUM>, a first small outer diameter portion <NUM>, and a second small outer diameter portion <NUM> from one end portion.

The middle outer diameter portion <NUM>, the first small outer diameter portion <NUM>, and the second small outer diameter portion <NUM> of the second shaft <NUM> penetrate and are coupled to the first shaft <NUM> from one side, and the large outer diameter portion <NUM> of the outer circumferential surface of the second shaft <NUM> is formed larger than the diameter of the small inner diameter portion <NUM> of the inner circumferential surface of the first shaft <NUM>. A predetermined gap is formed between the middle outer diameter portion <NUM> of the second shaft <NUM> and the small inner diameter portion <NUM> of the first shaft <NUM> such that friction does not occur therebetween when the second shaft <NUM> rotates.

As described above, the inner diameter of the first shaft <NUM> increases toward the other side, and the outer diameter of the second shaft <NUM> decreases toward the other side, and thus a predetermined space <NUM> may be provided. A plurality of second sealing members <NUM> and radial bearings <NUM> may be positioned in the predetermined space <NUM> from one side. The second sealing member <NUM> is for sealing between the first shaft <NUM> and the second shaft <NUM>, and the radial bearing <NUM> is for making the second shaft <NUM> rotatable with respect to the first shaft <NUM>. In the present embodiment, the radial bearing <NUM> is provided to rotate the second shaft <NUM> with respect to the first shaft <NUM>, but a bushing may be provided instead. Owing to the bushing, the second shaft <NUM> may rotate with respect to the first shaft <NUM>.

Here, the second sealing member <NUM> is a rotational seal for rotational motion that exhibits excellent sealing performance for rotational motion to be applicable to the second shaft <NUM> performing rotational motion, and thus a lip seal is used in the present embodiment, but this is only an example and the present disclosure is not limited thereto, and various types of rotational seals may be applied.

Meanwhile, a step protrusion <NUM> and a snap ring <NUM> are provided on the outer circumferential surface of the second shaft <NUM> on both ends of the radial bearing <NUM>, respectively, to fix the radial bearing <NUM>. The snap ring <NUM> may be inserted into and fixed to the outer circumferential surface of the second shaft <NUM> after positioning the radial bearing in a detachable form. In addition, the radial bearing <NUM> may be fixed once more by a third sealing member <NUM> disposed adjacent thereto and a bearing cover <NUM> provided on the other end portion of the first shaft <NUM>.

Meanwhile, the sealing apparatus capable of linear and rotational motion according to the present embodiment may include the third sealing member <NUM>. Like the second sealing member <NUM>, the third sealing member <NUM> may also be a rotational seal for rotational motion that exhibits excellent sealing performance for rotational motion to be applicable to the second shaft <NUM> performing rotational motion. In the present embodiment, a lip seal is used, but this is only an example, and the present disclosure is not limited thereto, and various types of rotational seals may be applied.

The third sealing member <NUM> may be provided on either the inner circumferential surface of the first shaft <NUM> or the outer circumferential surface of the second shaft <NUM>, and in the present embodiment, the third sealing member <NUM> is provided on the inner circumferential surface of the first shaft <NUM> by way of an example. The third sealing member <NUM> is provided adjacent to the radial bearing <NUM>. As shown in <FIG>, when the second shaft <NUM> is in a first position in the first shaft <NUM>, the inner circumferential surface of the third sealing member <NUM> is not in contact the outer circumferential surface of the second shaft <NUM>. Therefore, in the first position, the third sealing member <NUM> does not perform sealing between the first shaft <NUM> and the second shaft <NUM>. However, due to the long use of the sealing apparatus, the second sealing member <NUM> may end its life or be damaged. In this case, disassembling and reassembling the entire sealing apparatus to replace the second sealing member <NUM> may not be efficient. In this case, a user may remove the snap ring <NUM> and then push the second shaft <NUM> to one side (left in the present embodiment) within the first shaft <NUM> to move the second shaft <NUM> to a second position shown in <FIG>.

As shown in <FIG>, in the second position where the second shaft <NUM> is moved with respect to the first shaft <NUM>, the inner circumferential surface of the third sealing member <NUM> may be in contact with the outer circumferential surface of the second shaft <NUM>. As an example, the inner circumferential surface of the third sealing member <NUM> may contact a groove portion provided in the outer circumferential surface of the second shaft <NUM>, such that sealing between the first shaft <NUM> and the second shaft <NUM> may be performed. A ring-shaped coupling ring <NUM> provided separately on the second shaft <NUM> may be mounted on the groove portion. Therefore, even when the endurance life of the second sealing member <NUM> is exhausted, without having to disassembling the entire sealing apparatus and replacing the second sealing member <NUM> and then reassembling the entire sealing apparatus, after removing only the snap ring <NUM> and by simply relocating the second shaft <NUM> within the first shaft <NUM>, the third sealing member <NUM> may be used instead of the second sealing member <NUM>. In this case, the other side of the large outer diameter portion <NUM> of the second shaft <NUM> and one side of the small inner diameter portion <NUM> of the first shaft <NUM> may be spaced in the axial direction. A snap ring <NUM> may be provided to prevent relative motion in the axial direction of the second shaft <NUM> and the first shaft <NUM> in the second position.

Meanwhile, the bearing cover <NUM> is provided on the other end of the first shaft <NUM>, and the bearing cover <NUM> is for fixing the second sealing member <NUM>, the radial bearing <NUM> and the third sealing member <NUM> that are provided inside the first shaft <NUM> and simultaneously for fixing the flexible cover <NUM>.

The operation of the first embodiment configured as described above is as follows.

First, the operation of the sealing apparatus in the first position will be described with reference to <FIG>.

Although not shown in the drawing, a driving apparatus for performing rotational motion and linear motion of the first shaft <NUM> and the second shaft <NUM> are provided in the other side of the sealing apparatus.

The second shaft <NUM> rotates by the driving apparatus. Since the radial bearing <NUM> is provided between the first shaft <NUM> and the other side of the second shaft <NUM> and a predetermined gap is formed on one side, the first shaft <NUM> does not rotate. In addition, as described above, when a projection (not shown) extending in the axial direction is form on any one of the inner circumferential surface of the housing <NUM> and the outer circumferential surface of the first shaft <NUM>, and a groove (not shown) into which the projection is inserted is formed in the other one, the first shaft <NUM> may completely prevent rotation.

Meanwhile, the second shaft <NUM> may move in the axial direction by the driving apparatus. At this time, the axial movement of the second shaft <NUM> may be divided into two cases, when moving to one side and when moving to the other side.

Among these cases, when the second shaft <NUM> moves to one side, the snap ring <NUM> coupled to the outer circumferential surface of the second shaft <NUM> receives the force, and the force is transferred to the first shaft <NUM> through the third sealing member <NUM>, the radial bearing <NUM>, and the second sealing member <NUM>, and thus the first shaft <NUM> performs linear motion along the bushing <NUM>.

In addition, when the second shaft <NUM> moves to the other side, the large diameter portion of the second shaft <NUM> moves in contact with one end of the first shaft <NUM>, and thus, as described above, the first shaft <NUM> performs linear motion along the bushing <NUM>.

At this time, the rotational motion and the linear motion are simultaneously performed, and the radial bearing <NUM> is provided between the first shaft <NUM> and the second shaft <NUM>, and the projection extending in the axial direction and the groove are provided between the inner circumferential surface of the housing <NUM> and the outer circumferential surface of the first shaft <NUM>, and thus the first shaft <NUM> performs linear motion only.

Here, at least one end portion (preferably both end portions) of the first shaft <NUM> and the second shaft <NUM> may be polished to have a high hardness and a precise surface. The purpose of polishing is to bring the contact stress distribution and the temperature distribution between the first shaft <NUM> and the second shaft <NUM> and the sealing members <NUM> and <NUM> into uniformity. As described above, when the first shaft <NUM> and the second shaft <NUM> are polished, the airtightness between the first shaft <NUM> and the second shaft and the sealing members <NUM> and <NUM> may be further secured.

With regard to such a polishing process of the shafts <NUM> and <NUM> in detail, a predetermined coating material is coated to the surface of at least one end portion of the shafts <NUM> and <NUM> processed by using a method such as mechanical and heat treatment to a certain thickness and then, the coated surface is polished to have a uniform thickness. At this time, the reason for polishing after coating as described above is that the coating thickness may be arbitrarily adjusted and the uniform coating thickness may be obtained. However, the present disclosure is not necessarily limited thereto, and it is also possible to perform a coating operation after polishing.

Next, with reference to <FIG>, the operation of the sealing apparatus in the second position will be described.

When the second sealing member <NUM> performing sealing between the first shaft <NUM> and the second shaft <NUM> ends its life or is damaged, after the user removes the snap ring <NUM>, the user may push the second shaft <NUM> to one side in the first shaft <NUM> to move the second shaft <NUM> to the second position shown in <FIG>, and then remount the snap ring <NUM>. In addition, the snap ring <NUM> may be mounted to prevent relative motion in the axial direction of the second shaft <NUM> and the first shaft <NUM> in the second position.

The second shaft <NUM> rotates by the driving apparatus. Since the radial bearing <NUM> is provided between the first shaft <NUM> and the other side of the second shaft <NUM> and a predetermined gap is formed on one side, the first shaft <NUM> does not rotate. Meanwhile, the second shaft <NUM> may move in the axial direction by the driving apparatus. At this time, the axial movement of the second shaft <NUM> may be divided into two cases, when moving to one side and when moving to the other side.

In addition, when the second shaft <NUM> moves to the other side, the snap ring <NUM> coupled to the second shaft <NUM> receives the force while contacting one end portion of the first shaft <NUM>, and the force is transferred to the first shaft <NUM>, and thus the first shaft <NUM> performs linear motion along the bushing <NUM>.

<FIG> is a cross-sectional view showing a sealing apparatus capable of linear and rotational motion according to a second embodiment of the present disclosure.

As shown in <FIG>, in the second embodiment of the sealing apparatus capable of linear and rotational motion for vacuum pressure equipment, the radial bearing <NUM> is provided between the housing <NUM> and the first shaft <NUM> to allow the first shaft <NUM> to perform rotational motion, and the bushing <NUM> is provided between the first shaft <NUM> and the second shaft <NUM> to allow the second shaft <NUM> to perform linear motion. That is, the first shaft <NUM> is installed to enable rotational movement with respect to the housing <NUM>, and the second shaft <NUM> is installed to enable axial linear movement with respect to the first shaft <NUM>.

In addition, the second sealing member (a seal for rotation) <NUM> is provided between the housing <NUM> and the first shaft <NUM>, and the first sealing member (a linear seal) <NUM> is provided between the first shaft <NUM> and the second shaft <NUM>. At this time, as described above, an O-ring and a lip seal that exhibit excellent sealing performance for linear motion and rotational motion may be used as the sealing members <NUM> and <NUM> respectively.

In the second embodiment, as in the first embodiment, at least one end portion (preferably both end portions) of the first shaft <NUM> and the second shaft <NUM> may be polished by using a method such as heat treatment, plating and coating.

The second embodiment of the sealing apparatus capable of linear and rotational motion for vacuum pressure equipment configured as described above may obtain the same effect as the first embodiment. That is, a pair of shafts <NUM> and <NUM> are provided, and the shafts <NUM> and <NUM> perform linear motion and rotational motion, respectively, while the sealing members <NUM> and <NUM> that exhibit excellent sealing performance for linear motion and rotational motion are provided between the housing <NUM> and the first shaft <NUM> and between the first shaft <NUM> and the second shaft <NUM> to prevent a fluid from leaking therebetween.

Meanwhile, in the first embodiment and second embodiment, the O-ring and the lip seal respectively are examples of a pair of sealing members, that is, the first and second sealing members <NUM> and <NUM>. However, as described above, the present disclosure is not necessarily limited thereto, and various types of sealing members may be applicable.

In addition, in the second embodiment, as in the first embodiment, the third sealing member <NUM> may be provided between the housing <NUM> and the first shaft <NUM>. When the second sealing member <NUM> providing airtightness between the housing <NUM> and the first shaft <NUM> ends its life or is damaged, a user may move the first shaft <NUM> to one side in the housing <NUM> such that the third sealing member <NUM> may provide sealing between the housing <NUM> and the first shaft <NUM>. In this case, the inner circumferential surface of the third sealing member <NUM> may contact a groove portion provided in the outer circumferential surface of the first shaft <NUM> such that sealing may be performed between the first shaft <NUM> and the housing <NUM>. A ring-shaped coupling ring <NUM> provided separately on the first shaft <NUM> may be mounted on the groove portion.

As described above, the sealing apparatus capable of linear and rotational motion according to the embodiments of the present disclosure includes the pair of shafts to perform linear and rotational motion, respectively, and sealing members between the housing and the first shaft and between the first shaft and the second shaft to prevent the fluid from leaking therebetween.

In addition, a sealing member for rotational motion is additionally provided on either one of the first shaft and the second shaft (the first embodiment), or one of the housing and the first shaft (the second embodiment), and when the sealing member for rotational motion in use is damaged, the second shaft is moved with respect to the first shaft (the first embodiment), or the first shaft is moved with respect to the housing (the second embodiment), such that a new sealing member for rotational motion is disposed to a sealing possible position, and thus it is possible to extend the sealing effect with respect to rotational motion.

Hereinafter, a sealing apparatus capable of rotational motion according to an embodiment of the present disclosure will be described.

<FIG> is a perspective view showing a sealing apparatus capable of rotational motion, which does not fall under the scope of protection of the annexed claims, but was provided for illustrative purpose for better understanding state of the art, and <FIG> is an exploded perspective view showing the sealing apparatus capable of rotational motion, which does not fall under the scope of protection of the annexed claims, but was provided for illustrative purpose for better understanding state of the art. <FIG> is an exploded cross-sectional perspective view showing the sealing apparatus capable of rotational motion, which does not fall under the scope of protection of the annexed claims, but was provided for illustrative purpose for better understanding state of the art, and <FIG> is a cross-sectional view showing a first shaft of the sealing apparatus capable of rotational motion according to the disclosure of <FIG> disposed in a first position. <FIG> is a cross-sectional view showing the first shaft of the sealing apparatus capable of rotational motion according to the disclosure of <FIG> disposed in a second position.

Referring to <FIG>, the sealing apparatus capable of rotational motion may include a hollow housing <NUM>, a hollow first shaft <NUM> of which a part is inserted into the housing <NUM> and installed to be capable of rotational motion and motion in the axial direction with respect to the housing <NUM>, a second shaft <NUM> penetrating the first shaft <NUM> and rotating along with the first shaft <NUM>, and a first sealing member 1400a and a second sealing member 1400b provided between the housing <NUM> and the first shaft <NUM> to seal between the housing <NUM> and the first shaft <NUM>.

Here, the first shaft <NUM> is movable to the first position and the second position in the axial direction in the housing <NUM>, when the first shaft <NUM> is disposed in the first position in the housing <NUM> (see <FIG>), the first sealing member 1400a may seal between the housing <NUM> and the first shaft <NUM>, and when the first shaft <NUM> is disposed in the second position in the housing <NUM> (see <FIG>), the second sealing member 1400b may seal between the housing <NUM> and the first shaft <NUM>.

The first position is a position of the first shaft <NUM> shown in <FIG> where a protrusion portion <NUM> of the first shaft <NUM> is in contact with the first sealing member 1400a, and a space between the first shaft <NUM> and the housing <NUM> is sealed. The second position is a position of the first shaft <NUM> shown in <FIG> where the protrusion portion <NUM> of the first shaft <NUM> is in contact with the second sealing member 1400b, and the space between the first shaft <NUM> and the housing <NUM> is sealed.

The housing <NUM> may be formed in a cylindrical shape having a flange portion <NUM> so as to be fixed to a boundary surface between a high pressure region and a low pressure region, and a locking protrusion <NUM> protruding inward may be formed on one side of the inner circumferential surface of the housing <NUM>. A plurality of screw holes <NUM> are formed in the flange portion <NUM> so as to be fixed to the boundary surface. As shown in <FIG> and <FIG>, the first sealing member 1400a and the second sealing member 1400b may be provided between the housing <NUM> and the first shaft <NUM>, which is a space that may be generated when the first shaft <NUM> penetrates the hollow of the housing <NUM>. The first sealing member 1400a and the second sealing member 1400b are for sealing between the housing <NUM> and the first shaft <NUM>, and may be a rotating seal for rotational motion exhibiting excellent sealing performance for rotational movement. In the present example, an O-ring is used, but this is only an example, and the present disclosure is not limited thereto, and various types of rotating seals such as a lip seal may be applied.

The housing <NUM> may be formed in the multistep with an outer diameter increasing from one end to the other end, and a housing cover <NUM> may be provided on the other end, and the housing <NUM> and the housing cover <NUM> may be coupled by a coupling means such as a screw.

Also, the first sealing member 1400a and the second sealing member 1400b may be installed to be spaced apart from each other in the axial direction. A gap adjusting member <NUM> may be interposed between the spaced first sealing member 1400a and second sealing member 1400b. Due to the gap adjusting member <NUM>, the first sealing member 1400a and the second sealing member 1400b may be physically separated from each other. In addition, the first sealing member 1400a and the second sealing member 1400b may be fixed by the gap adjusting member <NUM> so as not to move within the housing <NUM>.

Referring to <FIG> and <FIG>, each of a plurality of first sealing members 1400a and the second sealing members 1400b may be configured as a washer <NUM> and a seal <NUM>. A step protrusion may be formed on one surface of the washer <NUM> and the seal <NUM> may be seated on the step protrusion.

Referring to <FIG> and <FIG>, the first sealing members 1400a and the second sealing members 400b each may be plural, and the gap adjusting member <NUM> may be provided between the plurality of second sealing members 1400b and the plurality of first sealing members 1400a to fix the positions of the second sealing member 1400b and the first sealing member 1400a while separating the second sealing member 1400b and the first sealing member 1400a. A housing cover <NUM> is provided on one end of the first sealing member 1400a to press the first sealing member 1400a, the second sealing member 1400b, and the gap adjusting member <NUM>, which are fitted side by side in the housing <NUM>. This structure has the advantage that the positions of the first sealing member 1400a and the second sealing member 1400b may be fixed in the housing even when the first sealing member 1400a and the second sealing member 1400b are not coupled to the housing <NUM> by separate coupling means.

The first shaft <NUM> may include a hollow formed therein and a step, and a protrusion portion <NUM> formed to extend from the outer circumferential surface thereof. In the first position illustrated in <FIG>, the first sealing member 1400a may seal between the protrusion portion <NUM> and the housing <NUM>. The protrusion portion <NUM> may include a protrusion portion outer diameter surface <NUM> and a protrusion portion locking protrusion <NUM> (see <FIG>). The protrusion portion outer diameter surface <NUM> and the first sealing member 1400a are in contact with each other to form sealing, thereby sealing between the housing <NUM> and the first shaft <NUM>.

Meanwhile, as illustrated in <FIG>, when the first shaft <NUM> is disposed in the first position, the protrusion portion outer diameter surface <NUM> of the first shaft <NUM> does not contact the second sealing member 1400b. Therefore, in the first position, the second sealing member 1400b does not perform sealing between the housing <NUM> and the first shaft <NUM>.

However, due to the long use of the sealing apparatus capable of rotational motion, the first sealing member 1400a may end its life or be damaged. In this case, disassembling and reassembling the entire sealing apparatus capable of rotational motion to replace the first sealing member 1400a may not be efficient. As a more efficient method, it is necessary to use a new sealing member without disassembling the entire sealing apparatus capable of rotational motion.

In the present example, a user may grip the first shaft <NUM> exposed to the outside of the housing <NUM>, for example, a second outer diameter portion <NUM> of the first shaft, and then push the first shaft <NUM> from the first position to the second position to move the first shaft <NUM> to the second position shown in <FIG>.

Then, as shown in <FIG>, the first shaft <NUM> may be disposed in the second position (the first shaft <NUM> is moved in the axial direction from the first position in the housing <NUM> and disposed in the second position), and the protrusion portion <NUM> may also be disposed in the second position in the housing <NUM>.

In the second position, the protrusion portion <NUM> of the first shaft <NUM> may contact the second sealing member 1400b to seal the space between the first shaft <NUM> and the housing <NUM>.

Accordingly, the sealing apparatus capable of rotational motion has the advantage of using the new second sealing member 1400b by moving the first shaft <NUM> in the axial direction even when the first sealing member 1400a is damaged or ends its life.

Meanwhile, since the first shaft <NUM> has a shape including the protrusion portion <NUM>, correspondingly, a part of the housing <NUM> may be formed in the multistep with an inner diameter increasing toward one end. The housing <NUM> is formed in the multistep having a first outer diameter portion <NUM> and a second outer diameter portion <NUM>, and a step protrusion <NUM> may be formed due to a difference in the outer diameter between the first outer diameter portion <NUM> and the second outer diameter portion <NUM>. When the first shaft <NUM> moves from the first position to the second position, that is, when the user physically pushes and moves the first shaft <NUM>, since the locking protrusion <NUM> of the protrusion portion <NUM> of the first shaft <NUM> is blocked by the step protrusion <NUM>, movement of the first shaft <NUM> may be restricted. Such a structure may allow the first shaft <NUM> to be disposed in the correct position of the second position when the first shaft <NUM> moves from the first position to the second position.

In addition, the plurality of first sealing member 1400a and the second sealing member 1400b may be fitted into the housing <NUM> along with the gap adjusting member <NUM> side by side as described above because of the structure of the housing <NUM> having the step protrusion <NUM>.

In addition, a third sealing member 1400c may be provided in a space of the hollow of the first shaft <NUM> in which the second shaft <NUM> may penetrate, that is, a space between the first shaft <NUM> and the second shaft <NUM>. The third sealing member 1400c may seal between the first shaft <NUM> and the second shaft <NUM>. The third sealing member 1400c may be an O-ring, but this is only an example and the present disclosure is not limited thereto, and various types of seals such as a lip seal may be applied.

In addition, when the first shaft <NUM> and the second shaft <NUM> are coupled by the coupling means <NUM>, and the first shaft <NUM> rotates, the second shaft <NUM> may also rotate in the same way.

Here, the coupling means <NUM> may be a clamping mechanism or a screw bolt, but is not limited thereto, and various types of coupling means such as a screw or a pin may be applied.

Here, as an example, when a clamping tool is used as the coupling means <NUM>, the clamping tool may be attached to surround the outer circumferential surface of the first shaft <NUM>, compress the outer circumferential surfaces of the first shaft <NUM> and the first shaft <NUM>, couple the first shaft <NUM> and the second shaft <NUM>, and prevent the first shaft <NUM> and the second shaft <NUM> from being detached from the housing <NUM> due to a step of the clamping tool generated by the coupling of the clamping tool. In addition, when moving the first shaft <NUM> from the first position to the second position, the user may release the clamping tool and move the first shaft <NUM> from the first position to the second position, and then again install the clamping tool in the first shaft <NUM>.

A separation preventing member <NUM> may be used as the coupling means <NUM>. In the sealing apparatus capable of rotational motion, the separation preventing member <NUM> may be coupled to the second outer diameter portion <NUM> of the first shaft exposed to the outside of the housing <NUM> to prevent the second shaft <NUM> from being detached from the housing <NUM>.

To this end, a first coupling portion <NUM> and a second coupling portion <NUM> may be formed in the second outer diameter portion <NUM> of the first shaft <NUM>. The first coupling portion <NUM> and the second coupling portion <NUM> may correspond to a coupling hole <NUM> formed in the flange portion <NUM> of the separation preventing member <NUM>. The first coupling portion <NUM> and the coupling hole <NUM> or the second coupling portion <NUM> and the coupling hole <NUM> corresponding to each other may be combined by the coupling means <NUM>, and accordingly the separation preventing member <NUM> may be coupled to the first shaft <NUM>.

Meanwhile, referring to <FIG> and <FIG>, the separation preventing member <NUM> may be coupled to the first shaft <NUM> or the second shaft <NUM> exposed to the outside of the housing <NUM>, and accordingly the coupled separation preventing member <NUM> may prevent the first shaft <NUM> or the second shaft <NUM> from being detached from the housing <NUM> due to another external force (e.g., gravity, etc.).

In addition, in a manner similar to that in which the separation preventing member <NUM> is coupled to the first shaft <NUM>, a coupling portion <NUM> to which the separation preventing member <NUM> may be coupled may be formed in the second shaft <NUM>. The above-described second shaft <NUM> and the separation preventing member <NUM> may be coupled to the coupling portion <NUM> and the coupling hole <NUM> formed in the flange portion <NUM> of the separation preventing member <NUM> by the coupling means <NUM>.

In addition, the coupling hole <NUM> of the flange portion <NUM>, the first coupling portion <NUM> or the second coupling portion <NUM> of the first shaft <NUM>, and the coupling portion <NUM> of the second shaft <NUM> may be coupled together by the coupling means <NUM>, and thus the separation preventing member <NUM>, the first shaft <NUM> and the second shaft <NUM> may be coupled together.

Here, when the coupling means <NUM> is coupled to the first coupling portion <NUM> of the first shaft <NUM> such that the first shaft <NUM> and the second shaft <NUM> are coupled, the first shaft <NUM> may be disposed in the first position, and when the coupling means <NUM> is coupled to the second coupling portion <NUM> of the first shaft <NUM> such that the first shaft <NUM> and the second shaft <NUM> are coupled, the first shaft <NUM> may be disposed in the second position.

Therefore, when the first sealing member 1400a ends its life or is damaged due to the long use of the sealing apparatus capable of rotational motion, the user may remove the coupling means <NUM> fastened to the first coupling portion <NUM> of the first shaft <NUM> and the coupling portion <NUM> of the second shaft <NUM>, move the first shaft <NUM> from the first position to the second position, and then fasten the coupling means <NUM> to the second coupling portion <NUM> of the first shaft <NUM> and the coupling portion <NUM> of the second shaft <NUM> again such that the first shaft <NUM> may be fixed to the second position.

Owing to such a structure, it is not necessary to disassemble the entire sealing apparatus capable of rotational motion to replace the sealing member due to breakage and damage of the sealing members 1400a and 1400b inside the housing <NUM>, and the life of the apparatus may also extend twice.

In another example, the first shaft <NUM> and the second shaft <NUM> may be coupled with a pin penetrating both the first shaft <NUM> and the second shaft <NUM> in a direction perpendicular to the axial direction of the shaft. In addition, a plurality of through holes (not shown) through which the pin may penetrate may be present in the first shaft capable of adjusting the coupling position of the first shaft <NUM> and the second shaft <NUM>. Accordingly, the user may adjust the coupling position of the first shaft <NUM> and the second shaft <NUM> according to positions of the through holes and couple the first shaft <NUM> and the second shaft <NUM>. In the present example, when the first shaft <NUM> is moved from the first position to the second position, only the pin coupling of the coupled first shaft <NUM> and second shaft <NUM> is disassembled, and after the first shaft <NUM> is moved from the first position to the second position, the pin coupling may be performed again.

Claim 1:
A sealing apparatus capable of linear and rotational motion comprising:
a housing (<NUM>);
a hollow first shaft (<NUM>) penetrating and coupled to the housing;
a first sealing member (<NUM>) provided between the housing (<NUM>) and the first shaft (<NUM>) to seal therebetween;
a second shaft (<NUM>) of which at least a part is inserted into the first shaft (<NUM>);
a second sealing member (<NUM>) provided between the first shaft (<NUM>) and the second shaft (<NUM>) to seal therebetween; and
a third sealing member (<NUM>) provided on either an inner circumferential surface of the first shaft (<NUM>) or an outer circumferential surface of the second shaft (<NUM>),
wherein the first shaft (<NUM>) is provided to be capable of linear motion in an axial direction with respect to the housing (<NUM>), and the second shaft (<NUM>) is provided to be capable of rotational motion and linear motion with respect to the first shaft (<NUM>), and
wherein the third sealing member (<NUM>) does not perform sealing between the first shaft (<NUM>) and the second shaft (<NUM>) when the second shaft (<NUM>) is in a first position in the first shaft (<NUM>), and performs sealing between the first shaft (<NUM>) and the second shaft (<NUM>) when the second shaft (<NUM>) moves to and is in a second position in the first shaft (<NUM>),
characterized by the fact that the third sealing member (<NUM>) is provided on the inner circumferential surface of the first shaft (<NUM>), and a groove portion (<NUM>) is provided in the second shaft (<NUM>) to form a predetermined gap with the inner circumferential surface of the third sealing member (<NUM>), wherein a ring-shaped coupling ring provided separately on the second shaft (<NUM>) is mounted on the groove portion (<NUM>), such that in the first position, the third sealing member (<NUM>) does not seal between the first shaft (<NUM>) and the second shaft (<NUM>), and in the second position, the third sealing member (<NUM>) seals between the first shaft (<NUM>) and the second shaft (<NUM>) by contacting the coupling ring on the second shaft (<NUM>).