KR20250060140A - Apparatus for sealing drive shaft - Google Patents

Abstract

The present invention discloses a rotary shaft sealing device installed between a blower including a drive shaft rotated by a drive motor, an impeller connected to the drive shaft by an axial joint to rotate, and a casing accommodating the impeller, the rotary shaft sealing device comprising: a sleeve fixed to an outer surface of the drive shaft via a packing, a seal housing covering the outer surface of the sleeve and having a plurality of sealing grooves arranged in the longitudinal direction of the drive shaft on an inner surface thereof, a plurality of seals arranged in the longitudinal direction of the drive shaft and divided into a plurality of segments so as to be able to expand radially between the sleeve and the seal housing, and an annular garter spring inserted into a spring groove on the outer surface of the seal to support a plurality of seals and an annular gap between the segments of the seals.

Description

{APPARATUS FOR SEALING DRIVE SHAFT}

The present invention relates to a sealing device for a drive shaft used for the purpose of transmitting power by directly rotating the shaft, and more specifically, to a rotary shaft sealing device for preventing leakage of process fluid such as air, steam, gas, or powder.

In general, the mechanical vapor recompression (MVR) system is a waste heat recovery process that evaporates low-temperature, low-pressure waste heat steam that is used and discarded in the production process in an evaporator using external power, compresses it into high-temperature, high-pressure steam, and reuses it as a heating source required in the production process.

These mechanical vapor recompression systems are equipped with transport devices such as blowers and pumps that transport vapor by the rotation of an electric motor.

That is, the transport device is fixed to the motor shaft of the electric motor and rotates the intake portion of the casing to draw air or steam into the casing by the passing impeller, and the steam compressed between the casing and the impeller is discharged to the outside of the casing through the discharge port.

However, in the past, there was a problem in that process fluids such as steam and gas discharged from the transfer device would leak toward the MVR system, deforming the journal and thrust bearings and drive shafts installed between them, and also reducing the lifespan of precision parts as foreign substances (scale) were attached or generated on the outer surface.

To solve this problem, a so-called mechanical seal is installed between the drive shaft connecting the impeller and the electric motor and the fixed housing to prevent the process fluid from leaking out.

However, these mechanical seals for drive shafts have a problem in that they are difficult to completely block the leakage of process fluids because they are subject to wear and damage due to friction with the drive shaft and heat generated when rotating at high speeds, which significantly reduces sealing performance.

In addition, mechanical seals have a mechanical characteristic that their sealing properties deteriorate under high pressure, so if they continue to rotate while high temperature and high pressure process fluids and powders are introduced into the contact surface between the rotor and the stator, i.e. the seal face, the internal pressure increases, and thus they have a limitation in not being able to continuously maintain sealing properties.

The background technology or prior art described herein is information that the inventor possesses or acquired in the process of deriving and completing the present invention, and is helpful in understanding the technical significance of the present invention and is useful for prior art searches and examinations, and is only stated here, and does not mean technology that was generally known and widely used in the technical field to which the present invention belongs prior to the filing of the present invention.

KR 10-2024-0141558 A 2024. 09. 27. KR 10-2029781 B1 2019. 10. 01. KR 10-2279237 B1 2021. 07. 13.

Accordingly, the inventor of the present invention comprehensively considered the above-mentioned matters and, at the same time, sought to solve the technical limitations and problems of the existing mechanical seal for a drive shaft by circulating a barrier fluid (compressed air, inert gas, nitrogen, etc.) for maintaining sealing in the gap between the drive shaft and the seal ring at a higher pressure than a process fluid such as steam or gas while the sealing surface of the sealing ring is in loose contact with the drive shaft, thereby forming a thin fluid dynamic lubricating surface and an airtight blocking layer (air proof), thereby preventing the process fluid or powder from leaking along the drive shaft and maintaining sealing performance, and furthermore, when the process fluid or powder flows between the drive shaft and the sealing ring, it can be sucked in and removed by the negative pressure action to protect against contamination. As a result, the inventor of the present invention has made great efforts and continued research to develop a new structure of a rotary shaft sealing device.

Therefore, the technical problem and purpose to be solved by the present invention is to provide a rotary shaft sealing device that can prevent leakage of process fluid or powder by providing a physical barrier between a drive shaft and a seal at a pressure higher than that of the process fluid.

Another technical problem and object of the present invention is to provide a rotary shaft sealing device capable of sucking and removing process fluid or powder introduced between a drive shaft and a seal by negative pressure.

The technical problems and objectives to be solved by the present invention are not limited to the technical problems and objectives mentioned above, and other technical problems and objectives not mentioned will be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

In order to solve the technical problem of the present invention as described above and to effectively achieve a specific technical purpose, a specific means according to an embodiment of the present invention is a rotary shaft sealing device installed between a transport device including a drive shaft rotated by a drive motor, an impeller connected to the drive shaft by a shaft coupling and rotating, and a casing accommodating the impeller, the rotary shaft sealing device comprising: a sleeve fixed to the outer surface of the drive shaft by means of packing; a seal housing covering the outer surface of the sleeve and having a plurality of sealing grooves arranged in the longitudinal direction of the drive shaft on the inner surface; a plurality of seal rings divided into a plurality of segments so as to be able to expand radially between the sleeve and the seal housing and accommodated in the sealing grooves of the seal housing and arranged in the longitudinal direction of the drive shaft; and an annular gap between the segments of the seal rings to support the sealing. A rotary shaft sealing device is presented, characterized by including an annular garter spring inserted into a spring groove on an outer surface.

Accordingly, the present invention can minimize leakage of process fluid by maintaining the sealing surface in direct contact with the drive shaft or in a loose contact state through a change of direction.

In addition, a preferred embodiment (aspect) of the present invention comprises a chamber formed on the inner surface of the seal housing between the seals, an inlet formed in the seal housing so as to communicate with the chamber for injecting a barrier fluid into the gap between the sleeve and the seal housing through the chamber, and an outlet formed in the seal housing so as to communicate with the chamber for discharging the barrier fluid injected through the inlet, thereby circulating a barrier fluid (compressed air, inert gas, nitrogen, etc.) for maintaining sealing in the gap between the drive shaft and the seal ring at a higher pressure than a process fluid such as steam or gas, thereby forming a thin fluid dynamic lubricating surface and an airtight barrier layer (air proof), thereby reliably blocking the process fluid or powder from leaking along the drive shaft and maintaining sealing performance.

In addition, a preferred embodiment (aspect) of the present invention further includes an intake formed in the seal housing so as to communicate with the inner surface of the seal housing to suction and remove process fluid or powder particles flowing into the gap between the sleeve and the seal housing by negative pressure action, so that even if process fluid or powder particles unexpectedly flow into the gap between the drive shaft and the seal, they can be quickly suctioned and removed by negative pressure action.

In addition, a preferred embodiment (aspect) of the present invention further includes a surge proof that is formed by protruding from one end edge of the sleeve and an outer peripheral surface of the sleeve corresponding to the position of the chamber, so that even if the pressure or flow rate of the barrier fluid flowing through the gap between the sleeve and the seal housing changes rapidly, the flow of the process fluid or powder escaping through the suction port is not affected, so that even if the pressure or flow rate of the barrier fluid changes rapidly, the process fluid or powder can smoothly escape through the suction port.

In addition, a preferred embodiment (aspect) of the present invention further comprises a detent built into the sealing groove of the seal housing and resisting a force for moving the seal to maintain the operating position and operating stroke of the seal constant, so that the sealing surface of the seal can maintain a loose contact state through direct contact or change of direction with the sleeve, thereby minimizing leakage of the process fluid.

According to an embodiment that implements the technical idea on which the unique solution is based in order to solve the technical problem of the present invention, a barrier fluid (compressed air, inert gas, nitrogen, etc.) for maintaining sealing is circulated in the gap between the sleeve and the seal housing at a higher pressure than the process fluid such as steam or gas, thereby forming a thin fluid dynamic lubricating surface and a physical barrier (air proof), thereby blocking the process fluid or powder from leaking along the drive shaft, thereby maintaining sealing performance.

In addition, since the sealing surface maintains a loose contact state with the sleeve through direct contact or change of direction depending on the flow of the barrier fluid, leakage of the process fluid can be minimized.

In addition, even if process fluid or powder particles enter the gap between the sleeve and the seal housing, they are sucked and removed by negative pressure action, thereby protecting against contamination and greatly extending the service life.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by a person skilled in the art to which the present invention pertains from the description of the claims.

FIG. 1 is a drawing for easily explaining a transport device in which a rotary shaft sealing device according to an embodiment of the present invention is installed.
FIG. 2 is a perspective view showing a rotary shaft sealing device according to an embodiment of the present invention.
FIG. 3 is a perspective view showing a part of a rotary shaft sealing device according to an embodiment of the present invention in an exploded manner.
FIG. 4 is a perspective view showing the main components of a rotary shaft sealing device according to an embodiment of the present invention.
FIG. 5 is a longitudinal cross-sectional view showing a rotary shaft sealing device according to an embodiment of the present invention.
FIG. 6 is a cross-sectional view to help understand the operating state of a rotary shaft sealing device according to an embodiment of the present invention.

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

Prior to this, it should be noted that the terms described below have been defined in consideration of their functions in the present invention, and should be interpreted as concepts consistent with the technical idea of the present invention and meanings commonly used or commonly recognized in the relevant technical field.

In addition, if it is determined that a detailed description of a known function or configuration related to the present invention may obscure the gist of the present invention, the detailed description is omitted.

The drawings attached herein may be exaggerated or simplified in some parts for the purpose of explaining the composition of the technology, the operation and working principles of the technology, for ease of understanding, and for clarity of the technology, and it is disclosed that each component in the drawings does not exactly match the actual size and shape.

In addition, the term and/or in this specification means a combination of a plurality of related described items or including any item among a plurality of related described items, and when it is said that a part includes a certain component, this does not mean that other components are excluded, but rather that other components may be further included, unless specifically stated otherwise.

That is, the terms “include,” “have,” etc., set forth in this specification should be understood to mean the presence of a feature, number, step, process, operation, component, part, or combination thereof, but not to exclude the possibility of the presence or addition of one or more other features, numbers, steps, processes, operations, components, parts, or combinations thereof.

Additionally, each process and step may occur in a different order than stated, unless the context clearly dictates otherwise. That is, each process and step may occur in the same order as stated, may be performed substantially simultaneously, or may be performed in the opposite order.

Meanwhile, the meaning of "part" and "unit" used in the present invention means a module type that performs a unit or role that processes at least one function or certain operation intended for a device or system, and this can be implemented by means such as hardware or software, or a combination of hardware and software, or a device or assembly that can perform independent operations.

And the meaning of "module" used in the present invention can mean a unit including one or more combinations of hardware and software, and can be used interchangeably with terms such as unit and component, and can be the minimum unit of an integrally configured component or a part thereof, can be the minimum unit or a part thereof that performs one or more functions, and can be implemented mechanically or electronically.

In addition, terms such as top, bottom, upper surface, lower surface, or upper, lower, upper side, lower side, front/back, left/right, etc. used in the present invention are used for convenience in distinguishing the relative positions of each component or in explaining the direction of movement. For example, the upper part in a drawing may be named or referred to as the upper part and the lower part as the lower part, and the length direction may be named or referred to as the front/back direction, and the width direction may be named or referred to as the left/right direction.

Additionally, the terms first, second, etc. used in the present invention can be used to describe various components. That is, the terms first, second, etc. can be used only for the purpose of distinguishing one component from another component.

[Best mode for carrying out the invention]

A rotary shaft sealing device (100) according to an embodiment of the present invention is installed between a drive shaft (30) rotated by a drive motor (10) and a transport device (20), as shown in FIG. 1.

Here, the transport device (20) is configured to include a drive shaft (30) and a rotating impeller (23) connected by an axial coupling, and a casing (25) that accommodates the impeller (23).

And the transport device (20) includes a driving motor (10) and a bearing module (40).

The drive motor (10) operates when power is supplied and provides rotational power to the drive shaft (30).

The bearing module (40) fixes the drive shaft (30) at a fixed position and supports the load applied to the drive shaft (30) while reducing frictional resistance to enable smooth rotation by the drive motor (10).

That is, the transport device (20) forcibly transports process fluids such as steam or gas, or powder or powder, by generating suction force through the rotation of the impeller (23) connected to the drive shaft (30) by the rotational driving force of the drive motor (10).

At this time, process fluids such as steam or gas or powder or powder flowing into the casing (25) of the transport device (20) are discharged through the discharge port (27).

The main elements constituting the rotary shaft sealing device (100) according to the embodiment of the present invention include a sleeve (110), a seal housing (120), a seal (130), a garter spring (140), and a detent (150) as shown in FIGS. 2 to 6.

The sleeve (110) is formed in a cylindrical shape and is fixed to the outer surface of the drive shaft (30) via a plurality of ring-shaped packings (111).

That is, the packing (111) is mounted on the contact surface between the inner surface of the sleeve (110) and the outer surface of the drive shaft (30) to stably seal the space between them.

And, a surge proof (112) is formed protruding on one end edge of the sleeve (110) and on the outer surface of the sleeve (110) corresponding to the position of the chamber (122) on the inner surface of the housing (120).

That is, the surge proof (112) serves to buffer the flow of process fluid or powder that escapes through the suction port (125) of the seal housing (120) so that it does not affect the flow even if the pressure or flow rate of the barrier fluid flowing through the gap between the sleeve (110) and the seal housing (120) changes rapidly.

And, at one end edge of the sleeve (110), a flange (113) for flange coupling (flange union) that is connected to the impeller (23) of the transport device (20) using bolts or the like is integrally formed.

The seal housing (120) is formed in a cylindrical shape to cover the outer surface of the sleeve (110), and on its inner surface, a plurality of sealing grooves (121) are formed at regular intervals in the axial direction of the drive shaft (30).

That is, the inner surface of the seal housing (120) is arranged with a certain gap from the outer surface of the sleeve (110) so that no contact interference occurs when the drive shaft (30) rotates, and the sealing grooves (121) are arranged adjacent to each other along the axis of the drive shaft (30).

And a chamber (122) is formed in the center of the inner surface of the housing (120).

That is, the chamber (122) is formed between the sealing rings (130) on the inner surface of the housing (120).

Additionally, an injection port (123) is formed in the housing (120) to allow the chamber (122) to communicate with the outside.

That is, the injection port (123) is perforated in the seal housing (120) to inject barrier fluid into the gap between the sleeve (110) and the seal housing (120) through the chamber (122).

Here, the injection port (123) can be connected to a nozzle or nipple of a separate device such as a compressor (C).

Additionally, the housing (120) is provided with an exhaust port (124) that allows the chamber (122) to communicate with the outside.

That is, the discharge port (124) is opened in the housing (120) to discharge the barrier fluid injected through the injection port (123) through the chamber (122).

Additionally, the housing (120) has a suction port (125) formed to allow the inner surface to communicate with the outside.

That is, the suction port (125) is opened in the housing (120) to suction and remove process fluid or powder flowing into the gap between the sleeve (110) and the housing (120) by negative pressure.

Here, the suction port (125) can be connected to a nozzle of a separate device such as a suction device (S) or a nipple.

And, at one end edge of the housing (120), a flange (126) for flange coupling (flange union) that is connected to the casing (25) of the transport device (20) using bolts or the like is integrally formed.

The sealing (130) is divided into several segments so as to be able to expand radially between the sleeve (110) and the sealing housing (120), and is accommodated in the sealing groove (121) of the sealing housing (120).

And the sealing (130) completely or partially closes the leak path by forming a boundary between it and the sleeve (110).

That is, the sealing (130) is arranged at a predetermined interval in the axial direction of the drive shaft (30) so that the inner periphery of the sealing surface seals the gap between the sleeve (110) and the sealing housing (120) by contact pressure to prevent the process fluid from leaking between the sleeve (110) that rotates together with the drive shaft (30) and the fixed sealing housing (120) through which the drive shaft (30) passes.

And, a spring home (131) is formed on the outer surface of the sealing (130) for inserting and mounting a part of a garter spring (140).

Here, the sealing (130) is preferably formed of a carbon material for machine structures that is chemically stable, wear-resistant, self-lubricating, and has the characteristics of being a good conductor of heat and resistant to heat changes.

The garter spring (140) is formed in an annular shape and is mounted on the outer surface of the sealing ring (130) to support the annular gap between the segments of the sealing ring (130).

That is, a portion of the garter spring (140) is inserted into a spring home (131) formed on the outer surface of the sealing (130).

The detent (150) is built into the sealing groove (121) of the seal housing (120) while being connected to the outer surface of the sealing (130) by the garter spring (140).

That is, the detent (150) is fixed to one side of the outer surface of the sealing (130) and acts to resist the force that moves the sealing (130) and to maintain the operating position and operating stroke of the sealing (130) constant.

[Operating Principle and Function]

The main actions, operating principles, and functions of the rotary shaft sealing device according to the embodiment of the present invention configured as described above are as follows.

First, as shown in Fig. 6, the injection port (123) of the housing (120) is connected to a nozzle of a separate device, such as a compressor (C), by a nipple, etc., so that the barrier fluid supplied from the compressor (C) is injected through the injection port (123), flows through the gap between the sleeve (110) and the housing (120), and is then discharged to the outside through the discharge port (124).

That is, a barrier fluid for maintaining sealing, such as compressed air, an inert gas, or nitrogen, is forcibly circulated at a higher pressure than the process fluid in the gap between the sleeve (110) and the seal housing (120) to form a thin fluid dynamic lubricating surface and a physical barrier (air proof), thereby preventing the process fluid, powder, or powder from leaking along the length direction of the drive shaft (30), thereby maintaining sealing performance.

In addition, the suction port (125) of the seal housing (120) is connected to a nozzle of a separate device such as a suction device (S) and a nipple, so that process fluid or powder flowing into the gap between the sleeve (110) and the seal housing (120) can be suctioned and removed by negative pressure.

That is, even if process fluid or powder particles are introduced into the gap between the sleeve (110) and the seal housing (120) due to long-term use, etc., they are forcibly sucked and removed by the negative pressure of the suction device (S), thereby protecting against contamination and greatly extending the service life.

Moreover, when the transport device (20) is started, the sealing surface of the sealing (130) is kept in loose contact with the sleeve (110) by the barrier fluid flowing through the gap between the sleeve (110) and the seal housing (120), so as not to impede the rotation of the drive shaft (30), and when the operation of the transport device (20) is terminated, the sealing surface of the sealing (130) is in direct contact with the sleeve (110), so that leakage of the process fluid can be minimized.

Meanwhile, the present invention is not limited to the above-described embodiment and the attached drawings, and can be variously modified and applied in various ways not illustrated within the scope that does not depart from the technical spirit of the present invention, and it is obvious to a person having ordinary skill in the art to which the present invention pertains that it can be widely applied by changing each component and equivalent other embodiment.

Therefore, the contents related to modifying and applying the technical features of the present invention should be interpreted as being included within the technical idea and scope of the present invention.

10: Drive motor 20: Blower
30: Drive shaft 40: Bearing
100: Rotating shaft sealing device 110: Sleeve
111: Packing 112: Surgeproof
113: Flange 120: Housing
121: Ceiling Home 122: Chamber
123: Inlet 124: Outlet
125: Inlet 126: Flange
130: Ceiling 131: Spring Home
140: Garter Spring 150: Detent

Claims (5)

A rotary shaft sealing device installed between a transport device including a drive shaft that is rotated by a driving motor, an impeller that is connected to the drive shaft by a shaft coupling and that rotates, and a casing that accommodates the impeller,
The above rotary shaft sealing device,
A sleeve fixed to the outer surface of the above drive shaft by means of packing;
A seal housing covering the outer circumference of the sleeve and having a plurality of sealing grooves formed on the inner surface in the axial direction of the drive shaft;
A plurality of seal rings, each of which is divided into a plurality of segments so as to be radially expandable between the sleeve and the seal housing and each of which is accommodated in a sealing groove of the seal housing; and
An annular garter spring mounted on the outer surface of the seal to support the annular gap between the segments of the seal;
A rotary shaft sealing device characterized by including a.
In the first paragraph,
A chamber formed in the center of the inner surface of the above housing;
An inlet formed in the housing so that the chamber communicates with the outside to inject a barrier fluid into the gap between the sleeve and the housing; and
An outlet formed in the chamber to communicate with the outside to discharge the barrier fluid injected through the injection port;
A rotary shaft sealing device characterized by further including:
In the second paragraph,
An intake formed in the seal housing so that the inner surface of the seal housing is connected to the outside to remove process fluid or powder flowing into the gap between the sleeve and the seal housing by suction using negative pressure;
A rotary shaft sealing device characterized by further including:
In the third paragraph,
Surge proof, which is formed by protruding from one end edge of the sleeve and the outer surface of the sleeve corresponding to the position of the chamber, so that even if the pressure or flow rate of the barrier fluid flowing through the gap between the sleeve and the seal housing changes rapidly, it does not affect the flow of the process fluid or powder escaping through the suction port;
A rotary shaft sealing device characterized by further including:
In the first paragraph,
A detent built into the sealing groove of the above seal housing and resisting the force for moving the seal to maintain the operating position and operating stroke of the seal constant;
A rotary shaft sealing device characterized by further including:

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