Sealing structure and compressor

Abstract

The sealing structure comprises a shell, a rotating shaft, an impeller and a pull rod, a containing cavity is formed in the shell, and an air inlet communicating with the containing cavity is formed in the shell; the rotating shaft extends into the containing cavity from the side away from the air inlet and is connected with the shell. The impeller is arranged in the containing cavity and connected with the rotating shaft, an impeller air inlet channel is formed in the impeller, a first air inlet channel is formed between the impeller and the shell, the impeller air inlet channel communicates with the first air inlet channel, and a pressure reducing piece is arranged in the first air inlet channel and on one side of the shell; the pull rod penetrates through the center of the impeller, the impeller is fixed to the center of the rotating shaft, the pull rod is provided with a pull rod air inlet channel, the pull rod air inlet channel is communicated with the first air inlet channel, and the pull rod, the impeller and the rotating shaft are concentrically arranged. On the basis, the high-temperature and high-pressure gas in the containing cavity becomes high-temperature and low-pressure gas after being subjected to pressure reduction through the pressure reduction piece, so that the gas sealing effect between the impeller and the shell is achieved, and the possibility of gas leakage caused by gaps is reduced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of compressor sealing, and particularly relates to a sealing structure and a compressor. BACKGROUND

[0002] When a centrifugal air compressor is in operation, external air enters the compressor and is sucked into the inlet of the compressor impeller. The air in normal pressure is compressed to high pressure by high-speed rotation of the impeller and is delivered to the outlet of the compressor. Since the impeller is a rotating component, a certain gap is generated when it is assembled with other stationary components of the compressor. After being compressed by the impeller, the air becomes high-pressure and high-temperature gas. Due to the high pressure, the air will flow to the low-pressure area along the gap between the impeller shaft and the impeller disc, resulting in leakage, which will affect the supply amount of compressed air and the outlet pressure, and adversely affect the operation efficiency and reliability of the whole machine.

[0003] In order to reduce the leakage of the compressor gas, the conventional method is to increase sealing teeth on the rotating component impeller disc at the position where the gap is generated. The sealing teeth are arranged in sequence, so that a series of throttling gaps and expansion cavities are formed in each tooth, forming a labyrinth seal structure. The high-pressure gas leaked from the outlet of the impeller flows out through the sealing structure, and the throttling effect is achieved to reduce the gas leakage. Generally, the more the number of sealing teeth, the better the sealing effect. The patent with publication number CN218882539U proposes a kind of impeller mouth circle sealing structure and centrifugal compressor, which relates to the technical field of compressor sealing. The impeller mouth circle sealing structure includes a circular sealing body and a counter-rotating flow resistance screen. The sealing body is sleeved on the impeller. The inner wall of the sealing body is uniformly provided with sealing teeth. Adjacent two sealing teeth and the baffle form a sealing cavity. The sealing gap is formed between the sealing cavity and the outer surface of the impeller. The gas flows through the sealing gap. The counter-rotating flow resistance screen array is arranged at the inlet side of the sealing body. The impeller mouth circle sealing structure provided by the utility model can block the airflow at the inlet of the sealing body, significantly reduce the airflow velocity at the inlet of the sealing body, reduce the cross stiffness coefficient, improve the effective damping coefficient of the sealing body, and effectively improve the stability of the centrifugal compressor unit.

[0004] The above-mentioned patent uses sealing teeth for sealing. However, the processing of the sealing teeth requires high cost and increases the complexity of the structure, which also affects the structural strength of the impeller and the sealing device. UTILITY MODEL CONTENTS

[0005] The sealing structure and the compressor provided by the embodiments of the present application improve the sealing performance of the compressor.

[0006] According to a first aspect of the present application, the embodiments of the present application provide a sealing structure, which can include:

[0007] A housing, the housing is internally provided with a containing cavity, and is provided with an air inlet communicated with the containing cavity;

[0008] A rotating shaft, the rotating shaft extends into the containing cavity from a side away from the air inlet, and is connected with the housing;

[0009] A impeller, the impeller is arranged in the containing cavity and connected with the rotating shaft, the impeller is provided with an impeller air inlet channel, a first air inlet channel is formed between the impeller and the housing, the impeller air inlet channel and the first air inlet channel are communicated, and the first air inlet channel is provided with a pressure reducing piece on a side of the housing;

[0010] A pull rod, the pull rod is arranged through the center of the impeller and fixes the impeller on the center of the rotating shaft, the pull rod is provided with a pull rod air inlet channel, the pull rod air inlet channel and the first air inlet channel are communicated, and the pull rod, the impeller and the rotating shaft are concentrically arranged.

[0011] Optionally, a concave platform is arranged on a side of the housing close to the impeller and away from the impeller, the impeller is matched with the concave platform, and the pull rod air inlet channel is formed between the impeller and the concave platform.

[0012] Optionally, a top of the concave platform is smoothly arranged on a side of the impeller away from the first air inlet channel.

[0013] Optionally, the number of the impeller air inlet channels is multiple, and the multiple impeller air inlet channels are circumferentially and regularly arranged around the pull rod.

[0014] Optionally, the number of the pull rod air inlet channels is multiple, and the multiple pull rod air inlet channels are circumferentially and regularly arranged around the pull rod, the number of the pull rod air inlet channels is consistent with and corresponds to the number of the impeller air inlet channels.

[0015] Optionally, an included angle is formed between the impeller air inlet channel and an impeller tangent line, the included angle is an acute angle on a side of the rotating direction of the impeller, and the impeller tangent line is a tangent line at an intersection point between the impeller air inlet channel and an outer periphery of the impeller.

[0016] Optionally, a first gas containing cavity is formed between the impeller and the rotating shaft, and the impeller air inlet channel and the pull rod air inlet channel are communicated through the first gas containing cavity.

[0017] Optionally, a second gas containing cavity is formed between the impeller and the housing, and the first air inlet channel and the pull rod air inlet channel are communicated through the first gas containing cavity.

[0018] Optionally, the pressure reducing piece is a sealing tooth.

[0019] According to a second aspect of the present application, a compressor is provided, which can include:

[0020] The sealing structure of any one of the first aspect.

[0021] The technical scheme provided by the embodiment of the application at least brings the following beneficial effects:

[0022] The sealing structure and the compressor provided by the embodiment of the application have the following beneficial effects: the low-temperature high-pressure gas can flow along the pull rod air inlet channel and the impeller air inlet channel, the high-temperature high-pressure gas in the original containing cavity is reduced in pressure by the pressure reducing piece in the first air inlet channel and becomes high-temperature low-pressure gas, the low-temperature high-pressure gas and the high-temperature low-pressure gas can be mixed with each other because the first air inlet channel, the impeller air inlet channel and the pull rod air inlet channel are in communication with each other, the pressure of the low-temperature high-pressure gas flowing from the pull rod air inlet channel is higher than that of the high-temperature low-pressure gas from the first air inlet channel, and therefore the gas sealing effect between the impeller and the shell is achieved, and the possibility of gas leakage caused by the gap between the impeller and the shell is reduced.

[0023] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the application. BRIEF DESCRIPTION OF DRAWINGS

[0024] The accompanying drawings incorporated in the specification and forming a part of it illustrate the embodiments consistent with the present application and together with the description serve to explain the principles of the application, but not to limit the application.

[0025] Figure 1 is a structural schematic diagram of a sealing structure according to an exemplary embodiment;

[0026] Figure 2 is a top view of an impeller air inlet channel in a sealing structure according to an exemplary embodiment.

[0027] REFERENCE NUMERALS

[0028] Serial number Name Serial number Name 100 Sealing structure 110 Housing 111 Accommodating cavity 111a First gas inlet passage 111b Second gas accommodating cavity 111c Gas inlet 112 Pressure reducing member 113 Recess 120 Rotating shaft 130 Impeller 131 Impeller gas inlet passage 132 First gas accommodating cavity 140 Pull rod 141 Pull rod gas inlet passage DETAILED DESCRIPTION

[0029] In order to more clearly understand the above-mentioned purposes, features and advantages of the present disclosure, the schemes of the present disclosure will be further described below. It should be noted that the embodiments of the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0030] In the following description, a large number of specific details are set forth in order to facilitate a thorough understanding of the present disclosure, but the present disclosure can also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only some of the embodiments of the present disclosure, not all the embodiments.

[0031] Based on this, the application provides a sealing structure and a compressor. First, the sealing structure provided by the embodiments of the application is introduced below.

[0032] Embodiment 1;

[0033] Figure 1 A structural schematic diagram of a sealing structure provided by one embodiment of the application is shown. As shown in the figure, it can include the following structure: Figure 1

[0034] The housing 110 is internally provided with a containing cavity 111, and the containing cavity 111 is provided with an air inlet 111c through which the gas enters the containing cavity 111;

[0035] The rotating shaft 120 extends into the containing cavity 111 from the side away from the air inlet 111c and is connected with the housing 110;

[0036] The impeller 130 is disposed in the containing cavity 111 and is connected with the rotating shaft 120, the impeller 130 is provided with an impeller air inlet passage 131, a first air inlet passage 111a is formed between the impeller 130 and the housing 110, the impeller air inlet passage 131 and the first air inlet passage 111a are communicated, and the first air inlet passage 111a is provided with a pressure reducing piece 112 on one side of the housing 110;

[0037] The pull rod 140 is connected with the center of the impeller 130 and fixes the impeller 130 on the center of the rotating shaft 120, the pull rod 140 is provided with a pull rod air inlet passage 141, the pull rod air inlet passage 141 and the first air inlet passage 111a are communicated, and the pull rod 140, the impeller 130 and the rotating shaft 120 are concentrically arranged.

[0038] The housing 110 is internally provided with a containing cavity 111, and the containing cavity 111 is provided with an air inlet 111c through which the gas enters the containing cavity 111; the rotating shaft 120 extends into the containing cavity 111 from the side away from the air inlet 111c and is connected with the housing 110; the impeller 130 is disposed in the containing cavity 111 and is connected with the rotating shaft 120; the pull rod 140 is connected with the center of the impeller 130 and fixes the impeller 130 on the center of the rotating shaft 120; the impeller 130 can rotate in the containing cavity 111 through the rotating shaft 120. Among them, the first air inlet passage 111a is formed between the impeller 130 and the housing 110, the pressure reducing piece 112 is arranged on one side of the housing 110 in the first air inlet passage 111a; the impeller air inlet passage 131 is arranged on the impeller 130 and can be communicated with the first air inlet passage 111a; the pull rod air inlet passage 141 is arranged on the pull rod 140 and can be communicated with the impeller air inlet passage 131.

[0039] ​The gas in the compressor is compressed by the previous compression structure to form high-pressure air. The compressed gas is high in temperature. The high-temperature gas is cooled by the intercooler in the compressor, and the high-temperature and high-pressure gas becomes low-temperature and high-pressure gas, and then comes to the air inlet 111c. The high-temperature and high-pressure gas at the air inlet 111c can be divided into two parts to continue to flow. Most of the gas enters the containing cavity 111, and then does work with the rotation of the impeller 130. This part of the low-temperature and high-pressure gas is compressed again into high-temperature and high-pressure gas to continue to flow. Another part of the low-temperature and high-pressure gas flows to the pull rod air inlet channel 141. For the high-temperature and high-pressure gas in the containing cavity 111, it flows into the first air inlet channel 111a. Since the shell 110 is provided with the pressure reducing piece 112 in the first air inlet channel 111a, the pressure reducing piece 112 can reduce the pressure of the high-temperature and high-pressure gas in the first air inlet channel 111a, so that the high-temperature and high-pressure gas becomes high-temperature and low-pressure gas, thereby continuing to flow from the first air inlet channel 111a to the pull rod air inlet channel 141 through the impeller air inlet channel 131. The low-temperature and high-pressure gas in the pull rod air inlet channel 141 flows along the pull rod air inlet channel 141, the impeller air inlet channel 131, and the first air inlet channel 111a. Therefore, the high-temperature and low-pressure gas and the low-temperature and high-pressure gas converge at a certain position in the first air inlet channel 111a, the impeller air inlet channel 131, or the pull rod air inlet channel 141. Since the low-temperature and high-pressure gas flowing from the pull rod air inlet channel 141 has higher pressure than the high-temperature and low-pressure gas from the first air inlet channel 111a, the gas sealing effect between the impeller 130 and the shell 110 is achieved, and the possibility of gas leakage due to the gap between the impeller 130 and the shell 110 is reduced. At the same time, since the pressure of the gas before passing through the pressure reducing piece 112 is higher than the pressure of the gas flowing into the pull rod air inlet channel 141, the possibility of gas backflow can be reduced.

[0040] Furthermore, the low-temperature and high-pressure gas flowing into the pull rod air inlet channel 141 can also be used for cooling the pull rod 140, the rotating shaft 120, and the impeller 130.

[0041] Preferably, the sealing piece can be a sealing tooth. The sealing tooth is a non-metallic or metallic element designed in the sealing device, which is usually arranged in a ring shape to form a series of throttling gaps and expansion cavities. These gaps and cavities work together to produce a throttling effect when the sealed medium passes through, thereby achieving the purpose of leakage prevention.

[0042] Optionally, in an example, the side of the shell 110 close to the impeller 130 is provided with a concave platform 113 facing away from the impeller 130. The impeller 130 is matched with the concave platform 113, and the pull rod air inlet channel 141 is formed between the impeller 130 and the concave and convex.

[0043] By setting a recess 113 on the side of the shell 110 close to the impeller 130, the recess 113 can match the shape of the impeller 130, and the impeller 130 can be placed in the cavity formed by the recess 113, thereby saving the internal space of the containing cavity 111, allowing more gas to be contained in the containing cavity 111, and allowing the impeller 130 to work on more gas.

[0044] Optionally, in an example, the side of the impeller 130 away from the first gas inlet passage 111a is smoothly arranged with the top of the recess 113. By smoothly arranging the side of the impeller 130 away from the first gas inlet passage 111a with the top of the recess 113, it helps to reduce the resistance of the gas in the containing cavity 111. This smooth transition reduces vortex and turbulence, allowing the gas to be more efficiently warmed by the impeller 130.

[0045] Optionally, in an example, the number of impeller gas inlet passages 131 is multiple, and the multiple impeller gas inlet passages 131 are arranged in a circular array around the pull rod 140. By arranging multiple impeller gas inlet passages 131, the gas can flow through the multiple impeller gas inlet passages 131, thereby improving the flowability of the low-temperature high-pressure gas, and allowing more low-temperature high-pressure gas to interact with the high-temperature low-pressure gas in a unit of time, thereby improving the gas sealing effect.

[0046] Optionally, in an example, the number of pull rod gas inlet passages 141 is multiple, and the multiple pull rod gas inlet passages 141 are arranged in a circular array around the pull rod 140, and the number of pull rod gas inlet passages 141 is consistent with and corresponds to the number of impeller gas inlet passages 131. Similarly, by arranging multiple pull rod gas inlet passages 141, more low-temperature high-pressure gas can flow through the pull rod gas inlet passages 141 to the impeller gas inlet passages 131, and the gas sealing effect can be further improved. Moreover, each pull rod gas inlet passage 141 has a corresponding impeller gas inlet passage 131, and the low-temperature high-pressure gas can flow through the pull rod gas inlet passage 141 to the impeller gas inlet passage 131.

[0047] Further, the pull rod gas inlet passage 141 can include a first branch and a second branch connected to each other, and the number of the second branches is multiple, and the multiple second branches are arranged in a circular array on the pull rod 140. Moreover, each second branch corresponds to and communicates with an impeller gas inlet passage 131.

[0048] Optionally, as Figure 2A sealed structure 100 is shown in a top view of an impeller inlet passage 131. The impeller 130 rotates in a counterclockwise direction. In an example, the impeller inlet passage 131 is formed at an angle with a tangent of the impeller 130. The angle is an acute angle on one side of the direction of rotation of the impeller 130. The tangent of the impeller 130 is a tangent of the impeller inlet passage 131 at a point of intersection of the impeller inlet passage 131 and the outer periphery of the impeller 130. The impeller 130 has a circular cross section. The impeller inlet passage 131 formed in the impeller 130 is formed at an angle with the tangent of the cross section of the impeller 130. The impeller 130 rotates in a first direction. The angle in the first direction is an acute angle. That is, the direction of inclination of the impeller inlet passage 131 is consistent with the direction of rotation of the impeller 130. Thus, the low-temperature and high-pressure gas in the impeller inlet passage 131 can flow better while the impeller 130 rotates, thereby reducing the gas pressure loss of the low-temperature and high-pressure gas in the impeller inlet passage 131.

[0049] Embodiment 2:

[0050] A first gas containing cavity 132 is formed between the impeller 130 and the rotating shaft 120. The impeller inlet passage 131 and the pull rod inlet passage 141 are connected through the first gas containing cavity 132. The impeller 130 and the rotating shaft 120 are specially designed so that when the impeller 130 is installed on the rotating shaft 120, the first gas containing cavity 132 is formed between the impeller 130 and the rotating shaft 120. The impeller inlet passage 131 and the pull rod inlet passage 141 are both connected to the first gas containing cavity 132. The low-temperature and high-pressure gas entering from the pull rod inlet passage 141 first enters the first gas containing cavity 132 and then enters the impeller inlet passage 131. At the same time, the first gas containing cavity 132 is provided to increase the installation operation space and facilitate the installation between the impeller 130 and the rotating shaft 120.

[0051] Optionally, a second gas containing cavity 111b is formed between the impeller 130 and the shell 110. The first inlet passage 111a and the pull rod inlet passage 141 are connected through the first gas containing cavity 132. A groove is provided on the side of the shell 110 close to the impeller 130. After the impeller 130 is installed on the rotating shaft 120, the second gas containing cavity 111b is formed between the impeller 130 and the shell 110. The high-temperature and low-pressure gas obtained by pressure reduction through the first inlet passage 111a can flow into the second gas containing cavity 111b. The low-temperature and high-pressure gas flowing from the pull rod inlet passage 141 also flows into the second gas containing cavity 111b along the pull rod inlet passage 141, the first gas containing cavity 132, and the impeller inlet passage 131. The high-temperature and low-pressure gas and the low-temperature and high-pressure gas interact in the second gas containing cavity 111b, thereby forming a gas seal between the impeller 130 and the shell 110.

[0052] Further, by arranging the first gas containing cavity 132 and the second gas containing cavity 111b on both sides of the impeller inlet channel 131, the gas flow is facilitated, and the total pressure is minimized and the static pressure is maximized.

[0053] The above-mentioned embodiment 2 can include and implement all the structures and implementation processes in embodiment 1, and can achieve the same technical effects. To avoid repetition, details are not described here.

[0054] Embodiment 3:

[0055] A compressor can include any one of the sealing structures 100 in the above-mentioned embodiments 1 and / or 2, and implement any one of the implementation processes in the above-mentioned embodiments 1 and / or 2, and can achieve the same technical effects. To avoid repetition, details are not described here.

[0056] The above is only a specific implementation of the present application, and those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the above-mentioned system, module and unit can refer to the corresponding process in the foregoing method embodiments, which will not be described here. It should be understood that the protection scope of the present application is not limited to this, and any person skilled in the art can easily think of various equivalent modifications or replacements within the technical range disclosed in the present application, and these modifications or replacements should be covered within the protection scope of the present application.

Claims

1. A seal structure, characterized by, The structure comprises: a housing, which is internally provided with a containing cavity and is provided with an air inlet opening communicated with the containing cavity; a rotating shaft, which extends into the containing cavity from a side away from the air inlet opening and is connected with the housing; a vane wheel, which is arranged in the containing cavity and is connected with the rotating shaft, the vane wheel is provided with a vane wheel air inlet channel, a first air inlet channel is formed between the vane wheel and the housing, the vane wheel air inlet channel and the first air inlet channel are communicated, and the housing is provided with a pressure reducing piece on a side in the first air inlet channel; a pull rod, which is arranged through the center of the vane wheel, fixes the vane wheel on the center of the rotating shaft, and is provided with a pull rod air inlet channel, the pull rod air inlet channel and the first air inlet channel are communicated, and the pull rod, the vane wheel and the rotating shaft are concentrically arranged.

2. The structure of claim 1, wherein A concave platform is arranged on a side of the housing close to the vane wheel and away from the vane wheel, the vane wheel is matched with the concave platform, and the pull rod air inlet channel is formed between the vane wheel and the concave platform.

3. The structure of claim 2, wherein A top of the concave platform is smoothly arranged on a side of the vane wheel away from the first air inlet channel.

4. The structure of claim 1, wherein The number of the vane wheel air inlet channels is multiple, the multiple vane wheel air inlet channels are circumferentially and regularly arranged around the pull rod.

5. The structure of claim 4, wherein The number of the pull rod air inlet channels is multiple, the multiple pull rod air inlet channels are circumferentially and regularly arranged around the pull rod, the number of the pull rod air inlet channels is consistent with and corresponds to the number of the vane wheel air inlet channels.

6. The structure of claim 4, wherein An included angle is formed between the vane wheel air inlet channel and a tangent line of the vane wheel, the included angle is an acute angle on a side in the rotation direction of the vane wheel, and the tangent line is a tangent line of an intersection point between the vane wheel air inlet channel and an outer periphery of the vane wheel.

7. The structure of claim 1, wherein A first gas containing cavity is formed between the vane wheel and the rotating shaft, and the vane wheel air inlet channel and the pull rod air inlet channel are communicated through the first gas containing cavity.

8. The structure of claim 7, wherein A second gas containing cavity is formed between the vane wheel and the housing, and the first air inlet channel and the pull rod air inlet channel are communicated through the first gas containing cavity.

9. The structure of claim 1, wherein The pressure reducing piece is a sealing tooth.

10. A compressor characterized by, The compressor comprises the sealing structure according to any one of claims 1-9.

Images