Impeller sealing structure and compressor

Abstract

The impeller sealing structure comprises an impeller and a sealing baffle, two circles of protruding teeth are arranged on the side face, opposite to the sealing baffle, of the impeller at intervals, and therefore a cavity is formed between the impeller and the sealing baffle. The impeller is provided with a spiral flow channel in the cavity, and the rotating direction of the spiral flow channel is opposite to the rotating direction of the impeller. The cavity is formed in the original sealing face of the impeller, the spiral flow channel can actually achieve a comb-tooth-shaped sealing effect, large energy loss can be generated in the gas leakage process, the spiral channel with the spiral direction opposite to the rotating direction is arranged, leaked gas flows relatively, and therefore the sealing effect of the impeller is improved. Therefore, the turbulence degree of the leaked gas is increased, the consumption of the leaked gas is increased, and the leakage amount is further reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of compressors, in particular to an impeller sealing structure and a compressor. Background Art

[0002] The energy efficiency of a centrifugal compressor is an important indicator to measure the quality of a compressor. In order to achieve higher energy efficiency, it is necessary to reduce the leakage loss inside the compressor. A centrifugal compressor is a speed-type compressor. Comb teeth are set between the rotating parts and the fixed parts. The fluid passes through a channel composed of many throttling gaps and expansion cavities. After multiple throttling, a large energy loss is generated, which greatly reduces the fluid pressure head and makes it difficult for the fluid to leak, so as to achieve the purpose of sealing. Therefore, the comb teeth can effectively reduce leakage losses.

[0003] However, there is a gap between the comb teeth as a stationary part and the rotating part, so there is still some leakage in the comb teeth part. In order to achieve higher energy efficiency, it is necessary to optimize the overall internal comb tooth structure.

[0004] In view of the above shortcomings, a new sealing structure is proposed to achieve the purpose of enhancing sealing and reducing leakage. Utility Model Content

[0005] In order to solve the technical problem of low impeller sealing efficiency in the above-mentioned prior art, the utility model provides an impeller sealing structure and a compressor.

[0006] The technical solution adopted by the utility model is:

[0007] The utility model proposes an impeller sealing structure, comprising: an impeller and a sealing baffle arranged on the sealing side of the impeller, characterized in that two circles of protruding teeth are arranged on the sealing side of the impeller to form a cavity between the impeller and the sealing baffle, and a spiral flow channel with a rotation direction opposite to the rotation direction of the impeller is arranged in the cavity.

[0008] The two circles of protruding teeth have the center of the impeller as the center of the circle, and the cavity between the two circles of protruding teeth is a circular ring cavity.

[0009] A spiral tooth is provided on the sealing side of the impeller and between two circles of the protruding teeth. The spiral tooth forms the spiral flow channel with the center of the impeller as the spiral center.

[0010] The thickness of the protruding teeth is four to six times the thickness of the spiral teeth.

[0011] The number of spiral turns of the spiral teeth is at least 9.

[0012] The distance between the inner wall surface of the protruding teeth of the outer ring and the outer wall surface of the protruding teeth of the inner ring is in the range of 1-1.5 mm.

[0013] The ratio of the distance d1 between the outer wall surface of the outer ring protrusion and the inner wall surface of the inner ring protrusion to the distance d2 between the inner wall surface of the outer ring protrusion and the outer wall surface of the inner ring protrusion is less than or equal to 1.4.

[0014] The impeller cover portion of the impeller is opposite to the sealing baffle, and the gap between the impeller cover and the sealing baffle is in the range of 0.05-0.15 mm.

[0015] The sealing baffle comprises a front sealing baffle and a rear sealing baffle, which are respectively arranged on the front and rear sides of the impeller cover. The cavity and the spiral flow channel are arranged on the front and rear sides of the impeller facing the front sealing baffle and the rear sealing baffle.

[0016] The present invention also provides a compressor, comprising the impeller sealing structure mentioned above.

[0017] Compared with the prior art, the utility model has the following advantages:

[0018] The sealing structure of the present invention is directional. The direction of the spiral flow channel is opposite to the direction of rotation. When the rotating part rotates, the fluid on the surface of the rotating part will be driven to rotate due to the viscosity of the flow. Under the action of the spiral flow channel, there is a tendency to move from the low-pressure side to the high-pressure side, thereby conflicting with the direction of gas leakage and increasing the fluid pressure in the sealed cavity. Therefore, when the part rotates, the resistance to gas leakage will increase, thereby improving the sealing effect. At the same time, due to the characteristics of the sealing structure and the radial arrangement, the fluid will be affected by centrifugal force, so the higher the rotation speed of the rotating part, the better the sealing effect.

[0019] Compared with the traditional structure, this structure not only consumes the energy of the fluid by throttling and expansion, but also increases the consumption of the interaction between the fluids themselves. Therefore, under the condition of the same number of teeth (length), this structure has a more significant sealing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0021] Figure 1 It is a partial cross-sectional view of the impeller and the front and rear sealing baffles in the embodiment of the utility model;

[0022] Figure 2 It is a partial cross-sectional view of the cooperation between the impeller and the rear sealing baffle in the embodiment of the utility model;

[0023] Figure 3 It is a partial cross-sectional view of the cooperation between the impeller and the front sealing baffle in the embodiment of the utility model;

[0024] Figure 4 This is a front structural schematic diagram of the impeller in the embodiment of the utility model;

[0025] Figure 5 This is a schematic diagram of the back structure of the impeller in the embodiment of the utility model;

[0026] 1. Impeller;

[0027] 11. Raised teeth; 12. Spiral teeth;

[0028] 21. Front sealing baffle;

[0029] 22. Rear sealing baffle;

[0030] 31. Cavity;

[0031] 32. Spiral flow channel. DETAILED DESCRIPTION

[0032] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0033] The principle and structure of the present utility model are described in detail below with reference to the accompanying drawings and embodiments.

[0034] A centrifugal compressor is a speed-type compressor. Comb teeth are set between the rotating parts and the fixed parts. The fluid passes through a channel composed of many throttling gaps and expansion cavities. After multiple throttling, a large energy loss is generated, which greatly reduces the fluid pressure head and makes it difficult for the fluid to leak, so as to achieve the purpose of sealing. Therefore, the comb teeth can effectively reduce leakage losses.

[0035] However, there is a gap between the comb teeth as a stationary part and the rotating part, so there is still some leakage in the comb teeth part. In order to achieve higher energy efficiency, it is necessary to optimize the overall internal comb tooth structure.

[0036] In view of the above shortcomings, the utility model proposes a novel impeller sealing structure, which enables the leaked gas to generate relative flow by itself by setting a spiral channel whose spiral direction is opposite to the rotation direction, thereby increasing the turbulence of the leaked gas, increasing the self-consumption of the leaked gas, and further reducing the leakage amount.

[0037] like Figures 1 to 5As shown, the impeller sealing structure specifically includes: an impeller 1 and a sealing baffle, wherein the impeller 1 is fixed on the main shaft, and the sealing baffle (specifically including a front sealing baffle 21 and a rear sealing baffle 22) is fixed to the casing by bolts or the like or is directly processed on the casing; two circles of protruding teeth 11 of different sizes are arranged at intervals on the side of the impeller 1 opposite to the sealing baffle (i.e., the sealing side of the impeller, specifically, the front and rear sides of the impeller cover), and the impeller 1, the sealing baffle and the area between the two circles of protruding teeth 11 form a cavity, and the impeller 1 is also provided with a spiral flow channel 32 in the cavity, the rotation direction of which is opposite to the rotation direction of the impeller.

[0038] The spiral flow channel can actually form a comb-tooth sealing effect, which can cause greater energy loss during gas leakage. By setting a spiral channel with a spiral direction opposite to the rotation direction, the leaked gas itself can produce relative flow, thereby increasing the turbulence of the leaked gas, increasing the self-consumption of the leaked gas, and further reducing the leakage amount.

[0039] In a specific embodiment, two circles of protruding teeth 11 are arranged on the impeller cover of the impeller 1. The two circles of protruding teeth 11 are centered on the center of the impeller 1 and are respectively close to the outer edge and the inner edge of the impeller cover. The position between the two circles of protruding teeth 11 is a cavity, that is, the cavity is a circular cavity.

[0040] A circular cavity is formed by arranging circular protruding teeth. The presence of the protruding teeth isolates the cavity to be sealed from the spiral flow channel, so that a distribution structure of gap-cavity-gap-cavity is formed in the axial direction, which can consume the energy of the leaked gas through the throttling-expansion-throttling-expansion process.

[0041] In a specific embodiment, a spiral tooth 12 is provided on the side of the impeller 1 opposite to the sealing baffle. The spiral tooth 12 takes the center of the impeller as the spiral center, and the spiral region of the spiral tooth forms a spiral flow channel 32 .

[0042] That is, the spiral flow channel is formed by setting spiral teeth on the impeller cover. The spiral teeth are set between two protruding teeth. During processing, it is only necessary to dig a spiral groove on the impeller cover to form the protruding spiral teeth. The position of the spiral groove is the spiral flow channel, and the processing method is simple.

[0043] During specific processing, both the protruding teeth and the spiral teeth can be formed by digging grooves on the impeller cover, which is simple to process and has a reliable structure.

[0044] In a specific embodiment, the thickness of the protruding teeth is four to six times the thickness of the spiral teeth. The protruding teeth need to define the boundary of the cavity and require a larger thickness to avoid deformation and leakage. The spiral teeth can be set to a smaller thickness, so that more turns can be set in the cavity to increase the sealing effect.

[0045] In a specific embodiment, the number of spiral turns of the spiral teeth is at least 9. A smaller number of spiral turns cannot achieve the effect of increasing the turbulence of the leaking gas, and more than 9 turns can bring better sealing effect.

[0046] In a specific embodiment, the distance between the inner wall of the outer ring protrusion and the outer wall of the inner ring protrusion is in the range of 1 mm to 1.5 mm, that is, the width of the cavity; if the width of the cavity is limited within a reasonable range, the sealing effect will be affected if the width of the cavity is too large or too small.

[0047] In a specific embodiment, the ratio of the distance d1 between the outer wall surface of the outer ring tooth and the inner wall surface of the inner ring tooth to the distance d2 between the inner wall surface of the outer ring tooth and the outer wall surface of the inner ring tooth is less than or equal to 1.4.

[0048] In order to ensure the sealing effect, the thickness of the over-protruding teeth is too large and the cavity is too small, which will affect the sealing effect.

[0049] In a specific embodiment, the impeller cover of the impeller is opposite to the sealing baffle, and the gap between the impeller cover and the sealing baffle is in the range of 0.05-0.15 mm. To ensure normal rotation, there must be a certain gap between the impeller and the baffle, but the gap cannot be too large to cause leakage.

[0050] In a specific embodiment, the sealing baffle includes a front sealing baffle and a rear sealing baffle, which are respectively arranged on the front and rear sides of the impeller cover, and the cavity and the spiral flow channel are arranged on the front and rear sides of the impeller facing the front sealing baffle and the rear sealing baffle.

[0051] The front sealing baffle plate 21 and the rear sealing baffle plate 22 are both processed into a shape that fits the wheel cover to ensure a small gap between the sealing cover plate and the impeller wheel cover. In addition, the sealing structure is used on both the front and rear sides of the impeller wheel cover to improve the sealing effect.

[0052] The utility model also provides a compressor, specifically a centrifugal compressor, which adopts the impeller sealing structure mentioned above.

[0053] The sealing structure of the present invention has directionality, and the direction of the spiral flow channel is opposite to the direction of rotation. When the rotating part rotates, due to the effect of flow viscosity, the fluid on the surface of the rotating part will be driven to rotate. Under the action of the spiral flow channel, there is a tendency to move from the low-pressure side to the high-pressure side, thereby conflicting with the direction of gas leakage and increasing the fluid pressure in the sealed cavity. Therefore, when the part rotates, the resistance that needs to be overcome by gas leakage will increase, thereby improving the sealing effect. At the same time, due to the characteristics of the sealing structure and the radial arrangement, the fluid will be affected by centrifugal force, so the higher the rotation speed of the rotating part, the better the sealing effect.

[0054] Compared with the traditional structure, this structure not only consumes the energy of the fluid by throttling and expansion, but also increases the consumption of the interaction between the fluids themselves. Therefore, under the condition of the same number of teeth (length), this structure has a more significant sealing effect.

[0055] It should be noted that the terms used above are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the utility model. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0056] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps described in these embodiments do not limit the scope of the utility model. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0057] In the description of the present utility model, it needs to be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present utility model and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present utility model; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0058] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0059] In addition, it should be noted that the use of words such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above words have no special meaning and therefore cannot be understood as limiting the scope of protection of the utility model. The above is only a preferred embodiment of the utility model and is not intended to limit the utility model. For those skilled in the art, the utility model can have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the utility model should be included in the scope of protection of the utility model.

Claims

1. An impeller sealing structure, comprising: The impeller and the sealing baffle arranged on the sealing side of the impeller are characterized in that two circles of protruding teeth are arranged on the sealing side of the impeller to form a cavity between the impeller and the sealing baffle, and a spiral flow channel with a rotation direction opposite to the impeller rotation direction is arranged in the cavity.

2. The impeller sealing structure according to claim 1, characterized in that: The two circles of protruding teeth have the center of the impeller as the center of the circle, and the cavity between the two circles of protruding teeth is a circular ring cavity.

3. The impeller sealing structure according to claim 1, characterized in that: A spiral tooth is provided on the sealing side of the impeller and between two circles of protruding teeth. The spiral tooth forms the spiral flow channel with the center of the impeller as the spiral center.

4. The impeller sealing structure according to claim 3, characterized in that: The thickness of the protruding teeth is four to six times the thickness of the spiral teeth.

5. The impeller sealing structure according to claim 3, characterized in that: The number of spiral turns of the spiral teeth is at least 9.

6. The impeller sealing structure according to claim 1, characterized in that: The distance between the inner wall surface of the protruding teeth of the outer ring and the outer wall surface of the protruding teeth of the inner ring is in the range of 1-1.5 mm.

7. The impeller sealing structure according to claim 1, characterized in that: The ratio of the distance d1 between the outer wall surface of the outer ring protrusion and the inner wall surface of the inner ring protrusion to the distance d2 between the inner wall surface of the outer ring protrusion and the outer wall surface of the inner ring protrusion is less than or equal to 1.

4.

8. The impeller sealing structure according to claim 1, characterized in that: The impeller cover portion of the impeller is opposite to the sealing baffle, and the gap between the impeller cover and the sealing baffle is in the range of 0.05-0.15 mm.

9. The impeller sealing structure according to claim 1, characterized in that: The sealing baffle comprises a front sealing baffle and a rear sealing baffle, which are respectively arranged on the front and rear sides of the impeller cover of the impeller. The cavity and the spiral flow channel are arranged on the front and rear sides of the impeller facing the front sealing baffle and the rear sealing baffle.

10. A compressor, characterized in that: The invention comprises an impeller sealing structure as claimed in any one of claims 1 to 9.

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