Roots vacuum pump rotor and roots vacuum pump

Abstract

The Roots vacuum pump rotor comprises a rotor body, the section, perpendicular to a rotating shaft of the rotor body, of the rotor body is of an 8-shaped leaf structure, the two leaf tops of the 8-shaped leaf structure are each provided with an installation groove, and openings of the installation grooves are formed in the radial direction of the rotor body in the direction facing a vacuum pump shell; and the sealing assembly comprises a sealing brush, and the sealing brush extends from the interior of the mounting groove to the exterior of the mounting groove in the direction of the opening of the mounting groove. A rotor body of the Roots vacuum pump rotor is installed in a vacuum pump shell of the Roots vacuum pump, in the operation process of the Roots vacuum pump, at least one blade top of the rotor body of the Roots vacuum pump rotor is in clearance fit with the vacuum pump shell, and sealing brushes at the blade tops make contact with the inner wall of the vacuum pump shell to form sealing. Therefore, the sealing effect of the roots vacuum pump is improved, and the overall pumping speed of the roots vacuum pump is improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to vacuum pump technical field, concretely relates to a roots vacuum pump rotor and roots vacuum pump. BACKGROUND

[0002] The shell of the roots vacuum pump is internally provided with two rotors which are arranged in parallel and synchronously reversely rotate, the rotors are in the form of a blade, and small gaps exist between the rotors and between the rotors and the shell of the roots vacuum pump and the rotors do not contact each other. SUMMARY

[0003] Embodiments of the present disclosure aim to at least solve one of the technical problems existing in the prior art, and provide a roots vacuum pump rotor and roots vacuum pump.

[0004] Embodiments of the first aspect of the present disclosure provide a roots vacuum pump rotor, which comprises:

[0005] A rotor body, a cross section of the rotor body perpendicular to a rotation axis of the rotor body is in the form of an 8-shaped blade, two blade tips of the 8-shaped blade are respectively provided with a mounting groove, and the mounting groove is opened in a direction of a vacuum pump shell along a radial direction of the rotor body;

[0006] A sealing assembly, the sealing assembly comprises a sealing brush, and the sealing brush extends from an inside of the mounting groove to an outside of the mounting groove in a direction of an opening of the mounting groove.

[0007] In some embodiments of the present disclosure, the sealing assembly further comprises:

[0008] A first stopper, the first stopper extends from a bottom of the mounting groove to the opening direction of the mounting groove, and the first stopper is located in front of the sealing brush along a rotation direction of the rotor body, a top end of the sealing brush is arranged to protrude from an edge of the blade tip, and a top end of the first stopper is arranged to be lower than a top end of a side wall of the mounting groove.

[0009] In some embodiments of the present disclosure, the sealing assembly further comprises:

[0010] A second stopper, the second stopper extends from the bottom of the mounting groove to the outside of the mounting groove in the opening direction of the mounting groove, a length of the second stopper protruding from the edge of the blade tip is less than a length of the sealing brush protruding from the edge of the blade tip, and the second stopper is located behind the sealing brush along the rotation direction of the rotor body.

[0011] In some embodiments of the present disclosure, the sealing assembly further comprises a first blocking piece and a second blocking piece arranged on opposite sides of the sealing brush, and the first blocking piece, the sealing brush and the second blocking piece are connected to the mounting groove by welding.

[0012] In some embodiments of the present disclosure, the sealing assembly further comprises a first blocking piece and a second blocking piece arranged on opposite sides of the sealing brush, and the first blocking piece and the second blocking piece are connected by bolts and clamp the sealing brush.

[0013] Alternatively, the sealing assembly further comprises a first blocking piece and a second blocking piece arranged on opposite sides of the sealing brush, and the first blocking piece and the second blocking piece clamp the sealing brush by a C-shaped clamp, and the first blocking piece and the second blocking piece are detachably connected.

[0014] In some embodiments of the present disclosure, the sealing brush is a wire bundle.

[0015] In some embodiments of the present disclosure, the material of the wire bundle is cobalt-based superalloy.

[0016] In some embodiments of the present disclosure, the mounting groove is a wedge-shaped groove.

[0017] Embodiments of the second aspect of the present disclosure provide a Roots vacuum pump, comprising a vacuum pump housing and a Roots vacuum pump rotor according to any of the above-mentioned embodiments, the Roots vacuum pump rotor being arranged in the vacuum pump housing, and during operation of the Roots vacuum pump, at least one blade tip of the rotor body of the Roots vacuum pump rotor is in clearance fit with the vacuum pump housing, and the sealing brush at the blade tip in clearance fit with the vacuum pump housing forms a seal with the inner wall of the vacuum pump housing.

[0018] In some embodiments of the present disclosure, the inner wall of the vacuum pump housing is provided with a wear-resistant layer, and when the rotor body rotates to a position where the blade tip of the rotor body is in clearance fit with the vacuum pump housing, the sealing brush is in contact with the wear-resistant layer, and the wear-resistant layer is a ceramic coating.

[0019] The disclosed Roots vacuum pump rotor and Roots vacuum pump include a rotor body and a sealing assembly. The rotor body has a figure-eight shaped cross-section perpendicular to its shaft. The shaft of the rotor body is located at the center of symmetry of the figure-eight shaped structure, i.e., the shaft bore of the rotor body is located at the center of symmetry of the figure-eight shaped structure. A mounting groove is provided at each of the two opposite blade tips of the figure-eight shaped structure. The mounting grooves are opened radially towards the vacuum pump housing. The sealing brush of the sealing assembly is mounted in the mounting groove and extends along the opening of the mounting groove to the outside of the mounting groove and protrudes from the figure-eight shaped structure. When the rotor body is installed inside the vacuum pump housing of the Roots vacuum pump, during the operation of the Roots vacuum pump, at least one blade tip of the rotor body of the Roots vacuum pump rotor has a clearance fit with the vacuum pump housing. The sealing brush at the blade tip that has a clearance fit with the vacuum pump housing contacts the inner wall of the vacuum pump housing and forms a seal. The sealing brush can prevent the gas in the vacuum pump housing of the Roots vacuum pump rotor from flowing from the high-pressure side to the low-pressure side, thereby reducing the gas leakage in the small gap between the blade tip of the rotor body and the vacuum pump housing, improving the sealing effect of the Roots vacuum pump, and thus improving the overall pumping speed of the Roots vacuum pump. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the Roots vacuum pump according to an embodiment of the present disclosure;

[0021] Figure 2 for Figure 1 The diagram shows a partial cross-sectional view of the Roots vacuum pump.

[0022] Figure 3 for Figure 1 The diagram shows the overall structure of the Roots vacuum pump rotor.

[0023] Figure 4 for Figure 2 A schematic diagram of the first connection method of the sealing assembly shown;

[0024] Figure 5 for Figure 2 The diagram shows a second connection method for the sealing assembly.

[0025] The labels in the attached diagram are as follows:

[0026] 100. Roots vacuum pump;

[0027] 10. Roots vacuum pump rotor; 11. Rotor body; 111. Mounting groove; 12. Sealing assembly; 121. Sealing brush; 122. First stop; 123. Second stop; 124. C-clamp; 125. Core wire; 126. Bolt; 13. Left shaft; 14. Right shaft; 101. Shaft hole; 103. Left rotor; 104. Right rotor;

[0028] 20. A vacuum pump housing. DETAILED DESCRIPTION

[0029] Example embodiments of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings. While example embodiments of the present disclosure are shown in the drawings, it is understood that the present disclosure can be embodied in many forms and should not be construed as limited to the implementations set forth herein. Rather, these implementations are provided as example so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0030] It should be understood that the terms used herein are for the purpose of describing particular example embodiments and are not intended to be limiting. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises" and / or "comprising," and / or "includes" and / or "including" and / or "has" and / or "having" when used herein, specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order in which they are described, unless specifically identified as an order dependent step. It is also to be understood that additional or alternative steps can be employed.

[0031] Although the terms first, second, third, and the like can be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as "first," "second," and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

[0032] For ease of description, spatially relative terms can be used herein for the purpose of illustrating one element's or feature's relationship to another element or feature as shown in the figures. Such spatially relative terms include "internal", "external", "inward", "outward", "under", "below", "above", "on", "above", and the like. These spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device is inverted, then an element described as "below" or "beneath" another element or feature would then be oriented "above" or "over" the other element or feature. Thus, the example term "below" can encompass both an orientation of above and below. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0033] As shown in the drawings, Figures 1 to 5 An embodiment of the first aspect of the present disclosure provides a Roots vacuum pump rotor 10, comprising: a rotor body 11 and a sealing assembly 12, specifically, the cross section of the rotor body 11 perpendicular to its rotation axis is in the shape of an 8-shaped blade, two blade tips of the 8-shaped blade are respectively provided with mounting grooves 111, the openings of the mounting grooves 111 are opened in the direction of the radial direction of the rotor body 11 towards the direction of the vacuum pump shell, and the sealing assembly 12 comprises a sealing brush 121, which extends from the inside of the mounting groove 111 to the outside of the mounting groove 111 in the direction of the opening of the mounting groove 111.

[0034] The Roots vacuum pump rotor 10 of the embodiments of the present disclosure comprises a rotor body 11 and a sealing assembly 12, wherein the cross section of the rotor body 11 perpendicular to its rotation axis is in the shape of an 8-shaped lobe structure, the rotation axis of the rotor body 11 is located at the center of symmetry of the 8-shaped lobe structure, i.e., the rotation axis hole 101 of the rotor body 11 is located at the center of symmetry of the 8-shaped lobe structure, one mounting groove 111 is arranged at each of the two opposite lobe tips of the 8-shaped lobe structure, the opening of the mounting groove 111 is arranged in the radial direction of the rotor body 11 and faces the direction of the vacuum pump housing, the sealing brush 121 of the sealing assembly 12 is mounted in the mounting groove 111, and the sealing brush 121 extends to the outside of the mounting groove 111 along the opening of the mounting groove 111 and protrudes beyond the outer edge of the lobe tip of the 8-shaped lobe structure. When the rotor body 11 is installed in the vacuum pump housing 20 of the Roots vacuum pump 100, during the operation of the Roots vacuum pump 100, the at least one lobe tip of the rotor body 11 of the Roots vacuum pump rotor 10 is in a clearance fit with the vacuum pump housing 20, the sealing brush 121 at the lobe tip in the clearance fit with the vacuum pump housing 20 is in contact with the inner wall of the vacuum pump housing 20 and forms a seal, and the sealing brush 121 can block the gas in the vacuum pump housing 20 of the Roots vacuum pump rotor 10 from flowing from the high-pressure side to the low-pressure side, thereby reducing the gas leakage amount of the small clearance between the lobe tip of the rotor body 11 and the vacuum pump housing 20, improving the sealing effect of the Roots vacuum pump 100, and further improving the overall pumping speed of the Roots vacuum pump 100.

[0035] In some embodiments of the present disclosure, the sealing assembly 12 further comprises a first blocking piece 122, which is arranged in the mounting groove 111 and extends from the bottom of the mounting groove 111 to the opening direction of the mounting groove 111. In the rotation direction of the rotor body 11, the first blocking piece 122 is located in front of the sealing brush 121, i.e., the first blocking piece 122 is located on the high-pressure side, and the side of the first blocking piece 122 away from the sealing brush 121 is in close contact with the side wall of the mounting groove 111, i.e., the first blocking piece 122 is located between the sealing brush 121 and the side wall of the mounting groove 111. The top end of the sealing brush 121 protrudes beyond the lobe tip edge, and the top end of the first blocking piece 122 is lower than the top end of the side wall of the mounting groove 111. By protruding the top end of the sealing brush 121 beyond the lobe tip edge and arranging the edge of the first blocking piece 122 lower than the side wall of the mounting groove 111, the structure formed by the sealing brush 121, the first blocking piece 122 and the mounting groove 111 can collect foreign matter between the rotor body 11 and the vacuum pump housing 20, prevent the rotor body 11 from being stuck, and ensure the normal operation of the rotor body 11.

[0036] In some embodiments of the present disclosure, the sealing assembly 12 further comprises a second blocking piece 123, which is located behind the sealing brush 121 along the rotation direction of the rotor body 11, i.e., the second blocking piece 123 is located on the low-pressure side, and the side of the second blocking piece 123 away from the sealing brush 121 is tightly attached to the side wall of the mounting groove 111, i.e., the second blocking piece 123 is located between the sealing brush 121 and the side wall of the mounting groove 111, and the side wall of the mounting groove 111 supports the second blocking piece 123. The second blocking piece 123 extends from the bottom of the mounting groove 111 to the outside of the mounting groove 111 in the opening direction of the mounting groove 111, i.e., the second blocking piece 123 protrudes from the blade tip edge of the rotor body 11, and the length of the second blocking piece 123 protruding from the blade tip edge is less than the length of the sealing brush 121 protruding from the blade tip edge. The second blocking piece 123 supports the flexible sealing brush 121, and the second blocking piece 123 is always in contact with the vacuum pump housing 20.

[0037] Specifically, the opposite sides of the sealing brush 121 are provided with the first blocking piece 122 and the second blocking piece 123, the first blocking piece 122 is located in front of the sealing brush 121 along the rotation direction of the rotor body 11, and the second blocking piece 123 is located behind the sealing brush 121, and the sides of the first blocking piece 122 and the second blocking piece 123 away from each other are respectively in close contact with the opposite two side walls of the mounting groove 111 to ensure the reliability of the installation of the sealing brush 121.

[0038] In some embodiments of the present disclosure, as shown in Figure 4 the first blocking piece 122, the sealing brush 121 and the second blocking piece 123 are connected to the mounting groove 111 by welding. Specifically, the first blocking piece 122 and the sealing brush 121, and the second blocking piece 123 and the sealing brush 121 can be connected by welding respectively, and then the sealing assembly 12 formed by welding the first blocking piece 122, the sealing brush 121 and the second blocking piece 123 is connected to the bottom of the mounting groove 111 by welding. The welding connection can ensure that the sealing assembly 12 does not move relatively, and at the same time, ensure that the sealing assembly 12 does not move relatively in the mounting groove 111, thereby improving the sealing reliability of the sealing assembly 12.

[0039] In some embodiments of the present disclosure, as shown in Figure 5 the first blocking piece 122 and the second blocking piece 123 are connected and clamped to the sealing brush 121 by the bolts 126. Specifically, the fixed end of the sealing brush 121 is bundled by the core wire 125, and then the outer wall of the core wire 125 is clamped by the C-shaped clamp 124, and the first blocking piece 122 and the second blocking piece 123 are connected and clamped to the C-shaped clamp 124 by the bolts 126, thereby realizing the fixation of the sealing brush 121. After the components of the sealing assembly 12 are connected by the bolts 126, they are fixed in the mounting groove 111 by welding or detachable connection.

[0040] In some embodiments of this disclosure, the sealing brush 121 is a metal wire bundle. Specifically, the sealing brush 121 is a high-density metal wire bundle with a certain circumferential angle and an elastic circular cross-section. The free end of the metal wire bundle protruding from the blade tip of the rotor body 11 contacts and rubs against the inner wall of the vacuum pump housing 20 to form a seal. Due to the non-uniformity of the gaps between the metal wires in the metal wire bundle, the uniform airflow entering the metal wire bundle becomes non-uniform, deflecting from the dense metal wire bundle area to the loose metal wire bundle area. These deflected flows gradually form co-current flows and jets between the metal wires, and generate random secondary flows and vortex flows. When the jet encounters the dense metal wire bundle in front, it changes its direction of motion and becomes a transverse flow perpendicular to the mainstream direction, i.e., a transverse flow. It is precisely because the metal wire bundle disrupts the flow and ensures the non-uniformity of the flow that the fluid produces a self-sealing effect. The transverse flow instead of the forward flow increases the total pressure drop flowing through the metal wires, thereby reducing leakage.

[0041] In some embodiments of this disclosure, the metal wire bundle is made of a cobalt-based superalloy, which is an austenitic superalloy with a cobalt content of 40-65%. Cobalt-based superalloys have the advantages of low brittleness and high toughness. The metal wire bundle of cobalt-based superalloy can ensure that the rotor body 11 does not break during rotation, while the high-performance welding process can ensure that the brush bristles do not fall off, and the reasonable thickness and height of the brush bristle bundle can ensure high-performance sealing.

[0042] In some embodiments of this disclosure, the mounting groove 111 is a wedge-shaped groove. When the rotor body 11 rotates at high speed, the wedge-shaped groove can ensure that the sealing assembly 12 will not come out, thereby improving the reliability of the connection between the sealing assembly 12 and the mounting groove 111.

[0043] like Figure 1 As shown, an embodiment of the second aspect of this disclosure provides a Roots vacuum pump 100, which includes a vacuum pump housing 20 and a Roots vacuum pump rotor 10 according to any of the above embodiments. Two Roots vacuum pump rotors 10 are disposed within the vacuum pump housing 20. During operation of the Roots vacuum pump 100, at least one blade tip of the rotor body 11 of the Roots vacuum pump rotor 10 is clearance-fitted with the vacuum pump housing 20, and a sealing brush 121 at the blade tip clearance-fitted with the vacuum pump housing 20 forms a seal with the inner wall of the vacuum pump housing 20.

[0044] The Roots vacuum pump 100 of the embodiments of the present disclosure, the rotor body 11 is installed in the vacuum pump shell 20 of the Roots vacuum pump 100, and during the operation of the Roots vacuum pump 100, at least one blade tip of the rotor body 11 of the Roots vacuum pump rotor 10 is in clearance fit with the vacuum pump shell 20. The sealing brush 121 at the blade tip in clearance fit with the vacuum pump shell 20 is in contact with the inner wall of the vacuum pump shell 20 and forms a seal. The sealing brush 121 can block the gas in the vacuum pump shell 20 of the Roots vacuum pump rotor 10 from flowing from the high-pressure side to the low-pressure side, thereby reducing the gas leakage amount of the small gap between the blade tip of the rotor body 11 and the vacuum pump shell 20, improving the sealing effect of the Roots vacuum pump 100, and further improving the overall pumping speed of the Roots vacuum pump 100.

[0045] During the operation of the Roots vacuum pump 100, one of the two blade tips of the rotor body 11 of the Roots vacuum pump rotor 10 is in clearance fit with the vacuum pump shell 20, or the two blade tips of the rotor body 11 are in clearance fit with different positions of the vacuum pump shell 20, respectively. When the blade tip of the rotor body 11 is in clearance fit with the vacuum pump shell 20, the sealing brush 121 provided at the blade tip forms a flexible seal with the inner wall of the vacuum pump shell 20 at the corresponding position.

[0046] Specifically, the two Roots vacuum pumps 10 in the vacuum pump shell 20 include a left rotor 103 and a right rotor 104, which rotate around their respective rotation axes, and the rotation axes of the left rotor 103 and the right rotor 104 are arranged in parallel, wherein one rotor is arranged vertically and the other rotor is arranged horizontally.

[0047] In some embodiments of the present disclosure, the inner wall of the vacuum pump shell 20 is provided with a wear-resistant layer (not shown in the figure), and when the rotor body 11 rotates to the clearance fit between the blade tip of the rotor body 11 and the vacuum pump shell 20, the sealing brush 121 at the blade tip is in contact with the wear-resistant layer. The provision of the wear-resistant layer can reduce the wear of the sealing brush 121, while improving the service life of the vacuum pump shell 20. Specifically, the wear-resistant layer is a ceramic coating, and the metal wire bundle of cobalt-based high-temperature alloy material and the wear-resistant layer of ceramic material can ensure the stable sealing of the vacuum pump shell 20 and the rotor body 11 and the safe operation of the Roots vacuum pump rotor 10.

[0048] It can be understood that the above embodiments are only exemplary embodiments adopted to illustrate the principles of the present disclosure, but the present disclosure is not limited thereto. Various modifications and improvements can be made by those of ordinary skill in the art without departing from the spirit and essence of the present disclosure, and these modifications and improvements are also considered within the protection scope of the present disclosure.

Claims

1. A Roots vacuum pump rotor, characterized by, The Roots vacuum pump rotor comprises: a rotor body, a cross section of the rotor body perpendicular to its rotation axis is in an 8-shaped blade structure, two blade tips of the 8-shaped blade structure are respectively provided with mounting grooves, and openings of the mounting grooves are opened in a direction of the rotor body along a radial direction of the rotor body towards a direction of a vacuum pump shell; a sealing assembly, the sealing assembly comprises a sealing brush, the sealing brush extends from an inside of the mounting groove to an outside of the mounting groove in a direction of the opening of the mounting groove.

2. - The Roots vacuum pump rotor according to claim 1, characterized in that, The sealing assembly further comprises: a first stopper, the first stopper extends from a bottom of the mounting groove to the opening direction of the mounting groove, in a rotation direction of the rotor body, the first stopper is located in front of the sealing brush, a top end of the sealing brush is arranged to protrude from an edge of the blade tip, and a top end of the first stopper is arranged to be lower than a top end of a side wall of the mounting groove.

3. A Roots pump rotor according to claim 1, wherein The sealing assembly further comprises: a second stopper, the second stopper extends from the bottom of the mounting groove to the outside of the mounting groove in the opening direction of the mounting groove, a length of the second stopper protruding from the edge of the blade tip is less than a length of the sealing brush protruding from the edge of the blade tip, and in the rotation direction of the rotor body, the second stopper is located behind the sealing brush.

4. The Roots vacuum pump rotor of claim 1, wherein, The sealing assembly further comprises the first stopper and the second stopper arranged on opposite sides of the sealing brush, and the first stopper, the sealing brush and the second stopper are connected to the mounting groove by welding.

5. The Roots vacuum pump rotor of claim 1, wherein, The sealing assembly further comprises the first stopper and the second stopper arranged on opposite sides of the sealing brush, and the first stopper and the second stopper clamp the sealing brush by bolts. Alternatively, the sealing assembly further comprises the first stopper and the second stopper arranged on opposite sides of the sealing brush, and the first stopper and the second stopper clamp the sealing brush by a C-shaped clamp, and the first stopper and the second stopper are detachably connected.

6. - Roots vacuum pump rotor according to any of claims 1 to 5, characterized in that The sealing brush is a wire bundle.

7. A Roots vacuum pump rotor according to claim 6, characterised in that A material of the wire bundle is cobalt-based superalloy.

8. The Roots vacuum pump rotor of claim 1, wherein, The mounting groove is a wedge-shaped groove.

9. A Roots vacuum pump, characterized in that The Roots vacuum pump comprises a vacuum pump shell and the Roots vacuum pump rotor according to any one of claims 1 to 8, the Roots vacuum pump rotor is arranged in the vacuum pump shell, during operation of the Roots vacuum pump, at least one blade tip of the rotor body of the Roots vacuum pump rotor is in clearance fit with the vacuum pump shell, and the sealing brush at the blade tip in clearance fit with the vacuum pump shell forms a seal with an inner wall of the vacuum pump shell.

10. The Roots vacuum pump according to claim 9, characterized in that An inner wall of the vacuum pump shell is provided with a wear-resistant layer, when the rotor body rotates to a position where a blade tip of the rotor body is in clearance fit with the vacuum pump shell, the sealing brush contacts the wear-resistant layer, and the wear-resistant layer is a ceramic coating.

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