Roots vacuum pump rotor, and roots vacuum pump and working method thereof

Abstract

A Roots vacuum pump rotor, and a Roots vacuum pump and a working method thereof, relating to the technical field of vacuum pumps. The Roots vacuum pump rotor (100, 200) comprises a rotating shaft (110, 210) and at least one stage of rotor component (120, 220) arranged in the axial direction of the rotating shaft; an air inlet channel (130, 230) is provided in the rotating shaft along the axial direction thereof, and an air inlet of the air inlet channel is located at the end close to a front cover plate of a Roots vacuum pump; at least one jet flow channel (140, 240) is provided in the rotor component along the axial direction thereof, a jet inlet of the jet flow channel is communicated with the air inlet channel, and a jet outlet (141, 241) of the jet flow channel is located at the lobed top of the rotor component; and an external air source flows along the air inlet channel into the jet flow channel and generates a jet flow ejected from the jet outlet, and the jet flow movement direction at the jet outlet is consistent with the rotation direction of the rotor. By providing a jet flow channel in a rotor and introducing an external air source, the loss caused by leakage between the rotor and the inner wall surface of a pump housing is reduced, the internal flow state in the vacuum pump housing is improved, and the heat generated during the operation of the vacuum pump is taken away, thereby achieving a cooling effect.

Description

Roots vacuum pump rotor, Roots vacuum pump and its working method Technical Field

[0001] This disclosure belongs to the field of vacuum pump technology, specifically relating to a Roots vacuum pump rotor, a Roots vacuum pump, and its working method. Background Technology

[0002] Roots vacuum pumps have advantages such as simple structure, flexible installation, no need for internal lubrication, and high volumetric efficiency, and have been widely used in many key sectors of the national economy, including petrochemicals, semiconductor manufacturing, energy development, light industry, and food processing.

[0003] In the internal operation of a Roots vacuum pump, the gaps between rotors, between the rotor and the pump casing, and between the rotor and the front and rear cover plates are crucial components. During pump operation, as the Roots rotor rotates continuously, the pressure in the outlet region gradually increases, forming a high-pressure zone. This pressure accumulation causes some leaked gas to flow back into the low-pressure zone through these gaps. Because this leaked gas is at a high temperature, it heats the subsequently flowing gas, causing an increase in the inlet gas volume, thereby reducing the pump's volumetric efficiency and consequently reducing the pump's mass flow rate. Furthermore, during rotor rotation, as the outlet pressure continuously accumulates, significant backflow impacts and airflow pulsations occur at the outlet, affecting the pump's operational stability and limiting its application range and development potential. Leakage flow and the resulting outlet backflow impact have a significant impact on the operating efficiency of the vacuum pump.

[0004] Therefore, improving the sealing performance of vacuum pumps and reducing outlet backflow impact are crucial for the advancement of Roots vacuum pumps. Summary of the Invention

[0005] This disclosure aims to at least solve one of the technical problems existing in the prior art, and to provide a Roots vacuum pump rotor, a Roots vacuum pump, and a method for operating the same.

[0006] In one aspect, this disclosure provides a Roots vacuum pump rotor, the Roots vacuum pump rotor comprising a rotating shaft and at least one stage rotor component arranged axially along the rotating shaft; wherein,

[0007] The rotating shaft has an air intake channel along its axial direction, and the air intake port of the air intake channel is located at one end near the front cover plate of the Roots vacuum pump.

[0008] The rotor component of any stage is provided with at least one set of jet channels along its axial direction, the injection inlet of the jet channel is connected to the air intake channel, and the injection outlet of the jet channel is located at the blade tip of the rotor component;

[0009] An external air source flows into the jet channel along the air inlet channel and is ejected through the jet outlet. The jet movement direction of the jet outlet is consistent with the rotation direction of the Roots vacuum pump rotor.

[0010] Optionally, the jet channel extends in a curved direction from the injection inlet to the injection outlet, with the curvature extending in the same direction as the rotation of the Roots vacuum pump rotor.

[0011] Optionally, the intake passage includes an axial passage arranged along the axis of rotation, and at least one set of connecting passages axially distributed along the axial passage; wherein,

[0012] The injection inlet of each set of jet channels is connected to the axial channel through each set of connecting channels.

[0013] Optionally, the rotor component of any stage is provided with multiple sets of jet channels spaced along its axial direction, and the rotating shaft is provided with multiple sets of connecting channels spaced along its axial direction.

[0014] Multiple jet channels correspond one-to-one with multiple connecting channels.

[0015] Optionally, any set of the connection channels includes a plurality of connection sub-channels, the plurality of connection sub-channels being distributed circumferentially at intervals along the rotation axis;

[0016] Each of the rotor components described in any one stage is provided with a jet sub-channel on multiple blades, and the multiple jet sub-channels correspond one-to-one with the multiple connecting sub-channels to form multiple arc-shaped channels.

[0017] Optionally, the radius of the arc of the arc-shaped channel is 20~120mm; and / or,

[0018] The inner diameter of the arc-shaped channel is 0.05~2mm; and / or,

[0019] The length of the axial channel is 10% to 80% of the length of the rotating shaft.

[0020] Optionally, the distance between the air inlet of the air intake channel and the first set of jet channels in the first-stage rotor component is 40% to 60% of the length of the rotating shaft; and / or,

[0021] The distance between the injection outlet and the rotating shaft is 4 to 20 mm.

[0022] Optionally, a primary rotor component is provided axially along the rotating shaft; wherein,

[0023] The rotor component in this stage is provided with multiple sets of jet channels at equal intervals along its axial direction.

[0024] Optionally, multiple stages of rotor components are provided at axial intervals along the rotating shaft; wherein,

[0025] Each stage of the rotor component is provided with at least one set of jet channels along its axial direction.

[0026] In one aspect, this disclosure provides a Roots vacuum pump, the Roots vacuum pump comprising: a pump housing and a left rotor and a right rotor disposed within the pump housing; wherein,

[0027] The left rotor and the right rotor are the Roots vacuum pump rotors described above.

[0028] In one aspect, this disclosure provides a method for operating the Roots vacuum pump described above, the method comprising:

[0029] S1. The left and right rotors rotate in opposite directions under the drive of their respective rotating shafts. An external air source is connected to the air intake channel of the rotating shaft, and gas flows in through the air inlet of the air intake channel.

[0030] S2. The gas flows along the intake passages of the left and right rotors to at least one set of jet passages, and generates a jet at the injection outlet.

[0031] S3. The jet is discharged from the injection outlet and interacts with the main airflow inside the pump casing.

[0032] This disclosure discloses a Roots vacuum pump rotor, a Roots vacuum pump, and a method for operating the same. The Roots vacuum pump rotor includes a rotating shaft and at least one stage rotor component arranged axially along the rotating shaft. The rotating shaft has an inlet channel along its axial direction. Each stage rotor component has at least one set of jet channels along its axial direction. The jet inlet of each jet channel is connected to the inlet channel, and the jet outlet is located at the blade tip of the rotor component. An external gas source flows into the jet channel along the inlet channel and is ejected through the jet outlet, generating a jet. The jet's motion direction is consistent with the rotation direction of the Roots vacuum pump rotor. This disclosure introduces an external gas source through the inlet channel. The introduced external gas source is ejected at the blade tip position through the jet channel structure on the rotor to form a jet. This reduces losses caused by leakage between the rotor and the pump casing inner wall, effectively blocks the backflow path from the high-pressure area to the low-pressure area, effectively reduces the impact of backflow at the pump outlet, improves the flow state inside the vacuum pump, and removes the heat generated during vacuum pump operation, achieving a cooling effect. Attached Figure Description

[0033] Figure 1 is a schematic diagram of the internal perforation structure of the rotor of the Roots vacuum pump with perforated jet according to Embodiment 1 of this disclosure;

[0034] Figure 2 is a schematic diagram of the internal perforation structure of the rotor of the Roots vacuum pump with perforated jet according to Embodiment 1 of this disclosure;

[0035] Figure 3 is a front view of the rotor of the Roots vacuum pump with an orifice jet according to Embodiment 1 of this disclosure;

[0036] Figure 4 is a top view of the rotor of the Roots vacuum pump with an orifice jet according to Embodiment 1 of this disclosure;

[0037] Figure 5 is a cross-sectional view of surface AA in Figure 4 of this disclosure;

[0038] Figure 6 is a partial enlarged view along the axial direction in Figure 5 of this disclosure;

[0039] Figure 7 is a cross-sectional view of plane BB in Figure 4 of this disclosure;

[0040] Figure 8 is a cross-sectional view of the CC plane in Figure 4 of this disclosure;

[0041] Figure 9 is a schematic diagram of the Roots vacuum pump of Embodiment 1 of this disclosure;

[0042] Figure 10 is a flowchart of the working method of the Roots vacuum pump in Embodiments 1-3 of this disclosure. Embodiments of the present invention

[0043] To enable those skilled in the art to better understand the technical solutions of this disclosure, the disclosure will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only for explaining this disclosure and are not intended to limit the disclosure. The described embodiments are some, but not all, of the embodiments of this disclosure. Based on the described embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this disclosure.

[0044] In some descriptions of this disclosure, the terms "comprising" or "including" do not limit the shapes, numbers, steps, operations, components and / or groups thereof mentioned, nor do they exclude the appearance or inclusion of one or more other different shapes, numbers, steps, operations, components and / or groups thereof.

[0045] In some descriptions of this disclosure, the terms “first” and “second” are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number and order of the indicated technical features.

[0046] In some descriptions of this disclosure, terms such as “connection,” “linked,” or “fixed” are not limited to direct connections, but can also refer to indirect connections through an intermediate medium.

[0047] As shown in Figures 1 to 8, one aspect of this disclosure provides a Roots vacuum pump rotor, including a rotating shaft and at least one stage rotor component arranged axially along the rotating shaft. The rotating shaft has an inlet channel along its axial direction, with the inlet located near the front cover of the Roots vacuum pump, i.e., the inlet is located on the side opposite to the airflow direction. External gas flows through the inlet along the inlet channel towards the rotor. Furthermore, each stage rotor component has at least one set of jet channels along its axial direction. The jet inlet of the jet channel is connected to the inlet channel, and the jet outlet is located at the blade tip of the rotor component. An external gas source flows into the jet channel along the inlet channel and is ejected as a jet through the jet outlet. The jet's motion direction at the jet outlet is consistent with the rotation direction of the Roots vacuum pump rotor.

[0048] In this embodiment, on the one hand, by opening an air intake channel in the axial direction of the rotating shaft, an external air source can be introduced, and the high-energy jet provided by the external air source ensures that the rotor has sufficient energy during rotation, forming an effective airflow blockage. On the other hand, by setting a jet channel on the rotor component that is connected to the air intake channel, the external gas is ejected from the injection outlet. When the rotor rotates to a position close to the exhaust port, the powerful jet mixes with the main airflow in the pump casing, increasing the gas molecule density in that area and raising the pressure in that area. This helps the internal and external pressures of the pump casing to reach equilibrium more quickly, suppressing backflow impact and pressure fluctuations at the pump casing outlet. Furthermore, since the jet movement direction at the injection outlet is consistent with the rotor rotation direction, and this jet direction is opposite to the leakage flow direction caused by the pressure difference at the gap, leakage losses at the blade tip gap can be reduced.

[0049] Furthermore, to ensure that the direction of the jet is consistent with the rotor's rotation direction, in some preferred embodiments, the jet channel can be bent and extended from the injection inlet to the injection outlet in the same direction as the rotor's rotation direction, thus ensuring that the jet exit direction at the injection outlet is the same as the rotor's rotation direction. In this way, after the external air source flows into the rotor, it first flows through the inlet channel to the jet channel. Then, the external air source flows within the jet channel along the bent extension direction of the jet channel, and further flows to the injection outlet as the rotor rotates, forming a jet at the injection outlet. The jet's movement direction is the same as the rotor's rotation direction, allowing the ejected fluid to expand along the inner wall of the pump casing, carrying away localized heat near the inner wall of the pump casing, thereby controlling the internal temperature of the pump casing and achieving a cooling effect.

[0050] In this embodiment, the injection outlet is located at the tip of the rotor component, which not only significantly reduces leakage at the tip of the blade, but also helps to reduce the heat load in the tip region.

[0051] It should be noted that when the rotor rotates clockwise, the jet channel provided on the rotor bends and extends in the clockwise direction, and when the rotor rotates counterclockwise, the jet channel provided on the rotor bends and extends in the counterclockwise direction.

[0052] It should be further noted that this embodiment does not specifically limit the shape and structure of the jet channel. For example, the channel is arc-shaped along its length and has a circular cross-section. That is, the jet channel is a curved and extended circular hole channel.

[0053] It should be noted that this embodiment does not specifically limit the number of rotor components arranged on the rotating shaft; it can be a single-stage rotor component or a multi-stage rotor component.

[0054] It should be understood that when there is only one stage rotor component, one or more sets of jet channels can be provided along the rotation axis of the rotor component. These multiple sets of jet channels can be distributed at equal intervals or unequal intervals. When there are multiple stages of rotor components, one or more sets of jet channels can be provided along the rotation axis of each stage rotor component. Similarly, the multiple sets of jet channels on any stage rotor component can be distributed at equal intervals or unequal intervals, thus providing one or more sets of injection outlets at the blade tip of the rotor component.

[0055] It should also be understood that when multiple stages of rotor components are arranged on a rotating shaft, and the length of each stage of rotor components decreases progressively along its axial direction, the number of jet channels provided on each stage of rotor components can be different. Furthermore, when the spacing between the multiple stages of rotor components also gradually decreases, the spacing between the jet channels provided on adjacent rotor components can be different.

[0056] It should be noted that this embodiment does not specifically limit the shape of the rotor component. For example, when the rotor is a two-lobe rotor, its rotor component has an 8-shaped outline; for example, when the rotor is a three-lobe rotor, its rotor component has a Y-shaped outline; for example, when the rotor is a five-lobe rotor, its rotor component has a flower-shaped outline. Of course, it can also be a rotor component of other shapes.

[0057] It should be understood that when the rotor component has two, three, five or other blades, a jet channel can be provided on each blade.

[0058] Furthermore, this embodiment does not specifically limit the length of the air intake channel, which can be determined based on the number of jet channels on the rotor component.

[0059] It should be noted that this embodiment does not specifically limit the structure of the air intake channel, as long as it can introduce external gas and connect with the jet channel on the rotor component. In other words, in addition to the axial opening of the rotating shaft, an opening should also be made on its side wall to achieve communication with the jet channel.

[0060] For example, the intake passage includes an axial passage arranged along the rotation axis and at least one set of connecting passages distributed axially along the axial passage; wherein the injection inlet of each set of jet passages is connected to the axial passage through each set of connecting passages. That is, a connecting passage corresponding to the jet passage is provided on the axial passage so that an external air source flows into the jet passage through the axial passage.

[0061] In some preferred embodiments, when multiple sets of jet channels are spaced apart along the axial direction on a primary rotor component or a multi-stage rotor component, correspondingly, multiple sets of connecting channels are spaced apart along the axial direction on the rotating shaft; the multiple sets of jet channels correspond one-to-one with the multiple sets of connecting channels.

[0062] In other preferred embodiments, any set of connecting channels includes multiple connecting sub-channels, which are distributed circumferentially along the rotation axis. Correspondingly, multiple blades of any stage rotor component are provided with jet sub-channels, which correspond one-to-one with the multiple connecting sub-channels to form multiple arc-shaped channels. That is, each set of jet channels consists of multiple jet sub-channels, and each set of connecting channels consists of multiple connecting sub-channels. Each jet sub-channel and each connecting sub-channel form an arc-shaped channel. The beginning of the arc-shaped channel is the axial center of the rotation axis, and the end of the arc-shaped channel is the blade tip (jet outlet). The beginning and end of the arc-shaped channel are located on the same straight line. In other words, the arc end point of the arc-shaped channel is determined by the axial center point of the rotation axis and the outermost point of the rotor component circumferentially.

[0063] As a further preferred option, the radius of the arc of the aforementioned arc channel is 20~120mm, for example, 20mm, 45mm, 65mm, 80mm, 100mm, 120mm, etc., which can be set according to the dimensions of the rotor component and the rotating shaft.

[0064] As a further preferred option, the inner diameter of the arc-shaped channel is 0.05~2mm, for example, 0.05mm, 0.5mm, 1mm, 1.2mm, 1.6mm, 2mm, etc. That is to say, the inner diameter of both the jet sub-channel and the connecting sub-channel is between 0.05~2mm.

[0065] As a further preferred embodiment, the length of the axial channel is 10% to 80% of the length of the rotating shaft, for example, 20%, 30%, 40%, 50%, 70%, or 80%. The specific length can be determined based on the number of jet channels provided on the rotor component. That is, the front end of the rotating shaft is open, and the rear end is closed to form an axial channel. The air inlet of this axial channel is located at the front end of the rotating shaft so that the flow direction of the external gas in the air inlet channel is the same as the flow direction of the main airflow.

[0066] As a further preferred embodiment, the distance between the air inlet of the air intake channel and the first set of jet channels in the rotor component is 40% to 60% of the length of the rotating shaft, for example, 40%, 50%, or 60%.

[0067] As a further preferred embodiment, the distance from the injection outlet to the axial center of the rotating shaft is 4 to 20 mm, for example, 4 mm, 10 mm, 15 mm, or 20 mm.

[0068] As shown in Figure 9, another aspect of this disclosure proposes a Roots vacuum pump, including: a pump housing 310 and a left rotor 100 and a right rotor 200 disposed in the pump housing 310; wherein, the left rotor 100 and the right rotor 200 are both Roots vacuum pump rotors described above, and have the ability to flow media. For the specific structure, please refer to the description above, and it will not be repeated here.

[0069] Furthermore, as shown in Figure 9, the left rotor 100 and the right rotor 200 rotate in opposite directions around their respective rotation axes; the axes of the left rotation axis 110 and the right rotation axis 210 are arranged parallel to each other.

[0070] It should be noted that this embodiment does not specifically limit the materials of the left and right rotors, as long as they have high strength and wear and corrosion resistance. For example, the materials of the left and right rotors are high-nickel alloy materials.

[0071] Furthermore, as shown in Figure 9, the pump casing 310 is provided with a pump inlet 320 and a pump outlet, wherein the pump inlet 320 is the inlet for the main airflow and the pump outlet is the outlet for the main airflow.

[0072] It should be understood that the external gas entering the rotor mentioned above is different from the main airflow entering the pump casing. In this way, the high-energy jet provided by the external gas source can be used to ensure that the rotor has sufficient energy during rotation, forming an effective airflow blockage and increasing the gas molecule density.

[0073] It should be noted that the Roots vacuum pump should also include a front cover plate and a rear cover plate. The front cover plate and the rear cover plate are located at the two ends of the pump casing, respectively, to form a closed cavity with the pump casing. The front cover plate is located at the end of the pump casing closer to the pump inlet (the right side of the pump casing in Figure 9), and the rear cover plate is located at the end of the pump casing closer to the pump outlet (the left side of the pump casing in Figure 9).

[0074] As shown in Figure 10, another aspect of this disclosure provides a method for operating a Roots vacuum pump, specifically including the following steps S1 to S3:

[0075] S1. The left and right rotors rotate in opposite directions under the drive of their respective rotating shafts. The external gas is connected to the air intake channel of the rotating shaft, and the gas flows in through the air intake port of the air intake channel.

[0076] S2. The gas flows along the intake passages of the left and right rotors to at least one set of jet passages, and generates a jet at the injection outlet.

[0077] S3. The jet is discharged from the injection outlet and interacts with the main airflow inside the pump.

[0078] Specifically, the external gas enters through the air inlets of the left and right rotors and flows continuously along the axial channel until it reaches the connecting channel that connects with the axial channel. The external gas flowing along the axial channel flows into different connecting channels and then further into different jet channels. Finally, jets are generated at the spray outlets of different jet channels. These discharged jets interact with the main airflow inside the pump casing, increasing the gas molecule density in this area. This leads to an increase in the number of intermolecular collisions and collisions between molecules and the container wall, thereby generating higher pressure in this area. This further increases the pressure near the outlet, helping the internal and external pressures of the pump to reach equilibrium more quickly and effectively suppressing backflow impacts and pressure fluctuations at the outlet.

[0079] The structure of the Roots vacuum pump and rotor will be described below with specific embodiments:

[0080] Example 1

[0081] As shown in Figures 1 to 9, the Roots vacuum pump includes a pump housing 310 and a left rotor 100 and a right rotor 200 disposed within the pump housing 310. Both the left and right rotors include a single-stage rotor assembly, and this rotor assembly has two blades with an 8-shaped outer contour.

[0082] As shown in Figures 1 to 9, the left rotor 100 includes a left rotating shaft 110 and a figure-eight-shaped left rotor component 120 arranged axially along the left rotating shaft 110. The left rotating shaft 110 has a left intake passage 130 arranged axially, which includes a left axial passage 131 arranged axially along the left rotating shaft 110 and seven sets of left connecting passages 132 evenly spaced axially along the left axial passage 131. Correspondingly, the left rotor component 120 has seven sets of left jet passages 140 evenly spaced axially, each set of left jet passages 140 corresponding to each set of left connecting passages 132. The left injection inlet of each set of left jet passages 140 is connected to the left axial passage 131 through each set of left connecting passages 132. Seven sets of left injection outlets 141 are located at the blade tip of the left rotor component 120.

[0083] Furthermore, as shown in Figures 1 to 7, since the left rotor component is figure-eight shaped and includes two left blades, each set of left jet channels 140 includes two left jet sub-channels 142. These two left jet sub-channels 142 are respectively arranged on each left blade of the left rotor component 120. That is, each left blade is provided with one left jet sub-channel 142, and the two left blades are provided with a total of two left jet sub-channels. These two left jet sub-channels form a set of left jet channels. In this way, when each left blade on the left rotor component contacts the inner wall of the pump casing, a jet will be ejected.

[0084] Furthermore, referring to Figures 1 through 8, two left connecting sub-channels 132a, penetrating the wall thickness, are provided on the left rotating shaft 110. Each left connecting sub-channel 132a is connected to each left jet sub-channel 142 to form a left arc-shaped channel 150. That is, a left arc-shaped channel 150 is provided from the left axial channel 131 of the left rotating shaft 110 toward the tip of the left blade, and the bending extension direction of the left arc-shaped channel 150 is the same as the rotation direction of the left rotor. For example, when the left rotor rotates counterclockwise, the left arc-shaped channel on the left rotor component bends and extends counterclockwise.

[0085] It should be understood that since the figure-eight rotor component is an axisymmetric structure, the left jet sub-channels set on its two blades should be centrally symmetrical. That is, the two left jet sub-channels are centrally symmetrically distributed along the axial center of the left rotor. Of course, the corresponding two left connecting sub-channels should also be centrally symmetrically distributed, and the left arc-shaped channel is also a centrally symmetrical structure.

[0086] In some preferred embodiments, the radius of the arc of the left arc channel is 20~120mm, for example, 20mm, 45mm, 65mm, 80mm, 100mm, 120mm, etc., which can be set according to the size of the left rotor component and the left rotating shaft.

[0087] As a further preferred option, as shown in Figures 3 and 8, the radius of the left arc-shaped channel 150 is 45 mm.

[0088] In some other preferred embodiments, the inner diameter of the left arc-shaped channel is 0.05~2mm, for example, 0.05mm, 0.5mm, 1mm, 1.2mm, 1.6mm, 2mm, etc.

[0089] As a further preferred option, as shown in Figure 8, the inner diameter of the left arc-shaped channel 150 is 2mm.

[0090] In some other preferred embodiments, the length of the left axial channel is 10% to 80% of the length of the left rotation shaft, for example, 20%, 30%, 40%, 50%, 70%, 80%, and the specific length can be determined according to the number of jet channels provided on the left rotor component.

[0091] As a further preferred option, as shown in Figure 5, the length of the left axial channel 131 is 80% of the length of the left rotation axis 110, which meets the requirement of setting up multiple sets of left jet channels.

[0092] In some other preferred embodiments, the distance between the left air intake of the left air intake passage and the first set of left jet passages in the left rotor component is 40% to 60% of the length of the left rotation shaft, for example, 40%, 50%, 60%.

[0093] As a further preferred embodiment, as shown in Figures 1 to 4, the distance between the left air intake of the left air intake channel 130 and the first set of left jet channels 140 in the left rotor component 120 is 40% of the length of the left rotation shaft 110.

[0094] In some other preferred embodiments, the distance from the left injection outlet to the center of the left rotation axis is 4 to 20 mm, for example, 4 mm, 10 mm, 15 mm, 20 mm.

[0095] As a further preferred embodiment, as shown in Figures 1 to 3, the distance between the left injection outlet 141 and the center of the left rotation axis 110 is 20 mm.

[0096] It should be understood that, generally speaking, the right rotor should have the same structure as the left rotor. When the left rotor has seven sets of left jet channels, the right rotor should also have seven sets of right jet channels. Of course, in other embodiments, the left rotor may be provided with other numbers of left jet channels, and the right rotor may be provided with other numbers of right jet channels. The number of sets of left jet channels and right jet channels may be equal or unequal, and no specific limitation is made in this regard.

[0097] Specifically, as shown in Figures 1 to 8, the right rotor 200 includes a right rotation shaft 210 and an 8-shaped right rotor component 220 arranged axially along the right rotation shaft 210. The right rotation shaft 210 has a right intake passage 230 arranged axially, which includes a right axial passage 231 arranged axially along the right rotation shaft 210 and seven sets of right connecting passages 232 evenly spaced axially along the right axial passage 231. Correspondingly, the right rotor component 220 has seven sets of right jet passages 240 evenly spaced axially, each set of right jet passages 240 corresponding to each set of right connecting passages 232, and each set of right jet passages 240 is connected to the right axial passage 231 through each set of right connecting passages 232. Seven sets of right injection outlets 241 are evenly spaced at the blade tip of the right rotor component 220.

[0098] Furthermore, as shown in Figures 1 to 8, based on the figure-eight-shaped outline of the right rotor component, which includes two right blades, each set of right jet channels 240 includes two right jet sub-channels 242. These two right jet sub-channels 242 are respectively arranged on each right blade of the right rotor component 220. That is, one right jet sub-channel 242 is arranged on one right blade. In this way, when each right blade on the right rotor component contacts the inner wall of the pump casing, a jet will be ejected.

[0099] Furthermore, referring to Figures 1 through 8, two right connecting sub-channels 232a, penetrating the wall thickness, are provided on the right rotating shaft 210. Each right connecting sub-channel 232a is connected to each right jet sub-channel 242 to form a right arc-shaped channel 160. That is, a right arc-shaped channel 160 is formed from the right axis of the right rotating shaft towards the tip of the right blade, and the bending extension direction of the right arc-shaped channel 160 is the same as the rotation direction of the right rotor. For example, when the right rotating shaft rotates clockwise, the right arc-shaped channel on the right rotor component bends and extends in a clockwise direction, which is opposite to the bending extension direction of the left arc-shaped channel.

[0100] In some preferred embodiments, as shown in Figures 3 and 8, the radius of the arc of the right arc channel 160 is 20~120mm. It can also be set according to the size of the right rotor component and the right rotating shaft. The radius of the arc of the right arc channel is the same as the radius of the arc of the left arc channel. For example, in this embodiment 1, 45mm is preferred.

[0101] In some other preferred embodiments, as shown in FIG8, the inner diameter of the right arc-shaped channel 160 is 0.05~2mm. The inner diameter of the right arc-shaped channel can be the same as the inner diameter of the left arc-shaped channel. For example, in this embodiment 1, it is preferred to be 2mm. Of course, the inner diameter of the right arc-shaped channel can also be different from the inner diameter of the left arc-shaped channel.

[0102] In some other preferred embodiments, as shown in FIG7, the length of the right axial channel 231 is 10% to 80% of the length of the right rotation axis 210. The length of the right axial channel can be the same as the length of the left axial channel. For example, in this embodiment 1, it is preferred to be 80%. Of course, the length of the right axial channel can also be different from the length of the left axial channel. Specifically, it can be determined according to the number of right jet channels that need to be set.

[0103] In some other preferred embodiments, as shown in Figures 1 to 4, the distance between the right air intake of the right air intake channel 230 and the first group of right jet channels 240 in the right rotor component 220 is 40% to 60% of the length of the right rotation shaft 210. For example, in this embodiment 1, 40% is preferred.

[0104] In some other preferred embodiments, as shown in Figures 1 to 3, the distance between the right injection outlet 241 and the axial center of the right rotation shaft 210 is 4 to 20 mm, for example, 20 mm is preferred in this embodiment 1.

[0105] It should be understood that this embodiment 1 is described using a single-stage rotor component on a rotating shaft as an example. In other embodiments, there may be a multi-stage rotor component. Each stage rotor component may have one set of jet channels or multiple sets of jet channels. Correspondingly, one or more sets of connecting channels should be provided on the rotating shaft. These multiple sets of connecting channels may be evenly spaced or unequally spaced.

[0106] Example 2

[0107] The Roots vacuum pump includes a pump casing and a left rotor and a right rotor disposed within the pump casing. Both the left and right rotors include a single-stage rotor assembly, and this rotor assembly has three blades that are evenly spaced and have a Y-shaped outer profile.

[0108] The left rotor includes a left rotating shaft and a first-stage left rotor component arranged axially along the left rotating shaft. The left rotor component has three left blades. The left rotating shaft has a left intake passage arranged axially, which includes a left axial channel arranged axially along the left rotating shaft and multiple sets of left connecting channels evenly spaced axially along the left axial channel. Correspondingly, the left rotor component has multiple sets of left jet channels evenly spaced axially along its axis. Each set of left jet channels corresponds one-to-one with each set of left connecting channels, and the left injection inlet of each set of left jet channels is connected to the left axial channel through each set of left connecting channels. Multiple sets of left injection outlets correspond to the blade tips of the left rotor component.

[0109] Similarly, the right rotor includes a right rotation shaft and a right rotor component arranged axially along the right rotation shaft. The right rotor component has three right blades with a Y-shaped profile. The right rotation shaft has a right intake passage arranged axially, which includes a right axial channel arranged axially along the right rotation shaft and multiple sets of right connecting channels evenly spaced axially along the right axial channel. Correspondingly, the right rotor component has multiple sets of right jet channels evenly spaced axially along its axis. Each set of right jet channels corresponds one-to-one with each set of right connecting channels, and the right injection inlet of each set of right jet channels is connected to the right axial channel through each set of right connecting channels. Multiple sets of right injection outlets correspond to the blade tips of the right rotor component.

[0110] It should be noted that this embodiment does not specifically limit the number of groups of left jet channel, left connecting channel, right jet channel, and right connecting channel. For example, three groups, five groups, seven groups, etc., can be set according to the size of the rotor.

[0111] Furthermore, since the left rotor component includes three left blades, each set of left jet channels includes three left jet sub-channels. These three left jet sub-channels are respectively arranged on each left blade of the left rotor component, and a left injection outlet is provided at the tip of each left blade. Secondly, three left connecting sub-channels penetrating the wall thickness are provided on the left rotation shaft. These three left connecting sub-channels are evenly distributed circumferentially along the left rotation shaft, forming a set of left connecting channels. Each left connecting sub-channel is connected to each left jet sub-channel to form a left arc-shaped channel, and the bending extension direction of this left arc-shaped channel is the same as the rotation direction of the left rotor. That is, when the left rotor rotates counterclockwise, multiple sets of left jet channels extending counterclockwise are provided on the left rotor component, and each set of left jet channels includes three left jet sub-channels extending counterclockwise.

[0112] Similarly, each set of right jet channels includes three right jet sub-channels, which are respectively arranged on each right blade of the right rotor component, and a right jet outlet is provided at the tip of each right blade. Secondly, three right connecting sub-channels penetrating the wall thickness are provided on the right rotating shaft. These three right connecting sub-channels are evenly distributed circumferentially along the right rotating shaft, forming a set of right connecting channels. Each right connecting sub-channel is connected to each right jet sub-channel to form a right arc-shaped channel, and the bending extension direction of this right arc-shaped channel is the same as the rotation direction of the right rotor.

[0113] It should be noted that this embodiment does not specifically limit the number of stages of the rotor component. It can be a single-stage rotor component or a multi-stage rotor component. When multiple stages of rotor components are provided on the rotating shaft, one or more sets of jet channels can be provided on each stage of the rotor component.

[0114] It should be further noted that the arc radius of the arc-shaped channel, the inner diameter of the channel, the length of the axial channel, the distance from the axial center of the rotating shaft of the right injection outlet, and the distance from the air inlet of the air inlet channel to the first group of jet channels in the rotor component, etc., in this embodiment can all be referred to the above description and can be set according to the specific dimensions of the rotor. No specific limitation is made here.

[0115] Example 3

[0116] The Roots vacuum pump includes a pump casing and a left rotor and a right rotor disposed within the pump casing. Both the left and right rotors include a single-stage rotor assembly, and this rotor assembly has five blades that are evenly spaced.

[0117] The left rotor includes a left rotating shaft and a left rotor component arranged axially along the left rotating shaft. The left rotor component has five left blades. The left rotating shaft has a left intake passage along its axial direction, which includes a left axial channel and multiple sets of left connecting channels evenly spaced along the axial direction of the left axial channel. Correspondingly, the left rotor component has multiple sets of left jet channels evenly spaced along its axial direction. Each set of left jet channels corresponds one-to-one with each set of left connecting channels, and the left injection inlet of each set of left jet channels is connected to the left axial channel through each set of left connecting channels. Multiple sets of left injection outlets correspond to the blade tips of the left rotor component. In other words, when the left rotor rotates counterclockwise, the left rotor component has multiple sets of left jet channels extending counterclockwise, and each set of left jet channels includes five left jet sub-channels extending counterclockwise.

[0118] Similarly, the right rotor includes a right rotation shaft and a right rotor component arranged axially along the right rotation shaft, the right rotor component having five blades. The right rotation shaft has a right intake passage arranged axially, the right intake passage including a right axial channel arranged axially along the right rotation shaft and multiple sets of right connecting channels evenly spaced axially along the right axial channel. Correspondingly, the right rotor component has multiple sets of right jet channels evenly spaced axially along its axis, each set of right jet channels corresponding one-to-one with each set of right connecting channels, and the right injection inlet of each set of right jet channels is connected to the right axial channel through each set of right connecting channels. Multiple sets of right injection outlets correspond to the blade tips of the right rotor component.

[0119] It should be noted that this embodiment does not specifically limit the number of groups of the left jet channel, the left connecting channel, the right jet channel, and the right connecting channel. For example, two groups, three groups, four groups, five groups, etc., can be set according to the size of the rotor.

[0120] Furthermore, since the left rotor component includes five left blades, each group of left jet channels includes five left jet sub-channels. These five left jet sub-channels are respectively arranged on each left blade of the left rotor component, and a left injection outlet is provided at the tip of each left blade. Secondly, five left connecting sub-channels penetrating the wall thickness are provided on the left rotating shaft. These five left connecting sub-channels are evenly distributed circumferentially along the left rotating shaft, forming a group of left connecting channels. Each left connecting sub-channel is connected to each left jet sub-channel to form a left arc-shaped channel. The bending extension direction of this left arc-shaped channel is the same as the rotation direction of the left rotor. For example, when the left rotating shaft rotates counterclockwise, the left arc-shaped channel on the left rotor component bends and extends counterclockwise.

[0121] Similarly, each set of right jet channels includes five right jet sub-channels, which are respectively arranged on each right blade of the right rotor component, and a right jet outlet is provided at the tip of each right blade. Secondly, five right connecting sub-channels penetrating the wall thickness are provided on the right rotating shaft. These five right connecting sub-channels are evenly distributed circumferentially along the right rotating shaft, forming a set of right connecting channels. Each right connecting sub-channel is connected to each right jet sub-channel to form a right arc-shaped channel, the bending extension direction of which is the same as the rotation direction of the right rotor. For example, when the right rotating shaft rotates clockwise, the right arc-shaped channel eye on the right rotor component bends and extends clockwise.

[0122] It should be noted that this embodiment does not specifically limit the number of stages of the rotor component. It can be a single-stage rotor component or a multi-stage rotor component. When multiple stages of rotor components are provided on the rotating shaft, one or more sets of jet channels can be provided on each stage of the rotor component.

[0123] It should be further noted that the arc radius of the arc-shaped channel, the inner diameter of the channel, the length of the axial channel, the distance from the axial center of the rotating shaft of the right injection outlet, and the distance from the air inlet of the air inlet channel to the first group of jet channels in the rotor component, etc., in this embodiment can all be referred to the above description and can be set according to the specific dimensions of the rotor. No specific limitation is made here.

[0124] This disclosure presents a Roots vacuum pump rotor, a Roots vacuum pump, and its operating method, which have the following advantages over the prior art:

[0125] First, this disclosure adds a jet structure with openings to the rotor and introduces external gas to form a high-energy jet, ensuring that the rotor has sufficient energy during rotation to form an effective airflow blockage.

[0126] Second, the jet direction formed by this disclosure is opposite to the leakage flow generated by the pressure difference at the gap, which can significantly reduce leakage loss at the blade tip gap.

[0127] Third, when the rotor rotates to a position close to the exhaust port, the powerful jet mixes with the main fluid, increasing the density of gas molecules in the region. This leads to an increase in the number of intermolecular collisions and collisions between molecules and the container wall, thereby generating higher pressure in the region. This, in turn, increases the pressure near the outlet side, which helps the internal and external pressures of the pump casing to reach equilibrium more quickly, effectively suppressing backflow impacts and pressure fluctuations at the outlet.

[0128] Fourth, this disclosure reduces the heat load in the blade tip region by setting a jet channel on the rotor. As the jet fluid expands along the inner wall of the pump casing, it can carry away the local heat near the inner wall of the pump casing, thereby achieving temperature control inside the pump casing and achieving a cooling effect. This not only helps maintain the temperature stability of the equipment, but also improves the overall efficiency and extends the service life of the equipment.

[0129] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of this disclosure, and this disclosure is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and substance of this disclosure, and these modifications and improvements are also considered to be within the scope of protection of this disclosure.

Claims

1. A rotor for a Roots vacuum pump, characterized in that, The Roots vacuum pump rotor includes a rotating shaft and at least one stage rotor component arranged axially along the rotating shaft; wherein... The rotating shaft has an air intake channel along its axial direction, and the air intake port of the air intake channel is located at one end near the front cover plate of the Roots vacuum pump. The rotor component of any stage is provided with at least one set of jet channels along its axial direction, the injection inlet of the jet channel is connected to the air intake channel, and the injection outlet of the jet channel is located at the blade tip of the rotor component; An external air source flows into the jet channel along the air inlet channel and is ejected through the jet outlet. The jet movement direction of the jet outlet is consistent with the rotation direction of the Roots vacuum pump rotor.

2. The Roots vacuum pump rotor according to claim 1, characterized in that, The jet channel bends and extends from the injection inlet to the injection outlet, and the direction of bending and extension is the same as the rotation direction of the Roots vacuum pump rotor.

3. The rotor of the Roots vacuum pump according to claim 1, characterized in that, The intake passage includes an axial passage arranged along the axis of the rotation, and at least one set of connecting passages distributed axially along the axial passage; wherein, The injection inlet of each set of jet channels is connected to the axial channel through each set of connecting channels.

4. The Roots vacuum pump rotor according to claim 3, characterized in that, The rotor component of any stage is provided with multiple sets of jet channels spaced apart along its axial direction, and the rotating shaft is provided with multiple sets of connecting channels spaced apart along its axial direction. Multiple jet channels correspond one-to-one with multiple connecting channels.

5. The Roots vacuum pump rotor according to claim 4, characterized in that, Each set of the connection channels includes multiple connection sub-channels, which are circumferentially spaced along the rotation axis; Each of the rotor components described in any one stage is provided with a jet sub-channel on multiple blades, and the multiple jet sub-channels correspond one-to-one with the multiple connecting sub-channels to form multiple arc-shaped channels.

6. The Roots vacuum pump rotor according to claim 5, characterized in that, The radius of the arc-shaped channel is 20~120mm; and / or, The inner diameter of the arc-shaped channel is 0.05~2mm; and / or, The length of the axial channel is 10% to 80% of the length of the rotating shaft.

7. The Roots vacuum pump rotor according to claim 1, characterized in that, The distance between the air inlet of the air intake channel and the first set of jet channels in the first stage rotor component is 40% to 60% of the length of the rotating shaft.

8. The rotor of the Roots vacuum pump according to claim 1, characterized in that, The distance between the injection outlet and the rotating shaft is 4 to 20 mm.

9. A Roots vacuum pump, characterized in that, The Roots vacuum pump includes: a pump housing and a left rotor and a right rotor disposed within the pump housing; wherein... The left rotor and the right rotor are Roots vacuum pump rotors as described in any one of claims 1 to 8.

10. A method for operating the Roots vacuum pump as described in claim 9, characterized in that, The working method includes: S1. The left and right rotors rotate in opposite directions under the drive of their respective rotating shafts. An external air source is connected to the air intake channel of the rotating shaft, and gas flows in through the air inlet of the air intake channel. S2. The gas flows along the intake passages of the left and right rotors to at least one set of jet passages, and generates a jet at the injection outlet. S3. The jet is discharged from the injection outlet and interacts with the main airflow inside the pump casing.

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