Combined rotor and dry vacuum pump

Abstract

The utility model provides a combined rotor and a dry vacuum pump, and belongs to the technical field of dry vacuum pumps. The combined rotor comprises a rotating shaft, a plurality of front-stage rotors and a plurality of rear-stage corrosion-resistant rotors, wherein the front-stage rotors and the rear-stage corrosion-resistant rotors are sequentially arranged on the rotating shaft in the gas flowing direction. Wherein the plurality of front-stage rotors and the rotating shaft are integrally formed; and the plurality of rear-stage corrosion-resistant rotors are integrally formed. The front-stage rotor and the rotating shaft are of an integrated structure, the multiple rear-stage corrosion-resistant rotors are of an integrated structure, and compared with a multi-stage rotor structure, the problem of accumulated errors generated in the assembling process can be avoided; moreover, the rear-stage corrosion-resistant rotor is made of a corrosion-resistant material, so that the corrosion resistance of the rear-stage corrosion-resistant rotor is more stable than that of a rotor which is provided with a corrosion-resistant coating.

Description

Technical Field

[0001] The present disclosure belongs to the technical field of dry vacuum pumps, and particularly relates to a combined rotor and a dry vacuum pump. Background Art

[0002] The structural components of existing dry vacuum pumps mainly include a stator and a rotor. Most of the stators and rotors of vacuum pumps are made of metal materials. Since dry vacuum pumps are used in environments with physical and chemical corrosive process gases, the process gases will contain corrosive gases such as chlorine, boron trichloride, hydrogen bromide, fluorine, and chlorine trifluoride. Prolonged operation causes the stator and rotor to be corroded to varying degrees due to chemical and physical reactions. As the amount of corrosion increases, the axial and radial clearances between the stator and the rotor become larger, and some gas will leak internally during the compression process, resulting in a decline in the performance of the dry vacuum pump such as pumping speed and ultimate vacuum, and at the same time greatly shortening the service life of the dry vacuum pump.

[0003] During the operation of the dry vacuum pump, the process gases compressed in the previous stage will flow through the rotor in the subsequent stage, resulting in a gradual increase in the pressure of the subsequent rotor. The corrosion degree of each rotor is inconsistent. According to actual operation analysis, the amount of corrosion of the subsequent rotors is more serious than that of the previous rotors.

[0004] In response to this, existing technologies have proposed using corrosion-resistant materials to prepare the rotor and stator to increase corrosion resistance and extend the service life of the vacuum pump. However, since the amount of corrosion of the vacuum pump stator during operation is small, this method will increase the manufacturing cost. Secondly, there are also existing technologies that set a corrosion-resistant coating on the surface of the rotor. This coating is prone to peeling off in a high-temperature environment, thus losing its corrosion-resistant function. Moreover, when preparing the coating on the surface of the rotor, the thickness requirements for the coating are relatively high. For example, the coating thickness needs to be controlled within 0.01 mm to

[0005] 2 mm. The thickness of the coating and the outer diameter of the rotor cannot be accurately controlled during the production process. When the clearance between the stator and the rotor is large, problems such as unqualified pumping speed and ultimate vacuum performance and short service life occur. When the clearance between the stator and the rotor is small, the working temperature of the vacuum pump is high, and problems such as downtime occur. Summary of the Utility Model

[0006] The present disclosure aims to at least solve one of the technical problems existing in the prior art, and provides a combined rotor and a dry vacuum pump.

[0007] On the one hand, the present disclosure provides a combined rotor, including: a rotating shaft, and a plurality of front-stage rotors and a plurality of rear-stage corrosion-resistant rotors sequentially arranged on the rotating shaft along the gas flow direction; wherein,

[0008] The plurality of front-stage rotors are integrally formed with the rotating shaft;

[0009] The multiple post-stage corrosion-resistant rotors are integrally formed.

[0010] Optionally, the post-stage corrosion-resistant rotor is any one of an iron-based alloy rotor, a nickel-based alloy rotor, and a cobalt-based alloy rotor.

[0011] Optionally, the post-stage corrosion-resistant rotor is a high-nickel alloy rotor.

[0012] Optionally, the multiple pre-stage rotors and the rotating shaft are made of different materials from those of the multiple post-stage corrosion-resistant rotors.

[0013] Optionally, the multiple pre-stage rotors are ductile iron rotors, and the rotating shaft is a ductile iron rotating shaft.

[0014] Optionally, a recessed groove structure is provided on either the outer surface of the rotating shaft or the inner surface of the multiple post-stage corrosion-resistant rotors, and a protruding structure is provided on the other of the outer surface of the rotating shaft and the inner surface of the multiple post-stage corrosion-resistant rotors, and the protruding structure is received in the groove structure.

[0015] Optionally, keyway structures are provided on both the rotating shaft and the multiple post-stage corrosion-resistant rotors;

[0016] The rotating shaft and the multiple post-stage corrosion-resistant rotors are connected by a key received in the keyway structure.

[0017] On the other hand, the present disclosure provides a dry vacuum pump, which includes a housing, and a left rotor and a right rotor disposed in the housing, and the left rotor and the right rotor adopt the combined rotor described above.

[0018] The present disclosure provides a combined rotor and a dry vacuum pump. The combined rotor includes: a rotating shaft, and a plurality of pre-stage rotors and a plurality of post-stage corrosion-resistant rotors sequentially arranged on the rotating shaft along the gas flow direction; wherein, the plurality of pre-stage rotors and the rotating shaft are integrally formed; the plurality of post-stage corrosion-resistant rotors are integrally formed. The pre-stage rotors and the rotating shaft of the present disclosure are of an integral structure, and the plurality of post-stage corrosion-resistant rotors are of an integral structure. By assembling, a segmented material combined rotor is formed. Compared with a multi-stage rotor structure, the problem of cumulative errors generated during the assembly process can be avoided; and, since the post-stage corrosion-resistant rotors are made of corrosion-resistant materials, compared with setting a corrosion-resistant coating on the rotors, the corrosion resistance of the post-stage corrosion-resistant rotors is more stable and not easily peeled off. Description of the Drawings

[0019] Figure 1 It is a schematic structural diagram of a combined rotor according to an embodiment of the present disclosure;

[0020] Figure 2Schematic diagram of the rotating shaft and multiple pre-stage rotors according to another embodiment of the present disclosure;

[0021] Figure 3 Schematic diagram of multiple post-stage corrosion-resistant rotors according to another embodiment of the present disclosure. Detailed implementation manners

[0022] To enable those skilled in the art to better understand the technical solutions of the present disclosure, the present disclosure will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners. It should be understood that the specific embodiments described herein are only used to explain the present disclosure, which are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present disclosure.

[0023] In some descriptions of the present disclosure, terms such as "including" or "comprising" etc. neither limit the mentioned shapes, numbers, steps, actions, operations, components, elements and / or their groups, nor exclude the occurrence or addition of one or more other different shapes, numbers, steps, actions, operations, components, elements and / or their groups.

[0024] In some descriptions of the present disclosure, terms such as "installed", "connected", "coupled" or "fixed" etc. similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirectly through an intermediate medium, and may be the communication inside two elements or the interaction relationship between two elements.

[0025] In some descriptions of the present disclosure, the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only used to represent the relative positional relationship. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0026] As Figures 1 to 3 shown, on one hand, the present disclosure provides a combined rotor 100, and the combined rotor 100 includes: a rotating shaft 110, multiple pre-stage rotors 120, and multiple post-stage corrosion-resistant rotors 130; wherein, the multiple pre-stage rotors 120 and the multiple post-stage corrosion-resistant rotors 130 are sequentially arranged on the rotating shaft 110 along the gas flow direction, the multiple pre-stage rotors 120 are integrally formed with the rotating shaft 110, and the multiple post-stage corrosion-resistant rotors 130 are integrally formed.

[0027] It should be understood that the gas entering the dry vacuum pump is inhaled and compressed by the rotating rotor. The front-stage rotor refers to the rotor through which the gas entering the dry vacuum pump first flows. The rotor through which the gas further flows after being compressed by the front stage is the rear-stage corrosion-resistant rotor. That is, the front-stage rotor is located at the front end of the rotating shaft along the gas flow direction, and the rear-stage corrosion-resistant rotor is located at the rear end of the rotating shaft along the gas flow direction. Generally speaking, the corrosion amount of the rear-stage corrosion-resistant rotor is more serious than that of the front-stage rotor.

[0028] In this embodiment, multiple rear-stage rotors adopt integrally formed corrosion-resistant rotors. By assembling them on the rotating shaft and jointly forming the dry vacuum pump rotor with multiple front-stage rotors, the corrosion amount of the vacuum pump rotor during operation can be reduced, and there is no need to prepare an anti-corrosion coating on the rotor surface. The combined rotor with this structure has better stability and corrosion resistance, and there is no problem of coating peeling off. Secondly, by setting multiple front-stage rotors and the rotating shaft as an integral structure, and setting multiple rear-stage corrosion-resistant rotors as an integral structure, the cumulative error problem generated during the assembly process can be avoided, thereby ensuring that the pumping speed and ultimate vacuum performance of the dry vacuum pump are qualified and extending the service life of the dry vacuum pump.

[0029] It should also be understood that since multiple front-stage rotors and multiple rear-stage corrosion-resistant rotors are set as two separate structures, a segmented material combined rotor can be formed. For example, multiple rear-stage rotors adopt corrosion-resistant rotors, and multiple front-stage rotors adopt ductile iron rotors. Of course, the rotating shaft is also preferably a ductile iron rotating shaft, which can not only reduce the corrosion amount but also reduce the manufacturing cost.

[0030] In some preferred embodiments, the rear-stage corrosion-resistant rotor is any one of an iron-based alloy rotor, a nickel-based alloy rotor, and a cobalt-based alloy rotor, and such rotors have good corrosion resistance.

[0031] As a further preferred solution, the rear-stage corrosion-resistant rotor is preferably a high-nickel alloy rotor. Among them, high-nickel alloys mainly include nickel, iron, manganese, magnesium, chromium, tungsten, molybdenum, cobalt, aluminum, titanium, boron, zirconium, silicon, etc., and no specific limitation is made thereto.

[0032] It should be noted that the number of multiple front-stage rotors and multiple rear-stage corrosion-resistant rotors in this embodiment is not specifically limited. For example, there are two or three front-stage rotors, two or three rear-stage corrosion-resistant rotors, etc.

[0033] It should also be understood that based on the fact that the rotating shaft and multiple front-stage rotors provided thereon are an integral structure, only the integrally formed multiple rear-stage corrosion-resistant rotors need to be installed on the rotating shaft. Compared with the current multi-stage rotor structure, the cumulative error problem generated during the assembly process can be avoided.

[0034] In some preferred embodiments, a recessed groove structure is provided on either the outer surface of the rotating shaft or the inner surface of the plurality of subsequent corrosion-resistant rotors, and a protruding structure is provided on the other of the outer surface of the rotating shaft and the inner surface of the plurality of subsequent corrosion-resistant rotors. The protruding structure is received in the groove structure to connect the rotating shaft to the plurality of subsequent corrosion-resistant rotors. This assembly method is simple and convenient for disassembly.

[0035] In some other preferred embodiments, keyway structures are provided on both the outer surface of the rotating shaft and the inner surface of the plurality of subsequent corrosion-resistant rotors; the rotating shaft and the plurality of subsequent corrosion-resistant rotors are connected by keys received in the keyway structures. It should be understood that the keyway structure is a groove machined on the outer diameter of the shaft or the inner diameter of the rotor to match the key for installing the key. The two sides of the key are respectively inserted into the keyway structure, and the connection between the rotating shaft and the subsequent corrosion-resistant rotor is realized through the connection of the key. This connection method has high stability and installation accuracy.

[0036] It should be noted that the shape of the keyway structure in this embodiment is not specifically limited and should be set according to the size and shape of the received key. For example, the key can be a flat key or other structures. And, the sizes of the keyway structures provided on the outer surface of the rotating shaft and the inner surface of the plurality of subsequent corrosion-resistant rotors are matched.

[0037] Exemplarily, as Figure 2 and Figure 3 shown, a first keyway structure 111 is provided on the outer surface of the rotating shaft 110, and a second keyway structure 131 is provided on the plurality of subsequent corrosion-resistant rotors 130. When assembling the rotating shaft 110 and the plurality of subsequent corrosion-resistant rotors 130, the flat key is simultaneously inserted into the first keyway structure 111 and the second keyway structure 131 to assemble a segmented material combination rotor.

[0038] In this embodiment, by directly using corrosion-resistant rotors for the subsequent rotors and setting the plurality of subsequent rotors as an integral structure, compared with setting a corrosion-resistant coating on the rotor surface, it has better stability, is not easy to fall off, and the finished product's outer dimension and thickness dimension can be obtained by machining with a machine tool. At the same time, problems such as large errors caused by uncontrollable coating thickness can also be avoided.

[0039] It should be understood that the plurality of subsequent corrosion-resistant rotors in this embodiment should be prepared from corrosion-resistant materials, and then the plurality of integrally formed subsequent rotors are assembled with the rotating shaft to form a combined rotor. Specifically, the manufacturing method of this combined rotor includes the following steps S1 to S4:

[0040] S1. Calculate the theoretical outer dimension and clearance of the vacuum pump rotor according to the pumping speed and ultimate vacuum performance index of the vacuum pump.

[0041] S2. Design the blank models of the rotating shaft, multiple front-stage rotors, and multiple rear-stage corrosion-resistant rotors, and reserve machining allowances.

[0042] It should be understood that when designing the blank models, machining allowances should be reserved according to the wall thickness and outer dimensions of the rotors. Generally, a machining allowance of 1.5 mm is reserved.

[0043] S3. Design the digital model after finish machining according to the blank models.

[0044] S4. Rough machine and finish machine the blanks of the rotating shaft, multiple front-stage rotors, and multiple rear-stage corrosion-resistant rotors, and assemble them to obtain a combined rotor.

[0045] Specifically, use round bar stock for rough machining of the blanks of the front-stage rotors, rotating shaft, and rear-stage corrosion-resistant rotors. Subject the machined blanks to 24-hour high-temperature artificial aging, then perform finish machining on the front-stage rotors, rotating shaft, and rear-stage corrosion-resistant rotors, and then conduct sample assembly and corrosion resistance performance testing on the obtained combined rotor.

[0046] Furthermore, the manufacturing method of the combined rotor further includes steps such as the design and development of the blank molds for the front-stage rotating shaft, multiple front-stage rotors, and multiple rear-stage corrosion-resistant rotors, the machining, assembly, and life testing of the corrosion resistance performance of the finalized rotating shaft, front-stage rotors, and rear-stage corrosion-resistant rotors. That is to say, the combined rotor obtained according to the foregoing steps can be further developed into blank molds for manufacturing rotors, so as to facilitate the subsequent multiple manufacturing of combined rotors and simplify the manufacturing process.

[0047] In this embodiment, through machine tool machining, an integrated structure of multiple front-stage rotors and the rotating shaft, and an integrated structure of multiple rear-stage corrosion-resistant rotors can be respectively manufactured. These two integrated structures can be made of different materials. Then, by assembling multiple rear-stage corrosion-resistant rotors and the rotating shaft, a segmented material combined rotor is formed. Its thickness dimension and outer dimension can be controlled, cumulative errors caused by the assembly process can be avoided, the cost is low, and the obtained rotor has stable corrosion resistance, is not easy to fall off, and can improve the performance such as the pumping speed and ultimate vacuum of the vacuum pump and its service life.

[0048] On the other hand of the present disclosure, a dry vacuum pump is proposed, which includes a housing, and a left rotor and a right rotor disposed in the housing. The left rotor and the right rotor adopt the combined rotor given above. For the specific structure and material, please refer to the foregoing description and will not be elaborated here.

[0049] Specifically, the left rotor includes a left rotating shaft, and a plurality of left front-stage rotors and a plurality of left rear-stage corrosion-resistant rotors arranged on the left rotating shaft. Among them, the plurality of left front-stage rotors are integrally formed with the left rotating shaft, and the plurality of left rear-stage corrosion-resistant rotors are integrally formed. Similarly, the right rotor includes a right rotating shaft, and a plurality of right front-stage rotors and a plurality of right rear-stage corrosion-resistant rotors arranged on the right rotating shaft. Among them, the plurality of right front-stage rotors are integrally formed with the right rotating shaft, and the plurality of right rear-stage corrosion-resistant rotors are integrally formed.

[0050] In some preferred embodiments, the plurality of left front-stage rotors and the plurality of right front-stage rotors are made of ductile iron rotors.

[0051] In some other preferred embodiments, the left rotating shaft and the right rotating shaft are made of ball-milled cast iron rotating shafts.

[0052] In some other preferred embodiments, the plurality of left rear-stage corrosion-resistant rotors and the plurality of right rear-stage corrosion-resistant rotors are made of corrosion-resistant rotors. For example, iron-based alloy rotors, nickel-based alloy rotors, cobalt-based alloy rotors, etc.

[0053] It should be understood that the left rotor and the right rotor rotate in opposite directions along their respective rotation axes, and the axis of the left rotating shaft corresponding to the left rotor and the axis of the right rotating shaft corresponding to the right rotor are arranged parallel to each other. It should be noted that the parallel arrangement here should be understood in a broad sense. Considering manufacturing and installation errors, the axes of the rotating shafts of the left rotor and the right rotor are allowed to show a certain angle of inclination within the error range, and this kind of inclination is also allowed.

[0054] The present disclosure proposes a combined rotor and a dry vacuum pump, which have the following beneficial effects compared with the prior art:

[0055] First, the plurality of rear-stage rotors of the present disclosure are corrosion-resistant rotors, having stable corrosion resistance, and are not easy to fall off compared with corrosion-resistant coatings and are more stable.

[0056] Second, the plurality of rear-stage corrosion-resistant rotors, the plurality of front-stage rotor shafts and the rotating shafts of the present disclosure are respectively set as two separate integral structures. The finished product's external dimension and thickness dimension can be obtained with high precision by machine tool processing, which can avoid the problem of cumulative errors caused by the assembly process. At the same time, compared with the coated rotors, it can also avoid the problem of dimensional deviation caused by the uncontrollable coating thickness, further improving the performance such as pumping speed and ultimate vacuum of the vacuum pump and its service life.

[0057] It can be understood that the above embodiments are only exemplary embodiments adopted to illustrate the principle of the present disclosure. However, the present disclosure is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present disclosure, and these modifications and improvements are also regarded as the protection scope of the present disclosure.

Claims

1. A combined rotor, characterized in that: include: A rotating shaft, and a plurality of front-stage rotors and a plurality of rear-stage corrosion-resistant rotors sequentially arranged on the rotating shaft along the gas flow direction; wherein, The plurality of front-stage rotors are integrally formed with the rotating shaft; The plurality of rear-stage corrosion-resistant rotors are integrally formed.

2. The combined rotor according to claim 1, characterized in that: The rear-stage corrosion-resistant rotor is any one of an iron-based alloy rotor, a nickel-based alloy rotor and a cobalt-based alloy rotor.

3. The combined rotor according to claim 2, characterized in that: The rear-stage corrosion-resistant rotor adopts a high-nickel alloy rotor.

4. The combined rotor according to any one of claims 1 to 3, characterized in that: The materials of the plurality of front-stage rotors and the rotating shaft are different from those of the plurality of rear-stage corrosion-resistant rotors.

5. The combined rotor according to claim 4, characterized in that: The plurality of front-stage rotors are ductile iron rotors, and the rotating shaft is ductile iron rotating shaft.

6. The combined rotor according to any one of claims 1 to 3, characterized in that: A groove structure recessed inwardly is provided on any one of the outer surface of the rotating shaft and the inner surfaces of the plurality of rear-stage corrosion-resistant rotors, and a protrusion structure protruding outwardly is provided on the other one of the outer surface of the rotating shaft and the inner surfaces of the plurality of rear-stage corrosion-resistant rotors, and the protrusion structure is accommodated in the groove structure.

7. The combined rotor according to any one of claims 1 to 3, characterized in that: The outer surface of the rotating shaft and the inner surfaces of the plurality of subsequent corrosion-resistant rotors are both provided with keyway structures; The rotating shaft and the plurality of subsequent corrosion-resistant rotors are connected via keys accommodated in the keyway structure.

8. A dry vacuum pump, characterized in that: The dry vacuum pump comprises: a housing, and a left rotor and a right rotor arranged in the housing, wherein the left rotor and the right rotor adopt the combined rotor according to any one of claims 1 to 7.

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