Multi-stage double-shaft rotary pump and multi-stage claw pump

Abstract

Provided is a multi-stage double-shaft rotary pump and a multi-stage claw pump that can efficiently cool a multi-stage pump chamber and a rotor by air cooling or water cooling. The pump chamber is provided in multiple stages, has two rotary shafts (20A, 20B) and two rotors (21A, 21B, 22A, 22B) disposed in each stage of the pump chamber (11, 12), and has, in an inter-stage portion (30) disposed between a front-stage pump chamber (11) having a front-stage pump exhaust-side end wall (11a) provided with an exhaust port (11b) and a rear-stage pump chamber (12) having a rear-stage pump intake-side end wall (12a) provided with an intake port (12b), an inter-stage communication chamber (33) that communicates the exhaust port (11b) and the intake port (12b) at a middle in a left-right direction, a one-side inter-stage liquid cooling flow path (31) that enables cooling air or a coolant to flow from a lower side to an upper side on one side of the left-right direction, and a other-side inter-stage liquid cooling flow path (32) that enables cooling air or a coolant to flow from a lower side to an upper side on the other side of the left-right direction.

Description

Technical Field

[0001] This invention relates to a multi-stage twin-shaft rotary pump, wherein a pump chamber with a cross-sectional shape in which a portion of two circles coincides in the left-right direction is configured as multiple stages. The multi-stage twin-shaft rotary pump comprises: two rotating shafts arranged parallel to each other in the pump chamber of each stage and rotating in opposite directions at the same speed via a pair of gears; and two rotors for each stage, which are configured to be arranged corresponding to the two rotating shafts in the pump chamber of each stage, rotating in a non-contact state and capable of discharging the inhaled gas. Background Technology

[0002] As an existing rotary pump, the applicant proposes the following solution: a rotor rotating within a pump chamber 10 is disposed at one end of a rotating shaft and supported in a cantilever state. The pump body is configured as a segmented structure, forming a cooling gap between the pump chamber body and the bearing body. The pump chamber body is provided with a cylinder body and end walls respectively disposed at both ends of the cylinder body to form the pump chamber. The bearing body is provided with a bearing portion that provides axial support for the rotating shaft, so that the rotor is disposed at one end of the rotating shaft and supported in a cantilever state (see Patent Document 1).

[0003] Based on this conventional rotary pump, the following effects are achieved: by using air cooling, the heat generated by the drive is reduced from being transferred to the main body of the bearing section, thereby extending the lifespan of functional components such as the bearing section.

[0004] In addition, as with conventional dual-shaft rotary pumps and claw pumps, the applicant has proposed the following solution: a pump chamber main body, two rotating shafts, two rotors rotating in a non-contact state, and a bearing main body. The pump chamber main body is configured to form a pump chamber, including a cylinder, one end wall, and the other end wall. The bearing main body is configured to form a structural wall with a bearing and also serves as a gearbox. The pump body is divided into a pump chamber main body and a bearing main body to form a cooling gap between the pump chamber main body and the bearing main body. A bearing coolant flow path is provided in the structural wall of the bearing main body located on the side of the pump chamber main body (see Patent Document 2).

[0005] Based on the conventional twin-shaft rotary pump and claw pump, this design enables the use of coolant to more effectively prevent overheating of the pump body and significantly improves the reliability of pump operation.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2021-67246 (Page 1) Figure 2 )

[0009] Patent Document 2: Japanese Patent Application Publication No. 2023-13385 (Page 1) Figure 1 ) Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] The problem to be solved regarding multistage twin-shaft rotary pumps and multistage claw pumps is that, for single-stage twin-shaft rotary pumps, as mentioned in the aforementioned prior art documents, structures have been proposed to appropriately prevent overheating of the pump body through air cooling or water cooling. However, for multistage twin-shaft rotary pumps requiring high vacuum performance, no suitable structure has been proposed. For example, in the single-stage twin-shaft rotary pump (single-stage water-cooled vacuum pump) shown in the aforementioned Patent Document 2, cooling the exhaust port side (exhaust side) of the pump chamber in the rotor is effective in avoiding contact between rotors. In this single-stage water-cooled vacuum pump, a water-cooled cooling circuit is added to the exhaust side for efficient cooling, but this results in an increased number of components and higher costs.

[0012] Therefore, the purpose of this invention is to provide a multi-stage twin-shaft rotary pump and a multi-stage claw pump that can reasonably prevent the rotor and pump body from overheating through air cooling or water cooling.

[0013] Solution for solving the problem

[0014] The present invention has the following structure in order to achieve the above-mentioned objectives.

[0015] According to one aspect of the multi-stage twin-shaft rotary pump of the present invention, a pump chamber with a cross-sectional shape in which portions of two circles coincide in the left-right direction is configured as multiple stages, and includes: two rotating shafts arranged parallel to each other in the pump chamber of each stage and rotating in opposite directions at the same speed via a pair of gears; and two rotors for each stage, which are formed to be arranged corresponding to the two rotating shafts in the pump chamber of each stage, and are capable of rotating in a non-contact state to discharge the intake gas, wherein the exhaust side end wall of the pre-stage pump chamber, which is provided with an exhaust port, and the exhaust side end wall of the subsequent pump chamber are configured as follows: The interstage portion between the front and rear stages, where the suction side end wall of the rear stage pump is provided with an air intake port, includes: an interstage communication chamber configured to connect the exhaust port of the front stage pump chamber to the air intake port of the rear stage pump chamber at the midpoint of the left-right direction of the two rotating shafts; a one-sided interstage air-cooling flow path configured to allow cooling air to flow from the bottom to the top on the side of one of the left-right directions of the two rotating shafts; and a other-sided interstage air-cooling flow path configured to allow cooling air to flow from the bottom to the top on the side of the other of the left-right directions of the two rotating shafts.

[0016] Furthermore, according to one aspect of the multi-stage biaxial rotary pump of the present invention, the interstage portion is characterized in that it comprises an exhaust-side end wall of the pre-stage pump and an intake-side end wall of the post-stage pump, and is integrally provided in such a manner that the interstage communication chamber, the interstage air-cooled flow path on one side, and the interstage air-cooled flow path on the other side are formed in the interstage portion.

[0017] Furthermore, according to one aspect of the multi-stage twin-shaft rotary pump of the present invention, a cooling gap is provided between the pump chamber main body having the multi-stage pump chamber and the bearing main body having a bearing portion that provides axial support for the two rotating shafts on the side transmitting driving force, and in a portion corresponding to the two rotating shafts, for allowing cooling air to flow from the lower side to the upper side.

[0018] Furthermore, according to one aspect of the multi-stage biaxial rotary pump of the present invention, a centrifugal fan is mounted on a coupling provided for transmitting the driving force of the drive motor of one of the two rotating shafts, and a cooling air guide is provided, which uses the airflow generated by the centrifugal fan as cooling air and guides it to flow from the lower side to the upper side in the cooling gap between the interstage air-cooling flow path on one side, the interstage air-cooling flow path on the other side, and the main body.

[0019] Furthermore, according to one aspect of the multi-stage claw pump of the present invention, the feature is that one of the interstage air-cooled flow paths on one side and the other interstage air-cooled flow path on the other side is disposed close to the exhaust port of the forestage pump chamber, which is eccentrically configured as a claw pump.

[0020] Furthermore, according to one aspect of the multi-stage twin-shaft rotary pump of the present invention, a pump chamber with a cross-sectional shape in which a portion of two circles coincides in the left-right direction is configured as multi-stage pump chambers, and includes: two rotating shafts arranged parallel to each other in the pump chambers of each stage and rotating in opposite directions at the same speed via a pair of gears; and two rotors for each stage, which are formed to be arranged in the pump chambers of each stage corresponding to the two rotating shafts, and are capable of rotating in a non-contact state to discharge the intake gas, wherein the exhaust side end wall of the pre-stage pump chamber, which is provided with an exhaust port, and the intake side wall of the subsequent pump chamber, which is provided with an intake port, are located at the exhaust side end wall of the pre-stage pump chamber. The interstage portion between the front and rear stages, located between the suction side end walls of the rear pump, includes: an interstage communication chamber configured to connect the exhaust port of the front pump chamber and the suction port of the rear pump chamber via the two rotating shafts at or above the midpoint of the left-right direction; a one-sided interstage liquid-cooled flow path configured to allow coolant to flow from the bottom to the top on the side of one of the two rotating shafts in the left-right direction; and a other-sided interstage liquid-cooled flow path configured to allow coolant to flow from the bottom to the top on the side of the other of the two rotating shafts in the left-right direction.

[0021] Furthermore, according to one aspect of the multi-stage biaxial rotary pump of the present invention, the upper side of one interstage liquid-cooled flow path is connected to the lower side of the other interstage liquid-cooled flow path via a coolant connection, such that the coolant is introduced from the lower side of the one interstage liquid-cooled flow path and discharged from the upper side, and then introduced from the lower side of the other interstage liquid-cooled flow path and discharged from the upper side.

[0022] Furthermore, according to one aspect of the multi-stage biaxial rotary pump of the present invention, a bearing portion liquid cooling flow path is provided in the bearing portion such that the coolant is introduced into the interstage liquid cooling flow path on one side after cooling the bearing portion supporting the two rotating shafts.

[0023] Furthermore, according to one aspect of the multi-stage biaxial rotary pump of the present invention, the interstage portion is characterized in that it comprises an exhaust-side end wall of the pre-stage pump and an intake-side end wall of the post-stage pump, and is integrally provided in such a manner that the interstage communication chamber, the interstage liquid-cooled flow path on one side, and the interstage liquid-cooled flow path on the other side are formed in the interstage portion.

[0024] Furthermore, according to one aspect of the multi-stage biaxial rotary pump of the present invention, the interstage liquid-cooled flow path on one side and the interstage liquid-cooled flow path on the other side are configured as flow paths through which coolant passes by sealing the upper and lower ends with sealing plates of their respective upper and lower parts, and by removing the sealing plates of the upper and lower parts, they become interstage air-cooled flow paths on one side and interstage air-cooled flow paths on the other side for cooling air circulation.

[0025] Furthermore, according to one aspect of the multi-stage claw pump of the present invention, the multi-stage biaxial rotary pump is characterized in that the multi-stage biaxial rotary pump is a claw pump, and the interstage liquid cooling flow path on one side and the interstage liquid cooling flow path on the other side are arranged on the side where the coolant is first introduced, and are arranged close to the exhaust port of the forestage pump chamber which is eccentrically configured as a claw pump.

[0026] Invention Effects

[0027] The multi-stage twin-shaft rotary pump and multi-stage claw pump according to the present invention have the particularly advantageous effect of reasonably preventing overheating of the rotor and pump body through air cooling or water cooling. Attached Figure Description

[0028] Figure 1 This is a perspective view illustrating an example of a multi-stage biaxial rotary pump (claw pump) with water cooling function according to the present invention.

[0029] Figure 2 yes Figure 1 A breakdown diagram of the method example.

[0030] Figure 3 yes Figure 1 A side view of an example of this method.

[0031] Figure 4 yes Figure 1 In the example of the method Figure 3 A sectional view along line AA.

[0032] Figure 5 yes Figure 1 In the example of the method Figure 3 BB line section view.

[0033] Figure 6 yes Figure 1 The main view of the example.

[0034] Figure 7 yes Figure 1 A top view of an example of this method.

[0035] Figure 8 yes Figure 1 The rear view of the example.

[0036] Figure 9 This is a perspective view illustrating an example of a multi-stage biaxial rotary pump (claw pump) with air cooling function according to the present invention.

[0037] Figure 10 yes Figure 9 A breakdown diagram of the method example.

[0038] Figure 11 yes Figure 9 A top view of an example of this method.

[0039] Figure 12 yes Figure 9 Example of the method Figure 11 A sectional view along line AA.

[0040] Figure 13 yes Figure 9 Example of the method Figure 11 BB line section view.

[0041] Figure 14 yes Figure 9 The main view of the example.

[0042] Figure 15 It means in Figure 9 A cross-sectional view of an example of a design that includes a cooling air guide component. Detailed Implementation

[0043] The following is based on the attached figures ( Figures 1-15 This invention provides two detailed examples of the multi-stage twin-shaft rotary pump (multi-stage claw pump) involved in the present invention. Figures 1-8 In the example, a water-cooled two-stage twin-shaft rotary pump is shown as the first method. Figures 9-15 In the example shown, an air-cooled two-stage twin-shaft rotary pump is represented as a second embodiment. These embodiments are also water-cooled or air-cooled vacuum pumps, but the present invention is not limited to these; they can also be used as blowers, gas compressors, etc., to use the discharged gas as product gas. Furthermore, as a cooling unit, coolant other than water or cooling gas other than the atmosphere can certainly be used.

[0044] First, based on Figures 1-8 The first method example will be explained.

[0045] In the multi-stage dual-shaft rotary pump of the present invention, as a basic structure (two-stage in this example), the pump chambers 11 and 12, whose cross-sectional shapes have a portion of two circles overlapping in the left-right direction, are configured as multi-stage (two-stage). They include: two rotating shafts 20A and 20B, which are arranged parallel to each other in the pump chambers 11 and 12 of each stage and rotate in opposite directions at the same speed via a pair of gears (not shown); and two rotors 21A, 21B, 22A, and 22B of each stage, which are formed to be arranged corresponding to the two rotating shafts 20A and 20B in the pump chambers 11 and 12 of each stage, rotating in a non-contact state and capable of discharging the inhaled gas. Furthermore, one of the gears is mounted on the rotating shaft 20A on the drive side, and the other is mounted on the rotating shaft 20B on the driven side, meshing inside the bearing body 40, which also serves as the gearbox.

[0046] Furthermore, in the multi-stage twin-shaft rotary pump involved in this invention, such as Figure 5 As shown, the interstage portion 30 provided between the exhaust side end wall 11a of the pre-pump chamber with exhaust port 11b and the suction side end wall 12a of the post-pump chamber with suction port 12b has the following structure.

[0047] That is, it includes: an interstage communication chamber 33, which is configured to connect the exhaust port 11b of the front pump chamber and the intake port 12b of the rear pump chamber in a manner that passes vertically between the two rotating shafts 20A and 20B in the middle of the left-right direction; a side interstage liquid cooling flow path 31, which is formed to allow coolant to flow from the bottom to the top on the side of one of the two rotating shafts 20A and 20B in the left-right direction; and a other side interstage liquid cooling flow path 32, which is formed to allow coolant to flow from the bottom to the top on the side of the other of the two rotating shafts 20A and 20B in the left-right direction.

[0048] Therefore, the upward flow direction of the coolant and the upward flow direction of the coolant due to heating are aligned in the same direction, allowing for smooth coolant flow and facilitating the upward movement and expulsion of air bubbles generated during coolant flow, thus enabling and maintaining high-level cooling performance. Therefore, the multi-stage twin-shaft rotary pump according to the present invention provides the advantageous effect of effectively preventing overheating of the rotor and pump body through water cooling.

[0049] Furthermore, in this embodiment, the interstage liquid cooling flow path 31 on one side and the interstage liquid cooling flow path 32 on the other side are flat flow paths (openings) that are wider in the left-right direction and narrower in the front-back direction, with a larger cross-sectional area compared to the piping (coolant connection path 35, etc.). Therefore, the surface area of ​​the coolant in contact with the exhaust side end wall 11a of the pre-pump and the suction side end wall 12a of the post-pump is increased, enabling efficient cooling of the pump chambers 11 and 12. In addition, the front-back direction in this embodiment refers to the direction in which the pre-pump chamber 11 and the post-pump chamber 12 overlap, which is along the axis of rotation 20A and 20B. Furthermore, since the interstage liquid cooling flow path 31 on one side and the interstage liquid cooling flow path 32 on the other side are formed in a layered region between the pre-pump chamber 11 and the post-pump chamber 12, both the front and back sides of these flow paths are used for cooling, thus creating a structure where condensation is unlikely to form. Therefore, compared with single-stage twin-shaft rotary pumps, it is possible to eliminate the need for dedicated components for condensation countermeasures, thereby reducing costs.

[0050] As described above, according to the present invention, pump chambers 11 and 12 can be cooled by water cooling, thereby simultaneously and efficiently cooling the front-stage rotors 21A and 21B and the rear-stage rotors 22A and 22B. This effectively prevents the two rotating rotors from contacting each other due to thermal expansion (rotor-to-rotor contact). Furthermore, with this efficient cooling effect, the cooling required for pump exhaust, as in a single-stage water-cooled pump like those in Patent Document 2, is eliminated. By reducing the number of components, cost reduction can be achieved.

[0051] It should be noted that by cooling the pre-exhaust section (including the exhaust port 11b of the pre-pump chamber), sublimation reaction byproducts (ammonium chloride) may be precipitated in the semiconductor manufacturing field. However, by adjusting the flow rate in the cold water circuit of the pre-exhaust section by using a bypass circuit or by inverter control of the pump that delivers cooling water, the precipitation can be suppressed by preventing excessive cooling.

[0052] Furthermore, the fore-pump chamber 11 is composed of a cylinder portion 11c of the fore-pump chamber with an inlet 11e at the top, a fore-pump bearing side end wall 11d, and a fore-pump exhaust side end wall 11a with an exhaust port 11b (see reference). Figure 2 (etc.). Additionally, the downstream pump chamber 12 (refer to...) Figure 2 ) is supplied by the suction port 12b, which has a downstream pump chamber (refer to Figure 5 The suction side end wall 12a of the post-stage pump (refer to) Figure 5 ), the cylinder section 12c of the downstream pump chamber (refer to) Figure 2 ), and exhaust port 12e with a downstream pump chamber (refer to Figure 2 The exhaust side end wall 12d of the post-stage pump (refer to) Figure 2 )constitute.

[0053] Furthermore, in this example, such as Figure 5 As shown, the upper side of one interstage liquid cooling flow path 31 and the lower side of the other interstage liquid cooling flow path 32 are connected by a coolant connection path 35, so that coolant is introduced from the lower side of one interstage liquid cooling flow path 31 and discharged from the upper side via the coolant inlet connection 31f, and then introduced from the lower side of the other interstage liquid cooling flow path 32 and discharged from the upper side. More specifically, the coolant connection path 35, which is composed of piping, connects the liquid cooling flow path connection 31d of the sealing plate 31b located at the upper part of one interstage liquid cooling flow path 31 to the coolant inlet connection 32f located at the lower part of the other interstage liquid cooling flow path 32, forming a flow path in which coolant flows from one interstage liquid cooling flow path 31 through the other interstage liquid cooling flow path 32.

[0054] Therefore, by setting up a water-cooled cooling circuit in such a way that the cooling water is preferentially cooled from the part that is prone to high temperature (e.g., the part on the side of the rotating shaft 20A on the drive side), the overheating of the rotor and pump body can be prevented more evenly.

[0055] In addition, bubbles are sometimes generated during the circulation of the coolant, but these bubbles are pushed upwards by the upward flow of the coolant. Furthermore, since the bubbles are gaseous and lightweight, they generate an upward force in the coolant, and this upward force is in the same direction as the upward flow of the coolant. Therefore, the bubbles are easily moved upwards. Thus, by providing venting units, namely venting valves 31e and 32e (see reference), to discharge (exhaust) these bubbles from the upper ends of one interstage liquid cooling flow path 31 and the other interstage liquid cooling flow path 32 to the outside (exhaust), these venting units are provided. Figure 5 This allows for easy and appropriate venting. In this example, an vent valve 31e is connected to the upper part of the liquid cooling flow path connection portion 31d on the upper side of the upper sealing plate 31b, and an vent valve 32e is connected to the upper part of the liquid cooling flow path connection portion 32d on the upper side of the upper sealing plate 32b. Furthermore, in this example, the upper sealing plate 31b, the upper sealing plate 32b, and the upper sealing plate 33b that blocks the upper end of the interstage communication chamber 33 between them are integrally arranged as a single plate, as shown in the example below. Figure 2 and Figure 5 As shown, but of course, they can also be set up separately as in the case of having interchangeability with the air-cooled type described later.

[0056] Furthermore, in this example, such as Figure 4 As shown, a bearing liquid cooling flow path 42 is provided in the bearing section 41 such that after the coolant cools the bearing section 41 that supports the two rotating shafts 20A and 20B on the side that transmits the driving force, it is introduced into the interstage liquid cooling flow path 31 on the side.

[0057] Furthermore, the bearing liquid cooling flow path 42 of this embodiment is formed into a flat opening that is wide in the vertical direction and narrow in the front-rear direction, thus increasing the surface area and achieving efficient cooling. Moreover, this bearing liquid cooling flow path 42 is located on the lower side of the bearing main body 40 (bearing part 41) of the gearbox, thereby enabling efficient cooling of the lubricating oil inside the gearbox. Additionally, the coolant flow path originates from an external coolant source via the coolant inlet 45 (see reference 42). Figure 6 and Figure 7 The coolant is introduced into the bearing section liquid cooling flow path 42, and from there it is connected via the coolant connection pipe 43 to the coolant inlet connection 31f of the interstage liquid cooling flow path 31 on one side (see reference). Figure 4In addition, the coolant that has passed through the interstage liquid cooling flow path 32 on the other side is discharged from this device through the flow path (piping) connected to the liquid cooling flow path connection part 32d.

[0058] Therefore, the coolant flows first in the bearing section liquid-cooled flow path 42 and then in the interstage liquid-cooled flow path 31 on one side. This allows the coolant, which is at a lower temperature, to flow in the bearing section liquid-cooled flow path 42, resulting in a well-balanced, efficient, and effective cooling system for the multi-stage twin-shaft rotary pump assembly. Specifically, the bearing section 41 is a lower temperature area compared to the heated pump chambers 11 and 12; by allowing the coolant to flow first in this area, efficient cooling with a lower temperature coolant can be achieved. Furthermore, an air vent valve 44 is connected to the upper part of the flow path forming the coolant connection pipe 43, which can appropriately discharge air bubbles generated in the flow path including the bearing section liquid-cooled flow path 42, thereby improving cooling efficiency.

[0059] Furthermore, in this example, such as Figure 2 As shown, the interstage section 30 includes the exhaust side end wall 11a of the pre-pump and the suction side end wall 12a of the post-pump, and is integrally arranged in such a way that an interstage communication chamber 33, an interstage liquid cooling flow path 31 on one side and an interstage liquid cooling flow path 32 on the other side are formed in the interstage section 30.

[0060] Through this integration, a cooling circuit consisting of an interstage liquid cooling flow path 31 on one side and an interstage liquid cooling flow path 32 on the other side can be combined with, for example, a cooling circuit consisting of, an interstage liquid cooling flow path 31 on one side and an interstage liquid cooling flow path 32 on the other side. Figure 2 By integrating the rear cylinder block 12c of the rear pump chamber 12 as shown, the number of parts can be reduced and the resulting assembly time can be reduced, thereby reducing costs.

[0061] Furthermore, in this example, such as Figure 5 and Figure 13 As shown, the interstage liquid cooling flow path 31 on one side and the interstage liquid cooling flow path 32 on the other side are configured to allow coolant to pass through by sealing the upper and lower ends with their respective upper and lower sealing plates 31b, 31c, 32b, and 32c (see reference). Figure 5 The configuration involves removing the upper and lower enclosure plates 31b, 31c, 32b, and 32c to create a cooling airflow path 31A on one side and a cooling airflow path 32A on the other side (see reference). Figure 13 In addition, in this embodiment, the upper sealing plate 33b and the lower sealing plate 33c of the interstage communication chamber 33 respectively seal the upper and lower ends of the interstage communication chamber 33 in either water cooling or air cooling.

[0062] Therefore, by making the components common to a two-stage air-cooled vacuum pump configured to cool pump chambers 11 and 12 and rotors 21A, 21B, 22A, and 22B by cooling gas, a reduction in overall cost can be achieved. Furthermore, as in this example, by constructing a structure that enlarges the openings of the flow paths forming one-sided interstage liquid-cooled flow path 31 and the other-sided interstage liquid-cooled flow path 32, which are components of the cooling circuit, it has the advantage of allowing cooling air (cooling gas) to flow effectively without requiring a cooling water circuit.

[0063] Furthermore, in this example, the multi-stage twin-shaft rotary pump described above is a multi-stage claw pump, such as... Figure 5 As shown, one of the interstage liquid cooling flow paths 31 and 32 is configured such that the coolant is first introduced into the flow path 31, and is located opposite the exhaust port 11b of the forestage pump chamber (see reference 32). Figure 2 The pump is positioned close to the front pump. That is, it becomes a multi-stage claw pump where the lower part of the interstage liquid-cooled flow path 31, on the side where coolant is first introduced, is adjacent to the exhaust side end wall 11a of the front pump (see reference). Figure 2 The lower side of the pump chamber, which is biased to the left or right, has an exhaust port 11b (see reference). Figure 2 The part is set close to the ground.

[0064] Therefore, a water-cooled cooling circuit can be configured so that the coolant (cooling water, etc.) flows preferentially from the part that is prone to high temperature (e.g., the exhaust port 11b of the fore-stage pump chamber located on one side), thereby preventing the rotor and pump body from overheating more evenly. Furthermore, in this embodiment, the exhaust port 12e of the rear-stage pump chamber (see...) Figure 2 The exhaust gas discharged from the muffler 60 comes from the muffler exhaust port 61 (see reference). Figure 8 ) through exhaust pipe 62 (refer to Figure 15 ), introduced into the second muffler 63, and from the exhaust port 64 (see reference) Figure 15 )discharge.

[0065] Next, based on Figures 9-15 The second embodiment (air-cooled two-stage twin-shaft rotary pump) will be described. For inventions with the same structure as those involved in the first embodiment (water-cooled two-stage twin-shaft rotary pump), the same symbols will be used and their descriptions will be largely omitted.

[0066] In the multi-stage twin-shaft rotary pump involved in this invention, such as Figure 10 As shown, the interstage portion 30, located between the exhaust side end wall 11a of the pre-pump with exhaust port 11b and the suction side end wall 12a of the post-pump with suction port 12b, includes: an interstage communication chamber 33 (see reference). Figure 13 It is configured as a passage connecting the exhaust port 11b of the pre-stage pump chamber and the intake port 12b of the post-stage pump chamber in the middle of the left and right directions of the two rotating shafts 20A and 20B; one side interstage air-cooled flow path 31A (refer to Figure 10 and Figure 13 (etc.), which is formed as a flow path that allows cooling air to flow from the lower side to the upper side on one side of one of the two rotating shafts 20A and 20B in the left-right direction; the other side interstage air cooling flow path 32A (refer to Figure 10 and Figure 13 (etc.), which is formed as a flow path that allows cooling air to flow from the lower side to the upper side on the side of the other side in the left-right direction of the two rotating shafts 20A and 20B.

[0067] Therefore, the upward flow direction of the cooling air and the upward direction of the heated cooling air are aligned in the same direction, allowing for smooth airflow and enabling high-level and sustained cooling performance. Thus, the multi-stage twin-shaft rotary pump according to the present invention provides the advantageous effect of effectively preventing overheating of the rotor and pump body through air cooling.

[0068] Furthermore, similar to the first embodiment, the interstage air-cooled flow path 31A on one side and the interstage air-cooled flow path 32A on the other side are flat flow paths (openings) that are wider in the left-right direction and narrower in the front-back direction, with a larger cross-sectional area compared to the piping. Therefore, the surface area of ​​the cooling air in contact with the exhaust side end wall 11a of the pre-pump and the suction side end wall 12a of the post-pump increases, enabling efficient cooling of the pump chambers 11 and 12.

[0069] As described above, according to the present invention, by means of air cooling, the rotors 21A and 21B of the preceding stage and the rotors 22A and 22B of the subsequent stage can be cooled simultaneously and efficiently, thus properly preventing the two rotating rotors from contacting each other due to thermal expansion (rotor-to-rotor contact).

[0070] Furthermore, in this embodiment, the interstage section 30 includes an exhaust-side end wall 11a of the pre-pump and an intake-side end wall 12a of the post-pump, and is integrally formed in the interstage section 30 to create an interstage communication chamber 33, an interstage air-cooled flow path 31A on one side, and an interstage air-cooled flow path 32A on the other side. Therefore, similar to the first embodiment, the number of components can be reduced, thereby lowering manufacturing costs.

[0071] Furthermore, in this embodiment, a cooling gap 50 is provided between the pump chamber main body 10, which is provided with multi-stage pump chambers 11 and 12, and the bearing main body 40, which is provided with a bearing part 41 that supports two rotating shafts 20A and 20B on the side that transmits driving force (drive motor 25 side), and at a position corresponding to the periphery of the two rotating shafts 20A and 20B, to allow cooling air to flow from the lower side to the upper side (see reference). Figure 12 , Figure 14 as well as Figure 15 wait).

[0072] Therefore, the upward flow direction of the cooling air and the upward direction of the heated cooling air are aligned in the same direction, allowing the cooling air to flow smoothly and enabling the cooling performance to be maintained at a high level. Thus, the multi-stage twin-shaft rotary pump according to the present invention provides the advantageous effect of preventing overheating of the pump chamber main body 10 and the bearing main body 40 through air cooling.

[0073] Furthermore, in this example, a centrifugal fan 26 is mounted on a coupling 25a, which is provided to transmit the driving force of the drive motor 25 of one of the two rotating shafts 20A and 20B, and a cooling air guide 55 is provided (see reference). Figure 15 The cooling air guide section 55 uses the airflow generated by the centrifugal fan 26 as cooling air, and guides it to flow from the bottom to the top in the cooling gap 50 between the interstage air-cooling flow path 31A on one side, the interstage air-cooling flow path 32A on the other side, and the main body. Furthermore, the centrifugal fan 26 is disposed inside the fan shroud 27 and is configured to supply air from the air outlet 27a located at the bottom (see reference). Figure 12 (etc.) exhaust the cooling airflow. Additionally, such as Figure 15 As shown, in this embodiment, the pump body is installed and supported on the base 16, forming a structure covered by the pump body cover 15.

[0074] The cooling air guide 55 can appropriately guide the cooling air generated by the centrifugal fan 26 to the interstage air cooling flow path 31A on one side, the interstage air cooling flow path 32A on the other side, and the cooling gap 50 between the main body, effectively cooling the multi-stage twin-shaft rotary pump involved in this invention. Therefore, it can simultaneously and efficiently cool the rotors 21A and 21B of the preceding stage and the rotors 22A and 22B of the subsequent stage, and can appropriately prevent the two rotating rotors from contacting each other due to thermal expansion (rotor contact), etc.

[0075] Furthermore, the multi-stage twin-shaft rotary pump in this example is a multi-stage claw pump, such as... Figure 13 As shown, one of the interstage air-cooled flow paths 31A and 32A is an interstage air-cooled flow path 31A, and the exhaust port 11b of the forestage pump chamber, which is eccentrically configured as a claw pump (see reference). Figure 10 (Set up close to the ground.)

[0076] Therefore, as Figure 13 As shown, the most heated part is the exhaust port 11b of the fore-stage pump chamber (refer to...). Figure 10The multi-stage claw pump is located close to the interstage air-cooled flow path 31A, thus enabling efficient heat exchange and achieving a balanced and effective cooling of the multi-stage claw pump as a whole, achieving the same effect as described above. Furthermore, in this embodiment, the wall thickness of the interstage portions 30 forming the interstage air-cooled flow path 31A and the exhaust port 11b of the forestage pump chamber (refer to...) Figure 10 The shape corresponds to the thinning (refer to) Figure 13 Thus, it is also possible to efficiently cool by the cooling air flowing in the interstage air-cooled flow path 31A on one side.

[0077] In addition, in the two embodiments described above, the secondary rotors 21A, 21B, 22A, and 22B are supported in a cantilever state via two rotating shafts 20A and 20B. However, the present invention is not limited to this and can also be effectively applied to multi-stage claw pumps including multi-stage claw pumps with structures that support two rotating shafts 20A and 20B from both sides.

[0078] The present invention has been described above with reference to preferred embodiments, but the present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the invention.

[0079] Symbol Explanation

[0080] 10—Main body of pump chamber; 11—Forestage pump chamber; 11a—Exhaust side end wall of forestage pump; 11b—Exhaust port of forestage pump chamber; 11c—Cylinder body of forestage pump chamber; 11d—Bearing side end wall of forestage pump; 11e—Suction port of forestage pump chamber; 12—Afterstage pump chamber; 12a—Suction side end wall of afterstage pump; 12b—Suction port of afterstage pump chamber; 12c—Cylinder body of afterstage pump chamber; 12d—Exhaust side end wall of afterstage pump; 12e—Exhaust port of afterstage pump chamber; 1 5—Pump body cover; 16—Base section; 20A—Rotating shaft (drive-side rotating shaft); 20B—Rotating shaft (driven-side rotating shaft); 21A—Pre-stage rotor; 21B—Pre-stage rotor; 22A—After-stage rotor; 22B—After-stage rotor; 25—Drive motor; 25a—Coupling; 26—Centrifugal fan; 27—Fan shroud section; 27a—Air outlet; 30—Interstage section; 31—One-sided interstage liquid cooling flow path; 31A— Interstage air-cooled flow path; 31b—Upper closed plate; 31c—Lower closed plate; 31d—Liquid-cooled flow path connection; 31e—Exhaust valve; 31f—Coolant inlet connection; 32—Interstage liquid-cooled flow path on the other side; 32A—Interstage air-cooled flow path on the other side; 32b—Upper closed plate; 32c—Lower closed plate; 32d—Liquid-cooled flow path connection; 32e—Exhaust valve; 32f—Coolant inlet connection; 33—Interstage connecting chamber; 33 b—Upper enclosed plate; 33c—Lower enclosed plate; 35—Coolant connection path; 40—Bearing main body (gearbox); 41—Bearing part; 42—Bearing liquid cooling flow path; 43—Coolant connection pipe; 44—Exhaust valve; 45—Coolant inlet; 50—Cooling gap between main bodies; 55—Cooling air guide; 60—Muffler; 61—Muffler exhaust port; 62—Exhaust pipe; 63—Second muffler; 64—Exhaust port.

Claims

1. A multi-stage twin-shaft rotary pump, comprising a pump chamber with a cross-sectional shape in which portions of two circles overlap in the left-right direction, configured as multi-stage pumps, and having the following features: Two rotating shafts, arranged parallel within each stage of the pump chamber, rotate in opposite directions at the same speed via a pair of gears; and The two rotors of each stage are configured to correspond to the two rotating shafts within the pump chamber of each stage, enabling them to rotate in a non-contact manner and discharge the intake gas. The characteristics of a multi-stage twin-shaft rotary pump are: The following features are provided in the interstage section between the exhaust side end wall of the pre-pump chamber (which has an exhaust port) and the suction side end wall of the post-pump chamber (which has an intake port): An interstage communication chamber is configured as a passageway connecting the exhaust port of the pre-stage pump chamber to the intake port of the post-stage pump chamber at the midpoint of the left-right direction of the two rotating axes. A side-stage air-cooled flow path is formed such that cooling air can flow from the lower side to the upper side on one side of the two rotation axes in the left-right direction; and The other side is an interstage air-cooled flow path, which is formed as a flow path that allows cooling air to flow from the lower side to the upper side on the other side in the left-right direction of the two rotating axes.

2. The multi-stage twin-shaft rotary pump according to claim 1, characterized in that, The interstage section includes the exhaust side end wall of the pre-pump and the intake side end wall of the post-pump, and is integrally arranged in such a way that the interstage communication chamber, the interstage air-cooled flow path on one side and the interstage air-cooled flow path on the other side are formed in the interstage section.

3. The multi-stage twin-shaft rotary pump according to claim 1, characterized in that, A cooling gap is provided between the pump chamber main body with the multi-stage pump chamber and the bearing main body with the bearing part that supports the two rotating shafts, and in the area corresponding to the two rotating shafts, so that cooling air can flow from the lower side to the upper side.

4. The multi-stage twin-shaft rotary pump according to claim 3, characterized in that, A centrifugal fan is mounted on the coupling, which is configured to transmit the driving force of the drive motor of one of the two rotating shafts. A cooling air guide is provided, which uses the airflow generated by the centrifugal fan as cooling air and guides it to flow from the bottom to the top in the cooling gap between the interstage air-cooling flow path on one side, the interstage air-cooling flow path on the other side, and the main body.

5. A multi-stage claw pump, which is the multi-stage twin-shaft rotary pump described in claims 1-4, characterized in that, The one-sided interstage air-cooled flow path and the other-sided interstage air-cooled flow path are arranged adjacent to the exhaust port of the forestage pump chamber, which is eccentrically configured as a claw pump.

6. A multi-stage twin-shaft rotary pump, wherein the pump chambers, with portions of two circles overlapping in the left-right direction, are configured as multi-stage pumps, and possess the following features: Two rotating shafts, arranged parallel within each stage of the pump chamber, rotate in opposite directions at the same speed via a pair of gears; and The two rotors of each stage are configured to correspond to the two rotating shafts within the pump chamber of each stage, enabling them to rotate in a non-contact manner and discharge the intake gas. The characteristics of a multi-stage twin-shaft rotary pump are: The following features are provided in the interstage section between the exhaust side end wall of the pre-pump chamber (which has an exhaust port) and the suction side end wall of the post-pump chamber (which has an intake port): An interstage communication chamber is configured as a passageway connecting the exhaust port of the pre-stage pump chamber and the intake port of the post-stage pump chamber above and below the midpoint of the two rotating shafts in the left-right direction, through the space between the two rotating shafts. A side-stage liquid cooling flow path is configured to allow coolant to flow from the lower side to the upper side on one side of the two rotating axes in the left-right direction; and The other side interstage liquid cooling flow path is formed to allow coolant to flow from the lower side to the upper side on the other side in the left-right direction of the two rotating axes.

7. The multi-stage twin-shaft rotary pump according to claim 6, characterized in that, The upper side of one interstage liquid cooling flow path is connected to the lower side of the other interstage liquid cooling flow path through a coolant connection, so that the coolant is introduced from the lower side of the one interstage liquid cooling flow path and discharged from the upper side, and then introduced from the lower side of the other interstage liquid cooling flow path and discharged from the upper side.

8. The multi-stage twin-shaft rotary pump according to claim 6, characterized in that, A bearing liquid cooling flow path is provided in the bearing section such that the coolant is introduced into the interstage liquid cooling flow path on one side after cooling the bearing section that supports the two rotating shafts.

9. The multi-stage twin-shaft rotary pump according to claim 6, characterized in that, The interstage section includes the exhaust side end wall of the pre-pump and the suction side end wall of the post-pump, and is integrally formed in the interstage section to create the interstage communication chamber, the interstage liquid cooling flow path on one side, and the interstage liquid cooling flow path on the other side.

10. The multi-stage twin-shaft rotary pump according to claim 6, characterized in that, The interstage liquid cooling flow path on one side and the interstage liquid cooling flow path on the other side are configured to allow coolant to pass through by sealing the upper and lower ends with their respective upper and lower sealing plates. By removing the upper and lower sealing plates, they become an interstage air cooling flow path on one side and an interstage air cooling flow path on the other side.

11. A multi-stage claw pump, which is the multi-stage twin-shaft rotary pump described in claims 6-10, characterized in that, The one-sided interstage liquid cooling flow path is configured to be the side where the coolant is first introduced, and is located adjacent to the exhaust port of the fore-stage pump chamber, which is eccentrically configured as a claw pump.

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