Vacuum pump

Abstract

The invention provides a vacuum pump capable of achieving sealing and compactness of an exhaust passage. The vacuum pump includes a housing including a pump chamber, and an intake passage and an exhaust passage communicating with the pump chamber. The housing includes: a first member having a convex portion in which a first exhaust passage of the exhaust passages is formed; and a second member that has a fitting hole that forms a second exhaust passage communicating with a first exhaust passage among the exhaust passages and that can be fitted to the protruding portion, and an outer peripheral edge portion that protrudes toward the first member on the outer peripheral side of the fitting hole. The vacuum pump is further provided with a sealing member which is held between the first member and the second member so as to be positioned between the projection of the first member and the outer peripheral edge of the second member in the radial direction, and which seals an exhaust passage including the first exhaust passage and the second exhaust passage.

Description

Technical Field

[0001] The present disclosure relates to vacuum pumps. Background Art

[0002] Conventionally, a vacuum pump is known for maintaining the pressure in a container at a pressure lower than the atmospheric pressure. For example, Patent Document 1 describes a vacuum pump for maintaining a negative pressure chamber of a brake booster in a vehicle such as an automobile at a pressure lower than atmospheric pressure.

[0003] Patent Document 2 describes a vacuum pump that can suppress the number of components and prevent liquid from splashing onto the exhaust port, considering that liquid such as splashes may adhere to the exhaust port depending on the use environment. Prior art literature Patent Literature

[0004] Patent Document 1: Japanese Patent Application Publication No. 2014-25413 Patent Document 2: Japanese Patent Application Publication No. 2020-76336 Summary of the invention 1. Technical issues to be resolved

[0005] In addition, the housing of the vacuum pump is generally formed by assembling a plurality of parts. At this time, there is a case where the exhaust passage of the vacuum pump is divided into a plurality of sections according to the layout of the internal flow path of the housing, and the exhaust passages of each section are dispersedly arranged in a plurality of housing components. By assembling a plurality of housing components, the exhaust passages of adjacent sections are connected to each other at the joint surface between the housing components.

[0006] As described above, when the exhaust passage divided into a plurality of sections is provided in a distributed manner on a plurality of casing members, it is necessary to provide a sealing member for sealing the exhaust passage on the joint surfaces between the casing members. However, securing a space for installing the sealing member on the joint surface between the housing members becomes an obstacle to making the vacuum pump more compact.

[0007] In view of the above circumstances, an object of at least some embodiments of the present invention is to provide a vacuum pump that can achieve both sealing of an exhaust passage and compactness. (II) Technical solution

[0008] A vacuum pump according to at least some embodiments of the present invention comprises a housing, The housing includes a pump chamber, and an air intake passage and an air exhaust passage communicating with the pump chamber. The housing includes: a first member having a protrusion having a first exhaust passage formed therein; and The second member has a fitting hole that forms a second exhaust passage that communicates with the first exhaust passage in the exhaust passage and can be fitted with the protrusion, and an outer peripheral edge portion that is provided on the outer peripheral side of the fitting hole and protrudes toward the first member. The vacuum pump further includes a sealing member held between the first member and the second member so as to be located between the convex portion of the first member and the outer peripheral edge portion of the second member in the radial direction and for sealing an exhaust passage including the first exhaust passage and the second exhaust passage. (III) Beneficial effects

[0009] According to at least some embodiments of the present invention, the sealing component is held between the first component and the second component in a manner that the sealing component is located between the convex portion of the first component and the outer peripheral edge portion of the second component in the radial direction, so there is no need to form a groove for accommodating the sealing component on either the first component or the second component. Therefore, the vacuum pump can be made compact. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a diagram schematically showing an internal flow path of a vacuum pump according to an embodiment. Figure 2 This is a diagram schematically showing an internal flow path of a vacuum pump according to another embodiment. Figure 3 This is a diagram schematically showing an internal flow path of a vacuum pump according to still another embodiment. Figure 4 This is a partial cross-sectional view of a housing of a vacuum pump according to an embodiment, showing the structure around an exhaust passage. Figure 5 Yes means Figure 4 FIG. 1 is a diagram showing a state of a housing of a vacuum pump before assembly. Figure 6 It is a partial cross-sectional view of a housing of a vacuum pump according to another embodiment, showing the structure around the exhaust passage. Figure 7 Yes means Figure 6 FIG. 1 is a diagram showing a state of a housing of a vacuum pump before assembly. Figure 8 It is a diagram showing the structure of an extension pipe in a vacuum pump according to an embodiment. Fig. 9 It is an exploded perspective view showing the overall structure of a vacuum pump according to one embodiment. Description of Reference Numerals 1 (1A ~ 1C) - vacuum pump; 2 (2A, 2B) - housing; 3 - housing body; 4 - pump cover; 5 - top cover; 10 - pump chamber; 20 - air intake passage; 30 - exhaust passage; 32 - first exhaust passage; 34 - second exhaust passage; 50 - first silencer chamber; 60 - second silencer chamber (silencer chamber); 70 - extension pipe; 72 - upstream side portion; 73 - connector; 74 - downstream side portion; 75 - hose; 100 - first component; 102 - convex portion; 106 - outer peripheral surface; 108 - flat surface; 113 - outer peripheral edge; 200 - second component; 202 - fitting hole; 210 - outer peripheral edge portion; 220 - recessed portion; 222 - bottom surface; 300 (300A, 300B) - sealing component. DETAILED DESCRIPTION

[0011] Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in the embodiments or shown in the accompanying drawings are not intended to limit the scope of the present invention, but are merely illustrative examples.

[0012] Figure 1 It is a diagram schematically showing an internal flow path of a vacuum pump 1A according to an embodiment. Figure 2 This is a diagram schematically showing an internal flow path of a vacuum pump 1B according to another embodiment. Figure 3 This is a diagram schematically showing an internal flow path of a vacuum pump 1C according to still another embodiment. Hereinafter, vacuum pumps of some embodiments including vacuum pumps 1A, 1B, and 1C may be collectively referred to as vacuum pump 1. The vacuum pump 1 is not limited to the vacuum pumps 1A, 1B, and 1C, and includes vacuum pumps of other embodiments not shown.

[0013] In some embodiments, Figure 1 to Figure 3 As shown, the vacuum pump 1 includes a pump chamber 10 , an air intake passage 20 and an air exhaust passage 30 communicating with the pump chamber 10 as internal flow paths of a housing of the vacuum pump 1 .

[0014] The pump chamber 10 has a suction port 12 and a discharge port 14 . When the vacuum pump 1 is a positive displacement vacuum pump, the vacuum pump 1 includes a gas transport unit 40 in the pump chamber 10 . The gas transport unit 40 is configured to periodically transport a predetermined volume of gas from the suction port 12 to the discharge port 14 .

[0015] The gas transport unit 40 includes a movable unit 42 that can adopt various structures depending on the type of the vacuum pump 1. The movable unit 42 is configured to be able to transport the gas by reciprocating movement or rotation. For example, when the vacuum pump 1 is a reciprocating pump, the gas transport unit 40 includes a movable unit 42 such as a diaphragm or a piston. In another embodiment, the vacuum pump 1 is a rotary pump, and the movable unit 42 of the gas transport unit 40 includes a rotor of various shapes.

[0016] The suction port 12 of the pump chamber 10 is connected to the suction passage 20, and the gas flowing through the suction passage 20 enters the pump chamber 10 through the suction port 12. On the other hand, the discharge port 14 of the pump chamber 10 is connected to the exhaust passage 30, and the gas exhausted from the pump chamber 10 is discharged into the atmosphere through the discharge port 14 and the exhaust passage 30.

[0017] The exhaust passage 30 may be any passage through which the gas exhausted from the pump chamber 10 flows, and the specific structure of the exhaust passage 30 is not particularly limited. For example, in Figure 1 as well as Figure 2 In the illustrated embodiment, the exhaust passage 30 is directly connected to the pump chamber 10 via the exhaust port 14. Figure 3 In the illustrated embodiment, one or more chambers (50, 60) are provided between the pump chamber 10 and the exhaust passage 30 in the gas flow direction, and the exhaust passage 30 is connected to the pump chamber 10 via the one or more chambers (50, 60) and the exhaust port 14.

[0018] The one or more chambers ( 50 , 60 ) provided between the pump chamber 10 and the exhaust passage 30 may include a muffler chamber 50 , 60 . exist Figure 3 In the illustrated exemplary embodiment, the first muffler chamber 50 is located below and to the side of the pump chamber 10, and receives the gas discharged from the pump chamber 10 through the discharge port 14. The first muffler chamber 50 is connected to the second muffler chamber 60 located above the pump chamber 10 via the communication passage 62. The second muffler chamber 60 is connected to the exhaust passage 30, and the second muffler chamber 60 is configured to guide the gas passing through the first muffler chamber 50 to the exhaust passage 30.

[0019] like Figure 1 as well as Figure 3 As shown, when the exhaust passage 30 as the internal flow path of the vacuum pump 1 is a downward flow path, in order to prevent water from entering the vacuum pump 1 from the exhaust passage 30, an extension pipe 70 may be connected to the exhaust passage 30. The extension pipe 70 has an outlet 71 at a position higher than the downstream end of the exhaust passage 30, and the outlet 71 is connected to the atmosphere. In another embodiment, Figure 2 As shown, the exhaust passage 30 is an upward flow passage, and the exhaust passage 30 is directly connected to the atmosphere without passing through the extension pipe 70. In addition, when the exhaust passage 30 is an upward flow passage, in order to prevent foreign matter from invading the exhaust passage 30, a cover (not shown) may be provided at the open end of the exhaust passage 30.

[0020] The housing of the vacuum pump 1 having the above-mentioned internal flow path is sometimes formed by assembling a plurality of parts. In this case, depending on the layout of the internal flow path of the housing, there is a case where the exhaust passage 30 is divided into a plurality of sections, and each section of the exhaust passage 30 is dispersedly arranged on a plurality of housing parts. The exhaust passages 30 in adjacent sections are connected to each other at the joint surface between the housing parts by assembling a plurality of housing parts.

[0021] Below, refer to Figure 4 to Figure 7 Next, a description will be given of a housing of the vacuum pump 1 in which respective sections of the exhaust passage 30 are dispersedly provided in a plurality of housing members. Figure 4 It is a partial cross-sectional view of a housing of a vacuum pump according to an embodiment, and shows the structure around the exhaust passage 30 . Figure 5 Yes means Figure 4 FIG. 1 is a diagram showing a state of a housing of a vacuum pump before assembly. Figure 6 It is a partial cross-sectional view of a housing of a vacuum pump according to another embodiment, and shows the structure around the exhaust passage 30 . Figure 7 Yes means Figure 6 FIG. 1 is a diagram showing a state of a housing of a vacuum pump before assembly.

[0022] In some embodiments, Figure 4 as well as Figure 6 As shown, the housing 2 (2A, 2B) of the vacuum pump 1 includes a first member 100 in which the first exhaust passage 32 of the exhaust passages 30 is formed, and a second member 200 in which the second exhaust passage 34 of the exhaust passages 30 is formed. Here, the first exhaust passage 32 and the second exhaust passage 34 correspond to two flow passage sections of the exhaust passage 30 that are dispersedly provided in the first component 100 and the second component 200. The number of components of the housing 2 and the sections of the exhaust passage 30 is not particularly limited, and the exhaust passage 30 divided into three or more sections may be dispersedly provided in three or more components. In this case, the first exhaust passage 32 and the second exhaust passage 34 that are respectively provided in the first component 100 and the second component 200 may be a pair of adjacent sections among the three or more sections of the exhaust passage 30.

[0023] exist Figure 4 as well as Figure 6In the exemplary embodiment shown, in the flow direction of the gas, the first exhaust passage 32 formed in the first component 100 is located on the upstream side of the second exhaust passage 34 formed in the second component 200. That is, the gas exhausted from the pump chamber 10 flows through the first exhaust passage 32 and the second exhaust passage 34 in sequence, and is finally exhausted to the atmosphere. In addition, the first component 100 may be formed with a second muffler chamber 60 (see Figure 3 ). In another embodiment, the second exhaust passage 34 of the second component 200 is located on the upstream side of the first exhaust passage 32 of the first component 100 in the flow direction of the gas.

[0024] The first member 100 has a convex portion 102 in which the first exhaust passage 32 is formed. The convex portion 102 is provided to protrude from the surface of the first member 100 (the surface facing the second member 200) along the extending direction of the first exhaust passage 32. The first exhaust passage 32 is formed by a through hole 104 provided in the convex portion 102. The through hole 104 opens at the top surface 103 of the convex portion 102, forming a flow path end 33 of the first exhaust passage 32. exist Figure 4 as well as Figure 6 In the illustrated embodiment, the projection 102 is cylindrical and has a circumferential outer surface 106. In addition to the projection 102, the first member 100 includes a flat surface 108 on the outer circumferential side of the outer surface 106 of the projection 102 and facing the second member 200. The projection 102 protrudes from the flat surface 108 toward the second member 200.

[0025] The second member 200 includes a fitting hole 202 forming the second exhaust passage 34 and an outer peripheral edge portion 210 located on the outer peripheral side of the opening end of the fitting hole 202. The outer peripheral edge portion 210 is provided to protrude toward the first member 100 from the surface of the second member 200 facing the first member 100.

[0026] The fitting hole 202 of the second component 200 has an inner diameter corresponding to the outer diameter of the convex portion 102 of the first component 100, and the convex portion 102 can be fitted into the fitting hole 202. Here, the "inner diameter corresponding to the outer diameter of the convex portion 102" refers to an inner diameter that is the same as the diameter of the outer peripheral surface 106 of the convex portion 102, or an inner diameter that is slightly larger than the diameter of the outer peripheral surface 106 of the convex portion 102. In addition, the relative positional relationship between the first component 100 and the second component 200 in the housing 2 is not particularly limited. Figure 4 to Figure 7 As shown, the first component 100 may be located above the second component 200. In this case, the convex portion 102 of the first component 100 is provided so as to protrude downward toward the second component 200 and is fitted into the fitting hole 202.

[0027] When the protrusion 102 of the first member 100 is fitted into the fitting hole 202 of the second member 200 , the passage end 33 of the first exhaust passage 32 is located in the fitting hole 202 forming the second exhaust passage 34 , and the first exhaust passage 32 and the second exhaust passage 34 communicate with each other. In addition, if Figure 4 to Figure 7 As shown, an extension pipe 70 may be connected to the end of the fitting hole 202 on the opposite side of the fitting portion of the protrusion 102. In this case, the gas passing through the first exhaust passage 32 and the second exhaust passage 34 is discharged into the atmosphere through the extension pipe 70.

[0028] exist Figure 4 to Figure 7 In the illustrated embodiment, the outer peripheral edge portion 210 protrudes toward the first component 100 on the outer peripheral side of the fitting hole 202, and abuts against the flat surface 108 of the first component 100. That is, the abutting surface 212 of the second component 200 with respect to the flat surface 108 of the first component 100 is the top surface of the outer peripheral edge portion 210. The abutting surface 212 of the second component 200 is a flat surface parallel to the flat surface 108 of the first component 100, and can also be provided in a substantially annular shape so as to surround the fitting hole 202.

[0029] In some embodiments, the vacuum pump 1 is Figure 4 as well as Figure 6 As shown, a sealing member 300 held between the first member 100 and the second member 200 is included.

[0030] The sealing member 300 may be an annular seal made of a polymer compound (elastomer) having elasticity. exist Figure 4 to Figure 7 In the exemplary embodiment shown, the cross section is an O-ring. In another embodiment, the sealing member 300 is an annular seal having a non-circular cross section. As the annular seal having a non-circular cross section, for example, an X-ring or a D-ring can be used.

[0031] The sealing member 300 is located between the convex portion 102 of the first member 100 and the outer peripheral edge portion 210 of the second member 200 in the radial direction of the annular sealing member 300. That is, the sealing member 300 is provided between the radial position of the outer peripheral surface 106 of the convex portion 102 and the radial position of the inner peripheral surface of the outer peripheral edge portion 210, and surrounds the convex portion 102. In addition, the sealing member 300 is located closer to the first member 100 than the top surface 103 of the convex portion 102 and the flow path end 33 of the first exhaust passage 32 in the axial direction.

[0032] When the first member 100 is assembled to the second member 200 , the sealing member 300 is crushed and deformed by the first member 100 and the second member 200 , thereby sealing the exhaust passage 30 including the first exhaust passage 32 and the second exhaust passage 34 . exist Figure 5 In the example shown, the thickness t of the sealing member 300A before deformation is greater than the height of the outer peripheral edge portion 210 (the distance from the bottom surface 222 to the contact surface 212). Figure 7 As shown in FIG. 1 , the width w of the sealing member 300B before deformation is larger than the radial gap between the outer peripheral surface 106 of the protrusion 102 and the inner wall surface of the fitting hole 202, and the outer peripheral surface 106 of the protrusion 102 is in contact with the sealing member 300B. Therefore, when the first member 100 is assembled to the second member 200 in such a manner that the protrusion 102 is fitted into the fitting hole 202, as shown in FIG. Figure 4 as well as Figure 6 As shown, the sealing member 300 (300A, 300B) is compressed in the axial direction or radial direction.

[0033] In some embodiments, Figure 4 as well as Figure 5 Like the illustrated housing 2A, the second member 200 has a recessed portion 220 located radially inward of the outer peripheral edge portion 210 , and the sealing member 300A is accommodated in the recessed portion 220 . Specifically, the recessed portion 220 is recessed on the radially inner side of the outer peripheral portion 210 and on the radially outer side of the fitting hole 202 with the outer peripheral portion 210 as a reference. The bottom surface 222 of the recessed portion 220 is located at a position on the inner side of the second component 200 than the abutting surface 212 of the outer peripheral portion 210 in the axial direction of the annular sealing component 300A, and is opposite to the flat surface 108 of the first component 100. The fitting hole 202 is opened in the bottom surface 222 of the recessed portion 220. The sealing component 300A is held between the first component 100 and the second component 200 in the state of being sandwiched between the flat surface 108 of the first component 100 and the bottom surface 222 of the recessed portion 220 of the second component 200 in the axial direction.

[0034] When assembling the housing 2A, Figure 5As shown, with the sealing component 300A placed on the bottom surface 222 of the recess 220, the first component 100 is assembled to the second component 200 in a manner that the protrusion 102 is engaged with the engaging hole 202. The sealing component 300A and the recess 220 before deformation satisfy the relationship of (ds-di)>(do-ds-2×w). That is, the radial distance from the inner peripheral end of the sealing component 300A before deformation to the opening edge of the engaging hole 202 is greater than the radial distance from the outer peripheral end of the sealing component 300A before deformation to the inner peripheral surface of the outer peripheral edge 210. Here, ds is the inner diameter of the sealing component 300A before deformation, w is the width of the cross section of the sealing component 300A before deformation, and di and do are the inner diameter and outer diameter of the bottom surface 222 of the recess 220, respectively. In addition, Figure 5 In the example shown, (do-ds-2×w)>0 is also satisfied. By satisfying the above relationship, after assembling the housing 2A, Figure 4 As shown, a radial gap is ensured between the outer peripheral surface 106 of the protrusion 102 of the first member 100 fitted in the fitting hole 202 and the sealing member 300A, and the sealing member 300A is in close contact with the inner peripheral surface of the outer peripheral edge portion 210 . Regarding the sealing member 300A and the recessed portion 220 before deformation, the ratio of the radial distance (ds-di) / (do-ds-2×w) may be 2 or more, or 3 or more.

[0035] In addition, Figure 4 as well as Figure 5 In the illustrated exemplary embodiment, the outer peripheral edge 113 of the top surface 103 of the protrusion 102 of the first member 100 is chamfered to be tapered. Therefore, when the first component 100 is assembled to the second component 200 , the tapered outer peripheral edge 113 of the first component 100 fulfills the function of guiding the protrusion 102 into the fitting hole 202 .

[0036] In another embodiment, Figure 6 as well as Figure 7 As shown in the housing 2B, the outer peripheral surface 106 of the convex portion 102 of the first component 100 has a step 107, and the sealing member 300B is held between the portion of the convex portion 102 closer to the front end side (top surface 103 side) than the step 107 and the fitting hole 202 of the second component 200. Specifically, the outer peripheral surface 106 of the convex portion 102 of the housing 2B has: a proximal region located closer to the proximal side than the step 107 and having an outer diameter corresponding to the inner diameter of the fitting hole 202; and a distal region located closer to the distal side than the step 107 and having a smaller diameter than the proximal region. In the housing 2B, the inner diameter of the outer peripheral edge portion 210 is consistent with the inner diameter of the fitting hole 202, and the inner peripheral surface of the outer peripheral edge portion 210 is connected to the inner wall surface of the fitting hole 202 without a step in the axial direction. In the assembled housing 2B, the sealing member 300B is maintained in the radial gap between the distal region of the outer peripheral surface 106 of the convex portion 102 and the inner wall surface of the fitting hole 202.

[0037] When assembling the housing 2B, Figure 7 As shown, in a state where the sealing component 300B is assembled to the front end side region of the convex portion 102 of the first component 100, the first component 100 is assembled to the second component 200 in a manner that the convex portion 102 is engaged with the engaging hole 202. The sealing component 300B, the convex portion 102, and the engaging hole 202 before deformation satisfy the relationship (d1+2×w)>d2. Here, d1 is the outer diameter of the front end side region of the outer peripheral surface 106 of the convex portion 102, d2 is the inner diameter of the engaging hole 202, and w is the width of the cross section of the sealing component 300B before deformation. By satisfying the above relationship, after the housing 2B is assembled, Figure 6 As shown, the sealing member 300B is in close contact with the inner wall surface of the fitting hole 202 , the front end side region of the outer peripheral surface 106 of the convex portion 102 , and the step surface of the step 107 of the convex portion 102 .

[0038] In some embodiments, Figure 4 to Figure 7 As shown, an extension tube 70 (see Figure 1 as well as Figure 3 ), the extension pipe 70 guides the downward exhaust gas flow passing through the first exhaust passage 32 and the second exhaust passage 34 in sequence to a higher position.

[0039] Figure 8 It is a diagram showing the structure of an extension pipe in a vacuum pump according to an embodiment. As shown in the figure, the extension pipe 70 is installed on the second component 200 in a manner that communicates with the exhaust passage 30 (the second exhaust passage 34), and is connected to the end of the fitting hole 202 located on the opposite side of the fitting portion with the protrusion 102. The extension pipe 70 includes: an upstream portion 72 extending downward from the second component 200; and a downstream portion 74 located on the downstream side of the upstream portion 72. The downstream portion 74 of the extension pipe 70 is bent back at the bottom 76 of the extension pipe 70 and extends upward to the outlet 71 of the extension pipe 70 located at a position higher than the second component 200. Figure 8As shown, the outlet 71 of the extension tube 70 may be located at a higher position than the first component 100 . The exhaust gas flow having passed through the exhaust passage 30 (second exhaust passage 34 ) sequentially flows through the upstream portion 72 and the downstream portion 74 of the extension pipe 70 , and is then discharged into the atmosphere from the outlet 71 of the extension pipe 70 .

[0040] exist Figure 8 In the illustrated exemplary embodiment, the extension tube 70 includes: a joint 73 that is pressed into the fitting hole 202 so as to extend downward from the second component 200; and a U-shaped hose 75 that is mounted on the joint 73. The hose 75 is connected to the protruding portion of the joint 73 from the second component 200 by a belt 78. The joint 73 forms the upstream portion 72 of the extension pipe 70 . On the other hand, the hose 75 forms the bottom portion 76 and the downstream portion 74 of the extension pipe 70 .

[0041] Next, a specific example of the overall structure of the vacuum pump 1 according to the above-described embodiment will be described. Fig. 9 1 is an exploded perspective view showing the overall structure of a vacuum pump 1 according to an embodiment. The vacuum pump 1 may be an electric vacuum pump for making a negative pressure in a negative pressure chamber of a brake booster (vacuum booster) in a vehicle such as an automobile, for example. Hereinafter, “upper” and “lower” refer to “upper” and “lower” in a state where the vacuum pump 1 is installed in a vehicle.

[0042] The vacuum pump 1 includes: a housing 2 ; and a movable portion 42 of a gas conveying portion 40 disposed in the housing 2 . In some embodiments, Fig. 9 As shown in FIG. 1 , the movable part 42 is a rotor 43 rotatably provided in the housing 2. The rotor 43 is driven by a motor M provided below the housing 2 and rotates around a central axis O.

[0043] like Fig. 9 As shown, the housing 2 has a pump chamber 10 that accommodates a rotor 43 as a movable portion 42. The pump chamber 10 is defined by a cam surface 11 that is a part of the inner wall surface of the housing 2. The cam surface 11 is defined by a non-circular (eg, elliptical) contour. On the other hand, the rotor 43 has an outer peripheral surface 44 defined by a circular contour centered at the point O. A plurality of slits 45 are formed on the outer peripheral surface 44. Each slit 45 is provided with a vane 46 for dividing the pump chamber 10 into a plurality of compartments.

[0044] exist Fig. 9In the example shown, the housing 2 includes: a housing body 3 having a recessed portion that forms the bottom and side surfaces of a pump chamber 10 that accommodates a rotor 43; and a pump cover 4 that forms the upper surface of the pump chamber 10. The pump cover 4 forms the pump chamber 10 together with the housing body 3 by blocking the opening of the recessed portion of the housing body 3 that forms the bottom and side surfaces of the pump chamber 10. A top cover 5 that covers the pump cover 4 is provided above the pump cover 4. On the other hand, a bottom cover 6 that covers the lower side of the housing body 3 is provided between the housing body 3 and the motor M.

[0045] A sealing member 90 is provided between the top cover 5 and the pump cover 4. The sealing member 90 includes an inner sealing portion 94, an outer sealing portion 96 surrounding the inner sealing portion 94, and a connecting portion 95 connecting the inner sealing portion 94 and the outer sealing portion 96 to each other.

[0046] When the top cover 5 is fastened to the pump cover 4, the sealing member 90 is elastically deformed in a manner of being compressed in the sealing groove 91, thereby blocking the gap between the pump cover 4 and the top cover 5. Thus, a second muffler chamber 60 is formed between the inner sealing portion 94 and the outer sealing portion 96 (see Figure 3 ). The second muffler chamber 60 is formed on the opposite side of the pump chamber 10 above the pump chamber 10 through the pump cover 4 and the top cover 5. The second muffler chamber 60 communicates with the first muffler chamber 50 formed in the housing body 3 through two openings 63 provided in the pump cover 4 and two communication holes 64 formed in the housing body 3. That is, two communication paths 62 (see FIG. 1 ) are formed to communicate the first muffler chamber 50 with the second muffler chamber 60 through the two sets of openings 63 and the communication holes 64. Figure 3 ).

[0047] The bottom cover 6 has a suction port 21 which is an inlet for gas to flow toward the pump chamber 10 . The air intake port 21 is guided to an air intake chamber 24 formed between the pump cover 4 and the top cover 5 via a communication passage 22 provided in the housing body 3 and a communication passage 23 provided in the pump cover 4. The communication passage 23 penetrates the pump cover 4, and the gas passing through the communication passage 22 provided in the housing body 3 flows into the air intake chamber 24 formed above the pump cover 4 through the communication passage 23.

[0048] The air intake chamber 24 is fluidically isolated from the second muffler chamber 60 around the partition wall portion 25 by the partition wall portion 25 and the inner seal portion 94 provided on the pump cover 4 . The suction chamber 24 is connected to the internal space of the pump chamber 10 via the suction port 12 (12A, 12B) of the pump chamber 10 provided in the pump cover 4. The pair of suction ports 12 (12A, 12B) are located on opposite sides of the central axis O of the rotor 43. Therefore, the suction chamber 24 extends from the communication passage 23 to the opposite side across the central axis O along the radial direction of the rotor 43 in a manner passing through the position of the pair of suction ports 12 (12A, 12B).

[0049] Thus, the gas sucked from the air intake port 21 passes through the communication passage 22, the communication passage 23, and the air intake chamber 24 in sequence, and then flows into the pump chamber 10 from the pair of air intake ports 12 (12A, 12B). Figure 1 to Figure 3 ) includes a connecting passage 22, a connecting passage 23 and an intake chamber 24.

[0050] A discharge port 14 of the pump chamber 10 is provided on the wall surface of the housing body 3 constituting the bottom surface of the pump chamber 10. Fig. 9 Although only one discharge port 14 is shown in the figure, another discharge port 14 (not shown) is provided at a circumferential position on the opposite side with respect to the central axis O. The gas flowing out of the pump chamber 10 through the pair of discharge ports 14 flows into the first muffler chamber 50 (see Figure 3 The gas after passing through the first muffler chamber 50 flows into the second muffler chamber 60 through the connecting hole 64 and the opening 63, and finally flows through the exhaust passage 30 (refer to Figure 1 to Figure 7 ) and extension tube 70 are discharged into the atmosphere.

[0051] exist Fig. 9 In the example shown, the exhaust passage 30 is formed inside the pump cover 4 as the first component 100 and the housing body 3 as the second component 200 in a manner of being located between the second muffler chamber 60 and the extension pipe 70. The convex portion 102 of the pump cover 4 is fitted into the fitting hole 202 of the housing body 3, and the first exhaust passage 32 provided inside the convex portion 102 is connected to the second exhaust passage 34 defined by the fitting hole 202, thereby forming the exhaust passage 30 including the first exhaust passage 32 and the second exhaust passage 34. The exhaust passage 30 is formed by a sealing member 300A (see FIG. 1 ) held between the pump cover 4 and the housing body 3. Figure 4 as well as Figure 5 The sealing member 300A is accommodated in the recessed portion 220, and the recessed portion 220 is recessed with reference to the annular outer peripheral edge portion 210 provided so as to surround the fitting hole 202 of the housing body 3.

[0052] Here, in Fig. 9 In the embodiment shown, two openings 63 and the first exhaust passage 32 in the convex portion 102 are provided in the pump cover 4 in a manner that penetrates the pump cover 4. The opening 63 is used to connect the second muffler chamber 60 with the first muffler chamber 50 ( Figure 3The first exhaust passage 32 is located at a position further outward from the opening 63 in the radial direction of the rotor 43 with the center axis O as a reference. The outer seal portion 96 and the seal groove 91 of the sealing member 90 bulge radially outward near the first exhaust passage 32 in a manner of surrounding the first exhaust passage 32. In order to achieve compactness of the housing 2, it is desirable to suppress the bulging of the outer seal portion 96 and the seal groove 91 radially outward. On the other hand, if the bulging of the outer seal portion 96 and the seal groove 91 radially outward is excessively suppressed, it is impossible to ensure a space for setting the sealing member 300A (a groove for setting the sealing member). In this regard, the sealing member 300A can be held between the convex portion 102 of the pump cover 4 and the outer peripheral edge portion 210 of the housing body 3 in the radial direction, and the housing 2 can be made more compact.

[0053] In addition, Fig. 9 In the example shown, the joint 73 is pressed into the fitting hole 202 of the housing body 3 as the second member 200 from below, and a U-shaped hose 75 is attached to the lower end of the joint 73. The joint 73 and the hose 75 are respectively equivalent to the reference Figure 8 The extension pipe 70 is depicted with an upstream portion 72 and a downstream portion 74 .

[0054] The characteristic structures of the vacuum pump 1 according to some of the above-mentioned embodiments are summarized as follows.

[0055] [1] In some embodiments, a vacuum pump (1) comprises a housing (2), The housing (2) includes a pump chamber (10), and an air intake passage (20) and an air exhaust passage (30) communicating with the pump chamber (10). The housing (2) comprises: a first member (100) having a convex portion (102) in which a first exhaust passage (32) of the exhaust passages (30) is formed; and A second component (200) having a fitting hole (202) which forms a second exhaust passage (34) communicating with a first exhaust passage (32) in the exhaust passage (30) and can be fitted with the convex portion (102), and an outer peripheral edge portion (210) which is provided on the outer peripheral side of the fitting hole (202) and protrudes toward the first component (100), The vacuum pump (1) further comprises a sealing component (300) which is held between the first component (100) and the second component (200) in a manner radially located between a convex portion (102) of the first component (100) and an outer peripheral edge portion (210) of the second component (200), and is used to seal an exhaust passage (30) including a first exhaust passage (32) and a second exhaust passage (34).

[0056] In the past, the sealing component was generally provided in a groove for providing the sealing component. The groove for providing the sealing component was formed between the inner circumferential side annular convex portion and the outer circumferential side annular convex portion. Therefore, forming a groove for providing the sealing component on the joint surface between the housing components would hinder the compactness of the vacuum pump. In this regard, according to the structure of [1] above, the sealing member (300) is held between the convex portion (102) of the first member (100) and the outer peripheral edge portion (210) of the second member (200) in the radial direction, so it is not necessary to form a groove for providing the sealing member on either the first member (100) or the second member (200). As a result, the vacuum pump (1) can be made compact.

[0057] [2] In some embodiments, in the structure of [1] above, The first component (100) is located above the second component (200), The convex portion (102) of the first component (100) is provided in a manner of protruding downward toward the second component (200) and is fitted into the fitting hole (202) of the second component (200).

[0058] According to the structure of [2] above, when the first component (100) is assembled to the second component (200), the visibility of the protrusion (102) and the fitting hole (202) is improved, making it easier to use the protrusion (102) and the fitting hole (202) to position the first component (100) relative to the second component (200).

[0059] [3] In some embodiments, in the structure of [2] above, The vacuum pump (1) includes an extension pipe (70) which is mounted on the second component (200) in a manner communicating with the exhaust passage (30) and connected to an end of the fitting hole (202) located on the opposite side of the fitting portion with the convex portion (102). The extension tube (70) comprises: an upstream portion (72) extending downward from the second member (200); and The downstream side portion (74) is located on the downstream side of the upstream side portion (72) and extends upward to a position higher than the second member (200). The extension pipe (70) is configured to guide the exhaust gas flow that has passed through the first exhaust passage (32) and the second exhaust passage (34) to an outlet (71) of the extension pipe (70) located at a position higher than the second member (200).

[0060] According to the structure of the above-mentioned [3], by extending the extension pipe connected to the exhaust passage (30), The outlet (71) of (70) is arranged at a position higher than the second component (200), which can prevent water from intruding into the vacuum pump (1) through the exhaust passage (30). In addition, the structure of [1] can make the vacuum pump (1) compact and seal the first exhaust passage. (32) A connection portion with the second exhaust passage (34). In this way, the vacuum pump (1) can be protected against water immersion with a simple and compact structure.

[0061] [4] In some embodiments, in the structure of [3] above, The extension tube (70) comprises: a joint (73) as an upstream side portion (72) pressed into a fitting hole (202) of the second member (200) in a manner extending downward from the second member (200); and The U-shaped hose (75) is a second member assembled in the joint (73). The downstream side portion (74) of the protruding portion starting from (200).

[0062] According to the structure of [4] above, by using a connector (73) pressed into the fitting hole (202) of the second component (200) and a hose (75) assembled on the connector (73), it is possible to realize an extension tube (70) having an outlet (71) located at a higher position than the second component (200) without providing an additional sealing component.

[0063] [5] In some embodiments, in the structure of any one of the above [1] to [4], The housing (2) comprises: A pump cover (4) as a first component (100); a housing body (3) as a second component (200); and A top cover (5) is located on the opposite side of the housing body (3) across the pump cover (4) and is mounted on the pump cover (4). The pump chamber (10) is formed by the pump cover (4) and the housing body (3) by blocking an opening of a recessed portion provided in the housing body (3) with the pump cover (4). A muffler chamber for guiding the gas exhausted from the pump chamber (10) to the first exhaust passage (32) (60) through the pump cover (4) and the top cover (5), above the pump chamber (10) through the pump cover (4) is formed on the opposite side of the pump chamber (10).

[0064] In the structure of [5] above, the pump cover (4) and the housing body (3) are respectively equivalent to the first component (100) and the second component (200) of the structure of [1] above. That is, the first exhaust passage (32) and the second exhaust passage (34) are dispersedly provided in the pump cover (4) as the first component (100) and the housing body (3) as the second component (200), and the exhaust passage (30) is retained by the sealing component between the pump cover (4) and the second component (200). (300) seal. The sealing member (300) is held radially between the convex portion (102) of the pump cover (4) and the outer peripheral edge portion (210) of the pump housing body (3), so there is no need to form a groove for providing the sealing member on either the pump cover (4) or the housing body (3). Thus, the vacuum pump (1) can be made compact.

[0065] [6] In some embodiments, in the structure of any one of the above [1] to [5], The first member (100) has a flat surface (108) facing the second member (200) on the outer peripheral side of the convex portion (102). The second component (200) has an outer peripheral edge portion (210) having an outer peripheral edge portion radially inside thereof. (210) is a concave portion (220) of a reference depression, The fitting hole (202) opens on a bottom surface (222) of a recess (220) facing the flat surface (108) of the first component (100). The sealing member (300A) is clamped in the axial direction by the flat surface of the first member (100). The state between (108) and the bottom surface (222) of the second component (200) is maintained.

[0066] According to the structure of [6] above, a space for accommodating the sealing component (300A) can be ensured between the outer peripheral surface (106) of the convex portion (102) and the inner peripheral surface of the outer peripheral edge portion (210). Therefore, it is not necessary to form a groove for arranging the sealing component on either the first component (100) or the second component (200). As a result, the vacuum pump (1) can be made compact.

[0067] [7] In some embodiments, in the structure of [6] above, The sealing component (300A) is arranged to be sandwiched between the flat surface (108) of the first component (100) and the bottom surface (222) of the second component (200) in the axial direction, with a radial gap between the sealing component and the outer peripheral surface (106) of the convex portion (102).

[0068] According to the structure of [7], since a radial gap is maintained between the outer peripheral surface (106) of the convex portion (102) and the sealing component (300A), when the first component (100) is removed from the second component (200), the sealing component (300A) remains in the recessed portion (220) of the second component (200). Therefore, when the vacuum pump (1) is disassembled, it is possible to prevent the sealing component (300A) from being unable to be easily removed from the convex portion (102) of the first component (100).

[0069] [8] In some embodiments, in the structure of [7] above, The sealing component (300A) is configured to be in close contact with the outer peripheral edge portion (210) of the second component (200) in a state of being sandwiched between the flat surface (108) of the first component (100) and the bottom surface (222) of the second component (200) in the axial direction.

[0070] According to the structure of [8] above, since the sealing component (300A) is also tightly attached to the outer peripheral edge portion (210) when clamped between the flat surface (108) of the first component (100) and the bottom surface (222) of the second component (200), a high sealing effect can be obtained based on the sealing component (300A).

[0071] [9] In some embodiments, in the structure of any one of the above [1] to [5], The sealing component (300B) is held radially sandwiched between the outer peripheral surface (106) of the protrusion (102) of the first component (100) and the inner wall surface of the fitting hole (202), and the inner wall surface of the fitting hole (202) is connected to the inner peripheral surface of the outer peripheral edge (210) of the second component (200).

[0072] According to the structure of [9] above, the sealing component (300A) is held between the outer peripheral surface (106) of the protrusion (102) and the inner wall surface of the fitting hole (202). Therefore, it is not necessary to form a groove for providing the sealing component on either the first component (100) or the second component (200). Thus, the vacuum pump (1) can be made compact.

[0073] In this specification, expressions such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric" or "coaxial" that indicate relative or absolute configurations do not only indicate configurations in a strict sense, but also indicate a state of relative displacement at an angle or distance with a tolerance or a degree that can achieve the same function. For example, expressions such as “same”, “equal”, and “homogeneous” indicating that things are equal do not only indicate a strictly equal state but also indicate a state in which there is a tolerance or a difference to the extent that the same function can be obtained. In the present specification, expressions such as a quadrilateral and a cylindrical shape do not only refer to shapes such as a quadrilateral and a cylindrical shape in a strict geometric sense, but also refer to shapes including concave and convex portions, chamfered portions, etc. within a range that can achieve the same effect. In addition, in this specification, the expression “including”, “comprising”, or “having” one component is not an exclusive expression excluding the presence of other components.

Claims

1. A vacuum pump comprising a housing, the housing including a pump chamber, and an air intake passage and an air exhaust passage communicating with the pump chamber, The housing comprises: a first member having a protrusion having a first exhaust passage of the exhaust passages formed therein; as well as a second member having a fitting hole which forms a second exhaust passage communicating with the first exhaust passage in the exhaust passage and can be fitted with the convex portion, and an outer peripheral edge portion which is provided on the outer peripheral side of the fitting hole and protrudes toward the first member, The vacuum pump further includes a sealing member held between the first member and the second member so as to be radially located between the convex portion of the first member and the outer peripheral edge portion of the second member and configured to seal the exhaust passage including the first exhaust passage and the second exhaust passage.

2. The vacuum pump according to claim 1, wherein: The first component is located above the second component, The protrusion of the first member is provided so as to protrude downward toward the second member and is fitted into the fitting hole of the second member.

3. The vacuum pump according to claim 2, wherein: The vacuum pump includes an extension pipe, the extension pipe being mounted on the second member in a manner communicating with the exhaust passage and connected to an end of the fitting hole on the opposite side of the fitting portion with the protrusion. The extension tube comprises: an upstream portion extending downward from the second member; and a downstream side portion, which is located on the downstream side of the upstream side portion and extends upward to a position higher than the second member, The extension pipe is configured to guide the exhaust gas flow that has passed through the first exhaust passage and the second exhaust passage to an outlet of the extension pipe located at a position higher than the second member.

4. The vacuum pump according to claim 3, wherein: The extension tube comprises: a joint as the upstream side portion that is press-fitted into the fitting hole of the second member so as to extend downward from the second member; and A U-shaped hose is mounted on the downstream side portion of the protruding portion from the second member in the joint.

5. The vacuum pump according to claim 1 or 2, wherein: The housing comprises: A pump cover as the first component; a housing body as the second component; and a top cover, which is located on the opposite side of the housing body across the pump cover and is mounted on the pump cover, The pump chamber is formed by the pump cover and the housing body by the pump cover blocking an opening of a recessed portion provided in the housing body. A muffler chamber for guiding the gas exhausted from the pump chamber to the first exhaust passage is formed above the pump chamber on the opposite side of the pump chamber via the pump cover and the top cover.

6. The vacuum pump according to claim 1 or 2, wherein: The first member has a flat surface on the outer peripheral side of the protrusion facing the second member, The second member has a recessed portion which is recessed radially inward of the outer peripheral edge portion with reference to the outer peripheral edge portion. The fitting hole opens on the bottom surface of the recessed portion facing the flat surface of the first member. The sealing member is held in a state of being sandwiched between the flat surface of the first member and the bottom surface of the second member in the axial direction.

7. The vacuum pump according to claim 6, wherein: The sealing member is disposed with a radial gap between the outer peripheral surface of the convex portion and the sealing member in a state of being sandwiched in the axial direction between the flat surface of the first member and the bottom surface of the second member.

8. The vacuum pump according to claim 7, wherein: The sealing member is configured to be in close contact with the outer peripheral edge portion of the second member in a state of being sandwiched between the flat surface of the first member and the bottom surface of the second member in the axial direction.

9. The vacuum pump according to claim 1 or 2, wherein: The sealing member is held in a state of being sandwiched in a radial direction between an outer peripheral surface of the convex portion of the first member and an inner wall surface of the fitting hole, and the inner wall surface of the fitting hole is connected to an inner peripheral surface of the outer peripheral edge portion of the second member.

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