Vacuum pump

Abstract

To provide a vacuum pump capable of making sealing of an exhaust passage compatible with compactification.SOLUTION: A vacuum pump 1 comprises a casing 2 including a pump chamber 10, an intake passage 20 and an exhaust passage 30 communicating to the pump chamber 10. The casing 2 includes: a first component 100 including a projection 102 in which a first exhaust passage 32 in the exhaust passage 30 is formed; and a second component 200 including a fitting hole 202 which forms a second exhaust passage 34 communicating to the first exhaust passage 32 in the exhaust passage 30 and to which the projection 102 can be fitted, and an outer peripheral edge 210 which is provided at an outer peripheral side of the fitting hole 202, while protruding toward the first component 100. The vacuum pump 1 further comprises a seal member 300, which is held between the first component 100 and the second component 200 so as to be positioned between the projection 102 of the first component 100 and the outer peripheral edge 210 of the second component 200 in a radial direction, for sealing the exhaust passage 30 including the first exhaust passage 32 and the second exhaust passage 34.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

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

[0003] Furthermore, Patent Document 2 describes a vacuum pump that can prevent liquid from splashing on the exhaust port while minimizing an increase in the number of parts, in consideration of the possibility that liquid such as water splashes may adhere to the exhaust port depending on the usage environment. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-25413 [Patent Document 2] Japanese Patent Publication No. 2020-76336 Summary of the Invention [Problem to be solved by the invention]

[0005] Generally, the casing of a vacuum pump is formed by assembling a plurality of parts. In this case, depending on the layout of the internal flow path of the casing, the exhaust passage of the vacuum pump may be divided into multiple sections, and the exhaust passages of each section may be distributed to multiple casing parts. By assembling the multiple casing parts, the exhaust passages of adjacent sections are connected to each other at the joint surfaces between the casing parts.

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

[0007] In view of the above circumstances, at least some embodiments of the present invention have an object to provide a vacuum pump that can seal an exhaust passage while being compact. [Means for solving the problem]

[0008] A vacuum pump according to at least some embodiments of the present invention comprises: a casing including a pump chamber and an intake passage and an exhaust passage communicating with the pump chamber; The casing is a first component having a protrusion in which a first exhaust passage is formed; a second component that defines a second exhaust passage that communicates with the first exhaust passage among the exhaust passages, the second component having a fitting hole into which the protrusion can be fitted, and an outer peripheral edge portion that is provided on the outer peripheral side of the fitting hole and protrudes toward the first component; Including, The engine further includes a sealing member that is held between the first and second parts so as to be positioned radially between the convex portion of the first part and the outer peripheral edge portion of the second part, and that seals the exhaust passage including the first exhaust passage and the second exhaust passage. [Effects of the Invention]

[0009] According to at least some embodiments of the present invention, the seal member is held between the first and second components so as to be positioned radially between the protrusion of the first component and the outer peripheral edge of the second component, eliminating the need to form a groove in either the first or second component to accommodate the seal member, thereby enabling the vacuum pump to be made more compact. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a diagram illustrating an internal flow path of a vacuum pump according to an embodiment. [Figure 2] FIG. 10 is a diagram schematically illustrating an internal flow path of a vacuum pump according to another embodiment. [Figure 3] FIG. 10 is a diagram schematically illustrating an internal flow path of a vacuum pump according to yet another embodiment. [Figure 4] 1 is a partial cross-sectional view of a casing of a vacuum pump according to an embodiment, showing the structure around an exhaust passage. [Figure 5] FIG. 5 is a diagram showing a state before assembly of a casing of the vacuum pump shown in FIG. [Figure 6] 10 is a partial cross-sectional view of a casing of a vacuum pump according to another embodiment, showing the structure around an exhaust passage. [Figure 7] FIG. 7 is a diagram showing a state before assembly of the casing of the vacuum pump shown in FIG. 6. [Figure 8] 1 is a diagram showing a configuration of an extension tube in a vacuum pump according to an embodiment. FIG. [Figure 9] 1 is an exploded perspective view showing the overall structure of a vacuum pump according to an embodiment; DETAILED DESCRIPTION OF THE INVENTION

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

[0012] Fig. 1 is a diagram schematically showing the internal flow path of a vacuum pump 1A according to one embodiment, Fig. 2 is a diagram schematically showing the internal flow path of a vacuum pump 1B according to another embodiment, and Fig. 3 is a diagram schematically showing the internal flow path of a vacuum pump 1C according to yet another embodiment. Hereinafter, vacuum pumps according to several embodiments, including vacuum pumps 1A, 1B, and 1C, may be collectively referred to as vacuum pump 1. Vacuum pump 1 is not limited to vacuum pumps 1A, 1B, and 1C, but also includes vacuum pumps according to other embodiments not shown.

[0013] In some embodiments, as shown in FIGS. 1 to 3, the vacuum pump 1 includes, as internal flow paths in the casing of the vacuum pump 1, a pump chamber 10, and an intake passage 20 and an exhaust passage 30 that communicate with the pump chamber 10.

[0014] The pump chamber 10 has an inlet 12 and an outlet 14 . When the vacuum pump 1 is a positive displacement vacuum pump, the vacuum pump 1 includes a gas transfer section 40 within the pump chamber 10. The gas transfer section 40 is configured to periodically transfer a predetermined volume of gas from the inlet 12 to the outlet 14.

[0015] The gas transfer section 40 includes a movable section 42 that can have various configurations depending on the type of vacuum pump 1. The movable section 42 is configured to be able to transfer gas by reciprocating or rotating. For example, if the vacuum pump 1 is a reciprocating pump, the gas transfer unit 40 includes a moving part 42 such as a diaphragm or a piston. In other embodiments, the vacuum pump 1 is a rotary pump, and the moving part 42 of the gas transfer unit 40 includes a rotor of various shapes.

[0016] The intake port 12 of the pump chamber 10 communicates with an intake passage 20, and gas flowing through the intake passage 20 is taken into the pump chamber 10 via the intake port 12. On the other hand, the discharge port 14 of the pump chamber 10 communicates with an exhaust passage 30, and gas discharged from the pump chamber 10 is released into the atmosphere via the discharge port 14 and the exhaust passage 30.

[0017] The exhaust passage 30 may be any passage through which the gas discharged from the pump chamber 10 flows, and the specific configuration of the exhaust passage 30 is not particularly limited. 1 and 2, the exhaust passage 30 is directly connected to the pump chamber 10 via the discharge port 14. In the embodiment shown in Fig. 3, 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 discharge port 14.

[0018] The one or more chambers (50, 60) provided between the pump chamber 10 and the exhaust passage 30 may include sound-absorbing chambers 50, 60. 3 , the first silencing chamber 50 is located below and to the side of the pump chamber 10, and receives gas discharged from the pump chamber 10 via the discharge port 14. The first silencing chamber 50 communicates with a second silencing chamber 60 located above the pump chamber 10 via a communication passage 62. The second silencing chamber 60 communicates with the exhaust passage 30, and the second silencing chamber 60 guides the gas that has passed through the first silencing chamber 50 to the exhaust passage 30.

[0019] 1 and 3, when the exhaust passage 30 serving as the internal flow path of the vacuum pump 1 is a downward flow path, an extension pipe 70 may be connected to the exhaust passage 30 to prevent water from entering the vacuum pump 1 from the exhaust passage 30. The extension pipe 70 has an outlet 71 at a higher position than the downstream end of the exhaust passage 30, and communicates with the atmosphere at the outlet 71. 2, the exhaust passage 30 is an upward flow path, and the exhaust passage 30 is directly connected to the atmosphere without the extension pipe 70. When the exhaust passage 30 is an upward flow path, a cover (not shown) may be provided at the open end of the exhaust passage 30 to prevent foreign matter from entering the exhaust passage 30.

[0020] The casing of the vacuum pump 1 having the above-described internal flow path may be formed by assembling a plurality of components. In this case, depending on the layout of the internal flow path of the casing, the exhaust passage 30 may be divided into a plurality of sections, and each section of the exhaust passage 30 may be distributed among a plurality of casing components. By assembling a plurality of casing components, adjacent sections of the exhaust passage 30 are connected to each other at the joint surfaces between the casing components.

[0021] Hereinafter, with reference to FIGS. 4 to 7, the casing of the vacuum pump 1 in which the sections of the exhaust passage 30 are provided in a distributed manner in a plurality of casing parts will be described. Fig. 4 is a partial cross-sectional view of a casing of a vacuum pump according to one embodiment, showing the structure around the exhaust passage 30. Fig. 5 is a view showing the casing of the vacuum pump shown in Fig. 4 in a state before assembly. Fig. 6 is a partial cross-sectional view of a casing of a vacuum pump according to another embodiment, showing the structure around the exhaust passage 30. Fig. 7 is a view showing the casing of the vacuum pump shown in Fig. 6 in a state before assembly.

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

[0023] 4 and 6, the first exhaust passage 32 formed in the first component 100 is located upstream of the second exhaust passage 34 formed in the second component 200 in the gas flow direction. That is, the gas discharged from the pump chamber 10 flows through the first exhaust passage 32 and then the second exhaust passage 34, and is finally released into the atmosphere. Note that the first component 100 may be formed with a second silencing chamber 60 (see FIG. 3) located upstream of the first exhaust passage 32. In another embodiment, the second exhaust passage 34 of the second part 200 is located upstream of the first exhaust passage 32 of the first part 100 in the gas flow direction.

[0024] The first component 100 has a protrusion 102 in which the first exhaust passage 32 is formed. The protrusion 102 is provided to protrude from the surface of the first component 100 (the surface facing the second component 200) along the extension direction of the first exhaust passage 32. The first exhaust passage 32 is formed by a through hole 104 provided in the protrusion 102. The through hole 104 opens to a top surface 103 of the protrusion 102 and forms a flow path end 33 of the first exhaust passage 32. 4 and 6, the protrusion 102 is cylindrical and has a circumferential outer surface 106. In addition to the protrusion 102, the first part 100 also includes a flat surface 108 that faces the second part 200 on the outer circumferential side of the outer surface 106 of the protrusion 102. The protrusion 102 protrudes from the flat surface 108 toward the second part 200.

[0025] The second component 200 includes a fitting hole 202 that forms the second exhaust passage 34, and an outer peripheral edge portion 210 that is located on the outer peripheral side of the open end of the fitting hole 202. The outer peripheral edge portion 210 is provided so as to protrude toward the first component 100 from the surface of the second component 200 that faces the first component 100.

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

[0027] When the protrusion 102 of the first part 100 is fitted into the fitting hole 202 of the second part 200, the flow path end 33 of the first exhaust passage 32 is located within the fitting hole 202 that forms the second exhaust passage 34, and the first exhaust passage 32 and the second exhaust passage 34 are connected to each other. 4 to 7, an extension pipe 70 may be connected to the end of the fitting hole 202 opposite to the fitting portion with the protrusion 102. In this case, the gas that has passed through the first exhaust passage 32 and the second exhaust passage 34 is released into the atmosphere via the extension pipe 70.

[0028] 4 to 7, the outer peripheral edge portion 210 protrudes toward the first part 100 on the outer periphery side of the fitting hole 202 and abuts against the flat surface 108 of the first part 100. In other words, the abutment surface 212 of the second part 200 that abuts against the flat surface 108 of the first part 100 is the top surface of the outer peripheral edge portion 210. The abutment surface 212 of the second part 200 may be a flat surface parallel to the flat surface 108 of the first part 100 and provided in a generally annular shape so as to surround the fitting hole 202.

[0029] In some embodiments, the vacuum pump 1 includes a seal member 300 held between the first part 100 and the second part 200, as shown in FIGS.

[0030] The seal member 300 may be an annular seal made of an elastic polymer compound (elastomer). 4 to 7, the seal member 300 is an O-ring having a circular cross section. In other embodiments, the seal member 300 is an annular seal having a non-circular cross section. Examples of annular seals having a non-circular cross section include an X-ring and a D-ring.

[0031] The seal member 300 is located between the protrusion 102 of the first part 100 and the outer peripheral edge 210 of the second part 200 in the radial direction of the annular seal member 300. In other words, the seal member 300 is provided between the radial position of the outer peripheral surface 106 of the protrusion 102 and the radial position of the inner circumferential surface of the outer peripheral edge 210, and surrounds the protrusion 102. Additionally, the seal member 300 is located closer to the first component 100 than the top surface 103 of the protrusion 102 and the flow path end 33 of the first exhaust passage 32 in the axial direction.

[0032] When the first part 100 is assembled to the second part 200, the seal member 300 is crushed and deformed by the first part 100 and the second part 200, thereby sealing the exhaust passage 30 including the first exhaust passage 32 and the second exhaust passage 34. 5, thickness t of sealing member 300A before deformation is greater than the height of outer peripheral edge portion 210 (the distance from bottom surface 222 to contact surface 212). Similarly, as shown in FIG. 7, width w of sealing member 300B before deformation is smaller than the radial gap between outer peripheral surface 106 of protrusion 102, which contacts sealing member 300B, and the inner wall surface of fitting hole 202. Therefore, when first part 100 is assembled to second part 200 so that protrusion 102 fits into fitting hole 202, sealing member 300 (300A, 300B) is crushed in the axial or radial direction, as shown in FIGS. 4 and 6.

[0033] In some embodiments, like the casing 2A shown in FIGS. 4 and 5, the second part 200 has a recess 220 located radially inward of the outer peripheral edge 210, and the seal member 300A is housed in the recess 220. Specifically, recess 220 is provided radially inward of outer peripheral edge portion 210 and radially outward of fitting hole 202, so as to be recessed with respect to outer peripheral edge portion 210. A bottom surface 222 of recess 220 is located more inward of second part 200 than abutment surface 212 of outer peripheral edge portion 210 in the axial direction of annular seal member 300A, and faces flat surface 108 of first part 100. Fitting hole 202 opens in bottom surface 222 of recess 220. Seal member 300A is held between first part 100 and second part 200 in a state where it is sandwiched between flat surface 108 of first part 100 and bottom surface 222 of recess 220 of second part 200 in the axial direction.

[0034] When assembling the casing 2A, as shown in FIG. 5, the seal member 300A is placed on the bottom surface 222 of the recess 220, and the first component 100 is attached to the second component 200 so that the protrusion 102 fits into the fitting hole 202. The seal member 300A and the recess 220 before deformation satisfy the relationship (ds - di) > (do - ds - 2 × w). That is, the radial distance from the inner peripheral edge of the seal member 300A before deformation to the opening edge of the fitting hole 202 is greater than the radial distance from the outer peripheral edge of the seal member 300A before deformation to the inner peripheral surface of the outer peripheral edge portion 210. Here, ds is the inner diameter of the seal member 300A before deformation, w is the cross-sectional width of the seal member 300A before deformation, and di and do are the inner and outer diameters of the bottom surface 222 of the recess 220, respectively. Note that in the example shown in FIG. 5, (do - ds - 2 × w) > 0 is also satisfied. By satisfying the above relationship, after the casing 2A is assembled, as shown in FIG. 4, a radial gap is secured between the outer peripheral surface 106 of the protrusion 102 of the first part 100 that is fitted into the fitting hole 202 and the sealing member 300A, while the sealing member 300A is in close contact with the inner peripheral surface of the outer peripheral edge portion 210. The ratio of the radial distances (ds-di) / (do-ds-2×w) between the seal member 300A before deformation and the recess 220 may be 2 or more, or may be 3 or more.

[0035] In the exemplary embodiment shown in FIGS. 4 and 5, the convex portion 102 of the first component 100 has an outer peripheral edge 113 of the top surface 103 chamfered to form a tapered shape. Therefore, when first component 100 is assembled to second component 200 , tapered outer peripheral edge 113 of first component 100 serves to guide protrusion 102 into fitting hole 202 .

[0036] In another embodiment, as in the casing 2B shown in Figures 6 and 7, the outer surface 106 of the convex portion 102 of the first part 100 has a step 107, and the sealing member 300B is held between the portion of the convex portion 102 closer to the tip (top surface 103) than the step 107 and the mating hole 202 of the second part 200. Specifically, the outer peripheral surface 106 of the protruding portion 102 of the casing 2B has a base-side region located proximal to the step 107 and having an outer diameter corresponding to the inner diameter of the fitting hole 202, and a tip-side region located distal to the step 107 and having a smaller diameter than the base-side region. In the casing 2B, the inner diameter of the outer peripheral edge portion 210 matches the inner diameter of the fitting hole 202, and the inner peripheral surface of the outer peripheral edge portion 210 continues without a step into the inner wall surface of the fitting hole 202 in the axial direction. In the assembled casing 2B, the seal member 300B is held in the radial gap between the tip-side region of the outer peripheral surface 106 of the protruding portion 102 and the inner wall surface of the fitting hole 202.

[0037] 7, when assembling the casing 2B, with the sealing member 300B attached to the tip region of the protrusion 102 of the first part 100, the first part 100 is assembled to the second part 200 so that the protrusion 102 fits into the fitting hole 202. Before deformation, the sealing member 300B, the protrusion 102, and the fitting hole 202 satisfy the relationship (d1 + 2 × w) > d2, where d1 is the outer diameter of the tip region of the outer circumferential surface 106 of the protrusion 102, d2 is the inner diameter of the fitting hole 202, and w is the cross-sectional width of the sealing member 300B before deformation. By satisfying the above relationship, after the casing 2B is assembled, as shown in Figure 6, the sealing member 300B adheres closely to the inner wall surface of the fitting hole 202, the tip 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, as shown in Figures 4 to 7, an extension pipe 70 (see Figures 1 and 3) is connected to the second component 200, which directs the downward exhaust flow that passes through the first exhaust passage 32 and the second exhaust passage 34 in that order to a higher location.

[0039] FIG. 8 is a diagram showing a configuration of an extension pipe in a vacuum pump according to one embodiment. As shown in the figure, the extension pipe 70 is attached to the second component 200 so as to communicate with the exhaust passage 30 (second exhaust passage 34), and is connected to the end of the fitting hole 202 on the opposite side from 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 downstream of the upstream portion 72. The downstream portion 74 of the extension pipe 70 turns back at a bottom 76 of the extension pipe 70 and extends upward to an outlet 71 of the extension pipe 70 located higher than the second component 200. As shown in FIG. 8, the outlet 71 of the extension pipe 70 may be located higher than the first component 100. The exhaust flow that has passed through the exhaust passage 30 (second exhaust passage 34) flows through the upstream portion 72 and downstream portion 74 of the extension pipe 70 in that order, and is then released into the atmosphere from the outlet 71 of the extension pipe 70.

[0040] 8, the extension tube 70 includes a nipple 73 press-fitted into the fitting hole 202 so as to extend downward from the second part 200, and a U-shaped hose 75 attached to the nipple 73. The hose 75 is connected to the portion of the nipple 73 protruding from the second part 200 using a band 78. The nipple 73 forms the upstream portion 72 of the extension pipe 70, while the hose 75 forms the bottom 76 and 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. 9 is an exploded perspective view showing the overall structure of a vacuum pump 1 according to one embodiment. The vacuum pump 1 may be, for example, an electric vacuum pump for creating a negative pressure in a negative pressure chamber of a brake booster (master vac) in a vehicle such as an automobile. In the following description, "upper" and "lower" refer to the "upper" and "lower" states when the vacuum pump 1 is installed in a vehicle.

[0042] The vacuum pump 1 includes a casing 2 and a movable part 42 of a gas transfer part 40 provided inside the casing 2. 9, the movable part 42 is a rotor 43 rotatably provided inside the casing 2. The rotor 43 is driven by a motor M provided below the casing 2, and rotates around a central axis O.

[0043] As shown in Fig. 9, the casing 2 has a pump chamber 10 in which a rotor 43 serving as a movable part 42 is housed. The pump chamber 10 is defined by a cam surface 11 that is part of the inner wall surface of the casing 2. The cam surface 11 is defined by a non-circular (e.g., elliptical) outline. On the other hand, the rotor 43 has an outer peripheral surface 44 defined by a circular contour centered at point O. A plurality of slits 45 are formed in the outer peripheral surface 44. Each slit 45 is provided with a vane 46 that divides the pump chamber 10 into a plurality of compartments.

[0044] 9, the casing 2 includes a casing body 3 having a recess that forms the bottom and side surfaces of a pump chamber 10 in which a rotor 43 is housed, and a pump cover 4 that forms the top surface of the pump chamber 10. The pump cover 4 forms the pump chamber 10 together with the casing body 3 by closing the opening of the recess in the casing 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. Meanwhile, a bottom cover 6 that covers the underside of the casing body 3 is provided between the casing body 3 and the motor M.

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

[0046] When the top cover 5 is fastened to the pump cover 4, the seal member 90 elastically deforms so as to be crushed within the seal groove 91, thereby closing the gap between the pump cover 4 and the top cover 5. As a result, a second silencing chamber 60 (see FIG. 3) is formed between the inner seal portion 94 and the outer seal portion 96. The second silencing chamber 60 is formed by the pump cover 4 and the top cover 5 above the pump chamber 10 on the opposite side of the pump chamber 10 with the pump cover 4 in between. The second silencing chamber 60 communicates with the first silencing chamber 50 formed in the casing body 3 via two openings 63 provided in the pump cover 4 and two communication holes 64 formed in the casing body 3. In other words, the two sets of openings 63 and communication holes 64 form two communication passages 62 (see FIG. 3) that communicate between the first silencing chamber 50 and the second silencing chamber 60.

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

[0048] The intake chamber 24 is fluidly isolated from the second silencing chamber 60 around the partition wall 25 by the partition wall 25 and the inner seal 94 provided in the pump cover 4 . The intake chamber 24 is in communication with the internal space of the pump chamber 10 via the intake ports 12 (12A, 12B) of the pump chamber 10 provided in the pump cover 4. The pair of intake ports 12 (12A, 12B) are located on opposite sides of the central axis O of the rotor 43. Therefore, the intake chamber 24 extends from the communicating passage 23 toward the opposite side of the central axis O along the radial direction of the rotor 43, passing through the positions of the pair of intake ports 12 (12A, 12B).

[0049] In this way, the gas taken in through the intake port 21 passes through the communicating passage 22, the communicating passage 23, and the intake chamber 24 in this order, and then flows into the pump chamber 10 through the pair of intake ports 12 (12A, 12B). That is, the intake passage 20 (see FIGS. 1 to 3) for taking in the gas into the pump chamber 10 includes the communicating passage 22, the communicating passage 23, and the intake chamber 24.

[0050] An outlet port 14 of the pump chamber 10 is provided in the wall surface of the casing body 3 that forms the bottom surface of the pump chamber 10. Although only one outlet port 14 is shown in Fig. 9, another outlet port 14 (not shown) is provided at a circumferential position on the opposite side of the central axis O. The gas that flows out of the pump chamber 10 through the pair of discharge ports 14 flows into the first silencing chamber 50 (see FIG. 3) formed by the casing body 3 and the bottom cover 6. After passing through the first silencing chamber 50, the gas flows into the second silencing chamber 60 through the communication hole 64 and the opening 63, and is finally released into the atmosphere through the exhaust passage 30 (see FIGS. 1 to 7) and the extension pipe 70 that communicate with the second silencing chamber 60.

[0051] In the example shown in FIG. 9 , the exhaust passage 30 is formed inside the pump cover 4 (first component 100) and the casing main body 3 (second component 200) so as to be located between the second silencing chamber 60 and the extension pipe 70. A protrusion 102 of the pump cover 4 fits into a fitting hole 202 of the casing main body 3, so that a first exhaust passage 32 provided inside the protrusion 102 communicates with a second exhaust passage 34 defined by the fitting hole 202, thereby forming an exhaust passage 30 including the first exhaust passage 32 and the second exhaust passage 34. The exhaust passage 30 is sealed by a seal member 300A (see FIGS. 4 and 5 ) held between the pump cover 4 and the casing main body 3. The seal member 300A is housed in a recess 220 recessed relative to an annular outer peripheral edge 210 provided to surround the fitting hole 202 of the casing main body 3.

[0052] In the embodiment shown in FIG. 9 , the pump cover 4 is provided with two openings 63 penetrating the pump cover 4 and a first exhaust passage 32 within the protrusion 102. The openings 63 are part of a communication passage 62 that connects the second silencing chamber 60 to the first silencing chamber 50 (see FIG. 3 ), which is provided below and to the side of the pump chamber 10. The first exhaust passage 32 is located outside the openings 63 in the radial direction of the rotor 43 relative to the central axis O. The outer seal portion 96 and seal groove 91 of the seal member 90 bulge radially outward near the first exhaust passage 32 so as to surround the first exhaust passage 32. To make the casing 2 compact, it is desirable to suppress the radially outward bulging of the outer seal portion 96 and seal groove 91. On the other hand, if the radially outward bulging of the outer seal portion 96 and seal groove 91 is excessively suppressed, it will be difficult to ensure space for installing the seal member 300A (a groove for installing the seal member). In this regard, the seal member 300A can be held between the protrusion 102 of the pump cover 4 and the outer peripheral edge 210 of the casing body 3 in the radial direction, and the casing 2 can be made compact.

[0053] 9, nipple 73 is press-fitted from below into fitting hole 202 of casing body 3 serving as second part 200, and U-shaped hose 75 is attached to the lower end of nipple 73. Nipple 73 and hose 75 correspond to upstream portion 72 and downstream portion 74, respectively, of extension pipe 70 described with reference to FIG.

[0054] The characteristic configurations of the vacuum pump 1 according to the above-described embodiments can be summarized as follows.

[0055] [1] In some embodiments, the vacuum pump (1) comprises: The pump includes a casing (2) including a pump chamber (10), an intake passage (20) communicating with the pump chamber (10), and an exhaust passage (30), The casing (2) is a first component (100) having a protrusion (102) in which a first exhaust passage (32) of the exhaust passage (30) is formed; a second component (200) that forms a second exhaust passage (34) that communicates with the first exhaust passage (32) of the exhaust passage (30) and has a fitting hole (202) into which the protrusion (102) can be fitted, and an outer peripheral edge portion (210) that is provided on the outer peripheral side of the fitting hole (202) and protrudes toward the first component (100); Including, The vacuum pump (1) further includes a sealing member (300) that is held between the first part (100) and the second part (200) so as to be positioned radially between the protrusion (102) of the first part (100) and the outer peripheral edge part (210) of the second part (200), and that seals the exhaust passage (30) that includes the first exhaust passage (32) and the second exhaust passage (34).

[0056] Conventionally, seals have typically been installed in grooves between the inner and outer annular convex portions. Therefore, forming grooves on the mating surfaces between casing parts can be a barrier to making vacuum pumps more compact. In this regard, according to the configuration [1], the seal member (300) is held between the protrusion (102) of the first component (100) and the outer peripheral edge (210) of the second component (200) in the radial direction, eliminating the need to form a groove for installing the seal member in either the first component (100) or the second component (200). This allows the vacuum pump (1) to be made more compact.

[0057] [2] In some embodiments, in the configuration of [1] above, The first part (100) is located above the second part (200), The protrusion (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) of the second component (200).

[0058] According to the configuration [2] above, when assembling the first part (100) to the second part (200), the visibility of the convex part (102) and the fitting hole (202) is improved, and the convex part (102) and the fitting hole (202) can be easily used to position the first part (100) relative to the second part (200).

[0059] [3] In some embodiments, in the configuration of [2] above, the vacuum pump (1) is attached to the second component (200) so as to communicate with the exhaust passage (30), and includes an extension pipe (70) connected to an end of the fitting hole (202) on the opposite side to the fitting portion with the protrusion (102); The extension pipe (70) an upstream portion (72) extending downward from the second part (200); a downstream portion (74) located downstream of the upstream portion (72) and extending upward to a position higher than the second component (200); Including, The extension pipe (70) is configured to guide the exhaust 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) that is located higher than the second component (200).

[0060] According to the configuration [3], the outlet (71) of the extension pipe (70) communicating with the exhaust passage (30) is located higher than the second component (200), thereby preventing water from entering the vacuum pump (1) through the exhaust flow path (30). Furthermore, according to the configuration [1], the vacuum pump (1) can be made compact, while sealing the connection between the first exhaust passage (32) and the second exhaust passage (34). In this way, a measure to prevent flooding of the vacuum pump (1) can be realized with a simple and compact configuration.

[0061] [4] In some embodiments, in the configuration of [3] above, The extension pipe (70) a nipple (73) as an upstream portion (72) press-fitted into a fitting hole (202) of the second part (200) so as to extend downward from the second part (200); a U-shaped hose (75) as a downstream portion (74) attached to a portion of the nipple (73) protruding from the second part (200); Includes:

[0062] According to the configuration [4] above, by using the nipple (73) press-fitted into the fitting hole (202) of the second part (200) and the hose (75) attached to the nipple (73), an extension pipe (70) having an outlet (71) located higher than the second part (200) can be realized without providing an additional sealing member.

[0063] [5] In some embodiments, in any of the configurations [1] to [4] above, The casing (2) is a pump cover (4) as a first part (100); a casing body (3) as a second part (200); a top cover (5) that is attached to the pump cover (4) and is located on the opposite side of the pump cover (4) from the casing body (3); Including, The pump chamber (10) is formed by the pump cover (4) and the casing body (3) by the pump cover (4) closing the opening of a recess provided in the casing body (3), A sound-absorbing chamber (60) that guides the gas discharged from the pump chamber (10) to the first exhaust passage (32) is formed by the pump cover (4) and the top cover (5) above the pump chamber (10) on the opposite side of the pump chamber (10) with the pump cover (4) in between.

[0064] In the configuration [5] above, the pump cover (4) and the casing body (3) correspond to the first component (100) and the second component (200) of the configuration [1] above, respectively. Specifically, the first exhaust passage (32) and the second exhaust passage (34) are provided separately in the pump cover (4) as the first component (100) and the casing body (3) as the second component (200). The exhaust passage (30) is sealed by a seal member (300) held between the pump cover (4) and the second component (200). The seal member (300) is held radially between the protrusion (102) of the pump cover (4) and the outer peripheral edge (210) of the pump casing body (3). Therefore, it is not necessary to form a groove for installing the seal member in either the pump cover (4) or the casing body (3). This allows the vacuum pump (1) to be made more compact.

[0065] [6] In some embodiments, in any of the configurations [1] to [5] above, The first component (100) has a flat surface (108) facing the second component (200) on the outer circumferential side of the protrusion (102), The second component (200) has a recess (220) that is recessed with respect to the outer peripheral edge portion (210) on the radially inner side of the outer peripheral edge portion (210), The fitting hole (202) opens to a bottom surface (222) of the recess (220) facing the flat surface (108) of the first component (100), The seal member (300A) is held in a state where it is sandwiched between the flat surface (108) of the first part (100) and the bottom surface (222) of the second part (200) in the axial direction.

[0066] According to the configuration [6], a space for accommodating the seal member (300A) can be secured between the outer peripheral surface (106) of the protrusion (102) and the inner peripheral surface of the outer peripheral edge portion (210). Therefore, it is not necessary to form a groove for accommodating the seal member in either the first component (100) or the second component (200). This allows the vacuum pump (1) to be made more compact.

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

[0068] According to the configuration [7] above, a radial gap is maintained between the outer peripheral surface (106) of the protrusion (102) and the sealing member (300A), so that when the first component (100) is detached from the second component (200), the sealing member (300A) remains in the recess (220) of the second component (200). This prevents the sealing member (300A) from becoming difficult to detach from the protrusion (102) of the first component (100) when the vacuum pump (1) is disassembled.

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

[0070] According to the configuration [8] above, the sealing member (300A) is sandwiched between the flat surface (108) of the first part (100) and the bottom surface (222) of the second part (200) and is also in close contact with the outer peripheral edge portion (210), thereby achieving a high sealing effect by the sealing member (300A).

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

[0072] According to the configuration [9], the seal member (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 installing the seal member in either the first component (100) or the second component (200). This allows the vacuum pump (1) to be made more compact.

[0073] In this specification, expressions expressing relative or absolute arrangement such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial" not only express such an arrangement strictly, but also express a state in which there is a relative displacement with a tolerance or an angle or distance to the extent that the same function is obtained. For example, expressions such as "identical," "equal," and "homogeneous" that indicate that something is in an equal state not only indicate a state of strict equality, but also indicate a state in which there is a tolerance or a difference to the extent that the same function is obtained. Furthermore, in this specification, expressions representing shapes such as a rectangular shape or a cylindrical shape not only represent rectangular shapes or cylindrical shapes in the strict geometric sense, but also represent shapes including uneven portions, chamfered portions, etc., to the extent that the same effect can be obtained. Furthermore, in this specification, the expressions "comprise," "include," or "have" a component are not exclusive expressions that exclude the presence of other components. [Explanation of symbols]

[0074] 1(1A~1C): Vacuum pump 2(2A, 2B): Casing 3: Casing body 4: Pump cover 5: Top cover 10: Pump room 20: Intake passage 30: Exhaust passage 32: First exhaust passage 34: Second exhaust passage 50: 1st sound deadening room 60:Second silencing room (silencing room) 70: Extension tube 72:Upstream part 73: Nipple 74: Downstream part 75: Hose 100: First part 102: Convex part 106: Outer surface 108 :Flat surface 113: Outer edge 200: Second part 202: Fitting hole 210: Outer periphery 220: Recess 222: Bottom 300 (300A, 300B): Sealing material

Claims

1. The pump includes a casing including a pump chamber and an intake passage and an exhaust passage communicating with the pump chamber, The casing comprises: a first part having a protrusion in which a first exhaust passage is formed; a second component that defines a second exhaust passage that is in communication with the first exhaust passage among the exhaust passages, the second component having a fitting hole into which the protrusion can be fitted, and an outer circumferential edge portion that is provided on an outer circumferential side of the fitting hole and protrudes toward the first component; Including, the exhaust passage further includes a seal member that is held between the first component and the second component so as to be positioned between the protrusion of the first component and the outer circumferential edge of the second component in the radial direction, and that seals the exhaust passage including the first exhaust passage and the second exhaust passage. Vacuum pump.

2. the first part is located above the second part, The protrusion of the first component is provided so as to protrude downward toward the second component and is fitted into the fitting hole of the second component.

2. The vacuum pump according to claim 1.

3. an extension tube attached to the second component so as to communicate with the exhaust passage, the extension tube being connected to an end of the fitting hole on an opposite side to an end of the fitting portion with the protruding portion; The extension tube is an upstream portion extending downward from the second component; a downstream portion located downstream of the upstream portion and extending upward to a position higher than the second component; Including, The extension pipe is configured to guide the exhaust flow that has passed through the first exhaust passage and the second exhaust passage to an outlet of the extension pipe that is located higher than the second component.

3. The vacuum pump according to claim 2.

4. The extension tube is a nipple as the upstream portion press-fitted into the fitting hole of the second component so as to extend downward from the second component; a U-shaped hose as the downstream portion attached to a portion of the nipple protruding from the second part; 4. The vacuum pump of claim 3, comprising:

5. The casing comprises: A pump cover as the first part; A casing body as the second part; a top cover that is attached to the pump cover and is located on the opposite side of the casing body with the pump cover in between; Including, The pump chamber is formed by the pump cover and the casing body by closing an opening of a recess provided in the casing body with the pump cover, A sound absorbing chamber that guides the gas discharged from the pump chamber to the first exhaust passage is formed by the pump cover and the top cover above the pump chamber on the opposite side to the pump chamber with the pump cover in between.

3. A vacuum pump according to claim 1 or 2.

6. the first component has a flat surface facing the second component on an outer circumferential side of the protruding portion, the second component has a recess that is recessed with respect to the outer circumferential edge portion on a radially inner side of the outer circumferential edge portion, the fitting hole opens to a bottom surface of the recess facing the flat surface of the first component, The seal member is held in a sandwiched state between the flat surface of the first component and the bottom surface of the second component in the axial direction.

3. A vacuum pump according to claim 1 or 2.

7. The seal member is disposed with a radial gap between the outer circumferential surface of the protruding portion and the flat surface of the first component and the bottom surface of the second component in the axial direction.

7. A vacuum pump according to claim 6.

8. The seal member is configured to be in close contact with the outer circumferential edge portion of the second component in a state where the seal member is sandwiched between the flat surface of the first component and the bottom surface of the second component in the axial direction.

8. A vacuum pump according to claim 7.

9. The seal member is held in a state where it is sandwiched between an outer peripheral surface of the protrusion of the first component and an inner wall surface of the fitting hole that is continuous with an inner peripheral surface of the outer peripheral edge portion of the second component in a radial direction.

3. A vacuum pump according to claim 1 or 2.

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