Vortex blower

Abstract

This improves the efficiency of pressurization by effectively rectifying the vortex flow in the annular channel and smoothing the gas flow from the upstream stage to the downstream stage. [Solution] The vortex blower comprises a case having an annular flow path inside, a motor, and an impeller housed in the case and rotated by the motor to generate a vortex in the annular flow path. The impeller has a disc-shaped partition that divides the annular flow path into multiple stages in the axial direction of the rotation axis, and the case has an intake port on its outer circumference that communicates with one end of the flow path on the upstream side of the multi-stage annular flow path and a discharge port that communicates with one end of the flow path on the downstream side, and has a connecting flow path inside that connects the other end of the flow path on the upstream side to the other end of the flow path on the downstream side. The surface of the outer circumference of the partition that faces the downstream side is formed as a flat surface, and the surface of the outer circumference of the partition that faces the upstream side has a concave curved surface.

Description

Technical Field

[0001] The present specification discloses a vortex blower.

Background Art

[0002] Conventionally, as this type of vortex blower, there has been proposed one including an electric motor, an impeller driven by the electric motor and having blades on both sides, and an outer casing formed by splitting into two parts and combined so as to sandwich the impeller from both sides, the outer casing having a suction port opening to the outer periphery at the suction end of one of the two air passages formed around the blades on both sides, a discharge port opening to the outer periphery at the discharge end of the other air passage, and a communication port communicating with both end portions of each air passage (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] In the above-described vortex blower, the surface facing one air passage and the surface facing the other air passage at the outer peripheral portion of the disc-shaped partition part that partitions one air passage (upstream stage side) and the other air passage (downstream stage side) of the impeller are both formed as flat surfaces. For this reason, the vortex is disturbed at the portion where the outer peripheral wall of the air passage and the partition part (flat surface) intersect perpendicularly, and sufficient pressure increasing efficiency may not be obtained in some cases.

[0005] The present disclosure has a main object of providing a multistage vortex blower that can properly rectify the vortex in the annular flow passage, smooth the gas flow from the upstream stage side to the downstream stage side, and further improve the pressure increasing efficiency.

Means for Solving the Problem

[0006] This disclosure employs the following means to achieve the primary objectives described above.

[0007] The vortex blower of this disclosure comprises a case having an annular flow path inside, a motor, and an impeller housed in the case and rotationally driven by the motor to generate a vortex in the annular flow path, wherein the impeller has a disc-shaped partition portion that divides the annular flow path into multiple stages in the axial direction of the rotation axis, the case has an intake port on its outer circumference that communicates with one end of the flow path on the upstream side of the multi-stage annular flow path and an outlet port on its outer circumference that communicates with one end of the flow path on the downstream side, and has a connecting flow path inside that connects the other end of the flow path on the upstream side and the other end of the flow path on the downstream side, the surface on the outer circumference of the partition portion facing the upstream side is formed as a flat surface, and the surface on the outer circumference of the partition portion facing the downstream side has a concave curved surface.

[0008] In the vortex blower of this disclosure, the impeller has a disc-shaped partition that divides the annular flow path into multiple stages in the axial direction of the rotation axis, and the case has an intake port on its outer circumference that communicates with one end of the flow path on the upstream side of the multi-stage annular flow path and a discharge port that communicates with one end of the flow path on the downstream side, and has a connecting flow path inside that connects the other end of the flow path on the upstream side to the other end of the flow path on the downstream side. The surface of the outer circumference of the partition that faces the upstream side is formed as a flat surface, and the surface of the outer circumference of the partition that faces the downstream side is a concave curved surface. As a result, the surface on the outer circumference of the partition that faces the upstream side (flat surface) allows gas to flow smoothly from the annular flow path on the upstream side to the connecting flow path, and the surface on the outer circumference of the partition that faces the downstream side (concave curved surface) allows the vortex flow to be straightened. As a result, the pressure boosting efficiency of the vortex blower can be further increased. [Brief explanation of the drawing]

[0009] [Figure 1] This is a perspective view of a vortex-type blower. [Figure 2] This is a plan view of a vortex-type blower. [Figure 3] This is a cross-sectional view AA in Figure 2. [Figure 4] Figure 2 is a cross-sectional view of BB. [Figure 5] Figure 2 is a cross-sectional view of CC. [Figure 6] Figure 2 is a cross-sectional view of the DD. [Figure 7] This is a cross-sectional view of EE in Figure 2. [Figure 8] This is an explanatory diagram showing the gas flow in a vortex-type blower. [Figure 9] This is an explanatory diagram showing the gas flow in a vortex-type blower. [Figure 10] This is an explanatory diagram showing the flow path cross-sectional area for each rotation angle of a vortex-type blower. [Modes for carrying out the invention]

[0010] Next, the forms for implementing this disclosure will be described with reference to the drawings.

[0011] Figure 1 is an external perspective view of the vortex blower 10, and Figure 2 is a plan view of the vortex blower 10. Figure 3 is a cross-sectional view AA of Figure 2, Figure 4 is a cross-sectional view BB of Figure 2, Figure 5 is a cross-sectional view CC of Figure 2, Figure 6 is a cross-sectional view DD of Figure 2, and Figure 7 is a cross-sectional view EE of Figure 2. As shown in the figures, the vortex blower 10 of this embodiment comprises a blower case 20 that forms an annular flow channel 23 inside, a motor 40, and an impeller 30 housed in the blower case 20 and rotationally driven by the motor 40 to generate a vortex (helical flow) in the annular flow channel 23. The vortex blower 10 can be applied, for example, to a fuel blower that supplies fuel gas to a fuel cell stack or an air blower that supplies air to a fuel cell in a fuel cell system that includes a fuel cell stack that generates electricity by an electrochemical reaction between fuel gas and oxidant gas (air). Because fuel cell stacks have high pressure loss, fuel blowers and air blowers require relatively high pressure boosting performance.

[0012] A through-hole with spline grooves on its inner circumferential surface is formed at the center of the rotation axis of the impeller 30, and a rotating shaft 41 having spline teeth on its outer circumferential surface is fitted into this through-hole. As shown in Figures 4 to 7, one end of the rotating shaft 41 is rotatably supported by the blower case 20 (first case half 21) via a bearing 51, and the other end of the rotating shaft 41 is rotatably supported by the blower case 20 (second case half 22) via a bearing 52. Annular sealing members 53 and 54 are installed between the fitting portion of the rotating shaft 41 with the impeller 30 and the bearing 51, and between the fitting portion of the rotating shaft 41 with the impeller 30 and the bearing 52, respectively. In this embodiment, the rotating shaft 41 is coaxially connected to the rotation axis of the motor 40 via a coupling (not shown). The rotating shaft 41 may be formed integrally with the rotation axis of the motor 40, or it may be connected to the rotation axis of the motor 40 via a belt.

[0013] As shown in Figure 1, the blower case 20 comprises a bowl-shaped first case half 21 and a second case half 22. The first case half 21 and the second case half 22 each have annular flanges 211 and 221 integrally at their outer edges. The two flanges 211 and 221 are overlapped with an annular sealing member 24 in between and joined by a plurality of bolts B. This defines an annular space (annular flow path 23) inside the blower case 20 (see Figures 4 to 7).

[0014] Furthermore, as shown in Figures 1 to 3, an inlet 212 is formed on the outer circumference of the first case half 21, and an outlet 222 is formed on the outer circumference of the second case half 22. The inlet 212 is formed to extend tangentially to the annular flow path 23. The outlet 222 is formed at a position offset by a predetermined angle in the circumferential direction from the inlet 212 when viewed from the axial direction of the blower case 20, parallel to the extending direction of the inlet 212 and extending radially to the axial direction of the blower case 20.

[0015] As shown in Figures 3 to 7, the impeller 30 includes a disc-shaped partition portion 31 that divides the annular flow passage 23 in the axial direction of the rotation shaft into a first-stage annular flow passage 231 (the annular flow passage on the downstream stage side) and a second-stage annular flow passage 232 (the annular flow passage on the upstream stage side), first blade portions 32 formed on one surface (the side of the first-stage annular flow passage 231) of the partition portion 31, and second blade portions 33 formed on the other surface (the side of the second-stage annular flow passage 232) of the partition portion 31. The first-stage annular flow passage 231 and the second-stage annular flow passage 232 communicate with each other via a communication flow passage 25.

[0016] The communication flow passage 25 is a space that allows the downstream end of the first-stage annular flow passage 231 and the upstream end of the second-stage annular flow passage 232 to communicate with each other. Specifically, as shown in Figures 1 to 6, the communication flow passage 25 is a space defined inside by being formed so as to bulge in a hemispherical shape between the suction port 212 and the discharge port 222 at the outer peripheral portions of the first case half 21 and the second case half 22. Thereby, the first-stage annular flow passage 231 extends in the circumferential direction over approximately 330° from the suction port 212 to the inlet of the communication flow passage 25, and the second-stage annular flow passage 232 extends in the circumferential direction over approximately 330° from the outlet of the communication flow passage 25 to the discharge port 222.

[0017] Further, as shown in Figures 7 to 9, the surface facing the first-stage annular flow passage 231 at the outer peripheral portion of the partition portion 31 is formed as a flat surface 311. A circumferential groove 211a is formed at the inner peripheral edge on the joint surface of the flange 211 of the first case half 21, and the portion on the first-stage annular flow passage 231 side at the outer peripheral portion of the partition portion 31 is fitted into the circumferential groove 221a so as to be movable in the circumferential direction. Further, on the surface facing the second-stage annular flow passage 232 at the outer peripheral portion of the partition portion 31, an annular protruding ridge 312 protruding upward in Figure 7 is formed. As shown in Figure 7, the inner peripheral side of the annular protruding ridge 312 is formed as a concave curved surface 312a so as to smoothly connect from the partition portion 31 to the outer peripheral wall of the second-stage annular flow passage 232. In addition, a two-step stepped circumferential groove 221a is formed at the inner peripheral edge on the joint surface of the flange 221 of the second case half 22, and the outer peripheral side of the annular protruding ridge 312 is fitted into the circumferential groove 221a so as to be movable in the circumferential direction.

[0018] In the vortex blower 10 configured in this manner, when the impeller 30 is rotationally driven by the motor 40, the gas sucked from the suction port 212 flows in the circumferential direction while forming a spiral flow (see FIG. 8) in the first-stage annular flow passage 231, then moves to the second-stage annular flow passage 232 via the communication flow passage 25, flows in the circumferential direction while forming a spiral flow (see FIG. 8) in the second-stage annular flow passage 232, and is discharged from the discharge port 222. Inside the blower case 20, the partition portion 31 partitions the annular flow passage 23 into the first-stage annular flow passage 231 and the second-stage annular flow passage 232, the first-stage annular flow passage 231 and the second-stage annular flow passage 232 are communicated via the communication flow passage 25, and spiral flows are formed in the first-stage annular flow passage 231 and the second-stage annular flow passage 232, whereby the pressurization performance can be improved while downsizing the vortex blower 10.

[0019] Further, an annular protruding strip 312 is formed on the surface of the outer peripheral portion of the partition portion 31 facing the second-stage annular flow passage 232, a two-step stepped peripheral groove 221a is formed on the inner peripheral edge of the joint surface of the flange 221 included in the second case half 22, and the outer peripheral side of the annular protruding strip 312 is fitted into the peripheral groove 221a so as to be movable in the circumferential direction. Thereby, the sealing performance between the first-stage annular flow passage 231 and the second-stage annular flow passage 232 can be sufficiently ensured by the labyrinth structure.

[0020] Further, the inner peripheral side of the annular protruding strip 312 is formed by a concave curved surface 312a so as to smoothly connect from the partition portion 31 to the outer peripheral wall of the second-stage annular flow passage 232. Thereby, the spiral flow in the second-stage annular flow passage 232 can be properly straightened. In addition, since the surface of the outer peripheral portion of the partition portion 31 facing the first-stage annular flow passage 231 is formed as a flat surface 311, as shown in FIG. 9, the flow of gas from the first-stage annular flow passage 231 to the communication flow passage 25 can be made smooth, and the pressure loss can be reduced. As a result, the pressurization performance of the vortex blower 10 can be further improved.

[0021] Furthermore, as shown in Figure 10, the first-stage annular channel 231 is formed such that its cross-sectional area decreases linearly as it moves downstream, and the second-stage annular channel 232 is formed such that its cross-sectional area at its upstream end is less than or equal to the cross-sectional area at the downstream end of the first-stage annular channel 231, and its cross-sectional area decreases linearly as it moves downstream. Specifically, the first-stage annular channel 231 and the second-stage annular channel 232 are formed such that the axial height of the central axis of the case 20 and the radial width of the central axis gradually decrease as they move downstream. This allows for efficient gas pressurization along the entire length from upstream to downstream.

[0022] It goes without saying that this disclosure is not limited in any way to the embodiments described above, and can be implemented in various forms as long as they fall within the technical scope of this disclosure.

[0023] For example, in the embodiment described above, the vortex blower 10 performs two-stage pressure boosting by partitioning the annular flow path 23 with one partition 31. However, three or more stages of pressure boosting may be performed by partitioning the annular flow path 23 with two or more partitions at predetermined intervals in the axial direction of the rotation axis of the impeller 30. [Industrial applicability]

[0024] This disclosure can be used in industries such as the manufacturing of vortex blowers. [Explanation of Symbols]

[0025] 10 Vortex blower, 20 Blower case (case), 23 Annular flow path, 25 Connecting flow path, 30 Impeller, 31 Partition section, 40 Motor, 212 Inlet, 222 Outlet, 311 Flat surface, 312 Convex groove, 312a Concave curved surface.

Claims

1. A vortex blower comprising a case having an annular channel inside, a motor, and an impeller housed in the case and rotationally driven by the motor to generate a vortex in the annular channel, The impeller has a disc-shaped partition that divides the annular flow path in multiple stages in the axial direction of the rotating shaft. The case has an intake port on its outer circumference that communicates with one end of the upstream channel of the multi-stage annular channel and a discharge port that communicates with one end of the downstream channel, and has a connecting channel inside that connects the other end of the upstream channel and the other end of the downstream channel. The outer periphery of the partition portion facing the upstream step is formed by a flat surface. The outer periphery of the partition portion facing the downstream step has a concave curved surface. Vortex blower.

2. A vortex blower according to claim 1, The aforementioned concave surface is a curved surface that curves in a concave shape so as to smoothly connect to the outer circumferential wall of the annular channel on the downstream side. Vortex blower.

3. A vortex blower according to claim 1 or 2, The case comprises a first case half in which the annular channel on the upstream side is formed, and a second case half in which the annular channel on the downstream side is formed. The first case half and the second case half each have flanges joined to each other on their outer edges, On the outer periphery of the partition portion, the surface facing the lower flow side has an annular protrusion that projects toward the downstream side. The concave surface is formed on the inner circumference side of the convex ridge, A stepped circumferential groove is formed on the inner periphery of the flange of the second case half, into which the outer periphery of the protrusion is fitted so as to be movable in the circumferential direction. Vortex blower.

4. A vortex blower according to claim 1 or 2, The annular channel on the upstream side is formed such that the channel cross-sectional area gradually decreases as it moves downstream. The downstream annular channel is formed such that the cross-sectional area of ​​the channel at the upstream end of the downstream annular channel is less than or equal to the cross-sectional area of ​​the channel at the downstream end of the upstream annular channel, and the cross-sectional area of ​​the channel gradually decreases as it moves downstream. Vortex blower.

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