Fluid machinery

Abstract

To improve maintainability of a fluid machine.SOLUTION: A fluid machinery includes a plurality of guide vanes (30) disposed while being arrayed in a circumferential direction of a support plate (20) so that a fluid flows radially inward from radially outward of the support plate (20), and formed so as to be recessed in a rotation direction of a runner (40) when being viewed from an axial direction of the runner (40).SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] This disclosure relates to fluid machinery.

Background Art

[0002] The hydraulic machinery described in Patent Document 1 has a runner provided on a rotating main shaft and a plurality of guide vanes for guiding water to the runner. The runner is rotated by the flowing water from the guide vanes, and accordingly the main shaft also rotates. The main shaft is connected to a generator motor, and the generator motor is driven by the rotation of the main shaft to generate electricity. The guide vanes are rotatable about a guide vane rotation axis in response to the drive of a servo motor for the guide vanes. The guide vanes adjust the flow rate of the water flowing into the runner by adjusting their angles by rotation. Thereby, the power generation output is adjusted.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above - described hydraulic machinery, it is necessary to check whether the operations of all the guide vanes and the operation of the servo motor for the guide vanes are normal during maintenance. Also, if there is a guide vane with a malfunction, it is necessary to repair or replace only that guide vane, etc., and the maintainability is not good enough.

[0005] An object of this disclosure is to improve the maintainability of fluid machinery.

Means for Solving the Problems

[0006] The first aspect of this disclosure is a casing (10), and An annular support plate (20) is placed inside the casing (10), Multiple guide vanes (30) are fixed on the support plate (20), A fluid machine comprising an axial or diagonal flow runner (40) positioned with the center of the support plate (20) as its axis, wherein fluid flows sequentially through the guide vane (30) and the runner (40), The multiple guide vanes (30) are arranged in a circumferential direction of the support plate (20) such that the fluid flows from the radially outward to the radially inward direction of the support plate (20), and when viewed from the axial direction of the runner (40), the runner (40) Convex in the opposite direction of rotation This is a fluid machine characterized by being formed in such a way.

[0007] In the first embodiment, since the guide vane (30) is fixed to the support plate (20), maintainability is improved compared to fluid machines having movable guide vanes. In addition, the guide vane (30) is fixed to the runner (40) Convex in the opposite direction of rotation By being formed in this manner, compared to guide vanes formed in a straight line, separation of the fluid from the guide vanes (30) when the fluid flows into the guide vanes (30) can be suppressed. As a result, the decrease in fluid velocity can be suppressed, and hydraulic losses can be reduced.

[0008] A second aspect of this disclosure is, in the first aspect, Viewed from the axial direction of the runner (40), The line connecting the first end (31), which is the radially outer end of the guide vane (30), and the rotation axis center (C) of the runner (40), and the first end (31) Circle of curvature When the angle formed with the tangent is α, the guide vane (30) It is formed such that -27° ≤ α ≤ 27°.

[0009] In the second embodiment, if the inflow angles of the fluid flowing into each guide vane (30) are different, the resistance of the fluid flowing into the guide vane (30) can be reduced by designing it so that -27° ≤ α ≤ 27°.

[0010] A third aspect of this disclosure is, in the second aspect, The casing (10) is provided with one inlet (18) through which fluid flows in perpendicular to the axial direction of the runner (40).

[0011] In the third embodiment, by providing the inlet (18) in this manner, the inflow angle of the incoming fluid differs depending on the position of the guide vane (30). Therefore, by designing the angle α of the guide vane (30) to be -27° ≤ α ≤ 27°, the resistance of the incoming fluid to the guide vane (30) can be suppressed.

[0012] A fourth aspect of this disclosure is that in any one of the first to third aspects, Viewed from the axial direction of the runner (40), When β is the angle formed by the tangent to the center circle of curvature at the second end (32), which is the radially inward end of the guide vane (30), and the concentric tangent to the rotation axis center (C) of the runner (40) at the second end (32), the guide vane (30) is formed such that β ≤ 37°.

[0013] In the fourth embodiment, the static pressure efficiency can be improved by shaping the angle β of the guide vane (30) so that β ≤ 37°.

[0014] A fifth aspect of this disclosure is a fourth aspect, The guide vane (30) is formed such that β ≤ 25°.

[0015] In the fifth embodiment, the static pressure efficiency can be further improved by shaping the angle β of the guide vane (30) so that β ≤ 25°.

[0016] The sixth aspect of this disclosure is, in any one of the first to fifth aspects, The casing (10) includes a first cylindrical member (11) with one end closed by a first end face (11a), and a second cylindrical member (12) disposed within the first cylindrical member (11) and having an open end (12a) with one end open. The support plate (20) is disposed between the first end face (11a) and the open end (12a). The runner (40) is disposed within the second cylindrical member (12).

[0017] In a sixth aspect, the fluid flows from the outside of the second cylindrical member (12), through the guide vanes (30), into the second cylindrical member (12), and passes through the runner (40). By designing the casing (10) to form such a fluid flow, the size of the product (fluid machine) can be made more compact.

[0018] A seventh aspect of the present disclosure is, in the sixth aspect, The inner edge portion (21) of the support plate (20) is formed in a curved surface shape so as to be smoothly connected to the open end of the second cylindrical member (12).

[0019] In the seventh aspect, the fluid passing through the guide vanes (30) flows more easily toward the runner (40).

[0020] An eighth aspect of the present disclosure is, in the first aspect, When viewed from the axial direction of the runner (40), The angle α formed by the line connecting the first end (31), which is the radially outer end of the guide vane (30), and the center (C) of the rotation axis of the runner (40), and the tangent line at the first end (31) satisfies -27° ≤ α ≤ 27°, and Circle of curvature The angle β formed by the tangent line of the center circle of curvature at the second end (32), which is the radially inner end of the guide vane (30), and the concentric tangent line of the center (C) of the rotation axis of the runner (40) at the second end (32) satisfies β ≤ 37°, All the guide vanes (30) provided on the support plate (20) are formed so as to have the same α and the same β. ​

[0021] In the eighth embodiment, by making the angle α and angle β of all guide vanes (30) the same, it becomes unnecessary to adjust the angle for each guide vane (30), thereby facilitating the manufacture of the fluid machine.

[0022] The ninth aspect of this disclosure is, in any one of the first to eighth aspects, The cross-sectional shape of all the guide vanes (30) provided on the support plate (20) is formed to be the same, perpendicular to the rotation axis of the runner (40).

[0023] In the ninth embodiment, the manufacture of fluid machinery can be facilitated.

[0024] The tenth aspect of this disclosure is, in any one of the first to ninth aspects, The number of guide vanes (30) and the number of runner vanes (41) on the runner (40) are relatively prime.

[0025] In the tenth embodiment, vibrations of the fluid machine can be suppressed. [Brief explanation of the drawing]

[0026] [Figure 1] Figure 1 is a schematic diagram showing the configuration of a hydraulic machine according to an embodiment. [Figure 2] Figure 2 shows the direction of water flow in a hydraulic machine. [Figure 3] Figure 3 shows the velocity distribution of water flowing on a support plate as viewed from the axial direction of the runner. (A) shows the velocity distribution of water for a support plate equipped with linearly formed guide vanes. (B) shows the velocity distribution of water for a support plate equipped with guide vanes according to the embodiment. [Figure 4] Figure 4 is an enlarged view of a portion of the support plate as seen from the axial direction of the runner. [Figure 5] Figure 5 shows the vector of water flowing into the support plate. [Figure 6]Figure 6 is a graph showing the relationship between the circumferential position of the support plate and the water inflow angle α. [Figure 7] Figure 7 shows the relationship between the outflow angle β and the static pressure efficiency. [Modes for carrying out the invention]

[0027] Embodiments of the present invention will be described below with reference to the drawings. The following embodiments are essentially preferred examples and are not intended to limit the scope of the present invention, its applications, or its uses. Furthermore, the embodiments, modifications, and other configurations described below can be combined or partially replaced to the extent that the present invention is implementable. In the following, "top" and "bottom" refer to the direction in which the hydraulic machine is viewed from the front.

[0028] (1)Hydraulic machinery As shown in Figure 1, the hydraulic machine (1) of this embodiment is connected to a water pipe (100) and generates electricity using the hydraulic force of the water flowing in the water pipe. This is an example of the fluid machine (1) of the present disclosure. The hydraulic machine (1) comprises a casing (10), a support plate (20), a guide vane (30), and a runner (40).

[0029] (1-2) Casing The casing (10) has a first cylindrical member (11) and a second cylindrical member (12). The first cylindrical member (11) is formed in a cylindrical shape. The first cylindrical member (11) is positioned so that its cylindrical axis is oriented vertically. The upper and lower ends of the first cylindrical member (11) are closed by end faces. The upper end face (11a) of the first cylindrical member (11) is the first end face (11a) of this disclosure. The first cylindrical member (11) has an inlet (18) and an outlet (19) that are connected to a water pipe (100). The inlet (18) and the outlet (19) are formed on the side surface (circumferential surface) of the first cylindrical member (11). The inlet (18) and the outlet (19) are positioned opposite each other. A water channel (P) is formed inside the casing (10) that connects the inlet (18) and the outlet (19). Details of the water channel (P) will be described later.

[0030] The second cylindrical member (12) is formed in a cylindrical shape. The upper end of the second cylindrical member (12) is open. The outer diameter of the second cylindrical member (12) is smaller than that of the first cylindrical member (11). The second cylindrical member (12) is positioned inside the first cylindrical member (11). The cylindrical axis of the second cylindrical member (12) is roughly the same as that of the first cylindrical member (11). A space is formed between the upper end of the second cylindrical member (12) and the upper end surface (11a) of the first cylindrical member (11). A connecting pipe section (15) that communicates with the outlet (19) is connected to the lower end of the second cylindrical member (12). The connecting pipe section (15) is formed in an L shape.

[0031] (1-3) Support plate The support plate (20) is an annular plate member placed inside the casing (10). The inner edge (20b) of the support plate (20) is connected to the upper end of the second cylindrical member (12). Specifically, the cross-section of the inner edge (21) of the support plate (20) is formed in an arc shape such that the inner edge (20b) extends toward the center of the support plate (20) and downwards. The downward-facing inner edge (20b) is connected to the open end, which is the upper end of the second cylindrical member (12). In this way, the inner edge (21) of the support plate (20) is formed in a curved shape so as to connect smoothly to the open end of the second cylindrical member (12).

[0032] The outer diameter of the support plate (20) is smaller than the inner diameter of the first cylindrical member (11). Therefore, a space is formed between the inner circumferential surface of the first cylindrical member (11) and the outer circumferential edge (20a) of the support plate (20).

[0033] (1-4) Guide vanes The guide vanes (30) are generally rectangular plate-shaped members. Multiple guide vanes (30) are fixed on the support plate (20). Specifically, the guide vanes (30) are positioned so as to stand up from the upper surface of the support plate (20) by fixing one of their long sides to the upper surface of the support plate (20). Each guide vane (30) is positioned so that its long side extends from the radially outward to the radially inward direction of the support plate (20). In this way, all the guide vanes (30) are arranged in a line around the circumferential direction of the support plate (20) so that water flows from the radially outward to the radially inward direction of the support plate (20) (see Figure 3(B)).

[0034] All guide vanes (30) are formed to the same shape. Furthermore, all guide vanes (30) are in the same orientation. For example, all guide vanes (30) are positioned perpendicular to the upper surface of the support plate (20). Thus, the cross-sectional shape of all guide vanes (30) perpendicular to the rotation axis of the runner (40) (details described later) is formed identically. The radially outward end of the guide vane (30) is designated as the first end (31), and the radially inward end is designated as the second end (32). Details of the shape of the guide vanes (30) will be described later.

[0035] (1-5) Runner The runner (40) in this embodiment is an axial flow runner. The runner (40) is positioned near the lower end of the second cylindrical member (12). The runner (40) has a runner boss (42) and runner vanes (41). The runner boss (42) is fixed to the lower end of the main shaft, which will be described later. Multiple runner vanes (41) are arranged in the same orientation in the circumferential direction of the runner boss (42). When viewed from the direction of the cylindrical axis of the second cylindrical member (12), the radially outward ends of the runner vanes (41) are close to the inner circumferential surface of the second cylindrical member (12). The number of runner vanes (41) and the number of guide vanes (30) are relatively prime. In this embodiment, there are 5 runner vanes (41) and 13 guide vanes (30).

[0036] (1-6) Main shaft and power generation section The hydraulic machine (1) of this embodiment has a main shaft (50) and a power generation unit (60). The main shaft (50) is inserted through the upper end surface (11a) of the first cylindrical member (11) and the center of the support plate (20). The upper end of the main shaft (50) is connected to the power generation unit (60). As the runner (40) rotates, the main shaft (50) rotates, and the power generation unit (60) generates electricity as a result.

[0037] (2) Water flow As shown in Figure 2, a water channel (P) is formed inside the casing (10). Water from the water pipe (100) flows into the casing (10) from the inlet (18), which is the upstream end of the water channel (P). Specifically, the water flows into the inlet (18) perpendicular to the axial direction of the runner (40). The water that flows into the inlet (18) flows upward between the inner surface of the first cylindrical member (11) and the outer surface of the second cylindrical member (12). The water that reaches the upper end of the second cylindrical member (12) flows from the outer edge (20a) to the inner edge (20b) of the support plate (20) through the guide vanes (30). From the inner edge (20b) of the support plate (20), the water flows into the second cylindrical member (12). The runner (40) rotates as the water that has flowed into the second cylindrical member (12) collides with the runner vanes. The water that has passed through the runner vane (41) flows through the connecting pipe section (15) and out through the outlet (19) toward the water pipe (100).

[0038] (3) Details of the shape of the guide vanes Typically, guide vanes are positioned such that their radially inward ends are located further forward in the rotational direction of the runner (40) than their radially outward ends (see Figure 3(A)). By arranging the guide vanes in this way, water flowing between adjacent guide vanes flows towards the runner, imparting hydraulic power to the runner vanes (41). This causes the runner to rotate and generate electricity.

[0039] However, as shown in Figure 3(A), it has been found that when the shape of the guide vanes is linear when viewed from the axial direction of the runner (40), the water flow separates from the guide vanes (30a) inside the guide vanes, and the flow velocity decreases. The decrease in the flow velocity of some of the water flowing over the support plate (20) leads to a decrease in the hydraulic force that rotates the runner (40), and as a result, the power generation efficiency decreases.

[0040] In response to this, as shown in Figure 3(B), the guide vane (30) of this embodiment is formed to be recessed in the direction of rotation of the runner (40) (arrow shown in Figure 3(B)) when viewed from the axial direction of the runner (40). With a guide vane (30) of this shape, separation of the water flow inside the guide vane (30) can be suppressed.

[0041] Furthermore, in this embodiment, the inflow angle α of water flowing into the guide vane (30) and the outflow angle β of water flowing out from the guide vane (30) were investigated. As shown in Figure 4, the inflow angle α is the line connecting the first end (31) and the rotation axis center (C) of the runner (40), and the first end (31) Center circle of curvature The outflow angle β is defined as the angle formed by the tangent to the center circle of curvature at the second end (32) and the concentric tangent to the rotation axis center (C) of the runner (40) at the second end (32).

[0042] First, let's discuss the consideration of the inflow angle α. In the case of a hydraulic machine in this embodiment, where water flows in from the inlet perpendicular to the rotation axis of the runner, the vector of the water flowing into the guide vanes differs depending on the arrangement of the guide vanes.

[0043] Let's explain this using Figures 5 and 6 as examples. Figures 5 and 6 show the relationship between the circumferential position of the support plate (20) without guide vanes and the water inflow angle. 0° is the angle (position) where the inlet (18) is located when the support plate (20) is viewed from above. At the 0° position of the support plate, it is the shortest distance from the inlet (18), so the flow rate is the highest, and the water flows in perpendicular to the tangent to the outer edge of the support plate (20). As you move away from 0° in the circumferential direction (approaching the 180° position), you can see that the water becomes more inclined relative to the tangent to the outer edge of the support plate (20). Around 180°, the amount of water inflow is less than at the 0° position, but the water flows in roughly perpendicular to the tangent to the outer edge. Looking at this in terms of the relationship between the outer edge position of the support plate (20) and the water inflow angle α (see Figure 6), it was found that the minimum value of the inflow angle α is -27° and the maximum value is 27°. In other words, by setting the first end (31) of the guide vane (30) within the range of -27° ≤ α ≤ 27°, the water resistance to the guide vane (30) can be reduced.

[0044] Next, we will explain the consideration of the outflow angle β using Figure 7. It is known that the static pressure efficiency of the hydraulic machine (1) differs depending on the outflow angle β. Here, in the case of a linear guide vane (see Figure 3(A)), the maximum value of the static pressure efficiency is 70% when the outflow angle β = 50°, and the static pressure efficiency decreases when the outflow angle β > 50° and β < 50° (dashed line in Figure 7). On the other hand, in the guide vane (30) of this embodiment, the static pressure efficiency increases as the outflow angle β decreases (solid line in Figure 7). When the outflow angle β = 37° (when the solid line and the dashed line intersect), when comparing the linear guide vane (30a) and the guide vane (30) of this embodiment, the static pressure efficiency is the same, but when the outflow angle β ≤ 37°, it was found that the static pressure efficiency is higher for the guide vane (30) of this embodiment than for the linear guide vane (30a). In particular, when the outflow angle β ≤ 25° or less, the guide vane (30) of this embodiment achieves a static pressure efficiency of 70% or more.

[0045] Based on the above findings, the inflow angle α and outflow angle β of the guide vane (30) in this embodiment were set to -27° ≤ α ≤ 27° and β ≤ 37°, respectively. Furthermore, the inflow angle α and outflow angle β of all guide vanes (30) in this embodiment are the same. For example, if the inflow angle α = 0° and the outflow angle β = 37° are set, then the inflow angle α and inflow angle β of all guide vanes (30) will be α = 0° and β = 25°, respectively.

[0046] (4) Features (4-1) Feature 1 In this embodiment of the hydraulic machine (1), the multiple guide vanes (30) are arranged in a circumferential direction of the support plate (20) such that the fluid flows from the radially outward to the radially inward direction of the support plate (20), and when viewed from the axial direction of the runner (40), the runner (40) Convex in the opposite direction of rotation It is formed in this way.

[0047] According to this embodiment, since the guide vane (30) is fixed to the support plate (20), maintainability is improved compared to hydraulic machines having movable guide vanes. Also, the guide vane (30) is fixed to the runner (40) In the opposite direction In contrast To protrude By being formed in this manner, the separation of the water flow from the guide vane (30) when water flows into the guide vane (30) can be suppressed compared to a guide vane (30a) that is formed in a straight line. As a result, the decrease in flow velocity can be suppressed and hydraulic power loss can be reduced.

[0048] (4-2) Feature 2 In this embodiment of the hydraulic machine (1), when viewed from the axial direction of the runner (40), the line connecting the first end (31), which is the radially outer end of the guide vane (30), and the rotation axis center (C) of the runner (40) is defined as the first end (31) Circle of curvature When the angle formed with the tangent line is α, the guide vane (30) is formed such that -27° ≤ α ≤ 27°.

[0049] According to this embodiment, when the inflow angles of the fluid flowing into each guide vane (30) are different, the resistance of the water flowing into the guide vanes (30) can be suppressed by designing the system so that -27° ≤ α ≤ 27°. As a result, the decrease in the flow velocity of the water circulating between the guide vanes (30) can be suppressed, and the decrease in the rotational speed of the runner (40) can be suppressed. Consequently, the decrease in power generation efficiency can also be suppressed.

[0050] (4-3) Feature 3 In this embodiment of the hydraulic machine (1), the casing (10) is provided with one inlet (18) through which fluid flows in perpendicular to the axial direction of the runner (40).

[0051] By providing the inlet (18) in this manner, the inflow angle of the water flows in differs depending on the circumferential position of the support plate (20) in this embodiment. Since it has been found that this inflow angle α is -27°≦α≦27°, the resistance of the fluid flowing into the guide vane (30) can be suppressed by designing the first end (31) of the guide vane (30) to -27°≦α≦27°.

[0052] (4-4) Feature 4 In the hydraulic machine (1) of this embodiment, when viewed from the axial direction of the runner (40), the guide vane (30) is formed such that β ≤ 37° when the angle formed by the tangent to the center circle of curvature at the second end (32), which is the radially inward end of the guide vane (30), and the concentric tangent to the rotation axis center (C) of the runner (40) at the second end (32) is denoted as β.

[0053] By shaping the guide vanes (30) in such a way that the outflow angle β ≤ 37°, the static pressure efficiency can be improved. As a result, the power generation efficiency of the hydraulic machine (1) can be increased.

[0054] (4-5) Feature 5 In this embodiment, the hydraulic machine (1) comprises a casing (10) which includes a first cylindrical member (11) whose one end is closed by a first end face (11a), and a second cylindrical member (12) which is disposed inside the first cylindrical member (11) and has an open end (12a) which is open at one end. A support plate (20) is disposed between the first end face (11a) and the open end (12a), and a runner (40) is disposed inside the second cylindrical member (12).

[0055] According to this embodiment, water flows from the outside of the second cylindrical member (12) through the guide vane (30) to the inside of the second cylindrical member (12) and passes through the runner (40). By designing the casing (10) to form such a water flow, the size of the product (hydraulic machine) can be made more compact.

[0056] (4-6) Feature 6 In the hydraulic machine (1) of this embodiment, the inner edge (21) of the support plate (20) is formed in a curved shape so as to smoothly connect to the open end of the second cylindrical member (12). This reduces resistance to the flowing water when water flows into the second cylindrical member (12), making it easier for water to flow into the runner (40). As a result, the decrease in the flow velocity of the water circulating in the runner (40) can be suppressed.

[0057] In this embodiment of the hydraulic machine (1), all guide vanes (30) provided on the support plate (20) are formed to have the same α and the same β. By making the α and β angles of all guide vanes (30) the same, it becomes unnecessary to set the angle for each guide vane (30), and the manufacturing of the fluid machine (1) can be made easier.

[0058] (4-7) Feature 7 In the hydraulic machine (1) of this embodiment, the cross-sectional shape of all the guide vanes (30) provided on the support plate (20) perpendicular to the rotation axis of the runner (40) is formed to be the same. By forming all the guide vanes (30) to be the same shape and providing them to stand vertically from the support plate (20), the formation of the guide vanes (30) and their fixing onto the support plate (20) can be made easier.

[0059] (4-8) Feature 8 In this embodiment of the hydraulic machine (1), the number of guide vanes (30) and the number of runner vanes (41) on the runner (40) are relatively prime. In this way, vibrations of the fluid machine can be suppressed.

[0060] (5) Other embodiments The above embodiment may also have the following configuration.

[0061] The runner (40) in the above embodiment may be of mixed flow.

[0062] The guide vane (30) in the above embodiment may be formed such that β ≤ 25°. This can further improve the static pressure efficiency.

[0063] The guide vane (30) in the above embodiment only needs to be formed in a concave shape with respect to the rotational direction of the runner (40), and α and β do not need to satisfy -27 ≤ α ≤ 27 and β ≤ 37, respectively.

[0064] While embodiments and modifications have been described above, it will be understood that a variety of changes in form and details are possible without departing from the spirit and scope of the claims. Furthermore, these embodiments and modifications may be combined or substituted as appropriate, as long as they do not impair the functions of the subject matter of this disclosure. The terms “First,” “Second,” etc., used above are used to distinguish the phrases to which these terms are attached, and do not limit the number or order of such phrases. [Industrial applicability]

[0065] As explained above, this disclosure is useful for fluid machinery. [Explanation of Symbols]

[0066] 1 Fluid machinery (hydraulic machinery) 10 Casing 11. First cylindrical member 11a 1st end surface (upper end surface) 12. Second cylindrical member 12a open end 18 Inlet 20 Support plate 21 Inner edge 30 Guide vanes 31 First end 32 Second end 40 Runner 41 Runnerbane

Claims

1. Casing (10) and An annular support plate (20) is placed inside the casing (10), Multiple guide vanes (30) fixed on the support plate (20), A fluid machine comprising an axial or diagonal flow runner (40) positioned with the center of the support plate (20) as its axis, wherein fluid flows sequentially through the guide vane (30) and the runner (40), The casing (10) is provided with an inlet (18) through which fluid flows in perpendicular to the axial direction of the runner (40). The multiple guide vanes (30) are, The fluid flowing from the inlet (18) to the radially outward side of the support plate (20) flows into the guide vane (30) at an inflow angle that changes according to the circumferential position of the support plate (20), and the fluid is arranged to flow from the radially outward to the radially inward side of the support plate (20), and When viewed from the axial direction of the runner (40), it is formed to protrude in the counter-rotational direction of the runner (40), The second end (32), which is the radially inward end of the guide vane (30), is positioned closer to the inner edge (21) than to the radially intermediate portion of the support plate (20). Viewed from the axial direction of the runner (40), When α is the angle formed by the line connecting the first end (31), which is the radially outer end of the guide vane (30), and the rotation axis center (C) of the runner (40), and the tangent to the circle of curvature at the first end (31), the guide vane (30) is formed such that -27° ≤ α ≤ 27°. A fluid machine characterized by the following features.

2. The casing (10) is provided with one inlet (18). The fluid machine according to feature 1.

3. Viewed from the axial direction of the runner (40), When β is the angle formed by the tangent to the center circle of curvature at the second end (32), which is the radially inward end of the guide vane (30), and the concentric tangent to the rotation axis center (C) of the runner (40) at the second end (32), the guide vane (30) is formed such that β ≤ 37°. The fluid machine according to claim 1 or 2.

4. The fluid machine according to claim 3, characterized in that the guide vane (30) is formed such that β ≤ 25°.

5. The casing (10) comprises a first cylindrical member (11) whose one end is closed by a first end face (11a), and a second cylindrical member (12) disposed within the first cylindrical member (11) and having an open end (12a) which is open at one end. The support plate (20) is positioned between the first end face (11a) and the open end (12a). The runner (40) is disposed within the second cylindrical member (12). A fluid machine according to any one of claims 1 to 4.

6. The fluid machine according to claim 5, characterized in that the inner edge (21) of the support plate (20) is formed in a curved shape so as to be smoothly connected to the open end of the second cylindrical member (12).

7. Viewed from the axial direction of the runner (40), The angle α formed by the line connecting the first end (31), which is the radially outer end of the guide vane (30), and the rotation axis center (C) of the runner (40), and the tangent to the circle of curvature at the first end (31), satisfies -27° ≤ α ≤ 27°, and The angle β formed by the tangent to the center circle of curvature at the second end (32), which is the radially inward end of the guide vane (30), and the concentric tangent to the rotation axis center (C) of the runner (40) at the second end (32), satisfies β ≤ 37°. All of the guide vanes (30) provided on the support plate (20) are formed to have the same α and the same β. The fluid machine according to feature 1.

8. The fluid machine according to any one of claims 1 to 7, characterized in that all of the guide vanes (30) provided on the support plate (20) have the same cross-sectional shape perpendicular to the rotation axis of the runner (40).

9. The fluid machine according to any one of claims 1 to 8, characterized in that the number of guide vanes (30) and the number of runner vanes (41) on the runner (40) are relatively prime.

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