Guide vanes and hydraulic machines

Abstract

To provide a guide vane which inhibits deterioration of the output and the efficiency of a hydraulic machine, and to provide the hydraulic machine.SOLUTION: A guide vane according to an embodiment is disposed so that a blade body can rotate around a spindle connected to the blade body between an upper cover and a lower cover of a hydraulic machine which face each other. The guide vane includes: grooves which form a hollow space in the blade body and are open in an axial direction of the spindle; protrusion plates each of which is disposed within the groove and may slide from the interior of the groove in the axial direction of the spindle; and slide mechanisms each of which is provided within the groove and causes the projection plate to slide.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] FIELD OF THE INVENTION An embodiment of the present invention relates to a guide vane and a hydraulic machine. [Background technology]

[0002] In typical hydroelectric machines, such as Francis turbines and fixed-blade propeller turbines, multiple guide vanes are arranged at circumferential intervals around the runner, radially outward of the runner, and multiple stay vanes are arranged at circumferential intervals around the guide vanes. A casing is also arranged radially outward of the stay vanes. The runner, guide vanes, and stay vanes are housed between opposing upper and lower covers, sandwiched from above and below. A gap is formed between the guide vanes and the upper and lower covers to allow the guide vanes to rotate on the spindle shaft. The guide vanes can change the area of ​​the flow passages formed between adjacent guide vanes by rotating. This allows the hydroelectric machine's power output to be adjusted by changing the amount of water that flows from the upper reservoir through the casing and stay vanes and into the runner after passing through the guide vanes. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-160865 [Patent Document 2] Japanese Patent Application Publication No. 9-195916 [Patent Document 3] Japanese Patent Application Publication No. 7-279809 Summary of the Invention [Problem to be solved by the invention]

[0004] In such hydraulic machines, water can leak through the gaps between the guide vanes and the upper and lower covers. This leakage flow, especially during partial-load operation with low power output, can cause a separation flow from the pressure side of the guide vane to the suction side, which does not follow the blade shape, potentially increasing hydraulic losses. Furthermore, the main flow entering the runner is disrupted by this leakage flow, which can also increase runner losses. As a result, these hydraulic and runner losses can reduce the output and efficiency of the hydraulic machine.

[0005] An object of the present invention is to provide a guide vane and a hydraulic machine that suppress a decrease in the output and efficiency of the hydraulic machine. [Means for solving the problem]

[0006] In order to solve the above problem, the guide vane of the embodiment is a guide vane arranged between an upper cover and a lower cover of a hydraulic machine facing each other, and arranged so that the blade base can rotate around a spindle connected to the blade base, and is equipped with a hollow space formed inside the blade body, a groove opening in the axial direction of the spindle, a protruding plate arranged inside the groove and slidable in the axial direction of the spindle from inside the groove, and a sliding mechanism provided inside the groove for sliding the protruding plate. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a cross-sectional view of a Francis turbine according to a first embodiment, viewed from the axial direction. [Figure 2] FIG. 1 is a meridian cross-sectional view of a Francis turbine according to a first embodiment. [Figure 3] FIG. 2 is a perspective view of a guide vane according to the first embodiment. [Figure 4] FIG. 2 is a cross-sectional view of the guide vane according to the first embodiment, taken along the center of the spindle shaft. [Figure 5] FIG. 2 is a view of the stay vanes and guide vanes according to the first embodiment viewed downward from above the z-axis. [Figure 6]5A and 5B are cross-sectional views taken along the line A1-A1 in FIG. 4, in which (a) shows the protruding state of the protruding plate, and (b) shows the retracted state of the protruding plate. [Figure 7] FIG. 10 is a cross-sectional view taken along the center of the spindle shaft of a guide vane according to a modified example of the first embodiment. [Figure 8] FIG. 10 is a diagram showing a guide vane according to a modification of the first embodiment, viewed downward from above the z-axis. [Figure 9] FIG. 10 is a cross-sectional view of a guide vane according to a second embodiment, taken along the center of a spindle shaft. [Figure 10] FIG. 10 is a cross-sectional view taken along line A2-A2 in FIG. [Figure 11] FIG. 10 is a partially enlarged cross-sectional view of a guide vane according to a modified example of the second embodiment. [Figure 12] FIG. 10 is a partially enlarged cross-sectional view of a guide vane according to a modified example of the second embodiment. [Figure 13] FIG. 10 is a view of a guide vane according to a modification of the second embodiment, viewed downward from above the z-axis. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments for carrying out the invention will be described.

[0009] (First embodiment) A first embodiment will be described with reference to Fig. 1 to Fig. 8. Fig. 1 is a cross-sectional view of a Francis turbine 1 according to this embodiment as seen from the axial direction, and Fig. 2 is a meridian cross-sectional view of the Francis turbine 1 according to this embodiment. The Francis turbine 1 includes a casing 10, stay vanes 20, guide vanes 30, a runner 40, a main shaft 50, a generator 60, an upper cover 70, a lower cover 80, and a draft tube 90. In the following description, the z-axis refers to the axial direction of the rotation axis C, with the generator 60 side being the upward direction of the z-axis and the draft tube 90 side being the downward direction of the z-axis.

[0010] The casing 10 is spirally disposed on the outer periphery of the runner 40, which will be described later. Water flowing in from an upper reservoir (not shown) passes through the casing 10, then passes through stay vanes 20 and guide vanes 30 (both of which will be described later) in sequence, before being supplied to the runner 40. The casing 10 is formed so that its cross-sectional diameter gradually decreases from the start of winding (upper reservoir side) to the end of winding (runner 40 side).

[0011] A plurality of stay vanes 20 are arranged at predetermined intervals on the inner peripheral side of the casing 10 and in the circumferential direction (hereinafter referred to as the circumferential direction) relative to the rotation axis C of the main shaft 50, which will be described later. A flow path through which water flows is formed between adjacent stay vanes 20.

[0012] The guide vanes 30 include a blade body 31, a spindle 32, holes 33, grooves 34a to 34d, and protruding plates 35a to 35d, and are arranged at predetermined intervals in the circumferential direction on the inner circumferential side of the stay vanes 20. A more detailed description of the guide vanes 30 will be given later.

[0013] The runner 40 is provided radially inward of the guide vanes 30 so as to be rotatable about a rotation axis C, and is connected to a generator 60 via a main shaft 50 .

[0014] The main shaft 50 is the rotation shaft of the runner 40, and is connected to a generator 60. When the rotational energy of the runner 40 is transmitted to the generator 60 via the main shaft 50, the generator 60 generates electricity.

[0015] The generator 60 may also function as an electric motor, and may be configured to rotate the runner 40 when supplied with electric power. In this case, water can be sucked up from a lower reservoir (not shown) through a draft pipe 90 (described later) and released into an upper reservoir, enabling the Francis turbine 1 to operate as a pump-turbine for pumping water.

[0016] The upper cover 70 and the lower cover 80 are provided so that the upper cover 70 faces each other from above in the z-axis direction, and the lower cover 80 faces each other from below in the z-axis direction, and house the stay vanes 20, the guide vanes 30, and the runner 40 so as to sandwich them from above and below. The space between the upper cover 70 and the lower cover 80, in which the stay vanes 20 and the guide vanes 30 are housed, forms a flow path for the water flowing between the casing 10 and the runner 40. Note that the blade body 31 of the guide vane 30 is not in contact with the upper cover 60 or the lower cover 70 in the z-direction, and is arranged with a predetermined gap therebetween so that the blade body 31 can rotate on the spindle 32 axis.

[0017] The draft pipe 90 is provided downstream (downward in the z-axis direction) of the runner 40, and supplies water flowing in from the runner 40 to a lower pond (not shown).

[0018] Next, details of the guide vane 30 will be described with reference to Figures 3 to 6. Figure 3 is a perspective view of the guide vane 30. Figure 4 is a cross-sectional view of the guide vane 30 taken along the axis of the spindle 32. The arrows in Figure 4 indicate the state in which the holes 33 are pressurized with fluid 37. The x-axis and y-axis are perpendicular to the z-axis, with the x-axis indicating the longitudinal direction of the blade body 31 of the guide vane 30 and the y-axis indicating a direction perpendicular to the x-axis and z-axis. Figure 5 is a view of the stay vane 20 and guide vane 30 viewed downward from above the z-axis. Note that the dotted line of the guide vane 30 in Figure 5 indicates the guide vane in an overloaded operating state, and the solid line indicates the guide vane in a partial-load operating state. The arrows in Figure 5 indicate the flow direction of water flowing out of the stay vane 20. Figure 6 is a cross-sectional view taken along line A1-A1 in Figure 4.

[0019] The guide vane 30 includes a blade body 31, a spindle 32, a hole 33, grooves 34a to 34d, and protruding plates 35a to 35d.

[0020] The blade body 31 is a rotating blade of the guide vane 30 extending in the x-axis direction in FIG. 3. The spindle 32 is a rotation axis of the guide vane 30 extending in the z-axis direction. The spindle 32 is connected to a drive unit (not shown), and the drive unit receives a control signal from a control unit (not shown), causing the spindle 32 to rotate via the drive unit. The blade body 31 and spindle 32 are rotatably connected around the spindle 32, and the opening degree of the blade body 31 can be controlled by rotating the spindle 32 via the drive unit. As a result, the flow path cross-sectional area of ​​the flow path formed between adjacent blade bodies 31 in the circumferential direction changes, making it possible to adjust the flow rate of the water flowing between adjacent blade bodies 31 in the circumferential direction.

[0021] As shown in Fig. 4, hole 33 passes through the interior of spindle 32 and blade body 31, branches off inside blade body 31, and connects to grooves 34a to 34d (hereinafter collectively referred to as grooves 34), which will be described later. Grooves 34 are spaces that communicate with hole 33, with grooves 34a and 34b opening upward in the z-axis direction of blade body 32 and grooves 34c and 34d opening downward in the z-axis direction of blade body 32. In other words, blade body 31 and spindle 32 have a hollow structure, and holes 33 and grooves 34 are the spaces that make up this hollow structure. Furthermore, groove 34 opens in the axial direction of spindle 32 (z-axis direction).

[0022] As shown in FIG. 3, protruding plates 35a to 35d (hereinafter collectively referred to as protruding plates 35) are formed to extend in the x-axis direction. As shown in FIG. 4, protruding plate 35a is arranged in groove 34a, protruding plate 35b in groove 34b, protruding plate 35c in groove 34c, and protruding plate 35d in groove 34d. Each protruding plate 35 has two recesses 36a recessed on both sides in the y-axis direction, as shown in FIG. 6, and a seal member 36b is arranged in each recess 36a. The seal member 36b is provided at a position where it can be accommodated in groove 34a even when protruding plate 35a is in the protruding state (as shown in FIG. 6(a)). This is to stop the flow of fluid 37 pressurizing groove 34a so that it does not leak out of groove 34a, as will be described later, or to stop the flow of water flowing through a flow path outside blade body 31 so that it does not flow into groove 34a.

[0023] As will be described later, groove 34 is pressurized by fluid 37 via hole 33, and this pressure causes protruding plate 35 to slide from a state in which it is housed inside groove 34 (the state shown in FIG. 6(b)) to a state in which it protrudes outward (the state shown in FIG. 6(a)). In other words, a force acts through hole 33 and groove 34 in the direction in which groove 34 opens, causing protruding plate 35 to slide outward from the opening of groove 34 and become exposed.

[0024] In addition, the groove 34 and the protruding plate 35 may each have an engaging portion (not shown) that abuts against each other when the protruding plate 35 protrudes, and this engaging portion may engage the protruding plate 35, thereby limiting the maximum distance that the protruding plate 35 can protrude.

[0025] As shown in FIG. 5, the guide vane 30 configured as described above can rotate around the spindle 32 to switch between an overload operation state and a partial load operation state. In FIG. 5, the guide vane in the overload operation state, indicated by the dotted line, is designated guide vane 30A, and the guide vane in the partial load operation state, indicated by the solid line, is designated guide vane 30B. The xA, yA, and z axes, indicated by the dotted lines in FIG. 5, are the axes of guide vane 30A, and the xB, yB, and z axes, indicated by the dotted lines, are the axes of guide vane 30B. The overload operation state, indicated by the dotted lines in FIG. 5, is a state in which guide vane 30A is fully open, i.e., the area of ​​the flow path formed between adjacent guide vanes 30A is maximized. Therefore, the amount of water flowing through the flow path and supplied to the runner 40 is maximized, thereby maximizing the power generation output. At this time, the direction of the water flowing from the stay vane 20 into the guide vane 30A is substantially parallel to the xA axis direction in which the blade body 31A of the guide vane 30A extends, and the water flow follows the blade shape of the guide vane 30A.

[0026] On the other hand, in the partial load operating state shown by the solid line in Figure 5, the flow path area formed by adjacent guide vanes 30B is smaller than in the overload operating state, so the amount of water flowing through that flow path and supplied to the runner 40 is small, and the power output of the generator is reduced. In this way, the guide vane 30 can adjust the power output by changing the rotational opening of the blade body 31 to change the amount of water supplied to the runner 40. In this case, the direction of the water flow flowing from the stay vane 20 into the guide vane 30B is inclined toward the yB axis from the xB axis direction along which the blade body 31B of the guide vane 30B extends, so there is a water flow component that does not follow the blade shape of the guide vane 30B.

[0027] Next, a method for protruding protruding plate 35 of guide vane 30 during partial load operation will be described. When guide vane 30 is in an overload operation state, protruding plate 35 is housed inside groove 34, so here we will describe a case where guide vane 30 switches from an overload operation state (a state with an opening degree indicated by guide vane 30A) to a partial load operation state (a state with an opening degree indicated by guide vane 30B), and protruding plate 35 changes from a state housed inside groove 34 (a state shown in FIG. 6(b)) to a protruding state (a state shown in FIG. 6(a)).

[0028] First, as shown by the arrows in FIG. 4 , fluid 37 is supplied from the spindle 32 side to the hole 33, and flows into the groove 34 through the blade body 31 side of the hole 33. Here, in this embodiment, the fluid 37 is a sliding mechanism that slides the protruding plate 35. Next, as shown in FIG. 6( a), the fluid 37 pressurizes the inside of the hole 33, thereby pressurizing the inside of the groove 34, and applies pressure to the protruding plate 35 housed inside the groove 34 in the direction of the opening of the groove 34. Note that the direction of pressure applied to the protruding plate 35 is upward along the z-axis for protruding plates 35a and 35b, and downward along the z-axis for protruding plates 35c and 35d. Then, when a pressure higher than a predetermined value acts on the protruding plate 35, the protruding plate 35 slides toward the opening of the groove 34 and protrudes outward from the opening.

[0029] The fluid 37 pressurized from the hole 33 is, for example, but not limited to, water, air, oil, etc. When water is used as the fluid 37, for example, a flow path (not shown) branching from the casing 10 to the hole 33 may be provided, and the water flowing through the casing 10 may be supplied to the hole 33 via this flow path.

[0030] Next, the operation of this embodiment will be described with reference to Figures 2, 3, and 6, taking as an example a case where the guide vane 30 is in a partial load operating state and the protruding plate 35 has protruded through the process described above.

[0031] When the turbine is operating, as shown in Figure 2, water from the upper reservoir passes through the casing 10, stay vanes 20, and guide vanes 30 in this order and is supplied to the runner 40. The runner 40 receives work from the water and is driven to rotate, and when this rotational energy is transmitted to the generator 60 via the rotating shaft 50, the generator 60 generates electricity. After performing work in the runner 40, the water flows through the draft pipe 90 and is supplied to the lower reservoir.

[0032] At this time, most of the water passing through the guide vanes 30 (hereinafter referred to as the mainstream) flows in the x-axis direction along the blade shape of the blade body 31 and flows into the runner 40 through the flow passages formed between adjacent guide vanes 30. On the other hand, the water components that do not flow as the mainstream pass through the gaps between the blade body 31 and the upper cover 70 and the lower cover 80 in a direction inclined from the x-axis to the y-axis shown in FIG. 3, and flow from the pressure side to the suction side of the blade body 31. At this time, if the protruding plates 35 of the guide vane 30 are protruded as described above (as shown in FIG. 6(a)), the flow of the water components that do not flow as the mainstream is obstructed by the protruding plates 35 and is guided to flow in the same direction as the mainstream.

[0033] That is, in a partial load operating state, the protruding protrusion plate 35 can guide water components that do not flow as the mainstream (water that tries to flow through the gaps between the blade body 31 and the upper cover 60 and the lower cover 70) to the mainstream. In other words, it is possible to prevent leakage flow that does not follow the blade shape of the blade body 31 and flows across the y-axis direction from the pressure surface side to the suction surface side of the blade body 31. Furthermore, because the protrusion plate 35 has a shape that extends in the x-axis direction along which the blade body 31 extends, it is possible to suppress only leakage flow in the y-axis direction without interfering with the mainstream that flows in the x-axis direction along the blade shape of the blade body 31.

[0034] In the case of an overload operation, as shown in Figure 6(b), it is preferable to reduce the pressure of the fluid 37 inside the hole 33 and accommodate the protruding plate 35 in the groove 34. This is because the purpose of the overload operation is to increase the power generation output compared to the partial load operation, and therefore it is preferable to accommodate the protruding plate 35 inside the groove 34 to increase the amount of water supplied to the runner 40. In addition, in the overload operation, the direction of the water flow from the stay vane 20 into the guide vane 30 is in the x-axis direction, which is roughly along the blade shape of the blade body 31, and the influence of leakage flow in the y-axis direction on hydraulic loss and turbulence of the water flow is small, so it is possible to accommodate the protruding plate 35 inside the groove 34.

[0035] The guide vane 30 in the first embodiment described above is provided with protruding plates 35 that can be protruded in the z-axis direction from inside the grooves 34 by pressurizing with fluid 37 from the holes 33, and thereby guides the water components that do not flow as the mainstream during partial load operation to flow in the same direction as the mainstream via the protruding plates 35. As a result, not only is hydraulic loss caused by the separated flow of the water components that do not flow as the mainstream (water that does not follow the blade shape of the blade body 31) supplied to the runner 40 reduced, but the mainstream is also prevented from being disturbed by this water flow, and a decrease in the output and efficiency of the Francis turbine 1 can be suppressed.

[0036] As a modification of this embodiment, as shown in FIG. 7, the guide vane 30 may further include a rod 38a and a gear 38b, which are a driving mechanism that drives the rod 38a in the z-axis direction as a sliding mechanism within the hole 33. In this case, the rod 38a is connected to the protruding plate 35, and the gear 38b is provided on the rod 38a so as to change the direction of the force acting on the rod 38a. The rod 38a may also be driven from the spindle 32 side by a driving force from a driving device (both not shown) that receives a control signal from a control device. In other words, the rod 38a may be driven within the hole 33, and the gear 38b may apply the driving force to the protruding plate 35 to which the rod 38a is connected, thereby sliding the protruding plate 35. Note that this driving mechanism may be a driving mechanism other than a rod and a gear, as long as it can drive the protruding plate 35 in the z-axis direction. This configuration not only provides the same effect as the present embodiment, but also eliminates the need for fluid 37 to pressurize holes 33, eliminating the possibility of fluid 37 leaking out of guide vane 30. Furthermore, by mechanically sliding protruding plate 35, protruding plate 35 can be controlled more quickly.

[0037] As another modification of this embodiment, as shown in FIG. 8 , the guide vane 30 may further include a communication hole 39 on the pressure surface side of the blade body 31, connecting the hole 33 with the outside. The arrows in FIG. 8 indicate the flow direction of water passing through the stay vane 20 and flowing into the guide vane 30. The communication hole 39 is preferably located at the stagnation point where the water pressure is highest when the guide vane 30 is operating at a partial load. When the guide vane 30 is operating at a partial load, the water pressure on the pressure surface side of the blade body 31 increases. This configuration allows water to flow in through the communication hole 39 when the guide vane 30 is operating at a partial load, pressurizing the inside of the hole 33 and the groove 34 and causing the protruding plate 35 to protrude, as described in the first embodiment. In other words, the water passing through the stay vane 20 and flowing into the guide vane 30 can be used as a sliding mechanism in place of the fluid 37. Furthermore, in the case of overload operation, the water pressure acting on the pressure surface of the blade body 31 is lower than in the case of partial load operation, so that water flows in through the communication holes 39, reducing the pressure that pressurizes the holes 33 and grooves 34, and the protruding plates 35 can be accommodated in the grooves 34 as shown in Figure 6(b). As a result, in addition to the same effects as in this embodiment, the sliding of the protruding plates 35 can be automatically controlled according to the opening degree of the guide vanes 30.

[0038] (Second embodiment) The second embodiment will be described with reference to Figs. 9 to 13. The same parts as those in the first embodiment are given the same reference numerals, and detailed description will be omitted. The main difference between this embodiment and the first embodiment is that the protruding plate 135 of the guide vane 130 is equipped with a magnet (not shown). As shown in Fig. 9, the blade body 131 and spindle 132 of the guide vane 130 are described by way of example, in which they do not have a configuration equivalent to the hole 33 in the first embodiment. Fig. 10 is a cross-sectional view taken along line A2-A2 in Fig. 9.

[0039] 9, guide vane 130 includes blade main body 131, spindle 132, grooves 134a to 134d (hereinafter collectively referred to as grooves 134), and protruding plates 135a to 135d (hereinafter collectively referred to as protruding plates 135). Blade main body 131 and spindle 132 have the same configuration as in the first embodiment, and detailed description thereof will be omitted. Grooves 134b to 134d have the same configuration as groove 134a, and protruding plates 135b to 135d have the same configuration as protruding plate 135a, and in this embodiment and its modified examples, groove 134a and protruding plate 135a will be described as examples.

[0040] As shown in FIG. 10, the groove 134a includes an electromagnet 142a disposed at its bottom (below the z-axis). A conductor (not shown) is connected to the electromagnet 142a, and the electromagnet 142a is excited when a current is supplied from the conductor. The protruding plate 135a includes a recess 136a, a seal member 136b, and a magnet 140a disposed at the end of the bottom side (below the z-axis) of the groove 134a. The recess 136a and the seal member 136b have the same configuration as in the first embodiment. The magnet 140a and the electromagnet 142a are disposed so that the opposing sides have the same pole. The magnet 140a and the electromagnet 142a function as a sliding mechanism in this embodiment, as will be described later.

[0041] In the guide vane 130 having this configuration, a case will be described in which the operation state is switched from an overload state to a partial load state, and the protruding plate 135a is caused to protrude from the state housed inside the groove 134a. At this time, no current is supplied to the electromagnet 142a, and the electromagnet 142a is not excited.

[0042] First, a current is supplied to electromagnet 142a via a conductor to excite electromagnet 142a. At this time, since magnet 140a and electromagnet 142a have the same pole on the opposing sides, when electromagnet 142a is excited, a repulsive force acts between magnet 140a and electromagnet 142a. Then, as shown in FIG. 10 , this repulsive force causes protruding plate 135a to slide toward the opening of groove 134a and protrude from this opening to the outside of groove 134a. In other words, protruding plate 135a is exposed to the outside of groove 134a due to the repulsive force between magnet 140a provided on protruding plate 135a and electromagnet 142a provided in groove 134a.

[0043] Furthermore, when switching from a partial load operation state to an overload operation state, the supply of current to the electromagnet 142a is stopped to demagnetize the electromagnet 142a, thereby eliminating the repulsive force between the magnet 140a and the electromagnet 142a and allowing the protrusion plate 135a to be accommodated in the groove 134a.

[0044] In the guide vane 130 of the present embodiment described above, a magnet 140a is provided on the protruding plate 135a and an electromagnet 142a is provided in the groove 134a, and by exciting the electromagnet 142 during partial load operation, the repulsive force between the magnet 140a and the electromagnet 142a causes the protruding plate 135a to protrude. By providing this configuration, the same effects as in the first embodiment can be obtained.

[0045] As a modification of this embodiment, as shown in FIG. 11, a configuration may be adopted in which a magnet 140a is provided at the end of the protruding plate 135a on the opening side (above the z-axis) as a sliding mechanism, and an electromagnet 144a is provided on the upper cover 70. For convenience, a cross section of the upper cover 70 is not shown in FIG. 11. In this case, the magnet 140a on the protruding plate 135a and the electromagnet 144a on the upper cover 70 are arranged so that the opposing sides have opposite poles. Similarly, magnets (not shown) may be provided on the protruding plates 135b to 135d, with the electromagnet facing the magnet on 135b being provided on the upper cover 70 and the electromagnet facing the protruding plates 135c and 135d being provided on the lower cover 80 (both not shown). Conductors (not shown) are connected to these electromagnets, and current can be supplied to the electromagnets via these conductors. With this configuration, when the guide vane 130 is in a partial load operating state, the electromagnet 144a is excited, and the attractive force between the magnet 140a on the protruding plate 135a and the electromagnet 144a on the upper cover 70 causes the protruding plate 135a to protrude, thereby achieving the same effect as in this embodiment.

[0046] As another modification of this embodiment, as shown in FIGS. 12 and 13, the electromagnet 144a provided on the upper cover 70 of the modification described above may be replaced with a magnet 146a (second magnet), which may be positioned to face the magnet 140a (first magnet) on the protruding plate 135a when the guide vane 130 is in a partial load operating state. In FIGS. 12 and 13, the partial load operating state is indicated by a solid line, and the overload operating state is indicated by a dotted line. Also, in FIG. 13, the magnet 140a on the protruding plate 135a is not shown for convenience. That is, the magnet 146a may be positioned so that it is positioned above the z-axis of the protruding plate 135a when the guide vane 130 is in a partial load operating state. In this case, when the guide vane 130 is in an overload operating state, the magnet 146a is positioned in the direction of rotation about the spindle 132 from the z-axis of the protruding plate 135a. Furthermore, a magnet facing magnet 135b is provided on upper cover 70, and magnets facing protruding plates 135c and 135d are provided on lower cover 80 (both not shown). These magnets may also be positioned to face protruding plate 135 during partial load operation. The magnets on protruding plate 135 and the magnets on upper cover 70 and lower cover 80 are positioned so that their opposing poles are opposite. With this configuration, when guide vane 130 switches from an overload operation state to a partial load operation state, magnet 140a and magnet 146a move closer to each other, causing protruding plate 135a to protrude due to the attractive force. On the other hand, when switching from a partial load operation state to an overload operation state, magnet 140a and magnet 146a move away from each other, weakening the attractive force, causing protruding plate 135a to be accommodated in groove 134a. As a result, in addition to the same effects as the present embodiment, the sliding of protruding plate 135 can be automatically controlled according to the opening degree of guide vane 130.

[0047] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0048] 1...Francis turbine, 10...casing, 20...stay vane, 30, 130...guide vane, 31, 131...blade body, 32, 132...spindle, 33...hole, 34a, 34b, 34c, 34d, 134a, 134b, 134c, 134d...groove, 35a, 35b, 35c, 35d, 135a, 135b, 135c, 135d...projection plate, 36a, 136a...recess, 36b, 136b...sealing member, 37...fluid, 38a...rod, 38b...gear, 39...communicating hole, 40...runner, 50...main shaft, 60...generator, 70...upper cover, 80...lower cover, 90...draft tube, 140a, 146a...magnet, 142a, 144a...electromagnet.

Claims

1. A guide vane is disposed between an upper cover and a lower cover of a hydraulic machine facing each other, and the blade base is rotatable around a spindle connected to the blade base, a groove formed inside the blade body, the groove opening in the axial direction of the spindle; a protruding plate disposed inside the groove and slidable in the axial direction of the spindle from inside the groove; a sliding mechanism provided inside the groove for sliding the protruding plate; Equipped with The sliding mechanism is a guide vane that includes a first magnet arranged on the protruding plate and a second magnet arranged on at least one of the upper cover and the lower cover.

2. The guide vane of claim 1 , wherein the second magnet is an electromagnet.

3. The guide vane according to claim 1 or 2, wherein the second magnet is disposed at a position facing the protruding plate when the guide vane is in a partial load operating state.

4. A hydraulic machine comprising the guide vane according to claim 1.

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