JP2013189972A - Hydraulic power generation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize a hydraulic power generation device having a spiral blade.SOLUTION: A hydraulic power generation device includes a hollow shaft 32 having a spiral blade 30 on an outer periphery, a power generator 40, and a transmission 50. The hollow shaft 32 is rotatably supported with a fixed shaft 20 so as to be rotated by a water current flowing toward the spiral blade 30. The power generator 40 is arranged inside the hollow shaft 32. The transmission 50 is arranged between an upstream end of the hollow shaft 32 and the power generator 40, in the hollow shaft 32, and transmits driving force from the hollow shaft 32 to a rotor 42 of the power generator 40.

Description

  The present invention relates to a hydroelectric generator, and more particularly to a hydroelectric generator provided with a spiral blade.

  In general, hydroelectric power generation is known in which a large-scale dam is constructed to generate a large power of several MW to several thousand MW. In addition to such a large-scale hydropower generation, there is a small hydropower generation that generates power of 100 kW or less using a relatively small drop or a small amount of water flow. As a water turbine for small hydroelectric power generation, a water turbine that is the same as a large hydroelectric power generation, a Pelton turbine, a Francis turbine, or a Kaplan turbine is used. In addition, a cross-flow turbine or a valve turbine suitable for medium-scale or smaller hydropower generation is used. In hydroelectric power generation using these water wheels, it is necessary to provide a closed water channel and guide the water flow to the water wheel.

  On the other hand, although the scale of power generation is further reduced, there are a top turbine, a bottom turbine, and a spiral turbine as a type of turbine installed in an open channel such as an agricultural channel. In particular, if an underwater turbine and a spiral turbine are used, power generation is possible with a low head of about 1 m or 1 m or less.

  Japanese Unexamined Patent Application Publication No. 2009-221882 (Patent Document 1), Japanese Unexamined Patent Application Publication No. 2007-154862 (Patent Document 2), Japanese Unexamined Patent Application Publication No. 63-57874 (Patent Document 3), Japanese Utility Model Application Publication No. 9356 The gazette (patent document 4) discloses a technique related to a spiral water turbine.

JP 2009-221882 A JP 2007-154862 A Japanese Unexamined Patent Publication No. 63-57874 Taisho 14 year utility model application publication No. 9356

  For example, as shown in FIG. 1 of JP-A-2009-221882, a hydraulic power generation apparatus using a spiral water turbine includes a generator, a shaft for transmitting driving force from the spiral water turbine to the generator, and a speed increasing speed. Equipped with a machine. Therefore, when installing the hydroelectric generator, it is necessary to secure a place for installing the generator, the shaft, and the speed increaser in addition to the place for installing the spiral water turbine. In particular, ordinary generators and gearboxes are not designed to be submerged, so it is necessary to install them above the water surface, and the shaft connecting the turbine body and these devices must be long enough. However, since it is assumed that the hydroelectric generator using a spiral water turbine is installed in a narrow space such as an agricultural waterway, it is desirable to configure the hydroelectric generator to be small.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to reduce the size of a hydroelectric generator.

  In one embodiment, the hydroelectric generator includes a hollow shaft provided with a spiral blade on the outer periphery, rotated by a water flow toward the spiral blade, a generator provided inside the hollow shaft, and a hollow shaft inside the hollow shaft. And a transmission member that is provided between the upstream end portion and the generator and transmits the driving force from the hollow shaft to the generator.

  According to this configuration, the generator and the transmission member are housed in the hollow shaft. Therefore, the size of the hydroelectric generator can be made equal to the size of the hollow shaft. As a result, the hydroelectric generator can be reduced in size.

  In another embodiment, the hydroelectric generator further includes a fixed shaft that is fixed to be non-rotatable and penetrates the hollow shaft in the axial direction. The generator includes a rotor connected to the transmission member, and a stator fixed to the fixed shaft.

  According to this configuration, a common fixed shaft is used for the shaft that supports the hollow shaft and the shaft that supports the generator. Thereby, the structure of a hydroelectric generator can be simplified.

In yet another embodiment, the transmission member is a transmission.
According to this configuration, the rotational speed of the hollow shaft can be changed to a desired speed and transmitted to the generator by the transmission.

In yet another embodiment, the transmission gear ratio is less than one.
According to this configuration, the rotation speed of the hollow shaft can be increased and transmitted to the generator.

In yet another embodiment, the transmission includes a planetary gear.
According to this configuration, the transmission shaft and the hollow shaft can be made the same by using the planetary gear. Therefore, the hydroelectric generator can be reduced in size.

In yet another embodiment, the transmission includes a plurality of planetary gears.
According to this configuration, by using a plurality of planetary gears, the rotational speed of the hollow shaft can be greatly increased or decreased and transmitted to the power generator.

In yet another embodiment, the transmission includes a traction drive.
According to this configuration, rotational vibration can be reduced by using a traction drive characterized by smooth rotation.

In yet another embodiment, the transmission includes a plurality of traction drives.
According to this configuration, by using a plurality of traction drives, the rotational speed of the hollow shaft can be greatly increased or decreased and transmitted to the power generator.

  In yet another embodiment, the hydroelectric generator includes a first sealing member that seals the upstream end of the hollow shaft in a range wider than the outer diameter of the upstream end of the hollow shaft, and a downstream of the hollow shaft. And a second sealing member that seals the downstream end of the hollow shaft within a range narrower than the outer diameter of the side end.

  According to this configuration, the hollow shaft is covered with the first sealing member at the upstream end portion, and the second sealing member is covered with the hollow shaft at the downstream end portion, so that water hardly enters the hollow shaft. it can.

  In yet another embodiment, the hydroelectric generator is fixed between the fixed shaft and the hollow shaft at the upstream end of the hollow shaft, and the fixed shaft that is fixed so as not to rotate and penetrates the hollow shaft in the axial direction. And a bearing with a contact seal provided between the fixed shaft and the hollow shaft at the downstream end of the hollow shaft.

  According to this configuration, the oil seal can prevent water from entering the vicinity of the generator and the transmission member at the upstream end near the generator and the transmission member. At the downstream end far from the generator and the transmission member, the friction resistance can be reduced by reducing the waterproofness while preventing a certain amount of water from entering by the bearing with the contact seal.

  In yet another embodiment, the hydroelectric generator further includes a frame member that is provided upstream of the hollow shaft and that has a water intake port only at a site below the axial center of the hollow shaft.

  According to this configuration, the amount of water toward the lower spiral wing can be made larger than the amount of water toward the upper spiral wing. Therefore, it is possible to reduce the rotational resistance due to water toward the upper spiral blade. Therefore, the power generation efficiency of the hydroelectric power generation device can be improved.

  In yet another embodiment, the hydroelectric generator further includes a cylindrical wall portion provided on the outer side in the radial direction than the spiral blade.

  According to this configuration, intrusion of water from the outside in the radial direction can be prevented by the cylindrical wall portion. Therefore, it is possible to suppress an increase in the rotational resistance of the water turbine composed of the spiral blade and the hollow shaft. Therefore, the power generation efficiency of the hydroelectric generator can be improved.

In yet another embodiment, the wall is formed integrally with the helical wing.
According to this configuration, it is possible to prevent a gap from being generated between the spiral blade and the wall portion. Therefore, the outflow of water can be prevented. Therefore, it is possible to suppress a decrease in the amount of water used to rotate the water wheel composed of the spiral blade and the hollow shaft. Therefore, the power generation efficiency of the hydroelectric generator can be improved.

  In yet another embodiment, the hydroelectric generator further includes a downstream frame member provided with a drain outlet having an area equal to or larger than the area of the water intake.

  According to this configuration, since the area of the drain port is equal to or larger than the area of the water intake port, the water flowing toward the spiral blade can flow downstream without staying around the spiral blade. For this reason, it is possible to suppress an increase in rotational resistance of the water turbine constituted by the spiral blade and the hollow shaft. Therefore, the power generation efficiency of the hydroelectric generator can be improved.

In yet another embodiment, the lower end of the water intake is released.
According to this configuration, it is possible to prevent dust and the like from accumulating at the water intake.

  In yet another embodiment, the hydroelectric generator further includes a lid member that seals an end face in the axial direction of the hollow shaft, and an O-ring provided between the end face and the lid member.

  According to this configuration, the O-ring for preventing water intrusion is provided on the end surface in the axial direction of the hollow member. Therefore, the O-ring can be arranged without moving the O-ring along the outer peripheral surface or the inner peripheral surface of the hollow shaft. Therefore, workability can be improved.

  In yet another embodiment, the hollow shaft and the lid member are connected by a bolt inserted into a screw hole provided in the end face. The screw hole does not penetrate the end of the hollow member in the axial direction, and is provided on the outer side in the radial direction than the O-ring.

  According to this configuration, since the screw hole does not penetrate the end surface of the hollow shaft, water can be prevented from entering from the screw hole.

  In yet another embodiment, the hollow shaft and the lid member are connected by a bolt inserted into a screw hole provided in the end face. The screw hole passes through the end of the hollow member in the axial direction and is provided on the inner side in the radial direction than the O-ring. A seal washer is sandwiched between the lid member and the bolt.

  According to this configuration, even if the end of the hollow member in the axial direction is thin and the screw hole has to penetrate the end, water can enter from the screw hole with the O-ring and the seal washer. Can be prevented.

  In yet another embodiment, the hydroelectric generator further includes a lid member that rotatably supports the hollow shaft at an end surface in the axial direction of the hollow shaft.

  According to this configuration, since the hollow shaft is supported from the outside, it is possible to avoid providing an opening on the end surface of the hollow shaft. Therefore, waterproofness improves.

It is a schematic block diagram of a hydroelectric generator. It is a figure which shows sectional drawing of a helical water wheel. It is a skeleton figure of a transmission. It is a figure which shows the modification 1 of a hydroelectric generator. It is a figure which shows the modification 2 of a hydroelectric generator. It is a figure which shows the hydraulic power unit of the modification 3. It is a figure which shows the upstream side surface of the hydroelectric generator of the modification 3. It is a figure which shows the side surface of the downstream of the hydraulic power unit of the modification 3. It is a figure which shows the spiral water wheel and ridge which were formed integrally. It is FIG. (1) which shows the edge part of the upstream of the hydraulic power unit of the modification 4. It is FIG. (2) which shows the edge part of the upstream of the hydraulic power unit of the modification 4. FIG. 11 is a diagram (No. 3) illustrating an upstream end portion of a hydroelectric generator of Modification Example 4; It is a figure which shows the edge part of the downstream of the hydraulic power unit of the modification 4.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  With reference to FIG. 1, the hydroelectric generator 10 includes a spiral water turbine 12 and a frame 14 surrounding the spiral water turbine. The helical water wheel 12 rotates within the frame 14. The electric power obtained by the rotation of the helical water wheel 12 is transmitted to, for example, the inverter 18 through the conductive wire 16. The inverter 18 rectifies the current and supplies electric power to electrical equipment such as lighting.

  The spiral water wheel 12 is installed in an open water channel having an appropriate inclination of about 20 to 30 degrees. The spiral water turbine 12 is installed so as to be submerged to the axial center. When the water surface is higher than the upper end of the hollow shaft 32, the water surface is resisted because it passes over the shaft. On the other hand, if the water surface is significantly lower than the shaft center, the effective amount of water received by the spiral water turbine 12 is reduced. This is because the amount of power generation cannot be obtained. When the spiral water turbine 12 is installed in a water channel with little inclination, the shaft may be inclined about 20 to 30 degrees with respect to the bottom surface of the frame.

  With reference to FIG. 2, the spiral water turbine 12 will be further described. The helical water wheel 12 includes a fixed shaft 20, a helical blade 30, a hollow shaft 32, a generator 40, and a transmission 50.

  The fixed shaft 20 is fixed to the frame 14 so as not to rotate, and penetrates the hollow shaft 32 in the axial direction. The spiral blade 30 is provided on the outer peripheral surface of the hollow shaft 32. The hollow shaft 32 has a cylindrical outer diameter. The hollow shaft 32 is rotatably supported by the fixed shaft 20 so as to be rotated by a water flow toward the spiral blade 30. Between the fixed shaft 20 and the hollow shaft 32, bearings 34 and 36 are provided at the upstream end portion and the downstream end portion of the hollow shaft 32, respectively. The bearings 34 and 36 are bearings with one-side contact seals as an example. Bearings 34 and 36 are provided so that the seal is on the outside. The type of bearing is not limited to a bearing with a one-side contact seal. Seals may be provided on both sides of the bearing. Other types of bearings may be provided.

  The opening at the upstream end of the hollow shaft 32 is sealed with a lid member 37. Similarly, the opening at the downstream end of the hollow shaft 32 is sealed by the lid member 38.

  The generator 40 is provided inside the hollow shaft 32. The generator 40 includes a rotor 42 rotatably supported on the fixed shaft 20 and connected to the output side of the transmission 50, and a stator 44 fixed to the fixed shaft 20. The generator 40 is an outer rotor type generator. The generator 40 generates power when the rotor 42 rotates. The electric power generated by the generator 40 is supplied to the inverter 18 through the conducting wire 16.

  The transmission 50 is provided between the upstream end of the hollow shaft 32 and the generator 40 inside the hollow shaft 32, and transmits the driving force from the hollow shaft 32 to the rotor 42 of the generator 40. The input side of the transmission 50 is connected to the hollow shaft 32. In the present embodiment, the transmission ratio of the transmission 50 is smaller than 1. That is, the transmission 50 increases the rotational speed of the hollow shaft 32 and transmits it to the generator 40. The gear ratio may be 1 or more. Further, the gear ratio may be changeable. If the gear ratio can be changed, the generator 40 can be driven at the most efficient speed even if the rotational speed of the helical water turbine 12 changes due to, for example, a change in the amount of water.

  In the hydroelectric generator 10 according to the present embodiment, since the generator 40 and the transmission 50 are housed in the hollow shaft 32, the size of the hydroelectric generator 10 is equal to the size of the hollow shaft 32. Can be. In particular, the length of the hydroelectric generator 10 can be made equal to the length of the hollow shaft 32. As a result, the hydroelectric generator 10 can be reduced in size.

  Moreover, since the common fixed shaft 20 is used for the shaft that supports the hollow shaft 32 and the shaft that supports the generator 40, the configuration of the hydroelectric generator 10 can be simplified.

  The transmission 50 will be further described with reference to FIG. The transmission 50 includes a first planetary gear 51 and a second planetary gear 52. The sun gear 51S of the first planetary gear 51 and the sun gear 52S of the second planetary gear 52 are fixed to the fixed shaft 20 so as not to rotate. The carrier 51 </ b> C of the first planetary gear 51 is connected to the hollow shaft 32. The ring gear 51 </ b> R of the first planetary gear 51 is connected to the carrier 52 </ b> C of the second planetary gear 52. The ring gear 52 </ b> R of the second planetary gear 52 is connected to the rotor 42 of the generator 40.

  By providing a plurality of planetary gears, the rotational speed of the hollow shaft 32 can be greatly increased or decreased. Alternatively, the first planetary gear 51 may be provided without providing the second planetary gear 52, and the ring gear 51 </ b> R of the first planetary gear 51 may be connected to the rotor 42 of the generator 40. Also, three or more planetary gears may be connected in the same manner as the configuration shown in FIG.

  By configuring the transmission 50 using planetary gears, the axis of the transmission 50 and the axis of the hollow shaft 32 can be made the same. Therefore, the transmission 50 can be housed in the hollow shaft 32 without increasing the outer diameter of the spiral water wheel 12. Therefore, the hydroelectric generator 10 can be reduced in size.

  Note that the transmission 50 may be configured using a traction drive instead of the planetary gear. In this case, the transmission 50 may be configured by connecting a plurality of traction drives. By using a traction drive characterized by smooth rotation, rotational vibration can be reduced.

[Modification 1]
A first modification will be described with reference to FIG. In the first modification, the lid member 60 that seals the opening at the upstream end of the hollow shaft 32 and the lid member 62 that seals the opening at the downstream end of the hollow shaft 32 are compared with the above-described embodiment. Is different.

  In the first modification, the lid member 60 seals the upstream end of the hollow shaft 32 in a range wider than the outer diameter of the upstream end of the hollow shaft 32. As shown in FIG. 4, the inner diameter of the lid member 60 is the same as or substantially the same as the outer diameter of the hollow shaft 32, and the lid member 60 covers the upstream end of the hollow shaft 32 on its inner circumferential surface. It faces the outer peripheral surface of the hollow shaft 32.

  On the other hand, the lid member 62 seals the downstream end of the hollow shaft 32 in a range narrower than the outer diameter of the downstream end of the hollow shaft 32. As shown in FIG. 4, the outer diameter of the lid member 62 is the same as or substantially the same as the inner diameter of the hollow shaft 32, and the outer peripheral surface of the lid member 62 faces the inner peripheral surface of the hollow shaft 32. That is, the lid member 62 is fitted inside the hollow shaft 32 so that the hollow shaft 32 covers the lid member 62.

  In this way, a gap between the hollow shaft 32 and the lid member 60 and a gap between the hollow shaft 32 and the lid member 62 are formed toward the downstream side of the water flow. In other words, no gap is formed toward the upstream side of the water flow. Therefore, it is possible to make it difficult for water to enter the hollow shaft 32.

[Modification 2]
Modification 2 will be described with reference to FIG. Modification 2 is different from the above-described embodiment in that an oil seal 70 is provided between the fixed shaft 20 and the hollow shaft 32 at the upstream end portion of the hollow shaft 32.

  Although the lid members 60 and 62 are also used in the second modification, the lid members 37 and 38 shown in FIG. 2 may be used instead of the lid members 60 and 62.

  As shown in FIG. 5, the oil seal 70 is provided only at the upstream end of the hollow shaft 32. The oil seal 70 is not provided at the downstream end of the hollow shaft 32, and only the bearing 36 with one-side contact seal is provided.

  According to this configuration, although the frictional resistance is increased at the upstream end near the generator 40 and the transmission 50, the oil seals excellent in waterproofness allow water to enter the vicinity of the generator 40 and the transmission 50. Can be prevented. On the other hand, at the downstream end portion far from the generator 40 and the transmission 50, the friction resistance can be reduced by reducing the waterproofness while preventing the infiltration of water to some extent by the bearing 36 with the contact seal.

[Modification 3]
Referring to FIG. 6, upstream side surface 14 </ b> A of frame 14 may open only a portion below the axis of hollow shaft 32 (spiral water turbine 12). An example of the opening is shown in FIG. This opening serves as a water intake, and water flows toward the spiral water turbine 12. The water flowing in from the intake port moves in the downstream direction while rotating the spiral water wheel 12 by pushing the spiral blade 30 by gravity. This water is generally present below the axial center of the spiral water wheel 12.

  If water is present in the upper half of the spiral water turbine 12, the upper water has a component that pushes the spiral blade 30 in the direction opposite to that of the lower water. Decrease. Therefore, it is not preferable that water flows into the upper half of the spiral water wheel 12. Therefore, the amount of water in the water channel is preferably small to some extent with respect to the size of the spiral water turbine 12 so that water does not flow into the upper half of the spiral water turbine 12. Therefore, a dedicated water channel with a stable amount of water was required.

  However, by opening only the lower half on the side surface 14A on the upstream side of the frame 14, an appropriate amount of water can be guided to the spiral water turbine 12 without providing a dedicated water channel in consideration of the amount of water. For example, an appropriate amount of water can be guided to the spiral water wheel 12 even with a simple water channel made of sandbags or gravel. Therefore, the hydroelectric generator 10 can be operated without reducing the power generation efficiency. In particular, if the generator 40 is provided inside the spiral water turbine 12, it can be installed in an existing waterway and used as an emergency generator during a disaster.

  The water that has reached the lowermost end of the spiral water turbine 12 flows out from an opening as a drain outlet provided on the downstream side of the frame 14. If the opening area on the downstream side is narrower than the opening area on the upstream side, water can be accumulated. Since the accumulated water becomes resistance and may reduce the efficiency of the hydroelectric generator 10, the opening area of the downstream side surface 14B is wider than the opening area of the upstream side surface 14A. In the modified example 3, as shown in FIG. 8, the side surface 14B on the downstream side is opened in the upper half in addition to the lower half. Although not shown in the figure, if there is a structure that obstructs the flow of water under the opening, dust will be caught. Therefore, both the upstream side surface 14A and the downstream side surface 14B may be completely open on the lower side. desirable.

  As described above, the hydroelectric generator 10 may be installed in an existing water channel, but water may be guided using a sandbag or gravel so that the water can easily enter the water turbine. When the hydroelectric generator 10 is installed in an existing water channel, it is difficult to set the water surface to a height suitable for the spiral water turbine 12. However, in the configuration of the modified example 3, since a predetermined amount or more of water does not flow, resistance due to the water flowing into the upper half of the spiral water turbine 12 does not occur.

  In the case of an existing water channel that is not suitable for the spiral turbine 12, water may flow into the turbine from the radial direction of the spiral turbine 12. If installed along the outer periphery, inflow of water from the side can be prevented.

  As shown in FIG. 9, the cylindrical flange 15 on the outer diameter side of the spiral blade 30 may be configured integrally with the spiral blade 30. If the spiral blade 30 and the kite are separate, there must be a gap between the spiral blade 30 and the kite for the spiral blade 30 to rotate. However, part of the water passes through this gap and does not contribute to the rotation of the spiral water wheel 12. Therefore, the efficiency of the hydroelectric generator 10 is reduced.

  Further, when the hydroelectric generator 10 is used in an existing waterway in an emergency, it is not a dedicated waterway, so that removal of dust and gravel becomes insufficient, and dust and gravel can flow into the hydroelectric generator 10. Although the spiral water wheel 12 allows more dust than other types of water turbines, if a foreign object having approximately the same size as the clearance between the spiral blade 30 and the rod enters and the foreign object is caught in the clearance, the rotation of the spiral water wheel 12 can be hindered. .

  However, in the configuration shown in FIG. 9, since the spiral water wheel 12 and the flange 15 are integrated, it is not necessary to provide a gap between the spiral blade 30 and the flange 15. Therefore, the potential energy of the water that flows into the spiral water turbine 12 can be used without waste. Further, since the foreign matter flows downstream along the shape of the spiral blade 30, the rotation of the spiral turbine 12 is not hindered.

  A protruding portion 14 </ b> C that protrudes toward the trough 15 is provided at the edge of the water intake port that is opened in the upstream side surface 14 </ b> A of the frame 14. The protrusion 14C prevents the water flowing in from the water intake from leaking to the outside. It is desirable that the upstream end of the ridge 15 is as large as possible. Therefore, it is desirable not to provide a structure such as a turn toward the inner diameter side at the upstream end of the flange 15.

  As described above, the configuration capable of being installed in the existing waterway is to store the hydroelectric generator 10 in, for example, a disaster storage warehouse, and install the hydroelectric generator 10 temporarily when power supply is insufficient due to a disaster. It is suitable for such a situation. Although it is desirable that the emergency hydroelectric generator 10 can be transported by human power, since it is small in size, a large output cannot be obtained. It is assumed that the electric power obtained here is suitable for charging information terminals such as a minimum illumination and a mobile phone, or is used by charging a 12V lead storage battery. Therefore, it is desirable that the hydroelectric generator 10 includes a 12V DC power output or a power output terminal using USB.

[Modification 4]
Referring to FIG. 10, the end surface on the upstream side in the axial direction of hollow shaft 32 may be sealed with housing (lid) 90A, and O-ring 92 may be provided between the end surface and housing 90A. In the example shown in FIG. 10, the hollow shaft 32 and the housing 90 </ b> A are fixed by a bolt 96 inserted into a screw hole 94 provided on the end surface of the hollow shaft 32. In the example shown in FIG. 10, the screw hole 94 does not penetrate the end of the hollow member in the axial direction, and is provided on the outer side in the radial direction than the O-ring 92.

  Since the spiral water wheel 12 is mainly formed using sheet metal, the tolerance of the diameter is ± 1 mm or more. Therefore, it is difficult to seal the inner diameter surface or outer diameter surface of the spiral water wheel 12 using an O-ring. Further, when the O-ring is used on the inner diameter surface or the outer diameter surface of the spiral water wheel 12, the distance for moving the O-ring in the axial direction when the spiral water wheel 12 is assembled can be increased. As a result, the assemblability deteriorates.

  However, as in the example shown in FIG. 10, by adopting a structure that prevents the intrusion of water from the outer diameter portion of the housing 90 </ b> A by the O-ring 92 at the end surface in the axial direction of the hollow shaft 32, It is only necessary to fit the O-ring 92 into the groove. Therefore, the assembly property of the spiral water wheel 12 can be improved.

In the example shown in FIG. 10, the oil seal 98 prevents water from entering from the outer diameter portion of the bearing provided between the housing 90 </ b> A and the fixed shaft 20 and the outer diameter portion of the fixed shaft 20. Since the oil seal 98 has a structure that prevents leakage from the seal lip side to the dust lip side, in the example shown in FIG. 10, the oil seal 98 is arranged so that the seal lip is outside the dust lip. As in the example shown in FIG. 10, the sealing effect is enhanced by using the oil seal 98 twice and enclosing grease between the oil seals. In addition, the grease improves the lubricity of the lip. Therefore, the torque of the spiral water wheel 12 can be reduced.
When the plate thickness of the end portion of the spiral water wheel 12 is thin, the screw hole 94 may penetrate therethrough. In this case, as shown in FIG. 11, a seal washer 100 may be sandwiched between the seating surfaces of the bolts 96 to prevent water from entering the inside of the hollow shaft 32 from the screw holes 94. In the example shown in FIG. 11, the screw hole 94 is provided on the inner side in the radial direction than the O-ring 92. If the screw hole 94 is on the outer diameter side of the O-ring 92, water can enter from the outer diameter side of the mating surface of the housing 90B and the hollow shaft 32, but the screw hole 94 has an inner diameter of the O-ring 92. By providing it on the side, the intrusion of water can be prevented by the O-ring 92.

  As shown in FIG. 12, the housing 90 </ b> C may be configured so as to rotatably support the hollow shaft 32 at the upstream end in the axial direction of the hollow shaft 32. In this case, the fixed shaft 20 is provided inside the hollow shaft 32. The housing 90C is fixed to the frame 14.

  In the example shown in FIG. 12, a short shaft 102 is formed at the end of the hollow shaft 32. As the shaft 102 is supported by the housing 90C, the spiral water wheel 12 is supported by the housing 90C. In this configuration, the opening can be eliminated in the upstream portion of the spiral water wheel 12. Therefore, it is possible to suitably prevent water from entering the hollow shaft 32. In the example shown in FIG. 12, the number of oil seals 98 provided between the hollow shaft 32 and the housing 90C may be one.

  On the other hand, the downstream end in the axial direction of the hollow shaft 32 is less likely to allow water to enter than the upstream end, so the downstream end has a simpler configuration than the upstream end. Also good. As shown in FIG. 13, the end in the axial direction on the downstream side may be greatly opened as a structure having a flange. In the example shown in FIG. 13, the hollow shaft 32 and the housing 90 </ b> D are fixed at the flange, and waterproofing is given by the O-ring 92. The number of oil seals provided in the bearing portion may be one.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  10 Hydroelectric generator, 12 Spiral turbine, 14 frame, 14A upstream side, 14B downstream side, 14C Projection, 15 mm, 16 conductor, 18 inverter, 20 fixed shaft, 30 spiral blade, 32 hollow shaft, 34, 36 Bearing, 37, 38, 60, 62 Lid member, 40 Generator, 42 Rotor, 44 Stator, 50 Transmission, 51, 52 Planetary gear, 51C, 52C Carrier, 51S, 52S Sun gear, 51R, 52R Ring gear, 70, 98 Oil seal, 90A, 90B, 90C, 90D housing, 92 O-ring, 94 screw hole, 96 bolt, 100 seal washer, 102 shaft.

Claims (19)

A spiral shaft provided on the outer periphery, and rotated by a water flow toward the spiral blade;
A generator provided inside the hollow shaft;
A hydroelectric power generator comprising: a transmission member provided between an upstream end of the hollow shaft and the generator inside the hollow shaft, and transmitting a driving force from the hollow shaft to the generator. A fixed shaft that is fixed so as not to rotate and penetrates the hollow shaft in the axial direction;
The generator is
A rotor coupled to the transmission member;
The hydroelectric generator according to claim 1, comprising a stator fixed to the fixed shaft.   The hydroelectric generator according to claim 1 or 2, wherein the transmission member is a transmission.   The hydraulic power generation device according to claim 3, wherein a transmission gear ratio of the transmission is smaller than one.   The hydroelectric generator according to claim 3 or 4, wherein the transmission includes a planetary gear.   The hydroelectric generator according to claim 5, wherein the transmission includes a plurality of planetary gears.   The hydroelectric generator according to claim 3 or 4, wherein the transmission includes a traction drive.   The hydroelectric generator according to claim 7, wherein the transmission includes a plurality of traction drives. A first sealing member for sealing the upstream end of the hollow shaft in a range wider than the outer diameter of the upstream end of the hollow shaft;
The hydroelectric generator according to claim 1, further comprising a second sealing member that seals the downstream end of the hollow shaft in a range narrower than the outer diameter of the downstream end of the hollow shaft. A fixed shaft fixed in a non-rotatable manner and passing through the hollow shaft in the axial direction;
An oil seal provided between the fixed shaft and the hollow shaft at the upstream end of the hollow shaft;
The hydroelectric generator according to claim 1 or 9, further comprising a contact seal bearing provided between the fixed shaft and the hollow shaft at a downstream end portion of the hollow shaft.   The hydroelectric generator according to claim 1, further comprising a frame member provided upstream of the hollow shaft and having a water intake port only at a portion below the axial center of the hollow shaft.   The hydroelectric generator according to claim 11, further comprising a cylindrical wall provided outside in the radial direction with respect to the spiral blade.   The hydroelectric generator according to claim 12, wherein the wall portion is formed integrally with the spiral blade.   The hydroelectric generator according to any one of claims 11 to 13, further comprising a downstream frame member provided with a drain outlet having an area equal to or larger than the area of the intake port.   The hydroelectric generator according to any one of claims 11 to 14, wherein a lower end of the intake port is released. A lid member for sealing an end face in the axial direction of the hollow shaft;
The hydroelectric generator according to claim 1, further comprising an O-ring provided between the end surface and the lid member. The hollow shaft and the lid member are connected by a bolt inserted into a screw hole provided in the end face,
The hydroelectric generator according to claim 16, wherein the screw hole does not penetrate an end portion in the axial direction of the hollow shaft and is provided on an outer side in a radial direction than the O-ring. The hollow shaft and the lid member are connected by a bolt inserted into a screw hole provided in the end face,
The screw hole passes through an end portion in the axial direction of the hollow shaft, and is provided on the inner side in the radial direction than the O-ring,
The hydroelectric generator according to claim 16, wherein a seal washer is sandwiched between the lid member and the bolt.   The hydroelectric generator according to claim 1, further comprising a lid member that rotatably supports the hollow shaft at an end surface in the axial direction of the hollow shaft.

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