阅读说明：本技术 水力发电装置的水轮机翼安装结构 (Water wheel wing mounting structure of hydroelectric generation device ) 是由 后藤知美 近藤博光 于 2019-08-19 设计创作，主要内容包括：水力发电装置(H)包括通过纤维强化塑料材料构成的水轮机翼(1)、以及接收水轮机翼(1)的旋转而进行发电的发电机(3)。水轮机轴(20)穿过水轮机翼(1)的贯通孔(50)。在水轮机翼(1)的贯通孔(50)的外周部(10)的两侧面设置有一对凸缘部件(51、52)。通过穿过螺栓孔(10a、51、52)的螺栓(53),将水轮机翼(1)和凸缘部件(51、52)紧固。凸缘部件(51、52)安装在水轮机轴(20)上。在水轮机翼(1)的螺栓孔(10a)的内周面与螺栓(53)的外周面之间,夹设有防止磨损部件(55)。(The hydroelectric power generation device (H) comprises a water turbine wing (1) made of fiber reinforced plastic material and a power generator (3) which receives the rotation of the water turbine wing (1) and generates power. The turbine shaft (20) passes through the through-hole (50) of the turbine wing (1). A pair of flange members (51, 52) are provided on both side surfaces of an outer peripheral portion (10) of a through hole (50) of a water turbine wing (1). The turbine wing (1) and the flange members (51, 52) are fastened by bolts (53) passing through the bolt holes (10a, 51, 52). The flange members (51, 52) are mounted on the water turbine shaft (20). An anti-wear member (55) is interposed between the inner peripheral surface of the bolt hole (10a) of the water turbine wing (1) and the outer peripheral surface of the bolt (53).)

1. A water wheel wing mounting structure of a hydroelectric power generating apparatus comprising a water wheel wing formed of a fiber-reinforced plastic material and a generator for generating power by receiving the rotation of the water wheel wing, wherein the water wheel wing is mounted on a water wheel shaft in an integrally rotating manner,

the turbine wing has a through hole in a center portion thereof through which the turbine shaft passes;

a pair of flange members are disposed on both side surfaces of an outer peripheral portion of the through hole of the turbine blade, and a bolt is inserted through bolt holes provided in the turbine blade and the pair of flange members to fasten the turbine blade and the pair of flange members together;

the pair of flange members are mounted on the water turbine shaft;

an anti-wear member is interposed between an inner circumferential surface of the bolt hole of the turbine wing and an outer circumferential surface of the bolt.

2. The turbine wing attachment structure of a hydroelectric power generation device according to claim 1, wherein the wear prevention member has a cylindrical shape fitted into an inner circumference of the bolt hole of the turbine wing.

3. The turbine wing installation structure of a hydroelectric power generation device according to claim 1 or 2, wherein the wear prevention member is formed of a resin material or a metal material.

4. The turbine wing installation structure of a hydroelectric power generation device as claimed in claim 3, wherein the wear prevention member is made of any one of thermosetting resins of unsaturated polyester, vinyl ester, and epoxy resin.

5. The turbine wing installation structure of a hydroelectric power generation device according to claim 3, wherein the wear preventing member is formed of the same kind of metal as the bolt.

6. The turbine wing installation structure of a hydroelectric power generation device according to claim 3, wherein the wear prevention member is formed of a different kind of metal from the bolt, and at least one of the wear prevention member and the bolt is subjected to corrosion resistance treatment.

7. The turbine wing installation structure of a hydroelectric power generation device according to any one of claims 1 to 6, wherein the wear prevention member is fixed to an inner peripheral surface of the bolt hole of the turbine wing by an adhesive.

8. The turbine wing installation structure of a hydroelectric power generation device as claimed in any one of claims 1 to 7, wherein the screw portion of the bolt is located axially outward of the turbine wing.

9. The turbine wing installation structure of a hydroelectric power generation device according to claim 1, wherein the wear prevention member is a resin material formed on an outer circumferential surface of the bolt by coating.

10. The turbine wing mounting structure of a hydroelectric power generating apparatus as claimed in claim 9, wherein said resin material is any one of thermosetting resins selected from unsaturated polyester, vinyl ester and epoxy resin.

11. The structure for mounting a water turbine blade of a hydroelectric power generating apparatus according to any one of claims 1 to 10, wherein the water turbine blade is a propeller turbine having a plurality of blades.

12. The structure for mounting a water turbine wing in a hydraulic power plant according to claim 11, wherein the axis of rotation is parallel to the direction of water flow in the water turbine wing as the propeller turbine.

Technical Field

The present invention relates to a water turbine wing mounting structure of a hydroelectric power generating apparatus, the water turbine wing having a water turbine wing made of a fiber-reinforced plastic material, the water turbine wing being disposed in a waterway and generating power by an impact force of water.

Background

The hydroelectric power generation device is provided with a water wheel wing for converting the energy of water into rotational energy and a generator for converting the rotational energy into electric energy. Further, a speed increaser for increasing the speed of rotation of the water turbine wing and transmitting the rotation to the generator, a control device for controlling the generator, and the like are provided as necessary.

When a fiber-reinforced plastic material is used for a water turbine wing of a small hydroelectric power generation device and the wing is mounted on a water turbine shaft as an input shaft of a speed increaser, first, both side surfaces of a central portion of the water turbine wing are sandwiched by a pair of flange members, and the pair of flange members and the central portion of the water turbine wing are fastened and fixed by bolts. The assembly of the turbine airfoil and the pair of flange members is mounted on the turbine shaft so as to be immovable and unrotatable in the axial direction at the flange member portion. When the turbine wing is rotated by the force of water, its rotational torque is transmitted to the flange member by the abrasion force, and the turbine shaft is rotated.

Patent document 1 relates to a vertical shaft type hydroelectric power generation device, and describes a technique for fixing a vertical rotating shaft and 3 blades by fastening with bolts and nuts.

Patent document

Patent document 1: JP patent publication No. 2017-8927

Disclosure of Invention

Problems to be solved by the invention

In a hydroelectric power generation apparatus installed in a waterway, a turbine wing receives a fluctuating load from water. For example, a water turbine wing is a propeller turbine whose rotation axis is parallel to the water flow direction, and when the upper portion of the water turbine wing exceeds the water surface, the blades of the water turbine wing are repeatedly in a state of being submerged in the water and in a state of being discharged from the water. Thereby, the load to which the blade is subjected varies greatly. When the water turbine wing receives such a load varying in the thrust direction, the bolts fastening the pair of flange members and the water turbine wing contact the inner peripheral surface of the bolt holes in the center portion of the water turbine wing due to the load variation, and the surface layer portions of the inner peripheral surface of the bolt holes are worn. Water soaks from the worn portion into the interior of the turbine airfoil.

Resin materials of fiber-reinforced plastic materials, such as vinyl ester resins, have excellent water resistance as compared with unsaturated polyester resins, and are less likely to deteriorate in strength even when they come into contact with water. On the other hand, the fiber material of the fiber reinforced plastic material is deteriorated in strength due to contact with water. Since the outer skin of the water turbine wing is a resin material, the strength reduction is not promoted even in the case of contact with water, but the strength reduction of the water turbine wing is caused by contact of the fiber material with water from the abraded portion.

The present invention provides a mounting structure for a water turbine blade of a hydroelectric power generation device, which can prevent a bolt from contacting and wearing an inner peripheral surface portion of a bolt hole at a center portion of the water turbine blade due to load fluctuation when the water turbine blade is made of a fiber-reinforced plastic material, and prevent the strength of the water turbine blade from being reduced due to water permeation from the worn portion into the fiber-reinforced plastic material.

Means for solving the problems

The invention provides a water turbine wing mounting structure of a hydraulic power generating apparatus including a water turbine wing formed of a fiber-reinforced plastic material and a generator for generating power by receiving rotation of the water turbine wing, wherein the water turbine wing is mounted on a water turbine shaft in an integrally rotating manner,

the turbine wing has a through hole in a center portion thereof through which the turbine shaft passes;

a pair of flange members are disposed on both side surfaces of an outer peripheral portion of the through hole of the turbine blade, and a bolt is inserted through bolt holes provided in the turbine blade and the pair of flange members to fasten the turbine blade and the pair of flange members together;

the pair of flange members are mounted on the water turbine shaft;

an anti-wear member is interposed between an inner circumferential surface of the bolt hole of the turbine wing and an outer circumferential surface of the bolt.

According to this configuration, the bolt does not contact the inner peripheral surface of the bolt hole by interposing the anti-abrasion member between the inner peripheral surface of the bolt hole of the turbine wing and the outer peripheral surface of the bolt. Therefore, even when the water turbine blade generates a fluctuating load in the thrust direction received from water, the inner peripheral surface portion of the bolt hole is hardly worn, and the penetration of water into the fiber-reinforced plastic material of the water turbine blade is suppressed. Thereby, the strength reduction caused by the material deterioration of the water turbine wing can be prevented.

The wear prevention member may be formed in a cylindrical shape fitted into an inner circumference of the bolt hole of the turbine wing. If the wear prevention member is cylindrical, not only the wear prevention member itself but also the bolt hole can be easily processed. Therefore, the strength of the water wheel wing can be prevented from being reduced at lower cost.

The wear prevention member may be made of a resin material or a metal material. Both the resin material and the metal material are easily processed.

When the wear prevention member is made of a resin material, any thermosetting resin of unsaturated polyester, vinyl ester, and epoxy resin is suitably used as the kind of the resin material.

In the case where the wear prevention member is made of a metal material, the wear prevention member may be made of the same kind of metal as the bolt, or the wear prevention member may be made of a different kind of metal from the bolt, and at least either one of the wear prevention member and the bolt may be subjected to corrosion resistance treatment. In the case where both the bolt and the wear prevention member are made of metal materials, if the two metal materials are different in kind, electric corrosion is easily caused between the two metal materials in water. By making the two metal materials the same kind of metal, the above-mentioned galvanic corrosion can be avoided. In addition, even when the two kinds of metal materials are different metals, the above-mentioned galvanic corrosion can be avoided by subjecting at least either one of them to a corrosion-resistant treatment.

The wear prevention member is fixed to an inner circumferential surface of the bolt hole of the turbine wing by an adhesive. In particular, when the wear prevention member is made of a metal material, the wear prevention member has a hardness higher than that of the water turbine blade made of a fiber-reinforced plastic material, and therefore, the wear prevention member may move relative to the bolt hole to cause wear of the inner peripheral surface portion of the bolt hole. By fixing the wear prevention member to the inner peripheral surface of the bolt hole with an adhesive, the wear prevention member does not move, thereby preventing wear of the surface layer of the inner peripheral surface of the bolt hole.

The screw portion of the bolt may be located axially outward of the turbine wing. Thus, the screw portion of the bolt is not in contact with the wear prevention member, and wear of the wear prevention member is reduced.

The wear prevention member may be a resin material formed on the outer circumferential surface of the bolt by coating. In the case where the bolt and the wear prevention member are formed separately, there are two sliding portions, i.e., a contact surface between the bolt and the wear prevention member and a contact surface between the wear prevention member and the inner circumferential surface of the bolt hole. In contrast, if the bolt and the wear prevention member are integrated, only the contact surface between the wear prevention member and the inner circumferential surface of the bolt hole becomes a sliding portion. Therefore, abrasion can be further prevented. Further, the wear prevention member formed on the outer peripheral surface of the bolt by coating can be made thinner than a wear prevention member separate from the bolt. Thereby, the inner diameter of the bolt hole can be reduced. Further, the wear prevention member is formed by coating the outer peripheral surface of the bolt, so that the bolt and the wear prevention member are integrated, and the number of components can be reduced. This improves the assembling workability.

As the above resin material for the coating layer, any of thermosetting resins of unsaturated polyester, vinyl ester and epoxy resin is preferable.

The water wheel wing mounting structure of the hydroelectric generation device is suitable for occasions where the water wheel wing is a propeller water turbine with a plurality of blades. In particular, the water turbine blade as the propeller turbine is suitable for use in a case where the rotation axis is parallel to the water flow direction. In any case, the water turbine wing bears a large variable load, so the water turbine wing mounting structure has a large effect.

Any combination of at least two structures disclosed in the claims and/or in the description and/or in the drawings is comprised in the present invention. In particular, any combination of two or more of each of the claims is encompassed by the present invention.

Drawings

The invention will be more clearly understood from the following description of preferred embodiments with reference to the accompanying drawings. However, the embodiments and drawings are only for illustration and description and are not intended to limit the scope of the present invention. The scope of the invention is determined by the claims. In the drawings, like reference characters designate like or corresponding parts throughout the several views.

Fig. 1 is a front view of a hydroelectric power generation device to which a water wheel wing mounting configuration according to embodiment 1 of the present invention is applied;

FIG. 2 is a side view of the hydro-power generation device;

FIG. 3 is a side view showing the main part of FIG. 2, with a portion shown in section;

FIG. 4 is an enlarged view of section IV of FIG. 3;

fig. 5 is a sectional view showing a water wheel wing mounting structure according to embodiment 2 of the present invention;

FIG. 6 is a view showing a bolt having an abrasion prevention member formed on an outer peripheral surface thereof by coating;

fig. 7 is a sectional view showing a water wheel wing mounting structure according to embodiment 3 of the present invention;

FIG. 8 is a cross-sectional view of the hub and wear prevention components of the water wheel wing in the water wheel wing installed configuration;

fig. 9 is a sectional view showing a mounting structure of a water wheel wing according to embodiment 4 of the present invention;

FIG. 10A is an enlarged view of section XA of FIG. 9;

fig. 10B is an enlarged view of the XB portion of fig. 9.

Detailed Description

[ embodiment 1 ]

< hydroelectric Power Generation >

Fig. 1 and 2 are a front view and a side view of a hydraulic power generation device H to which the water turbine wing mounting structure according to embodiment 1 is applied. The hydroelectric power generating apparatus H is installed in a waterway, generates power by utilizing hydraulic power, and includes a turbine blade 1, a speed-increasing gearbox 2, a generator 3, and a support device 4. The hydro-power generation device H is provided with a control device (not shown) for controlling the generator 3, and the like.

The water turbine wing 1 is a propeller turbine in which a plurality of (for example, 5) blades 11 radially extend from the outer periphery of a cylindrical hub 10. The water turbine wing 1 is disposed such that the rotation axis O thereof is parallel to the water flow direction a of the water path. The tip of each vane 11 is inclined toward the upstream side. The hub 10 and the blades 11 are formed as one body. A rotor 12 is mounted on the front surface of the hub 10 on the upstream side. The hubs 10, blades 11 and spinner 12 are made of fibre reinforced plastic material.

The speed increaser 2 is a device for increasing the speed of rotation of the water turbine wing 1. A turbine shaft 20 as an input shaft of the speed-increasing gearbox 2 protrudes upstream from the speed-increasing gearbox 2. The turbine airfoil 1 is fixed to the turbine shaft 20 in an integrally rotating manner.

As shown in fig. 3, the speed increasing mechanism 21 of the speed-increasing gear 2 is composed of a pair of bevel gears 22, 23 that mesh with each other. The input-side bevel gear 22 is mounted on the water turbine shaft 20. The output-side bevel gear 23 is mounted on a rotary drive shaft 24 extending in the vertical direction. The rotation transmission shaft 24 is a shaft that transmits the rotational force increased in speed by the speed-increasing gearbox 21 to the generator 3. The rotary drive shaft 24 is arranged inside the pillar 25. As shown in fig. 2, the upper end of the strut 25 is fixed to the support device 4, and the speed-increasing gear 2 is supported by the lower end of the strut 25.

In fig. 2, the generator 3 has a downwardly extending generator system 30. The generator shaft 30 is connected to the rotary transmission shaft 24 via a rotary joint 31. Thus, the rotation of the turbine blade 1 is increased in speed by the speed-increasing gearbox 2 and transmitted to the generator 3, and the generator 3 generates power. The generator 3 is, for example, a three-phase ac generator.

As shown in fig. 1 and 2, the support device 4 includes: two beams 40 extending between the side walls 5 on both sides of the water channel, a rack 41 placed on the beams 40, two generator brackets 42 provided on the rack 41, and a base plate 43 provided to connect the upper portions of the two generator brackets 42. The generator 3 is disposed between the mount 41 and the substrate 43 and fixed to the substrate 43.

< waterwheel wing installation Structure >

The structure of the turbine wing 1 attached to the turbine shaft 20 will be described. As shown in fig. 3, the turbine shaft 20 has a large diameter portion 20a protruding upstream from the speed-increasing gearbox 2 (left side in fig. 3), and a small diameter portion 20b extending upstream from the tip of the large diameter portion 20 a. A male screw 20c is formed on the outer peripheral surface of the small diameter portion 20b except for the base end.

The pair of annular flange members 51, 52 are fastened and fixed to the turbine airfoil 1 by bolts 53 on both the upstream side and the downstream side of the hub 10. The hub 10 has a cylindrical shape having a through hole 50 at the center, and the portion other than the through hole 50 is formed in a solid shape. The hub 10 corresponds to the "outer peripheral portion of the through hole in the turbine wing" described above in the claims.

The upstream flange member 51 has an inner diameter smaller than the inner diameter of the through hole 50 of the hub 10, and is fitted into the small diameter portion 20b of the water turbine shaft 20. The downstream flange member 52 has a cylindrical portion 54 whose inner circumferential surface can be fitted into the large diameter portion 20a of the water turbine shaft 20 and whose outer circumferential surface can be fitted into the through hole 50 of the hub 10.

As shown in fig. 4, bolt holes 10a, 51a, and 52a are provided in the hub 10 and the pair of flange members 51 and 52 of the water turbine wing 1, respectively. The bolt 53 is inserted through the bolt holes 10a, 51a, and 52 a. In this embodiment, the bolt holes 52a of the downstream flange member 52 are screw holes, and the turbine wing 1 and the pair of flange members 51, 52 are fastened by screwing the screw portions 53a of the bolts 53 inserted into the bolt holes 51a, 10a from the upstream side into the bolt holes 52a as the screw holes. The bolt holes 52a of the downstream flange member 52 are not screw holes, and nuts (not shown) are screwed into the screw portions 53a of the bolts 53 penetrating the bolt holes 52a to fasten the turbine airfoil 1 and the pair of flange members 51, 52.

The inner diameters of the bolt holes 10a of the hub 10 of the water turbine wing 1 are larger than the inner diameters of the bolt holes 51a and 52a of the flange members 51 and 52, and a wear prevention member 55 is interposed between the inner circumferential surface of the bolt hole 10a of the hub 10 and the outer circumferential surface of the bolt 53. The wear prevention member 55 of the present embodiment is cylindrical and fitted into the inner periphery of the bolt hole 10 a. Considering creep deformation of the fiber reinforced plastic material of the hub 10 due to the screwing of the bolts 53, when the wear prevention member 55 is made of a metal material, the axial dimension is slightly shorter than the axial dimension of the hub 10. When the wear prevention member 55 is made of a resin material, the axial dimension may be the same as the axial dimension of the hub 10.

The material of the wear prevention member 55 may be a resin material or a metal material. Is easy to process. When the wear prevention member 55 is made of a resin material, any of thermosetting resins such as unsaturated polyester, vinyl ester, and epoxy resin is preferable. When the wear prevention member 55 is made of a metal material, the wear prevention member 55 is preferably made of the same metal as the bolt 53 made of a metal material. In the case of dissimilar metals, galvanic corrosion can be avoided by surface-treating either or both of the metal materials.

As shown in fig. 3, the water turbine blade 1 is assembled with the pair of flange members 51 and 52 and is attached to the water turbine shaft 20 with the water turbine shaft 20 inserted through the through hole 50 of the hub 10. Specifically, the upstream flange member 51 is fitted to the base end of the small diameter portion 20b of the water turbine shaft 20, and the downstream flange member 52 has the cylindrical portion 54 fitted to the large diameter portion 20a of the water turbine shaft 20. Then, the upstream flange member 51 is brought into contact with the stepped surfaces 20d of the large diameter portion 20a and the small diameter portion 20b, and the upstream flange member 51 is attached to the water turbine shaft 20 so as not to be movable in the axial direction by a nut 56 screwed to the male screw 20c of the small diameter portion 20 b. Further, the key 57 is engaged with the key groove provided in the large diameter portion 20a of the turbine shaft 20 and the cylindrical portion 54 of the downstream flange member 52, whereby the downstream flange member 52 is non-rotatably attached to the turbine shaft 20.

< Effect of Water turbine wing mounting Structure >

In this way, by interposing the wear prevention member 55 between the inner peripheral surface of the bolt hole 10a of the hub 10 of the water turbine wing 1 and the outer peripheral surface of the bolt 53, the bolt 53 does not contact the inner peripheral surface of the bolt hole 10 a. Therefore, even when the water turbine wing 1 generates a fluctuating load in the thrust direction received from water, the wear of the inner peripheral surface portion of the bolt hole 10a can be prevented. As a result, the penetration of water into the interior of the fiber reinforced plastic material, which is the material of the water turbine wing 1, can be suppressed, and the strength reduction due to the deterioration of the material of the water turbine wing 1 can be prevented.

Further, since the wear prevention member 55 is cylindrical, not only the wear prevention member 55 itself but also the bolt hole 10a can be easily processed. Therefore, the strength of the water wheel wing 1 can be prevented from being reduced at low cost.

In particular, when the wear prevention member 55 is made of a metal material, the wear prevention member 55 has a higher hardness than the fiber-reinforced plastic material of the water turbine blade 1, and therefore, the wear prevention member 55 moves relative to the bolt hole 10a, and there is a possibility that the inner peripheral surface portion of the bolt hole 10a is worn. To prevent this, the wear prevention member 55 may be fixed to the inner circumferential surface of the bolt hole 10a with an adhesive so that the wear prevention member 55 does not move.

In addition, in water, galvanic corrosion easily occurs between two different metals. Therefore, when the wear prevention member 55 is made of a metal material, it is preferable that the wear prevention member 55 is made of the same metal material (for example, SUS304) as the bolt 53 in order to avoid galvanic corrosion with the bolt 53.

As in the present embodiment, if the axial dimension of the wear prevention member 55 is made slightly shorter than the axial dimension of the hub 10, when the variable load is applied to the water turbine blade 1 and pressure is applied to the center portion of the water turbine blade 1 from the pair of flange members 51 and 52, the wear prevention member 55 receives the pressure, and the hub 10 can be prevented from receiving a large pressure. This prevents creep deformation of the hub 10. By preventing creep deformation of the hub 10, loosening of the bolts 53 can be prevented, and a reduction in the fastening force between the hub 10 and the flange members 51, 52 can be avoided.

Further, since the fastening force of the hub 10 and the flange members 51, 52 is ensured, even when an alternating load is applied to the turbine wing 1, a gap is not generated between the hub 10 and the flange members 51, 52 or the gap is closed, and fretting wear is not caused at the contact surfaces of the hub 10 and the flange members 51, 52. Therefore, water is prevented from penetrating from the end face of the hub 10 into the fiber-reinforced plastic material, and the strength of the water turbine wing 1 is prevented from being reduced due to the deterioration of the material of the fiber-reinforced plastic material.

[ 2 nd embodiment ]

Fig. 5 shows a 2 nd embodiment of the water wheel wing mounting structure. In this turbine wing attachment structure, a recess 58 having a circular cross section and extending outward from the bolt hole 52a is provided on the inner surface of the flange member 52 on the downstream side in the axial direction, and the upstream end of the wear member 55 is prevented from fitting into the recess 58. The threaded portion 53a of the bolt 53 is screwed into the bolt hole 52a as a threaded hole. The base end position P of the threaded portion 53a is located within the axial range of the recess 58 or the bolt hole 52 a. That is, the threaded portion 53a of the bolt 53 is located axially outward of the turbine wing 1. Thus, unlike the above-described embodiment (see fig. 4), a part of the threaded portion 53 of the bolt 53 does not contact the wear prevention member 55, and wear of the wear prevention member 55 is reduced.

< other examples of wear prevention Member >

Fig. 6 shows a wear prevention member integrated bolt 59 in which a wear prevention member 55 is formed on the outer peripheral surface of the bolt 53 by coating. As the resin material for the coating layer, any of thermosetting resins of unsaturated polyester, vinyl ester, and epoxy resin is suitably used.

When the bolt 53 and the wear prevention member 55 are separate bodies (see fig. 4), two sliding portions are provided, namely, a contact surface between the bolt 53 and the wear prevention member 55 and a contact surface between the wear prevention member 55 and the inner peripheral surface of the bolt hole 10 a. In contrast, like the wear member preventing integrated bolt 59 of fig. 6, if the bolt 53 and the wear member 55 are integrated, only the contact surface between the wear member 55 and the inner peripheral surface of the bolt hole 10a is a sliding portion. Therefore, wear can be more effectively prevented.

The wear prevention member 55 formed on the outer peripheral surface of the bolt 53 by coating can be made thinner than the wear prevention member 55 that is separate from the bolt 53. Thereby, the inner diameter of the bolt hole 10a can be reduced.

Further, the wear prevention member 55 is formed on the outer peripheral surface of the bolt 53 by coating, and the bolt 53 and the wear prevention member 55 are integrated, whereby the number of components can be reduced. This improves the assembling workability.

[ embodiment 3 ]

In embodiment 3 shown in fig. 7, bolts 53 for fixing the hub 10 and the flange members 51 and 52 are inserted through the bolt holes 10a, 51a, and 52a, as in the above-described embodiments. Further, an anti-wear member 55 is interposed between the inner circumferential surface of the bolt hole 10a of the hub 10 and the outer circumferential surface of the bolt 53.

As shown in fig. 8, when the wear prevention member 55 is made of a metal material, the length is slightly shorter than the axial width of the hub 10. Specifically, the length of the wear prevention member 55 is determined as follows. That is, when the length of the wear prevention member 55 is L and the axial width of the hub 10 is L,

l ═ L-dl (formula 1)

The relationship of (1) holds. Here, dl represents the displacement amount of the upper limit of elastic deformation of the hub 10. In fig. 8, dl is shown in an exaggerated manner, but the actual dl is so small that it is difficult to visually recognize it.

In this way, if the length l of the wear prevention member 55 is a length that satisfies expression 1, the hub 10 is deformed to the upper limit of the elastic deformation in the state where the bolts 53 are fastened. Therefore, fastening of the bolt 53 becomes firm, and the bolt 53 becomes more difficult to loosen.

When the wear prevention member 55 is fixed by an adhesive, as shown in fig. 8, the wear prevention member 55 can be fixed so as to be positioned at the center of the bolt hole 10 a. In this case, the elastic deformation of the hub 10 due to the fastening of the bolts 53 is preferably performed equally on both sides in the axial direction.

[ 4 th embodiment ]

In the 4 th embodiment shown in fig. 9, the axial widths of the pair of flange members 51 and 52 fastened to the hub 10 of the water turbine wing 1 are the same as each other, and the contact areas with the hub 10 are the same as each other. As shown in fig. 10A and 10B, chamfered portions 61 and 62 having an arc-shaped cross section are provided on the edges of the contact surfaces of the flange members 51 and 52 with the hub 10. The chamfered portions 61 and 62 may have other cross-sectional shapes. For example, the shape may be a curve such as a quadratic curve. In some cases, the shape may be a cut-out straight shape.

As described above, since the axial widths of the pair of flange members 51, 52 are the same and the contact areas with the hub 10 are the same, the magnitudes of the pressures received from the flange members 51, 52 on both sides of the hub 10 can be made substantially the same, and therefore, uniform abrasion force acts between the hub 10 and the flange members 51, 52, and the balance is good. Further, if the chamfered portions 61 and 62 are provided at the edges of the contact surfaces of the flange members 51 and 52 with the hub 10, the edge load can be reduced and the occurrence of wear can be prevented.

The above embodiments show the mounting structure of the water turbine blade applied to the hydraulic power generator H in which the water turbine blade 1 is a propeller turbine and the rotation axis O is parallel to the water flow direction, but the present invention is also applicable to the case where the rotation axis O of the water turbine blade 1 is not parallel to the water flow direction. In addition, the present invention is also applicable to a hydroelectric power generation system in which the turbine blade 1 is not a propeller turbine.

The embodiments for carrying out the present invention have been described above based on examples, but the embodiments disclosed herein are illustrative in all respects and are not limited thereto. The scope of the present invention is defined by the claims, not by the above description, and includes all modifications equivalent in meaning and scope to the claims.

Description of reference numerals:

reference numeral 1 denotes a water wheel wing;

reference numeral 3 denotes a generator;

reference numeral 10 denotes a hub (outer peripheral portion of the through hole)

Reference numerals 10a, 51a, 52a denote bolt holes;

reference numeral 11 denotes a blade;

reference numeral 20 denotes a water turbine shaft;

reference numeral 50 denotes a through hole;

reference numerals 51, 52 denote flange members;

reference numeral 53 denotes a bolt;

reference numeral 53a denotes a threaded portion;

reference numeral 55 denotes a wear prevention member;

symbol O represents the rotation axis;

symbol H denotes a hydroelectric power generation device.