JP4948924B2 - Hydroelectric generator - Google Patents

Description

  The present invention relates to a hydroelectric generator installed in the middle of a water pipe through which water flows so as to communicate with the inside of the water pipe, and more particularly to a bearing structure and a cooling system thereof.

  In recent years, small hydropower generation using water and sewage, small rivers, agricultural water, factory effluent and the like has attracted attention as one of new power generation methods. In the first place, hydroelectric power generation is a renewable power generation method that does not emit carbon dioxide gas. In particular, small hydroelectric power generation is expected to be a future power generation method because it does not require a dam.

  At present, it is evaluated that there are about 240,000 kW of unused hydropower resources such as water and sewage capable of generating small-scale power generation of 1000 kW or less and rivers with different elevations in Japan. In addition, the demand for small hydroelectric generators in other countries, such as the non-electrified areas in Southeast Asia, is immeasurable.

  Such a small hydroelectric generator has a structure capable of generating power efficiently even with a low drop and a small flow rate. For example, it is applied to a low drop of about 1 m to 20 m and a flow rate of about 0.06 m 3 / s to 3 m 3 / s. Some devices can obtain power of about 2 kW to 300 kW.

For example, Patent Document 1 discloses an example of a generator that can be applied to a small hydroelectric generator. The small hydroelectric generator is provided in a casing provided so as to communicate with a fluid passage, a stator provided with a stator coil and provided on an outer peripheral portion of the casing, and rotatably provided in the casing. A cylindrical rotor yoke, a rotor magnet provided on the outer periphery of the rotor yoke, and a blade provided inside the rotor yoke and rotated integrally with the rotor yoke by a fluid passing through the inside of the casing. It will be.
Japanese Unexamined Patent Publication No. 5-111216

  However, in the hydroelectric generator as in Patent Document 1, the rotor yoke having blades therein is rotatably supported by a ceramic bearing. However, the thrust component generated in the rotor yoke by the water flow is large. The friction loss in the bearing is large.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a hydraulic power generator that can efficiently counter the thrust force generated by the water flow and has a small friction loss in the bearing.

A hydroelectric generator according to the present invention is a hydroelectric generator installed in the middle of a water pipe through which water flows so as to communicate with the inside of the water pipe, and is rotated by the flow of water in the water pipe. And a propeller blade surrounded by a cylindrical runner, a permanent magnet provided around the runner, rotating integrally with the runner, and a casing coupled to a water pipe, and a stator provided along the permanent magnet, the disposed in the annular space between the runner and said casing, and flowing upstream end of the water and the downstream end of the runner Re rotation allows each it to radial support to, and a water lubricated bearing separate from said casing and said runner, water lubricated bearing for radial support of the downstream end of the runner, also rotatably slide downstream face of the runner Collected by support, the said casing, characterized in that the water supply channel which opens to face the downstream end surface of the water lubricated bearing is formed.

  According to such a configuration, it is possible to efficiently counter the thrust force generated by the water flow, and the friction loss in the bearing is small.

The water-lubricated bearing that radially supports the downstream end of the runner is provided with a through hole that communicates with the water supply path and discharges water toward the downstream side surface of the runner so as to resist thrust force. It may be.

A radial groove for feeding water to the radial bearing surface of the water-lubricated bearing may be formed on the upstream end surface of the water-lubricated bearing that radially supports the downstream end portion of the runner.

A recess facing the opening of the water supply path may be formed on the downstream end surface of the water-lubricated bearing that radially supports the downstream end of the runner.

The propeller blade further includes a stationary guide vane that is provided upstream of the propeller blade and guides the flow direction of water to an angle suitable for the propeller blade, and the propeller blade extends along a center of rotation of the propeller blade. A first boss that rotates integrally with the blade, and the guide vane is formed separately from the first boss in a shape that is continuous with the first boss upstream of the first boss. The first boss and the second boss may be separated from each other. According to such a configuration, since the water in the water pipe is concentrated on the outer peripheral portion of the propeller blade, the propeller blade can be rotated with a smaller water force. Further, since the boss reduces the cross-sectional area of water flow in the water pipe, the flow rate of water can be increased.

Instead of this configuration, a stationary guide vane that is provided upstream of the propeller blade and guides the flow direction of water to an angle suitable for the propeller blade, the guide vane includes the propeller blade. A boss extending along the center of rotation is provided, and the boss has a gap between the inner end of the propeller blade projecting radially inward from the runner and the outer peripheral surface of the boss. it may extend downstream of the propeller blades through toward the center space of the propeller blades downstream. According to such a configuration, since the boss is formed separately from the propeller blade, the propeller blade becomes lighter and the propeller blade can be rotated with a smaller water force. The operation of the boss itself is the same as the above configuration.

The water-lubricated bearing may be lubricated with water in the water pipe , and may be formed by forming a ceramic on the bearing surface of the stainless steel body . According to such a configuration, it is not necessary to separately provide a water supply device for lubrication with water in the water pipe. In addition, foreign matter may be mixed in the water in the water pipe, but since the bearing surface is made of ceramic, even if the foreign matter is caught, it is pulverized and flows together with water, so that maintenance is unnecessary. In addition, if this ceramic part is made detachable, replacement at the time of damage is easy.

The water lubricated bearing may be provided with a shock absorbing member made of O-ring to each of the non-bearing surface of the radial and thrust directions. According to such a configuration, it is possible to reduce the impact of contact with the surrounding wall when the water-lubricated bearing is tilted, such as when the foreign matter is caught.

The supply of water to the downstream end face of the water-lubricated bearing that radially supports the downstream end of the runner may be made through a water supply pipe that extracts water in the water pipe from the upstream side of the propeller blade. According to such a configuration, water can be pumped to the water-lubricated bearing without a pump due to the static pressure difference between the water take-out position and the water supply position.

Another hydroelectric generator according to the present invention is a hydroelectric generator installed in the middle of a water pipe through which water flows so as to communicate with the inside of the water pipe, and is rotated by the flow of water in the water pipe. A propeller blade surrounded by a cylindrical runner, a permanent magnet provided around the runner and rotating integrally with the runner, and a stator provided along the permanent magnet The runner is radially supported by a water-lubricated bearing at the upstream end and downstream end of the water flow, and at least one of the water-lubricated bearings is supplied with water on the downstream side surface. The runner is configured to function as a thrust bearing of the runner, and the supply of water to the downstream end face of the at least one water-lubricated bearing is performed by supplying water in the water pipe from the upstream side of the propeller blade. Is made through the water supply pipe issuing Ri, the water supply pipe extends along the outer periphery of the stator, and is configured to cool the stator. According to this configuration, water used for water lubrication can be used for cooling the stator, and a special cooling system (including its drive system) is not required.

  According to the present invention, it is possible to provide a hydroelectric generator that can efficiently counteract the thrust force generated by the water flow and has a small friction loss in the bearing.

  Hereinafter, a hydraulic power generator according to the present invention will be specifically described with reference to the accompanying drawings.

(First embodiment)
FIG. 1 is a partially broken perspective view showing a configuration of a hydraulic power generator according to a first embodiment of the present invention, FIG. 2 is an exploded perspective view showing a water turbine portion thereof, and FIG. FIG. 4 is a side sectional view showing the internal structure, and FIG. 4 is a longitudinal sectional view showing the structure of the power generation portion.

  The hydroelectric generator 10 according to the present embodiment includes an upstream pipe part 20 that is an upstream part thereof, a downstream pipe part 30 that is a downstream part, and a generator main body part 40 that is disposed between these parts. It consists of three sections.

  The hydroelectric generator 10 is installed in the middle of the water pipe 90 (shown by a broken line in FIG. 3), and has an inner diameter that is the same as that of the water pipe 90. The hydroelectric generator 10 is flange-coupled to the water pipe 90 via an O-ring (not shown). Specifically, the upstream flange 251 provided at the upstream end of the upstream piping portion 20 is coupled to the upstream water pipe 90, and the downstream flange provided at the downstream end of the downstream piping portion 30. At 352, it is coupled to the downstream water pipe 90.

  A cylindrical vane base 21 is fixed to the inner peripheral surface of the upstream pipe portion 20, and a plurality of guide vanes 22 equally distributed in the circumferential direction are fixed to the inner peripheral surface of the vane base 21. Yes. A cylindrical boss 23 is fixed to the inner end of the guide vane 22 at the center position of these guide vanes 22 extending inward in the radial direction. The boss 23 is rounded into a warhead shape on the upstream side of the guide vane 22 to reduce water resistance. The boss 23 also extends to the downstream side of the guide vane 22, and a plurality of propeller blades 41 that are curved in an axial flow type are disposed around the outer periphery of the boss 23 via a predetermined gap (that is, not with the boss 23. It is evenly distributed in the circumferential direction. The boss 23 extends further downstream of the propeller blade 41 and is rounded into a warhead shape to reduce cavitation.

  As is clearer in FIGS. 1 and 2, the guide vane 22 has an axial flow type that is curved in a direction opposite to the inclination of the propeller blade 41, and the water flow is at an appropriate angle to the propeller blade 41. It is designed to guide you to hit.

  The propeller blade 41 is located inside the generator main body portion 40, and its outer periphery is fixed to the inner peripheral surface of the blade base 42a having a cylindrical shape. The blade base 42a is fitted and fixed to a cylindrical runner 42. A runner shoulder 42B is provided on the outer peripheral surface of the runner 42 so as to protrude outward. A permanent magnet 44 is provided in the runner shoulder 42B. It is arranged on the outer peripheral surface side.

  The outer peripheral surface of the runner 42 is covered with a two-part generator casing 40C of the generator main body 40. The generator casing 40C is U-shaped in cross section and has a bobbin shape as a whole, and the front and rear end surfaces thereof are provided with a downstream flange 252 provided at the downstream end of the upstream piping portion 20 and a downstream piping portion 30. Are connected to upstream flanges 351 provided at the upstream end of each.

  In the annular space between the runner shoulder 42B and the downstream flange 252 of the upstream pipe portion 20, an upstream water-lubricated bearing 61 having a substantially rectangular cross section is disposed, and the upstream side of the runner shoulder 42B and the downstream pipe portion 30 A downstream water-lubricated bearing 62 having a substantially rectangular cross section is disposed in the annular space between the flange 351.

  The water-lubricated bearings 61 and 62 support the outer peripheral surface of the runner 42 in a radial manner. In particular, the downstream-side water-lubricated bearing 62 is configured to thrust-support the runner 42 through the downstream side surface of the runner shoulder 42B (details). Will be described later).

  A stator core (laminated iron core) 45 and a stator coil 451 wound around the stator core 45 are disposed on the outer peripheral surface of the permanent magnet 44 via a can 44a, and are fixed to the generator casing 40C. ing. The outer peripheral sides of the stator core 45 and the stator coil 451 are closely covered with a generator cover 46 having a U-shaped cross section.

  With the configuration as described above, the water flowing from the upstream water pipe 90 flows through the upstream pipe portion 20, is guided to the outer peripheral portion of the pipe by the boss 23, and the direction is adjusted by the guide vane 22. The speed is increased along with the propeller blade 41. As a result, the propeller blade 41 rotates efficiently.

  The rotation of the propeller blade 41 causes the runner 42 (blade base 42a) to rotate integrally, and the permanent magnet 44 fixed to the runner 42 is rotated relative to the stator core 45. As a result, a change in the induced magnetic field generated in the stator core 45 induces a voltage in the stator coil 451 to generate power (see also FIG. 4).

  Next, the bearing structure of the hydroelectric generator 10 according to the present embodiment will be described in detail. As is clearer in FIG. 3, a water supply port 301 is formed on the outer peripheral surface of the downstream pipe portion 30. The water supplied to the water supply port 301 passes through the upstream flange 351 and is guided to the downstream end face of the downstream water-lubricated bearing 62 disposed therein.

  A recess 62r is formed on the downstream end surface of the downstream water-lubricated bearing 62 so that the water guided to the downstream end surface can be reliably received and can resist a large thrust force. A hole penetrating to the upstream end surface is formed in the recess 62r, and the received water is sent to the upstream end surface (thrust bearing surface). Thereby, the thrust bearing surface is lubricated with water. Further, a radial groove (shown by a broken line in FIG. 3) is formed on the upstream end surface, whereby water is sent to the inner peripheral surface (radial bearing surface) through the groove, and the radial bearing surface is Water lubricated.

  Further, the water passes through the groove to the downstream end surface of the upstream water-lubricated bearing 61 through a predetermined gap formed between the outer peripheral surface of the runner shoulder 42B and the permanent magnet 44 and the inner peripheral surface of the can 44a. It has come to be given. A groove in the radial direction (shown by a broken line in FIG. 3) is also formed on the downstream side end face, so that water is sent to the inner peripheral surface (radial bearing surface) through the groove, and the radial bearing surface is water-lubricated. Is done.

  The water after being used for the lubrication of the upstream water lubrication bearing 61 is discharged, for example, into the downstream pipe portion 30 through a water channel (not shown).

  The water-lubricated bearings 61 and 62 are made of stainless steel, and as shown in FIG. 3, the bearing surfaces 691 and 692 are made of ceramic. As a result, even if foreign matter is mixed in the water supplied to the water-lubricated bearings 61 and 62, it can be crushed on the bearing surfaces 691 and 692 and flow together with the water, so that the maintenance-free operation can be achieved. Is possible. It should be noted that the bearing surfaces 691 and 692 can be made of ceramic by using a known vapor deposition technique. The entire water-lubricated bearings 61 and 62 can be made of ceramic, and a ceramic block or the like can be fixed to the water-lubricated bearings 61 and 62.

  In addition, when foreign matter is caught in the bearing surfaces 691 and 692, a force that tilts the runner 42 and the propeller blade 41 may act. In order to avoid this, the non-bearing surfaces of the water-lubricated bearings 61 and 62 Shock absorbing members 65 and 66 are disposed at 671 and 672 (see also FIG. 4). In the present embodiment, the shock absorbing members 65 and 66 are shown as O-rings. However, the shock absorbing members 65 and 66 can elastically absorb the falling of the water-lubricated bearings 61 and 62 when a foreign object is caught. For example, another member such as a spring may be used.

  Next, the cooling system of the hydroelectric generator 10 according to the present embodiment will be described in detail. As is clearer in FIG. 3, the cooling system of the hydroelectric generator 10 according to the present embodiment is configured to also function as the water supply system of the water-lubricated bearings 61 and 62 described above. The cooling system takes out water from a water intake 302 formed at the position of the upstream pipe portion 20 upstream of the guide vane 21. The water intake port 302 is provided with a filter 303, and removes foreign matter that can be contained in the water to be removed to some extent. The water taken out through the filter 303 is supplied to the water supply port 301 described above through the water supply pipe 305.

  Thus, the water intake 302 and the water supply port 301 are separated in the axial direction, and due to the action of static pressure between them, no pumping means such as a pump is required, and the downstream side water-lubricated bearing 62 Water pressure sufficient to generate thrust resistance can be supplied. Such an action can also be carried out by direct water supply to the upstream water circulation bearing 61, but can be generated because the downstream water circulation bearing 62 has a larger distance from the water intake 302. The water pressure can also be increased.

  The water supply pipe 305 is also configured to act as a cooling system for the hydroelectric generator 10 according to the present embodiment. As is clearer in FIGS. 5 and 6, the water supply pipe 305 is bifurcated in the middle and is alternately wound around the generator cover 46. As shown in FIGS. 1 and 3, the stator 45 is in close contact with the inner peripheral surface of the generator cover 46, so that the stator 45 efficiently removes heat generated during power generation through the generator cover 46. Can be done.

  The two water supply pipes 305 are further branched into two before reaching the water supply port 301, for a total of four. These four water supply pipes 305 are connected to four water supply ports 301 that are equally distributed in the circumferential direction of the downstream pipe portion 30, and in the circumferential direction with respect to the downstream water circulation bearing 62 (see FIG. 1). Supply uniform water pressure.

(Second Embodiment)
As shown in FIG. 7, in the hydroelectric generator 10B according to the present embodiment, the downstream half 48 of the boss is fixed to the propeller blade 41B so that the propeller blade 41B and the downstream half 48 of the boss rotate together. It is configured. That is, the boss has a structure separated by the upstream half part 23B and the downstream half part 48, and the upstream half part 23B is the guide vane 22 in the same manner as the boss 23 in the first embodiment. It is fixed to.

  The separation position between the upstream half 23B and the downstream half 48 is the downstream end of the guide vane 22 in the present embodiment.

  Even with the configuration of the hydroelectric generator 10B according to the present embodiment, it is possible to achieve substantially the same operation as the hydroelectric generator 10 according to the first embodiment. Reference numerals are assigned and explanations thereof are omitted.

  As described above, the present invention can be applied to a use for providing a hydroelectric generator that can efficiently counter the thrust force generated by the water flow and has a small friction loss in the bearing.

It is a perspective view which shows the structure of the hydroelectric generator which concerns on embodiment of this invention. It is a disassembled perspective view which shows the structure of the flow path inner side part of the hydroelectric generator shown in FIG. It is a longitudinal cross-sectional view which shows the structure of the hydroelectric generator shown in FIG. It is typical sectional drawing which shows the structure of the water turbine shown in FIG. 1, especially a water turbine and a generator part. It is a perspective view which shows especially the structure of the water supply pipe | tube of the hydroelectric generator shown in FIG. FIG. 6 is a perspective view of the water supply pipe shown in FIG. 5. It is a longitudinal cross-sectional view which shows the structure of the hydroelectric generator which concerns on another embodiment of this invention.

10, 10B hydroelectric generator
22 Guide vanes
23 Boss
23B Upstream boss half (first boss)
41 Propeller blade
42 Lanna
42B Lanna Shoulder
44 Permanent magnet
44a can
45 Stator core (laminated iron core)
48 Downstream boss half (second boss)
61, 62 Water lubricated bearing
65, 66 Shock absorbing member (O-ring)
90 water pipe
301 Water supply port
302 Water intake
303 filters
305 water supply pipe
451 stator coil
671,672 Non-bearing surface
691, 692 Bearing surface

Claims (10)

A hydroelectric generator installed in the middle of a water pipe through which water flows so as to communicate with the inside of the water pipe,
A propeller blade configured to rotate by the flow of water in the water pipe and surrounded by a cylindrical runner;
A permanent magnet provided on the outer periphery of the runner and rotating integrally with the runner;
A stator provided integrally with the casing coupled to the water pipe and provided along the permanent magnet ;
Wherein arranged in the annular space between the runner and said casing, flowing upstream end of the water of the runner and a downstream end for radial support to be, respectively it rotating, said casing and said runner comprises a water-lubricated bearings separate,
The water-lubricated bearing that radially supports the downstream end portion of the runner also thrust-supports the downstream side surface of the runner in a rotatable manner, and the casing has a water opening that faces the downstream end surface of the water-lubricated bearing. A hydroelectric generator characterized in that a supply path is formed. The water-lubricated bearing that radially supports the downstream end of the runner is provided with a through hole that communicates with the water supply path and discharges water toward the downstream side surface of the runner so as to resist thrust force. The hydroelectric generator according to claim 1, wherein A radial groove for feeding water to the radial bearing surface of the water-lubricated bearing is formed on the upstream end surface of the water-lubricated bearing that radially supports the downstream end portion of the runner. Item 3. The hydroelectric generator according to item 2. 4. A recess facing the opening of the water supply passage is formed on a downstream end face of a water-lubricated bearing that radially supports a downstream end of the runner. The hydroelectric generator described. A stationary guide vane that is provided upstream of the propeller blade and guides the direction of water flow to an angle suitable for the propeller blade;
The propeller blade includes a first boss that extends along the rotation center thereof and rotates integrally with the propeller blade, and the guide vane is continuous with the first boss upstream of the first boss. 5. The second boss formed separately in such a shape is provided, and the first boss and the second boss are separated from each other . A hydroelectric generator according to any one of the above. A stationary guide vane that is provided upstream of the propeller blade and guides the direction of water flow to an angle suitable for the propeller blade;
The guide vane includes a boss extending along a rotation center of the propeller blade,
The boss faces the central space of the propeller blade downstream with a gap between the inner end of the propeller blade projecting radially inward from the runner and the outer peripheral surface of the boss. 5. The hydraulic power generator according to claim 1, wherein the hydraulic power generator penetrates and extends downstream from the propeller blade. 6. The hydroelectric generator according to any one of claims 1 to 6 , wherein the water-lubricated bearing is lubricated by water in the water pipe, and ceramic is formed on a bearing surface of a stainless steel main body . The hydroelectric generator according to any one of claims 1 to 7 , wherein the water-lubricated bearing includes an impact absorbing member made of an O-ring on each non-bearing surface in the radial direction and the thrust direction . The supply of water to the downstream end face of the water-lubricated bearing that radially supports the downstream end of the runner is performed through a water supply pipe that takes out water in the water pipe from the upstream side of the propeller blade. The hydroelectric generator according to any one of claims 1 to 8 . A hydroelectric generator installed in the middle of a water pipe through which water flows so as to communicate with the inside of the water pipe,
A propeller blade configured to rotate by the flow of water in the water pipe and surrounded by a cylindrical runner;
A permanent magnet provided on the outer periphery of the runner and rotating integrally with the runner;
A stator provided along the permanent magnet,
The runner is radially supported by a water-lubricated bearing so that the upstream end and the downstream end of the water flow are rotatable,
At least one water-lubricated bearing is configured to function as a thrust bearing of the runner by supplying water to the downstream side surface,
The supply of water to the downstream end face of the at least one water-lubricated bearing is made through a water supply pipe that takes out water in the water pipe from the upstream side of the propeller blade,
The water supply pipe extends along the outer periphery of the stator, water power generator characterized in that it is configured to cool the stator.

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