JP3963375B2 - Small capacity tubular turbine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a small-capacity tubular turbine, which is called a microtubular turbine having an output capacity of several hundred kW or less, and in particular, a tubular turbine in which the runner vane is movable so that the flow rate can be controlled by the runner vane. Concerning water wheel.
[0002]
[Prior art]
As shown in FIG. 4, a small-capacity tubular turbine called a microtubular turbine is generally small, and therefore, a turbine runner 20 supported by an inner casing 12 in an outer casing 11 that forms a flow path 10. The generator 30 is installed outside the outer casing 11, and the rotation shaft 25 of the water turbine runner 20 and the drive shaft 35 of the generator 30 are connected via a rotation transmission mechanism 40 using a belt or the like. Has been. The water turbine runner 20 is rotated by the water flow supplied from the flow path 10, and this rotational force is transmitted to the generator 30 by the rotation transmission mechanism 40 and is driven to generate electric power (see Patent Document 1).
[0003]
In such a conventional small-capacity tubular water turbine power generator, since the casings 11 and 12 are small, the generator cannot be accommodated in the inner casing 12, and this is installed outside the outer casing 11. Yes.
[0004]
Further, when the flow rate of the water flow supplied from the flow path 10 changes, the runner vane 22 of the water turbine runner 20 is rotated around an axis perpendicular to the rotation shaft 25 according to the change in the flow rate, and the pitch angle thereof is changed. It is well known that if the adjustment is made, the reduction of the efficiency of the water turbine with respect to the flow rate change is suppressed, and the operation with high efficiency is possible in a wide flow rate range.
[0005]
And as an apparatus which drives a runner vane, as shown in patent documents 2 and 3, an electric drive apparatus using an electric motor as a drive source is more suitable for a river or the like than a hydraulic drive apparatus using hydraulic pressure. Since there is no leakage of oil and it is advantageous in protecting the environment, it is increasingly used. However, in a small capacity tubular turbine, it is impossible to incorporate a generator in the inner casing, so it is impossible to incorporate such a runner vane electric drive device.
[0006]
For this reason, in conventional small-capacity tubular turbines, only runner vane fixed type turbines with fixed runner vane pitch angles are used, and when the flow rate necessary for operation cannot be secured, operation must be stopped. There is a disadvantage that the operable flow rate range is narrowly limited.
[0007]
[Patent Document 1]
JP 2002-295395 A (page 3, FIG. 1)
[Patent Document 2]
Japanese Patent Laid-Open No. 2-181075 (second page, FIG. 1)
[Patent Document 3]
Japanese Patent Laid-Open No. 3-206364 (second page, FIG. 1)
[0008]
[Problems to be solved by the invention]
The present invention eliminates the above-mentioned disadvantages and expands the operable flow range of the small-capacity tubular turbine, so that the runner vane in the macro tubular turbine can be moved and driven by an electric drive device. The object is to provide a capacity tubular turbine.
[0009]
[Means for Solving the Problems]
In order to achieve such an object, the first aspect of the invention is an outer casing that forms a flow path, an inner casing that is fixedly accommodated in the outer casing, and is rotatably supported by the inner casing. A motion conversion mechanism for rotating a runner vane into a linear motion in the inner casing, and a shaft for rotating the runner vane so that the pitch angle can be adjusted to a runner boss of the water turbine runner. An operating shaft that is linearly movable in the direction, and an electric motor for driving the runner vane is installed outside the outer casing, and the runner vane can be rotated by the motion conversion mechanism via the operating shaft. The motion conversion mechanism and the runner vane are coupled, and the motion conversion mechanism is driven to rotate by the runner vane driving motor. In small-capacity tubular water wheel formed by coupling the runner vane driving electric motor and the motion converting mechanism via a belt rotation transmission mechanism so as to obtain,
The pulley on the motion conversion mechanism side of the belt-type rotational transmission mechanism includes a belt guide that regulates belt movement, and the pulley on the drive motor side has an axial width on which the belt moves in the axial direction. Characterized by being expanded as possible .
[0010]
The invention of claim 2 is characterized in that, in the invention of claim 1, the belt and pulley of the belt-type rotational transmission mechanism are a toothed belt and a pulley .
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described based on examples shown in the drawings. FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention, and FIG. 2 is an enlarged longitudinal sectional view showing an essential part thereof in a simplified manner.
[0012]
In FIG. 1 and FIG. 2, 10 is a flow path constituted by the outer casing 11 and the inner casing 12, and 20 is an axial flow turbine runner that is rotatably supported by the inner casing 12 in the flow path 10. . The inner casing 12 is fixedly supported by the outer casing 11 via a stay vane 13 and a communication stay 14. Reference numeral 16 denotes a guide vane that rectifies the water flow in the flow path between the outer casing 11 and the inner casing 12. The water turbine runner 20 includes a runner boss 21 and a runner vane 22 that is rotatably supported by the boss 21, and is coupled to a rotary shaft 25 that is rotatably supported by the inner casing 12 via a thrust bearing 28 and the like. . Further, in the runner boss 21, a rotation shaft 23 of the runner vane 22 and an operation shaft 26 inserted so as to be linearly movable in the hollow rotation shaft 25 are connected, and the rotation shaft of the runner vane is moved by linear movement of the operation shaft 26. A link mechanism 24 for rotating 23 is housed.
[0013]
Reference numeral 30 denotes a generator installed outside the outer casing 11. The generator 30 is connected to the rotary shaft 25 of the turbine runner 20 by a rotary transmission mechanism 40 including a pulley 41 and 42 and a transmission belt 43, and is driven to rotate by the turbine runner 20.
Reference numeral 50 denotes a motion conversion mechanism that converts the rotational motion provided at the shaft end opposite to the runner vane attachment end of the rotating shaft 25 of the water turbine runner 20 into linear motion. The motion conversion mechanism 50 is coupled to the shaft end of the operation shaft 26 that passes through the rotation shaft 25 of the water turbine runner 20 and protrudes on the opposite side of the runner boss 21, and on the other hand, the toothed pulleys 71 and 72 and the teeth. It is connected to a runner vane driving motor 60 installed outside the outer casing 11 through a rotation transmission mechanism 70 comprising a timing belt 73 attached thereto. On the outside of the motion conversion mechanism 50, a position detection device 80 including a linear position indicator piece 81 and position sensors 82 and 83 for detecting the position of the support piece 81 is provided.
[0014]
As shown in detail in FIG. 2, the motion conversion mechanism 50 includes a feed screw mechanism 52 supported by a support frame 51 fixed to the inner casing 12, and a screw shaft 53 of the feed screw mechanism 52 is a rotation transmission mechanism. Coupled to 70 toothed pulleys 72. The pulley 72 is rotatably coupled to the operation shaft 26 via a bearing 75 at the shaft end of the operation shaft 26 inserted into the rotation shaft 25 of the hollow water turbine runner.
[0015]
The runner vane driving motor may include a geared motor that has a built-in reduction gear mechanism and can drive a pulley 71 coupled thereto at a relatively low speed. Since such a geared motor can use a small electric motor at high speed, it is optimal as an actuator for driving a runner vane.
In the small-capacity tubular turbine configured as described above, the turbine runner 20 is rotated by the water flow supplied from the flow path 10, and the generator 30 is connected via the rotational transmission mechanism 40 coupled to the rotating shaft 25. To generate electricity. In this case, the runner vane 22 of the water turbine runner 20 can adjust its pitch angle by rotating the rotating shaft 23 in the direction of the arrow R shown in FIG. Even if changes, the turbine runner 20 can be controlled so that the output of the generator 30 becomes the maximum at the flow rate at that time.
[0016]
The runner vanes 22 are controlled as follows.
[0017]
That is, when a change occurs in the amount of supplied water or the generator output, an optimal pitch angle of the runner vane 22 for maintaining the generator output constant is obtained by a control device (not shown), and the positive or negative direction is correspondingly determined. A direction rotation command is given to the drive motor 60. As a result, the drive motor 60 rotates in the direction of the command and rotationally drives the pulley 72 on the motion conversion mechanism side via the pulley 71 and the belt 73. Therefore, the screw shaft 52 of the feed screw mechanism 52 is rotated, and the rotation direction thereof. Accordingly, the screw shaft 52 is fed in the left or right direction by the action of the screw and moves linearly. Thus, the feed screw mechanism 52 operates to convert rotational motion into linear motion. For this reason, the pulley 72 and the operating shaft 26 coupled to the screw shaft 53 are linearly driven in the axial direction, and the tip of the operating shaft 26 moves linearly as indicated by an arrow D in FIG. The pivot shaft 23 is pivoted in the direction of the arrow R via the, and the pitch angle of the runner vanes 22 is varied. The pitch angle of the runner vanes 22 can be detected by detecting the linear displacement amount of the pulley 72 coupled to the operation shaft 26 by the displacement detecting device 80, so that the drive motor 60 is reached when the commanded pitch angle is reached. The rotation command is stopped and the rotation of the driving motor 60 is stopped.
[0018]
As described above, when the rotation of the driving motor 60 is stopped and the force that acts on the operation shaft in the axial direction is lost, a reaction force from the runner vane 22 causes a force to return the operation shaft 26 to the original state. Since the screw of the feed screw mechanism 52 can be prevented from being reversed by using a screw having a reverse rotation-preventing property (self-locking property) such as a trapezoidal screw, the driving force by the driving motor 60 is released. Even so, the runner vanes 22 can be held at the position of the pitch angle.
[0019]
In this embodiment, the pulley 72 on the feed screw mechanism 52 side of the rotation transmission mechanism 70 is provided with a guide piece 74 for guiding the belt 73. The belt guide piece 74 restricts the belt 73 from moving on the pulley in the axial direction. The pulley 71 on the drive motor 60 side of the rotation transmission mechanism 70 is formed so that its axial width is wider than that of the belt 73. This is because when the pulley 72 on the feed screw mechanism 52 side is rotationally driven by the drive motor 60 and moves in the axial direction together with the screw shaft 53, the belt 73 is smoothly moved in the axial direction by the guide piece 74. This is to prevent the belt 73 thus moved from coming off from the pulley 71 side. For this reason, the width in the axial direction of the pulley 71 is usually selected to be a value that is wider than the width of the belt and sufficiently larger than the maximum movement distance of the operation shaft 26.
[0020]
As the motion conversion mechanism in the embodiment, a worm gear mechanism including a worm and a worm wheel can be used in addition to the feed screw mechanism. Also in this case, since there is a self-locking property, it is not necessary to provide a reverse rotation prevention mechanism on the operation shaft, and the configuration can be simplified.
[0021]
【The invention's effect】
The present invention provides a small-capacity tubular turbine having an outer casing forming a flow path, an inner casing fixedly accommodated in the outer casing, and a turbine runner rotatably supported by the inner casing. A runner vane is rotatably attached to the runner boss of the water turbine runner so that the pitch angle can be adjusted, and a motion conversion mechanism that converts rotational motion into linear motion in the inner casing and linearly movable in the axial direction. An operation shaft, and a runner vane driving motor is installed outside the outer casing, and the motion conversion mechanism and the runner vane are connected via the operation shaft so that the runner vane can be rotated by the motion conversion mechanism. The motion conversion mechanism can be rotationally driven by the runner vane driving motor. Since the runner vane drive motor and the motion conversion mechanism are combined via the rotary electric mechanism, the runner vane drive motor can change the pitch angle of the runner vane of the water turbine runner and control the flow rate. As shown by the characteristic line A in FIG. 3, high efficiency of 80% or more can be obtained in a wide flow range from 0.4 to 1.2 of the rated flow rate (1.0), and the operable flow range is expanded. be able to. Incidentally, a tubular turbine with a fixed runner vane can achieve an efficiency of 80% or more only in the flow rate range of 0.8 to 1.2 as shown by the characteristic line B in FIG.
[0030]
In addition, according to the present invention, since the runner vane drive device is an electric drive device, oil does not leak during operation of the water turbine, so that the effect of not affecting the water quality of rivers and the like can be obtained.
[0022]
Furthermore, in the present invention, among the devices for driving the runner vanes, a relatively large driving motor is disposed outside the outer casing, and the inner casing with limited accommodation space is provided with a feed screw mechanism or the like. Since the motion conversion mechanism configured is provided, and the drive motor and the motion conversion mechanism are connected by a rotational transmission mechanism such as a belt, an electric motor is also used for a small-capacity tubular turbine called a microtubular turbine. A runner vane drive can be installed.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a small capacity tubular turbine according to an embodiment of the present invention.
FIG. 2 is a longitudinal sectional view showing an enlarged main part in the embodiment shown in FIG. 1 of the present invention.
FIG. 3 is a diagram showing efficiency characteristics of a small-capacity tubular turbine according to an embodiment of the present invention.
FIG. 4 is a longitudinal sectional view showing a conventional example of a small capacity tubular turbine.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10: Flow path 11: Outer casing 12: Inner casing 20: Turbine runner 21: Runner boss 22: Runner vane 23: Runner vane rotation axis 24: Link mechanism 25: Runner rotation axis 26: Operation axis 30: Generator 40: Generator drive Rotation transmission mechanism 50: Rotation-linear motion conversion mechanism 60: Runner vane drive motor 70: Runner vane drive rotation transmission mechanism

Claims (2)

An outer casing that forms a flow path, an inner casing that is fixedly accommodated in the outer casing, and a turbine runner that is rotatably supported by the inner casing, and a pitch angle of the runner boss of the turbine runner. A runner vane rotatably attached to the inner casing, a motion conversion mechanism for converting a rotary motion into a linear motion, and an operation shaft linearly movable in the axial direction are provided in the inner casing, and An electric motor for driving the runner vane is installed outside the outer casing, and the motion conversion mechanism and the runner vane are coupled via the operation shaft so that the runner vane can be rotated by the motion conversion mechanism. The runner shaft is driven via a belt-type rotational transmission mechanism so that the motion conversion mechanism can be rotated by an electric motor. In small-capacity tubular water wheel formed by coupling the emissions driving electric motor and the motion conversion mechanism,
The pulley on the motion conversion mechanism side of the belt-type rotational transmission mechanism includes a belt guide that regulates belt movement, and the pulley on the drive motor side has an axial width on which the belt moves in the axial direction. A small-capacity tubular turbine characterized by being expanded as possible. 2. The small capacity tubular turbine according to claim 1, wherein the belt and pulley of the belt-type rotational transmission mechanism are a toothed belt and a pulley.

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