JPH066231Y2 - Once-through turbine - Google Patents

Description

Detailed Description of the Invention A. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a once-through turbine that does not have blade damage due to the inclusion of foreign matter in running water.

B. Outline of the invention A torque limit mechanism is provided between the blade end plate of the once-through turbine and the turbine rotation shaft, and even if foreign matter is caught in the blade and the rotation of the blade stops, the torque limit mechanism slips and the permeability of the turbine rotation shaft is reduced. Allows rotation and prevents the blade from rotating around the turbine axis, preventing damage to the blade.

C. 2. Description of the Related Art A cross-flow turbine, which is a type of once-through turbine, has a very simple structure and is widely used in turbine generators and the like. FIG. 5 shows a cross-sectional view of an example of such a cross flow turbine.
FIG. 6 is a sectional view taken along line AA of the runner portion shown in FIG.

As shown in FIGS. 5 and 6, the cross-flow turbine has an inlet pipe 1 for vertically dropping running water and intake water,
There is a casing 2 connected to the tip of the inlet pipe 1 for adjusting the direction of the flow of water, and an outlet pipe 3 connected to the casing 2 for discharging the water in the casing 2 to form a water channel. Inside the casing 2, a plurality of blades 5 arranged in parallel and annularly for receiving the flow of water whose flow is directed by the casing 2 and both ends of the blades 5 are fixed and fixed to a water wheel rotating shaft 7. A runner 4 including a pair of end plates 8 and 8 is provided. The water wheel rotating shaft 7 of the runner 4 penetrates the wall of the casing 2 and is rotatably supported. A generator or the like (not shown) that uses the rotational force of the runner 4 is connected to one end of the water wheel rotating shaft 7.
Reference numeral 6 is a control valve for adjusting the flow rate with a guide vane.

As shown in FIG. 5 and FIG. 6, in the cross-flow turbine, the water flowing from the inlet pipe 1 is applied to the blades 5 of the runner 4 through the casing 2 and imparts a rotational force to the runner 4, and then passes through the outlet pipe 3. Is released. When foreign matter is present in the water flowing into the water turbine, the blade 5 of the runner 4 collides with the water to decelerate or stop the runner 4, and the blade 5 is damaged by the forced rotation of the water turbine rotating shaft 7.
Therefore, a screen is generally provided on the upstream side to remove foreign matter.

D. Problems to be Solved by the Invention When the cross-flow turbine is relatively small, if the eyes of the screen provided upstream of the inlet pipe 1 for preventing the inflow of foreign matter from the water are made fine, clogging occurs and the flow of water is disturbed. It is not a good idea because it is disadvantageous in terms of energy usage. Therefore, when the eyes of the screen are enlarged, a relatively large foreign substance flows in, the foreign substance is bitten into the blade 5 of the water turbine, and a large impact force is applied to the blade.
It may be deformed or damaged.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to provide a penetrating water turbine in which damage to the blade is automatically prevented even when foreign matter flows in and is caught in the blade of the runner. To do.

E. The structure of the once-through water turbine according to the present invention comprises a plurality of blades 5 arranged in parallel with each other in an annular shape, and a pair of ends in which both ends of these blades are integrally connected. A plate, a water turbine rotating shaft that penetrates these end plates in parallel with the blade and is rotatable relative to the end plate, and a disk provided on the water turbine rotating shaft so as to face the end plate and the end plate. And a torque limit mechanism that presses and supports one of the end plate and the circular plate through the friction plate and presses the other by an elastic member. To do.

F. Action Normally, the rotational force given to the blades by the water flow flowing between the blades is transmitted from the pair of end plates supporting the blades to the turbine rotation shaft via the torque limit mechanism, but foreign matter flows in and bites into the blades. When it is caught, the rotary shaft of the water turbine tries to maintain the rotation due to inertia, and a large torque acts on the torque limit mechanism to cause slippage. As a result, inertial rotation of the water turbine rotating shaft is allowed, rotation of the blade with respect to the water turbine rotating shaft is prevented, and damage to the blade is prevented.

G. Example An example of a cross-flow turbine, which is a type of a once-through turbine, will be described as an example of the once-through turbine according to the present invention. A cross-sectional view of the runner portion of such a cross-flow turbine is shown in FIG. The inlet pipe 1 and casing 2 of the cross flow turbine
The structure of the guide vanes 6 provided on the outlet pipe 3 and the inlet pipe 1 is the same as that shown in FIG.

As shown in FIG. 1, a runner 11 of a cross-flow turbine according to the present invention has a plurality of blades 12 arranged in parallel with each other in an annular shape and a pair of end plates 13, 13 for fixing both ends of each blade 12. And a water wheel rotating shaft 1 parallel to the blade 12 at the center of the end plates 13, 13 of the runner 11.
5 penetrates with a gap. The runner 11 and the water wheel rotating shaft 15 are rotatably supported by bearing devices (not shown). A generator (not shown) or the like is connected to one end of the water wheel rotating shaft 15.

The turbine rotating shaft 15 has a pair of end plates 13 and 13 of the runner 11.
The discs 16 and 16 are fixed so as to face the end plate 13
A plurality of friction plates 17 slidable with respect to the disc 16 are disposed between the disc and the disc 16 on the disc-opposing surface of the end plate 13 at equal intervals in the circumferential direction. These friction plates 17 and 17 are elastically pressed against the discs 16 and 16 with a predetermined surface pressure. The elastic load mechanism of the friction plates 17 and 17 to the discs 16 and 16 is It is configured as follows. That is, one end plate 13 has two holding screw support portions that slidably support the holding screw 19 elastically abutted against the friction plate 17 via the contact plate 18 in a loosely fitted state. A spring 20 is mounted between the holding screw support portions, and a desired pressing force is applied to the holding screw 19 by pressing the spring 20 between the nut 21 screwed to the holding screw 19 and one of the holding screw support portions. ing.

Holding screw 1 elastically supported by one end plate 13
9 presses the friction plate 17 against the disc 16 with a desired surface pressure via the contact plate 18, and the reaction force acting on the end plate 13 elastically supporting the cap screw 19 passes through the other end plate 13. Acting on the other friction plate 17, and the other friction plate 17 is pressed against the other disc 16 with the same surface pressure. In this way, by pressing the friction plates 17, 17 against the circular plates 16, 16 with a predetermined surface pressure, the torque for transmitting the torque of the runner 11 to the rotary shaft of the water turbine within the range of the maximum transmission torque determined by the predetermined surface pressure. It constitutes the limit mechanism. Therefore, the maximum transmission torque of the torque limit mechanism is arbitrarily adjusted by adjusting the screwing position of the nut 21 with respect to the cap screw 19 mounted on the end plate 13. The maximum transmission torque is determined on the condition that the impact force acting on the blade 12 when the foreign matter is caught in the blade 12 does not damage the blade 12.

According to the runner of the cross-flow turbine of the present invention shown in FIG. 1, the runner 11 normally generates a rotational force by the flowing water which hits the blade 12 of the runner 11, and the runner 11 has both end plates 1
It is transmitted to the water turbine rotating shaft 15 via the torque limit mechanism installed in the turbines 3 and 13, and further transmitted to a generator or the like connected to the water turbine rotating shaft 15. However, when foreign matter is mixed in during inflow and is caught by the blade 12 of the runner 11 provided in the casing 2, the foreign matter is caught between the casing 2 and the runner 11, and the runner 11 is suddenly decelerated or stopped. To do. However, the water wheel rotating shaft 15 continues to rotate because it is connected to a generator or the like that rotates with inertia. Therefore, when the runner 11 is fixed to the water wheel rotating shaft 15, the runner 11 tries to rotate due to the inertial rotation of the water wheel rotating shaft 15, so that the blade 12 fixed to the runner 11 and the blade 12 are bitten. The foreign matter causes a large impact force to damage the blade 12. However, in the present invention, the water turbine rotating shaft 15 and the runner 1
Since the torque limit mechanism is interposed between 1 and 1, foreign matter tries to decelerate or stop the runner 11, and the water turbine rotating shaft 15 tries to maintain inertia rotation, so that a large torque difference is generated in the torque limit mechanism. When this torque difference becomes equal to or greater than the maximum transmission torque, slippage occurs on the pressure contact surface between the discs 16 and 16 and the friction plates 17 and 17 of the torque limit mechanism, and the water turbine rotating shaft 15 maintains inertial rotation to rotate the water turbine. The rotation of the runner 11 with respect to the shaft 15 is not forced, and the blade 12 is not damaged.

Next, when the foreign matter that has been caught in the blade 12 of the runner 11 is removed by removing the foreign matter or spontaneously spilling it, between the discs 16 and 16 forming the torque limit mechanism and the friction plates 17 and 17. The torque difference is less than or equal to the maximum transmission torque, and the rotational force of the runner 11 due to the flowing water is transmitted to the water wheel rotating shaft 15 again via the torque limit mechanism.

In the present embodiment described above, the pair of end plates 13, 13 holding the blade 12 and the end plate 1 fixed to the water wheel rotating shaft 15 are provided.
The friction plates 17 and 17 are provided between the discs 16 and 16 provided adjacent to the discs 3 and 13, and the friction plates 17 and 17 are simultaneously provided by the elastic load mechanism provided to the one end plate 13.
A torque limit mechanism is configured so as to be in pressure contact with 16. However, as in the other embodiment shown in FIG. 2, an elastic load mechanism is provided in the end plate space 14 of at least one end plate 13 of the runner 11, and the one disk 16 fixed to the water wheel rotating shaft 15 is provided. The torque limit mechanism may be constructed by sandwiching the pair of friction plates 17, 17 to which the elastic force is applied by the elastic force applying mechanism.

The same reference numerals as those in FIG. 1 in FIG. 2 indicate the same parts.

H. Advantages of the Invention According to the once-through turbine of the present invention, a torque limit mechanism is provided between the end plate fixing the blade and the rotary shaft of the turbine, and foreign matter is mixed into the running water and bites into the blade of the runner to rapidly run the runner. When the rotation of the turbine is about to stop, the torque limit mechanism allows inertial rotation of the turbine rotation shaft, preventing the blade from rotating with respect to the turbine rotation shaft,
It is possible to prevent damage to the blade and the water turbine rotating shaft due to foreign matter. Therefore, a large-sized screen can be used even in a small cross-flow turbine, and the amount of flowing water can be effectively used. Further, the device according to the present invention has a simple structure, and even if it is installed in water, adjustment and maintenance are easy, and it is extremely practical.

[Brief description of drawings]

1 is a sectional view of a runner portion of an embodiment of a once-through turbine according to the present invention, and FIG. 2 is a sectional view of another embodiment of the present invention,
FIG. 3 is a sectional view of a conventional cross flow turbine, and FIG. 4 is a sectional view taken along the line AA in FIG. In the drawing, 11 is a runner, 12 is a blade, 13 is an end plate, 14
Is an end plate space, 15 is a water wheel rotating shaft, 16 is a disc, 17 is a friction plate, 18 is a pad, 19 is a cap screw, 20 is a spring, and 21 is a nut.

Claims (1)

[Scope of utility model registration request] 1. A plurality of blades arranged in parallel with each other in an annular shape, a pair of end plates in which both ends of these blades are integrally connected, respectively, and a pair of end plates which penetrate the end plates in parallel with the blades. In addition, a friction plate is interposed between the water turbine rotating shaft that is relatively rotatable with respect to the end plate, and the end plate and a disk provided on the water wheel rotating shaft facing the end plate. And a torque limit mechanism that presses and supports one of the end plate and the circular plate with an elastic member that presses the other through the through-flow turbine.