JP2510234B2 - Runner blade support device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a runner blade support device for a movable blade straight flow turbine.

[Conventional technology]

The straight-flow turbine is a horizontal-axis turbine that is applied to a point with a low head and large flow of less than about 25 m in head. Fig. 5 is a sectional view showing the straight-flow turbine, and Fig. 6 is Fig. 5. FIG. 6 is a cross-sectional view showing the runner blade support device for the straight flow type water turbine of FIG. In FIG. 5 or FIG. 6, the runner boss 4 has a blade shaft 5 for each of the plurality of runner blades 3.
Are movably supported via a link mechanism 6, and hydraulically drive a servo motor to operate the link mechanism 6.

The rotor is attached to the outer circumference of the runner blade 3 via a rotor retaining ring 9.
2a is attached and a stator 2b is provided facing the rotor 2a. The water turbine shaft 7 is supported by bearings 8 in front of and behind the runner blades 3, and the front side of the water turbine shaft 7 is covered by the valve 1. Water flows in the direction of the arrow, and the water turbine shaft center 13 is used as a rotation center to rotate the water turbine shaft 7. , The runner blade 3 is rotated integrally with the runner boss 4, and the weight of the rotor 2a is the runner blade 3, the runner boss 4,
A load is applied to the bearing 8 via the water wheel shaft 7. There is a slight gap in the radial direction of the runner boss 4 that bears the thrust load at the fitting portion of the blade shaft 5 of the runner boss 4 for rotating these blade shafts 5.

Runner blade 3 with the same model as the straight flow turbine
In the case of a tubular turbine that does not have the rotor 2a on the outer circumference, even if this gap exists, each part inside the runner boss 4 is always pressed to the outer peripheral side due to the centrifugal force acting on the runner blade 3 during the runner rotation. The runner blade 3 does not rattle during rotation because it is in the open state. On the other hand, in the case of a straight flow type water turbine, the weight of the rotor 2a is applied to the runner blades 3, and this load is often larger than the centrifugal force acting on the runner blades 3. Therefore, every time the runner blade 3 makes one revolution, the blade shaft 5 of the runner blade 3 repeatedly moves in and out of the radial gap of the runner boss 4 in the fitting portion of the runner boss 4, and the blade of the water wheel shaft 7 or the runner boss 4 is repeated. The fitting portion of the shaft 5 may be worn or damaged.

[Problems to be Solved by the Invention]

In order to eliminate such a gap in the fitting portion, a cotter-shaped pin 10 is conventionally provided at the center of the water turbine shaft 7, and the shaft end of the blade shaft 5 of the runner blade 3 is provided with a thrust piece 11 to achieve the slope effect of the pin 10. The runner vane 3 is always pressed against the thrust bearing surface of the runner boss 4 by pressing from the inside. This pin 10 springs in the direction parallel to the water wheel shaft 7.
The runner blades 3 are pushed outwardly in the radial direction with respect to the water turbine shaft 7 via the thrust pieces 11 by being pushed by the spring 12 and pushing the pin 10 by the spring 12. However, in general, there is a machining error in the blade shaft 5 of the runner blade 3, the thrust bearing surface of the runner boss 4, the thrust piece 11 and the pin 10 itself. When the pin 10 has a conical shape, the pin 10 and the thrust piece 11 are different from each other. Since there is only one point of contact and not the entire surface, there is a problem in that it is deformed under an excessive load and its function cannot be fully exerted.

According to the present invention, even if there is a processing error in the blade shaft 5 of the runner blade 3, the thrust bearing surface of the runner boss 4, the thrust piece 11 and the pin 10 itself, the pin 10 and the thrust piece 11 pushed by the spring 12 are provided.
Is intended to maintain full contact.

[Means for solving the problem]

In order to solve the above-mentioned problems, the present invention is arranged so as to be movable along the axis of the turbine shaft, has the same center line as the axis of the turbine shaft, and has one end having the same number of side surfaces as the runner blades. A tapered pin shaped like a truncated pyramid, and an abutting surface of an inclined plane that is rotatably fitted to the end of the impeller shaft axis side of each of the blade shafts and that faces the truncated pyramid-shaped side surface of one end of the pin. And a spring attached to the water wheel shaft for moving the pin in the direction of the tapered one end.

[Action]

According to the present invention, a tapered pin having one end formed of a truncated pyramid shape having the same number of side faces as the blade shaft, and a tapered one end of the pin attached to the end of each blade shaft on the axial center of the water turbine shaft. The pins are pressed by the springs so that they are in full contact with each other and press the runner blades in the outer peripheral direction with the contact surfaces of the thrust pieces of the inclined flat surfaces facing the side surfaces of the truncated pyramid shape.

〔Example〕

Hereinafter, description will be given with reference to FIGS. 1 to 4 showing the embodiments of the present invention. FIG. 1 is a detailed sectional view showing a main part of a runner blade supporting device according to an embodiment of the present invention, showing a half above the center line 13, FIG. 2 is a side view showing one end of a pin 10, and FIG. FIG. 4 is a front view of the pin 10 seen from one end, and FIG. 4 is a sectional view taken along line AA of FIG.

In FIG. 1, the pin 10 is arranged so as to be movable along the turbine shaft axis 13 with a clearance fit to the turbine shaft 7.
A truncated pyramid having the same center line 13 as 13 and one left side end portion thereof having the same number of side surfaces 10a (three in this example) as the runner blades 3 as shown in FIGS. It is shaped into a taper. On the other hand, a circular hole 14 is provided at the end of each blade shaft 5 on the side of the water turbine shaft center 13, and a thrust piece 11 having a circular shaft-shaped fitting portion 11a at one end is rotatably fitted in the circular hole 14. The other end of the thrust piece 11 has a contact surface 11b of an inclined flat surface facing the side surface 10a of the truncated pyramid shape (triangular truncated pyramid shape in this example) of one end of the pin 10. The other end of the pin 10 is stepped, and a spring 12 is provided, and the spring 12 is fixed to the water wheel shaft 7 by a retaining ring 16 for a hole via a collar 15.

In the runner blade support device of the present invention configured as described above, the pin 10 having the same center line 13 as that of the water wheel shaft 7 is the spring 12.
Is moved by being pressed toward the tapered one end portion along the water turbine shaft axis 13 by the contact surface 1 facing the side surface 10a.
The thrust piece 11 having 1b is abutted against and pressed against the side surface 10
By the wedge-shaped slope effect of a, the thrust piece 11 is moved in the thrust direction toward the outer periphery at right angles to the center line 13, so that the blade shaft 5 is also pressed and moved in the thrust direction via the thrust piece 11. The runner blade 3 is constantly pressed against the thrust bearing surface of the runner boss 4 with a desired pressing force to eliminate rattling of the runner blade 3 in the thrust direction. The side surface 10a of the pin 10 and the contact surface 11b of the thrust piece 11 are in contact with each other in the same inclined plane, and even if the contact position of the pin 10 and thrust piece 11 changes, the contact is in the same plane. Therefore, always keep the whole surface contact. Runner blade 3
Is operated by rotating the link mechanism 6 to change the opening of the blade, and the thrust piece 11 having the circular shaft-shaped fitting portion 11a is rotatably fitted in the circular hole 14 at the end of the blade shaft 5. Therefore, even if the blade shaft 5 rotates, the thrust piece 11 is brought into contact with the pin 10 in a plane-to-plane relationship with each other.
It is locked to rotate with. Therefore, the blade shaft can be freely rotated to change the opening of the blade.

Since the pin 10 is loosely fitted to the water wheel axle 7,
Its one end can be slightly swung from the turbine shaft axis 13. Even if there is a processing error in the blade shaft 5 of the runner blade 3, the thrust bearing surface of the runner boss 4, the thrust piece 11 and the pin 10 itself, the pin 10 is self-aligning so that the pin 10 abuts the three thrust pieces 11 in a balanced manner. Slight runout, thrust piece 11
Since it also swings slightly until its fitting gap, the abutting state of the planes is still maintained.

〔The invention's effect〕

According to the present invention, the tapered pyramid-shaped side surface of one end of the pin movably arranged along the turbine shaft axis and the end of the impeller shaft on the turbine shaft axis side are rotatably fitted. The contact surface of the inclined plane of the thrust piece is such that the pins are pressed by the spring and come into full contact with each other and press the blade shaft through the thrust piece in the outer peripheral direction due to the inclined surface effect. Eliminates rattling and eliminates wear or damage around the blade axis. Also, the blade axis of the runner blade,
Even if there is a processing error on the thrust bearing surface of the runner boss, the thrust piece, and the pin itself, one end of the pin swings automatically so that the pin contacts the three thrust pieces in a balanced manner. The planes are still in contact with each other because they swing slightly to the clearance. Further, since the thrust piece is rotatably fitted to the blade shaft, even if the blade shaft rotates, the thrust piece does not circulate with the blade shaft, and the flat plane contact state is maintained. As described above, since the flat surfaces are kept in contact with each other at all times, the contact surface receives an appropriate surface pressure and can exhibit a sufficient function without being deformed.

[Brief description of drawings]

1 to 4 are views showing an embodiment of the present invention.
1 is a detailed sectional view showing a main part of a runner blade supporting device according to an embodiment of the present invention, showing a half above the center line 13, FIG. 2 is a side view showing one end of a pin 10, and FIG. 3 is one end. 5 is a front view of the pin 10 seen from above, FIG. 4 is a sectional view taken along line AA of FIG. 2, and FIG.
FIG. 6 is a sectional view showing a straight flow type turbine, and FIG. 6 is a sectional view showing a runner blade supporting device of the straight flow type turbine of FIG. 3 ... runner blade, 4 ... runner boss, 5 ... blade shaft,
7 …… Water axle, 10 …… Pin, 11 …… Thrust piece, 12 ……
Spring, 13 ... Turbine shaft center.

Claims (1)

(57) [Claims] 1. A plurality of runner blades, the blade shafts of which are movably supported by a runner boss integrally formed with a water turbine shaft, a rotor mounted on the outer periphery of the runner blades via a rotor holding ring, and the rotation. In a straight-flow turbine with a stator facing the child, a straight flow type turbine is arranged so as to be movable along the axis of the turbine and has the same center line as the axis of the turbine, and one end of which has the same number of side surfaces as the runner blades. A tapered pin having a truncated pyramid shape and a slanting plane that is rotatably fitted to the end of each blade shaft on the axial center side of the water turbine and that faces the truncated pyramid-shaped side surface of one end of the pin. A runner blade support device comprising: a thrust piece having a surface; and a spring attached to a water wheel shaft for moving the pin in the direction of the tapered one end thereof.