JPH04287872A - Thrust reducing device for s-type tubular water turbine - Google Patents

Abstract

PURPOSE:To reduce thrust applied to a thrust bearing at the time of switching the runner impeller of an S-type tubular water turbine. CONSTITUTION:A spring 14 for pressing a cross head 11 in the water flow direction is provided horizontally between a runner boss 6 and the cross head 1. At the time of closing a runner impeller 7, the spring 14 is compressed, and at the time of opening the runner impeller 7, a runner impeller operating rod 5 is moved in the water flow direction by the expanding force stored in the spring 14 through the cross head 11, so that thrust applied to a thrust bearing is reduced.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thrust reduction device for an S-type tubular water turbine, in which the flow passage on the outlet side of the runner is bent into an S-shape so that the main shaft protrudes outside the flow passage on the downstream side.

0002

2. Description of the Related Art FIG. 2 is a longitudinal sectional view of an S-type tubular water turbine, with arrows indicating the direction of water flow. In FIG. 2, the flow path on the outlet side of the runner is bent into an S-shape, the main shaft 8 is made to protrude outside the suction pipe 9 which is the downstream flow path, and the main shaft 8 is mounted on a thrust bearing 10 outside the suction pipe 9. I support it. When the servo motor 1 is operated, the operating force is transmitted to the runner blade operating rod 5 that penetrates the inside of the main shaft 8 via the operation link 2, link 3, and bearing box 4, and the runner blade 7 supported by the runner boss 6 is moved. Open and close.

FIG. 3 is a cross-sectional view of the runner boss 6 shown in FIG. The runner boss 6 is connected to the main shaft 8, and the runner blades 7 are rotatably supported by the runner boss 6. The runner blade operating rod 5 is supported by the runner boss 6 so as to be movable in the horizontal direction. A crosshead 11 is attached to the end of the runner blade operating rod 5, and a runner blade arm 13 at the base of the runner blade 7 is connected to the crosshead 11 via a link 12.

In FIG. 3, when the runner blade operating rod 5 is driven in the horizontal direction, the crosshead 11 connected to the end of the runner blade operating rod 5 moves in the horizontal direction, and is further connected to the runner blade arm via the link 12. 13 is rotated, and the runner blade 7 coupled to the runner blade arm 13 is rotated to open and close the runner blade 7. Since a water thrust force Fw is generated in the runner blade 7 in the direction of the main axis, a thrust bearing 10 for receiving this force is provided between the suction pipe 9 and a generator (not shown). A water thrust force Fw acts on the thrust bearing 10 via the runner boss 6 and the main shaft 8. When closing the runner blade 7, operate the runner blade operating rod 5 in the opposite direction of the flowing water, and the operating force F1 of the runner blade operating rod 5 will be applied to the crosshead 11, link 12, runner blade arm 13, runner blade 7, and runner boss 6. , water thrust Fw via the main shaft 8
Since the force acts on the thrust bearing 10 in the opposite direction, the resultant force acting on the thrust bearing 10 becomes Fw - F1.

However, when opening the runner blade 7, the runner blade operating rod 5 is operated by the operating force F2 in the same direction as the flowing water, so the resultant force applied to the thrust bearing 10 is Fw
+F2, which is greater than the water thrust Fw. Therefore, the thrust bearing 10 needs to be designed to withstand a thrust of Fw +F2.

[0006] When installing the suction pipe 9 of the S-type tubular water turbine, there is a space restriction in the place where the thrust bearing 10 is installed, and there are drawbacks such as the inability to provide a large foundation for the thrust bearing 10. Therefore, it is necessary to reduce the load on the thrust bearing 10, and the water thrust Fw and the runner blade opening operating force F2 act on the thrust bearing 10, but the water thrust Fw is determined by the head of the water turbine and cannot be changed. Therefore, it is necessary to reduce the runner blade opening operating force F2.

SUMMARY OF THE INVENTION An object of the present invention is to provide a thrust reduction device for reducing the thrust applied to a thrust bearing when opening and closing runner blades in an S-type tubular water turbine.

[0008]

[Means for Solving the Problems] A flow path on the outlet side of the runner bent in an S-shape, a thrust bearing that supports the main shaft protruding outside of the suction pipe on the outside of the flow path, and a thrust bearing supported by the runner boss. In an S-type tubular water turbine equipped with a movable runner blade and a runner blade operating rod that opens and closes the runner blade, the cross head is attached between the runner boss and the crosshead attached to the end of the runner blade operating rod. By installing a spring that presses the head in the direction of water flow,
Achieve the above objectives.

Furthermore, in the thrust reduction device for an S-type tubular water turbine according to claim 1, the tension force of the spring provided between the runner boss and the crosshead is controlled by the operation required to operate the runner blade operating rod in the direction of flowing water. If it is made equal to the force, it is suitable for reducing the thrust force applied to the thrust bearing.

0010

[Operation] This invention provides a spring that is placed horizontally between the runner boss and the crosshead and presses the crosshead in the direction of water flow, and when closing the runner blades, the runner blade operating rod is operated in the direction opposite to the flow of water. Compress the spring,
When opening the runner blades, the tension force stored in the spring pushes the runner blade operating rod in the same direction as the flowing water to open the runner blades, so the thrust force applied to the thrust bearing can be reduced at this time. Note that if the tension force of the spring is made equal to the operating force required to operate the runner vane operating rod in the direction of the flowing water, no operating force is required to operate the runner vane operating rod when opening the runner vane. At this time, the thrust applied to the thrust bearing can be only water thrust.

[0011]

[Embodiment] The structure of the S-type tubular water turbine is the same as that shown in FIG. 2, so a description thereof will be omitted. FIG. 1 is a sectional view of a runner boss of an S-type tubular water turbine equipped with a thrust bearing device according to an embodiment of the present invention. In FIG. 1, the same parts as in FIG. 3 are given the same reference numerals. A water thrust force Fw is acting on the runner blade 7. In the thrust reduction device according to the present invention, a spring 14 is provided horizontally between the runner boss 6 and the crosshead 11 to press the crosshead 11 in the direction of water flow.

When closing the runner blade 7, the runner blade operating rod 5 is moved in the opposite direction to the flowing water, and the runner blade arm 13 is rotated via the crosshead 11 and link 12. At this time, the spring 14 interposed between the black head 11 and the runner boss 6 is compressed. If the tension force of the spring 14 is Fs, and the operating force of the runner blade operating rod 5 required for the closing operation without the spring 14 is F1, then
When the spring 14 is present, the operating force required for the closing operation is F1 +F
s, and this force is applied to the crosshead 11, link 12,
Runner blade arm 13, runner blade 7, runner boss 6,
The force acts on the thrust bearing 10 via the main shaft 8, and Fw −F1 −Fs acts on the thrust bearing 10 as a resultant force.

When opening the runner blade 7, the runner blade operating rod 5 is moved in the same direction as the flowing water, and the runner blade arm 13 is rotated via the crosshead 11 and link 12. If the extension force of the spring 14 is Fs, and the operating force of the runner blade operating rod 5 required to open the runner blade 7 when the spring 14 is not present is F2, then when the spring 14 is present, the runner blade opening operating force is F2 - Fs. becomes. At this time,
If the tension force Fs of the spring 14 is made equal to the opening force F2 of the runner blade operating rod 5 which is required when the spring 14 is not present, there is no need to apply an operating force to the runner blade operating rod 5 from the servo motor. , runner vane operating rod 5
is pushed in the direction of water flow by the tension force Fs of the spring 14, and this tension force Fs acts on the runner blade 7 to open the runner blade 7, and this force Fs is not transmitted to the thrust bearing 10. Therefore, when the runner blade 7 is operated in the opening direction, only the water thrust force Fw acts on the thrust bearing, so that the thrust applied to the thrust bearing can be reduced compared to the conventional case.

[0014]

[Effects of the Invention] This invention provides a spring that is placed horizontally between the runner boss and the crosshead and presses the crosshead in the direction of water flow, and when closing the runner blades, the runner blade operating rod is moved in the opposite direction to the flow of water. When the spring is compressed and the runner blade is opened, the tension stored in the spring pushes the runner blade operating rod in the same direction as the flowing water and opens the runner blade, so the thrust is applied to the thrust bearing at this time. can be reduced. Therefore, the thrust bearing can be made compact and the cost can be reduced. Furthermore, restrictions on the foundation of the thrust bearing due to the S-shaped suction pipe are reduced, and the degree of freedom in design can be increased.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a runner boss of an S-type tubular water turbine equipped with a thrust reduction device according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of an S-type tubular water turbine.

FIG. 3 is a cross-sectional view of the runner boss of the S-type tubular water turbine in FIG. 2;

[Explanation of symbols]

5 Runner vane operation rod 6 Runner Boss 7 Runner blade 8 Main shaft 9 Suction pipe 10 Thrust bearing 11 Cross head 12 Link 13 Runner vane arm 14 Spring

Claims (2)

[Claims] Claim 1: A flow path on the outlet side of the runner bent in an S-shape, a thrust bearing that supports a main shaft protruding outside the suction pipe on the outside of the flow path, and a movable runner blade supported by the runner boss. and a runner blade operating rod for opening and closing the runner blade, the crosshead is installed between the runner boss and the crosshead attached to the end of the runner blade operating rod in the water flow direction. A thrust reduction device for an S-type tubular water turbine, characterized by being provided with a spring that presses against. 2. In the thrust reduction device for an S-type tubular water turbine according to claim 1, the stretching force of the spring provided between the runner boss and the crosshead is controlled by the operation required to operate the runner blade operating rod in the direction of flowing water. A thrust reduction device for an S-type tubular water turbine, which is characterized by equalizing the force.