JPH018698Y2 - - Google Patents

Description

[Detailed description of the invention] (Technical field to which the invention pertains) The invention is a Kaplan water turbine that is rotatably guided by the runner boss with its axis in the radial direction, and connected to a link mechanism built into the runner boss at the intermediate part. a runner blade shaft, which is provided with an arm lever that rotates integrally with the runner, and has a connecting portion with the runner blade and a first bearing on the outer diameter side of the runner boss, and a second bearing on the inner diameter side of the boss. Regarding bearings.

(Prior art and its problems) Generally, in the runner blades of this type of Kaplan water turbine, the reciprocating motion of the servo motor is converted into rotational motion and transmitted to the shaft of the runner blade through a link mechanism built into the runner boss. , the opening degree of the runner blades can be changed automatically according to changes in load. The bearing that supports the shaft of the runner blade is divided into an inner and an outer bearing, and the outer bearing receives large loads in both radial and thrust directions that are generated on the runner blade by centrifugal force and water pressure during water turbine operation. The inner bearing, like the outer bearing, bears a large load in the radial direction, but it is desired that the thrust load be kept at about the weight of the runner blades when the water turbine is stopped, increasing its economic efficiency and making it easy to adjust the gap.

FIG. 1 shows a conventional example, and is a sectional view of the main part of a runner boss of a Kaplan water turbine. In the figure, 1
1 is a runner boss of a Kaplan water turbine with a built-in servo motor (not shown), and this runner boss 1 is formed of a runner hub 2, an intermediate boss 3, and a runner cone 4, and a fixed piston rod 5 is installed inside the runner hub 2.
A servo motor (not shown) is constructed by connecting the two. Reference numeral 6 denotes a runner blade, and the runner blade 6 is coupled to a runner blade arm 7 provided within the runner hub 2. Hereinafter, this portion will be collectively referred to as the shaft portion of the runner blade. The shaft portion 8 of this runner blade
is supported by two inner and outer bearings 9 and 10, and an arm lever 11 formed on the runner vane arm 7 is connected to a link mechanism constructed on a movable cylinder (not shown) that slides on the fixed piston rod 5, The linear reciprocating motion of the movable cylinder is converted into rotational motion via a link mechanism, and the angle of the runner blade 6 can be changed by rotating the shaft portion 8 of the runner blade.

In such a configuration, centrifugal force in the direction of arrow A and water pressure in the direction of arrow B act on the runner blades 6 during operation of the water turbine. For this reason, the outer bearing 10 is a flange bearing to bear a large thrust load in the direction of centrifugal force, and the radial load due to water pressure is shared with the inner bearing 9. However, the inner bearing 9 is formed as a flange bearing, and when the water turbine is stopped, it receives a load equivalent to the weight of the runner blade 6, but that load is small, and the flange of the inner bearing 9 is used to adjust the gear of the runner blade 6 in the direction of arrow C. The role of the flange is large, and if there is a dimensional error during assembly or if it wears out, replacing it will be wasteful and time consuming, and since the flange is manufactured by cutting it out, the yield will be reduced. The disadvantages were that it led to poor performance and increased costs.

(Purpose of the invention) An object of the present invention is to eliminate the above-mentioned drawbacks, and to provide a runner vane bearing for a Kaplan water turbine that has a simple structure, is easy to adjust the gap, and is economical in handling loads.

(Key Points of the Invention) According to the invention, the above purpose is to ensure that the first bearing, which supports the shaft of the relatively large-diameter runner blade on the outside of the runner boss, receives a thrust load in the direction of centrifugal force and a radial load. In addition, the bearing that supports the shaft of the relatively small diameter runner blade inside the runner boss is divided into a second bearing that shares the radial load with the outer bearing, and a third bearing that receives the thrust load in the opposite direction to the centrifugal force. the third bearing is formed into a fan shape, and the fan shape of the third bearing covers the rotation range of the arm lever when the arm lever is coupled to the link mechanism, and is linked to the arm lever. This is achieved by rotating the arm lever so that the third bearing can be attached or detached when the mechanism is disconnected.

(Embodiments of the invention) The present invention will be described in detail below based on drawings showing embodiments. 2 and 3 show an embodiment of the present invention, FIG. 2 is a sectional view of the main part of the runner blade shaft of a Kaplan turbine, FIG. 3 is a detailed view of the P section shown in FIG. 2, and FIG. A shown in FIG. 1 is a cross-sectional view thereof, and b is a plan view thereof. In the figure, the same components as shown in FIG. 1 are denoted by the same reference numerals, and their explanation will be omitted. The runner blade 6 is combined with the runner blade arm 7 in the runner hub 2, and is connected to a plurality of bolts 21 and a plurality of torque pins 22 that transmit torque.
The intermediate connecting portion 23 is an intermediate fit. 24 is a first bearing that takes charge of the thrust load and radial load of the runner blade shaft portion 20 caused by centrifugal force in the direction of arrow A and water pressure in the direction of arrow B;
A shaft portion 20 of a relatively large-diameter runner blade that protrudes toward the outside of the runner boss 1 is supported. 25
is a second bearing, which is formed in a cylindrical shape so as to share with the first bearing 24 the radial load of the runner blade shaft portion 20 caused by water pressure in the direction of arrow B, and protrudes toward the inside of the runner boss 1. The shaft portion 20 of the runner blade, which has a relatively small diameter, is supported. A third bearing 26 takes charge of the centrifugal force in the direction of arrow C and the thrust load of the runner blade shaft portion 20 in the opposite direction. Since this thrust load is as small as the weight of the runner blade 6 when the water turbine is stopped, the third bearing 26
is the presser of the second bearing 25 and the runner blade shaft portion 2
It is provided only in the range where the arm lever 11 moves in the direction of the arrow D, and serves as a cap adjustment to restrict the movement of the arm lever 11 in the direction of the arrow C.
7 and is fixed to a fixed piston rod 5.

With the above configuration, if a dimensional error occurs in the third bearing 26 during assembly, it is possible to remove it by rotating the arm lever 11, adjust the thickness to an appropriate size, and reinstall it. . Further, when the third bearing 26 becomes worn out, it can be replaced independently of the second bearing 25.

(Effects of the invention) As described above, the present invention divides the bearing inside the runner boss into the second bearing that handles the radial load and the third bearing that handles the thrust load. The radial load caused by water pressure is shared with the first bearing, and the relatively large thrust load caused by centrifugal force is handled by the first bearing.
The third bearing only needs to take on the thrust load, which is about the weight of the runner blades when the water turbine is stopped, and the structure is simple. When a gap occurs in the axial direction, it is reasonable and economical to select a bearing that facilitates adjustment, saves bearing material, and has strength that can handle the load.

[Brief explanation of the drawing]

Fig. 1 shows a conventional embodiment, a sectional view of the main part of the runner boss of a Kaplan water turbine, Figs. 2 and 3 show an embodiment of the present invention, and Fig. 2 shows the main part of the runner vane shaft of a Kaplan water turbine. The cross-sectional view, FIG. 3, is a detailed view of the P section shown in FIG. 2, and in FIG. 3, a is a cross-sectional view thereof, and b is a plan view thereof. 1: Runner boss, 11: Arm lever, 20:
Shaft portion, 23: Coupling portion, 24: First bearing, 25:
Second bearing, 26: Third bearing.

Claims (1)

[Scope of utility model registration request] It is rotatably guided by the runner boss of the Kaplan water turbine with the radial direction of the boss as its axis, and has an arm lever in the middle that is connected to a link mechanism built in the runner boss and rotates integrally, and is attached to the outer diameter side of the runner boss. The connecting part with the runner blade and the first
and a second bearing on the inner diameter side of the boss, wherein the first bearing carries a radial load and a thrust load due to the centrifugal force of the runner blade, The second bearings are each configured to receive only a radial load,
A third bearing formed in a fan shape that receives a thrust load in a direction opposite to the centrifugal force is provided on the inner diameter side of the boss of the arm lever, and the arm lever applies the fan shape of the third bearing to the link mechanism. Covering the rotation range of the arm lever when coupled, and allowing the third bearing to be attached or detached by rotating the arm lever when the arm lever and the link mechanism are disengaged. Kaplan turbine's runner blade bearing features.