JPH071032B2 - Rotor support bearing mounting structure for straight flow turbine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a rotor support bearing mounting structure for a 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. 3 is a schematic vertical sectional view of a straight flow type water turbine, and FIG. 3 is a vertical sectional view showing a mounting structure of a rotor support bearing of a conventional straight flow type water turbine. In FIG. 2 or 3, each of the plurality of runner blades 4 is movably supported by the runner boss 5 via a link mechanism, and the servomotor is hydraulically operated to operate the link mechanism. .

Via a rotor support ring 8 on the outer circumference of the runner blade 4, a rotor side bearing 10 composed of a spherical convex side member 9a mounted on the outer circumference of the runner blade 4 and a concave side member 9b mounted on the rotor holding ring 8. The rotor 2a is attached, and the stator 2b faces the rotor 2a.
And a generator 3 is formed from the rotor 2a and the stator 2b. The water turbine shaft 6 is supported by the rotor support bearings 10 in front of and behind the runner blade 4, and the head side of the water turbine shaft 6 is covered by the valve 1. Water flows in the direction of the arrow to rotate the runner blade 4, The weight of the rotor 2a is applied to the rotor support bearing 10 via the runner blade 4, the runner boss 5, and the water wheel shaft 6.
Even when the angle of the blades 4 changes due to the operation of the link mechanism, the rotor holding ring 8 is supported perpendicularly to the water wheel shaft 6 through the rotor supporting bearing, but the convex bearing 9a of the rotor supporting bearing is used.
There is a slight radial gap between the concave bearing 9b and the concave bearing 9b.

[Problems to be solved by the invention]

In the case of a fixed blade type straight flow turbine, since the rotor retaining ring 8 is rigidly attached to the outer peripheral end of the runner blade 4, the runner rotates and the rotor retaining ring 8 is rotated by the centrifugal force to the outer diameter side. Even if it shifts to, there is no gap in the connecting portion between the runner blade and the rotor retaining ring.

On the other hand, in the case of a movable blade type straight flow turbine, the angle of the runner blade 4 changes with respect to the rotor retaining ring 8, so that the spherical convex member 9a is attached to the outer periphery of the runner blade 4 by a bolt. The concave side member 9b is fixed to the rotor holding ring 8 side. The weight of the rotor 2a is 3 ~
This load applied to the five runner blades 4 is often larger than the centrifugal force of the runner blades 4. Therefore, a severe load acts on the rotor support bearing 10, so that the rotor is supported during rotation. Due to the centrifugal force generated, a gap is created between the convex side member 9a and the concave side member 9b of the rotor support bearing 10. This gap is likely to occur when the runner blade 4 is located below. Therefore, each time the runner rotates, contact and separation of the convex side member 9a and the concave side member 9b are repeated, so that the rotor support bearing 10 may be damaged.

It is an object of the present invention to provide a rotor support bearing structure in which a gap does not occur in the sliding portion of the rotor support bearing during rotation of the runner.

[Means for solving problems]

According to the present invention, the above object is achieved by providing a compression spring and a spring retainer between the concave side member of the rotor support bearing and the rotor holding ring that holds the concave side member.

[Action]

According to the present invention, since the rotor support bearing is pressed toward the inner diameter side by the compression spring against the displacement in the outer diameter direction generated in the rotor due to the centrifugal force during rotation, the displacement is absorbed by the centrifugal force. Even if there is displacement on the outer diameter side, no gap is created in the rotor support bearing.

〔Example〕

FIG. 1 is a vertical sectional view showing a mounting structure of a rotor support bearing of a straight flow type water turbine according to an embodiment of the present invention, and the same parts as those in FIG. 3 are denoted by the same reference numerals. In FIG.
A rotor support bearing 10 including a convex side member 9a attached to the outer circumference of the runner blade 4 and a concave side member 9b held inside the rotor retaining ring 8 so as to engage with the convex side member 9a is a bearing case.
It is housed in 11. A plurality of disc springs 12 as compression springs capable of supporting a large load in a small space are stacked on the outer peripheral side of the rotor support bearing 10, and the spring retainer 13 is opposed to the centrifugal force of the rotor 2a during rotation. Since the rotor support bearing 10 is pressed toward the inner diameter side by the compressive force of the disc spring held by, no gap is formed between the convex side member 9a and the concave side member 9b of the rotor support bearing 10. The compression force of the disc spring 12 can be adjusted by the driving position of the taper key 14 when the bearing device is assembled.

〔The invention's effect〕

According to the present invention, the rotor support bearing is supported by the compression spring 12 against the displacement in the outer diameter direction generated in the rotor due to the centrifugal force during rotation.
Since 10 is pressed to the inner diameter side to absorb the displacement, there is no gap between the convex side member 9a and the concave side member 9b of the rotor support bearing 10, and therefore wear damage of the bearing is prevented. There is an effect that can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a rotor support bearing mounting structure of a straight flow type water turbine according to an embodiment of the present invention, FIG. 2 is a schematic vertical sectional view of a straight flow type water turbine, and FIG. 3 is a conventional straight flow type. It is a longitudinal cross-sectional view showing a rotor support bearing mounting structure of the model water turbine. 2a: rotor, 2b: stator, 4: runner blade, 9a: convex member, 9
b: concave member, 10: rotor support bearing, 11: bearing case, 12:
Compression spring, 13: Spring retainer.

Claims (1)

[Claims] 1. A plurality of runner blades whose blade shafts are movably supported by a runner boss, a convex side member attached to the outer periphery of the runner blade, and a rotor holding ring held so as to engage with the convex side member. In a straight flow water turbine equipped with a rotor supported by the runner blades via a rotor support bearing made of a concave member, and a stator facing the rotor,
A compression spring and a spring retainer are provided between the concave side member and the rotor retaining ring, and the rotor supports the rotor with the compression spring against the displacement in the outer diameter direction generated in the rotor by the centrifugal force during rotation. A rotor support bearing mounting structure for a straight flow type water turbine, characterized in that the above-mentioned displacement is absorbed by pressing the inner diameter side.