JPS6345572Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an improvement of a bearing device for a water turbine guide vane.

[Conventional technology]

A conventional guide vane bearing device for a tubular water turbine will be explained with reference to FIGS. 1 to 3.

A waterway 4 is formed between an inner guide vane case 2 and an outer guide vane case 3 of a hydraulic machine main body 1. Water is flowing in the direction of arrow A in the waterway. The flow of water is controlled by opening and closing a plurality of guide vanes 5 arranged in the water channel. A plurality of guide vanes 5 are arranged on the circumference with the radial direction centered at the 0 point in FIG. 1 as the axis. Main shafts 6 provided at both ends of the guide vane 5 are inserted into bearings 7 and 8 formed in the inner and outer guide vane cases 2 and 3, respectively. The main shaft end extending from the bearing part 8 is operated by a link mechanism 9 or a servo motor (not shown), and is used for adjusting the flow rate of pressurized water to the runner 10, opening and closing a flow path, etc.

Therefore, in order not to impair the opening/closing function, gaps G ₁ , G 2 , G ₂ , G ₁ ′ and G ₂ ′ are required.

However, the gap needs to be kept to the minimum necessary size in order to prevent water leakage as much as possible when the flow path is blocked. In addition, when blocking the flow path, operate the guide vane 5 to the fully closed state shown in the solid line in Fig. 3.
The guide vanes are brought into contact with each other, but the contact point Y
In order to prevent water leakage, each guide vane 5
The entire span of the wings must be in close contact with each other.

The accuracy of each of the above parts is greatly influenced by the processing accuracy of each part, but in the conventional technology, the inner and outer guide vane cases 2 and 3 having the radially arranged bearings 7 and 8 are manufactured using special machine tools. This structure makes it extremely difficult to obtain sufficient machining accuracy.

For example, if the center extension lines of the bearing parts 7, 8 of the inner and outer guide vane cases 2, 3 do not converge at the center point "O", or if the bearing parts 7, 8 of the inner and outer guide vane cases 2, 3 If the center positions of the opposing bearing parts are different, the gaps G _{1 and 5} between the inner and outer guide vane cases 2 and 3 and the guide vane 5
G ₂ , G ₁ , G ₂ may become unbalanced, and depending on the amount of error, the inner and outer guide vane cases 2,
3 and guide vane 5 may come into contact with each other, and at the same time, the degree of adhesion between the contact surfaces of each guide vane 5 when the flow path is blocked decreases, resulting in an excessive amount of water leakage, which significantly reduces the function of guide vane 5. It appears as a phenomenon. Similarly, the same problem occurs when a plurality of guide vanes 5, which must be arranged at equal positions on the circumference, are misaligned.

Further, another example of the prior art will be explained using FIG. 4. This is an application of a technology known as a guide vane bearing adjustment device to tubular water turbines. The bearing part 8 is inserted into an insertion part 10 formed in the outer guide vane case 3, and an adjusting body 11 having a spherical shape is installed between the bearing part 8 and the insertion part 10 to freely adjust the inclination of the bearing part 8. It exists where it is possible.

However, the adjustment body 11 and the outer guide vane case 3 are not formed into a spherical shape whose center point O (the center point of the sphere RA) coincides with each other. As a result, the machining accuracy of the bearing part 8 and the insertion part 10 is poor. For example, if the bearing part 8 is installed with a _deviation from the normal position abutting, and the left end 5A is a gap
Move in the direction of increasing G ₁ . Further, if the bearing portion 8 is mounted shifted from the normal position X to the _X1 position, the gaps _G1 and _G2 move in the opposite direction to that described above. Therefore, not only is it not easy to adjust the gap to a constant gap, but also when rotating the guide vane 5, the guide vane 5 comes into contact with the outer guide vane case 3, making it difficult to rotate, and the guide vanes are mutually The adhesion force when two parts are in close contact with each other becomes weaker, causing water leakage.

[Purpose of invention]

The purpose of this invention is to keep the gap between the guide vane and the outer guide vane case constant even if there are accuracy errors in the bearing section and the insertion section, thereby preventing the guide vane from coming into contact with the outer guide vane case. An object of the present invention is to provide a bearing device for a water turbine guide vane.

[Summary of the idea]

The bearing device of the present invention consists of an insertion part that protrudes outward from the outer casing, and a bearing part inserted into the insertion part and through which the main shaft is inserted, and the contact surface between the bearing part and the insertion part and the outer casing. The inner circumferential surface and the outer circumferential surface of the guide vane are formed into spherical shapes whose center points coincide with each other.

[Example of idea]

An embodiment of the present invention will be described below with reference to FIGS. 5A to 5C. Components in the drawings that are the same as those in FIGS. 1 to 4 are designated by the same reference numerals, and their explanations will be omitted.

The main shaft 6 is inserted into the inside of the bearing part 8 via a bearing metal 20. The bearing part 8 is inserted into the insertion part 10, and after the flange surface 8A of the bearing part 8 and the end face 10A of the insertion part 10 are brought into contact, the tightening bolt 21 and the dowel pin 22 are inserted into the bearing part 8 and the insertion part 10, Then, the bearing part 8 is fixed to the insertion part 10 by tightening. There is a gap G ₃ between the bearing part 8 and the insertion part 10 that is sufficient to allow movement in all directions, from left to right and front to back.

A first packing 23 is installed between the main shaft 6, the bearing metal 20, and the insertion portion 10, and a second packing 24 is installed between the flange surface 8A and the end surface 10A to seal off flowing pressurized water. ing. The inner peripheral surface 25 and contact surface 26 between the outer guide vane case 3, the flange surface 8A, and the end surface 10A are formed into a spherical shape in which the center point O (the point where the spheres RA ₀ and RA ₁ coincide at the center) coincides. are doing. This spherical shape and the outer peripheral surface of the guide vane 5 are also the same shape.

This configuration is changed from a state in which the bearing part 8 is installed at the normal position _X1 as shown in FIG. Even if _the device is shifted from the normal position X to the left side position Even when moving on the contact surface, the gaps G ₁ and G ₂ always move at a constant interval.

[Effect of idea]

Therefore, not only can the gaps G ₁ and G ₂ be easily adjusted, but also the main shaft 6 can be smoothly rotated, and the adhesion between the guide vanes when fully closed can be improved.

[Brief explanation of the drawing]

Fig. 1 is a schematic side sectional view showing the entire conventional tubular type water turbine, Fig. 2 is a side sectional view showing the vicinity of the conventional guide vane bearing, and Fig. 3 is the − of Fig. 2.
FIG. 4 is a side sectional view of a guide vane bearing device showing another embodiment of the prior art, and FIG. 5A is a diagram showing the guide vane according to an embodiment of the present invention. Figures B and C are side sectional views of the bearing device, with some parts of Figure A omitted. 1... Hydraulic machine main body, 2... Inner guide vane case, 3... Outer guide vane case, 4... Water channel, 5... Guide vane, 6... Main shaft, 7, 8...
... Bearing part, 9 ... Insertion part, 25 ... Inner peripheral surface, 26
...Contact surface.

Claims (1)

[Scope of utility model registration request] A guide vane placed between the outer guide vane case of the flow channel and the inner guide vane case on the hydraulic machine body side installed in the flow channel, the main shaft provided on the guide vane, and the main shaft connected to the inner and outer guide vanes. In the case that is supported by a bearing device formed in the case, the bearing device on the outer guide vane case side has an insertion portion that protrudes outward from the outer guide vane case, and a bearing portion that is inserted into the insertion portion and has the main shaft inserted therethrough. A water turbine guide vane characterized in that the contact surface between the bearing part and the insertion part, the inner circumferential surface of the outer guide vane case, and the outer circumferential surface of the guide vane are formed in a spherical shape whose center points coincide with each other. Bearing device.