Butter type main shaft sheath structure of horizontal water turbine

Abstract

The beef tallow type main shaft sheath structure is composed of a main shaft sheath, a hexagon socket screw, a main shaft, a sealing strip, a baffle, beef tallow, a main shaft sheath sectioning surface fixing bolt, a main shaft sheath sectioning surface positioning pin, a beef tallow filling screwed plug and an oil testing screwed plug. The solid beef tallow of the closed sealing cavity is used for preventing corrosive media from entering the root of the spindle flange, the purpose of protecting the root of the spindle flange from corrosion is achieved, and corrosion fatigue cracks of the root of the spindle flange are avoided.

Description

Technical Field

[0001] The invention belongs to the field of water turbines, and in particular relates to a butter type main shaft sleeve structure of a water turbine of a horizontal water turbine generator set. Background Art

[0002] In my country's hydropower industry, the working environment of the main shaft flange of the horizontal turbine is harsh. It is in direct contact with river water, and the humidity of the air is also high if it is not in direct contact. Due to the harsh working environment, the corrosion of the main shaft flange root causes insufficient fatigue safety margin, and cracks in the main shaft flange root have occurred repeatedly. The industry usually adopts measures such as increasing the main shaft stress area and the flange root fillet, replacing higher-grade main shaft materials, and mechanically protecting the flange root to solve the fatigue crack problem. Increasing the main shaft stress area and root fillet, due to the limited flow channel space, not only limits the scope of increase but also leads to an increase in manufacturing costs. Replacing higher-grade materials will also lead to an increase in manufacturing costs.

[0003] One of the measures taken in the prior art is that no anti-corrosion measures are provided at the transition radius of the main shaft flange, and the corrosion fatigue safety design is performed according to the underwater working environment of the main shaft. Compared with the non-corrosive working environment, the cross-sectional area of ​​the main shaft or the transition radius of the flange root needs to be increased to reduce the stress value, and the fatigue-resistant material needs to be replaced to meet the fatigue safety design margin. However, this method requires a lot of cost to ensure safety. Another method is to provide a main shaft sleeve at the root of the main shaft flange for protection. The main shaft sleeve must be made into a petal structure to ensure smooth installation, and the sealing effect of the petal surface directly affects the actual use environment of the main shaft flange root. The petal surface of the main shaft sleeve is sealed by water-sealing welding or bolts, and a sealing strip is provided to seal the water. Considering the requirements for long-term safe and stable operation of the turbine, the working environment of the main shaft also needs to consider the harsh water vapor environment. The present invention urgently needs to solve the following existing technical problems:

[0004] (1) After the turbine has been running for a long time, the bolts of the split face are loosened, the split face seal fails, and water vapor enters the root of the main shaft flange, causing corrosion at the root of the flange, resulting in insufficient fatigue safety margin;

[0005] (2) The water sealing welding of the petal surface of the spindle sleeve generates welding residual stress and new stress concentration points, resulting in insufficient fatigue safety margin;

[0006] (3) In order to meet the fatigue safety design margin, the spindle cross-sectional area and spindle flange transition radius are increased and high-grade spindle materials are used, resulting in increased manufacturing costs. Summary of the invention

[0007] In order to overcome the deficiencies of the above-mentioned prior art, the present invention provides a butter type main shaft sleeve structure of a horizontal turbine. The technical solution adopted by the present invention is composed of a main shaft sleeve, a hexagon socket bolt, a main shaft, a sealing strip, a baffle, butter, a main shaft sleeve split surface fixing bolt, a main shaft sleeve split surface positioning pin, a butter filling plug, and an oil testing plug. The main shaft sleeve is divided into multiple petals, and the main shaft sleeve split surface fixing bolt and the main shaft sleeve split surface positioning pin form a whole circle. A sealing strip is provided on the split surface and end surface of the main shaft sleeve; the main shaft sleeve is fixed to the flange end surface of the main shaft with a hexagon socket bolt, and the inner diameter of the main shaft sleeve and the outer diameter of the main shaft are transitionally matched; the main shaft sleeve and the main shaft form a closed sealing cavity, and the hole of the sealing cavity oil filling plug is filled with heated liquid butter. When filling butter, the oil filling plug hole is located at the bottom, and the oil testing plug is located at the top of the main shaft flange.

[0008] As a preferred implementation, the sealing strip is made of fluororubber.

[0009] As a preferred embodiment, the material of the tallow is industrial grade tallow.

[0010] As a preferred implementation, the spindle sleeve and the spindle are made of forged steel.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] (1) Taking advantage of the fact that the freezing point of butter is 40-46°C, the butter is heated to above 65°C to achieve filling with heated liquid butter. After the butter solidifies into a solid at room temperature, it covers the transition fillet and surrounding area of ​​the spindle flange, cutting off the channel for water vapor to enter the spindle, avoiding spindle corrosion and increasing the service life of the spindle.

[0013] (2) There is no need to increase the radius of the spindle transition flange to increase the spindle force area, and there is no need to upgrade the spindle material to solve the spindle corrosion fatigue problem.

[0014] (3) There is no need to change the design structure. The problem of spindle corrosion fatigue can be solved by simply setting up a closed sealing chamber at the spindle flange and filling it with butter. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic cross-sectional view of a butter type spindle sleeve;

[0016] Figure 2 This is a plan view of a butter type spindle sleeve.

[0017] Drawing marking instructions

[0018] 1-spindle sleeve 1, 2-hexagon socket bolt, 3-spindle, 4-sealing strip, 5-baffle, 6-butter, 7-spindle sleeve petal surface fixing bolt, 8-spindle sleeve petal surface locating pin, 9-butter filling screw plug, 10-oil testing screw plug. DETAILED DESCRIPTION

[0019] In order to make the technical solutions and beneficial effects of the present invention more clear, the technical solutions in the embodiments of the present invention are clearly and completely described below in conjunction with the accompanying drawings.

[0020] like Figure 1 , Figure 2 As shown, the butter type spindle sleeve structure mainly consists of a spindle sleeve 1, a hexagon socket bolt 2, a spindle 3, a sealing strip 4, a baffle 5, butter 6, a spindle sleeve petal surface fixing bolt 7, a spindle sleeve petal surface positioning pin 8, a butter filling screw plug 9, and an oil testing screw plug 10.

[0021] The spindle sleeve 1 is divided into multiple petals, and the spindle sleeve petal surface fixing bolts 7 and the spindle sleeve petal surface positioning pins 8 form a whole circle. The spindle sleeve petal surface and end surface are provided with sealing strips 4 to play a sealing role. The spindle sleeve 1 is fixed to the flange end surface of the spindle 3 by the hexagon socket bolts 2. The inner diameter of the spindle sleeve 1 and the outer diameter of the spindle 3 are in transition fit contact. The spindle sleeve 1 and the spindle 3 form a closed sealing cavity.

[0022] After the spindle sleeve is rounded and assembled with the spindle, a 0.5MPa air pressure test is performed on the closed sealing cavity to check the installation quality of the spindle sleeve.

[0023] After the air pressure test is qualified, the butter is heated to above 65℃ in liquid state by taking advantage of the characteristic of butter solidification point of 40~46℃, and then the heated liquid butter 6 is filled through the hole at the position of the oil filling plug 9 in the sealing chamber. When filling butter 6, the oil filling plug hole 9 is located at the bottom, and the oil testing plug 10 is located at the top. When oil comes out from the oil testing plug position, it proves that the closed sealing chamber is completely filled with butter 6. After butter 6 fills the closed sealing chamber, it is cooled to room temperature and solidified into a solid. After the turbine has been running for a long time, although the fixing bolts 7 of the split surface may loosen or the sealing strip 4 may fail, the root of the main shaft flange is wrapped by solid butter 6, which cuts off the channel for water vapor to enter the transition position of the main shaft 3 flange, thereby ensuring that the main shaft 3 will not suffer from corrosion fatigue and improving the fatigue safety margin of the main shaft 3.

[0024] Finally, the protection scope of the present invention is not limited to the above-mentioned embodiments. Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the scope and spirit of the present invention. If these changes and modifications fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these changes and modifications.

Claims

1. A butter type main shaft sleeve structure of a horizontal turbine, characterized by: It consists of a spindle sleeve ⑴, hexagon socket bolts ⑵, a spindle ⑶, a sealing strip ⑷, a baffle ⑸, butter ⑹, a spindle sleeve petal surface fixing bolt ⑺, a spindle sleeve petal surface positioning pin ⑻, a butter filling plug ⑼, and an oil testing plug ⑽. The spindle sleeve ⑴ is divided into multiple petals, and the spindle sleeve petal surface fixing bolts ⑺ and the spindle sleeve petal surface positioning pin ⑻ ​​form a whole circle. A sealing strip ⑷ is arranged on the petal surface and the end surface of the spindle sleeve; the spindle sleeve ⑴ is fixed to the flange end surface of the spindle ⑶ by the hexagon socket bolts ⑵; the spindle sleeve ⑴ and the spindle ⑶ form a closed sealing cavity, and the hole of the butter filling plug ⑼ in the sealing cavity is filled with heated liquid butter ⑹. When filling butter, the butter filling plug ⑼ is located at the bottom of the spindle sleeve, and the oil testing plug ⑽ is located at the top of the spindle sleeve.

2. A butter type main shaft sleeve structure of a horizontal turbine according to claim 1, characterized in that: The material of the sealing strip (4) is fluororubber.

3. A butter type main shaft sleeve structure of a horizontal turbine according to claim 1, characterized in that: The material of the butter (6) is industrial grade butter.

4. A butter type main shaft sleeve structure of a horizontal turbine according to claim 1, characterized in that: The material of the main shaft sleeve (1) and the main shaft (3) is forged steel.

Images