CN104389641A

CN104389641A - Forked blade root locking structure of moving blades in high-temperature section of steam turbine

Info

Publication number: CN104389641A
Application number: CN201410656673.2A
Authority: CN
Inventors: 曹守洪; 张东连; 黄彪; 李泽培; 刘全; 周振杰; 胡国光
Original assignee: DEC Dongfang Turbine Co Ltd
Current assignee: DEC Dongfang Turbine Co Ltd
Priority date: 2014-11-18
Filing date: 2014-11-18
Publication date: 2015-03-04
Anticipated expiration: 2034-11-18
Also published as: CN104389641B

Abstract

The invention discloses a forked blade root locking structure of moving blades in a high-temperature section of a steam turbine. The forked blade root structure comprises an impeller and the moving blades, wherein the moving blades are arranged on the impeller, blade roots of the moving blades are forked blade roots, assembling grooves which are matched with the forked blade roots are formed in the circumferential surface of the impeller, the blade roots of the moving blades are arranged in the assembling grooves, the moving blades are fixedly locked on the impeller by enabling a pin to penetrate through the blade roots and the impeller, and the pin is called as a core through pin and is positioned at the center positions of the blade roots; a blade root connecting seam of two adjacent moving blades is also provided with a pin, the pin penetrates through the blade roots and the impeller, and the pin which is arranged in the two adjacent blades in a crossing way is called as a seam crossing pin. According to the forked blade root locking structure of the moving blades in the high-temperature section of the steam turbine, disclosed by the invention, the heat stress can be reduced, and the safety of the blades is enhanced.

Description

Steam turbine high-temperature section moving vane fork type blade root locking mechanism

Technical field

The present invention relates to steam turbine blade, specifically, is a kind of high temperature section moving vane fork type blade root locking mechanism.

Background technique

At the moving vane of steam turbine high-temperature section, the governing-stage moving blade that especially operating temperature is the highest, its blade root is fork type blade root, and blade is worn pin with one and run through blade root, impeller, fastened on impeller by blade lock after loading impeller.The material used because of moving vane, impeller and pin is each different, and thermal expansion coefficient there are differences, and at high temperature, pin, blade root, impeller connecting part can produce very large thermal stress, pin may be cut off, cause leaf abscission, lead to a disaster.

Summary of the invention

For the problems referred to above, the invention provides a kind of high temperature section moving vane fork type blade root locking mechanism, can thermal stress be reduced, strengthen the Security of blade.Its technical solution is:

A kind of steam turbine high-temperature section moving vane fork type blade root locking mechanism, comprise impeller and be arranged on the moving vane on impeller, the blade root of described moving vane is fork type blade root, described impeller side face has the fitting recess with fork type blade root adaptation, the blade root of described moving vane is contained in this groove, runs through blade root, impeller, be locked by moving vane on impeller by a pin, this pin is called that logical core pin is followed closely, and is positioned at blade root central authorities; It is characterized in that, in the blade root seam of adjacent moving vane, be also provided with pin, this pin runs through blade root, impeller, straddles the blade root of adjacent two blades, is called junction of the edges of two sheets of paper pin.

The Pitch radius at described junction of the edges of two sheets of paper pin place is less than the Pitch radius at logical core pin nail place, and the line of centres of described logical core pin nail, left adjacent junction of the edges of two sheets of paper pin, right adjacent junction of the edges of two sheets of paper pin three is isosceles triangle.

Beneficial effect of the present invention:

Substitute a traditional pin with three pins, as long as the sectional area sum of three pins is not less than the sectional area of a former pin, just can ensure join strength, and the diameter of three pins can do little, swell increment is little, and thermal stress is just corresponding reduction also; And because junction of the edges of two sheets of paper pin 4 is located in the blade root seam of adjacent moving vane, seam can receive expansion, reduce pin-and-hole thermal stress, this just substantially increases the Security of blade.

Because logical core pin nail, left adjacent junction of the edges of two sheets of paper pin, right adjacent junction of the edges of two sheets of paper pin are that isosceles triangle is arranged, blade root, impeller cooperation have three strong points, and its relative positional accuracy is higher, and linkage structure is more stable, and during rotor operation, the vibration of blade is less.

Accompanying drawing explanation

Fig. 1 is the plan view of this structure

Fig. 2 is the A-A view of Fig. 1.

Embodiment

See Fig. 1, Fig. 2:

This steam turbine high-temperature section moving vane fork type blade root locking mechanism, the moving vane 1 comprising impeller 2 and be arranged on impeller 2, the blade root of described moving vane 1 is fork type blade root, the side face of described impeller 2 has the fitting recess with fork type blade root adaptation, the blade root of described moving vane 1 is contained in this groove, runs through blade root, impeller, be locked by moving vane on impeller by a pin 3, this pin 3 is called that logical core pin is followed closely, and is positioned at blade root central authorities; In the blade root seam of adjacent moving vane, be also provided with pin 4, this pin 4 runs through blade root, impeller, straddles the blade root of adjacent two blades, is called junction of the edges of two sheets of paper pin.Like this, substitute a traditional pin with three pins, as long as the sectional area sum of three pins is not less than the sectional area of a former pin, just can ensure join strength, and the diameter of three pins can do little, swell increment is little, and thermal stress is just corresponding reduction also; And because junction of the edges of two sheets of paper pin 4 is located in the blade root seam of adjacent moving vane, seam can receive expansion, eliminate thermal stress.This just substantially increases the Security of blade.

The Pitch radius at described junction of the edges of two sheets of paper pin 4 place is less than the Pitch radius that logical core pin follows closely 3 places, and the line of centres of described logical core pin nail, left adjacent junction of the edges of two sheets of paper pin, right adjacent junction of the edges of two sheets of paper pin three is isosceles triangle.Like this, blade root, impeller cooperation have three strong points, and the relative positional accuracy of blade root, impeller is higher, and linkage structure is more stable, and during rotor operation, the vibration of blade is less.

Claims

1. a steam turbine high-temperature section moving vane fork type blade root locking mechanism, comprise impeller and be arranged on the moving vane on impeller, the blade root of described moving vane is fork type blade root, described impeller side face has the fitting recess with fork type blade root adaptation, the blade root of described moving vane is contained in this groove, runs through blade root, impeller, be locked by moving vane on impeller by a pin, this pin is called that logical core pin is followed closely, and is positioned at blade root central authorities; It is characterized in that, in the blade root seam of adjacent moving vane, be also provided with pin, this pin runs through blade root, impeller, straddles the blade root of adjacent two blades, is called junction of the edges of two sheets of paper pin.

2. steam turbine high-temperature section moving vane fork type blade root locking mechanism as claimed in claim 1, it is characterized in that, the Pitch radius at described junction of the edges of two sheets of paper pin place is less than the Pitch radius at logical core pin nail place, and the line of centres of described logical core pin nail, left adjacent junction of the edges of two sheets of paper pin, right adjacent junction of the edges of two sheets of paper pin three is isosceles triangle.