JPH02161106A - Turbine rotor blade connecting device - Google Patents

Abstract

PURPOSE:To deter each turbine rotor blade from untwisting by installing projections and plate members which are to be mutually engaged in the front and the back of each rotor blade of a turbine, and engaging the projections and plate members through respective tapered slopes when required. CONSTITUTION:A projection 2 and a plate member 3 are installed on the tip of respective rotor blades 1a, 1b of a turbine. A plural number of slopes 5, 6 are formed on the projection 2 while on the inside face of the plate member 3, a dovetail groove 4 having a plural number of slopes 7, 8 is formed. At assembling, furthermore, the projection 2 of a turbine rotor blade 1b is inserted into the plate member 3 of other turbine rotor blade 1a. When so required, the dovetail groove 4 of a turbine rotor blade 1a is engaged with the projection 2 of other turbine rotor blade 1b, and respective slopes 5, 7; 6, 8 are mutually brought into contact. This detects each turbine rotor blade 1a, 1b from untwisting.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a coupling device for the tip of a turbine rotor blade, and particularly to a coupling device suitable for coupling turbine rotor blades having a large helix angle.

[Conventional technology]

The conventional structure for connecting the tips of turbine rotor blades was developed in 1986.
As described in Japanese Patent No. 8-157701, mutually opposing protrusions are provided at the ends of adjacent turbine rotor blades,
It is well known to provide a hole passing through the protrusion approximately perpendicularly, and to connect adjacent rotor blades by disposing a cover piece having a pin that can be inserted into the hole. Also, JP-A-56-3200
As described in Publication No. 3, holes penetrating vertically through the eaves of adjacent turbine rotor blades are provided, a rotor blade cover with a pin that can be inserted into this hole is provided, and the blades of adjacent rotor blades are It has been well known that a stopper portion of a rotor blade cover inserted into a gap in an eave portion prevents the rotor blade from twisting back. Incidentally, examples of related ins of this type include JP-A-57-26208, JP-A-57-83605, and JP-B-Sho 59-25087.

The above-mentioned conventional technology is effective when the gap between adjacent rotor blades is sufficiently wide, and is not applicable to the ljJ blade coupling device when the gap between adjacent turbine rotor blades with a large helix angle is very narrow. It wasn't taken into account.

[Problem to be solved by the invention]

When applying the above conventional technology to turbine rotor blades with a large helix angle, it is difficult to secure enough space to attach the connecting member to the blade tip because the gap between adjacent rotor blades is narrow. Yes, and the connecting member cannot be attached. Further, even if a connecting member is attached, the connecting member itself needs to be made small, which poses a problem in the strength of the connecting member itself.

An object of the present invention is to provide a turbine rotor blade connecting device that can connect adjacent rotor blades even when the gap between adjacent aX is narrow in turbine rotor blades with a large twist angle.

[Means to solve the problem]

The above purpose is one turbine il! ! A plate member is provided at the trailing edge of the tip of the J wing, and the plate member projects approximately perpendicularly to the plane in the spanwise direction, and the plate member extends approximately perpendicularly to the spanwise direction on the inner side with respect to the rotor center of this plate member. A groove is provided at the leading edge of the rotor blade, and a protrusion extending substantially perpendicularly to the blade span direction and having a shape that matches the dovetail groove of the protruding plate member provided at the trailing edge is provided at the leading edge of the tip of the rotor blade. When assembled to the rotor, the dovetail groove on the rear tread of one turbine rotor blade and the protrusion on the leading edge of the adjacent turbine rotor blade are arranged to face each other,
During turbine rotation, the dovetail groove on the trailing edge of the adjacent rotor blades fits into the protrusion on the leading edge due to untwisting of the rotor blade due to centrifugal force acting on the turbine rotor blade. This is achieved by locking the untwist to a predetermined size and connecting adjacent rotor blades to each other.

[Effect]

A tapered protrusion extending approximately perpendicularly to the blade span direction is provided at the leading edge of the tip of the rotor blade, and a plate member protruding approximately perpendicularly to the plane in the blade span direction is provided at the trailing edge of the rotor blade. By providing a tapered dovetail groove on the inner surface of the member with a shape that matches the tapered protrusion extending substantially perpendicular to the blade span direction, the tapered dovetail groove on the trailing edge of one turbine rotor blade and the adjacent tapered dovetail groove are provided. The tapered protrusions on the leading edge of the turbine rotor blade are assembled to face each other, and when the turbine rotor blade is untwisted, the dovetail groove and the protrusion fit together.

The pA contact rotor blades will be connected to each other, thereby making it possible to lock the untwist at a predetermined magnitude and at the same time connect the rotor blades to each other.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of a tip of a rotor blade equipped with a rotor blade coupling device according to the present invention, and the tip of a turbine rotor blade 1a includes:
Protrusion 2. The plate member 3 is provided so as to be substantially perpendicular to the longitudinal direction of the rotor blade.

The protrusion 2 is provided with slopes 5 and 6, and the inner surface of the plate member 3 is provided with a dovetail groove 4.
, 8 are all formed in a tapered shape. FIG. 2 is a top view showing the assembled state of adjacent rotor blades, in which a protrusion 2 provided on the front twill portion of the turbine rotor blade 1b and a plate member 3 provided on the rear edge portion of the adjacent turbine rotor blade 1a. The dovetail groove 4 provided on the inner surface of the plate member 3 and the protrusion 2 are arranged facing each other so that they can be inserted, and the slope of the protrusion 2 is 5°6.
, the slopes 7.8 of the dovetail groove 4 are assembled over the entire circumference in such a manner that they can be in close contact with each other. In the above configuration, as shown in FIG. 2, when untwist occurs in the turbine rotor blade, the trailing edge of the rotor blade 1a and the leading edge of the rotor blade 1b are displaced in a direction in which they diverge from each other. , motion 71. The protrusion 2 of the rotor blade 1b is fitted into the dovetail groove 4 of l a, and the untwist is locked at a position where the tapered slopes 5 and 7 and the slopes 6 and 8 contact each other. Can be done.

Furthermore, centrifugal force acts outward in the radial direction on the plate member 3 that protrudes from the trailing edge of the rotor blade at approximately right angles to the surface in the plane of the blade span during turbine rotation. By fitting the dowel groove 4 with the protrusion 2 provided on the leading edge of the tip of the adjacent rotor blade, centrifugal stress acting on the plate member 3 is reduced.

According to this embodiment, the rotating rotor blade is displaced by untwisting, and the dovetail groove 4 and the protrusion 2 fit together, so that the tapered slopes 5 and 7 and the slopes 6 and 8 are formed in a tapered shape. By contacting, the vibration energy of the rotor blades can be absorbed, and the slopes 5 and 7 or the slopes 6 and 8
By coming into close contact with each other, the rotor blades 1a and 1b are connected to each other, and the untwist can be locked at a predetermined position.

3 and 4 show other embodiments of the invention.

Figure 3 shows the protrusion 2 provided on the front edge of the movable gla of the above embodiment.
Instead, a dovetail groove 9 is provided, and a protrusion 10 is provided in place of the dovetail groove 4 provided on the inner surface of the plate member 3 provided at the rear edge. The dovetail groove 9 and the slopes 11.12 and 13.14 of the protrusion 10 are formed in a tapered shape, and have the same effect as explained in FIG. 2, making it possible to connect the rotor blades over the entire circumference. The untwist can be locked in a predetermined position.

In addition, in FIG. 4, a protrusion 15 and a stopper 17 are provided in place of the protrusion 2 provided on the leading edge of the moving blade 1a of the embodiment, and a plate member 3 provided on the trailing edge is provided in the longitudinal direction of the moving blade. An oblong hole 16 is provided at a substantially right angle, and a stopper 18 is provided on the inner surface of the plate member 3. If you configure it like this,
Adjacent rotor blades can be connected, and the untwist can be locked at a predetermined position. That is, the protrusion 15 provided on the leading edge of the rotor blade is inserted into the hole 16 provided on the trailing edge of the adjacent rotor blade, and the tip of the protrusion 15 is caulked so as to be movable within the hole 146. , the radial outward centrifugal stress acting on the plate member is reduced, and the untwist is locked at a predetermined size by the contact between the front edge stopper 17 and the rear edge stopper 18, and the adjacent The rotor blades can be connected to each other.

Furthermore, in the embodiment of the present invention shown in FIGS. 1 to 3, the dovetail grooves 4 and 9 and the protrusions 2 and 10 are described as being tapered in a direction substantially perpendicular to the wing span direction. 4,
9 and the protrusions 2 and 10 may fit into each other to reduce the centrifugal force acting on the plate member 3 protruding approximately perpendicularly to the plane in the span plane direction, and do not necessarily have to be tapered. A stopper 17.1 as shown in FIG. 4 may also be provided as a locking means for fixing the untwist to a predetermined size.

〔Effect of the invention〕

According to the present invention, lj
Since the vibration energy of Jm can be absorbed, blade vibration can be attenuated.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of one embodiment of the present invention, FIG. 2 is a top view showing the connection state of adjacent rotor blades, and FIGS. 3 and 4 are perspective views of other embodiments of the present invention. be. la, lb - turbine rotor blade, 2, 10, 15 - protrusion, 3... plate member, 4.9... dovetail groove, 5, 6, 7° 8... slope, 11, 12, 13.14...Slope, 1
6...hole, 17.18...stopper.

Claims (1)

[Scope of Claims] 1. A turbine rotor blade coupling device in which a leading edge of a turbine rotor blade tip and a trailing edge of an adjacent rotor blade tip are successively connected to each other by a connecting means, comprising: providing a plate member protruding substantially perpendicularly to the plane in the longitudinal direction of the blade at the trailing edge, and providing a dovetail groove extending substantially perpendicularly to the spanwise direction on the inner surface of the plate member with respect to the rotor center; On the other hand, a protrusion extending substantially perpendicularly to the blade span direction at the leading edge of the tip of the turbine rotor blade and having a shape that matches the dovetail groove of the protruding plate member provided at the trailing edge is provided; Dovetail grooves and protrusions similar to those of the turbine rotor blades are provided on the trailing edge portion and the leading edge portion of the adjacent turbine rotor blades, and when the turbine rotor blades are assembled to the rotor, the The dovetail groove on the trailing edge and the front edge of the adjacent turbine rotor blade are arranged to face each other, and the dovetail groove on the trailing edge and the front edge of the adjacent turbine rotor blade are arranged to face each other, and the dovetail groove and the groove on the leading edge of the adjacent turbine rotor blade are arranged to face each other. As the blade twists back, the dovetail grooves on the trailing edges of the adjacent rotor blades fit into the protrusions on the leading edges, and the twisting phenomenon reaches a predetermined size. A turbine rotor blade connecting device characterized in that: a turbine rotor blade connecting device is characterized in that adjacent rotor blades are connected to each other by being provided with a means for locking the rotor blades. 2. In claim 1, the dovetail groove on the trailing edge of one rotor blade and the front groove of the adjacent rotor blade serve as means for locking the untwisting phenomenon to a predetermined size. A turbine rotor blade coupling device characterized in that a protrusion on an edge is tapered in a direction substantially perpendicular to the blade span direction.