JPS6196103A - Multi-layered bucket of rotary machine - Google Patents

Abstract

PURPOSE:To improve a hydrodynamic property of a steam turbine by forming a bucket of an axial machine into a structure having a plurality of layers wherein the number of buckets is made integer times as the buckets are separated from a rotary shaft and a bucket root part of a short bucket formed on the upper layer is engaged with a stub provided on an intermediate portion of a long bucket. CONSTITUTION:Bucket root parts 3 of two long buckets 1 are fitted to a rotary shaft 4. A large-sized stub 2 is fixed at the center of the long bucket 1, and a bucket root part 5a of a short bucket 5 is engaged with the center of the large sized stub 2 by making use of centrifugal force without fail. Thereupon, the tip end of the short bucket 5 and the tip end of the long bucket 1 are formed so to be aligned with each other. In addition, the number of the tip end buckets and the number of the root part buckets are formed in a ratio of 2:1. Hereby, an area of a passage for steam can be increased in the vicinity of a rotary shaft 4, and the number of the buckets can be increased at their tip ends for keeping a proper interval thereamong, whereby a steam flow can be made uniform for improving a hydrodynamic property of the rotary machine.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is used in steam turbines, gas turbines, blowers, compressors, and the like.

2. Description of the Related Art A conventional rotary wiping machine shown in FIGS. 7 to 10 is installed in the form of several pieces 2 connected together as shown in FIG. The rotor blade 01 is connected to the adjacent rotor blade 01 by a fitting stub 02 in the middle thereof, and the blade root 03 is connected to the rotary shaft 04 so as not to be exposed. The X direction in FIG. 12 indicates the axial direction, y indicates the rotational direction of the shaft, and 2 indicates the blade direction.

Taking a steam turbine as an example, by flowing steam between the adjacent stations and blades in Figure 11, the lift force (steam power) generated at The basic principle of a steam turbine is to convert thermal energy into rotational energy of the rotating shaft, but if the rotational speed is very high, the centrifugal force acting on the blades becomes extremely large.

Problems to be Solved by the Invention The blade 01 has a large cross-sectional area along B-B near the blade root 03 in FIG.
It is necessary to reduce the tensile stress caused by centrifugal force by reducing the cross-sectional area of the As a result, generally speaking, the steam passage area near the B-B cross section becomes too narrow, resulting in poor steam flow, and near the C-C cross section at the tip, the steam passage area becomes too wide when viewed from the axial direction X. The trend is -0, and the steam does not flow along the C-C cross section, but instead blows through in the axial direction
This causes a reduction in fluid performance of the steam turbine.

Means to Solve the Problems In order to solve the above problems, the present invention provides a sufficiently large steam passage area near the blade root of the blade, and an appropriate steam passage area near the blade tip. This is a multilayer structure board that reduces the number of blades in areas with a small radius and increases the number of blades in areas with a large radius.

Example A first embodiment of the present invention will be described with reference to FIGS. 1 and 2.

Rotate the blade roots 3 of the two long wings 1! Fits into I14.

Length 1;, :(1, ■ Fix large stub 2 to the middle part,
The blade root part 5a of the short blade 5 is engaged with the middle of the large stub 2 so as not to come off due to centrifugal force. The lengths of the tip of the short R5 and the tip of the long blade l are formed to match.

The ratio of the number of tip blades to the number of base blades is 2×1.

Since the I'iij structure is made as shown in "Effects", the steam passage surface, + Spacing can be maintained, resulting in uniform steam flow and improved fluid performance.

A second embodiment of the present invention will be explained with reference to FIGS. 3 and 4.

The roots of the two long wings 1.1 (1 ζ part 3.3 are fitted and fixed on the rotating shaft 4, the large stub 2 is fixed to the middle part of the length R1, 1, and the large stub 2 is fixed between the lengths 1 AI and 1. 2 short R5', 5
The blade roots 5b of the blades 5' are interlocked and fixed so as not to come off due to centrifugal force.The short blades 5' are arranged so as to divide the space between adjacent long blades 1.1 into 3 parts.Similarly to the first embodiment, the blade roots 5b of the steam turbine Fluid performance can be improved.

A third embodiment of the present invention will be explained with reference to FIGS. 5 and 6.

11 is a long blade with a large stub 12 formed in the middle part, and a root blade part 13 is fixed to the rotating shaft 14, and between adjacent large stubs 12, the blade root part 15a of medium and short R15 is prevented from coming off due to centrifugal force. They are interlocked.

Another stub 12a is provided near the tip of the long wing 11, and another stub 5b is also provided near the tip of the short and medium wing 15.

A blade root portion 16a of a smaller short blade 16 is engaged between the stub 12a and the stub 1.5b,
Adjacent length ")'J, 11 is divided into four at the tip,
The middle part is divided into two parts, and has a three-layer structure in which the number of hits is 4:2:l starting from the tip. First example,
Since the flow of steam can be controlled more precisely than in the second embodiment, the fluid performance of the steam turbine is improved.
! : There is.

[Brief explanation of drawings]

Fig. 1 is a front view of the first embodiment of the present invention, Fig. 2 is a conceptual diagram of CI1, Fig. 4 is a conceptual diagram of the second embodiment, Fig. 4 is the same front view [λ1, Fig. 5] (d Conceptual diagram of the third embodiment, Figure 6 is a rotation Ini diagram, Figures 71 to 13 are conventional examples, Figure 7 is a front view of the beam, Figure 8 is a front view of the mano and A side view, FIG. 9 is a plan view of the wing viewed from the radial direction, FIG. 10 is a sectional view taken along line X-X in FIG. 2, FIG. 11 is a perspective view of the sliding door, and FIG. 12 is a perspective view of the wing. Figure 13 is a conceptual diagram of the conventional example.■...Long path, 2...Stub, 3...Blade root, 4...Rotation l extraction, 5...Scissors i 3j?, :, 5a... - Wing root. Alpha group, 7 people Masami Kimura\. (7 idiots) Calculation IIQ Calculation 2 Diagram 3 Figure '11.4 Figure 5 Figure 6 Figure 7 Figure 6 t) J Figure 9 Figure 10

Claims (1)

[Claims] The blades of axial flow rotating machines have a multi-layer structure, and the number of blades is increased by an integral multiple as the distance from the rotation axis increases, and the blade roots of the short blades formed in the upper layer are engaged with stubs provided in the middle of the long blades. A multi-layered rotor blade for rotating machinery.