JP3464753B2 - Assembled integrated impeller and method of manufacturing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an assembly-integrated impeller used for, for example, a rotary machine and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, a compressor has been used in a gas turbine as a rotary machine, for example, and as an impeller as a means for rotating the compressor, for example, one shown in FIG. 6 is known. . As shown in FIGS. 6 and 7, the impeller 101
Is an impeller main body 102 formed by arranging a plurality of blades 102A.
And a first shaft 103 and a second shaft 104 which are continuous on both sides of the impeller body 102, and alloy steel for machine structure (for example, SCM435 or SCM440) is used as a material. First shaft 103, impeller body 102, second shaft 104
Is formed with the shaft hole 105 penetrating therethrough.

The above-mentioned impeller 101 is machined out as follows. After the material is prepared and subjected to heat treatment such as quenching, the first shaft 10 is
No. 3 bearing support surface 103A, second shaft 104 bearing support surface 104A, and shaft hole 105 inner peripheral surface 105A engaging portion 10
5B, blade 102A of blade main body 102 and blade 102A
The outer peripheral surface of the radial tip end portion 102B is machined. In this case, accuracy is required for the radial dimension from the central axis of the shaft hole 105 to the outer peripheral surface of the radial tip portion 102B of the blade 102A, and the bearing support surface 103A of the first shaft 103 and the second shaft 10 are provided.
The bearing supporting surface 104A of No. 4 is required to have accuracy of the radial dimension from the central axis of the shaft hole 105.

A shaft 106 penetrates the shaft hole 105 of the impeller 101, and the shaft 106 is fastened to the impeller 101 by a screw 107. The bearing support surface 103A on the outer peripheral surface of the first shaft 103 is supported by the first bearing 108, and the bearing support surface 104A on the outer peripheral surface of the second shaft 104 is supported by the second bearing 109.

[0005]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
Can be processed with high precision because it is machined using alloy steel for machine structure that has been heat treated such as quenching, but the alloy steel for machine structure that has been heat treated such as quenching is hard and There is a problem that it is long and the productivity is low.

[0006] Further, as a processed portion, a bearing support surface 103A of the first shaft 103 and a bearing support surface 10 of the second shaft 104.
4A, the engaging portion 105B of the inner peripheral surface 105A of the shaft hole 105,
There is a blade 102A of the impeller body 102 and a radial tip portion 102B of the blade 102A. The impeller 101 having many such processing parts has to process various processing parts with a single machine tool in a single process, which requires a long processing time.
There is a problem of low productivity. Although it is conceivable that the machine process is divided into a plurality of processes to configure the line, the equipment scale becomes large and it takes a long time to carry, which is not preferable especially in the case of high-mix low-volume production.

Further, the entire impeller can be manufactured by precision casting. In this case, the entire volume of the impeller is increased, the possibility of material defects is increased, and the reliability is reduced. In addition, there is a problem that casting yield is deteriorated, which is not preferable. Further, the impeller 101 is replaced by the impeller body 1
02, first axis 103, second axis 104,
Although it is conceivable that they are integrated by friction welding, there is a limit to the size of the diameter to be joined in friction welding, and it is limited to small parts. Moreover, a large amount of "burr" occurs in friction welding.
A finishing operation for removing "burrs" is required, and post-processing takes time, which is not preferable.

The present invention has been made in order to solve the above-mentioned problems, and an object thereof is to process a plurality of parts with high accuracy and to achieve high productivity when processing accuracy is required for a plurality of parts. It is an object of the present invention to provide an assembly-integrated impeller capable of ensuring the property and a manufacturing method thereof.

[0009]

The invention according to claim 1 is
An impeller body including a body portion having an axial hole, a plurality of blades surrounding the body portion and continuously arranged in the body portion, and a circular shaft portion protruding from an end surface of the body portion, and a wing. A cylindrical shaft having annular flanges having shaft holes at both ends of the car body is provided at one end, and the impeller body and the cylinder shaft are burned in a state where the center axis of the shaft hole of the impeller body and the axis of the cylinder shaft coincide with each other. It is characterized by being integrally assembled by a fitting process.

According to a second aspect of the present invention, in the assembly-integrated type impeller according to the first aspect, the inner peripheral surface of the annular flange of the cylindrical shaft is integrated with the outer peripheral surface of the circular shaft portion of the main body of the impeller by shrink fitting. It is characterized by being attached to. The invention according to claim 3 is composed of a body portion having an axial hole, a plurality of blades surrounding the body portion and continuously arranged on the body portion, and a circular shaft portion provided on an end surface of the body portion. The impeller body is made by precision casting and is formed on the outer peripheral surface of a cylindrical shaft that has an outer diameter approximately equal to the outer diameter of the body of the impeller body and has an annular flange at one end around the shaft hole. The bearing surface thus processed is processed to an accuracy close to finishing accuracy, the outer peripheral surface of the circular shaft portion of the impeller body is fitted with the inner peripheral surface of the annular flange of the cylindrical shaft, and the cylindrical shaft is attached to the impeller body. Align the axis with the central axis of the shaft hole of the impeller body and assemble by shrink fitting, and then finish the outer peripheral surface of the radial tip of the blade of the impeller body and the bearing surface of the cylindrical shaft. Is characterized by.

(Operation) In the invention according to claim 1,
The impeller body and the cylindrical shaft are integrally assembled by shrink fitting with the central axis of the shaft hole of the impeller body and the axis of the cylindrical shaft aligned. The outer peripheral surface of the portion and the inner peripheral surface of the annular flange of the cylindrical shaft are integrated by shrink fitting.

At this time, when the assembly-integrated impeller rotates,
The impeller body and the cylindrical shaft are subjected to centrifugal force, and the circular shaft portion of the impeller body and the annular flange of the cylindrical shaft are deformed radially outward by the centrifugal force. Here, since the cylindrical shaft has an outer diameter substantially equal to the outer diameter of the body portion of the impeller body, the centrifugal force acting on the impeller body is larger than the centrifugal force acting on the cylindrical shaft. Therefore,
The amount of radial deformation of the circular shaft portion of the impeller body is larger than the amount of radial deformation of the annular flange of the cylindrical shaft.

The tightening margin between the outer peripheral surface of the circular shaft portion of the impeller body and the inner peripheral surface of the annular flange of the cylindrical shaft is increased, and the connection between the impeller body and the cylindrical shaft is further strengthened. In the invention according to claim 3, the machining process is divided for each impeller body and the cylindrical shaft, and as a sub-process, the impeller body and the cylindrical shaft are machined in parallel to each other in advance to a precision close to finishing accuracy.

That is, a body portion having an axial hole, and a plurality of blades surrounding the body portion and continuously arranged on the body portion,
The impeller body including a circular shaft portion provided on the end surface of the body portion is manufactured by precision casting. Further, the bearing surface formed on the outer peripheral surface of the cylindrical shaft having an outer diameter substantially equal to the outer diameter of the body portion of the impeller body and having an annular flange at one end around the shaft hole is close to finishing accuracy. Processed to precision.

Then, on the outer peripheral surface of the circular shaft portion of the impeller body,
The inner peripheral surface of the annular flange of the cylindrical shaft is fitted, and the cylindrical shaft is assembled to the impeller body with its axis aligned with the central axis of the axial hole of the impeller body. Next, the outer peripheral surface of the radial tip of the blade of the impeller body and the bearing surface of the cylindrical shaft are finished.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 5, an assembly-integrated impeller according to an embodiment of the invention described in claims 1 to 3 and a method for manufacturing the same will be described with reference to a gas turbine. First, the assembly-integrated type impeller will be described.

In FIG. 1, an assembly-integrated impeller 1 has an impeller main body 2 and a first cylindrical shaft 3 and a second cylindrical shaft 4 projecting from both ends of the impeller main body 2, which are integrally formed by shrink fitting. Is installed in. The central axis 5A of the shaft hole 5B of the impeller body 2 and the axis 1 of the first cylindrical shaft 3 in the assembled state
0A, the axis line 14A of the second cylindrical shaft 4 coincides, and the inner peripheral surface 11A of the annular flange 11 of the first cylindrical shaft 3 is shrink-fitted to the outer peripheral surface 8B of the first circular shaft portion 8 of the impeller body 2. Are assembled together.

A detailed description will be given below. The impeller body 2 has a body portion 5 having an axial hole 5B, a plurality of blades 6 surrounding the body portion 5 and arranged continuously with the body portion 5, and projecting from the end surfaces 5C and 5D of the body portion 5. The first circular shaft portion 8 and the second circular shaft portion 9 are formed. The body part 5 has end faces 5 on both sides.
A shaft hole 5B penetrating from C to the end surface 5D is formed.

In FIGS. 1 and 3, a plurality of blades 6 twisted into a three-dimensional shape are integrally provided in the body portion 5 around the central axis 5A of the shaft hole 5B. Each feather 6
The impeller flow paths 7 for circulating the air are formed in a three-dimensional shape. Shaft hole 5 of body part 5 of impeller body 2
Thickness near B (from the end surface 8A of the first circular shaft portion 8 to the second
The distance to the end surface 9A of the circular shaft portion 9 is larger than the thickness dimension L1 of the radial tip portion 6A of the blade 6.

As a material of the main body 2 of the impeller, for example, SUS63
Equivalent to 0 or SUS631 is used. As will be described later, the impeller main body 2 including the blades 6 is manufactured by precision casting, and compared with the shape and accuracy of the surface of the blades 6, the blade 6 has a radial direction from the central axis 5A of the shaft hole 5B to the blades 6. Accuracy is required for the diameter dimension of the tip portion 6A up to the outer peripheral surface 6B.
This is to eliminate the imbalance of centrifugal force during rotation of the assembly-integrated impeller 1.

A first circular shaft portion 8 and a second circular shaft portion 9 are provided on the end surfaces 5C and 5D of the body portion 5 so as to project, and the central axis line 5 of the shaft hole 5B.
It is located around A. The first cylindrical shaft 3 has a large diameter portion 3C formed on one end side and a small diameter portion 3 continuous with the large diameter portion 3C.
A and alloy steel for machine structure (for example, SCM435 or SCM440) is used as a material.
The SCM material is excellent in hardenability and toughness by adding Mo to Cr steel, and its coefficient of thermal expansion is almost the same as that of the material of the impeller body 2.

A shaft hole 10 is formed in the small diameter portion 3A and the large diameter portion 3C of the first cylindrical shaft 3, and the axis line 10A of the shaft hole 10 coincides with the central axis line 5A of the shaft hole 5B of the impeller body 2. There is. The large diameter portion 3C is provided with an annular flange 11 around the axis 10A of the shaft hole 10. The diameters of the small-diameter portion 3A and the large-diameter portion 3C are smaller than the outer diameter of the body portion 5, but when the size of the blade 6 is taken as a reference, the large-diameter portion 3 of the first cylindrical shaft 3 is used.
C, the small diameter portion 3A has an outer diameter substantially equal to the outer diameter of the body portion 5 of the impeller body 2. Therefore, the weight of the first cylindrical shaft 3 is smaller than the weight of the impeller body 2. Further, the distance from the axis line 10A of the first cylindrical shaft 3 to the centrifugal force acting point G ₂ during rotation is smaller than the distance from the central axis line 5A of the impeller body 2 to the centrifugal force acting point G ₁ .

On the inner peripheral surface 10B of the shaft hole 10, a drive transmission engaging portion 12 composed of two flat surfaces is formed as a connecting portion with a shaft 29 described later. Drive transmission engaging portion 1
2 is in the same position as the large diameter portion 3C in the direction of the shaft hole 10. A bearing surface 13 is formed on the outer peripheral surface 3B of the step portion 3E of the small diameter portion 3A of the first cylindrical shaft 3 on the right side of FIG. The bearing surface 13 is required to have accuracy (a diameter dimension from the axis 10A of the first cylindrical shaft 3 to the bearing surface 13) for mounting a first bearing 34 described later.

The annular flange 11 is required to have a high accuracy in diameter dimension from the axis of the first cylindrical shaft 3 to the inner peripheral surface 11A. A gap D is formed between the end surface 8A of the first circular shaft portion 8 and the inner bottom portion 11B of the annular flange 11 of the first cylindrical shaft 3, and the first cylindrical shaft 3 has a large diameter portion from the gap D. 3C
An air passage C is formed over the outer peripheral surface 3D.

The second cylindrical shaft 4 is composed of a large-diameter portion 4A formed on one end side and a small-diameter portion 4B continuous with the large-diameter portion 4A, and is made of alloy steel for machine structure (for example, SCM435).
Alternatively, SCM440) is used, and its coefficient of thermal expansion is almost the same as that of the impeller body 2.

A shaft hole 14 is formed in the large diameter portion 4A and the small diameter portion 4B of the second cylindrical shaft 4, and the axis line 14A of the shaft hole 14 coincides with the central axis line 5A of the shaft hole 5B of the impeller body 2. There is. The diameters of the large diameter portion 4A and the small diameter portion 4B are smaller than the outer diameter of the body portion 5, but when the size of the blade 6 is taken as a reference, the large diameter portion 4A and the small diameter portion 4B of the second cylindrical shaft 4 are used. Has an outer diameter substantially equal to the outer diameter of the body portion 5 of the impeller body 2. Therefore, the weight of the second cylindrical shaft 4 is smaller than that of the impeller body 2. Also, the axis line 14A of the second cylindrical shaft 4 during rotation
To the centrifugal force acting point G ₃ is smaller than the distance from the central axis 5A of the impeller body 2 to the centrifugal force acting point G ₁ .

In the large diameter portion 4A on one end side of the second cylindrical shaft 4,
An annular flange 15 is provided around the shaft hole 14.
Precision is required for the diameter dimension from the axis 14A of the second cylindrical shaft 4 of the annular flange 15 to the inner peripheral surface 15A. On the outer peripheral surface 4C of the small diameter portion 4B of the second cylindrical shaft 4, a spline engaging portion 16, a bearing surface 17 located on the right side of FIG. 1 of the spline engaging portion 16, and a step portion 4E are sequentially illustrated. 1 is formed from the left side. The bearing surface 17 is required to have accuracy (a diameter dimension from the axis of the second cylindrical shaft 4 to the bearing surface 17) for mounting a second bearing 35 described later.

Air passages 18, 18 are formed from the inner peripheral surface 14B of the shaft hole 14 to the outer peripheral surface 4D of the large diameter portion 4A. As shown in FIGS. 1 and 2, from the air passages 18, 18 to the tip of an intake guide casing 19 described later and the second cylindrical shaft 4
By guiding the air into the gap between the outer peripheral surfaces 4D of the large diameter portion 4A, the oil particles of the second bearing 35 as well as the labyrinth seal 43, which will be described later, are reliably prevented from being scattered to the assembled integrated impeller 1. .

Further, reference numeral S is a fastening means, and the fastening means S
Is the shaft hole 5B of the impeller body 2, the shaft hole 10 of the first cylindrical shaft 3,
A shaft 29 that penetrates the shaft hole 14 of the second cylindrical shaft 4 and is an output shaft, and a pair of nips on both sides of the impeller body 2, the first cylindrical shaft 3, and the second cylindrical shaft 4 that are provided at both ends of the shaft 29. And a sandwiching portion 29B, and the sandwiching portion 29B.
They are integrated by tightening the (screw 39). 29 A of clamping parts consist of the step part of the turbine impeller 27.

Next, a gas turbine to which the assembly-integrated impeller 1 is applied will be described. As shown in FIG. 2, in the gas turbine GT, an intake guide casing 19, a compressor casing 20, a support member 21, and a discharge side casing 22 are sequentially arranged from the left side in the drawing. The intake guide casing 19 is formed in an umbrella shape, and a hole 19B is formed at the tip thereof.

Outer peripheral surface 19A of the intake guide casing 19
Between the compressor and the casing 20 for compressor
Are formed. The compressor casing 20 is formed with a discharge path 24 that guides the compressed air to a combustor (not shown) along the radial direction. A first hole portion 21A is formed on one side of the support member 21, and a second hole portion 21B is formed on the other side, so that the first hole portion 21A and the second hole portion 21B communicate with each other.

A compressor casing 20 and a discharge side casing 22 are attached to both sides of the support member 21. The discharge side casing 22 has a cylindrical discharge port 25,
A gas introduction path 26 is formed on one side of the exhaust port 25 and guides combustion gas from the combustor. The assembly-integrated impeller 1 is arranged between the compressor casing 20 and one side of the support member 21, and the discharge side casing 22 and the support member 2 are arranged.
A turbine wheel 27 is arranged between the other side of the turbine 1.

The turbine impeller 27 is composed of a turbine impeller main body 28 in which a plurality of twisted blades 28A are radially and three-dimensionally arranged, and the shaft 29 integrated with the turbine impeller main body 28. There is.

Impeller flow paths (not shown) for circulating air are formed in a three-dimensional shape between the blades 28A. The shaft 29 includes the shaft hole 5B of the impeller body 2 of the assembly-integrated impeller 1, the shaft hole 10 of the first cylindrical shaft 3, and the second cylindrical shaft 4.
Of the first annular gap 30A and the second annular gap 30A in the radial direction between the shaft 29 and the assembly-integrated impeller 1.
An annular gap 30B is formed.

A chamfered portion 31 and a support portion 32 having a D-shaped cross section are formed in the middle of the shaft 29, and the screw portion 3 is provided at the tip.
3 is formed. A gap 32A is formed in the support portion 32, and the first annular gap 30A and the second annular gap 3 are formed.
0B communicates with each other through the gap 32A. A first bearing 34 is fitted on the bearing surface 13 of the first cylindrical shaft 3, and the first bearing 34 is attached to the support member 21.

On the bearing surface 17 of the second cylindrical shaft 4, the second bearing 3
5 is fitted, and the second bearing 35 is mounted on a block 36 provided on the back side of the intake guide casing 19. A sleeve 38 is attached to the spline engagement portion 16 of the second cylindrical shaft 4.
Are splined together, and the sleeve 40 is screwed onto the sleeve 38 by tightening the screw 40 screwed onto the second cylindrical shaft 4.
And the second bearing 35.

A pair of holding portions 29A, 29B of the fastening means S
Thereby, the impeller body 2, the first cylindrical shaft 3, and the second cylindrical shaft 4 are sandwiched from both sides, and the screw 39 screwed into the screw portion 33 at the tip of the shaft 29 is tightened to be integrated. Therefore, the turbine impeller 27 and the assembly-integrated impeller 1 are integrated and are rotatably supported by the first bearing 34 and the second bearing 35.

The sleeve 38 has a driving force extracting member 3
8A (indicated by a chain double-dashed line) is connected. Further, a labyrinth seal 41 is interposed between the outer peripheral surface 29D of the root portion of the shaft 29 and the inner peripheral surface of the first hole portion 21A of the support member 21. There is. The labyrinth seal 41 allows the first bearing 3
The oil particles of No. 4 are prevented from scattering on the turbine wheel main body 28.

A labyrinth seal 42 is interposed between the outer peripheral surface 3D of the large diameter portion 3C of the first cylindrical shaft 3 and the inner peripheral surface of the second hole portion 21B of the support member 21. Labyrinth seal 4
2, the oil particles of the first bearing 34 are assembled to form the integrated impeller 1
It is prevented from scattering to. Outer peripheral surface 4D of large-diameter portion 4A of second cylindrical shaft 4 and hole 1 of intake guide casing 19
A labyrinth seal 43 is interposed between the inner peripheral surfaces of 9B. The labyrinth seal 43 prevents the oil particles of the second bearing 35 from being assembled and scattered to the integrated impeller 1.

The air guided to the annular intake port 23 is compressed into compressed air by the rotation of the assembly-integrated impeller 1. The compressed air is guided to a combustor (not shown) via the outlet passage 24, and combustion gas is generated by the combustor. The combustion gas is guided from the combustor to the turbine impeller 27 via the gas introduction path 26, imparts a rotational force to the turbine impeller 27, and is discharged to the discharge port 25.

The rotational force of the turbine impeller 27 is the turbine impeller main body 28 → the chamfered portion 31 → the first cylindrical shaft 3 → the integrally assembled impeller 1 → the second cylindrical shaft 4 → the sleeve 38 → the driving force extracting member 38A. The driving force is transmitted to the driving force extracting member 38A in order.
Next, the operation of the assembly-integrated impeller 1 will be described. The outer peripheral surface 8B of the first circular shaft portion 8 of the impeller body 2 and the first cylindrical shaft 3
The inner peripheral surface 11A of the annular flange 11 is integrated by shrink fitting, and the outer peripheral surface 9B of the second circular shaft portion 9 of the impeller body 2 and the annular flange 15 of the second cylindrical shaft 4 are The inner peripheral surface 15A is in a state of being integrated by shrink fitting, and by the pair of clamping portions 29A and 29B of the tightening means S,
The impeller main body 2, the first circular shaft portion 8 and the second circular shaft portion 9 are sandwiched from both sides, and are fastened and integrated by a screw 39 screwed to a screw portion 33 at the tip of the shaft 29.

At this time, when the assembly-integrated impeller 1 rotates, the impeller body 2, the first cylindrical shaft 3, and the second cylindrical shaft 4 receive a centrifugal force. Due to the centrifugal force, the first circular shaft portion 8 of the impeller body 2
The annular flange 11 is deformed radially outward. Further, due to the centrifugal force, the annular flange 15 of the second circular shaft portion 9 of the impeller body 2 is deformed radially outward.

The first cylindrical shaft 3 and the second cylindrical shaft 4 are the impeller body 2
The centrifugal force acting on the impeller main body 2 has the same outer diameter as the outer diameter of the body portion 5 of the first cylindrical shaft 3,
It is larger than the centrifugal force acting on the cylindrical shaft 4. Therefore, the radial deformation amount of the first circular shaft portion 8 of the impeller body 2 is larger than the radial deformation amount of the annular flange 11 of the first cylindrical shaft 3, and the impeller body 2 Second circular shank 9
The amount of deformation of the circular flange 1 of the second cylindrical shaft 4 is
It is larger than the amount of outward deformation of No. 5.

Therefore, the outer peripheral surface 8B of the first circular shaft portion 8 of the impeller body 2 and the inner peripheral surface 1 of the annular flange 11 of the first cylindrical shaft 3 are arranged.
The tightening margin of 1A increases, and the impeller body 2 and the first cylindrical shaft 3
Will be tightly bound. The tightening margin between the outer peripheral surface of the second circular shaft portion 9 of the impeller body 2 and the inner peripheral surface of the annular flange 15 of the second cylindrical shaft 4 increases. The connection between the impeller body 2 and the second cylindrical shaft 4 becomes strong.

When the assembly-integrated impeller 1 is rotated, the centrifugal force in the impeller body 2 is maximized on the inner diameter side, and the outer diameter of the impeller body 2 is the first cylindrical shaft 3 Since the outer diameter of the second cylindrical shaft 4 is larger, the impeller body 2
The stress on the inner diameter side of the shaft becomes large, but the shaft hole 5B of the impeller body 2
The thickness dimension in the vicinity (the distance from the end surface 8A of the first circular shaft portion 8 to the end surface 9A of the second circular shaft portion 9) is larger than the thickness dimension L1 of the radial tip portion 6A of the blade 6. Therefore, the stress is relieved.

By the rotation of the assembly-integrated impeller 1,
Since the air in the portion A has a high pressure and the air in the portion B has a negative pressure, the air is in the portion A → air passage C → gap D → first annular gap 30A → support portion 32 in FIG.
32A on the side of → the second annular gap 30B → the air passage 1
It is guided to the labyrinth seal 43 in the order of 8 and 18, and together with the labyrinth seal 43, the oil particles of the second bearing 35 are surely prevented from scattering to the assembled integrated impeller 1.

According to the above-mentioned structure, even if the impeller body 2 and the first cylindrical shaft 3 and the second cylindrical shaft 4 are separately assembled and integrally assembled by shrink fitting, the assembly-integrated impeller 1 During rotation, the centrifugal force of the impeller body 2 causes the first cylindrical shaft 3 and the second cylindrical shaft 4 to rotate.
And the tightening margin of the outer peripheral surface 8B of the first circular shaft portion 8 of the impeller main body 2 and the inner peripheral surface 11B of the annular flange 11 of the first cylindrical shaft 3 increases and the second circular shape increases. Outer peripheral surface 9B of shaft portion 9 and annular flange 11 of second cylindrical shaft 4
The tightening margin of the inner peripheral surface 11B can be increased, the connection can be strengthened, and the strength of the assembled integrated impeller can be secured.

The assembly-integrated impeller 1 includes an impeller body 2,
Since the first cylinder shaft 3 and the second cylinder shaft 4 are made up of three parts, the machining process is divided for each part, and the impeller body 2, the first cylinder shaft 3, and the second cylinder shaft are subprocessed. 4 in parallel,
Machining can be performed in advance to an accuracy close to finishing accuracy, and high productivity can be secured. Further, the impeller body 2, the first cylindrical shaft 3, the second
By assembling the cylindrical shaft 4 integrally and machining it to finishing accuracy, the assembly-integrated impeller 1 can be made highly accurate.

Next, a method of manufacturing the assembly-integrated impeller according to this embodiment will be described. The impeller body 2 having the above structure is manufactured by precision casting. The material made by precision casting is machined, and the outer peripheral surface 6B of the radial tip portion 6A of the blade 6 of the impeller body 2, the bearing surface 13 of the first cylindrical shaft 3, the second
The processed portion of the bearing surface 17 of the cylindrical shaft 4 has an accuracy close to the finishing accuracy.

On the other hand, the first cylindrical shaft 3 and the second cylindrical shaft 4 are subjected to heat treatment such as quenching and tempering, and then processed to an accuracy close to finishing accuracy. In addition, the drive transmission engaging portion 12 of the first cylindrical shaft 3 is double-faced. The spline engagement portion 16 of the second cylindrical shaft 4 is splined, and the air passages 18, 1
8 is punched.

The inner peripheral surface 11A of the annular flange 11 of the first cylindrical shaft 3 and the outer peripheral surface 3D of the large diameter portion 3C of the first cylindrical shaft 3 are cut by coaxial machining to ensure concentricity. Inner peripheral surface 15A of the annular flange 15 of the second cylindrical shaft 4, the second cylindrical shaft 4
The outer peripheral surface 4D of the large-diameter portion 4A is cut by coaxial processing to ensure concentricity. First circular shaft portion 8 of the impeller body 2
The outer peripheral surface 8B of the first cylindrical shaft 3 and the inner peripheral surface 11A of the annular flange 11 of the first cylindrical shaft 3 are joined by shrink fitting so that the first cylindrical shaft 3 is assembled to the impeller body 2.

Outer peripheral surface 9B of the second circular shaft portion 9 of the impeller body 2
By coupling the inner peripheral surface 15A of the annular flange 15 of the second cylindrical shaft 4 with the shrink fitting process, the second cylindrical shaft 4 is assembled to the impeller body 2. The interference margin between the impeller body 2 and the first cylindrical shaft 3 and the second cylindrical shaft 4 in the shrink fitting process differs depending on the transmission torque between the impeller body 2 and the first cylindrical shaft 3 and the second cylindrical shaft 4. It is necessary to increase the tightening margin and increase the temperature difference as the transmission torque increases.

The impeller body 2 is cooled to -150 ° C, and the first cylindrical shaft 3 and the second cylindrical shaft 4 are heated to 120 ° C to be shrink-fitted. The temperature difference between the impeller body 2 and the first cylindrical shaft 3 and the second cylindrical shaft 4 becomes 270 ° C. and they are joined by shrink fitting, but the temperature of the first cylindrical shaft 3 and the second cylindrical shaft 4 is 120 ℃
The reason for heating to 1 is that when the temperature of the first cylindrical shaft 3 and the second cylindrical shaft 4 is higher than 120 ° C. or higher, the first cylindrical shaft 3 and the second cylindrical shaft 4 that have undergone heat treatment such as quenching and tempering This is to prevent the heat treatment from returning to the original state.

Next, the integrated impeller body 2, the first cylindrical shaft 3 and the second cylindrical shaft 4 are connected to each other at the X portion (the outer peripheral surface 3 of the large diameter portion 3C).
D) and the Y portion (the outer peripheral surface 4D of the large diameter portion 4A) are used as a reference for positioning. That is, the outer peripheral surface 6B of the radial tip portion 6A of the blade 6 of the impeller body 2 is chucked on a machine tool (not shown), and the diameter deviation of the X portion and the Y portion is measured with a dial gauge, and the X portion is measured. , The chucking is fixed to the X part and the Y part in a state where virtual lines connecting the centers of the diameters of the Y part and the center of rotation of the machine tool coincide with each other. As a result, the line connecting the centers of the diameters of the X part and the Y part becomes the processing center, and becomes the axis line at the time of the rotation of the finally integrated assembly-type impeller 1.

In this positioning state, the blades 6 of the impeller body 2 are
The outer peripheral surface 6B of the radial tip portion 6A, the bearing surface 13 of the first cylindrical shaft 3, and the bearing surface 17 of the second cylindrical shaft 4 are finished. According to the assembly-integrated impeller 1 configured as described above, the following effects are obtained in addition to the effects of the assembly-integrated impeller 1.

After machining the first cylindrical shaft 3 and the second cylindrical shaft 4 made of steel to an accuracy close to finishing accuracy, the impeller body 2 is shrink-fitted with the first cylindrical shaft 3 and the second cylindrical shaft 4. One assembly, and then the bearing surface of the impeller main body 2 or the first cylindrical shaft 3 and the bearing surface 17 of the second cylindrical shaft 4 are finally finished, so that the machining allowance is reduced, the machining time is shortened, and Productivity can be secured.

Since the assembly-integrated impeller 1 has a three-part structure including the impeller body 2, the first cylindrical shaft 3, and the second cylindrical shaft 4, the impeller body 2 and the first cylindrical shaft 3 Compared with the case of considering a two-division type structure in which the above is manufactured by precision casting and integrated, the processed portion (drive transmission engaging portion 12) of the inner peripheral surface of the shaft hole 5B in the first cylindrical shaft 3 is easier. It can be processed on two sides.

Further, the first is made of alloy steel for machine structure.
In the impeller body 2 which is a cast product having a lower allowable stress than the cylindrical shaft 3 and the second cylindrical shaft 4, it is possible to avoid the complicated shape on the inner diameter side where the stress is highest, and to improve the reliability of the product. Can be secured.

The second cylindrical shaft 4 made of alloy steel for machine structure is compared with the case of considering a two-division type structure in which the impeller main body 2 and the second cylindrical shaft 4 are integrally formed by precision casting. Since the spline engaging portion 16 is provided on the upper side, it is possible to secure reliability as a product, as compared with processing on a precision cast product. In the present embodiment, the impeller body 2 and the first cylindrical shaft 3 and the second cylindrical shaft 4 are joined by shrink fitting, but if the transmission torque is small, it is also possible to use an interference fit.

Further, in this embodiment, the assembly-integrated impeller 1 includes the impeller body 2, the first cylindrical shaft 3, and the second cylindrical shaft 4.
However, for example, the impeller main body 2 and the second cylindrical shaft 4 can be made into two parts by precision casting and the impeller main body 2 and the first cylindrical shaft 3 can be integrated. It can also be divided into two by precision casting. Further, in the present embodiment, the drive transmission engagement portion 12 of the first cylindrical shaft 3 is double-faced, and the drive transmission engagement portion 12 of the first cylindrical shaft 3 is engaged with the shaft 29. However, the drive transmission engaging portion 12 may be spline processed or key processed.

[0061]

According to the invention described in claim 1, since the cylindrical shaft is assembled to the impeller main body by shrink fitting after machining the cylindrical shaft to an accuracy close to finishing accuracy, the cutting margin is small. Therefore, the processing time can be shortened and high productivity can be secured.
Also, since the assembly-integrated impeller is composed of an impeller body, a cylindrical shaft, and multiple parts, the machining process is divided for each part and the impeller body and cylindrical shaft are pre-finished in parallel as sub-processes. Highly productive can be secured because it can be machined to a precision close to that of precision.

Further, by integrally machining the impeller body and the cylindrical shaft to finish accuracy, the integrated integral impeller can be made highly accurate. According to the second aspect of the present invention, at the time of rotation of the assembly-integrated impeller, even if the impeller body and the cylindrical shaft are separately assembled and assembled together, the cylindrical shaft is attached to the outer peripheral surface of the circular shaft portion of the impeller body. Since the inner peripheral surface of the annular flange is connected, the interference between the outer peripheral surface of the circular shaft portion of the impeller body and the inner peripheral surface of the annular flange of the cylindrical shaft increases, and the outer periphery of the circular shaft portion of the impeller body increases. The strength of the assembled integrated impeller can be secured by strengthening the connection between the surface and the inner peripheral surface of the annular flange of the cylindrical shaft.

According to the invention of claim 3, in addition to the effect of the invention of claim 1, the following effect is exhibited. After machining the cylindrical shaft to a precision close to the finishing accuracy and assembling the cylindrical shaft to the main body of the impeller, the radial tip of the blade of the main body of the impeller and the bearing surface of the cylindrical shaft are finally finished. Cost can be reduced, processing time can be shortened, and high productivity can be secured.

[Brief description of drawings]

FIG. 1 is a partial sectional side view of an assembly-integrated impeller according to an embodiment of the present invention.

FIG. 2 is a cross-sectional side view of a gas turbine to which an assembly-integrated impeller according to an embodiment of the present invention is applied.

FIG. 3 is a perspective view showing an impeller body of the assembly-integrated impeller of FIG. 1.

FIG. 4 is a cross-sectional view showing an assembled state of the chamfered portion of the shaft and the first cylindrical shaft in FIG.

5 is a cross-sectional view showing a gap in a support portion of the shaft in FIG.

FIG. 6 is a sectional side view showing a conventional impeller.

FIG. 7 is a perspective view showing a blade of a conventional impeller.

[Explanation of symbols]

1 Assembly-integrated impeller 2 wing wheel body 2A end face 2B end face 3 First cylinder axis 4 Second cylindrical shaft 4 First cylinder axis 5 body 5A central axis 5B shaft hole 6 feathers 6A Radial tip 6B outer peripheral surface 8 First circular shaft 9 Second circular shaft 10 shaft holes 10A axis 11 annular flange 13 Bearing surface 14 shaft hole 14A axis 15 annular flange 17 Bearing surface 29 shaft 29A clamping part 29B clamping part S tightening means

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ identification code FI F02C 7/00 F02C 7/00 D (56) References JP-A-6-56546 (JP, A) JP-A-7-332002 ( JP, A) JP 8-254102 (JP, A) JP 8-226302 (JP, A) JP 4-171298 (JP, A) JP 4-103805 (JP, A) JP Flat 4-103806 (JP, A) Actual Open 3-30534 (JP, U) Actual Open 3-89938 (JP, U) Actual Open Sho 62-46634 (JP, U) Actual Open Sho 63-2801 (JP , U) Actually open 61-47402 (JP, U) Actually open 1-134736 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F01D 25/00 F01D 1/06 F01D 5/04 F02B 39/00 F02C 7/00

Claims (3)

(57) [Claims] 1. A wing composed of a body portion having an axial hole, a plurality of blades surrounding the body portion and continuously arranged on the body portion, and a circular shaft portion protruding from an end surface of the body portion. The vane main body includes a car body and a cylindrical shaft having annular flanges having shaft holes at both ends of the vane car body, and the central axis of the shaft hole of the vane car body and the axis of the cylindrical shaft are aligned. , The integrated integrated type impeller, wherein the cylindrical shaft is integrally assembled by shrink fitting. 2. The assembly-integrated type according to claim 1, wherein the inner peripheral surface of the annular flange of the cylindrical shaft is integrally assembled to the outer peripheral surface of the circular shaft portion of the impeller body by shrink fitting. Wing wheel. 3. A wing comprising a body portion having an axial hole, a plurality of blades surrounding the body portion and continuously arranged on the body portion, and a circular shaft portion provided on an end surface of the body portion. The car body
Finished the bearing surface formed on the outer peripheral surface of the cylindrical shaft that is made by precision casting and has an outer diameter that is almost the same as the outer diameter of the body of the impeller body and has an annular flange at one end around the shaft hole. Processed to a precision close to the precision, fit the inner peripheral surface of the annular flange of the cylindrical shaft to the outer peripheral surface of the circular shaft part of the impeller body, and set the cylindrical shaft to the impeller body and its axis to the impeller body. It is assembled by shrink fitting so as to match the central axis of the shaft hole, and then the outer peripheral surface of the radial tip end of the blade of the impeller body and the bearing surface of the cylindrical shaft are finished and processed. Manufacturing method of impeller.