JPH03229902A - Turbine rotor coupling structure to rotary shaft - Google Patents

Abstract

PURPOSE:To prevent the destruction of a cylinder boss, by inserting a rotary shaft into the inside of the cylinder boss of a turbine rotor, coupling both through coupling members, and making a constitution so that heat conduction from a turbine rotor side that becomes high temperature to coupling members coupled with the rotary shaft may be able to be restrained. CONSTITUTION:A hollow cylinder boss 43 is projectingly formed at a turbine rotor 37, and at its tip and at the back of a compressor impeller 39 opposing this, coupling portions 45, 47 that are respectively made up by forming projections at equal intervals circumferentially, are formed. An adaptor 49 that is made of a ceramic material of high strength and a low heat conduction rate, is interveniently provided between both coupling portions 45, 47, and meshed with respective coupling portions 45, 47. Also, a male screw portion 51 is formed at the adaptor 49 vicinity outer periphery surface of a tie shaft 41 that is inserted into the inside of the cylinder boss 43, and a collar 53 is screwed on to the male screw portion 51, and at the collar 53, engaging members 63 are put on four 61s formed at equal intervals circumferentially, and these are butted against the step portion 67 of the cylinder boss 43.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Application Field) This invention provides a system in which a rotating shaft is inserted into a cylindrical boss of a turbine rotor, and the rotating shaft and the turbine rotor are coupled via a coupling member. The present invention relates to a structure for coupling a turbine rotor to a rotating shaft.

(Prior Art) Fig. 4 is a cross-sectional view of a single-shaft regenerative gas turbine in which a compressor impeller 1 and a ceramic turbine rotor 3 are coaxially attached to a tie shaft 5, which is a rotating shaft. AIJTOHOTIVE TE
CHNOLOGY DEVELOPMENT CONT
RACTOR8C00RDINATION HEETI
NG+ October 27-30, 1986). The turbine rotor 3 is supplied with combustion gas burned in the combustor 7 and rotates together with the compressor impeller 1 and the tie shaft 5. The high-temperature exhaust gas discharged from the turbine rotor 1 passes through the combustion gas passage 8 and reaches the rotary regenerator heat exchanger 9 to heat it, while the combustor impeller 3
The compressed air flowing out passes through the air passage 10 and the heated heat exchanger 9, where it receives heat and is used as combustion air, improving the cycle efficiency of the gas turbine.

FIG. 5 shows the main part of FIG. 4, that is, the coupling structure between the turbine rotor 3 and the compressor impeller 1 side in the gas turbine. The turbine rotor 3 has a hollow cylindrical boss 11, and the outer periphery of the cylindrical boss 11 serves as a journal portion of a foil bearing 13. A hollow cylindrical metal component called a collet 15 is fitted inside the cylindrical boss 11 . As shown in FIG. 6, the collet 15 has a plurality of slits 17 formed in the axial direction at equal intervals in the circumferential direction. When the collet 15 is inserted into the cylindrical boss 11, the slit 17 is formed so that the protrusion 19 at the tip of the collet 15 narrows toward the axis, and after the insertion is completed, it returns to its original shape and the protrusion 19 is placed inside the cylindrical boss 11. This is for engaging with the stepped portion 21 of.

The proximal outer circumferential surface of the collet 15 is in close contact with the inner circumferential surface of the cylindrical boss 11, and serves as a centering portion 22 between the turbine rotor 3 and the tie shaft 5. A screw hole 23 is formed in the inner peripheral surface of the centering portion 22, and the tie shaft 5 is screwed into the screw hole 23.

The tie shaft 5 passes through the compressor impeller 1, and the back surface of the compressor impeller 1 and the tip of the cylindrical boss 11 of the turbine rotor 3 are engaged with each other by a curved coupling 27 having protrusions formed at equal intervals in the circumferential direction. combined.

On the opposite side of the compressor impeller 1 from the turbine rotor 3, there is a collar 29. A thrust bearing 31, a ball bearing 32, and a retainer 33 are fitted on the tie shaft 5 in this order, and are fastened and fixed by a lock nut 35.

(Problems to be Solved by the Invention) However, in such a conventional coupling structure of a turbine rotor to a rotating shaft, the outer circumferential surface of the collet 15 coupled to the tie shaft 5, including one protrusion and the centering portion 22, Turbine rotor 3 becomes extremely hot due to combustion gas
Because the collet 15 comes into contact with the inner surface of the cylindrical boss 11, the collet 15 itself becomes extremely hot and bends during use, reducing the overall fastening force of the tie shaft 5. As a result, the vibration of the turbine rotor 3 increases during rotation, and there is a risk that the turbine rotor 3 will come into contact with the turbine shroud and be damaged. Further, the centering portion 22 of the collet 15 is located at the cylindrical boss 11.
The fat expands due to the heat received from the cylindrical boss 11, causing strong interference with the cylindrical boss 11, and there is a risk that the cylindrical boss 11 made of ceramic may be destroyed.

Therefore, an object of the present invention is to suppress heat transfer from the turbine rotor side, where the temperature increases, to the coupling member with the rotating shaft.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention includes forming a protruding cylindrical boss on a turbine rotor, and arranging the end face of the cylindrical boss and a compressor impeller at mutually opposing positions. In a coupling structure to a rotating shaft of a turbine rotor, in which the rotating shaft provided on the compressor impeller side is inserted into a cylindrical boss, the rotating shaft is meshed with the provided meshing portion, and between the cylindrical boss and the rotating shaft,
A cylindrical coupling member that is partially fitted into the cylindrical boss side with a small gap is fixed to the rotating shaft, and a plurality of engagement members that can protrude toward the outer periphery of the cylindrical coupling member in the radial direction are provided. , an engaging portion is provided on the inner surface of the cylindrical boss to which an engaging member protruding from the cylindrical coupling member toward the outer periphery in the radial direction can engage with the engaging member.

(Function) A part of the cylindrical coupling member interposed between the cylindrical boss of the turbine rotor and the rotating shaft comes into contact with the inner surface on the cylindrical boss side, which becomes hot, and prevents centering between the turbine rotor and the rotating shaft. conduct,
On the other hand, the engaging member is engaged with an engaging portion on the inner surface of the cylindrical boss, thereby coupling the turbine rotor and the rotating shaft. Since the contact portion of the cylindrical coupling member side with the cylindrical boss side of the turbine rotor, which becomes hot, is only a part of the outer peripheral surface of the cylindrical coupling member and the engagement member, the temperature of the cylindrical coupling member is prevented from increasing. .

(Example) Hereinafter, an example of the present invention will be described based on FIGS. 1 to 3.

FIG. 1 shows a coupling structure of a ceramic turbine rotor 37 in a gas turbine, three compressor impellers, and a tie shaft 41 that is a rotating shaft. The rest of the structure is similar to the conventional gas turbine shown in FIGS. 4 to 6.

A hollow cylindrical boss 43 is formed to protrude from the turbine rotor 37, and at the tip of the cylindrical boss 43 and on the back surfaces of the three compressor impellers facing this, there are car as meshing parts in which protrusions are formed at equal intervals in the circumferential direction. Big coupling portions 45 and 47 are formed. Further, between the carpic coupling parts 45 and 47, a curvic coupling made of a ceramic material having low thermal conductivity and high strength such as zirconia and meshing with the curvic coupling parts 45 and 47 at both ends is provided. Four adapters each having a section formed therein are interposed. The turbine rotor 37 and the compressor impeller 39 are coupled by interposing the four adapters.

A male threaded portion 51 is formed on the outer peripheral surface of the tie shaft 41 inserted into the cylindrical boss 43 near the four adapters.
A collar 53 as a metal cylindrical coupling member is screwed into this male threaded portion 51 via a female threaded portion 55 until it abuts on the flange 57 . Flange 57 of cylindrical boss 43
The side end portion has a larger diameter than other portions and contacts the inner circumferential surface of the adapter 49 with a slight gap, thereby forming a centering portion 59 with respect to the turbine rotor side 37.

Four holes 61 are provided at equal intervals in the circumferential direction on the tip side of the collar 53.
An engaging member 63 made of a ceramic material such as zirconia is fitted into the hole 61 so as to protrude to the outside of the collar 53 .

Side surface 6 of the portion of the engagement member 63 that protrudes toward the cylindrical boss 43 side
5 contacts and engages with a stepped portion 67 as an engaging portion formed by expanding the inside of the cylindrical boss 43. Between the engaging member 63 and the five centering portions, six gaps are formed between the collar 53 and the turbine rotor 37.

The inner surface 71 of the engagement member 63 is in contact with the outer circumferential surface 73 of the tie shaft 41 on the distal end side. A protrusion 75 is formed on the engagement member 63 along its inner surface 71 and protrudes toward the distal end side of the tie shaft 41, and the protrusion 75 is fitted into a recess 77 formed in the collar 53 and fixed. .

Further, seven tapered portions are formed at the distal end portion of the tie shaft 41. The tapered portion 79 is connected to the tie shaft 41
When inserting the collar 53 into the cylindrical boss 43 and screwing it into the collar 53, the engaging member 63, which is originally projected inside the collar 63, is inserted in order to insert the collar 53 into the cylindrical boss 43. It has the function of pushing outward and creating the state shown in Figure 1.

In such a structure in which the turbine rotor is coupled to the rotating shaft, the turbine rotor 37 becomes hot due to combustion gas.
Heat flows from the cylindrical boss 43 to the metal collar 53 through the ceramic adapter 49 and engagement member 63.
Since the heat does not flow directly to the collar 53, the amount of heat flowing into the collar 53 is reduced and the collar 53 is prevented from becoming sagging. As a result, the overall fastening force of the tie shaft 41, such as the connection between the turbine rotor 37 and the tie shaft 41, is maintained strong, the swing of the turbine rotor 37 during rotation is prevented, and contact with and damage to the turbine shroud is avoided.

Moreover, the centering part 59 of the collar 53 fits into the four adapters with a slight gap, but in the case of ceramic such as zirconia that makes up the four adapters, the coefficient of thermal expansion is relatively close to that of metal. Therefore, together with the above-described effect of reducing the amount of heat flowing in from the turbine rotor 37 side, the difference in thermal expansion between the collar 53 and the cylindrical boss 43 side at the centering portion 59 is alleviated, and as a result, the outer surface of the collar 53 Destruction of the four adapters that come into contact with is prevented.

[Effects of the Invention] As explained above, according to the present invention, the inflow of heat from the turbine rotor, which becomes high temperature, into the cylindrical coupling member for coupling the turbine rotor and the rotating shaft is reduced by The licking, which is performed only from a part of the outer peripheral surface and the engaging member, can prevent the cylindrical coupling member from becoming hot, and the bending of the cylindrical coupling member and the accompanying rotational vibration of the turbine rotor can be avoided, and as a result, the turbine The resultant force between the rotor and the rotating shaft is maintained, and the turbine rotor is prevented from coming into contact with the turbine shroud, thereby avoiding damage. Further, since the temperature of the cylindrical coupling member is prevented from increasing, strong interference of the outer peripheral surface of the cylindrical coupling member with the cylindrical boss is prevented, and destruction of the cylindrical boss can be avoided.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a coupling structure of a turbine rotor to a rotating shaft showing an embodiment of the present invention, Fig. 2 is a sectional view taken along the line ■-■ of Fig. 1, Fig. 3 is a perspective view of an adapter, and Fig. 4 The figure is a cross-sectional view of a gas turbine equipped with a conventional coupling structure, FIG. 5 is a cross-sectional view of the coupling structure of the turbine rotor to the rotating shaft in the gas turbine shown in FIG. 4, and FIG. 6 is the coupling shown in FIG. 5. FIG. 3 is a perspective view of a collet used in the structure. 37...3 turbine rotors...compressor impeller 43--cylindrical boss 41...tie shaft (rotating shaft) 45.47...curvic coupling (meshing part) 5
3...Collar (cylindrical coupling member) 63...Engaging member 67...Step part (engaging part)

Claims (1)

[Claims] A cylindrical boss is formed protrudingly on the turbine rotor, the end face of the cylindrical boss and a compressor impeller are meshed and connected at a meshing part provided at mutually opposing parts, and a rotating shaft provided on the compressor impeller side is inserted into the cylindrical boss. In the coupling structure of a turbine rotor to a rotating shaft, a cylindrical coupling member, which is partially fitted with a small gap with respect to the cylindrical boss side, is interposed between the cylindrical boss and the rotating shaft and fixed to the rotating shaft. the cylindrical coupling member, and a plurality of engagement members capable of protruding toward the outer circumferential side of the cylindrical coupling member in the radial direction thereof are provided, and the engagement member protruding from the cylindrical coupling member toward the outer circumferential side of the cylindrical coupling member engages with the engagement portion. A structure for connecting a turbine rotor to a rotating shaft, characterized in that the inner surface of a cylindrical boss is provided with: