JP2013044312A - Rotor of turbomachinery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotor of turbomachinery having an improved fatigue strength and product life.SOLUTION: There is adopted a rotor 100 of a turbocompressor 1 including: an impeller 11 that is installed at an end part 6a of a rotating shaft 6 and has a first linear expansion coefficient in the axial direction; a tension bolt 13 that fastens the impeller 11 to the end part 6a of the rotating shaft 6 in the axial direction and has a second linear expansion coefficient higher than the first linear expansion coefficient in the axial direction; and a thermal expansion member 14 that is fastened to the end part 6a of the rotating shaft 6 in the axial direction together with the impeller 11 by the tension bolt 13 and has contact end faces 14a at both sides in the axial direction which are perpendicular to the axial direction and a third linear expansion coefficient higher than the second linear expansion coefficient.

Description

  The present invention relates to a rotor of a turbomachine.

Patent Document 1 below discloses a turbo compressor that compresses air or the like in multiple stages as an industrial turbo machine. The rotor of this turbo compressor has an impeller connected to the end of the rotating shaft, and is configured to rotate by a drive motor via a gear train.
The impeller provided at the end of the rotating shaft is connected by a tension bolt (bolt fastening body). The bolt fastening body is configured to express an axial force by tightening the impeller in the axial direction toward the end of the rotating shaft, and to smoothly transmit torque from the rotating shaft to the impeller.

JP 2008-133745 A

By the way, as in the above-described prior art, the impeller and the bolt fastening body formed separately are different from each other in the linear expansion coefficient in the axial direction due to the difference in material, and the axial force caused by tightening the bolt fastening body due to thermal displacement. However, inevitably fluctuates when the device is operating and when the device is stopped.
In order to improve the fatigue strength and further extend the product life, it is desirable to reduce the stress amplitude difference due to the fluctuation of the axial force that is repeated when the apparatus is operating and when the apparatus is stopped.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a turbomachine rotor with improved fatigue strength and product life.

In order to solve the above problems, the present invention provides an impeller that is provided at an end portion of a rotating shaft and has a first linear expansion coefficient in the axial direction, and the impeller toward the end portion of the rotating shaft. A bolt fastening body that is tightened in the axial direction and has a second linear expansion coefficient larger than the first linear expansion coefficient in the axial direction, and the impeller toward the end of the rotating shaft by the bolt fastening body And a thermal expansion member that is tightened in the axial direction, has contact end faces on both sides in the axial direction perpendicular to the axial direction, and has a third linear expansion coefficient larger than the second linear expansion coefficient; The rotor of the turbomachine having
By adopting this configuration, in the present invention, the thermal expansion member that is tightened together with the impeller even when the axial force is reduced due to the difference in thermal expansion between the impeller and the bolt fastening body during operation of the apparatus, Axial force when the device is operating or when the device is stopped, because the contact end surface perpendicular to the axial direction of the impeller and bolt fastening body causes thermal expansion that is proportionally greater than that of the impeller and bolt fastening body. The difference in the stress amplitude due to the fluctuations can be reduced.

Moreover, in this invention, the said thermal expansion member employ | adopts the structure that it is arrange | positioned between the edge part of the said rotating shaft, and the said impeller in the said axial direction.
By adopting this configuration, in the present invention, the space between the end of the rotating shaft and the impeller in the axial direction corresponds to the root portion of the impeller, and the root portion is the impeller on the intake side. Since this is a part where the temperature is higher during operation of the apparatus than the tip part of the material, it is possible to appropriately develop a thermal expansion action that suppresses the difference in stress amplitude by disposing a thermal expansion member in the part. .

Moreover, in this invention, the structure that the length in the said axial direction of the said thermal expansion member is set based on the length which a clamping force acts on the said impeller in the said axial direction is employ | adopted.
By adopting this configuration, in the present invention, the decrease in the axial force due to the difference in thermal expansion between the impeller and the bolt fastening body corresponds to the length in which the tightening force acts on the impeller in the axial direction. Based on the length, the length of the thermal expansion member in the axial direction is set.

In the present invention, the length of the thermal expansion member in the axial direction is further set based on the amount of axial displacement associated with the centrifugal force during operation of the impeller. To do.
By adopting this configuration, in the present invention, during operation of the apparatus, displacement due to axial contraction due to centrifugal force further occurs, which also leads to a decrease in axial force. Therefore, the amount of axial displacement associated with the centrifugal force is reduced. Based on this, the length of the thermal expansion member in the axial direction is set.

Moreover, in this invention, the said thermal expansion member employ | adopts the structure of having a torque transmission part which transmits the torque of the said rotating shaft to the said impeller.
By adopting this configuration, in the present invention, the thermal expansion member can also be used as a torque transmission portion, whereby torque can be efficiently transmitted with a smaller axial force.

Moreover, in this invention, the said thermal expansion member employ | adopts the structure of having a seal part which airtightly seals between the edge part of the said rotating shaft, and the said impeller.
By adopting this configuration, the present invention can be used as a gasket when the operating environment is a corrosive atmosphere by using the thermal expansion member also as a seal portion.

In the present invention, the contact end face is formed in an annular shape around the bolt fastening body, and the contact end face includes a first annular region having a first surface roughness, and the first end face. A configuration in which a second annular region having a second surface roughness different from the surface roughness is employed.
By adopting this configuration, in the present invention, by providing two annular regions having different surface roughnesses on the contact end surface of the thermal expansion member, in one annular region, the surface roughness is increased, It is possible to function as a torque transmission part that increases the friction coefficient, and in the other annular region, the surface roughness can be reduced and the seal part can be functioned as a seal part that improves sealing performance by being in close contact with the contact member.

According to the present invention, the impeller provided at the end of the rotating shaft and having the first linear expansion coefficient in the axial direction, and the impeller is tightened in the axial direction toward the end of the rotating shaft and the above-described A bolt fastening body having a second linear expansion coefficient larger than the first linear expansion coefficient in the axial direction, and the bolt fastening body tightened in the axial direction together with the impeller toward the end of the rotating shaft. And a thermal expansion member having a third linear expansion coefficient larger than the second linear expansion coefficient, with contact end surfaces on both sides in the axial direction being formed perpendicular to the axial direction, and a rotor of a turbomachine By adopting, even when the axial force is reduced due to the difference in thermal expansion between the impeller and the bolt fastening body during operation of the device, the thermal expansion member tightened together with the impeller Stress due to fluctuations in axial force when the machine is operating or when the machine is stopped, due to the fact that the contact end surface perpendicular to the axial direction expands in proportion to the thermal expansion of the fastening body and develops an axial force that compensates for the reduction of the axial force. The amplitude difference can be kept small.
Therefore, the present invention can provide a turbomachine rotor with improved fatigue strength and product life.

It is sectional drawing which shows the principal part of the turbo compressor in embodiment of this invention. It is sectional drawing which shows the structure of the rotor of the turbo compressor in embodiment of this invention. It is a figure which shows the contact end surface of the thermal expansion member in another embodiment of this invention. It is sectional drawing which shows the structure of the rotor of the turbo compressor in another embodiment of this invention.

  Hereinafter, embodiments of a rotor of a turbomachine according to the present invention will be described with reference to the drawings. In the following description, a turbo compressor is exemplified as the turbo machine.

FIG. 1 is a cross-sectional view showing a main part of a turbo compressor 1 according to an embodiment of the present invention.
A turbo compressor (turbo machine) 1 includes a gear device 3 connected to an output shaft 2 of a drive motor, and a gas G such as air sucked from the outside from a first stage compressor 10 to a second stage compressor 20, And a gas flow path (not shown) that leads to the third-stage compressor 30 and the fourth-stage compressor 40 in this order.

  The gear device 3 includes a first gear 5 connected to the end of the output shaft 2 in the gear case 4, a second gear 7 provided on the rotating shaft 6, and a third gear 9 provided on the rotating shaft 8. And have. The first gear 5 is provided to mesh with the second gear 7 and the third gear 9, respectively. Thereby, the rotating shaft 6 and the rotating shaft 8 rotate in synchronization with the rotation of the output shaft 2 of the drive motor.

The rotating shaft 6 is disposed in parallel with the output shaft 2 and is rotatably supported with respect to the gear case 4. An impeller 11 of the first stage compressor 10 is provided at one end of the rotating shaft 6, and an impeller 21 of the second stage compressor 20 is provided at the other end.
On the other hand, the rotating shaft 8 is disposed parallel to the output shaft 2 and on the opposite side of the rotating shaft 6 with the output shaft 2 interposed therebetween, and is rotatably supported with respect to the gear case 4. An impeller 31 of the third stage compressor 30 is provided at one end of the rotating shaft 8, and an impeller 41 of the fourth stage compressor 40 is provided at the other end.

  The impellers 11, 21, 31, and 41 are radial impellers, and have blades including a three-dimensional twist (not shown) that guides the gas G sucked in the axial direction in the radial direction. Diffuser flow paths are provided around the impellers 11, 21, 31, and 41, respectively, and the gas G led out in the radial direction is compressed and boosted in the flow paths, and further provided around the diffuser flow paths. It is possible to supply the compressor to the next stage through the scroll flow path.

  According to the turbo compressor 1 having the above configuration, when the output shaft 2 of the drive motor is driven to rotate, the gas G is introduced from the intake port 12 of the first stage compressor 10 and is compressed in the first stage. Thereafter, the gas G passes through an unillustrated gas flow path through the intake port 22 of the second stage compressor 20, the intake port 32 of the third stage compressor 30, and the intake port 42 of the fourth stage compressor 40. The gas G introduced in sequence and subjected to multistage compression is supplied to a device such as an internal combustion engine (not shown) connected to the turbo compressor 1.

Next, the configuration of the rotor of the turbo compressor 1 will be described with reference to FIG.
FIG. 2 is a cross-sectional view showing the configuration of the rotor 100 of the turbo compressor 1 according to the embodiment of the present invention.
In the following description, the rotor 100 of the first stage compressor 10 will be described as an example of the rotor.

  The rotor 100 includes an impeller 11 provided at the end 6 a of the rotating shaft 6, a tension bolt (bolt fastening body) 13 that tightens the impeller 11 in the axial direction toward the end 6 a of the rotating shaft 6, and a tension bolt 13. The thermal expansion member 14 is tightened in the axial direction together with the impeller 11 toward the end portion 6a of the rotating shaft 6.

  The tension bolt 13 is formed with a male screw 15 at its tip, and a tensile force is applied when the members (the impeller 11 and the thermal expansion member 14) are attached, and the reaction force (axial force) A member disposed between the base end portion and the tip end portion is configured to be tightened (pressed) in the axial direction. The tension bolt 13 of the present embodiment is provided separately from the rotary shaft 6 and is fastened and fixed to the end portion 6a of the rotary shaft 6 by a male screw 16 formed at the base end portion thereof.

  On the other hand, a through hole 11 a for inserting the tension bolt 13 is formed at the center of the impeller 11. The length of the through hole 11a in the axial direction is shorter than the length of the tension bolt 13 in the axial direction, and the male screw 15 of the tension bolt 13 projects from the opening at the tip. Then, a nut 17 is screwed onto the male screw 15 to develop a predetermined axial force by pulling the tension bolt 13, so that the impeller 11 and the thermal expansion member 14 are always not loosened and the end 6 a of the rotating shaft 6. Fastened and fixed to.

  The impeller 11 and the tension bolt 13 have different linear expansion coefficients in the axial direction due to the difference in material. In the present embodiment, for example, the impeller 11 is formed of a titanium-based metal material, and the tension bolt 13 is formed of an iron-based metal material, which is greater than the linear expansion coefficient (first linear expansion coefficient) of the impeller 11. The tension bolt 13 has a larger linear expansion coefficient (second linear expansion coefficient).

  The thermal expansion member 14 has a third linear expansion coefficient larger than the second linear expansion coefficient, and is configured to be thermally expandable in proportion to the impeller 11 and the tension bolt 13. . For example, the thermal expansion member 14 is formed of an aluminum-based metal material with respect to the impeller 11 and the tension bolt 13 formed of the metal material. Further, the thermal expansion member 14 has contact end surfaces 14a on both sides in the axial direction perpendicular to the axial direction, and in a direction perpendicular to the surface (axial direction) with respect to a member that contacts the contact end surface 14a by thermal expansion. It is the structure which can make axial force act.

The thermal expansion member 14 is formed in an annular shape around the tension bolt 13 and has a substantially washer shape as a whole. The thermal expansion member 14 is disposed between the end 6 a of the rotating shaft 6 and the impeller 11 in the axial direction, that is, at the root portion of the impeller 11.
The length (thickness) t in the axial direction of the thermal expansion member 14 is set to a length that can follow the thermal displacement between the impeller 11 and the tension bolt 13 during operation of the apparatus.

Specifically, the first linear expansion coefficient of the impeller 11 is α ₁ , the second linear expansion coefficient of the tension bolt 13 is α ₂ , and the third linear expansion coefficient of the thermal expansion member 14 is α _3. If the temperature difference between the time and when the apparatus is stopped is ΔT, and the length of the tightening force acting on the impeller 11 in the axial direction is L, it can be expressed by the following equation (1).

  When the expression (1) is expanded, the length t can be expressed by the following expression (2) with the length L as a variable. That is, the length t in the axial direction of the thermal expansion member 14 is set based on the length L at which the tightening force acts on the impeller 11 in the axial direction.

For example, the first linear expansion coefficient α ₁ = 8.8 × 10 ⁻⁶ (/ ° C.), the second linear expansion coefficient α ₂ = 11.8 × 10 ⁻⁶ (/ ° C.), and the third linear expansion coefficient. Assuming that α ₃ = 23.9 × 10 ⁻⁶ (/ ° C.) and length L = 100 (mm) and substituting into equation (2), thermal displacement between the impeller 11 and the tension bolt 13 during operation of the apparatus The length t of the thermal expansion member 14 that can follow this is 12.5 (mm).
By the way, in practice, a temperature distribution is created inside the part, and a part of the temperature is a predetermined temperature. Therefore, the above calculation example is a simple calculation when it is assumed that the inside of the component is uniformly at a predetermined temperature.

Then, the effect by the rotor 100 of the said structure is demonstrated. In the following description, the description will be made on the assumption that the inside of the component is uniformly at a predetermined temperature for ease of explanation.
When the apparatus is stopped, the temperature of the rotor 100 is normal temperature (for example, 20 ° C.). However, during operation of the apparatus, that is, when the rotor 100 rotates at a higher speed and reaches a predetermined operating speed, the temperature reaches a predetermined temperature (for example, 150 ° C.). Raise the temperature.

  During the operation of the apparatus, the axial force applied by the tension bolt 13 may be reduced due to the difference in thermal expansion caused by the difference in material between the impeller 11 and the tension bolt 13. However, during the operation of the apparatus, the thermal expansion member 14 that is fastened together with the impeller 11 has a third linear expansion coefficient, so that the thermal expansion member 14 thermally expands relatively larger than the impeller 11 and the tension bolt 13. Then, the thermal expansion member 14 pushes the end 6a and the impeller 11 of the rotating shaft 6 in the direction perpendicular to the surface (axial direction) by the contact end surface 14a perpendicular to the axial direction, pulls the tension bolt 13, and the shaft An axial force that compensates for the decrease in force is developed. For this reason, the difference in the stress amplitude due to the fluctuation of the axial force when the apparatus is operating and when the apparatus is stopped can be kept small.

  Further, the reduction in the axial force due to the difference in thermal expansion between the impeller 11 and the tension bolt 13 corresponds to the length L at which the tightening force acts on the impeller 11 in the axial direction, so that the thermal expansion is based on the length L. By setting the length t of the member 14 in the axial direction, the thermal expansion member 14 can be thermally expanded following the thermal displacement between the impeller 11 and the tension bolt 13. For this reason, the axial force which compensates the fall of the said axial force can be optimized, and the stress amplitude difference by the fluctuation | variation of an axial force can be suppressed smaller.

  Further, the thermal expansion member 14 is disposed between the end 6 a of the rotating shaft 6 and the impeller 11 in the axial direction. The space between the end 6a of the rotating shaft 6 and the impeller 11 in the axial direction corresponds to the root of the impeller 11, and the root is the tip of the impeller 11 on the intake side to which the gas G is blown. Compared to the portion (the portion where the nut 17 is provided), the temperature is higher during operation of the apparatus (for example, the tip is 50 ° C. and the root is 150 ° C.). Therefore, by disposing the thermal expansion member 14 at the base portion that is at a high temperature, it is possible to appropriately exhibit a thermal expansion action that suppresses the difference in stress amplitude.

  Furthermore, since the temperature of the root portion of the impeller 11 is increased by heat conduction from the maximum outer diameter side (trading edge side) that becomes a high temperature, the influence of disturbance (as compared to the tip portion of the impeller 11 on the intake side) ( For example, the influence of fluctuations in the temperature and flow rate of the gas G to be taken in is small. For this reason, there is almost no situation in which the thermal expansion member 14 frequently expands and contracts in the axial direction during the operation of the apparatus due to a temperature change due to the influence of a disturbance, and the stress amplitude difference due to the fluctuation of the axial force due to it hardly occurs. Occurrence can be prevented.

Therefore, according to the above-described embodiment, the impeller 11 provided at the end 6a of the rotating shaft 6 and having the first linear expansion coefficient in the axial direction, and the impeller toward the end 6a of the rotating shaft 6 are provided. A tension bolt 13 that tightens 11 in the axial direction and has a second linear expansion coefficient larger than the first linear expansion coefficient in the axial direction, and the impeller 11 toward the end 6a of the rotating shaft 6 by the tension bolt 13 A thermal expansion member 14 that is clamped in the axial direction, has contact end faces 14a on both sides in the axial direction perpendicular to the axial direction, and has a third linear expansion coefficient larger than the second linear expansion coefficient. By adopting the rotor 100 of the turbo compressor 1 having, even when the axial force is reduced due to the difference in thermal expansion between the impeller 11 and the tension bolt 13 during operation of the apparatus, The thermal expansion member 14 fastened together with the root wheel 11 thermally expands relatively larger than the impeller 11 and the tension bolt 13, and a shaft that compensates for the decrease in the axial force by the contact end surface 14 a perpendicular to the axial direction. Since the force is expressed, the stress amplitude difference due to the fluctuation of the axial force when the apparatus is operating and when the apparatus is stopped can be suppressed to a small value.
Therefore, in this embodiment, since the accumulation of fatigue can be suppressed to a small extent even when the device operation and the device stop are repeated, the rotor 100 of the turbo compressor 1 with improved fatigue strength and product life can be provided.

  As mentioned above, although preferred embodiment of this invention was described referring drawings, this invention is not limited to the said embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

For example, in the above embodiment, it has been described that the length t in the axial direction of the thermal expansion member 14 is set by the formula (2) based on the length L in which the tightening force acts on the impeller 11 in the axial direction. The invention is not limited to this. That is, during operation of the apparatus, displacement due to axial contraction due to the centrifugal force applied to the impeller 11 also occurs, which also leads to a decrease in axial force. Therefore, thermal expansion is performed based on the amount of axial displacement associated with the centrifugal force. The length t in the axial direction of the member 14 may be set.
Considering the amount of axial displacement associated with the centrifugal force, the length t in the axial direction of the thermal expansion member 14 can be expressed by the following equation (3).

X in Equation (3) is the rotational speed when the rotor 100 is in operation, and β is a physical property value indicating the amount of displacement in the axial direction of the impeller 11 based on the rotational speed.
Thus, the length t in the axial direction of the thermal expansion member 14 is further set based on the amount of axial displacement associated with the centrifugal force during operation of the impeller 11, so that the apparatus is operating and the apparatus is stopped. The stress amplitude difference due to the fluctuation of the axial force at can be further reduced.

Further, for example, by changing the material and surface roughness of the thermal expansion member 14, the coefficient of friction with the contact member such as the end 6 a of the rotating shaft 6 and the impeller 11 is increased, whereby the thermal expansion member 14 is torqued. The torque can also be efficiently transmitted with a smaller axial force by being used as a transmission portion. When the axial force is reduced, the stress amplitude difference is also relatively reduced, so that fatigue strength and product life can be improved.
Also, for example, when the operating environment is a corrosive atmosphere, depending on the material of the thermal expansion member 14, it can also be used as a seal portion and can be used as a gasket. Thereby, corrosion resistance improves.

For example, as shown in FIG. 3, by adopting two annular regions having different surface roughnesses on the contact end surface 14 a of the thermal expansion member 14, a configuration that achieves both the torque transmission part and the seal part is adopted. Also good.
As shown in FIG. 3, the contact end surface 14a includes a first annular region A having a first surface roughness and a second annular region B having a second surface roughness different from the first surface roughness. And have.

  The first annular region A is arranged on the outer diameter side of the second annular region B, and the first surface roughness is larger (coarse) than the second surface roughness. Thereby, in the 1st cyclic | annular area | region A, it can be made to function as a torque transmission part which enlarges a friction coefficient with a contact member. The outer diameter side is more advantageous in terms of torque transmission than the inner diameter side.

On the other hand, the second annular region B is arranged closer to the inner diameter side than the first annular region A, and the second surface roughness is smaller (densely) than the first surface roughness. Thereby, in the 2nd cyclic | annular area | region B, it can be made to function as a seal part which improves a sealing performance by contacting a contact member closely.
When it is desired to secure sealing performance over torque transmission performance, the arrangement of the first annular area A and the second annular area B shown in FIG. 3 is reversed, that is, the surface roughness is small. The second annular region B may be disposed on the outer diameter side, and the first annular region A having a large surface roughness may be disposed on the inner diameter side.

  Further, for example, in the above embodiment, it has been described that the thermal expansion member 14 is disposed between the end 6a of the rotating shaft 6 and the impeller 11 in the axial direction. 20, in the rotors of the third stage compressor 30 and the fourth stage compressor 40, the temperature of the gas G is also increased to a high temperature, and the temperature due to the temperature distribution of the tip and root portions of the impellers 21, 31, and 41 is increased. When the difference is small, the thermal expansion member 14 may be disposed between the tip portion, that is, the impeller 11 and the nut 17 in the axial direction.

  Further, for example, in the above-described embodiment, the tension bolt 13 is exemplified as the bolt fastening body. However, the bolt fastening body that contacts the impeller 11 (for example, the case where the impeller 11 is a female screw and the bolt fastening body is a male screw, or You may employ | adopt the case etc. which fix the impeller 11 and the rotating shaft 6 with a bolt fastening body.

  Moreover, when the bolt fastening body which contacts with the impeller 11 is adopted, since the temperature rise of the bolt fastening body can be sufficiently expected due to heat transfer from the impeller 11, the temperature distribution inside the component becomes small, and the above-described thermal expansion member The effect of reducing the axial force drop due to 14 (reducing the stress amplitude) can be sufficiently obtained.

  On the other hand, when a bolt fastening body that does not come into contact with the impeller 11 like the tension bolt 13 shown in FIG. 4 is adopted, the temperature rise of the bolt fastening body due to heat transfer from the impeller 11 is not sufficient, and the inside of the component In some cases, the axial force increases (increases the stress amplitude). In this case, if the thermal expansion member 14 that has a large linear expansion coefficient and is susceptible to thermal displacement is cooled and contracted by air cooling or heat exchange with a refrigerant such as lubricating oil, the increase in axial force is reduced (reduction in stress amplitude). )can do. Therefore, in order to more reliably reduce the stress amplitude, a cooling device for cooling the thermal expansion member 14 may be additionally provided.

  DESCRIPTION OF SYMBOLS 1 ... Turbo compressor (turbo machine), 6 ... Rotary shaft, 6a ... End part, 11 ... Impeller, 13 ... Tension bolt (bolt fastening body), 14 ... Thermal expansion member, 14a ... Contact end surface, 100 ... Rotor, A ... first annular region (torque transmission part), B ... second annular region (seal part), L ... length, t ... length

Claims (7)

An impeller provided at an end of the rotating shaft and having a first linear expansion coefficient in the axial direction;
A bolt fastening body that tightens the impeller in the axial direction toward the end of the rotating shaft and has a second linear expansion coefficient larger than the first linear expansion coefficient in the axial direction;
The bolt fastening body is tightened in the axial direction together with the impeller toward the end of the rotating shaft, and contact end surfaces on both sides in the axial direction are formed perpendicular to the axial direction and the second line A thermal expansion member having a third linear expansion coefficient greater than the expansion coefficient;
A rotor of a turbomachine characterized by comprising:   2. The turbomachine rotor according to claim 1, wherein the thermal expansion member is disposed between an end portion of the rotating shaft and the impeller in the axial direction.   3. The turbo machine according to claim 1, wherein a length of the thermal expansion member in the axial direction is set based on a length in which a clamping force acts on the impeller in the axial direction. Rotor.   The length in the said axial direction of the said thermal expansion member is further set based on the amount of displacement of the said axial direction accompanying the centrifugal force at the time of the operation | movement of the said impeller. Turbomachine rotor.   The said thermal expansion member has a torque transmission part which transmits the torque of the said rotating shaft to the said impeller, The rotor of the turbomachine as described in any one of Claims 1-4 characterized by the above-mentioned.   6. The rotor of a turbomachine according to claim 1, wherein the thermal expansion member includes a seal portion that hermetically seals between an end portion of the rotating shaft and the impeller. . The contact end surface is formed in an annular shape around the bolt fastening body,
The contact end surface includes a first annular region having a first surface roughness and a second annular region having a second surface roughness different from the first surface roughness. The turbomachine rotor according to any one of claims 1 to 6.

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