JP6878063B2 - Rotating machine and rotor support rigidity adjustment method - Google Patents

Description

The present invention relates to a rotary machine and a method for adjusting rotor support rigidity.

Conventionally, as a rotating machine such as a low-pressure chassis of a steam turbine, it is integrally provided at the axle-oriented end of the vehicle interior body and the vehicle interior body, which are supported by a gantry in a tubular shape centered on the axis. A vehicle compartment having a cylindrical cone portion whose diameter decreases toward the inside of the vehicle interior body, a bearing box supported by the cone portion and having a bearing inside, and a bearing box supported by the bearing in the axial direction. It is known that a bearing box provided with an extending rotor is supported in the passenger compartment. In this case, the manufacturing cost is reduced because the bearing span is shorter and the diameter of the rotor rotating shaft does not need to be increased as compared with the foundation support type in which the bearing box is arranged outside the cone and supported by the foundation. There is an advantage that it can be suppressed.

In such a rotating machine, since the natural frequency of the cone portion is near the frequency (for example, 50 Hz) at the rated rotation speed (for example, 3000 rpm), there is a mode in which the cone portion vibrates (resonates). Therefore, the vibration of the cone portion may increase the shaft vibration of the rotor. In addition to this, when the natural frequency of the rotor is also close to the rated rotation speed, the mode of the cone portion and the mode of the rotor are coupled, and there is a possibility that the shaft vibration further increases.
Therefore, as a countermeasure against such a problem, for example, a vibration absorber as shown in Patent Document 1 is installed outside the vehicle interior to reduce shaft vibration, and the vibration absorber has vibration energy. By absorbing the above, the shaft vibration can be reduced.

Japanese Unexamined Patent Publication No. 2013-104297

In the conventional rotary machine, the balance is adjusted so that the mode is not excited by adding an unbalance to the current rotor unbalance at an arbitrary place so as not to excite the mode. It is common. In this case, the shaft vibration of the rotor can be reduced by adjusting the balance, but the shaft vibration level may not be sufficiently reduced only by adjusting the balance, and large-scale improvement work such as reinforcement by welding is carried out. Therefore, there is a problem that it is necessary to reduce the shaft vibration level by increasing the dynamic rigidity.
Even if the shaft vibration can be reduced by adjusting the balance, an imbalance that is not caused by residual unbalance such as contact or thermal bending may occur, and the shaft vibration may increase. There was room for improvement.

The present invention has been made in view of the above-mentioned problems, and it is possible to reduce the shaft vibration level by efficiently detuning the natural frequency from the rated rotation speed, which requires time-consuming additional reinforcement work and the like. It is an object of the present invention to provide an unnecessary rotating machine and a method for adjusting rotor support rigidity.

In order to achieve the above object, the rotating machine according to the present invention is integrally provided at the vehicle interior body supported by the gantry in a tubular shape centered on the axis and at the end of the vehicle interior body in the axial direction. A vehicle compartment having a cylindrical cone portion whose diameter decreases toward the inside of the vehicle interior body, a bearing box supported by the cone portion and having a bearing inside, and a bearing box supported by the bearing. A rotor extending in the axial direction and a support portion provided so as to support the cone portion from the inner surface of the passenger compartment, the rigidity of which can be adjusted, and a plurality of support portions arranged in the axial direction are provided . A bearing support rib connecting the cone portion and the bearing box is provided, and the bearing support ribs extend in the circumferential direction and are arranged at least one of the bearing support ribs at intervals in the axial direction. One has been characterized Rukoto is disposed in a position that coincides with the bearing in the axial direction.

According to the present invention, a support portion is interposed between the cone portion that supports the rotor and the inner surface of the vehicle interior, and the rotor can be supported via the cone portion by the support portion adjusted to a predetermined rigidity. .. That is, the bending rigidity of the cone portion can be changed by installing a support portion whose rigidity can be adjusted with respect to the cone portion which affects the support rigidity of the rotor and adjusting the rigidity of the support portion. That is, it is possible to adjust the rigidity of the cone portion based on the axial end of the passenger compartment body in the cone portion, and the cone portion or the coupled mode of the cone portion and the rotor, or the shaft system (hereinafter referred to as the shaft system). , Simply called the cone part) can change the natural frequency.

In this way, the natural frequency of the cone portion can be changed by adjusting the rigidity of the cone portion, and the shaft vibration level is reduced by detuning from the rated rotation speed. This makes it possible to avoid resonance in which the cone portion vibrates near the rated rotation speed of the rotating machine and the shaft vibration of the rotor increases.
Further, in the present invention, the natural frequency of the cone portion is changed by adjusting the rigidity of the support portion itself, and the shaft vibration level is reduced more reliably as compared with the conventional method of performing balance adjustment. Can be made to.

Further, in the rotary machine according to the present invention, a vehicle interior rib extending in the axial direction is provided on the inner surface of the vehicle interior body, and the support portion supports the cone portion from the inner end of the vehicle interior rib. It is preferable that it is provided as such.

According to such a configuration, since the support portion is provided on the vehicle interior rib that reinforces the inner surface of the vehicle interior body to support the cone portion, the rigidity of the support portion can be adjusted according to the rigidity of the vehicle interior rib. , The rigidity adjustment range can be expanded.
Further, in the present invention, since the distance between the inner end of the vehicle interior rib and the cone portion is reduced, the support portion can be miniaturized and can be arranged in a stable posture, so that the rigidity of the cone portion can be adjusted accurately. be able to.

Further, the rotary machine according to the present invention may be characterized in that the support portion is a hydraulic cylinder having a piston rod that can be expanded and contracted by flood control.

According to such a configuration, the rigidity of the support portion of the hydraulic cylinder can be adjusted by changing the area of the tip of the piston rod that comes into contact with the cone portion and the characteristics of the oil. For example, it can be an adjustment method that changes the characteristics of oil (oil temperature, etc.). In this case, by detecting the natural frequency and oil temperature of the rotor, the rigidity of the hydraulic cylinder is adjusted appropriately during the operation of the rotating machine. It can be easily adjusted to the value.

Further, in the rotary machine according to the present invention, the support portion includes a male screw member into which a nut is screwed, and a base portion having a shaft hole into which the male screw member is inserted so as to be able to advance and retreat in the screw axis direction. The base portion may be fixed to the inner surface of the passenger compartment, the tip of the male screw member may be fixed to the cone portion, and the male screw member may advance or retreat in the screw axial direction by the rotation of the nut.

According to such a configuration, the rigidity of the support portion can be adjusted by changing the area of the tip of the male screw member and the protruding length of the male screw member from the base portion.

Further, the rotor support rigidity adjusting method according to the present invention is a rotor support rigidity adjusting method for adjusting the rigidity of the support portion that supports the rotor by using the rotary machine described above, and is the method of adjusting the rotor support rigidity of the support portion. It is characterized in that the rigidity of the support portion is adjusted by increasing or decreasing the arrangement quantity in the axial direction.

According to the present invention, the rigidity of the cone portion based on the axial end portion of the vehicle interior body in the cone portion supported by the support portion can be adjusted by increasing or decreasing the arrangement quantity of the support portion in the axial direction. It becomes possible to change the natural frequency of the cone portion. In this case, the rigidity is not adjusted by the support portion itself, but the rigidity can be easily changed by simply adjusting the quantity and position of the support portion.

According to the rotating machine of the present invention and the rotor support rigidity adjusting method, the shaft vibration level can be reduced by efficiently detuning the natural frequency from the rated rotation speed, which requires time-consuming additional reinforcement work and the like. It becomes unnecessary.

It is a schematic diagram which shows the structure of the rotary machine by 1st Embodiment of this invention. It is a side sectional view which shows the cone part and the main part of the bearing box in the rotary machine shown in FIG. FIG. 2 is a view taken along the line AA shown in FIG. FIG. 2 is a cross-sectional view taken along the line BB shown in FIG. It is a side sectional view which shows the cone part of the rotary machine and the main part of a bearing box by 1st modification, and is the figure corresponding to FIG. It is sectional drawing which shows the cone part of the rotary machine and the main part of a bearing box by 2nd modification, and is the figure corresponding to FIG. It is a side sectional view which shows the cone part and the main part of the bearing box in the rotary machine by 2nd Embodiment. It is a vertical cross-sectional view which a part of the elastic rod shown in FIG. 7 was broken.

Hereinafter, the rotary machine according to the embodiment of the present invention and the rotor support rigidity adjusting method will be described with reference to the drawings. Such an embodiment shows one aspect of the present invention, does not limit the present invention, and can be arbitrarily changed within the scope of the technical idea of the present invention.

(First Embodiment)
As shown in FIG. 1, the rotary machine 1 according to the first embodiment will be described in detail with reference to the drawings. The rotary machine 1 shown in FIG. 1 is intended for a low-pressure cabin of a steam turbine.
The rotary machine 1 of the present embodiment is integrally provided at the vehicle interior main body 11 which has a tubular shape centered on the axis O and is supported by the gantry 2 and the end portion of the vehicle interior main body 11 in the axial direction. The vehicle interior 10 has a cylindrical cone portion 12 whose diameter decreases toward the inside of the vehicle interior main body 11, the bearing box 20 supported by the cone portion 12 and having a bearing 21 inside, and the bearing 21. The rotor 30 is supported and extends in the axial direction, and the cone portion 12 is supported from the inner surface 11a of the passenger compartment 10 (the inner end 13a of the passenger compartment rib 13 described later) so that the rigidity can be adjusted. It is provided with a hydraulic cylinder 40 (support portion).

Here, in the present embodiment, the direction in which the axis O extends is defined as the axis direction Da. Further, in a plan view seen from the axis O direction, the direction orthogonal to the axis O is the radial direction Dr (see FIGS. 3 and 4), and the direction that orbits around the axis O is the circumferential direction Dc.

The vehicle interior main body 11 has a tubular shape that covers the rotor 30 from the outer peripheral side. On the inner peripheral surface of the vehicle interior main body 11, a plurality of (here, eight) interior ribs 13 extending in the axial direction O are provided while being arranged at regular intervals in the circumferential direction Dc (FIG. 4). reference). Further, a plurality of stationary blades (not shown) are provided at the inner end of the vehicle interior rib 13 at intervals in the axial direction Da. These stationary blades are arranged so as to be staggered in the axial direction Da with a plurality of moving blades 31 provided on the outer peripheral surface of the rotor 30.
The space formed inside the vehicle interior body 11 is a room through which high-temperature and high-pressure steam guided from a steam generation source (not shown) led through an intake port (not shown) flows. The steam guided into the vehicle interior body 11 alternately collides with the moving blades 31 and the stationary blades from one side to the other side in the axial direction Da, thereby giving a rotational force to the rotor 30 and then. It is discharged to the outside from the exhaust port. Then, the rotational movement of the rotor 30 is taken out by, for example, a generator connected to the shaft end.

As shown in FIG. 2, both end faces of the vehicle interior body 11 in the axial direction Da are formed by sandwiching the cone portion 12 and sandwiching the inner peripheral end plate 11A inside the radial direction Dr and the outer peripheral end plate 11B outside the radial direction Dr. Have. A tubular bearing box 20 is provided on the inner peripheral edge of the inner peripheral end plate 11A.

The cone portions 12 are provided at both ends of the vehicle interior main body 11 in the axial direction Da. In each cone portion 12, the end portion (inner end 12a) on the vehicle interior side is connected to the outer peripheral edge of the inner peripheral end plate 11A of the vehicle interior body 11 in the axial direction Da, and the end portion (outer end 12b) on the outer side of the vehicle interior is connected. Is connected to the inner peripheral edge of the outer peripheral end plate 11B. That is, these cone portions 12 form recesses having a shape in which the end faces on both sides of the vehicle interior body 11 in the axial direction Da are recessed inside the vehicle interior body 11 in the axial direction Da.

As shown in FIG. 2, the bearing box 20 supported by the passenger compartment 10 is provided in each of the recesses formed by the cone portions 12 on both sides, and is composed of a rolling bearing that rotatably supports the rotor 30 inside. A bearing 21 is provided. The outer surface 12c of the cone portion 12 and the outer peripheral surface 20a of the bearing box 20 extend in the circumferential direction Dc and are arranged at intervals in the axial direction Da (here, two) bearing support ribs 14A. , 14B (see FIGS. 3 and 4). One of the first bearing support ribs 14A located on the vehicle interior side in the axial direction Da is arranged at a position corresponding to the bearing 21 in the axial direction Da.
As shown in FIGS. 3 and 4, the bearing support ribs 14A and 14B are each divided into two when viewed from the axial direction Da. The number of divisions of the bearing support ribs 14A and 14B can be changed as appropriate, and may be provided integrally.
Further, in the present embodiment, the rolling bearing is targeted as the bearing 21, but a sliding bearing often used in a steam turbine may be used.

Further, a flange (not shown) extending in the axial direction Da is provided at a position facing each other on the outer peripheral surface of the vehicle interior main body 11 when viewed from the axial direction Da. The passenger compartment 10 is fixed with the flanges mounted on the gantry 2, and the lower half portion of the passenger compartment 10 is installed in a floating state.

As shown in FIGS. 1 and 2, the vehicle interior rib 13 is formed with an extension portion 13A in which both ends in the axial direction Da extend toward the axis O side, and a flange 13B is formed at the tip of the extension portion 13A. It is formed.

As shown in FIG. 4, the hydraulic cylinder 40 is interposed between the vehicle interior ribs 13 and the cone portions 12 located at intervals of 90 ° in the circumferential direction. Specifically, as shown in FIGS. 2 and 4, a plurality of hydraulic cylinders 40 (here, two) are fixed at one location on the flange 13B of the vehicle interior rib 13 at intervals in the axial direction Da, and they are fixed. The tip portion 41a of the cone portion 12 is attached in a state of being in contact with the inner surface 12d of the cone portion 12. That is, the portion for fixing the hydraulic cylinder 40 may be a portion that does not vibrate together with the cone portion 12 that vibrates via the rotor 30. The hydraulic cylinder 40 located on the vehicle interior side in the axial direction Da is arranged at a position substantially coincident with the bearing 21 and the first bearing support rib 14A in the axial direction Da. That is, the bearing 21, the first bearing support rib 14A, and the hydraulic cylinder 40 are arranged on the line in the radial direction Dr, and the load received by the bearing 21 is supported by the hydraulic cylinder 40.

The hydraulic cylinder 40 has a piston rod 41 that can be expanded and contracted by flood control, and has an area of a tip portion 41a of the piston rod 41 that comes into contact with the cone portion 12 and oil characteristics (oil type (volume stiffness), oil temperature, etc.). By changing the above, the rigidity of the hydraulic cylinder 40 as a support portion can be adjusted. For example, in the case of the adjustment method of changing the oil temperature, the rigidity of the hydraulic cylinder 40 can be easily adjusted to an appropriate value during the operation of the rotary machine 1 by detecting the natural frequency and the oil temperature of the rotor 30. it can. Further, when the rigidity of the hydraulic cylinder 40 is lowered, it is possible to prevent the oil from flowing.

Next, the operation of the rotary machine having the above-described configuration and the method for adjusting the rotor support rigidity will be specifically described with reference to the drawings.
As shown in FIGS. 1 and 2, in the rotary machine 1 as described above, a hydraulic cylinder 40 is interposed between the cone portion 12 that supports the rotor 30 and the vehicle interior rib 13 provided on the inner surface of the vehicle interior 10. The rotor 30 can be supported via the cone portion 12 by a hydraulic cylinder 40 which is mounted and adjusted to a predetermined rigidity.
That is, the bending rigidity of the cone portion 12 can be changed by installing a hydraulic cylinder 40 capable of adjusting the rigidity of the cone portion 12 that affects the support rigidity of the rotor 30 and adjusting the rigidity of the hydraulic cylinder 40. .. That is, it is possible to adjust the rigidity of the cone portion 12 with the end portion (outer end 12b) in the axial direction of the vehicle interior body 11 in the cone portion 12 as the base end, and the cone portion 12 (or the cone portion and the rotor) can be adjusted. The natural frequency of the coupled mode or shaft system) can be changed.

As described above, in the present embodiment, the natural frequency of the cone portion 12 can be changed by adjusting the rigidity of the cone portion 12, and the vibration is detuned from the rated rotation speed (for example, 3000 rpm described above). Reduces the shaft vibration level. This makes it possible to avoid resonance in which the cone portion 12 vibrates near the rated rotation speed of the rotating machine 1 and the shaft vibration of the rotor 30 increases.
Further, in the present embodiment, the natural frequency of the cone portion 12 is changed by adjusting the rigidity of the hydraulic cylinder 40 itself, which is more reliable than the conventional method of performing balance adjustment. The vibration level can be reduced.

Further, in the present embodiment, since a support portion is provided on the vehicle interior rib 13 that reinforces the inner surface 11a of the vehicle interior main body 11 to support the cone portion 12, the rigidity of the hydraulic cylinder 40 is increased according to the rigidity of the vehicle interior rib 13. Can be adjusted, and the rigidity adjustment range can be expanded.
Further, in the present embodiment, since the distance between the inner end 13a of the vehicle interior rib 13 and the cone portion 12 is small, the hydraulic cylinder 40 can be miniaturized and can be arranged in a stable posture, so that the cone portion 12 can be arranged. The rigidity of the corn can be adjusted accurately.

Further, in the present embodiment, it is also possible to adopt a rotor support rigidity adjusting method for adjusting the rigidity of the hydraulic cylinder 40 by increasing or decreasing the arrangement quantity of the hydraulic cylinder 40 in the axial direction Da.
For example, in the rotary machine 1A according to the first modification shown in FIG. 5, the number of hydraulic cylinders 40 provided in the axial direction Da in one vehicle interior rib 13 is increased, and here, four hydraulic cylinders 40 are provided. There is.
As described above, according to the first modification, by increasing or decreasing the arrangement quantity of the hydraulic cylinder 40 in the axial direction Da, the cone portion 12 having the outer end 12b of the cone portion 12 supported by the hydraulic cylinder 40 as the base end The rigidity can be adjusted, and the natural frequency of the cone portion 12 can be changed. In this case, the rigidity is not adjusted by the hydraulic cylinder 40 itself, but the rigidity can be easily changed by simply adjusting the quantity and position of the hydraulic cylinder 40.

In the rotary machine and rotor support rigidity adjusting method according to the above-described embodiment, the shaft vibration level can be reduced by efficiently detuning the natural frequency from the rated rotation speed, which is a time-consuming additional reinforcement work. Etc. are not required.

Next, the rotary machine of the present invention and other embodiments and modifications according to the rotor support rigidity adjusting method will be described with reference to the accompanying drawings. The same reference numerals will be used to omit the description, and a configuration different from the embodiment will be described.

(Second modification)
The rotary machine 1B according to the second modification shown in FIG. 6 has a configuration in which hydraulic cylinders 40 are provided on all eight vehicle interior ribs 13.
As described above, the position of the circumferential direction Dc of the hydraulic cylinder 40 can be appropriately set according to the length (magnitude) of the axial direction Da of the flange 13B of the vehicle interior rib 13, the size of the hydraulic cylinder 40, and the like. In order to equalize the rigidity balance of the circumferential direction Dc, it is preferable to arrange them at regular intervals in the circumferential direction Dc.

(Second Embodiment)
Next, as shown in FIG. 7, in the rotary machine 1C according to the second embodiment, instead of the hydraulic cylinder 40 (see FIG. 2) described above, the elastic rod 40A (support portion) is used on the inner surface 11a of the passenger compartment 10. That is, it is provided so as to support the cone portion 12 from the vehicle interior rib 13 so that the rigidity can be adjusted.
As shown in FIG. 8, the elastic rod 40A has a male screw member 42 into which a nut 44 is screwed and a base portion 43 having a shaft hole 43a into which the male screw member 42 is inserted so as to be able to advance and retreat in the screw shaft C direction. I have. A fixing plate 42A that can be fixed to the cone portion 12 with a bolt or the like is formed at one end of the male screw member 42 in the screw shaft C direction. The elastic rod 40A can adjust the length in the screw axis C direction, that is, the protruding length of the male screw member 42 from the tip surface 43b of the base portion 43 by rotating the nut 44 in the forward and reverse directions. In the elastic rod 40A, as shown in FIG. 7, the base portion 43 is fixed to the inner surface of the vehicle interior 10 (inner end 13a of the vehicle interior rib 13), and the fixing plate 42A of the male screw member 42 is fixed to the cone portion 12. The male screw member 42 moves forward and backward in the screw shaft C direction due to the rotation of the nut 44.

In the second embodiment, the rigidity of the support portion can be adjusted by changing the area of the fixing plate 42A at the tip of the male screw member 42 and the protruding length of the male screw member 42 from the base portion 43.
Further, also in this case, it is possible to adopt a rotor support rigidity adjusting method for adjusting the rigidity of the elastic rod 40A by increasing or decreasing the arrangement quantity of the elastic rod 40A in the axial direction Da.

Although the embodiment of the rotary machine and the rotor support rigidity adjusting method according to the present invention has been described above, the present invention is not limited to the above embodiment and can be appropriately changed without departing from the spirit of the present invention. is there.

For example, in the present embodiment, the support portion of the hydraulic cylinder 40 and the elastic rod 40A is arranged at the inner end 13a of the vehicle interior rib 13 provided on the inner surface 11a of the vehicle interior main body 11, but the mounting position of the support portion is provided. It is not limited to the vehicle interior rib 13. For example, in the case of the vehicle interior 10 in which the vehicle interior rib 13 is omitted, the support portion may be provided directly on the inner surface 11a of the vehicle interior main body 11.

Further, as the support portion whose rigidity can be adjusted, the hydraulic cylinder 40 and the elastic rod 40A are adopted in the above-described embodiment, but in addition to these, a spring such as a coil spring or a disc spring is adopted. It may be.

Further, the configuration of the vehicle interior body 11 of the vehicle interior 10, the inclination angle of the cone portion 12, the positions of the bearing support ribs 14A and 14B, the quantity, and the like can be appropriately changed according to the conditions.

In addition, it is possible to replace the components in the above-described embodiments with well-known components as appropriate without departing from the spirit of the present invention, and the above-described embodiments may be combined as appropriate.

1, 1A, 1B, 1C Rotating machine 2 Stand 10 Car room 11 Car room body 11a Inner surface 12 Cone part 12b Outer end (Axial end of car room body)
13 Car interior rib 13a Inner end 14A, 14B Bearing support rib 20 Bearing box 21 Bearing 30 Rotor 31 Rotor blade 40 Hydraulic cylinder (support part)
40A elastic rod (support part)
41 Piston rod O Axial line Da Axial direction Dr Radial direction Dc Circumferential direction

Claims (5)

It is integrally provided at the end of the vehicle interior body in the axial direction and the vehicle interior body supported by the gantry in a cylindrical shape centered on the axis, and the diameter is reduced toward the inside of the vehicle interior body. A passenger compartment with a cylindrical cone and
A bearing box supported by the cone and having a bearing inside,
A rotor supported by the bearing and extending in the axial direction,
A support portion provided so as to support the cone portion from the inner surface of the vehicle interior, the rigidity can be adjusted, and a plurality of support portions are arranged in the axial direction.
Equipped with a,
A bearing support rib that connects the cone portion and the bearing box is provided.
The bearing support ribs extend in the circumferential direction, and a plurality of the bearing support ribs are arranged at intervals in the axial direction.
Rotary machine wherein at least one bearing support rib but that will be placed in a position that coincides with the bearing in the axial direction. An interior rib extending in the axial direction is provided on the inner surface of the vehicle interior body.
The rotary machine according to claim 1, wherein the support portion is provided so as to support the cone portion from the inner end of the vehicle interior rib. The rotary machine according to claim 1 or 2, wherein the support portion is a hydraulic cylinder having a piston rod that can be expanded and contracted by hydraulic pressure. The support portion includes a male screw member into which a nut is screwed, and a base portion having a shaft hole into which the male screw member is inserted so as to be able to advance and retreat in the screw axis direction. The rotating machine according to claim 1 or 2, wherein the tip of the male screw member is fixed to the cone portion, and the male screw member advances and retreats in the screw axis direction by rotation of the nut. A rotor support rigidity adjusting method for adjusting the rigidity of the support portion that supports the rotor by using the rotary machine according to any one of claims 1 to 4.
A rotor support rigidity adjusting method in which the rigidity of the support portion is adjusted by increasing or decreasing the arrangement quantity of the support portion in the axial direction.

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