Patent Application
20190301289
The present invention relates to a rotary machine. Priority is claimed on Japanese Patent Application No. 2018-62690, filed on Mar. 28, 2018, the contents of which are incorporated herein by reference.
In rotary machines, such as gas turbines or jet engines, a configuration is known in which dampers are each installed between turbine rotor blades adjacent to each other. The damper comes into contact with the turbine rotor blade when the rotary machine rotates. In addition, when an excitation force acting on the turbine rotor blade and vibration occurs, the vibration is attenuated by a frictional force at a contact location between the damper and the turbine rotor blade.
For example, Japanese Unexamined Patent Application, First Publication No. 2016-217349 discloses a rotary machine provided with damper pins that come into contact with both of the platforms of turbine rotor blades adjacent to each other.
However, wear occurs in the damper pin due to the frictional force with a platform. In particular, in a case where the sectional shape of the damper pin is circular, since the damper pin and the platform come into line-contact with each other, a surface pressure received by the damper pin increases. Therefore, the wear on the damper pin surface is more likely to progress. When the wear of the damper pin progresses, the attenuating characteristics of the damper pin may change, and there is a case where it is not possible to apply an appropriate damper effect to the excitation force.
Considering such a situation, an object of the present invention is to provide a rotary machine which can suppress progress of wear of a damper pin.
According to a first aspect of the present invention, a rotary machine includes: a rotating shaft configured to rotate around an axial line; a plurality of rotor blades which are arranged in a peripheral direction on an outer peripheral side of the rotating shaft, and each having a blade root attached to the rotating shaft, a platform installed on an outer side of the blade root in a radial direction, and a blade main body extending to the outer side from the platform in the radial direction; and damper pins each installed on an inner side of the platform in the radial direction between the rotor blades adjacent to each other, in which the platforms are each in a shape of a flat surface extending in an axial line direction and include damper abutting surfaces extending to be close to each other as approaching the outer side in the radial direction while opposing each other in the peripheral direction in each of the platforms adjacent to each other, and in which the damper pin forms a regular polygonal prism extending in the axial line direction and includes a damper pin main body in which an angle formed by two side surfaces among a plurality of side surfaces corresponds to an angle formed by the damper abutting surfaces between the rotor blades adjacent to each other.
According to the rotary machine of the above-described aspect, when the damper pin comes into contact with the pair of damper abutting surfaces, the two side surfaces of a parent damper pin come into contact with the pair of damper abutting surfaces corresponding thereto. In other words, both of the two side surfaces of the damper pin come into contact with the pair of damper abutting surfaces in a state where a contact area is largely ensured. Therefore, compared to a case where the damper pins come into line-contact with the damper abutting surfaces, it is possible to reduce a surface pressure acting on the outer peripheral surface of the damper pin.
In addition, when the rotation of the rotary machine is stopped and the centrifugal force disappears, the damper pin is separated from the damper abutting surface. In addition, when the centrifugal force is applied again, any two side surfaces of the damper pin having a regular polygonal prism shape come into contact with the pair of damper abutting surfaces corresponding thereto. In other words, since the side surface of the damper pin on which the frictional force acts changes with each start and stop of the rotary machine, it is possible to apply attenuation by using not only the specific side surface of the damper pin but also each of the side surfaces. Therefore, it is possible to avoid only the specific side surface wearing.
In the rotary machine, the damper pin may further include a curved surface-forming portion that is provided across vertexes of both ends of the side surface on at least one of the side surfaces in a sectional view orthogonal to the axial line, and forms an outer peripheral curved surface that forms an arc shape having a larger radius of curvature than that of a circle that passes through each of the vertexes of the damper main body.
Accordingly, compared to a case where the sectional shape of the damper pin is circular, it is possible to increase the contact area when the damper pin comes into contact with the damper abutting surface. Therefore, it is possible to reduce the surface pressure acting on the damper pin, and it is possible to suppress the progress of wear.
According to a second aspect of the present invention, a rotary machine includes: a rotating shaft configured to rotate around an axial line; a plurality of rotor blades which are arranged in a peripheral direction on an outer peripheral side of the rotating shaft, and each having a blade root attached to the rotating shaft, a platform installed on an outer side of the blade root in a radial direction, and a blade main body extending to the outer side from the platform in the radial direction; and damper pins each installed on an inner side of the platform in the radial direction between the rotor blades adjacent to each other, in which the platforms are each in a shape of a flat surface extending in an axial line direction and include damper abutting surfaces extending to be close to each other as approaching the outer side in the radial direction while opposing each other in the peripheral direction in each of the platforms adjacent to each other, and in which the damper pins uniformly extend in the axial line direction and each having an outline having a sectional shape orthogonal to the axial line, which forms a non-rotationally symmetrical shape.
When the rotation of the rotary machine stops and the centrifugal force disappears, the damper pin is separated from the damper abutting surface, and then, when the rotary machine rotates and the centrifugal force acts on the damper pin, the damper pin comes into contact with the damper abutting surface again. Here, in the present aspect, since the outline having a sectional shape of the damper pin has a non-rotationally symmetrical shape, the position of the outer peripheral surface when the damper pin comes into contact with the damper abutting surface again is randomly determined. Accordingly, it is possible to suppress the progress of the wear only at a specific location as only the specific location of the outer peripheral surface of the damper pin comes into contact with the damper abutting surface.
Furthermore, as each of the damper pins disposed at different locations randomly comes into contact with the damper abutting surfaces, attenuation aspects in each of the damper pins become different from each other. Accordingly, it is possible to apply the attenuation to a wide range of excitation force as a whole of the rotary machine.
Furthermore, since the contact location on the damper abutting surface also changes, it is also possible to suppress the wear on the platform side.
In the rotary machine according to the aspect, in the damper pin, the outline having a sectional shape orthogonal to the axial line may be formed of a plurality of arcs which are convex outward and have radiuses of curvature different from each other, and a plurality of line segments that connect the arcs to each other.
Accordingly, the outline of the outer peripheral surface of the damper pin has a non-rotationally symmetrical shape, and it is possible to randomly change the contact location of the damper pin. Since the region where the outline is a line segment has a shape of a flat surface, it is also possible to reduce the surface pressure.
According to the rotary machine of the present invention, it is possible to suppress the progress of wear of the damper pin.
Hereinafter, a gas turbine 1 according to a first embodiment of the present invention will be described with reference to
As illustrated in
The compressor 2 includes a compressor rotor 3 configured to rotate around an axial line O, and a compressor casing 4 that covers the compressor rotor 3 from an outer peripheral side. The compressor rotor 3 has a columnar shape extending along the axial line O. A plurality of compressor rotor blade stages 5 arranged at intervals in an axial line O direction are installed on an outer peripheral surface of the compressor rotor 3. Each of the compressor rotor blade stages 5 includes a plurality of compressor rotor blades 6 arranged at intervals in a peripheral direction of the axial line O on the outer peripheral surface of the compressor rotor 3.
The compressor casing 4 has a cylindrical shape around the axial line O. A plurality of compressor stationary blade stages 7 arranged at intervals in the axial line O direction are installed on an inner peripheral surface of the compressor casing 4. The compressor stationary blade stages 7 are alternately arranged with respect to the compressor rotor blade stages 5 when viewed from the axial line O direction. Each of the compressor stationary blade stages 7 includes a plurality of compressor stationary blades 8 arranged at intervals in the peripheral direction of the axial line O on the inner peripheral surface of the compressor casing 4.
The combustor 9 is installed between the compressor casing 4 and a turbine casing 12 which will be described later. The compressed air generated by the compressor 2 is mixed with a fuel on the inside of the combustor 9 to become a premixed gas. In the combustor 9, the combustion gas having a high temperature and a high pressure is generated by combusting the premixed gas. The combustion gas is introduced into the turbine casing 12 to drive the turbine 10.
The turbine 10 includes a turbine rotor 11 configured to rotate around the axial line O, and the turbine casing 12 that covers the turbine rotor 11 from the outer peripheral side. The turbine rotor 11 has a columnar shape extending along the axial line O. A plurality of turbine rotor blade stages 20 arranged at intervals in the axial line O direction are formed on an outer peripheral surface of the turbine rotor 11. Each of the turbine rotor blade stages 20 includes a plurality of turbine rotor blades 30 arranged at intervals in the peripheral direction of the axial line O on the outer peripheral surface of the turbine rotor 11. The turbine rotor 11 is integrally connected to the compressor rotor 3 in the axial line O direction to form the gas turbine rotor.
The turbine casing 12 has a cylindrical shape around the axial line O. A plurality of turbine stationary blade stages 13 arranged at intervals in the axial line O direction are formed on an inner peripheral surface of the turbine casing 12. The turbine stationary blade stages 13 are alternately arranged with respect to the turbine rotor blade stages 20 when viewed from the axial line O direction. Each of the turbine stationary blade stages 13 includes a plurality of turbine stationary blades 14 arranged at intervals in the peripheral direction of the axial line O on the inner peripheral surface of the turbine casing 12. The turbine casing 12 is connected to the compressor casing 4 in the axial line O direction to form the gas turbine casing. In other words, the gas turbine rotor is integrally rotatable around the axial line O in the gas turbine casing.
Turbine Rotor Blade
Next, the turbine rotor blade 30 will be described in more detail with reference to
The turbine rotor blade 30 has a blade root 31, a platform 32, and a blade main body 41.
The blade root 31 is a part attached to the turbine rotor 11 in the turbine rotor blade 30. The turbine rotor 11 is configured by stacking a plurality of disk-like disks 11a around the axial line O in the axial line O direction. The blade root 31 is integrally attached to the disk 11a by being inserted from the axial line O direction into a recessed groove (not illustrated) of the disk 11a formed on the outer peripheral surface of the disk 11a. Accordingly, the turbine rotor blades 30 are radially disposed at intervals in the peripheral direction with respect to the disk 11a.
The platform 32 is integrally formed on the outer side of the blade root 31 in the radial direction. The platform 32 projects from an end portion on the outer side of the blade root 31 in the radial direction in the axial line O direction and in the peripheral direction. An outer peripheral surface 33 that faces the outer side in the platform 32 in the radial direction is exposed to the combustion gas that passes through the turbine 10.
A platform side surface 34 that faces the peripheral direction in the platform 32 extends in the radial direction and in the axial line O direction. The platform side surfaces 34 oppose each other in the peripheral direction between the platforms 32 of the turbine rotor blades 30 adjacent to each other.
On the platform side surface 34, a recess portion 37 that is recessed from the platform side surface 34 and extends in the axial line O direction is formed. A damper accommodation space R1 extending so as to penetrate the platform 32 in the axial line O direction according to the shape of the recess portion 37 is defined by the recess portions 37 of the platforms 32 adjacent to each other. The damper accommodation space R1 is formed between all of the platforms 32 adjacent to each other. Therefore, the same number of damper accommodation spaces R1 are formed as that of the turbine rotor blades 30.
Each of the platform side surfaces 34 is divided by the recess portion 37 in the radial direction. On the platform side surface 34, a part on the outer side of the recess portion 37 in the radial direction is an outer peripheral side surface 35, and a part on the inner side of the recess portion 37 in the radial direction is an inner peripheral side surface 36.
As illustrated in
The damper abutting surfaces 38 of the platforms 32 adjacent to each other oppose each other in the peripheral direction. The damper abutting surfaces 38 are inclined such that an opposing distance becomes shorter as approaching the outer side in the radial direction. The pair of damper abutting surfaces 38 are disposed in line symmetry with a straight line along the radial direction when viewed in the axial line O direction as a target axis.
As illustrated in
The blade main body 41 extends toward the outer side in the radial direction from the outer peripheral surface 33 of the platform 32. In other words, a base end of the blade main body 41 is integrally connected to the end portion on the outer side of the platform 32 in the radial direction. The blade main body 41 has a blade-shaped sectional shape orthogonal to an extending direction of the blade main body 41.
Damper Pin
As illustrated in
In the damper pin main body 51, the sectional shape orthogonal to the axial line O is a regular polygonal shape. In other words, the damper pin main body 51 is in a regular polygonal columnar shape. In the present embodiment, in the damper pin main body 51, the sectional shape orthogonal to the axial line O is a regular hexagonal shape. Therefore, the damper pin main body 51 has six side surfaces 52 having the same rectangular shape. An angle formed between the pair of side surfaces 52 adjacent to each other is set to 120°. The distance between the side surfaces 52 that face the side opposite to each other in the damper pin main body 51 is set to be larger than the distance between the pair of platform side surfaces 52, that is, the distance between the pair of outer peripheral side surfaces 35. In other words, a dimension (a diameter of an inscribed circle of the outline of the section orthogonal to the axial line O of the damper pin main body 51) of the smallest outer diameter among the outer diameters of the damper pin main body 51 is set to be larger than the interval between the pair of outer peripheral side surfaces 35.
Corresponding to the shape of the damper pin main body 51, an angle formed by the pair of damper abutting surfaces 38 that defines the damper accommodation space R1 in which the damper pin main body 51 is accommodated is set to be the same as an angle formed by the side surfaces 52 adjacent to each other in the damper pin main body 51. Accordingly, in the present embodiment, the angle formed by the pair of damper abutting surfaces 38 is set to 120°. In this case, an inclination angle of the damper abutting surface 38 is set to 30°.
In other words, the angle formed by the two side surfaces 52 adjacent to each other among the plurality of side surfaces 52 of the damper pin main body 51 corresponds to the angle formed by the pair of damper abutting surfaces 38.
Functional Effect
When the turbine 10 rotates, the centrifugal force is generated on the damper pin 50, and the side surfaces 52 of the damper pins 50 each come into contact with the damper abutting surfaces 38 of the pair of platforms 32. In the present embodiment, the angle formed by the side surfaces 52 adjacent to each other of the damper pin 50 corresponds to the angle formed by the pair of damper abutting surfaces 38. Therefore, the pair of side surfaces 52 adjacent to each other in the damper pin 50 comes into contact with the pair of damper abutting surfaces 38 in a one-to-one correspondence. In other words, both of the two side surfaces 52 of the damper pin 50 come into contact with the pair of damper abutting surfaces 38 in a state where the contact area is largely ensured.
Here, for example, in a case where the outline of the sectional shape of the damper pin 50 is circular, the damper pin 50 comes into line-contact with the damper abutting surface 38. Therefore, as a result of the large action of the surface pressure on the damper pin 50, the wear of the damper pin 50 progresses early.
In addition, even when the outline of the sectional shape of the damper pin 50 is in a polygonal shape, when the angle of the damper abutting surface 38 is not set to correspond thereto, a corner portion of the sectional shape of the damper pin 50 comes into contact with the damper abutting surface, and the wear of both of the damper pin 50 and the damper abutting surface 38 is promoted.
In the present embodiment, since the two side surfaces 52 of the damper pin main body 51 preferably come into surface-contact with the damper abutting surface 38, it is possible to reduce the surface pressure acting on the outer peripheral surface of the damper pin main body 51. Accordingly, it is possible to suppress the early progress of the wear of the outer peripheral surface of the damper pin main body 51.
In addition, when the rotation of the turbine 10 is stopped and the centrifugal force disappears, the damper pin 50 is separated from the damper abutting surface 38. In addition, when the turbine 10 rotates and the centrifugal force is applied again, the two side surfaces 52 adjacent to each other in the damper pin main body 51 having a regular polygonal prism shape come into contact with the pair of damper abutting surfaces 38 corresponding thereto. In other words, since the side surface 52 of the damper pin 50 on which the frictional force acts changes with each start and stop of the turbine 10, it is possible to apply attenuation by using not only the specific side surface 52 of the damper pin 50 but also each of the side surfaces 52. Therefore, it is possible to avoid only the specific side surface 52 wearing. In other words, it is possible to suppress the progress of wear of the damper pin 50 as a whole.
Here, as a modification example of the first embodiment, as illustrated in
In addition, the damper pin 50 is not limited to the configuration as long as the shape is a regular polygonal prism shape.
For example, the outline of the sectional shape orthogonal to the axial line O of the damper pin 50 may have a regular nonagonal shape or a regular octadecagonal shape. In this case, the inclination angle of the pair of damper abutting surfaces 38 is set to 20° or 40°. For example, the outline of the sectional shape orthogonal to the axial line O of the damper pin 50 may have a square shape, a regular octagonal shape, or a regular hexadecagonal shape. In this case, the angle formed by the pair of damper abutting surfaces 38 is set to 45°. In addition, the outline of the sectional shape orthogonal to the axial line O of the damper pin 50 may have a regular icosikaitetragonal shape. In this case, the angle formed by the pair of damper abutting surfaces 38 is set to 30°.
In other words, the damper pin 50 may be in a regular polygonal shape, and the angle formed by the pair of damper abutting surfaces 38 may correspond to the angle formed by any two side surfaces 52 among the plurality of damper pins 50. Accordingly, since any two side surfaces 52 of the damper pin 50 simultaneously come into surface-contact with the damper abutting surface 38, it is possible to suppress the wear of the damper pin 50.
Next, a second embodiment of the present invention will be described with reference to
A damper pin 60 of the second embodiment includes a curved surface-forming portion 61 in addition to the damper pin main body 51 similar to the first embodiment.
The curved surface-forming portion 61 is integrally formed on each of the side surfaces 52 of the damper pin main body 51. The curved surface-forming portion 61 is formed over the entire region of each of the side surfaces 52. The curved surface-forming portion 61 has an arc-shaped outline extending across vertexes of both ends of the side surface 52 in a sectional view orthogonal to the axial line O. An arc 62 of the curved surface-forming portion 61 is the arc 62 which is convex on the outer peripheral side of the damper pin 60. The arc 62 of the curved surface-forming portion 61 has a radius of curvature larger than a radius of curvature of a reference circle (a circumscribed circle of the damper pin main body 51) that passes through each of the vertexes when viewed from a section orthogonal to the axial line O of the damper pin main body 51. Accordingly, the outline of the sectional shape orthogonal to the axial line O of the damper pin 60 has a shape in which a plurality (six in the present embodiment) of arcs 62 are combined with each other. Each of the arcs 62 adjacent to each other is connected to each other at the vertex of the damper pin main body 51.
Accordingly, on the side surface 52 of the damper pin 60, an outer peripheral curved surface 63 having the same radius of curvature as that of the arc 62 is formed. The outer peripheral surface of the damper pin 60 has a configuration in which a plurality of outer peripheral curved surfaces 63 are combined with each other. A ridge line extending in the axial line O direction is formed between the outer peripheral curved surfaces 63 adjacent each other. In other words, the outer peripheral curved surfaces 63 adjacent to each other are connected to each other in the axial line O direction via the ridge line.
Functional Effect
According to the configuration, in addition to the functional effect of the first embodiment, compared to a case where the sectional shape of the damper pin 60 is circular, it is possible to increase the contact area when the damper pin 60 comes into contact with the damper abutting surface. Therefore, it is possible to reduce the surface pressure acting on the damper pin 60, and it is possible to suppress the progress of wear.
In addition, in the configuration, an example in which the curved surface-forming portion 61 is formed on all of the side surfaces 52 of the damper pin main body 51 has been described, but the curved surface-forming portion 61 may be formed on at least one side surface 52 among the plurality of side surfaces 52.
Next, a third embodiment of the present invention will be described with reference to
A damper pin 70 of the present embodiment extends in a uniform shape in the axial line O direction. The outline of the sectional shape orthogonal to the axial line O of the damper pin 70 has a non-rotationally symmetrical shape.
In the present embodiment, the outline shape orthogonal to the axial line O of the damper pin 70 may be formed of a plurality of arcs 71 which are convex outward and have radiuses of curvature different from each other, and a plurality of line segments 72 that connect the arcs 71 to each other, as an example of the non-rotationally symmetrical shape.
Accordingly, the outline shape of the damper pin 70 has a non-rotationally symmetrical shape in which the same shape that overlaps the outline shape does not appear even when a part of the outline shape is rotated around any rotating shaft line.
Functional Effect
In the present embodiment, since the outline having a sectional shape of the damper pin 70 has a non-rotationally symmetrical shape, when the start and stop of the turbine 10 is repeated, the position of the outer peripheral surface when the damper pin 70 comes into contact with the damper abutting surface 38 again is randomly determined. Accordingly, it is possible to suppress the progress of the wear only at a specific location as only the specific location of the outer peripheral surface of the damper pin 70 comes into contact with the damper abutting surface 38. Furthermore, since the contact location of the damper pin 70 on the damper abutting surface 38 also changes, it is also possible to suppress the wear on the platform side.
Furthermore, as each of the damper pins 70 disposed at different locations randomly comes into contact with the damper abutting surfaces 38, attenuation aspects in each of the damper pins 70 become different from each other. Accordingly, it is possible to apply the attenuation effect to a wide range of excitation force as a whole of the turbine 10.
In particular, by forming the outline of the sectional shape orthogonal to the axial line O of the damper pin 70 from the different arcs 71 and line segments 72, it is possible to easily set the outline of the outer peripheral surface of the damper pin 70 to have a non-rotationally symmetrical shape. Accordingly, it is possible to more randomly change the contact location of the damper pin 70. In addition, since the region of the line segment 72 of the outline has a shape of a flat surface, it is possible to reduce the surface pressure by being in surface-contact with the damper abutting surface.
In addition, weight adjustment of the damper pin 70 may be performed by forming holes or hollow portions in the damper pin 70, for example, such that the contact locations of the damper pin 70 with the damper abutting surface 38 become more random.
Moreover, the damper pin 70 is not limited to the sectional shape illustrated in
Above, although the embodiments of the present invention have been described, not being limited thereto, the present invention can be appropriately changed within the range which does not depart from the technical idea of the invention.
In addition, in the first, second, and third embodiments, an example has been described in which the pair of damper abutting surfaces 38 are disposed in line symmetry with the straight line along the radial direction when viewed in the axial line O direction as the target axis. However, not being limited thereto, for example, one of the pair of damper abutting surfaces 38 may be inclined similar to the embodiment, and the other damper abutting surface 38 may extend in the radial direction. In addition, the pair of damper abutting surfaces 38 may be inclined at angles different from each other. Further, the angle formed by the pair of damper abutting surfaces 38 may correspond to the angle formed by any two side surfaces 52 among the plurality of side surfaces 52 of the damper pin main body 51.
1 Gas turbine
2 Compressor
3 Compressor rotor
4 Compressor casing
5 Compressor rotor blade stage
6 Compressor rotor blade
7 Compressor stationary blade stage
8 Compressor stationary blade
9 Combustor
10 Turbine
11 Turbine rotor
11
a Disk
12 Turbine casing
13 Turbine stationary blade stage
14 Turbine stationary blade
20 Turbine rotor blade stage
30 Turbine rotor blade
31 Blade root
32 Platform
33 Outer peripheral surface
34 Platform side surface
35 Outer peripheral side surface
36 Inner peripheral side surface
37 Recess portion
38 Damper abutting surface
39 Recess portion bottom surface
40 Recess portion lower surface
41 Blade main body
50 Damper pin
51 Damper pin main body
52 Side surface
60 Damper pin
61 Curved surface-forming portion
62 Arc
63 Outer peripheral curved surface
70 Damper pin
71 Arc
72 line segment
R1 Damper accommodation space
O Axial line
| Number | Date | Country | Kind |
|---|---|---|---|
| 2018-062690 | Mar 2018 | JP | national |
