Rotating device and gas turbine

Abstract

The present invention discloses a rotating device, including a rotating shaft, a turbine and a housing, wherein the turbine is fixedly mounted on the rotating shaft, and the rotating shaft and the turbine are mounted in the housing; a bearing ring is sleeved on the radial outer side of the turbine, and the gap between the bearing ring and the housing forms an air film gap of a gas bearing, and the bearing ring, the housing and the gap therebetween form a gas bearing, and an air film is formed when the turbine rotates relative to the housing around the axis to support the turbine relative to the housing, thereby improving the radial swing of the turbine during high-speed operation and increasing the stability of the turbine during rotation. The present invention also discloses a gas turbine including the rotating device.

Description

Technical Field

[0001] The invention relates to a rotating device and a gas turbine, belonging to the technical field of gas turbines. Background Art

[0002] A gas turbine uses a continuously flowing gas as a working fluid to drive the impeller to rotate at high speed, converting the energy of the fuel into useful work. It is a rotating impeller heat engine, which mainly includes three major components: a compressor, a combustion chamber and a turbine. Among them, the compressor inhales air from the external atmospheric environment and compresses it step by step to increase the pressure, and the air temperature also increases accordingly; the compressed air is pressed into the combustion chamber and mixed with the injected fuel to burn to generate high-temperature and high-pressure gas; then it enters the turbine to expand and do work, driving the turbine to drive the compressor and the external load rotor to rotate at high speed, realizing the partial conversion of the chemical energy of the gas or liquid fuel into mechanical work, and can output electrical energy by connecting to a generator.

[0003] In the rotor system of a gas turbine, the turbine needs to rotate at high speed and have a high operating temperature. For example, for a small-power gas turbine, the speed of the rotor system of the gas turbine can reach or exceed 140,000 RPM (revolutions per minute), the operating temperature of the turbine can reach 950-1000°C, and the working linear speed of the turbine impeller is extremely high, so the centrifugal force it carries is as high as 100 MPa. The turbine often uses high-strength and high-temperature resistant materials (such as nickel) to meet the requirements of working under high speed and high temperature conditions. Such materials are usually high in density, the turbine mass is large, and the turbine is usually located at the cantilever end of the rotor system. In this way, when the rotor system rotates at high speed, the turbine will swing significantly.

[0004] Non-contact bearings (such as gas bearings) are increasingly used in some high-speed applications due to their low friction coefficient and friction torque, high motion accuracy, etc. Gas bearings rely on the pressure gas film in the bearing gap to support the rotor system. Summary of the invention

[0005] In view of the above-mentioned prior art, in order to improve the rotation stability of the turbine end, the present invention provides a rotating device and a gas turbine. The present invention supports the turbine end by arranging a gas bearing at the turbine end of the rotating device / gas turbine, thereby effectively improving the rotation stability of the turbine end.

[0006] The present invention is achieved through the following technical solutions:

[0007] A rotating device comprises a rotating shaft, a turbine and a casing, wherein the turbine is fixedly mounted on the rotating shaft, and the rotating shaft and the turbine are mounted in the casing; a bearing ring is sleeved on the radial outer side of the turbine, the bearing ring is in a circular ring shape, and a gap is provided between the bearing ring and the casing, and when the turbine rotates relative to the casing around an axis, the gap can form an air film gap of an air film, and the bearing ring, the casing and the gap form a gas bearing to support the turbine relative to the casing, thereby improving the radial swing of the turbine during high-speed operation and increasing the stability of the turbine during rotation.

[0008] Furthermore, the gas bearing formed by the bearing ring, the housing and the gap therebetween is any one of a static pressure bearing, a dynamic pressure bearing or a static-dynamic mixed bearing.

[0009] Furthermore, the turbine may be a centripetal turbine.

[0010] Furthermore, the turbine has a radially large end and a radially small end which are axially opposite to each other, and the bearing ring is located at the radially small end of the turbine.

[0011] Furthermore, the bearing ring can be assembled to the turbine in a very large interference fit manner, that is, the bearing ring can be hot-mounted or the turbine can be cold-mounted.

[0012] Furthermore, the bearing ring and the turbine may be fixedly connected by welding, which may be laser welding or welding with a suitable solder.

[0013] Furthermore, the bearing ring and the turbine may be fixedly connected by interference fit and welding to improve the reliability of the interference fit.

[0014] Furthermore, the turbine has a plurality of blades extending axially, and the inner annular surface of the bearing ring is welded to radial outer edges of the plurality of blades.

[0015] Furthermore, at the radial small end of the turbine, at least some of the blades have a protrusion extending axially outward, and the protrusion is fixedly connected to the bearing ring. The provision of the protrusion can increase the contact area between the turbine and the bearing ring, which can not only increase the connection stability, but also increase the air film area of ​​the gas bearing here, thereby improving the supporting effect of the gas bearing.

[0016] Further, when some of the blades have protrusions, the blades with the protrusions and the blades without the protrusions may be arranged alternately.

[0017] Furthermore, all blades of the turbine have projections.

[0018] Furthermore, the protrusion is arranged at a radially outer position of the radially small end of the turbine, so as to provide support while minimizing the influence on the aerodynamic effect of the turbine.

[0019] Furthermore, the turbine and the bearing ring can be made of high temperature resistant materials, and the high temperature resistant materials are selected from high temperature resistant metals, such as cast nickel.

[0020] Furthermore, the turbine and the bearing ring are made of the same high-temperature resistant material, which is beneficial to improving the joining strength after laser welding.

[0021] A gas turbine includes a rotating device of the above structure and a compressor, wherein the compressor is mounted on a rotating shaft. The structure of the gas turbine also includes a combustion chamber, an exhaust section, etc.

[0022] Furthermore, a first radial bearing and a thrust plate are provided on the rotating shaft; the rotating shaft has an axial first end and an axial second end which are axially opposite to each other, the first radial bearing and the thrust plate are located at the axial first end of the rotating shaft, the turbine is located at or adjacent to the axial second end of the rotating shaft, the thrust plate is located between the first radial bearing and the turbine, and the compressor is located between the thrust plate and the turbine; a thrust bearing is provided on one or both sides of the thrust plate.

[0023] Furthermore, the casing may be a gas turbine casing, a combustion chamber casing, an exhaust section casing, or an intermediate casing connected to the above casings.

[0024] Furthermore, the first radial bearing may be a gas bearing.

[0025] Furthermore, the thrust bearing may be a gas bearing.

[0026] Furthermore, the gas bearing is any one of a static pressure bearing, a dynamic pressure bearing or a static-dynamic mixed bearing.

[0027] Furthermore, the gas turbine also includes a reinforcement ring, which is annular and fixedly connected between the turbine and the compressor.

[0028] Furthermore, a second radial bearing is provided on the radial outer side of the reinforcement ring; the second radial bearing may be a gas bearing.

[0029] Furthermore, a positioning structure for positioning the reinforcement ring is provided on the opposing surfaces of the compressor and the turbine; the positioning structure is: a positioning ring groove is provided on the surface of the compressor close to the turbine, and a protrusion is provided on the surface of the turbine close to the compressor, the protrusion constitutes an annular positioning stop, one end of the reinforcement ring is inserted into the positioning ring groove, and the other end is inserted into the inner circumference of the annular positioning stop.

[0030] Furthermore, exhaust holes are arranged on the side wall of the reinforcement ring, and the number of the exhaust holes may be 4.

[0031] The rotating device and gas turbine of the present invention are provided with a bearing ring at the turbine end, and the gap between the bearing ring and the casing forms an air film gap of the gas bearing. The bearing ring, the casing and the gap thereof form a gas bearing. When the turbine rotates relative to the casing around the axis, an air film is formed in the gap to support the turbine relative to the casing, thereby improving the radial swing of the turbine during high-speed operation and increasing the stability of the turbine during rotation.

[0032] In some further solutions, the bearing ring may be arranged at the radially small end of the turbine, where the centrifugal force it is subjected to is relatively small, thereby minimizing deformation, degeneration or breakage of the bearing ring due to centrifugal force under the same material.

[0033] In some further schemes, a protrusion extending axially outward may be provided at the radial small end of the turbine to increase the contact area between the turbine and the bearing ring, which can not only increase the connection stability, but also increase the air film area of ​​the gas bearing here, thereby improving the supporting effect of the gas bearing.

[0034] When the bearing structure mentioned in this article is a hydrostatic bearing, it has the following structure: it includes a bearing body and a bearing sleeve nested from the outside to the inside, the bearing sleeve and the rotating shaft have a predetermined radial clearance in the radial direction (when the bearing is a radial bearing), or the bearing sleeve and the thrust plate are installed opposite to each other in the axial direction of the rotating shaft and have a predetermined axial clearance (when the bearing is a thrust bearing); an annular air cavity is provided on the outer peripheral surface of the bearing sleeve, and a through hole is provided on the bearing sleeve that passes through the annular air cavity and the gap (radial gap or axial gap); an air hole is provided on the bearing body that connects the annular air cavity with an external air source; in order to facilitate processing and not affect the gas pressure in the gap, the through hole can be a variable diameter hole, that is, the diameter of the through hole is larger on the side away from the gap, and the diameter is smaller on the side close to the gap.

[0035] When the bearing structure mentioned in this article is a dynamic pressure bearing, it has the following structure: it includes a bearing body, the bearing body and the rotating shaft have a predetermined radial clearance in the radial direction (when the bearing is a radial bearing), and the inner diameter surface of the bearing body or the part of the rotating shaft where the bearing body is installed is provided with a dynamic pressure generating groove; or: the bearing body and the thrust plate are installed opposite to each other in the axial direction of the rotating shaft and have a predetermined axial clearance (when the bearing is a thrust bearing), and the end surface of the bearing body facing the thrust plate or the end surface of the thrust plate facing the bearing body is provided with a dynamic pressure generating groove.

[0036] When the bearing structure mentioned in this article is a static-dynamic mixed bearing, its structure has the characteristics of both a static-dynamic bearing and a dynamic-dynamic bearing. The present invention will not be described in detail.

[0037] The various terms and phrases used in the present invention have the general meanings known to those skilled in the art. If the terms and phrases mentioned are inconsistent with the commonly known meanings, the meanings expressed in the present invention shall prevail. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 : Schematic diagram of the structure of the rotating device of Example 1.

[0039] Figure 2 : A schematic structural diagram of a bearing ring of the present invention.

[0040] Figure 3 : Schematic diagram of the structure of the rotating device of Example 2.

[0041] Figure 4 : Schematic diagram of the structure of the gas turbine of Example 3.

[0042] Figure 5 : Schematic diagram of the structure of the gas turbine of Example 5.

[0043] Among them, 100, rotating shaft; 110, thrust plate; 200, turbine; 210, protrusion; 300, casing; 400, bearing ring; 500, compressor; 610, first radial bearing; 620, thrust bearing; 640, second radial bearing; 700, reinforcement ring. DETAILED DESCRIPTION

[0044] The present invention will be further described below in conjunction with the examples. However, the scope of the present invention is not limited to the following examples. Those skilled in the art will appreciate that various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention.

[0045] Embodiment 1 A rotating device

[0046] A rotating device includes a rotating shaft 100, a turbine 200 and a housing 300. The turbine 200 is fixedly mounted on the rotating shaft 100. The rotating shaft 100 and the turbine 200 are mounted in the housing 300. The turbine 200 is a centripetal turbine. Figure 1 As shown ( Figure 1 Only part of the housing 300 is shown); the radial outer side of the turbine 200 is provided with a bearing ring 400, and the bearing ring 400 is annular, such as Figure 2 As shown; there is a gap between the bearing ring 400 and the housing 300 (specifically, the outer ring surface of the bearing ring 400 is called the first bearing surface, the surface of the housing 300 corresponding to the first bearing surface is called the second bearing surface, and there is a gap between the first bearing surface and the second bearing surface), and the gap can form an air film gap of the gas bearing. The bearing ring 400, the housing 300 and the gap form a gas bearing. When the turbine 200 rotates around the axis relative to the housing 300, an air film is formed in the gap to support the turbine 200 relative to the housing 300, thereby improving the radial swing of the turbine 200 during high-speed operation and increasing the stability of the turbine 200 during rotation.

[0047] The gas bearing formed by the bearing ring 400, the housing 300 and the gap may be any one of a static pressure bearing, a dynamic pressure bearing or a static-dynamic mixed bearing.

[0048] The turbine 200 has an axially opposite radial large end and a radial small end, and the bearing ring 400 is located at the radial small end of the turbine 200; when the turbine 200 rotates at a high speed, the bearing ring 400 will be subjected to a large centrifugal force. Since the magnitude of the centrifugal force is positively correlated with the diameter of the bearing ring 400 relative to the axis of rotation, the centrifugal force received by the radial small end of the turbine 200 is relatively small, so that under the same material, the bearing ring 400 can be prevented from being deformed, degenerated or broken due to the centrifugal force as much as possible.

[0049] The bearing ring 400 can be assembled to the turbine 200 in a manner of great interference fit, that is, the bearing ring 400 can be assembled by heat-fitting or by cold-fitting the turbine 200 .

[0050] The bearing ring 400 and the turbine 200 can also be fixedly connected by welding, which can be laser welding or welding with suitable solder. Specifically, the turbine 200 has a plurality of blades extending axially, and the inner annular surface of the bearing ring 400 is welded to the radial outer edges of the plurality of blades.

[0051] The bearing ring 400 and the turbine 200 may also be fixedly connected by interference fit and welding to improve the reliability of the interference fit.

[0052] Since the turbine 200 is located at the hot end of the gas turbine (the operating temperature can reach 950-1000°C), the turbine 200 and the bearing ring 400 can be made of high temperature resistant materials, and the high temperature resistant materials are selected from high temperature resistant metals, such as cast nickel. Specifically, the turbine 200 and the bearing ring 400 are made of the same high temperature resistant material, which is conducive to improving the joint strength after laser welding.

[0053] Embodiment 2 A rotating device

[0054] The structure is the same as that of Example 1, except that: Figure 3As shown, a protrusion 210 extending axially outward is provided at a radially outer position of the radial small end of the turbine 200, and the protrusion 210 is fixedly connected to the bearing ring 400. The protrusion 210 can be located on the blades of the turbine 200. Specifically, in some examples, all blades of the turbine 200 have the protrusion 210. In other examples, at least some of the multiple blades of the turbine have the protrusion 210, and the blades with the protrusion 210 and the blades without the protrusion 210 can be arranged alternately. The provision of the protrusion 210 can increase the contact area between the turbine 200 and the bearing ring 400, which can not only increase the connection stability, but also increase the air film area of ​​the gas bearing here, improve the support effect of the gas bearing, and try not to affect the aerodynamic effect of the turbine 200 while providing support.

[0055] Example 3 A gas turbine

[0056] A gas turbine includes a rotating shaft 100, a turbine 200, a casing 300 and a compressor 500. The turbine 200 and the compressor 500 are fixedly mounted on the rotating shaft 100. The rotating shaft 100, the turbine 200 and the compressor 500 are mounted in the casing 300. The turbine 200 is a centripetal turbine. Figure 4 As shown; a bearing ring 400 is sleeved on the radial outer side of the turbine, and the bearing ring 400 is in a circular ring shape; there is a gap between the bearing ring 400 and the housing 300 (specifically, the outer ring surface of the bearing ring 400 is called the first bearing surface, and the surface of the housing 300 corresponding to the first bearing surface is called the second bearing surface, and there is a gap between the first bearing surface and the second bearing surface), and the gap can form an air film gap of the gas bearing, and the bearing ring 400, the housing 300 and the gap form a gas bearing.

[0057] The rotating shaft 100 is also provided with a first radial bearing 610 and a thrust plate 110; the rotating shaft 100 has an axial first end and an axial second end which are axially opposite to each other, the first radial bearing 610 and the thrust plate 110 are located at the axial first end of the rotating shaft 100, the turbine 200 is located at or adjacent to the axial second end of the rotating shaft 100, the thrust plate 110 is located between the first radial bearing 610 and the turbine 200, and the compressor 500 is located between the thrust plate 110 and the turbine 200; thrust bearings 620 are provided on both sides of the thrust plate 110.

[0058] When the gas turbine is working, the shaft 100, the compressor 500, and the turbine 200 rotate at high speed around the axis relative to the casing 300, the first radial bearing 610 provides support at the first axial end to control the swing or movement of the shaft 100 in the radial direction, and the thrust bearing 620 provides support in the axial direction to control the swing or movement of the shaft 100 in the axial direction; at the same time, during the high-speed rotation of the shaft 100 and the turbine 200, an air film is formed in the gap between the bearing ring 400 and the casing 300, and the bearing ring 400, the casing 300 and the gap form a gas bearing, which provides support at the second axial end to control the swing or movement of the shaft 100 and the turbine 200 in the radial direction; the first radial bearing 610, the thrust bearing 620, and the gas bearing formed by the bearing ring 400, the casing 300 and the gap cooperate with each other to play a supporting role together, thereby increasing the stability of the gas turbine when it is working and preventing the shaft 100, the compressor 500, and the turbine 200 from swinging or moving to a large extent.

[0059] Understandably, Figure 4 Only one example of a gas turbine according to an embodiment of the present invention is shown. In other optional examples, the thrust plate 110 and its corresponding bearing may be located between the compressor 500 and the turbine 200, and the bearing ring 400, the casing 300 and the gap therebetween, which are sleeved on the radially outer side of the turbine 200, may form a gas bearing, which may support the turbine 200 relative to the casing 300, and may increase the stability of the turbine 200 during rotation, especially when the turbine 200 is heavy.

[0060] The casing 300 may be a gas turbine casing, a combustion chamber (not shown in the figure) casing, an exhaust section (not shown in the figure) casing, or an intermediate casing connected to the above casings.

[0061] The first radial bearing 610 and the thrust bearing 620 may be gas bearings, and the gas bearings may be any one of static pressure bearings, dynamic pressure bearings, or dynamic-static mixed pressure bearings.

[0062] The turbine 200 has an axially opposite radial large end and a radial small end, and the bearing ring 400 is located at the radial small end of the turbine 200; when the turbine 200 rotates at a high speed, the bearing ring 400 will be subjected to a large centrifugal force. Since the magnitude of the centrifugal force is positively correlated with the diameter of the bearing ring 400 relative to the axis of rotation, the centrifugal force received by the radial small end of the turbine 200 is relatively small, so that under the same material, the bearing ring 400 can be prevented from being deformed, degenerated or broken due to the centrifugal force as much as possible.

[0063] The bearing ring 400 can be assembled to the turbine 200 in a manner of great interference fit, that is, the bearing ring 400 can be installed by heat or the turbine 200 can be installed by cold.

[0064] The bearing ring 400 and the turbine 200 can also be fixedly connected by welding, which can be laser welding or welding with suitable solder. Specifically, the turbine 200 has a plurality of blades extending axially, and the inner annular surface of the bearing ring 400 is welded to the radial outer edges of the plurality of blades.

[0065] The bearing ring 400 and the turbine 200 may also be fixedly connected by interference fit and welding to improve the reliability of the interference fit.

[0066] Since the turbine 200 is located at the hot end of the gas turbine (the operating temperature can reach 950-1000°C), the turbine 200 and the bearing ring 400 can be made of high temperature resistant materials, and the high temperature resistant materials are selected from high temperature resistant metals, such as cast nickel. Specifically, the turbine 200 and the bearing ring 400 are made of the same high temperature resistant material, which is conducive to improving the joint strength after laser welding.

[0067] Example 4 A gas turbine

[0068] The structure is the same as that of Example 3, except that: the radial small end of the turbine 200 has a protrusion 210 extending axially outward, the protrusion 210 is fixedly connected to the bearing ring 400, and the protrusion 210 can be located on the blades of the turbine 200. Specifically, in some examples, all blades of the turbine 200 have protrusions 210. In other examples, at least some of the multiple blades of the turbine have protrusions 210, and blades with protrusions 210 and blades without protrusions 210 can be arranged alternately. The arrangement of the protrusion 210 can increase the contact area between the turbine 200 and the bearing ring 400, which can increase the connection stability, increase the air film area of ​​the gas bearing here, improve the support effect of the gas bearing, increase the stability of the gas turbine, and try not to affect the aerodynamic effect of the turbine 200 while providing support.

[0069] Example 5 A gas turbine

[0070] The structure is the same as that of the third embodiment, except that when the compressor 500 is located between the thrust plate 110 and the turbine 200, it further includes a reinforcement ring 700, which is annular. Figure 5 As shown, the reinforcement ring 700 is fixedly connected between the turbine 200 and the compressor 500. The reinforcement ring 700 can improve the rigidity of the compressor 500 and the turbine 200, and can also indirectly improve the rigidity of the rotating shaft 100 between the compressor 700 and the turbine 200, increase the critical speed of the rotor system to adapt to the normal working speed, and reduce the vibration of the rotating shaft 100 to avoid the resonance area.

[0071] A second radial bearing 640 is disposed on the radial outer side of the reinforcement ring 700 ; the second radial bearing 640 is a gas bearing.

[0072] A positioning structure for positioning the reinforcement ring 700 may also be provided on the opposing surfaces of the compressor 500 and the turbine 200; the positioning structure may be: a positioning ring groove is provided on the surface of the compressor 500 close to the turbine 200, and a protrusion is provided on the surface of the turbine 200 close to the compressor 500, the protrusion constitutes an annular positioning stop, one end of the reinforcement ring 700 is inserted into the positioning ring groove, and the other end is inserted into the inner circumference of the annular positioning stop.

[0073] The side wall of the reinforcement ring 700 may be provided with exhaust holes, and the number of exhaust holes may be 4. The exhaust holes are used to discharge the gas in the reinforcement ring to ensure that the pressure inside and outside the reinforcement ring is equal, so as to avoid the heat generated by the working airflow when the compressor 500 and the turbine 200 are working, which will cause the heat inside the reinforcement ring 700 to increase, and the pressure inside the ring to increase, thereby affecting the service life of the reinforcement ring 700 or even damaging the reinforcement ring 700.

[0074] Although the above describes the specific implementation methods of the present invention in combination with the embodiments, it is not intended to limit the scope of protection of the present invention. Technical personnel in the relevant field should understand that various modifications or variations that can be made by technical personnel in the field without creative work on the basis of the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. A rotating device, comprising a rotating shaft, a turbine and a housing, wherein the turbine is fixedly mounted on the rotating shaft, and the rotating shaft and the turbine are mounted in the housing; characterized in that: A bearing ring is sleeved on the radial outer side of the turbine, and a gap is provided between the bearing ring and the housing, the gap forming an air film gap of the gas bearing, and the bearing ring, the housing and the gap form a gas bearing; The turbine is a centripetal turbine, and has a radial large end and a radial small end axially opposite to each other, and the bearing ring is located at the radial small end of the turbine; The bearing ring is assembled to the turbine in a manner of great interference fit; and / or: the bearing ring and the turbine are fixedly connected by welding; The turbine has a plurality of blades extending axially, and the inner annular surface of the bearing ring is welded to the radial outer edges of the plurality of blades; At the radially small end of the turbine, at least part of the blades have a protrusion extending axially outward, and the protrusion is fixedly connected to the bearing ring.

2. The rotating device according to claim 1, characterized in that: The gas bearing formed by the bearing ring, the housing and the gap therebetween is any one of a static pressure bearing, a dynamic pressure bearing or a static-dynamic mixed bearing.

3. A gas turbine, characterized in that: It comprises the rotating device as claimed in claim 1 or 2 and a compressor, wherein the compressor is mounted on a rotating shaft.

4. The gas turbine according to claim 3, characterized in that: The rotating shaft is also provided with a first radial bearing and a thrust plate; the rotating shaft has an axial first end and an axial second end which are axially opposite to each other, the first radial bearing and the thrust plate are located at the axial first end of the rotating shaft, the turbine is located at or adjacent to the axial second end of the rotating shaft, the thrust plate is located between the first radial bearing and the turbine, and the compressor is located between the thrust plate and the turbine; a thrust bearing is provided on one side or both sides of the thrust plate.

5. The gas turbine according to claim 4, characterized in that: The casing is a gas turbine casing, a combustion chamber casing, an exhaust section casing, or an intermediate casing connected to the gas turbine casing, the combustion chamber casing and / or the exhaust section casing.

6. The gas turbine according to claim 4, characterized in that: The gas turbine also includes a reinforcement ring which is fixedly connected between the turbine and the compressor.

Images