A rotor system and a micro gas turbine generator set

Abstract

The present invention provides a rotor system and a micro gas turbine generator set, comprising: a rotating shaft, the rotating shaft is an integrally formed structure; and a motor, a radial bearing, a compressor, an integrated bearing, and a turbine arranged on the rotating shaft in sequence; wherein the motor comprises a motor stator and a rotor core, the motor stator is sleeved on one end of the rotating shaft, and a motor rotor core installation cavity is arranged at one end of the rotating shaft where the motor stator is sleeved, the rotor core is installed in the motor rotor core installation cavity, and the port of the motor rotor core installation cavity is not closed. In the present invention, the layout of the rotor system is compact, the axial dimension of the rotor system is short, the high-speed operation stability is good, the rotating shaft adopts an open structure, the motor rotor core has good heat dissipation, the rotating shaft is not easy to deform, and the precision is high.

Description

Technical Field

[0001] The present invention relates to the technical field of rotor dynamics, and in particular to a rotor system and a micro gas turbine generator set. Background Art

[0002] Micro gas turbine is a newly developed small thermal engine with a single unit power range of 25 to 300kW. Its basic technical features are the use of radial impeller machinery and heat recovery cycle. Micro gas turbine mainly includes three major components: compressor, combustion chamber and turbine. After entering the compressor, the air is compressed into high-temperature and high-pressure air, and then supplied to the combustion chamber to mix and burn with fuel. The high-temperature and high-pressure combustion gas generated expands in the turbine to do work. When the rotor rotates at high speed, the rotor will be subjected to radial and axial forces. In order to limit the radial and axial movement of the shaft, radial bearings and thrust bearings need to be installed in the rotor system. Traditional radial bearings and thrust bearings are both ordinary contact bearings. With the increase of rotor speed, especially when the rotor speed exceeds 40,000 revolutions per minute, ordinary contact bearings can no longer meet the requirements of the working speed due to large mechanical wear.

[0003] For a micro gas turbine generator set, the high-speed rotation of the gas turbine rotor drives the generator rotor to rotate and generate electricity. However, the rotor system of the micro gas turbine generator set in the prior art has the following defects:

[0004] In the prior art, a coupling is usually used to connect the gas turbine rotor to the generator rotor. The coaxiality deviation causes poor stability of the rotor system. At the same time, the setting of the coupling limits the setting position of the thrust bearing. This is because as the rotor speed increases, the axial force on the rotor will further increase. If the thrust bearing is set between the compressor and the turbine, the center of gravity of the entire rotor system will be biased toward the turbine side, resulting in poor stability of the rotor system. If the thrust bearing is set on the side of the coupling facing the generator, the axial force of the rotor will all act on the coupling, which is easy to cause damage to the coupling.

[0005] It can be seen that there is an urgent need to provide a new rotor system to solve the above-mentioned problems existing in the existing micro gas turbine generator sets. Summary of the invention

[0006] In order to solve the above technical problems, the purpose of the present invention is to provide a rotor system and a micro gas turbine generator set, which adopts an integrated rotating shaft to connect the gas turbine rotor and the generator rotor, and the rotating shaft has a short axial length, strong rigidity, easy processing, low manufacturing cost, and good stability of high-speed operation of the rotor system.

[0007] The technical solution of the present invention is as follows:

[0008] According to one aspect of the present invention, there is provided a rotor system, comprising:

[0009] A rotating shaft, wherein the rotating shaft is an integrally formed structure;

[0010] and, a motor, a radial bearing, a compressor, an integrated bearing, and a turbine sequentially arranged on the rotating shaft;

[0011] Wherein, the motor includes a motor stator and a rotor core, the motor stator is sleeved on one end of a rotating shaft, a motor rotor core installation cavity is provided on the end of the rotating shaft on which the motor stator is sleeved, the rotor core is installed in the motor rotor core installation cavity, and the port of the motor rotor core installation cavity is not closed.

[0012] Furthermore, the rotating shaft includes a first shaft section and a second shaft section, the diameter of the first shaft section is larger than the diameter of the second shaft section, and a step surface is formed at the transition between the first shaft section and the second shaft section;

[0013] The motor and radial bearing are arranged on the first shaft section, the compressor, integrated bearing and turbine are arranged on the second shaft section, one end of the compressor is in contact with the step surface; the motor stator is sleeved on the end of the first shaft section away from the second shaft section.

[0014] Furthermore, the radial bearing and the integrated bearing are both gas bearings.

[0015] Furthermore, the motor stator includes a stator core and a stator winding;

[0016] The stator winding is wound on the stator core, the radial bearing is sleeved between the stator winding and the rotating shaft in the radial direction, and the stator winding is provided with an air inlet hole of the radial bearing.

[0017] Furthermore, the motor stator is provided with a plurality of air inlet passages axially penetrating the motor stator;

[0018] The motor stator comprises a stator core and a stator winding;

[0019] The stator core is cylindrical, and a through hole for installing the rotating shaft is formed at the center of the cylinder;

[0020] The outer diameter side of the stator core is formed with a plurality of outer line slots extending along the axial direction of the cylinder and uniformly distributed along the circumference of the cylinder, and the inner diameter side of the stator core is formed with a plurality of inner line slots extending along the axial direction of the cylinder and uniformly distributed along the circumference of the cylinder;

[0021] The stator winding is wound in the outer wire slot and the inner wire slot along the axial direction of the cylinder, and the air inlet passage is formed in the inner wire slot.

[0022] Furthermore, the integrated gas bearing comprises:

[0023] A first thrust plate and a second thrust plate are fixedly mounted on the rotating shaft, the first thrust plate and the second thrust plate are arranged opposite to each other, and an annular groove is formed between the two;

[0024] And, a bearing stator is installed in the annular groove and connected to the housing of the rotor system, and the two end faces of the bearing stator have a first axial gap and a second axial gap with the first thrust plate and the second thrust plate respectively, forming a thrust gas bearing part, and a radial gap is formed between the inner diameter surface of the bearing stator and the bottom of the annular groove, forming a radial gas bearing part.

[0025] Furthermore, the bearing stator is provided with an annular air cavity, and the annular air cavity is connected to an external air source through an air inlet hole;

[0026] The annular air cavity is connected to the first axial gap through the first vent hole, the annular air cavity is connected to the second axial gap through the second vent hole, and the annular air cavity is connected to the radial gap through the third vent hole.

[0027] Furthermore, the first vent hole and the second vent hole are provided in plurality and are evenly distributed around the rotating shaft on the first thrust plate and the second thrust plate respectively, and the third vent hole is provided in plurality and is evenly distributed around the rotating shaft at the bottom of the annular groove.

[0028] Furthermore, a dynamic pressure generating groove is provided on the end surface of the first thrust plate facing the bearing stator or on the end surface of the bearing stator facing the first thrust plate;

[0029] Furthermore, a dynamic pressure generating groove is provided on an end surface of the second thrust plate facing the bearing stator or on an end surface of the bearing stator facing the second thrust plate.

[0030] Further, a first air groove is provided on a side of the first thrust plate facing the bearing stator or a side of the bearing stator facing the first thrust plate and a side of the second thrust plate facing the bearing stator or a side of the bearing stator facing the second thrust plate;

[0031] A second air groove is provided on the inner diameter surface of the bearing stator along the circumferential direction or on the circumferential surface of the annular groove.

[0032] Furthermore, an anti-rotation component is provided between the bearing stator and the rotor system housing, and the anti-rotation component is used to prevent the bearing stator from rotating along the circumferential direction with the first thrust plate and the second thrust plate.

[0033] Furthermore, the back end surface of the compression wheel of the compressor is set as a smooth end surface, and the end surface serves as the first thrust plate of the integrated bearing.

[0034] According to another aspect of the present invention, there is provided a micro gas turbine generator set, comprising a motor casing, a gas turbine casing, a combustion chamber and the above-mentioned rotor system;

[0035] The motor casing cover is arranged on the outer periphery of the motor, and the gas turbine casing cover is arranged on the outer periphery of the compressor, the integrated bearing and the turbine, and is connected to the motor casing;

[0036] The combustion chamber is connected to the gas turbine casing, and the air inlet of the combustion chamber is connected to the exhaust port of the compressor, and the exhaust port of the combustion chamber is connected to the air inlet of the turbine. The bearing stator of the integrated bearing is connected to the gas turbine casing through an anti-rotation component.

[0037] Furthermore, a diffuser is provided between the exhaust port of the compressor and the air inlet of the combustion chamber.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] 1. In the present invention, the rotor system has a compact layout, a short axial dimension, good high-speed running stability, an open structure for the rotating shaft, good heat dissipation of the motor rotor core, and the rotating shaft is not prone to deformation and has high precision.

[0040] 2. The back winding structure of the motor of the present invention can further shorten the length of the rotating shaft. At the same time, the air intake duct provided can be used for the air intake of the compressor. At the same time, the air intake of the compressor can cool the motor stator of the motor.

[0041] 3. The present invention adopts an integrated bearing, the rotor system has high axial and radial verticality, stable operation and long service life.

[0042] 4. The back end surface of the compression wheel of the compressor of the present invention serves as a thrust plate of the integrated bearing, which has a compact structure and saves costs.

[0043] 5. The micro gas turbine generator set of the present invention has a compact layout, good heat dissipation performance and stable operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a structural diagram of the rotor system of the present invention.

[0045] Figure 2 This is a diagram of the motor structure of the first embodiment of the present invention.

[0046] Figure 3 It is a half-section view of the motor according to the first embodiment of the present invention.

[0047] Figure 4 This is a structural diagram of a motor stator core according to Embodiment 1 of the present invention.

[0048] Figure 5This is a structural diagram of a silicon steel sheet according to Embodiment 1 of the present invention.

[0049] Figure 6 This is a structural diagram of the end surface wire groove of the first embodiment of the present invention.

[0050] Figure 7 This is a structural diagram of an integrated bearing according to embodiment 2 of the present invention.

[0051] Figure 8 This is a structural diagram of the first air slot in embodiment 2 of the present invention.

[0052] Fig. 9 This is a structural diagram of the first air slot in embodiment 2 of the present invention.

[0053] Fig.10 This is another structural diagram of a rotor system of the present invention. DETAILED DESCRIPTION

[0054] In order to better understand the technical solution of the present invention, the present invention is further described below in conjunction with specific embodiments and the accompanying drawings of the specification.

[0055] According to one aspect of the present invention, a rotor system is provided.

[0056] like Figure 1 As shown, it includes:

[0057] The rotating shaft 100 includes a first shaft section 110 and a second shaft section 120 which are integrally formed. The diameter of the first shaft section 110 is larger than the diameter of the second shaft section 120. A step surface 130 is formed at the transition between the first shaft section 110 and the second shaft section 120.

[0058] The motor 600, radial bearing 500, compressor 300, integrated bearing 400 and turbine 200 are sequentially arranged on the rotating shaft 100; wherein, the motor 600 and radial bearing 500 are arranged on the first shaft section 110, the compressor 300, integrated bearing 400 and turbine 200 are arranged on the second shaft section 120, and one end of the compressor 500 abuts against the step surface 130; the motor 600 includes a rotor core 620 and a motor stator 610, the motor stator 610 is sleeved on one end of the first shaft section 110 away from the second shaft section 120, and a motor rotor core installation cavity 111 is provided at one end of the first shaft section 110 sleeved with the motor stator 610, the rotor core 620 is installed in the motor rotor core installation cavity 111, and the port of the motor rotor core installation cavity 111 is not closed.

[0059] The rotor system of the present invention is only provided with one radial bearing and one integrated bearing, and has a compact structure, a short axial dimension, a high critical speed of the rotor system, and good stability in high-speed operation; at the same time, one end of the shaft 100 where the rotor core 620 is mounted is not closed, and the heat dissipation is good. Since the shaft port is not closed, the shaft does not need to undergo a welding process, will not produce thermal deformation, and has high precision.

[0060] The rotor system of the present invention is provided with radial bearings 500 and integrated bearings 400 between the motor 600 and the compressor 300 and between the compressor 300 and the turbine 200. The axial weight distribution of the rotor system is uniform and the stability is good.

[0061] Preferably, the radial bearing 500 and the integrated bearing 400 are both gas bearings, which can meet the needs of high-speed rotation of the rotor system. At the same time, there is no mechanical wear between the bearing and the rotating shaft 100, and the service life of the bearing and the rotor system is long.

[0062] Preferably, the motor stator 610 includes a stator core 611 and a stator winding 612 , the stator winding 612 is wound around the stator core 611 , the radial bearing 500 is sleeved between the stator winding 612 and the rotating shaft 100 in the radial direction, and the stator winding 612 is provided with an air inlet 613 of the radial bearing 500 .

[0063] Since the radial bearing 500 is installed between the stator winding 612 of the motor 600 and the rotating shaft 100 , the length of the rotating shaft 100 can be further shortened, thereby improving the high-speed operation stability of the rotor system.

[0064] This method is suitable for the structure of the motor 600 formed by a conventional winding method. A radial bearing can be installed at the position where the stator winding exceeds the stator core in the axial direction, saving axial size.

[0065] Embodiment 1

[0066] In this embodiment, a motor structure is provided in which a stator winding is wound in a back-winding manner.

[0067] Specifically, Figure 2 As shown, the motor 600 includes: a motor stator 610, a motor rotor 620 (not shown in the figure), and a motor housing 630. The motor stator 620 is sleeved on the rotating shaft 100 and maintains a certain gap with the rotating shaft 100 in the radial direction. The motor housing 630 is covered on the outer periphery of the motor stator 410. The motor stator 610 is provided with a plurality of air inlet ducts 640 axially penetrating the motor stator 610.

[0068] Since the air inlet 640 is provided, the air intake of the compressor 300 can enter the compressor 300 through the air inlet 640 , so that the air intake of the compressor 300 is more sufficient. At the same time, the normal temperature air passing through the air inlet 640 can play a certain cooling role on the motor stator 610 .

[0069] Specifically, the formation of the above-mentioned air inlet 640 can be achieved through the following structure and winding method. Figure 3 , is a half-section diagram of the motor; and Figure 4 , structural diagram of motor stator core 611.

[0070] The motor stator 610 includes a stator core 611 and a stator winding 612. The stator core 611 is cylindrical and has a through hole 6111 at the center of the cylinder for installing the rotating shaft 100. The outer diameter side of the stator core 611 is formed with a plurality of first winding partitions 6112 extending along the axial and radial outer sides of the cylinder and evenly distributed along the circumference of the cylinder. The inner diameter side of the stator core 611 is formed with a plurality of second winding partitions 6113 extending along the axial and radial inner sides of the cylinder and evenly distributed along the circumference of the cylinder. The through hole 6111 is formed at one end of the second winding partition 6113 close to the center of the cylinder. The first winding partition 6112 and the second winding partition 6113 are arranged opposite to each other on the outer diameter side and the inner diameter side of the cylinder, the two adjacent first winding partitions 6112 and the outer circumferential surface of the cylinder form an outer wire groove 6114, the adjacent second winding partitions 6113 and the inner circumferential surface of the cylinder form an inner wire groove 6115, the stator winding 612 is wound in the outer wire groove 6114 and the inner wire groove 6115 along the axial direction of the cylinder, and the stator winding 612 and the two adjacent second winding partitions 6113 constitute the air intake duct 640.

[0071] Optionally, the stator core 611 is formed by stacking and pressing a plurality of silicon steel sheets 6116 of identical shape in the axial direction of a cylinder. The structure of the silicon steel sheets is as follows: Figure 5 shown.

[0072] By setting the above-mentioned stator core 611 structure, the stator winding 612 can be wound in the outer wire slot 6114 and the inner wire slot 6115 of the stator core 611, and after the stator winding is arranged in the inner wire slot 6115, an air inlet 640 is still formed. Therefore, in this structure, most of the stator winding 612 of the motor 600 is located in the wire slot, and only a small amount of stator winding leaks out at both ends of the stator core 611. Conventional motors use conventional winding methods, and the entire winding is located on the inner side of the stator core. Due to the limited space inside the stator core, it is difficult to form a regular air inlet. Even if an air inlet is formed, the air inlet is very narrow, which is not conducive to the passage of gas, and mushroom-shaped windings will be formed at both ends of the stator core. Compared with the two, the motor 600 of this structure is shorter in length in the axial direction and the overall volume is reduced. Therefore, when the motor 600 of this structure is used in a rotor system, the axial length of the entire rotor system can be greatly shortened, and the running stability of the rotor system can be improved. At the same time, the motor 600 of this structure has an air inlet 640 for air or cooling air to pass through formed on the motor stator 610, which is beneficial to the heat dissipation of the motor stator 610 and the rotating shaft 100. At the same time, when the motor 600 is used at the front end of a compressor or other equipment that requires air intake, it will not block the air intake of the rear end equipment and will not increase the axial length of the rotor system.

[0073] Alternatively, if Figure 6 As shown, the structure of the stator core 611 can be further optimized, that is, end surface wire grooves 6117 are set at the positions of the outer wire grooves 6114 and the inner wire grooves 6115 at both ends of the stator core 611, so that the entire winding can be set in the wire grooves, making the overall wiring of the motor 400 neater and cleaner.

[0074] Optionally, the surface of the stator core 611 is coated with an insulating layer or painted with insulating paint.

[0075] Optionally, the number of the first winding partitions 6112 and the second winding partitions 6113 is 10, 16, 18, 24, etc.

[0076] Optionally, in order to facilitate heat dissipation of the motor stator 610 and the rotating shaft 100 and air intake of the air inlet 640, the motor 600 of this structure may not be provided with left and right end covers, or may be provided with left and right end covers but mesh air holes are provided on the left and right end covers.

[0077] Since the motor 600 adopts the back winding method, the axial dimension of the motor 600 is short, which can further shorten the length of the rotor system, reduce the mass of the rotor system, and improve the high-speed operation stability of the rotor system. In this method, the motor 600 adopts the back winding method, and the axial dimension of the motor 600 itself is short. In this structure, the radial bearing 500 can only be installed in series with the motor 600.

[0078] Embodiment 2

[0079] In this embodiment, a structure of an integrated bearing 400 is provided, which includes a radial bearing portion and a thrust bearing portion. The radial bearing portion and the thrust bearing portion are integrally formed or finely machined after assembly. Therefore, the verticality between the center axis of the radial bearing portion and the thrust surface of the thrust bearing portion is high, the rotor system has high installation accuracy, and runs smoothly.

[0080] Specifically, see Figure 7 , the one-piece bearing 400 comprises:

[0081] A first thrust plate 410 and a second thrust plate 420 are fixedly mounted on the second shaft section 120. The first thrust plate 410 and the second thrust plate 420 are arranged opposite to each other, and an annular groove 430 is formed therebetween;

[0082] A bearing stator 440 is installed in the annular groove 430 and connected to the rotor system housing 450, and the two end faces of the bearing stator 440 have a first axial gap and a second axial gap with the first thrust plate 410 and the second thrust plate 420 respectively, forming a thrust gas bearing part, and a radial gap is formed between the inner diameter surface of the bearing stator 440 and the bottom of the annular groove 430, forming a radial gas bearing part.

[0083] Furthermore, an annular air cavity 441 is provided on the bearing stator 440, and the annular air cavity 441 is connected to the external air source through the air inlet hole 442; the annular air cavity 441 is connected to the first axial gap through the first air hole 443, the annular air cavity 441 is connected to the second axial gap through the second air hole 444, and the annular air cavity 441 is connected to the radial gap through the third air hole 445.

[0084] The first vent hole 443 and the second vent hole 444 can be provided in plurality and evenly distributed around the rotating shaft 100 on the first thrust plate 410 and the second thrust plate 420 . The third vent hole 445 can be provided in plurality and evenly distributed around the rotating shaft 100 at the bottom of the annular groove 430 .

[0085] The integrated bearing 400 may be any one of a static pressure gas bearing, a dynamic pressure gas bearing, or a static and dynamic mixed pressure gas bearing.

[0086] When it is a static pressure gas bearing, it is only necessary to connect the air inlet 442 to the external pressure air source;

[0087] When it is a dynamic pressure gas bearing, a dynamic pressure generating groove can be set on the end surface of the first thrust plate 410 facing the bearing stator 440 or on the end surface of the bearing stator 440 facing the first thrust plate 410 and on the end surface of the second thrust plate 420 facing the bearing stator 440 or on the end surface of the bearing stator 440 facing the first thrust plate 420.

[0088] As a preference, Figure 8 , 9 As shown, in this embodiment, a first air groove 470 is provided on a side of the first thrust plate 410 facing the bearing stator 440 or a side of the bearing stator 440 facing the first thrust plate 410 and a side of the second thrust plate 420 facing the bearing stator 440 or a side of the bearing stator 440 facing the second thrust plate 420;

[0089] The inner diameter surface of the bearing stator 440 is provided with a second air groove 480 along the circumferential direction or on the circumferential surface of the annular groove 430 to improve the air conductivity. When the shaft 100 rotates and gradually accelerates, the flowing gas in the bearing gap is pressed into the second air groove 480 and flows rapidly along the second air groove 480, thereby achieving directional high-speed flow of the gas. Under the condition of meeting the air pressure load of the bearing, the shaft 100 and the air bearing can dissipate heat and conduct air better.

[0090] Preferably, the first air groove 470 is an arc groove, which is evenly distributed in the circumference and symmetrical in the center, with one end of the arc groove adjacent to the center of the circle and the other end adjacent to or intersecting the circumference. The number of arc grooves is set according to the rotation speed of the shaft 100 so that the air flow rate and pressure reach a reasonable ratio. When the shaft 100 rotates forward or reverse, the rigidity and load capacity of the bearing can be maintained, and the air can flow smoothly, which can prevent air from being blocked in the flow channel.

[0091] Preferably, viewed from the air intake direction, when the rotating shaft 100 rotates clockwise, the arc grooves on the end faces of the first thrust plate 410 and the second thrust plate 420 are left concave arcs, and the bearing stator 440 is right concave arcs. When the rotating shaft 100 rotates counterclockwise, the arc grooves on the end faces of the first thrust plate 410 and the second thrust plate 420 are right concave arcs, and the bearing stator 440 is left concave arcs, thereby realizing axial air flow from left to right.

[0092] Preferably, the first air groove 470 can be formed by forging, rolling, etching or stamping; meanwhile, the first thrust plate 410 and the second thrust plate 420 can be made of stainless steel material to facilitate the processing of the first air groove 470 .

[0093] Preferably, the second air groove 480 is in the shape of a parallel skew groove or a spiral groove. Compared with the parallel skew groove, the spiral groove has a smaller flow capacity than the parallel skew groove, but can increase axial damping. During the air circulation process, when the pitch is small, the air flow will slow down and increase the pressure, and when the pitch is large, the air flow will increase the speed and reduce the pressure. Therefore, the spiral groove parameters can be set according to the rotation speed of the rotating shaft. When the rotation speed of the rotating shaft is high, the spiral groove is set to a large pitch and the spiral line gap is sparse. When the rotation speed of the rotating shaft is low, the spiral groove is set to a small pitch and the spiral line gap is dense.

[0094] Preferably, the parallel inclined grooves are continuous or discontinuous; the lead angle of the spiral groove is α, the pitch is P, the depth of the spiral groove is HL, the diameter of the rotating shaft is DL, 30° < α < 60°, 1 / 2DL < P < 5DL; P = 3DL, α = 45°; the spiral groove winds around the shaft for half a turn or 1 / 3 of a turn.

[0095] The parallel inclined grooves or the spiral grooves are arranged such that when the rotating shaft rotates forward or backward, the stiffness and load capacity of the bearing can be maintained, the air flow is smooth, and air blockage in the flow channel can be prevented.

[0096] Preferably, the second air groove 480 is arranged in the middle part of the position of the rotary annular groove 430 corresponding to the installation of the bearing stator 440, or is arranged as two independent parts symmetrically distributed on both sides of the middle part.

[0097] Preferably, when viewed from the intake direction, when the rotating shaft 100 rotates clockwise, the inclination direction of the parallel inclined grooves or the spiral grooves is leftward, and when the rotating shaft 100 rotates counterclockwise, the inclination direction of the parallel inclined grooves or the spiral grooves is rightward, so as to realize the axial air flow from left to right.

[0098] Preferably, the shape of the second air groove 480 also includes a herringbone shape, an inverted V shape, a V shape. The inverted V-shaped groove, the herringbone-shaped groove or the V-shaped groove is arranged such that when the rotating shaft 100 rotates forward or backward, the bearing can support the rotating shaft 100 in a non-contact manner in a desired manner, and has a high load capacity and good stability; an inverted V-shaped groove, a herringbone-shaped groove or a V-shaped groove is arranged at a position where the load of the rotating shaft 100 is large or the stiffness is insufficient, and parallel inclined grooves or spiral grooves are arranged at a position where the air flow is insufficient. The inverted V-shaped groove, the herringbone-shaped groove, the V-shaped groove and / or the parallel inclined grooves, the spiral grooves are arranged at intervals.

[0099] The ventilation efficiency of the second air groove 480 varies with the angle, groove width, number of grooves, length, depth and flatness of the second air groove 480. The ventilation speed is related to the rotation speed of the rotating shaft 100 and the bearing clearance. In addition, in reality, the cross-section of the rotating shaft 100 cannot be an ideal circle. When the non-circularity affects the pressure of the air film during rotation, the radial distribution of the clearance between the rotating shaft 100 and the bearing stator 440 is uneven, and the pressure in the space with a small clearance becomes larger while the pressure in the place with a large clearance decreases. The second air groove 480 can be matched and set according to the actual working conditions.

[0100] When the rotor system is at low speed, the longer the shaft length, the greater the low-speed zero-crossing stiffness; at high speed, the longer the shaft length, the greater the resistance, which increases exponentially. Therefore, after grooving, the shaft stiffness is not affected at low speed, and the thrust remains unchanged. At high speed, the dynamic pressure working capacity is reduced, and the air will flow to the air groove, the stiffness decreases, and the actual working length of the dynamic pressure is the length of the shaft minus the length of the groove. The resistance becomes smaller and the shaft length can be increased; the flow guidance is achieved without reducing the stiffness of the shaft. After the air groove is set, the gas is guided to form a directional flow at low speed. When the dynamic pressure is switched at high speed, the airflow still flows in a directional manner and no impact airflow is formed; at the same time, after the air groove is set in the bearing, the ability of the rotor to resist disturbed eccentric collision with the wall can be improved, thereby also improving the bearing's load-bearing capacity.

[0101] Embodiment 3

[0102] In this embodiment, an anti-rotation structure for the integrated bearing 400 in the second embodiment is provided. The bearing stator 440 of the integrated bearing 400 is installed in the rotor system housing 450 and the rotor system end cover 460. The rotor system housing 450 is sleeved on the circumference and one end face of the bearing stator 440. The rotor system end cover 460 is sleeved on the rotating shaft 100 and is located on the other end face of the bearing stator 440 to achieve axial limitation on the other side of the bearing stator 440. An anti-rotation component is provided between the rotor system housing 450 and the bearing stator 440. The anti-rotation component is used to achieve circumferential positioning of the bearing stator 440 relative to the rotor system housing 450 to prevent the bearing stator 440 from rotating with the first thrust plate 410 or the second thrust plate 420.

[0103] Specifically, one end of the anti-rotation component is fixedly connected or integrally formed with the rotor system housing 450, and the other end of the anti-rotation component is detachably connected with the bearing stator 440; or, one end of the anti-rotation component is detachably connected with the rotor system housing 450, and the other end of the anti-rotation component is fixedly connected or integrally formed with the bearing stator 440; the anti-rotation component can be provided as one or more, and the anti-rotation component can be provided as a pin or a pin or a key or a spherical body, etc. The one-piece bearing is provided with an anti-rotation component, and the bearing body will not rotate with the shaft, and has a long service life and stable operation.

[0104] As a preferred embodiment of the present invention, see Fig.10 The back section of the compression wheel of the compressor 300 is set to a smooth end face, and the end face serves as the first thrust plate 410 of the integrated bearing 400. This can effectively utilize the back end face of the compression wheel of the compressor 300, shorten the axial length of the rotor system, and further improve the stability of the high-speed operation of the rotor system.

[0105] As a preferred solution of the present invention, in order to reduce the influence of heat conduction at the hot end of the turbine on the efficiency of the compressor, the turbine can be manufactured using ceramic turbine materials or other materials with lower thermal conductivity.

[0106] The rotor system rotating shaft 100 of the present invention has a short axial dimension and a light weight, and the critical speed of the rotor system is high, so the rotor system runs smoothly at high speed; the integrated bearing is arranged between the turbine 200 and the compressor 300, and has a compact structure. When thermal expansion occurs around the position where the turbine wheel of the turbine 200 is installed on the rotating shaft 100, the integrated bearing (thrust bearing) can simultaneously generate axial displacement at both ends of the rotating shaft 100. Compared with installing the thrust bearing at the leftmost end of the rotor system, it is less likely to cause the compression wheel of the compressor 300 and the turbine wheel of the turbine 200 to collide with the gas turbine casing.

[0107] According to another aspect of the present invention, the present invention also provides a micro gas turbine generator set using the above rotor system, the generator set comprising:

[0108] The above-mentioned rotor system includes a motor casing 810, a gas turbine casing 820 and a combustion chamber 830; the motor casing 810 is covered on the outer periphery of the motor 600, the gas turbine casing 820 is covered on the outer periphery of the compressor 300, the integrated bearing 400 and the turbine 200, and is connected to the motor casing 810, the combustion chamber 830 is connected to the gas turbine casing 820, and the air inlet of the combustion chamber 830 is connected to the exhaust port of the compressor 300, the exhaust port of the combustion chamber 830 is connected to the air inlet of the turbine 200, and the bearing stator 440 of the integrated bearing 400 is connected to the gas turbine casing 820 via an anti-rotation component.

[0109] Preferably, a diffuser 840 is provided between the exhaust port of the compressor 300 and the air inlet of the combustion chamber 830 to further increase the pressure of the high-temperature and high-pressure gas entering the turbine 200 to perform work.

[0110] The micro gas turbine generator set of the present invention has a compact layout, a short axial dimension of the rotating shaft 100, and good high-speed operation stability; one end of the rotor core 620 of the motor 600 is exposed, and the heat dissipation is good; an integrated bearing 400 is arranged between the compressor 300 and the turbine 200, which simultaneously supports the micro gas turbine generator set in the radial and axial directions, and has high installation accuracy; and the back end face of the compression wheel of the compressor 300 can be used as a thrust plate of the integrated bearing, and the overall structure is simple.

[0111] The micro gas turbine of the present invention has a simple and compact structure, saves installation space, is easy to install and carry quickly, and can well meet the small-scale and decentralized needs of distributed power supply; it has few moving parts and a simple and compact structure, so it has good reliability, low manufacturing cost and maintenance cost; it has the advantages of good environmental adaptability and high power supply quality.

[0112] The whole system has only one moving part and uses air bearings, with an operating reliability rate of up to 99.996%, and an average annual downtime for maintenance of no more than 2 hours. The bearing / rotor system of the present invention can be used for micro gas turbines of 10 to 100KW models, such as 15 / 30 / 45KW models.

[0113] Single microturbine:

[0114] The speed of a 15KW micro-turbine with a regenerator is 0-140000RPM. When the fuel is kerosene, the fuel consumption is 50g / kWh-600g / kWh; when the fuel is natural gas, the natural gas consumption is 0.15m 3 / kWh~0.5m 3 / kWh. The speed of a 15KW micro-turbine without a regenerator is 0~140000RPM. When the fuel is kerosene, the fuel consumption is 400g / kWh~1000g / kWh; when the fuel is natural gas, the natural gas consumption is 0.4m 3 / kWh~1m 3 / kWh.

[0115] The speed of a 45KW micro-turbine with a regenerator is 0-80000RPM. When the fuel is kerosene, the fuel consumption is 200g / kWh-500g / kWh; when the fuel is natural gas, the natural gas consumption is 0.2m 3 / kWh~0.5m 3 / kWh. The speed of a 45KW micro-turbine without a regenerator is 0~80000RPM. When the fuel is kerosene, the fuel consumption is 400g / kWh~900g / kWh; when the fuel is natural gas, the natural gas consumption is 0.5m 3 / kWh~1m 3 / kWh.

[0116] The above description is only a preferred embodiment of the present invention and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present invention is not limited to the technical solutions formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features have similar functions to those disclosed in the present invention (but not limited to).

Claims

1. A rotor system, characterized in that: include: A rotating shaft, wherein the rotating shaft is an integrally formed structure; and, a motor, a radial bearing, a compressor, an integrated bearing, and a turbine sequentially arranged on the rotating shaft; The motor comprises a motor stator and a rotor core, wherein the motor stator is sleeved on one end of a rotating shaft, and a motor rotor core installation cavity is provided on one end of the rotating shaft where the motor stator is sleeved, and the rotor core is installed in the motor rotor core installation cavity, and a port of the motor rotor core installation cavity is not closed; The rotating shaft comprises a first shaft section and a second shaft section, the diameter of the first shaft section is larger than the diameter of the second shaft section, and a step surface is formed at the transition between the first shaft section and the second shaft section; The motor and radial bearing are arranged on the first shaft section, the compressor, integrated bearing and turbine are arranged on the second shaft section, one end of the compressor is in contact with the step surface; the motor stator is sleeved on the end of the first shaft section away from the second shaft section; The radial bearing and the integrated bearing are both gas bearings.

2. The rotor system according to claim 1, characterized in that The motor stator comprises a stator core and a stator winding; The stator winding is wound on the stator core, the radial bearing is sleeved between the stator winding and the rotating shaft in the radial direction, and the stator winding is provided with an air inlet hole of the radial bearing.

3. The rotor system according to claim 1, characterized in that The motor stator is provided with a plurality of air inlet passages axially penetrating the motor stator; The motor stator comprises a stator core and a stator winding; The stator core is cylindrical, and a through hole for installing the rotating shaft is formed at the center of the cylinder; The outer diameter side of the stator core is formed with a plurality of outer line slots extending along the axial direction of the cylinder and uniformly distributed along the circumference of the cylinder, and the inner diameter side of the stator core is formed with a plurality of inner line slots extending along the axial direction of the cylinder and uniformly distributed along the circumference of the cylinder; The stator winding is wound in the outer wire slot and the inner wire slot along the axial direction of the cylinder, and the air inlet passage is formed in the inner wire slot.

4. The rotor system according to claim 1, characterized in that The one-piece bearing comprises: A first thrust plate and a second thrust plate are fixedly mounted on the rotating shaft, the first thrust plate and the second thrust plate are arranged opposite to each other, and an annular groove is formed between the two; And, a bearing stator is installed in the annular groove and connected to the housing of the rotor system, and the two end faces of the bearing stator have a first axial gap and a second axial gap with the first thrust plate and the second thrust plate respectively, forming a thrust gas bearing part, and a radial gap is formed between the inner diameter surface of the bearing stator and the bottom of the annular groove, forming a radial gas bearing part.

5. The rotor system according to claim 4, characterized in that The bearing stator is provided with an annular air cavity, and the annular air cavity is connected to an external air source through an air inlet hole; The annular air cavity is connected to the first axial gap through the first vent hole, the annular air cavity is connected to the second axial gap through the second vent hole, and the annular air cavity is connected to the radial gap through the third vent hole.

6. The rotor system according to claim 5, characterized in that The first vent holes and the second vent holes are provided in a plurality and are evenly distributed around the rotating shaft on the first thrust plate and the second thrust plate, respectively. The third vent holes are provided in a plurality and are evenly distributed around the rotating shaft at the bottom of the annular groove.

7. The rotor system according to any one of claims 4 to 6, characterized in that: The end surface of the first thrust plate facing the bearing stator or the end surface of the bearing stator facing the first thrust plate is provided with a dynamic pressure generating groove; Furthermore, a dynamic pressure generating groove is provided on an end surface of the second thrust plate facing the bearing stator or on an end surface of the bearing stator facing the second thrust plate.

8. The rotor system according to claim 7, characterized in that A first air groove is provided on a side of the first thrust plate facing the bearing stator or a side of the bearing stator facing the first thrust plate and a side of the second thrust plate facing the bearing stator or a side of the bearing stator facing the second thrust plate; A second air groove is provided on the inner diameter surface of the bearing stator along the circumferential direction or on the circumferential surface of the annular groove.

9. The rotor system according to claim 4, characterized in that An anti-rotation component is provided between the bearing stator and the rotor system housing, and the anti-rotation component is used to prevent the bearing stator from rotating along the circumferential direction with the first thrust plate and the second thrust plate.

10. The rotor system according to claim 4, characterized in that The back end surface of the compression wheel of the compressor is set as a smooth end surface, and the end surface serves as the first thrust plate of the integrated bearing.

11. A micro gas turbine generator set, characterized in that: It comprises a motor casing, a gas turbine casing, a combustion chamber and a rotor system as claimed in any one of claims 1 to 10; The motor casing cover is arranged on the outer periphery of the motor, and the gas turbine casing cover is arranged on the outer periphery of the compressor, the integrated bearing and the turbine, and is connected to the motor casing; The combustion chamber is connected to the gas turbine casing, and the air inlet of the combustion chamber is connected to the exhaust port of the compressor, and the exhaust port of the combustion chamber is connected to the air inlet of the turbine. The bearing stator of the integrated bearing is connected to the gas turbine casing through an anti-rotation component.

12. A micro gas turbine generator set according to claim 11, characterized in that: A diffuser is arranged between the exhaust port of the compressor and the air inlet of the combustion chamber.

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