Axially unloading closed radial oil and gas turbine

Abstract

The present application relates to the field of aero-engine power systems, and provides an axial unloading closed centripetal oil-gas turbine, which comprises a turbine rotor disc (4) including a plurality of rotor blades spaced apart from each other to form a plurality of flow channels, a turbine outer cover plate (1) covering one side of the rotor blades of the turbine rotor disc (4), a back assembly arranged on the side of the turbine rotor disc (4) away from the turbine outer cover plate (1), and a plurality of turbine stator vanes (3) arranged at the outer peripheral edge of the turbine rotor disc (4) and configured to guide airflow into the flow channels of the turbine rotor disc (4), wherein a through hole (41) is formed in the center of the turbine rotor disc (4) in addition to a shaft hole, and the through hole (41) is configured to enable the side of the back assembly to be in fluid communication with the outlet side of the turbine rotor disc (4). The axial unloading closed centripetal oil-gas turbine can reduce the total axial force of the centripetal turbine, improve the working life of the bearing, and improve the operation safety of the whole machine.

Description

Technical Field

[0001] This invention relates to the field of aero-engine power systems, and more specifically to an axially unloaded closed radial oil-gas turbine. Background Technology

[0002] Hypersonic vehicles often face the problem of "excessive heat and insufficient electricity" during operation. Given the lack of rotating components in scramjet engines that can directly drive generators, converting excess heat into electricity to continuously power onboard equipment has become a significant technical challenge in the energy management of hypersonic vehicles. Among various thermoelectric conversion technologies, oil-gas turbine power generation technology utilizes high-temperature, high-pressure oil and gas to drive the rotor components in the turbine, outputting mechanical energy, which in turn drives the generator to produce electricity. This technology can fully utilize the excess waste heat in the oil and gas to continuously provide power to the onboard equipment of hypersonic vehicles, potentially solving the aforementioned technical challenge.

[0003] When designing gas-oil turbines, considering that a large intake air volume would reduce the engine's main cycle efficiency, the turbine intake air volume is constrained based on the required output power. The aim is for the gas-oil turbine to provide sufficient output power while maintaining a small size and mass, thereby minimizing the overall space occupied by the aircraft, increasing the payload of the hypersonic vehicle, and ensuring that the power generation unit can provide sufficient electricity. Currently, the selection of gas-oil turbines mainly falls into two categories: centripetal turbines and axial-flow turbines. Centripetal turbines perform work through centrifugal force and Coriolis inertial force, achieving high power and efficiency even with low intake air volume and high speed. They also have advantages such as lighter weight and more compact structure. Therefore, single-stage centripetal turbine designs are more commonly used in gas-oil turbine design.

[0004] Axial force balance is a major challenge in the design of centripetal gas turbines. In aircraft, to prevent fuel film boiling in the cooling channels, which leads to heat transfer deterioration, and to ensure good fuel mixing in the combustion chamber, the pressure in the cooling channels generally needs to exceed the fuel's critical pressure. However, due to fuel cracking at high temperatures, the pressure in the cooling channels continues to rise, eventually causing the turbine inlet pressure to reach 6 MPa or even higher. The pressure of the cracked fuel gas after expansion in the turbine can also reach 1-3 MPa. Under such high pressure, even with a small turbine size and a small total force-bearing area, the total axial force (pointing towards the turbine front plate) will reach over 1000 N. Since gas turbine generators lack coaxial components to supply a similar magnitude of reverse axial force to the turbine, most of this axial force will be transmitted to the casing through bearings. Under prolonged axial load overload, the bearings' service life is greatly reduced, severely threatening the overall operational safety. In summary, high absolute pressure and high load pose a significant challenge to the turbine's axial force balance; therefore, designing a centripetal turbine with a smaller total axial force is essential.

[0005] Chinese patent application CN202310600265.4 (publication number CN117569871A) discloses a high-pressure oil-gas centripetal turbine structure considering axial force balance. This application, also filed by the applicant, provides a solution for axial unloading of open turbines. The applicant previously attempted to apply this centripetal turbine structure to closed turbines to achieve the same effect of reducing axial force, but without success. Significant differences exist between the two types of turbines. Using the same annular through-hole at the center of the turbine impeller and setting grates at the impeller's mid-diameter position did not yield satisfactory results. Therefore, a solution specifically designed for reducing axial load in closed centripetal oil-gas turbines is needed. In view of this, the present invention is proposed. Summary of the Invention

[0006] The purpose of this invention is to at least partially overcome the deficiencies of the prior art and provide an axially unloaded closed radial oil-gas turbine.

[0007] The present invention also aims to provide an axially unloaded closed radial oil-gas turbine, thereby reducing the total axial force of the radial turbine.

[0008] The present invention also aims to provide an axially unloaded closed radial oil-gas turbine to improve the service life of the bearing.

[0009] The present invention also aims to provide an axially unloaded closed radial oil-gas turbine to improve the overall operational safety of the machine.

[0010] To achieve the above-mentioned objectives or one of them, the technical solution of the present invention is as follows:

[0011] An axially unloaded closed radial oil-gas turbine, the oil-gas turbine comprising:

[0012] A turbine bladed disk includes a plurality of moving blades spaced apart from each other to form a plurality of flow channels, the flow channels being configured such that circumferential airflow entering from the edge of the turbine bladed disk flows through the moving blades and then flows out axially from the center of the turbine bladed disk.

[0013] The turbine outer cover plate is installed on one side of the moving blades of the turbine moving blade disk;

[0014] The back assembly is located on the side of the turbine rotor disk away from the turbine outer cover plate; and

[0015] Multiple turbine stator blades are located at the outer periphery of the turbine rotor disk and are configured to guide airflow into the flow channel of the turbine rotor disk.

[0016] The turbine impeller disk has a through hole in its center, except for the shaft hole. The through hole is configured to allow fluid communication between one side of the back assembly and the outlet side of the turbine impeller disk.

[0017] According to a preferred embodiment of the present invention, the oil and gas turbine further includes a turbine wheel cover, which is located between the moving blades of the turbine moving blade disk and the turbine outer cover plate, and covers the moving blades of the turbine moving blade disk, so that the plurality of flow channels are closed on one side.

[0018] The turbine wheel cover is fixed relative to the turbine moving blade disk, so that the turbine wheel cover and the turbine moving blade disk can rotate together.

[0019] According to a preferred embodiment of the present invention, the number of through holes is multiple.

[0020] According to a preferred embodiment of the present invention, the cross section of each through hole perpendicular to the axial direction of the oil-gas turbine is elliptical.

[0021] According to a preferred embodiment of the present invention, the extension direction of the through hole is parallel to the axial direction of the oil-gas turbine.

[0022] According to a preferred embodiment of the invention, the through hole is configured such that the through hole twists circumferentially along the turbine bladed disk as it extends from the side near the back assembly toward the outlet side of the turbine bladed disk.

[0023] According to a preferred embodiment of the present invention, there is a gap between the turbine outer cover plate and the turbine wheel cover, and grating teeth are provided in the gap.

[0024] According to a preferred embodiment of the present invention, the grating teeth are disposed near the outlet side of the turbine blade disk.

[0025] According to a preferred embodiment of the present invention, the grating teeth are provided on the side of the turbine wheel cover facing the turbine outer cover plate; or

[0026] The grating teeth are provided on the side of the turbine outer cover plate facing the turbine wheel cover; or

[0027] The turbine wheel cover and the turbine outer cover plate are both provided with the grating teeth on the side facing each other.

[0028] According to a preferred embodiment of the present invention, the turbine outer cover plate has two bent edges, which respectively cover the two ends of the turbine wheel cover.

[0029] According to a preferred embodiment of the present invention, the oil-gas turbine further includes a rotating shaft, and the turbine blade disk is mounted on the rotating shaft in an interference fit manner.

[0030] According to a preferred embodiment of the present invention, the back-side assembly includes:

[0031] Bearings;

[0032] Turbine casing;

[0033] A turbine backplate, which is installed inside the turbine casing;

[0034] Motor housing, the motor housing being connected to the turbine backplate; and

[0035] Mechanical seal housing, which is fixedly connected to one side of the motor housing.

[0036] According to a preferred embodiment of the present invention, the portion of the rotating shaft near the back assembly is fixedly connected to a bushing by an interference fit, and the bushing is provided with a step seal;

[0037] The outer ring of the mechanical seal is provided inside the mechanical seal housing, and a baffle is fixedly connected to the side of the mechanical seal housing away from the turbine blade disk.

[0038] According to a preferred embodiment of the present invention, an expansion ring is provided between the motor housing and the mechanical seal housing.

[0039] According to the present invention, in the closed radial oil-gas turbine with axial unloading, high-temperature and high-pressure oil-gas enters the oil-gas turbine through the turbine stator inlet port, and the stator outlet port is connected to the turbine moving blade disk inlet port. After passing through the stator, the oil-gas will be divided into three streams and flow out. The main flow of oil and gas enters the turbine impeller as the first airflow, driving the impeller to rotate and converting its kinetic and thermal energy into mechanical work for the turbine shaft. The gas then flows out of the impeller's flow path. A small portion of the airflow (the second flow) flows into the impeller cavity due to oil and gas leakage, creating significant pressure on the impeller back plate (the side of the back assembly). The pressure difference between the back plate and the turbine front plate (the side of the turbine outer cover) generates an axial force pointing towards the turbine front plate. By creating an elliptical through-hole near the impeller center, the impeller cavity is connected to the turbine outlet, reducing the pressure difference across the impeller. Furthermore, the elliptical through-hole reduces the total force-bearing area of ​​the front and rear plates, thus lowering the total axial force on the impeller and consequently reducing the overall axial force of the oil and gas turbine.

[0040] Furthermore, the turbine blade disk employs elliptical through-holes, which are more suitable for closed turbines and achieve better axial load reduction compared to circular or annular through-holes. In addition, the elliptical through-holes allow for better shape adjustment, minimizing the total stress-bearing area of ​​the turbine and increasing the through-hole area while reducing its total mass. If structural strength design requirements are not met, they can be achieved by adjusting the shape of the through-holes. Furthermore, the elliptical through-hole design provides additional geometric parameters (length-to-width ratio), giving designers more freedom to adapt to specific application needs and operating conditions. When structural strength design requirements are not met, they can be achieved by adjusting the ratio of the major and minor axes of the ellipse, which facilitates structural adjustments. Elliptical through-holes contribute to a more uniform stress distribution on the disk because the stress distribution along the major and minor axes of the ellipse may differ. The curvature of the elliptical through-hole helps disperse these stress concentration points, thereby reducing local stress and offsetting uneven stress. The elliptical through-holes are axially uniformly distributed and can be 4 or 6 in number; the preferred number in this invention is 6.

[0041] Furthermore, the turbine wheel cover is connected to the rim of the turbine impeller disk, and the turbine outer cover plate covers the outside of the turbine wheel cover. A small portion of the oil and gas (the third stream of airflow) will flow into the gap between the turbine wheel cover and the turbine outer cover plate. A grate is installed at the oil and gas outlet of the turbine wheel cover. This grate is preferably at an angle of approximately 60° to the horizontal direction. The oil and gas are compressed within the tooth gap between the grate of the turbine wheel cover and the turbine outer cover plate (the gap between the tip of the grate and the turbine outer cover plate), resulting in increased velocity and decreased pressure. Meanwhile, within the tooth cavity... As the flow channel suddenly expands, the oil and gas also form strong vortices. Therefore, the oil and gas lose some kinetic energy every time they pass through the tooth gap and tooth cavity, and their speed continues to decrease. The sealing effect brought by the grates on the turbine wheel cover gradually improves. The grates structure near the turbine moving blade disk outlet end forms an efficient throttling effect on the working fluid in the gap between the turbine wheel cover and the turbine outer cover plate, which increases the pressure on the top surface of the turbine outer cover plate and generates an axial force pointing towards the turbine back plate, which greatly reduces the total axial force of the turbine.

[0042] Therefore, the axially unloaded closed radial oil-gas turbine of the present invention reduces the total axial force of the radial turbine, thereby eliminating the need for the bearing to bear overload, improving the bearing's service life, and enhancing the overall operational safety. Attached Figure Description

[0043] Figure 1 A schematic cross-sectional view of an axially unloaded closed radial oil-gas turbine according to an embodiment of the present invention;

[0044] Figure 2A partial perspective view of an axially unloaded closed radial oil-gas turbine according to an embodiment of the present invention, showing the positional relationship between the turbine outer cover plate and the turbine moving blade disk;

[0045] Figure 3 A partial perspective view of an axially unloaded closed radial oil-gas turbine according to an embodiment of the present invention, wherein the turbine outer cover plate is removed, showing the positional relationship between the turbine wheel cover and the turbine moving blade disk;

[0046] Figure 4 This is a perspective view of the turbine blade disk of an axially unloaded closed radial oil-gas turbine according to an embodiment of the present invention. Detailed Implementation

[0047] Exemplary embodiments of the present invention are described in detail below with reference to the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements. Furthermore, in the following detailed description, numerous specific details are set forth for ease of explanation to provide a thorough understanding of the embodiments disclosed herein. However, it will be apparent that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and apparatuses are illustrated to simplify the drawings.

[0048] To address the problem of balancing axial forces in centripetal gas turbines in aircraft, as mentioned in the background section, this invention proposes a closed-loop centripetal gas turbine for high-pressure working fluids. This design considers the difficulty in balancing axial forces in closed-loop centripetal gas turbines, significantly reducing the total axial force and alleviating the problem to some extent. The following describes in detail, with reference to the accompanying drawings, an embodiment of the closed-loop centripetal gas turbine with axial unloading (balancing axial forces). Figure 1 As shown, the oil-gas turbine includes a turbine outer cover plate 1, a turbine wheel cover 2, a turbine stationary blade 3, a turbine moving blade disk 4, a shaft end nut 5, a shaft end retaining ring 6, a rotating shaft 7, a step seal 8, a shaft sleeve 9, a baffle 10, a mechanical seal housing 11, a countersunk screw 12, a motor housing 13, a turbine back plate 14, and a turbine housing 15.

[0049] The turbine blade disk 4 includes multiple moving blades spaced apart from each other to form multiple flow channels, such as... Figure 4 As shown, the flow channel is configured such that the circumferential airflow entering from the edge of the turbine bladed disk 4 flows through the blades and then flows out from the central axis of the turbine bladed disk 4; the turbine outer cover plate 1 covers one side of the blades of the turbine bladed disk 4; the turbine wheel cover 2 is located between the blades of the turbine bladed disk 4 and the turbine outer cover plate 1, and covers the blades of the turbine bladed disk 4, so that the multiple flow channels are closed on one side, and the turbine wheel cover 2 is fixed relative to the turbine bladed disk 4, so that the turbine wheel cover 2 and the turbine bladed disk 4 can rotate together.

[0050] The baffle 10, mechanical seal housing 11, motor housing 13, turbine backplate 14, and turbine housing 15 together form a back assembly, located on the side of the turbine moving blade disk 4 away from the turbine outer cover plate 1. Multiple turbine stator blades 3 are located at the outer peripheral edge of the turbine moving blade disk 4 and are configured to guide airflow into the flow channel of the turbine moving blade disk 4. The outlet port of the stator blades 3 is connected to the inlet port of the turbine moving blade disk 4, the turbine wheel cover 2 is connected to the rim of the turbine moving blade disk 4, and the turbine outer cover plate 1 covers the outside of the turbine wheel cover 2, but the two are not connected.

[0051] Preferably, the turbine outer cover 1 has two bent edges, which respectively cover the two ends of the turbine wheel cover 2, such as... Figure 1 As shown.

[0052] Because the present invention connects a fully enclosed turbine cover to the moving blade, the turbine cover can provide good sealing performance to reduce gas leakage when the airflow flows into the moving blade channel. Compared with open turbines, the moving blades in the present invention reduce gap leakage losses and can achieve higher efficiency.

[0053] The turbine cover connects to the turbine blade rim, completely enclosing the turbine flow channel and providing a continuous geometry. This uninterrupted structure helps maintain overall rigidity, resulting in higher bending and torsional resistance. The cover and blades form a seamless whole, allowing mechanical and thermal stresses acting on the turbine to be evenly distributed across the entire disk, reducing localized stress concentration. The closed turbine exhibits lower dynamic imbalance and vibration response at high speeds, contributing to improved stability and reliability during long-term operation. The structural integrity and uniform stress distribution of the closed turbine also help extend its service life and reduce the risk of damage and failure due to fatigue.

[0054] The rotating shaft 7 is a stepped rotating shaft, forming multiple shaft segments of different diameters. The turbine impeller 4 is mounted on the middle segment of the rotating shaft 7 with an interference fit. The portion of the rotating shaft 7 near the back-side assembly is fixedly connected to the bushing 9 with an interference fit. The back-side assembly mainly includes a bearing, a turbine casing 15, a turbine backplate 14, a motor casing 13, and a mechanical seal housing 11. The bearing is mounted on the bushing 9. The turbine casing 15 forms a housing that surrounds the back-side assembly. The turbine backplate 14 is installed inside the turbine casing 15. The motor casing 13 is connected to the turbine backplate 14, and the mechanical seal housing 11 is fixedly connected to one side of the motor casing 13 by countersunk screws 12. An expansion ring is provided between the motor casing 13 and the mechanical seal housing 11. A shaft end retaining ring 6 is installed on the outlet side of the rotating shaft 7 near the turbine impeller 4, and a shaft end nut 5 is connected to the side of the shaft end retaining ring 6 away from the turbine impeller 4. A step seal 8 is provided on the bushing 9, and the outer ring of the step seal 8 is provided inside the mechanical seal housing 11. A baffle 10 is fixedly connected to the side of the mechanical seal housing 11 away from the turbine blade disk 4 to seal the airflow at the gap of the back side assembly.

[0055] Specifically, the turbine bladed disk 4 has a through hole 41 at its center, excluding the shaft hole. This through hole 41 is configured to allow fluid communication between one side of the back assembly and the outlet side of the turbine bladed disk 4, such as... Figure 1 As shown. Advantageously, the number of through holes 41 is multiple. In the illustrated embodiment, the number of through holes 41 is six, but the number of through holes 41 can be other, such as three, four, five or more, of which six through holes 41 are preferred.

[0056] Specifically, the through-hole 41 is an elliptical through-hole, a special shape adopted for closed turbines. Through comparative experiments, the elliptical through-hole has better achieved the purpose of reducing axial load; that is, the cross-section of each through-hole 41 perpendicular to the axial direction of the oil-gas turbine is elliptical. To enable fluid communication between the back assembly side and the outlet side of the turbine bladed disk 4, the extension direction of the through-hole 41 is most directly set to be parallel to the axial direction of the oil-gas turbine. However, the applicant has found that the through-hole 41 can also be configured such that the through-hole 41 twists circumferentially along the turbine bladed disk 4 as it extends from the side near the back assembly toward the outlet side of the turbine bladed disk 4. When the twisting direction of the through-hole 41 is consistent with the twisting direction of the blades of the turbine bladed disk 4, the fluid communication effect is better. For this purpose, multiple through-holes 41 can be set with the same twisting direction and synchronized with the twisting angle of the blades of the turbine bladed disk 4.

[0057] The turbine moving blade disk is a device that converts the kinetic and thermal energy of oil and gas from the stationary blades into mechanical work of the turbine shaft. It has an elliptical through hole near the center of the disk. The through hole is evenly distributed along the axial direction, which can reduce the turbine weight, increase the effective load, and connect the blade disk cavity with the outlet side of the turbine moving blade disk. The front and rear force surfaces of the turbine are reduced and the front and rear pressures are balanced to reduce the total axial force of the turbine.

[0058] As an extended embodiment of the present invention, the torsion directions of adjacent through holes 41 are opposite, and the torsion angles of through holes 41 gradually increase sequentially in the through holes 41 that are torsion in the same direction. In this way, it can be ensured that when the turbine moving blade disk 4 is driven to rotate at different rotation speeds, both the back assembly side and the outlet side of the turbine moving blade disk 4 have good pressure-boosting effects.

[0059] Furthermore, there is a gap between the turbine outer cover plate 1 and the turbine wheel cover 2, and a grate 21 is provided in the gap. Preferably, the grate 21 is located near the outlet side of the turbine impeller disk 4. Specifically, the grate 21 is provided on the side of the turbine wheel cover 2 facing the turbine outer cover plate 1; or the grate 21 is provided on the side of the turbine outer cover plate 1 facing the turbine wheel cover 2; or the grate 21 is provided on both the turbine wheel cover 2 and the turbine outer cover plate 1 on their respective sides facing each other.

[0060] When the turbine cover has a grating-like structure near the blade outlet, the throttling of the oil and gas generates an axial force that counteracts the axial force at the turbine's back, resulting in a lower total axial force compared to an oil-gas turbine without a cover. Furthermore, the turbine outer cover plate covers and is fixed to the outside of the turbine cover, cooperating with the turbine cover to generate a force that counteracts the axial force at the turbine's back.

[0061] In practical applications, the grates are trapezoidal, and the number of trapezoidal grates is usually selected from 3 to 5. However, due to different operating conditions, such as changes in temperature, pressure, and flow rate, the total axial force on the turbine will also be different. This requires that the design of the grates be adjusted according to the specific operating conditions. In this invention, the size of the elliptical through hole of the turbine moving blade disk is also an important factor affecting the total axial force. When designing the grates, it is necessary to comprehensively consider the influence of the elliptical through hole of the turbine moving blade disk and the specific requirements of the turbine. Through precise calculation and simulation analysis, the most suitable size and number of grates can be determined.

[0062] According to the present invention, in the closed radial oil-gas turbine with axial unloading, high-temperature and high-pressure oil-gas enters the oil-gas turbine through the turbine stator inlet port, and the stator outlet port is connected to the turbine moving blade disk inlet port. After passing through the stator, the oil-gas will be divided into three streams and flow out. The main flow of oil and gas enters the turbine impeller as the first airflow, driving the impeller to rotate and converting its kinetic and thermal energy into mechanical work for the turbine shaft. The gas then flows out of the impeller's flow path. A small portion of the airflow (the second flow) flows into the impeller cavity due to oil and gas leakage, creating significant pressure on the impeller back plate (the side of the back assembly). The pressure difference between the back plate and the turbine front plate (the side of the turbine outer cover) generates an axial force pointing towards the turbine front plate. By creating an elliptical through-hole near the impeller center, the impeller cavity is connected to the turbine outlet, reducing the pressure difference across the impeller. Furthermore, the elliptical through-hole reduces the total force-bearing area of ​​the front and rear plates, thus lowering the total axial force on the impeller and consequently reducing the overall axial force of the oil and gas turbine.

[0063] Furthermore, the turbine blade disk employs elliptical through-holes, which are more suitable for closed turbines and achieve better axial load reduction compared to circular or annular through-holes. In addition, the elliptical through-holes allow for better shape adjustment, minimizing the total stress-bearing area of ​​the turbine and increasing the through-hole area while reducing its total mass. If structural strength design requirements are not met, they can be achieved by adjusting the shape of the through-holes. Furthermore, the elliptical through-hole design provides additional geometric parameters (length-to-width ratio), giving designers more freedom to adapt to specific application needs and operating conditions. When structural strength design requirements are not met, they can be achieved by adjusting the ratio of the major and minor axes of the ellipse, which facilitates structural adjustments. Elliptical through-holes contribute to a more uniform stress distribution on the disk because the stress distribution along the major and minor axes of the ellipse may differ. The curvature of the elliptical through-hole helps disperse these stress concentration points, thereby reducing local stress and offsetting uneven stress. The elliptical through-holes are axially uniformly distributed and can be 4 or 6 in number; the preferred number in this invention is 6.

[0064] Furthermore, the turbine wheel cover is connected to the rim of the turbine impeller disk, and the turbine outer cover plate covers the outside of the turbine wheel cover. A small portion of the oil and gas (the third stream of airflow) will flow into the gap between the turbine wheel cover and the turbine outer cover plate. A grate is installed at the oil and gas outlet of the turbine wheel cover. This grate is preferably at an angle of approximately 60° to the horizontal direction. The oil and gas are compressed within the tooth gap between the grate of the turbine wheel cover and the turbine outer cover plate (the gap between the tip of the grate and the turbine outer cover plate), resulting in increased velocity and decreased pressure. Meanwhile, within the tooth cavity... As the flow channel suddenly expands, the oil and gas also form strong vortices. Therefore, the oil and gas lose some kinetic energy every time they pass through the tooth gap and tooth cavity, and their speed continues to decrease. The sealing effect brought by the grates on the turbine wheel cover gradually improves. The grates structure near the turbine moving blade disk outlet end forms an efficient throttling effect on the working fluid in the gap between the turbine wheel cover and the turbine outer cover plate, which increases the pressure on the top surface of the turbine outer cover plate and generates an axial force pointing towards the turbine back plate, which greatly reduces the total axial force of the turbine.

[0065] Therefore, the axially unloaded closed radial oil-gas turbine of the present invention reduces the total axial force of the radial turbine, thereby eliminating the need for the bearing to bear overload, improving the bearing's service life, and enhancing the overall operational safety.

[0066] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that variations may be made to these embodiments without departing from the principles and spirit of the invention. The scope of the invention is defined by the appended claims and their equivalents.

[0067] List of reference numerals in the attached diagram:

[0068] 1. Turbine outer cover plate;

[0069] 2. Turbine wheel cover;

[0070] 21. Fang teeth;

[0071] 3. Turbine stator blades;

[0072] 4. Turbine impeller disk;

[0073] 41. Through hole;

[0074] 5. Shaft end nut;

[0075] 6. Shaft end retaining ring;

[0076] 7. Shaft;

[0077] 8. Stephan;

[0078] 9. Bushing;

[0079] 10. Baffle;

[0080] 11. Mechanical seal housing;

[0081] 12. Countersunk screws;

[0082] 13. Motor housing;

[0083] 14. Turbine backplate;

[0084] 15. Turbine casing.

Claims

1. An axially unloaded closed radial oil-gas turbine, characterized in that, The oil-gas turbine includes: The turbine bladed disk (4) includes a plurality of moving blades spaced apart from each other to form a plurality of flow channels, the flow channels being configured such that circumferential airflow entering from the edge of the turbine bladed disk (4) flows through the moving blades and then flows out axially from the center of the turbine bladed disk (4). The turbine outer cover plate (1) is installed on one side of the moving blades of the turbine moving blade disk (4); The back assembly is located on the side of the turbine blade disk (4) away from the turbine outer cover plate (1); and Multiple turbine stator blades (3) are disposed at the outer peripheral edge of the turbine moving blade disk (4) and are configured to guide airflow into the flow channel of the turbine moving blade disk (4). The oil and gas turbine also includes a turbine cover (2), which is located between the moving blades of the turbine moving blade disk (4) and the turbine outer cover plate (1), and covers the moving blades of the turbine moving blade disk (4), so that the multiple flow channels are closed on one side. The turbine bladed disk (4) has a through hole (41) in the center, except for the shaft hole. There are multiple through holes (41). The cross section of each through hole (41) perpendicular to the axial direction of the oil and gas turbine is elliptical. The through holes (41) are configured to allow fluid communication between the back assembly side and the outlet side of the turbine bladed disk (4). The through holes (41) are configured to twist along the circumference of the turbine bladed disk (4) as they extend from the side near the back assembly to the outlet side of the turbine bladed disk (4). The twisting direction of the multiple through holes (41) is the same, consistent with the twisting direction of the blades of the turbine bladed disk (4), and synchronized with the twisting angle of the blades of the turbine bladed disk (4). The turbine outer cover plate (1) has two bent edges, which respectively cover the two ends of the turbine wheel cover (2). The bent edge of the turbine outer cover plate (1) near the turbine stationary blade (3) points horizontally to the turbine stationary blade (3), and the bent edge of the turbine outer cover plate (1) near the outlet side of the turbine moving blade disk (4) points vertically to the axis of the turbine moving blade disk (4).

2. The axially unloading closed radial oil-gas turbine according to claim 1, characterized in that: The turbine wheel cover (2) is fixed relative to the turbine moving blade disk (4), so that the turbine wheel cover (2) and the turbine moving blade disk (4) can rotate together.

3. The axially unloading closed radial oil-gas turbine according to claim 2, characterized in that: There is a gap between the turbine outer cover plate (1) and the turbine wheel cover (2), and a grating tooth (21) is provided in the gap.

4. The axially unloading closed radial oil-gas turbine according to claim 3, characterized in that: The grating teeth (21) are located near the outlet side of the turbine blade disk (4).

5. The axially unloading closed radial oil-gas turbine according to claim 3, characterized in that: The turbine wheel cover (2) has the grates (21) on the side facing the turbine outer cover plate (1); or The turbine outer cover plate (1) has the grates (21) on the side facing the turbine wheel cover (2); or The turbine wheel cover (2) and the turbine outer cover plate (1) are both provided with the grating teeth (21) on the side facing each other.

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