High-stability variable geometric section turbine assembly for engine exhaust gas turbocharger

Abstract

A high-stability variable geometric section turbine assembly for an engine exhaust gas turbocharger comprises a rotating blade set, an adjusting ring, a VGT body, a deflector rod and an electric push rod, one end of the deflector rod is hinged to the output end of the electric push rod, the other end of the deflector rod is hinged to an adjusting hole in the inner side of the adjusting ring, and the adjusting ring is installed in cooperation with a limiting groove in the VGT body through a limiting boss. A ring hole in the outer side of the adjusting ring and the rotating blade set are installed in a clearance mode, in the engine starting or low-power operation stage, the electric push rod drives the rotating blade set to rotate through the driving lever and a transmission mechanism of the adjusting ring, the through-flow area between blades is reduced, and the air inlet density is increased. In the normal operation stage of the engine, the through-flow area between the blades is increased, the engine power is improved, and therefore the output characteristic of the engine in the full-power stage is improved. The reliability of the VGT assembly under the high-temperature and high-pressure conditions is improved, and the VGT assembly has the advantages of being simple in structure, relatively isolated from the external environment, capable of achieving reverse locking, accurate in adjustment and the like.

Description

Technical Field

[0001] This invention belongs to the field of turbocharger technology, specifically relating to a highly stable variable geometry turbocharger (VGT) assembly for engine exhaust gas turbochargers. Background Technology

[0002] A turbocharger uses the energy of exhaust gases from the engine to drive a turbine, which in turn drives a compressor to increase intake air density and enhance engine power output. To improve engine performance during startup and low-power conditions, variable geometry turbocharger (VGT) technology was developed. This technology adjusts the blade angle to change the exhaust gas flow cross-sectional area. At low power conditions, it reduces the flow area to increase exhaust gas velocity and turbine speed, thus improving turbocharging; at high power conditions, it increases the flow area to reduce exhaust back pressure, improving overall engine efficiency.

[0003] However, existing VGT assemblies still have several technical shortcomings in practical applications:

[0004] 1. As can be seen from the working principle of turbochargers, their interiors are in a high-temperature and high-pressure environment for a long time. Existing VGTs adopt a structure with the regulating ring on the outside and the blades on the inside. After being subjected to repeated impacts from leaking high-pressure exhaust gas, this structure will eventually lead to a decrease in the strength of the parts and reduce the structural reliability of the turbocharger.

[0005] 2. The existing VGT uses a pneumatic control method, that is, compressed air is used as power to drive the adjustment ring to rotate. Because air is compressible, this mechanism is difficult to achieve accurate adjustment position when subjected to high-pressure exhaust gas impact. At the same time, the entire mechanism will be impacted and vibrate, resulting in noise, fatigue damage to parts and other adverse effects.

[0006] Therefore, there is an urgent need to develop a VGT assembly with a more rational structure, which can effectively isolate harsh working environments and has high adjustment precision and long-term operational stability, in order to improve the performance and reliability of turbochargers across the entire operating range. Summary of the Invention

[0007] This invention aims to solve the problems of poor reliability and insufficient adjustment accuracy of existing VGT structures under high temperature and high pressure environments, and provides a highly stable variable geometry turbine (VGT) assembly.

[0008] The technical solution of the present invention is as follows:

[0009] This invention discloses a highly stable variable geometry turbine assembly for engine exhaust gas turbochargers, comprising:

[0010] The VGT body is a disc-shaped structure with inner and outer layers. The inner side has a recess and a boss. The recess has a limiting groove, a positioning hole and a mounting hole for installing the rotating blade assembly. The boss has multiple positioning holes for fixing the VGT assembly.

[0011] The rotating blade assembly is rotatably mounted in the mounting holes of the VGT body;

[0012] An adjustment ring is arranged in the recess of the VGT body. The adjustment ring has an adjustment hole on the inner side, an annular hole on the outer side, and a limiting boss at the bottom. The limiting boss cooperates with the limiting groove on the VGT body.

[0013] The electric linear actuator has a self-locking function;

[0014] The lever has its middle part hinged to the fixed part of the exhaust gas turbocharger via a mounting shaft, one end of which is hinged to the output end of the electric push rod, and the other end is hinged to the adjustment hole of the adjustment ring.

[0015] The disc-shaped layered structure of the VGT body encloses the transmission connection part of the adjusting ring and the lever, forming a relatively isolated transmission chamber. The electric push rod drives the adjusting ring to rotate within the angle range defined by the limiting groove through the lever. The adjusting ring drives the blades to rotate synchronously through the cooperation of its ring hole with the rotating blade group.

[0016] Furthermore, the blades of the rotating blade assembly adopt an aerodynamic configuration with a short and thick leading edge and a slender trailing edge.

[0017] Furthermore, the leading edge thickness of the blade is 1.5-2 times the trailing edge thickness, and the two ends of the blade are transitioned with small rounded corners of R0.5-R1.

[0018] Furthermore, the limiting boss of the adjusting ring and the limiting groove of the VGT body adopt an arc-shaped clearance fit structure. The arc length of the limiting groove is greater than the arc length of the limiting boss, and the circumferential gap between the two constitutes the rotation limiting mechanism of the adjusting ring.

[0019] Furthermore, the circumferential gap between the limiting groove and the limiting boss is 1-3 mm, which is used to precisely control the rotation angle range of the adjusting ring to ±15°—±25°.

[0020] Furthermore, the VGT body has an integrated lubrication and cooling channel inside, which includes an oil inlet hole, an oil return hole, and an annular distribution channel for introducing lubricating oil or coolant.

[0021] Furthermore, the electric push rod employs a worm gear transmission mechanism to achieve a self-locking function, with a positioning accuracy error of less than ±0.1°.

[0022] Furthermore, the height of the inner boss of the VGT body is greater than the thickness of the adjusting ring, forming an axial assembly gap with a gap value of 0.5-1 mm.

[0023] Furthermore, the lever arm ratio between the mounting shaft of the lever and the adjusting boss is 1.5-2.5:1, forming a lever amplification mechanism.

[0024] Furthermore, the disc-shaped layered structure of the VGT body has a heat-insulating coating in the transmission chamber area, with a coating thickness of 50-100 micrometers.

[0025] Furthermore, the clearance between the annular hole of the adjusting ring and the rotating blade assembly is 0.1-0.3 mm, forming a backlash-free transmission mechanism.

[0026] Workflow:

[0027] When the engine starts or operates at low power, the electronic control unit (ECU) sends a command to the electric push rod 4, causing its output shaft to extend. The thrust of the electric push rod 4 is transmitted through the thrust boss 502 at one end of the lever 5, pushing the lever 5 to rotate counterclockwise around its mounting shaft 503. The adjusting boss 501 at the other end of the lever 5 moves accordingly, actuating the adjusting hole 201 on the inner side of the adjusting ring 2, causing the adjusting ring 2 to rotate in the direction allowed by the limiting groove 301. The rotation of the adjusting ring 2 is transmitted to all rotating blades 1 through its outer annular hole 202, causing each blade to rotate synchronously, reducing the flow area between the blades, increasing the exhaust gas velocity, and thus enhancing the turbocharging effect. When the engine enters high-power operation, the ECU controls the output shaft of the electric push rod 4 to retract, driving the adjusting ring 2 to rotate in the opposite direction through the lever 5, thereby driving the rotating blade assembly 1 to increase the flow area, reduce exhaust back pressure, and optimize engine power output. Throughout the adjustment process, the self-locking function of the electric push rod 4 ensures the precise maintenance of the blade angle, and the sealed structure of the VGT body 3 effectively protects the internal transmission mechanism from the direct impact of high-temperature and high-pressure exhaust gas.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The VGT body is designed as a disc-shaped part with inner and outer layers, which can enclose the adjustment ring, lever, electric push rod and other parts, thereby relatively isolating the high temperature and high pressure environment inside the turbocharger, providing a better working environment and extending the service life of the parts;

[0030] 2. The VGT body itself is relatively large, so lubrication and cooling pipes can be machined inside it. When the turbocharger is running, lubricating oil and coolant are introduced to reduce the internal temperature and provide lubrication, thereby reducing the thermal stress on the parts and extending their service life.

[0031] 3. Using an electric actuator as the power source for the device, the self-locking characteristic of the electric actuator can ensure that the rotating blades are in the accurate position, while reducing vibration and improving the overall performance of the device. Attached Figure Description

[0032] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0033] Figure 1 This is a schematic diagram of the overall assembly three-dimensional structure of the present invention during use. Figure 1 ;

[0034] Figure 2 This is a schematic diagram of the three-dimensional structure of the VGT main body in this invention;

[0035] Figure 3 This is a schematic diagram of the three-dimensional structure of the adjusting ring in this invention;

[0036] Figure 4 This is a schematic diagram of the three-dimensional structure of the lever in this invention. Detailed Implementation

[0037] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The high-stability exhaust gas turbine VGT assembly of the present invention is mainly used to provide a relatively isolated high-temperature, high-pressure exhaust gas working environment for the adjustment mechanism in the engine turbocharger, so as to extend the service life of the parts and at the same time ensure the accuracy and reliability of blade angle adjustment.

[0038] Combined with reference Figures 1 to 4 The present invention relates to a high-stability exhaust gas turbine (VGT) assembly, comprising a rotating blade assembly 1, an adjusting ring 2, a VGT body 3, an electric push rod 4, and a lever 5.

[0039] The VGT body 3 serves as the core support structure. Through three positioning holes 305 on its inner boss 304, bolts or other fasteners pass through a fixing part (not shown in the figure) of the exhaust gas turbocharger, securing the entire VGT assembly to the exhaust gas turbine. The VGT body 3 adopts a layered disc structure, with its inner recess forming a relatively enclosed transmission chamber. The adjusting ring 2 is installed within the transmission chamber through the engagement of its bottom limiting boss 203 with the limiting groove 301 within the recess of the VGT body 3. The arc length of the limiting groove 301 is slightly greater than that of the limiting boss 203, with a circumferential gap of approximately 1.5 mm. This gap determines the maximum rotation angle of the adjusting ring 2 (e.g., ±20°), effectively preventing motion interference between the blades. Each blade in the rotating blade assembly 1 is rotatably mounted in the mounting holes 303 of the VGT body 3 via a rotating shaft. The working part of the blade (i.e., the blade body) passes through the annular hole 202 on the outer side of the adjusting ring 2. There is a fitting clearance of about 0.2 mm between the annular hole 202 and the blade shank, which allows the adjusting ring 2 to smoothly drive all blades to rotate synchronously, achieving backlash-free transmission. The mounting shaft 503 in the middle of the lever 5 is mounted on the fixed part of the aforementioned exhaust gas turbine, allowing the lever 5 to rotate around this shaft. The adjusting boss 501 at one end of the lever 5 extends into the transmission chamber of the VGT body 3 and is hinged to the adjusting hole 201 on the inner side of the adjusting ring 2; the thrust boss 502 at the other end is hinged to the output end of the electric push rod 4 arranged outside the VGT assembly.

[0040] The number of blades in the rotating blade assembly 1 can be flexibly adjusted according to operating conditions to meet the needs of different engine models. The blades adopt an aerodynamically optimized design, with a shorter and thicker leading edge (inlet edge) to withstand higher airflow impact, and a thinner and longer trailing edge (outlet edge) to improve airflow stripping. Both ends of the blade body are machined with small rounded corners of R0.8, which significantly reduces stress concentration and improves fatigue life.

[0041] The VGT body 3 has an inner recess with a limiting groove 301, a positioning hole 302, and a mounting hole 303 that mates with the rotating blade assembly 1. The inner boss 304 has three positioning holes 305 for fixing the VGT assembly. The limiting groove 301 and the limiting boss 203 have the same curvature, and the arc length of the limiting groove 301 is greater than that of the limiting boss 203. The two cooperate with each other to ensure that the adjusting ring 2 is installed on the VGT body 3. The arc length of the limiting groove 301 is greater than that of the limiting boss 203 to limit the rotation angle of the adjusting ring 2, ensuring that the blades of the rotating blade assembly 1 will not interfere with each other during the adjustment process. The positioning hole 302 is used to ensure the position of the VGT assembly on the exhaust turbine.

[0042] In this embodiment, the electric actuator 4 uses an electric actuator with a worm gear self-locking function. It has high position control accuracy (error less than ±0.1°) and can reliably lock the position after stopping the drive, resisting the impact of exhaust gas pulses and ensuring the stability of the blade angle.

[0043] The adjusting ring 2 has an adjusting hole 201 on its inner side and an annular hole 202 on its outer side. A limiting boss 203 is provided at the bottom. The inner adjusting hole 201 is hinged to the adjusting boss 501 to transmit thrust. The outer annular hole 202 is used to adjust the position of the rotating blade assembly 1, thereby adjusting the flow area between the blades.

[0044] The lever 5 has an adjustment boss 501 at one end and a thrust boss 502 at the other end. The thrust boss 502 is used to hinge with the output end of the electric push rod to transmit thrust. The middle part has a mounting shaft 503 for connecting the lever 5 with other components of the exhaust gas turbocharger, so that the entire lever 5 can rotate around the mounting shaft 503.

[0045] The specific working process of this invention is as follows (refer to the appendix). Figure 1 It should be noted that there is a fixed part (not shown) inside the exhaust gas turbine between the inner boss 304 and the lever 5. In use, the VGT assembly is installed on the exhaust gas turbine through the three positioning holes 305. The mounting shaft 503 on the lever 5 is installed on the fixed part. First, the electric push rod 4 pushes the lever 5 to rotate around the mounting shaft 503. The adjusting boss 501 on the lever 5 pushes the adjusting ring 2 to rotate. However, since the limiting boss 203 on the adjusting ring 2 is restricted by the limiting groove 301, the adjusting ring 2 can only swing within a certain range. The adjusting ring 2 pushes the rotating blade group 1 to rotate, thereby changing the flow area between each blade of the rotating blade group 1.

[0046] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-stability variable-geometry- cross-section turbine assembly for an engine exhaust gas turbocharger, characterized by, The application relates to a variable geometry turbocharger (VGT) assembly. The VGT body (3) is a disc-type structure with inner and outer layers, the inner side is provided with a concave pit and a convex platform (304), the concave pit is internally provided with a limiting groove (301), a positioning small hole (302) and a mounting hole (303) for mounting a rotating vane group, the convex platform (304) is provided with a plurality of positioning holes (305) for fixing the VGT assembly; The rotating vane group (1) is rotatably mounted in the mounting hole (303) of the VGT body (3); The adjusting ring (2) is arranged in the concave pit of the VGT body (3), the inner side of the adjusting ring (2) is provided with an adjusting hole (201), the outer side is provided with a ring hole (202), the bottom is provided with a limiting convex platform (203), and the limiting convex platform (203) is matched with the limiting groove (301) on the VGT body (3); The electric push rod (4) has a self-locking function; The middle part of the push rod (5) is hinged to a fixed part of the exhaust turbocharger through a mounting shaft (503), one end is hinged to the output end of the electric push rod (4), and the other end is hinged to the adjusting hole (201) of the adjusting ring (2); The disc-type layered structure of the VGT body (3) wraps the transmission connection part of the adjusting ring (2) and the push rod (5) inside, forms a relatively isolated transmission chamber, the electric push rod (4) drives the adjusting ring (2) to rotate in the angle range defined by the limiting groove (301) through the push rod (5), and the adjusting ring (2) drives the vane to rotate synchronously through the cooperation between the ring hole (202) and the rotating vane group (1).

2. The high stability variable geometry cross-section turbine assembly of claim 1, wherein, The vane of the rotating vane group (1) adopts an aerodynamic configuration with a thick front edge and a long rear edge.

3. The high stability variable geometry cross-section turbine assembly of claim 2, wherein, The front edge thickness of the vane is 1.5-2 times the rear edge thickness, and the two ends of the vane adopt a small R0.5-R1 round corner transition.

4. The high stability variable geometry cross-section turbine assembly of claim 1, wherein, The limiting convex platform (203) of the adjusting ring (2) and the limiting groove (301) of the VGT body (3) adopt an arc gap matching structure, the arc length of the limiting groove (301) is greater than that of the limiting convex platform (203), and the circumferential gap between the two constitutes a rotating limiting mechanism of the adjusting ring.

5. The high stability variable geometry cross-section turbine assembly of claim 4, wherein, The circumferential gap value of the limiting groove (301) and the limiting convex platform (203) is 1-3 mm, and the rotating angle range of the adjusting ring for accurate control is + / - 15-25 degrees.

6. The high stability variable geometry cross-section turbine assembly of claim 1, wherein, The VGT body (3) is internally integrated with a lubricating and cooling flow channel, the flow channel comprises an oil inlet hole, an oil return hole and an annular distribution channel, and is used for passing in lubricating oil or cooling liquid.

7. The high stability variable geometry cross-section turbine assembly of claim 1, wherein, The electric push rod (4) adopts a worm gear transmission mechanism to realize the self-locking function, and the positioning accuracy error is less than + / - 0.1 degree.

8. The high stability variable geometry cross-section turbine assembly of claim 1, wherein, The height of the inner side convex platform (304) of the VGT body (3) is greater than the thickness of the adjusting ring (2), thereby forming an axial assembly gap, and the gap value is 0.5-1 mm.

9. The high stability variable geometry cross-section turbine assembly of claim 1, wherein, The force arm ratio between the mounting shaft (503) and the adjusting convex platform (501) of the push rod (5) is 1.5-2.5:1, thereby forming a lever force increasing mechanism.

10. The high stability variable geometry cross-section turbine assembly of claim 1, wherein, The disc-type layered structure of the VGT body (3) is provided with a heat insulation coating at the transmission chamber part, and the coating thickness is 50-100 microns.

11. The high stability variable geometry cross-section turbine assembly of claim 1, wherein, The cooperation clearance between the ring hole (202) of the adjusting ring (2) and the rotating blade group (1) is 0.1-0.3mm, forming a back-lash-free transmission mechanism.

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