Sliding type variable geometry mechanism for radial flow turbine nozzle

Abstract

The invention provides a radial flow turbine nozzle sliding type variable geometry mechanism which comprises a turbine box, a nozzle blade, a lower end wall fixing piece, a nozzle upper end wall sliding piece, a nozzle upper end wall labyrinth assembly, a nozzle upper end wall sealing cover plate and a sealing accessory, the nozzle upper end wall sliding piece can be driven by the transmission control mechanism to slide relative to other fixing parts in the height direction of the nozzle blade, and the height of the nozzle blade is reasonably adjusted. The sealing accessories are used for enhancing the air tightness between the turbine box and the nozzle upper end wall labyrinth assembly and between the nozzle upper end wall labyrinth assembly and the nozzle upper end wall sealing cover plate. According to the sliding type variable geometry mechanism for the radial flow turbine nozzle, the problem of serious leakage of a gap of the nozzle can be effectively solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of power equipment, and in particular relates to a sliding variable geometry mechanism for a radial turbine nozzle. Background Art

[0002] In the research and development fields such as internal combustion engines, exhaust gas turbocharging is a common technology used to improve the power per liter and fuel economy of internal combustion engines and reduce exhaust gas and noise pollution. However, the turbine lag effect often causes the air supply capacity of the supercharger to lag behind the actual demand of power devices such as internal combustion engines during engine startup and acceleration. The variable geometry nozzle can, in the case of insufficient exhaust energy, adjust the actual operating expansion ratio of the supercharger turbine by changing the nozzle opening, effectively alleviating the turbine lag problem. However, most of the common variable geometry nozzles on the market at present are rotational adjustments, which have problems such as deterioration of the angle of attack matching in the target working conditions and serious leakage of the nozzle gap. Summary of the Invention

[0003] In view of this, the present invention aims to propose a sliding variable geometry mechanism for a radial turbine nozzle to solve the problem of serious leakage of the nozzle gap.

[0004] To achieve the above object, the technical solution of the present invention is realized as follows: A sliding variable geometry mechanism for a radial turbine nozzle, including a turbine housing, nozzle vanes arranged above it, a lower end wall fixing member, an upper end wall sliding member of the nozzle, an upper end wall labyrinth combination member of the nozzle, an upper end wall closing cover of the nozzle, and a sealing fitting. The upper end wall sliding member of the nozzle can relatively slide along the height direction of the nozzle vanes relative to other fixed components under the drive of a transmission control mechanism to realize reasonable adjustment of the height of the nozzle vanes. The sealing fitting is used to strengthen the airtightness between the turbine housing and the upper end wall labyrinth combination member of the nozzle, and between the upper end wall labyrinth combination member of the nozzle and the upper end wall closing cover of the nozzle.

[0005] Further, the upper end wall sliding member of the nozzle respectively or simultaneously forms a labyrinth seal with the nozzle vanes and the lower end wall fixing member, with the upper end wall labyrinth combination member of the nozzle, and with the upper end wall closing cover of the nozzle at different sliding stages. The limit of the sliding stroke of the upper end wall sliding member of the nozzle is determined by the labyrinth seal settings of the above fixed components.

[0006] Further, while forming a labyrinth seal with the upper end wall sliding member of the nozzle, the upper end wall labyrinth combination member of the nozzle is jointly assembled in the installation space formed by the turbine housing and the upper end wall closing cover of the nozzle.

[0007] Further, the upper end wall closing cover of the nozzle can form a labyrinth seal with the upper end wall sliding member of the nozzle at a large opening, and at the same time form a sliding component assembly space with the turbine housing.

[0008] Further, the sealing fitting is a sealing rubber strip or a sealing carbon ring.

[0009] Furthermore, the power source of the transmission control mechanism is electromagnetic force or pneumatic force.

[0010] Furthermore, the interaction form between the transmission control mechanism and the sliding member on the upper end wall of the nozzle is any one or a combination of a connecting rod, a slider, a belt, a gear, a spring, and magnetic attraction.

[0011] Compared with the prior art, the sliding variable geometry mechanism of the radial flow turbine nozzle of the present invention has the following advantages: (1) For the sliding variable geometry mechanism of the radial flow turbine nozzle of the present invention, the nozzle opening is controlled by the way of end wall sliding, which can effectively solve the problems of serious clearance leakage of the rotary nozzle and poor matching of the rotating and static attack angles at small openings.

[0012] (2) For the sliding variable geometry mechanism of the radial flow turbine nozzle of the present invention, the overall airtightness of the device is ensured by adding sealing fittings between the turbine box and the maze assembly on the upper end wall of the nozzle and between the maze assembly on the upper end wall of the nozzle and the closed cover plate on the upper end wall of the nozzle. Description of the Drawings

[0013] The drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings: Figure 1 It is a schematic diagram of the sliding variable geometry mechanism of the radial flow turbine nozzle according to the embodiment of the present invention; Figure 2 It is a schematic diagram of the gear meshing transmission mechanism according to the embodiment of the present invention; Figure 3 It is a feasible configuration of the connection between the mandrel of the working gear and the transmission shaft of the sliding member on the upper end wall of the nozzle according to the embodiment of the present invention.

[0014] Description of the Reference Numerals in the Drawings: 1 - Turbine box; 2 - Nozzle blade and lower end wall fixing member; 3 - Sliding member on the upper end wall of the nozzle; 4 - Maze assembly on the upper end wall of the nozzle; 5 - Closed cover plate on the upper end wall of the nozzle; 6 - Sealing fitting. Detailed Embodiments

[0015] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0016] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0017] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected", "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific situations.

[0018] The present invention will be described in detail below with reference to the drawings and in conjunction with embodiments.

[0019] A sliding variable geometry mechanism for a runoff turbine nozzle, as Figure 1 shown, includes a turbine casing 1, nozzle vanes disposed above it, a lower end wall fixing member 2, an upper end wall sliding member 3 of the nozzle, an upper end wall labyrinth assembly 4 of the nozzle, an upper end wall closing cover plate 5 of the nozzle, and a sealing fitting 6. The upper end wall sliding member 3 of the nozzle can slide relative to other fixed components along the height direction of the nozzle vanes under the drive of a transmission control mechanism, so as to realize reasonable adjustment of the height of the nozzle vanes.

[0020] The upper end wall sliding member 3 of the nozzle can respectively or simultaneously form labyrinth seals with the nozzle vanes and the lower end wall fixing member 2, with the upper end wall labyrinth assembly 4 of the nozzle, and with the upper end wall closing cover plate 5 of the nozzle at different sliding stages. The sliding stroke limit of the upper end wall sliding member 3 of the nozzle is determined by the labyrinth seal arrangement with the above-mentioned fixed components.

[0021] While forming a labyrinth seal with the upper end wall sliding member 3 of the nozzle, the upper end wall labyrinth assembly 4 of the nozzle is jointly assembled in the installation space formed by the turbine casing 1 and the upper end wall closing cover plate 5 of the nozzle.

[0022] The upper end wall closing cover plate 5 of the nozzle can form a labyrinth seal with the upper end wall sliding part 3 of the nozzle at a large opening degree, and at the same time form a sliding component assembly space together with the turbine casing 1.

[0023] The sealing fitting 6 can further enhance the airtightness between the turbine casing 1 and the upper end wall labyrinth assembly 4 of the nozzle, and between the upper end wall labyrinth assembly 4 of the nozzle and the upper end wall closing cover plate 5 of the nozzle, including but not limited to forms such as sealing rubber strips and sealing carbon rings.

[0024] The power sources of the transmission control mechanism include but are not limited to forces such as electromagnetic and pneumatic, and the interaction forms with the upper end wall sliding part 3 of the nozzle include but are not limited to ways such as link-slider, belt, gear, spring, magnetic attraction, etc.

[0025] The sliding variable geometry mechanism of the radial turbine nozzle is only an example scheme based on the deviation of the upper end wall of the nozzle, and does not exclude schemes such as the components of the upper and lower end walls of the nozzle being exchanged with each other to form a deviation design of the lower end wall of the nozzle.

[0026] According to actual requirements, the nozzle blade and the lower end wall fixing part 2 are processed separately, or the nozzle blade and the lower end wall fixing part 2 are integrally designed and processed with the turbine casing 1, the heat insulation cover or the bearing body.

[0027] In one embodiment, taking the upper end wall deviation scheme as an example, the structural characteristics of a sliding variable geometry mechanism of the nozzle are shown. It mainly changes the nozzle opening degree by the upper end wall sliding part 3 of the nozzle sliding along the blade height; as Figure 2 shown in the schematic diagram of the gear meshing transmission mechanism, a transmission control method of a sliding variable geometry mechanism of the nozzle is schematically shown by gear meshing transmission, where A is the driving gear, B is the transmission gear, and C is the working gear; all three are restricted from changing their relative positions by devices including but not limited to end face bearings; the spindle of the driving gear A is connected to a power source such as a motor; the spindle of the working gear C is connected to the transmission shaft of the upper end wall sliding part 3 of the nozzle through a thread; a feasible configuration of the two shafts is as Figure 3 shown, where C represents the working gear. By restricting the thread stroke and the relative positions of the two shafts, it is ensured that the threads of the two shafts are always in a mating state during the adjustment of the nozzle opening degree. During operation, first, a power source such as a motor drives the driving gear A to rotate. During the movement of the driving gear, it drives the transmission wheel B to rotate. When the transmission wheel B rotates, it drives the four working gears C to rotate synchronously, causing the spindles of the working gears to rotate relative to the transmission shaft of the upper end wall sliding part 3 of the nozzle and generating synchronous axial displacements, thereby driving the change of the nozzle opening degree.

[0028] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A radial flow turbine nozzle sliding variable geometry mechanism, characterized in that: It includes a turbine box and nozzle blades and lower end wall fixings arranged above it, a nozzle upper end wall sliding part, a nozzle upper end wall labyrinth assembly, a nozzle upper end wall closing cover plate, and sealing accessories. The nozzle upper end wall sliding part can slide relative to other fixed parts along the nozzle blade height direction under the drive of the transmission control mechanism to achieve reasonable adjustment of the nozzle blade height. The sealing accessories are used to enhance the air tightness between the turbine box and the nozzle upper end wall labyrinth assembly, and the nozzle upper end wall labyrinth assembly and the nozzle upper end wall closing cover plate.

2. A radial flow turbine nozzle sliding variable geometry mechanism according to claim 1, characterized in that: The upper end wall sliding part of the nozzle, the nozzle blades and the lower end wall fixing parts, the upper end wall labyrinth assembly of the nozzle and the upper end wall closing cover plate of the nozzle form a labyrinth seal separately or simultaneously in different sliding stages. The sliding stroke limit of the upper end wall sliding part of the nozzle is determined by the labyrinth seal setting of the above-mentioned fixed parts.

3. The radial flow turbine nozzle sliding variable geometry mechanism according to claim 1, characterized in that: The nozzle upper end wall labyrinth assembly forms a labyrinth seal with the nozzle upper end wall sliding member and is assembled together in the installation space formed by the turbine box and the nozzle upper end wall closing cover plate.

4. The radial flow turbine nozzle sliding variable geometry mechanism according to claim 1, characterized in that: The nozzle upper end wall closing cover plate can form a labyrinth seal with the nozzle upper end wall sliding member at a large opening, and at the same time form a sliding component assembly space together with the turbine box.

5. The radial flow turbine nozzle sliding variable geometry mechanism according to claim 1, characterized in that: The sealing accessories are sealing strips or sealing carbon rings.

6. The radial flow turbine nozzle sliding variable geometry mechanism according to claim 1, characterized in that: The power source of the transmission control mechanism is electromagnetic force or pneumatic force.

7. The radial flow turbine nozzle sliding variable geometry mechanism according to claim 1, characterized in that: The interaction form between the transmission control mechanism and the sliding part of the upper end wall of the nozzle is any one or more combinations of connecting rods, sliding blocks, belts, gears, springs, and magnetic attraction.

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