TURBOCHARGER WITH A DOUBLE-VANE NOZZLE SYSTEM

Abstract

Disclosed is a turbocharger with a dual-blade nozzle system, comprising a turbine housing, a fixed nozzle ring (1), a linearly moving nozzle disk (2), a mid-housing (5), a rack (4), rocker arm rods (3), and a gear (6), wherein airfoil-shaped fixed blades (8) are provided on the front end face of the fixed nozzle ring (1), with blade-type holes (9) provided between the fixed blades (8), and the fixed nozzle ring (1) is sheathed around the outside of the mid-housing (5) and fixed to the mid-housing (5) via screws; the linearly moving nozzle disk (2) is provided on the rear end of the fixed nozzle ring (1), a group of moving blades (7) is provided on the front end face of the linearly moving nozzle disk (2), the moving blades (7) are movably inserted into the blade-type holes (9), the rear end face of the linearly moving nozzle disk (2) is fixedly connected to two rocker arm rods (3), with the rocker arm rods (3) inserted into the mid-housing (5) and engaged with the rack (4) via the gear (6). The provision of an additional blade along a nozzle flow passage in the turbocharger with the dual-blade nozzle system can not only reduce the cross-sectional area of the passage, but also separate the original nozzle into two gas passages to reduce the loss of gas flow due to transverse flow; in addition, the gas flow can flow at an optimum gas flow angle according to the original design, so that the turbine can keep working in the high efficiency region.

Description

FIELD OF TECHNOLOGY

The present invention relates to a turbocharger with a double-vane nozzle system, belonging to the field of an automobile device.

BACKGROUND OF TECHNOLOGY

Waste gas discharged from an engine can work for the turbine in the supercharger, but it can only operate within a narrow high-efficiency zone. Even through the design point of the vehicular supercharger is set within a range of 50-70%, when the engine is operating at full load, the over-speed of the supercharger occurs. Therefore, an exhaust bypass valve mechanism is arranged on the supercharger in order to improve the reliability while a portion of available energy of gas is wasted.

An effective method to improve the aerodynamic performance of the turbine is to employ a variable nozzle structure, and it is also generally acknowledged and practiced by each of the world-wide supercharger manufacturers. At present, there are three different solutions:

The Chinese patent application No. 200710152744.5 filed by HONEYWELL INTERNATIONAL INC, entitled “Vane assembly and method of assembling a vane assembly for a variable-nozzle turbocharger”, discloses a method for varying the nozzle geometry by changing the vane angle. Such method has an advantage that the cross-section area of nozzle is decreased with the decreasing of the vane angle, the reduction ratio of the cross-section area of nozzle may be up to 50% above. The method has the following shortcomings that, when the nozzle angle alpha (a) is too big (starting state), airflow C″r impacts the convex face of the turbine blade; the nozzle angle alpha (a) is too small (fully load state), the airflow C′r impacts the concave face of the blade (see FIG. 11), so that the heat efficiency of the supercharger is reduced regardless of operating at low or high working conditions.

The Chinese patent application No. 00819834.9, filed by HONEYWELL GARRETT SA, entitled “Variable Geometry Turbocharger With Sliding Piston”, discloses a simple variable sectional geometry mechanism, wherein the nozzle is composed of a fixing blade and a blade-free air passage. Adjustable area is only at the side of the blade-free air passage. Certainly, the adjustable area of 50% is enough. However, the aerodynamic performance is not good. When the blade-free passage is opened, the airflow will pass through both the blade passage and the blade-free passage at the same time. Because the angles of flow of the two passages are different, the airflow passed the nozzle will be turbulent, and the flow loss of the airflow is increased, and the heat efficiency of the turbine is reduced.

According to a variable nozzle structure developed by British HOLSET Power Engineering Company, a shielding ring is mounted on the fixed nozzle blades. A part of the flow path of the nozzle can be shielded by moving the shielding ring so as to achieve the adjustment of the cross-section area of the nozzle. Just like the second solution, its shortcomings are that the airflow passing from the volute to the nozzle inlet is turbulent due to shielding the part of the flow path of the nozzle. It also reduces the heat efficiency of the turbine decreasing.

SUMMARY OF THE INVENTION

Above-mentioned shortcomings are overcome by the present invention which provides a turbocharger with a dual-vane nozzle system. A new vane is arranged along and within the flow path of the nozzle, thus the section area of the passage is reduced, and the nozzle is partitioned into two air passages so as to reduce the cross flow losses of the airflow. Meanwhile, the airflow flows at the originally designed optimum angle of flow, so as to keep the turbine operating in the high-efficiency zone.

In order to solve above-mentioned technical problems, the present invention provides a technical solution as follows:

A turbocharger with a double-vane nozzle system, comprising a turbine housing, a fixed nozzle ring, a linearly moving nozzle disk, a middle-housing, a rack, rocker arm rods, and a gear, wherein a group of airfoil shaped fixed vanes are provided on the front end face of the fixed nozzle ring, with blade-shaped holes arranged between the fixed vanes, the fixed nozzle ring is provided with a center hole at the center, and sheathed around the circumference of the middle-housing and fixed to the middle-housing via screws, the linearly moving nozzle disk is mounted to the rear end of the fixed nozzle ring, a group of moving blades is provided on the front end face of the linearly moving nozzle disk, and the shape of the moving blade is consistent with that of the blade-shaped hole, the moving blades are movably inserted into the blade-shaped holes, the linearly moving nozzle disk is provided with a center hole at its center and sheathed around the circumference of the middle-housing, the rear end face of the linearly moving nozzle disk is fixedly connected with two rocker arm rods, the rocker arm rods are inserted into the middle-housing, each of the rocker arm rods is provided with teeth at one end and engaged with a rack via the gear, the rack is connected to a driving device.

Furthermore, the intake angle of the blade is ranged from about 18 to 24 degrees.

Furthermore, 4 to 11 fixed vanes may be employed and 4 to 11 moving blades may also be employed.

Furthermore, the driving device connected to the rack is an air packet executor or a solenoid valve.

The turbocharger with a dual-vane nozzle system according to the present invention is provided with new blades along the flow path of the nozzle, so as to both reduce the section area of the passage and partition the original nozzle into two air passages, so that the cross flow loss is reduced. Meanwhile, the airflow flows at the originally designed optimum angle of flow, and the turbine operates in the high-efficiency zone. The moving blades and the fixed vanes are arranged in the same streamwise direction, thereby avoiding the turbulence caused by the above second solution and the third solution, reducing the flow resistance losses. By increasing or decreasing the number of the blades, the area of the nozzle outlet can be adjusted. When the moving blades are completely inserted into the fixed vanes, the reduction ratio of the section area of the flow path can be adjusted by the thickness of the blade, so that the demands of the variable working condition of the engine can be satisfied. Depend on the actual demands, the thickness of blade is different in different turbochargers.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are used for further understanding of the present invention and form a part of the description, which explain the present invention with the embodiments and is not intended to limit the scope of the present invention. In the drawings:

FIG. 1 is a schematic diagram of the structure of the turbocharger with a dual-vane nozzle system according to the present invention;

FIG. 2 is a schematic diagram of the structure of the linearly moving nozzle disk according to the present invention;

FIG. 3 is a schematic diagram of the structure of the fixed nozzle ring according to the present invention;

FIG. 4 is a schematic side view of the fixed nozzle ring according to the present invention;

FIG. 5 is a schematic diagram of the assembly of the linearly moving disk and the rocker arm rods according to the present invention;

FIG. 6 is a schematic diagram of the structure of the rocker arm rod according to the present invention;

FIG. 7 is a schematic diagram of the structure of the rack according to the present invention;

FIG. 8 is a schematic side view of the structure of the gear according to the present invention;

FIG. 9 is a schematic front view of the structure of the gear according to the present invention;

FIG. 10 is a schematic diagram of the assembly of the linearly moving nozzle disk, the fixed nozzle ring and the rocker arm rods according to the present invention;

FIG. 11 is a schematic diagram of the technical analysis of the first solution in the background of the technology.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The preferred embodiments of the invention will be described by taking in conjunction with the accompanying drawings, it should be understood that the preferred embodiments illustrated herein is only intended to illustrate and explain the present invention rather than limiting the scope of the present invention.

Embodiment I

It is given that there are eight fixed vanes 8 and eight moving blades 7, and the intake angle of the blade, i.e. the blade incidence is 21 degree.

As shown in FIGS. 1, 4, and 10, a group of airfoil fixed vane 8 are provided on the front end face of the fixed nozzle ring 1, blade-shaped holes 9 are arranged between the fixed vanes 8, the fixed nozzle ring 1 is provided with a center hole at the center and sheathed around the circumference of the middle-housing 5 and fixed to the middle-housing 5 via screws, a linearly moving nozzle disk 2 is mounted on the rear end of the fixed nozzle ring 1.

As shown in FIGS. 2 and 10, a group of moving blades 7 are provided on the front end face of the linearly moving nozzle disk 2, the shape of the moving blade 7 is consistent with that of the blade-shaped hole 9, the moving blades 7 are moveably inserted into the blade-shaped holes 9.

As shown as in FIGS. 1, 5, 6, and 10, two rocker arm rods 3 are fixed to the rear end face of the linearly moving nozzle disk 2 via screws, the moving blade 7 on the front end face of the linearly moving nozzle disk 2 are inserted into the blade-shaped holes 9 in the fixed nozzle ring 1, the fixed nozzle ring 1 and the linearly moving nozzle disk 2 are sheathed around the circumference of the middle-housing 5, and two rocker arm rods 3 are inserted into corresponding openings in the middle-housing 5, the openings in the middle-housing are located at the edge of an oil scavenge cavity of the middle-housing 5 and free from interference with the oil scavenge in the middle-housing 5. Teeth are provided on the end of the rocker arm rods 3 which engage with a rack 4 via a gear 6.

As shown in FIGS. 1 and 3, the fixed nozzle ring 1 are provided with four round holes in the central part thereof which aligned with the threaded holes in the middle-housing 5, and fixedly connected to the middle-housing 5 by tightening screws. After debugging, it is required that the moving blades 7 be able to slide within the blade-shaped holes 9 in the fixed nozzle ring 1 smoothly.

With respect to the range of the movement of the moving blades 7, the maximum position is flushed with the front end of the fixed vane 8 while the minimum position is flushed with the rear end face of the fixed nozzle ring 1.

As shown in FIGS. 6, 7, 8, and 9, both ends of the rack 4 are provided with teeth, and the end of the rocker arm rod 3 is provided with teeth, an air packet executor pushes the rack 4 upward and downward, since the rack 4 is engaged with the gear 6, the gear 6 is driven to rotate, and the gear 6 is engaged with the teeth on the end of the rocker arm rod 3, thereby the rocker arm rod 3 is driven leftward and rightward. The rocker arm rods 3 are fixedly connected to the linearly moving nozzle disk 2 through screws, thereby the linearly moving nozzle disk 2 being moved laterally, and realizing the action of moving the moving blades 7 into or from the blade-shaped holes 9.

According to the demands of the variable working conditions of the engine, the linearly moving nozzle disk 2 is moved so that the moving blades 7 insert into the fixed nozzle ring 1 gradually until a complete insertion being achieved, so that the number of the vanes of the nozzle is increased, or the moving blades 7 are gradually retracted from the fixed nozzle ring 1 until the front end face of the moving blade 7 be moved to a position flushed with the rear end face of the fixed nozzle ring 1, so that the number of the vanes of the nozzle is decreased. The purpose of adjusting the outlet area of the nozzle is achieved by adjusting the number of the vanes.

The turbocharger with a dual-vane nozzle system according to the present invention is provided with new blades along the flow path of the nozzle, so as to reduce the section area of the passage and partition the original nozzle into two air passages, so that the cross flow loss is reduced. Meanwhile, the airflow flows at the originally designed optimum angle of flow, and the turbine operate in the high-efficiency zone. The moving blades and the fixed vanes are arranged in a streamwise direction, thereby avoiding the turbulence caused by the second solution and the third solution, reducing the flow resistance losses. By increasing or decreasing the number of the blades, the area of the nozzle outlet can be adjusted. When the moving blades insert into the fixed vanes completely, the reduction ratio of the section area of the flow path can be adjusted by the thickness of the blade, so that the demands of the variable working conditions of the engine can be satisfied. Depend on the actual demands, the thickness of blade is different in different turbochargers.

Embodiment II

The difference between the present embodiment II and the embodiment I is that the driving device pushing the rack upward and downward is a solenoid valve.

Finally, it shall be noted that the above description is the preferred embodiments of the present invention only, it is not intended to limit the scope of the present invention. Although the present invention has been described in detail with respect to the above-mentioned embodiments, the technical solution disclosed in the embodiments described above can be modified by the skilled person in the art, or equal substitution of some technical features can be made. Any modification, equal substitution, and improvement without departing from the spirit and principle of the invention shall be within the scope of the append claims.

Claims

1. A turbocharger with a double-vane nozzle system, comprising a turbine housing, characterized in that it further comprises a fixed nozzle ring, a linearly moving nozzle disk, a middle-housing, a rack, a gear and rocker arm rods,

wherein a plurality of airfoil shape fixed vanes are provided on a front end face of the fixed nozzle ring, with blade-shaped holes arranged between the fixed vanes, the fixed nozzle ring is provided with a center hole at the center, and sheathed around circumference of a middle-housing and fixed to the middle-housing via screws, a linearly moving nozzle disk is mounted to a rear end of the fixed nozzle ring, a plurality of moving blades is provided on a front end face of the linearly moving nozzle disk, and the shape of the moving blade is consistent with that of the blade-shaped hole, the moving blades are movably inserted into the blade-shaped holes, the linearly moving nozzle disk is provided with a center hole at its center and sheathed around the circumference of the middle-housing, the rear end face of the linearly moving nozzle disk is fixedly connected with two rocker arm rods, the rocker arm rods are inserted into the middle-housing, each of the rocker arm rods is provided with teeth at one end and engaged with a rack via the gear, the rack is connected to a driving device.

2. The turbocharger with a double-vane nozzle system according to claim 1, characterized in that an intake angle of the blade is ranged from about 18 to 24 degrees.

3. The turbocharger with a double-vane nozzle system according to claim 1, characterized in that 4 to 11 fixed vanes are employed and 4 to 11 moving blades are employed.

4. The turbocharger with a double-vane nozzle system according to claim 1, characterized in that the driving device connected to the rack is an air packet executor or a solenoid valve.