Vaned diffuser and turbocharger

Abstract

The vaned diffuser comprises a base plate, diffusion blade sets and a blade angle adjusting device, the multiple diffusion blade sets are arranged layer by layer in a concentric ring shape in the radial direction, each diffusion blade set comprises a plurality of diffusion blades evenly distributed in the circumferential direction, and the blade angle adjusting device is arranged on the base plate. The diffusion blades are rotatably arranged on the first side disc face of the chassis, the blade angle adjusting devices are arranged on the chassis, each diffusion blade set is correspondingly in transmission connection with one blade angle adjusting device, and the blade angle adjusting devices are used for driving the diffusion blades in the diffusion blade sets to rotate synchronously. When the turbocharger works under different working conditions, the airflow flowing direction of airflow in the bladed diffuser is changed by controlling the rotating angle of each layer of diffusion blades, the effects of guiding airflow flowing and controlling the airflow flowing speed and the output pressure are achieved, and therefore the turbocharger can adapt to working scenes under different working conditions; and the whole turbocharging system can keep higher working efficiency at different rotating speeds.

Description

Technical Field

[0001] This utility model relates to the field of turbocharging technology, and in particular to a vaned diffuser and a turbocharger. Background Technology

[0002] A turbocharger is a device that uses exhaust gas energy to compress air and increase the intake air volume, thereby allowing more fuel to be injected and significantly improving the engine's power and torque. A turbocharger mainly consists of a turbine and a compressor. The exhaust gas from the engine drives the turbine inside the turbine, which in turn drives the impeller coaxially mounted inside the compressor. The impeller compresses the intake air. The diffuser is located inside the compressor and uses the difference in flow cross-sectional area to convert velocity energy into pressure energy.

[0003] Diffusers come in two types: bladeless and bladed. Bladeless diffusers are simple to manufacture, but their potential for efficiency improvement is limited. They have poor diffusion capacity and low efficiency, which leads to increased fuel consumption, wasted energy, increased vehicle exhaust emissions, and environmental pollution. Bladed diffusers, on the other hand, are more effective than bladeless diffusers and are therefore more widely used.

[0004] Currently, bladed diffusers consist of a chassis and compressor casing forming a flow channel. Specific airfoil-shaped blades are installed within this channel, and the shape of the blades restricts the airflow direction, thereby shortening the overall structural dimensions of the diffuser channel. This allows for both deceleration and pressurization of the airflow with a short flow path and only a slight increase in diameter. However, most bladed diffusers currently have fixed, non-adjustable blades, which cannot be adjusted for different operating conditions. They can only maintain a single velocity and pressure state, limiting their effectiveness in variable operating environments. Utility Model Content

[0005] The first objective of this invention is to provide a vaned diffuser that can adapt to different working conditions and enable the entire booster system to maintain high efficiency at different speeds.

[0006] The second objective of this invention is to provide a turbocharger that includes the aforementioned bladed diffuser.

[0007] To achieve the above objectives, this utility model provides the following technical solution:

[0008] A vane diffuser, comprising:

[0009] Chassis;

[0010] A diffuser blade assembly, wherein multiple diffuser blade assemblies are arranged in concentric rings along the radial direction, the diffuser blade assembly includes multiple diffuser blades evenly distributed along the circumference, and the diffuser blades are rotatably disposed on the first side surface of the chassis;

[0011] A vane angle adjusting device is arranged on the bottom disc, and each of the variable stator vane groups is correspondingly connected with a vane angle adjusting device, which is used to drive each of the variable stator vanes in the variable stator vane group to rotate synchronously.

[0012] In an embodiment of the present application, each of the variable stator vane groups is arranged at equal intervals in the radial direction.

[0013] In an embodiment of the present application, the thickness of the variable stator vane gradually decreases from the middle to both ends of the variable stator vane.

[0014] In an embodiment of the present application, the vane angle adjusting device comprises:

[0015] A gear ring is arranged on the inner or outer circumferential surface of the gear ring.

[0016] A gear set comprises a plurality of transmission gears, each of which is coaxially fixedly connected with one of the variable stator vanes of the variable stator vane group, and the gear ring is engaged with each of the transmission gears of the gear set.

[0017] A driving assembly is in driving cooperation with the gear ring to drive the gear ring to reciprocating rotate.

[0018] In an embodiment of the present application, the driving assembly comprises:

[0019] A rotary motor;

[0020] A driving gear is arranged on the motor shaft of the rotary motor, and the driving gear is engaged with the gear ring.

[0021] In an embodiment of the present application, the driving assembly comprises:

[0022] A rotary motor;

[0023] A worm is arranged on the motor shaft of the rotary motor;

[0024] A worm wheel is arranged on the outer circumferential surface of the gear ring, and the worm wheel is engaged with the worm.

[0025] In an embodiment of the present application, the vane angle adjusting device comprises:

[0026] A connecting block group, the connecting block group comprising a plurality of connecting blocks and a plurality of connecting rods, a first end of each of the connecting blocks of the connecting block group being fixedly connected with each of the variable area vanes of the variable area vane group one by one through a connecting shaft, two ends of the connecting rods being rotatably connected with second ends of two adjacent connecting blocks respectively;

[0027] A driving assembly, the driving assembly being in transmission connection with one of the connecting blocks in the connecting block group to drive the connecting block to reciprocating swing around the connecting shaft as the rotation axis.

[0028] In an embodiment of the present application, the driving assembly comprises:

[0029] A rotary motor;

[0030] A driving gear, the driving gear being arranged on a motor shaft of the rotary motor;

[0031] An arc-shaped tooth portion arranged on an edge of a second end of one of the connecting blocks in the connecting block group, the driving gear being in meshing connection with the arc-shaped tooth portion.

[0032] In an embodiment of the present application, the driving assembly comprises:

[0033] A rotary motor;

[0034] A worm, the worm being arranged on a motor shaft of the rotary motor;

[0035] A worm gear tooth portion arranged on an edge of a second end of one of the connecting blocks in the connecting block group, the worm being in meshing connection with the worm gear tooth portion.

[0036] A turbocharger, the turbocharger comprising a compressor casing, the compressor casing being provided with the vaneed variable area diffuser.

[0037] It can be seen from the above technical solutions that the utility model discloses a vaneed variable area diffuser, which comprises a base plate, a variable area vane group and a blade angle adjusting device, wherein the base plate is used for mounting the variable area vane group and the blade angle adjusting device, a plurality of variable area vane groups are arranged in a concentric ring shape in the radial direction, the variable area vane group comprises a plurality of variable area vanes that are uniformly distributed in the circumferential direction, the variable area vanes are rotatably arranged on a first side disc surface of the base plate, the blade angle adjusting device is arranged on the base plate, each variable area vane group is correspondingly connected with one blade angle adjusting device, and the blade angle adjusting device is used for driving the variable area vanes in the variable area vane group to synchronously rotate.

[0038] The above-mentioned vane diffuser has multiple layers of diffuser vane groups arranged in concentric circles, the angles of each diffuser vane in the diffuser vane groups can be synchronously adjusted, and each diffuser vane group can be independently adjusted, when the turbocharger works under different working conditions, by controlling the rotation angles of the diffuser vanes of each layer, the flow direction of the airflow in the vane diffuser is changed, the airflow flow is guided, the airflow flow rate and the output pressure are controlled, so that the working scene under different working conditions can be adapted, and the entire turbocharging system can maintain high working efficiency under different rotation speeds.

[0039] The turbocharger provided by the application has all the technical effects of the above-mentioned vane diffuser, and details are not repeated herein. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments or the prior art description will be briefly introduced as follows. Obviously, the drawings in the following description only show some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0041] Figure 1 A structural schematic view of the vane diffuser provided by the embodiment of the present application is shown in the figure.

[0042] Figure 2 A structural schematic view of the vane diffuser provided by the embodiment of the present application under low-speed and low-load working conditions is shown in the figure.

[0043] Figure 3 A structural schematic view of the vane diffuser provided by the embodiment of the present application under high-speed and high-load working conditions is shown in the figure.

[0044] In the figure:

[0045] 100 is a chassis.

[0046] 200 is a diffuser vane group; 210a is a first diffuser vane; 210b is a second diffuser vane; and 210c is a third diffuser vane. DETAILED DESCRIPTION

[0047] One of the cores of the present application is to provide a vane diffuser, the structural design of the vane diffuser enables it to adapt to working scenes under different working conditions, and enables the entire turbocharging system to maintain high working efficiency under different rotation speeds.

[0048] Another core of the present application is to provide a turbocharger comprising the above-mentioned vane diffuser.

[0049] The technical solutions in the embodiments of the present application will be clearly and completely described with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all the other embodiments obtained by those skilled in the art without creative efforts belong to the scope of the present application.

[0050] Please refer to Figure 1 , Figure 1 The structural schematic diagram of the vane diffuser provided in the embodiments of the present application is shown.

[0051] The embodiment of the present application discloses a vane diffuser, which comprises a base plate 100, a diffuser vane group 200 and a vane angle adjusting device.

[0052] The base plate 100 is disc-shaped or ring-shaped, and the base plate 100 is provided with a first side disc surface and a second side disc surface opposite to each other in the axial direction. The base plate 100 is used for mounting the diffuser vane group 200 and the vane angle adjusting device. It should be noted that the base plate 100 can be an integrated structure or a split structure, that is, according to the number of the diffuser vane group 200, a plurality of ring-shaped parts are provided, and one or more diffuser vane groups 200 are arranged on each ring-shaped part.

[0053] The plurality of diffuser vane groups 200 are arranged in concentric ring layers in the radial direction. The diffuser vane group 200 comprises a plurality of diffuser vanes distributed uniformly in the circumferential direction. The diffuser vanes are rotatably arranged on the first side disc surface of the base plate 100. The number, size and shape of the diffuser vanes in each diffuser vane group 200 can be the same or different. When the number of the diffuser vane group 200 is three or more, the distance between the adjacent two diffuser vane groups 200 can be the same or different.

[0054] The vane angle adjusting device is arranged on the base plate 100. Each diffuser vane group 200 is correspondingly connected with one vane angle adjusting device in a transmission mode, that is, each diffuser vane group 200 can be adjusted individually. The vane angle adjusting device is used for driving the diffuser vanes in the diffuser vane group 200 to rotate synchronously. The vane angle adjusting device can be arranged on the second side disc surface of the base plate 100 or arranged on one side of the base plate 100 in the radial direction of the base plate 100. The vane angle adjusting device can comprise a plurality of drivers. The number of the drivers is the same as the number of the diffuser vanes in the diffuser vane group 200. Each driver drives one diffuser vane to rotate. The vane angle adjusting device can also comprise one driver and a transmission mechanism. The driver is connected with the diffuser vanes in the diffuser vane group 200 in a transmission mode, so as to drive the plurality of diffuser vanes to rotate by one driver.

[0055] In a specific embodiment of the present application, as Figures 1 to 3As shown, the vane diffuser comprises three sets of diffuser vane groups 200, and the number, shape and size of the diffuser vanes in each set of diffuser vane groups 200 are the same.

[0056] Compared with the prior art, the vane diffuser provided in the embodiment of the utility model has a plurality of layers of diffuser vane groups 200 arranged in concentric circles, the angles of each diffuser vane in the diffuser vane groups 200 can be synchronously adjusted, and each diffuser vane group 200 can be independently adjusted. When the turbocharger works under different working conditions, by controlling the rotation angles of the diffuser vanes of each layer, the gas flow direction of the gas flow in the vane diffuser is changed, the gas flow is guided, the gas flow rate and the output pressure are controlled, and thus the working scene under different working conditions can be adapted, and the entire turbocharging system can maintain a high working efficiency under different rotation speeds.

[0057] Specifically, when under a low-speed low-load working condition, for example, Figure 2 As shown, the angles of the diffuser vanes in each diffuser vane group 200 are adjusted, so that the diffuser vanes of each layer are coincident in the gas flow direction, that is, the diffuser vanes at the corresponding positions of each set of diffuser vane groups 200 are basically arranged in a straight line. At this time, the cross-sectional area through which the gas flows is reduced, the gas flow path is shortened, the speed is increased, and the pressure is reduced. The intake amount can be limited, and the intake vortex can be enhanced, so as to promote the full mixing of fuel and air and improve the combustion efficiency.

[0058] In the embodiment shown in Figure 2 There are three sets of diffuser vane groups 200 in total, wherein the diffuser vanes in the innermost layer are first diffuser vanes 210a, the diffuser vanes in the middle layer are second diffuser vanes 210b, and the diffuser vanes in the outermost layer are third diffuser vanes 210c. In the state shown in Figure 2 The radial angles of the first diffuser vanes 210a, the second diffuser vanes 210b and the third diffuser vanes 210c at the corresponding positions are basically the same.

[0059] When under a high-speed high-load working condition, for example, Figure 3 As shown, the angles of the diffuser vanes in each diffuser vane group 200 are adjusted, so that the diffuser vanes of each layer are distributed in a staggered manner in the gas flow direction. The cross-sectional area through which the gas flows increases from the inside to the outside, and the gas flow path between the diffuser vanes is lengthened. This will cause the speed of the gas to decrease, and the pressure of the gas to increase, so as to increase the intake amount and reduce the intensity of the intake vortex to meet the demand of the engine for power output.

[0060] When the engine changes from the low-speed low-load working condition shown in Figure 2 to the high-speed high-load working condition shown in Figure 3 , the first diffuser vanes 210a, the second diffuser vanes 210b and the third diffuser vanes 210c are respectively adjusted fromFigure 2 The positions are rotated counterclockwise by an angle, wherein the rotation angle of the first diffuser vane 210a is smaller than the rotation angle of the second diffuser vane 210b, and the rotation angle of the second diffuser vane 210b is smaller than the rotation angle of the third diffuser vane 210c.

[0061] In the transition working condition, the rotation angle of each layer of diffuser vanes needs to be dynamically adjusted to adapt to the changing working condition requirements in the transition process from low speed to high speed and from low load to high load of the engine. The specific adjustment angle can be obtained by modeling simulation and testing in actual operation. By adjusting the angle of each layer of diffuser vanes according to the engine working condition, the airflow flow direction in the vaned diffuser can be changed in real time according to the engine working condition, so as to guide the airflow flow, control the airflow flow rate and the output pressure, and achieve the effect of keeping the entire turbocharging system at a high working efficiency under different rotating speeds.

[0062] In a specific embodiment of the present application, as shown in Figures 1 to 3 Each diffuser vane group 200 is arranged at equal intervals in the radial direction, and the equal interval arrangement of the diffuser vane group 200 means that the rotation axes of each layer of diffuser vanes are arranged at the same interval in the radial direction of the base plate 100.

[0063] The shape of the diffuser vane, mainly the cross-sectional shape perpendicular to the rotation axis of the diffuser vane, can be designed according to actual requirements, which can be a straight line or an arc, as shown in the embodiment Figures 1 to 3 In the present application, the thickness of the diffuser vane gradually decreases from the middle to both ends of the diffuser vane to form a structure similar to a shuttle, and the rotation axis of the diffuser vane can be at the center of symmetry of the diffuser vane or deviate from the center of symmetry of the diffuser vane, which is not limited herein.

[0064] It should be noted that the vane angle adjusting device can also adopt various structures, as long as it can realize the synchronous rotation of each diffuser vane in the same diffuser vane group 200. Specifically, in an embodiment, the vane angle adjusting device comprises a gear ring, a gear set and a driving assembly, wherein the gear ring is rotatably arranged on the second side surface of the base plate 100, and the inner or outer circumferential surface of the gear ring is provided with a gear ring. Of course, according to the relative position relationship between the driving assembly and the gear ring and the gear set, the gear ring can be provided with a gear ring only on the inner circumferential surface, in which case the gear set is located inside the gear ring, and the driving assembly can be arranged inside or outside the gear ring, or the gear ring can be provided with a gear ring only on the outer circumferential surface, in which case the gear set is located outside the gear ring, and the driving assembly can be arranged inside or outside the gear ring, or the gear ring can be provided with a gear ring on the inner and outer circumferential surfaces respectively, in which case one of the gear set and the driving assembly is located inside the gear ring, and the other is located outside the gear ring.

[0065] The gear set comprises a plurality of transmission gears, each transmission gear of the gear set is coaxially and fixedly connected with each guide vane of the guide vane set 200 in one-to-one correspondence, the gear ring is engaged with each transmission gear of the gear set, the driving assembly is in transmission cooperation with the gear ring to drive the gear ring to reciprocating rotate, when the driving assembly drives the gear ring to rotate, the gear ring drives each transmission gear to rotate synchronously, thereby driving each guide vane of the same guide vane set 200 to rotate synchronously.

[0066] Specifically, in a specific embodiment of the present application, the driving assembly comprises a rotary motor and a driving gear, the driving gear is arranged on the motor shaft of the rotary motor, the driving gear is engaged with the gear ring, and it should be noted that the driving gear can be directly arranged on the motor shaft of the rotary motor, or can be arranged on the motor shaft of the rotary motor through a reduction gear set, at this time, according to the different structures of the gear ring, the driving gear and the transmission gear can be engaged with the gear ring on the same side of the gear ring, or can be engaged with the gear ring on the inner side and the outer side of the gear ring respectively.

[0067] In another embodiment, the driving assembly comprises a rotary motor, a worm and a worm wheel, the worm is arranged on the motor shaft of the rotary motor, the inner circumferential surface of the gear ring is provided with a gear ring, the outer circumferential surface of the gear ring is provided with a worm wheel, the worm wheel is engaged with the worm, and the rotary motor drives the worm to drive the worm wheel to rotate, thereby driving the gear ring to rotate.

[0068] In addition to using a rotary motor as a driver, a driver that outputs linear motion such as a piston cylinder can also be used to realize the reciprocating rotation of the guide vanes, for example, the above-mentioned driving assembly can comprise a piston cylinder, a swing piece, a gear ring and a gear set, the gear ring and the gear set are arranged in basically the same way as in the above-mentioned embodiment, one end of the swing piece is fixedly arranged on the gear ring, the other end is provided with a sliding groove, a push rod is arranged on the piston rod of the piston cylinder, the push rod is perpendicular to the piston rod, and the push rod is slidingly arranged in the sliding groove, when the piston rod of the piston cylinder extends or retracts, the push rod reciprocatingly slides in the sliding groove, thereby realizing the driving of the gear ring, it should be noted that the extension direction of the piston rod of the piston cylinder and the extension direction of the sliding groove always have an included angle.

[0069] The vane angle adjusting device can also adopt a connecting rod structure, that is, the vane angle adjusting device comprises a connecting block set and a driving assembly, wherein the connecting block set comprises a plurality of connecting blocks and a plurality of connecting rods, the first end of each connecting block of the connecting block set is fixedly connected with each guide vane of the guide vane set 200 in one-to-one correspondence through a connecting shaft, the two ends of the connecting rod are respectively rotatably connected with the second ends of the adjacent two connecting blocks, and the driving assembly is in transmission cooperation with one connecting block in the connecting block set to drive the connecting block to reciprocating swing with the connecting shaft as the rotation axis.

[0070] Specifically, in the above embodiment, the driving assembly comprises a rotary motor, a driving gear and an arc-shaped tooth portion arranged at the second end edge of one of the connecting blocks in the connecting block set, the driving gear is arranged on the motor shaft of the rotary motor, the driving gear is engaged with the arc-shaped tooth portion, and when the rotary motor drives the driving gear to rotate, the driving gear drives the connecting block to swing back and forth through the arc-shaped tooth portion.

[0071] Of course, the driving assembly is not limited to the above structure, and the driving assembly can also comprise a rotary motor, a worm and a worm gear tooth portion arranged at the second end edge of one of the connecting blocks in the connecting block set, the worm is arranged on the motor shaft of the rotary motor, and the worm is engaged with the worm gear tooth portion.

[0072] Of course, the structure of the connecting rod transmission can also use a piston cylinder as a driver, and only the arc-shaped tooth portion or the worm gear tooth portion arranged on the connecting block needs to be replaced with a sliding groove, and then a push rod on the piston cylinder is arranged in the sliding groove.

[0073] Further optimization of the above technical solution can be foreseen that, since the rotation angle of the outer layer of the variable-pitch vane is generally larger than that of the inner layer of the variable-pitch vane during adjustment, when designing, the adjustable angle of the vane angle adjusting device connected with the outer layer of the variable-pitch vane is required to be at least not less than the adjustable angle of the vane angle adjusting device connected with the inner layer of the variable-pitch vane.

[0074] The embodiment of the present application also provides a turbocharger, which comprises the vaneed variable-pitch vane as described in the above embodiment, and since the turbocharger adopts the vaneed variable-pitch vane in the above embodiment, the technical effects of the turbocharger refer to the above embodiment.

[0075] As shown in the present application and claims, unless the context clearly indicates otherwise, the words "one", "an", "a", and / or "the" do not specify a singular form only, but also include a plural form. Generally, the terms "comprise" and "include" only indicate the inclusion of the steps and elements explicitly identified, and these steps and elements do not constitute an exclusive list, and the method or device can also include other steps or elements. The element defined by the statement "comprising a" does not exclude the presence of another same element in the process, method, product or device comprising the element.

[0076] In the description of the present application, unless otherwise explicitly limited, the words such as arrangement, installation, connection and the like should be understood in a broad sense, and the person skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical solution.

[0077] The embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other.

[0078] The principles and implementations of the present application are described in detail with specific examples in this paper, and the above examples are only used to help understand the method and its core idea of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the principles of the present application, some improvements and modifications can be made to the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A vaned diffuser, characterized by, Comprising: a base plate (100); a plurality of variable-area vanes (200) arranged in a plurality of concentric rings in the radial direction, each of the variable-area vanes (200) being rotatably arranged on a first side of the base plate (100); a plurality of vane angle adjusting devices arranged on the base plate (100), each of the variable-area vanes (200) being connected to one of the vane angle adjusting devices, the vane angle adjusting devices being configured to drive the variable-area vanes (200) to rotate synchronously.

2. The vaned diffuser of claim 1, wherein, The variable-area vanes (200) are arranged at equal intervals in the radial direction.

3. The vaned diffuser of claim 1, wherein, The thickness of the variable-area vanes gradually decreases from the middle to the ends of the variable-area vanes.

4. The vaned diffuser of any one of claims 1-3, wherein, The vane angle adjusting device comprises: a ring gear rotatably arranged on a second side of the base plate (100), the ring gear being provided with a ring gear ring on the inner or outer circumferential surface thereof; a plurality of transmission gears, each of the transmission gears being coaxially fixedly connected to one of the variable-area vanes (200), the ring gear ring being engaged with each of the transmission gears; a driving assembly in driving engagement with the ring gear to drive the ring gear to rotate back and forth.

5. The vaned diffuser of claim 4, wherein, The driving assembly comprises: a rotary motor; a driving gear arranged on the motor shaft of the rotary motor, the driving gear being engaged with the ring gear.

6. The vaned diffuser of claim 4, wherein, The driving assembly comprises: a rotary motor; a worm arranged on the motor shaft of the rotary motor; a worm wheel, the inner circumferential surface of the ring gear being provided with the ring gear ring, the outer circumferential surface of the ring gear being provided with the worm wheel, the worm wheel being engaged with the worm.

7. The vaned diffuser of any one of claims 1-3, wherein, The vane angle adjusting device comprises: a plurality of connecting blocks and a plurality of connecting rods, the first end of each of the connecting blocks being fixedly connected to one of the variable-area vanes (200) via a connecting shaft, the two ends of each of the connecting rods being rotatably connected to the second ends of two adjacent connecting blocks; a driving assembly in driving engagement with one of the connecting blocks of the connecting block group to drive the connecting block to swing back and forth about the connecting shaft as the rotation axis.

8. The vaned diffuser of claim 7, wherein, The driving assembly comprises: a rotary motor; a driving gear arranged on the motor shaft of the rotary motor; an arc-shaped tooth portion arranged on the edge of the second end of one of the connecting blocks of the connecting block group, the driving gear being engaged with the arc-shaped tooth portion.

9. The vaned diffuser of claim 7, wherein, The driving assembly comprises: a rotary motor: a worm arranged on the motor shaft of the rotary motor; a worm gear tooth portion arranged on the edge of the second end of one of the connecting blocks of the connecting block group, the worm being engaged with the worm gear tooth portion.

10. A turbocharger characterized by, The turbocharger comprises a compressor casing, the compressor casing being provided with the variable-area vanes as claimed in any one of claims 1-9.

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