CN107035427B

CN107035427B - Variable nozzle assembly of turbocharger and assembly method thereof

Info

Publication number: CN107035427B
Application number: CN201710231457.7A
Authority: CN
Inventors: 朱明明; 顾茸蕾; 刘伟
Original assignee: Eason Technology Jiangsu Co ltd
Current assignee: Eason Technology Jiangsu Co ltd
Priority date: 2017-04-11
Filing date: 2017-04-11
Publication date: 2023-02-28
Anticipated expiration: 2037-04-11
Also published as: CN107035427A

Abstract

The invention discloses a variable nozzle assembly of a turbocharger, which comprises an integrally formed blade assembly and a nozzle ring; one end of the blade assembly is a blade, the middle part of the blade assembly is a rotating shaft, the other end of the blade assembly is a rocker arm, and the rocker arm drives the blade to move through the rotating shaft; the inner wall of the nozzle ring is provided with a rocker arm mounting groove and a rotating shaft through hole communicated with the rocker arm mounting groove, so that the rotating shaft is arranged in the rotating shaft through hole, and the blades and the rocker arms respectively extend out of two ends of the rotating shaft through hole; the end of the rocker arm connected with the rotating shaft faces inwards, and the other end of the rocker arm faces outwards; the rocker arm can pass through the rocker arm mounting groove. The invention also discloses an assembly method of the cable. The invention changes the set angle of the blade to adjust the exhaust flowing to the turbine, and simultaneously adopts the integrally formed blade assembly, thereby eliminating the design of a separate rocker arm, reducing the number of parts, improving the integral reliability, simplifying the assembly process, reducing the cost and having wide market prospect.

Description

Variable nozzle assembly of turbocharger and assembly method thereof

Technical Field

The invention belongs to the field of machinery, and particularly relates to a variable nozzle assembly of a turbocharger and an assembly method thereof.

Background

Turbochargers are devices used in conjunction with internal combustion engines to increase the power output of the engine by compressing air that is delivered to the engine intake for mixing with fuel and combustion in the engine. A turbocharger includes a compressor wheel mounted in a compressor housing and a turbine wheel mounted in a turbine housing. Wherein the turbine housing is formed separately from the compressor housing and a further intermediate housing is connected between the turbine housing and the compressor housing for mounting of the bearings. The turbine housing defines a generally annular flow passage surrounding the turbine. The turbine assembly includes a nozzle that channels into the turbine. Exhaust gas flows from the flow passage through the nozzle to the turbine and drives the turbine to rotate. The turbine rotates a coaxially connected compressor. The air is compressed by the compressor wheel and then connected from the housing outlet to the engine air intake.

One challenge in boosting engine performance with a turbocharger is achieving a desired amount of engine power output over the entire operating range of the engine. It has been found that this objective is not generally readily achieved with a fixed nozzle size turbocharger, and variable nozzle size turbochargers have been developed with the goal of providing a greater degree of control over the amount of boost provided by the turbocharger. One type of variable-size turbocharger is a Variable Nozzle Turbocharger (VNT), which includes a set of variable vanes in a turbine nozzle. The vanes are rotatably mounted in the nozzle ring and connected to a drive mechanism that enables the vane angle to be varied. Changing the setting angle of the vanes has the effect of changing the effective flow area in the turbine nozzle, and therefore the flow of exhaust gas to the turbine can be regulated by controlling the relative position of the vanes. In this way, the power output of the turbine can be adjusted, which enables the output of engine power to be controlled to a greater extent than is typically possible with a fixed nozzle size turbocharger.

Typically, the variable-vane assembly comprises a nozzle ring that rotatably supports the vanes adjacent one face of the nozzle ring. The vanes have pivot shafts that extend through mounting holes in the nozzle ring, and vane rocker arms are rigidly secured to the ends of the shafts that project beyond the opposite face of the nozzle ring. Thus, the vane can be rotated about the axis defined by the rotating shaft by rotating the vane rocker arm, thereby changing the setting angle of the vane.

The other side of the variable nozzle assembly is provided with a plurality of parts, the processing precision requirement is extremely high, the assembly process is complex, the reliability of the product is strictly tested, the variable nozzle technology is widely applied to the diesel engine turbocharger at present, but when facing the gasoline engine turbocharger with higher temperature, the reliability and the consistency of the product cannot be ensured by the current design structure, and meanwhile, the variable nozzle ring on the existing diesel engine turbocharger is high in part cost due to the complex process.

The variable nozzle cascade design of current blade subassembly formula, its blade all adopt separately to produce processing with the rocking arm, assemble again, and the assembly adopts welding or riveting, and this kind of project organization has following shortcoming:

1. the blades and the rocker arms are separately designed, so that the number of parts is increased to a great extent, and the reliability is reduced;

2. the blades and the rocker arm are generally assembled by adopting a welding or riveting process, and the blades need to be welded/riveted for a plurality of times, so that the assembly difficulty is increased, the assembly time is prolonged, and the product cost is increased;

3. the assembly angle of the blade and the rocker arm is mainly guaranteed by the tool, the tool has large errors, and therefore the problem that the angle consistency of the blade and the rocker arm is poor exists after assembly is completed, the opening degree of each blade is inconsistent, and performance fluctuation of the supercharger is caused.

Disclosure of Invention

The invention provides a variable nozzle assembly with a simple structure and process, which achieves the purposes of reducing the cost of parts and improving the reliability of the parts by reducing the number of the parts and simplifying the production and assembly processes of the parts. The invention is realized by the following technical scheme that the variable nozzle component of the turbocharger comprises a blade component and a nozzle ring which are integrally formed; one end of the blade assembly is a blade, the middle part of the blade assembly is a rotating shaft, the other end of the blade assembly is a rocker arm, and the rocker arm drives the blade to move through the rotating shaft; the inner wall of the nozzle ring is provided with a rocker arm mounting groove and a rotating shaft through hole communicated with the rocker arm mounting groove, so that the rotating shaft is arranged in the rotating shaft through hole, and the blades and the rocker arms respectively extend out of two ends of the rotating shaft through hole; the end of the rocker arm connected with the rotating shaft faces inwards, and the other end of the rocker arm faces outwards; the rocker arm can pass through the rocker arm mounting groove. The aperture of the through hole of the rotating shaft is matched with the maximum outer diameter of the rotating shaft.

The number of the blade assemblies can be obtained by matching calculation according to different supercharger models, and can be 9, 11 or any other suitable number; all blade assemblies on the same variable nozzle assembly of turbocharger have the same shape and size, and each blade assembly is assembled and is followed end to end, and the waste gas volume and the waste gas angle that pass through are controlled through the aperture between the front end of preceding blade assembly tail end and the following blade assembly. The blades provide a guiding function for the airflow, and the blades can be set to be in different shapes, and can be plane or curved. The length of the blades and the height of the blades need to be calculated according to the air inflow of the supercharger, and the work efficiency of the exhaust gas on the turbine needs to be maximized. The rotating shaft is connected with the blades into a whole to provide rotating support for opening and closing the blades. Preferably the shaft is cylindrical. The rocker arm provides driving force for the rotation of the blades, and one end of the rocker arm is connected with the rotating shaft into a whole.

Further, the rotating shaft is sequentially divided into a first section, a middle section and a third section; the intermediate section has an outer diameter less than the outer diameter of the first section and the outer diameter of the third section. Because the pivot is very high to diameter size precision requirement, need carry out the precision finishing processing, the interlude designs for the minor diameter section can reduce the processing work load of pivot, reduces the processing cost, simultaneously, can also reduce the frictional force loss through reducing the area of contact of pivot and circular through-hole. The diameter of the through hole of the rotating shaft of the nozzle ring is slightly larger than the diameter of the first section and the third section of the rotating shaft, and the through hole is used for rotatably supporting the blade assembly.

Furthermore, the outer diameter of the part of the rocker arm connected with the rotating shaft is smaller than that of the third section of the rotating shaft, so that the installation is convenient. Preferably, the outer diameter of the first section of the shaft is equal to the outer diameter of the third section of the shaft.

Furthermore, two ends of the rocker arm are connected by adopting a plane body and are in smooth transition.

Further, the blade assembly is integrally manufactured through casting. Other suitable methods are also possible. Each part of the blade assembly is made of the same material, and the aim is to ensure the strength of the blade assembly.

Further, the device also comprises a synchronous ring; the rocker arm is arranged in a groove of the inner wall of the synchronizing ring, so that the rocker arm can move along with the rotation of the synchronizing ring, and the blades are driven to move.

Further, the device also comprises an insert and a spacer sleeve; the insert is connected with the nozzle outer ring through the spacer sleeve; the spacer sleeve is sequentially divided into a first spacer sleeve section, a second spacer sleeve section and a third spacer sleeve section; the outer diameter of the second interval casing section is larger than the outer diameter of the first interval casing section and the outer diameter of the third interval casing section; the insert is provided with a hole matched with the outer diameter of the first interval sleeve section for the first interval sleeve section to insert; the nozzle ring is provided with a hole matched with the outer diameter of the third spacer sleeve section for the third spacer sleeve section to insert; the vanes are disposed in a space enclosed by the second spacer sleeve section and the insert and nozzle ring, and the vanes are movable in the space.

The space is just large enough for the blade to move. The face of the nozzle ring facing the vanes is planar, primarily to engage the base of the vanes, and the amount of exhaust gas leakage from this gap is controlled by the size of the gap (i.e. the size of the space enclosed by the second spacer sleeve section and the insert, nozzle ring) between the two planes (i.e. the face of the nozzle ring facing the vanes and the face of the insert facing the vanes). If the clearance is bigger, the exhaust gas leakage quantity is more, leads to turbine efficiency to reduce, and is especially obvious when the blade is closed, if the clearance is less, can have the high temperature and lead to the jamming because of the inflation to the functional failure. The spacer sleeve mainly functions to provide support for the insert and to ensure clearance between the insert and the nozzle ring.

Further, a piston ring is provided on the insert. Facilitating a sealed connection with other components of the turbocharger. The insert is located between the vane and the volute of the turbocharger. Wherein, the one end of inserts towards the blade is discoid, provides sealed and axial protection for the blade to and have certain clearance between the up end of blade, prevent to lead to the blade jamming because of high temperature expansion, this clearance effect is equal to the clearance between blade and the nozzle ring. The end of the insert facing away from the vane is designed to be cylindrical, and the cylindrical structure is inserted into a cylindrical exhaust hole of the scroll. Piston rings are provided on the insert at the portion inserted into the exhaust funnel of the scroll for reducing exhaust gas leakage caused by the gap between the insert and the scroll. The number of piston rings is 1 or more. When multi-pass, it is axially aligned on the portion of the insert that is inserted into the scroll discharge casing. Preferably 2 lanes.

Furthermore, the number of the spacing sleeves is more than or equal to 3. Preferably 3-5.

Further, the rocker arm mounting groove comprises an inner side section, a middle section and an outer side section which are connected in sequence; the outer section is connected with the through hole of the rotating shaft; the thickness of the inner section is less than that of the middle section; the thickness of the middle section is smaller than that of the outer section; the thickness of the outer section is equal to that of the through hole of the rotating shaft. The thickness of the bosses on the two sides of the inner side section is the same as that of the inner side section. The bosses on either side of the inner section are included for axial support of the nozzle ring by the heat shroud when the nozzle ring is assembled to the turbocharger.

Furthermore, an annular opening bulge is arranged around the rotating shaft through hole on the side, facing away from the blades, of the nozzle ring, so that the rocker arm is axially supported.

Further, the number of blade assemblies is 8-16; the rocker mounting grooves and the rotating shaft through holes are the same as the blade assemblies in number. The synchronous ring is provided with grooves which are equal to the blade assemblies in number and are matched with the tail ends of the rocker arms, and the grooves are used for driving the blade assemblies to synchronously move with the synchronous ring.

Furthermore, the outer diameter of the part of the rocker arm connected with the rotating shaft is smaller than that of the third section of the rotating shaft, so that the installation is convenient. As described below, the outer diameter of the part of the rocker arm connected with the rotating shaft is smaller than the outer diameter of the third section of the rotating shaft, so that the rotating shaft in the first step can be arranged in the rotating shaft through hole with the diameter matched with that of the rotating shaft.

The invention also discloses an assembly method of the variable nozzle component of the turbocharger, which comprises the following steps:

step one, mounting a blade assembly on a nozzle ring, specifically, enabling a rocker arm to face the direction of a rocker arm mounting groove, aligning a rotating shaft with a rotating shaft through hole, enabling the rocker arm to penetrate through the rocker arm mounting groove, mounting the rotating shaft into the rotating shaft through hole, and exposing blades out of the rotating shaft through hole;

step two, rotating the rocker arm to the direction back to the rocker arm mounting groove;

step three, installing a spacer sleeve and an insert;

step four, installing a synchronous ring;

no sequence exists between the third step and the fourth step.

Further, step three is specifically to insert the third spacer section of the spacer into the hole in the nozzle ring matching the outer diameter of the third spacer section, and then insert the first spacer section of the spacer into the hole in the insert matching the outer diameter of the first spacer section.

The beneficial effects are as follows:

1. the blades, the rotating shaft and the rocker arm are designed by adopting an integrated production and machining method, so that an independent rocker arm design is omitted, the number of parts is reduced, and the overall reliability is improved;

2. the rocker arm mounting groove for mounting the blade assembly is designed on the nozzle ring, so that the assembly process is greatly simplified, the part cost is reduced, and the assembly time is shortened;

3. because integrated into one piece, therefore the angle and the clearance of blade and rocking arm are mainly guaranteed through mould and machine tooling, and is better for assembly fixture uniformity.

Drawings

FIG. 1 is an exploded view of the turbocharger variable nozzle assembly of the present invention.

FIG. 2 is a schematic structural diagram of a blade assembly of the present invention.

Fig. 3 is a sectional view of the blade assembly of the present invention.

Fig. 4 is a schematic view of the structure of the nozzle ring of the present invention.

Fig. 5 is a schematic structural view two of the nozzle ring of the present invention.

FIG. 6 is an enlarged partial schematic view of the vane assembly of the present invention mounted to the nozzle ring via the rocker mounting slots and the pivot through-holes.

Fig. 7 is a schematic sectional view of the vane assembly and nozzle ring of the present invention.

FIG. 8 is a second schematic exploded view of the turbocharger variable nozzle assembly of the present invention.

FIG. 9 is a schematic view of the mounting of the vane assembly of the present invention to the nozzle ring via the rocker mounting slots and the pivot through holes.

Fig. 10 is a schematic view of the assembled vane assembly and nozzle ring of the present invention.

Fig. 11 is a schematic structural view of the vane assembly of the present invention after the assembly with the nozzle ring and the synchronizing ring is completed.

Fig. 12 is a schematic view of a variable nozzle turbocharger turbine tip cut-away structure.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings.

Fig. 1 shows a specific embodiment of the present invention. In this embodiment, the turbocharger variable nozzle assembly comprises an insert 1, a vane assembly 2, a nozzle ring 4, a unison ring 5, and a spacer sleeve 3. The insert 1 is provided with 2 piston rings 11. The blade assembly 2 is an integrally formed structure, and has a blade 21 at one end, a rotating shaft 22 in the middle, and a rocker 23 at the other end. The turbocharger variable nozzle assembly in this embodiment comprises 11 identical blade assemblies 2. The number of blade assemblies may vary from turbocharger variable nozzle assembly to turbocharger variable nozzle assembly and is not limited to 11.

The end of the insert 1 facing the vane 21 is disc-shaped to provide sealing and axial protection for the vane 21, and has a certain clearance with the upper end face of the vane 21 to prevent the vane from being stuck due to high temperature expansion. The end of the insert 1 facing away from the vane 21 is designed as a cylinder, and 2 piston rings 11 are arranged axially on this cylindrical structure of the insert 1.

The inner wall of the nozzle ring 4 is provided with a rocker arm mounting groove 42 and a rotating shaft through hole 41 communicated with the rocker arm mounting groove 42. The rotating shaft 22 is arranged in the rotating shaft through hole 41 in a matching mode, and the blade 21 and the rocker arm 23 are exposed out of two ends of the rotating shaft through hole 41 respectively. The number of the rotation shafts 22 is the same as that of the rotation shaft through holes 41.

The end of the rocker arm 23 of the assembled turbocharger variable nozzle assembly that is connected to the rotating shaft 22 faces inward, and the other end of the rocker arm 23 faces outward, as shown in fig. 7. The inner wall of the synchronizing ring 5 is provided with a groove 51 for mating with the rocker arm 23, in which the tail end of the rocker arm 23 is disposed. When the synchronizing ring 5 rotates, the rocker arm 23 is driven to rotate, and the blades 21 are driven to rotate through the rotating shaft 22, so that the angle of the blades is adjusted, and the exhaust gas flowing to the turbine is adjusted.

The spacer 3 is divided in turn into a first spacer section 31, a second spacer section 32 and a third spacer section, as shown in fig. 8. The outer diameter of the second spacer sleeve section 32 is larger than the outer diameter of the first spacer sleeve section 31 and the outer diameter of the third spacer sleeve section. The insert 1 is provided with a hole 12 (shown in fig. 8) matching with the outer diameter of the first spacer sleeve section 31 for the first spacer sleeve section 31 to be inserted; the nozzle ring 4 is provided with apertures 43 (as shown in figure 4) matching the outer diameter of the third spacer section for insertion of the third spacer section. The vanes 21 are arranged in the space enclosed by the second spacer sleeve section 32 and the insert 1, the nozzle ring 4. The blade 21 is not jammed in the space but can move in the space.

Fig. 2 and 3 show one embodiment of a blade assembly 2. The shaft 22 is divided into a first section 24, an intermediate section 25 and a third section 26 in that order. The outer diameter of the intermediate section 25 is smaller than the outer diameter of the first section 24 and the outer diameter of the third section 26. The outer diameter of the first section 24 and the outer diameter of the third section 26 are equal. The outer diameter of the portion 27 of the rocker arm which meets third section 26 is smaller than the outer diameter of third section 26. The first section 24 is connected to the blade 21. The blade assembly 2 is integrally cast or otherwise fabricated as a one-piece structure. The bore diameter of the shaft through hole 41 matches the maximum outer diameter of the shaft 22.

Fig. 4 and 5 mainly show the configuration of the face of the nozzle ring 4 facing towards and away from the vanes, respectively. As shown in fig. 4 and 5, the rocker arm mounting groove 42 includes an inner section 46, a middle section 45, and an outer section 44 connected in sequence; the outer section 44 is connected to the shaft through hole 41. The thickness of the inner section 46 is less than the thickness of the middle section 45; the thickness of the middle section 45 is less than the thickness of the outer section 44. The thickness of the outer section 44 is equal to the thickness of the shaft through hole 41. An annular opening projection 43 is provided around the through-hole 41 of the rotary shaft on the side of the nozzle ring 4 facing away from the vanes to provide axial support for the rocker arm. The bosses 47 on both sides of the inner section 46 have the same thickness as the inner section 46. The bosses 47 on either side of the inner section 46 serve to provide axial support for the nozzle ring 4 by the heat shroud through the bosses 47 on either side of the inner section 46 when the nozzle ring is assembled to the turbocharger.

The assembly process, as shown in fig. 6-11, includes the following steps:

step one, mounting the blade assembly on the nozzle ring 4, specifically, directing the rocker arm 23 toward the rocker arm mounting groove 42, aligning the rotating shaft 22 with the rotating shaft through hole, so that the rocker arm 23 passes through the rocker arm mounting groove 42, the rotating shaft 22 is mounted in the rotating shaft through hole, and the blade 21 is exposed out of the rotating shaft through hole, as shown in fig. 6 and 9.

Step two, the rocker arm 23 is rotated to the direction back to the rocker arm mounting groove 42, as shown in fig. 7 and 10;

and step three, installing the spacing sleeve and the inserting piece. Specifically, the third spacer section of the spacer 3 is inserted into a bore in the nozzle ring 4 matching the outer diameter of the third spacer section, and then the first spacer section 31 of the spacer 3 is inserted into a bore 12 in the insert 1 matching the outer diameter of the first spacer section 31.

And step four, mounting the synchronizing ring 5, so that the tail end of the rocker arm 23 is mounted in the groove 51 of the inner wall of the synchronizing ring 5.

No sequence exists between the third step and the fourth step.

FIG. 12 illustrates the position of the turbocharger variable nozzle assembly in the turbocharger, with region A circled the general position of the turbocharger variable nozzle assembly of the present invention. It can be seen from the figure that the turbocharger comprises a turbocharger variable nozzle assembly, a turbine 100, a volute 101 and an intermediate casing 102. The annular flow passage of the volute 100 receives exhaust gas from the engine, the annular turbocharger variable nozzle assembly is arranged between the turbocharger flow passage and the turbine 100, the exhaust gas in the volute flow passage is guided to be blown to the turbine 100, and the angle of the airflow blown to the turbine 100 can be adjusted, so that the work efficiency of the turbine 100 is adjusted. The turbine 100 drives the coaxial pinch roller to compress the intake air of the engine to do work.

The above detailed description of the present invention is provided only for the purpose of illustrating the technical concepts and features of the present invention, and is intended to enable those skilled in the art to understand the present invention and implement the present invention, and not to limit the scope of the present invention. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.

Claims

1. A turbocharger variable nozzle assembly comprising an integrally formed blade assembly, nozzle ring, synchronizing ring, insert and spacer sleeve; one end of the blade assembly is a blade, the middle of the blade assembly is a rotating shaft, the other end of the blade assembly is a rocker arm, and the rocker arm drives the blade to move through the rotating shaft; the inner wall of the nozzle ring is provided with a rocker arm mounting groove and a rotating shaft through hole communicated with the rocker arm mounting groove, so that the rotating shaft is arranged in the rotating shaft through hole, and the blades and the rocker arms respectively extend out of two ends of the rotating shaft through hole; one end of the rocker arm connected with the rotating shaft faces inwards, and the other end of the rocker arm faces outwards; the rocker arm can penetrate through the rocker arm mounting groove; the rocker arm is arranged in a groove on the inner wall of the synchronizing ring, so that the rocker arm can move along with the rotation of the synchronizing ring, and the blades are driven to move; the insert is connected with the nozzle ring through the spacer sleeve; the spacer sleeve is sequentially divided into a first spacer sleeve section, a second spacer sleeve section and a third spacer sleeve section; the outer diameter of the second spacer sleeve section is greater than the outer diameter of the first spacer sleeve section and the outer diameter of the third spacer sleeve section; the insert is provided with a hole matched with the outer diameter of the first interval sleeve section, and the first interval sleeve section is inserted into the hole; the nozzle ring is provided with a hole matched with the outer diameter of the third spacer sleeve section for the third spacer sleeve section to insert; the vanes are arranged in a space enclosed by the second spacer sleeve section, the insert and the nozzle ring, and the vanes can move in the space; the rocker arm mounting groove comprises an inner side section, a middle section and an outer side section which are connected in sequence; the outer section is connected with the rotating shaft through hole; the thickness of the inner side section is smaller than that of the middle section; the thickness of the middle section is smaller than that of the outer section; the thickness of the outer section is equal to that of the rotating shaft through hole.

2. The turbocharger variable nozzle assembly of claim 1, wherein the shaft is divided into a first section, an intermediate section, and a third section in sequence; the intermediate section has an outer diameter less than the outer diameter of the first section and the outer diameter of the third section.

3. The turbocharger variable nozzle assembly of claim 1, wherein the insert is provided with piston rings thereon.

4. The turbocharger variable nozzle assembly of claim 1, wherein an annular opening boss is provided around the shaft through-hole on the face of the nozzle ring facing away from the vanes to provide axial support for the rocker arm.

5. The turbocharger variable nozzle assembly of claim 1, wherein the number of blade assemblies is 8-16; the rocker arm mounting groove with the pivot through-hole all with the quantity of blade subassembly is the same.

6. A method of assembling a turbocharger variable nozzle assembly as defined in claim 1, comprising the steps of:

the method comprises the following steps that firstly, a blade assembly is installed on a nozzle ring, specifically, a rocker arm faces to the direction of a rocker arm installation groove, a rotating shaft is aligned to a rotating shaft through hole, the rocker arm penetrates through the rocker arm installation groove, the rotating shaft is installed in the rotating shaft through hole, and blades are exposed out of the rotating shaft through hole;

secondly, rotating the rocker arm to the direction back to the rocker arm mounting groove;

step three, installing a spacer sleeve and an insert;

step four, installing a synchronous ring;

and the third step and the fourth step do not have the sequence.

7. The method of assembling as claimed in claim 6, wherein said third step is carried out by inserting a third spacer section of said spacer sleeve into a bore in said nozzle ring matching an outer diameter of said third spacer section, and then inserting a first spacer sleeve section of said spacer sleeve into a bore in said insert matching an outer diameter of said first spacer sleeve section.