Claims:We claim
1. A mixed flow turbocharger with variable geometry turbine (151), comprising of:
a. atleast a turbine wheel (15), positioned at one end of the shaft (16), wherein said turbine wheel (15) is positioned downstream the engine exhaust;
b. atleast a compressor wheel (17), positioned at other end of the shaft (16), wherein said compressor wheel (17) is positioned upstream the engine inlet, wherein said compressor wheel (17) along with the turbine wheel (15) and the shaft (16) provides a rotating rotor assembly (14);
c. a turbine housing (19), accommodating the said turbine wheel (15);
d. a compressor housing (18), accommodating the said compressor wheel (17);
e. a bearing housing (13), supporting the said rotor assembly (14) by means of hydrodynamic bearing assembly, wherein said turbine wheel (15) and shaft (16) of rotor assembly provides a axial rotating rotor axis (A0 - A0);
f. a variable turbine cartridge assembly (2), comprising of :
i. a plurality of nozzle vane spindles (34), positioned in an inclined position with respect to the rotor axis A0 - A0, wherein said nozzle vane spindle axis (A2 – A2) is in an inclined direction with respect to the turbine rotor axis (A0 - A0), wherein said each of the nozzle vane spindle is provided with a first end (152) and second end (153);
ii. a plurality of nozzle vanes (21), positioned circumferentially on a spherical plane, wherein said each of the nozzle vane (21) is positioned at first end (152) of the nozzle vane spindle (34), wherein said rotational movement of each of nozzle vane (21) is in accordance to the movement of the each of the corresponding nozzle vane spindle (34);
iii. an outer vane bearing ring (31), provided at the rear end of the said plurality of nozzle vane (21), wherein said outer vane bearing ring (31) is provided with a spherical surface (33) corresponding to the external surface of the said plurality of nozzle vanes (21), wherein said outer vane bearing ring (31) is provided with an extended wall surface (59) extending towards the rotor axis centre A0 - A0;
iv. an inner vane bearing ring (28), provided at front end of the said plurality of nozzle vane (21), wherein said inner vane bearing ring (28) is provided with a spherical surface (30) corresponding to the interior surface of the said plurality of nozzle vanes (21); wherein said inner vane bearing ring (28) is provided with an extended wall surface (58) extending towards the rotor axis centre A0 - A0;
v. a plurality of screw pins (38) positioned in between the inner and outer vane bearing rings (28 and 31), wherein said plurality of screw pins (38) maintains a uniform distance between the said inner (28) and outer (31) vane bearing rings enabling free nozzle vane (21) movement;
vi. atleast an actuating ring device (39) positioned at the rear end of the inner vane bearing ring (28) in a radial plane with respect to the rotor axis A0 - A0, wherein said actuating ring device (39) is provided with a plurality of radial slots (41) corresponding to the number of nozzle vanes (21), wherein said axis of the actuating ring device (A4 – A4) coincides with the said rotor axis (A0 - A0);
vii. a plurality of vane lever (36), having a first end (157) and a second end (158), wherein first end (157) of the vane lever (36) is operatively coupled to the said second end (153) of the nozzle vane spindle (34), wherein the second end (158) of the vane lever (36) is operatively affixed to the corresponding radial slot (41) in the adjusting ring device (39);
viii. atleast a flow stopper (44) positioned on the said actuating ring device (39), wherein said flow stopper (44) limits the rotating angle of the actuating ring device (39) with respect to the turbine rotor axis (A0 - A0);
ix. an inner actuation lever (45), positioned on the actuating ring device (39);
x. an external actuating spindle (46), positioned on the internal actuating lever (45), wherein said axis of the external actuating spindle (46) A5-A5, is arranged in a parallel orientation with respect to the said rotor axis, A0-A0;
xi. an external actuating lever (47), positioned at other end of the external actuating spindle (46), Wherein said external actuating lever (47) is actuated by an external actuator (not shown) via a control rod (48).

2. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1, wherein said turbine housing (19) is provided with a turbine housing volute (25) with a turbine housing volute exit passage (20).

3. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1 & 2, wherein said turbine housing volute exit passage (20), plurality of nozzle vanes (21) and the turbine wheel (15) are positioned accordingly to make the fluid flow entering the nozzle vanes (21) at the nozzle vane entry (22) and exiting the nozzle vanes (21) at the nozzle vane exit (23) forms a spherical axis A1-A1 with respect to the said rotor axis, A0-A0 .

4. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1, wherein said fluid flow enters the turbine wheel (15) in an inclined direction (24) to the said rotor axis A0-A0.

5. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1, wherein said turbine housing volute exit flow passage (20) is provided with an inclined wall, positioned in an inclined direction to the rotor axis A0-A0, making the flow leaving the turbine volute (25) in an inclined direction to the rotor axis A0-A0.

6. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1, wherein said fluid flow entering the nozzle vane (21) at the entry point (22) and exiting the nozzle vane (21) at the exit point (23) is in an inclined direction to the rotor axis A0-A0.

7. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1, wherein said inner vane bearing ring (28) is provided with a plurality of pivot holes (35) corresponding to the number of plurality of nozzle vanes (21), wherein said plurality of pivot holes is spaced at angular distance normal to the spherical surface at pitch circle spherical diameter named PCSD1.

8. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1 and claim 7, wherein said centre axis of the pivot hole (35) (A3-A3) coincides with the nozzle vane spindle axis (A2 – A2) and is in inclined direction to the turbine rotor axis (A0-A0).

9. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1, wherein said plurality of nozzle vanes (21) positioned circumferentially on a spherical plane is provided with an inner spherical surface (26) having a spherical axis (SR1) and an outer spherical surface (27) having a spherical axis (SR2).

10. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1,wherein said inner vane bearing ring (28) is provided with a spherical surface (30) having a spherical axis (SR3).

11. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1, wherein said outer vane bearing ring (31) is provided with a spherical surface (33) having a spherical axis (SR4).

12. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1, wherein said plurality of nozzle vanes (21) is provided with a spherical radius (SR5) along the central spherical axis of the plurality of nozzle vanes A1- A1.

13. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1,wherein said spherical axis SR1 of the nozzle vane inner spherical surface (26), spherical axis SR2 of nozzle vane outer spherical surface (27), spherical axis SR3 of inner vane bearing ring spherical surface (30), spherical axis SR4 of outer vane bearing ring spherical surface (33) and the said spherical radius (SR5) of the plurality of nozzle vanes (21) coincides on the rotor axis (A0-A0), at single point “O”, enabling a uniform gap between the nozzle vane inner spherical surface (26) and inner vane bearing ring spherical surface (30); and between the nozzle vane outer spherical surface (27) and outer vane bearing ring spherical surface (33).

14. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1 & claim 13, wherein said uniform gap enables free movement of the said plurality of nozzle vanes (21).

15. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1 & claim 13, wherein said uniform gap accommodates for the thermal expansion of the said plurality of nozzle vanes (21) and the said inner and outer vanes bearing rings (28 and 31).

16. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1, wherein said uniform distance between the said inner (28) and outer (31) vane bearing rings is the flow path width (37), equivalent to the sum of nozzle vane (21) width and the uniform gap between nozzle vane inner spherical surface (26) and inner vane bearing ring spherical surface (30); and the uniform gap between the nozzle vane outer spherical surface (27) and outer vane bearing ring spherical surface (33).

17. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1, wherein said variable turbine cartridge assembly (2) is positioned in the turbine housing (19) so as to maintain the flow path width (37) of the nozzle vanes equivalent to the flow path (40) at the turbine volute exit path (20).

18. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1, wherein said actuating ring device (39) is additionally provided with a first slot (42) and a second slot (43).

19. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1, wherein said first slot (42) of the actuating ring device (39) is used to locate the minimum flow stopper (44) for limiting the rotating angle of the said actuating ring (39) in both clockwise and anticlockwise direction, with respect to the rotor axis A0-A0.

20. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1, wherein said second slot (43) of the actuating ring device (39) is engaged with the said inner actuating lever (45).

21. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1, wherein said rotating axis A4-A4 of the actuating ring device (39) is co-axially aligned with the turbine rotor axis A0-A0.

22. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1, wherein said adjusting ring device (39) rotates partially with respect to its axis A4-A4.

23. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1, wherein said external actuating spindle (46) rotates partially with respect to its axis A5-A5.

24. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1, wherein said nozzle vane spindle (34) rotates partially with respect to its axis A2-A2.

25. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1, wherein said second end (158) of the vane lever (36) is provided with a radial frame (49) having a spherical profile (53) on the side surface enabling a positive contact of the second end (158) of vane lever (49) with the actuating ring device (39) in the corresponding radial slot (41).

26. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1, wherein said second end (158) of the vane lever (36) is provided with a radial frame (49) having a flat profile (54 and 55) on the upper and the lower sides of the vane lever.

27. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1, wherein said first end (157) of the vane lever (36) is provided with a coupling slot (56) enabling smooth fitting with the said second end (153) of the nozzle vane spindle (34).

28. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1,wherein said radial frame (49) and the first end (157) of the vane lever (36) is connected via an angular frame (51), wherein said angular frame (51) of the vane lever (36) is aligned in a perpendicular direction with respect to the nozzle vane spindle axis A2-A2.

29. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1 & claim 26, wherein said coupling slot (56) is “D” shaped.

30. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1, wherein said second end (153) of the nozzle vane spindle (34) is provided with a mating counterpart with analogous “D” shape (57) for mating with the said coupling slot (56) positioned at the first end (157) of the vane lever (36).

31. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1, wherein positioning of the coupling slot (56) on the first end (157) of the vane lever (36) and the counter profile mating counterpart (57) on the second end (153) of the nozzle vane spindle (34) is selected based on the nozzle vane (21) orientation with respect to nozzle vanes spindle (34) axis A2-A2 in the nozzle vanes cartridge assembly (2).

32. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1, wherein said extended wall surface (58 and 59) of the inner (28) and outer (31) vane bearing ring extending towards the rotor axis centre A0 –A0, provides extended flow guidance from the nozzle vanes exit (23) to the turbine wheel inlet (24).

33. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1, wherein said extended wall surface (58 and 59) are positioned in a spherical plane.

34. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1, wherein said inner vane bearing ring (28) is additionally provided with an extended wall surface (61) towards turbine rotor axis A0-A0, positioned in a radial plane.

35. A mixed flow turbocharger with variable geometry turbine (151), as claimed in claim 1 & claim 34, wherein said extended wall surface (61) of the inner vane bearing ring (28) acts as a heat shield between turbine (11) hot zone and bearing system (13) having a relatively lower temperature.

36. A method of operation of the mixed flow turbocharger (151) with variable geometry turbine, comprising steps of:
a. Stimulating external actuator movement based on the engine operating condition (input), wherein said stimulation of external actuator imparts movement to the control rod (48);
b. Actuating the external actuating lever (47) by means of transferring the movement from the control rod (48) to the external actuating lever (47);
c. Transmitting the motion from the external actuating lever (47) to the internal actuating lever (45) via the external actuating linkage spindle (46);
d. Transferal of motion from the internal actuating lever (45) to the actuating ring device (39) of the nozzle vanes cartridge assembly (2);
e. Actuation of the plurality of the nozzle vanes (21), wherein said actuation of the plurality of the nozzle vanes (21) is performed by transmission of motion from the actuating ring device (39) to the said plurality of nozzle vanes (21) via the plurality of vane lever (36) and the corresponding nozzle vane spindle (34);
f. Rotation of the nozzle vane spindle (34) with respect to its axis A2-A2, wherein said rotation of nozzle vane spindle (34) actuates the rotation of the corresponding nozzle vane (21); and
g. Varying the nozzle flow area in accordance with rotation of the said plurality of nozzle vanes (21), wherein closing of the plurality of nozzle vanes (21) provides a minimum (156) flow area with increased flow velocity at the nozzle vane exit (23), wherein opening of the plurality of nozzle vanes (21) provides a maximum (155) flow area with reduced level of flow acceleration at the nozzle vane exit (23).

37. A method of operation of the mixed flow turbocharger (151) with variable geometry turbine, as claimed in claim 36, wherein said adjusting ring device (39) rotates partially with respect to its axis A4-A4.

38. A method of operation of the mixed flow turbocharger (151) with variable geometry turbine, as claimed in claim 36, wherein said external actuating spindle (46) rotates partially with respect to its axis A5-A5.

39. A method of operation of the mixed flow turbocharger (151) with variable geometry turbine, as claimed in claim 36, wherein said nozzle vane spindle (34) rotates partially with respect to its axis A2-A2.

40. A method of operation of the mixed flow turbocharger (151) with variable geometry turbine, as claimed in claim 36, wherein said rotation of plurality of nozzle vanes (21) opening to maximum (155) position or closing to minimum (156) position is determined based on the direction of motion initiated by the said external actuator. , Description:MIXED FLOW TURBOCHARGER WITH VARIABLE GEOMETRY TURBINE
FIELD OF THE INVENTION
The present invention is related to a turbocharger with variable geometry turbine. In particular, the present invention is related to a turbocharger with mixed flow variable geometry turbine with improved method of nozzle vane actuation.
BACKGROUND OF THE INVENTION
Turbochargers are generally used to increase the performance of an internal combustion engine. A turbocharger extracts energy from engine exhaust via a turbine to drive the compressor that compresses the intake air and direct it to the engine. Turbochargers generally supplies air at a higher pressure than the atmosphere creating a forced induction / charging system allowing more amount of air into the internal combustion engine than the naturally aspirated engine. With this higher air mass flow rate, the fuel is burned effectively and results in higher engine power output along with lower engine out emissions. Thus higher power output is achieved for a given engine size or reverse is also possible achieving target power output with smaller engine size known as “engine downsizing”, both are advantageous in view of cost effectiveness and less space requirement for an engine installation.
Turbochargers typically comprises of a radial turbine wheel at one of the shaft and a centrifugal compressor wheel at another end of a shaft forming a rotating rotor assembly, and a bearing system to support the rotating rotor assembly. The bearing housing connects the compressor housing and turbine housing. The exhaust gas from the engine drives the turbine wheel. As the turbine wheel rotates, the compressor wheel also rotates sucking in the air from the atmosphere into the compressor and delivering the air at higher pressure to the engine intake system. In case of fixed geometry turbine, also called vaneless turbine which is devoid of flow guiding nozzle vanes before the turbine wheel, the exhaust gas from the engine is directly supplied to the turbine wheel with fixed flow area in the turbine housing. In an alternate turbine design, the flow from the engine exhaust is allowed through the turbine housing and a set of flow guiding nozzle vanes arranged circumferentially upstream to the turbine wheel entry, called the variable geometry turbine or vaned nozzle turbine. The opening and closing of the nozzle vanes varies the flow area of the turbine and changes the mass flow rate through the turbine. The flow velocity at the entry of the turbine rotor varies according to the nozzle vanes opening position for the given exhaust gas mass flow rate, turbine inlet temperature and pressure upstream to the nozzle vanes.
Based on the nature of flow direction in the turbine, the turbine is classified as axial, radial inflow and mixed flow turbine. In axial flow turbine, the entry and exit of the exhaust gas flow through the turbine is in axial direction along the rotor axis, at entry and exit of the turbine. In radial flow turbine, the flow entry to the turbine wheel is in a radial direction, normal to the turbocharger rotor axis, and the flow leaves turbine wheel in an axial direction. In a mixed flow turbine, the flow entry to the turbine wheel is in both radial and axial direction, i.e. in an inclined direction towards rotor axis and the flow leaves turbine wheel in an axial direction. Mixed flow turbine possesses the best features of the radial and axial flow turbines with higher mass flow rate, higher combined turbine efficiency at lower velocity ratio and higher specific speed. The mixed flow turbine is advantageous over radial flow turbine for the similar size of the turbine. Currently many forms of mixed flow turbocharger are available in the market.
Chinese patent document 108699912 provides a mixed-flow turbine wheel of a turbocharger, comprising a plurality of blades that are distributed along the circumference of the turbine wheel; at least one blade includes a leading edge that has an at least partly curved axial-radial orientation with a varying blade angle relative to an axis of rotation of the turbine wheel; when viewed along the leading edge, the blade angle has a minimum in a central region between a hub end and a casing end of the blade.
US patent document 6877955 discloses a mixed flow turbine having a hub attached to a rotation axis and a plurality of rotor blades. Each of the plurality of rotor blades is attached to the hub in a radial direction, and the hub is rotated based on fluid supplied to a rotation region of the plurality of rotor blades. Each of the plurality of rotor blades has a curved shape that convexly swells on a supply side of the fluid.

Chinese patent document 102182546 relates to a mixed flow turbocharger with variable nozzle ring comprising of a compressor impeller, a compressor casing, a bearing body, an actuating mechanism, a bearing, a nozzle ring blade, a turbine casing, a turbine shaft and a turbine impeller, wherein the actuating mechanism comprises an actuator, a rocker arm component, a driving ring and spatial link mechanisms; the right angle shaped by the central line of the radial section outlet of the turbine casing and the axial direction can be changed into an obtuse angle. The top surface and the bottom surface of the nozzle ring blade are designed to concentric circular arcs, and the opening of the mixed flow turbine nozzle ring blade is adjusted to rotate by utilizing the spatial link mechanisms, thus realizing the best matching of the mixed flow turbocharger with the variable nozzle ring and each changing working condition of the internal combustion engine.
Chinese patent document 108223442 relating to a split forming mixed flow turbine comprises an outer flow guide cover and an inner flow guide cover, and a plurality of first blades arranged around the central axis of any one of the inner wall of the outer flow guide cover and the outer wall of the inner flow guide cover; a flow guide air channel is formed among the first blades, the outer wall of the inner flow guide cover and the inner wall of the outer flow guide cover; and a plurality of second blades are arranged on the outer wall of the outer flow guide cover and around the central axis. The split forming mixed flow turbine has the advantages of being capable of preventing leakage and effectively improving the air supply performance.
US patent application 14/374,393 provides a turbocharger having a variable turbine geometry comprising of a turbine wheel with a turbine axis of rotation that extends in an axial direction and a plurality of guide vanes selectively movable between a range of angular positions. Each one of the guide vanes is supported for pivotal movement about a guide vane axis of rotation and each guide vane axis of rotation is non-parallel to the turbine axis of rotation
US patent document 7670107 provides a variable-vane assembly for a variable nozzle turbine comprising of a nozzle ring supporting a plurality of vanes affixed to vane arms that are engaged in recesses in the inner edge of a unison ring. The unison ring is rotatable about the axis of the nozzle ring so as to pivot the vane arms, thereby pivoting the vanes in unison. A plurality of radial-axial guide pins for the unison ring are inserted into the apertures in the nozzle ring and are rigidly affixed therein such that the radial-axial guide pins are non-rotatably secured to the nozzle ring with a guide portion of each radial-axial guide pin projecting axially from the face of the nozzle ring. Each guide portion defines a groove for receiving the inner edge of the unison ring such that the unison ring is restrained by the radial-axial guide pins against excessive movement in both radial and axial directions.
All of the above cited prior-art documents relate to a mixed flow turbine assembly mainly focusing on the turbine wheel blade orientation and distribution. Few documents which are dealing with the actuation mechanism involve multiple linkages for nozzle vane actuation. Therefore there exists a need in the art for providing a mixed flow variable geometry turbine with improved method for nozzle vane actuation. The present invention provides a mixed flow variable geometry turbine with the nozzle vane spindle axis is in an inclined direction to the rotor axis. The present invention provides an inner and an outer vane bearing ring with spherical profile, which are positioned in an inclined plane in accordance with the nozzle vane position, while maintaining the nozzle actuation ring in a radial plane with respect to the rotor axis. Further the present invention provides a plurality of nozzle vanes with spherical profile arranged circumferentially in order to maintain a uniform gap between the nozzle vanes and the vane bearing rings on both sides. Thus the present invention provides a mixed flow VTG cartridge assembly with vane lever having a combination of radial and inclined frames for connecting the nozzle vane spindle which is positioned in an inclined plane and the actuating ring which is positioned in a radial plane. Further the present invention also provides an improved and reliable nozzle vanes actuating mechanism for actuating the mixed flow variable turbine geometry with nozzle vanes positioned in an inclined direction to the rotor axis.

OBJECT OF THE INVENTION
The primary objective of the present invention is to provide a mixed flow variable turbine geometry cartridge assembly with a plurality of nozzle guide vanes having its spindle axis pivoted in an inclined axis with respect to the turbine rotor axis.
Another objective of the present invention is to provide a mixed flow variable turbine geometry cartridge assembly with inner and outer vane bearing ring having a spherical profile positioned in an inclined plane in accordance with the nozzle vane position.
Another objective of the present invention is to provide a mixed flow variable turbine geometry cartridge assembly with a nozzle actuation ring positioned in a radial plane with respect to the turbine rotor axis.
Still another objective of the present invention is to provide a mixed flow variable turbine geometry cartridge assembly with a plurality of nozzle vanes with spherical profile arranged circumferentially in order to maintain a uniform gap between the nozzle vanes and the vane bearing rings on both inner and outer sides.
Yet another objective of the present invention is to provide a mixed flow VTG cartridge assembly with vane lever geometry having a combination of inclined and radial frames for connecting the nozzle vane spindle, which is positioned in an inclined plane and the actuating ring, which is positioned in a radial plane.
Further objective of the present invention is to provide a mixed flow VTG cartridge assembly with an inner vane bearing ring having an extended wall surface in a radial plane towards the centre of the rotor axis providing extended flow guidance towards the turbine wheel inlet.
Final objective of the present invention is to provide a mixed flow VTG cartridge assembly with an inner vane bearing ring having an extended wall surface in a radial plane towards the centre of the rotor axis acting as a heat barrier preventing the heat transfer from turbine side hot zone to bearing side cold zone.
SUMMARY OF THE INVENTION
The present invention provides a mixed flow turbocharger with variable geometry turbine (151), comprising of: atleast a turbine wheel (15), positioned at one end of the shaft (16); atleast a compressor wheel (17), positioned at other end of the shaft (16); a turbine housing (19) accommodating the said turbine wheel (15); a compressor housing (18), accommodating the said compressor wheel (17); a bearing housing (13), supporting the said rotor assembly by means of hydrodynamic bearing assembly, wherein said turbine wheel (15) and shaft (16) of rotor assembly provides a axial rotation rotor axis (A0 - A0 ); a variable turbine cartridge assembly (2), consisting of : a plurality of nozzle vane spindles (34), positioned in an inclined position with respect to the rotor axis A0 - A0, wherein said each of the nozzle vane spindle is provided with a first end (152) and second end (153); a plurality of nozzle vanes (21), positioned circumferentially on a spherical plane, wherein said each of the nozzle vane (21) is positioned at first end (152) of the nozzle vane spindle (34); an outer vane bearing ring (31), provided at the rear end of the said plurality of nozzle vane (21); an inner vane bearing ring (28) provided at front end of the said plurality of nozzle vane (21); a plurality of screw pins (38) positioned in between the inner and outer vane bearing rings (28 and 31); atleast a actuating ring device (39) positioned at the rear end of the outer vane bearing ring in a radial plane with respect to the rotor axis A0 - A0, wherein said actuating ring device (39) is provided with a plurality of radial slots (41) corresponding to the number of nozzle vanes (21); a plurality of vane lever (36), having a first end (157) and a second end (158); atleast a flow stopper (44) positioned on the said actuating ring device; an inner actuation lever (45), positioned on the actuating ring device (39); an external actuating spindle (46) positioned on the internal actuating lever (45); an external actuating lever (47), positioned at other end of the external actuating spindle (46), Wherein said external actuating lever (47) is actuated by an external actuator by means of a control rod (48).
In an embodiment of the present invention, Wherein said turbine housing (19) is provided with a turbine housing volute (25) with a turbine housing volute exit passage(20), wherein said volute exit passage(20), nozzle vanes (21) and the turbine wheel (15) are positioned accordingly so as to make the fluid flow enter the nozzle vanes (21) at the nozzle vane entry (22) and exit the nozzle vanes (21) at the nozzle vane exit (23) in a spherical axis A1-A1, wherein the said fluid flow entering the turbine wheel (15) is in an inclined direction (24) to the said rotor axis A0-A0.
In another embodiment of the present invention, wherein said vane lever (36) connects the nozzle vanes spindle (34) at its first end (157) and actuating ring device (39) at its second end (158). Wherein said second end (158) of the vane lever (36) is provided with a radial frame (49) having a spherical profile (53) on the side surface and a flat profile (54 and 55) on the upper and the lower sides of the vane lever. This enables a positive contact of the second end (158) of vane lever (49) with the actuating ring device (39) in the corresponding radial slot (41). Wherein said radial frame (49) and the first end (157) of the vane lever (36) is connected via an angular frame (51), wherein said angular frame (51) of the vane lever (36) is aligned in a perpendicular direction with respect to the nozzle vane spindle axis A2-A2.
In another embodiment of the present invention, wherein said first end (157) is provided with a coupling slot (56) which is “D” shape and said second end (153) of the nozzle vane spindle (34) is provided with a mating counterpart with analogous “D” shape (57) for mating with the said coupling slot (56). Wherein positioning of the “D” shape coupling slot (56) and the counter profile “D” shape mating counterpart (57) is based on the nozzle vane (21) orientation with respect to nozzle vanes spindle (34) axis A2-A2 in the nozzle vanes cartridge assembly (2).
In another embodiment of the present invention, wherein said inner (28) and outer (31) vane bearing ring are provided with an extended wall surface (58 and 59) extending towards the rotor axis centre A0 –A0, providing extended flow guidance from the nozzle vanes exit (23) to the turbine wheel inlet (24). wherein said extended wall surface (61) of the inner vane bearing ring (28) positioned in a radial plane acts as a heat shield between turbine (11) hot zone and bearing system (13) having a relatively lower temperature.
In another embodiment of the present invention, the method of operation of the mixed flow turbocharger (151) with variable geometry turbine according to the present invention, comprises steps of : Stimulating external actuator movement based on the engine operating condition (input), wherein said stimulation of external actuator imparts movement to the control rod (48); Actuating the external actuating lever (47) by means of transferring the movement from the control rod (48); Transmitting the motion from the external actuating lever (47) to the internal actuating lever (45); Transferal of motion from the internal actuating lever (45) to the actuating ring device (39); Actuation of the plurality of the nozzle vanes (21) by transmission of motion from the actuating ring device (39) via the plurality of vane lever (36) and the corresponding nozzle vane spindle (34); Rotation of the nozzle vane spindle (34) with respect to its axis A2-A2, wherein said rotation of nozzle vane spindle (34) actuates the rotation of the corresponding nozzle vane (21); and Varying the nozzle flow area in accordance with rotation of the said plurality of nozzle vanes (21), wherein closing of the plurality of nozzle vanes (21) provides a minimum (156) flow area with increased flow rate at the nozzle vane entry (22), wherein opening of the plurality of nozzle vanes (21) provides a maximum (155) flow area with reduced level of flow acceleration at the nozzle vane exit.
BRIEF DESCRIPTION OF THE DIAGRAM
Figure 1 depicts the partial sectional view of turbocharger with compressor housing (18), bearing housing (13) and the turbine housing (11).
Figure 2 illustrates the exploded view of the mixed flow turbocharger with variable geometry turbine according to the present invention.
Figure 3 illustrates the variable turbine cartridge assembly with plurality of nozzle vane spindle (34) with rotating axis A2 –A2, positioned in an inclined direction to the turbine rotor axis A0 –A0 according to the present invention.
Figure 4 illustrates the variable turbine cartridge assembly with plurality of nozzle vanes (21) positioned in a spherical profile sandwiched between the spherically profiled inner vane bearing ring (28) and spherically profiled outer vane bearing ring (31).
Figure 5 represents the nozzle vane (21), nozzle vane spindle (34) and vane lever assembly (36) according to the present invention.
Figure 6 shows the variable turbine cartridge assembly (2) according to the present invention.
Figure 7 shows the opening and closing position of the plurality of nozzle vanes (21) resulting in a maximum (155) and minimum (156) opening of nozzle vanes with varied flow area and varies fluid flow rate at the nozzle vane entry (22) and exit (23) positions.
While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention as embodied by “Mixed flow turbocharger with variable geometry turbine”, succinctly fulfils the above-mentioned need(s) in the art. The present invention has objective(s) arising as a result of the above-mentioned need(s), said objective(s) being enumerated below. In as much as the objective(s) of the present invention are enumerated, it will be obvious to a person skilled in the art that, the enumerated objective(s) are not exhaustive of the present invention in its entirety, and are enclosed solely for the purpose of illustration. Further, the present invention encloses within its scope and purview, any structural alternative(s) and/or any functional equivalent(s) even though, such structural alternative(s) and/or any functional equivalent(s) are not mentioned explicitly herein or elsewhere, in the present disclosure. The present invention therefore encompasses also, any improvisation(s)/modification(s) applied to the structural alternative(s)/functional alternative(s) within its scope and purview. The present invention may be embodied in other specific form(s) without departing from the spirit or essential attributes thereof.
Throughout this specification, the use of the word "comprise" and variations such as "comprises" and "comprising" may imply the inclusion of an element or elements not specifically recited.
The present invention provides a mixed flow turbocharger with variable geometry turbine (151), comprising of: atleast a turbine wheel (15), positioned at one end of the shaft (16), wherein said turbine wheel (15) is positioned downstream the engine exhaust; atleast a compressor wheel (17), positioned at other end of the shaft (16), wherein said compressor wheel (17) is positioned upstream the engine inlet, wherein said compressor wheel (17) along with the turbine wheel (15) and the shaft (16) provides a rotating rotor assembly (14); a turbine housing (19) accommodating the said turbine wheel (15); a compressor housing (18), accommodating the said compressor wheel (17); a bearing housing (13), supporting the said rotor assembly by means of hydrodynamic bearing assembly, wherein said turbine wheel (15) and shaft (16) of rotor assembly provides a axial rotation rotor axis (A0 - A0 ); a variable turbine cartridge assembly (2), consisting of : a plurality of nozzle vane spindles (34), positioned in an inclined position with respect to the rotor axis A0 - A0, wherein said nozzle vane spindle axis (A2 – A2) is in an inclined direction with respect to the turbine rotor axis (A0 - A0), wherein said each of the nozzle vane spindle is provided with a first end (152) and second end (153); a plurality of nozzle vanes (21), positioned circumferentially on a spherical plane, wherein said each of the nozzle vane (21) is positioned at first end (152) of the nozzle vane spindle (34), wherein said rotational movement of nozzle vane (21) corresponds to the movement of the nozzle vane spindle (34); an outer vane bearing ring (31), provided at the rear end of the said plurality of nozzle vane (21), wherein said outer vane bearing ring (31) is provided with a spherical surface (33) corresponding to the external surface of the nozzle vanes; an inner vane bearing ring (28) provided at front end of the said plurality of nozzle vane (21), wherein said inner vane bearing ring (28) is provided with a spherical surface (30) corresponding to the interior surface of the nozzle vanes; wherein said inner vane bearing ring (28) is provided with an extended wall surface (58) extending towards the rotor axis centre A0 - A0, wherein said outer vane bearing ring (31) is provided with an extended wall surface (59) extending towards the rotor axis centre A0 - A0; a plurality of screw pins (38) positioned in between the inner and outer vane bearing rings (28 and 31) for maintaining the distance between the said vane bearing rings enabling free nozzle vane (21) movement; atleast a actuating ring device (39) positioned at the rear end of the inner vane bearing ring (28) in a radial plane with respect to the rotor axis A0 - A0, wherein said actuating ring device (39) is provided with a plurality of radial slots (41) corresponding to the number of nozzle vanes (21), wherein said axis of the actuating ring device (A4 – A4) coincides with the said rotor axis (A0 - A0); a plurality of vane lever (36), having a first end (157) and a second end (158), wherein first end (157) of the vane lever (36) is operatively coupled to the said second end (153) of the nozzle vane spindle (34), wherein the second end (158) of the vane lever (36) is operatively affixed to the corresponding radial slot (41) in the adjusting ring device (39); atleast a flow stopper (44) positioned on the said actuating ring device, wherein said flow stopper (44) limits the rotating angle of the actuating ring device (39) with respect to the turbine rotor axis (A0 - A0); an inner actuation lever (45), positioned on the actuating ring device (39); an external actuating spindle (46) positioned on the internal actuating lever (45), wherein said axis of the external actuating spindle (46) A5-A5, is parallel to the said rotor axis, A0-A0; an external actuating lever (47), positioned at other end of the external actuating spindle (46), wherein said external actuating lever (47) is actuated by an external actuator by means of a control rod (48).
In the preferred embodiment of the present invention, wherein said turbine housing (19) is provided with a turbine housing volute (25) with a turbine housing volute exit passage(20).
In the mixed flow turbine of the present invention, wherein the said turbine housing volute exit passage (20), nozzle vanes (21) and the turbine wheel (15) are positioned accordingly so as to make the fluid flow enter the nozzle vanes (21) at the nozzle vane entry (22) and exit the nozzle vanes (21) at the nozzle vane exit (23) in a spherical axis A1-A1.
In the mixed flow turbine of the present invention, wherein the said fluid flow enters the turbine wheel (15) in an inclined direction (24) to the said rotor axis A0-A0. This is not in accordance with the radial flow turbine in which, the flow from the turbine housing volute exit, nozzle vanes entry and exit; and entry to the turbine wheel is positioned in a radial direction to the rotor axis A0-A0.
In the preferred embodiment of the present invention, wherein cross sectional area of the said turbine housing volute (25) is calculated based on the maximum mass flow handling capacity of the turbocharger for specific purpose. Wherein shape of the turbine housing volute (25) is selected from circular, semi-circular, snail shell shape and/or combinations thereof, considering the space available for accommodating the turbine housing (19).
In conventional radial flow turbine, the exit flow passage which allows the flow from turbine housing volute to the turbine wheel is provided with a parallel wall for the flow passage, making the flow leaving the turbine housing in a radial direction, perpendicular to the rotor axis A0-A0.
In the mixed flow turbine of the present investigation, the exit flow passage (20), which allows the flow from turbine housing volute (25) to the nozzle vanes entry (22) is provided with an inclined wall, positioned in an inclined direction to the rotor axis A0-A0. Thus, the flow leaving the volute (25) is in an inclined direction to the rotor axis A0-A0. Wherein the said fluid flow entering the nozzle vane entry (22) and leaving the nozzle vane exit (23) is in an inclined direction to the rotor axis A0-A0.
In the preferred embodiment of the present invention, wherein said inner vane bearing ring (28) is provided with a plurality of pivot holes (35) corresponding to the number of plurality of nozzle vanes (21). Wherein said plurality of pivot holes is spaced at angular distance normal to the spherical surface at pitch circle spherical diameter named PCSD1. Wherein said centre axis of the pivot hole A3-A3 coincides with the nozzle vane spindle axis (A2 – A2) and is in inclined direction to the turbine rotor axis A0-A0.
In the preferred embodiment of the present invention, wherein said plurality of nozzle vanes (21) positioned circumferentially on a spherical plane is provided with an inner spherical surface (26) having a spherical axis (SR1) and an outer spherical surface (27) having a spherical axis (SR2). Wherein said inner vane bearing ring (28) is provided with a spherical surface (30) having a spherical axis (SR3) and the outer vane bearing ring (31) is provided with a spherical surface (33) having a spherical axis (SR4). Wherein said plurality of nozzle vanes (21) is provided with a spherical radius (SR5) along the central spherical axis of the plurality of nozzle vanes A1- A1. Wherein said spherical axis SR1 of the nozzle vane inner spherical surface (26), spherical axis SR2 of nozzle vane outer spherical surface (27), spherical axis SR3 of inner vane bearing ring spherical surface (30), spherical axis SR4 of outer vane bearing ring spherical surface (33) and the spherical radius (SR5) of the plurality of nozzle vanes (21) coincides on the rotor axis, at single point “O”. This maintains a uniform gap between the nozzle vane inner spherical surface (26) and inner vane bearing ring spherical surface (30); and between the nozzle vane outer spherical surface (27) and outer vane bearing ring spherical surface (33), during the nozzle vane (21) movement with respect to nozzle vanes spindle (34) axis A2-A2. Wherein said uniform gap enables free movement of the nozzle vanes. Wherein said uniform gap also accommodates for the thermal expansion of the said plurality of nozzle vanes (21) and the said inner and outer vanes bearing rings (28 and 31).
In the preferred embodiment of the present invention, wherein said plurality of screw pins (38) are employed to maintain the distance between the inner vane bearing ring (28) and the outer vane bearing ring (31). Wherein said distance is the flow path width (37) which equals the sum of nozzle vane (21) width and the uniform gap between nozzle vane inner spherical surface (26) and inner vane bearing ring spherical surface (30); and the uniform gap between the nozzle vane outer spherical surface (27) and outer vane bearing ring spherical surface (33).
In the preferred embodiment of the present invention, wherein said variable turbine cartridge assembly (2) accommodating the said plurality of nozzle vanes (21) is positioned in the turbine housing (19) so as to maintain the flow path width (37) of the nozzle vanes equivalent to the flow path (40) at the turbine volute exit path (20). Wherein the fluid flow exiting the said plurality of nozzle vanes (21) proceeds towards the turbine wheel (15) in an inclined direction (23) at the turbine entry point (24).
In the preferred embodiment of the present invention, wherein said actuating ring device (39) is additionally provided with a first slot (42) and a second slot (43). Wherein said first slot (42) is used to locate the minimum flow stopper (44) for limiting the rotating angle of the said actuating ring (39) in both clockwise and anticlockwise direction, with respect to the rotor axis A0-A0. Wherein the extreme rotating positions of the actuating ring device (39) corresponds to the nozzle vanes (21) maximum (155) and minimum (156) opening positions. Wherein said second slot (43) is engaged with the said inner actuating lever (45).
In the preferred embodiment of the present invention, wherein said rotating axis A4-A4 of the actuating ring device (39) is co-axially aligned with the turbine rotor axis A0-A0.
In the preferred embodiment of the present invention, wherein nozzle vane (21) is positioned at first end (152) of the nozzle vane spindle (34) and the second end (153) of the spindle (34) is operatively coupled to the first end (157) of the vane lever (36), wherein the second end (158) of the vane lever (36) is operatively affixed to the corresponding radial slot (41) of the adjusting ring device (39). Based on the incoming mass flow rate to the turbine and engine operating condition, the external actuator actuates the control rod (48); the control rod (48) transfers the actuator motion to the inner actuating lever (45) via the said external actuating lever (47) and the actuating spindle (46), wherein said external actuating spindle (46) rotates partially with respect to its axis A5-A5. Through the movement of the inner actuating lever (45), the adjusting ring (39) movement is achieved which in turn actuates the plurality of vanes levers (36) assembled on the radial slots (41). The said movement at the second end (158) of the vane levers (36) on the radial slots (41) provides a rotational movement to the vane spindle (34) coupled to the first end (157) of the vane levers (36) thereby stimulating the rotational movement of the nozzle vanes (21). The maximum (155) and minimum (156) opening of the nozzle vanes (21) is determined based on the direction of rotation of adjusting ring device (39) with respect to its axis A4-A4 and the nozzle vanes spindle (34) rotation with respect to the spindle axis, A2-A2.
In the preferred embodiment of the present invention, wherein said adjusting ring device (39) rotates partially with respect to its axis A4-A4.
In the preferred embodiment of the present invention, wherein said external actuating spindle (46) rotates partially with respect to its axis A5-A5.
In the preferred embodiment of the present invention, wherein said nozzle vane spindle (34) rotates partially with respect to its axis A2-A2.
In an embodiment of the present invention, wherein said vane lever (36) connects the nozzle vanes spindle (34) at its first end (157) and actuating ring device (39) at its second end (158). Wherein said second end (158) of the vane lever (36) is provided with a radial frame (49), wherein said first end (157) of the vane lever (36) is provided with a coupling slot (56) enabling smooth fitting with the said second end (153) of the nozzle vane spindle (34). Wherein said radial frame (49) and the first end (157) of the vane lever (36) is connected via an angular frame (51), wherein said angular frame (51) of the vane lever (36) is aligned in a perpendicular direction with respect to the nozzle vane spindle axis A2-A2. Wherein said radial frame (49) is provided with a spherical profile (53) on the side surface towards actuating ring device side (50) and a flat profile (54 and 55) on the upper and the lower sides of the vane lever. This enables a positive contact of the second end (158) of vane lever (49) with the actuating ring device (39) in the corresponding radial slot (41). During the vane lever (36) movement of the nozzle vanes (21) maximum opening (155) position to minimum opening (156) position, the spherical profile (53) provides a positive contact with the corresponding radial slots (41) of the actuating ring device (39).
In the preferred embodiment of the present invention, wherein said first end (157) of the vane lever (36) which is operatively coupled to the said second end (153) of the nozzle vane spindle (34), is provided with a coupling slot (56). Wherein shape of the said coupling slot (56) is “D” shaped. Wherein said second end (153) of the nozzle vane spindle (34) is provided with a mating counterpart with analogous “D” shape (57) for mating with the said coupling slot (56) positioned at the first end (157) of the vane lever (36).
In the preferred embodiment of the present invention, wherein positioning of the “D” shape coupling slot (56) on the vane lever (36), and the counter profile “D” shape mating counterpart (57) on the vane spindle shaft (34) is selected based on the nozzle vane (21) orientation with respect to nozzle vanes spindle (34) axis A2-A2 in the nozzle vanes cartridge assembly (2). Wherein said “D” shape coupling slot (56) in the vane lever (36) and counter profile “D” shape mating counterpart (57) on the vane lever spindle (34) enables easy assembly of the vane lever (36) with the corresponding nozzle vane spindle (34) in a defined nozzle vane orientation with respect to each other. This reduces the complex fixture - arrangement required for assembling the nozzle vane spindle (34) and vane lever (36) with required nozzle vanes opening position (orientation). Poka-yoke for the nozzle vanes (21) position and the vane lever (36) orientation is ensured along with the actuating ring device (39).
In an embodiment of the present invention, wherein said extended wall surface (58 and 59) of the inner (28) and outer (31) vane bearing ring extending towards the rotor axis centre A0 –A0, provides extended flow guidance from the nozzle vanes exit (23) to the turbine wheel inlet (24). Wherein said extended wall surface (58 and 59) are positioned in a spherical plane. This is advantageous for the mixed flow turbine wheel (15), as shown in Fig. 2 resembling the shape of the turbine wheel with scalloped nature (60) at turbine wheel inlet (24).
In the preferred embodiment of the present invention, additionally the inner vane bearing ring (28) is provided with an extended wall surface (61) towards turbine rotor axis A0-A0, positioned in a radial plane.
In the preferred embodiment of the present invention, wherein said extended wall surface (61) of the inner vane bearing ring (28) acts as a heat shield between turbine (11) hot zone and bearing system (13) having a relatively lower temperature.
In an embodiment of the present invention, provides the method of operation of the mixed flow turbocharger (151) with variable geometry turbine, comprising steps of:
a) Stimulating external actuator movement based on the engine operating condition (input), wherein said stimulation of external actuator imparts movement to the control rod (48);
b) Actuating the external actuating lever (47) by means of transferring the movement from the control rod (48) to the external actuating lever (47);
c) Transmitting the motion from the external actuating lever (47) to the internal actuating lever (45) via the external actuating linkage spindle (46);
d) Transferal of motion from the internal actuating lever (45) to the actuating ring device (39) of the nozzle vanes cartridge assembly (2);
e) Actuation of the plurality of the nozzle vanes (21), wherein said actuation of the plurality of the nozzle vanes (21) is performed by transmission of motion from the actuating ring device (39) to the said plurality of nozzle vanes (21) via the plurality of vane lever (36) and the corresponding nozzle vane spindle (34);
f) Rotation of the nozzle vane spindle (34) with respect to its axis A2-A2, wherein said rotation of nozzle vane spindle (34) actuates the rotation of the corresponding nozzle vane (21); and
g) Varying the nozzle flow area in accordance with rotation of the said plurality of nozzle vanes (21), wherein closing of the plurality of nozzle vanes (21) provides a minimum (156) flow area with increased flow velocity at the nozzle vane entry (22), wherein opening of the plurality of nozzle vanes (21) provides a maximum (155) flow area with reduced level of flow acceleration at the nozzle vane exit.
In the preferred embodiment of the present invention, wherein said adjusting ring device (39) rotates partially with respect to its axis A4-A4.
In the preferred embodiment of the present invention, wherein said external actuating spindle (46) rotates partially with respect to its axis A5-A5.
In the preferred embodiment of the present invention, wherein said nozzle vane spindle (34) rotates partially with respect to its axis A2-A2.
In the preferred embodiment of the present invention, wherein said rotation of plurality of nozzle vanes (21) opening to maximum (155) position or closing to minimum (156) position is determined based on the direction of motion initiated from the said external actuator.
In the preferred embodiment of the present invention, wherein said rotation of the nozzle vanes (21) to closing position results in a minimum (156) flow area (the space between nozzle vanes) and accelerates the flow, which enters the nozzle vanes entry (22), thus the input energy (heat and potential energy) is converted into kinetic energy in the nozzle vanes (21) and the flow leaves the nozzle vanes at exit (23). The flow further enters to the turbine wheel (15) at the entry point (24). This condition is required for the engine to accelerate from idling or lower speed and load condition to the higher speed and load condition, the engine transient conditions.
In an embodiment, when running the engine at higher speed and load condition, the gas flow rate from engine is higher with higher temperature and pressure; and hence higher energy is available to the turbine (11). Wherein said nozzle vanes (21) are opened to have a larger flow area (155) with reduced level of flow acceleration, thereby regulating the kinetic energy at nozzle vane exit (23) before entering the turbine wheel (15) at the entry point (24).
In the preferred embodiment of the present invention, wherein nozzle vanes (21) flow area is varied from maximum (155) to minimum (156) in accordance with the flow rate coming out of the engine exhaust based on the operating conditions. The maximum (155) and minimum (156) flow area of the plurality of nozzle vanes (21) is selected based on the required maximum and minimum flow handling capacity. So, for the given engine application, the optimum size of the nozzle vanes (21) set up is required to handle the operating flow range.
EXAMPLE 1
During engine transient condition or when there exists a requirement for the engine to accelerate from idling or lower speed load condition to the higher speed and load conditions, accelerated flow is required. In such conditions, the external actuator of the mixed flow turbocharger is stimulated based on the engine operating condition (input), and provides the movement to the control rod (48).The control rod (48) actuates external actuating lever (47) by means of transferring its movement to the external actuating lever (47). The external actuating lever (47) in turn transmits the motion to the internal actuating lever (45) through external actuating linkage spindle (46). The internal actuating lever (45) transfers the motion to actuating ring device (39) of the nozzle vanes cartridge assembly (2). The motion from the actuating ring device (39) is transmitted to the plurality of nozzle vanes (21) through the said plurality of vane levers (36) and the corresponding nozzle vane spindle (34). The nozzle vane spindle (34) rotates partially with respect to its axis A2-A2, wherein said rotation of nozzle vane spindle (34) actuates the rotation of the corresponding nozzle vane (21) to a closing position. With rotation of the plurality of nozzle vanes (21), the nozzle flow area is varied. Closing of the nozzle vanes (21) forms the flow area (the space between nozzle vanes) to minimum (156) level and accelerates the flow, which enters the nozzle vanes entry (22), thus the input energy (heat and potential energy) is converted into kinetic energy in the nozzle vanes (21) and the flow leaves the nozzle vanes exit (23) with accelerated flow velocity, wherein said accelerated flow enters the turbine wheel (15) at the entry point (24) in an inclined position with respect to the rotor axis A0-A0 .
EXAMPLE 2
During the engine operation at higher speed and load condition, the gas flow rate from the engine is higher with higher temperature and pressure; hence higher energy is available to the turbine (11) which requires a regulated flow condition. In such conditions, the external actuator of the mixed flow turbocharger is stimulated based on the engine operating condition (input), and provides the movement to the control rod (48).The control rod (48) actuates external actuating lever (47) by means of transferring its movement to the external actuating lever (47). The external actuating lever (47) in turn transmits the motion to the internal actuating lever (45) through external actuating linkage spindle (46). The internal actuating lever (45) transfers the motion to actuating ring device (39) of the nozzle vanes cartridge assembly (2). The motion from the actuating ring device (39) is transmitted to the plurality of nozzle vanes (21) through the said plurality of vane levers (36) and the corresponding nozzle vane spindle (34). The nozzle vane spindle (34) rotates partially with respect to its axis A2-A2, wherein said rotation of nozzle vane spindle (34) actuates the rotation of the corresponding nozzle vane (21) to an opening position. With rotation of the plurality of nozzle vanes (21), the nozzle flow area is varied. Opening of the nozzle vanes (21) forms the larger flow area (155) and hence reduces the flow acceleration. Thus the kinetic energy of the flow exiting the nozzle vanes (21) at its exit point (23) is regulated before entering the turbine wheel (15) at the entry point (24) in an inclined position with respect to the rotor axis A0-A0.
It will be apparent to a person skilled in the art that the above description is for illustrative purposes only and should not be considered as limiting. Various modifications, additions, alterations, and improvements without deviating from the spirit and the scope of the invention may be made by a person skilled in the art.