VTG mechanism assembly using wave spring

Abstract

A turbocharger unit (10) incorporating variable turbine geometry. The unit (10) has a turbine housing (12) for receiving exhaust gases from an engine, a turbine wheel (14) located inside a turbine housing (12), and a bearing housing (24) connected to the turbine housing (12), having a recessed portion (28). A spring member is located in the recessed portion (28), and a heat shield (32) receives apply force from the spring member. There is also a cartridge for providing variable turbine geometry located in the turbine housing (12); the cartridge is held in contact with the turbine housing (12) by the spring member in the form of a contoured sleeve (26). The apply force received by the heat shield (32) from the spring member transfers through the cartridge, and holds the cartridge in place in the turbine housing.

Claims

1. A turbocharger unit comprising: a turbine housing having a turbine wheel; a compressor housing having a compressor wheel; a bearing housing between the turbine housing and the compressor housing and having a bearing for a shaft carrying the turbine wheel and the compressor wheel, the shaft having a shaft axis, the shaft provided with a piston ring seal; a VTG cartridge comprising a first disk (34), a second disk (40), and a series of variable angle vanes (38) between the first disk (34) and second disk (40) in the turbine housing providing variable turbine geometry, the VTG cartridge having a turbine housing facing side and a bearing housing facing side; a substantially planar heat shield, with an outer periphery contacting the bearing housing facing side of the VTG cartridge, and an axial force transmitting member, located in a circumferential recess in said bearing housing axially adjacent said substantially planar heat shield outer periphery, said axial force transmitting member pressing the substantially planar heat shield against the VTG cartridge, wherein the axial force transmitting member is a wave spring member between the heat shield and the bearing housing, the wave spring member having a first axial spring face contacting the bearing housing and a second axial spring face contacting said outer periphery of said heat shield, wherein the first and second spring faces have the same radius from the shaft axis as said outer periphery of said heat shield, and the first and second spring faces are spaced axially perpendicular to the outer periphery of the heat shield, wherein the first disk (34), the second disk (40), and the series of variable angle vanes (38) between the first disk (34) and the second disk (40) of the VTG cartridge are held in place after assembly into the turbine housing by transfer of applied force from the wave spring member through the substantially planar heat shield to the VTG cartridge.

2. The turbocharger unit of claim 1, wherein said VTG cartridge includes the series of variable angle vanes, wherein the angle of each variable angle vane relative to the turbine wheel can be changed to alter a flow of exhaust gas through said turbine wheel.

3. The turbocharger unit of claim 1, wherein said applied force received by said substantially planar heat shield from said wave spring member positions said substantially planar heat shield in said housing between said bearing housing and said turbine housing.

4. The turbocharger unit of claim 1, wherein said wave spring member maintains the position of said heat shield relative to said turbine wheel.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:

(2) FIG. 1 is a side view of a turbocharger unit, according to the present invention; and

(3) FIG. 2 is a plan view of a wave spring used in a turbocharger unit, according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(4) The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

(5) A turbocharger unit incorporating the present invention is generally shown at 10. There is a turbine housing 12, which surrounds a turbine wheel 14. The turbine wheel 14 is mounted on a shaft 16; the shaft 16 extends through, and is supported by, a set of bearings 18. The bearings 18 feature a set of oil passages 20, which are connected to a primary oil passage 22. The turbine housing 12 is connected to a bearing housing 24. The turbine housing 12 has a contoured sleeve 26 which circumferentially surrounds the turbine wheel 14.

(6) The bearing housing 24 includes a recessed portion 28 for supporting a spring member, which in this embodiment is a wave spring 30. The wave spring 30 rests between the recessed portion 28, and a heat shield 32. The heat shield 32 also rests against a first disk 34. The first disk 34 rests against a spacer 36 which provides axial separation between the disks so that a series of vanes 38 provided between the disks can be adjusted to vary the amount of exhaust gas flowing into the turbocharger unit 10. The spacer 36 also contacts a second disk 40, which is held in position to rest against the turbine housing 12 by the apply force provided by contoured sleeve 26.

(7) The bearing housing 24 also includes a water cooling jacket 42, which is used to circulate coolant, such as water, through the bearing housing 24.

(8) In operation, exhaust gas flows into the turbine housing 12 and through the vanes 38 of the cartridge 36. The flow of exhaust gas causes the turbine wheel 14 to rotate, which in turn causes the shaft 16 to rotate as well. The shaft 16 is connected to a compressor (not shown) which compresses air and forces the air into the intake manifold of an engine, increasing power. The shaft 16 is lubricated by oil that flows from the primary oil passage 22 into the oil passages 20 and onto the shaft 16. The wave spring 30 has a bearing housing facing side 31 which applies a force to the bearing housing 24 and a heat shield facing side 33 which applies a force to the heat shield 32, which transmits the force to the first disk 34 of the cartridge 36. The load applied to the first disk 34 is also applied to the spacers 36, and via the spacers to the second disk 40 of the cartridge 36. Essentially, the function of the wave spring 30 is to hold the cartridge 36 in place after assembly into the turbine housing 12 by transferring an applied load through the heat shield 32 to the cartridge 36. It should be noted that the spring member is not limited to being a wave spring 30; the spring member could also be any type of spring capable of holding the cartridge 36 in place.

(9) The exhaust gas flows through the turbine housing 12 at very high temperatures; the heat shield 32 functions to protect the wave spring 30 from being exposed directly to the exhaust gas, preventing distortion of the wave spring 30. The heat shield 32 also provides the advantage of allowing the bearings 18 to support the shaft 16 in a position closer to the turbine wheel 14, as well as allow the water cooling jacket 42 to be formed in the bearing housing 24 closer to the turbine wheel 14, allowing for more efficient cooling of the turbocharger unit 10.

(10) Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the present invention can be implemented in a variety of forms. Therefore, while this invention has been described in connection with particular examples thereof, the true scope of the invention should not be so limited, since other modifications will become apparent to the skilled practitioner upon a study of the drawings, specification and following claims.