US3010697A

US3010697A - Turbocharger

Info

Publication number: US3010697A
Application number: US742071A
Authority: US
Inventors: Luis R Lazo; Barish Benjamin
Original assignee: Thompson Ramo Wooldridge Inc
Current assignee: Northrop Grumman Space and Mission Systems Corp
Priority date: 1958-06-16
Filing date: 1958-06-16
Publication date: 1961-11-28
Anticipated expiration: 1978-11-28

Description

Nov. 28, 1961 R. I Azo ET Al.

TURBOCHARGER 5 Sheets-Sheet l Filed June 16, 1958 ha :LED T5 Luis .72. Lazo B enjamizz .BamS/L 4A/WH Z 7775 Nov. 28, 1961 L, R. LA zo ETAL 3,010,697

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TURBOCHARGER Filed June 16, 1958 3 Sheets-Snead; 3

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l Een 'amm .Baflh United States Patent O 3,010,697 TURBOCHARGER Luis R. Lazo, Mentor, and Benjamin Barish, Lyndhurst, Ohio, assignors to Thompson Ramo Wooldridge Inc., a corporation of Ohio Filed June 16, 1958, Ser. No. 742,071 4' Claims. (Cl. 253-55) The present invention relates to improvements in turbine driven superchargers known to the art as turbo chargers.

Turbo charger units of the type known to the art are driven by heated gas and deliver a supply of compressed air for supercharging an internal combustion engine. 'I'he present invention contemplates the provision of an improved turbo charger unit which is capable of withstanding extremely high inlet temperatures of the operating gas, such as in the neighborhood of over 1500 F. and will have a long operating life under most severe ternperature conditions and at highest operating speeds. In turbo chargers heretofore provided, the turbine housing was split to allow separate entries of exhaust gas from the engine used to drive the turbine so that separate entries were provided for each bank of engine cylinders. A double scroll design was commonly used requiring a long dividing rweb which was buried in the hot gas stream. This created intense temperature effects on the dividing web and resulted in cracks in the web material, and other undesirable heating and cooling effects. A feature of the present invention is the provision of an improved divided inlet for receiving exhaust gases from the engine for driving the turbine, which has a massive inlet base divided by a short shaped generally radially extending web shape to allow lengthwise expansion, with the gas distributed to the turbine through separate scrolls which are divided at their ends with a twisted wall so that undesirable and damaging effects from heat and other undesirable effects are avoided, and an improved flow arrangement for operating gases is provided.

A further feature of the present invention is the provision of stator nozzle vanes which are formed in a separate unit mounted in non-rigid relationship to the housing, and carried by a support ring to be spring biased into position to distribute gas to the turbine rotor whereby free and independent expansion can occur between the housing and vanes and whereby the assembly can be more economically and quickly manufactured and assembled.

The manufacture of turbo chargers of the type having vaneless diffusion of the compressor made it necessary to cast the housing with an ejection fence extending within the involute discharge chamber that prevented back wash of air within the chamber. A feature of the present invention is the provision of an assembly which enables forming the housing in a simplified structure without the complicated molding required in forming the boundary layer flow back preventing fence, and wherein boundary layer flow back is prevented by a simple and inexpensive fabricated structure,

In accordance with the foregoing, an object of the invention is to provide an improved turbo charger for supercharging internal combustion engines which has improved performance characteristics, maintains high eiciencies at high pressure ratios, has improved compression performance, and is capable of long operating life at high temperature conditions.

A more specific object of the invention is to provide an improved gas operated turbine for use in a turbo charger or the like provided with improved means for receiving dual flows of operating gas.

Another object of the invention is to provide an improved gas driven turbine for a turbo charger assembly ice or the like with improved stator vane construction for directing the flow of gases to the rotor.

Another object of the invention is to provide an improved compressor construction for a turbo charger wherein an improved structure is provided for preventing back wash in the compressed air receiving scroll.

Other objects and advantages will become more apparent with the teachings of the principles of the present invention in the description and illustrations in the specification, claims and drawings, in which:

FIGURE 1 is a side elevational View of a turbo charger embodying the principles of the present invention;

yFIGURE 2 is a vertical Sectional view taken along line II-II of FIGURE 1, and illustrating the details of the interior of the turbo charger;

FIGURE 3 is vertical sectional view taken along line II-II of FIGURE 1, illustrating the construction of the gas distributing scroll of the turbine;

lFIGURE 4 is a sectional view taken along line III-III of FIGURE 1, illustrating details of the stator or nozzle vane assembly;

FIGURE 5 is a detailed elevational view of the spring for holding'the stator vanes in place; and,

FIGURE 6 is a detailed elevational view of the fence for preventing back wash in the compressor discharge chamber.

As shown on the drawings:

FIGURE 1 illustrates a turbo charger 10 embodying the features of the invention. The turbo charger is enclosed in a housing 12. At the compressor end, the housing 12 has a housing part 12a secured to a part 12b which in turn is secured to another part 12a` at the turbine end. Parts 12a and 12b are formed with annular meeting faces and a gasket 14 is located between the faces to seal the parts. Bosses, such as 16 and 18, may project from the housing parts to receive bolts 19 for, securing the parts 12a and 12b together.

The housing parts 12b and 12e are provided with flanges 12d and 12e which are utilized for clamping the housing parts 12b and 12e together by an annular clamping band 20. The band is provided with inclined inner faces which mate with the inclined outer faces of the flanges 12d and 12e to securely clamp the parts together, and the band 20 may be loosened for relatively rotationally shifting the parts 12e and 12b to change the relative positions of the compressor end and turbine end of the turbo charger. This variation in rotational position between the ends can be illustrated by reference to FIG- URES 1 and 2. In FIGURE l, the housing part 12a is provided with a compressed air discharge outlet fitting 22, and the housing part 12C is provided with a large inlet boss 24 for hot gases. The conduits to which these fittings connect and their positions can be better accommodated with relative rotational shifting of the

parts

12a and 12e.

Extending axially through the housing is a shaft 26 supported in bearing means 28 with seals 30 and 32 along the shaft to prevent the escape of lubricant and to prevent the pressurized ,air and hot operating gases from entering the lubricant compartments. Lubricating oil is fed downwardly through a passage 3'3 in the housing part 12b and feeds to lubricating branches 34 and 36, which supply openings in the bearings. The lubricant flows from the bearings down to a lubricant drain compartment 38, and through a lubricant drain opening 40.

At one end of the housing 12 the parts 12a and 12b form a compressor rotor chamber 42 in which rotates a vaned compressor rotor 44. The compressor rotor has a hub 46 mounted on the shaft 26 and held thereon by a threaded nut 48. The compressor rotor is provided with impeller vanes 50' which force the air centrifugally outwardly to compress it in a known manner. Air is taken in through an air inlet opening 52 formed by an annular hub 54 on the housing part 12a. The housing pant 12b has a. radial Hat face 56 extending outwardly from the rotor and with an opposing inwardly facing surface 58 on the housing part 12a forms an air flow throat 60 extending radially outwardly for the flow of air from the vanes 50 of the compressor rotor 44. The air passes outwardly from the throat .60 into an involute scroll air chamber 62. As the compressor'rotor 44 forces the compressed -air outwardly through the throat 60, it enters the chamber 62 and is discharged out through the fitting 22. The air flowing outwardlyalong the llat wall 56 tends to circle in the chamber 62 and ow inwardly along the inner surface y64 to interfere with the flow all through the throat 60. This effect may be referred to as back wash or as boundary layer ow back.

A fence 466 in the form of an annular ring is secured to the Wall 58 beside the throat and projects radially outwardly into the chamber 62. The fence ring 66, shown in detail in FIGURE 6, is somewhat spiral in shape having a generally spiral inner edge and a generally spiral outer edge to follow the contourpof the involute chamber 62. The ring is interrupted by a gap to follow the shape of the chamber 62. The fence ring is provided with circumferentially spaced holes 67 through which are insented screws 68 threadedinto threaded holes 70 in the housing part 12a to, secure the fence ring 66 in place. The fence ring may also be fastened by welding or bond- Heretofore, the housing part 12a has been made by casting with a fence formed by curving the casting material outwardly. Thisl created numerous coring and molding problems. We have found that it is unnecessary to exercise the care in forming a smooth fence heretofore used, and'that it is unnecessary to form a cast-in shape with the smoothness provided. With the provision of a simply manufactured, inexpensive, casting for parts 12a and 12b and an inexpensive stamped ring, a coacting assembly is obtained preventing boundary layer flow back.

The shaft 26 is driven by a turbine rotor 72 mounted at the other end of the shaft. The turbine rotor has a hub 74 suitably secured on the shaft with shaped outwardly extending vanes 76. The turbine rotor vanes 76 face outwardly toward a slot or throat 78 through which the heated operating gases flow to drive the rotor. The gases are discharged through an exhaust passage 80, formed in an annular hub 82 which is part of the housing part 12C. The operating gases are supplied to the throat through a scroll or operating gas chamber 84 which extends annularly around the throat 78 which supplies the rotor chamber 86.

Within the throat 78 are stator or nozzle vanes 88 secured to a nozzle vane plate or ring 90. As illustrated in FIGURES 2 and 4, beside the throat 78 and extending axially therefrom is an annular recess 92 in which the vane ring is located. The annular recess also provides a location for a spring ring 94. The spring ring is backed against the wall 92a, and urges the vane ring and vanes E88 against the side 78a of the throat 78. The vane ring has an annular flange 90a with an inner surface 90b that centers the spring ring 94.

Thus, the housing par-t 12C can be inexpensively made, and the vane ring 90 and vanes 88 are substantially independent of the housing in contraction and expansion with temperature change. This greatly reduces the cost of manufacture and improves the safety and operational performance, avoiding expensive mountings for vanes and the cost of constructions of the type heretofore used.

The spring ring 94, as shown in FIGURES 2, 4 and 5, may take various forms, as will be appreciated by those skilled in the art, but is especially advantageous in being formed with a ring shaped annular back 94a from which facing tongues such as 94b and 94C are cut to resiliently project outwardly and engage the vane ring 90. This forms an inexpensive, easily assembledrspring arrangement, yand the vane assembly and 'spring assembly comprise only two parts.

A divided hot gas inlet is provided for improved operation and for the receipt of operating gas from dual banks of cylinders when the turbo charger is used in an engine having cylinders arranged in banks. The divided inlet is illustrated as preferably formed integrally within the housing part 12e, and is illustrated in detail in FIGURES 2 and 3. The inlet connector 24 has an outwardly extending flange 24a for connecting a gas supply conduit which is of a size to `supply the passage 96 and the passage 98, and'has dual passages.

Operating gas distribution is obtained by the annular extending chamber 84 which is divided into two parts. At the upper end, the chamber is divided by a generally radially extending Wall 100, which is twisted about a substantially radial axis R passing radially through the center of the wall, for directing the now of operating gases in their radially inward direction toward the nozzle vanes 88, and for preventing cracking with expansion and contraction. The wall 100 divides the chamber 84 into a rst part 84a and a second part 84b. The part 84a extends around the outside of the turbine rotor chamber 86 ina rst direction and the part '84b extends in the other direction. The inlet passage 96 Supplies the part 84a, and-the passage 9 8 supplies the part y84b. The'passages 96 and 9S are separated by a twisted wall 102 which is substantially diametrically opposite the Wall 100. Wall 102 is also twisted about a substantially radial axis R, which passes radially through the center of the wall and also resists cracking with heat expansion and contraction. The wall 102 extends substantially radially outwardly and with the Wall 100 forms the only common walls for the passages 84a and 84b. These common walls which are subjected to the heat in both passages, extend substantially radially and avoid the distorting and cracking effects and other undesirable elfects of heating found in structures heretofore used. f

In operation of the turbo charger 10, a heated operating gas is directed to the inlet fitting 24 and the gas divides to the

passages

96 and 98 to ow in opposite di-rections through the passages 84a and 841;. The gas flows inwardly through the openings defined by the nozzle vanes 88 to drive the turbine rotor 72. With temperature change, the vanes andtheir supporting ring expand and contract substantially independently of the 'housing part 12o, and are held in firm operating position by the spring ring 94. The compressor rotor 44 draws in air through the inlet 52 forcing it outwardly through the throat 60 and into the involute compressor chamber 62. Boundary layer flow back of air is prevented by the spiral fence ring 66, and the compressed air is discharged through the iitting 22.

Thus, it will be seen that we have provided an improved turbo charger structure which meets the objectives, advantages and features hereinbefore set forth. Improved operational performance is achieved in obtaining a lightweight impe-ller, and turbine with low inertia which also has instant response for changes in operating'conditions. The structure obtains a mechanism which has a long operating life at extreme temperatures. The construction makes possible the use of straight rotor vanes in the compressor with vaneless diffusion to maintain compression ratios over a large air flow range. This achieves a smaller, less complex unit which is lower in first cost, and. easier to maintain. The simpleI straight rotor vanes which are possible with the construction, simplify compressor design, maintaining high eiciencies at lower rotor speeds.

We have, in the drawings and specification, presented a detailed'disclosure of the preferredV embodiments of our invention, and it is to be understood that we do not intend to limit the invention to the specific form disclosed, but intend to cover all modifications, changes and alternative constructions and methods falling within the principles taught by our invention.

We claim as our invention:

1. A turbine driven by a pressurized heated fluid comprising a housing defining a turbine rotor chamber therein, a rotary turbine rotor mounted for rotation said chamber, an exhaust passage leading from said chamber, stator openings annularly arranged to direct heated operating fluid inwardly to said rotor chamber to drive the rotor, a iirst inlet passage leading circumferentially around in a irst direction and opening to distribute uid to a first group of stator openings, a second inlet passage leading circumferentially around in the opposite direction and opening to distribute uid to a second group of stator openings, and operating uid inlet means for connecting said inlet passages to iiuid supply lines having a generally radially extending twisted separating wall twisted about a substantially radial axis to divide said inlet means into said passages whereby expansion and contraction etects of heat will not severely aiect the passages and the heat will act on one surface of the passages except for said radial twisted separating wall which will resist cracking with temperature change.

2. A turbine driven by a pressurized heated fluid comprising a housing deiining a turbine rotor chamber therein, a rotary turbine rotor mounted for rotation within said chamber, an exhaust passage leading from said chamber, a single gas inlet chamber extending circumerentially around the housing adjacent the rotor, stator openings annularly arranged to direct heated operating tluid inwardly to said rotor chamber' to drive the rotor, said single passage opening inwardly to all of said stator openings, a tirst partition extending generally radially across said inlet chamber to divide it into rst and second chamber parts and twisted to resist the eiects of temperature change, a second partition positioned substantially circumferentially opposite the rst partition and extending generally radially and facing said iirst and second charnber parts and twisted to resist the eiects of temperature change, and means defining an inlet opening into said inlet chamber at said second partition whereby a ow of inlet uid will divide to ow into said parts and only said partitions will be exposed to heated iluid from both parts.

3. A turbine driven by a pressurized heated iluid comprising a housing dening a turbine rotor chamber therein, a rotary turbine rotor mounted for rotation within said chamber, an exhaust passage leading from said chamber, a single vgas inlet chamber extending circumferentially around the housing adjacent the rotor, stator openings annularly arranged to direct heated operating fluid inwardly to said rotor chamber to drive the rotor, said single chamber opening inwardly to all of said stator openings, a irst partition extending generally radially across said inlet chamber to divide it into rst and second chamber parts, a second partition positioned substantial-ly circumferentially opposite the first partition and extending generally radially and facing said iirst `and second chamber parts and gradually twisting radially inwardly with the surfaces of the walls facing circumerentially at their outermost surface areas and facing axially at their innermost surface areas to gradually deilect the how of heated fluid in circumferential opposite directions around said chamber parts, and means deiining an inlet opening into said inlet chamber at said second partition whereby a ilow o inlet fluid will divide to tlow into said parts and only said partitions will be exposed to heated liuid from both parts.

4. A turbine driven by a pressurized heated fluid comprising a housing defining a turbine rotor chamber therein, a rotary turbine rotor mounted for rotation within said chamber, an exhaust passage leading from said chamber, and a divided hot iiuid inlet for the rotor including a iirst inlet passage leading circumferentially around the housing and opening to direct operating tluid to the rotor, a second inlet passage leading circumferentially around the housing in the opposite direction and opening to direct operating fluid to the rotor at a different circumferential location whereby the passages do not overlap and each may be exposed only to the operation by fluid iiowing through its passage and not be severely aiected by the effects of heated operating iluid ilow, and a twistedseparating wall twisted about a substantially radial axis between said passages whereby the cracking elfects of temperature change are avoided.

References Cited in the tile of this patent UNITED STATES PATENTS 790,090 Truesdel May 16, 1905 1,259,430 Monson Mar. 12, 1918 2,646,210 Kehlmann et al July 21, 1953 2,654,566 Boyd et al. Oct. 6, 1953 2,702,688 Ericson Feb. 22, 1955 2,792,197 Wood May 14, 1957 2,798,657 Darrow July 9, 1957 2,803,396 Darrow Aug. 20, 1957 FOREIGN PATENTS 1,021,808 Germany Dec. 27, 1957 (Kl. 88a 12)