US1423459A - Geared turbine - Google Patents

Description

H, F. SCHMIDT. GEARED TURBINE. APPLICAT ON FILED AUG-31,1917.

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F i l l F. SCHMIDT, 9F PITTSBURGH, PENNSYLVANIA, ASSIGNOR T WEEJTINGI'IOUSE ELECTRIC 8?. MANUFACTURING (30., A CORPORfiEION OF PENNSYLVANIA.

GEARED TURBINE.

Specification of Letters Patent.

Patented July 18,

To all to /1 m it may concern Be it known that I, HENRY F. SCH IDT, a citizen of the United States, and a resident oi Pittsburgh, in the county of Allegheny and State of Pennsylvania, have made a new and useful lnvention in Geared Turbine, of which the following is a specification.

This invention relates to turbines and has for an object to produce a new and improved geared turbineunit which is simpler and more compact than similar units now in use and known to me. i

A further object is to produce a geared turbine which is sell-contained, rigid and is capable of being assembled asa unit.

A. further object is to produce a marine turbine unit in which the turbine section or sections, the reduction gearing thrust bearing, form a part of an organized apparatus which is capable of being secured to the ships structure by a single seating.

These and other objects, which will be made apparent throughout the further description of the inventiomare attained by means of apparatus embodying the :Eeatu'res herein described and illustrated in the drawings accompanying and forming a parthereof.

in the drawings: 1 is a sectional view oi a' geared turbine unit embodying my invention.

Fig. 2 is a diagrammatic sectional view illustrating a compound turbine as a, part 01: a geared unit embodying my invention.

Fig. l is a perspective View, on an enlarged scale, of blading forming a detail of the apparatus illustrated in 1.

(l: is a iragmcntal sectional view of a turbine and illustrates an arrangement of turbine elements which may be employed in the low pressure section of the compound turbine of Fig. 2.

Fig. is a diagrammatic view of a modified arrangement of teeth on the reduction gearing.

Fig. 6 is a side elevation of a modified form 01 casing for the gearing and turbine. w s

The unit illustrated in Fig. 1 includes a reduction gearing 41 having a large driven gear 5, with which a driving pinion 6 meshes. The shaft 7 of the gear is shown operatively coupled to a propeller shaft 7* and the and the shaft 7 is provided with a thrust bearing 8 for taking up the longitudinal tirust imparted to 1t by the propeller 9.

As is customary, the gearing 41 is provided with a casing 10, which is shown in section in Fig. 1,and on which the bearings 11 and 11 of the shaft of the pinion 6 are mounted. The thrust bearing 8, which may be of any suitable type, is also mounted on the casing 10.

The pinion 6 is driven by a turbine 12, which includes a rotor element 18 directly connected to the shaft out the pinion 6, and

casing or housing 14: surrounding the rotor element and integrally formed with the casing of the gearing. The "'otor element 13 is shown mounted on an overhanging end 01. the shaft 01 the pinion 6, and as illus trated, is provided with, a single row of radially disposed blades 15, to which steam or motive fluid is delivered by one or more expansionnozalcs 16. These nozzles communicate with a steam chest 17 to which steam is delivered through an inlet port 18. The turbine illustrated is of the reentry type; the nozzles 16 are adapted to expand the steam to exhaust or condenser pressure and the steam so expanded is directed and redirected through the blades until the kinetic energy, rendered available by the expansion, is abstracted by the blades.

In Fig.1, I have illustrated more or less diagrammatically a redirecting passage 19, which receives the steam after it'has mado the initial pass through the blades 15 and redirects the steam for a second pass through the blades. While two or more redirecting passages i ay be employed, l have illustrated a turbine which is preferably adapted to employ an odd number of redirecting passages, since'the exhaust port 20 is located on the same side or" the rotor 13 as the delivery nozzles 16.

While anyform of reversing section may be employed, for the sake of compactness and simplicity, I have illustrated a sinple form of reversing section, in which the reversing blades or buckets 21 are mounted. on or are formed integrallv with the ahead blades 15. As shown in Fig. 8, the blades 15 are shrouded and the reversing buckets are formed in the shroud member. These buckets are shown slightly inclined and overlapping and receive steam from one or more nozzles 22, which are so located as to direct the steam issuing from them in approximately tangential streams, with relation to the row of buckets 21. The nozzle or nozzles 22 are located on one side of the center line of the buckets 21, so that the steam delivered by them issues from the blades on the opposite side of the center line. \Vith such an arrangement, the buckets 21 may serve as a part of a re-entry turbine element, in which casethe redirecting passages will be located on one side or the other of the center line of the blades. The nozzle or nozzles 22 communicate with a steam chamber 23, formed within the turbine casing 14 and to which steam is delivered through an inlet port 24.

For conveniencein assembling, the shaft packing 24, which seals the interior of the turbine casing, and also for the purpose of conveniently taking care of lubricant leaking from the bearing 11' or sealing li uid leaking from the packing 24, I have il ustrated the housing 14 of the turbine so formed as to provide an open pocket 25 through which free access may be had to the end of the bearing 11' and to the packing 24. For convenience of assembling the turbine, the housing 14 is preferably divided along a plane passing transversely through the projected axis of the rotor, and the nozzles 16 and the steam chamber 17 are preferably mounted on the segregated annular portion 14 of the housing. The casing 10 and the housing 14 are divided at A along a horizontal plane passing through the axis of the pinion 6. This divides the casing 11 so as to form a part 10, which serves as a cover for the bearing housings of the pinion 6. The division of the housing 14, above described, also segregates the semi-cylindrical portion .14 from the housing 14. This segregated portion may be into rally formed with the cover 10 by means 0 two or more webs 14 \Vith this arrangement, the cover 10? and the portion 14 may be removed without disturbing the remainder of the vasm' ing 10 and without disturbing the annular portion 14 of the housing 14. This is particularly desirable, since both the inlet pipe 18 and the exhaust pipe 20' are connected to the portion 14 In apparatus arranged as illustrated in Fig. 1, that is, with the pinion 6 located above the shaft 7 of the driven gear 5, it is necessary to divide the casing 10 at B on a horizontal plane passing through the axis of the shaft 7, so that access may be had both to the bearings of the shaft 7 and to the thrust bearing 8. Where the pinion 6 and the shaft 7 are in the same horizontal plane as illustrated in Fig. 6, the casing 10 may be divided at C, along a plane passing through the axes of the pinion 6, and'shaft 7 into two pieces only. With such an arrangement the lower portion of the turbine housing 14 will be formed integrally with the lower or base portion of the casings 10, and the upper portion of the turbine housing may be formed integrally with the upper or cover portion of the casing 10. Such a division of the turbine housing need not interfere with the transverse division which segregates the portion 14, since it may be desirable to retain this portion in place on the base of the turbine housing, so as to obviate the necessity of disconnecting exhaust and steam piping.

Vith the arrangement of turbine and gearing illustrated there is no possibility of a misalinement of the turbine and pinion shafts, since these shafts are one and the same. In addition to this, difficulties due to misalinement of bearin s are reduced to a minimum, since all 0 the bearings are formed in a single casing and are located on the portion of the casing which is of relatively simple configuration and which forms the casing proper of the gearing. Another advantage inherent in the apparatus illustrated is that the turbine gearing and thrust bearing have a common frame or casing and consequently may be installed by a single seating in a vessel or wherever the organized apparatus is to be employed.

In Fig. 2, I have illustrated diagrammatically another embodiment of my invention, in which a compound turbine is employed. In this embodiment I have shown the gearing 4' as provided with a single driven gear 5', and two pinions 6 and 6". both of which mesh with the gear 5. The turbine is divided into a high pressure section 26 and a low pressure section 27, and these sections are cross-compounded in the usual manner. The section 26 may be similar in structural details to the turbine illustrated in Fig. 1, and its rotor element 26 is mounted on the overhanging end of the shaft of the pinion 6 The casing 26 of this section is integrally formed with the casing 10 of the gearing 4', and the bearings of both the pinion shafts 6 and 6 are formed in the casing 10'. The low pressure section 27 delivers power to the gearing 4' through the pinion 6", to which its rotor element 27 is directly connected. The structural details, so far as concerns the mounting of the rotor 27 on the shaft of the pinion 6', may be in substantial particulars the same as is illustrated in connection with the rotor 13 and the shaft of the pinion 6, Fig. 1. It will, of course, be understood that any suitable means may be employed for mounting the rotor elements on the pinion shafts, and that under certain conditions of speed and power it may be desirable to forge or otherwise integrally form the rotor element and the shaft on which the element is mounted.

The low pressure section may be of the same type of turbine element as the high pressure element, but as illustrated it includes a series of nozzles 28 which communicate with a steam chest 29 formed within the casing 27 and receiving partially expanded motive fluid or steam from the section 26 through a conduit or passage 30, which extends across the reduction gearing and places the exhaust port 18 of the initial section in communication with the inlet port of the low pressure section. It will, of course, be understood that the initial section expands the steam to a pressure intermediate inlet and condenser or exhaust pressure and that the low pressure section expands the steam received by it to condenser or exhaust pressure. The steam issuing from the blades 15 of the low pressure section is discharged through the exhaust port 31 of that section, which for the purpose of providing a free exhaust is substantially of the same area as the cross-sectional area of the casing 27. For practical reasons I have illustrated a reversing element in the low pressure section only. It will,'however, be apparent to those skilled in the art that each section may be provided with a reversing element. The reversing element of the low pressure section 27 is substantially similar to that illustrated in Fig. 1.

In Fig. 2, I have shown pinions of diii'en ent diameters, the pinion 6* being larger than the pinion 6. It will, of course, be understood that the diameters of pinions may be so selected that the sections may be operated at their most economical ,speed and at the same time eifectively transmit power to the driven gear 5.

For convenience of illustration, I have omitted the thrust bearing in Fig. 2. This bearing will, however, preferably be provided on. the side of the gearing 5, adjacent to the high pressure section 26. I have also illustrated the casing 27 as formed integrally with the casing 11 and I have shown a pocket 33 between each end wall of v.each turbine casing and the adjacent side wall of the gearing. The casing 10 of the apparatus of Fig. 2 will preferably be divided so that one portion in effect forms a removable cover for the other portion or base. The conduit 30 and the exhaust port 18 of the high pressure section 26, and the inlet port of the low pressure section 27 will, of course, be so disposed as to facilitate. the removal of the cover portion.

One of the objects of the present invention is to provide a compact and at the same time an efficient turbine. For mechanical reasons it is essential that the overhanging rotor elements shall be as light as possible and that the critical speed of the pinion shaft shall be above the normal running speed. For thermodynamic reasons it is essential that the energy of the steam shall be abstracted in steps. By employing a reentry type of turbine in installations such is hown in. Fig. 1, or for the initial stage in installation such as shown in Fig. 2, I am able to meet the mechanical and thermodynamic requirements and to provide an installation which is mechanically elli'ective and thermodynamically eliicient. The conditions governing the selection of turbine elements, capable of being employed the low pressure section in installations such as illustrated in Fig. 2, are similar to those above noted. In addition to this, the low pressure section must be capable of provid ing adequate area through its final row of blades for completely expanding the steam issuing from the high pressure section, and it must also be capable of eiiiciently abstracting the available energy of the steam resulting from such expansion. The low pressure section 27 illustrated in Fig. .2, fulfills the conditions encountered, since the rotor element is light, is of simple construction and the working elements may be so dcsigned as to eiiiciently expand and abstract the available energy of the steam received' by them. In Fig. 41, I have illustrated in fragmental sectional view a multiple velocity drop turbine stage which may he cmployed in place of the turbine elements of the section 27. While such a stage will adequately fulfill the necessity of providing the same area through the last row of blades as the element illustrated in Fig. 2, the rotor element must of necessity he heav ier, and to this extent the modification of Fig. I is not as desirable as the apparatus illustrated in Fig. 2.

In Fig. 5, I have illustrated diagrammatically an arrangement of teeth on the gear 5 and the pinion 6 which may be employed for the purpose ofequalizing the tooth pressure occasioned by the unbalanced 105 thrust resulting from the difference in pres sure on opposite sides of the glands 2 1-, Fig.

1. With gears employing the herringbone arrangement of gear teeth, this unbalanced pressure is taken up by one set of gear teeth, consequently that set is subjected to materially greater tooth pressure than the other set. For the purpose of equalizing the tooth pressures and uniformly distributing the working pressure over the two sets of teeth, I contemplate making the tooth faces of the two sets of unequal length. For example, in Fig. 5, the tooth faces of the set 5 may be made approximately twice the length of the tooth faces of the set 5 It will, of course, be apparent that the dif i'en ence in length of the tooth faces of the two sets will depend upon the lateral thrust encountered. The structure shown in 5 constitutes the basis for claims in my plication, Serial No. 4L66,059, filed May 9,, 1921, which is a division of this application. While I have described and illustrated but two embodiments of my invention, it will be apparent to those skilled in the art that various modifications, changes, additions and omissions may be made in the apparatus illustrated without departing from the spirit and scope of the invention as set forth in the appended claims.

What I claim is:

1. In an organized power developing apparatus, a gearing comprising a driving gear, a driven gear, and a casin in which said gears are journaled, in com ination with a turbine comprising a rotor element, mounted on an overhanging end of the shaft of the driving gear, a housing for the rotor element, divided along planes corresponding to divisions of the casing.

2. In combination in a geared turbine, 21. reduction gearing, a casing therefor, a turbine comprising a rotor element mounted on an overhanging end of the shaft of the gearing, a housing for the rotor secured to the casing, and divided into sections so that the rotor and the gearing shaft on which it is mounted may be removed without disconnecting the steam piping from the housing.

3. In a geared turbine unit, a gearing in combination with a compound turbine, the separate sections of which are located on opposite sides of the gearing, and in which the rotor element of one section is mounted on the overhanging end of a shaft of the gearing.

4. In a geared turbine unit, a gearing comprising a driven gear, and two driving gears of different diameters meshing therewith, in combination with a compound turbine, having rotor elements disposed on opposite sides of the driven gear, one of the said rotors being mounted on an overhanging end of one of said driving gears, and the other on an overhanging end of the other of said driving gears.

5. In a geared turbine unit, a gearing comprising a driven gear and a plurality of driving gears meshing therewith, in combination with a plurality of turbine sections arranged on opposite sides of the driven gear and distributed over the shafts of the driving gears whereby each section can be arranged to run at its most economical speed independently of the speed of the driven gear, the rotor element of each section being mounted on one of the driving shafts of the gearing.

6. In a geared turbine unit, a gearing comprising two driving gears, a driven gear meshing therewith, in combination with a re-entry turbine section, the rotor of which is mounted on the sha'ftof one of the driving gears and disposed at one side ofthe driven gear. and a low pressure section, the

. rotor of which is mounted on the shaft of gearing, including a gear and a pinion meshing therewith, in combination with a turbine having an axial flow ahead section and a peripheral bucket reversing section surrounding the blades of the ahead section, and a single rotor wheel on which the elements of both sections are mounted, and which is mounted on the shaft of the pinion.

8. In an organized power developing apparatus, a gearing comprising a driving and driven gear, a casing in which said gears are mounted, a thrust bearing mounted on the casing, in combination with a turbine comprising a rotor element mounted on the shaft of the pinion, ahead and reversing blading mounted on said element, and a housing enclosing said element and mounted on said casing.

9. In an organized power developing apparatus, a gearing comprising a driving and a driven gear, a casing in which said gears are mounted, in combination with a turbine comprising a rotor element mounted on an overhanging end of the shaft of the driving gear, a housing for said element, so mounted on the casing as to form an open pocket for receiving oil drip from a bearing of the driving shaft, and drip from a sealing gland of the turbine, and a sealing gland between the housing and the driving shaft.

10. In a geared turbine unit, a transmission gearing comprising intermeshing gears, and a casing for the gears in which the shafts of the gears are mounted, and a compound turbine comprising separate turbine sections. the rotor elements of which are mounted on overhanging ends of shafts of said gearing, and casings for the rotor elements mounted on the said gear casing.

11. In combination in a power developing unit, a gear casing, reduction gearing journaled in the casing and enclosed thereby, including a driving gear and a driven gear intermeshing therewith, the said driving gear being journaled in the casing at opposite sides of the casing and having an end overhanging the casing, and a rotor mounted on the overhanging end for rotating the driving gear.

12. In combination in a power developing unit, a gear casing, reduction gearing journaled in the casing and enclosed thereby. including a driving gear and a driven gear intermeshing therewith. the said driven gear being journaled in the casing at opposite sides of the casing and having an end overhanging the casing, and a rotor mounted on the overhanging end for rotating the driving gear, and a casing therefor mounted on the gear casing.

13. In combination in a power developing unit, a gear casing, reduction gearing journa led in the casing and enclosed thereby. including a driving gear and a driven gear intermeshing therewith, the said driving gear being journaled in the casing at opposite sides of the casing, and having an end overhanging the casing, a rotor mounted on the over-hanging end for rotating the drivinggear and a thrust bearing for the driven gear mounted on the casing.

14E. In combination in a power developing unit, a gear easing, reduction gearing journaled in the casing and enclosed thereby, including a driving gear and a driven gear intermeshing therewith, the said driving gear being journaled in the casing at opposite sites of the casing, and having an end overhanging the casing, a rotor mounted on the over-hanging end for rotating the driving gear and a thrust bearing for the driven gear mounted on the side of the casing opposite the side on which the rotor is supported.

1-5. In combination in a power developing device, reduction gearing including a driving gear and a driven gear, a fluid operated rotor mounted on the driving gear,;a casing for the gearing and the rotor divided hori- Zontally on a planev cutting the axis of the driving gearend supporting the driving'gear between the rotor and the said gear, and an end casing overlapping the divided portions gear between the rotor and the said gear, and

an end casing overlapping the divided portions of the casing adapted to enclose the rotor.

17. In a marine geared turbine, a gearing comprising a driven gear and a driving gear, a turbine rotor mounted on an overhanging end of the shaft of the driving gear, ahead elements and reversing elements mounted on said rotor. a casing surrounding said rotor and provided with means for delivering inotive fluid to the ahead and the reversing elements.

18. In a marine geared turbine, a gearing comprising a driven gear, a pinion meshing therewith, a casing in which said gear and pinion are journaled, a turbine wheel mounted on an overhanging end of the pinion, ahead and reversing elements mounted on said wheel and a casing for the wheel provided with fluid passages for delivering fluid to the ahead and reversing elements and mounted on said-gear casin 19. In a geared turbine installation, a gearing comprising a driven gear and a driving pinion meshing therewith, a shaft on which said pinion is mounted, a turbine wheel mounted on an overhanging end of said shaft, a casing for the gearing, a casing for the turbine wheel mounted on the gear casing and provided with a motive fluid admission passage, and an exhaust port substantially axially aligned with said wheel.

20. In a geared turbine, a reduction gearing comprising; a driven gear, a driving gear, shafts on which said gears are mounted, a casing for the gearing in which said shafts are journaled, a turbine rotor mounted on an overhanging end of the shaft on which the driving gear is mounted, a casing for said rotor mounted on the gear casing and provided with a fluid admission port, and an exhaust port located in the side of the casingoppositethe mounting shaft of the rotor and having an area approximately equal to the circle bounded by the working elements mounted on the rotor.

21. In a geared turbine installation, a gear, a pinion cooperating therewith, a shaft on which said pinion is mounted, bearings for the shaft on'each side of the pinion, the shaft having an overhanging end extending beyond one of said bearings, a rotor mounted on the overhanging end of the shaft, a. casing enclosing the rotor and having an axially extending exhaust passage concentric with the rotor and shaft and extending away from the rotor on the side thereof opposite from the shaft.

22. A turbine having a rotor mounted on. the overhanging end of a shaft, a casing enclosing the rotor, a sealing gland formed between the casing and the shaft, and an exhaust passage extending axially away from the rotor on the side opposite from the shaft, said passage being unobstructed by bearings.

23. A geared turbine unit comprising a reduction gearing, a casing for said gearing in which said gears are journaled, a turbine rotor mounted on an overhanging end. of a shaft of said gearing, a casing for the turbine rotor provided with an opening through which the shaft projects, an inlet port for motive fluid and an exhaust port located in the end of the casing opposite said opening, and a packing located between said shaft and the edges of said opening.

In testimony whereof, I have hereunto subscribed my name this 29th day of August, 1917.

HENRY F. SCHMIDT. Witness:

C. W. MOGHEE.

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