US1990045A - Hydraulic turbine - Google Patents

Description

C. R. MARTIN HYDRAULIC TURBINE Feb. s, 1935.

2 Sheets-Shet 1 Filed Jan. 24, 1931 fw y Feb. 5, 1935. c. R. MARTIN HYDRAULIC TURBINE Filed Jan. 24, 1931 2 Sheets-Sheet 2 @NW1/MQ@ Patented Feb. s, 1935 i, UNITED STATES PATENT OFFICE- HYDRAULIC TURBINE Charles R. Martin, Wauwatosa, Wis., vassigner to Allis-Chalmers Manufacturing Company, Mil- Waukee, Wis., a corporation of Delawarel l Application January 24, 1931, serial No. 510,890 Y 10 Claims.

more efhcient than the turbines of thistype at present known to the art.

Another object of the invention is to provide a hydraulic turbine of the above named type which l has a more accessible and effective arrangement for grease lubrication than havethose of this type at present known to the art.

Another Aobject of theinvention is to provide a hydraulicturbine of the above named type in which the regulating shaft forl operating theA shifting ring isnot extended down through the intake fiume to form an obstruction in front of the guide vanes, but is of relatively short length and cooperates with the cover plate mounting of the shifting ring and levers connected thereto jin a manner such that a Ivery material decrease in the size and cost of the governor and the connections thereto is Irealized over the governors required in the prior art turbines of the above named i type, while at the vSametime providing a better mechanical arrangement due to the direct and simple connections. This mounting of the, shifting ring also makes it possible to lubricate the shifting ring bearing surfaces on the cover plate and the guide vane bearings and this further reduces the costof the yrequired governor.

Another object of the invention is to provide a hydraulic turbine ofthe named type in which the cover plate is supported by the guide vane stems thus dispensing with the flow obstructing stay vanes found in thev prior art turbines of the said type.

Another object of the invention is to provide a hydraulic turbine comprising a rconcrete inlet casing having an apertured ceiling portion, a xed cover plate in substantial registration with and retractable through said aperture in said ceiling portion, a shifting ring carried by the periphery of. said cover plate, the, cooperating peripheral portions of said cover plate .and said shifting ring being provided With means permitting the cover plate to carry and support the shifting ring under normal operating conditions of the turbine and permitting further.r through arelative rotation of the shifting ring with respect to the cover.

plate a removal of the cover plate axially through said aperture in saidceiling portion. f

It has been customary in hydraulic power installations to mount the shifting ring,v which simultaneously operates an annular series of guide vanes, adjacent the discharge ring, in which cases vit was necessary to extend the regulating shaft vertically through the turbine casing, in turbines having the double spiral type of intake casings, near the nose thereof and inthe path of the inilowing Water.' The regulating shaftinv this position caused a disturbed ilowinto Athe turbine, readily detectable by piezometers placednear the regulating shaft. n o l s If theregulating shaft wereremoved from said position to a position Within the nose of the intake casing, in order to obviate and avoid the above described disturbed flow,it would be found that the connecting rods extending angularly from the regulating shaft wouldgbe lined up more or less in the direction of the upwardly iiowingA water which flows along the iioor, to form undesirable collecting traps for sticks and other solid, floW-deterring materials that escaped collection in the trash rack provided for that purpose.

Placing the shifting ring upon the periphery of the cover plate of the turbine casing eliminates the named disadvantageous features and at the same time adds an advantageous feature, namely, dispensing with aconsiderable length of regulating shafting and connections between the governor and the shifting ring.

This manner of mounting the shifting ring further permits the provision of a better arranged, more effective, yet less expensive lubricating system lfor the turbine. It also permits the Support for the cover plate to be provided by stationary, guide vane stems and thereby dispenses with the flow obstructing stay varies, usually provided for this purpose, which is another advantageous feature of the present invention. It further precludes the necessity of employing a speed ring and since the shifting ring rests upon the cover plate at the periphery thereof and is located in an annular recess provided in the ceiling portion of the intake casing and is therefore located out of the direct water passage through the intake casing to the runner, another advantageous feature is realized.

Lubrication of the main shaft bearing is effected with Water'conveyed by a combined ejector and Water supply pipe or pipes, carried by a sealing flange, which communicates with the space underneath the peripheral portion of the cover plate, to'. remove any air present in this space which would decrease the height of the inflowing water column. After the evacuation of said air, a replacement of said space with a portion of the hydraulic motive fluid ensues which fluid lubricates the bearing surfaces of the shifting ring and cover plate and this elevated iluid also serves as the source of lubricant for lubrieating the main shaft bearing, as before stated.

Other objects and advantages of the present invention will be apparent from a consideration of the detailed description hereinafter found in the specification when taken in connection with the accompanying drawings wherein aV preferable embodiment of the present invention is shown.

and on which like characters of reference refer to similar parts in all of the several views.

Fig. 1 is a vertical sectional view of a hydraulic power installation embodying this invention;

Fig. 2 is a horizontal sectional view taken substantially along line I-II of Fig. 1, looking in the direction of the arrows.

Fig. 3 is an enlarged, fragmentary, vsectional View taken substantially along broken line III-III of Fig. 2, and shows an embodiment of the improved hydraulic turbine forming the subject of the present invention.

Fig. 4 is an enlarged, fragmentary vertical sectional view of the hydraulic turbine shown in Figs. 2 and 3 provided with a preferred,l mod` ied form of shifting ring operating means.

Fig. 5 is a fragmentary plan view of the turbine shown in Fig. 4.

The hydraulic power installation shown in Figs. 1 and 2 is of the closed flume type and comprises in general a concrete setting forming an intake fiume or casing 1, a tail race 2.a web support 3 for a generator 4 direct-connected to the main shaft 5 of a hydraulic turbine 6 having a runner '7.

The water entering the turbine 6 through the intake casing or flume 1 is directed around and into the annular series of guide vanes 8 which control the quantity and the direction of the water ilowing against the runner '7, by reason of the double spiral construction of the intake casing 1 and the pier 9 cooperating therewith. The water flowing against the runner '7 after'having given up most of its kinetic energy thereto passes through the draft'tube 10 in which the'velocity head is changed to pressure head by reasonlof the bell-shaped form thereof, after which the water enters the tail race 2. f

The closed flume turbine 6 to which this invention is directed, and as to which the driven element be it generator or other machine is immaterial, will now be described in detail. It is to be understood, however, that the closed Aflume turbine although shown of the vertical shaft type may equally well be positioned so that the shaft 5 thereof is directed horizontally and be within the purview of this invention.

The concrete setting above described includes a portion 12 forming the ceiling of the intake casing 1, said portion being provided with a circular opening large enough to permit of the removal of the cover plate 13 therethrough. The cover plate is normally supported in a concentric and aligned relation to said opening and ,to the draft tube 10, directly by the stationary stems 14 of the annular series of guide vanes 8. This support is effected by providing the discharge ring 15 with internally threaded bosses 16- equal in number to the number of guide vanes in the annular series of guide vanes v8 and inserting therein internally and externally threaded bushings 17, the internal threads of which receive the threaded, reduced, extreme lower ends of stems 14. Each guide vane in this end portion is preferably provided with a bearing 18 which receives the enlarged portion of the stem 14. The flat, peripheral portion of cover plate 13 is similarly provided with a series of openings that are concentric with and in axial alignment with the cylindrical apertures in bosses 16. 'Ihe other end of the stems 14 may be received directly within these latter openings or in bushings similar to the threaded bushings 1'7 at the rst mentioned end of the stems, located in the discharge ring 15. The adjacent, lower peripheral surface ofthe cover plate 13 is made at and substantially parallel tothe plane of movement of the adjacent end surfaces of guide vanes 8. Nuts 19 are screwed'onto the cover plate end of the stems 14 and hold the cover plate in firm engagement with the adjacent enlargement or shoulder portions in stems 14 which serve as supports for said cover plate. The upper portion of each guide vane is provided with a bearing 29 which receives the other enlarged portion of the stem 14. Each stem may further be provided with a tube 50 of somewhat larger diameter than the intermediate portion of the stern between its two enlarged portions to which the tube is secured as by welding, which tube serves to conduct grease to the bea-ring bushings 18 and 20 after it has been forced through transverse openings 63 in the intermediate portion that communicate with a bore 62 terminating in a pressure grease fitting 64 at the upper or cover plate end of each stem 14.

The shifting ring 21 for simultaneously adjusting the annular series of guide vanes 8 is supported from the periphery of the cover plate by means of a plurality of overhanging, spaced, segmental lugs 22 on the shifting ring 21. The lugs 22 cover sufficient portions of the periphery of the cover plate, outlined by the segmental lubricating pads 35, between adjacent ones of which are provided recesses 44, in each of the extreme positions of the shifting ring corresponding to each of the extreme positions of the guide vanes 8. When, however, it becomes desirable to remove the cover plate from the intake casing 1 the regulating shaft may be rotated further in either direction from its position corresponding toy an extreme position of the guide vanes 8 to cause a registration of the lugs 22 and recesses 44, as illustrated by Fig. 5.

The shifting ring 21 is connected to each guide vane by means of la series of links 23 each of which is journaled in an undercut portion of a guide vane near the water entrance edge thereof by means of a pin 65. The shifting ring 21 may be provided with a pair of circumferentially spaced ears 24 to each of which a connecting rod 25 is secured through the intermediary of a forked head 26, as shown in Figs. 2 and 3. The otherends of said connecting rods are in turn connected to the arms of a bell crank lever 27 which is fixed to a regulating shaft 28 positioned at one sidev of the turbine main shaft 5 and passing transversely into the recess 29 in ceiling portion 12 as clearly shown in Fig. 2. The side location of the regulating shaft 28 is necessary in order that the said connecting rods may move free from interference with the pier 9 and nose 11 ofthe intake flume 1. A plate 30 is provided to cover the recess 29 in ceiling portion 12 and to form a smooth guide for the water within the intake casing 1 in the general plane of the cover means is the preferred means for v'accomplishing this result. This means' comprises a segmental rack 49 secured to the periphery of the shifting ring, the teeth of which are operatively engaged by the similar teeth of a pinion 48 fixed to a regulating shaft 28 extending transversely through the ceiling portionl l2 in more close proximity to the pit liner 31' than does the regu-f lating shaft 28 of the modified form of shifting ring rotating means just described andVf as shown in Figs. 2 and 3. This closer positioning ofthe regulating shaft l23 necessitates a smaller recess 59 in ceiling portion 12 and-a correspondingly smaller plate 30 than what is required in theturbine shown in Figs. 2 and 3. Referring further to Fig.y 4,y 46 is'an electric motor for driving the regulating` y shaft 28 through a reduction gear unit 45. The segmental `rack 49 provided on shifting ring 21 is designed and arranged to coact with the pinion rv48 associated with the gear reduction unit 45 in a manner such that a greater movement of the shifting ring '21 lmay thereby be effected than that necessary to move the guide vanes 8 from their open to their closed positions o'r vice versa. In this specification closed position is understood to mean aposition of-the guide vanes whereby the water flow therethrough is a minimum andppen position is that position of the guide vanes'necessary in a hydraulic turbine for effecting a maximum flow of the liquid through the guide vanes to the turbine runner. This greater range of movement is appreciated whenit is desirable to change thev positions of the guide vanes to effect eicient opposite direction of the water through the spiral casing incident to the operation of the machine as a pump. If desired the regulating shaft may be driven manually by means of a hand Wheel 60 on vertical shaft 47 which is drivingly connected to a horizontal shaftl 61 ofthe reduction gear unit 45 through a pair ofengaging bevel gears.

These locations of the shiftingv ring 21 andthe regulating shaft 28 operatively connected therewith space the upper surface of the peripheral portion of the cover plate 13 from the unrecessed edge portion, above the recesses 29 and 5 9, ofthe concrete setting surrounding the cover plateretracting circular opening in the ceiling portion 12, already described. In order that the upper surfaces of the cover plate 13 be sealed from the intake flume l, or in other words the cover plate 13 be sealed againstleakage through said cover plate-retracting opening the said circular, cover plate-retracting opening is lined with a circular pit liner 31 suitably grouted into the concrete setting. A webbed sealing flange 33 is provided as a detachable part of the cover plate 13 and this sealing flange is shown secured to a perforated disk 34 positioned over the cover plate ends of guide vane stems 14 and which disk is in turn secured to the peripheral portion of cover plate 13. In view of the fact that it is difficult to roll the pit liner 31 and the sealing flange 33 to? true diameters, rings 69 and 70 which are readily machineable are respectively, secured to the pit liner and to the sealingv flange. A ring 32 mounted concentrically on theA ring 69 o-f the pit liner 31 may be used to compress a suitable packing 72 against the registering circumferential faces of the rings 69 and 70, as more clearly shown in Fig. 4. The pit liner 31 and sealing flange 33,

therefore, provide aflexible joint by 'reason of the packing 72 and the telescopic relation between liners 69 and 70. The arrangement is such that by merely removing or retracting the sealing flange 33 upwardly the link pins 65 and the adjusting mechanism on the shifting ring 21 are readily accessible for inspection, replacement and lubricating purposes, and the sealing flange 433 may be of sectional construction to facilitate this removal. The sealing flange 33 may also be utilized to support the ceiling portion 12. through the guide vane stems 14 by fixedly securing by meansr such as bolts 66 the sealing flange 33 to the material of ceiling portion 12 which. bounds said cover plate-retracting opening.

` In order that the contacting surfaces of the shifting ring 21 and the cover plate 13, which carries it, may be properly lubricated, the outer circumferential edge of the coverplate is provided with a plurality of circumferentally spaced lubricating pads 35, preferably of bronze. Each of these pads is supplied with a lubricant, under pressure, through a communicating pipe 36 carried by an annular feeder pipe 67 that is mounted 0n the shifting ring 21. The annular feeder pipe 67 may also be provided with connections such as 68 for supplying lubricating material to the various bearings of the guide vane operating mechanism. A flexible conduit 37 may be used to connect the feeder pipe 67 with a fixed supply pipe 38. f

The cover plate 13v is provided with a flange 39 which is used to lsuspend the cover plate extension 40 therefrom. The cover plate extension 40. provides a reaction wall for the water that has passed the guide vanes and also provides a support for a lignum vitae bearing casing 41 the bearing of which snugly surrounds the main shaft 5. The casing 41 is formed with an upper reservoir portion that is supplied with water for libricating` the main shaft bearing through a pipe or pipes 42 which'act as combined ejector and water supply pipes. The pipe 42 is received within an opening in the webbed sealing flange 33 so as to communicate with the intake casing 1 through the recess 29 or 59, as the case may bei in the ceiling portion 12. The open inner end of pipe 42 in the position shown, will normally when .the turbine is in operation communicate with a vacuum space which serves to remove the annular body of air which may be present directly underneath the lower surface of the cover plate and adjacent the periphery thereof, which air if permitted to remain would be detrimental to the efficiency of operation` of the turbine because it would decrease the effective length of guide vanes 8. With the evacuation of this body of air and subsequent rising of the water level in the intake casing 1 above the joint formed between the shifting ring and the cover plate, a mechanical feature is also realized by said pipe, namely, the additional lubrication of the bearing surfaces at said joint by the water. And the pipe 42 will continue to convey some of this water into the reservoir of the casing 41 from which it is allowed to gravitate along the main shaft bearing for the purpose of lubricating the same. The ejector pipes 43 which communicate at their outer ends with the space adjacent the cover plate end'of the guide vanes, and inside of the guide vane circle a sub-atmospheric region, during operation of the turbine, may be used to remove the water which may collect upon the cover plate 13.

The inlet casing 1 it will be noted is provided with ramp surfaces in Vits ceilingand iioor portions, the one intheiioor `being a. substantially continuous ramp surface which provides a less disturbedflow of the .water lpassingv the guide varies 8, reduces the nature and extent of the eddies in the turbine and consequently obviates wear through pitting of the turbine parts and enhances the power and the eiciency of the turbine. This ramp feature of the disclosed hydraulic turbine is disclosed and broadly claimed in an appiication'by the applicant, Serial No. 496,864, led November 20,1930. yThe disclosed location of the shifting ring, since it removes the regulating shaft from a position within the intake casing, where it would cause a disturbed flow of the water, eiects a similar result as does the ramp surface construction in the ceiling and in the oorportions .ofthe intake casing and together and along vwith the novel features above described cooperate to produce an improved turbine. i l

It should be understood that it is not desired to limit the invention to the exact details of construction herein shown and. described for various modiication within the scope of the claims may occur to persons skilled in the art.

It is `claimed andy desired to secure by Letters Patent:

l. In a hydraulic'turbine, a spiral intake casing provided with an opening, a cover plate mounted within said` casing in alignment with opening, annular series of guide vane stems secured-to andsupporting said cover plate from a portion of said casing, .a shifting ring mounted onvthe periphery of said cover plate, means for sealing said cover plate against iiuid leakage through'said opening, and a combined ejector and-.water supply pipe communicating at one side of said sealing means with the interior of said casing, said pipe conducting air and water to a point substantially centrally of said opening.

2. In a hydraulic turbine', a fixed cover plate, a shifting ring mounted` upon the periphery of said cover plate, circumferentially spaced lubricating pads carried by the cover plate, and an annular feeder pipe, having pipesV communicating with said pads, carried by the shifting ring.

3. In a hydraulic turbine, a-concrete spiral intake casing provided with a floor and a ceiling portion, said casing having a substantially continuous ramp surface in at least one of said portions, an opening in said ceiling portion, a cover plate mounted within said casing and in substantial alignment with said opening, a shifting ring carried by the periphery of said cover plate, and means terminating substantially within said ceiling portion for rotating said shifting ring.

fi. In a hydraulioturbine, a concrete spiral intake casing provided with a floor and a ceiling portion, said casing having a substantially continuous ramp surface in at least one of vsaid portions, an opening in said ceiling portion, a cover plate mounted within said casing and insubstantial alignment with said, opening, anv annular series of stems for supporting said cover plate from said casingfioor portion, a shifting ring carried by the periphery of said cover plate, and means terminating substantially within said ceiling portion for rotating said shifting ring.

5. In a hydraulic turbine, a spiral casing having a wail portionv provided with an opening, a cover plate, having a sealingA flange, mounted within said casing, an annular series of guide vane stems secured to and supporting said cover plate from a portion of said casing, said sealing ange of said cover plate being rigidly secured to said wall portion for ,the purpose of supporting said wall portion through said guide vane stems.

6. In a hydraulic turbine, a spiral casing having a wall provided with an opening, a cover plate carrying a sectional, sealing iiange, mounted in said casing in substantial alignment with said opening, and a shifting ring carried by the periphery of said cover plate, saidsealingjnange being of sectional construction to permit of its being readily removed from the cover plate to provide an avenue of access to the adjacent guide vane link pins and shifting ring adjusting mechanism for purposes of replacement, lubrication and repair thereof.

'7. In a hydraulic turbine, an intake casing provided with an annular opening, an annular cover plate mounted withinsaid casing in alinement with said opening, a shifting ring mounted on the periphery of said cover plate, annular means onv said cover plate having sealing engagement with an annular surface bounding said opening of said casing, for sealing said cover plate and casing against fluid leakage rthrough saidr opening, and a combined ejector and Water supply pipe communicating at one side of said-annularmeans with the interior of said casing, said pipe conducting air and hydraulic working fluid to a point at vacuum pressure and located above and substantially centrally of said cover plate.

8. In a hydraulic turbine, an intake casing having an opening, a cover plate mounted within said casing and in Asubstantial alinement with said opening, a shifting ring, means on said shifting ring for supporting it from the periphery of said cover plate, said means cooperating with recesses in said cover plate whereby the axial displacement of said cover plate with respect to said shifting ring and removal thereof through said opening is effected.

9. In a hydraulic turbine, a spiral casing having an opening, a cover plate mounted within said casing in substantial alinement with said opening, a stem having a reduced intermediate portion and enlarged end portions, secured to and supporting said cover plate from a portion of said casing, a guide vane rotatably associated with said stem and having bearings surrounding said stem enlarged portions, said stem being provided with a bore in its cover plate end portion terminating in transverse openings in an intermediate portion, and a. tube surrounding the intermediate stem portion whereby grease under pressure passed through said bore may be utilized to lubricate said bearings.

10. A hydraulic turbine, comprising a casing having an opening in the top thereof, a cover plate having peripheral recesses mounted within said opening and adapted to be withdrawn therethrough, and a shifting ring having inwardly extending lugs and positioned to be supported by said lugs upon the edge of said cover plate to rotate thereon, said lugs being disposed to register with said recesses when said ring is turned to a predetermined position to permit removal of said cover plate through said opening without disturbing said ring.

. CHARLES R. MARTIN.

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