US3260311A - Vane adjusting device for pump impellers and turbine wheels - Google Patents

Description

July 12, 1966 A. KovATs 3,260,311

VANE ADJUSTING DEVICE FOR PUMP IMPELLERS AND TURBINE WHEELS Filed July 5, 1963 :5 Sheets-Sheet 1 ATTORNEY July 12, 1966 A. KOVATS 3,260,311

VANE ADJUSTING DEVICE FOR PUMP IMPELLERS AND TURBINE WHEELS Filed July 5, 1965 5 Sheets-Sheet 2 lNvENToR A/v/QE K0 VA 75 BY /ff/M/ ma ATTORNEY y' July 12, 1966 A. KOvA-rs 3,260,311

VANE ADJUSTING DEVICE FOR PUMP IMPELLERS AND TURBINE WHEELS Filed July 5, 1965 5 Sheets-Sheet 3 ATTORNEY United States Patent O York Filed July 5, 1963, Ser. No. 292,940 2 Claims. (Cl. Htl-160.31)

This invention relates to a servomotor mechanism for feather'ing the v'anes of hydraulic pump impellers or of turbine wheels. The invention is equally applicable to radial-flow or centrifugal, mixed-now, and axial-now or propellerV pumps and turbines. For the purposes of this application, the term rotor shalll be deemed to include impeller and wheel mechanisms for all of the above types of pumps or turbines.

In connection with water reclamation projects, there is an increasing demand for large circulating pumps with adjustable Va'nes for flow regulation. It is, therefore, an object of this invention to provide improved means by which adjustability of impeller vanes, and in particular vanes for mixed-now impellers of large circulating pumps, may be effected. It is a further object of the invention to provide a servo-motorV mechanism for a rotor and vanes thereof wherein components of the mechanism are located within the rotor housing and shaft, and are fully accessible for adjustment, maintenance and repair purposes without removal of the rotor. A further object of the invention is to provide a servomotor mechanism in which adjustment of the rotor vanes is achieved in either direction without play or fluttering of the vanes. A further object of the invention is to provide an hydraulic control system in which over-speeding of the rotor is automatically prevented in the event of loss of pressure in the system.

These and other objects will become apparent from the following description with reference to the accompanying drawings, in which:

FIGURE l is a section view taken along line 1-1 of FIG. 2 with parts shown in plan view and with certain parts broken away of a rotor and servomotor mechanism in accordance with the invention;

FIGURE 2 is a section view taken along line 2 2 of FIG. l with certain parts broken away;

FIGURE 3 is an axial section view of a distributor valve and control rod assembly on a larger scale taken along line 3'-3 of FIG. 1;

FIGURE 3A is a sectional view taken along line 3'A-3A o f FIG. 1;

FIGURE 4 is a sectional view in accordance with the invention of a radial-flow or centrifugal'y pump; and

FIGURE 5 illustrates the invention as applied to an axial-flow or propeller (Kaplan) type pump.

Referring to FIGS. 1 and 2, there is illustrated a mixedflow pump impeller consisting of a rotor housing 12 having a` cone-shaped bottom plate 14 and a cover plate 16. The rotor is secured to a pump shaft 18 by means of bolts 20, the cover plate 16 and bottom plate 14 making up the hub 22 of the rotor.

Attached to and pivoted on the hub are a plurality ot vanes 24 mounted on' trunnions 26 which are pivoted in bearings 28 and 30, the bearing 28 being a part of the bottom plate 14, andl the bearing 30 being of the split ring type. The trunnions are turned by lever arms 32 connected to the trunnions between the bearing surfaces 28 and 30.

Engaging the lever arms 32, at an enlarged end portion 33 removed from the trunnions, are split slider blocks 34, illustrated in detail in FIG. 3A. The slider blocks which are made up of split members 34a and 34h clamping on the enlarged end portions of the lever arms, are retained 3,268,3ll Patented July l2, 1966i ice in slots 36 annularly spaced around the periphery of a disc 38, the split members being held together in clamping position by means of liller pieces 4t), but at the same time being capable of movement radially on the periphery of the disc with rotation of the disc. Exact adjustment and spacing of the lever arms circumferentially around the disc 38 is made by using iiller pieces of different thicknesses to move the split members circumferentially in one direction or the other.

Supporting the disc 38 for rotational movement is a shaft 42, to which the disc 38 is keyed. The shaft pivots in bearings 44 and 46 fixed to the bottom and top cover plates (14, 16) respectively. Intermediate the upper and lower shaft bearings 44 and 46 are radially projecting lever arms 48. In the embodiment illustrated, the two lever arms extend radially from the shaft 42 in opposite directions, the free ends of the lever arms being connected, through oppositely directed piston rods 49, to pistons 50 sliding in hydraulic cylinders 52. Also acting on the lever arms 48 are compression springs 54, the hydraulic cylinders 52 and springs 54 being pivotally mounted on pinions 56 and S8 extending between and seated in opposed bearings 57 and 59 fixed to the bottom plate and cover plate. The springs are arranged to exert a force in a direction approximately opposite to the direction of force exerted by the pistons 50 on the lever arms.

With respect to the latter force, the larger surface 69 on one side of the pistons, as compared to the surface 62 on the other side reduced in area by the cross sectional area taken-up by the piston rod 49, creates a resultant force, which in FIG. 2, effects a counter-clockwise torque on the shaft 42, when the pressure is equal on oposite sides of the piston 5t). This resultant force is counterbalanced by the springs 54. Since the pistons 50 and springs 54 exert forces in opposite directions, there is no play at any of the pivot points of the assembly. The slider block assembly 34 also eliminates play in the linkage between the disc 38 and the vanes, so that during and after adjustment of the rotor vanes, no play or fluttering of the vanes results.

Also making up part of the servomotor mechanism is a distributor valve 64 (FIGS. 1 and 3), coaxial with and partly contained by the pump rotor shaft 18, comprising a cylindrical valve stem 66 and a control rod 68 capable of axial movement within the valve stem. The control rod, which may be actuated from the top of the rotor shaft by a governor or perhaps manual control means, consists of a hollow, tubular pipe 70, arranged to deliver oil under pressure to the servomotor mechanism, and lower and upper spaced pistons 72 and 74 secured to the lower end of the pipe and connected by ribs 76. The pistons are arranged to coincide with annular chambers 78 and 80, spaced longitudinally along the valve stem 66, and to cover the chambers when appropriately positioned. Connected to the chambers are flexible lines 82 and 84 leading to opposite sides of the pistons 50 within the hydraulic cylinders S2, whereby on movement of the control rod, upwardly or downwardly, oil under pressure is fed from the control rod pipe into one or the other of the annular chambers 78, and-to' the hydraulic cylinders on one side of the pistons 50.

The distributor valve 64 also comprises an annular channel 86 leading upwardly within the valve stem 66 between the stem and the inner control rod 68, spaced openings 88 leading from the inside of the rotor hub to the channel 86, and a lower channel 9i) extending below the control rod pistons 72 and 74. Openings 92 in the disc shaft 42 provide a passageway for the flow of oil from the lower channel 90 to the inside of the rotor hub.

In operation of the servomotor mechanism, when it is desired to change the vane positioning, the control rod 68 is moved upwardly or downwardly so that oil flows through the control rod pipe 70 into either annular channel 78 or 80 to one side of the other of pistons 50. The oil pressure moves the pistons 50, which, in turn, move the lever arms 48, shaft 42, and disc 38, adjusting the positioning of the vanes through lever arms 32. If the control rod is moved downwardly, the lower annular chamber 78 is exposed so that oil flows into the lower flexible line 82 and to the larger area side 60 of the hydraulic pistons 50 moving the piston so as to force the lever arms in a counterclockwise direction (FIG. 2) against the force of the springs 54. At the same time, the upper chamber 80 is exposed permitting oil to ow from the smaller area side 62 of the pistons into the annular channel 86 and upwardly in the valve stem. As the springs compress, the force exerted by the springs is increased, but the arrangement is such that the torque exercised on the trunnions 26 resulting from the flow around the vanes 24 is also increasing. The variation in this torque depends upon the position of the vane pivot axis relative to the width of the vanes in the direction of llow. In accordance with the invention, the axis or pivot point for the vanes is selected such that the increase in torque coincides with the increase in spring force whereby the variation in pressure required on opposite sides of the piston 50 for movement of the vanes is reduced to a minimum.

When the control rod is moved upwardly, the oil from the inside of the control rod ows into the upper chamber 80 through the flexible line 84 and to the smaller face of the pistons 50. This forces the pistons and lever arms 48 in a clockwise direction. Oil flows outwardly through the flexible line 82, into the lower annular chamber 78 which is exposed, and downwardly through the lower channel 90. From the lower channel the oil flows outwardly through openings 92 into the rotor hub 22, and from there to openings 88 and into the annular channel 86 within the valve stem. Thus, the rotor hub serves as an oil reservoir.

As a feature of the invention, the shaft 42 is provided with a threaded cylindrical member 94 which encompasses the lower end 96 of the distributor valve 64. The cylindrical member and lower end of the distributor valve are each provided with engaging threads 98 and 100 by which, as the lever arms 48 rotate, along with shaft 42, and disc 38, the distributor valve is caused to be raised or lowered. The valve is guided by means of keys 102 in the pump rotor shaft 18 for longitudinal or axial movement only. Accordingly, the distributor valve 64 follows the positioning of the control rod 68, such that after the vanes are turned to a predetermined position by movement of the control rod, the annular chambers 72 and 74 are blocked off locking the servomotor pistons 50, and thus vanes, in the selected position. Accordingly, for each position of the control rod 68, there is also a specific position for the vanes 24.

If, for any reason, for instance, `a change in torque on the vanes 24, or leakage in the servomotor mechanism, the position of the vanes should change, this will also cause the distributor valve 64 to change in position relative to the control rod, admitting oil pressure to the servomotor pistons to restore the proper positioning of the vanes.

As a further safety feature, should all pressure be lost by virtue of leakage, or for any other reason, the springs turn the vanes to an extreme position, which may be a wide-open or closed position depending upon whether the unit is a turbine or pump, to prevent over-speeding of the unit. In the embodiment illustrated, for a mixed-flow pump, if all pressure is lost, the springs 54 will turn the vanes to a wide-open position or maximum torque position preventing over-speeding of the pump. The reverse situation could be achieved simply by interchanging the spring and hydraulic cylinder positions, or by other obvious suitable means.

It should be apparent from the above description that the entire servomotor mechanism, including the distributor valve, is accessible from the bottom of the rotor housing, the mechanism, being located within the rotor hub. For maintenance, or adjustment, it is a simple matter to remove the bottom plate 14.

In the embodiment illustrated in FIG. 4, the pump is adapted for radial or centrifugal flow. The operation of components is exactly the same as in FIGS. 1-3A, except that the rotor is provided with a suction-side shroud connected to top cover plate 112 by means of rods 114. The vanes 116 pivot around the rods 114 being fixed to lever arms 118. This is accomplished by providing the vanes with extensions 120, extending through the bottom plate 122 of the rotor, to which the lever arms are fixed.

In the embodiment of FIG. 5, for a rotor of the propeller type, again, the components are substantially the same as those of FIGS. l-3A except that the hub 284 is attached directly to the rotor shaft 18 by means of bolts 206. No cover plate is required. The vanes 208 are provided with trunnions 210 which extend at an axis perpendicular to the axis of the rotor shaft 18.

Although the invention has been describedwith respect to specic embodiments, many variations within the scope and spirit of the invention as dened in the following claims will be apparent to those skilled in the art.

What is claimed is:

1. A runner assembly comprising:

a runner shaft;

a runner housing on said shaft having a cover plate and a removable bottom plate aflixed to the Cover plate;

vane means supported from said housing bottom plate;

linkage means in said housing for rotating said vane means comprising a second shaft coaxial with said runner shaft, a rotatable disc supported on said second shaft, lever arms extending between said disc and vane means;

a motor mechanism also in said housing for rotating said second shaft comprising reversible hydraulic cylinder means having a normally resultant force acting in one direction on said second shaft, spring means arranged to act on said second shaft exerting a force in a direction opposite to that of said cylinder means, said spring means and vane means being dimensioned whereby an increase or decrease in torque on said vane means effects a corresponding and substantially equal increase or decrease in the force exerted by said spring means such that only a small change in the resultant force exerted by said cylinder means is required to rotate said vane means;

means for transmitting a hydraulic pressure to said cylinder means;

and a valve positioner means comprising a cylindrical valve casing coaxial with said runner and second shafts, a control rod means movable within and relative to said valve casing means and operatively associated with the valve casing means for regulating said pressure transmitted to the hydraulic cylinder means, and means operatively engaging said valve casing with said second shaft for longitudinal movement of the Valve casing to an equilibrium position following a change in position of said vane means, whereby for each position of the control rod there is also a position for the said second shaft and the vane means;

said above-mentioned means being accessible by removal of said bottom plate.

2. A runner assembly comprising a shaft;

a runner housing on said shaft;

vane means supported from said housing;

linkage means in the housing comprising a first arm attached to said vane means, and a second arm pivotable about the axis of said housing connected to said first arm;

5 6 hydraulic cylinder means including piston means con- References Cited by the Examiner nected to the second arm at a point removed from UNITED STATES PATENTS the housing axis, the piston means being reversible to urge the linkage means in opposite directions; R@ 21,108 5/1939 Zlpay -7 17016031 control means adapted to transmit a hydraulic pressure 5 1803858 5/1931 Ma'cclatchle 17o-16031 to opposite sides of said piston means, said piston 1'931710 10/1933 Snuth et al- 17o-16051 means having unequal surface areas on opposite 1,987,650 1/1935 Wlegand 17o-16031 sides thereof to provide a resultant force in one of 2551920 9/1941 Englesson 17o-16032 2,518,925 8/ 1950 Nussbaum. 2,801,068 7/1957 Deriaz. l 2,995,190 8/1961 Chilman 170-160.13 X

said directions when the pressure is equal on opposite sides thereof; 10

spring means connected to said second arm at a point between the point of connection of the piston means 34461989 9/1964 Boyd 170'16032 X and the housing axis exerting a continuous com- FOREIGN PATENTS pressive biasing force on the linkage means in the 111099 10/1928 Austria. .ther.f Sald dlrectons; 15 789,794 s/1935 France. said spring means and vane means bein-g dimensioned 985 885 5/1949 Franca whereby an increase or decrease in torque on said 605:091 7 /19 48 Great Britain vane means achieves a corresponding and substantially equal increase or decrease in the force exerted 20 MARTIN P, SCHWADRON, Primary Examiner,

.by .Sad Spfmg means? JULIUS E. WEST, SAMUEL LEVINE, Examiners. said linkage means, spring means and cylinder means being situated in said runner housing. E A- POWELL, JR, ASSl'Sldn Examiner-

Claims (1)

1. A RUNNER ASSEMBLY COMPRISING: A RUNNER SHAFT; A RUNNER HOUSING ON SAID SHAFT HAVING A COVER PLATE AND A REMOVABLE BOTTOM PLATE AFFIXED TO THE COVER PLATE; VANE MEANS SUPPORTED FROM SAID HOUSING BOTTOM PLATE; LINKAGE MEANS IN SAID HOUSING FOR ROTATING SAID VANE MEANS COMPRISING A SECOND SHAFT COAXIAL WITH SAID RUNNER SHAFT, A ROTATABLE DISC SUPPORTED ON SAID SECOND SHAFT, LEVER ARMS EXTENDING BETWEEN SAID DISC AND VANE MEANS; A MOTORO MECHANISM ALSO IN SAID HOUSING FOR ROTATING SAID SECOND SHAFT COMPRISING REVERSIBLE HYDRAULIC CYLINDER MEANS HAVING A NORMALLY RESULTANT FORCE ACTING IN ONE DIRECTION ON SAID SECOND SHAFT, SPRING MEANS ARRANGED TO ACT ON SAID SECOND SHAFT EXERTING A FORCE IN A DIRECTION OPPOSITE TO THAT OF SAID CYLINDER MEANS, SAID SPRING MEANS AWND VANE MEANS BEING DIMENSIONED WHEREBY AN INCREASE OR DECREASE IN TORQUE ON SAID VANE MEANS EFFECTS A CORRESPONDING AND SUBSTANTIALLY EQUAL INCREASE OR DECREASE IN THE FORCE EXERTED BY SAID SPRING MEANS SUCH THAT ONLY A SMALL CHANGE IN THE RESULTANT FORCE EXERTED BY SAID CYLINDER MEANS IS REQUIRED TO ROTATE SAID VANE MEANS; MEANS FOR TRANSMITTING A HYDRAULIC PRESSURE TO SAID CYLINDER MEANS; AND A VALVE POSITIONER MEANS COMPRISING A CYLINDRICAL VALVE CASING COAXIAL WITH SAID RUNNER AND SECOND SHAFTS, A CONTROL ROD MEANS MOVABLE WITHIN AND RELATIVE TO SAID VALVE CASING MEANS AND OPERATIVELY ASSOCIATED WITH THE VALVE CASING MEANS FOR REGULATING SAID PRESSURE TRANSMITTED TO THE HYDRAULIC CYLINDER MEANS, AND MEANS OPERATIVELY ENGAGING SAID VALVE CASING WITH SAID SECOND SHAFT FOR LONGITUDINAL MOVEMENT OF THE VALVE CASING TO AN EQUILIBRIUM POSITION FOLLOWING A CHANGE IN POSITION OF SAID VANE METER WHEREBY FOR EACH POSITION OF THE CONTROL ROD THERE ALSO A POSITION FOR THE SAID SECOND SHAFT AND THE VANE MEANS; SAID ABOVE-MENTIONED MEANS BEING ACCESSIBLE BY A MOVAL OF SAID BOTTOM PLATE.

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