US1725421A - Gate-operating mechanism - Google Patents

Description

- Au 20, 1929. F. H. ROGERS. 1,725,421

GATE OPERATING IECHMIISI Original Filed Juno 7, 1921. 3 Sheets-Sheet. l

' Aug. 20, 1929. F. H. ROGERS GATE OPERATIRG IIBQHAIISI 3 Sheets-Sheet 2 Original Filed Juno '7, 1921 Ill/21 Aug. 20, 1929. H. ROGERS 1,725,421

' GATE OPERATING IIECHANISI Original Filed June 7, 1921 3 Sheets-Sheet I5 Patented Aug. 20, 1929.

UNITED STATES PATENT OFFICE.

FRANK H. ROGERS, 01? PHILADELPHIA. PENNSYLVANIA, ASSIGNOR, BY MESNE AS- SIGNMENTS, TO I. P. MORRIS CORPORATION, A CORPORATION 01' DELAWARE GATE-OPERATING MECHANISM.

Original application filed- .Tune 7, 1921, Serial No. 475,600. Divided and this application filed December 17, 1925. Serial No. 75,912.

This invention relates to hydraulic machines and particularly to the operating mechanism for the adjustable gates or guide vanes of hydraulic turbines and 7 pumps.

These gates or guides control the flow through the turbine or pump and one object of the invention is to provide for the operation of the gates in such manner that the control will be made steady at reduced flow under small loads and at the same time quickly responsive andefiective under normal fullload conditions. Another object of the invention is to provide for less force on the turbine gates at large loads on the turbine and greater force on the gates at small loads on the turbine, in order to suit the actual hydraulic conditions. Another object of the invention is'to provide for the tight closing of the gates so as to avoid leakage. Further objects of the inven tion particularly in interposing a yielding connection between each gate and the operat ingmeans as a protection against excessive strains on the gates, will appear from the following description taken in connection with the accompanying drawings in which Fig. 1 is a horizontal sectional view with parts broken away of a turbine having adj ustable intake gates,

Fig. 2 is a detail of mechanism shown in Fig. l,

Fig. 3 is a view partly in sect-ion of one of the safety links shown in Fig. 1,

Fig. 4 is a sectional view on line L-4 of Fig. 3, v

Figs. 5, 6, 7, 8, 9 and 10 are views of modified forms of links, and

Figs. 11 and 12 show diagrammatic layout of forces. 7

In the specific embodiment of the invention shown in the drawings a hydraulic turbine with a runner having a vertical shaft S receives its flow through the intake 5 having fixed stay vanes 6 and adjustable guide vanes or gates 7 the stems 8 of the guide vanes pass upward through the cover casing 9 of the turbine and at their upper ends are keyed to lever arms 10 by which they are turned to either the closed position shown in full lines in Fig. 2 or to wide open position as shown by dotted lines in Fig. 201' to any desired intermediate adjustment as shown in Fig. 1. The arms 10 are connected by links 11 to the operating ring or cylinder 12 rotatably iounted on the cover casing 9 and this operating ring in turn is connected at 13 to the piston rod 14 of a fluid pressure operated piston in cylinder 15. Fluid pressure on one face or the other of this piston will move the operating ring 12 clockwise or counterclockwise to close or open the gates 7. The fluid pressure supply to the ends of cylinder 15 is controlled by governor mechanism operating to open or close the gates .according as the speed of shaft S falls below or rises above a desired normal.

In moving the vanes 7 from open to closed position, it is highly desirable that: First, for a constant force from the operating ring 12, the force applied to the vanes should increase as the vanes close; and second, for a constant movement of the operating ring 12, the movement of the vanes should decrease as the vanes close.

The first result is desirable because as the vanes 7 close, they are turned more directly across the flow lines, so that the pressure resisting the closing is increased, becoming a maximum at the closed gate position. It is therefore advantageous to have a larger force applied to the vanes as they close. The means by which this is accomplished is illustrated by diagram of forces Fig. 11.

Let R=tangential force exerted at end of radial line 1 of operating ring 12 having a center of rotation G.

Let F=tangential force exerted at end of radial line 1 of lever 10 pivotally moving around a center C.

i. e., the tangential forces exerted on the ends There are two extreme positions:

(I) where f=O hence F=O (II) where r hence F =infinity.

and

Therefore the force F may vary from zero to infinity as the operating ring moves from position I to II. The range of stroke is actually placed between these two limits, wide open gate position being toward I and the closed position being toward II.

If the radial lines 1 and 1 are parallel and therefore 172R If from this'position the link 11 moves toward the right side, angle 9" becomes greater than angle f, their difference increasing with the motion, so that force F becomes less than force R.

In like manner, if the link 11 moves from the parallel position of the radial lines 1 and 1 toward the left, angle f becomes greater than angle 1" and'hence force F becomes greater than force R.

As already explained, as the vanes 7 close the pressure resisting the closing is increased, becoming a maximum at the closed gate position, so that the described arrangement of gearing suits the actual conditions. For the open position of the vanes the radial lines 1 and 1 are parallel or nearly so, hence F =1? and therefore as the vanes 7 close force F becomes greater'than force R, reaching its maximum value for the closed position of the vanes.

In addition to meeting the requirements of hydraulic load this maximum force F is of considerable value in closing the vanes 7 tight, thereby cutting down the water leakage. By means of this arrangement of gearing, the size of the operating cylinder 15, which moves the operating ring 12, may be reduced as it is only necessary to design the cylinder forthe force R required to produce the force F at the open vane position, and at the closed vane position the same force R will produce the greater force F required at the vane. In'

former types of operating mechanism the angle which the link 11 makes with the lever 10 is approximately equal to the angle which the link makes with the radius of the operating ring for all positions of the gates and therefore the force exerted on the lever and the movement of'the lever is practically the same as the force and movement of the operating ring for all positions. In the structure of this invention the ratio of the angle between the link and the lever to the angle between the link and the radius of the operating ring increases as the gates move from open to ring type turbine the radius of the gate circle will be greater than the sum of the length of the lever and the radius of the operatin To apply this same princi le to the outside operating ring type turbine the radius of the gate circle will be less than the difference between the radius of the operating ring and the length of the lever arm.

The second result mentioned above is that for a constant movement of the ring 12, the movement of the vanes 7 should decrease as the vanes close. This action is of great importance from the viewpoint of speed regula tion of the hydraulic turbine. At large gate openings the efficiency curve of the turbine is quite fiat, whereas at small gate openings the curve is steep. This means that for a given load change, the angular turn of the vanes 7 should be greater if the unit is operating at large gate openings, than if operating at small gate openings. ing the governor will produce the same angular turn at the operating ring 12, for a given load change, and it is therefore desirable that for constant angular turn of the operating ring, the angular turn of the vanes 7 should vary, being greater at full gate and less at closed gate. The means by which this requirement is accomplished is shown by a further study of the diagram shown in Figure 11.

Let W =angular velocity of radial line 1,

of operating ring 12. W angular velocity of radial line 1 of lever 10. V =tangential velocity at end of 1 V =tangential velocity at end of 1. then VRZ11 WR. and. VFZIZ Neglecting friction the energy transmitted by the operating ring 12 equals the energy imparted to the lever 10.

Therefore RV FV Kr E V F For an 1 ats open- Substituting for V and V the values given above and 12 WF 5 1 W F As is a constant, we have KLQ 3 i. e., the angular velocities vary inversely as the tangential forces. Substituting from Formula (1) we have W sine r 4 wg any giving W sine r sine r W K* OI K W]; "(5) For position (I) where f=0 inis highly desirable under these conditions that the governor should hold the vanes steady and thus maintain uniform speed. No load changes are occurring on the generator, but the poor hydraulic conditions within the turbine, due to the small gate opening, cause small instantaneous speed changes resulting in the governor moving the operating ring 12. \Vith the former designs of operating gearing, nearly equal movements occur at the vanes, causing increased governor action or hunting. Under these variations in speed, synchronizing becomes a very difiicult and dangerous operation. The special gearing henein described however overcomes these difiiculties, for at small gate openings, the movements of the operating ring 12 caused by the governor result in very much smaller vane movements, so that the governor action is not aggravated, the speed remains steady and the generator may readily be synchronized.

By varying the relative angles and lengths of the links 11 and arms 10 the relation between the movement of the ring 12 and the gates 7 may be varied to suit the particular circumstances of any installation. The mechanism giving a varying movement of the gates for the same regulating movement of a governing menrber at different "ate openings is not necessarily limited to the l1nkages between the ring 12 and the gates 7 but may be applied to other points in the train of the governing mechanism.

The principle of the invention has been illustrated in connection with what is known as the inside operating ring type of turbine, i. e., the operating ring in this type of turbine is located inside of the vane ring circle. In certain types of turbines it is often desirable to reverse this condition and locate the operating ring outside of the gate vane circle. This latter type is known as the outside operating ring type. The special arrangementof the operating mechanism of this invention is applicable in exactly the same manner to the outside operating ring type as shown in Fig. 12 which gives the diagram of force for the outside operating ring type corresponding to the diagram shown in Fig. 11 and reading on the above description and formulae.

It sometimes happens that the closing movement of one or more gates may be prevented by an obstruction caught, for instance, between the gates, or the opening movement may be stopped by something catching between a gate and a stationary part such as one of the fixed stay vanes 6. In such case the entire moving force for all the gates may be concentrated on a single gate which jammed. To permit the remaining gates to be operated and at the same time to avoid breakage of some part which is difficult and expensive to replace, the links 11 are formed as safety members in such manner as to yield when excessively stressed either in compression during closing or in tension during opening.

Preferably each link 11 is formed with one end 25 slidable in the other end 26 but held against sliding by replaceable member such as the split ring 27 set in exterior groove 28 of the end 25 and interior groove 29 of the sleeve end 26. \Vhen the force applied to a certain gate exceeds a safe amount either in compression or tension the ends 25, 26 will transversely shear the ring 27 into portions remaining in the respective grooves 28, 29 and the portion 25 will be free to slide back and forth in the sleeve 26 so as not to apply any turning force to the jammed gate and at the same time to permit operation of the remaining gates. Upon removal of the obstruction the sheared split ring is quickly replaced by another one by simply unscrewing the end26 of the sleeve 26, removing the old ring and inserting a new one and screwing the end 26 of the sleeve 26 back into the place in the position shown in Fig. 3. This ready replacement of the yielding element is very advantageous since jams and breakages most often occur at times of heavy loads and when the shutting down of a unit means great loss in power.

In Fig. 5 a modified form of safety link is shown. Figs. 6 and 7 are sectional views on lines 66 and 77 of Fig. 5. In this link the parts 35 and 36 are cast integral by small intermediate webs 37. In this construction the metal at sections 37 is made of such thickness as to fail by shearing at the desired load on the link and hence the link will break either in tension or compression. The band 38 is cast integral with piece 35 to prevent bending action on the arms of piece 35, so that the link will fail by shear at sections 37. The distance 6 is made about equal to the stroke so that when the linkfails the piece 36 will slide inside of piece 35 and thereby retain the broken portion of the link from projecting into the path of the gate operating means and thus protect the jammed arm and gate the length of movement of piece 36 within piece 35 being limited by the end of the slot so as to form a mechanical stop to limit the free motion of the gate after breakage of the link. With the operating ring in the closed position, the gate will be prevented from being forced into contact with the runner vanes in case an obstruction lodges between the gates. These principles of opera-- tion are also applicable to the Fig. 3 form.

In Fig. 8 the portions and 46 of the link are relatively slidable and are held together by the replaceable pins 47. By relatively staggering the holes 48, 49 in the members 45, 46 as shown adjustment of the length of the link is provided. In the link shown the end of the portion 46 and the base of the bifurcated portion 45 have beveled or inclined surfaces so that in case of breakage of pins 47 and on compression the two parts will be relatively displaced and thrown clear of each other and out of any interference with the moving parts of the operating mechanism.

In Fig. 9 the two portions 55, 56 of the link are bolted together by bolts 57 which tightly bind the parts but are made of such transverse strength as to shear off when the stress exceeds a predetermined maximum. In Fig. 10 the link is cast as a single piece in the form shown. with the two portions 65, 66 connected by sections 67 which after casting may be machined at 68 to accurately dimension these sections for shearing above a certain load.

Any jamming of the gates occurs more usually when the gates are near their closed position and at this time the arms 10 are turned outward away from interference with the operating parts. Even at wide open position the arms 10 do not extend into the path of movement of any of the projecting parts of the ring 12. Consequently the breaking of the link frees the jammed vane entirely from the operating mechanism and the arm 10 cannot be subsequently engaged by another operating part. This is an important advantags as in prior structures the jamming of the gate will sometimes occur with the end of arm 10 between the bearing projections 42 (Fig. 2) of ring 12 so that after the safety link broke as intended, the further rotation of the ring 12 would engage the end of the arm 10 and forcibly turn the arm until some part of the gate mechanism was broken. WVith the arms 10 permanently clear of the operating ring as in the combination of this invention such interference and breakage cannot take place.

I claim:

1. In a turbine a plurality of movable gates and operating means therefor including a plurality of links each connected to a movable gate, said links being breakable in termediate their ends upon a predetermined closing force applied thereto and means for retaining a broken portion of said link from projecting into the path of said operating means.

2. In a hydraulic machine the combination with pivoted gates, of operating means therefor comprising safety links, each link being adapted to separate into relatively movable parts under compressive forces before any remaining portions of the mechanism fail, said parts being maintained in alignment with each other after separation, and while subjected to said compressive forces.

3. In a hydraulic turbine the combination with a circular series of pivoted gates, of operating mechanism for said gates comprising a series of arms on said gates and links connected to said arms, each of said links being under compression during closing of the vanes and having means for II'QG'. ing the gate from the operating pressure whenever said pressure exceeds a predetermined amount, said mechanism having provision whereby when a gate is freed from theoperating pressure the motion of said gate in at least one direction is mechanically limited. 1

4. In a hydraulic turbine the combination with a circular series of pivoted gates, of operating mechanism for said gates comprising a series of arms on said gates and links connecting said arms to an operating ring, each of said links requiring a compressive force to close the vanes and having means including an element adapted to fail by shearing for freeing the gate from connection with the operating ring whenever said force exceeds a predetermined amount, and means whereby when a gate is freed from said connection its possible free angular motion in an opening direction is definitely limited.

5. In a hydraulic turbine the combination with a circular series of pivoted gates, of operating mechanism for said gates comprising a series of arms on said gates and links connecting said arms to an operating ring, each of said links requiring a compressive force to close the vanes and having means including an element which fails by shearing for freeing the gate from connection with the operating ring whenever said force exceeds a predetermined amount, the

parts of said mechanism being so disposed that the angular motionof the freed gate in the opening direction will be limited to a predetermined amount not greater than substantially full open under any conditions during turbine operation.

6. In a hydraulic turbine the combination with a circular series of pivoted gates, of operating mechanism for said gates comprising a series of arms on said gates and links connecting said arms to an operating ring, each of said links requiring a compressive force to close the vanes and having means for freeing the gate from connection with the operating ring whenever said force exceeds a predetermined amount, the parts of said mechanism being so disposed that the angular motion of the freed gate in the opening direction will be limited to a predetermined amount preventing the gate opening substantially further than its full gate position.

7 In a hydraulic turbine the combination with a circular series of pivoted gates, of operating mechanism for said gates comprising a series of arms on said gates and links connecting said arms to an operating ring, each of said links requiring a compressive force to close the vanes and having means for freeing the gate from connection with the operating ring whenever said force exceeds a predetermined amount, the parts of said mechanism being so disposed that when a gate is freed from said connection the relative motion of the gate in at least one direction relative to the operating ring will be definitely limited by a mechanical stop.

8. In a hydraulic turbine an operating mechanism comprising a turbine gate and operating means therefor, including a link having as a part thereof a breakable portion, and means for holding said portion in an operative relation prior to breakage, including a screw threaded connection.

9. In a hydraulic turbine an operating mechanism comprising a turbine gate and operating means therefor, including a breakable member, and means for holding said member in an operative conditionprior to breakage, including a collar having threaded engagement with said member and a renewable breakable member held in position by said collar.

10. In a hydraulic turbine an operating mechanism comprising a turbine gate and operating means therefor, including a breakable member, and means for holding said member in an operative condition prior to breakage, including a renewable breakable element, and means movable relative to said member adapted to hold said element in position.

11. A turbine gate operating link compris ing separable parts, and means for holding the same in operative relation, comprising a renewable breakable element, and means movable relative to said member for holding said element in position.

12. A turbine gate operating link compris ing separable parts and means for holding the same in operative relation, comprising a re newable breakable element, and means movable relative to said element for holding the same in position, whereby when said separable parts have relative movement upon breakage of said element, a portion of the breakable element will be held in fixed relation to one of said parts.

13. In combination, a rotor, a movable vane for directing fluid relative to said rotor, a shifting ring rotatable about the axis thereof, and means for connecting said ring and vane including elements constituting a vane arm and a link connecting the end of said arm with said ring, one of said elements having sectional members, and means, including a breakable member, adapted to hold said sectional members in a rigid relation to effect actuation of the vane, and adapted to maintain said sectional members in a connected relation when said breakable member is broken.

14. Operating mechanism for hydraulic turbine comprising an operating ring, a gate, and means for transmitting an operating force from said ring to said gate in either direction, including a normally rigid member adapted to have relatively movable parts whenever said operating force exceeds a predetermined safe amount in either direction, and also being adapted to maintain said parts in a connected relation during relative movement therebetween.

15. In a hydraulic turbine the combination comprising a circular series of pivoted gates, operating mechanism for said gates including a shifting ring and elements connecting said ring and gates, said elements including a gate arm and a link connecting said arm with said ring, and means associated with said elements and gates for freeing the gate from a force-transmitting connection with the operating ring whenever the force from said shifting ring exceeds a pre-determined amount, and means limiting to a pre-determined amount the angular motion of the freed gate in the opening direction.

16. In a hydraulic turbine the combination comprising a circular series of pivoted gates, and operating mechanism for said gates comprising an operating ring and elements for connecting said ring and gates, said elements including gate arms and links connecting said arms to said ring, each of said links requiring a compressive force to close the vanes, and means associated with said elements for freeing the gate from a force-transmitting connection with the operating ring whenever the operating forceexceeds a pre-determined amount, said operating mechanism being adapted when a gate is freed from said connection to positively limit movement of the free gate by a mechanical stop.

17. In a hydraulic turbine, the combination comprising a circular series of pivoted gates, and operating mechanism for said gates including a shifting ring and elements connecting said ring and gates, said elements including a gate arm and a link connecting said arm With said ring, one of said elements being so constructed as to free the gate from 1 a force-transmitting connection with the operating ring Whenevert-he force from said shifting ring exceeds a predetermined amount, and means limiting to a predetermined amount theangular motion of the freed 15 gate in an opening direction.

FRANK H. ROGERS.

Images