US 3601497 A
Description (OCR text may contain errors)
United States Patent Inventor Howard A. Mayo, Jr. York, Pa.
Appl. No. 869,038
Filed Oct. 24, 1969 Patented Aug. 24, 1971 Assignee Allis-Chalmers Manufacturing Company Milwaukee, Wis.
WICKET GATE END SEAL FOR HYDRAULIC MACHINE 1 Claim, 3 Drawing Figs.
US. Cl 415/163, 415/216 Int. Cl F0ld 17/12 Field ofSearch ..4l5/l48l65.
 References Cited UNITED STATES PATENTS 2,776,107 l/l957 Willi 415/164 3,101,926 8/1963 Weber 415/164 FOREIGN PATENTS 10,710/42 9/1942 Japan 415/163 88,257 1/1937 Sweden 415/160 1,317,759 1/1963 France 415/151 Primary Examiner-Henry F. Raduazo Attorneys-John P. Hines, Robert B. Benson and Arthur M.
Streich ABSTRACT: A piston seal is slidably contained in a slot provided in the ends of the wicket gates. Means are provided to urge this piston seal into liquid sealing engagement with the adjacent hydraulic turbine stationary components. These means are preferably in the form of pressurized hydraulic fluid directed to the chamber behind the piston seal.
WICKET GATE END SEAL FOR HYDRAULIC MACHINE This invention pertains in general to wicket gates for hydraulic turbines and more particularly to a means for providing a seal between the end surfaces of the wicket gates and the turbine head cover and bottom ring.
In hydraulic turbines, it is the usual practice to utilize an annular series of movable wicket gates cooperating with the stationary head cover and bottom ring located at the ends of the gates to control the admission of water to the hydraulic turbine runner. The successive wicket gates of the series are ordinarily pivotally adjustable about parallel axes and a slight clearance is usually provided between the ends of each gate andthe adjacent stationary surfaces. When the gates are in closed position, the adjacent gates coact with each other to shut off the major portion of the water flow. However, the working clearances at the ends of the gates allow considerable water to leak from the supply into the runner chamber.
' Seals have been provided between the stationary surfaces and the ends of the wicket gates in an effort to control this leakage. However, as pressures have increased, more efficient sealing has become necessary; and it is the main object of this invention to provide an improved seal between the stationary surfaces and the ends of the wicket gates.
A further object of the subject invention is to provide a seal means between the turbine stationary components and the ends of the wicket gates which includes a piston seal slidably contained in either the stationary component or wicket gate and which is urged by pressurized hydraulic fluid into sealing engagement with the opposite member.
A further object of the subject invention is to provide a wicket gate end seal wherein a piston seal is slidably contained in a slot in the end of the wicket gates and is urged into sealing engagement with the stationary water passageway surfaces of the turbine head cover and bottom ring.
These and other objects of the subject invention will become more fully apparent as the following description is read in light of the attached drawing wherein:
FIG. 1 is a fragmentary horizontal sectional view showing I two wicket gates in the open position;
. bine generally designated 7. The wicket gates are pivotally supported at one or both ends to the concrete foundation by means of trunnions 8 and define an annulus about the turbine runner (not shown). Each wicket gate has a general air foil configuration having a leading edge 9 and a trailing edge 11. When in the closed position the leading edge of one wicket gate contacts the trailing edge of the adjacent wicket gate ef-.
fecting a seal along the contacting vertical surfaces.
Annularstationary components 12, herein shown as sideplates, are providedin the concrete foundation adjacent opposite ends of the wicket gates. In the preferred embodiment of this invention as best shown in FIG. 2, a stepped shoulder 13 is provided at each end of each wicket gate. A plate 14 is rigidly connected to the ends of wicket gates by any conventional means such as screws 16 covering the laterally open end of the shoulder. This plate 14 and the shoulder 13 define a slot 17 in the end of each wicket gate. A piston seal 18 is slidably contained in each slot. The seal is preferably constructed of a metallic substance such as stainless steel and extends from the trailing edge 11 around the leading edge 9 beyond the point of vertical contact between adjacent gates. The piston seal and the walls of the slot 17 define a pressure fluid chamber 19 therebetween. It should be understood that if a trunnion is not employed at both gate ends, the slot 17 would preferably be machined in the gate end surface. A pressure fluid supply pipe or conduit 21 is connected to a passageway provided in the wicket gate trunnions 8. This passageway 22 is connected in fluid communication with the pressure fluid chamber 19. Pressurized fluid can then be provided through the conduit 21 into the chamber 19 to urge the piston seal l8 into liquid sealing engagement with the sideplates 12. Because the trunnions pass through the sideplates when the wicket gates are rotated, a portion of the piston seal will be always engaged with the sideplates to ensure that the piston seal does not slip out of the slot 17.
With this arrangement, is a very effective and complete seal can be provided between the ends of the wicket gates and the sideplates. Because the seals are in the wicket gates themselves rather than in the sideplates the seals are not exposed to abrasive material that flows over the sideplates when the gates are open. Also, with the seals in the gates rather than the sideplates, smaller pieces are machined and assembled thereby simplifying these operations. Furthermore, with the preferred embodiment disclosed, the seals can be applied to existing units without requiring the machining of major components of the turbine which may not in some instances be thick enough to accommodate the seals.
The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
1. In combination with a hydraulic machine including a plurality of wicket gates having at least one trunnion pivotally supported in stationary machine components located adjacent to opposite ends of the gates, means providing a liquid seal between said stationary components and said gate ends comprising: walls defining a groove in at least one end of said gates from the leading to trailing edge thereof, said groove being open to the end and one face of said gates; a plate releasably connected to the face of said gates and overlying said groove,
- said plate and the walls of said groove defining a fluid chamber having one open end overlying the adjacent stationary component when the gates are in a closed position; said means including a seal piston slidably contained within said chamber and replacable when said plate is removed; and fluid conduit means in fluid communication with said chamber to direct pressure fluid thereto for urging said piston seal into liquid sealing engagement with one of the stationary components.