Title of Invention

"A GUIDE APPARATUS LINKAGE FOR HYDRO TURBINES"

Abstract

A guide apparatus linkage for hydro turbinescomprising a coupler (32) having left hand (33) and right hand (34) threads, right and left hand locknuts (35, 36) regulating ring (8)and strp (14) fixed to the guide vanes (1), link pins (37A, B), spacers (38), buses (39, 40), characterised in that said coupler (32) having left hand (33) and right hand (34) threads at both ends directly being coupled with said link pins (37A, B) with locknuts (36, 37) and connects said regulating ring (8) wiht strap (14) fixed to the guide vanes (1), wherein the space between said link pin (37A, B) centres holds only two lock nuts (35, 36) for a compact linkage.

Full Text

This invention relates to a guide apparatus linkage for hydro turbines. In a typical hydro power station, water is conveyed from a dam or forebay through a penstrock to the hydro turbines. In hydro "turbines of Francis and Kaplan types, water from the penstock enters a spiral casing, which admits water uniformly around the runner. The guide vanes, which are located in-between the spiral casing and the runner, regulate the quantity of water to the runner for controlling the output. Generally, there are 20 to 24 guide vanes in a turbine, which are positioned uniformly around the runner. The guide vanes are part of an important subassembly of hydro turbine, called guide apparatus. For moving the guide vanes, for opening or closing the turbine, force is provided through a .set of mechanical guide apparatus linkage. The guide apparatus linkage is a means for transmitting force of servomotors, exerted on it through a regulated ring, to the guide vanes. A pre-requisite for closing the guide vianes is that there should be proper bedding of guide vanes i.e. there should not be jany gap between the adjacent guide vanes at the sealing surfaces. For this, there should be provision of increasing or decreasing the length of the linkage. Thus, a "guide apparatus linkage" should serve the following functions : a) It should be strong enough to transmit the mechanical forces b) should have enough provision for adjustment of .length, absorbing manufacturing inaccuracies and to cater for water (of guide vane bedding surfaces) during operation c) should be simple and economical to manufecture. There are principally two types of guide apparatus linkages currently being used in-.Hydraulic Turbines. They are (!) Eccentric Pin Arrangement and (2) Turn Buckle Arrangement as represented in the accompanying drawings and described below There is also a modified guide apparatus linkage as shown in Fig.3, Fig. 1 -Guide apparatus linkage with eccentric pin arrangement: Fig. 2 -Guide apparatus linkage with turn buckle arrangement Fig. 3 -Modified guide apparatus linkage: Fig,4 -Guide apparatus linkage according to the present invention, 1) ECCENTRIC PIN ARRANGEMENT . An eccentric pin as shown in Fig.l is known in the art for adjusting the length linkage of each guide vane (1). The linkage comprises a link plate (6) connected through two pins, one at each end, and known as concentric pic (7) and eccentric pin (4). The concentric pic (7) connects the link plate (6) with a regulating ring (8) and the eccentric pin (4) joins the link plate (6) with strap (3), which in turn is fixed with the guide vane (1) through the guide vane lever (2). The eccentric pin (4) has a square head (5) at the top and is fixed to the link plate (6) by the locking plate (9) with a square hole (10) matching the square head (5) holes in fixed to the link plate (6) with four screws provided, The concentric pin (7) is fixed to the link piste (6) with help of a locking strip (11) and four screws provided The eccentric pin consists of upper and lower cylindrical portions, which fare eccentric to each other. Effective lonqlh of the linkage ca be increased or decreased by adjusting angular position of the eccentric pin. When the eccentricity is along the length of the link plate, effective length of the linkage t increases or decreases depending upon whether the eccentricihy is towards or away from the link. If eccentricity of pin is 6mm then the maximum adjustment possible is 12 mm i.e. from -6mm to +6mm. However, in a particular position when the eccentricity of the pin happens to be perpendicular to axis of the link plate, the effective length is same as that of the link plate itself. Limitation of this arrangement is that adjust-ment provided is small, requiring precision machining of components, thus increasing the cost. 2) TURNBUCKLE ARRANGEMENT Another construction known in the- art is a turn buckle arrangement (Fi.2) comprising a coupler rod (20), having'right, hand threads (19) at one end and left hand~threads (18)- at the other end is used for adjusting length of linkage of each guide vane. The threaded ends of the coupler (20) engage in corresponding eye-ends (12, 13), which have female threads and fixed with the L.H. and R.H. lock Nuts (16,17). One of the eye-ends ( 1.2),: connects the coupler (20) with regulatin ring (8) and the other one (13) joins' it with the strap (14) with link pin (15,22) which in-turn is fixed with the guide vane. The link Pins;(15,22) each provided with flat milled heads (21,23) to prevent rotation. length of the linkage can be increased or decreased by turning the coupler. Turning the coupler in one direction pulls the linkage inside, thus decreasing the length. Whereas, turning in opposite direction will push the linkage and increase the length. If the coupler length is long, ample adjustment is possible, however, for short couplers only limited adjustment is possible. Thisjlimitation of inadequate adjustment is predominant in smaller turbines, on account of limited space avaiblable for accomodating items of the linkae. Further, for very small turbines (small in size, may not be small in capacity), 3) MODIFIED GUIDE APPARATUS LINKAGE There is also a modified version of guide apparatus linkage with link rod arrangement (Fig. 3) with two link pins,(24, 25) at two ends of the link rod (32) with R.H. threads 30, 31). The link rod is provided with R.H. Nut (28,29) and locking washer (26, 21). A disadvantage of such a construction is that reliability is not high, as the bedding of guide vanes can get disturbed due to possible shift of link rod in the clearance hole of link pin. Therefore, the main object of the present invention is to provide a simple, effective and a versatile guide apparatus linkage for hydro turbines which can be used for all types of turbines, big and small. An object of the present invention is to propose a construction of a guide apparatus linkage for hydro turbines which is compact whereby it is possible ot use it in very small turbine also. Another object of the present invention is to propose a construction of a guide apparatus linkage for hydro turbines which has.a much wider range of adjustability of linkage length for use in bi turbines. Yet another object of the present invention is to propose a construction of a guide apparatus linkage for hydro turbines in which there is a reduction of components. A further object "of the present invention is to propose a construction of a guide apparatus linkage for hydro , tiurb.ihes in which the components require fewer process of manufacture and there is an elimination of fabrication work. A still further object of the present invention is to • propose. a construction of a guide apparatus linkage for hydro turbines, in which components require lesser precision involving simpler and lesser machining operation and there is a substantial' cost reduction and enchanced productivity. Yet a further object of the present invention is to propose a standardisation of components thereby reducing inventory. According to the present invention there is provided a guide apparatus linkage for hydro turbines comprising : i) a Coupler (32) having right and left hand threads(34,33) ii) right and left hand locknuts (35,36) (iii) regulating ring (8) and strap (14) (iv) link pins (37A & B) (v) spacers (38) (vi) bushes (39, 40) One of the said coupler link pin (37A) connected to the Regulating Ring (8) and at the other end the said coupler link pin (37B) connected to the strap (14) through bushes (40,39). The nature of the invention, its objective and further advantages residing in the same will be apparent from the following description made with reference to non limiting exemplary embodiments of the invention represented in the accompanying drawings. The present invention provides a guide apparatus linkage for hydro turbines comprising a coupler having left hand and right hand threads, right and left hand locknuts, regulating ring and strap fixed to the guide vanes, link pins, spacers, bushes, characterized in that said coupler having left hand and right hand threads at both ends directly being coupled with said link pins with locknuts and connects said regulating ring with strap fixed to the guide vanes, wherein the space between said fink pin centers holds only two nuts for a compact linkage. In accordance with the present invention, a coupler having right hand threads at one end and left hand threads at the other end is used. The right hand and left hand threaded ends of the coupler engage directly in the tight hand and left hand link pins respectively. The present invention of guide apparatus linkage can be used for both big and small turbines. Linkage arrangement shown in figure 4 is for very small turbines; for medium and big turbines, the lock-nuts can be positioned on the inside of linkage i,e between link pins, if required, for tightening convenience In this design right hand and left hand threads are made directly in the pins for adjusting the length; whereas in the tumbuckle arrangement threads are made in separate forks/eye ends The design basically consists of a coupler/link rod (32) having right hand threads (34) on one end and left hand threads (33) at the other end. Unlike the previous designs, the coupler does not engage in the eye ends but engages directly in the threaded holes (33,34) made in the link pins (37A & B). connectin. regulating ring (8) with the guide vane strap (14). Thus in this modified design the intermediate eye ends are eliminated, which makes the design so compact that is can be used for small turbines also. This is because of the fact that the space between the link pin centres is only for the two lock nuts (35,36). Another salient feature of this design is that with minor modification in the location of lock - nuts and orientation of the link pins; as shown in figure 4 this design can be used for very small turbines, for which eccentric - pin, arrangement was thought to be the only alternative. The invention described hereinabove is in relation , to a non-limiting embodiment and as defined by the accompanying ;;,ela„ims. WE CLAIM: 1- A guide apparatus linkage for hydro turbines comprising a coupler (32) having left hand (33) and right hand (34) threads, right and left hand lockouts (35, 36), regulating ring (8) and strap (14) fixed to the guide vanes (1), link pins (37A, B)$ spacers (38), bushes (39, 40), characterised in that said coupler (32) having left hand (33) and right hand (34) threads at both erais directly being coupled with said link pins (37A, B) with locknuts (36, 37) and connects said regulating ring (S) with strap (14) fixed to the guide vanes (1), wherein the space between said link pin (37A, B) centres holds only two lock nuts (35, 36) for a compact linkage. 2. A guide apparatus linkage as claimed in claim 1 wherein I the orientation of the lock nuts (35, 36) are located within the link pins (37A, B) for bigger turbines and are located outside the said link pins (37A, B) for smaller turbines. 3. A guide apparatus linkage as claimed in claim 1, wherein said link pins (37A, B) are devoid of intermediate eye ends (12, 13) for a compact linkage. 4. A guide apparatus linkage as claimed in claim 1 wherein the right hand and left hand threads (33, 34) are made directly in the link pins (37A, B) for adjustment of radius for s compact 1inkage. 5. A guide apparatus linkage for hydro turbines substantially as hereinabove described and as illustrated in the drawings.

Documents:

1567-del-1995-abstract.pdf

1567-del-1995-claims.pdf

1567-del-1995-correspondence-others.pdf

1567-del-1995-correspondence-po.pdf

1567-del-1995-description (complete).pdf

1567-del-1995-drawings.pdf

1567-del-1995-form-1.pdf

1567-del-1995-form-2.pdf

1567-del-1995-form-29.pdf

1567-del-1995-form-3.pdf

1567-del-1995-form-4.pdf

1567-del-1995-form-5.pdf

1567-del-1995-form-6.pdf

1567-del-1995-gpa.pdf