US2070601A - Hydraulic machine - Google Patents

Description

Feb. 16, 1937-. I G. A. JESSOPYEI' AL 2,070,601

HYDRAULIC MACHINE Filed Au 22, 1955 2 Sheets-Shea; 1

INVENTORS GEORGE A. JESSOP AND BY TORLEH': NORBOM ATTORNEY Feb. 16, 1937. G. A. JESSOP ET AL 2,070,501

HYDRAULIC MACHINE Filed Aug 22, 1955 '2 Sheets-Sheet 2 we e awe/whorls GEORGE AJESSOP AND TORLEW NORBOM Patented F eb. 16, 19 37 STATES PATENT OFFICE HYDRAULIC MACHINE Application August .22, 1935, Serial No. 37,349

4 Claims.

This invention relates to hydraulic machines, such as hydraulic turbines, pumps and the like, and more particularly to the type of hydraulic machines having runners with movable or adjustable blades. The hubs of the runners of the above type of hydraulic machines are filled with oil for lubricating the blade operating mechanism within the runner hub, and the present invention relates more particularly to specific mechanical details for supplying oil under pressure to the hub of the runner from a suitable reservoir carried by the shaft of the hydraulic machine.

An object of the invention is to provide improved means for maintaining a predetermined pressure of lubricating oil in the runner hub of adjustable blade hydraulic machines.

Another object of the invention is to provide an improved means for maintaining the lubricating oil in the runner hub of an adjustable blade hydraulic turbine at a predetermined pressure by means of compressed air.

Another object of the invention is to provide an improved lubricating system for hydraulic machines of the character mentioned, Which is simple in construction, and reliable and exact in function under all conditions of service.

The invention also comprises certain new and useful improvements in the construction, arrangement and combination of the several parts of which it is composed, as will be hereinafter more fully described and claimed.

In the accompanying drawings:

Figure l is a view partly in section of an adjustable blade hydraulic turbine embodying the present invention;

Fig. 2 is an enlarged vertical section of a portion of the runner of the turbine shown in Fig. 1;

Fig. 3 is a horizontal section taken on the line 33 of Fig. 2; and

Fig. 4 is an enlarged vertical section of the servomotor for operating the runner blade adjusting mechanism.

Referring to the drawings, wherein the turbine is. shown connected to an electric generator for the purpose of operatirg the same, the complete generating unit may comprise ahydraulic turbine H, an electrical generator I2, and a governor mechanism l3.

As is well known in the art, the governor I3 is .adapted to automatically control the operation of the turbine, so that the turbine will operate at a substantially uniform speed, irrespective of the variations of the load.

The turbine H has a runner which is made with. adjustable blades, the angular positions of which are adapted to be varied according to the load, so that the turbine will operate at its highest efiiciency at all times.

In mechanisms falling within the scope of the present invention, the controlling fluid is generally oil, means being provided for controlling the oil in such a manner that when the governor l3 operates to adjust the angles of the wicket gates of the turbine, the runner blades will be caused to rotate in a similar direction so as to efiect a corresponding adjustment in the angles or positions thereof. In this Way the parts of the turbine will be simultaneously adjusted so that all of the parts Will at all times retain their correct relationship with each other and the turbine will operate with maximum eiliciency and smoothness and with minimum vibration.

For the purpose of controlling the actuation of the runner blade operating mechanism, a control device l5 may be employed. This control de- 20 vice may be operatively connected with the governor l3 and function in the manner shown and described in McCormack Patent No. 1,937,772, granted December 5, 1933, for Hydraulic turbine.

The turbine ll may comprise a casing I6 which forms a peripheral water inlet in which are mounted an annular series of Wicket gates I l and guide vanes I 4.

Projecting from the lower ends of the wicket gates H, are trunnions I 8 which are journalled in the adjacent portion of the casing.

Likewise, stems I 9 project upwardly from the wicket gates H and terminate a suitable distance thereabove. The stems i 9 are rotatably mounted in the upper portion of the casing I6.

The wicket gates I! are adapted to be simultaneously rotated into different angular positions to control the flow of water into the turbine in the usual manner, and for this purpose the upper ends of the stems l9 are usually provided with gate operating arms 20 which are fixed to said stems and connected by links to a gate adjusting ring 2|. The gate adjusting ring 2! is connected by link means 22 to a shaft 23 of the governor mechanism l3.

The lower portion of the turbine casing l6 forms an axially directed chamber 27 in which the runner 28 operates.

The hub of the runner 28 is fixed to the lower end of a hollow or tubular shaft 29. The upper end of shaft 29 is connected to the shaft 3.! of the generator l2 as shown in Figs. 1 and 4.

Any suitable type of setting may be used for the turbine installation, a concrete setting 32 being shown in the present instance. The electrical generator [2 may rest on top of the setting as shown in Fig. l.

- A suitable number of blades 34 are rotatably supported in the hub of the runner 28 and project radially therefrom.

The inner end of each blade 34 is formedwith a trunnion 35 which is journalled in bearings 35 supported in the hub.

Means are provided for simultaneously rotating all of the blades 34 and for maintaining them in equal angular relationship, such means comprising preferably an arm 38 rigidly fixed on the trunnion 35 of each blade and links 33 which connect the arms on the different blades to a cross head 43 fixed to the lower end of an operating rod 43 which extends upwardly through the hollow runner shaft 29. As shown in Fig. 4 the upper end of the operating rod 43 is fixed to the piston 44 of a servomotor 45. which is mounted in the runner shaft 29 adjacent the point where the runner shaft is joined to the generator shaft 3!.

The servomotor piston 44 may be contained in a cylinder which may be formed as an enlargement of the runner shaft 29, the upper portion of said cylinder being closed by the lower portion of a bearing for the operating rod 43, provides means through the shaft 3| to a head 55 which is by means of a passage or port 54 formed in the shaft 3 l the generator shaft 31, as shown in Fig. 4.

The upper portion of the operating rod 43 passes through a bushing 46 mounted in the runner shaft 29, and this bushing besides forming for closing the chamber 41 on the lower side of piston 44.

The servomotor in order to supply oil to both sides thereof for the purpose of operating the same in both directions, two tubes or pipes 48 and 49 are employed. The pipes 48 and 49 are mounted within the hollow generator shaft 3| and rotate therewith, said pipes extending from the servomotor upwardly mounted on top of the generator i2 as shown in Fig. 1. The lower end of pipe 49 is in communication with chamber 41 on the lower side of the servomotor piston 44, and the lower end of pipe "48 is in communication with chamber 5! on the upper side of piston 44.

The lower end of pipe 49 is fixed to a cap 52 carried by the piston 44, and chamber 53 formed within the cap, is connected to piston chamber 4'? piston 44, so that oil supplied through pipe 49 will flow into chamber 41.

The lower end of pipe 48 terminates above the cap 52, so as to be in communication with chamber SI of the servomotor. The lower end of pipe 48 may be secured to the lower end of the generator shaft 3| by means of a member 55 having a peripheral flange which is bolted or otherwise secured to the adjacent portion of the generator The member 55 provides means for closing the lower end of the hollow generator shaft 3i and thereby cuts off communication from the chamber 5| to the space within said shaft ex- .teriorly of the pipes 48 and 49.

' valve device iii of the governor mechanism is through pipes i5! and 12, respectively. As fully explained in Patent 1,937,772 above referred to,

through the action of the governor in accordance with variations in load, oil will be supplied to the chambers on the opposite sides of the servomotor piston 44 to operate the same and thereby effect rotationof the runner blades.

- 'The mechanism within the hub of therunner piston 44 is double acting, and

28 requires thorough lubrication. Therefore, it

has been customary to fill the hub of the runner with some suitable heavy lubricating oil, since the comparatively light oil used in the governor mechanism for operating the servomotor 45 does not possess sufficient lubricating properties for satisfactorily lubricating the blade operating mechanism within the runner hub.

With two kinds of oil thus used in the turbine, several problems have been confronted in actual practice. One of these. problems has been the provision of suitable means for preventing the two oils from becoming mixed together to such an extent as to prove ruinous to the proper functions of either, i. e., to provide means whereby the light oil supplied to the servomotor 45 is prevented from flowing down through the hollow turbine shaft 29 and mixing with the heavy lubricating oil in the hub of the runner 28.

Another problem has been to provide suitable seals around the joints where the trunnions 35 of the adjustable blades 34'enter the hub of the turbine, so as to prevent leakage of the lubricating oil in the hub outwardly through these joints and the entrance of water, sand and other impurities inwardly through these joints.

It is almost impossible to provide a seal which will entirely prevent leakage of the governor oil from the bottom of the servomotor 45 into the hollow runner shaft 29 leading downwardly to the runner hub. It is much better to have any oil leakage which occurs here to be in the direction such that the light governor oil passes to the heavy lubricating oil, rather than have the heavy oil mix with the light oil. This is because of the delicacy of the governor 13 which would have its functions interfered with if any substantial quantity of the heavyv oil should become mixed with the light governor oil. On

the hub and substantially reduce its viscosity.

As shown in Fig. 4, rod 43 fits snugly in bushing 48 and the latter functions to close the upper end of the hollow runner shaft 29 and thus prevent oil in chamber 4"! from entering the hollow runner shaft 29 in appreciable quantities.

According to thepresent invention the heavy lubricating oil for the hub of the runner 28 is supplied to interior of the hub through a port or passage 6E! in runner shaft 29. This port or passage may be located at any convenient place in the runner shaft 29 between the topof the runner and the bottom of servomotor 45.

In the present instance it is shown disposed slightly above the upper portion of the turbine casing I6.

Surrounding the runner shaft 29 and enclosing the outer end of port or passage 60 is athe hub of the runner. 28, and in order to proheavy lubricating oil for the mechanism within vide means whereby oil may be supplied thereto from time to time in order to replenish the amount contained therein, the wall of the chamber 6| is formed with two openings which are normally closed by screw plugs 64 and 65, respectively. As shown in Fig. 2, the openings may be superposed, one being disposed near the bottom of chamber 6| and the other near the top.

Chamber 6| is also provided with a sight glass or other element 66 by which the level of the oil within the chamber will be indicated.

Heretofore it has been the practice to employ an open oil reservoir which was located on the revolving runner shaft at a distance below the servomotor. The maximum level of the heavy lubricating oil in the hub was therefore a considerable distance below the servomotor.

In installations where the head is relatively high the pressure of the water on the runner blades is for the most part of the operating range higher than the oil pressure in the hub. Since the pressure of water in the runner hub is undesirable, and since it is practically impossible to keep the packings of the runner blade trunnions absolutely tight, it is necessary, in order to prevent water leakage, to keep the pressure of the oil within the runner hub higher than the maximum pressure of the water outside of the hub. To do this it is necessary to maintain the pressure of the lubricating oil within the runner hub sufficiently high, so that the natural oil level is higher than the elevation of the servomotor. However, since this is not possible to do, by the present invention, it is proposed to increase the pressure of the lubricating oil within the runner hub and maintain the oil under increased pressure by means of compressed air supplied to the oil chamber 6|.

'With compressed air in the chamber 6| the pressure of the oil within the hub of the runner can be such that the lubricating oil will have a natural level equal to the elevation of the part of the turbine oil head which supplies the oil to the chamber 41 on the underside of the servomotor piston 44, and still not have a tendency for the heavy hub oil to leak into the light governor oil with which the servomotor is operated.

In filling the runner hub with heavy oil, sulficient oil is used so that the chamber 6| is approximately half filled with oil. Then compressed air is introduced into chamber 6| and the pressure raised to the desired point. This pressure can be the equivalent to the pressure which would be obtained if the free level of the hub oil ex tended up to the part of the oil head of the turbine which feeds the bottom chamber 41 of the servomotor 45, or to any elevation desired between the servomotor and said point in the oil head. The pressure of the governor oil in chamber 41 of the servomotor 45 is always substantially the equivalent to the static head of oil between the oil head and the bottom of the servomotor cylinder. If the pressure in the chamber 6|, therefore, does not exceed the limit as described above, there will never be any tendency for leakage of the heavy lubricating oil into the light governor oil. In the event that, through the process of governing, high pressure is introduced below the servomotor piston 44, then, of course, there will be a tendency for the light oil to leak into the heavy oil.

The vertical operating rod 43 moves up and down to operate the runner blades. When rod 43 pressed air, so that the variation in pressure at the'extreme oil levels will be small, and'so that in any event the oil pressure maintained is sufficient to prevent leakage of water into the hub of the runner around the joints between the trunnions of. the runner blades and the hub.

The chamber 6 I, which revolves with the main shaft 29 of the turbine, should be fastened toshaft 29 in such a way that the chamber 61 is tight against oil leakage on the bottom and air leakage on the top. Chamber 6| should be balanced so that there will be no unbalanced revolving load on the shaft 29. It is necessary to have means,- such as provided by the opening closed by plug 64, so that an instrument can be attached to the chamber 6| to check the pressure therein at any time the apparatus is shut down and also by which additional air under pressure can be introduced into chamber 6|. The lower opening which is normally closed by plug 65 provides a connection whereby oil can be introduced into or removed from chamber 6|.

Mechanisms of the type herein described, when installed in hydro-electric power plants, have to be shut down from time to time for the purpose of lubrication, inspection and adjustment. When the mechanisms are being inspected, it is customary to remove the plug 65 and replenish the supply of oil in chamber 6|. After the supply of oil has been replenished, it is then customary to remove plug 64 and insert in the opening closed by plug 64 a hose leading from a source of supply of compressed air and thus supply additional air under pressure to chamber 6| to bring the pressure of air in said chamber up to the desired amount, after which the air hose is removed and the plug reinserted in its opening.

By designing the hydraulic and mechanical balance of the runner blades in such a way, that it is always necessary to maintain some pressure underneath the servomotor piston 44 in order to keep the servomotor from moving downwards, it is possible to maintain an oil pressure in the hub of the runner 28 so that the normal level of the oil will be higher than the elevation of the oil head and still not have a tendency for the heavy oil to leak into the light governor oil.

It should be noted that the oil connection from chamber 6| to the passage around the blade operating rod 43, provided by port or passage 60, connects to chamber 6| at or near the bottom of said chamber. This is done so that the air in the chamber 6| is positively trapped and can never enter the oil space around operating rod 43 as long as there is oil in the chamber 6|.

Having thus described our invention what we claim is:

1. In a hydraulic machine, a runner having a hollow hub, a plurality of blades rotatably mounted in said hub, mechanism within the hub for rotating said blades, a hollow shaft connected to the hub, said hub and said shaft containing oil for lubricating the blade operating mechanism within the hub, and means for maintaining the pressure of the lubricant in the hub a predetermined amount, comprising a fluid tight oil chamber surrounding the runner shaft and rotatable therewith, and means connecting the interior of said chamber with said shaft, said chamber con taining air under pressure for increasing the static pressure of the lubricating oil in the hub.

2. In a hydraulic machine, a runner having a hollow hub, a plurality of blades rotatably mounted in said hub, mechanism within the hub for rotating said blades, a hollow shaft connected to the hub, said huband said shaft containing oil for, lubricating the blade operating mechanism within the hub, and means whereby the pressure of the oil in the hub may be maintained a predetermined amount, comprising a fluid tight oil chamber surrounding the runner shaft and rotatable therewith, a passage connecting said chamber and said shaft, means formed on said chamber whereby oil may be supplied to the chamber, and means formed on said chamber above said oil supply means whereby air under pressure can be supplied to said chamber.

oil, a hollow shaft connected to said hub, a fluid tight chamber rotatably carried by said shaft and in communication with the interior thereof, and

means whereby air under pressure may be sup plied to said chamber for maintaining the static; pressure of the oil in said hub a predetermined:

whereby oil may be supplied to said chamber,

said chamber being adapted to be only partly filled with oil, and means located above the normal level of oil in said chamber whereby air may be introduced under pressure into said chamber to increase the static pressure of the oil in the hub.

GEORGE A. JESSOP. TORLEIF NORBOM;

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