US2357228A

US2357228A - Hydraulic turbine

Info

Publication number: US2357228A
Application number: US434628A
Authority: US
Inventors: Seewer Paul Werner
Original assignee: English Electric Co Ltd
Current assignee: English Electric Co Ltd
Priority date: 1941-03-07
Filing date: 1942-03-13
Publication date: 1944-08-29
Anticipated expiration: 1961-08-29
Also published as: DE845930C; GB568530A; CH249223A

Description

Aug. 29, 1944. P. w. SEEWER HYDRAULIC TURBINE Filed March 13, 1942 4 Sheets-Sheet 2 Aug. 29, 1944. P. w. SEEWER HYDRAULIC TURBINE Filed March 13, 1942 4 Sheets-Sheet 3 ii ilil P. w. SEEWER 2,357,228

HYDRAULIC TURBINE 4 Sheets-Sheet 4 Filed March 13, 1942 Patented Aug. 29, 1944 HYDRAULIC TURBINE Paul Werner Seewer, Rugby, England, assignor to The English Electric Company Limited, London, England, a British company Application Mai-ch 13, 1942, Serial No. 434,628 In Great Britain March 7,, 1941 4 Claims.

This invention relates to water turbine and pump 'rotors and to marine and aeroplane propellers of the swivelling blade type, and since it has for its object blade swivelling gear which can overcome forces of considerable magnitude acting on each blade the invention will be described as applied to a hydraulic turbine. v

The invention uses inside the rotor an axially reciprocating hydraulic servo-motor, a crank substantially rigid with each swivelling blade and operative connections directly between each crank and the servo-motor. In order that the servo-motor acts on each crank with considerable leverage and in order to accommodate in the rotor operating gear for six or eight blades the present invention provides that each crank extends, in one of its working positions, parallel to the rotor axis, while the operative connections are disposed to transmit to the cranks a bladeswivelling force in a direction at a considerable angle to the axis of the rotor. According to a further feature of the invention, each crank extends at the side of and outside the servo-motor and the operative connections are similarly located so that when the cover or hood is removed from thehub the servo-motor, cranks and operative connections are all exposed. According to another feature of the invention using an axially reciprocating servo-motor, a member reciprocable with the servo-motor has therein a plurality of'flat-sided channels (one per crank) inclined at an angle to the axis of the rotor and the cranks which extend substantially axially from the blades inside the rotor each carry a flat-sided slider block mounted on the end of the crank, said slider blocks being each a sliding fit within the said flat-sided grooves.

The invention is illustrated by the accompanying drawings of which Fig. 1 is a vertical cross section through the rotor axis of one form of hydraulic turbine according to the invention, Fig. 2 is a sectional plan transverse to Fig. 1, Fig. 3 is a partly diagrammatic view showing the servo-motor piston, a prismatic grooved member reciprocating therewith, the slider block and the crank which actuates one of the swivelling blades, Fig, 4 is a partly diagrammatic view showing the servomotor cylinder partly cut away to expose the piston therein and showing also the cross-head member secured to the lower end of the piston rod but with the prismatic grooved member removed, Fig. 5 is a diagrammatic side view of a crank with'its slider block in the groove in the prismatic member, while Fig. 6 is a cross-section-corresponding to Fig. 1--through a modifled form of turbine according to the invention.

As shown in Fig. 1, eachv swivelling turbine.

blade I is cast in one piece with its spindle la and with an operating crank lb depending there. from or is fabricated by welding the crank to the spindle or is otherwise formed integrally with the spindle and crank. The spherical hub 2a of the rotor incorporates bearings for the spindles la. Each spindle is provided with an inner and an outer bearing, each crank being located bebearings are split are scraped t ether and securely joined by a tightening solution or other tightening agent and thereby sealed both against the ingress of water and the egress of lubricating oil, The rotor is completed by the hood Ila secured to the hub 2a and which may terminate in a separate nose l3 and is closed by the manhole cover l4. 4

'Pivotally mounted on the lower end of each crank lb is a block 5 with flat edges slidably fitting in a fiat-edged groove 61; in one face of a hollow prismatic member 6 disposed around the axis of the hub. The crank lb and the swivelling slider block 5 are shown separated from each otherand from the prismatic member 6 in Fig. 3. For an eight-bladed rotor theprismatic, member 6 is octagonal as shown in- Fig. 3 and in plan in Fig. 2. The fiat-edged groove Ea is inclined to the axis of the hub, as in Figs. 3 and 5; a similar groove is cut in each face of the prismatic member 6, as indicated in Figs. 2 and 3.

As shown in Fig. 1, thelower end of the prismatic member 6 is supported by a cross member I which, as shown also in-Fig. 4, is rigidly connected to the lower end of a'hollow axial servomotor piston'rod 8 carrying a piston 9 which can reciprocate in the cylinder. Ill secured to the hub member 2a and co-axial therewith. The periphery of the member 1' is provided with a diametrically opposite pair of projections lb which engage and can slide axially between channelled guide members I la projecting inwardly from the wall of the hood. The prismatic member 6 fits over the'iocating spigot is on the member I and between the guide proiectlons'lb. The spigot Ia and projections 'lb -before the member l is mtinplaceareshownin1'i8.4whichalso shows the rim I provided on the fixed cylinder II and over which the member i can slide. The lower portion oi. the piston rod 8 slides through a packed gland in the cylinder cover l2.

A stationary p pe 1 an s ly fiuid under pressure from-the control valve through the hollow interior or the upper part 01' the cylinder II and thegrwvesQDinthepistonrodBtotl-ie cylinder above the piston O. The inner pipe l.- which is secured to and reciprocates with the pistcnrodisothatitsupperendcanbeusedto indicate the position or the piston and or the blades-also supplies fluid through the interior of piston rod 8 and through discharge openings la to the cylinder space below the piston 9. The space between the outer pipe l5 and the bore 01' the turbine shaft l! is used for the supply oi lubricating oil to the interior of the hub and the hood; the level of the lubricating oil accordingly alters with up and down movement or the servomotor, surplus oil going back to the source of s pp y- It will be appreciated that downward withdrawal of the hood II and nose. ll from the hub without any further dismantling of the rotor ex;

the prismatic member 6 lying outside and aroimd the servo-motor, to the cranks lb and blocks i (since these lie outside the servo-motor) and to the blade bearings. Downward withdrawal of the cross member I and of the cylinder cover I! then give access to the piston 8. It will be further understood that the described construction reduces the number of operating parts substantially to a minimum. By reducing also the number of parts which have to be crowded into the diameter of the hub, the space available for the bearings is considerably increased and bearings 01 ample size can be provided.

In operation the axial reciprocating movement of the piston 9, the cross member I and the prismatic member 6 imparts a swivelling movement to the cranks lb (and hence to the blades I) through the slider 5 and the groove in, different positions of the crank and slider for different axial positions of the member C being shown in Fig. 5. The line of action of the force acting on the end of each crank l b is perpendicular to the side face of the groove 6a and is accordingly inclined at an angle to both the horizontal and the vertical. The eflective leverage is accordingly the perpendicular distance from this line to the blade axis and this distance again is inclined ata considerable angle to the horizontal. It will be appreciated that accordingly for a given diameter of the hub and hood and a given number of blades the effective leverage can be considerably greater than in arrangements in which this distance is horizontal. The centre line of the crank when the latter is in its mid position could be vertical but is preferably inclined to the vertical as in Fig. 5. If this centre line in the mid position were parallel to the sides of the grooves b the sliding movement relativeill to these grooves would be reduced to a minimum and the leverage would remain substantially constant. If space conditions make this impossible, then as a compromise the crank may be arranged to swing about a mid position which lies between the vertical and a direction parallel to the sides of the grooves 6b. The force be accordingly considerably reduced (which allows the servo-motor'to be accommodated, as described, within the hood) the stroke oi the piston being, however, correspondingly increased. It will be understood that the total work done on each blade and all the blades for any given operating condition including the extreme conditions hereinbeiore mentioned remains unaltered and hence the maximum work to be done by the servo-motor remains as before; the work is done, however, by employing a smaller force acting through a longer stroke. The force applied to the lever is transmitted directly to the blade since the lever is integral with the latter and the risk of backlash developing in operation is eliminated.

The modification shown in Fig. 6 difiers from the arrangement shown in Fig. 1 in that the servo-motor piston is stationary while the'hollow prismatic member 8 serves also as the servomotor cylinder.

The piston rod 8, which is hollow and carries the piston l as previously described, is secured by its upper flange to to the huh 2 coaxially therewith. The combined prismatic member and cylinder i has its upper boss 8b by a-cover it having a boss Ila also bored to fit on the lower portion of the piston rod I and also carrying the diametrically'opposite pair of projections llb which engage and can slide axially between the channel guide members Ila. The lower end of the boss Ila is closed by the cap llc which is securely fixed thereto and which also closes up the lower end of the pipe l8 which is fixed to the cap and so moves up and down with the cylinder 8.

The stationary pipe II can supply fluid through the hollow interior of the piston rod I and the discharge openings la to the cylinder space above the piston 9. The inner pipe I can supply fluid through the discharge openings lia and the grooves 8b in the lower part of the piston rod 8 to the cylinder below the piston 9. I

In the application of the invention to marine and aeroplane propellers the rotor axis will be horizontal instead of vertical and directions referred to in the description as horizontal will remain transverse to the propeller axis and will therefore be vertical.

What I claim as my invention and desire to secure by Letters Patent is: L-

l. A vertical hydraulic turbine rotor comprising a hub incorporating a plurality of horizontal bearings, a plurality of swivelling propeller blades mounted in said bearings and projecting from said hub, a reciprocating hydraulic servomotor inside said rotor below the blade bearings and reciprocable axially of the rotor, a crank substantially rigid with and extending downwardly from each swivelling blade and located inside the rotor but at the side of and outside of'saidservo-motor, an operative connection between the servo-motor and the lower end of each said crank for transmitting to said end a blade-swivelling force in a direction at a considerable angle to the axis of the rotor, and a hood removable from said hub to expose said servo-motor, cranks and operative connections.

2. A swivelling-propeller-bladed rotor comprising a hub, bearings incorporated therein, a plurality of swivelling propeller blades mounted in said bearings and projecting radially from said hub, a reciprocating hydraulic servo-motor inside said rotor and reciprocable axially of the rotor, a crank inside the rotor substantially rigid with each swivelling blade and extending therefrom in one of its working positions parallel to the rotor axis, a slider block pivotally mounted on the end of each of the said cranks, said servo-motor having an axially reciprocable member formed with a plurality of channels respectively slidably receiving the said respective blocks and inclined at an angle to the axis of the rotor receiving said blocks, each of the latter having sides shaped to correspond to the sides of the corresponding channel in which the said block is a. sliding fit.

3. A swivelling-propeller-bladed rotor comprising a hub, bearings incorporated therein, a plurality of swivelling'propeller blades mounted in said bearings and projecting radially from said hub, a reciprocating hydraulic servo-motor inside said rotor and reciprocable axially of the rotor, a crank inside the rotor'substantially rigid with each swivelling blade and extending therefrom parallel to the rotor axis in one of the working positions of said blade, a flat sided.

block pivotally mounted on the end of each of the said cranks and a hollow prismatic member disposed around, and axially reciprocable as part of, the said servo-motor, said prismatic member having a number of side faces equal to the numberof swivelling blades and in each face a fiat sided channel inclined at an angle to the axis of the rotor, each of said blocks being a sliding fit within one of said flat sided channels.

4. A vertical hydraulic turbine rotor comprising a hub incorporating a plurality of horizontal bearings, a plurality of swivelling propeller blades mounted in said bearings and projecting from said hub, a reciprocating hydraulic servomotor inside said rotor below the blade bearings and reciprocable axially of the rotor, a hollow member around said servo-motor, axially reciprocable as part thereof and having in its outer surface a plurality of channelssteeply inclined to the horizontal, rigid guides in said rotor for said channeled member, a plurality of cranks respectively substantially rigidwith and extending downwardly from the respective swivelling blades and inside of the rotor at the side of the channelled member, a plurality of slider blocks respectively pivotally mounted on the ends of the respective cranks, said blocks respectively having sides shaped to correspond to the sides of the corresponding channel of the respective channels in which the respective blocks make a sliding fit, and a hood removable from said hub to expose the said servo-motor, channelled member, cranks and slider blocks.

PAUL WERNER SEEWER.