US2689528A

US2689528A - Gaseous fluid turbine pump unit

Info

Publication number: US2689528A
Application number: US200632A
Authority: US
Inventors: Horace S Rainbow
Original assignee: Armstrong Siddeley Motors Ltd
Current assignee: Armstrong Siddeley Motors Ltd
Priority date: 1950-01-25
Filing date: 1950-12-13
Publication date: 1954-09-21
Anticipated expiration: 1971-09-21
Also published as: BE500182A; FR1029366A; GB682402A; DE860296C; GB682403A; DE860294C

Description

Sept- 21, 1954 H. s. RAINBOW 2,689,528

GASEOUS FLUID TURBINE PUMP UNIT Filed Dec. 13, 1950 2 Sheets-Sheet 2 23 Isa.

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Patented Sept. 21, 1954 GASEQUS FLUID TURBINE PUMP UNIT Horace S. Rainbow, Coventry, England, assignor to Armstrong Siddeley Motors Limited, Coventry, England Application December 13,1950, Serial N 0. 200,632

Claims priority, application Great Britain January 25, 1950 Claims. (01. 103-47) This invention relates to a pump driven by a. gaseous fluid turbine, and particularly to such a unit as will serve for delivering relatively large supplies of fuel to the exhaust of a gas-turbine engine for re-heat purposes, in which case the motive fluid for the turbine of the unit may be air compressed by the compressor of the engine.

The main object of the invention is to provide a simple and robust construction of such a unit.

According to the invention, the turbine of the unit is of the kind including a ring of stationary nozzles which are generally tangential to a coacting rotor disposed within the ring of nozzles, and the pump is of the screw type including a helix or worm driven by the rotor and disposed end to end with a stationary coacting worm of opposite hand.

In the accompanying drawings:

Figure 1 is a sectional elevation, taken on the line l[ of Figure 2, of a turbine pump unit according to the invention;

Figure 2 is a sectional plan of the turbine pump unit, the top half being taken on theline Za-Za and the bottom half on the line 2b-2bof Figure 1; and i Figure 3 is a perspective view of the main governor parts'shown separated from one another.

In the construction shown, the axis of the rotor isvertical, with the rotor formed as a disc 1 l at the lowerend of a vertical shaft 12 which is supported by athrust and journalbearing l3 detachably secured to the casing l5 of the turbine of the unit. Thecasing is conveniently formed of main upper and lower portions, l5a, lib, detachably secured toone another and jointly providing an annular chamber l5 to which the motive fluid (for example, compressed air from the compressor of agas-turbine engine) is delivered tangentially from an inlet IT. The radially inner wall 18 of the annular chamber is formed with a ring of nozzles 19 which are substantially tangential to the rotor disc and are throated in a well understood manner and which extend in the direction of the swirl of air in the annular chamber I6. I

The disc I I has a periphery which extends axially (see Figure 1) from the inner ends of the nozzles upwardly, and round the periphery of the disc are milled bucket-like cavities 21 such that motive fluid passing through the nozzles will impinge upon the walls of the cavities and drive the rotor in the same direction as the air swirl in the annular chamber-anti-clockwise in Figure 2'. The motive fluid then exhausts upwardly of the bucket-like cavities into a volute chamber 22 ar- 2 ranged above the annular chamber 16 and vided with a tangential outlet 23.

The volute chamber and its outlet are conveniently formed in the upper casing portion l5a. This upper portion may be extended upwardly centrally to provide a cylindrical casing 25 for the stationary and rotary worms of the pump, the rotary worm- 26 being mounted above the stationary worm 21 at the upper end of the rotor shaft. The latter can be j'ournalled, as by means of a ball or other bearing 28 which is beneath the rotary worm, in the hollow interior of the stationary worm 21. Each worm may comprise two or more parallel threads as shown.

The stationary worm is formed at its lower end with a radially extending flange 39 which provides a seal with the lower end of the cylindrical casing 25. The outlet 3! of the pump is tangential to the lower end of the stationary worm chamber, the inlet 32 to the rotary worm being an axial one, For example, the casing 25 round the rotary worm can be formed with a flange 33 to be bolted against the under-side of a tank (not shown) containing fuel or other fluid to be 1 pumped, the tank having an appropriate open- 36 of the axially extending flange having axial clearance from the upper edge 31" of the periphery of the turbine disc I I.

Lastly, a seal is provided between the shaft [2 and the hollow interior of the stationary worm 21. Such seal may include a carbon or like ring 39 carried from the stationary worm by a flexible sleeve 40 and pressed downwardly, as by means of a coil spring il, onto a machined flat upper surface (for example, of a hardened steel, which may, if desired, be chromium plated) of a radial flange 42* formed on or splined to the shaft.

For construction purposes the inner wall [8 of the annular chamber I6 is conveniently formed by a separate ring secured to the lower casing portion i517, as by pins or the like 55. The nozzles may be formed as plain inclined slots provided in the upper face of this ring and fitted internally with throat producing portions 46 secured in position as by rivets 41, the upper edges of the slots being closed by the adjacent part of th upper casing portion 15a. 1

In the present instance the disc H is slidably splined, as indicated at 48', upon the rotor shaft and biased downwardly, to bring its periphery pro to the operative position shown, by means of a compression spring 49 acting between the hub 50 of the disc and the flange 42 on the shaft upon which bears the sealing ring 39 for the pump.

The under-face of the hub is engaged by a frusto-conical ring 52 which is concave downwardly and'which coacts with a ring of balls (for example, of three balls, only one, 53, appearing in the drawing) carried in slots 54 in a cage 55, both the ring and the cage being slidably splined upon the shaft splines 48. The balls react against an axial abutment 56 splined to the lower end of the shaft, just above the lower bearing I 3.

The mass of the balls is such that at suitable speeds of the rotor the axial force applied to the frusto-conical ring 52 by the centrifugal action of the balls will not exceed the axial thrust of the main compression spring 46; but, when higher speeds are reached, the centrifugal action of the balls, as they attempt to move outwardly along the slots 54 in the cage, will suddenly overcome the static friction and move outwards. This then generates an increased centrifugal force due to the increasing radius at which the balls are acting, thus rapidly forcing the ring 52, and with it. the disc I I upwardly, and substantially instantaneously reducing the effectiveness of the motive fluid on the bucket-like cavities in the periphery of the disc. The disc will remain in the raised position until the speed falls and enables the spring 49 to overcome the reduced centrifugal force generated by the balls.

The cage may, as shown, be formed with radially extending arms 58 to engage appropriate grooves 59 formed in the under-side of the frustoconical ring 52 so as adequately to guide the balls radially as they move under centrifugal action.

What I claim as my invention and desire to secure by Letters Patent of the United States is:

l. A gaseous fluid turbine pump unit, including a casing formed of upper and lower portions detachably secured to one another and jointly providing at their adjoining ends an outer wall of an annular chamber having a tangential passage leading thereto for the supply of motive fluid for the turbine, the inner wall of said annular cham-' ber constituted mainly by a ring providing a circle of nozzle openings which are generally tangential to the inner periphery of said ring, a rotor disc having its periphery adjacent the inner periphery of said ring and formed with cavities so that the motive fluid passing through said nozzle openings into said cavities, to drive said disc, will exhaustinto said upper portion as the rotor is rotated, the upper casing portion providing the outer wall of a volute chamber having a tangential outlet for the exhaust, a shaft drivingly connected with said disc and journalled in the lower casing portion on the non-exhaust side of said disc, a rotating worm fast with said shaft on the exhaust side of said disc, a stationary worm of opposite hand to the rotating worm disposed adjacent to said rotating worm and between it and said disc, said upper casing portion having a cylindrical extension forming a pump chamber for both of said worms, said pump chamber being open at its end remote from said disc, and having at its end adjacent said disc an opening through its wall for a fluid to be pumped, said stationary worm having a radially extending flange forming an end wall of said pump chamber adjacent said disc, said flange having an axially-extending flange providing part of the 4 inner wall of said volute chamber, and means journalling the upper end of said shaft in the interior of said stationary worm.

2. A gaseous fluid pum unit, comprising a sectional turbine casing including a first and second section detachably secured together, means including the adjoining peripheral portions of said casing sections forming an annular inlet chamber for the supply of motive fluid, a shaft rotatably mounted in the casing, a turbine rotor mounted on the shaft within the casing, an integral extension on said second section forming a pump casing, a pump unit including a rotatable part and a stationary part disposed in said pump casing, a radially extending flange on said stationary part of the pump unit sealingly closing the end of said pump casing adjacent the second section of the turbine casing, the other end of the pump casing being open to provide an inlet and said pump casing having a lateral outlet opening, said shaft sealingly and rotatably extending through said flange on said stationary part of the pump unit into the pump casing and said rotatable part of the pump unit being mounted on the shaft, an axial peripheral flange on said flange of, said stationary part of the pump unit extending into the turbine casing and ra-- dially spaced from an axially-extending peripheral wall of volute form of the second section to form therewith a volute chamber having an out let for the exhaust of motive fluid.

3. The combination of claim 2, wherein said stationary part has an axial opening and said shaft extends through the axial opening and the rotatable part of the pump unit is fixedly mounted on the part of the shaft extending beyond the stationary part and means is provided for sealing said shaft where it passes through said opening in the stationary part of the pump unit.

4. A gaseous fluid pump unit, comprising a sectional turbine casing including a first and a second section detachably secured together, said first section having an axially extending peripheral flange and said second section having an outwardly extending lateral flange, said flanges being detachably joined together, an inwardly extending flange on said second section adjacent the lateral flange and a ring interposed between the inwardly extending flange and the first section to form with said inwardly extending flange an inner wall of an annular inlet chamber for the supply of motive fluid, the outer wall of said chamber being defined by the axially extending flange on said first section and the outwardly extending lateral flange on the second section, a shaft rotatably mounted in the casing, a turbine rotor mounted on the shaft within the casing, an integral extension on said second section forming a pump casing, a pump unit including a rotatable and a stationary part disposed in said pump casing, a radially extending flange on said stationary part of the pump unit sealingly closing the end of said pump casing adjacent the second section of the turbine casing, the other end of the pump casing being open to provide an inlet and said pumpcasing having a lateral outlet opening, said shaft sealingly and rotatably extending through said radially extending flange into the pump casing and said rotatable part of the pump unit being mounted on the shaft, an axial peripheral flange on said radially extending flange of the stationary part of the pum unit extending into the turbine casing and radially spaced from an axially-extending peripheral wall of volute form of the second section to form therewith a volute chamber having an outlet for the exhaust of motor fluid.

5. A gaseous fluid pump unit, comprising a sectional turbine casing including a first and a second section detachably secured together at their peripheral edges, means including the adjoining peripheral ortions of said casing sections forming an annular inlet chamber, said chamber having a tangential passage leading thereto for the supply of motive fluid, a shaft rotatably mounted at one end in the first section of the casing and extending axially of said sections, a turbine rotor mounted on the shaft within the casing, an integral cylindrical extension centrally extending from said second section and forming a pump casing, a pump unit in said pump casing and including a rotatable part and a stationary part, said stationary part being interposed between the rotatable part and said turbine rotor and having a laterally extending flange sealingly closing the end of said pump casing adjacent the secondsection of the turbine casing, the other end of the pump casing being open to provide an inlet and said pump casing having a lateral outlet opening, said shaft sealingly and rotatably extending through said flange and through the stationary part of the pump unit and having the rotatable part fixed thereto, an annular peripheral flange on the flange of said stationary part of the pump unit extending axially within the second section of the turbine casing and spaced radially from an axially-extending peripheral wall of volute form of the second section to form therewith a volute chamber having a tangential outlet for the exhaust of the supply fluid, said turbine rotor being movable axially of the shaft and resilient means retaining said turbine rotor against movement axially of the shaft.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,930,381 Boone Oct. 10, 1933 2,238,502 Muir Apr. 15, 1941 2,382,412 Grey Aug. 14, 1945 FOREIGN PATENTS Number Country Date 244,176 Great Britain Dec, 14, 1925