US3370831A

US3370831A - Turbine control apparatus

Info

Publication number: US3370831A
Application number: US522086A
Authority: US
Inventors: Jeffrey M Lazar
Original assignee: Honeywell Inc
Current assignee: Honeywell Inc
Priority date: 1966-01-21
Filing date: 1966-01-21
Publication date: 1968-02-27
Anticipated expiration: 1985-02-27

Description

Feb. 27, 1968 J. M. LAZAR TURBINE CONTROL APPARATUS Filed Jan. 21, 1966 FIG. 2

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F I G I INVENTOR.

JEFFREY M AZA W ATTORNEY United States Patent Oflflce 3,370,831 Patented Feb. 27, 1968 3,370,831 TURBINE CONTROL APPARATUS Jelfrey M. Lazar, Rosemount, Minn., assignor to Honeywell Inc., Minneapolis, Minn., a corporation 7 of Delaware Filed Jan. 21, 1966, Ser. No. 522,086 4 Claims. (Cl. 253-52) This invention relates to the field of control apparatus and more particularly to means for controlling the speed of operation of equipment powered by turbines and similar fluid actuated driving means.

The primary object of this invention is to provide speed control apparatus characterized by freedom from flyweights, springs, and moving parts generally, so that the speed control is simple, eflicient, and economical to manufacture, and may be made integral to some extent with the power source being controlled.

FIGURE 1 in the annexed drawing, which forms a further part of this disclosure, is a schematic showing of a speed control system according to the invention, and FiGURE 2 is a view taken along the line 2-2 of FIGURE 1.

In the drawing 10 is a power shaft carried in suitable bearings such as 11, for driving any suitable output load. A reaction wheel 12 is fixed to shaft 10 for rotation therewith, and is provided with a plurality of shaped blades or turbine buckets 13 at its periphery. The web 14 of wheel 12 is traversed axially by a plurality of equally spaced apertures 15.

Concentric with wheel 12 is a mounting ring 16 which carries a plurality of

fluid amplifiers

17, 18, and so forth spaced around the center of the ring and secured thereto by suitable means 19. The amplifiers are shown as if transparent for clarity and illustration. Each comprises an inlet port 20, a control port 21, a first output port 22 through which fluid from inlet port is initially discharged, and a second outlet port 23 through which the fluid is discharged when a signal is supplied to the control port. Outlet ports 22 act as nozzles for supplying reaction fluid to blades 13 of wheel 12. Inlet ports 20 are connected through a manifold 24 to a source of fluid under pressure.

Mounted in any suitable manner on opposite sides of wheel 12 are a pair of tubes 25 and 26. The common axis of these tubes is aligned with the axis of shaft 12, and its radial displacement from the shaft is the same as the radius of the circle on which apertures 15 appear. Tube 25 is connected to the source of fluid under pressure. Tube 26 is connected through a restriction 27 to a resonant chamber 30 one dimension of which is Variable by a piston 31 slideable within the chamber by a rack and pinion drive 32 to determine the resonant frequency of the chamber. The output of chamber 30 is transmitted through the fluid amplifier 33 of one or more stages, an integrator 34, and a conduit 35 to the control port of fluid amplifier 17. Outlet port 23 of this amplifier is connected by a conduit 36 to control port 21 of amplifier 18, and so on around ring 15.

The operation of my system is as follows. When it is desired to operate some load device driven by shaft 10, fluid under pressure is supplied to manifold 24 and tube 25. The fluid passes through outputs 22 of

amplifiers

17, 18, and so on and impinges on turbine blades 13', causing rotation thereof which moves apertures 15 past tubes 25 and 26. This results in a train of fluid pulses in tube 26 at an initial low frequency. The frequency corresponding to the maximum speed of shaft 20 may be computed, and piston 31 is set to adjust the dimensions of chamber 30 so that the chamber is broadly resonant at frequencies beginning with this value and extending over a range of 20 percent for example. Unless the pulses have a frequency within this range, the chamber merely attenuates them and they do not emerge with suflicient amplitude to trigger amplifier 33. When the frequency is within the predetermined range resonance results in reinforcement of the pulses and they become large enough to trigger the amplifier and thus supply a signal through integrator 34 and conduit 35 to the first amplifier 17..The signal is a step function which causes the fluid stream to transfer from outlet port 22 to outlet port 23, thus supplying a signal to transfer the fluid stream in amplifier 18, and so on. The result is that fluid flow to drive the turbine wheel is quickly interrupted: there is no delay required to overcome the momentum of any rotating parts.

When the fluid flow is cut off the turbine speed naturally begins to decrease. In some applications a single increase of speed beyond the predetermined maximum calls for permanent stopping of the apparatus until some supervisory action, such as an inspectionof the device driven by shaft 10 for example, may be accomplished. In this sort of an

application amplifiers

17, 18, and so on may be bistable, so that once the stream has transferred to outlets 23 it continues there after the control signal in conduit 35 disappears, if such happens to be the case. Deliberate reset of the system is accomplished by temporarily interrupting the supply of power fluid to manifold 24: when the supply of fluid is then established amplifier, 17, 18, and so on once more deliver fluid through output ports 22. This is an overspeed cutofl system.

In other applications it is suflicient merely to reduce the speed until it is again less than the maximum value, continuous operation of the system being desired. In this case amplifiers 17, 18, and so on must be monostable, so that if the control signal disappears after the streams have transferred to outlet ports 23, the streams automatically revert to outlet ports 22. This is a speed control system.

It will be understood that the full stream from outlet port 23 of the first amplifier 17 may be more than sufficient to control subsequent amplifier 18 and that a tap in port 23 may be taken for the control function, the remainder of the stream in port 23 being dumped. One advantage of my invention is that outlet ports 23 may be continued to discharge against the back face of blades 23, thus providing a braking action, where this is desired.

I claim as my invention:

1. Turbine control apparatus comprising:

a rotatable reaction wheel having a plurality of peripheral blades;

a first fluid amplifier for driving said wheel having an inlet port adapted to be connected to a source of fluid under pressure, a first outlet port oriented to act as a nozzle for normally directing fluid against said blades, a second outlet port for discharging fluid remote from said blades, and a control port which, when energized, provides a fluid control signal to interrupt the normal flow of fluid through said first outlet port and initiate flow of said fluid through said second outlet port;

means for producing a train of fluid pulses having a frequency which varies with the speed of rotation of said wheel;

a resonant chamber having an inlet connected to receive said train of fluid pulses and an outlet, said resonant chamber producing an output signal only when the frequency of said train of fluid pulses is substantially the same as the resonant frequency of said chamber;

a second fluid amplifier having an inlet port adapted to be connected to a source of fluid under pressure, said second fluid amplifier having a control port and an outlet port through which fluid is discharged when a signal is provided at said control port;

me'ans connecting said outlet of said resonant chamber to said control port of said second fluid amplifier; an integrator connected to receive fluid from said outlet port of said second fluid amplifier, said integrator being operable to supply a signal to said control port of said first fluid amplifier, thereby interrupting the flow of fluid normally discharged against said blades of said reaction wheel when the speed of said wheel substantially corresponds to the resonant frequency of said resonant chamber.

2. The apparatus of claim 1 wherein:

the size of said resonant chamber is adjustable, thereby providing an adjustable speed control for said wheel.

3. The apparatus of claim 1 wherein:

a plurality of fluid amplifiers are provided for driving said wheel, said plurality of amplifiers being arranged circumferentially around said wheel, each of said plurality of amplifiers having an inlet port adapted to be connected to a source of fluid under pressure, a first outlet port oriented to act as a nozzle for normally discharging fluid against said blades, a second outlet port for discharging fluid remote from said blades, and a control port which, when energized, provides a fluid control signal to interrupt the normal flow of fluid through said first outlet port and initiate flow of said fluid through said second outlet port. 1

4. The apparatus of claim 1 wherein:

said means for producing a train of fluid pulses includes the web of said rotatable reactionwheel having aplurality of equally spaced axial apertures UNITED STATES PATENTS 2,982,902 5/1961 Gates et a1. 253 59 X 3,136,326 6/1964 Bryant 253s9 x 3,260,271 7/1966 Katz 1373 6 EVERETIE A. POWELL-1a., Primary Examiner.

Claims

1. TURBINE CONTROL APPARATUS COMPRISING: A ROTATABLE REACTION WHEEL HAVING A PLURALITY OF PERIPH ERAL BLADES; A FIRST FLUID AMPLIFIER FOR DRIVING SAID WHEEL HAVING AN INLET PORT ADAPTED TO BE CONNECTED TO A SOURCE OF FLUID UNDER PRESSURE, A FIRST OUTLET PORT ORIENTED TO ACT AS A NOZZLE FOR NORMALLY DIRECTING FLUID AGAINST SAID BLADES, A SECOND OUTLET PORT FOR DISCHARGING FLUID REMOTE FROM SAID BLADES, AND A CONTROL PORT WHICH, WHEN ENERGIZED, PROVIDES A FLUID CONTROL SIGNAL TO INTERRUPT THE NORMAL FLOW OF FLUID THROUGH SAID FIRST OUTLET PORT AND INITIATE FLOW OF SAID FLUID THROUGH AND SECOND OUTLET PORT; MEAND FOR PRODUCING A TRAIN OF FLUID PULSED HAVING A FREQUENCY WHICH VARIES WITH THE SPEED OF ROTATION OF SAID WHEEL; A RESONANT CHAMBER HAVING AN INLET CONNECTED TO RECEIVE AND TRAIN OF FLUID PULSED AND AN OUTLET, SAID RESONANT CHAMBER PRODUCING AN OUTPUT SIGNAL ONLY WHEN THE FREQUENCY OF SAID TRAIN OF FLUID PULSES IS SUBSTANTIALLY THE SAME AS THE RESONANT FREQUENCY OF SAID CHAMBER; A SECOND FLUID AMPLIFIER HAVING AN INLET PORT ADAPTED TO BE CONNECTED TO A SOURCE OF FLUID UNDER PRESSURE, SAID SECOND FLUID AMPLIFIER HAVING A CONTROL PORT AND AN OUTLET PORT THROUGH WHICH FLUID IS DISCHARGED WHEN A SIGNAL IS PROVIDED AT SAID CONTROL PORT; MEANS CONNECTING SAID OUTLET OF SAID RESONANT CHAMBER TO SAID CONTROL PORT OF SAID SECOND FLUID AMPLIFIER; AN INTEGRATOR CONNECTED TO RECEIVE FLUID FROM SAID OUTLET PORT OF SAID SECOND FLUID AMPLIFIER, SAID INTEGRATOR BEING OPERABLE TO SUPPLY A SIGNAL TO SAID CONTROL PORT OF SAID FIRST FLUID AMPLIFIER, THEREBY INTERRUPTING THE FLOW OF FLUID NORMALLY DISCHARGED AGAINST SAID BLADES OF SAID REACTION WHEEL WHEN THE SPEED OF SAID WHEEL SUBSTANTIALLY CORRESPONDS TO THE RESONANT FREQUENCY OF SAID RESONANT CHAMBER.