US986943A - Governing of fluid-operated motors. - Google Patents

Description

O. A. PARSONS & A. Q. CARNEGIE. GOVERNING 01" FLUID OPERATED MOTORS.

APPLICATION PILrD JAN. 11, 1910.

Patented Mar. 14, 1911.

3 BHEETBSHEET 1.

InZJeN/Z'ERS: Charis; A ,Paw-somfz,

- A v e by (A O. A. PARSONS & A. Q. CARNEGIE. GOVERNING or FLUID OPERATED, mo'rons.

Arm-101111011 rmzn mun, 1910. 986,943. Patented Mar. 14, 1911.

' 3 sums-sum 2.

I I flush/Tons.- C /zarZesA ,Panmmffiz,

wk. am

O. A. PARSONS & A. Q. CARNEGIE. GOVERNING OF FLUID OPERATED MOTORS.

APPLIOA'IION FILED JAN. 11, 1910.

986,943, Patented Mar. 14, 1911.

3 SHEETS-SHEET 3.

Ira/62am Parsan d'arrze g ww/w 21 has been proposed I pressure CHARLES ALGEBNON PARSONS AND ALFRED QUIN'I'IN CARNEGIE, OF NEWCASTLE UPON-TYNE, ENGLAND; SAID CARNEGIE ASSIGNOR T0 SAID PARSONS.

GOVERNING OF FLUID-OPERATED MOTORS.

Specification of Letters Patent.

Patented Mar. 14., 1911.

Application filed January 11, 1910. Serial No. 537,573.

To all whom it may concern:

Be it known that We, CHARLES YALGERNON Pnnsons and ALFRED QUINTIN CARNEGIE, subjects of the King of Great Britain and Ireland, residing at Heaton Works, Newcastle-upon-Tyne, in the county of Northumberland, En land, have invented certain new and usefuf'lmprovements Relating to the Governing of Fluid- OperatedMotors, of which the following is a specification.

This invention relates to improvements in the governingof fluid operated motors of the kind which are operable by fluid of more than one pressure.

In mixed pressure turbine plants either of the, type in which the turbine normally runs on low pressure working fluid but is provided with means for changing to high pressure supply or of the type in which'the turbine normally runs on high ressure working fluid but is provided with means 'for changing to a low.pressure supply a considerable alteration of speed may occur in changing from high pressure supply to low supply or vice versa, this alteration being additional to the variations which occur on account of changes of load. For

instance, a turbinenormally driven by low pressure fluid may rotate say three per cent. faster than when it is being driven by high pressure fluid; this may occur even with such governing gear in whicha special device is provided to close the low pressure inlet valve independently of the action of the governor when a predetermined reduction in exceeded. Hitherto however no means have been produced for varying the load on the governor to control the amount of alteration of speed which occurs in thus changing from one pressure to another, although it to operate the high and low pressure valves simultaneously through floating levers or the like from the movement of the governor under variations of speed consequent upon changes of load.

The object of the invention is to provide means for varying the load onthe governorof a mixed pressure plant so as to correct the alteratlon of speed which occurs in consequence of changing the source of supply.

The invention consists in a device for con trolling or regulating the alterations of speed which may occur in mixed pressure turbines consequent upon changing the the pressure of the low pressure supply is source of pressure supply, said device being adapted to vary the load on the governor.

The invention also consists in combining the above mentioned controlling device for speed variations consequent upon changing the source of supply with a controlling device for speed alterations under load changes, both devices being adapted to operate on one governor.

The invention further consists in combining the above device for controlling speed alterations consequent upon changing the source of supply with such controlling means in which a device isprovided to close the low pressure inlet valve independently of the action of the governor when a predetermined reduction 1n the pressure of the 7 low pressure supply is exceeded.

The invention further consists in the speed governing or controlling devices for mixed pressure turbines hereinafter described.

Referring now to the accompanying drawings:-Figure 1 shows one wa of carrying the invention into effect, in w iich a Bourdon tube is used to influence the governor. Fig. 2 is a modification of the arrangement shown in Fig. l in which the leverage of the Bourdon tube can be varied. Figs. 3 and 4 show other arrangements for carrying out the invention, the latter figure showing one form of the device as applied to a mixed pressure turbine.

\Vhile the mixed pressure turbine is running on the low pressure steam or other fluid the high pressure element is running idly, and there is no difference of pressure between the two ends of that element but as soon as the supply of low pressure fluid falls and the high pressure fluid comes into action, there is a difference of pressure, and we utilize this difference of pressure to make the speeds at both working pressures-the same as one another. It will be seen that a difference in speed will occur as a difference of pressure must be established across the high pressure element, but this actual alteration from the normal speed is a momentary one only, that is, one lasting only while the changing over is actually taking place so that the turbine shall run at the same speed with either pressure.

In carrying this invention into effect according to one construction in which a Bourdon tube, a, be used as is shown in Fig. 1 one end of it is fixed opposite to a steam pipe, Z), connected to the high pressure part, t, of the/turbine or engine at or near the high pressure inlet and the other end is connccted by suitable means-say a link, c to a rod, 01, passing through a stuifing box, e, in a steam tight casing, 7", which incloses the Bourbon tube, a. This casing f, is connected with the turbine or engine at or in front of the low pressure inlet to the low pressure element. The points ofconnection are rep-. resented in Fig. 3 by the reference letters, 5 and u respectively. through the stufling box, 6, is connected directly or through any suitable means to the end of a lever g, which acts upon the governor h: This lever is provided with a hand regulating spring, 2', in order to vary at will the loading of the governor h.

In operation the difference of pressure across the high pressure element when high pressure fluid is being admitted to it will cause the curvature of the tube, a, to. change and consequently the lever, g, which acts upon the governor, 12., will be moved so as to shift the governor collar j. Where as shown a ball governor is used in. which with reduced speed the balls approach each other and raise the governor collar to open the valve, the Bourdon tube .a, will through the operating lever g, pressin an upward direction on the governor collar, 7', and thus bring the balls of the governor together faster than they would come together under ordinary circumstances by the action of the spring, is, thus causing the steam supply .valve to be opened quicker than the governor by itself would effect. The result of this is that the duration and amplitude of the speed variation are both reduced.

It will be understood that the connection from the Bourdon tube, a, to the operating lever, 9, may be of any suitable kind and in the modification of the invention shown in Fig. 2 the rod 01, or other element which passes through the. stuffing box a, from the end of the Bourdon tube a, is connected to one end of a lever 'mwhich is mounted on a fixed pivot *n, at the other end. Between the extremities of this lever m, are several holes, 0, to any one of which one end of a link, p may be connected the other end of said link being connected at anyjone of a corresponding number of holes 9 formed in the end of the lever, g, which acts on the governor, IL. The object of this ar- -rangement is to enable some regulation to be obtained between the force produced in the Bourdon tube. a, by a given difference of pressure and that required to influence or correct the governor, h, to the desired amount. It is of course obvious that any other suitable device may be used which will give suitable regulation in the leverage between the Bourdon tube or its equivalent and the governor. A hand regulating spring,

The rod, (1, passing to a weight, 2, wh ch straddles over the end of a lever, 3, pivoted at an intermediate point 4, and connected directly or by suitable linkage to. the free end of a pivoted lever, g, which engages with the governor, h,

this lever, g, being the same as that hereinbefore referred to. A lian'd regulating spring, 2', as previously described, is also provided. When the device is arranged for a mixed pressure turbine running normally on the low pressure, the bottom of thecylinder, a, is connected by a pipe, 13, to the high pressure element at or near the high pressure inlet, and the top of the cylinder, 'w, is connected by a pipe, 14:, to the low pressure element at or in front of the low pressure admission point the two points of, connection being represented in Fig. 4 by the high pressure and low pressure inlet valves, 5 and u, respectively as already mentloned. When the turbine is running on' lowpressure, the piston, 00, is in its lowest position, and its connection with they weight, 2, is of such a kind that the weight is lifted free of the lever, g, this operation taking place by gravity, the weight of the piston at being greater than the weight, 2. Under these circumstances the governor ll, controls the speed of the turbine in the ordinary manner, and. takes care of changes of load.- In changing over from low to high pressure supply, a difference of pressureis produced between the two points of connection 5 and a) of the cylinder, w, to the turbine, and the piston, :1 is raised toward the top of the cylinder; this allows the weight, 2, to sink upon the lever,g, and thereby loads the governor,-h, but the connection between the piston lever, y, and the weight, 2, is such that the piston, as, may continue its up movement,,'after the weight, 2, has. become stationary. The effect of this is that the governor, h, is prevented from cutting off or throttling the supply, until the speed of the turbine has become normal. By adjusting the load supplied to the governor h, by this stance the lever, y, might be extended and provided with a series of holes to which the 'hnk, p, could be attached, thereby adjusting the distance of'the weight, 2, from the fulcrum, 4, of the lever, 3. v

A further modification is shown in Fig. 4

"der, in which case the as applied to a mixed pressure turbine to which the high pressure steam is admitted by the valve, 5, and low pressure steam by the valve, u. The piston, :10, within the cyl-. index-,4, is arranged to act upon the governor lever, g, by a link, -7, to which the piston, :20, is connected by a spring, 6, which is always under slight compression to insure that the piston, m, shall return to the bottom of the cylinder, w, when no diflerence of pressure exists. The normal position of the piston, 00, when the turbine is running on low pressure, is at the bottom of the cylingovernor h, is free to operate in its usual manneiybut when changing from low to high pressure, the difference of pressure produced raises the piston, 01:, which thereby acts upon the governorh, in such a way as to load it, no

weight being employed. In order to insure the correct pressure being applied to the governor lever the piston, :11, is made relatively large and its motion is limited by means of suitable stops. The size of the piston is such that a very small pressure diflc'erence say one or two pounds per square inch is sufficient to raise it to the top of its stroke and so enable it to apply a definite and prearran ed correction to the governor. It will e understood of course that the speed correction when changing over 21, the

from one source of supply to the other is a fixed amount and is independent of change of load and the same correction is required at no load as at' full load. The governor-lever, g, is pivoted at one end at 8 and hasattached to its other end a piston, 9, working within a dash-pot 10. A spring 11, is also provided and arranged as shown, this spring being capable of regulation by the hand'wheel, 12. This spring, 11 is equivalent to the hand controlled spring, i, previously described.

The governor, h, controlling the speed of the turbine is geared to the turbine shaft, 18, by a belt, 19, runningon pulleys, 20 and latter of which drives a governor shaft by means of bevel wheels, 16 and 17. Any convenient means may be employed for "connecting the operating element with the governor, for instance, levers, links, chains, pulleys and the like may be used. Also throttle valves may be fitted in the connections leading to the cylinder, w, etc., and be fitted. The invention may than of also be applied to governors other to fluid the centrifugal type, for instance, governors.

In cases where the mixed pressure turbine is run normally on high pressure steam, the device may be suitably inverted in a manner which will be evident so that the governor shall beloaded in the opposite manner to that previously described.

* Any of these devices for taking care of the alterations of speed, consequent upon changing the source of pressure may be used in conjunction with any device for taking care of variations of speed, consequent upon changes of load, and if desired, in combination also with such controlling means in which a device is provided for closing the low pressure inlet valve independently of the action of the governor when a predetermined reduction in the pressure of the low pressure supply is exceeded.

Having now fully described and ascertained our sa-id invention and in what manner the same is to be performed, we declare that what we claim is 1. In combination in a fluid operated plant having a motor, a plurality of sources supplying working fluid to said motor at various pressures, a speed controlling device operable on'a pressure difference in the interior of said motor between the admission points thereto being established or removed.

2. In combination in a fluid operated plant having a motor, a plurality of sources supplying working fluid to said motor at various pressures, means governing the speed of said motor, a speed controlling device operable on a pressure difference in the interior of said motor between the admission points thereto being established or removed,

- whereby on changing the source of fluid supply to the motor, said device influences said governing means the speed of the motor.

3. In combination in a fluid operated planthaving amotor, a lurality of sources supplying working fiui various pressures, means governing the speed of said motor under a variation of load and means controlling'said governing means, the operation of said controlling means being consequent upon changing the source of fluid supply to said motor.

ll In combination in a fluid operated plant havin a motor, a plurality of sources supplying fluid to said motor at various pressures, means governing the speed of the motor, means acting upon said governing means to restrain the movements thereof and means acting upon the governing means in opposition to said restraining means to control any change of speed consequent upon changing the source of fluid supply to said motor.

plant having a motor, a low pressure and a high pressure source supplying working fluid to said motor and speed controlling means subjected to the pressure of the fluid in the high pressure source and to the pressure of that in the low pressure source whereby on changing the source of fluid supply to said motor, said means control any change in the speed of the motor.

6. In combination in a fluid operated plant having a motor, a high pressure and a to control any variation in to said motor at low pressure source supplying working fluid to said motor, means governing the speed of said motor under a variation of load, an element adapted to be subjected to the pressure of the fluid in the high pressure and low pressure fluid sources and connected to said governing means, whereby said element influences said speed governing means to control any change of speed when the source supplying fluid to said motor is changed.

7. In a fluid operated plant having a motor, a'highpressure and a low pressure source supplying working fluid to said motor, a rotary governor regulating the speed of said motor, a sleeve on said governor and a controlling device connected to said governor sleeve and operable on a pressurediflerence between the admission points to said motor being. established or removed, thereby controlling the speed of said motor on the 'sourceof fluid supply thereto being changed.

8. In a fluid operated plant having a motor, a high pressure and a low pressure source of working fluid'for said motor, a rotary governor regulating the speed of said motor and hand operated means .to restrain the movement of said governor occasioned by a change of'load on the motor, a device comprising a cylinder and a piston movlng therein, said piston being subjected on one side to the high pressure fluid on the latter being supplied to the motor while the other side is always subjected to the low pressure fluid, suitable connections between said piston and governor, whereby, on the source supplying the working fluid to said motor being changed, said device acts upon the governor to control any change inthe speed of the motor. L

9. In combination in a fluid operated plant having a motor, a high pressure and a low pressure source supplymg working fluid to said motor, rotary governing means regulating the speed of said motor under a variation of load, an element subjected to the pressure of said fluid sources, lever means -.onnecting said element with the governing means, and hand operated spring means connected to said lever means-for varying the load on the governing means, whereby on the source supplying working fluid to said motor being changed said element acts upon the overning means to control any change in t e speed of the motor. 10. Inv combination in a fluid operated plant having a motor, a high pressure and a lowpressure source supplying working fluidto said motor, governing means regulatingthe speed of said motor under a .variation of load, a cylinder, a piston movable in said cylinder and adapted to be subjected to the fluid pressure of both sources, lever means connecting said element with the govermng means, and hand operated spring tor, a murce of high fluid to said motor, rotarygoverning means regulating the speed of said motor under a variation of load, an element Wl'llCll can be subjected to the pressure of both of said sources, lever means connecting said element and governing means, hand operated spring means connected to said lever means for varying the load on said governing means,

means for weighting said lever means, said weighting means being connected to said element and removable by the movements of the latter whereby on changing the source of supply to said motor, said element causes the weighting means to load the governing means and thus to control any change in the speed of the motor.

12. In combination with a-turbine having a high pressure and a low pressure part, two sources of fluid at different pressures supplying working fluid to said parts and a speed controlling device subjected to the pressure of the fluid at the inlet point to each of said parts and operable on a dilference of pressure between said inlet points being established or removed.

13. In combination with a turbine having a high pressure and a low pressure part, means governing the speed of said turbine and an element connected to said governing means and subjected to the difference of pressure across the high pressure part of the turbine, whereby on said high pressure part being connected with the low press! c part said, element acts upon thegoverni means to control any change in the'spee ofthe turbine. i

14. In combination with a turbine having a high pressure and a low pressure part, means for governing the speed of said turbine under a variation of load, an element subjected to the difference of pressure established across said high pressure turbine part when the latter is supplied'w'ith working fluid, lever means connecting said governing means with' said element and hand operated means connected to' said lever means and adapted to var the load on said governing means, where y on said high pressure turbine being supplied with work- 1ng fluid said'element acts upon said gov-' ernmg means to control any change in the speed of the turbine.

15. In a fluid operated plant having a mo- 4 ressure and a source oflow pressure worklng fluid, means controlling the var1at1on 1n the speed of said motor consequent upon changing the source of fluid supply and means acting independently of any speed governing means to shut off the low pressure source when a redetermined reduction of pressure in the ow pressure source is exceeded. i

16. In combination with a turbine having a high pressure and a low pressure part, means for governingthe speed of said turbine under a variation of load, a cylinder and a piston moving therein, said piston being subjected on one side to the pressure of the fluid in the high pressure turbine part and on the other side to the fluid pressure in the low pressure turbine part, lever-means connecting said piston with the governor means and hand adjustable means acting to load th'egoverning means and also connected to said lever means, whereby on one of said turbine parts being put out of action, said piston moves within the cylinder and controls the amount of load put on the governing means b the loading means thus preventing asu den change in the speed of the motor.

In testimony whereof we aflix our signatures in presence of 'two witnesses.

CHARLES ALGERNON PARSONS. ALFRED QUINTIN CARNEGIE. Witnesses:

FREDERICK GORDON HAY BEnFoRn, ALBERT \VILLIAM PARK.

Images