US1575138A

US1575138A - Governing apparatus

Info

Publication number: US1575138A
Application number: US726883A
Authority: US
Inventors: Henry R Trotter
Original assignee: Westinghouse Electric and Manufacturing Co
Current assignee: CBS Corp
Priority date: 1924-07-18
Filing date: 1924-07-18
Publication date: 1926-03-02
Anticipated expiration: 1943-03-02

Description

March 2 9 H. R. TRQTTER GOVERNING APPARATUS Filed July fia BY ATTORNEY WITNESS 1 2 4221 Patented Mar. 2, 1926.

UNITED. STAKES PATENT OFFICE.

HENRY R TBOTTEB, OI MORTON, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

GOVERNING APP AT S- Application fil d J ly .18, 1924.. Seri NO- 726,883-

1 '0 all idiom-it may concern.

Be it known that I, HENRY R. Tno'rrnn, a tizen of the United States, and a resident of Morton, in the county of Delaware and I5 State of liennsylvania, have invented a new and useful, Improvement in Governing Apparatus, of which the following is a specification.

My invention relates to variable fluid pressure'operated governing apparatus and it has for an object to provide apparatus of the character designated which shall be simple in design, reliable in operationand which shall permit a wide range of control of the machine governed.

Another object of my invention is to pro-.

ride a over-nin an )aratus for a n'ime mover having an admission valve wherein manually operable means may be employed for opening and closing the admission valve and wherein the admission valve, after being manually opened is controlled by means responsive to variations in fluid pressure;

A more specific object of my invention is to provide a variable fluid pressure governing apparatus embodying mechanism actuated by the variable fluid pressure and res iionsive to increases in pressure for moving an admission valve in a closing direction, and a spring opposing the variable fluid pressure acting against said mechanism permitting the admission valve to be moveu 151 an opening direction, and to PIOVlC c therein means whereby the force of the spring may also be exerted for moving the valve in a closing direction. {a 7 Apparatus made in accordance with my invention is illustrated in the accompanying drawing, in which Fig. 1 is a view, partly in section, of a steam or other fluid pressure. turbine having my improved governing: apparatus applied thereto; Fig. 2 is a sectional iew of an auto-stop governor which may be employedwith the a-l'iparatus; Fin. 3 is a sectional view of the governor; and F l a detail view of a part of the governor.

The usual type of variable fluid pressure governor tor a steam turbine embodies a pump for developing fluid under a pressure 50 varying as-a function of the speed of the turbine, a cylinder having a piston for actuating the admission valve, said piston being subjected on one side to the variable fluid piessure and on the opposite side to the force exerted by a spring. As the speed of the turbine increases, increasing the pressure of the governing fluid, the'force ot the spring: is overcome and the piston is moved in a directionfor closing the admission valve. Upon decreases in speed and governing pressure, the "force of the spring causes the piston to move in the opposite direction, moving the alve in an opening direction. i

In such apparatus, if there be a failure of governing pressure, the'force exerted by the spring moves thevalve to a wide open position, the'governing effect is destroyed and the turbine overspeeds. To 'pre ent overspeeding, it is customary to provide the tar-- bine with a second valve held open by some releasable mechanism and to provide an auto-stop ,ggovernor responsive to a 'prede tern'iined ovcrspeed of the turbine for releasing the releasable mechanism, permitting the second valve to be closed. In order to start. the turbine it is also customary to provide a manually operated throttle valve which may be opened and closed when the turbine is started or shut down.

In accordance with mv invention, I employ only one/valve which may be manually opened and closed. The means for manually opening the valve are retained in a fixed;

position by a tripoing mechanism which may be either manuallyoperated or tripped by the usual auto-stop governor, whereupon the valve is automatically closed. lVhen the valve is moved to an open position and the i'nanual means for opening the same retained, its position is controlled in the usual way by the variable fluid pressure acting a rainst a piston in opposition to the force eiaerted by a spring.

Referring now to the drawing for a fuller understanding of my invention, I show at 10 in Fig. 1 a steam or other fluid turbine having an admission valve 11 controlled by my improved variable fluid pressure governing apparatus at 152. Fluid employed in the governing apparatus is supplied from a reservoir 13'to an impeller pump 14, driven by a. shaft 16 of the turbine 10. The pump 14; develops pressure of the fluid varying with the speed of the prime mover and delivers the fluid to the overning apparatus at 12 through a conduit 17. Disposed within a diametral recess 18 of the shaft 16 is a well known type of auto-stop governor embodying a weight 19 held in position by a spring 21,. Upon a predeterminedspeed of the prime mover, centrifugal force overcomes the force exerted by the spring 21 and the weight 19 is forced outwardly, striking a member 22 (Fig. 2) forcing outwardly a rod 23, leading to the governing apparatus at 12. This causes the admission valve 11 to be closed in a manner to be more fully described later.

Referring to Fig. 3, I show a cylinder 24 supplied at the top with variable fluid pressure by the conduit 17. lVithin the cylinder is a piston 26 against which the variable fluid pressure acts. tending to force it downwardly. Movement of the piston 26 in a downwariil direction is transmitted to the valve 11 by a valve rod 27 which is held in abutting relation to said piston by a spring 28 disposed between a. collar 29 provided on the valve rod 27, and a fixed abutment 31 formed on the lower base of the governing apparatus and through which the valve rod 27 is free to move. The spring 28 is only of suiiicient strength to overcome the friction of the valve rod 27 and to raise the valve 11 to an open position when other opposition is removed. It may be seen from the drawings that the force exerted by the variable fluid pressure acting against the piston 26 tends to force it downwardly and to force the valve 11 in a closing direction.

Opposing the force of the variable fluid pressure acting against the piston 26 is a relatively heavy governing spring 32 which bears, at its upper end, against the piston 26 and at its lower end, against an abutment 33. hen the turbine is in operation, the force exerted by the spring 32 is suflicient to withstand the force exerted by the variable fluid pressure at normal operating speed. Upon increases in pressure, the force of the spring 32 is overcome, forcing the piston 26 downwvardly and the valve 11 in a closing direction. Upon decreases in pressure the spring 32 forces the piston 26 upwardly, permitting the relatively light spring 28 to move the valve 11 in an opening direction.

T he abutment 33 is slidably mounted with respect to a web 54: forming the lower end of the cylinder 2%, and is slidable with respect to the valve rod 27. Bearing against the abutment 33 is a hollow adjusting screw 36 through which thd valve rod 27 is free to move. The adjusting screw 36 screws into a supporting ring 37, which is in turn supported by a bell crank lever 38 pivoted at- 39 to the casing of the governing apparatus 12. A hand wheel 41 is provided on the adjusting screw 36 for screwing it in or out of the supporting ring 37, whereby the distance between the abutment 33 and the supporting ring 37 may be increased or decreased, the initial load on the spring increased or decreased. and the speed of the turbine thereby varied.

The bell crank lever 38 is provided with manual operating means 42 by means of which the supporting ring 37 may be raised or lowered. The supporting ring 37 (Fig. 4) is provided on each side with pins 43 and the bell crank lever 38 has two forked ends 4% (only one of which is shown) engaging the pins i3. By means of this connection the supporting ring 37 may be freely raised or lowered by the bell crank lever 38. It will be seen that raising or lowering the supporting ring 37 opens or closes the admission valve 11.

When the turbine is in operation, the supporting ring 37 is held in its upper position by means of a latch -l6 carried by a second bell crank lever 17 which is in turn connected to the rod 23 leading to the auto-stop governor which disengages said latch upon a predetermined speed of the prime mover as heretofore described. anual means d8 are also provided on the bell crank lever -17 whereby the latch 46 may be disengaged from the bell crank lever 38 when e; Jed.

hen the latch d6 disengaged from the bell crank lever 38, the spring 32 forces the slidable abutment 33 and the supporting ring 37 downwardly. The supporting ring 37 then engages the collar 29 on the valve rod 27, overcomes the upward force exerted by the spring 28 and forces the admission valve 11 closed. By this means, the turbine may be shut down when desired. Fluid leaking by the piston 26 drains into a sump 49 and from thence through a pipe 51 back to the reservoir 13.

The operation of the apparatus is as follows: lVhen it is desired to start the turbine, the supporting ring 37 for the slidable abutment 33 is raised by the manual means 42 of the bell crank lever 38 and the latch -16 of the bell crank lever 47 is engaged with the bell crank lever 38. The spring 32 now forces the piston upwardly and the spring 23, acting against the collar 29 on the valve rod 27, opens the valv ll, admitting steam to the turbine. Q'Vith the turbine in operation, fluid under a pressure varying as a function of the speed thereof is developed by the pump 1% and is delivered to the upper end of the cylinder 24; through the conduit 17. As the speed increases, the fluid pressure incrcasesand overcomes the force exerted by the spring 32 on the opposite side of the piston 26, forcing the piston 26 and the valve 11 downwardly, thus throttling the supply of steam to the turbine. Upon decreases in speed and consequent decreases in fluid pressure, the spring 32 forces the piston 26 upwardly permitting the spring to open the admission valve 11 wider.

If for any reason, the turbine should overspeed, the weight 19 of the auto-stop governor moves outwardly due to centrifugal force, striking the member 22, forcing the rod 23 upwardly and disengaging the latch 46 which holds the bell crank lever 38 in its .tixed position, This action causes the *alve 11 to be closed in a manner already described.

From the foregoing it will be apparent that I have in ented an improved variable fluid pressure governing apparatus for a prime mover having an admission valve cmbodying i'nechanisin actuated by the variable Fluid pressure in opposition to'the force can erted by a spring for closing the admission valve, wherein the admission valve may be manually opened and closed and wherein the :1: rec exerted by the governor spring may also be rendered etiective for closing said valve.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susieptible of various other changes and ll'lOfllilCtltiOIlS, without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed there upon as are imposed by the prior art or as are specifically set forth in the appended claims.

What I claim is:

1. In a variable fluid pressure governing apparatus forv a prime mover, the combination of a piston subjected on one side to the variable fluid pessure, an admission valve, a valve rod for actuating, the admission vaive, said valve rod having a collar provided thereon near its inner end and being in abutting relation to the piston at its outer end, a relatively heavy spring bearing at one end against the piston and opposing the variable fluid pressure, an abutment for the opposite end of the spring, saidabutment surrounding the valve rod and being slidable with respect thereto, means for supporting the abutment, releasable means for retaining the supporting means; in a fixed position, and means for releasing the re leasable means, whereby the relatively heavy spring forces the abutment and supporting means against the collar on the valve rod forcing the valve to a closed position.

' 2. In a variable fluid pressure g verning apparatus for a prime mover, the combination of a piston subjected on one side to the variable fluid pressure, an admission valve, a valve rod for actuating the admission valve, said valve rod having a collar provided thereon near its inner end and being in abutting relation to the piston at its outer end, a relatively heavy spring bearing at one end against the piston and opposing the variable fluid pressure, an abutment for the opposite end of the spring, said abutment surrounding the valve rod and being slidable with respect thereto, means disposed between the abutment and the collar on the valve rod for supporting the abutment, releasable means for retaining the supporting means in a fixed position, and means for releasing the releasable means, whereby the relatively heavy spring forces the abutment and supporting means against the collar on the valve rod forcing the valve to a closed position.

3. In avariable fluid pressure governing apparatus for a prime-mover having an ads mission valve, the combination of a valve rod for actuating the admission valve, a cylinder having a piston therein in abutting relation to the valve rod and actuated by the fluid pressure in a direction for closing the valve, a relatively heavy spring hearing at one end against the piston and opposing the variable fluid pressure, an abutment for the opposite end of the spring, said abutment being slidable with respect to the valve rod, a movable support for the abutment, a collar provided on the valve rod between the movable support and the valve, a relatively light s 'iring disposed between said collar and a fixed abutment, the force of said spring being exerted toward opening the valveyreleasable means for retaining the movable support in a fixed position out of engagement with the collar on the valve rod, manually operable means for the releasable means, and means operable upon a predetermined overspced of the prime mover for releasing said releasable means.

4. In a variable fluid pressure governing apparatus for a prime mover having an ad mission valve, the combination of a valve rod for actuating the admission valve, a cylinder having a piston therein in abutting relation to the valve rod and actuated by the fluid pressure in a direction for closing the valve, a relatively heavy spring bearing at one end against the piston and oppos ing the variable fluid pressure, an abutment for the opposite end of the spring, said abutment beingslidable with respect to the valve rod, a movable support for the abutment, a collar provided on the valve rod between the movable support and the Valve, a relatively light spring disposed between said collar and a fixed abutment, the force of said spring being exerted toward opening the valve, releasable means for retaining the movable support in a fixed position out of engagement with the collar on the valve rod, manually operable means for moving the movable support to said position, manually ope able means for releasing the releasable means, and means operable upon a predetermined overspeed ofthe prime mover for re leasing said releasable means.

5. In a variable fluid pressure governing apparatus for a prime mover having an admission valve, the combination of a valve rod for actuating the admission valve, a cylinder having a piston therein in abutting relation to the valve rod and actuated by the fluid pressure in a direction for closing the valve, a relatively heavy spring hearing at iii) one end against the piston and opposing the variable fluid pressure, an abutment for the opposite end of the spring, said abutment being slidable with respect to the valve rod, a movable support for the abutment, a collar provided on the valve rod between the movable support and the valve, a relatively light spring disposed between said collar and a fixed abutment, the force of said spring being exerted toward opening the valve, a latch for retaining the movable support in a fixed position out of engagement with the collar on the valve rod, manually operable means for moving the movable support to said position, means associated with the manually operable means for varying the relative positions of the movable support and the abutment, thereby varying the load on the relatively heavy spring, manually operable means for releasing the latch, and 183115 operable upon a predetermined overspecd of the prime mover for releasing said latch.

(5. In a variable fluid pressure governing apparatus for a prime mover having an admission valve, the combination of a valve rod for actuating the admission valve, a cylinder having a piston therein in abutting relation to the valve rod and actuated by the fluid pressure in a direction for closing the valve, a relatively heavy spring bearing at one end against the piston and opposing the variable fluid pressure, an abutment for the opposite end of the spring, said abutment being slidable with respect to the valve rod, a movable support for the abutment, a collar provided on the valve rod between the movable support and the valve, a relatively light spring disposed between said collar and a fixed abutment, the force or said spring being exerted toward opening the valve, a latch for retainin-gthe movable support in a fixed position out of engagement with the collar on the valve rod, manually operable means for moving the movable support to said position, an adjusting screw carried by the movable support for increasing or decreasing the load on the relatively heavy spring, manually operable means for disengaging the latch and means operable upon a predetermined overspeed ot the prime mover tor disengaging said latch.

7. In a. governing mechanism for a prime mover, the combination of means for developing fluid pressure varying as a function of the speed of the prime mover, a valve for controlling the admission or fluid to the prime mover, a cylinder, an operating piston disposed within said cylinder and subjected on one side to the variable fluid pressure, a valve rod in abutting relation to the piston for transmitting the movements thereof to the valve in a closing direction, a governing spring associated with the piston and opposing the variable fluid pressure, said spring during normal operation or the prime mover opposing the movement of the piston in closing the valve and being situated between a movable abutment surrounding the valve rod and slidable with respect thereto and the operating piston, a releasable support for the abutment, a collar provided on the valve rod between the relez sable support and the valve, a second spring relatively lighter than the first mentioned spring dis posed between a fixed abutment and the collar on the valve rod, the force of said spring being exerted toward moving the valve in an opening direction, manually operable means and means responsive to a predetermined overspeed of the prime mover for releasing the releasable support, whereby the force exerted by the first mentioned spring is transmitted through the movable abutment, the releasable support and the collar to the valve, moving said valve in a closing direction.

8. In a turbine, a valve for controlling the admission of steam thereto, a valve rod for actuating said valve, means for developing fluid pressure varying with the speed of the turbine, a piston actuated in one direetion by the variable fluid pressure for mov ing the valve in a closing direction, a relatively light springsurrounding the valve rod and bearing against a collar thereon for moving the valve in an opening direction and for holding the valve rod in abutting relation to the piston, a slidable abutment surrounding the valve rod and disposed between the collar on the valve rod and the piston, a second spring disposed between the.

HENRY R. TROTIER.