Speed regulating apparatus for fluid driven prime movers

Abstract

Claims

May 5, 1953 c. H. LANGWORTHY SPEED REGULATING APPARATUS FOR FLUI D DRIVEN PRIME MOVERS Filed Aug. 9, 1950 INVENTOR. HTTOENEYfi Patented May 5, 1953 UNITED STATES?! PATENT OFFICE SPEED REGULATING APPARATUSJFOR FLUID DRIVEN PRIME MOVERS Application August 9, 1950, SerialNo. 1785415 1 -Claims. 1. This invention. relatesto apparatus frregulatingthe speed. of fluid driveniprime. movers, and moreiparticularlvto such apparatus in which a governor-controlled. valve. can he closed...inde pendently of the governor. In. certain operations it is .necessarytooperate a prime-mover intermittently; forexample when a steam turbine drives ablower whose discharge isuserl only at intervals. In such cases it is preferredto reducethe speed of the blower to apoint where lit-will deliver very little gas, butwhere it w llremainflrunning and. be ready to be brought quickly up to normal-operating. speed. In the past this generally hasbeen .done by operating a shutoff valve whichisalternately. wideopen and fully closed. "When. closed, asmall amount of steamic bypassed. around -the valve to nozzleswith which the steam turbine is equipped,- sothat theturbine will"teepjrunning. A major disadvantage in suchoa system-is the necessity for introduoinga separate control valve to controllthe speed of the turbine while the shut-ofi valve is open. It is mung the objects of this invention to provide speed control apparatus for fluid driven prime movers, which doesnot require an independent shut-oh" valve, which operates smo'othl which does not require frequentservicing, and which is always ready'to bring the speed or the turbine 01 .ickly unto its prop operating range. Another object is to providesuch'apparatus' in. whicha speed control valve 'also servesas aehut-oif valve; In accordance with this invention a governor valve is mounted in supply line of a mov that drive by fluid pressure. The valve includes a :novablerncmbcr for controlling fluid ficwit. Thismernher is movedhy an. s. 'movable stern projecting from the h Mounted adjacent the outer endof the stem is a rod which movable axially by'means' actuated in" accordance with thespeed of the prime mover. The rod operatively connected to the store in such a way that movement of the rod in one its two directions or movement will close the valve. A spring is provided for opening the valve. Selectively operable means are provided for moving the stern against the resistance of the spring to close the valve independentlv of the position of the rod. 'lhe pref-cried embodiment of the invention is illustrate which Fig. l is a vertical section through the apparatus with the valve about half way open; Fla. 2 is a side View, partly in section, with the valve closed; and Fig. 3 is a fragmentary end view of the apparatus shown in Fig. l. . O in the accompanying drawings in Referrin to. the drawings, a. governor. valve housing. i is. provided withaniinlet 2. in its side and with. an outlet Slat one end. This valve housingcanmbe connected inv a. fluid pressure line, such. as-lthe line that suppliessteam to. aturbine (not shown). that may drive a blower or. other piece ofequi-pment which is-used intermittentlybut which iswkept-.in.oontinuous operation. in- side thevalve housingits inlet is separated frmn its outlet .bya sleeve ilcoaxial.With-.the outlet. This sleeveis providedinteriorly with apair of spaced annular ribs 3 and 7 that form valve seats" Between these ribsv the sleeve is. provided-with .a series of. circumferentially spaced steamportsti TheendLof thesleeve next to the valve outlet is. providedwith radial spokes 9, the inner. ends of whichare joined together to form a bearing-1! l in which oneend-of. a horizontal valvestern lt is slidably mounted. The opposite endof the stem extends slidably through. a. packing-gland 53, with which the end of. the valve housing-is provided Insiclethe valve sleeve a valve member it isrigidlymounted on the valve stem for movement with it. This member is formedfor engagementwith both valve seats simultaneously. The valve member is hollow so-thatwhen it is pulled away-from the seats'some of the steam can flow past theinner seat landthen out through the valve member to the valve outlet. When the valve :is closed, steam is delivered to theidling nozzles of the turbine through an idling connection. it communicating with the space he tween the valve housing and sleeve i.- The inner end of the valve supports a bracket H on whichal'iuid pressure actuated controlv H3 is'mounted. This control includes a diaphragm' it that supports a control stem or rod 2t which extends slidably through the top of the bracket. The diaphragmais flexed by liquid pressureunder the-control of a conventional governor on the turbinet- Asthe speed of the turbine-increases,- the diaphragm is pressed down, and it is pressed upward when the turbine speed diminishes. Slidably mounted on the control rod below the top of bracket El is a block 22 which is provided with a pair of pins that project in opposite directions into the upper fork of a bell crank 24 which is supported by a pivot 25 from the bracket. The lower end of the crank also is forked and straddles a pin El pivotally mounted in'the opposite sides of a yoke 23 supported by the outer end of the valve stem. It will be seen that if the upper end of the crank is swung up or down the lower end of the crank will move the valve stem out or in and open or close the valve. The upper end of the crank is swung down by a pair of jam nuts 30 mounted on rod 20 and engaging the top of the sliding block which as shown in Figs. 1 and 3, normally is held up against these nuts by a coil spring 3| compressed between the bottom of the block and lock nuts 32 on the lower end of the rod. Consequently, when the control rod is moved downward by diaphragm IS the jam nuts 38 swing the crank in a clockwise direction to close the valve. When the rod is moved upward by the diaphragm, the coil spring 3| swings the crank in the opposite direction to open the valve. The openin and closing of the valve therefore are under the control of the diaphragm which, in turn, is responsive to the speed of the prime mover in a well-known manner. In this way the prime mover can be operated at a constant speed. When it is desired to slow down the turbine to idling speed the valve is closed by a separate mechanism which is operated at Will by an operator or automatically. Although control rod 20 will be in a position to hold the valve open, it will not interfere with closing of the valve because block 22, which will be moved downward by crank 24, can slide down the rod and compress spring 3| as shown in Fig. 2. At the same time the rod will be moved upward, because the reduction in speed of the turbine will cause its governor to call for wider opening of the valve. Of course, this upward movement of the rod at this time can do nothing except compress the spring still more. The mechanism by which the valve is closed independently of the position of the control rod consists of a crank 35 that can be swung back and forth by a fluid pressure motor. The crank is pivotally mounted in the outer end of a bracket 36 supported by a plate 31 that extends downward from the valve. The motor includes a cylinder 38 oscillatably mounted in the bracket, and a piston rod 39 that projects from the upper end of the cylinder and is pivotally connected to the inner end of the crank. Ordinarily fluid pressure is delivered to the lower end of the cylinder so that the free end of the crank will be swung outward away from the valve as shown in Fig. 1. When it is desired to close the valve independently of the control rod, fluid pressure is delivered to the upper end of the cylinder in any suitable manner. in a counter-clockwise direction and cause its free outer end to move the valve stem to valve closing position. To cushion the impact of crank 35 against the valve stem, a socket member 4| is screwed on the outer end of yoke 28. The outer end of this member is provided with an axial opening in which a plunger 42 is slidably mounted. Inside of the socket the plunger has a collar 43 which normally is pressed against the outer end of the 6 This will swing crank 35 I against the collar and the yoke. When, as shown in Fig. 2, crank 35 is swung toward the valve stem, it strikes the projecting end of this plunger which can slide into the socket against the resistance of the spring therein and thereby cushion the impact. As long as the crank is held in valveclosing position, the fluid pressure on diaphragm l9 has no effect on the valve. When the crank is swung in the opposite direction the compressed coil spring 3| on the control rod immediately slides block 22 up the rod to jam nuts 30 and thereby swings bell crank 24 counter-clockwise to fully open the valve, because the diaphragm already is in position to hold the valve wide open. This brings the speed of the turbine up quickly to its operating range. According to the provisions of the patent statutes, I have explained the principle of my invention and have illustrated and described what I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the appended claim, the invention may be practiced otherwise than as specifically illustrated and described. Iclaim: Speed regulating apparatus comprising a valve housing, a valve member in the housing for controlling fluid fiow through it, an axially movable stem connected to the valve member for moving it and projecting from the housing, a control stem mounted adjacent the outer end of the valve stem at an angle thereto, means operatively connected to the control stem for moving it axially, a crank pivotally mounted beside the adjacent ends of the two stems, means operatively connecting one end of the crank to the valve stem for movement therewith in opposite directions, the opposite end of the crank being movable lengthwise of the control stem, means on the control stem limiting movement of References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,425,412 Norwood Aug. 8, 1922 1,575,138 Trotter Mar. 2, 1926 2,276,227 Dillman Mar. 10, 1942 2,319,336 McCullough May 18, 1943

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Patent Citations (4)

    Publication numberPublication dateAssigneeTitle
    US-1425412-AAugust 08, 1922Taylor Instr CosValve mechanism
    US-1575138-AMarch 02, 1926Westinghouse Electric & Mfg CoGoverning apparatus
    US-2276227-AMarch 10, 1942Detroit Lubricator CoControl device
    US-2319336-AMay 18, 1943Phillips Petroleum CoRegulating mechanism for valves

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    US-3987998-AOctober 26, 1976Chandler Evans Inc.Servo valve control system
    US-4183690-AJanuary 15, 1980Farm Equipment Company, Inc.Apparatus for coupling a rotatable control device to a stationary switch
    US-4527769-AJuly 09, 1985Xomox CorporationApparatus for moving a controlled member to a predetermined position
    US-6722528-B2April 20, 2004Fisher Controls International, Inc.Rotary pneumatic actuator