US2137589A - Flywheel governor for steam driven compressors - Google Patents

Description

Nov. 22, 1938. W RAYM ND 2,l37,589

FLYWHEEL GOVERNOR FOR STEAM DRIVEN COMPRESSORS Filed Nov. 4, 1935 2 Sheets-Sheet l IN V EN TOR.

Nov. 22, 1938. w RAYMQND 2,137,589

FLYWHEEL GOVERNOR FOR STEAM DRIVEN COMPRESSORS Filed Nov. 4, 1935 2 Sheets-Sheet 2 IN VEN TOR.

' WBI'dR: mand N \gq. BY

I m ATTOR EY Patented Nov. 22, 1938 UNITED STATES FLYWHEEL GOVERNOR FOR STEAM DRIVEN COMPRESSORS Ward Raymond, .Easton, Pa., assignor to Pennsylvania Pump and Compressor Company, a corporation of Pennsylvania Application November 4, 1935, Serial No. 48,161

3 Claims.

This invention relates to a speed and load governor for a steam engine directly connected to a compressor for air or gas.

An objectof the invention is to provide a governor of the fiy-wiheel type having a spring loaded centrifugal member connected to and varying the position of a valve operating member to regulate the speed of the engine, there being a supplementary means acting upon the centrifugal member to reduce the speed of the engine when the compressor driven by the engine is unloaded.

Another object of the invention is to provide a pressure actuated plunger acting upon the centrifugal member of the governor, pressure being applied to move this plunger and force the centrifugal member toward a speed reducing position when the fluid compressed by the compressor has reached a predetermined pressure.

And finally it is an important object of the invention to provide a speed responsive element on the governor and a load responsive element acting upon the speed responsive element, these members acting to position the valve controlling member of a steam engine governor such as an eccentric, so that the speed of the engine may be maintained substantially constant during normal loaded operation of the compressor and may be maintained at a materially reduced speed when the compressor is running unloaded.

In the operation of steam driven compressors, it isdesirable to employ a standard form of governor to'control the speed of the engine as by varying the position of the valve gear of the engine by means of which the admission of steam to the engine cylinder is cut off at different points in the stroke of the "piston. An excessive speed is prevented by this type of governor and the speed will be held substantially constant at all times. Without some additional means being provided, however, this same maximum and constant speed will be maintained during those periods when the compressor may be running entirely unloaded. During such periods the speed of the engine should advantageously be reduced materially and when the compressor is again operating normally under load the speed should again :be increased as called for up .to its standard or predetermined speed.

The above objects are accomplished by de creasing .the force exerted upon the centrifugal element of the governor. for the engine by the speed regulating spring when the compressor is unloaded and the engine is rotating without appreciable load. A particular object of .theinvention therefore is to provide means, preferably fluid pressure means, acting upon the centrifugal element .of a fly-wheel governor to materially reduce the speed of the engine when the engine is running substantially unloaded.

With the above and other objects in view, my invention includes the features of construction and operation .set forth in the following specification and illustrated in the accompanying drawings.

In'the accompanying drawings annexed hereto and forming apart of this specification, I have shown my invention applied to a steam driven air compressor of the straight line type, but it will be understood that the invention can be otherwise embodied and that the drawings are 35 not to be construed as defining or limiting the scope of the invention, the claims appended to this specification being relied upon for that pur pose.

In the drawings: v

Fig. l is ,a longitudinal view of a complete steam driven compressor shown generally in outline.

Fig. 2 is a side elevation partly in section of a fly-wheel governor having the present invention applied thereto.

Fig. 3 is a cross sectional view of the parts shown in Fig. '2 taken through the axis of 0scillation :of the centrifugal member.

Fig. 4715 a sectional view of a modified form 39 of one of the details of the present invention.

In the above mentioned drawings, I have shown but :one embodiment .of the invention and a slight variation thereof, which are now deemed preferable, but it is to be understood that changes and modifications may be made within the scope of the appended claims without departing from the spirit of the invention.

Briefly, and in its preferred aspect, my invention may include the following principal parts: 40 First, a fly-Wheel governor with which a steam engine drivingly connected to a compressor may be provided; second, an oscillatory centrifugal member pivotally mounted thereon; third, an adjustable spring disposed between a portion of the fly-wheel and the centrifugal element for controlling the oscillated position of the centrifugal element at different speeds of the engine; fourth, valve gear for the engine operated by means mounted on the fiy-wheel, the position of which is controlled (by the oscillated positions of the centrifugal element; fifth, pressure operated means applicable to act upon said centrifugal element in opposition to the speed controlling spring; and sixth, connections to apply fluid :un-

der pressure to said pressure operated means from the compressor receiver.

Referring more in detail to the figures of the drawings, I show in Fig. 1 a complete general View of a steam driven compressor to which the invention has been applied. The steam cylinder is shown at H) and the compressor cylinder at l l. Pistons I2 and I3 respectively within these cylinders are on the same piston rod l4, one end of which is connected to a cross head IS. A connecting rod l6 drivingly connects the main crank shaft I lof the engine with the cross head l5. On the main crank shaft I1 is one or more flywheels |8, one of which mounts the governor controlling the admission of steam to the steam cylinder Hi. It will be understood that the governor operates by means of an eccentric, the eccentricity of which is varied and which in turn varies the movements of the steam admitting valve (not shown).

Referring now to the fly-wheel governor shown in Figs. 2 and 3, I provide an elongated arm, which is pivotally mounted on the fly-wheel I8 and forms a centrifugal element 2|. This element 2| is of the usual form of centrifugal element as used on speed responsive regulators or governors generally of the fly-wheel type. The pivot 22 by means of which the element 2| is supported upon the fly-wheel may extend through the hub of the fly-wheel l8, the element 2| being mounted on the outer side. As shown in Fig, 3, the element 2| is keyed to the pivot 22, so that oscillatory movements of the element 2| will oscillate the pivot or shaft 22. Closely adjacent the inner face of the fly-wheel is an eccentric plate 23, which may be integral with the pivot 22, and to which may be adjustably secured an eccentric 24. The peripheral surface of eccentric 24 is engaged by the eccentric strap 25 directly connected to the valve gear (not shown) of the engine by eccentric rod 26. The above described members are all of well known and usual construction employed on directly coupled steam driven compressors and therefore will not reqire further description.

The element 2| is limited in its oscillatory movements by stops 28 provided on the inner portion of the fly-wheel rim and is forced in one direction by an adjustable spring 29. It will be understood that by adjustment of the spring 29 movement outward of the element will be resisted by greater or less force so that the engine may be driven at a predetermined speed governed by the tension of spring 29. I

In addition to the spring 29 acting upon the element 2| by means of which the speed of the engine may be controlled, there is a supplemental means acting upon the element 2| in opposition to the direction of action of this spring 29. This supplemental means includes a small cylinder 32 mounted directly upon the fly-wheel l8. To one end of this cylinder 32 fluid pressure may be admitted as by means of a tube 33 the opposite end of which enters a rotating part 34. This member or fitting 34 is mounted in alignment with the axis of rotation of the fly-wheel l8. This fitting 34 is surrounded by a fixed member 35 to which fluid may be admitted as from a vertical pipe 36 extending to and supported within a stand 31 from the floor. This pipe 36 is supplied with fluid under pressure from the receiver or discharge pipe 38 of the compressor. For that purpose a tube or pipe 39 extends from the pipe 36 and stand 31 directly to discharge 38.

With fluid admitted to the small cylinder 32 a plunger 42 is forced in a direction to compress a spring 43 and force a plunger 44 outwardly. This second plunger 44 is attached by means of a suitable link 45 to the extended portion of the centrifugal element 2|. In the form of cylinder 32 shown in Fig. 2, there is an intermediate inwardly extending shoulder 46 which prevents movement of the plunger 42 beyond a central position. This shoulder 46 limits the amount to which the spring 43 may be compressed and therefore limits the force exerted against the centrifugal element 2| in a direction to oppose spring 29. I

In Fig. 4, a modified form of cylinder 50 is shown corresponding to cylinder 32, in which the force of compression exerted against the spring corresponding to spring 43 is unlimited by any shoulder and the force acting upon the centrifugal element 2| may be Widely variable by movement of piston 42. To prevent the element 2| from oscillating rapidly due to slight change in pressure within the cylinder 32 or 50, a dash pct 52 preferably may be provided, attached by its piston rod 53 to the outer end of the extended portion ofthe element 2|. Rod 53 is retarded in its movement in and out of the dash pct 52 by any usual means.

In the connection or pipe 39 between the discharge pipe 38 of the compressor and connection 36 to cylinder 32 or 50 there may be interposed a pilot valve 56. This pilot valve 56 may also control admission of fluid at receiver pressure to unloading devices with which the compressor may be supplied (not shown). Until the predetermined discharge or receiver pressure is reached therefore, no pressure will exist in the connections 39 and 36. As soon, however, as a. particular discharge pressure is reached pilot valve56 opens and admits the fluid under pressure to the cylinder 32 or 5.0 and tends to force the centrifugal member 2| toward a position which reduces the eccentricity of the eccentric 24 and thus materially reduces the speed of the engine.

With cylinder 32 the force exerted upon the member 2| by the plunger 44 is limited and with pilot valve 56 in the connection 39 the pressure of plunger 44 will be exerted upon the element 2| only when the pressure for which pilot valve 56 is adjusted is exceeded. With cylinder 32 employed but without a pilot valve in connection 39 variations of pressure of plunger 44 will be exerted against the element 2| up to the maximum permitted by the movement of the piston 42 to the intermediate position limited by projecting flange 46. With cylinder 59 employed to force plunger 44 toward element 2| and without a pilot valve 56 in the connections 39, the element 2| is subjected at all times to a variable force dependent upon the pressure of the compressed fluid, this force acting to move the eccentric 24 to a speed reducing position and in opposition to the force exerted upon the element 2| by the spring 29.

In either case when the compressor is unloaded or operating without substantialload, the centrifugal element 2| of the governor for the engine is in effect adjusted for a different and lower speed than when the engine is operating with the compressor loaded. This adjustment is accomplished by the variation in load and acts directly upon the centrifugal element of the flywheel governor.

I claim:

1. In combination, a compressor, a steam englne for driving said compressor, a governor for said engine comprising a centriiugally operated element pivoted on said flywheel and connected to control the speed of said engine, spring means resisting the action of centrifugal force on said element, a cylinder on said flywheel adjacent said element and having a fluid operated plunger therein, means connecting said plunger to said element, and means to admit fluid discharged by said compressor to said cylinder to force said plunger in a direction to reducethe force exerted by said spring upon said element, whereby the speed of the engine may be reduced when the compressor is operating in its unloaded condition.

2. In combination, a compressor, a steam engine for driving said compressor, a governor for said engine comprising a centrifugally operated element pivoted on said flywheel and connected to control the speed of said engine, spring means resisting the action of centrifugal force on said element, a cylinder on said flywheel adjacent said element and having a fluid operated plunger therein, means to limit the movement of said plunger within said cylinder, means connecting said plunger to said element, and means to admit fluid discharged by said compressor to said cylinder to force said plunger to its limited position toward said element to reduce the force exerted by said spring upon said element, whereby the speed of the engine may be reduced a predetermined amount when the compressor is operating in its unloaded condition.

3. In combination, a compressor, a steam engine for driving said compressor, a governor for said engine comprising a centrifugally operated element pivoted on said flywheel and connected to control the speed of said engine, spring means resisting the action of centrifugal force on said element, a cylinder on saidnflywheel adjacent said element and having a fluid operated plunger therein, means to limit movement of said plunger Within said cylinder, means connecting said plunger to said element, means to admit fluid pressure to said cylinder to force said plunger to its limited position toward said element when the compressor discharge reaches a predetermined pressure to reduce the force exerted by said spring upon said element, whereby the speed of the engine may be reduced when the compressor is operating in its unloaded condition.

WARD RAYMOND.

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