US551749A - Steam-engine governor - Google Patents

Description

(No ModeL) I 2 8heets8heet 1. F; H.& B. 0. BALL. STEAM ENGINE GOVERNQR- No. 551,749. Patented Dec. 24, 1895.

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(No Model.) 2 SheetsSheet 2.

"11H. &B.'O.BALL, STEAM ENGINE GOVERNOR.

' Paltented Dec. 24. 1895.

INVENZ'OHS 7M/VM r 6 6. [43M- A TTORNEYJ UNITED STAT S PATENT UFFICE.

FRANK H. BALL AND BERT 0. BALL, OF ELIZABETH, NEW JERSEY.

STEAM-ENGINE GOVERNOR.

SPECIFICATION forming part of Letters Patent No. 551,749, dated December 24, 1895.

Application filed June 5, 1895. Serial No. 551,741. (No model.) 7

To all whom it may concern;

Be it known that we, FRANK H. BALL and BERT 0. BALL, citizens of the United States,

I with the governor in place thereon.

residingat Elizabeth, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Steam- Engine Governors; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to steam-engine governors; and it consists in certain improvements in the construction thereof, as will be hereinafter fully described, and pointed out in the claims.

Figure 1 shows a side elevation of a fly-wheel Fig. 2 shows a section on the line 2 2 in Fig. 1, the point of view being from above. Figs. 3, 3, 3 3, 4, 4:, 1 and 4 show diagrams explanatory of the act-ion of the governor.

The governor maybe placed on any revolving carrier, but preferably on the crank-shaft within the fly-wheel, as here shown, which may be generally described as follows:

A marks the crank-shaft, and B the flywheel.

An inertia mass is composed of a main part C and an extension 0 carried by an arm 0. This mass is pivoted on the pivot 0, extending from the fly-wheel, and the parts 0 and O are so proportioned as to be balanced as to gravity on this pivot. The weight E which is arranged to be acted upon by centrifugal force as ordinarily to affect the regulating movement is carried by an arm epivoted upon the fly-wheel at e and is connected with the inertia mass by a link F, A spring G is connected with the weight-arm 6, so as to act centripetally upon the weight. A dash-pot H with a spring-link H is connected with an extension e on the arm 6 and has the usual steadying efiect.

The inertia mass 0 is composed of a slotted back part c and front plate 0 which carries the valve-connecting means. As shown, the valve-connecting means is a pin D, but of course it will be understood that this pin may be so enlarged as to become what is termed an eccentric without changing the effect. In the diagrams the front plate is removed and the center of the shaft is indicated by a and the position of the center of the valve-connecting means by d. v

p The weight E has been described as being acted upon by centrifugal force in the opera tion of the governor. This weight is also so located with reference to the axis aand the pivot e that its angular inertia during every change in the rate of rotation develops aforce which, acting on tangential lines, supplements any centrifugal or centripetal tendencies of the weight and thus facilitates rapid adjustment. The mass C O, pivoted at c, is also so distributed in the wheel as to bestrongly influ- 6 5 enced by the inertia forcesj ust described, and acting in harmony with the coincident forces developed by the weight E still further contributes to the governing forces.

The utilization of the angular or tangential 7o inertia of the relatively-moving parts of a governor to act in harmony with that other manifestation of inertia known as centrifugal force we do not consider new to the art, early examples of which may be foundin pat- 7 5 ents to Kendall, No. 163,662, of 1875; Kendall, No. 269,678, of 1882; Thompson, No. 310,479, of 1885, and Begtrop, No. 326,092, of 1885.

Therefore, although the mechanism embodying our invention is one peculiarly adapted to a full use of all the inertia forces, its chief novelty consists in the form and relation of the parts by which some of the difficulties are overcome which commonly prevent a delicate action in response to these governing forces. These difficulties or obstacles consist chiefly of friction of the moving parts of the governor upon their bearings, the disturbing action of gravitation acting on the unbalanced parts, the reciprocating inertia of the valve with its connections, together with the friction of these reciprocating parts.

The effects of each of the foregoing maybe separately stated as follows: Friction of the 5 moving parts of the governor produces sluggishness and uncertainty of action in response to slight changes of speed and this difficulty is so well recognized that various devicessuch as knife-edges, rollerbearings, &c. are used to reduce the friction to aminimum. Examples of such construction are found in the patents to Sweet, No. 252,276, Begtrop, No. 326,092, and Carpenter, No. 526,856.

Gravitation of unbalanced parts of the governor displaces them from their normal orbit of rotation about the shaft by drawin them toward the shaft during half of each revolution and during the other half these unbalanced parts are moved away from the shaft, thus producing regular vibrations of equal extent each side of the normal orbit and thereby changing it to an orbit eccentric to the shaft, which causes an unequal distribution of steam on opposite sides of the piston. To prevent this action, it is common to use two centrifugal weights arranged in opposite sides of the wheel, so that the gravity of one shall balance the gravity of the other, it being well understood that even with h igh-speed engines a centrifugal weight unbalanced against gravity will fall from its orbit during a half-revolution of the wheel a distance far greater than is permissible.

\Vhere single centrifugal .weights are used it has been found necessary to provide some counterbalance against gravity. An early example of this practice is found. in the patent to Sweet, No. 252,27 6, in which the swinging eccentric is made to counterbalance the gravity of the centrifugal weight. Among later examples are the patents to Riter, No. 355,717, to Carpenter, No. 526,856, and to Riter, No. 527,720.

Even with constructions where the centrifugal weights are balanced against gravity it has often been thought necessary by designers of shaft-governors to provide a gravitybalanee for the swinging eccentric. Examples of this construction are found in the following patents: Thompson, No. 204,924, of 1878; Fosdick, No. 221,296, of 1879, and Thompson, No. 265,991, of 1882.

Reciprocating inertia of the valve and its connections causes a violent thrust when reversing the direction of motion of the valve, which occurs twice in each revolution and is feltat the center of theeccentric acting in line with the eccentric-rod and tending to thrust the eccentric or valve-connecting means out of its proper position. This will be more fully illustrated farther 011. Friction of the valve and its reciprocating connections, like the illertia of these parts, produces a thrust which is communicated by the eccentric-rod to the eccentric, and like the thrust of inertia tends to displace the eccentric and its connections. These thrusts of the eccentric-rod often cause serious disturbance of the governing mechanism and particularly when unbalanced valves are used, and it is common practice to interpose something in the nature of cams, wedges or screws to prevent these disturbing thrusts from displacing the eccentric or valveconnecting means and its rotating connections, examples of which are found in the following patents: to Kendall, No. 163,662, of 1875; Kendall, No. 269,678, of 1882; Richards, No. 290,113, of 1883; Cook, No. 299,963, of .1881; Ball, No. 45i,511, of 1891, and \Vright, No. 506,964, of 1893.

The nature and effect of all these disturbances that have been considered will be better comprehended by reference to the following figures and diagrams.

Fig. 23 represents a governor-wheel mounted on. an engine-shaft, and pivoted on the arm of this wheel are an eccentric and centrifugal weight such as our invention. contemplates and connected by a link similar in all respects to the construction shown in Fig. 1 so far as these parts are concerned. As shown in Fig. 5 the centrifugal weight is in its position nearest the shaft and the pin or eccentric has its greatest throw. 4

In Fig. i the mechanism is shifted to its other extreme position and the pin or eccentric has its least throw and the valve which may be connected therewith its shortest travel.

For convenience in investigating the effect of disturbing forces in the operation of the governor, Figs. 3 and i are made to represent the position of these parts at intervals of ninety degrees in the rotation, thus completing a revolution in four periods. \Vith these diagrams the effect of the disturbing forces that has been mentioned may be analyzed, and in effecting this analysis those forces that tend to draw the centrifugal weight E toward the shaft will be called centripetally-acting forces and those having the opposite effect will be described as centrifugally-acting forces. Beginning now with the action of gravitation in the unbalanced centrifugal. weight E, it is evident that in the position shown in Fig. 4 gravity will act-as a centripetal force until rotation has moved the parts forward ninety degrees to the position shown in Fig. 4, where it becomes neutral. From this position forward through the position of Fig. 4 to that of Fig. 4 gravity has become a centrifugally-acting force, and so on through each succeeding one hundred and eighty degrees it acts alternately between the two forces and causes the weight E to vibrate or swing on its pivot e. If disconnected from any other part, the amplitude of this vibration would depend on the interval. of time required for each half-revolution, and a large mass at I) would fall just as far and no farther than a small one, because a pound falls the same distance as a ton in a given time when acted upon by gravitation. To neutralize these vibrations of the weight E an equal mass must be arranged to be acted on by gravity in the opposite direction at all times as another weight on the opposite side of the wheel according to the usual custom. These vibrations may be reduced in extent to any desired amount by connecting the weight E with a mass, pivoted. so as to be balanced within itself against gravity and centrifugal force, and so connectcd with the weight E that it shall oppose the vibration of the weight E by its own inertia. Thus in Figs. and 4c the mass C with its counterbalance O is pivoted at its center of gravity (2, and through its connection with the weight E is made to vibrate by the action I of gravity on the weight E, and the amplitude of this vibration is determined by the relation which the weight E bears to the balanced mass that vibrates about the pivot c. Vibrations of this kind in any degree have heretofore been considered objectionable and have been prevented in many ways, some of which have been described. It is the purpose of our invention to control these vibrations instead of preventing them, and to limit them to a permissible amount which shall be fixed and determined by the relation which the mass pivoted at c bears to the mass of the weight E. These controlled vibrations are made to serve a useful purpose in overcoming the friction of the pivots c and c, thus making the governor practically frictionless when a change of speed requires the mechanism to change its position relatively to the wheel. When these relatively-moving parts of the governor are permitted to remain stationary on their pivots the static friction of these pivots offers an appreciable resistance and prevents delicate adjustment, but with a positive and regular motion in the nature of vibration or oscillation, however slight,the least unbalanced condition of the opposing forces of the governor will result in a change of adjustment, because each vibration in the direction of the greater force will overreach the former limit in that direction and will not then return to the former position, but will continue the vibrations the same as before but in a new position. The mass balanced and pivoted at c in combination with the weight E is also made to modify in a novel manner the disturbing thrusts produced by the valve and communicated by the eccentricrod. These thrusts have already been described as due to the inertia of the valve and its connections and the friction of these parts.

From a study of Figs. 3 and 4 and their accompanying diagrams it is evident that the thrusts due to inertia and those due to friction are not coincident at all times either in direction or in magnitude, and that the net effect of these combined causes which is communicated by the eccentric-rod and is felt at the center at of the pin or eccentric is not effective to turn the mass 0 O on its pivot 0 when the axis of the pivot o and the point d are in the same plane with the eccentric-rod, which occurs twice in each revolution of the wheel. Therefore these valve disturbances, so far as their effect in turning the mass on its pivot c is concerned, are both reciprocating and intermittent, and because of the frequent change of direction it is possible to absorb them in the mass pivoted at c and limit the effect to permissible vibration about this pivot. It is further evident from a study of these thrusts that they are not equally divided between'centrifugally and centripetally acting forces according to the definition previously given of these terms, and that the preponderance is largely on the side of the latter. This is not a matter of great importance, except for the fact that in shifting the governing mechanism from one extreme position to the other this centripeta1ly-acting force changes in magnitude enormously, and

the change is not a uniform one for each intermediate position, but when diagramed follows a somewhat curved line, thus making it impossible to harmonize it with the force of the centripetally-actin g spring when seeking isochronous adjustment of the governor. To overcome this we have devised a peculiar manner of connecting the pin or eccentric carrying mass G C with the weight E by which the effect of a preponderance of centripetallyacting force exerted in the eccentric by the valve will be modified by the angle of the connecting-link F, which communicates the force to the weight E.

By comparing Figs. 3 and 411; will be observed that the angle of the connectinglink is such that when the greatest force is present in the pin or eccentric (when it has its greatest throw) the link F and the arm 6 approach more nearly a straight line-a position less favorable to produce centripetal effect on the weight Eand that the change of angle of the link as it recedes from a line with the arm 6 to the other extreme is not at a uniform rate, but is represented when diagramed by a somewhat curved line not unlike the curved line already mentioned as representing the force, so that the net force communicated to theweightE has its maximum greatly reduced and is made to more nearly follow a uniform rate of change through the range of motion of the parts, and this force will therefore harmonize better with the centripetall acting springs and a more isochronous adjustment may be obtained.

What we claim as new is 1. In a steam engine governor the combination of a centrifugally acting governor weight; a centripetally acting spring operating thereon; and a swinging inertia mass balanced as to gravity, and being so proportioned relatively to the governor weight as to control but not prevent the vibrations incident to the action of gravity on said governor weight.

2. In a steam engine governor, the combination of a centrifugally acting governor weight; a centripetally acting spring operat ing thereon; and a swinging inertia mass balanced as to gravity and arranged to be actuated by the tangential inertia forces and being so proportioned relatively to the governorweight as to control but not prevent the vibrations incident to the action of gravity on said governor-weight.

3. In a steam engine governor, the combination with the governor weight arranged to be acted upon by the centrifugal and tangen tial inertia forces; a centripetally acting spring operating thereon; and a swinging inertia mass balanced as to gravity and arranged to be actuated by the tangential inated by the tangential inertia forces, and bein g so proportioned relativelyto the governor weight as to control but not prevent the vi brations incident to the action of gravity on I 5 said governor weight.

I11 testimony whereof we affix onr signatures in presence of two witnesses.

FRANK II. BALL. BERT 0. BALL. Witnesses:

W. H. SUsTEN, Jr, W. A. MORRELL.

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