US742842A - Automatic governor. - Google Patents

Description

PATENTED NOV. 3, 1903.

A. R. DODGE. AUTOMATIC GOVERNOR.

APPLIOATION nun AUG. 21, 1902.

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UNITED STATES Patented November 3, 1903.

PATENT QEFIO AUSTIN R. DODGE, OF SCHENECTADY, NEw YORK, ASSIGNOR TO GENERAL ELEOTR O OOMPANY, A CORPORATION OF NEW YORK.

SPECIFICATION forming part of Letters Patent NO. 742,842, dated November 3, 1903.

Application filed August 21, 1902. Serial No. 120,484. (No model.)

ling-valve, while in the latter, where the regulation is accomplished by varying the cut-0E, there is a period in each revolution wherein the pressure on the valve is balanced, and at this point the governor can adjust the valve.

I meet the problem by providing a fiy-ball.

governor of improved construction and com bining with it an inertia device which acts on the ball or balls in such a manner as to produce a differential efiect on the regulating mechanism, thereby decreasing the speed fluctuations due to changes in load.

For a further description of what I consider to be novel and my invention reference is made to the description and to the accompanyin g drawings, which drawings represent an embodiment of my'invention, wherein- Figure 1 is a longitudinal section of a governor, and Fig. 2 is a cross-section taken on line 2 2 of Fig. 1.

Referring to the drawings, 1 represents the driving-shaft, the speed of which is to be governed, or it may represent a shaft geared to the main shaft. The shaft is supported in suitable bearings 2,0nly one of which is shown. Keyed to the end of the shaft is a support 3, and mounted thereon are the centrifugallyacting weights 4 and 5, which move toward and away from the center of revolution as the speed of the shaft changes. The particular form of the weights is immaterial; but those shown will be found to operate very satisfactorily.

Referring to the specific structure shown, (and as both sides are alike a description of one of them will be sufficient,) two weights are mounted on the lever 6 and at opposite sides of the pivot 7. By using two weights and placing them on opposite sides of the pivot the adjustable counterbalancing-spring 8 can be made somewhat shorter than where a single weight only is used. The pivot, as shown, is nearer one weight than the other, which permits one Weight to overpower the other; but any other equivalent arrangement can be employed. The levers 6 are mounted in forks which are formed on or secured to the support 3. The forks are slotted to receive the hardened plates 9, the latter constituting the bearing-surfaces for the knife-edge ends of the pivot 7. Extending parallel with the shaft and between it and the ends of the forks are bolts 10, which hold the knife-edge pivots in place, at the same time permitting entire freedom of movement. The portion of the lever between the shaft and the left-hand weight is cylindrical, and surrounding it is an antifriction-roller. Extending from the weight-supporting lever and rigidly secured thereto is a lever-arm 11. It will be seen that the weight-supporting lever as a whole is substantially T-shaped. The lever-arm 11 extends through a slot formed in the support 3 and at its end is provided with a groove to receive the knife-edge 12. The knife-edge is formed on a connecting rod 13, which extends substantially parallel with the shaft and Within the coiled compression-spring 8. The outer end of the rod is screw-threaded and is provided with an adjustable piece having a knife-edge 14, which rests on the hardenedsurface of the disk 15 or movable abutment. The parts are held in place by a nut and a check-nut. The disk or movable abutment is provided with a hub-like extension, and surrounding this and also a similar extension on the support 3 is the compression-spring.

It is important in my improved governor to reduce the friction of the moving elements to a minimum, and this is attained in part by providing knife-edges at the joints and so arranging the parts that they can turn or twist slightly without binding.

The end of the shaft is provided with a cylindrical bore or opening, and mounted therein is a pivotal piece or ball 16, which is secured by a rod 17 to the disk 15. The shaft is transversely slotted at 18, and extending through the slot and the ball is a pin 19, which secures the ball to a sliding collar 20, the lat- IOO ter being arranged to surround the shaft and slide freely thereon under the control of the weights. The ball is free to turn about the pin 19 as a center, and by reason ofthis construction the disk 15 can assume positions more or less eccentric to the shaft withoutcausing a binding of the parts. This arrangement permits the abutment and outer end of the spring to rotate about their own center of gravity or rotation. The collar has a peripheral groove and mounted therein is a ring 21, the latter being connected to a forked lever 22. The forked lever may be suitably connected to a valve regulating'the delivery of steam or water or it may be connected to any other regulating mechanism. The ring 21 is grooved at the top and is arranged to receive the oil-ring 23, the latter receiving oil from the oil-well 24, formed in the bearingstandard. It is advantageous to mount the sliding collar and the ring 21 in the bearing casing or standard, because it simplifies the matter of oiling.

The right-hand end of the bearing-case is provided with a shouldered flange 25, and mounted thereon is a flanged disk 26, the latter supporting the inclosing casing 27, which protects the parts from injury and keeps out the dirt.

The apparatus described will govern the speed of a moving shaft when properly connected to a valve or equivalent regulating mechanism within certain limits; but in order to make the regulation closer I provide an inertia device, which in the present embodiment of my invention takes the form of a wheel 30. This wheel is loosely sleeved on the cylindrical exterior of the support, and hence it can have a certain amount of rotary movement independent thereof, other things being properly arranged. The wheel is provided with a hub, which is connected to the rim by a web. The web is provided with two slots, each of which is angularly disposed with respect to a radius, and located adjacent to the slots are adjustable cams 31 and 32 for moving the weights. In the present instance the center lines of the cams are parallel and each makes an angle of forty-five degrees with a given diameter. Consequently they are diametrically opposite. Extending through the slots and between the cams are the weighted arms 6, and surrounding each of the arms at the point where it passes through the slot is an antifriction-roller 33. The parts, as shown in the drawings, are at rest; but in Fig. 2 is illustrated in dotted lines an intermediate position of the parts approximating the normal running condition.

The particular governor illustrated was designed to control the speed of a steam-turbine running at seventeen hundred revolutions per minute; but it can be arranged to regulate for other speeds, if desired. The shaft and wheel revolve in the direction of the arrow, Fig. 2, and when the speed of the shaft decreases, due to increase in load, the inertiawheel tends to keep on revolving at the same speed. This causes the cams on the wheel to depress the inner or left-hand ends of the levers, which in turn permit the spring 8 to ex-' tend and force the disk 15 outward. As the disk moves outward it moves the sliding collar 20 through the medium of the rod 17 and pivot 19. As the collar moves it moves the lever 22 in a direction to cause more energy to be applied to the moving shaft. In the case of the turbine it admits more steam. On the other hand, if the speed of the shaft rises the disk still attempts to hold its speed, resulting in-a certain amount of independent movement between the inertia-wheel and the shaft, which'canses the cams to move the weighted arms outward and the lever 22 to decrease the amount of energy supplied to the shaftas, for example, by decreasing the amount of steam applied to a turbine. It

will be noted that the inertia-wheel and the v balls or weight operate difierentially, in that the cams oppose the free movement of the balls in and out due to speed variations.

Actual tests made on the governor illustrated show that it will when properly connected control the speed of an elastic-fluid in a different way, the controlling mechanisms will assume a definite position when the shaft revolves at sixteen hundred and fifty revolutions per minute under conditions of rising speed, and it will assume exactly the same position for the same speed under fallin'g conditions of speed. The diiference in position assumed by a governor for a given speed under rising and falling speed conditions is called the lag and is highly objectionable, and the amount of said lag determines the efficiency of the governor. The tests referred to show that the friction in the governor itself is so small that it can be disregarded.

The weights of the governor will vary the energy supplied to the turbine or other mechanism as the speed changes; but their action is relatively slow, which results in considerable variations in speed. This is obviated by the addition of the inertia-wheel 30. I attribute the accuracy of my improved governor to two principal features when working in conjunction-first, the inertia-wheel, which has a slight amount of rotary movement independent of the driving-shaft and operates on the weights of the fly-ball governor, as it is sometimes called, and, second, to the freedom with which the several parts can move with respect to each other, whereby objectionable strains and friction are reduced to a minimum, particular reference being made to the connections between the weights and the sliding collar 20.

I do not broadly claim a governor comprisin g a shaft or revolving support with centrifugally and differentially acting weights ar ranged in pairs on opposite sides of the shaft or revolving support with means for opposing the resultant action of each pair of weights, because it is the invention of another.

In accordance with the provisions of the patent statutes I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood that the apparatus shown is only illustrative and that the invention can be carried out by other means.

What I claim as new, and desire to secure by Letters Patent of the United States, is-

1. A fiy-ball governor in combination with an inertia-wheel which has a limited rotary movement independent of the governor-shaft and is arranged to act on the balls in response to speed variations.

2. In combination, a weight driven by a moving shaft and arranged to move toward and away from its center of revolution under speed changes, a device for transmitting movement from the weight to a regulating mechanism, an inertia-wheel having its plane of movement at right angles to the shaft, and loosely mounted on the shaft whereby it can move independently thereof, and means attached to the wheel which cause it to act upon the regulating mechanism through the said device, the weight and wheel acting differentially.

3. Inagovernor, adriving-shaft, a centrifugally-acting weight connected thereto,-an inertia-wheel loosely mounted on the shaft and capable of rotary motion independent thereof, and a connection between the wheel and the weight whereby the wheel is caused to act on the weight in a manner to retard its changes in position due to speed variations.

at. In a governor, the combination of a driving-shaft, a support secured thereto, a pair of oppositely-disposed weights mounted thereon, a valve-lever, a connection between the lever and the weights whereby the position of the lever is changed,an inertia-wheel which is loosely mounted on the shaft and has a limited rotary movement independent thereof,

and means actuated by the wheel during the period of independent movement for moving the weights.

5. In a governor, the combination of a driving-shaft, a support rigidly mounted thereon, a pair of oppositely-disposed weights moun ted on the support, an inertia wheel which is loosely carried by the shaft and has a limited rotary movement independent thereof and is provided with openings through which the weights project, the said weights being moved toward and away from the center of revolurat 0 tion as the wheel and shaft move independently.

6. In a governor, the combination of the driving-shaft, a support mounted thereon, a pair of oppositely-disposed weights carried by the support, an inertia-wheel loosely mounted on the support and capable of rotating independent thereof, levers which pass through the wheel and support the weights, and cams on the wheel which move the weights toward or away from the center of revolution as the wheel and its support rotate independently.

7. In a governor, the combination of a driving-shaft having an opening formed therein, a support secured to the shaft, a disk, a spring situated between the shaft and the disk, a sliding collar mounted on the shaft, a connection between the disk or abutment and the collar, a lever which is also connected to the disk or abutment, a weight mounted on the lever, and an inertia wheel which is loosely mounted on the shaft and actuates the weight.

8. In a governor, the combination of a driving-shaft, a pair of weight-carrying levers, a compression-spring, an abutment therefor, a link connection between each lever and the abutment, and knife-edge joints between the links and the abutment and weight-carrying levers.

9. In a governor, the combination of a shaft having an opening formed in the end, a pivoted piece mounted therein, a sliding collar surrounding the shaft and secured to said piece, a support which surrounds the shaft and is secured thereto,weight-carrying levers mounted therein, a disk or abutment, a spring between the shaft and the disk or abutment, a rod which connects the disk or abutment with the pivoted piece, and links for connecting the levers to the disk.

10. In a governor, the combination of a driving-shaft, a pair of centrifugally-acting weights which are connected together and located on opposite sides of a pivot, one of said weights being nearer the pivot than the other, a support for the Weights, a spring which opposes the movements of the weights, and an inertia device which is movable independently of the weights and their support and changes the position of the weights under changes in speed of the shaft.

11. In a governor, the combination of a rotating element,weights driven thereby, a con.- trolling device actuated by the weights, and an inertia-wheel capable of a limited amount of rotary movement independent of said elements and the weights which is connected with said controlling device.

In witness whereof I have hereunto set my hand this 6th day of August, 1902.

AUSTIN B. DODGE.

Witnesses:

BENJAMIN B. HULL, Jos. A. S. ENDRES.

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