US902220A - Governing mechanism. - Google Patents

Description

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GOVERNING MECHANISM. APPLICATION FILED 0014, 1905. 902,220. Y Patented 005-27, 1908,

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GOVERNING MECHANISM. APPLICATION FILED 00124, 1905.

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UNITED STATES PATENT OFFICE.

WILLIAM L. R. EMMET AND OSCAR .IUNGGREN, OF SCHFNECTADY, NEW YORK, ASSIGNORS TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

GOVERNING MECHANISM.

Specification of Letters Patent.

Patented Oct. 27, 1908.

Original application filed May 8, 1903, Serial No. 156,142. Divided and this application filed October 4, 1905.

Serial No.

To all whom it may concern:

Be it known that we, WILLIAM L. R. EM- MET and OSCAR JUNGGREN, citizens of the United States, and residents of Schenectady, county of Schenectady, and State of New York, have invented certain new and use ful Improvements in Emer ency Governing Mechanism, of which the fofiowing is a speciiication.

The present invention is a division of our pending application, Serial N 0. 156,142, filed May 8, 1903, and is made at the requirement of the United States Patent Oflice under the provisions of Rules 41 and 42 of Oflice Practree.-

The invention relates to governing mechanisms for prime movers, such for instance, as elastic fluid turbines, and has for its object to provide a simple and eflicient governing mechanism of improved construction for cutting oil the supply under abnormal load conditions when the speed tends to become excessive.

In the accompanying description and the claims appended thereto, We shall proceed to set forth with particularity and exactness What we believe to be novel and our invention.

In the accompanying drawings which illustrate one embodiment of the invention, Figure 1 is a detail view in section of the emergency governor, Fig. 2 is a detail view in side elevation of one of the weights and its holders for actuating theemergency governor;

Fig. 3 is a plan view, partially in section, of

the structure shown in Fig. 2 Fig. 4 is a detail view in side elevation of the means employed to trip the cutoff valve; Fig. 5 is a front elevation of the structure shown in shaft becomes Fig. 4; and Fig. 6 is a plan view of the modified form of the emergency governor wherein slightly different means are employed for tri ping the shut-off valve.

n order to prevent racing of the turbine in case of failure of the main governor to operate, an auxiliary emergency governor is provided. Mounted on the main shaft 26 of the turbine, or other prime mover or on a shaft driven therefrom at one or more points are frames 57 which carry centrifugally acting weights. These weights are normally held within a certain prescribed ath by suitable means, but when the rotative speed of the excessive they fly outwardly 1 ing the butterfly valve will be described.

beyond their normal path and cause the interruption of the steam sup ly. Fig. 3 best shows the construction and arrangement of these weights.

58 represents a weight which is pivoted to the frame 57, the latter being secured to the shaft by a number of bolts. The weight is provided with two arms, one of which is.

tween the short arm of the weight 58 and the movable abutment 60 is at one side of the straight line connecting the center of the trunnion 62 and the center of the pivot 58. As the shaft rotates, the weight 58 tends to move outwardly and compress the spring. In doing so the oint of contact more nearly coincides with tie line connecting the centers of movement above referred to. As designed, so long as the speed of the turbine is normal, the oint of contact between the short arm and the abutment is always on the side of the center line as shown, but under excess speed conditions the point of contact crosses the dead center and the effect of the compression spring is then added to that of the centrifugally acting weight. By this means a blow is imparted to the plunger 59 which insures the prompt action of a butterfly or other valve'for interrupting the supply of fluid. The right-hand end of the plunger engages with a lever 64 which is pivotally connected to a rod 65. This rod extends outwardly from the shaft and is attached at its outer end to a lever or latch 66 which trips or releases the mechanism that actuates the butterfly valve 67, the latter being mounted in the steam-carrying conduit 68 which serves as the valve casing at a point between a main or gate valve and the conduit 8 which conveys fluid to the groups of turbine nozzles. The butterfly valve by reason of the distribution of the parts at tached thereto has a tendency to close.

Referring to Figs. 4 and 5, the construction and operation of the means for actuat- The valve is pivotally supported on a shaft or pivot 69 mounted in the valve casing and to which is attached an arm or lever 7 O. This arm is provided with a pin 71, shown in dot ted lines in Fig. 4 and full lines in Fig. 5, that engages the stop 72 for preventing the arm from rising above the position shown, it being free however to move downward under the action of the releasing mechanism. Pivotally attached to the arm is a V-shaped lever 73 the short arm of which engages with and is locked in osition by a shoulder, latch or trigger forme on the lever 66. The lever 73 is provided with a heel or projection 73 which limits the upward movement of the lever about its pivot on the lever 7 0 and causes the latch to hold the two levers in position as if they were one lever structure. To the long arm of the V-shaped lever is attached a link 74 that supports the weight 75. The pivot 7 0 of the weight lever 73 is located at a point above and eccentric to the pivot 69. The result of this arrangement is to in crease the effective leverage of the weight on the valve when said weight has been tripped and the valve moved to its closed position. That is, the leverage is greater than it would be if the pivot were on or below the center line of the lever 70. conditions the long arm of the lever 73 is separated from the upper side of the lever 70 as shown. When the speed of rotation increases beyond a predetermined amount the latch on the lever 66 is released from engagement with the lever 73 by the emergency governor and the weight 75 falls through a short distance, thus acquiring some momentum, before the lever 73 swinging about its pivot comes in contact with the lever 70 and strikes a hammer blow on the latter lever which tends to overcome any inertia or stick" ing of the valve and to accelerate its closing. After coming in contact as described the two levers move as one about the pivot 69. With our arrangement, we secure all the advantages of a single lever and in addition thereto the desirable hammer blow effect.

Attached to the side of the conduit or casing 68 is the relief pipe 76 containing a valve 77. This pipe enters the' conduit on the side of the valve 67 which is toward the turbine. As shown the valve is provided with a stem 78 which projects slightly from the valve casing and is adapted to engage with and be depressed by a cam 79 that is attached to and moves with the valve shaft 69. The object of this valve is to discharge the contents of the steam-carrying conduit 8 into a condenser or to the atmosphere, as the case may be, whenever the emergency governor operates and shuts off the further supply of steam to the conduit 8 by closing the valve 67. By relieving the conduit of all of the steam contained therein after the valve 67 is closed the turbine may be quickly Under normal service stopped, otherwise it might be run for a con siderable time by the steam so trapped between the valve 67 and the turbine admission valves providing it had been relieved of its load.-

In order to release the butterfly valve by hand when for any reason it is desirable, handles 81 are attached to the lever 66. These handles are best shown in Fig. 5. It will be noted that they are situated on opposite sides of the conduit where they are readily accessible. The relation between the cam 79 and the valve stem 78 is also well shown in said figure. In the present instance the relief valve is normally held against its seat by a spring and is opened by the cam 79 which compresses the spring, but any other suitable form of valve can be employed. The relation of the pin 71 to the arm 70 for preventing the latter from rising beyond a certain predetermined point is also clearly shown in this figure. By the arrangement described the turbine can be quickly brought to a standstill without letting air into the condenser.

Referring to Fig. 6, we have shown a slight modification of our invention wherein the actuating lever 64 is arranged to work in a horizontal plane instead of a vertical plane. The object of this arrangement is to cause the centrifugally acting weight 58 to strike the lever a glancing blow as the heavier end moves outward under conditions of abnormal speed. The weight 58 is provided with a pivot 58 located at a point between its ends, and the trailing portion 82 of the weight is heavier than the leading portion and thus overpowers it. Under conditions of excess speed the heavier portion 82 moves outward while the forward and lighter end moves inward. By reason of this differential action the spring which opposes the weight can be made shorter. The weight is carried by a frame 57 that is bolted to the main shaft 26. The lever 64 is mounted in a support 83 which is bolted to a stationary part of the turbine frame. It is made in the form of a bell-crank and the short arm is attached by the rod 65 to the trigger or tripping device 66 shown in Fig. 1. There is a certain amount of lost motion between the short arm of the lever 64 and the nuts on the rod 65. The object of this arrangement is to decrease the pounding efifect of the blow from the weight 58 on the curved arm of the lever 64. In this figure, as well as in Fig. 3, the relative arrangement of the parts may be such that after the speed of the turbine decreases by a certain amount the weight 58 will return to its normal position. It can, however, be so arranged that it requires the operator to push the weight back manually before restarting the turbine into operation.

In accordance with the provisions of the patent statutes, we have described the principle of operation of our invention together with the apparatus which we now consider to represent the best embodiment thereof;

but we desire to have it understood that the apparatus shown is only illustrative, and that the invention can be carried out by other means.

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

1. In combination, a motor, with an emergency governor therefor, comprising a centrifugally acting weight, and a spring which normally opposes the action of the weight and is situated on one side of the dead center and crosses said center and acts accumulatively with said weight under abnormal speed conditions.

2. In a governor, the combination of a pivotally supported weight, a spring acting on said weight and arranged to work on either side of a dead center, and an actuator which is moved by the weight.

3. In a governor, the combination of a support, a weight pivotally mounted thereon, a spring and abutment for opposing the centrifugal action of the weight and arranged to work on either side of a dead center, and a pivotal support for the spring and abutment.

4. In a governor, the combination of a support, a weight pivotally attached to the support, an actuator arranged to engage with the weight under abnormal conditions, and a spring and movable abutment engaging with the weight, the abutment being arranged to work on either side of a dead center.

5. In a governor, the combination of a support, a centrifugally acting weight pivotally attached thereto, a spring and abutment for opposing the action of the weight, and a piv otally supported holder for the spring and abutment, which is arranged to swing from one side of a dead center to the other when the speed exceeds a certain predetermined amount.

6. In a governor, the combination of a pivoted weight having its free end normally moving in the path described by the pivot, a spring disposed at one side of the weight and having its line of action substantially parallel with the length thereof, and a connection between the weight and spring which permits the line of action to shift its position.

7. In a governor, the combination of a pivoted weight, a spring for opposing the movement of the weight which is fixed at one end and extends toward the pivot of the weight, and a connection between the weight and the movable end of the spring.

8. In a governor, the combination of a support, a centril'ugally acting weight pivoted adjacent one end of the support, and a spring mounted on the support for opposing the movement of the weight which is disposed between the pivot of the latter and the opposite end of the support and acts in the direction of the pivot.

9. In a governor, the combination of a support, a centrifugally acting weight pivoted thereon, and a spring mounted on the support which opposes the movement of the weight, the longitudinal dimensions of the spring and weight being substantially parallel to that of the support.

10. In a governor, the combination of a rotating support, a centrifugally acting weight which is pivoted thereto, and a spring for normally opposing the movement of the weight which is mounted on the support and disposed between the latter and the free end of the weight with its axis or line of action substantially tangent to the direction of rotation and located on that side of the pivot of the weight which is toward the center of rotation.

11. In a governor, the combination of a centrifugally acting Weight which is pivotally supported at its front end, a spring for opposing the movement of the weight which is disposed under the free end of the weight and approximately parallel thereto with its line of action directed toward the pivot of the weight, means for pivotally supporting the spring to permit the direction of its line of action to vary with respect to the pivot of 9 the weight, and a connection between the weight and spring.

12. In an emergency governor, the combi nation of a pivotally supported weight responsive to abnormal speed conditions, a

spring acting on said weight and arranged to act on either side of a dead center with respect to the pivot of the weight, a lever pivoted to move in the plane of the weight when struck a glancing blow thereby, a valve, and a means actuated by the lever for starting the valve into motion.

13. In combination, a conduit, an emergency valve mounted therein, an arm attached to the valve, a weight-carrying lever pivotally attached to the arm, and a tripping device which holds the weight lever in position to strike the arm a blow when released.

14. In a governing mechanism, the combination of a valve, a casing therefor, a device mounted on the casing for holding the valve open during normal operating conditions, a load-responsive mechanism for releasing the valve from the control of the device under abnormal conditions, and a motor arranged to first im art a hammer-blow to the valve when so re eased to close it and then hold it closed.

15. In a governing mechanism, the combination of a valve, a device for holding the valve open during normal operating conditions, a speed-responsive mechanism which releases the valve from the control of the device when the speed becomes abnormal, and a motor that becomes active on the release of cessive.

said device which is arranged to move a limited distance independently of the valve and then impart a hammerblow thereto and move with it during closure.

16. In a governing mechanism, a valve, a member attached to the valve, means co6pcrating with the member to hold the valve open, a speed-responsive mechanism which releases said means when the speed becomes excessive, and a weighted device which becomes operative on the release of said means to first impart a hammer blow to said memher to close the valve and then act through the member to hold the valve closed.

17. In a governing mechanism, the combination of a valve, an arm attached thereto for opening and closing it, weighted member attached to the arm and mounted to have a limited independent movement to impart a hammer blow to the arm, and a lock which normally holds the arm and member set and the valve in open position.

18. In governing mechanism, a valve, an arm or opening and closing the valve which is secured to its pivot, a lever pivoted to the arm at a point eccentric to the pivot of the valve and arranged to move independently of the arm. for imparting a hammer blow thereto, and a latch engaging the lever for holding the valve open.

19. In a governing mechanism, the combination of a casing, a valve therein, a member attached to the valve which is exterior to the casing, and a weighted device which is arranged to move independently during a portionof its movement for imparting a blow to the member to close the valve suddenly.

20. In a governing mechanism, the combination of a shut-oil valve, a lover attach l thereto for actuating it, and an arm loosely attached to the lever for moving it through a lost-motion when the speed becomes ex- 21. In a mechanism of the character described, the combination of a valve which is locked open under normal service conditions, a casing for the valve, a motor which closes the valve when said valve is released from its locked position, a lever mounted on the casing and connected with the valve which lever when locked in a given position prevents said motor from closing the valve, a member pivoted on the lever, a latch engaging said memher and restraining or looking the lever and valve against the tendency of the motor to close the valve, and a speed governor responsive to a predetermined increase in speed for disengaging the latch and said member and permitting the motor to close the valve.

22. In a mechanism of the character described, the combination of a valve which has a tendency to close, a casing for the valve, a lever mounted on the casing and connected with the valve, a member pivoted on the lever, a latch mounted on the casing which engages the member and locks the valve open under normal service conditions, and an emergency governing device which disengages the latch and said member and permits the valve to close when the speed increases a predetermined amount above the normal rate.

23. In a mechanism of the character described, the combination of a valve which has a tendency to close and is locked open against said tendency during normal service conditions, a casing for the valve, a motor which closes the valve when it is released from said locked position, a lever which prevents the motor from closing the valve, a member pivoted on the lever, a latch sup ported by the casing which engages the member and restrains the lever against the tendency of the motor to close the valve, and a governor responsive to a predetermined increase in speed for disengaging the latch and said member to permit the motor to close the valve.

In witness whereof we have hereunto set our hands this second day of October, 1905.

WILLIAM L. R. EMMET. OSCAR JUNGGREN.

Witnesses BENJAMIN B. HULL, IVIARGARET E. VJooLLnY.

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