US993832A - Emergency governing mechanism for turbines. - Google Patents

Description

0. JUNGGREN.

EMBRGENGY'GOVERNING MECHANISM FOR TUBBINES.

APPLICATION FILED NOV. 4, 1909.

Patented May 30. 1911.

N v DD VD QN 0N mN PM mm 0| 9 0 MN 0 0 EN OD MN Inventor Oscar Jun gran,

Witnesses:

UNITED STATES PATENT OFFICE.

OSCAR JUNGGREN, OF SGHENECTADY, NEW YORK, ASSIGNOR 'IO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

EMERGENCY GOVERNING MECHANISM FOR TURBINES.

Specification of Letters Patent.

Application filed November 4, 1909. Serial No. 526,231.

To all whom it may concern:

Be it known that I, OSCAR JUNcennN, a citizen of the United States, residing at Schenectady, in the county of Schenectady, State of New York, have made certain new and useful Improvements in Emergency Governing Mechanism for Turbines, of

which the following is a specification.

My invention relates to mechanisms for shutting down engines in emergencies and more especially to those intended for use with mixed-pressure elastic-fluid turbines and has for its object to provide such a mechanism of improved construction.

For a consideration of what I believe to be novel and my invention, attention is directed to the accompanying description and claims appended thereto.

In the accompanying drawing my invention is shown in connection with a mixedpressure turbine meaning by mixed-pressure a turbine that is actuated by lowpressure or exhaust steam and also by highpressure or live steam direct from a boiler.

1 indicates the base of the machine and rising therefrom are pillars 2 that support the casing 3 of the turbine. Low-pressure steam is admitted to the turbine by the inlet 4 and high-pressure steam by the inlet 5.

The admission of low-pressure steam is controlled by the butterfly valve 6 which is rigidly attached to the spindle 7. Keyed to the spindle is an actuator 7 that closes the valve when the weight is released. Loosely'mounted on the spindle is an arm 8 which carries a weight 9 on its outer end. When the arm moves under the action of the weight it delivers a hammer blow to the actuator 7 and closes the valve. The arm is normally held in the position shown by the part 10 which engages and is held by the latch 11. The latch is made in the form of a bell-crank lever pivoted at 12 with a weighted end 13 to assist in resetting. To one arm of the lever is attached a rod 14 which in the present illustration is horizontal and may be supported at an intermediate point by the link 14: This rod extends through a stationary guide 15. lo cated between the guide and a collar fixed on the rod is a compression spring 16 that tends at all times to move the rod to the right and trip the valves. This tendency is resisted by the trigger 17 that is pivoted to the fixed guide or other support. On the trigger is a finger or projectlon 18 that engages a shoulder 19 carried by the rod. The left-hand end of the trigger is so arranged that it can be actuated or moved in a direction to cause the finger to disengage the shoulder 19 by the emergency governor 20. The latter is of the type comprising a ring that is normally concentric with the turbine shaft 21 and moves to an eccentric position against the action of a'spring under conditions of excess speed. This governor is designed to trip the valve 6 when the speed of the turbine shaft reaches a predetermined speed, for example 10% above normal.

In a mixed-pressure machine it is necessary in an emergency condition such as the sudden and complete loss of load to close the valve in the live-steam pipe at the same time that the valve in the pipe conveying exhaust or low-pressure steam to the turbine is closed, since otherwise the machine would run as a high-pressure machine, the two sources of motive fluid being independent. To this end the rod 14 is also connected to the tripping mechanism of the combined emergency and throttle valve 22. This valve is rovided with a sliding sleeve or nut 23 whlch is threaded internally to receive the spindle of the valve, said spindle being provided with a hand wheel 24 for normal operation. The sliding sleeve or nut is pivotally attached to a lever 25 that is supported by a link 26 at one end. The free end of the lever is supported by a cam member 27 containing a notch to receive a pin or roller 0n the lever. The cam member is pivotally supported by the pivot pinr28 that also carries the hand lever 29 for tripping the valve by hand. The lever 29 is connected by a link with the upper end of a lever 30, and the lower end of the latter is connected to the rod 14:. The valve has a tendency to close which is resisted so long as the 1efthand end of the lever 25 is sustained. When it is released by moving the lower end of the cam 27 to the right the valve closes suddenly. By properly shaping the cam as shown the roller on the lefthand end of the lever will roll alon the cam surface and hold the rod 14; in its right-hand position. This causes the shoulder 19 to ride on the finger or projectionlS and thus hold the left-hand end of the trigger 17 out of en-- gagement with the emergency governor and prevent the governor from delivering successive blows thereto. I may use other forms of emergency governors than the one shown as will readily be understood. Since the two valves are simultaneously tripped it suliices to provide a single means for holding the trigger 17 out of the path of the speed governor after said trigger has been struck by the governor and the rod 1 released under emergency conditions.

To reset the parts after an emergency operation, the hand wheel 24 is rotated in the valve-closing direction and since the valve is on its seat and the nut 23 is unconfined, the nut will move up the spindle carrying with it the lever 25 until the roller at its end drops into the notch in the cam 27. Under these conditions the hand lever 29 acts as a weight to reset the cam. The next step is to reset the butterfly valve 6 which may be done by raising the lever 8, weight 9, and cooperating parts by hand, until the part 10 passes under the latch 11 and is retained thereby. The valve 22 may then be opened by the hand wheel in the usual way. Usually another hand valve will be located between the engine and the turbine so as to control the; passage of the exhaust from the engine.

It sometimes happens that it is desirable to shut down the turbine suddenly from the switch-board or some other point while the operating conditions in so far as the turbine is concerned are normal. In order to simplify this as much as possible, and to avoid undue complications, I provide a suitably supported electro-magnet 31 which may advantageously be of the solenoid type. The core; 32 of the magnet is attached to one end of the trigger 17 and I may if desired use a spring or equivalent device 33 to balance wholly or partially the weight of said core. However the parts are arranged, care should be exercised to see that the core does not release the trigger unless the magnet is energized. The magnet is controlled by a switch 34 whichv is arranged to connect it with and disconnect it from the mains 35. The latter may be supplied from the lighting or exciting circuit or from any other suitable source of power.

I regard the feature of tripping both valves from the switch-board or other place by actuating the trigger 17 as being a prominent and important feature of my invention since it avoids complications, decreases the cost of manufacture, makes for simplicity, enables I me to test out the apparatus without running the turbine over speed, and insures both valvesclosing simultaneously.

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 shownis 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. In combination, a prime mover, a shaft 7 driven thereby, an emergency speed governor carried by the shaft, a rod mounted adjacent to the governor with its axis transverse to the axis of the shaft, means which tends to move the rod longitudinally, a trigger which holds the rod against movement and is adapted to be released by the governor when the speed of the shaft; exceeds a predetermined limit, an electro-magnet which can also actuate the trigger to re lease the rod, a controller for the circuit of the magnet, a device for controlling the sup-' ply of motive fluid to the prime mover, and means connecting the rod to said device.

2. In an apparatus of the character described, the combination of a turbine, a shaft driven thereby, a shut-down valve for the turbine, an emergency speed governor mounted on the shaft, mechanism for holding the valve open, a trigger pivoted intermediate its ends and arranged adjacent the governor, the axis of the pivot being paral-' lel to the axis of the shaft and'one end of the trigger being moved by the governor to cause it to release the valve under certain conditions, an electro-magnet which can actuate the other end of the trigger to release the valve, and a controller for the circuit of the magnet.

3. In combination, a mixed-pressure turbine, conduits admitting fluid thereto from different sources, a valve in each conduit, a trigger for controlling certain movements of the valves, and a means controllable from a distance for actuating the triggeri 4. In combination, a mixed-pressure turbine, conduits admitting fluid thereto from different sources, a valve in each conduit, a trigger for controlling certain movements of the valves, a means controllable from a distance for actuating the trigger, and a speed governor that is also capable of actuating the trigger under certain conditions.

5. In combination, a turbine, a conduit for supplying it with exhaust steam, a conduit for supplying it with live steam, said turbine being driven by steam from either or both of these sources, a quick-closing valve in each conduit, mechanism for holding the 1 valves open, a trigger that controls said mechanism, a governor for moving the trigger, and a means for moving the trigger, both the governor and means causing the trigger to release said mechanism.

6. In combination, a turbine, conduits ad mitting motive fluid thereto at diiferent In Witness whereof, I have hereunto set points, a $11K? 'in eaclh oi the conduits, 1a my hand this 3rd day of November, 1909.

means for 0 in eac va ve 0 en, a sin e trigger for contr olling all of said mea i is, OSCAR JUNGGREN' 5 and a speed governor and auxiliary device, Witnesses:

both of which are capable of actuating the BENJAMIN B. HULL,

trigger. HELEN ORFORD.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. 0.

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