US1054935A

US1054935A - Governing mechanism for elastic-fluid turbines.

Info

Publication number: US1054935A
Application number: US64483511A
Authority: US
Inventors: Millard M Pearson
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1911-08-18
Filing date: 1911-08-18
Publication date: 1913-03-04
Anticipated expiration: 1930-03-04

Description

M. M. PEARSON.

GOVERNING MECHANISM FOR ELASTIC FLUID TURBINES.

APPLICATION rnnn' AUG, 18. 1911.

1,054,935. v Patented'Mar.4,1913.4

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Patented Mar. 4, 1913.

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M. M. PEARSON.

GOVERNING MECHANISM FOR ELASTIC FLUID TURBINES.

APPLIOA-TIOI'NTILED AUG.18, 1911.

M. M. PEARSON.

GOVERNING MECHANISM FOR ELASTIC FLUID TURBINES.

APPLIGATION FILED AUG. 18, 1911.

1,054,935, Patented Mar. 4, 1913.

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Inventor Millard MPeaF-Son IDBMW His J ttorneg.

UNITED. STATES PATENT OFFICE.

MILLARD M. PEARSON, or SCHENECTADY, NEW YORK, ASSIGNOR ro GENERAL ELECTRIC COMPANY, A conrona'rron or NEW ronx.

eovnnmne MncnA rsmron ELASTIC-FLUID 'IURLBINES.-

Specification of Letters Patent.

Patented Mar. 4., 1913.

Application filed August 18, 1911. Serial No. 644,835

To all whom it may concern:

Be it known that I, M nnano M. PEARSON, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Governing Mechanism for Elastic-Fluid Turbines, of which the following is a specification.

This invention relates to elastic fluid turbines, and especially to those of the low 1 pressure or mixed pressure types, in which exhaust steam from high pressure engines, or from heating or other industrial apparatus,'is utilized to drive the turbine. It is customary to control the flow of low pressure steam to the turbine by means of a valve of the butterfly type, connected to an operating motor which is controlled by the's'peed governor. In case the turbine races, an emergency governor trips certain automatic mechanism which closes the valve independently of the ordinary operating devices.

The purpose of the present invention is to improve the emergency mechanism for operating a butterfly valve of this kind.

In the accompanying drawings, Figure 1 is an end elevation of a mixed pressure turbine equipped with my butterfly valve, which s shown in its wide open position. Fig. 2

the valve is closed by the emergency gov ernor. Figs. 5 and 6 are perspective views of two of the levers forming part of the valve operating mechanism. Fig. 7 is asectional elevation of the valve at right angles to Fig. 3. Fig. 8 is a section of a portion of amodification. Fig. 9 is a side elevation of the same, partly broken away.

The turbine illustrated is a horizontal mixed pressure machine of the Curtis type, having a 'casing 1 supported on a base. 2. Certain nozzles receive low pressure steam through a large conduit 3, while another set of nozzles is supplied with steam at high pressure througha pipe enterin chest 5. The ow pressure conduit is controlled by a valve 6 of the butterfly type, which is opened and closed by a crank arm 7 connected bya rod 8 to a lever 9 which is arranged to be actuated by a motor 10 controlled by the speed governor 11. This same motor also actuates the valve or valves cona steam trolling the admissionof high pressure I steam'to the turbine, although its operation of the low pressure and high pressure valves is not simultaneous but successive, opening -ria1l No. 641,264, on which Patent 1,017 ,555

of February 13, 1912, was granted.

Referring again to the butterfly valve 6 it will be observed that it consists of a disk preferably stiffened by transverse ribs 12 and secured upon a spindle 13 which crosses it diametrically and forins journals 14 at each side of the disk. These journals are received in suitable steam-tight bearings in bosses 15 formed on the valve-casing 1 6. A bracket 17 is secured to one of said bosses, being preferably provided with a sleeve 18 concentric with the spindle '13; the bearing,

in the boss being enlarged to receive, said sleeve. The spindle extends through said bracket and has keyed to it an arm 19, which in-the drawings, is shown as standing at right angles to the valve 6; though its particular position is of course immaterial. Loosely mounted on the spindle and adjacent to the arm 19 is the crank 7, having on its hub a shoulder 20 which abuts against a lip 21 on the arm 19. The hub of the crank 7 also has a notch 22, withv which engages a latch 23 pivoted on the arm 19 and urged toward the hub of the crank 7 by a spring 24: seated at one end in a socket in a lug 25 on said arm, and at the other end in a socket in the back of the latch. The crank is connected by the rod 8 with the governing mechanisnn'so that said governor can vary the effective opening of the valve to correspend with the demand for steam; the valve being normally locked to the/crank by the shoulder 20 and lip 21, the notch 22 and latch 23.

Alongside of the crank 7 there is loosely journaled on the shaft 13 a tripping plate 26 on which. is :1 lug 27 adapted to strike the latch 23 and disengage-it from the notch 22 when said tripping plate is rotated. A strong spring 28 is attached at one end to said plate and at the other-end to ahanger 29 do )ending from the bracket 17. vThe .plate 18 held up, so that the lug 27 is out of the normal range of movement ofthe latch 23, by means of a trip lever 30 provided with a hardened steel catch 31 which engages a similar catch 32 on the plate. A small spring 33keeps the catches in engagement. In this position the spring 28 is under considerable tension. On the same rock shaft as the trip lever is an arm 34 connected by a rod. 35 with any suitable emergency governor, arranged to actuate said rod when the speed of the turbine runs up to an abnormal degree. The lever 30 also has a handle 36 so that it can be tripped by hand, if de-' sired. The end of lever 34 is slotted to allow for tripping by hand, independently of the emergency governor. I

The operation of the device is as follows :Under normal conditions, the speed governing mechanism moves the rod 8 t0 and fro, and the interlocked crank 7 and arm 19 turn the valve 6 to open or closeit more or less, as determined by the governor. In case the engine begins to race, the emergency governor actuates the rod 35 and thereby trips the lever 30, disengaging the

catches

31,, 32, and allowing the spring 28 to pull the tripping plate suddenly to the position shown in Fig. 4. In moving to this position, the lug 27 strikes the latch 23, disengages it from the notch 22, and carries it and its arm 19 and with them the valve 6 to the position shown in Fig. 4, thus closing the valve. The spring 28 keeps the lug 27 pressed firmly against the latch 23, so that the valve is held tightly closed. To reset the tripping plate, a bar is inserted into a socket in a boss 37 on one edge of said plate, whereupon a downward pull on said bar will return the plate to the position shown in Fig. 3 and enable the

catches

31, 32, to reengage and lock the plate. The reietting bar is indicated by dotted lines in the squared end 38 of the spindle 13 and openthe valve, thereby turning the arm 19 until the latch 23 can again snap into the notch 22, and the parts will be ready for normal operation as shown in Fig. 2.

The shoulder 20 and lip 21 form a safety device to enable the speed governor to close the valve even when the latch is disengaged from the arm 7, moreover, the shoulder forms a positive stop to prevent anybody from opening the valve by applying a wrench to the squared end 38 ofthe spindle when the governor has partly or wholly closed said valve; an action which might cause the engine to run away and do considerable damage.

In the inodification'shown in Figs. 8 an 9, the helical spring 28 is replaced by a coiled spring 39 concentric with the spindle of the valve; said coiled spring being attached at one end to astud 40 on the trip- After the tripping plate has been reset, the attendant can apply a wrench to ping plate and at the other to a stud 40' on a sleeve 41 surrounding the hub of the tripping plate and provided with means for adjusting it angularly so as to vary the tension of the spring. This may be accomplished by means of a segment gear 42 on said sleeve, meshing with a worm 4:3 journaled in suitable bearings on the'bracket 17 and having a milled head 44 by which it can be turned to actuate said gear and vary the tension of the spring 39. In all other respects this modification operates the-same as 'the construction shown in Figs. 1 to 7 inelusive.

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.

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

1. Governing mechanism for controlling a butterfly valve comprising an arm fixed on the outer end of the spindle of said valve, a crank loose on said spindle that is arranged on the inner side of the arm and has a notch "in its hub, a latch pivoted on said arm and engaging with said notch, a spring-actuated tripping plate loose on said spindle and acting to disengage said latch and turn said arm and valve, and a tripping lever for locking said tripping plate.

2. Governing mechanism for controlling a butterfly valve comprising an arm fixed on the outer end of the spindle of said valve, a spring latch pivoted on said arm, a crank loose on said spindle that is arranged on the inner side of the arm and has a notch in its hub engaged by said latch, a tripping plate loose on said spindle and arranged on the inner side of the crank, a spring biasing said plate to turn, alug onsaid plate adapted to trip said latch, a catch on said plate, and a pivoted tripping lever engaging therewith.

3. Governing mechanism for controlling a rotary'valve, comprising an arm fixed on the spindle of said valve and having a lip, a spring latch pivoted on said arm, a crank loose on the spindle and having a shoulder engaging with said lip and a notch engaged by said latch, and a spring-actuated tripping-plate for disengaging said latch and turning said arm and valve.

4. The combination with a steam turbine having a speed governor, an emergency governor, and a butterfly valve for regulating the admission of steam to the turbine that is controlled by said governors, of mechanism for controlling the butterfly valve, comprising an arm fixed on the spindle of said valve, a crank loose on said spindle and controlled by the speed governor, detachable connec- -a tripping lever carried by said shaft and engaging with the catch on the tripping plate, and an arm on said rock shaft controllable by said emergency governor.

5. Governing mechanism for controlling a butterfly valve comprising an arm fixed on the spindle of said valve, a crank loose on said spindle, a latch locking said arm to said crank, a trippingplate pivoted on said spindle, a sleeve concentric with said spindle and carrying a segment gear, a worm meshing with said gear, a coiled spring attached at one .end to said plate and at the other to said sleeve, and a tripping lever for releasing said tripping plate.

6. Governing mechanism for controlling a rotary valve comprising a spindle for the valve, an arm fixed on the spindle and having a lip on its hub portion, a latch carried by the arm, a crank loosely mounted on the spindle adjacent to the arm, the hub portion of the crank having a shoulder for engaging said lip and also a device for engaging the latch, a tripping plate for releasing the latch that is mounted for rotation about the spindle, means. tending to turn the plate, and a device for normally preventing the plate from turning. I

7. Governing mechanism for controlling arotary valve comprising a spindle for the valve, an arm fixed on the outer end of the spindle, a latch pivoted to the inner side of the arm, a crank loosely mounted on the spindle adjacent to the inner side of the arm and provided with a device for engaging the latch, a tripping plate loosely mounted on the spindle adjacent to the inner side of the crank and havin means adapted to trip the latch, means ten ing to turn the plate, and a device for'normally preventing it from turnmg.

a rotary valve comprising a spindle having its outer end shaped to receive a wrench, an arm fixed to the outer portion of the spindle next to said shaped end, a latch mounted on the inner side of the outer end of the arm, a crank loosely mounted on the spindle adjae nt the inner side of the arm and provided wTith a notch to receive the end of the latch, a tripping plate loosely mounted on the spindle adjacent to. the inner side of the crank and provided with a laterally projecting lug, means that tends to turn the tripping plate and bring the lug into engagement with the latch to release the crank and arm, and a latch that normally holds the plate from turning.

In witness whereof, I have hereunto set my hand this 17th day of August, 1911.

MILLABD M. PEARSON.

8. Governing mechanism for controlling