US1387915A - Regulating mechanism for turbo-mechanical-machine plants - Google Patents

Description

O. A. WIBERG AND G. KARL-SSON. REGULATING MECHANISM FOR TURBO MECHANICAL MACHINE PLANTS.

APPLICATION FILED MAY]. 1920.

Patented Aug. 16, 1921.

oscAR ANTON WI'BERG ,AND ,GEORG' 'KARLSSON, or rrnsrono, SWEDEN.

'REGULATING MECHANISM roe s.runeo mncnsmcannaenrnn- PLANTS.

Application filed May '7,

To all whom it may concern. 7 1

Be it known that we, OsoAR ANTON VVI- nnne and Gnono KAnLssoN, subjects of the King of Sweden, whose post-office addresses are Finspong, Sweden, have invented new and useful Improvements in Regulating Mechanism for Plants, (for which we have'filed application in Sweden J an. 20, 1919), of which the following is a specification.

This invention relates to turbo-mechanical machine plants having a mechanical reversing device controlled by a hand-wheel or the like. In such machine plants it has proved desirable to reduce the number of revolutions of the turbine while the reversal of the direction of rotation of the driven shaft is taking place.

The object of the invention is to provide means whereby the number of revolutionsof the turbine is automaticall reduced, previous to said reversal. To t is end the said hand-wheel is operatively connected to a device for adjusting the s eed governor of the turbine in such a way that upon turningthe hand-wheel to effect the reversal, an adjustment of the governor. for a reduced number of revolutions of the turbine will take place.

I11 the accompanyingdrawing, a diagrammatical View of a regulating mechanism according -to this invention is shown, certain parts of said mechanism being shown .in section.

\Vith reference to the drawing, the character A indicates the-centrifugal governor of a turbo-mechanical machine plant, the .latter, however, "being not illustrated, as it does not form any part of this invention. .The character B indicates the steam inlet valve of the turbine, said inlet valve being con trolled by the governor A, and at C parts of a mechanical reversing device are shown. Said device'may be mountedon the. driven shaft of the machine, plant or on any suitable intermediate shaft.

The centrifugal. governor shown is designed to operate at twoJdifierent numbers of revolutions of the turbine, as for instance, at 8,000 and 1,500 revolutions per minute, the. higher. number of revolutions corre-, sponding to the normalsspeed. of .the turbine. The governor. comprises a rotary casing '1, in which are mounted two swinging weights 2 acted on by two coiled tension springs 3,4;

Turbo-Mechanical-Machine Specification of Letters Patent. 8 'P'atellted Aug, 16, 1921.

1920. Serial no, 379,613. 5

ofwhich the former is rigidly secured with its one end to the governor weights, while the corresponding end of the spring a is attached to a disk 5. Freely extending through said disk is .a reduced portion 6 of a head of. a rod serving to only move the disk 5 in opposition tothe action of the spring a after the governor weights have made a certain .thro

The governor weights are connected by means of. a rod 7 to a slide-valve 8 controlling the supply of pressure medium to the cylinder 9 of a piston motor serving to di rectly control the steam inlet valve 13. The pressure medium is supplied from .a pump 10 through a conduit 11 leading tothe stationary slide-valve casing 12 said casing being connected at its opposite side to the cylinder 9 by means ofthe conduit 13. The

cylinder 9 contains a piston 14 the rod 15 of which carries, the movable steam inlet valve body 16. On the side of the piston 14 opposite to the conduit 13, the casing 9 contains a I pressure springl'r' acting onsaid piston. v

Toadjust the governor for different numbers of revolutions and to adjust the slide valve 8, 12 after each movement of the steam inlet valve, the following arrangement is provided. Inserted between the stationary slide valve casing 12-and the slide valve 8 is a movable slide valve casing 18 having three chambers communicating with the, conduit 11, the conduit '13 and a discharge conduit (not shown), respectively, the communication with said discharge conduit being effected by. openings 19. The slide valve casing. 18 is connected through a link 20 to one arm of a rocking lever 21, the other arm of which is connected bymeans of a link 22 to one end of a shifting lever 23, pivotally connected as at 24 to the rod 25 of the piston 27 of a shift control motor. The other end of the shiftinglever 23 is connected to the piston rod15 carrying the steam inlet valve 16. The piston 27 of the shiftlcontrol motor is adapted to move in the one direction under the action of a spring 28 and in the other direction under the action of a pressure medium supplied by the pump 10. I he communication between the pump 10 and the cylinder 27 comprises a conduit 30 having a return valve 29, a branch conduit 31 extending from said'conoluit'30, a controlling mechanism including a stationary slide valve casing 32 and a slide-valve 33, and a connectlng conduit 34 between the slide-valve casing 32 and the cylinder 26. The slide-valve 33 is pivotally connected as n han d-wheel 39 of the turbine machineplant.

7 piston Said shaft also carries a gear wheel 40 engaging a rack 41 by means of which the reversing mechanism C may be controlled from the hand-wheel 39.

The reversing mechanism is only shown partially, as the construction thereof has nothing to do with this invention. The reversing mechanism comprises two lamination friction couplings, that is, one ahead coupling 42 and one back coupling 43, a set of hydraulic pistons44, a piston 45 connected to said pistons 44 and acting directly on'the back coupling disks 43, and. a link system 46, by means of which the disks of the ahead coupling 42 may be operated from the piston 45. The pistons 44 (one of which only is shown in the drawing) are operated by means of a pressure medium supplied from the conduit 30 under the control of. a slidevalve 47, in turn controlled by the pistons 44 and the hand-wheel 39, the slide-valve 47 being connected to one of the pistons 44 by means of a lever 48 also connected to the rack 41. Leading to the back coupling disks 43 is a lubricating conduit 49 controlled by a.

valve 50 operated by a pressure medium under the control of the slide valve 47. Assuming the pressure medium consists of oil, the valve 50 controls the connection between the conduit 49 and a branch 51 of the conduit 30. 4

The operation of the system described is as follows: In the position of the parts of the system shown in the drawing, the reversing mechanism C and thus also the driven shaft are assumed to be released and the machine plant is assumed to operate with reduced speed. If it is desired to throw the driven shaft into action for operation at a certain speed ahead, the hand wheel 39 is turned in the direction of the arrow a. The rack 41 is thereby moved to the left thus moving the slide valve 47 to the left so as to connect the conduit 30 with the left-hand side of the pistons 44, thereby causing the pistons 44 to move to the right. Through the link system 46 the piston 45 operates the friction clutch 42 so as to throw in the same partially. In the movement of the piston 44 .to the right, said piston will turn the lever 48 so as to cause the same to again move the slide valve 47 to the right. When the valve piston 44 in this movement again reaches the central position shown in the drawing, the oil supply to the pistons 44 is cut ed. Upon further movement of the hand-wheel, the operation described again takes place and the coupling 42 will thus be thrown in successively according as the hand-wheel is turned. Only after the pistons 44 reach their extreme right position, the slide valve 47 will open completely to permit pressure oil to operate the pistons to throw in the coupling 42 completely and maintain it in operative position. This will take place when the hand-wheel 39 is turned to such an extent as to bring the connecting rod 37 into the position I. The driven shaft is now thrown in for ahead operation and rotates'with the above said reduced speed.

During the said turning of the hand-wheel, the valve 50 has been keptoclosed under the action of the pressure oil.

The hand-wheel, when turned into said position, has moved the lever 36 so as to dcpress the slide valve 33. During the whole movement, however, the connection between the conduits 31 and 34 has been cut off at the slide-valve 33, and said slide valve is ready to restore saidconnection at the completion of said movement. Thus, if the hand-wheel 39 is moved farther in the direction above referred to, pressure oilwill enter the cylinder 26 below the piston 27 and raise the latter against the action of the spring 28. The lever 36 is then caused to turn about its connection with the connecting rod 37 and will thus raise the slide valve 33 so that the latter will again out off the connection between the conduits 31 and 34. The length ofthe movement of the piston 27 depends on the rotation of the hand wheel 39 beyond the position thereof corresponding to the position I of the connecting rod 37.

In the said movement of the piston 27, the lever 23 is also turned about its connection with the piston rod 15, the link 22 being thereby raised and the movable slidevalve casing19 lowered so as to interconnect the conduit 11 and the conduit 13 to permit pressure oil to enter the cylinder 9 below the piston 14. Said piston will thus be raised to open the steam inlet valve 16 by means of the rod 15 to increase the speed, of the turbine. lVhen the rod 15 is thus m ved upwardly, the lever 24 swings back and the movable slide-valve casing 19 is moved upwardly so as to again out off the connection between the conduits11 and 13. The steam inlet valve will remain in its position and the turbine will operate with a speed corresponding to the opening of the steam inlet. The magnitude of the opening of the steam inlet depends on the movement of the piston 27 and said movement, in turn, depends on the rotation of the hand- Wheel 39. A continued rotation of the handwheel in the direction indicated will further open the steam inlet valve and it is thus possible to manually control the speed of the turbine by means of the hand-wheel.

The manual control above described is possible with respect to turbine speeds between the values for which the governor is designed to operate, that is in this case for speeds lying between 3,000 and 1,500 revolutions per minute. As soon as the speed of the turbine in the manual control exceeds such values, the governor begins to operate and will control the steam inlet valve by means of the slide valve 8 in well known manner.

When the movement of the driven shaft is to be'rev'ersed, the hand-wheel is turned back out of theposition, into which it has been moved in the increase of the speed above described. In this movement, the connecting rod 37 is moved upward and the slide valve 33 is raised to out ofi the connection between the conduits 31 and 34-and to further connect the conduit 34 to an outlet 52., The spring 28 is now free to depress the piston 27 thereby causing the slide-valve 33 to close the outlet 52 and raising the movable slide-valve casing 19 so as to bring the cylinder chamber below the piston 14 in communication with an outlet through the openings 19. The spring 17 is now free to depress the piston 14 to close the inlet valve 16. As in the increase of the speed, the closing of the inlet valve 16 takes place successlvely according as the hand-wheel is turned back.

In the turning back of the hand-wheel,

' the rack 41 is moved to the right to operate the slide-valve 47 so as to permit pressure oil to act upon the right-hand side of the pistons 44, while the pressure oil to the left of said pistons is allowed to escape. At the same time, the pressure oil is drawn off from the right-hand side of the piston valve 50 thereby allowing the latter, under the action of its spring, to interconnect the conduits 51 and 49 for the purpose mentioned below. In the same way as the movement of the pistons 44 to the right, previously described, the movement of the pistons 44 to the left will take place successively. The hand-wheel having againreached the neutral position shown in the drawing, the

' pistons 44 are again moved to their central position in which they will maintain both the couplings 42 and 43 released. The driven shaft, therefore, will now be at rest. At the same time, the steam-inlet 16 is closed to such an extent that the speed of the turbine is reduced to the lower one of the two speeds for which the governor can operate. The governor will thus be set into operation to maintain the turbine at said reduced speed.

If the hand-wheel is turned beyond the neutral position, the rack 41 continues to move to the right, the pistons 44 being there- During the rotation of the hand-wheel I into the position, corresponding to the position II of the connecting rod 37, the slide valve 33 is so operated as to be ready to interconnect the conduits 31 and 34 at the completion of .said rotation. In the continued rotation of the hand-wheel, said connection will thus take place and the piston 27 of the reversing motor will be set into operation in the same way as above describechto initiate the opening of the steam inletvalve 16 which will then be opened gradually according as the hand-Wheel is rotated thereby increasing the speed of the turbine, while the governor still remains out of action. hen the speed of the turbine reaches the highest value, for which the governor is designed, the governor will again commence its action.

During all the time that the back coupling 43 is in action, pressure oil may be freely supplied to the disks of said coupling through the conduits 51, 49. This oil supply has for its object to consume the heat generated due to the friction which occurs when the coupling is thrown into action.

From the above description it will be seen that the operation of the reversing mechanism will always take place at a reduced speed of the turbine which will secure a soft and quiet reversal.

It should also be noted that the reduction of the speed of the turbine and the reversal of the turbine are effected by means of one and the same hand-wheel the speed reduction leading in respect to the reversal, the said hand-wheel also enabling a manual speed control of the machine in the range lying between the two speeds for which the governoris designed to operate. Only in the event of areduction of the speed below the lowest value for which the governormay operate, an adjustment of the steam in let by means other than the said handwheel is necessary.

Having now described our said invention we declare that what we claim is 1. Regulating mechanism for turbo mechanical machine plants, comprising in combination amechanical reversing device, a hand-wheel for controlling said reversing device, a turbine speed governor, a connection between said hand-wheel and said speed governor sodesigned that in turning the hand wheel for effecting a reversal an adjustment of the governor to operate for a distinct reduced speed will take place previous to the said reversal.

2. Regulating mechanism for turbomechanical machine plants, comprising in combination a turbine speed governor, a hydraulic piston for adjusting said governor to operate for two diiierent speeds, a hand-wheel for controlling the operation of said piston, a reversing device, hydraulic pistons for operating said reversing device, slide-valves for controlling the admission of pressure medium to said last-mentioned pistons, and a connection between said hand-wheel and said last-mentioned pistons so designed that in turning the handwheel, the reversing device is operated after the operation of the piston controlling the governor.

3. Regulating mechanism for turbomechanical machine plants, comprising in combination a speed governor, means for adjusting said governor to operate for different speeds, a reversing device, means for controlling said reversing device, a handwheel so connected with said means as to hold the reversing device out of action when in a neutral position and to operate the means for adjusting the governor, when moving within a certain range on each side of said neutral position, while operating the means for controlling the reversing device when moving outside of said range.

4:. Regulating mechanism for turbomechanical machine plants, comprising in combination a speed governor, a handwheel controlling said speed governor, a reversing device, including a laminated friction coupling for ahead motion and a laminated friction coupling for back motion, an oil supply to said back coupling, said oil supply being controlled by said hand-wheel.

In testimony whereof we have signed our names.

OSCAR ANTON WIBERG. snone KARLSSON.

Images