US1859437A - Governing mechanism for marine power plants - Google Patents

Description

y- 1932- w. B. 'FLANDERS 1,859,437

GOVERNING MECHANISM FOR MARINE POWER PLANTS Filed May 21, 1931 2 Sheets-Sheet 1 EmxPzQm-rm Er qm:

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ATTORNE Y" May 24, 1932. w. B. FLANDERS GOVERNIRG MECHANISM FOR MARINE POWER PLANTS 2 Sheets-Sheet 2 Filed May 21, 1951 Fxa 2 H- P. STE/4M 45mm 7M5. Sscr m H m a m A \m u o mmwm F & 2 a w M W A H INVENTOR WITNESSES:

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Patented May 24, 1932 UNITED srATEs PATENT orrics WARREN B. rLANnERs, or ,rHILAnnLrnI rENNsYLvANIA, ASSIGNOR-TO wEsT1 G HOUSE ELECTRIC a MANUFACTURING COMPANY, a con-PoaeTIoN or PENNSYL- VANIA GOVERNING MECHANISM ron MARINE rowan PLANTS Application fil ed; May 21,

My invention relates to a. control mechanism for the ahead and astern admission valves of a reversible prime mover, and ithas for its object to provide improved apparatus of the character set forth. i

A more particular object is toprovide a control mechanism which is operative, upon movement of the control lever'from ahead position to astern position, to open fully the astern admission valve for the purposeof breaking the ahead speed, to maintain the valve open 'for acceleration in astern direction until a predetermined speed is attained, and then to move the valve in closing direction, and which mechanism will operate in a similar manner to open the ahead admission valve upon shifting the control lever from astern position to ahead position.

it has already bcenproposed, in connection with a reversible prime moversuch as a steam turbine, upon reversingv the direction of operation, to admit motive fluid for'the purpose of breaking the speed of the'prime mover in one direction and then to admit further motive fluid for acceleration in the opposite direction. It has also [been proposed to admit such motive fluid under control of a speed responsive governor," Ordinary governing mechanism, however, responds alike to speed in eitherdirection and would be late, thereforeyin[admitting steam for braking the speed of the primemoverin the direction in which it hasbee'n operating In accordance; with my inven'tio npI overcome this 'dithculty by providing a Inech anism which is operative,'-upon 'moving the control memberfro'm ahead to asternposi-j tion, for releasing the asternadrnission valve from the action of the speed responsive g ver. nor; the mechanism being arranged, however, to restore the effectiveness of the, governor as the prime mover slows down, so thatft-he ad mission will be controlled by the governor after speed in astern directionhas been attsined. The ahead valve is similarly opers ated upon shifting the control member from astern to ahead position r The above and other obj ects are efi'ected by my invention as will be apparent from the following description and claims, taken in 1931. Serial No. 539,083.

connection with the accompanying drawings, forming a part of this application, in which: Fig. 1. is a diagrammatic view showing the control mechanism applied to a low pressure turbine, associated with a reciprocating engine in a marine propulsion arrangement; and

Figs. 2 and '3 are sectional, diagrammatic views showing modified forms of valve-opersis ating mechanism that may be substituted in I the apparatus shown in Fig. 1.

connnunicates with'the ahead section 14; and

with an exhaust connection 22 between the turbine '13 and a condenser 23. In normal ahead operation, the exhaust from the reciprocating engine is conveyed to the ahead sectionll, while during astern operation it is conveyed through the connection 22 to the condenser 23.

.In order'to overcome the high inertia of the turbine to permit quick reversal of the turbine, it is desirable to admit high pressure steam for braking the speed of the turbine in the direction in which it has been operating and to accelerate the speed in the opposite direction. High pressure steam for the ahead section 14 is supplied from any suitablesource through a conduit 24, and its admission to the ahead section is controlled by a Valve 25. It is also adapted to be out off by a manually operated valve 26. High pressure steam for the astern section is supplied through a conduit 27 and its admission to the astern section is controlled by a valve 28. It mayalso be shut ofi" by a manually-operated valve 29. r i

The reciprocating engine is provided with anysuitable form of reversing mechanism,

.is actuated by a servo-motor 37 such as shown at 31. On the drawings, which are diagrammatic, the reversing mechanism has been shifted from its correct position with respect to the engine in order to show its operative relation to the control mechanism hereafter described. The reversing mechanism is controlled by an engine reversing lever 32 fulcrumed at 33, which is connected thereto by a link 34, a bell crank lever 35 and a link 36.

7 To facilitate control of the apparatus, thevalves controlling admission of motive fluid to the turbine are controlled by the engine reversing lever 32. The change-over valve 21 which includes a piston 38 connected to the valve and operating in a cylinder 39. A spring 41 biases the piston 38 to the left. The servomotor 37 is controlled by a pilot valve 42, which is connected to the reversing lever 32 and operates in a casing 43. The casing 43 is formed with two ports 44 and 45, which communicate with the left-hand end and. the

' right-hand end of the cylinder 38, respectivewith any suitable source of fluid pressure,

having a port 59 through ly, through conduits 46 and 47. A central port 48 communicates through a conduitf49 or example,a governor pump 51 driven by the turbine. The end portions of the casing 43 communicate with an exhaust conduit 52.

The ahead admission valve 25 is controlled by a servo-motor 53 which includes a piston 54 connected to the valve and operatingin a cylinder 55. A spring 56 biases the piston in valve-closing direction. 1

The servo-motor 53's controlled by arelay valve 57 disposed in a casing 58, the latter which communicates a conduit 61 with the lower end portion of thecylinder 55. The casing is provided with anexhausjt port 62 disposed above the port 59 and with a pressure supply port 63, disposed below the port 59 and communicating with thepressure supply conduit 49. The pilot valve 57 is formed with piston portions 64, 65 and 66, which are adapted to place the port 59 in communication with either the exhaust port 62 or thefluid'supplyport 63. p

The pilot valve 57 is connected to and is adapted to be actuated by the reversing lever 32. Itis connected through alink 67 to the horizontal arm of a bell crank lever 68/ The 'vertical arm' of the bell crank lever is con nected through a two-part rod 69 tothe lever 32. The part connected to the lever 32 has a tubular portion 71 in which there is telescoped a stem 72 integral with the part of the rod connected to the bell crank lever 68. The two parts of the rod aredrawn toward eachother by a tension spring 73.

' Agoverning' mechanism 741s provided in order to effect closingof the ahead high pressureadmissi'on valve 25 when the turbine has obtained sufficient speed in ahead direction.

speed of the turbine, in this case provided by the governor pump 51, conveyed through the'conduit 49 and admitted to the upper portion of the cylinder 76. A piston rod 78 extends downwardly through thelower end of the cylinder and carries a collar 79 which is bevelled on its upper edge. A vertical'link 81 is pivoted to the hori zontal arm of the bell crank lever 68 and carries atooth 82. The governing mechanism 74 is so arrangedthat the collar 79 is adapted to en gage the tooth82 upon suflicient clownward movement of the collar in response to increase in speed. The link 81 is adapted to be moved .to the left to disengage the collar 79 from the tooth 82 by a link 83; The lefthand end of the link83 is connected to a lever 84 fnlcrumed at 85. V

The lever 84 includes a projection 86 constituting a stop'member which abuts against a stationary part to limit the clockwise movement of'the lever 84 about its fulcrum. A lever 87 1 is pivoted tothe upper end of the lever 84 and carries a stop 88; The latter is adaptedto abutothe lever 84 to limit counterclockwise movement of the lever 87 relative to thelever 84and about its pivotal connection therewith. The lower end of the lever 87 is connected to a tension spring 89 which biases the same to the right, and which also biases-the lever 84 tothe right through the lever 87 The lever 87 carries a tooth 91 extending in wardly and-adapted to be engaged by a nger 92carried on the part of the rod 69 connected to the reversing lever 32.

The astern hi gh pressure admission valve Thesegparts bear the same reference numerals withthe prime mark afiixed. The tooth 82 is likewise adapted to be engaged by a col lar 7 9 ,ofa governing mechanism 74, which is controlled by fluid pressure conveyed through the conduit 49 to respond to the I speed of the turbine 13.

The operation ofthe above described apparatus-is as follows: 1

Assume the apparatus to bein shut down position as shown on the drawings, in which position the pilot valves 57 and 57 place the ports 59 and 59 in communication with the exhaust ports '62 and 62 respectively. Operating fluid is accordingly exhausted from the servo- motors 53 and 53 and the springs therein bias the pistonsto maintain the high pressure admission valves 25 and 28in fully closed position.

Assume now that it is desired to begin operation in ahead direction. The handle of the reversing lever 32 is moved to the left to the ahead position, thereby shifting the reversing mechanism 31 to the position pro: viding ahead operation ofthe reciprocating engine 10. The valve 18 is then opened to admit high pressure steam to the engine. The movement of the reversing lever 32 moves the pilot valve 42 to the right admitting fluid pressure through the conduit 47 to the right hand end of the servo-motor 37. The latter moves the changeover valve 21 to the position conveying the exhaust from the engine to the ahead section of the turbine.

The movement of the reversing lever 32 to the left moves the pilot valve 57' down: wardly through the rod 69' and the bell crank lever 68. The pilot valve 57 maintains the port 59 in communication with the exhaust port 62 and the astern admission valve 28 remains shut. The lever 32 also moves the pilot valve 57 upwardly through the rod 69 and the bell cranklever 68. The movement of the rod 69 to the left also causes the finger 92 to engage the tooth .91. This action, which does not have any efi'ect on the operation of the mechanism when starting from shut-down, will be described later. The pilot valve 57 in the upper position places the port 59 in communication with the pressure supply port 63, admitting fluid pressure to the servo-motor 53 and causing the latter to open the ahead admission valve 25.

The high pressure steam admitted by the valve 25 assists the exhaust steam from the reciprocating engine to more quickly accelerate the speed of the turbine in ahead direction, reducing the time required to bring the turbine and engine to full speed. As'more economical operation is eflected by using only exhaust steam in the turbine, it is desirable to out off the high pressure steam to the turbine when full speed is approached. This may be. done at any partial speed such as one-half speed or three-quarter speed. The piston 7 5 of the governing mechanism 74 moves downwardly under force of the increasing fluid pressure developed by the pump 51. The collar 78 moves into engage ment with the tooth 82 and moves the bell crank lever 68 in clockwise direction against the force of the spring 73. As the desired predetermined speed is attained, the piston portion 65 of the pilot valve 57 passes the port 59 and places the same in communication with the exhaust port 62' Fluid pressure is exhausted fromthe servo-motor 53, the spring 56015 which shuts the valve 25. The

turbine then continues to operate on partially expanded steam exhausted from-the reciprocating engine.

Assume now that it is desired to reverse rection. It also moves the pilot valve 12 to V the left, admitting fluid pressure to the left hand end of the servo-motor 37 and exhausting fluid from the "right hand end. ,The servo-motor 37 moves the changeover valve 21 to the 'right,admitting the exhaust from the reciprocatingengine to the condenser 23 through the connection 22. V

, The movement ofthe reversing lever 32 to the right also moves the rod 69 and the adjacent part of the; rod169 to the right. .The pilot valve 57 being already held in lowermost position'by the governingmechanism 74, this movement, so far as the rod 69 is concerned, merely serves to telescope-the parts 71 and 72 and to take up the deflection of the spring.7 3. The finger 92 engages the tooth 91, but the latter returns to its normal position under force of the spring 89 as soon as the finger 92has passed,

As the lever 32 begins movement from ahead position to asternposition, it tends to move the pilot valve 57, upwardly through the extensible rod 69 and the bell crank lever 68. Upward movement of the pilot valve 57 during the first part. ofthe movement is prevented by the engagement of the collar 79 with the tooth 82, said collar being in lowermost position due to full speed of the turbine in ahead direction. Consequently,

as the lever 32 moves to theright, the" rod 69 and the spring 73 are extended;

As the lever 32 moves beyond the neutra position, the finger 92rcomes into. engagement with the tooth 91. V ment of the stop 88 against the lever 84:, the levers 87 and 84 are moved to the right as a unit, and move the link83 to the right. The tooth 82 is drawn outfof engagement with the collar 79, permitting the spring 73 l V to move the pilot valve 57 upward ly through the bell crank lever. GSQtaking up the-lost motion in the rod 69. When the finger 9 2" has passedthe tooth 91"" the spring 89 returns the levers 87 and. 84 to the left. 'The 31'3" pilot valve 57 then continues tomove vup- Wardly as the movement ofthe lever 32: to astern position is completed.

' The pilot valve 57 admits fluid pressure to the servo-motor'53 which thereby moves :Due to the abutthe astern admission valve 2 8 to full open edge of the tooth 82, the spring 89 moves the link 81 to the left, placing the tooth82 in engageable relation with respect to the collar 79, so that as the speed in the asterndirection begins to increase the tooth 82' is moved downwardly by the collar 79. As a predetermined speed is attained, the pilotvalve 57 effects closing of the pilot valve 28.

Upon shifting the reversing lever 32 from astern position to ahead position, the mechanism will operate in a manner similar to that just described to open the ahead high pressure admission valve 25.

In the abovedescribed embodiment, the pilot valves 57 and 57 cause the pistons of the servo-motors to be moved throughout their entire travel at one time. In Fig. 2, I show a modified form of servo-motor which moves the high pressure admission valve incrementally through its travel in response to increase in speed through a-limited range. The servo-motor includes a piston 94 connected to the high pressure admission valve 28 and operating in a cylinder 95. A spring 96 biases the piston 94 in closing direction and serves to close the valve 28 when the apparatusis shut down. The servo-motor 'is controlled by a pilot valve 97 disposed in a casing 98. Passages 99'and 101 provide communication between the pilot valve casing and the upper and lower ends of the cylinder and are normally covered by piston portions 103 and 104 of the, pilot valve. The pilot valve casing is also provided with fluid pressure supply ports 105 and 106 and a fluid discharge port 107. A floating lever 108 is connected at its ends to the operating piston 94 and pilot valve 97 and intermediate its ends to the bell crank lever 68' through the link 67.

The operation of this mechanism is as follows: 7 Upon clockwise movement of the bell crank lever 68', the pilot valve 97 is moved upwardly. Fluid pressure is admitted to the lower end of the cylinder 95 and exhausted from the upper end, moving the piston 94 upwardly and providing opening movement of the valve 28. After the piston 94 moves upward- 1y, it tilts the lever 108 about the pivotal con; nection with the link 67 and returns the pilot valve 97 to cut off position.

: Upon movement of the bell crank lever 68 in counter-clockwise direction, the pilot valve 97 is moved downwardly. Fluid pressure is admitted to the upper end of the cylinder 95 and exhausted from the lower end, moving the piston 94 downward. In this case, a

movement of the valve 28 in closing direction is provided. Downward movement of the piston 94, through the lever 108, returns the pilot valve 97 to cut off position.

' This valve operating mechanism may be substituted for either or both of the servomotors 53 and 53" and the pilot valves 57 and 57. The operation of the mechanism as a whole is the same, the only diiference' being that as the speed of the turbine increases, the admission valve is opened incrementally through a small being moved throughout its full travel as the speed increases beyond a single predeterrange of speed, instead of a function of the position of the bell crank lever 68, saidlever being moved by the governing mecha nism 74 in accordance'with the speed of the turbine. The pressure device 109 includes a sleeve 111, disposed in a casing 110 and connected through the link .67 to the bell crank lever 68, and having a fluid admission port 112 and a fluidexhaust port 113. Disposed within the sleevelll is an inner sleeve 114, which has fluid admission ports 115 and fluid exhaust ports 116, which are disposed adjacent to the ports 112 and 113, respectively, and intermediate said two groups of ports, as will be more apparent from Fig. 3 of the drawings. ,7 7 The interior of the innersleeve 114 is in communication, through the lower end of the casing 110 and a conduit 118, with the lower end of the cylinder 55 of the servomotor 53. 'The sleeve 114 is closed at its upper end, and a spring 117 is connected to the sleeve and to the casing 110 to bias the sleeve downwardly. The sleeve 114 is biased upwardly against the force of the spring 117 by the fluid pressure within its interior and in the lower end of the casing 110. Accordingly, the sleeve 114 is moved up and down by variations in fluid pressure, assuming a position which is a functionofthe pressure.

The operation of this mechanism is as follows Upon downward'movement of the sleeve 111, such as caused by downward movement of the governing mechanism 74 in response to increase n speed, the exhaust ports 113 and 116 are placed incommunication, per

mitting discharge of fluid from the interior of the sleeve 114. The pressure thereof decreases until the spring 117 moves the inner sleeve 114 downwardly to cut-off position. In response to this decrease inpres sure, the spring 56 of the servo-motor 53' moves the valve 28 in closing direction a distance proportional to the decrease in fluid pressure.

Upon upward movement of the sleeve 111, such as caused by upward movement of the governing mechanism 74; in response to decrease in speed, the ports 112 and 115 are placed in communication. Fluid under pressure is admitted to the interior of the inner sleeve 114 and increases the pressure of the fluid therein until the inner sleeve 114 moves upwardly to cut ofi further admission of fluid. In response to the increased fluid pressure, the piston 54 of the governor 53 rection.

From the above description, it will be seen that I have provided a mechanism in which the valve closing action of the governing mechanism is overcome, in response to shifting of the reversing lever, during braking of the turbine speed in the direction in which it has been operating.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications, without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

at I claim is:

1. The combination with a reversible prime mover having an ahead and an astern admission valve, of a control mechanism for the valves comprising means including and controlled by a control member for opening either of said admission valves, means responsive to the speed of the prime mover for effecting closing movement of each valve in response to increase in speed of the prime mover, and means for releasing either admission valve from the control of the speedresponsive means upon movement of the control member to the position calling for opening of the valve, and means for restoring said control upon slowing down of the prime mover to a predetermined speed.

2. The combination with a reversible prime mover having an ahead and an astern admission valve, of a'control mechanism for the valves comprising a control member adapted to be positioned for ahead operation or astern operation, valve-operating mechanism adapted to be controlled by said control member for each of the admission valves, means responsive to the speed of the prime mover and adapted to cause each valve operatin mechanism to operate in valve-closing direction upon predetermined increase in speed, and means for releasing the ahead valve-operating mechanism from the control of the speedresponsive means upon movement of the conmoves the valve 28 in opening di- The combination with a reversible prime mover having an aheadand an astern admission valve, of a control mechanismfor the valves comprising a control member adapted to be positioned for ahead operation or astern operation, valve-operating mechanism adapted to be controlled by said control member for each of the admission valves, means responsive to the speed of the prime mover and adapted to cause each valve operating mechanism to operate in valve-closing direction upon predetermined increase in speed, means for releasing the ahead valve-operating mechanism from the control of the speed-resp0nsive means upon movement of the control member from astern to ahead position and for releasing the astern valve-operating .mechanism' from. the control of the speed-responsive means upon movement of the control member from ahead to astern position, and means for restoring the control of the speedresponsive means upon decrease in the speed of the prime mover to a predetermined low speed.

4. The combination with a reversible prime mover having an ahead and an-astern admission valve, of a control mechanism for said valves comprising a control member movable to ahead, astern and neutral positions, means for operating the admission valves in accordance with the position of the control member, means responsive to a predetermined speed of the prime mover for causing closing movement of the valves against the action of the control member, means for releasing the action of the speed-responsive means on either valve upon movement of the control member from neutral position to the position calling for opening of the valve, and means for reestablishing the en ectiveness of the speed responsive means upon sufficient decrease in speed of the prime mover, whereby upon movement of the control member to ahead or astern position, the admission valve corresponding to the position of the control mem her is opened until the speed of the prime mover has decreased and thereafter again increased.

5. The combination with a reversible prime mover having an ahead admission valve and I an astern admission valve, of a control mechanism for said valves comprising speed-responsive means for effecting closing of said valves in response to increase above a predetermined speed, control means including a- 7.

control member for causing opening of either of said valves, and means for disengaging the speedaresponsive means from either valve when the control member is moved to the position calling for opening of that valve and for .i anism out of engageable restoring the speed-responsive means to control of the valve when the speed of the prime mover decreases to' a predetermined low speed.

6. The combination with a reversible prime mover having an ahead and an astern admis sion valve, of a control mechanism for said valves comprising a control member movable tepositions calling for ahead and astern i, operation of the prime mover and to'neutral position, and a valve operating mechanism for each admission valve adapted to move the admission valve in opening or closing direction as dictated by the position of the control member, speed-responsive means movable upon increase in speed into engaging relation with a controlling part of each valve-operatin g mechanism to effect closing movement ofthe admission valve operated thereby upon sufficient increase in speed, means responsive to movement of the control member from neutral position to ahead or astern position for temporarily bringing the controlling part of the corresponding valve-operating mechrelation with the speed-responsive means, said speed-responsive means snapping into engageable relation with said part upon suflicient decrease in speed so that upon subsequent increase in speed to a predetermined speed, the valve operating mechanism will move the valve in closing direction. In testimony whereof, I have hereunto subscribed my name this 19th day of Ma 1931.

' WARREN B. FLAND RS.

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