US1628621A - Prime-mover control system - Google Patents

Description

May 10 1 927.

c. B. TAYLOR PRIME MOVER CONTROL SYSTEM Filed D60. 1926 Patented May 1927.

UNITED STATES CHARLES B. TAYLOR, O F MILWAUKEE, WISCONSIN, ASSIGNOR TO ALLIS-CIIALMEBS MANUFACTURING DELAWARE.

COMPANY, OF MILWAUKEE, WISCONSIN, A. CORPORATION OF PRIME-MOVER CONTROL SYSTEM.

Application filed December 13, 1926. Serial No. 154,888.

This invention relates to prime mover control systems. It is particularly adapted for prime movers which it IS desired to start automatically.

A prime mover usually has a comparatively large starting resistance, that 18, more operating fluid must be admitted to start t from rest than may be necessary to bring it to a predetermined speed after it is once started. This necessitates first admitting a comparatively large quantity of operating fluid, then reducing the amount and then again increasing it. It is EIIlObJBCt of this invention to provide ,meanswhereby these' results may be accomplished automatically. and, more particularly, in a simple and efficient manner. I

A more specifioobject is the provision of a control system for accomplishing the hereinbefore mentioned objects in which the prime mover is also controlled by means of a speed governor.

A further more specific object is the provision of acontrol system for accomplish ng the hereinbefore mentioned objects in which a fluid pressure operated servo-motor is utilized for controlling the admission of operating fluid to the prime mover. Other objects will appear hereinafter as the description of the invention proceeds. I

The novel features of the invention will appear from this specification and the ac compa'nying drawing forming a part thereof and illustrating one embodiment of the invention and all these novel features are intended to be pointed out in the claims.

The single figure of the drawing 18 a diagrammatic representation showing how the invention may be applied in the control of a hydraulic turbine.

Referring to the drawing, the prime mover which is to be controlled is here shown as a hydraulic turbine 1 which is adapted to drive a generator 2. The generator 2 may feed a line or distribution system 3 when a circuit breaker 4 is closed. The circuit breaker 4; may be'provided with an operating magnet 5 which may be energized in any suitable manner. The circuit breaker 4: is here also shown as provided with a normally closed auxiliary contact 6 for a purpose to be hereinafter set forth. 7

The supply of water to the turbine 1 may be controlled by any suitable means such as the gate 7. It is of course understood that the supply of operating fluid to the prime mover may be controlled in any usual manner as by valves, guide vanes etc; Hereinafter the term gate will be used for the sake of brevity to designate any means for controlling the admission of operating fluid to the prime mover. The gate 7 may be operated by any suitable means as for example a servo-motor 8 having its operating piston connected through a crank 9 to the ate 7 Fluid under pressure may be admitted selectively to theservo-motor to cause it to move in one direction or the other by means of a regulating valve 10 supplied by fluid under pressure through a pipe 11. The regulating valve is operated by means of a valve stem 12 suitably connected to a pivot 13 at one end of the floating lever 14. The connection between the regulating valve and floating lever is here shown as including a spring cage 15 and a spring 16.

In the position of the parts as shown a control finger l7 pivoted at 18 is adapted to hold the regulating valve 10 in its illustrated position by engagement with a projection 54 associated directly or indirectly with the valve stem 12. In this position of the regulating valve fluid under pressure from pipe 11 is admitted by the regulating valve to theservo-inotor so that the gate 7 may moved to the closed position.

A rod 19 is operatively associated with the control finger 17 by means of a pin and slot connection 21. The rod 19 may be biased so as to in turn bias the control finger 17 in a clockwise direction, by means of a spring 20. The rod 19 may be moved against the bias of spring 20 by means of a core and magnet 22, 23. Any suitable means such as a dash pot 24 may be utilized to retard the motion of the control finger 17. Any other suitable means for operating control finger 17 may be utilized.

The floating lever 14 is controlled by means of fly balls 25, which may be suitably driven in response to the speed of the prime mover, as for example by means of a belt :26. The fly balls are connected to the floating lever at a floating pivot 27. Another end of the floating lever 14 is provided with apivoted nut 28 adapted to receive a screw 29. The screw 29 is for the usual purpose of adjusting the relative position of the nut 28 and a' shaft 30 which is associated with thescreW 29. The shaft or rod 30 is associated with one element 'oia dash pot or compensating device 31, the' other. element of which is operatively related to the gate 7 as. by means of a bell crank 32, a link 33 and an arm .34 movable in unison with the gate 7. A. switch 37, 38 is here shown as held in the closed position by means of an extension on the arm 34 which engages the projection 35 adjustable on an operating rod 36 for the switch 37, 38. The switch rod 36 may be biased toward the other position by means of a spring 39. The bias of spring 39 may also be overcome by means of a core and coil 40, 41 associated with the switch rod 36.

The prime mover is provided with means responsive to a predetermined degree of rotation thereof, here shown as including a centrifugally responsive device 42 which when a predetermined degree of rotation occurs is adapted to actuate switches 43, 44.

Any suitable sourceof current 48 may be provided for operating the control circuits. .4 master control switch 45 for the control circuits is here shown, and this switch may be located at any desired place. When the control switch 45 is closed, a pair of control buses 46, 47 is energized.

lhe electrical connections of the control system will be best understood by a description of the operation of the system as a whole. In the following description relays will be referred to by their operating coils. The operation is as follows. Upon energizetion or the control buses 46, 47 by closure or" switch 45 a relay 49 is energized from bus 46 through the normally closed or back contacts and a movable member 50 of a relay 51, from thence through coil of relay 49 to bus 47. Energization of relay 49 closes a contact 52 thereof thereby energizing mag net or coil" 23 from buses 46, 47 as is clear.

' This causes a counter-clockwise movement at a predetermined rate of control finger 17. The projection 54, and consequently the valve stem 12, follows this movement of control finger 17 under the influence of moved toward the open position. 'When sufficient'water is admitted to the turbine 1 to cause' it to=start from rest the gate 7 is ordinarily opened considerably further than is necessary to bring the prime mover up to.

normal speed and maintain it at that speed.

Whenthe prime mover has attained a predetermined degree oi rotation the device 42 will effectively operate switches 43, 44. It will be noted that the closure of switch 43 will not complete any circuit through coil 41 for the reason that as the gate 7 opened the spring 39 pulled the switch rod 36 toward the left as viewed in the drawing, being permitted to do so by reason of the counterclockwise movement of arm 34. The closure of contact 44, however, completes a circuit for a relay 51, from bus 46 through aresistance 53, through auxiliary contact (3, through coil 51 through contact 44 to bus 47. Relay 51 is consequently energized opening its back contacts and closing its front or up- ,per contacts. It will be noted that the front contacts of relay 51 serve to bypass contact 44 and consequently relay 51 is maintained energized. The opening of the back contacts of relay 51 dcenergizcs relay 49 which in turn deencrgizes coil 23. The spring 20 consequently moves the control finger 17 in a clockwise direction thereby returning the regulating valve 10 to the position shown in the drawing and causing the servo-motor to reclose the gate 7. Reclosure ot' the gate 7 causes the switch rod 3610 again assume the position shown in the drawing. Inasmuch as the switch 43 is now closed and contact 38 is also closed, a circuitis completed for the coil 41 which acts upon core 40. The closure of switch 37 is adapted to short circuit the coil of relay 51 thereby deenergizing that relay. It is of course obvious that the relay 51 may be deenergized in some 95 other manner than by short circuiting the same. The deenergization of relay 51 causes that relay to reclose its back contacts thereby again energizing relay 49 and consequently also coil 23. The control finger 17 is there- In fore again moved in a counter-clockwise direction to thereby, as previously described, move the gate 7 toward the open position. Inasmuch as, coil 41 is now energized, the switches 37, 38 will be maintained in the closed position even though arm 34 moves away from projection 35.

Meanwhile the prime mover has been increasing. in speed and at a predetermined speed the fly balls 25 assume control of. the 1m regulating valve 10, the control finger 17 having moved out of the way of the projection 54 thereby permitting full control by means of the 'fly balls. Asv the gate 7 opens the bell crank 32 is rotated in a clockwise direct-ion to provide compensating movement through dash pot 31 acting on nut 28 to rotate the floating lever 14 about its floating pivot 27 in the well known manner to readjust the regulating valve 10. When the 1-30 prime mover has attained a speed which .corresponds in frequency to the frequency of line 3. the coil 5 may be energized in any suitable manner *to close circuit breaker 4, the generator 2 then supplying energy to line 3. The closure oi circuit breaker 4 opens auxiliary contact 6 thereby avoiding any waste of current in resistance It should be understood that it is not de sired to limit the invention to the exact de- Ill) (it I mined amount, and means effective when said gate has been moved sald predetermined amount for causing said controlling means to effectmovement of said gate toward open position. I

2. In a control system for a prime mover having a gate for admitting operating fluid thereto, a servo-motor for operating said gate, a regulating valve for said servo-motor, means for causing said regulating valve to move to gate-open position to thereby open said gate and start said prime mover from rest, means responsive to a predetermined degree of rotation of said prime mover forcausing said regulating valve to move to the gate-closed position, and means effective when saidgate has been-moved a predetermined amount toward closed position for causing said regulating valve to move to the gate-open position to thereby reopen. said gate.

3. In a having a gate for admitting operating fluid thereto, operating means for said gate, means including a magnet for controlling said operating means, means for initially energizing said magnet to cause said operating means to open said gate, meansresponsive to a predetermined degree of rotation of said prime mover for deenergizing said magnet to thereby cause. closing movement of said gate, means responsive to the predetermined closing movement of said gate for reenergizing said magnet to thereby reopen said gate, and means for maintaining said magnet energized after said gate reopens.

4; In a control system for a prime mover having a gate forv admitting operating fluid thereto, a servo-motor for operating said gate, a regulating valve for servomotor, mean; including a magnet tor causing said regulating valve'to move to gateopen position to thereby open said gate and start said prime mover from rest, means rcsponsive to a predetern'iined degree of rotation of said prime mover for decnergizmg said magnet to thereby cause closing movementof said gate, means responsive to a predetermined closing movement oi raid gate for rcenergizing said magnet to thereby reopen said gate, and means for maintaining control system for a prime mover said vmagnet energized after said gate reopens.

5. Ina control system for a prime mover havingla gate for. admitting operating fluid thereto, operating means for said gate,'means including a magnet for controllingsaid op: 5

crating means, means for initially energizing said magnet to cause said operating,

means to open said gate, means responsive to a predetermined degree of'rotation of said prime moverior deenergizing said magnet to thereby "cause clos ngmovement of said gate, meansinclu'ding a switch responding,

to a predetermined closing movement of said gate jor reenergizing said magnet to thereby reopen said gate, and means responsive to the closure of said switch for mai'ntaining said switch closed after said gate reopens.

6, Ina control system for a prime mover having a gate for admitting operating fluid thereto, operating means for said gate,

means including a magnet for controlling said operating means, means for in tially energ zmg said magnet to causesa d oper ating means to open said gate, means responsive to a predetermined degree of ro-' tation of said prime mover for deenergizmg 'said magnet to thereby cause closing movement of said gate, means responsive to i the predetermined closing movement of saidgate for reenerglzlng said magnet to there-V by reopen said gate, means for maintaining said magnet energized after said gate reopens, and a governor responsive to the speed of said prime mover for controlling said gate-operating controlling means.

7. In a control system for a prime mover having a gate for admitting operating fluid thereto, operatin means for said gate, means for controlling said operating means, means including a magnet which when en ergized or deenergized respectively causes said controlling means to eti'ect opening or closing movement respectively of said gate, a relay for controlling said magnet, means for initially energizing said relay, a second relay having a contact in the circuit of said first relay, means responsive to a predetermined amount of rotation of said prime mover for energizing said second relay, means for maintaining said second relay energized in response to the operation thereof, switch means, means operativeiy related to said gate for actuating said switch means as said gate moves out of and into a predetermined closed position, means Where by actuation of said switch n'irans in response to closing movement of said gate deenergizes said second relay, and means for maintaining said switch. means closed in response to actuation thereof,

8 In a control system for a prime mover having a gate for admitting operating fluid thereto, means tor operating said gate, means tor controliing said operating means,

means for initially causing said controlling means to open said gate, means responsive to a predetermmed'degree of rotation of said prime mover for causing said control-- ling means to .close said gate, means re- I sponsi've to the position of said gate for controlling said controlling means, and means ointly respons ve to said gate-responsive .meansand said rotation-responsive -1neans for controlling'said gate-responsive means.

.9. In a control system for a prime mover 15 to cause said gate to open a predetermined amount, means responsive to a. predetermined degree of rotation of said prime mover for causing said controlling means to effect movement of said gate toward closed position to a predetermined amount, means effective when said gate has been moved said predetermined amount for causing said controlling means to effect movement of said gate -toward open position, and a governor responsive to the speed of said prime mover for controlling said gate-operating control- 1mg means. A

In testimony whereof, the. signature of the inventor is affixed hereto.

CHARLES B. TAYLOR.

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