Патент USA US2404262код для вставки
July 16, 1946. .1.,y E. WHITFIELD ` 2,404,262 - SERVOMOTOR AND CONTROL Filed sept. 27, 1945 s sheets-'sheet 1 Patented July 16, 1946 2,404,262 UNITED STATES 'PATENT oFFlCE 2,404,262 sERvoMoToR AND CONTROL Joseph E. Whitfield, Hamilton, ohio Application September 27, 1943, Serial No. 503,955 14 claims. (ci. `eso-_16) 1 _ This invention relates generally to expansible chamber motors and more particularly to a fluid pressure actuated servomotor for operating ap paratus that is rotated in opposite directions to 2 v - Fig. 3, is a view in horizontal section of the servomotor showing the vane in one extreme po sition. ` " ‘ Fig. 4 is a view similar to Fig. 3 showing the perform a function, such .as operating a revers vane in a first intermediate positionlr ` ing valve. This servomotor is adaptable tovmany differ ent applications but was specifically designed vane in a second intermediate position. Fig. 5 is a View similar to Fig. 3 showing the " Fig. 6 is a view similar to Fig. 3 showing the for operating a reversing valve which controls vane in the other extreme position. _ ' Fig-'7 is a diagrammatic view of a Diesel engine the flow of scavenging or supercharglng air pro 10 with reversing control circuit. ' duced by a screw blower for a reversible Diesel engine wherein the blower is driven directly from Fig. 8 is a vertical sectional View 'of the servo the shaft of the engine. ' motor showing a portion of the vane andhous The principal object of this invention is' the provision of a servomotor in which the diminish ing chamber ahead of the vane is supplied with a charge >of the motivating fluid under pressure to retard the vane adjacent the end of its stroke. Another object is the provision of apparatus for supplying from the expanding chamber a charge of the motivating ñuid under pressure to the diminishing chamber ahead of the vane to cushion the movement of the vane intermediate of or adjacent the end of its stroke. ing with their ports in registration. ' Referring to Figs. 1 and 2 of the drawings, the housing 9 of the servomotor is provided with a cylindrical chamber II which is' closed at the top by the removable cover l 2 and 'at the'bottom by the integral end wall- I3. The cover I2'and the wall I3 are provided> with axially aligned bearings I4 in which the servomotor shaft 'I5' is journaled. The shaft I5 is coaxial with the- cy lindrical chamber I I and extends above the "cover I2 lto receive the hand operating arm `I6 forman' Another object is the provision of apparatus for 25 ually rotating the servomotor shaft. ' ï ‘ ‘ supplying a charge of compressed fluid in the The lower side of the housing 9 and wall ‘I3 is provided with an annular seat I'I arranged to fit diminishing chamber of a servomotor and for the mating seat I8 which defines the upper' open venting the fluid under pressure in the expanding ing of the adapter casting I9> which in turn has chamber to cushion the movement of the vane a stepped connecting ñt with thereversing‘valve toward the end of its stroke. housing 20 which encloses a reversing valve that Another object is the provision of a vane type is employed in’ combination with the screw expansible chamber servomotor'wherein the vane blower to change the direction of flow of scaveng functions as a valve at the end of its stroke for controlling the passage of the motivating fluid ing air to a Diesel engine when the'latter is re'- ‘ versed. The valve may be seenv in> Patent No. under pressure. ` Another object is the provision of a Diesel en 2,345,780, issued April 4, 1944. 'I‘hel lower end of the shaft I5 is provided with the coupling mem gine reversing control circuit which includes a servomotor that operates a reversing valve and ber 2l> which is arranged to receive the'r end ‘of the upper gudgeon 220i the valves” ` ’ then completes the control circuit to start the 40 The cylindrical chamber II in the servomotór engine in the opposite direction. Another object is the provision of a method for housing is provided with a removable sector or charging the expanding chamber, charging the stationary abutment 23 which is fastened 'tothe diminishing chamber, and discharging the eX housing by the bolts 24 as shown in Fig. 2. The v panding chamber in sequence of a servomotor in outer cylindrical surface of the stationary abut termediate of its complete operating stroke. Other objects and advantages will be apparent ment mates with the cylindrical wall ofthe from the disclosure shown on the drawings and in the following description and claims: lin theY accompanying drawings a practical em bodiment illustrating the principles of this inven tion is shown wherein: Fig. 1 is a small perspectivev view of the servo moto-r. Fig. 2 is a View in vertical section of the servo motor, ' ' ' chamber II and the inner' cylindricaly surface mates with the surface of the vane 'hub125`as , shown in Figs. 3 to 6. , 'I‘he inner arcuate surface of the stationary 50 abutment has a running'clearance with Vthe ad jacent surface of the vane hub 25. In order to preventA fluid under pressure from leakingfbe tween‘these surfaces to either, side of thesta tionary abutment, a sealing shoe 26 is placed in 5 Ul the vertical slot 21 of the abutment yand is urged 2,404,262 3 Í fr " may kenter the valve mechanism through theright port 5I moving the valve 52 to the left permitting against the cylindrical surface of the hub 25 by means of the coil springs 2B which are inserted in the tapped holes that receive the bolts 24, which holes are aligned with the slot. The wearing face and the upper and lower that passes through the right end vof the sta tionary abutment 23'into the chamber I I in back ends „of the shoe 26 are grooved asindicated at 30 and small holes 3I connect the face of the long groove 35 with the/bottom of the slot 21. der pressure moves the. vane 33 to the position shown in Fig. 4 Where yit may flow into the re the air to continue flowing through the port 53 ‘ of the vane 33 as shown in Fig. 3. The fluid un-V cess 41 and through the port 45'into thecharg . ing connects the `lower end of the groove 30 with 10 ing chamber -44 within the vane. The fluid under pressure continues to move the’interior of the reversing valve housing 20.` the vane in a counterclockwise direction until it The passage 32 could extend to the atmosphere. reaches the position shown in Fig. 5 where the However if compressed air is employed as the charge of fluid under pressure within the charg- '_ motivating fluid for the servomotor, and the re-î “ ing chamber 44 escapes through the port 45 )and versing valve controls the flow of air under a ` A passageway 32through the wall I3 of the hous-` ` ' the Yrecess 48 to the chamber II on the leading ‘ side of the vane. At this instant the diminishing relatively low pressure, any leakage or discharge of air passed Vto the abutment will flow yto the chamber in the housing 20 and cannot accumu-~ portion _of the chamber II is substantially equal in volume to .the charging chamber 44 in the late on either side of the abutment but seeks'the 20 vane. Thus aportion of the charge of fluid low pressure area through these passages. under pressure fills the diminishing portion of î rThe vane 33 with the abutment 23 occupy sub the chamber II and retards the“ movement of the vane'in 'accordance with the differential in pres sure on each side of the vane less the forceV stantially one-half the volumeof the chamber I I and the hub 25 of the vane is splined .on the shaft I5 as shown in Fig. 2. , The outer arcuate surface of the hub and vane have a slight run of inertia of the latter. § 'Y The vane continues to move at a decreasing ' ning clearance `with the abutment andthe walls of the chamber II which prevents wear between these surfaces having relative rotary movement. speed until it engages theleft side of the sta This .clearance also permits the motivating or en- Y tiona'ry abutment 23 as shown in Fig. 6. It will benoted that the port 54 is closed by the valve ' trapped fluid to ñow orvexhaust therebetween and prevents the motivating fluid from reaching> ing theleading' face of the >vane and thus check its charge of fluid under pressure has been added movement. ‘ Thus the running clearance, which thereto. 52 rso‘the fluid in frontof the moving vaneV is be continuously compressed even ' though a Thus the fluid seeks its escape from the Y . diminishing portion of the chamber II to the exhausts the fluid under pressure from either side of the vane,'is 'a defined orifice the size of which 35 low pressure areas by means of rthe grooves 35 and 31.in the shoes 26 and 35 of the stationary determines the rate of discharge. >A sloping or triangularly shaped radially extending slot., 34 abutment and vane respectively.> These leakage ' >paths act asa choke and thus cushion themove is provided in the center ofthe vane and is ar ranged to receive a similarly shaped shoe 35. mentr of the vane toward the end of yits stroke. y Just before the vane is about to strike the sta _This shoe'is provided with a plurality _of pock ets for receiving the. coil springs 35 which'bear against theb'ottom of the slot 34 and force'one leg surface of the triangular shaped shoe 35 into » tionary abutment 23 the trailing edge of the vane uncovers one ofthe ports` 55 or 56, depending on engagement with the under surface'of the cover the direction of movement of the vane. ' Thus the vane acts as a valve in conjunction with I2 and the otherleg surface into engagement ~ these ports. IThese ports are'in the 'lower >part withfthe cylindrical -wall of the chamber-,I I.. A :groove 31 is centered in the wearing faces of the surfaces of the triangular shoe 35, which groove ~ matches with similarY grooves in“ the upper and lower surfacesof the vane. The holes 38 through 50 the’ shoe 35 connect the groove 31 with the bot -tom of the slot 34. The inner end of the groove 31 .in the bottom face of the vane is connected of .theI chamber II as indicated in Figs. 2 and 8 and do not'mate‘with the ports of the charging y chamber in thel vane. As shownr Vin Fig/.16 the fluid under pressure in back of the vane escapes through the port 55 and travels _through a pipeV to the port 51 which is‘opened by thesetting of Y the valve 52 and permits thefluid to flow out the port 58.V _The port 56 islikewise connected by a pipe to the port 59, which in Fig;Y 6 is closed c to the enlarged bore forming an annularcham ber 40 adjacent the shaft I5. A hole 4I connects. 55 by the valve 52 Yfor performing the same func tion when the servomotor is operated in the op the chamber 40 to the axial passageway 42 vin posite direction. . A ' the lower end of the Vshaft I5 which in ‘turn is If the servomotoris to be reversed the left hand connected with the radial passage 43. Any ñuid port 50 is connected to fluid under -pressure and flowing to theV center of the vane may leak into the groove 31 of the shoe and mayY thus. flow` 60 the valve 52 is moved to the right, which admits air through the port 54 causing the vane to swing through the passages 4I), 4I, 42and 43 into the clockwise and follow the- same sequence of events e chamber of theïvalve housing 20. Twodirect passageways for the flow of fluid are Yprovided «just Ydescribed in the other direction. between the- servomotor chamber I I to the valveA housing 20. ' . ’ Y ' 'I'he vane 33 is hollow having the charging 65 y i If the fluid .under pressure is continuously ap plied to the servomotorjwhenY in one position a vcertainportion will/be continuously discharged chamberf44 which'is> provided'with ports 45, 46 through the dual passages in the shoes 26 and 35 'to the reversing valve chamber.V However it will adjacent the ends thereof. These 'ports are in `be noted that Ythe motivating rfluid is discharged 'the Vupper part '.of the vane andare arranged to connect the charging chamber with the chamber 70 through the‘port 55 as soon as the latter is opened -II through recesses'41 and 48 in thecylindrical Wallïof the chamber II, as shown in Fig’. 8. Ya slight amount which is prior to theend of the vane Stroke, and the inertia of the mass, making > Y The Lservomotor is controlled by the valve up the vane and the movable parts connected mechanism 50 secured to the front'of the hous->> «ing 9. As shown in Figs. 3 `to 6, compressed` air thereto,ris depended'upon for completing the Vstroke of the vane. By varying or changing the 2,404,262 5 , positions of the recesses 41 and 48 and the ports 55 and 56 and controlling the pressure of the 6 through the manual control valve 1l. However motivating fluid the desired operating charac the servomotor l0 is provided with an independ ent. discharge or leakagev path which continuously teristics of the vane and device it actuates may be obtained. exhausts fluid under pressure simultaneously from either side of the servomotor. When the piston 15 completes its stroke the selected valve ' One application of the servomotor is shown in 80 admits fluid under pressure through the cor diagrammatic view, Fig. 7, where the source of responding> control line to the Aservomotor l0. fluid pressure is received by the pipe line 62 As shown in Fig. 7 the line 12, which is ener which in this case is compressed air employed for starting the Dieselengine. The supply line 62 is 10 gized, with compressed air, is connected to the port 5I of a servomotor I0. The compressed air connected to the lower chamber 63 of the relay having swung the vane counterclockwise,y and valve 64. ` properly positioning the reversing valve for di. The relay valve is provided with a valve 65 at recting the scavenging air to the engine when the tached at one end to the stem 66 `which is pro vided with a piston head 61 at the other end. 15 latter is set to move `the boat or train ahead, it is permitted to flow out the port 58 to the pipe The piston is operated in the chamber 68 and is lin where it travels to thef chamber 68" of the-re urged upwardly by the coil spring 69, Thus the fluid pressure and the spring tend to maintain _ lay valve‘64 where it forces the piston 61'downQ wardly against the fluid pressure in the cham the valve 65 closed but the piston 61 is larger in diameter than the valve, thus requiring a 20 Vber 63 and compressing the spring 69 to open the valve 65 admitting compressed air to Ythe air lower differential in pressure to open thevalve. start header 82. v , . Assuming that the valve 65 is closed and air After leaving the servomotor the compressed under pressure is supplied to the chamber63, this air in the control line’may be employed to check air is effective in the control line 10 to the man or operate other devices about the engine. ual control valve 1I which when in its neutral The header 32 is connected to -a series of valves 'position maintains the line 1D closed and ex 83 that admit the compressed air to the cylinders hausts both control lines 12 and 13 but when of the Diesel engine in timed sequence by the cam moved to the position indicated “Ahead” admits shaft 11. Some of the valves 83 are open regard compressed air to the line 12 and the line 13 not being charged is connected to the exhaust re 30 less of the position of the engine cam shaft and the compressed .air enters the cylinders forcing turn line 14 and when moved to the position in . the pistons down and causing the engine to turn dicated “Reverse” admits compressed air to the over. As the Diesel engine gains speed as an air line 13 and connects line 12 to exhaust. motor, it is switched to fuel oil Vand operates as The lines 12 and 13 are connected to opposite sides ofthe fluid motor piston 15 which through 35 an internal combustion engine. Thus each re versing device must properly function before the the linkage and sector gears 16 shift the valve . engine can be revolved in the opposite direction. actuating ycam shaft 11 of the Diesel engine, I claim: thereby changing the fuel cams 18 and the start-> 1. In a fluid circuit for starting and reversing ing air distributor 19 for operating theengine in either the forward or reverse direction. Thus when the selected control line 12. is er1 ergized the piston 15 moves downwardly, causing 40 a Diesel engine as an air motor the combination of ailuid pressure supply, a normally closed fluid actuated master relay valve arranged to connect the supply to the valve-controlled cylinders of the cam shaft 11 to move to the right. The lower Diesel engine to operate the same, a manual con sector engages a compressible check which in~ sures a complete movement of the cam shaft in 45 trol valve, a fluid motor for shifting a distributor and valve operating cam shaft reversing gear either direction. The connecting rod which supports the piston mechanism which control the ope-ration of the Diesel engine, a fluid servomotor for controlling 15 is provided with valves 80 at each end thereof a blower reversing valve of said engine, a pair of for permitting the compressed air to continue to flow through the lines 12 and 13 only after the 50 fluid control lines connecting the associated sides ' of the servomotor, the fluid motor and the man cam shaft has completed its movement to the ual control valve thelatter of which selectively selected position. When the manual control conects one control line to said supply andthe valve 1I is moved to a selected> operating position other to exhaust, and a. third fluid control line to reverse the engine the discharge line 14 re~ connected to the master relay valve and arranged leases the pressure inthe opposite control line to receive fluid under pressure from the selected through its corresponding valve 8,!) to the servo control line through the servomotor after the lat motor I0, the control line 8| and the chamber ter has functioned, to open the master relay valve 68 of the master relay valve 64 and also continues and admit fluid under pressure from the supply to drain the chamber of the piston 15 before fluid to the valve controlled cylinders lto turn over the under pressure is admitted to the opposite side engine. . of the second section of the control line. As pre 2. The structure of claim 1 which also includes viously stated the shoes 26 and 3570i the abut a valve in each control line leading to the servo ment and the vane respectively of the servomotor motor and operated by the fluid .motor to admit l0 are provided with restricted discharge pas sages that are constantly open to the atmosphere 65 fluid to the alternate sides of the servomotor only after the fluid motor has functioned. . or to the chamber of the housing 20; Thus after 3. The structure of claim 1 >wherein the control the selected control line is closed by the move valve exhausts the .control line circuitV when ment of the piston 15 the entrappedl air in front neither control is connected to the supply. of the moving vane in the servomotor I0» escapes 4. In a fluid. circuit for starting and reversing past the shoes 26 and 35 and passes directly to a 70 a-_Diesel engine equipped with a‘ direct drive air low pressure discharge, thus preventing the vane blower. the combination of a fluid pressure-supply, from being blocked from movement. Initial a normally closed master relay valve arranged to . movement of the piston 15» closes -the valve 80 connect the supply tovalve-controlled cylinders and- thus blocks further discharge of the sec ond- .section of the nonselected control, line of. the Diesel engine to: Startthe'same, a manual v2,404,262 7 8 . t control valve,~a iiuid motori for shifting a dis connected thereto, a doubleaction fluid motor, tributor and valve operating cam shaft reversing gear mechanism which4 control'the operation of the Dieself engine in either direction, a ñuid ser-1 a double action ñuid servomotor, a single action fluid .moton a pair of fluidV control lines in two sections connecting the Vassociated vsides of the manual control valve, the double action fluid mo vomotor for actuating a blower reversing valve ofthe engine, a pair of `iìuid control lines in two . sections connecting the associated sides of the manual control valve, the ñuid motor and the servomotor inthe order named, the manual con trol valve arranged to selectively connect the first l s'ection'ofr one control'line to exhaust and the other tov said supplyrto energize the ñuíd motor and the'servomotor, means operatedl by the fluid » motor Y'at the end of its energized movement to tor and the double action fluid servo-motorl in the order named- a third control line connecting the single action fluid motor with the double ac'«Y . tion fluid servomotor, the manual control valve being arrangedto 'selectively connect the source of iluid'underV pressure with one of said pair .of control lines, and means to prevent the operation of themotors in the sequencea'named Yjuntilij the precedingmotor has functioned. . . . tor,„and a third Vcontrol line. connected tothe' ?8. The structure of claim '7Í characterized?n that. lsaid means includes a fvalve4 in >the second section of each control line operatedby the dou master relay valve and energized by the servo ble action fluid motor as the latter- completes its motor after the'latter has-functioned, to open stroke. the master relay valve to admit fluid under’pres- . 9. The structure of claim 7 characterizedin that said means includes a -valve for directing :connect theisecon-dsection to theñrst section of the selected control line to energize the servomo- . ï sure from the supply tothe valve controlled cyl'-V inders to turn over the engine. ter completes its stroke.- 25 inders of the Diesel engine to start the same, a manual control valve, a ñuid motor for shifting _« Y ,~ Y , f ` v 10. The structure of claimv '7 characterized in that said means includes a valve actuated by. the ñuid flowing through'the selected control line for directing the fluid ilow to the third control line. ll.. They structure _of claim 7 characterized in normally and arranged lwhen opened to connect the fluid pressure supply to valve-controlled cyl a distributor and valve operating cam shaft re , the flow of huid to the third> control line from the double action fluid servomotor when the lat » 5.*In a iluid circuit for starting and reversing ‘a Diesel engine equippedV with a direct drive air Vblower the _combination of ay fluid pressure sup ply, a differential master valve biased to close> ~ 30 versing mechanism which control the operation that said> means includes a valve actuated'byïthe iluid flowing throughl the selected control line for directing the fluid flow. to vthethird controlline of the Diesel engine in either direction, a fluid from the doubleaction fluid servomotor whenthe servomotor for actuating .a blower reversing valve of the engine, a pair of- ñuid control lines> in two 35 latter completes its stroke. - , 12. In a fluid circuit the- combination cfa ' sections connecting the associated sides of the source of fluid kunder pressure, arvdischarge, a manual control valve, the fluid motor and the servomotor in the order named, a third control line connecting the servomotor to the differential manual control valve, connected with thesupply and'with the.f discharge, Aa double action’fluid mo tor, a double action fluidservomotor.having‘ran masterV valve, theY manual control valve arranged 40 independent restricted outlet constantly openfto discharge, a` single actionfluid motor, a’pairl of to selectivelyconnect the ñrst section of one of ,control lines in two sections vconnecting thel as sociated sides' of the manualfcontrolïvalve, the double action ñuid motor and the double action fluid servomotor in the order named, said manual control valve arranged to selectively. connect one control line to the iluid source andthe other to discharge or both control _lines to discharge, a . said pairs _of >control lines to the fluid pressure i supply and the alternate control line to exhaust, means actuated by the completed movement of the ñuid motor to energize the fluid servomotor through the second section of the selected con Y trol hline, and means actuated bythe completed 4movement of the fluid servomotor through the valve in each control line operated by thedouble third control lineto energize the differential mas ter valve and open the latter to admit fluid to the ,action iluid motor for controlling the ñow of fluid to the double action ñuid servomotor, a third con trol line connecting the servomotor >with the sin gle action fluid motor, and'means to direct the fluid to the third control line to operate the Asingle valve controlled cylinders of the Diesel engine to Ísta'rt the same. ' . . . . 6. In a fluid circuit the combination of a source of fluid under pressure, a manual control‘valve ~ connected thereto, a double action iluid motorga doubleraction fluid servomotor, a singleiaction fluid motor, a pair of fluid control lines connect ing the associated sides of the manual control -valve andthe double action fluid motor, a second pair offluid control lines Vconnecting the associ 55 action fluid motor from aV selected one ,ofthe pair of control lines after the double action fluid servomotor has completed itsV stroke; , _ » 13. In a fluid circuit for starting and vreversing a Diesel engine as an air motor which consists in aìsupply of air under pressure,l a discharge, ated sides of the double action fluid motor and 60 a manual controlvalve connected with .the sup ply and with the discharge, a double action air the double action fluid servomotona third control Lline connecting the double action fluid servomo Y motor for 'shifting a distributor and cam shaft tor with the single action ñuid motor, the man reversing mechanism which control the operation ual control valve being arranged to connect the of the engine, a double action air servomotor'for source of fluid under'pressure with a selected con 65 actuating a blower reversing valve of said engine, trol line to operate the double action ñuid mo a single actionair motor arranged to operateÍa ' to'r, means operated by the double action iluid valve which connects the supply to valve-con’ motor `as it completes its stroke to operate the double acting iiuid servomotor through a selected same as anï air motor, a pair of control lines con 'control line of the second pair, and means op trolled cylinders of the engine to operate .the 70 ‘erated by the vdouble action fluid servomotor as it'completes its stroke toV operate the single act ingV fluid motor through‘the third controlline.V „7., AInl a fluid circuit the'combination of a source .oftiluid ‘under pressure,` a manual control valve necting theassociated sides of the manual con trol valve, the double action motor and the dou-Y ble action servomotor, Vsaid manual control valve 75 arranged to selectively connect'one control vline -to the supplyand the other todischarg'e 'or both control linesA to discharge, a' valve inA eachV control ' 2,404,262 line operated by the double action motor for con trolling the ñow of air to the servomotor, a third control line connecting the servomotor with the single action motonand means to prevent the operation of the motors in the sequence named until the preceding motor has functioned. 14. In a fluid circuit for starting and reversing 10 -V cylinders of the engine to operate the same Aas an air motor, a pair of control lines connecting the associated sides of the manual control valve, the double action motor and the double action servo- i motor, said manual control valve arranged to . selectively connect one control line to the supply and the other to ydischarge or both control lines to discharge, a valve in each control line oper a Diesel engine as an air motor which consists ated by the double action motor for controlling in a supply of air under pressure, a discharge, a manual control valve connected with the supply 10 the flow of air to the servomotor, a third control line connecting the -servomotor With the single and with the discharge, a double action air motor action motor, and means to direct the air to the for shifting a distributor and cam shaft reversing third control line from a selected one of the pair mechanism which control the operation of the en of control lines after the servomotcr has com gine, a double action air servomotor for actuating pleted its stroke to operate the single action a. blower reversing valve of said engine, a single motor. action air motor arranged to operate a v-alve which connects the supply to valve-controlled JOSEPH E. WHITFIELD.