US3324871A

US3324871A - Jet pipe regulator with null position adjustment

Info

Publication number: US3324871A
Application number: US445624A
Authority: US
Inventors: Jr Edward H Farnan; Robert E Kay
Original assignee: Sperry Rand Corp
Current assignee: Vickers Inc
Priority date: 1965-04-05
Filing date: 1965-04-05
Publication date: 1967-06-13
Anticipated expiration: 1984-06-13
Also published as: DE1523650B1; FR1473791A; GB1115885A

Description

3mm E. h. FARNAN, JR. ETAL 3324,71

JET PIPE REGULATOR WITH NULL POSITION ADJUSTMENT Filed April 5, 1965 FIGE.

FIG. 2.

ENVENTOWS.

EDWARD H. FARNAi, JR. ROBERT EKAY United States Patent 3,324,871 JET PIPE REGULATQR WITH NULL POSITION ADJUSTMENT Edward H. lFarnan, Jr., Arlington Heights, 111., and

Robert E. Kay, Birmingham, Mich., assiguors to Sperry Rand Corporation, Troy, Mich., a corporation of Delaware Filed Apr. 5, 1965, Ser. No. 445,624 12 Claims. (Cl. 137-83) This invention relates to power transmissions and is particularly applicable to those of the type comprising two or more fluid pressure energy translating devices, one of which may function as a pump and another as a fluid motor.

The invention is more particularly concerned with electro-hydraulic jet pipe control systems. In systems of this type, the first stage of the system comprises a jet pipe having a nozzle at one end through which a high velocity fluid jet issues toward two closely spaced receiver ports leading or connected to output ports of the first stage. The output ports of the first stage may be directly connected to an output member such as an actuating cylinder or to a second stage fluid pressure actuated directional control valve.

If the jet pipe nozzle is acurately positioned or centered over the two receiver ports, no differential pressure is created at the output ports of the first stage when the jet pipe is in what is known as the null position as the two receiver ports are adapted in the null position of the jet pipe to receive an equal amount of fluid so as to create a pressure balance. The jet pipe may be pivoted, swung, or flexed by a torqueor force motor in response to signals communicated thereto for shifting the jet pipe, thus shifting the nozzle more or less over one of the receiver ports in order to create a differential of pressure at the output ports of the first stage. Generally, adjustable stops are provided to limit movement of the jet pipe in opposite directions for preventing overshifting of the jet pipe and thus loss of communication of the nozzle with the receiver ports.

In systems of this type, it is essential that the receiver ports be centered as closely as possible relative to the jet pipe nozzle with the jet pipe in the null position as deviations from the centered position lead to instability and inaccurate response. In order to provide proper centering, it has been necessary, after assembly and after being in service, to make final or corrective adjustments necessitating the use of gauges and special aligning instruments and tools which is time-consuming and expensive.

It is, therefore, an object of this invention to provide an improved hydraulic jet pipe control system.

It is another object of this invention to provide a hydraulic jet pipe control system having means for automatically centering the receiver ports relative to the nozzle in the null position of the jet pipe.

It is still another object of this invention to provide in an electro-hydraulic jet pipe control system a receiver port member which is self-centering relative to the jet pipe nozzle and which is then locked in the centered position for normal operation of the system.

It is a further object of this invention to provide in a system of the type aforementioned, a receiver port spool which may be automatically centered relative to the jet pipe nozzle in the null position of the jet pipe by pressure fluid from the nozzle delivered through the receher ports to balanced end areas of the spool member and then locked in the centered position.

It is another object of this invention to provide an improved electro-hydraulic jet pipe control system having a built-in, self-centering adjusting feature which is simple in construction, economical, and which provides a compact and efiiciently operating system.

Further objects and advantages of the present invention will be apparent from the following description, refer ence being had to the accompany drawing wherein a preferred form of the present invention is clearly shown.

In the drawing:

FIGURE 1 is a sectional View of an electro-hydraulic jet pipe control system embodying a preferred form of the present invention.

FIGURE 2 is a fragmentary sectional view on an enlarged scale of a portion of the jet pipe control system shown in FIGURE 1.

FIGURE 3 is a top view of the receiver spool shown in FIGURE 2.

FIGURE 4 is a sectional view of the receiver spool taken on line 44 of FIGURE 3.

Referring now to the drawing and more particularly FIGURES l and 2, there is shown an electro-hydraulic et pipe control system, indicated generally by the numeral I10, comprising a housing 12 within which there is mounted a first stage force motor 14 for operating a jet pipe 16 having a nozzle 18 at one end thereof, which is accurately positioned in the null position shown over two

jet receiver ports

20 and 22 of a receiver spool 24. There is also shown a second stage directional control valve spool 26 operated by fluid pressure differential controlled by the jet pipe. It should be understood, however, that the second stage may comprise a directly actuated output member, such as a motor of the actuating cylinder type. It should also be noted that for purposes of more clearly illustrating the pro-operation or in service, self-adjusting centering features of the receiver spool positionwise relative to the jet pipe nozzle, hereinafter described, the receiver spool and jet nozzle end of the jet pipe are shown in FIGURES 2 and 3 as if the complete system shown in FIGURE 1 has been rotated counterclockwise.

The jet pipe 16 is provided with an enlarged externally threaded portion 28 at the end thereof opposite to the nozzle Which serves to anchor the pipe in one end of a longitudinal bore 30 which extends completely through the housing. The force motor 14 comprises a coil 32 surrounding a magnet 34, all of which is protected by a cover 35 fastened to the housing 12, the coil 32 being clamped at 36 to the jet pipe near the nozzle end thereof for flexing the pipe in the bore 30 in response to signals imposed through wiring 38 connected to the force motor 14.

The output member of the second stage part of the system comprising control valve spool 26 is shiftably mounted within a longitudinal bore 40 of the housing 14). Bore 40 is provided with an annular pressure supply port 42 located between two operating or motor ports 44 and 46 and two return or tank ports 48 and 59, respectively, equally spaced on opposite sides of the two operating or motor ports 44 and 46. The control valve spool 26 is provided with centrally located spaced apart

land members

52 and 54 and

extreme end lands

56 and 58, respectively, having balanced pressure effective

end surface areas

57 and 59. The valve spool 26 is biased to the position shown closing off communication between all ports by means of spring members 61 and 63, respectively, mounted in fluid

pressure end chambers

65 and 67. A differential of,

pressure in the

chambers

65 and 67 created by flexing of the jet pipe 16 and acting on the balanced

spool end areas

57 and 59 is adapted to shift the valve spool 26 to conduct a pressure fluid supply source connected to pressure port 42 to one of the motor ports 44 or 46 while connecting the remaining motor port to one of the tank ports. Thus, when the spool 26 is shifted leftwardly, the pressure port 42 is connected to motor port 44 and motor port 46 is connected to the tank port 50; and when the valve spool 26 is shifted rightwardly, pressure port 42 is connected to motor port 46 and the motor port 44 is connected to the tank port 48.

The same pressure fluid supply source connected to the pressure port 42 of the second stage control valve 26 is also adapted to be connected through a pressure reducing valve, not shown, to a plurality of transverse ports 60 at the enlarged end of the first stage jet pipe, which ports are directly connected to the hollow portion of the pipe, indicated by the numeral 61, terminating in the jet nozzle 18.

The receiver spool member 24 is mounted in a bore 62 of the housing which extends from that side of the housing in which the force motor is mounted. Bore 62 is perpendicular to and intersects both longitudinal bore 30, in which the jet pipe is mounted, and chamber 65 at one end of bore 40, in which control valve spool 26 is mounted. A plug 64 maintained by a snap ring 66 closes the bore 62.

Referring now to FIGURES 2, 3, and 4, the receiver spool 24 is constructed with a centrally located cutaway or recessed portion 27 and on two opposing side walls of which are formed ledges or shelves 29 on which is fixedly located a thin plate member 68 having a guide slot 70 for the jet pipe 16. The slot 70 is accurately positioned over the receiver ports and 22 which open to a flat surface 31 in the bottom of the recessed portion 27. End wall surfaces 72 and 74 of the slot 70 limit the movement of the jet pipe in opposite directions so that the jet pipe nozzle 18 is never out of communication with either of the

receiver ports

22 or 20; and thus, when the jet pipe is flexed, the jet stream will always be directed into one or the other of the receiver ports. The left receiver port 22, as viewed in FIGURES 2 and 3, extends angularly into the spool and intersects a cross passage 76 which extends completely axially through the spool to the right end thereof, opening to a chamber 78 in which is exposed a receiver spool right end surface area 80. The right receiver port 20 extends angularly into the spool in a direction opposite to that of port 22 and intersects a cross passage 82 which extends axially completely through the spool to a chamber 84 at the left end of the spool in which a receiver spool left end pressure surface area 86, equal in area to that of the right end surface 80, is exposed.

Chamber 84 to which receiver port 20 is connected and which is formed at the interior end of bore 62 in which the receiver spool 24 is mounted, intersects chamber 65 of bore 40 in which control spool 26 is mounted. Chamber 78 which is formed at the opposite outer end of bore 62 in which receiver spool 24 is mounted and to which receiver port 22 leads, is connected by suitable passages to the end chamber 67 of bore 40 in which control valve 26 is mounted, only one of said passages being shown and indicated by the numeral 87. Thus, the

chambers

78 and 84 serve as output ports of the first stage to which the output member of the second stage is connected. A common return port for the two stages of the system adapted to be connected to a reservoir or tank is indicated in FIGURE 1 by the numeral 95.

The nozzle end of the jet pipe 16, at assembly of the control system, is inserted through the slot 70 of the receiver spool 24, the longitudinal axis of the guide slot 70 being in the same plane as the common centerline of the receiver ports and the slot width being sufficient to allow free movement of the jet pipe nozzle along the common axis of the receiver ports.

During normal operation of the control system, a differential of pressure on

pressure surface areas

80 and 86 of the receiver spool 24 is ineffective to shift the spool as the spool 24 is locked in the position shown by a locking screw 88. The locking screw 88 is threaded into the bore and has a stub end 90 which is fitted into another 4 slot 92 into the receiver spool 24 opposite the

receiver ports

20 and 22. The stub end 90 is located in the slot 92 and contacts a surface 93 of the receiver spool for locking the receiver spool and which also prevents the receiver spool from rotating.

The jet pipe 16 which extends through the receiver guide slot 70, issues a high velocity fluid jet through the nozzle 18 toward the

receiver ports

20 and 22. The receiver ports are adapted to receive the jet stream and convert its kinetic energy into a differential static pressure.

After assembly of the control system but before operation or in field service, the receiver spool will be self-adjusting for accurately positioning or centering the jet nozzle 18 over the two

receiver ports

20 and 22 merely by loosening the locking screw 88 to permit slight axial movement of the receiver spool 24. With the locking screw 88 loosened, a source of pressure fluid supply connected to the jet pipe ports 60, and with no input signal being applied to the force motor 14, so as to maintain the jet pipe in the bore 30 in the null position shown, any pressure differential at opposite ends of the receiver spool caused by one receiver port getting more fluid than the other will shift the receiver spool unitil the receiver ports are accurately centered about the jet stream and nozzle 18. The differential pressure in

chambers

78 and 84 at opposite ends of the receiver spool bore 62 acting on receiver spool end surface areas and 86 causes the receiver spool 24 to move or shift until a pressure balance exists between both receiver ports and their respective correlated chambers to which they are connected. This pressure balance will only be created when the nozzle 18 is accurately centered or positioned over the receiver ports. This balance is reached almost immediately, and when achieved, the locking screw 88 is tightened to impose the stub end on the receiver spool surface 93, thus accurately fixing or locking the receiver spool position for normal operation of the control mechanism. The receiver guide slot 70 serves to keep the jet pipe (and jet stream) on the common axis of the receiver ports and to limit its travel to the position of maximum pressure recovery. No gauges, special tools or instruments, or disassembly of the system are required to provide proper centering of the receiver ports relative to the nozzle.

Upon operation of the force motor and with the receiver spool in the locked position, .the jet pipe is flexed and the differential pressure caused by directing the jet stream into one or the other of the receiver ports is used to control the movement of the directional valve spool 26 or may be used to directly actuate a second stage output member other than control valve spool 26.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, all com ing within the scope of the claims which follow.

What is claimed is as follows:

1. In a hydraulic cont-r01 system having a jet pipe with a nozzle at one end thereof and including means for connecting pressure fluid thereto and means for shifting the pipe in opposite directions from a stationary null position,

the combination of a receiver port member having a surface with two receiver ports opening thereto, said ports being independently connected to oppositely disposed end chambers in which are respectively exposed pressure elfective opposed end surfaces of the receiver port member,

said chambers being adapted for connection to an output member,

said receiver port member, with the jet pipe in the null position and pressure fluid connected to the jet pipe, being shiftable in opposite directions in response to a differential of pressure on the end surfaces of said member until the receiver ports are centered relative to the jet pipe nozzle at which time a pressure balance exists at the opposed ends of the member,

and means for locking said receiver port member in the centered position relative to the nozzle while said jet pipe is in the null position for normal operation of said control system.

2. The hydraulic control system of claim 1 wherein the locking means comprises a locking screw, an end surface of which is adapted to engage the receiver port member.

3. The hydraulic control system of claim 2 wherein the receiver port member is provided with a jet pipe guide slot spaced from the receiver port surface and through which the jet nozzle end of the jet pipe extends,

said slot including opposed wall surfaces limiting movement of the jet pipe from the null position and preventing loss of communication of the nozzle with the receiver ports.

4. The hydraulic control system of claim 3 wherein the longitudinal axis of the guide slot is in the same plane as the common centerline of the receiver port openings, and the slot width is suflicient to allow free movement of the nozzle end of the jet pipe along the common axis of the receiver port openings.

5. The hydraulic control system of claim 1 wherein the receiver port member is provided with a jet pipe guide slot through which the nozzle end of the jet pipe extends and which is formed with oppositely disposed fixed end wall surfaces limiting movement of the jet pipe in opposite directions from the null position and preventing loss of communication of the nozzle with the jet receiver ports.

6. The hydraulic control system of claim 5 wherein a second slot is provided in the receiver port member opposite the reeciver port surface, and the locking member comprises a screw member extending through the second slot and engaging a surface of the receiver port member opposed to the receiver port surface.

7. The hydraulic control system of claim 1 wherein the locking member comprises a screw member engaging a surface of the receiver member on the side of the receiver port member opposite to the receiver port surface and also serving to prevent rotation of the receiver member while being adjusted to the centered position.

8. An electro-hydraulic jet pipe control system comprisa housing having a first bore perpendicular to and intersecting a second bore,

a jet pipe in the first lbore having a nozzle at one end and adapted to be connected to a pressure fluid supply source,

means associated with the jet pipe responsive to an electric signal for shifting the pipe to opposite sides of a null position,

a receiver port member having opposed end surfaces shiftably mounted in the second bore and forming chambers in said bore at opposite ends of the member adapted for connection to an output member,

said receiver port member having a surface between the end surfaces opposed to and spaced from the nozzle and with two closely spaced receiver ports opening thereto,

said receiver ports being independently cross-connected to the end chambers of the receiver member.

said receiver port member with the jet pipe in the null position and a pressure fluid supply source connected to the jet pipe being self-adjustable in response to a differential of pressure in said end chambers for centering itself and the receiver port openings relative to the nozzle, at which time a pressure balance exists in the end chambers and on the opposed end surfaces of said member,

means for locking said receiver member in said adjusted centered position relative to the nozzle for normal operation of the system,

and means for limting movement of said jet pipe on opposite sides of the null position to prevent loss of communication of the nozzle with the receiver ports.

9. An electro-hydraulic jet pipe control system as in claim 3 wherein the receiver port member is provided with a slot opposed to the receiver port surface, and the locking means comprises a screw member threadable into the housing having an end surface extending through said slot to prevent rotation of the receiver member and engaging said receiver port member for locking the same in the centered position in said second bore.

10. An electro-hydraulic jet pipe control system as in claim 9 wherein the receiver port member is provided with a jet pipe guide slot spaced from and accurately located over the receiver ports, the nozzle end of the jet pipe extending through said jet pipe guide slot, and two opposed end surfaces of the jet pipe guide slot limiting movement of the jet pipe in opposite directions from the null position to prevent loss of communication of the nozzle with the receiver ports, the longitudinal axis of the jet pipe guide slot is in the same plane as the common centerline of the receiver port openings, and the jet pipe guide slot width is sufficient to allow free movement of the nozzle end of the jet pipe along the common axis of the receiver ports.

11. An eletcro-hydraulic jet pipe control system as in claim 8 wherein the receiver port member is provided with a slot spaced from and accurately located over the receiver ports, the nozzle end of the jet pipe extending through said slot, and two opposed end surfaces of the slot limiting movement of the jet pipe in opposite directions from the null position to prevent loss of communication of the nozzle with the receiver ports.

12. An electro-hydraulic jet pipe control system as in claim 11 wherein the longitudinal axis of the slot is in the same plane as the common centerline of the receiver port openings, and the slot width is sufiicient to allow free movement of the nozzle end of the jet pipe along the common axis of the receiver ports.

References Cited UNITED STATES PATENTS 2,601,207 6/1952 Jacques 13783 X 3,205,782 9/1965 Fourtellotte 13783 X FOREIGN PATENTS 475,741 5/ 1929 Germany.

ALAN COHAN, Primary Examiner.

Claims

1. IN A HYDRAULIC CONTROL SYSTEM HAVING A JET PIPE WITH A NOZZLE AT ONE END THEREOF AND INCLUDING MEANS FOR CONNECTING PRESSURE FLUID THERETO AND MEANS FOR SHIFTING THE PIPE IN OPPOSITE DIRECTIONS FROM A STATIONARY NULL POSITION, THE COMBINATION OF A RECEIVER PORT MEMBER HAVING A SURFACE WITH TWO RECEIVER PORTS OPENING THERETO, SAID PORTS BEING INDEPENDENTLY CONNECTED TO OPPOSITELY DISPOSED END CHAMBERS IN WHICH ARE RESPECTIVELY EXPOSED PRESSURE EFFECTIVE OPPOSED END SURFACES OF THE RECEIVER PORT MEMBER, SAID CHAMBERS BEING ADAPTED FOR CONNECTION TO AN OUTPUT MEMBER, SAID RECEIVER PORT MEMBER, WITH THE JET PIPE IN THE NULL POSITION AND PRESSURE FLUID CONNECTED TO THE JET PIPE, BEING SHIFTABLE IN OPPOSITE DIRECTIONS IN RESPONSE TO A DIFFERENTIAL OF PRESSURE ON THE END SURFACES OF SAID MEMBER UNTIL THE RECEIVER PORTS ARE CENTERED RELETIVE TO THE JET PIPE NOZZLE AT WHICH TIME A PRESSURE BALANCE EXISTS AT THE OPPOSED ENDS OF THE MEMBER, AND MEANS FOR LOCKING SAID RECEIVER PORT MEMBER IN THE CENTERED POSITION RELATIVE TO THE NOZZLE WHILE SAID JET PIPE IS IN THE NULL POSITION FOR NORMAL OPERATION OF SAID CONTROL SYSTEM.