DE1500459A1 - Electro-hydraulic servo control system - Google Patents

Description

Munich, the ^ Ä. (1.1969

Patent attorneys

Dr.-Ing. hl A NS RUSCHKE ^{P 15 00 459 8}

Vipl-lng. ΗΪΝΖ AGlJlAH Our reference: N 386

8 Munich SO, Pienzenauerstr. 2

North American Aviation, Inc. El Segundo, California (V.St.A.)

Electro-hydraulic servo control system

The invention relates to an electro-hydraulic servo control system with an input control terminal, a Numerous operating channels connected in cascade, one Output part, which is operated in response to a flow medium by means of an actuating device, and with a feedback arrangement for regulating the amount of the flow medium flowing through each actuation channel.

A major source of unreliability is in the construction and operation of electro-hydraulic servo control systems the electrical signal network including the electro- ° hydraulic control valve »which are used to

α to control the flow of liquid to the hydraulic servo motor cn.

Tl The system according to U.S. Patent 3,070,071 contains

1500A59

an expandable link having a plurality of actuators or servomotors mechanically linked in tandem and responding collectively to an input signal, the failure of one motor reducing the range and efficiency of the overall system. Another system, as described in U.S. Patent 3,095,783, uses a plurality of actuators mechanically connected to an actuator, the separate signal channel for each actuator including an electromechanical transducer to generate a negative feedback control signal for that signal channel . If the signal channel for one of the three actuators works poorly, the other two actuators must be able to provide more power. Therefore, the force metering of each actuator must be 150% of the nominal force metering and the combined force metering of the three units is therefore 450%. In addition to the increased force metering of the actuating device group, the associated pressurized hydraulic power source (pump, etc.) must be increased accordingly. An arrangement excess and oversized 'actuating means in cooperation with surplus electric signal channels to improve the reliability requires brings therefore substantial disadvantages with approved, since it requires vergröseertes weight of the actuating device group ", and more cost and space» ^ i ^ s ^ PfjSf 9 f ^{uv e} * ⁿ single servo channel

ORIGINAL INSPECTED

used with a valve and an actuator, as at the arrangement provided in German Auslegeschrift 1 007 625, the failure of only one servo component will result with it that the entire system becomes inoperable.

The object of the invention is to create an electrohydraulic servo control system which has the disadvantages mentioned the increased weight, the costs, as well as the space and power requirements, without compromising the reliability of the Endanger operation.

According to the invention this is achieved in that said A single actuation device for operating the output part, in response to the application of a controlled one Fluid flow, arranged hydraulic motor and that at least three actuation channels are provided, each of which includes a position sensor which cooperates with said motor, to generate signals indicative of the driven position of the output member with respect to the motor that a summing amplifier is provided, the first input terminal of which is jointly uninterruptedly connected to said input terminal and of which a second input terminal is continuously connected to the output of the position sensor for this channel, and that a proportional flow control valve is present, which is constantly responsive in electrical circuit with the output of the summing amplifier for that channel is connected, the system continuing

00982B / 0U2

is characterized by a manifold block, which fixes the three control valves and jointly connects corresponding openings of the control valves in the fluid circuit, 'on the hydraulic motor in top to control proportionally in tune with the combined fluid flow from the valves, the manifold block has a clamp side, the sealing abuts a main housing of the engine and has cavities for sealingly installing the valves in mutually separated parallel relationship and side by side, with corresponding openings of the valves in a common cross-sectional plane of the manifold _{block 5,} said block having an annular groove in each cavity on each side which has cross-sectional planes and passages extending radially dax ^ in from the grooves, the passages in a given cross-sectional plane terminating at an intersection of a series of passages to allow fluid communication between the grooves of said plane, d the block furthermore has an equal number of separate openings which lie in the terminal side of the block and extend perpendicular to this side, each opening ending at an intersection with one of the mutually adjoining, intersecting passages of the said rows.

This design of the servo system has the advantage that at safe operational readiness and reliability compared to the known systems weight and cost savings as well as reduced space requirements are available.

00 9825 / Q U2

The invention is illustrated below with reference to the drawing, for example explained in more detail. Show it:

Fig. 1 is a functional block diagram of a system using the invention;

Fig '2 is a d-, s schematic arrangement Vy' rdulischen circuit for the apparatus of Figure 1, wherein the interaction between the hydraulic 2u ~ is represented sairiTuenfassungseinrichtung and the hydraulic motor for a three-way valve assembly?.

Figure 3 is an isometric drawing, partially broken away a preferred embodiment of the invention;

Figure 4 is an isometric drawing, partially broken away the manifold block of the device according to Fig. 3,

In the figures, the same reference symbols relate to the same individual parts.

In FIG. 1, there is a functional block diagram of a Servo system according to the invention shown. It will be an electro-hydraulic one Servo system with an electrical input control terminal 10 and a mechanical output part 11 is shown. There are also three independent signal channels 12 and 14 for the transmission of signals from the input control terminal 10 provided, each channel having an electro-hydraulic

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hydraulic flow control valve 15 has that so is designed to operate from a common source of pressurized hydraulic fluid connected and responsive in circuit with the input terminal 10 connected. A hydraulic motor 16 is also provided which is driving with the output member 11 is connected. The liquid pooling device 17 couples the hydraulic motor 16 in the fluid circuit with the valves 15a, 15b and 15c the hydraulic motor 16 to supply fluid. Position converter 18, 19 and 20, which are jointly responsive to movement of the outlet part, create negative feedback itingsposition signals for corresponding signals of signal channels 12, 13 and 14.,

Each of the signal channels 12, 13 and Ik further includes signal combining means 21, such as a signal combining amplifier, which is arranged to receive the common input signal (applied to the common input terminal 10) and the negative feedback signal from a mutually exclusive one of the position transducers 18, 19 and 20 combined. If an AC input signal system is used and converters 18, 19, and 20 are AC converters, aggregation amplifiers 21a, 21b, and 21c further have phase sensitive demodulating means to convert the aggregated signals into DC signals which can be converted for use by the electro-hydraulic system.

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1 500A59

cal valves 15a, 15b and 15c are suitable. The 'lauwr-JGt · and arrangement of the amplifiers 21a, 21b and 21c are .1er. Well known to those skilled in the art and they are therefore lediriici; :.: \ Block form or symbolic form shown

Initiate in normal operation of the arrangement according to FIG Input signals that are sent to the input cycle 10 Are brought into action, each of the flow valves 15a, 15b and 15c a controlled flow of liquid to create the same sense or direction in speaking to input signals that are routed to input terminal XO will. The fluid flow is combined at the manifold 17 and fed to the hydraulic motor 16 for actuation of the outlet part 11 in a selected direction which corresponds to the direction of the controlled liquid flow. The position transducers 18, 19 and 20 generate position feedback signals in response to the movement of the output member 11 indicating the position of the output part 11 and one of a direction which is opposite to that of the input signals, which are brought into action on the end clamp 10. The position feedback signals from each transducer are to the input of an associated one of the integration amplifiers returned. Each of the summary amplifiers 21a, 21b and 21c speak to the algebraic Sum of or the difference in amplitude between the two inputs to a liquid flow of the corresponding flow valve 15 to the hydraulic

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Motor 16 to produce such a direction as to cause the output part 11 to move in one direction to move, which has the tendency to reduce the amplitude difference to zero, as in the case of technology of negative feedback control systems is clear. When the outputs from each of the transducers 18, 19 and 20 the applied input from the clamp are equal and opposite, then the resulting one is Current created by the associated control valves is zero. When the combined electricity to the motor 16 is stopped, the motor holds the output part in a position that corresponds to the direction and the Amplitude of the signal applied to the terminal 10, with the system corresponding changes in position generated in the output part 11 to subsequent changes in the input signal.

In the event of a channel malfunctioning, such as the failure of a control valve or a feedback transducer or amplifier, the system still continues to function as a position servo. For example, if either or both amplifiers 21a and valve 15a were to fail to provide a zero output, the remaining amplifiers 21b and 21c would continue to control associated valves ISb and 15c to provide a controlled flow of fluid to hydraulic motor 16 deliver in accordance with the amplitude un-009Ö25 / ÜU2

difference between the negative feedback position signals and an input signal sent to the input terminal 10 is brought into effect. In other words, the system works as a position servo further if there is a null signal failure in one of the feedforward control loops occurs without change either in the closed loop reinforcement (output shift per volt input) or servo force (maximum achievable displacement). Indeed the system works so on in case of zero signal failure in all, with Except for one of the forward loops, as long as a remaining loop is fully working.

Another type of failure that can occur is a so-called "just above" (hard over) failure, with a maximum signal provided in the forward loop becomes what becomes a bias current or maximum current a selected direction originates from approximately the valve 15a. Such failure can occur as a result of a particular one Type of failure in the valve 15a itself or as a result of the opening of a feedback resistor in a feedback stage of amplifier 21a in the presence of a small but definite input or as a result of failure a position transducer 18 in the presence of a certain input signal (other than zero) of the clamp 10. In such a case, the resulting movement of the output member 11 generated by the

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Bias flow is generated by valve 15a, position error signals at the outputs of corresponding amplifiers 21b and 21c (as well as amplifiers 21a). Such position error signals or flow control signals are supplied to valves 15b and 15c, which are controlled Create fluid flow that coincides with the bias flow from malfunctioning valve 15a Using the flow combining elbow is combined in this way this Voüpannungsstrom balance and cause the motor 16 to drive the output part 11 in the correct position. in the solid state, the two fully working valves 15b and 15c create a combined equalizing flow, which exactly the direction and size of the bias current equalized by valve 15a- With this equalized flow condition or zero net current is a small displacement error in the position of the output part 11 related to the desired position, by applying a fixed state error voltage to the corresponding one Outputs of the amplifiers 21b and 21c is generated, which is sufficient to increase one half of the required equalizing flow rate on each of the valves 15b and 15c. This state of affairs error is usually negligible for ordinary system reinforcements. Furthermore, and where the position servo according to Fig, 1 in another (outer) closed Loop system is used, such as a flight

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vehicle height control device, can have the effect of such Position error on the outer loop avoided are acted upon by the interposition of signal integrating means between these sources brought input signal (not shown) and the input terminal 10, as is well known in the servo control art.

An embodiment of the concept of FIG. 1, using three-way transfer valves, is shown in FIG Fig. 2 shown.

Referring to Fig. 2, there is shown a schematic arrangement of an embodiment of the invention. It's a single hydraulic Motor 16 is provided which has a single cylinder 25 which is adapted to be with A carrier can be connected and a single one movable piston 26 in a cylinder 25, which is connected to a single mechanical output part 11 extending axially from a first side of the piston 26. This arrangement of the piston 26 creates the first and second chambers 27 and 28 in cylinder 25 on first and second sides of piston 26, respectively, wherein the effective hydraulic area of the first side is preferably half that of the second side for reasons which are explained in more detail below.

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1500A59

There are still at least three electro-hydraulic ^ Three-way servo valves 15a, 15b and 15c are provided, each of which has a pressure inlet port, one being controlled Has a flow outlet port and a return pressure port. It an input end terminal 10 is also provided, first, second and third signal channels 12, 13 and IM ·, a Flow inlet manifold 17 and first, second and third position transducers 18, 19 and 20, all so arranged are that they functionally cooperate with the hydraulic motor 16 in the same way as the same designated elements according to FIG. 1.

Transfer valves 15a, 15b and 15c are similarly constructed and arranged and are three-way electrohydraulic servovalves such as those commercially available from, for example, Moog Valve Co. of Aurora, New York. Each of the valves 15a, 15b and 15c in Fig. 2 has an inlet pressure port, a controlled flow outward port, and a return pressure port. The return pressure ports are designed to usually connect to the return _{pressure side P 7} , a source of pressurized hydraulic fluid (not shown). The manifold 11 normally connects the outlet openings of the valves 15a, 15b and 15c with the second chamber 28 of the hydraulic motor 16. The second chamber 27 of the motor and the inlet pressure openings of the valves 15a, 15b and 15c

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are designed so that they are usually connected to the high pressure inlet side P to the source of pressurized liquid (not shown) can.

Knowledge of the mode of operation of the three servo valves 15a, 15b and 15c is useful for understanding the operation of the arrangement of FIG. 2. The arrangement and FIG Operation of valves 15a, 15b and 15c is similar, so an explanation of the arrangement and operation of the Valve 15c, as shown schematically in FIG. 2, is sufficient.

The servo valve 15c consists of a hydraulic circuit and a magnetically operated device for controlling the hydraulic flow circuit. The fluid control circuit comprises a valve spool 30 which is slidably mounted in a valve spool cylinder 31 and has first and second end piston portions 32 and 33 which are axially spaced from a central piston portion 3H and connected therewith by two intermediate coil portions 35 and 36, whereby the cylinder 31 is divided into two end chambers 37 and 38 and two intermediate chambers 39 and UO. The two end chambers 37 and 38 and one of the intermediate chambers 39 are usually connected to the high pressure side P_ of the pressure fluid source (not shown), while the other intermediate chamber 40 has an opening to the back pressure side P of the pressurized

009825/0142

liquid source is open. There are also two pipettes or tassel openings, one of which each in fluid communication with the pressurized one Liquid in one of the mutually exclusive end chambers 37 and 38 of the valve spool cylinder stands and arranged opposite in relation to a magnetically operated flap valve ZL in one Volume that is connected in the liquid circuit to the pressure return line P in a manner not shown is «A mechanical return line is between the coil and the flap valve with the help of the interposition a fine spring is provided, which is indicated schematically as element 42.

When the flap valve41 is at rest (or is not actuated), the valve spool 30 is in the illustrated center position of the valve spool cylinder held by the feedback member 42 and the central cylinder portion 34 blocks the annular controlled fluid outlet. The same and opposite acting pressures exerted on the symmetrical hydraulic areas of the piston areas of the spool * exerting zero net force with the coil in the center position due to the restraint effect the feedback spring 42 is held. In such a state of the valve spool, the neutral is defeated Leak-through or the necessary minimum leak-through flow from the high pressure (P) intermediate chamber 39 to the lower 009825/0142

pressure intermediate chamber (P _r ) 40 two separate pressure drops: one (Δ P,) which leads from the high pressure (P_) intermediate _{chamber opening 39 to the controlled pressure (P c} ) outlet opening 43 and the other (^ P ₂ ) when flowing along the controlled pressure (P _c ) outlet port 43 to the low pressure (P) intermediate chamber 40.

P ₁ = P ₃ - P _c (1)

(2)

In the described symmetrical state, the two pressure drops are the same:

P ₂ <3)

Now equations 1 and 2 are combined and equation 3 is substituted:

Resolved for P,:
PP

in which equation 5 is incorporated into equation 1 and solved for P _c results in:

00982 5 / 0U2

P ₀ = P ₃ - ^ p ₁ =

c ⁼

^p c ⁼ Τ *

Accordingly is for the inactivated state of everyone of the valves 15a, 15b and 15c the usual corresponding control pressure P applied to the second chamber 28 of the hydraulic Motor 16 is brought into action one half of the line pressure P_. Accordingly, the force F is the is exerted on the right side of the piston 26 of the motor 16 by this pressure (as shown in Fig. 2) equal to the product of the area Aj of the left side of the Piston 26 and the pressure applied to it:

P A

r _r = -V (8)

This force is just _{compensated by the force F 1} , which is exerted on the left side of the piston 26 (as shown), which is equal to the product of the system pressure P_ and the effective area Α _{Λ of} the right side of the piston 26.

F ₁ = P ₈ A ₁ (9)

now

A ₂
A ₁ = -f- (10)

^P s ^A

= F _r (11)

009 825 / 0U2

Accordingly, in the inactivated state of the valve (s), the forces on the piston 26 (the hydraulic Motor 16) is balanced and there is no movement on the output part 11.

When an excitation current of a selected direction (from the drive amplifier) is applied to the winding around the flap valve 41, the interaction of the resulting electromagnetic field with the magnetic elements N and S creates a torque or moment which presses the flap valve onto a selected one of the pipettes and thereby throttles the discharge of liquid therefrom. This throttling in the pipette delivery causes a pressure build-up in the associated end chamber of the pressure valve and thereby causes the hydraulic forces on the valve spool 30 to become unequal. This pressure imbalance or force imbalance displaces the valve spool in relation to the annular control flow opening, which leads to a change in the control pressure P. This change in the control pressure P is expressed by a flow of fluid in a selected direction (ie, either into or out of the chamber 28 of the motor 16), which results in movement of the component 11 in a corresponding direction. This movement continues until the position feedback signal from an associated position transducer is of sufficient size to counteract an applied input signal to the end terminal 10.

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set, thereby reducing the actuation current in the flapper valve winding to substantially zero. In such a de-energized condition, the flap valve returns to zero and the follower spring 42 brings the The valve spool returns to the neutral flow position, thereby stopping both the actuation of the motor 16 and the also the movement of the output part 11.

In normal operation of the arrangement according to FIG. 2, all three valves 15a, 15b and 15c would be identical and synchronous work. However, should a failure occur on the signal channel to which a valve belongs, so is a flow To cause zero out of it, the other two valves would continue to operate to provide a controlled flow of fluid to or from the chamber 28 of the motor 16 as required, in accordance with the Position difference signal inputs to these valves from the associated driver amplifiers 21a, 21b and 21c. However, in the event of a signal channel failure to bias flow through the associated flow control valve should result, then the valves of the remaining effective signal channels would be combined into one Create balance flux to balance both this bias flow, and the motor 16 in the desired Direction to operate in the same way as in connection with the arrangement of FIG. 1 described.

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Should, for example, the flap element 11 for the valve 15 to be pressed to the left, as shown in Fig. 2, the throttling of the left pipette would reduce the resulting pressure in the left end chamber 37 of the valve cylinder increase in relation to that of the right valve chamber 3 8 and would thereby cause the valve coil 30 to move to the right. Such rightward movement of the valve spool 30 sets the control valve outlet opening 43 of the pressurized intermediate chamber 39 and thereby generates a flow of liquid from the Opening "+3 to the manifold 17, which would have the tendency to actuate the engine piston 26 to the right. In the absence of a control signal to input terminal 10, is the only input to each of the drive amplifiers that is to the working valves, the position feedback signal from the corresponding position transducers. The response the working valves on this input signi. creates the combined electricity that is necessary to make the movement of the motor 26 and the component 11 (as determined by the converters). Hence it arises in the solid Condition a flow of fluid from manifold 17 towards each of the working valves, the combined flow being equal to the Flow from the pressurized valve is. In other words, the output part 11 is slightly to the right of the desired or reference position shifted to the extent necessary to obtain a control signal from each the drive amplifier 21 of the working signal channels

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to create what is a compensating current of opposite Direction creates and of one half the size of the pressure for an associated valve.

If either the flap element Hl of the pressurized valve would be pushed to the right, the resulting greater pressure in the right end chamber 38 of the valve spool cylinder pushes the valve spool 30 to the left (as shown in Fig. 2) and thereby gives the outlet opening U3 to the pressure return intermediate chamber UO free, which leads to a flow from the manifold 17 to the control port 43. This pressure flow tends to actuate the piston 26 to the left from a reference position, which leads to a position error signal at the outputs of the drive amplifiers of the operating signal channels. The response of the service valves to this error signal creates the combined flow necessary to prevent piston 26 from moving. Thus, in the solid state, there is a flow of liquid from each of the two service valves to manifold 17, the combined flow there being equal to the flow from manifold 17 to the pressurized valve. In other words, the output member 11 is slightly shifted to the left from the desired or reference position and that to the extent that is necessary _t in order to create a compensation current of opposite direction and of half the size of the print from each of the two working valves.

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A preferred embodiment of part of the schematic The arrangement according to FIG. 2 is shown in detail in FIGS.

Referring to Figures 3 and 4, there is an isometric view of a preferred embodiment of the actuator shown schematically in FIG. 2, the elements of which have the same reference numerals as in FIG Fig. 2, which corresponds to the same functional elements. A main housing 57, in addition to enclosing the hydraulic motor element 26 and the chambers 27 and 28 also the three position transducers 18, 3.9 and 20 of FIG on, one of which is shown partially broken away in FIG. The three displacement transducers are close to each other one to the other and parallel to the longitudinal axis of the motor (represented by the output element 11) and installed mechanically with the movable element 11 by a coupling device 48 connected. The transducers are preferably of the AC induction type for improved resolution with a magnetically permeable cylindrical coil core 54 within a transformer element 55 with a primary winding and a secondary winding concentric to it, as detailed in the U.S. patent Mr. 3,136,224 issued June 9, 1964 to A.S. Escobosa exhibited, described. Accordingly, the housing would be preliminary must be constructed of a material that has a low magnetic permeability (in order to allow the

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Converter not to disturb) and high resistance, (To withstand the high hydraulic pressures that are commonly used on the hydraulic motor are brought) combined. Such a typical material is austenitic stainless steel, standard type 303.

The pressure inlet (P_) and the hydraulic return line (P) Fittings 60 and 61 are provided near the rear end of the main body, thereby making the device operational can be connected to a source of pressurized hydraulic fluid. A Pressure line elbow 45 usually connects the engine chamber 27 and a manifold block 47 with a pressure fitting 60, while a control manifold line 17 connects the engine chamber 28 to the manifold block 47. A pressure return line 46 connects a return pressure fitting 61 and the manifold block 47. As shown in FIG 47 has an end face 50, at least a portion of which is sealingly attached to the rear end of the main housing 57 in FIG. 3 strikes.

The hydraulic transfer valves 15a, 15b and 15c of Fig. 2 are preferably in the manifold block 47 of the device installed according to FIG. 3, which manifold lock is better shown in detail in FIG. The commercially available Available types of such three-way valves are usually cylindrical in shape, the

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1500A59

three hydraulic parts .of which are axially spaced along this cylindrical surface. Therefore, when the valves are installed in matching cavities 51a, 51b and 51c which are provided for this purpose in the manifold block 47, corresponding openings lie in the same transverse vertical plane through the block 47, as shown in FIG. For example, the pressure return openings (P _r ) of the three valves lie in the vertical plane 49 parallel to the end surface 50 of the block 47, which is shown in FIG. 4 by the block 47 being partially broken away. Therefore, if a narrow annular groove or cavity 52 is turned out in each of the valve cavities 51a, 51b and 51c in plane 49 and an offset turning out further in such radial directions as to create a communicating cavity between corresponding annular cavities 52, a means is provided, which allows fluid communication between respective ports of the transfer valves. Then, when drilling through the surface 50 of the block 47, an opening 46 is created which may be such that it sealingly mates with and complements the pressure return line 46, which is shown in FIG.

In the same way, a control pressure CP _C ) »elbow 17 and a supply pressure (P_) elbow 45 are provided in block 47 in order to seal the same lines.

0OS82 5/0142

lines to fit and to supplement these, which are partially shown in FIG.

Electrical conductors not shown can be used for the necessary circuit connections of the valves and position feedback transducers be provided, as is clear in the art.

Therefore, the arrangement of FIGS. 3 and U illustrates effective Means for completing the schematic arrangement according to FIG. 2.

Although the preferred embodiment of the invention as a hydraulic motor in conjunction with three-way valves has been illustrated, the spirit of the invention is not so limited and includes optional use of four-way valves, as is clear in the art. Furthermore and although the illustrated embodiment is a special one Ax't of valve can be wildly used with a valve spool controlled by a single flap valve different types of servovalves with a variety of flapper elements in cooperation with the valve spool can be used without thereby abandoning the idea of the invention.

Accordingly, an improved electrohydraulic "" actuator with increased reliability has been described above. _: «It is highly efficient and economical

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and of limited weight and volume. Such savings while achieving improved reliability are achieved through the use of flow combining means in combination with a single hydraulic motor.

Although the invention has been shown and described in detail, it is clear that this has been done by way of illustration and example, and not as Limitation, as the spirit and scope of the invention are to be limited only by the appended claims.

0 0 9 8 2 5/0 U 2

Claims (3)

Patent claims; 1. Electro-hydraulic servo control system with an input control terminal, a large number of cascaded actuating channels, a mechanical output part j which is operated by means of an actuating device responsive to a flow medium, and with a feedback arrangement for regulating the amount of the flow medium flowing through each actuating channel characterized in that said actuating device consists of a single hydraulic motor arranged to operate the output member in response to the application of a controlled flow of fluid, and in that at least three actuating channels are provided, each of which includes a position sensor which cooperates with said motor To generate signals which indicate the driven position of the output part with respect to the motor, that a summing amplifier is provided, the first input terminal of which is uninterrupted in common with said input sklemme is connected and of which a second input terminal is connected continuously to the output of the position sensor 0 0 9 8 2 5/0 U 2 is connected for this channel, and that a proportional flow control valve is present, which is constantly responsive in electrical circuit with the output of the summing amplifier for this channel, the system is further characterized by a manifold block which attaches the three control valves and common corresponding openings of the Connects control valves in the fluid circuit in order to proportionally control said hydraulic motor in accordance with the combined fluid flow from the valves, the manifold block having a terminal side that sealingly abuts a main housing of the motor and cavities for sealingly installing the valves in mutually separated ¹ Parallel relationship and side by side, with corresponding openings of the valves lying in a common cross-sectional plane of the manifold block, said block having an annular groove in each cavity on each side of the cross-sectional planes and radially in front of the N has grooved passages, the passages in a given transverse frying plane at an intersection of a series of passages to allow fluid communication between the grooves of said plane, the block still having an equal number of separate openings which lie in the kneef side of the block and O09825 / 0U2 extend perpendicular to this side, with each opening at an intersection with a «m of each other subsequent, intersecting passages of the said rows ends. 2. System according to claim 1, characterized in that the engine comprises a single cylinder which can be connected to a carrier, that a single movable piston is arranged in the cylinder and connected to said output part which extends axially from the first side of said piston, the piston creating first and second chambers in the cylinder on the first side and on a second side of the piston, the effective hydraulic area of the first side being one half of the area of the second side, each control valve consisting of one electrohydraulic three-way transfer valve having a pressurized inlet port and an outlet port with controlled flow, and wherein the manifold block jointly connects the respective inlet and outlet ports of the valves in the fluid flow circuit with the first and second chambers, respectively, and wherein said first chamber and the Inlet pressure ports n commonly connected to a pressure fluid source 009825 / 0U2 can be. 3. System according to claim 2, characterized in that »the scanners include linearly moving transducers, each of which is responsive to relative movements between the piston and the cylinder to generate negative feedback signals. 009825 / ■ 0 U 2