Torque motor, especially for the rudder gear of a flying object
Rossm anith 1 TORQUE MOTOR, ESPECIALLY FOR THE RUDDER GEAR OF A FLYING OBJECT [75] Inventor: Otto Rossmanith, Ottobrunn,  
 Germany [73] Assignee: Messerchmitt-Boelkow-Blohm GmbH, Munich, Germany [22] Filed: Dec. 20, 1973 [21] Appl. No.: 426,551  
 [30] Foreign Application Priority Data Dec. 28, 1972 Germany 2263792 [52] US. Cl 335/230, 335/279, 335/281 [51} Int. Cl. Hlt 7/08 [58] Field of Search 335/229, 230, 266, 268, 335/279, 281, 256  
 [56] References Cited UNITED STATES PATENTS 2,690,529 9/1954 Lindblad 335/256 X 2,695,165 11/1954 Hansen 335/229 X FORElGN PATENTS OR APPLICATIONS 845,935 8/1960 United Kingdom 335/230 Apr. 1, 1975 [57] ABSTRACT The present torque motor, especially for controlling the rudder gear of a flying object, such as a missile, comprises a cross-shaped armature preferably having four free ends which cooperate with respective electromagnets to impart movement to the armature in reponse to the size and direction of current flowing through the energizing coils of the magnets. The armature is supported substantially in its center of gravity by pivot bearing means permitting a universal, pivotal movement of the armature relative to said magnets. in one embodiment bounce or deflection plates are carried, preferably adjustably, by said free ends of the armature and each of these plates cooperates with a respective one of a corresponding number of nozzle means for controlling the position of rudder blades.  
 17 Claims, 5 Drawing Figures TORQUE MOTOR, ESPECIALLY FOR THE RUDDER GEAR OF A FLYING OBJECT BACKGROUND OF THE INVENTION The present invention relates to torque motors, especially for the rudder gear of a flying object such as a missile. The armature of the motor is arranged symmetrically relative to the electromagnets and the armature is movable in response to the size as well as to the direction of the current flowing through the energizing coils of the electromagnets.  
  Torque motors of the above type are rapid and precise electromagnetic drives which have been used heretofore, for example, in precision engineering as control or correction elements, as stepping switches, as valve drive means, and similar control purposes.  
  Where a torque motor is used as a drive means for a flow control valve, for example, in the form ofa system comprising nozzle means cooperating with bounce or deflecting plate means, the stator commonly has an E- shape and the outer legs of the E-shape carry the energizing coils. The center plate constituting the rotor is connected with a pivot or rocker bearing. Such systems or flow control valving mechanisms are employed for controlling the pressure medium drive of the rudder of a flying object such as a missile. Tappet means carrying bounce or deflecting plates at their free ends are supported at the outer ends of the plates. The deflecting plates cooperate with nozzles facing said plates and located in conduits carrying a medium under pressure. These conduits are connected to piston cylinder arrangements which in turn supply the control forces for displacing the rudder blades.  
  Reference is made in this connection to Fluid Power Control,&#34; published by Krauskopf, I962, Volume 2, page 522.  
  A control system as described above thus comprises but one input. Depending on the polarity of the input signal, a positive or negative control value or control output will be produced by these systems of the prior art. However. for many purposes it is necessary to have two control inputs. For example, two control inputs are required for the control system of the rudder gear of a flying object which comprises four rudder blades arranged in a cross shape and in such a manner that the two rudder blades opposite each other are interconnected to form a pair. In such an arrangement, the rudder blades forming a pair and arranged opposite each other must be displaced synchroneously with each other. Therefore, the respective control system requires two control inputs.  
  In order to provide a symmetrical arrangement of elements relative to each other, the piston rods of prior art devices ofthe above type are arranged in pairs diagonally opposite each other and the ends of the piston rods are pivoted to two shafts which cross each other. These shafts carry the rudder blades arranged opposite each other but in a common plane. Thus, the respective working cylinders of the piston cylinder arrangement are also located in one plane symmetrically relative to each other. In such an arrangement the control of the pressure medium supply to the working or operating cylinders must then be accomplished by means of two control systems, which, due to lack of space are either arranged next to each other or in series relative to each other. As a result, the control conduits for one operating cylinder are longer than the respective conduits for the other operating cylinder. This difference in the length of the control conduits is undesirable, because on the one hand it results in a non-symmetrical structural arrangement of the elements and, on the other hand, it may result in control errors causing an erroneous displacement of the rudders. The latter disadvantage has especially been noted in connection with hot gas drive means as a non-symmetric arrangement of the elements results in heat transfer surfaces of differing size, causing said control errors.  
 OBJECTS OF THE INVENTION In view of the above, it is the aim of the invention, to achieve the following objects singly or in combination:  
 to overcome the drawbacks of the prior art described above, more specifically to provide a torque motor or electromagnetic drive apparatus comprising two separate inputs as well as two separate outputs;  
 to construct an electromagnetic drive or torque motor in such a manner that all its elements may be symmetrically arranged while simultaneously requiring but little space;  
 to provide a torque motor in which the available control power is used efficiently so that loss of control power is substantially avoided;  
 to provide a torque motor especially of symmetrical construction which is capable to provide control movements about two axes extending perpendicularly to each other in response to energizing currents supplied to its two separate inputs, whereby the outputs provide two respective separate output control signals;  
 to provide a torque motor or an electromagnetic drive apparatus which is substantially insensitive to accelerations;  
 to provide a torque motor, the deflection plate and nozzle means of which are adjustable relative to each other prior to the installation of the unit;  
 to provide a torque motor of symmetrical and compact construction capable of controlling two pairs of rudder blades in response to electrical control signals supplied to separate inputs of the torque motor; and  
 to provide a torque motor having an armature of such a shape that the armature may be pivotally supported substantially at its center of gravity.  
 SUMMARY OF THE INVENTION According to the invention, there is provided a torque motor or electromagnetic control apparatus having a plurality of electromagnets arranged symmetrically relative to an armature, said magnets having energizing coils for displacing the armature in response to the direction and size of the current flowing through said energizing coils. The armature has a cross shape and armature bearing means pivotally support the armature substantially at its center of gravity, so that the cross-shaped armature is universally movable. The free ends of the cross-shaped armature cooperate with respective electromagnets. Preferably, the armature has four free ends and the electromagnets are also arranged in a cross configuration.  
  The bearing means preferably comprise an elastically yielding member such as a bearing pin which connects the armature to the housing of the torque motor. In a preferred embodiment the cross-shaped armature is provided at its center of gravity with a bearin g bushing or hub. An axial bore extends through the bushing or hub. A support plate is secured to said housing and said bearing pin extends centrally away from said support plate. The bearing pin has an enlarged diameter end section which reaches into said axial bore of the bearing bushing or hub of the armature, whereby the armature is secured to said enlarged diameter end section of the bearing pin. for example by a press fit. Between the plate and the end section of the bearing pin there is provided a section of reduced diameter which is spaced from the walls of the axial bore through the bearing bushing to provide an e lastical yielding and thus a pivoting support for the armature. Preferably, the bearing pin is also provided with an axial bore extending through the pin as well as through the support plate.  
  Preferably the support plate has a square shape and is connected to the cross-shaped housing of the motor by means of support bolts connected to the corners of the support plate. The cross-shaped housing of the motor is made of non-magnetic material and said support bolts hold the support plate centrally within the housing. The housing supports the ferromagnetic legs of the electromagnets which in turn carry the respective energizing coils. The electromagnets with their coils form magnetic gaps corresponding in number to the free ends of said armature. The gaps are symmetrically distributed so that said free ends of the armature reach into said gaps.  
  Where the present torque motor is used as a valve drive means of the rudder gear of a flying object, the free ends of the cross-shaped armature of the torque motor carry each an adjustable bounce or deflection plate which cooperates with a corresponding nozzle directly connected to the housing of the torque motor. Preferably, the nozzles are secured, for example, by a press fit in bores ofa flange forming part of the housing and arranged in such a manner that said nozzles face the respective deflection plates. The system further comprises noncontrolled nozzles which are also supported in respective bores of a further housing member, preferably by a press fit. The further housing member may support the first mentioned housing of the motor proper, for example, by screwing said flange to said further housing member which preferably is a cylindrical housing member.  
  According to a preferred embodiment of the invention, the deflecting plates are carried at one end of tap pet members which extend through bores in the housing of the motor proper, said tappet members being secured to the free ends of the armature by means of a screw connection which is accessible via said bores so that the tappet members are individually adjustable for adjusting the spacing between the deflection plate and the corresponding nozzle.  
 BRIEF FIGURE DESCRIPTION In order that the invention may be clearly understood. it will now be described, by way of example. with reference to the accompanying drawings, wherein:  
  FIG. 1 illustrates a sectional view through a torque motor according to the invention adapted for use as a drive means for the control system of a rudder gear of a flying object, said control system including nozzle and deflection plate means;  
  FIG. 2 is a view in the direction of the arrows IlIl in FIG. 1 and partially in section along the section line Il-Il in FIG. 4;  
  FIG. 3 is a somewhat simplified view in the direction of the arrow A in FIG. 1;  
  FIG. 4 is a side view of the torque motor according to FIG. 1 looking toward any of the free ends of the armature of the torque motor, and  
  FIG. 5 is a sectional view through the rudder gear of a flying object, which gear is controlled by the torque motor according to FIG. 1.  
 DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS:  
  FIG. 1 illustrates a sectional view of a polarized torque motor 10 according to the invention. The motor 10 is located in the housing of a flying object 27. The motor 10 comprises housing means preferably including two housing sections 11 and 11&#39;. Eight magnets are arranged in pairs 12, 12&#39;; 13, 13&#39;; I4, 14&#39;; and l5, l5 and supported by the housing means 11, 11&#39;, please see also FIG. 2. The just mentioned magnets ofthe present torque motor are arranged in a cross-shape to provide magnetic gaps G which receive the free ends 22, 23, 24 and 25 of a cross-shaped armature 18.  
  The housing means 11, 11&#39; are connected to a further housing member 26 held in the housing 27 of the flying object. For example, the housing means 11, 11 may be provided with a flange 20 which is provided with screw holes S through which screws S extend for connection of the flange 20 to the housing member 26 as best seen in FIG. 1.  
  Each of the magnets 12 to 15 comprises two U- shaped legs 14a and 14b and so forth as best seen in FIG. 4. The North and South poles of these magnets are aligned opposite each other respectively also as shown in FIG. 4. The energizing or driving coils 32, 33, 34 and 35 of the electromagnets are interconnected in pairs and the inputs and outputs of these energizing coils constitute the two control inputs of the torque motor.  
 The armature 18 is symmetrically supported relative to the electromagnets by hearing means comprising an elastically yielding member to permit a pivotal, universal movement of the armature 18 in response to the size and direction of current flow through the driving coils of the magnets. For this purpose, the armature 18 is provided substantially in its center of gravity with a bearing bushing 29 having a central axial bore 28. A support plate 38 secured in the housing means 11, 11, for example, by means of bolts 40 screwed into the support plate 38 as shown at D, is provided with an elastically yielding bearing pin 37 extending centrally away from said support plate 38 and preferably having an axial bore B through the bearing pin and the plate 38. The bearing pin 37 has an outer end 36 of increased diameter which reaches into the axial bore of the arma ture l8 and holds the armature, for example by a press fit between the enlarged diameter end 36 and the inner walls of the axial bore of the armature 18. The bearing pin 37 is provided with a reduced diameter section between its outer end and the support plate 38. This reduced diameter section leaves a free space between the bearing pin and the axial bore of the armature 18, whereby the pivotal movement of the armature 18 is facilitated. The just described bearing means for the armature .l8 supports the armature 18 in the housing means ll, 11&#39; for universal movement. Therefore, the armature 18 may be displaced in a positive or negative sense in all directions like a swash-plate depending on the excitation of the electromagnets 12 to 15.  
 According to the invention eachrreeenasaz to 355st; Althoagl&#39;r &#39;iihednventinifzhas beeh deseribed with i&#39;e fthe armature 18 is providedwith&#34; a threaded&#39;holejn which there is secured a-respective threaded sham-es atappet member42, 43, 44 and-.45, The-outwardly&#39;afao ing end of-each tappet member=may..-forexamplet&#39;,be  
 provided. withaslot so that the relative positions-oftheI p e&#39;m her my b a j sted byza s r wdriver -Ihe other endof each tappet membercarriesai&#39;respectis e bouncing or deflection plate 52.t-o ,55.These dfiflwiio&#39;n&#39; plates 52-andzso forthface noz zlemeans fl to 65,,Eo&#39;r&#39; lO this purpose,. t he above mentionedflange isaspaeed from the rear surface 2 of thehou&#39;sing sectionj 1 1 o&#39;icov&#39;er all ma ifilc Ions housing m ans an to said dross: panama-rerp&#39;i&#39;vot&#39;ally. suppor in whereby a ring space is formedibetween&#39;theflan-ge 20 and the rear surface 21,.Thedeflectioh plates 52, to 55 reach into the ring space 30 to face nozzlemeansfl to which, for example, are secured in holes 58059 (FIG. 3,) ,of the flange 20. The nozfzles may ,;fo r in.- stance, be held in position by. a pr e ss fit,  
  The nozzles 62 to 65 co&#39;operatefwith further nozzle means 162 to 165 which are held,,&#39;for example, by refsaid arrhatilrgiit l aid housiiifi means substantially symtitetritz&#39;ally relative to said .el&#39;e&#39;ctromagnets s&#39;othaLeach free argna-tnreend ,co operates with therespective electroht&#39;agnet whereby&#39;ithe armature is&#39; universally disglagbkjfl response tqlthe siz e and direction of curspective nipples N in the housing member 26. Thesenipples N may be secured in respective bores or the housing member 26 by a,&#39;press Further, the nipples have a reduced diameter end portion reaching towardthe respective nozzle 62 to 65 without contacting&#34; the nozzles 62 to 65. This separation of the nozzle means has the advantage that temperature expansions are neutralized. r  
  Referring to FIGS. 1 and 5, the&#39;nozzles 162 to&#39; 165 are connected by means of cross bores 72 to 75 to operating cylinders 82 to 85 of respective piston cylinder arrangements. The piston rods 86 to 89 of these piston cylinder arrangements are pivoted in pairs to respective shafts 96 and 97 crossing each other like crankshafts. The shaft 96 carries rudder blades 93 and 95. The shaft 97 carries rudder blades 92 and 94. The blades 93 and 95 are flush with the blades 92 and 94. The outer ends of the piston rods 86 to 89 are pivoted through levers 102 to 105 to said shafts 96 and 97. Thus, the rudder blades 93 and 95 connected to the shaft 96 at opposite ends thereof are actuated by the piston rods 86 and 88. On the other hand. the rudder blades 92 and 94 are connected to the shaft 97 at opposite ends thereof are actuated by the piston rods 87 and 89. This actuation may, for example, be accomplished by a pyrotechnical gas generator producing the necessary hot gas which is supplied through an opening 76 and through a filter 77 into the space 78. The hot gas generator 70 may be connected to the housing member 26 in any conventional manner. The hot gas is supplied from the hollow space 78 to the operating cylinders through the cross bores 72 to under the control of the nozzle and deflection plate systems 52/62 to 55/65. Accordingly, the  
 displacements of the pistons in the operating cylinders 82 to is controlled by the torque motor as described above, and the rudder blades 92 to are controlled accordingly.  
  In view of the above description, it will be appreciated that the present invention provides a torque motor, the armature of which supplies control forces which may become effective in the positive as well as the negative sense and in directions extending at right angles to each other simultaneously. This is accomplished especially by the cross-shaped armature l8 and by the arrangement of the electromagnets in a cross configuration, whereby two control inputs are provided for the motor which in turn has two controlling outputs.  
 reiitflowing through saidelectromagnets.  
  The torquegm oto r&#39; according to-claim I, wherein said Tbearing&#39; inean s pivotallys upporting said crossshaped armature in said housing means are secured to the Icross;shap ed armature in the center of gravity thereof,  
  said ibea ringfinieansi for said cross-shaped armature comprise a support plate secured to said housing means and elasticallyyielding. support means operatively interposed between said. supportplate and said crossshaped armature for pivotally supporting said armature.  
  4. The torque motor according to claim 4, wherein said elastically yielding support means comprise a bearing bushing secured to said cross-shaped armature substantially at the center of gravity of said armature, said bearing bushing having a central bore therethrough and an elastically yielding bearing pin secured to said support plate and extending into said central bore of said bearing bushing to secure said armature to said elastically yielding bearing pin.  
  5. The torque motor according to claim 4, wherein said elastically yielding bearing pin has a longitudinal bore therethrough, said pin extending away from said support plate and having a larger diameter portion at its outer end and a smaller diameter portion between said support plate and said outer end, said bearing bushing of said armature being secured to said larger diameter portion of said bearing pin, said smaller diameter portion of said bearing pin providing a spacing between said bearing pin and said bearing bushing of the armature.  
  6. The torque motor according to claim 5, wherein said longitudinal bore through the bearing pin extends also through said support plate.  
 7. The torque motor according to claim 4, wherein i said bearing pin is secured to the center of said support plate to extend away from said support plate substantially at a right angle.  
  8. The torque motor according to claim 4, wherein said housing means comprise housing members of nonmagnetic material arranged to form a cross-shape with a square space inside said housing means, said support plate having a square shape with four corners fitting into said square space, said means securing said support plate to said housing means comprising four support bolts one arranged in each of said four corners for holding said support plate inside said housing means.  
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 3. &#39;The torque motdr according to claim 1, wherein 9. The torque motor according to claim 1, wherein said plurality of electromagents comprise ferromagnetic yokes held in said housing and energizing coils held in said yokes to form four magnetic gaps, said cross-shaped armature having four free ends each reaching into a respective one of said magnetic gaps.-  
  10. The torque motor according to claim I, wherein said cross-shaped armature has a number of free ends. said motor further comprising nozzle means securely held in said housing means. said nozzle means facing towardsaid free ends of said armature.  
  11. The torque motor according to claim 10, further comprising deflecting plate means carried by said free ends of said armature and facing toward said nozzle means.  
  12. The torque motor according to claim 11. wherein each of said free ends of said armature is provided with a threaded hole axially extending toward said nozzle means. each of said deflecting plate means comprising a tappet member with a threaded shank at one end thereof adjustably held in the respective threaded hole and with a deflecting plate at the other end thereof facing a respective one of said nozzle means, whereby each tappet member is adjustable back and forth relative to the respective nozzle means to vary the spacing between the deflecting plate and the corresponding nozzle means.  
  13. The torque motor according to claim 10, further comprising a flange as part of said housing, holes in said flange wherein said nozzle means are held with a press fit, and wherein said flange is spaced from the housing means proper by a ring space, said nozzle means facing into said ring space.  
  14. The torque motor according to claim 13, wherein said housing means comprise a further housing member. means for securing said flange to said further housing member, a number of bores in said further housing member facing said nozzle means when the flange is connected to the further housing member, and further nozzle means secured in said bores.  
  l 5. The torque motor according to claim 14, wherein said further nozzle means are secured in said bores by a press fit.  
  16. The torque motor according to claim 14, wherein each of said further nozzle means comprise a nozzle member and a nipple held in the respective bore by said press fit, each nipple having a reduced diameter end facing toward the respective one of the first mentioned nozzle means, said nozzle member being held by its nipple which is spaced from said first mentioned nozzle means.  
  17. The torque motor according to claim 12, wherein said housing means comprise through-holes adjacent to said free ends of said cross-shaped armature, each tappet member extending through its respective through-- for adjustment through the through-hole.  
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