DE2351495A1 - Spacecraft equipment inertial platform protection - has rigid clamping that may be separated when in orbit to resume gimbal operation - Google Patents

Abstract

In order to protect the gimbal mounted components of an inertial platform from the high 'g' forces during lift-off a technique is used to rigidly constrain the platform relative to a fixed base. Vertical strips of rigid material have a lip at the top edge that locates in a groove in the platform similarly at the bottom end of the strip a lip locates in a groove in the base plate. A wire band securely holds the strips to the platform to act as a rigid box structure. Once the spacecraft is in orbit the rigid structure can be dispensed with to allow the stabilising function. The retaining wire is of a fusable material that can be melted by applying low electrical power after which coil springs pull the rigid strips clear of the platform.

Description

235U9.5

TEIBIX GmI) H
6900 Heidelberg
Grenzhöfer Weg 36

Heidelberg, October 5, 1973 G / Pt-Sch / Pr E-302

Device for a gimbal-mounted flywheel

The invention relates to a device for a device mounted by means of a cardan frame relative to a base frame Flywheel.

Problem

Flywheels can be used in space technology for stabilization used by satellites »Since the flywheel has a relatively large hate, kick in particular large deceleration and vibration forces during the launch phase of the spacecraft, which normally occur must be absorbed by the gimbals and their bearings. Because due to the ,,. Albeit small, elastic Deformability of the gimbal frame is a system capable of oscillation, when the resonance frequency is reached Load peaks occur that primarily endanger the bearings. It therefore had to be used when dimensioning of the flywheel and, corresponding to the Kardanrahiaen Collateral are taken into account and the creams as well

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Storage can be designed accordingly large and heavy. However, this is contrary to that in space technology essential requirements for low weight and small volume.

Task and solution

The present invention is based on the task to avoid the disadvantages mentioned and with simple means and while maintaining the performance data the To increase the functional reliability of the flywheel. These The object is achieved according to the features of the first claim.

Advantages and training

With the device according to the invention, a direct mechanical connection between the flywheel and the in the The base frame attached to the satellite structure is achieved by eliminating the gimbal frame. This connection is in rigid and torsionally stiff, so that relative movements of the flywheel in the direction or around the three spatial axes are prevented. This will be used during the startup phase of the satellite kept the acceleration and vibration forces away from the gimbals and their bearings, so that this dimensioned only for comparatively low loads during the mission time of the satellite Need to become. It is true that a certain amount of additional material, i.e. weight, is required for the connecting elements, however, due to the smaller dimensions that are now possible, the total weight of the cardan-mounted Flywheel "can be significantly reduced.

An advantageous embodiment is created according to the features of the second claim, which characterized by an extremely simple structure. Means

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the panels or support walls mounted on the base frame, which engage with their upper ends in grooves of the inner gimbal, becomes a rigid one and torsionally rigid connection established so that relative movements of the flywheel does not occur in relation to the base frame fastened in the satellite structure.

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th can. Are / said panels according to the sixth The said connection is braced against one another by means of a wire or wire rope very easily detachable by cutting the wire rope. Instead of the wire or rope you can of course bands or the like made of suitable materials can also be provided. The separation takes place preferably by means of a pyrotechnic element and a separating device that can be actuated by this. To trigger of the pyrotechnic element only needs a very small amount of energy *. for example a short voltage pulse, are fed. .

Another training that is very simple in terms of structure and puncture is created according to the tenth patent claim. By means of the movable threaded sleeve or spindle that engages the base frame stands and brought into engagement with corresponding threaded parts of the flywheel by means of a drive device a secure and rigid mechanical connection can be established for the start-up phase of the satellite. If the threaded parts are still clamped against each other, which is advantageous by approaching the Spindle or sleeve takes place against a stop, so a backlash-free connection is created. It's about to Note that the tensioning takes place on the shortest path via the threaded parts themselves, so that cardan frames and Bearings do not have to absorb any preload forces. Is according to the eleventh claim between the drive device, Sleeve or spindle a self-winding gear provided, this way the connection is maintained even after the drive has been switched off.

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It has also proven to be very important that after completion of the start-up phase of the satellite and separation this connection can be restored at any time. This can occur in the event of malfunctions in the cardan frame bearing for example due to defective bearings or errors in the electrical tracking system of the frame be. Normally, with such malfunctions, the flywheel is unusable in its entire function, the satellite can no longer keep stable on its orbit and thus the mission time inevitably ends. Vird now the connection mentioned is restored, the flywheel has a limited function as a stabilizer The gyro can still be used and the satellite can still be safely stabilized. As special It proves to be advantageous for this case if, according to the fifteenth or eighteenth patent claim, with moving the spindle or sleeve by means of a pressure plate, the flywheel initially in its zero position and then the connection is established.

Embodiments

The invention will be explained in more detail using the exemplary embodiments shown in the drawing. It" demonstrate:

Fig. 1 - a schematic representation of a gimbal mounted flywheel ^5;

2 - a detailed view or a section through the connecting elements designed as plates according to FIG. 1;

Fig. 5 -. A view of a further example with

Connection elements containing one on the . Base frame arranged actuator with an axially displaceable sleeve nut ^

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FIg. 4- - a third embodiment similar to Fig. 3 » however, with a rotatable lead screw;

FIG. 5 shows a fourth exemplary embodiment similar to FIG. 3, but with a shaft arranged on the base frame, on which a sleeve nut can be axially displaced.

1 shows a schematic representation of a gimbal-mounted flywheel 1, of which only the housing is shown for the sake of simplicity and which contains a rotor that can rotate about the axis 2. Said flywheel is arranged on a gimbal 3, which is rotatably mounted in a second gimbal frame 5 by means of the bearings 4 about the axis running perpendicular to the plane of the drawing. The frame 5 is in turn arranged so as to be rotatable about an axis 8 relative to a base frame 7 by means of bearings 6. In the neutral position of the flywheel the nailed nn th axes are mutually perpendicular. Between the inner frame 3 and the base frame 7, four flat plates 9 are arranged symmetrically to the longitudinal axis 2, the plates 9 engaging on the base frame in a recess with a square base.

The arrangement of the plates between the inner frame 3 and the base frame 7 is explained with reference to FIG. Each plate \ has at its lower end a lug 10, with WEL © former. Engage a groove 11 of said cavity 12. There is also provided at the upper end of each plate a projection 1A- pointing inwardly to the longitudinal axis 2, which engages in a hat 15 of a cross member 17 ″ of the frame 5. The plates 9 are designed in such a way that their edges 18 rest against one another and thus support each other, whereby the edges at an angle of 45 ° to the enlargement of the bearing surfaces

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Longitudinal axis 2 are beveled towards. Between the plates and tension springs 20 are arranged on the base frame. By means of a wire rope 21 spanning the plates 9, these held in the position shown. This is a rigid mechanical between the flywheel 1 and the base frame 7 Connection by switching off the cardan frames 3 »5 and the Rahiaenlager 4-, 6 established. This connection has a high torsional rigidity in particular about the longitudinal axis 2 on. A pyrotechnic element 23 is arranged on a plate, which a separating device for the wire rope 21 is assigned. By activating it by means of a short voltage pulse, it can be connected to the ignition line 24- the pyrotechnic element can be ignited. It is by means of the separating device, which in a known manner contains a bolt provided with a cutting edge, the wire rope 21 is severed. By means of the springs 20 now the plates 9 pulled onto the base frame. This is the mechanical connection between the flywheel and the base frame solved, and the gimbal-mounted flywheel can be used in a known manner to stabilize a satellite can be used. To ensure a secure solution for the connection mentioned, it is preferred to turn off Reasons of redundancy, at least one further pyrotechnic element including separating device (not shown) arranged on the same or a different plate 9.

In Fig. 3, a further embodiment for the connecting elements between Grundrah m en 7 and inner frame 3 is shown. A drive motor 31 ″ and a self-contained gear 32 are arranged on the base frame 7. The output shaft 33 is connected in a rotationally fixed manner to a sleeve nut 35, the sleeve nut 35 being movable in the direction of the longitudinal axis 2 provided with a thread 36, which in a corresponding inner

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thread 38 of a component connected to the base frame 7 34- intervenes. Hit the inner frame is still a component 39 is connected, in many cases it has an internal thread 40, suitable for the external thread '36 of the sleeve nut 35

In the right half of Fig. 3, the sleeve nut is in a lower end position drawn. This is on the flywheel arranged on the frame 3 over the frame 3 »5 mounted movably relative to the base frame. If the flywheel is not in its zero position and takes the component 39, for example, the position shown in dashed lines, the flywheel is by means of the Bearings 4, 6 of the cardan frames 3 »5 provided torque generators (not shown) initially in the zero position brought. Subsequently, the momentum is set to pest " rades the energy source 41 with respect to the base frame connected to the drive motor 31, with a current limiting device between the energy source 41 and the motor 42 is switched. Thus, by means of the shaft 33, the sleeve nut 35 is moved in the direction of the longitudinal axis 2 moved up. In the course of this movement, the sleeve nut 35 comes into engagement with the internal thread 40. Has the front face 43 of the sleeve nut 35 the 'bottom surface 44 of the component 39 is reached, further movement is no longer possible and is engaged Standing threaded parts of the sleeve nut are braced with the internal thread 40 or 38 (see left part of 3? Igi 3) Since the current of motor 31 now rises sharply, comes, the current limiting device 42 to trigger, so that the motor 31 is switched off. Due to the self-locking Effect of the gear 32 remains the above. Tension of the threaded parts exist * Thus there is a backlash connection between flywheel 1 and base frame 7

so that the earthan frames 3 »5 as well as the bearings 4iv6 are safely relieved and. Acceleration ^ and ■ vibration powers of. keep this away. " -To solve the mentioned connection between the flywheel and ". Basic" frame, the direction of rotation of the motor 31 is reversed, where-

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with the sleeve nut 35 v / ieder in the direction of the longitudinal axis is moved back down into the position shown in the right part of FIG. Now the gimbal can · Flywheel can be used in a known way to stabilize a satellite.

If during the mission time of the flywheel there are disruptions in the frame system, for example due to excessively large ones Frictional torques in bearings 4, 6 as a result of the destruction of the lubrication system, it may be necessary to remove the flywheel again with regard to the base frame 7. This is done first in the manner outlined above Zeroing the flywheel by activating the motor $ 1 and then tensioning said threaded parts. The flywheel can function as a limited Stabilization gyro can still be used.

4 shows a third exemplary embodiment for the connecting elements between the base frame 7 and the frame 3 shown, containing a motor drive 50 arranged on the base frame with which a self-locking Gear 51 a threaded spindle 52 in the direction the longitudinal axis 2 is displaceable. Said threaded spindle has a square cross-section at its lower end . Provided, which in a correspondingly formed recess 56 belonging to the transmission Gear 67 engages. The spindle 52 is still by means of external thread 58 in one on the base frame 7 fixed component 59 out. At the upper end of said spindle 52 two pressure plates 60, 61 are provided, the lower pressure plate 60 firmly connected to the spindle and the upper pressure plate 61 in the axial Direction is shiftable. A spring 62 is arranged between said pressure plates. The frame 3 is connected to a component 63 which has a blind bore 65 with an internal thread 64.

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In the right half of Fig. 4 is the threaded spindle drawn in their lower end position. This is on the frame 3 arranged flywheel via the frame 3r and the bearings 4, 6 are movable relative to the base frame 7 stored. If the flywheel is not in its zero position and the component 63 takes, for example, the position shown in dashed lines, it is activated with of the motor 50, the spindle 52 initially a little moved up. The upper pressure plate 61 comes into contact with the inner surface 6Si of the component 63. As the spindle 52 continues to move, the component then becomes 63 in the position shown and thus the flywheel brought to its zero position. The spindle is inserted into the Thread 64 screwed in the blind bore 65 until the front face 68 on the bottom of the Blind bore 65 rests and the two pressure plates 60 rest against one another. The threaded parts of the Spindle 52 compared to those of component 63 and the Component 59 clamps the current limiting device up as a result of the increasing current of the drive motor 50 the motor 50 switches off from the energy source 67. Because of the self-locking effect of the gear 5Ί remains the one mentioned Maintain tension and thus the backlash-free connection between the flywheel and the base frame 7. This connection remains in place during the start-up phase of the satellite carrying the base frame, so that from Eardanrahinen 3 »5 as well as bearings 4, 6 acceleration and Vibrating forces are kept away. Oh, termination the start phase is used to break the said connection the direction of rotation of the motor '50 reversed, so that the Spindle 52 back in its end position (according to the right half in Fig. 4) is turned back ^. If there are malfunctions in the frame system during the mission time of the flywheel, so by turning up the spindle again, the flywheel can again with respect to the base frame, like already described, fixed and the flywheel as a stabilization gyro It should be noted that in this embodiment by means of the pressure plates the flywheel into its zero

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Position is brought so that even in the event of malfunctions Torque generators and position sensors arranged in the frame and the setting of the flywheel can be carried out in the electrical position control loops.

FIG. 5 shows a fourth exemplary embodiment for the connecting elements between base frame 7 and frame 3 shown, containing a arranged on the base frame 7 motor drive 711 kit which has a self-locking Gears 72 a sleeve nut 73 in the direction of the Longitudinal axis 2 is displaceable.

Said sleeve nut 73 has an internal thread 75, with which it with an external thread 76 a Shaft 78 is in engagement, the shaft 78 being fixedly connected to the base frame 7. The sleeve nut 73 is continue to be guided in the axial direction in a crown gear 81, which via a crown gear 82 with the Transmission 72 is in communication. A pressure plate 80 is also provided, which is non-rotatably connected with respect to the crown gear 81 by means of bolts 84. Means of the springs 85 is the pressure plate 80 against one in the Shaft 78 fastened locking ring 86 pressed. On the A component 87 and a threaded bolt 88 with an external thread 89 are arranged in the frame 3. The sleeve nut is located 73 in the drawn lower end position, the flywheel is above the frame 3, 5 with respect to the base frame 7 cardanic bearings.

By controlling the motor 71 by means of the energy source 90, the crown gear 81 is made to rotate and the sleeve nut 73 is rotated upwards in the direction of the longitudinal axis 2. At the same time, due to the. Springs B ^ the pressure plate 80 moved upwards. If the flywheel is not in its zero position and if the component 87 assumes the position shown in broken lines, for example, then after the pressure plate 80

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to the lower end face 93 of the component 8? this with the further upward movement of the pressure plate 80 brought into the drawn zero position. Subsequently arrives the sleeve nut 73 with the threaded bolt 88 in Intervention. If the upper end face of the sleeve nut has reached the bottom of component 87, the threaded parts are the sleeve nut 73 with respect to those of the bolt 88 and the shaft 75 braced until as a result of the growing Current of the motor 71, the current limiting device the motor from the energy source. 90 turns off. So is corresponding to the exemplary embodiments according to FIG. 3 »4- a Connection between frame 3 and base frame 7 established To release the connection mentioned, the direction of rotation of the drive motor 71 reversed so that the sleeve nut 73 is turned downwards. Has the sleeve nut reached the lower end position shown and it is attached to the The base frame 7 is pressed on by means of the current limiting device 91 exactly as in the exemplary embodiments according to FIG. 3 * 4-, the drive motor is switched off. If faults occur in the frame system during the mission time, the flywheel can - as already described brought into its zero position and fixed with respect to the base frame 7. Additional measures or Devices are not required, as is the case with the exemplary embodiment according to FIG. 4-. So that is allows further use of the flywheel as a stabilization gyro.

- patent claims -

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Claims (18)

235H95 Claims Device, in particular for a flywheel mounted by means of a cardan frame opposite a base frame, characterized in that connecting elements are preferably arranged on the base frame with which a mechanical connection can be established between the flywheel and base frame, and that gowns are provided for releasing said connection. 2. Device according to claim Ί, characterized in that that preferably two support walls or at least three plates are provided as connecting elements, which are mounted with their lower ends in the base frame and with their upper ends in grooves or Engage the receiving surfaces of the cardan frame carrying the flywheel and thus create a rigid, torsionally rigid connection is established. 3. Device according to claim 2, characterized in that the plates are directed inward at their upper ends Have approaches with a preferably semicircular cross-section, which are preferably / triangular or trapezoidal grooves of a cross member of said frame engage. 4. Apparatus according to claim 2, characterized in that the plates are directed outwards at their lower ends Have approaches with a preferably semicircular cross-section, which in grooves of the base frame intervention. 5 · Device according to one of claims 2 to 4-, characterized characterized in that four substantially flat plates are arranged symmetrically to the longitudinal axis of the flywheel 509817/0118 E-502, 235U95 are, with their lower ends in a recess engage the base frame with a preferably square base. 6. Device according to one of claims 2 to 5 »da-. characterized in that the plates preferably with a wire or wire rope, which in a to Longitudinal axis perpendicular plane runs, are arranged braced against each other, the plates with their essentially parallel or slightly conical to the longitudinal axis of contact surfaces against each other prop up. 7. Device according to claim 6, characterized in that that the contact surfaces lie in radial planes running through the longitudinal axis. '8. Device according to claim 6 or 7 s characterized in that that preferably on a plate at least one pyrotechnic element for actuating a separating device for the wire or the wire rope. 9 · Device according to one of claims 2 to 8, characterized characterized in that tension springs are preferably provided between the plates and the base frame, with polygons the plates are essentially drawn onto the base frame after the wire or wire rope has been severed will. 10. The device according to claim 1, characterized in that a drive device on the base frame, it is preferably provided for a spindle and / or sleeve movable in the direction of the longitudinal axis that said sleeve or spindle is threaded at least at its upper end and that 509817/0115 2-302, «-r the cardan frame carrying the flywheel or a component connected to it has threaded parts, into which the spindle or sleeve with its named thread can be introduced. 11. The device according to claim 1O _1, characterized in that a gear is connected with a self-tapping effect between the drive device and the sleeve or spindle. 12. Apparatus according to claim 11 or 12, characterized in that to limit the axial movement of Sleeve or spindle on both gimbals and stops are provided on the base frame and that füx ' the drive device designed as an electric motor ' a current limiting device is provided. 13 · Device according to one of claims 10 to 12, characterized characterized in that said sleeve has an external thread with which it is in the internal thread a component provided on the base frame is rotatably arranged and that the output shaft of the transmission has a square profile, which in a correspondingly designed bore of the said sleeve intervenes. 14. Device according to one of claims 10 to 12, characterized in that said spindle on - its lower end, preferably by means of a square profile, coaxially engages in a gear wheel of the transmission, that the spindle is otherwise provided with an external thread, with a soft one in the internal thread the component arranged in the base frame. 15. Device according to claim 14, characterized in that a pressure plate is provided at the upper end of the spindle is that the flywheel continues to carry 509817/0115 . 235U95 lowing gimbal frame a component designed in this way it is provided that if the flywheel deviates from its zero position and actuation of the drive, the pressure plate initially rests against the contact surfaces of the component and when the drive is operated again the flywheel is brought to its neutral position. 16. The device according to claim 14, characterized in that that said pressure plate is axially displaceable and by means of spring arrangements on another pressure plate supports. 17 · Device according to one of claims 10 to 12, characterized characterized in that a threaded bolt with an external thread is arranged on the base frame which the sleeve having an inner shell is rotatable is arranged and that a correspondingly designed second Gexiindebolzen is provided on the cardan frame is. 18. Device according to claim 17 *, characterized in that that a pressure plate "entrained by the axial movement of the sleeve" is provided, which when it is in contact to a contact surface of a with the gimbal frame connected component, this optionally brings it into the zero position, so that then the sleeve can be safely brought into engagement with the threaded bolt of the cardan frame. Heidelberg, October 5th, 1973
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