JPH04503562A - Fault Tolerant Ball Screw Actuator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] name of invention Fault Tolerant Ball Screw Actuator Technical field The invention relates to the field of actuators, particularly actuators for moving pylons in aircraft. Regarding the tuator.

In aircraft design, some moving elements of the aircraft are considered in relation to other reactionary elements. A large number of actuators are required to move the parts. Use like this An example is the activation of a flag on a conventional fixed-wing aircraft. . As in any aircraft environment, the actuators ideally Extremely reliable, lightweight, compact, and above all, it has a small starting point. Energy requirements must be minimal.

Ball screw actuators are commonly used in aircraft applications. It is something that For simple installations, round screw actuators can be Includes a nut with an associated thread and a screw with an external thread.

Multiple spherical goals are captured within the threads of the nut and engage with the threads on the screw. The nut rotates about its central axis while resisting the similar rotation of the two mating screws. This causes the screw to move axially through the nut.

Obviously, the recoil screw on the movable element in the aircraft, forming the actuator It is possible to place a nut on the element. Ball screw actuator is Natsu The resistance to failure (fault tolerance) is higher than that of a simple threaded engagement between a screw and a screw. much lower (much less resistant to jammlng ) Failures can occur. Furthermore, there is a possibility that the ball will be lost from Natsuto, The ability to axially translate the engine will be reduced or eliminated. On top of that , the screw may be the only fixed connection between the moving and reaction elements; If it cracks, the consequences could be catastrophic.

In recent years, aircraft commonly referred to as tilt rotorcraft have been developed. child aircraft, it is possible to rotate on the aircraft between conventional flight mode and helicopter mode. On top of the Byron, which can be turned, there is a rotor or propeller and a The power plant that was removed was placed there. In conventional flight mode, this propeller Rotates in a vertical plane to propel the aircraft forward as in conventional propeller-driven aircraft. drive in the direction. However, at this time, Byron and the propeller were... The aircraft can operate as a rotary wing for vertical takeoff and landing as a helicopter. In order to position the propeller in essentially one horizontal plane such that it is driven Can be converted or rotated. In such an environment, aircraft mode and High reliability for proper operation of the pylon in converting between helicopter modes A highly efficient actuator is required.

According to one embodiment of the invention, the button located between the first element and the second element A screw actuator is provided. This actuator has a ball trajectory. a first nut and a first screw having a ball track, and a first axis and center; support the nut and screw concentrically relative to each other (this first nut and includes a plurality of drive wheels engaged within the goal trajectory of the screw and centered about the first axis; The relative rotation between the first nut and the first screw is their relative rotation along the first axis. a first ball screw drive unit causing relative movement between the I'm reading. A second ball screw drive unit is also provided, which includes a goal a second nut having a track and a second screw having a goal track; This second nut supports the nut and screw concentrically relative to each other about the axis. and a plurality of drive balls engaged within the goal trajectory of the second screw; The relative rotation between the second nut and the second screw about the axis is along the second axis causing relative movement between these. This first nut connects the first axis It is mounted on the first element for rotation about the center. The second screw connects the second shaft It is mounted on the second element for rotation about the center.

The first screw and the second nut have their first and second axes aligned so that they rotate simultaneously. They are fixed together in the same state.

According to another aspect of the invention, located between the first element and the second element A beer screw actuator is provided. This actuator , includes a nut with a goal trajectory and a screw with a ball trajectory. first Multiple drive bolts are used to support nuts and screws concentrically relative to each other around the shaft. A ball is engaged within the ball track of the nut and screw. Centered on the first axis The relative rotation between the nut and screw is the relative rotation between them along the first axis. cause movement. The screw has first and second ends. The present invention further provides a screw It also includes a member that extends along the screw and confines the end of the screw to form an indeterminate load path. For a more complete understanding of the invention, the following description, taken in conjunction with the accompanying drawings: Please refer to the explanation. In addition, in the drawing, Figure 1 shows the book for converting Byron between airplane mode and helicopter mode. FIG. 3 is a diagram illustrating the operating range of the actuator forming the first embodiment of the invention; ; FIG. 2 is a vertical cross-sectional view of the actuator and Byron in airplane mode; FIG. 3 is a horizontal cross-sectional view of the actuator and Byron in airplane mode; FIG. 4 is a cross-sectional view of one element of the ratio actuator taken from line 4--4 in FIG. 2; FIG. 5 is a side view of the elements of FIG. 4.

FIG. 6 is a schematic diagram of the actuator.

FIG. 7 is a schematic diagram of the actuator.

FIG. 8 is a cross-sectional view illustrating the internal ball screw assembly of the actuator.

Figure 9 illustrates the inner and outer ring screw assemblies of the actuator. FIG.

FIG. 1 OA-I OC indicates the operating range of the actuator.

FIG. 11 is a cross-sectional view illustrating a modified form of the actuator.

detailed description In particular, each drawing in which the same reference number designates the same or corresponding parts throughout several figures Referring to FIG. 1, an actuator 10 forming a first embodiment of the invention is illustrated. It is shown. This actuator 10 is a recoil actuator, which in this case is a wing 12 of an aircraft. It is mounted between the element and a movable element, in this case Byron 14 (FIG. 2).

The Byron carries the tilt rotorcraft's rotor blades and their power plants. a The actuator 10 has a retracted position 16 and an extended position 18, as described in detail below. Byron and the rotor are activated to move between the aircraft models. and helicopter mode. Similarly, as explained below, The tuator 10 has failure strength and has dual or static constant load to improve safety. A path is provided.

The basic structure of the actuator 10 will be explained with reference to FIG. 6. Acti 10 both move between a fully retracted position and a fully expanded position. The inner ring screw drive unit 20 and the outer ball screw drive unit 20 are activated to move the actuator. This is a deal ball screw actuator including a ball screw unit 22. dua If one of the screw drive units fails due to the use of screw drive units, The other drive unit is operable for a reduced operating range of the actuator. You get a failsafe mode that allows you to stay in the state.

Referring to FIGS. 6 to 11t, the inner ball screw drive unit 20 includes an inner ball screw drive unit 20. It can be seen that a screw assembly 24 and an inner nut 26 are included. This inner button The round screw assembly 24 includes a concentric inner round screw 28 and an inner tube 30t. I'm here. The outer surface of the inner surface of the cine 22 is provided with a spiral goal track 32. has been done. The inner surface 26 of the inner nut 26 is provided with a similar beer track 34. It is. A plurality of actuators are connected between the nut 26 and the ball orbit of the screw 28. Seal 36 is engaged. Inner nut 26 captures ball 36 for recirculation do. When the nut 26 rotates in relation to the screw 28, the nut and screw They will move axially in relation to each other along axis 38.

Inner tube 60 constitutes an important aspect of the invention.

Internal goal screw 28 has ends 40 and 42. The tubes 30 each have an end 40 and shoulders 44 and 46 extending around and 42 . Therefore, the inner round screw If a crack occurs within 28, the load supported by the goal screw is usually It can be supported through a 60t tube, providing a non-static or dual load path. It will be done. Preferably, this inner ball screw 28 is formed of metal and is tubular. 30 is made of carbon fiber composite material for its lightness and strength.

The outer ball screw drive unit 22 includes an outer ball screw assembly 48. ing. The outer ring screw assembly 48 includes an outer nut 50 and an outer goal screw 5. 3 and an outer tube 54. An outer nut 50 is formed on the inner surface thereof. It has a round track 56, while the outer round screw 52 has a round track 58t.

As in the case of the inner @ circle screw assembly 24, the outer nut centered on the axis 3'8 The relative rotation between the nut 50 and the outer ball screw 52 corresponds to the relative axis between the nut and the screw. A plurality of balls 36 are placed within the outer nut to cause directional movement. Captured. As with the inner tube 60, the outer tube 54 has an outer ball screw gear. The outer ball provides a variable or dual load path for the assembly. Ends 60 and 62 of screw 52 are enclosed by shoulders 64 and 66 on outer tube 54. The outer ball screw 52 extends along the outer ball screw 52. Here too, the outside is the same The thread 52 is made of metal, while the outer tube 54 is made of carbon fiber composite material. .

The operation of the actuator can be better explained with particular reference to FIG. . The outer ball screw 52 is attached to the inner nut so that the outer ball screw 52 rotates simultaneously around the shaft 38. Fixed at one end. The outer nut 50 is located between the thrust roller bearings 70 and 72. is mounted in a thrust ring 68 for rotation about an axis 38. outside An annular ring ear 7 as part of the side nut 50 or mounted on the outer nut 4 is formed. In order to rotate the ear 74 and the outer nut about the shaft 38, a first hydraulic drive motor assembly 76 and a second hydraulic motor drive assembly. 78 is provided. Each hydraulic motor drive assembly includes a hydraulic motor 80 ゜Hydraulic brake 82. A suitable lunoid control valve 84 is provided to provide a separate hydraulic supply. 86 and 88. Each hydraulic motor 80 is associated with a drive ear 74. It has a drive ear 92 and a drive shaft 90 for mating.

As best seen in FIGS. 2-5, the thrust ring 68 is connected to the shaft 152. Conversion actuator spindle 1 for pivoting movement about both axes 154 It is pivotably mounted on the wing 12 of the aircraft between 7 oaks on 50.

Similarly, as can be seen from Figures 2 to 5, Byron has lugs 94 that can pivot. It is listed in . This lug has an inner bore in relation to the lug along axis 38. The inner side around the axis 58 in relation to the lug 94 of the one that fixes the screw 28 A first end 96 of the inner screw 28 to allow rotation of the ball screw 28. t-accommodate. FIG. 6t - As best seen, the inner round screw 28 The end 9 of 1 rotates within a lug 94 about an axis 102 perpendicular to axis 38. A worm wheel 98 is provided which engages the worm ear 100 mounted in the manner shown in FIG. ing. The shaft 104 on which the warm ears 100 are fixed is the ear 106 and extends to 108. Ear 106 has an internal motor brake 112 The drive shaft of the electric motor 110 is engaged with the drive shaft of the electric motor 110 . Ear 108 is in the second mode. engages with the brake 114.

During normal operation, motor brakes 112 and 114 are 00, thus causing the inner ball screw 28 to rotate about the shaft 38. is activated to prevent Rotation of one or both of the hydraulic motors 80 is caused by rotation of the shaft 38 This causes rotation of the outer nut 50 about the . Inner round screw 2 Since 8 is fixed, the outer ring screw 50 and the inner ring screw are attached along the axis 38. An axial displacement will occur between 28 and 28, which will cause the Byron 14 to intersect with the aircraft wing 12. Pivot in a relationship.

In moving between fully retracted and fully extended positions, both nuts It will run the entire length of the screw it is engaging. However, actue As the data moves between these limits, at a given position, The outer ring screw can move through the outer nut, and the inner nut can move through the inner ring. can move along the screw, or both movements can occur simultaneously . Under ideal conditions, the inner nut will move from the retracted position to the extended position t. runs along the inner ball screw throughout its maximum operating range, while the outer ball The inner screw is expected to run through the outer nut throughout its maximum operating range. be done. Byron controls motors and all brakes 82.112 and 114. Depending on the combination of applications, it can be stopped and can be maintained.

Movement of the nut and screw is limited by a plurality of stops within the actuator.

The stopper 120 is located outside when the actuator is in the fully retracted position. It rests on the outer ring screw 52 for engagement with the nut. Rene on the outside A stop 122 on the opposite side of the screw 52 prevents the outer ball screw assembly 48 from being completely removed. When it is fully extended, it engages with the outer nut 50. The stopper 122 is connected to the outer nut 50 When engaged with the external ring screw assembly, the engagement is Side nut 50. The outer ring screw 52 and the inner nut 26 are caused to rotate simultaneously. It is performed with sufficient force to

Similarly, the movement of the inner nut is restricted in the extended position of the inner ring screw assembly. To prevent this, a stopper 12 is provided at the end 126 of the inner ball screw 28 opposite to the end 96. 4 (not shown) is placed. Also, the retraction position of the inner ♂-ru screw assembly A stopper 127 is placed on the end 9 to restrict the movement of the inner nut. has been done.

Actuator 10 offers significant advantages in reliability and versatility. hydraulic Each of motor drive assemblies 76 and 78 independently actuates an actuator. It is designed to. If both of these assemblies fail, each motor The hydraulic brake in the cylinder 80 automatically engages to prevent the outer nut 50 from rotating in the D direction.

At this time, brakes 112 and 114 are released and electric motor 110 is activated. The actuator can be actuated from the end of the actuator. Hidden As a result, dual failure mode indeterminacy is obtained.

If one of the groove screw assemblies fails in any position, there is no need to worry The ball screw assembly still has the full range of motion provided by its ball screw assembly. It can be used to move the actuator through the range. For example, In applications where actuators actuate the pylons of tilt rotorcraft. The rotor is moved from the airplane mode position by actuation of a single round screw assembly. Moved to an intermediate position between airplane mode and helicopter mode, the rotor blade touches the ground This makes it possible to land an aircraft without having to do so.

The dual or variable load paths provided by composite tubes 30 and 54 also This is an important advantage of the invention. As mentioned above, one of the round screws has failed and the To prevent complete failure of the actuator 10, the loads are tied together in a nine-concentric configuration. It can be supported by a tube.

One groove screw failure is linked to the groove screw assembly IJ t-failure. The remaining ball screw assembly can be used to prevent restricted movement of the pylon It is possible to provide

In a single actuator 10 made in accordance with the teachings of the present invention, the actuator The eta is designed to move 44 inches between retracted and extended positions.

This movement is carried out on the translation spindle 160 when mounted between the aircraft wing and the pylon. The pylon is rotated through an arc of approximately 90 degrees about its translation axis 128, and the - Provide an arc of motion of 45° for each threaded assembly. both hydraulic When the actuator is ready for actuation, the actuator moves 6.6 inches per second. It is designed to.

Although not shown, the pylon has a fixed base on the wing at the limit of its movement. Engages with the topper. These stockings are your friend to reduce vibration especially in airplane mode. apply a large force on the pylon to hold it against one of the Actuator 10 can also be used for this purpose. For example, the hydraulic motor 80 It is activated continuously, loads the actuator, and rests on the wing in airplane mode. Applying a force of 13000 pounds pushing the pylon against the stopped stop Can be done.

Figure 11 is similar in many respects to the previous one and is therefore identified with the same reference numerals. A modified form of the actuator 10 is shown. However, the motor 110 is Attached to the first end 9 of the side groove screw, the aforementioned worm wheel and rotates an annular wheel 140 that replaces the worm wheel. Ru.

Only one embodiment of the invention is illustrated in the accompanying drawings and in the foregoing detailed description. Although described, the invention is not limited to the disclosed embodiments. , numerous rearrangements, changes and modifications of parts and elements without departing from the spirit of the invention. It is possible to add substitutions.

Special Table Sen4-503562 (6) Procedural amendment (flag) March 12, 1992

Claims (6)

[Claims] 1. a ball screw actuator located between the first element and the second element; Leave it behind - a first nut with a ball track and a first screw with a ball track; and , for supporting a nut and a screw concentrically relative to each other about a first axis. a plurality of drive balls engaged within ball tracks of the nut and the first screw; Relative rotation between the first nut and the first screw about the first axis the first ball screw drive causing relative movement between them along the dynamic unit; - a second nut with a ball track and a second screw with a ball track; and , for supporting the nut and screw concentrically relative to each other about a second axis. a plurality of drive balls engaged within ball tracks of the nut and the second screw; relative rotation between the second nut and the second screw about the second axis a second ball screw drive causing relative movement between them along the dynamic unit; and the first nut rotates about the first axis. The second screw is mounted in a freely rotatable manner, and the second screw is centered on a second axis. rotatably mounted on said second element so as to rotate with said second element; The screw and the second nut are arranged such that the first and second nuts rotate simultaneously about coincident axes. A ball characterized in that the second axis is aligned and fixed together. screw actuator. 2. mounted on the second element to prevent rotation of the second screw about a coincident axis. Matched brakes and actuators can be extended or retracted. placed on the first element for coaxially centering the first nut about the axis The ball screw actuator according to claim 1, further comprising a prime mover. Data. 3. mounted on the first element to prevent rotation of the first nut about a coincident axis. placed brake, and a second screw for rotating the second screw about the coincident axis. Claim 2 further including a prime mover (motor) mounted on the element of 2. The actuator described in section. 4. The first element is the wing and the second element is the pylon, retracted position and extension be movable between positions; the pylon is in the retracted position in airplane mode; An actuator according to claim 1 in an extended position in helicopter mode. . 5. - a nut with a ball track; - a screw having first and second ends and further having a ball track; - said nut and screw for supporting the nut and screw concentrically relative to each other about the first axis; The nut and screw are engaged within the ball orbits of the nut and screw and are centered on the first axis. The relative rotation between the two causes a relative movement between them along the first axis. eel, multiple balls, and - the first of the respective screws to provide an indeterminate load path between the first and second elements; and having first and second shoulders extending about the second end. parts, a ball neck located between the first element and the second element, characterized in that actuator. 6. The ball screw according to claim 5, wherein this member is a carbon fiber composite material.