Hydraulic lock for thrust vector actuator

A hydraulic lock for a thrust vector actuator includes a lock cylinder. The lock cylinder includes at least one slot and at least one bore. The slot is defined through a perimeter of the lock cylinder, and the bore is defined through a portion of the lock cylinder at a second end to extend towards a first end. The hydraulic lock includes at least one biasing member coupled to the bore. The hydraulic lock includes at least one pawl having a first pawl end and a second pawl end. The first pawl end is releasably coupled to the shaft of the thrust vector actuator. The second pawl end is coupled to the slot. The pawl is movable relative to the slot between a first, locked position in which the first pawl end is coupled to inhibit movement of the shaft, and a second, unlocked position.

TECHNICAL FIELD

The present disclosure generally relates to thrust vector actuators, and more particularly relates to a hydraulic lock for a thrust vector actuator.

BACKGROUND

Thrust vector actuators may be employed to control a position of one or more nozzles of a rocket engine. For example, a thrust vector actuator may be coupled to a launch vehicle for launching a payload for spaceflight, and the thrust vector actuator may be actuated to control a position of the rocket engine associated with the launch vehicle during flight. During transport of the thrust vector actuator, installation of the thrust vector actuator onto the launch vehicle, and during certain engine tests and inspections, the thrust vector actuator may be required to maintain a fixed position, while being subjected to large loads.

Accordingly, it is desirable to provide a hydraulic lock for a thrust vector actuator, which maintains the thrust vector actuator in a fixed position while subjected to large loads during installation and transport. Moreover, it is desirable to provide a lock for a thrust vector actuator, which requires positive locking and unlocking of the lock. Further, it is desirable to provide a lock for a thrust vector actuator, which locks in a neutral position. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.

SUMMARY

The various teachings of the present disclosure provides a hydraulic lock for a thrust vector actuator having a movable shaft. The hydraulic lock includes a lock cylinder having a first end and a second end. The lock cylinder includes at least one slot and at least one bore. The at least one slot is defined through a perimeter of the lock cylinder adjacent to the second end, and the at least one bore is defined through a portion of the lock cylinder at the second end to extend towards the first end. The hydraulic lock includes at least one biasing member coupled to the at least one bore. The hydraulic lock also includes at least one pawl having a first pawl end and a second pawl end. The first pawl end is releasably coupled to a groove defined in the shaft of the thrust vector actuator. The second pawl end is coupled to the at least one slot. The at least one pawl is movable relative to the at least one slot between a first, locked position in which the first pawl end is coupled to the groove to inhibit movement of the shaft, and a second, unlocked position in which the first pawl end is released from the groove. The hydraulic lock also includes a cover coupled to the at least one biasing member. A movement of the lock cylinder towards the cover moves the at least one pawl from the first, locked position to the second, unlocked position.

Further provided is a hydraulic lock for a thrust vector actuator having a movable shaft. The hydraulic lock includes a lock cylinder having a first end and a second end. The lock cylinder includes at least one slot and at least one bore. The at least one slot is defined through a sidewall of the lock cylinder adjacent to the second end, and the at least one bore is defined through a portion of the lock cylinder at the second end to extend towards the first end. The sidewall has a first surface opposite a second surface, and a ledge that extends from the second surface towards the first surface. The hydraulic lock includes at least one biasing member coupled to the at least one bore. The hydraulic lock also includes at least one pawl having a first pawl end and a second pawl end. The first pawl end is releasably coupled to a groove defined in the shaft of the thrust vector actuator, and the second pawl end is coupled to the at least one slot. The at least one pawl is movable relative to the at least one slot between a first, locked position in which the first pawl end is coupled to the groove to inhibit movement of the shaft, and a second, unlocked position in which the first pawl end is released from the groove. The second pawl end has a first ramp surface that engages with the ledge as the at least one pawl moves from the first, locked position to the second, unlocked position. The hydraulic lock includes a cover coupled to the at least one biasing member and the at least one pawl. A movement of the lock cylinder towards the cover moves the at least one pawl from the first, locked position to the second, unlocked position.

Also provided is a thrust vector actuator having a movable shaft. The thrust vector actuator includes a lock housing that surrounds the shaft and defines at least one conduit in fluid communication with a hydraulic source to receive a hydraulic fluid. The lock housing includes at least one lock piston received within the at least one conduit. The thrust vector actuator includes a lock. The lock includes a lock cylinder having a first end and a second end. The lock cylinder includes at least one slot and at least one bore. The at least one slot is defined through a sidewall of the lock cylinder adjacent to the second end, and the at least one bore is defined through a portion of the lock cylinder at the second end to extend towards the first end. The sidewall has a first surface opposite a second surface, and a ledge that extends from the second surface towards the first surface. The lock includes at least one biasing member coupled to the at least one bore and at least one pawl having a first pawl end and a second pawl end. The first pawl end is releasably coupled to a groove defined in the shaft of the thrust vector actuator. The second pawl end is coupled to the at least one slot. The at least one pawl is movable relative to the at least one slot between a first, locked position in which the first pawl end is coupled to the groove to inhibit movement of the shaft, and a second, unlocked position in which the first pawl end is released from the groove. The second pawl end having a first ramp surface that engages with the ledge as the at least one pawl moves from the first, locked position to the second, unlocked position. The lock includes a cover coupled to the at least one biasing member. Upon receipt of the hydraulic fluid, the at least one lock piston contacts the first end of the lock cylinder to move the lock cylinder towards the cover, and the movement of the cover moves the at least one pawl from the first, locked position to the second, unlocked position.

DETAILED DESCRIPTION

The following detailed description is merely exemplary in nature and is not intended to limit the application and uses. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description. In addition, those skilled in the art will appreciate that embodiments of the present disclosure may be practiced in conjunction with any mobile platform or vehicle, such as an aircraft, rocket marine vessel, and the like that would benefit from thrust vector control with a thrust vector actuator having a hydraulic lock, and that the thrust vector actuator described herein for use with a launch vehicle is merely one exemplary embodiment according to the present disclosure. Moreover, while the hydraulic lock is described herein as being used with a thrust vector actuator for a launch vehicle, the various teachings of the present disclosure can be used with projectile, such as a ballistic or tactical missile. Further, it should be noted that many alternative or additional functional relationships or physical connections may be present in an embodiment of the present disclosure. In addition, while the figures shown herein depict an example with certain arrangements of elements, additional intervening elements, devices, features, or components may be present in an actual embodiment. It should also be understood that the drawings are merely illustrative and may not be drawn to scale.

As used herein, the term “axial” refers to a direction that is generally parallel to or coincident with an axis of rotation, axis of symmetry, or centerline of a component or components. For example, in a cylinder or disc with a centerline and generally circular ends or opposing faces, the “axial” direction may refer to the direction that generally extends in parallel to the centerline between the opposite ends or faces. In certain instances, the term “axial” may be utilized with respect to components that are not cylindrical (or otherwise radially symmetric). For example, the “axial” direction for a rectangular housing containing a rotating shaft may be viewed as a direction that is generally parallel to or coincident with the rotational axis of the shaft. Furthermore, the term “radially” as used herein may refer to a direction or a relationship of components with respect to a line extending outward from a shared centerline, axis, or similar reference, for example in a plane of a cylinder or disc that is perpendicular to the centerline or axis. In certain instances, components may be viewed as “radially” aligned even though one or both of the components may not be cylindrical (or otherwise radially symmetric). Furthermore, the terms “axial” and “radial” (and any derivatives) may encompass directional relationships that are other than precisely aligned with (e.g., oblique to) the true axial and radial dimensions, provided the relationship is predominately in the respective nominal axial or radial direction. As used herein, the term “transverse” denotes an axis that crosses another axis at an angle such that the axis and the other axis are neither substantially perpendicular nor substantially parallel.

With reference toFIG. 1, a thrust vector actuator10is shown. The thrust vector actuator10may be coupled to a launch vehicle8to control a position of a rocket engine associated with the launch vehicle8during a flight of the launch vehicle8. In one example, the thrust vector actuator10is hydraulically actuated, and includes a housing assembly12, a piston assembly16and a lock18. As will be discussed, the lock18is actuated by a hydraulic source20to move the lock from a first, locked position to a second, unlocked position to enable the movement of the piston assembly16relative to the housing assembly12. Generally, the lock18moves to the second, unlocked position upon the application of a hydraulic pressure by the hydraulic source20above a predefined threshold, and moves to the first, locked position when the hydraulic pressure drops below the predefined threshold. Thus, in this example, the hydraulic source20is employed to actively unlock the lock18. The lock18also provides for locking the thrust vector actuator10in a neutral position. In this regard, the lock18enables the thrust vector actuator10to be locked such that a piston102of the piston assembly16is in a neutral position.

The housing assembly12includes a main housing22, a manifold24and a hydraulic supply and return device26. As will be discussed further herein, the hydraulic supply and return device26is fluidly coupled to the hydraulic source20. The hydraulic source20is fluidly coupled to the lock18and a servo motor valve actuator or servo valve26′″ associated with the hydraulic supply and return device26to supply hydraulic fluid to the lock18and to the servo valve26′″. The servo valve26′″ controls the thrust vector actuator10with the hydraulic fluid received from the hydraulic source20. With reference toFIG. 2, the main housing22includes a first housing portion30, a second housing portion32and a third housing portion33, which cooperate to couple a portion of the piston assembly16to the main housing22. The main housing22is generally formed of a metal or metal alloy, and may be cast, machined, forged, etc.

The first housing portion30is substantially cylindrical, and with reference toFIG. 2, the first housing portion30extends from a first end34to a second end36. The first end34is coupled to a portion of the piston assembly16and to the third housing portion33. In one example, the first end34includes a mounting flange38, which includes one or more threaded bores for receipt of a respective one or more mechanical fasteners, such as bolts, to couple the second housing portion32and the third housing portion33to the first housing portion30. The second end36defines a central bore40, and may include a sealing flange42defined about the central bore40. The central bore40enables a portion of the piston assembly16to move relative to the main housing22. The sealing flange42is defined about a perimeter of the central bore40along a first surface of the second end36, and includes a recess44. The recess44receives a sealing member46, which prevents or inhibits the leakage of hydraulic fluid from the main housing22during the movement of the portion of the piston assembly16. A second surface of the second end36, which is substantially opposite the first surface and the sealing flange42, is coupled to a portion of the piston assembly16. As will be discussed, the portion of the lock18is coupled to the second end36of the first housing portion30so as to enable fluid communication between the manifold24and the lock18.

The first housing portion30also cooperates with the third housing portion33to define a hydraulic chamber48. The hydraulic chamber48is defined between the first end34and the second end36and receives hydraulic fluid from the hydraulic source20. In this example, the first housing portion30also defines a first inlet bore50, a second inlet bore52and a lock inlet bore53(FIG. 2A). Each of the first inlet bore50, the second inlet bore52and the lock inlet bore53are in fluid communication with the manifold24to receive hydraulic fluid. In this example, the first inlet bore50is defined near, adjacent to or at the first end34, and supplies the hydraulic chamber48with hydraulic fluid from the manifold24. Thus, the first inlet bore50is in fluid communication with the manifold24and the hydraulic chamber48to supply the hydraulic chamber48with hydraulic fluid from the manifold24on a first face140of a piston102of the piston assembly16. The second inlet bore52is defined near, adjacent to or at the second end36, and supplies the hydraulic chamber48with hydraulic fluid from the manifold24on a second face142of a piston102of the piston assembly16. The lock inlet bore53is in fluid communication with the manifold24and the lock18to supply the lock18with hydraulic fluid from the manifold24. With reference toFIG. 2A, the lock inlet bore53directs the hydraulic fluid from the first housing portion30to the lock18, and generally includes a first passage53′, a second passage53″ and a third passage53′″ (FIG. 4) defined within the first housing portion30. The first passage53′ is substantially perpendicular to a second passage53″ to direct the hydraulic fluid from the manifold24towards the lock18. With brief reference toFIG. 4, the third passage53′″ fluidly couples the second passage53″ to the lock18. With reference back toFIG. 2A, a plug may be inserted into an end of the first passage53′ to inhibit the hydraulic fluid from flowing out of the lock inlet bore53.

With reference toFIG. 2, the second housing portion32is coupled to the piston assembly16. The second housing portion32is substantially hat-shaped, and includes a first portion end60, a second portion end62and a mounting extension64. The first portion end60is circumferentially closed, and encloses a portion of the piston assembly16. The mounting extension64is coupled to the first portion end60, and extends outwardly from the first portion end60along a longitudinal axis L of the thrust vector actuator10. The mounting extension64defines a bore66, which receives and is coupled to a spherical bearing68. The spherical bearing68is coupled to a portion of the launch vehicle8, such as a thrust frame, for example.

The first portion end60and the second portion end62cooperate to define a second chamber70, which receives the portion of the piston assembly16. The second portion end62includes a second mounting flange72, which is defined about the perimeter of the second portion end62. Generally, the second mounting flange72defines one or more throughbores, which each receive a respective one of the one or more mechanical fasteners therethrough for coupling the second housing portion32to the third housing portion33.

The third housing portion33is positioned between the first housing portion30and the second housing portion32. The third housing portion33is substantially circular, and is sized to seal against the first housing portion30to form the hydraulic chamber48. The third housing portion33is generally coupled between the first housing portion30and the second housing portion32via the mechanical fasteners received through the throughbores of the second mounting flange72, which pass through corresponding throughbores defined about a perimeter of the third housing portion33and matingly engage with the plurality of bores defined in the mounting flange38. The third housing portion33defines a bore33′, which receives a portion of the piston assembly16. The third housing portion33may also define a groove120, which receives a sealing member120′ to inhibit or prevent a leakage of hydraulic fluid from the hydraulic chamber48.

The manifold24is coupled to the first housing portion30, and in this example, is coupled to a sidewall30′ of the first housing portion30. The manifold24is composed of a metal or metal alloy, and is cast, forged, machined, selective laser sintered, etc. With reference toFIG. 1, in one example, the manifold24is coupled to the sidewall30′ via one or more mechanical fasteners, which threadably engage threaded bores defined in the sidewall30′. It should be noted, however, that the manifold24may be coupled to the housing assembly12via any suitable technique, such as welding, brazing, etc. or may be integrally formed with the housing assembly12. With reference back toFIG. 2, the manifold24is in fluid communication with the first inlet bore50, the second inlet bore52, the lock inlet bore53and the hydraulic source20to distribute the hydraulic fluid from the hydraulic source20into the first inlet bore50, the second inlet bore52and the lock inlet bore53. Generally, the manifold24defines a first fluid passage80in fluid communication with the second inlet bore52, a second fluid passage82in fluid communication with the first inlet bore50and a third fluid passage83in fluid communication with the lock inlet bore53(FIG. 2A). In one example, the hydraulic supply and return device26controls the flow of the hydraulic fluid into the first inlet bore50and the second inlet bore52of the manifold24, and enables the flow of hydraulic fluid into the lock inlet bore53.

In this example, with reference toFIG. 1, the hydraulic supply and return device26includes a hydraulic inlet26′, a hydraulic outlet26″ (FIG. 2) and the servo valve26′. The hydraulic inlet26′ is fluidly coupled to the manifold24and is fluidly coupled to the hydraulic source20. The hydraulic inlet26′ receives the hydraulic fluid from the hydraulic source20, and directs the hydraulic fluid into the lock inlet bore53and to the servo valve26′. The hydraulic outlet26″ is in fluid communication with the hydraulic source20, and serves to return hydraulic fluid from the manifold24. The servo valve26′ controls the flow of hydraulic fluid into the first inlet bore50and the second inlet bore52from the manifold24to control the thrust vector actuator10. In this example, the servo valve26′ is a four-way, two-stage, electro-hydraulic servo-valve (EHSV), which is closed-center. Generally, with one polarity (of received electrical input) the servo valve26′″ routes hydraulic fluid into the first inlet bore50and routes hydraulic fluid from the second inlet bore52into the hydraulic outlet26″; while for the opposite polarity the servo valve26′″ routes the hydraulic fluid to the second inlet bore52and routes hydraulic fluid from the first inlet bore50into the hydraulic outlet26″.

With reference toFIG. 2, the piston assembly16is at least partially received within the housing assembly12. In one example, the piston assembly16includes a sensor100, the piston102and a rod end104. In this example, the sensor100is a linear variable differential transformer (LVDT), which observes a position of the piston102and generates sensor signals based thereon. The sensor100is coupled to the third housing portion33and to the piston102.

The piston102is movable within the first housing portion30. The piston102includes a head130and a piston shaft132. The head130and the piston shaft132may be composed of a metal or metal alloy, and may be cast, forged, machined, selective laser sintered, etc. The head130is received within the first housing portion30, and is slidable linearly within the first housing portion30from the first end34to the second end36. The head130is circular, and includes at least a first guide ring134and a piston seal136, which are each received in respective recesses138defined about the perimeter or circumference of the head130. The head130has a first face140substantially opposite a second face142, and defines a head bore143through the first face140and the second face142. The hydraulic fluid from the first inlet bore50acts against the first face140to move the piston102within the hydraulic chamber48. The second face142is coupled to the piston shaft132. The hydraulic fluid from the second inlet bore52acts against the second face142to move the piston102within the hydraulic chamber48. The head bore143is defined about a central axis of the head130, and enables a portion of the sensor100to pass through the head130.

The piston shaft132is substantially cylindrical, and includes a first piston shaft end144and a second piston shaft end146. A central shaft bore148is defined from the first piston shaft end144to the second piston shaft end146, and is in communication with the head bore143. The first piston shaft end144is coupled to the second face142, and the second piston shaft end146is coupled to the rod end104. Generally, a portion of the sensor100extends through the head bore143and into the central shaft bore148at the first piston shaft end144. The sensor100extends into the central shaft bore148and is coupled to a sensor mounting flange147defined within the central shaft bore148between the first piston shaft end144and the second piston shaft end146. The second piston shaft end146is circumferentially open, and is coupled to the rod end104. Generally, a portion of the rod end104is received within the central shaft bore148to assist in coupling the rod end104to the second piston shaft end146. The second piston shaft end146may also include a nut146′, which may threadably engage one or more threads defined on an exterior surface104′ of the rod end104to couple the rod end104to the piston shaft132.

The piston shaft132also includes an annular recess or groove149defined about a perimeter or circumference of the piston shaft132. The annular groove149may be defined by milling, machining, etc. The annular groove149receives a portion of the lock18to enable the lock18to fix the position of the piston shaft132. The annular groove149has a substantially U-shaped cross-section; however the annular groove149may have any cross-section. In this example, the annular groove149is defined so as to be continuous about the perimeter or circumference of the piston shaft132to enable the piston shaft132to rotate relative to the lock18. It will be understood, however, that the annular groove149need not be continuous about the circumference of the piston shaft132. Rather, the annular groove149may be interrupted or discontinuous such that a portion of the annular groove149is defined for each respective portion of the lock18to engage in instances where the piston shaft132is inhibited from rotating relative to the lock18. In addition, the annular groove149may include one or more alignment features, if desired, to assist in coupling the lock18to the piston shaft132.

The rod end104is coupled to the piston shaft132at the second piston shaft end146, and may be at least partially received within the central shaft bore148of the piston shaft132to aid in coupling the rod end104to the piston shaft132. The rod end104includes a body210that defines a first rod end212and a second, opposite rod end214. The body210may define a plurality of threads between the first rod end212and the second rod end214, which matingly engage with the nut146′ to couple the rod end104to the piston shaft132.

The first rod end212is received within the central shaft bore148of the piston shaft132. The second rod end214includes a bore216, which receives a second spherical bearing218. The second spherical bearing218is coupled to the bore216and the second spherical bearing218is coupled to a thrust nozzle, for example, such that movement of the piston102relative to the housing assembly12results in a corresponding movement of the thrust nozzle.

The piston assembly16may also include an end cap186. The end cap186is substantially hat-shaped, and defines a first cap end204, a second cap end206and a central cap bore208, which extends from the first cap end204to the second cap end206. The first cap end204is coupled to the cover mounting flange196of an enclosure cover184, and includes a plurality of bores, which receive a respective one of a plurality of mechanical fasteners to couple the end cap186to an enclosure housing182of the lock18. The second cap end206is substantially opposite the first cap end204. The central cap bore208receives a portion of the piston shaft132, and may receive and retain a bushing to aid in the movement of the piston shaft132relative to the end cap186.

With reference toFIG. 3, the lock18is shown in greater detail. InFIG. 3, the lock18is in the first, locked position such that the movement of the piston shaft132relative to the housing assembly12is inhibited or prevented. In one example, the lock18includes the enclosure housing182, the enclosure cover184, a lock housing229, a lock cylinder230, the springs200, and at least one or a plurality of pawls232. In this example, as shown inFIG. 4, there are 8 pawls232and 8 springs200employed with the lock18. It should be understood, however, that the lock18may include any number of pawls and springs, and that the use of 8 is merely exemplary.

In this example, with reference toFIG. 2, the enclosure housing182is substantially cylindrical, and is coupled about the lock housing229. The enclosure housing182encloses the lock housing229and may protect the lock housing229from the environment surrounding the thrust vector actuator10. The enclosure housing182includes a first enclosure end188substantially opposite a second enclosure end190. The first enclosure end188includes a plurality of bores defined about a perimeter or circumference of the enclosure housing182, which receive a plurality of mechanical fasteners to couple the enclosure housing182to the second end36of the first housing portion30. The second enclosure end190is coupled to the enclosure cover184, and defines a plurality of threaded bores to receive a respective one of a plurality of mechanical fasteners to couple the enclosure cover184to the enclosure housing182.

The enclosure cover184is positioned between the enclosure housing182and the end cap186. The enclosure cover184is annular, and includes a plurality of spring seats192, a plurality of pawl recesses193, a lip recess194and a cover mounting flange196. The enclosure cover184is composed of a metal or a metal alloy, such as aluminum, and may be stamped, cast, forged, etc. With reference toFIG. 2B, each of the plurality of spring seats192are substantially cylindrical, and are each defined about a perimeter or circumference of the enclosure cover184. The plurality of spring seats192are spaced apart about the circumference of the enclosure cover184at a first end184′ to correspond with a spacing of at least one or a plurality of biasing members or springs200of the lock18. Each of the plurality of spring seats192receive a respective one of the plurality of springs200to provide a seat for an end of the respective spring200.

With reference toFIGS. 2B and 7, the plurality of pawl recesses193are shown in greater detail. Each of the plurality of pawl recesses193are substantially V-shaped, and are defined about a perimeter or circumference of the enclosure cover184. Generally, with reference toFIG. 2B, the pawl recesses193alternate with the spring seats192about the circumference of the enclosure cover184such that pawl recesses193are substantially aligned with a portion of the lock18. With reference toFIG. 7, each of the pawl recesses193includes a first, angled surface195and a second, planar surface197, which are joined together by a curved wall199. Each of the angled surface195, the planar surface197and the curved wall199cooperate with the portion of the lock18to enable the lock18to move between the first, locked position and the second, unlocked position.

With reference back toFIG. 2, the lip recess194is defined along a central bore202defined by the enclosure cover184. Generally, the lip recess194is an area of the central bore202that has a larger diameter than a remainder of the central bore202to receive the lip336of a second lock housing portion294of the lock housing229. In one example, the lip recess194is sized to form an interference fit with a lip336of the second lock housing portion294to assist in coupling the enclosure cover184to the lock housing229. Generally, the piston shaft132is received through the central bore202.

With continued reference toFIG. 2, the cover mounting flange196is defined about a perimeter or circumference of the enclosure cover184at a second end184″ of the enclosure cover184, with the second end184″ substantially opposite the first end184′. The cover mounting flange196defines a plurality of bores, through which a respective plurality of mechanical fasteners may pass to couple the enclosure cover184and the end cap186to the enclosure housing182.

The lock housing229is coupled to the first housing portion30at the second end36. The lock housing229substantially surrounds a portion of the piston shaft132. With reference toFIG. 5, the lock housing229is shown in greater detail. The lock housing229is composed of a metal or metal alloy, and may be forged, cast, machined, selective laser sintered, etc. In one example, the lock housing229includes a first lock housing portion292and a second lock housing portion294. Generally, the first lock housing portion292is spaced apart from the second lock housing portion294about the circumference of the piston shaft132to define a channel296. The channel296enables a portion of the lock18to engage with the annular groove149of the piston shaft132. The first lock housing portion292includes a first lock housing end300substantially opposite a second lock housing end302, a conduit portion304and a lock seat306. A central lock housing bore308is defined through the first lock housing portion292from the first lock housing end300to the second lock housing end302. The central lock housing bore308substantially surrounds the piston shaft132.

The first lock housing end300includes a lock housing flange310, which includes a plurality of bores310′ spaced apart about a perimeter of the first lock housing end300. The conduit portion304is defined adjacent to the lock housing flange310so as to be positioned between the lock housing flange310and the lock seat306. The conduit portion304defines a first annular conduit ring312and a second annular conduit ring314. The first annular conduit ring312includes a plurality of cross-bores316, and substantially concave recesses318. Each of the plurality of cross-bores316are defined into an exterior surface312′ of the first annular conduit ring312so as to extend along an axis substantially transverse or oblique to the longitudinal axis L of the thrust vector actuator10.

With reference toFIG. 5A, each of the cross-bores316are defined through a portion of the exterior surface312′ to define a respective hydraulic passage320into the lock housing229. The hydraulic passages320may be defined by drilling, for example. Once the hydraulic passages320are defined, a respective plug is inserted into each of the cross-bores316to inhibit or prevent hydraulic fluid from exiting the hydraulic passages320. Each of the hydraulic passages320supply hydraulic fluid to a respective conduit322associated with the second annular conduit ring314. In this example, there are four hydraulic passages320supplying hydraulic fluid to five conduits322, however, any number of hydraulic passages320may be employed. The hydraulic passages320are in fluid communication about the perimeter of the first annular conduit ring312and are in fluid communication with an inlet320′ to receive the hydraulic fluid from the second passage53″ of the lock inlet bore53.

The concave recesses318are defined through the exterior surface312′ along a second axis, which is substantially parallel to the longitudinal axis L. Generally, each of the concave recesses318receives a head of a respective mechanical fastener to couple the lock housing229to the second end36of the housing assembly12.

The second annular conduit ring314includes a plurality of conduits322defined about a perimeter or circumference of the second annular conduit ring314. Generally, the conduits322are substantially evenly spaced apart from each other about the circumference of the second annular conduit ring314. Each of the conduits322has a first conduit end324and a second, opposite conduit end326. Each of the first conduit ends324of the conduits322are in fluid communication with a respective one of the hydraulic passages320to enable hydraulic fluid to flow into each of the conduits322; and the second conduit ends326are in communication with a portion of the lock18to apply a force F (FIG. 3) from the hydraulic fluid to the lock18. The force F from the hydraulic fluid acts against the lock18to positively unlock the lock18as will be discussed in greater detail herein. The conduits322are illustrated herein as being substantially cylindrical; however, the conduits322may have any desired shape.

With reference toFIG. 3, each of the conduits322also includes a respective one of a plurality of lock pistons328. The lock pistons328are received within a portion of the conduits322and are movable by the hydraulic fluid relative to the respective conduits322of the lock housing229. In this example, each of the lock pistons328is movable relative to the respective one of the conduits322to extend a distance beyond the second conduit end326. The extension of each of the lock pistons328beyond the conduits322causes the lock pistons328to contact a portion of the lock18and move the lock18to a second, unlocked position, as will be discussed herein. The lock pistons328are illustrated herein as being substantially cylindrical; however the lock pistons328may have any desired shape. The lock pistons328each have a first piston end330and a second piston end332. With reference toFIG. 3, the first piston end330is in fluid communication with the respective conduits322to receive the hydraulic fluid, and the second piston end332contacts the portion of the lock18as the lock piston328is moved by the hydraulic fluid toward the second conduit end326. Thus, the hydraulic fluid applies the force F to the first piston end330, which causes the second piston end332to advance beyond the second conduit end326and thereby contact the portion of the lock18to move the lock18to the second, unlocked position.

With reference back toFIG. 5, the second annular conduit ring314is defined adjacent to the lock seat306, and the lock seat306extends to the second lock housing end302. The lock seat306has a wall thickness that is less than a wall thickness of the second annular conduit ring314to enable a portion of the lock18to be positioned about the lock seat306.

With reference toFIG. 3, the second lock housing portion294is spaced apart from the first lock housing portion292along the piston shaft132to define the channel296, which enables the lock18to engage the groove149. The second lock housing portion294has a first end294′ opposite a second end294″. The first end294′ is substantially cylindrical, and has a wall thickness that enables the enclosure housing184to be positioned about the circumference of the first end294′. The second end294″ has a wall thickness greater than the wall thickness of the first end294′ to define a lip336. The lip336extends about a perimeter or circumference of the second lock housing end302, and assists in retaining the lock18about the perimeter of the piston shaft132. A central bore294′″ is defined through the second lock housing portion294to enable the second lock housing portion294to be positioned about the piston shaft132.

With reference toFIG. 6, the lock cylinder230is shown. The lock cylinder230is composed of a metal or a metal alloy, and may be stamped, cast, forged, etc. In this example, the lock cylinder230is annular, and has a first housing end234and a second housing end236. A central lock housing bore238is defined through the lock cylinder230from the first housing end234to the second housing end236, and enables the lock cylinder230to be positioned about the piston shaft132(as shown inFIG. 3). The lock cylinder230also includes at least one slot240and at least one bore242. In one example, the at least one slot240comprises a plurality of slots240and the at least one bore242comprises a plurality of bores242. Generally, the number of slots240correspond with the number of pawls232, and the number of bores242correspond with the number of springs200.

The first housing end234is substantially planar or flat, and the second housing end236is substantially opposite the first housing end234. Generally, the first housing end234is adjacent to the enclosure housing182(FIG. 2). Generally, the slots240are each defined in a respective one of a plurality of sidewalls244that extend between adjacent ones of the bores242. Thus, the plurality of slots240alternate with the plurality of bores242about a perimeter or circumference of the lock cylinder230.

In this example, each of the slots240includes a first slot246and a second slot248, which are defined through the perimeter of the lock cylinder230between a rib250of the sidewall244and a portion252of the sidewall244. Generally, with reference toFIG. 7, each of the sidewalls244includes a first surface254and a second, opposite surface256. The first surface254is an exterior surface of the lock cylinder230, and is adjacent to the enclosure housing182, and the second surface256is an interior surface, and is adjacent to the piston shaft132. The rib250cooperates with a portion of the bores242to define the second housing end236. The rib250generally extends from the first surface254toward the second surface256for a first distance D1, which is less than a second distance D2defined between the first surface254and the second surface256. Stated another way, the rib250extends from the first surface254the first distance D1to define a cut-out or opening for receipt of a respective one of the pawls232. The rib250may include a rounded or filleted surface250′ to assist in a movement of the respective one of the pawls232from a second, unlocked position to a first, locked position.

The portion252extends between the first surface254and the second surface256, and thus, extends for the distance D2. The first slot246is spaced apart from the second slot248by the portion252such that the first slot246is separate or discrete from the second slot248. In this example, the first slot246includes a ledge258, which extends axially from the portion252for a length L2. The ledge258is coupled to the portion252and extends outward from the portion252towards the rib250. Stated another way, the ledge258extends from the portion252towards the second housing end236. The ledge258extends upward from the second surface256a third distance D3, which is greater than the first distance D1and less than the second distance D2. In other words, the ledge258is defined in the first slot246below the first surface254, and extends from the second surface256toward the first surface254. The ledge258also includes a rounded or filleted surface258′, which also assists in a movement of the respective one of the pawls232from the first, locked position to the second, unlocked position. Generally, the filleted surface258′ is defined at a first ledge end260, which is opposite a second ledge end262. The second ledge end262is coupled to the portion252.

The second slot248is defined through the sidewall244from the first surface254to the second surface256. The second slot248may provide mass savings for the lock cylinder230, and may be optional.

With reference back toFIG. 6, the bores242are defined in the lock cylinder230at the second housing end236to extend towards the first housing end234. Each of the bores242is substantially cylindrical, and may be defined through a respective one of a plurality of substantially cylindrical sleeve portions264of the lock cylinder230. It should be noted that while the bores242are illustrated as being defined through a respective substantially cylindrical sleeve portion264of the lock cylinder230, the bores242may be defined through any suitably shaped portion, such as cylindrical. The plurality of cylindrical sleeve portions264are defined about a perimeter or circumference of the lock cylinder230and are each spaced apart by a respective one of the plurality of sidewalls244. Thus, the perimeter of the lock cylinder230is defined by alternating respective ones of the plurality of sidewalls244and the plurality of cylindrical sleeve portions264. With reference toFIG. 3, the bores242each receive a respective one of the springs200, and a respective one of the springs200is coupled to a respective one of the bores242. Each of the bores242cooperate with a respective one of the spring seats192to retain a respective spring200.

Each of the springs200are positioned between a respective one of the bores242and a respective one of the spring seats192. In this example, the springs200are metal or metal alloy compression coil springs, which resist the movement of the lock cylinder230toward the end cap186. Generally, the springs200each exert a spring force F2against an end wall242′ of each of the bores242, and bias the lock cylinder230toward the first housing portion30in the first, locked position as shown inFIG. 3. As discussed, there are 8 springs200associated with the lock18; however, it will be understood that the number of springs may vary based on the unlock force requirements associated with the lock18. In this example, the springs200maintain the lock cylinder230in the first, locked position until the force F applied by the hydraulic fluid acting on the lock pistons328exceeds the predefined threshold for hydraulic pressure, which in this example is about 1000 pounds per square inch (psi).

The pawls232are each movable between a first, locked position and a second, unlocked position to enable the lock cylinder230, and thus, the lock18to move from the first, locked position to the second, unlocked position. Each of the pawls232may be composed of a metal or metal alloy, which may be cast, stamped, forged, selective metal sintered, etc. With reference toFIG. 8, each of the pawls232has a first pawl end270and a second pawl end272. The first pawl end270is substantially opposite the second pawl end272and is coupled to the second pawl end272via a body274. The first pawl end270includes a first pawl surface276that is coupled to the body274and a second, opposite pawl surface278. In this example, the second pawl surface278is substantially arcuate, and is configured to correspond with a curvature of the piston shaft132. Generally, the first pawl end270has a first arm270′ and a second arm270″ that extend outwardly from the body274, and thus, the pawl232. The first arm270′ and the second arm270″ increase a contact surface area of the second pawl surface278against the piston shaft132. In this regard, in the first, locked position, the first pawl end270is received within the annular groove149(FIG. 3) of the piston shaft132such that the second pawl surface278contacts a surface149′ of the annular groove149to inhibit or prevent the movement of the piston shaft132. As will be discussed, the first pawl end270is releasably coupled to the annular groove149(FIG. 3) of the piston shaft132of the thrust vector actuator10.

With reference toFIG. 8, the second pawl end272includes a slot engagement feature280and a tail282. The slot engagement feature280couples the second pawl end272of the pawl232to a respective one of the slots240. Generally, the movement of the second pawl end272relative to the respective one of the slots240couples and uncouples the first pawl end270from the annular groove149. In this example, the slot engagement feature280is a wedge, and includes a first ramp surface284, a flat or planar surface286and a second ramp surface288. The first ramp surface284is substantially opposite the second ramp surface288. The first ramp surface284extends upward from the body274, and with reference toFIG. 7, is defined at an angle α relative to an axis A defined through the pawl232. In one example, the angle α is about 40 to about 45 degrees when in the first, locked position. The first ramp surface284contacts the filleted surface258′ during a movement of the lock cylinder230to guide the pawl232between the first, locked position and the second, unlocked position, as will be discussed herein.

The planar surface286interconnects the first ramp surface284and the second ramp surface288. The planar surface286contacts the rib250of the lock cylinder230, which maintains or holds the pawl232in the first, locked position. The second ramp surface288extends downward from the planar surface286and interconnects the planar surface286with the tail282. The second ramp surface288is defined at an angle β relative to the axis A defined through the pawl232. In one example, the angle β is about 30 to about 35 degrees when in the first, locked position. The second ramp surface288contacts the filleted surface250′ of the rib250during a movement of the lock cylinder230to guide the pawl232between the second, unlocked position and the first, locked position, as will be discussed herein.

The tail282of the second pawl end272is received within a respective one of the pawl recesses193of the enclosure cover184. The tail282generally extends outwardly from the body274for a length L3. The length L3is generally less than a distance D4defined between the second housing end236and the curved wall199of the respective pawl recess193such that a gap290is defined between an end282′ of the tail282and the curved wall199when the lock cylinder230is in the first, locked position. The gap290enables the tail282to move or translate towards the curved wall199during a movement of the lock cylinder230toward the enclosure cover184, which assists in releasing the planar surface286from engagement with the rib250.

The hydraulic source20is associated with the launch vehicle8. Generally, the hydraulic source20is a supply of hydraulic fluid, which may be supplied to the manifold24via at least one conduit (e.g. flexible hose). In one example, the hydraulic source20is a hydraulic pump, which is driven by an engine of the launch vehicle8. In this example, the hydraulic pump supplies hydraulic fluid under pressure to the manifold24, via the at least one conduit, and the third inlet conduit of the manifold24directs the hydraulic fluid to the lock inlet bore53to enable the movement of the lock between the first, locked position and the second, unlocked position.

In order to assemble the thrust vector actuator10, in one example, with the components of the housing assembly12, the piston assembly16and the lock18formed, the first guide ring134and the piston seal136are coupled to the head130of the piston102. The piston102is inserted into the first housing portion30. The sensor100is coupled to the sensor mounting flange147and the bore33′ of the third housing portion33. The second housing portion32, with the spherical bearing68coupled to the mounting extension64, is coupled to the first housing portion30to couple the second housing portion32and the third housing portion33to the first housing portion30.

The first lock housing portion292, with the lock pistons328coupled to the conduits322, is positioned about the piston shaft132and coupled to the first housing portion30. The pawls232are coupled to the annular groove149of the piston shaft132, and the lock cylinder230is positioned about each of the pawls232such that the planar surface286of each of the pawls232contacts each of the ribs250. The second lock hosing portion294is positioned about the piston shaft132so as to be spaced apart from the first lock housing portion292. The springs200are inserted to each of the bores242of the lock cylinder230, and the enclosure housing182is positioned about the lock cylinder230and coupled to the first housing portion30. The enclosure cover184is coupled to the enclosure housing182such that an end of each of the springs200is received in a respective one of the spring seats192and the tail282of each of the pawls232is received within a respective one of the pawl recesses193. The end cap186is coupled to the enclosure cover184and the enclosure housing182. The rod end104is coupled to the second piston shaft end146, with the second spherical bearing218coupled to the bore216.

The manifold24is coupled to the housing assembly12, and the hydraulic supply and return device26is coupled to the manifold24. The hydraulic supply and return device26is coupled to the hydraulic source20, so as to be in fluid communication with the hydraulic source20to receive the hydraulic fluid.

With the thrust vector actuator10assembled, the lock18is in the first, locked position (FIG. 3). In the first, locked position, the first pawl end270of each of the pawls232is received within the annular groove149of the piston shaft132to inhibit the movement of the piston shaft132. Upon the receipt of the hydraulic fluid into the third fluid passage83of the manifold24, the hydraulic fluid flows through the lock inlet bore53and via the inlet320′ flows into the hydraulic passages320of the first lock housing portion292(FIG. 5A). From each of the hydraulic passages320, the hydraulic fluid flows into the conduits322and applies pressure to the first piston end330of the respective lock pistons328(FIG. 3).

With reference toFIG. 9, as the applied pressure from the hydraulic fluid increases, the lock pistons328are moved beyond the second conduit end326and apply the force F to the first housing end234. The application of the force F causes the lock cylinder230to move in a direction D6toward the enclosure cover184. The movement of the lock cylinder230causes each of the pawls232to translate within the respective one of the pawl recesses193until the end282′ of each of the tails282contacts the curved wall199. The movement of each of the pawls232in the direction D6also causes the first ramp surface284to contact the filleted surface258′ of the ledge258.

With reference toFIG. 10, once the hydraulic fluid pressure exceeds the predefined threshold, the force F2of the springs200is overcome, and the lock cylinder230moves until the lock cylinder230contacts the enclosure cover184. As the lock cylinder230moves or translates in the direction D6toward the enclosure cover184, the first ramp surface284advances along the filleted surface258′ of the ledge258of the first slot246. This advancement of the second pawl ends272into the first slot246also causes each of the tails282to pivot within the respective pawl recesses193such that each of the tails282are adjacent to the angled surface195. The pivoting of each of the tails282raises the second pawl surface278of the first pawl end270out of engagement with the annular groove149, thereby enabling a movement of the piston shaft132. Thus, the pressure applied by the hydraulic fluid actively or positively unlocks the lock18. In this example, the predefined threshold is about 1000 pounds per square inch.

As the hydraulic pressure received from the hydraulic source20decreases, the force F2of the springs200begins to overcome the force F of the hydraulic fluid, and the springs200move the lock cylinder230toward the first housing portion30(e.g. in a direction opposite the direction D6). The movement of the lock cylinder230toward the first housing portion30causes the first ramp surface284to slide down the filleted surface258′ of the ledge258of the first slot246. This movement of the second pawl ends272from the first slot246also causes each of the tails282to pivot within the respective pawl recesses193such that each of the tails282are adjacent to the planar surface197. The pivoting of each of the tails282lowers the second pawl surfaces278of the first pawl ends270into engagement with the annular groove149, thereby preventing the movement of the piston shaft132(FIG. 4). Thus, the force applied by the springs200actively or positively locks the lock18.

Accordingly, the lock18of the thrust vector actuator10provides for both positive locking and positive unlocking of the lock18. This ensures that the piston shaft132remains in a fixed positon even while experiencing large loads during transport and installation. For example, the lock18maintains the first, locked position while experiencing loads up to 40,000 pounds.

In addition, it should be noted that in various embodiments, the lock18may also include a lock sensor. In this embodiment, the lock cylinder230includes a permanent magnet target coupled to the lock cylinder230. In one example, the permanent magnet target is coupled at or near the second slot248. In this embodiment, the enclosure housing182also includes a magnet sensor, such as a Hall effect or proximity sensor. The sensor coupled to the enclosure housing182observes the permanent magnet target coupled to the lock cylinder230and generates sensor signals based on this observation, which are processed by a processor to determine a position of the lock18.

In another embodiment, the lock sensor may comprise a sensor that observes a color band defined on the lock cylinder230. In this embodiment, the enclosure housing182may define a window or aperture, through which the sensor observes the color band coupled to the lock cylinder230, and generates sensor signals based on this observation, which are processed by a processor to determine a position of the lock18.

Moreover, it will be understood that the movement of the lock from the first, locked position to the second, locked position may be reversed, such that the lock18may be in the second, unlocked position when the hydraulic pressure is less than the predefined threshold. Furthermore, while a single annular groove149is described and illustrated herein, the piston shaft132may include a number of annular grooves149, which enable the piston shaft132to be locked into various detents upon the application of a predefined hydraulic force.