Locking compound rotary actuator

Abstract

A rotary lock assembly (260) includes a first epicyclic gear assembly (210) having a first sun gear assembly (220, 230), a first ring gear assembly (222, 232), and a first planetary gear assembly (224, 234) mechanically engaged to the first sun gear assembly (220, 230) and the first ring gear assembly (222, 232), and a second epicyclic gear assembly (210) having a second sun gear assembly (220, 230) configured to rotate through the first ring gear assembly (222, 232), a second ring gear assembly (222, 232), and a second planetary gear assembly (224, 234) mechanically engaged to the second sun gear assembly (220, 230) and the second ring gear assembly (222, 232).

Description

[0001] Claiming priority This application claims priority to U.S. Patent Application No. 17 / 107149, filed November 30, 2020, the entire contents of which are hereby incorporated by reference. Technical Field

[0002] This specification relates to a rotary-to-linear motion conversion device for use with an aircraft blade cascade reversing actuator. Background Technology

[0003] Conventional linear actuators have an output ram, which can be driven by a motor or by pneumatic or hydraulic pressure. The actuator may have a locking mechanism to hold the output in a fixed position. Known locking mechanisms, such as those taught by Tootle in U.S. Patent No. 4,463,661, engage the actuator synchronization system and thus provide only indirect locking of the output ram. Direct locking mechanisms for linear actuators have been developed and typically include multi-piece housings with increased size and mass. Such actuators include pinlocks, examples of which are disclosed by Carlin in U.S. Patent No. 5,267,760. While some pinlock arrangements allow for single-piece housing actuators, they have the disadvantage of using flexural locking elements with fatigue considerations. Locking actuators can be operated by a rotary source, rather than hydraulically or pneumatically. Current rotary source-operated actuators, such as those disclosed by Grimm in U.S. Patent No. 4,603,594, have the disadvantage of requiring an electrically operated solenoid mechanism (or other mechanical input separate from the rotary source) to unlock the actuator lock before the movement of the indenter can begin. Ball lock mechanisms, such as those taught by Sue in U.S. Patent No. 4,703,683, by Deutch in U.S. Patent No. 4,240,332, and by Della Rocca in U.S. Patent No. 4,742,758, have the disadvantage of low external load-bearing capacity of the indenter due to the point contact stress imposed on the lock ball. Linear motion lock sleeve and key arrangements, such as those disclosed by Kopecek (the inventor of this disclosure) in British Patent GB 2,435,877, include a rotary-to-linear motion conversion mechanism for the lock sleeve and the associated complexity. Rotary lock sleeve and key arrangements have also been disclosed by Kopecek in US 8,715,132. Therefore, it would be ideal to provide a linear actuator arrangement that overcomes at least some of the problems identified above. Summary of the Invention

[0004] Generally, this document describes a rotary-to-linear motion conversion device. More specifically, this document describes a rotary-to-linear motion conversion device for use with an aircraft blade cascade reversing actuator.

[0005] In a first example, a rotary lock assembly includes: a first rotary gear assembly including a first sun gear assembly, a first ring gear assembly, and a first planetary gear assembly mechanically engaged to the first sun gear assembly and the first ring gear assembly; and a second rotary gear assembly including a second sun gear assembly, a second ring gear assembly configured to rotate via the first ring gear assembly, and a second planetary gear assembly mechanically engaged to the second sun gear assembly and the second ring gear assembly.

[0006] In the second example, according to Example 1, the rotary lock assembly further includes: a lock key configured for radial displacement between a first lock key configuration and a second lock key configuration; and a lock rotor configured to rotate via a second planetary gear assembly between a first rotor configuration that prevents the lock key from radially displacing from the first lock key configuration to the second lock key configuration and a second rotor configuration that allows the lock key to radially displacing from the first lock key configuration to the second lock key configuration.

[0007] In the third example, according to Example 2, the rotary lock assembly further includes: a first locking rotor stop configured to prevent the locking rotor from rotating in a first direction under a first rotor configuration; and a second locking stop configured to prevent the locking rotor from rotating in a second direction under a second rotor configuration.

[0008] In the fourth example, according to example 2 or 3, the rotary lock assembly further includes a key holder configured to move linearly between a first key holder configuration that prevents the key from radially shifting from the second key configuration to the first key configuration and a second key holder configuration that allows the key to radially shift from the second key configuration to the first key configuration.

[0009] In the fifth example, according to any one of Examples 2 to 4, the rotary lock assembly further includes a linear output assembly configured to move axially relative to the radial movement of the lock key, and having an outer surface defining a groove between a first axial groove surface and a second axial groove surface, and configured to receive the lock key in the first lock key configuration, and prevented from moving linearly based on mechanical interference between the lock key and at least one of the first axial groove surface and the second axial groove surface.

[0010] In the sixth example, according to any one of Examples 1 to 5, the rotary lock assembly further includes: a screw lead that engages with the first planetary gear assembly and responds to rotation of the first planetary gear assembly; and a nut that engages with the screw lead and is axially movable along the screw lead in response to rotation of the screw lead.

[0011] In the seventh example, according to any one of Examples 1 to 6, the rotary lock assembly further includes: a housing engaged with a second ring gear assembly; and an input shaft coupled to a first sun gear assembly and rotatable relative to the housing.

[0012] In the eighth example, according to any of Examples 1 to 7, the second ring gear assembly is configured to remain stationary relative to the motion of the second sun gear assembly.

[0013] In the ninth example, a method for locking a linear actuator includes: receiving torque at a first sun gear of a first planetary gear assembly; transmitting torque from the first sun gear to a first ring gear of the first planetary gear assembly via a first planetary gear assembly of the first planetary gear assembly; transmitting torque from the first planetary gear assembly to a screw; actuating a linear output component by a nut configured for linear movement based on the rotation of the screw; transmitting torque from the first ring gear to a second sun gear of a second planetary gear assembly; and transmitting torque from the second sun gear to a second planetary gear engaged between the second sun gear and the second ring gear.

[0014] In the tenth example, according to Example 9, the method further includes driving the lock key radially from the first lock key configuration to the second lock key configuration based on the linear movement of the linear output component.

[0015] In the eleventh example, according to Example 10, the method further includes: contacting a locking key with an axial groove surface of a groove based on movement of a linear actuator, the groove being defined in a linear output member and configured to receive a locking key in a first locking key configuration; preventing linear movement of the linear output member based on interference between the locking key and the axial groove surface; preventing rotation of a screw based on the prevented linear movement of the linear output member; preventing rotation of a first planetary gear assembly based on the prevented rotation of the screw; and transmitting substantially all of the torque received at the first sun gear to the first ring gear.

[0016] In the twelfth example, according to any one of Examples 9 to 11, the method further includes: transmitting torque from the second planetary gear to the lock rotor; and rotating the lock rotor from the first lock rotor configuration to the second lock rotor configuration.

[0017] In the thirteenth example, according to Example 12, the first locking rotor configuration is a first rotational position defined by a first locking rotor end stop configured to interfere with the rotation of the locking rotor in a first direction, and the second locking rotor configuration is a second rotational position defined by a second locking rotor end stop configured to interfere with the rotation of the locking rotor in a second direction opposite to the first direction.

[0018] In the fourteenth example, according to Example 12 or 13, the lock rotor is configured to prevent the lock key from radially shifting from the first key structure to the second key structure under the first lock rotor configuration, and is configured to allow the lock key to radially shift from the first key structure to the second key structure under the second lock rotor configuration.

[0019] In the fifteenth example, a linear actuator includes: a housing; a rotary input member rotatably movable relative to the housing; a linear output member axially movable between a first output position relative to the housing and a second output position relative to the housing; and a rotary lock assembly disposed within the housing and constrained against axial movement, the rotary lock assembly including: a first planetary gear assembly including a first sun gear assembly, a first ring gear assembly, and a first planetary gear assembly mechanically engaged to the first sun gear assembly and the first ring gear assembly; and a second planetary gear assembly including a second sun gear assembly, a second ring gear assembly configured to rotate via the first ring gear assembly, and a second planetary gear assembly mechanically engaged to the second sun gear assembly and the second ring gear assembly.

[0020] In the sixteenth example, according to Example 15, the rotary lock assembly further includes: a lock key configured for radial displacement between a first lock key configuration and a second lock key configuration; and a lock rotor configured to rotate via a second planetary gear assembly between a first rotor configuration that prevents the lock key from radially displacing from the first lock key configuration to the second lock key configuration and a second rotor configuration that allows the lock key to radially displacing from the first lock key configuration to the second lock key configuration.

[0021] In the seventeenth example, according to Example 16, the rotary lock assembly further includes: a first locking rotor stop configured to prevent the locking rotor from rotating in a first direction in a first rotor configuration; and a second locking stop configured to prevent the locking rotor from rotating in a second direction in a second rotor configuration.

[0022] In the eighteenth example, according to example 16 or 17, the rotary lock assembly further includes a key holder configured to move linearly between a first key holder configuration that prevents the key from radially shifting from the second key configuration to the first key configuration and a second key holder configuration that allows the key to radially shift from the second key configuration to the first key configuration.

[0023] In the nineteenth example, according to any one of Examples 16 to 18, the rotary lock assembly further includes a linear output assembly configured to move axially relative to the radial movement of the lock key, and having an outer surface defining a groove between a first axial groove surface and a second axial groove surface, and configured to receive the lock key in the configuration of the first lock key, and prevented from moving linearly based on mechanical interference between the lock key and at least one of the first axial groove surface and the second axial groove surface.

[0024] In the twentieth example, according to any one of Examples 15 to 19, the rotary lock assembly further includes: a screw guide that engages with and responds to rotation of the first planetary gear assembly; and a nut that engages with the screw guide and is axially movable along the screw guide in response to rotation of the screw guide.

[0025] In the twenty-first example, according to any one of Examples 15 to 20, the rotary lock assembly further includes: a housing engaged with a second ring gear assembly; and an input shaft coupled to a first sun gear assembly and rotatable relative to the housing.

[0026] In the twenty-second example, according to any of Examples 15 to 21, the second ring gear assembly is configured to remain stationary relative to the motion of the second sun gear assembly.

[0027] In an example embodiment, a rotary lock assembly includes: a first rotary gear assembly having a first sun gear assembly, a first ring gear assembly, and a first planetary gear assembly mechanically engaged to the first sun gear assembly and the first ring gear assembly; and a second rotary gear assembly having a second sun gear assembly, a second ring gear assembly configured to rotate via the first ring gear assembly, and a second planetary gear assembly mechanically engaged to the second sun gear assembly and the second ring gear assembly.

[0028] Various embodiments may include some, all, or none of the following features. The rotary lock assembly may further include: a locking key configured for radial displacement between a first locking key configuration and a second locking key configuration; and a locking rotor configured to rotate via a second planetary gear assembly between a first rotor configuration that prevents radial displacement of the locking key from the first locking key configuration to the second locking key configuration and a second rotor configuration that allows radial displacement of the locking key from the first locking key configuration to the second locking key configuration. The rotary lock assembly may further include: a first locking rotor stop configured to prevent rotation of the locking rotor in a first direction under the first rotor configuration; and a second locking stop configured to prevent rotation of the locking rotor in a second direction under the second rotor configuration. The rotary lock assembly may further include a locking key holder configured to move linearly between a first locking key holder configuration that prevents radial displacement of the locking key from the second locking key configuration to the first locking key configuration and a second locking key holder configuration that allows radial displacement of the locking key from the second locking key configuration to the first locking key configuration. The rotary lock assembly can also include a linear output assembly configured for axial movement relative to the radial movement of the lock key, and having an outer surface defining a groove between a first axial groove surface and a second axial groove surface, and configured to receive the lock key in the configuration of the first lock key, and prevented from linear movement based on mechanical interference between the lock key and at least one of the first and second axial groove surfaces. The rotary lock assembly can also include: a screw guide that engages with and responds to rotation of the first planetary gear assembly; and a nut that engages with the screw guide and is axially movable along the screw guide in response to rotation of the screw guide. The rotary lock assembly can also include: a housing that engages with a second ring gear assembly; and an input shaft that is coupled to a first sun gear assembly and is rotatable relative to the housing. The second ring gear assembly can be configured to remain stationary relative to the movement of the second sun gear assembly.

[0029] In an example implementation, a method for locking a linear actuator includes: receiving torque at a first sun gear of a first planetary gear assembly; transmitting torque from the first sun gear to a first ring gear of the first planetary gear assembly via a first planetary gear assembly of the first planetary gear assembly; transmitting torque from the first planetary gear assembly to a screw; actuating a linear output component by means of a nut configured for linear movement based on the rotation of the screw; transmitting torque from the first ring gear to a second sun gear of a second planetary gear assembly; and transmitting torque from the second sun gear to a second planetary gear engaged between the second sun gear and the second ring gear.

[0030] Various embodiments may include some, all, or none of the following features. The method may also include radially displacing a locking key from a first locking key configuration to a second locking key configuration based on linear movement of the linear output member. The method may also include: contacting the locking key with an axial groove surface of a groove defined in the linear output member and configured to receive the locking key in the first locking key configuration based on movement of the linear actuator; preventing linear movement of the linear output member based on interference between the locking key and the axial groove surface; preventing rotation of the screw based on the prevented linear movement of the linear output member; preventing rotation of the first planetary gear assembly based on the prevented rotation of the screw; and transmitting substantially all of the torque received at the first sun gear to the first ring gear. The method may also include: transmitting torque from the second planetary gear to the locking rotor; and rotating the locking rotor from the first locking rotor configuration to the second locking rotor configuration. The first locking rotor configuration can be a first rotational position defined by a first locking rotor end stop configured to interfere with the rotation of the locking rotor along a first direction, and the second locking rotor configuration can be a second rotational position defined by a second locking rotor end stop configured to interfere with the rotation of the locking rotor along a second direction opposite to the first direction. The locking rotor can be configured to prevent the locking key from radially shifting from the first key configuration to the second key configuration in the first locking rotor configuration, and configured to allow the locking key to radially shift from the first key configuration to the second key configuration in the second locking rotor configuration.

[0031] In another example embodiment, the linear actuator includes: a housing; a rotary input member rotatably movable relative to the housing; a linear output member axially movable between a first output position relative to the housing and a second output position relative to the housing; and a rotary lock assembly disposed within the housing and constrained against axial movement, the rotary lock assembly having: a first planetary gear assembly including a first sun gear assembly, a first ring gear assembly, and a first planetary gear assembly mechanically engaged to the first sun gear assembly and the first ring gear assembly; and a second planetary gear assembly including a second sun gear assembly, a second ring gear assembly configured to rotate via the first ring gear assembly, and a second planetary gear assembly mechanically engaged to the second sun gear assembly and the second ring gear assembly.

[0032] Various embodiments may include some, all, or none of the following features. The rotary lock assembly may further include: a locking key configured for radial displacement between a first locking key configuration and a second locking key configuration; and a locking rotor configured to rotate via a second planetary gear assembly between a first rotor configuration that prevents radial displacement of the locking key from the first locking key configuration to the second locking key configuration and a second rotor configuration that allows radial displacement of the locking key from the first locking key configuration to the second locking key configuration. The rotary lock assembly may further include: a first locking rotor stop configured to prevent rotation of the locking rotor in a first direction under the first rotor configuration; and a second locking stop configured to prevent rotation of the locking rotor in a second direction under the second rotor configuration. The rotary lock assembly may further include a locking key holder configured to move linearly between a first locking key holder configuration that prevents radial displacement of the locking key from the second locking key configuration to the first locking key configuration and a second locking key holder configuration that allows radial displacement of the locking key from the second locking key configuration to the first locking key configuration. The rotary lock assembly can also include a linear output assembly configured for axial movement relative to the radial movement of the lock key, and having an outer surface defining a groove between a first axial groove surface and a second axial groove surface, and configured to receive the lock key in the configuration of the first lock key, and prevented from linear movement based on mechanical interference between the lock key and at least one of the first and second axial groove surfaces. The rotary lock assembly can also include: a screw guide that engages with and responds to rotation of the first planetary gear assembly; and a nut that engages with the screw guide and is axially movable along the screw guide in response to rotation of the screw guide. The rotary lock assembly can also include: a housing that engages with a second ring gear assembly; and an input shaft that is coupled to a first sun gear assembly and is rotatable relative to the housing. The second ring gear assembly can be configured to remain stationary relative to the movement of the second sun gear assembly.

[0033] The system and technology described herein can provide one or more of the following advantages. First, the system is able to lock the linear actuator to prevent unintentional extension. Second, the system is able to provide more reliable unlocking operation, especially under conditions of high mechanical load on the linear actuator. Third, the system is able to automatically provide the additional torque required to perform unlocking. Fourth, the system is able to provide additional torque in the absence of additional control or power input.

[0034] Details of one or more embodiments are set forth in the accompanying drawings and in the description below. Other features and advantages will be apparent from the description and drawings and from the claims. Attached Figure Description

[0035] Figure 1 A front perspective view of an example linear actuator is shown.

[0036] Figure 2 and Figure 3 A cross-sectional view of an example locked rotary actuator mechanism in a locked configuration is shown.

[0037] Figure 4 A cross-sectional view of an example locked rotary actuator mechanism in a partially unlocked configuration is shown.

[0038] Figure 5 and Figure 6 A cross-sectional view of an example locked rotary actuator mechanism in an unlocked configuration is shown.

[0039] Figure 7A and Figure 7B The example lock key is shown in the front perspective view and cross-sectional view.

[0040] Figure 8 A cross-sectional view of an example locking rotary actuator mechanism is shown.

[0041] Figure 9 Another cross-sectional view of an example locking rotary actuator mechanism is shown.

[0042] Figure 10 Another cross-sectional view of an example locking rotary actuator mechanism is shown.

[0043] Figure 11 Show Figure 1 Another cross-sectional view of an example linear actuator.

[0044] Figure 12 A flowchart is shown for an example process of operating a linear actuator. Detailed Implementation

[0045] This document describes a system and technique for providing rotational to linear motion using an actuator device that can be locked to prevent unintentional movement. Some previous locking designs are limited in the amount of tensile load that can be applied to the actuator head, while still allowing the lock key to unlock. The design described in this document provides the ability to unlock the actuator under high tensile loads generated by a thrust reverser of the latest technology. As will be discussed in more detail below, the actuator includes the feature of automatically redirecting the input torque when needed to overcome restraint or lock the member under high input forces. Generally, the actuator's rotational to linear conversion function is achieved using a multi-stage planetary gearbox, wherein one stage drives the rotation to linear conversion, and the resistance to this conversion drives a second stage to perform the unlocking action. The second stage is geared to provide increased torque to perform the unlocking, which is helpful in situations where high linear forces may cause the locking member to become restrained or otherwise difficult to unlock.

[0046] Figure 1 The figure shows a front perspective view of an example linear actuator 100 that incorporates aspects of the disclosed embodiments. The actuator 100 has a housing 104 and an output pressure head 108 (e.g., a linear output assembly). The output pressure head 108 is axially movable or retractable (depicted by directional arrow 110) into and out of the housing 104, such as from... Figure 1 The retracted output position is shown. In some embodiments, the linear actuator 100 can be part of a thrust reverser actuation system (TRAS). As a non-limiting example, the pressure head 108 can be attached to a door, panel, or engine thrust reverser, while the housing 104 is attached to the frame of a larger object such as, but not limited to, an aircraft. Movement of the pressure head 108 thereby determines the position of the door, panel, thrust reverser, or other attached surface.

[0047] Within housing 104, an actuator (not shown) drives the extension and retraction of the output pressure head 108 based on rotational energy received from a synchronous shaft (not shown) connected to the actuator via apertures 122a and / or 122b. This actuator will... Figure 2-6 The description is more detailed in the description. In some embodiments, the linear actuator 100 may also include a sensor configured to provide a position signal or information representing the linear output position (e.g., extension or retraction) of the output head 108.

[0048] When the output pressure head 108 retracts into the housing 104, the locking rotary actuator mechanism 120 can be locked to prevent the pressure head 108 from accidentally or unintentionally extending from the housing 104. The locking rotary actuator mechanism 120 for the linear actuator 100 is discussed in more detail below.

[0049] Figure 2 and Figure 3 A cross-sectional view of an example locking rotary actuator mechanism 200 in a locked configuration is shown. In some embodiments, the locking rotary actuator mechanism 200 can be... Figure 1 Example of a locking rotary actuator mechanism 120.

[0050] The locking rotary actuator mechanism 200 includes a housing 202, a rotary input shaft assembly 204, and a linear output assembly 206. Rotation of the rotary input shaft assembly 204 (e.g., via a synchronous shaft, via a direct-drive motor) actuates the linear output assembly 106 via a rotary gear assembly 210, a rotary lock assembly 260, and a rotation-to-linear motion conversion assembly 280. The rotation-to-linear motion conversion assembly 280 includes a screw guide 282, which rotates via the rotary gear assembly 210; and a nut 284, which is engaged with the linear output assembly 206 and linearly driven as the screw guide 282 rotates.

[0051] The rotary lock assembly 260 includes a collection of lock keys 262 configured for radial displacement and configured to engage with a groove 264 defined in the radially outer surface of the linear output assembly 206. The groove 264 includes an axial groove surface 266a and an axial groove surface 266b. The axial groove surface 266b is configured with a ramp complementary to the ramp 263 of the lock key 262. In some embodiments, the ramp 263 is typically angled at approximately 25 degrees from the radially outward direction. When locked, the lock key 262 prevents the linear output assembly 206 from extending by contacting the axial groove surface 266b. A lock rotor 270 prevents radial outward movement of the lock key 262 from the locked position. The lock rotor 270 can be partially rotated to selectively prevent and allow radial movement of the lock key 262. Figure 11 This will be discussed in more detail in the description.

[0052] The rotary gear assembly 210 includes rotary gear subassemblies 212a and 212b. The screw guide 282 is rotated by the rotary input shaft component 204 via the rotary gear subassembly 212a. The lock rotor 270 is rotated by the rotary input shaft component 204 via the rotary gear assembly 212b.

[0053] The planetary gear subassembly 212a includes a sun gear assembly 220, a ring gear assembly 222, and a planetary gear assembly 224. The planetary gear subassembly includes a sun gear assembly 230, a ring gear assembly 232, and a planetary gear assembly 234. The ring gear assembly 232 is connected (e.g., grounded) to the housing 202 or otherwise prevented from rotating relative to the rotary input shaft component 204, the screw guide 282, and other components of the planetary gear assembly 210. The sun gear assembly 230 is connected to the ring gear assembly 222 or otherwise configured to be driven by rotation of the ring gear assembly 222. The planet carrier 225 connects the planetary gear assembly 224 to the screw guide 282 such that rotation of the planetary gear assembly 224 can drive rotation of the screw guide 282. The planet carrier 235 connects the planetary gear assembly 234 to the lock rotor 270 such that rotation of the planetary gear assembly 224 can drive rotation of the lock rotor 270.

[0054] The locking rotary actuator mechanism 200 employs a non-moving mechanism incorporating a rotary gear assembly 210, which operates as a star gear (e.g., a grounded planetary gear assembly 224, where the sun gear assembly 220 drives the ring gear assembly 222) during the unlocking process of the locking key 262, and then as a planetary gear (e.g., a grounded ring gear assembly 222, where the sun gear assembly 220 drives the planetary gear assembly 224). In some embodiments, this arrangement can provide the force for unlocking the lock as long as the tension load on the output pressure head 108 is not too large. This is because the tension load on the piston is reacted by the ramp 263 and the axial groove surface 266b into a radially outward force on the locking key 262. The tension load on the piston thus results in increased friction between the locking key 262 and the inner surface of the locking rotor 270. This friction counteracts the unlocking torque on the ring gear assembly 222 when the rotary gear subassembly 212a is operating in star (unlocked) mode.

[0055] Now for reference Figure 3 The example locking rotary actuator mechanism 200 is shown in its initial unlocked state. In the illustrated example, high tension exists on the linear output assembly 206. The high tensile load imposed on the linear output assembly 206 during the unlocking process (e.g., by an advanced technology thrust reverser) generates friction between the locking key 262 and the locking rotor 270, high enough to prevent the locking rotor 270 from rotating during the unlocking process. Such friction can prevent unlocking in some cases without the aid of additional mechanical force provided by the rotary gear subassembly 212b.

[0056] With the linear output assembly 206 locked, operation of the rotation to the linear motion conversion assembly 280 is substantially prevented, and rotation of the screw guide 282 is also substantially prevented. Consequently, movement of the planetary carrier 225 and the planetary gear assembly 224 is also substantially prevented. Thus, the carrier 225 of the planetary gear assembly 224 is substantially grounded.

[0057] Rotary input shaft component 204 is rotated, which drives the rotation of sun gear assembly 220. Substantially all the torque provided by sun gear assembly 220 is transmitted to ring gear assembly 222 via planetary gear assembly 224 (e.g., currently grounded). Ring gear assembly 222 rotates, thereby driving the rotation of sun gear assembly 230.

[0058] Since the ring gear assembly 232 is grounded to the housing 202, the rotation of the sun gear assembly 230 drives the rotation of the planetary gear assembly 234. The rotation of the planetary gear assembly 234 is transmitted along the planet carrier 235 to drive the rotation of the lock rotor 270. In the illustrated example, substantially all the torque provided at the rotary input shaft assembly 204 is transmitted to the lock rotor 270, and the planetary gear subassembly 212b provides a gear reduction that multiplies the force available to overcome friction between the lock key 262 and the lock rotor 270.

[0059] Figure 4 A cross-sectional view of an example locking rotary actuator mechanism 200 in a partially unlocked configuration is shown. Once the friction between the locking key 262 and the locking rotor 270 has been overcome, the locking rotor 270 can begin to rotate, allowing the locking key 262 to move radially outward. As the locking key 262 can move, the linear output assembly 206 and the rotation-to-linear motion conversion assembly 280 can also begin to move.

[0060] As the screw guide 282 can rotate, the planet carrier 225 and the planetary gear assembly 224 can also begin to rotate. At this stage, a relatively small portion of the torque at the sun gear assembly 220 can be transmitted through the planetary gear assembly 224 and the planet carrier 225 to initiate the initial rotation of the screw guide 282 and cause the initial extension movement of the linear output assembly 206. The movement of the linear output assembly 206 causes mechanical interference between the axial groove surface 266b and the inclined surface 263, which pushes the locking key 262 radially outward.

[0061] The key retainer 290 is also included. Figure 4 As can be seen, the key retainer 290 is configured to move linearly between a first key retainer configuration that prevents the key 262 from radially shifting from the unlocked position to the locked position and a second key retainer configuration that allows the key 262 to radially shift from the unlocked position to the locked position. The key retainer 290 includes a stationary portion 292, which is directly or indirectly attached to the housing 202 to remain substantially stationary relative to the movement of the linear output assembly 206. The key retainer 290 also includes a movable portion 294 configured to move linearly relative to the stationary portion 292. The key retainer 290 also includes a biasing member 296 (e.g., a spring) partially compressed between the stationary portion 292 and the movable portion 294 to push the movable portion 294 into contact with the linear output assembly 206. In the illustrated example, the key retainer 290 is compressed and inactive, but the function of the key retainer 290 will... Figure 5 Further discussion will follow in the description.

[0062] Figure 5 and Figure 6A cross-sectional view of an example locking rotary actuator mechanism 200 in an unlocked configuration is shown. The locking rotor 270 is configured to rotate through a limited, predetermined angular range (e.g., approximately 15 degrees) between a hard stop at a position corresponding to the locking configuration (e.g., where the locking key 262 can be fully disengaged from the groove 264) and another hard stop at a position corresponding to the fully unlocked configuration (e.g., where the locking key 262 is prevented from disengaging from the groove 264). The locking rotor 270 is configured in… Figure 11 This will be discussed in more detail in the description.

[0063] exist Figure 5 In this configuration, the locking rotor 270 is hard-stopped at a position corresponding to the unlocking mechanism. The hard stop prevents further rotation of the locking rotor 270, thereby essentially grounding the locking rotor 270 and preventing further rotation of the planetary carrier 235, planetary gear assembly 234, sun gear assembly 230, and ring gear assembly 222. With the ring gear assembly 222 effectively grounded, substantially all the torque provided at the rotary input shaft component 204 is directed through the planetary gear assembly 224 and planetary carrier 225 to the screw guide 282 to drive the linear output assembly 206 to extend. The linear output assembly 206 can extend as the locking key 262 completely disengages from the recess 264.

[0064] As the linear output assembly 206 extends to its output position, the biasing member 296 expands between the stationary portion 292 and the movable portion 294, thereby pushing the movable portion 294 to follow the linear output assembly 206 as it extends. The movable portion 294 provides a radial surface that substantially extends the outermost radial surface of the linear output assembly 206. As the linear output assembly 206 extends past the axial output position portion of the locking key 262, the movable portion 294 moves to provide a physical barrier that holds the locking key 262 in a radially extended unlocked position.

[0065] exist Figure 6 As the locking key 262 remains in its unlocked position, the linear output assembly 206 continues to extend. Retraction of the linear output assembly 206 is performed by reversing the rotation of the rotary input shaft assembly 204, causing the linear output assembly 206 to return to contact with the movable portion 294, thereby compressing the biasing member 296 and allowing the locking key 262 to move radially outward from the unlocked position toward the locking configuration within the recess 264. Once the linear output assembly 206 is fully retracted, the sun gear assembly 230 is effectively grounded, and torque is directed toward the locking rotor 270 toward the locked position. The locking rotor 270 is configured to push the locking key 262 radially inward into the recess 264 and prevent radial displacement of the locking key 262 (e.g., due to tension on the linear output assembly 206).

[0066] Figure 7A and Figure 7B The diagram shows a front perspective view and a cross-sectional view of an example lock key 700. In some embodiments, the lock key 700 can be... Figure 2-6 Example lock key 262. Lock key 700 has a front 702 and a rear 704. Rear 704 includes a bevel 706 (e.g., angled at approximately 25 degrees relative to the rear). In some embodiments, bevel 706 can be bevel 263. In the locking configuration, bevel 706 contacts an axially recessed surface 266b to prevent the linear output assembly 206 from extending.

[0067] The locking key 700 has a bottom surface 710 configured to rest against the linear output assembly 206 in the locked configuration and against the movable portion 294 of the locking key holder 290 in the unlocked configuration. The bottom surface 710 includes ramps 712a and 712b capable of guiding the locking key 700 radially inward (e.g., to a locked position within the recess 264).

[0068] The locking key 700 also has a crown 720 configured to contact the locking rotor 270. In the locked configuration, the top surface 722 of the crown contacts the inner radius of the locking rotor 270 to hold the locking key in a radially inward locking configuration. In the unlocked configuration, the crown 720 extends into a corresponding radially outward recess in the locking rotor, which is rotatable to be radially aligned with and rotate out of radial alignment with the crown 720.

[0069] The crown 720 includes a radial face 724a and a radial face 724b. During locking, the locking rotor 270 rotates relative to the locking key 700, and the radial faces 724a-724b act as ramps against the circumferential ends of the locking rotor recess to push the locking key 700 radially inward into the locking configuration.

[0070] Figure 8-11 An exemplary embodiment of the lock assembly 800 is depicted. In some embodiments, the lock assembly 800 may be... Figure 2-6 Example rotary lock assembly 260. Lock assembly 800 includes a rotary gear assembly, such as example rotary gear subassembly 212b.

[0071] The sun gear 840 of the planetary gear arrangement (e.g., example sun gear assembly 230) can provide mechanical drive input to the gear assembly, and the planet carrier 852 connects the screw guide (e.g., screw guide 282) to the planet gear 844 to provide energy to extend and retract the linear output assembly 206. The outer diameter of the ring gear 848 of the planetary gear arrangement ( Figure 9 and Figure 10The annular portion shown can be nested in the bearing race and directly attached to the rotor via the rotor extension 856. Figure 11 The lock rotor 816 (e.g., lock rotor 270) is visible in the image. In operation, the ball screw acts as a drive, and the linear output component moves axially in response to the rotation of the ball screw.

[0072] In an exemplary embodiment, rotating the lock rotor 816 to move it to the unlocked position can be provided by the rotary gear assembly initially operating in a mode known as a "star" mode during the inactive motion stroke. (See reference...) Figure 9 The rotor extension 856 (which is coupled to the ring gear 848) acts as a key engaging the radial slot 860, which defines a rotational end stop for the lock rotor 816 from the locked position to the unlocked position. In some embodiments, a torsion spring may be included to directly bias the lock rotor 816 to the locked position.

[0073] In use, energy is input (e.g., via a motor) to the sun gear assembly 230 to extend the linear output assembly 206. Since the linear output assembly 206 is constrained by a set of locking keys 820 (e.g., locking key 262) to prevent any axial movement or movement, the screw guide 282 cannot cause the linear output assembly 206 to rotate and advance. Therefore, the planetary carrier 852 is locked until an invalid movement unlocks the locking key 820. Accordingly, the only response to a rotational input from the sun gear 840 is to rotate the ring gear 848 coupled to the locking rotor 816. Unlocking the locking key 820 in response to the rotation of the locking rotor 816 mechanically coincides with the rotor extension 856 bottoming out in the slot 860. Botting the rotor extension 856 out of the slot 860 and unlocking the locking key 820 results in locking the ring gear 848 and releasing the planetary carrier 852, allowing the planetary gear 844 to rotate around the sun gear 840. Therefore, the arrangement of the planetary gears changes from a star configuration (fixed planetary carrier 852, free sun gear 840, and free annular portion 848) to a planetary configuration (fixed annular portion 848, free sun gear 840, and free planetary carrier 852). In the planetary configuration, the energy input to the sun gear 840 causes the planetary gear 844 to rotate around the sun gear 840 and drives the planetary carrier 852, which in turn drives the screw guide 282, thereby causing the linear output assembly 206 to move axially via the nut 284.

[0074] To retract the linear output assembly 206 and rotate the locking rotor 816 to the locked position, the process is reversed. The motor driving the sun gear 840 reverses the direction. The ring gear 848 reverses the load direction and attempts to rotate the locking rotor 816 from the unlocked position to the locked position. However, the locking key 820 is constrained by the locking key holder 290 into a retracted position within the groove 838 of the locking rotor 816, thereby preventing any rotation of the locking rotor 816. This effectively locks the ring gear 848 (e.g., via the rotor extension 856) and defines the cycle pattern. Therefore, the input rotation of the sun gear 840 is transmitted to the planetary carrier 852, which causes the screw guide 282 to rotate and retract the linear output assembly 206.

[0075] In response to the linear output assembly 206 reaching its fully retracted position, the locking key holder 290 is pushed out of the path (axially) by the linear output assembly 206, and the locking key 820 aligns with the recess 264 in the linear output assembly 206. In response to the linear output assembly 206 being fully retracted and thus no longer capable of any further axial movement, the screw guide 282 (and therefore the planetary carrier 852) is locked, and the planetary gear arrangement transitions from a planetary configuration to a star configuration. This now allows the locking rotor 816 to rotate from the unlocked position to the locked position, thereby pushing the locking key 820 radially inward into the recess 264, thus relocking the linear output assembly 206.

[0076] It will be appreciated that the output rotation direction of the ring gear 848 and locking rotor 816 during the inactive motion stroke (e.g., star mode) is opposite to the output rotation direction of the planetary carrier 852 and screw guide 282 during the extension of the linear output assembly 206 (e.g., planetary mode). This is a fundamental characteristic of planetary gears operating in both star and planetary modes. This inactive motion characteristic results in a design that is self-locking and self-unlocking, requiring no additional commands or signals other than the drive torque.

[0077] To improve clarity, as described herein and... Figure 8 Additional cross-sectional view of the lock assembly 800 shown in the figure. Figure 9 Depicting Figure 8 The cross-sectional view of the circumferential arrangement shown includes a sun gear 840, a planetary gear 844, a ring gear 848, and a planet carrier 852. Figure 10 Depicting Figure 8 The cross-sectional view of the circumferential arrangement shown includes a ring gear 848, a planetary carrier 852, and a rotor extension 856. Figure 11 A cross-sectional view of the lock rotor 816 is depicted, with the lock key 820 in the locked position.

[0078] like Figure 11 As shown, the locking rotor 816 is coaxially disposed with the linear output assembly 206 and includes a bore 828 having an inner surface 817 that interfaces with the crown 832 of the locking key 820. The locking ring 836 is grounded (e.g., fixed relative to the housing) and includes a groove 838 that guides and constrains the displacement of the locking key 820 to radial motion. In an exemplary embodiment, when the locking key 820 engages with the radial groove 824, the inner radius of the bore 828 will be approximately equal to the outer radius of the crown 832. In use, in response to the locking rotor 816 being disposed on... Figure 2 and Figure 3 In the locked position, the bore 828 is connected to the crown 832 of the locking key 820 via an interface, and the locking key 820 is prevented from making any outward radial movement (e.g., such as...). Figure 4 (The locking key movement is illustrated in the figure). Therefore, the locking key 820 engages the groove 824 of the linear output assembly 206 by rotating the input shaft component 204 and is held or retained within the groove 824 of the linear output assembly 206.

[0079] Figure 12 A flowchart illustrating an example process 1200 for operating a linear actuator is shown. In some embodiments, process 1200 can be performed by... Figure 1 Example linear actuator 100 and / or Figure 2-6 The example locks all or part of the rotary actuator mechanism 200.

[0080] At 1210, torque is received at the first sun gear of the first planetary gear assembly. For example, torque from the rotary input shaft component 204 can be received at the sun gear assembly 220.

[0081] At 1220, torque is transmitted from the first sun gear to the first ring gear of the first planetary gear assembly via the first planetary gear assembly of the first planetary gear assembly. For example, torque can be transmitted from the sun gear assembly 220 to the ring gear assembly 222 via the planetary gear assembly 224.

[0082] At 1230, torque is transmitted from the first planetary gear assembly to the screw. For example, rotation of the planetary gear assembly 224 can drive the screw guide 282 to rotate through the planet carrier 225.

[0083] At 1240, the movement of the linear output component is actuated by a nut configured for linear movement based on the rotation of a screw. For example, rotation of the screw guide 282 relative to the nut 284 can actuate the linear output assembly 206 to move linearly.

[0084] 1250, torque is transmitted from the first ring gear to the second sun gear of the second planetary gear assembly. For example, rotation of the ring gear assembly 222 can drive rotation of the sun gear assembly 230.

[0085] At 1260, torque is transmitted from the second sun gear to the second planetary gear engaged between the second sun gear and the second ring gear. For example, torque applied to the sun gear assembly 230 can be transmitted to the planetary gear assembly 234, which is engaged between the sun gear assembly 230 and the ring gear assembly 232.

[0086] In some embodiments, process 1200 may also include radially displacing the lock key from a first lock key configuration to a second lock key configuration based on linear movement of the linear output component. For example, the lock rotor 270 may be moved from a locked rotation position to an unlocked rotation position, which may allow the lock key 262 to move radially outward from the locked configuration to the unlocked configuration.

[0087] In some embodiments, process 1200 may further include contacting a locking key with an axial groove surface of a recess defined in the linear output member and configured to receive the locking key in a first locking key configuration based on movement of the linear actuator. In the first configuration, the locking key can prevent linear movement of the linear output member based on mechanical interference between the locking key and the axial groove surface, and can prevent rotation of the screw based on the prevented linear movement of the linear output member. With rotation of the screw prevented, rotation of the first planetary gear assembly is also prevented based on the prevented rotation of the screw, which can cause substantially all torque received at the first sun gear to be transmitted to the first ring gear. For example, the linear output member 206 can contact the locking key 262 in the recess 264 to prevent further axial movement of the linear output member 206. With movement of the linear output member 206 stopped, rotation of the screw guide 282, the sun gear assembly 230, and the planet carrier 225 stops. With movement of the planet carrier 225 prevented, substantially all torque from the sun gear assembly 220 is transmitted to the ring gear assembly 222.

[0088] In some embodiments, process 1200 may further include: transmitting torque from the second planetary gear to the lock rotor; and rotating the lock rotor from a first lock rotor configuration to a second lock rotor configuration. For example, movement of the planetary gear assembly 234 may be transmitted to the lock rotor 270 via the planet carrier 235.

[0089] In some embodiments, the first locking rotor configuration may be a first rotational position defined by a first locking rotor end stop configured to mechanically interfere with rotation of the locking rotor in a first direction, and the second locking rotor configuration may be a second rotational position defined by a second locking rotor end stop configured to mechanically interfere with rotation of the locking rotor in a second direction opposite to the first direction. For example, an example radial slot 860 may define a rotational end stop for the locking rotor 816 from a locked position to an unlocked position.

[0090] In some embodiments, the locking rotor can be configured to prevent the locking key from radially shifting from the first key structure to the second key structure in the first locking rotor configuration, and configured to allow the locking key to radially shift from the first key structure to the second key structure in the second locking rotor configuration. For example, Figure 11 The lock rotor 816 is shown to include a groove 838 that guides the lock key 820 and constrains its displacement to radial movement. In response to the lock rotor 816 being positioned in... Figure 2 and Figure 3 In the locked position, the bore 828 can be connected to the crown 832 of the locking key 820 via an interface, and the locking key 820 can be prevented from making any outward radial movement (e.g., such as...). Figure 4 (The locking key movement is illustrated in the figure). Therefore, the locking key 820 engages with and is held or retained within the groove 824 of the linear output assembly 206 by rotating the input shaft component 204. When the locking rotor 816 is rotated such that the groove 838 is radially aligned with the crown 832, the locking key 820 has sufficient space to move radially outward, disengaging from contact with the linear output assembly 206 (and thus unlocking).

[0091] Although several embodiments have been described in detail above, other modifications are possible. For example, the logical flow depicted in the figures does not require the specific order or sequence shown to achieve the desired result. Additionally, other steps may be provided, or steps may be excluded from the described flow, and other components may be added to or removed from the described system. Therefore, other embodiments are within the scope of the following claims.

Claims

1. A method for locking a linear actuator, the method comprising: Torque is received at the first sun gear of the first rotating gear assembly; Torque is transmitted from the first sun gear to the first ring gear of the first planetary gear assembly via the first planetary gear assembly of the first planetary gear assembly. Torque is transmitted from the first planetary gear assembly to the screw; The linear output component is moved by a nut configured to move linearly based on the rotation of the screw; The second sun gear transmits torque from the first ring gear to the second planetary gear assembly; and Torque is transmitted from the second sun gear to the second planetary gear that is engaged between the second sun gear and the second ring gear.

2. The method of claim 1, further comprising driving the locking key radially from the first locking key configuration to the second locking key configuration based on the linear movement of the linear output component.

3. The method according to claim 2, further comprising: The locking key is brought into contact with the axial groove surface of the groove based on the movement of the linear actuator, the groove being defined in the linear output member and configured to receive the locking key in the first locking key configuration; Linear movement of the linear output component is prevented by the interference between the locking key and the axial groove surface; The rotation of the screw is prevented based on the prevented linear movement of the linear output component; The rotation of the first planetary gear assembly is prevented based on the prevented rotation of the screw; and Essentially all the torque received at the first sun gear is transmitted to the first ring gear.

4. The method according to any one of claims 1 to 3, further comprising: Torque is transmitted from the second planetary gear to the lock rotor; and The locking rotor is rotated from the first locking rotor configuration to the second locking rotor configuration.

5. The method according to claim 4, wherein, The first locking rotor configuration is defined by a first locking rotor end stop configured to interfere with the rotation of the locking rotor in a first direction, and the second locking rotor configuration is defined by a second locking rotor end stop configured to interfere with the rotation of the locking rotor in a second direction opposite to the ... rotation position is defined by a second locking rotor end stop configured to interfere with the rotation of the locking rotor in a second direction opposite to the first direction.

6. The method according to claim 4, wherein, The locking rotor is configured to prevent the locking key from radially shifting from the first key configuration to the second key configuration under the first locking rotor configuration, and is configured to allow the locking key to radially shift from the first key configuration to the second key configuration under the second locking rotor configuration.

7. The method according to claim 5, wherein, The locking rotor is configured to prevent the locking key from radially shifting from the first key configuration to the second key configuration under the first locking rotor configuration, and is configured to allow the locking key to radially shift from the first key configuration to the second key configuration under the second locking rotor configuration.

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