Rotary locking actuator

Abstract

The subject matter of this specification may be embodied in, among other things, an epicyclic gear assembly having a sun gear assembly, a ring gear assembly, and a planetary gear assembly having a set of planetary gears, a rotary lock assembly includes a sun gear assembly having a set of planetary gears mechanically engaged to the sun gear assembly and the ring gear assembly, the planetary gear assembly further having a planet carrier mechanically engaged to the planetary gears and configured to be rotated by the planetary gears, the rotary lock assembly further including a lock rotor and a rotary output assembly, the lock rotor is configured to be rotated by the ring gear assembly, and the rotary output assembly is configured to be rotated by the planet carrier.

Description

[0001] Priority declaration

[0002] This application claims priority to U.S. Patent Application No. 17 / 811,458, filed on July 8, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present description relates to mechanically lockable rotary actuators and, more particularly, to rotary actuators having a positive engagement. Background Art

[0004] Conventional technology for locking a rotary actuator uses a motor brake to "lock" the rotary actuator. Motor brakes typically use a spring-loaded brake plate with solenoid actuation. However, conventional motor brake designs have known disadvantages. The motor brake is not a true lock because it has no form mechanical engagement (i.e., direct mechanical interference) with the rotor output shaft of the actuator. The motor brake also relies on the coefficient of friction between the plates. If the brake plate is contaminated with oil, water, dust, etc., the coefficient of friction may drop significantly. If the brake plate is contaminated, this can result in a loss of load carrying capacity.

[0005] Brakes are not suitable for applications where locking safety is critical, such as aircraft flight controls, landing gear actuation, thrust reversers, doors, etc. Many aircraft manufacturers' actuator specifications specifically prohibit the use of locking elements that rely on the coefficient of friction.

[0006] Alternatively, linear solenoid operated latch locks have been used to prevent the output shaft of a rotary actuator from rotating. Solenoid operated latch locks require control of the solenoid. In addition, linear solenoids have a relatively short stroke. As the solenoid stroke increases, the size of the solenoid coil increases exponentially, thereby adding weight that may be undesirable, especially in aerospace applications. Summary of the invention

[0007] In general, this document describes the automatic locking and unlocking of a rotary actuator with a form-fitting engagement.

[0008] In an overall example embodiment, a rotary lock assembly includes an epicyclic gear assembly, the epicyclic gear assembly having a sun gear assembly, a ring gear assembly and a planetary gear assembly, the planetary gear assembly having a set of planetary gears, the set of planetary gears being mechanically engaged to the sun gear assembly and the ring gear assembly, the planetary gear assembly also having a planet carrier, the planet carrier being mechanically engaged to the planetary gears and being configured to be rotated by the planetary gears, the rotary lock assembly also including a lock rotor and a rotary output assembly, the lock rotor being configured to be rotated by the ring gear assembly, and the rotary output assembly being configured to be rotated by the planet carrier.

[0009] Various embodiments may include some or all of the following features or exclude any of the following features. The rotation lock assembly may include a lock key, the lock key being configured to radially shift between a first lock key configuration and a second lock key configuration, wherein the lock rotor may be configured to be rotated by the ring gear assembly between the first lock rotor configuration and the second lock rotor configuration, in which the radial shift of the lock key from the first lock key configuration to the second lock key configuration is prevented, and in which the radial shift of the lock key from the first lock key configuration to the second lock key configuration is allowed. The rotation lock assembly may include a first lock rotor stopper and a second lock stopper, the first lock rotor stopper being configured to prevent the lock rotor from rotating in a first direction in the first lock rotor configuration, and the second lock stopper being configured to prevent the lock rotor from rotating in a second direction in the second lock rotor configuration. The rotary output assembly may be configured to rotate relative to the radial movement of the lock key, and has an outer surface defining a recess between a first rotating recess face and a second rotating recess face, and is configured to receive the lock key in the first lock key configuration and be prevented from rotating based on mechanical interference between the lock key and at least one of the first rotating recess face and the second rotating recess face. The rotary lock assembly may include a housing and a key guide, the key guide being grounded to the housing and having a radial groove, the radial groove being configured to provide radial guidance for radial displacement of the lock key and to prevent rotational movement of the lock key within the housing. The rotary lock assembly may include a biasing member, the biasing member being configured to bias the rotation of the lock rotor toward the first lock rotor configuration. The sun gear assembly may be configured to be rotated by a rotary power source. The ring gear assembly may include the lock rotor. The rotary lock assembly may include an electric motor, the electric motor being configured to cause rotation of the sun gear assembly.

[0010] In an overall example embodiment, a method of locking a linear actuator includes receiving torque at a sun gear assembly of an epicyclic gear assembly, transmitting the torque from the sun gear assembly to a ring gear assembly of the epicyclic gear assembly through a set of planetary gears of a planetary gear assembly of the epicyclic gear assembly, causing rotation of a lock rotor based on rotation of the ring gear assembly, causing rotation of a planet carrier by orbital motion of the planetary gears around the sun gear assembly, and transmitting the torque from the planet carrier to a rotational output assembly.

[0011] Various embodiments may include some or all of the following features or none of the following features. The method may include: causing radial displacement of the lock key from a first lock key configuration to a second lock key configuration based on rotational movement of the rotational output assembly. The method may include: contacting the lock key with a radial groove surface of a groove defined in the rotational output assembly and configured to receive the lock key in the first lock key configuration based on movement of the rotational output assembly; preventing rotational movement of the rotational output assembly based on interference between the lock key and the radial groove surface; preventing rotation of the planetary gear assembly based on the prevented rotational movement of the rotational output assembly; and transmitting substantially all of the torque received at the sun gear assembly to the ring gear assembly. The method may include: rotating the lock rotor from a first lock rotor configuration to a second lock rotor configuration. The first lock rotor configuration may be a first rotational position defined by a first lock rotor end stop configured to interfere with rotation of the lock rotor in a first direction, and the second lock rotor configuration may be a second rotational position defined by a second lock rotor end stop configured to interfere with rotation of the lock rotor in a second direction opposite to the first direction. The lock rotor may be configured to prevent radial displacement of the lock key from a first key configuration to a second key configuration in the first lock rotor configuration, and may be configured to allow radial displacement of the lock key from the first key configuration to the second key configuration in the second lock rotor configuration. The method may include providing torque at the sun gear assembly by an electric motor.

[0012] In another general embodiment, a rotary actuator includes: a housing; a rotary input member, which is rotatably movable relative to the housing; a rotary output member, which is rotatably movable between a first output position relative to the housing and a second output position relative to the housing; and a rotary lock assembly, which is disposed within the housing and is restricted from rotational movement, the rotary lock assembly having a first epicyclic gear assembly, the first epicyclic gear assembly having a sun gear assembly, a ring gear assembly and a planetary gear assembly, the planetary gear assembly having a set of planetary gears, the set of planetary gears being mechanically engaged to the sun gear assembly and the ring gear assembly, the planetary gear assembly also having a planet carrier, the planet carrier being mechanically engaged to the planetary gears and being configured to be rotated by the planetary gears; a lock rotor, the lock rotor being configured to be rotated by the ring gear assembly; and a rotary output assembly, the rotary output assembly being configured to be rotated by the planet carrier.

[0013] Various embodiments may include some or all of the following features or exclude any of the following features. The rotation lock assembly may include a lock key, the lock key being configured to radially shift between a first lock key configuration and a second lock key configuration, wherein the lock rotor may be configured to be rotated by the ring gear assembly between the first lock rotor configuration and the second lock rotor configuration, in which the radial shift of the lock key from the first lock key configuration to the second lock key configuration is prevented, and in which the radial shift of the lock key from the first lock key configuration to the second lock key configuration is allowed. The rotation lock assembly may include a first lock rotor stopper and a second lock stopper, the first lock rotor stopper being configured to prevent the lock rotor from rotating in a first direction in the first lock rotor configuration, and the second lock stopper being configured to prevent the lock rotor from rotating in a second direction in the second lock rotor configuration. The rotational output member may be configured to rotate relative to radial movement of the detent, and the rotational output member may include an outer surface defining a groove between a first radial groove surface and a second radial groove surface, and is configured to receive the detent in the first detent configuration and be prevented from rotating based on mechanical interference between the detent and at least one of the first radial groove surface and the second radial groove surface. The rotary actuator may include an electric motor configured to cause rotation of the sun gear assembly.

[0014] The systems and techniques described herein may provide one or more of the following advantages. First, the system may provide a rotary actuator with automatic locking and unlocking. Second, the system may implement locking and unlocking driven by the rotation of a motor without the need for electromechanical components. Third, the system may provide a form engagement that does not rely on friction. Fourth, the system may provide a configurable gear ratio between a rotary input and a rotary output.

[0015] The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features and advantages will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A longitudinal cross-sectional view of an example locking rotary actuator assembly is shown in a locked configuration.

[0017] Figure 2 Shows Figure 1 An axial cross-sectional view of an example locking rotary actuator assembly.

[0018] Figure 3 Shows Figure 1 Longitudinal cross-sectional view of an example locking actuator assembly during an unlocking process.

[0019] Figure 4 Shows Figure 3 An axial cross-sectional view of an example locking rotary actuator assembly.

[0020] Figure 5 A longitudinal cross-sectional view of an example locking actuator assembly is shown in an unlocked configuration.

[0021] Figure 6 Shows Figure 5 An axial cross-sectional view of an example locking rotary actuator assembly.

[0022] Figure 7 An example lock key is shown.

[0023] Figure 8 is a flow chart illustrating an example of a process for unlocking an example locking actuator assembly. DETAILED DESCRIPTION

[0024] This document describes systems and techniques for automatically locking and unlocking a rotary actuator with a form-fitting. The described systems and techniques do not rely on the coefficient of friction and do not require a separate lock actuating solenoid. In general, a mechanical locking mechanism is integrated into an epicyclic gearbox and is automatically activated and deactivated based on the torque transmitted through the gearbox. In very general terms, when the rotary output is locked and effectively retained, a torque from a rotary input (e.g., a motor) is transmitted to the rotary lock, rotating the lock into a hard stop in a position that allows unlocking. When the rotary lock is effectively retained in the unlocked position, the torque from the rotary input is transmitted to the unlocked rotary output.

[0025] Figure 1 A longitudinal cross-sectional view of an example locking rotary actuator assembly 100 in a locked configuration is shown. Assembly 100 includes a motor 101. In some embodiments, motor 101 may be an electric motor, a fluid motor, or any other suitable rotating input member or device that may provide torque and / or rotational motion. In the illustrated example, motor 101 is directly connected to sun gear assembly 110 by shaft 102 so that the motor may cause rotation of sun gear assembly 110. In some embodiments, motor 101 may be indirectly coupled to sun gear assembly 110. For example, motor 101 may drive shaft 102 and / or sun gear via a gearbox, a pulley system, a universal joint, a flexible shaft, a rack and pinion assembly, or any other suitable mechanism that may transmit torque, linear motion, and / or force to cause sun gear assembly 110 to rotate.

[0026] The sun gear assembly 110 is mechanically coupled to a planetary gear assembly 120, which includes a set of planet gears 122 and a planet carrier 124. For example, rotation of the sun gear assembly 110 may cause rotation of the planet gears 122, or it may cause the planet gears 122 to orbit around the sun gear rotating assembly 110 and cause rotation of the planet carrier 124, or a combination of both actions, as will be discussed in more detail below.

[0027] The planetary gear assembly 120 is mechanically coupled to the ring gear assembly 130. The ring gear assembly 130 is configured to rotate the lock rotor assembly 131 in response to the action of the planetary gear assembly 120. The ring gear assembly is configured to rotate through a predetermined range of motion (e.g., partial rotation) limited by hard stops (not shown) at predetermined clockwise positions and predetermined counterclockwise positions. When at the limit of rotational motion, the ring gear assembly 130 effectively becomes retained to prevent further movement in that direction, and substantially all of the torque from the motor 101 is transmitted to the rotation output assembly 140 through the planet carrier 124. Conversely, when the rotation output assembly 140 is retained, substantially all of the torque from the motor 101 is transmitted to the ring gear assembly 130 through the planetary gears 122. When neither the rotation output assembly 140 nor the ring gear assembly 130 is retained, the torque from the motor 101 is shared between the rotation output assembly 140 and the ring gear assembly 130, causing rotation of both.

[0028] Assembly 100 includes housing 150. In some embodiments, housing 150 is attached to sun gear assembly 110 and / or rotational output assembly 140 and is substantially mechanically retained relative to rotation of sun gear assembly 110 and / or rotational output assembly 140. Housing cover assembly 152 is removably attached to housing 150. Housing cover assembly 152 includes end caps 154 and key guide assembly 156. In some embodiments, end caps 154 can prevent foreign matter (e.g., loose parts, debris, fingers) from intruding into the internal working area of ​​assembly 100. Key guide assembly 156 will be discussed in more detail below.

[0029] The assembly 100 also includes a set of detents 160. The detents 160 are configured to move radially inwardly and outwardly relative to the rotational output assembly 140 to selectively lock and unlock the rotational output assembly 140 to selectively prevent and allow rotation of the rotational output assembly 140. In the illustrated configuration, the detents 160 are recessed in a set of recesses 142 defined in an outer surface 144 of the rotational output assembly 140. The operation and configuration of the detents 160 will be discussed in more detail below. The epicyclic gearbox formed by the sun gear assembly 110, the planetary gear assembly 120, the ring gear assembly 130, and the housing 150 combine to provide the functionality of the rotational lock assembly.

[0030] Figure 2 Shows that Figure 114. An axial cross-sectional view of an example locking rotary actuator assembly 100 in an example configuration shown in FIG. 14. In the illustrated example, a detent 160 is maintained in a recess 142 defined in an outer surface 144. Each of the recesses 142 is defined between a rotational recess face 146 and a rotational recess face 148 and provides space to accommodate partial radial insertion of a detent 160. A key guide assembly 156 includes a set of guide slots 158 defined as radial slots or holes (e.g., radial relative to the rotational output assembly 140) configured to provide radial guidance of movement of the detent 160. The guide slots 158 are sized to allow radial movement of the detent 160 but prevent rotational or orbital movement of the detent 160 (e.g., around the rotational output assembly 140).

[0031] In the illustrated "locked" configuration, the detent 160 is prevented from radially moving away from the rotational output assembly 140 and from disengaging from the recess 142 by the lock rotor assembly 131, which concentrically surrounds the key guide assembly 156. Rotation of the rotational output assembly 140 is prevented because such rotation would result in mechanical interference between the detent 160 and the rotational recess faces 146 and / or 148. Since the detent 160 is substantially unable to move in the illustrated configuration, rotation of the rotational output assembly 140 is substantially prevented (e.g., locked).

[0032] Figure 3 and Figure 4 A longitudinal cross section and an axial cross section of the example locking rotary actuator assembly 100 during an example unlocking process are shown, respectively. During unlocking, the motor 101 is energized to cause rotation of the shaft 102 and the sun gear assembly 110 .

[0033] The planet carrier 124 is also substantially retained in this configuration because the rotational output assembly 140 is substantially locked at the beginning of the unlocking process and the planet carrier 124 is coupled to the rotational output assembly 140. With the planet carrier 124 retained, rotation of the sun gear assembly 110 causes rotation of the planet gears 122 (e.g., but without orbital motion).

[0034] The rotation of the planetary gear 122 causes the rotation of the lock rotor assembly 131. The lock rotor assembly 131 includes a set of recesses 132. The recesses 132 are defined in the inner surface 134 of the lock rotor assembly 131. Each of the recesses 132 is defined between a rotating recess face 136 and a rotating recess face 138, and provides space to accommodate partial radial insertion of the lock key 160.

[0035] Rotation of the lock rotor assembly 131 rotates the recess 132 to radially align with the guide slot 158 ​​and the lock key 160. The lock rotor stop (not shown) is configured to stop the rotation of the lock rotor assembly 131 at the point of alignment (e.g., unlocked lock rotor configuration). In some embodiments, the lock rotor assembly 131 can be configured to have a predetermined amount of angular travel relative to the housing (e.g., about 15 degrees). Another lock rotor stop (not shown) is configured to stop the rotation of the lock rotor assembly 131 in the locked lock rotor configuration, in which the recess 132 is not aligned with the guide slot 158. In some embodiments, when the lock rotor assembly 131 is hard stopped in the unlocked lock rotor configuration, the ring gear assembly 130 becomes substantially fixed in this direction, thereby substantially preventing static rotation of the planetary gears 122 and promoting rotation of the planet carrier 124, which in turn promotes rotation of the rotation output assembly 140.

[0036] With the recess aligned with the guide slot 158, the detents 160 are provided with additional space in which they can move radially away from the rotational output assembly 140. The mechanical contact between the detents 160 and the rotational recess faces 146, 148 that initially prevented the rotational output assembly 140 from further rotation (e.g., because the detents 160 were previously prevented from radial movement) can now cause the detents 160 to radially shift out of the recess 132 and into the recess 142. The rotational recess faces 146, 148 are ramped or inclined to cause the detents 160 to move radially outward, thereby completing the unlocking action. When the detents 160 are disengaged from the recess 142, the rotational output assembly 140 is allowed to rotate further.

[0037] Figure 5 and Figure 6 1 and 2 show a longitudinal section and an axial section of the example locking rotary actuator assembly 100 in an example unlocked configuration, respectively. In the illustrated configuration, the locking key 160 has been moved from a locked configuration (e.g., Figure 1-2 142). In the illustrated configuration, detents 160 are unable to provide substantial mechanical interference with recess 142, which allows rotational output assembly 140 to rotate (e.g., based on torque provided by motor 101 and transmitted through sun gear assembly 110 and planet carrier 124). In some embodiments, if one or more of detents 160 exhibit unintentional radially inward movement, rotation of rotational output assembly 140 will again push the detents radially outward.

[0038] Locking of the locking rotary actuator assembly 100 may be achieved by substantially reversing the direction of the motor 101, which in turn may result in a reversal of the unlocking operation. The lock rotor assembly 131 may be rotated back to Figure 1-2As the ring gear rotates, the radially inclined ramps on the lock key crown match the inclined ramps on the inner diameter of the lock rotor assembly 131, and the lock key 160 is urged out of the recess 132, radially inward toward the rotation output assembly 140 and into the recess 142. In some embodiments, a biasing member (e.g., a torsion spring) can be configured to bias the rotation of the ring gear assembly 130 and the lock rotor assembly 131 toward the locked configuration. When the lock key 160 is in the Figure 1-2 In the example position shown in , the lock rotor assembly 131 can be rotated into a locked lock rotor configuration (e.g., against a lock hard stop) with the recess 132 misaligned with the guide slot 158, thereby preventing the lock key from radially disengaging from the recess 142 and maintaining mechanical interference with the rotation of the rotational output assembly 140.

[0039] Figure 7 An example lock key 700 is shown. In some embodiments, the lock key 700 may be Figure 1-6 An example locking key 160 is shown. The locking key 700 includes a key body 710 and a key crown 720.

[0040] The key body 710 includes a radially inclined ramp 712. In some embodiments, the radially inclined ramp 712 can be configured to be substantially complementary to the angle of the rotational recessed face 138 and / or 148 of the recess 132 and / or 142. In some embodiments, the radially inclined ramp 722 can have (or can average) an angle of approximately 30°. In some embodiments, the ramp 138 can be an undercut (reverse) convex angle with a radial ramp angle (e.g., approximately 25 degrees) that can be substantially complementary to the ramp angle on the key crown 720.

[0041] The key crown 720 includes a radially inclined ramp 722. In some embodiments, the radially inclined ramp 722 can be configured to be substantially complementary to the angle of the rotational recessed face 136 and / or 146 of the recess 132 and / or 142. In some embodiments, the radially inclined ramp 722 can have (or can average) an angle of approximately 30°.

[0042] Figure 8 8 is a flow chart illustrating an example of a process 800 for unlocking an example locking actuator assembly. In some embodiments, the process 800 may be performed by Figure 1-6 The example components 100 may be implemented in whole or in part.

[0043] At 810, torque is received at the sun gear assembly of the epicyclic gear assembly. For example, motor 101 can cause rotation of sun gear assembly 110. In some embodiments, an electric motor can provide torque at the sun gear assembly. For example, motor 101 can be an electric motor.

[0044] At 820 , torque is transferred from the sun gear assembly to the ring gear assembly of the epicyclic gear assembly through a set of planet gears of the epicyclic gear assembly. For example, rotation of the sun gear assembly 110 may cause rotation of the planet gears 122 and the ring gear assembly 130 .

[0045] At 830, the rotation of the lock rotor is caused based on the rotation of the ring gear assembly. For example, when the ring gear assembly 130 rotates, the lock rotor assembly 131 also rotates.

[0046] In some embodiments, process 800 may include: contacting a detent with a radial groove surface of a groove defined in the rotational output assembly and configured to receive the detent in a first detent configuration based on movement of the rotational output assembly; preventing rotational movement of the rotational output assembly based on interference between the detent and the radial groove surface; preventing rotation of the planetary gear assembly based on the prevented rotational movement of the rotational output assembly; and transmitting substantially all of the torque received at the sun gear assembly to the ring gear assembly. For example, when the rotational output assembly 140 is locked, the detent 160 contacts the rotating recessed surfaces 136, 138, 146, and / or 148 to prevent rotation of the rotational output assembly, which may result in substantially all of the torque provided by the motor 101 being transmitted to the ring gear assembly 130.

[0047] In some embodiments, process 800 may include rotating the lock rotor from a first lock rotor configuration to a second lock rotor configuration. For example, lock rotor assembly 131 may be rotated from a first lock rotor configuration to a second lock rotor configuration. Figure 1-2 The example configuration shown in FIG. 1 is rotated to Figure 3-6 In some embodiments, the first lock rotor configuration can be a first rotational position defined by a first lock rotor end stop that is configured to interfere with rotation of the lock rotor in a first direction, and the second lock rotor configuration can be a second rotational position defined by a second lock rotor end stop that is configured to interfere with rotation of the lock rotor in a second direction opposite the first direction.

[0048] In some embodiments, process 800 may include configuring the lock rotor to prevent radial displacement of the lock key from a first key configuration to a second key configuration in the first lock rotor configuration, and configuring the lock rotor to allow radial displacement of the lock key from the first key configuration to the second key configuration in the second lock rotor configuration.

[0049] The orbital motion of the planet gears about the sun gear assembly causes rotation of the planet carrier at 840. For example, rotation of the sun gear assembly 110 may cause rotation of the planet carrier 124.

[0050] At 850 , torque is transferred from the planet carrier to the rotational output assembly. For example, rotation of the planet carrier 124 may cause rotation of the rotational output assembly 140 .

[0051] In some embodiments, process 800 may include causing radial displacement of the detent from a first detent configuration to a second detent configuration based on rotational movement of the rotational output assembly. Figure 2-6 In the example unlocked configuration, rotation of the rotational output member 140 may cause radial displacement of the detent 160 from the recess 142 .

[0052] Although some embodiments have been described in detail above, other modifications are possible. For example, the logic flow depicted in the figure does not require the specific order or sequential order shown to achieve the desired result. In addition, other steps can be provided, or steps can be eliminated from the described flow, and other components can be added to or removed from the described system. Accordingly, other embodiments are within the scope of the appended claims.

Claims

1. A rotary lock assembly, comprising: An epicyclic gear assembly, the epicyclic gear assembly comprising: Sun gear assembly; a ring gear assembly; and A planetary gear assembly, the planetary gear assembly comprising: a plurality of planet gears mechanically engaged to the sun gear assembly and the ring gear assembly; and a planet carrier mechanically engaged to the planet gears and configured to be rotated by the planet gears; a lock rotor configured to be rotated by the ring gear assembly; and A rotation output assembly is configured to be rotated by the planet carrier.

2. The rotary lock assembly of claim 1 , further comprising a lock key configured to radially shift between a first lock key configuration and a second lock key configuration, wherein: The lock rotor is configured to be rotated by the ring gear assembly between a first lock rotor configuration in which radial displacement of the lock key from the first lock key configuration to the second lock key configuration is prevented, and a second lock rotor configuration in which radial displacement of the lock key from the first lock key configuration to the second lock key configuration is permitted.

3. The rotary lock assembly as described in claim 2 further includes a first lock rotor stop portion and a second lock stop portion, wherein the first lock rotor stop portion is configured to prevent the lock rotor from rotating in a first direction under the first lock rotor configuration, and the second lock stop portion is configured to prevent the lock rotor from rotating in a second direction under the second lock rotor configuration.

4. The rotary lock assembly of claim 2, wherein: The rotational output assembly is configured to rotate relative to radial movement of the lock key, and has an outer surface defining a recess between a first rotational recessed surface and a second rotational recessed surface, and is configured to receive the lock key in the first lock key configuration and be prevented from rotating based on mechanical interference between the lock key and at least one of the first rotational recessed surface and the second rotational recessed surface.

5. The rotary lock assembly of claim 2, further comprising: shell; as well as A key guide is retained to the housing and has a radial slot configured to provide radial guidance for radial displacement of the locking key and to prevent rotational movement of the locking key within the housing.

6. The rotary lock assembly of claim 2, further comprising a biasing member configured to bias rotation of the lock rotor toward the first lock rotor configuration.

7. The rotary lock assembly of claim 1, wherein: The sun gear assembly is configured to be rotated by a rotational power source.

8. The rotary lock assembly of claim 1, wherein: The ring gear assembly includes the lock rotor.

9. The rotary lock assembly of claim 1, further comprising an electric motor configured to cause rotation of the sun gear assembly.

10. A method of locking a linear actuator, the method comprising: receiving torque at a sun gear assembly of the epicyclic gear assembly; transmitting torque from the sun gear assembly to the ring gear assembly of the epicyclic gear assembly through a plurality of planet gears of the planetary gear assembly of the epicyclic gear assembly; causing rotation of a lock rotor based on rotation of the ring gear assembly; The planet carrier is rotated by the orbital motion of the planet gears around the sun gear assembly; as well as Torque is transmitted from the planet carrier to a rotary output assembly.

11. The method of claim 10, further comprising: A radial displacement of the detent from a first detent configuration to a second detent configuration is facilitated based on rotational movement of the rotational output assembly.

12. The method of claim 11, further comprising: upon movement of the rotational output assembly, bringing the detent into contact with a radial groove surface of a groove defined in the rotational output assembly and configured to receive the detent in the first detent configuration; preventing rotational movement of the rotational output assembly based on interference between the locking key and the radial groove surface; preventing rotation of the planetary gear assembly based on the prevented rotational movement of the rotational output assembly; as well as Substantially all of the torque received at the sun gear assembly is transferred to the ring gear assembly.

13. The method of claim 10, further comprising: The lock rotor is rotated from a first lock rotor configuration to a second lock rotor configuration.

14. The method of claim 13, wherein: The first lock rotor construction is a first rotational position defined by a first lock rotor end stop, the first lock rotor end stop being configured to interfere with rotation of the lock rotor in a first direction, and the second lock rotor construction is a second rotational position defined by a second lock rotor end stop, the second lock rotor end stop being configured to interfere with rotation of the lock rotor in a second direction opposite to the first direction.

15. The method of claim 13, wherein: The lock rotor is configured to resist radial displacement of the lock key from a first key configuration to a second key configuration in the first lock rotor configuration, and is configured to allow radial displacement of the lock key from the first key configuration to the second key configuration in the second lock rotor configuration.

16. The method of claim 10, further comprising: Torque is provided at the sun gear assembly by an electric motor.

17. A rotary actuator comprising: shell; a rotational input member rotatably movable relative to the housing; a rotational output member rotatably movable between a first output position relative to the housing and a second output position relative to the housing; as well as A rotation lock assembly, which is disposed in the housing and is restricted from rotational movement, and comprises: A first epicyclic gear assembly, the first epicyclic gear assembly comprising: Sun gear assembly; a ring gear assembly; and A planetary gear assembly, the planetary gear assembly comprising: a plurality of planet gears mechanically engaged to the sun gear assembly and the ring gear assembly; and a planet carrier mechanically engaged to the planet gears and configured to be rotated by the planet gears; a lock rotor configured to be rotated by the ring gear assembly; and A rotation output assembly is configured to be rotated by the planet carrier.

18. The rotary actuator of claim 17, wherein: The rotary lock assembly also includes a lock key, which is configured to radially shift between a first lock key configuration and a second lock key configuration, wherein the lock rotor is configured to be rotated by the ring gear assembly between the first lock rotor configuration and the second lock rotor configuration, in which, in the first lock rotor configuration, radial shifting of the lock key from the first lock key configuration to the second lock key configuration is prevented, and in the second lock rotor configuration, radial shifting of the lock key from the first lock key configuration to the second lock key configuration is allowed.

19. The rotary actuator of claim 18, wherein: The rotary lock assembly also includes a first lock rotor stopper configured to prevent the lock rotor from rotating in a first direction in the first lock rotor configuration and a second lock stopper configured to prevent the lock rotor from rotating in a second direction in the second lock rotor configuration.

20. The rotary actuator of claim 18, wherein: The rotational output member is configured to rotate relative to radial movement of the lock key, and the rotational output member includes an outer surface defining a groove between a first radial groove surface and a second radial groove surface, and is configured to receive the lock key in the first lock key configuration and be prevented from rotating based on mechanical interference between the lock key and at least one of the first radial groove surface and the second radial groove surface.

21. The rotary actuator of claim 17, further comprising an electric motor configured to cause rotation of the sun gear assembly.

Images