Linear actuator with ball joint

Abstract

Embodiments of the present invention pertain to a linear actuator with a ball joint. The ball joint provides the ability to rotate between the linear actuator and an external structure to which the linear actuator is connected. The ball joint prevents external forces from entering the linear actuator and / or prevents misalignment between components of the linear actuator when the external structure moves or displaces. The ball joint can be configured such that it is parallel to the translational component of the linear actuator. For example, the axis of the hollow channel within the ball joint can be parallel to and / or coincide with the axis of the translational component. When actuated, the translational component can pass through the hollow channel of the ball joint.

Description

[0001] Cross-references to related applications This application claims the benefit of U.S. Provisional Patent Application No. 63 / 569981, filed March 26, 2024, entitled “Linear Actuator With A Spherical Bearing,” pursuant to 35 USC §119(e), the disclosure of which is incorporated herein by reference in its entirety for all purposes. Background Technology

[0002] Linear actuators are prone to unintended misalignment between their internal components. If an external structure shifts or moves, the linear actuator attached to it may experience bending or torsional loads. These loads can cause stress or movement in the various components within the linear actuator, leading to misalignment. Misalignment results in increased loads on the internal components of the linear actuator, which can cause damage to the linear actuator and / or the system incorporating it, reduced operating efficiency, and shortened service life.

[0003] The embodiments address these problems as well as others. Summary of the Invention

[0004] Embodiments of the present invention provide a linear actuator comprising: a housing; a translation member configured to translate relative to the housing; and a spherical joint coupled to the housing and oriented parallel to a longitudinal axis of the translation member, wherein the translation member is configured to translate relative to the spherical joint and the housing.

[0005] According to various embodiments, the spherical joint includes a hollow channel, and the translational member is at least partially disposed within the hollow channel.

[0006] According to various embodiments, the spherical joint includes a hollow channel, and a translation member is at least partially disposed within the hollow channel, wherein the translation member is configured to translate through the hollow channel when the linear actuator is operated.

[0007] According to various embodiments, the longitudinal axis of the translation member is a first longitudinal axis, wherein the hollow channel has a second longitudinal axis, and the first longitudinal axis is parallel to the second longitudinal axis.

[0008] According to various embodiments, a portion of the housing is disposed within a hollow channel, and a translational member is at least partially disposed within that portion of the housing within the hollow channel.

[0009] According to various embodiments, the linear actuator further includes a coupling to a first end of the translation member, wherein the translation member is configured to translate relative to the ball joint and the housing, and wherein the ball joint and the housing are positioned between the first end of the translation member and a second end provided opposite to the first end.

[0010] According to various embodiments, the spherical joint is a first spherical joint, and the connecting member is a second spherical joint oriented perpendicular to the longitudinal axis of the translation member. The second spherical joint has a fixed position relative to the translation member and is oriented perpendicular to the first spherical joint.

[0011] According to various embodiments, the ball joint is configured to connect the housing to the first structure, and the connector is configured to connect the translation member to the second structure, such that the linear actuator is configured to cause the second structure to move relative to the first structure.

[0012] According to various embodiments, the linear actuator further includes: a drive member coupled to the housing and provided around the translation member, and configured to cause translation of the translation member; and an electric motor provided within the housing and configured to operate the drive member.

[0013] According to various embodiments, the translational member is configured to translate relative to the ball joint, housing, drive member, and electric motor, wherein the ball joint, housing, drive member, and electric motor are configured to remain in a fixed position relative to each other.

[0014] According to various embodiments, the linear actuator further includes a drive member coupled to the housing and provided around the translation member, wherein the translation member is coaxial with the drive member.

[0015] According to various embodiments, the linear actuator further includes a coupling connected to the translation member, wherein the ball joint is configured to connect the housing to the first structure, wherein the coupling is configured to connect the translation member to the second structure, and wherein the ball joint is configured to passively adjust its positioning in response to a change in position of the first or second structure, thereby maintaining alignment between the translation member and the drive member.

[0016] According to various embodiments, the spherical joint includes: a bracket configured to be coupled to a first structure; an outer ring coupled to the bracket; and an inner ring disposed within the outer ring and coupled to a housing, the inner ring having a spherical shape with a hollow channel, wherein a portion of the housing is disposed within the hollow channel, and a translational member is at least partially disposed within that portion of the housing within the hollow channel.

[0017] According to various embodiments, the inner ring is configured to rotate within the outer ring, such that the spherical joint is configured to passively adjust its position in response to external forces.

[0018] According to various embodiments, the inner ring has at least two rotational degrees of freedom.

[0019] According to various embodiments, the linear actuator further includes notches and tabs configured to constrain the inner ring to rotate about the longitudinal axis of the translation member.

[0020] According to various embodiments, the linear actuator has a stroke-to-length ratio equal to or less than 1.2 to 1.

[0021] Other embodiments of the present invention provide an aircraft including a tiltable propulsion system coupled to a linear actuator.

[0022] Other embodiments of the invention provide a system including a linear actuator comprising: a housing; a translation member configured to translate relative to the housing; and a spherical joint coupled to the housing and oriented parallel to a longitudinal axis of the translation member, wherein the translation member is configured to translate relative to the spherical joint and the housing; the system further comprising a first structure coupled to the housing via the spherical joint; and a second structure coupled to the translation member, wherein the translation member is configured to cause the second structure to move relative to the first structure when the translation member is actuated.

[0023] According to various embodiments, the first structure is a support structure for the aircraft, the second structure is a tiltable propulsion system for the aircraft, and the translation member is configured to cause the tiltable propulsion system to tilt when the translation member is actuated.

[0024] According to various embodiments, the ball joint is configured to passively adjust in response to changes in the position or angle of the first or second structure, thereby maintaining the internal alignment of the linear actuator.

[0025] Further details regarding embodiments of the invention can be found in the detailed description and figures. Attached Figure Description

[0026] Various embodiments of the invention are disclosed in the following detailed description and accompanying drawings. In the drawings, similar components or features may have the same reference numerals. Furthermore, various components of the same or similar type may be distinguished by adding a hyphen after the reference numeral, and by a second numeral to differentiate similar components.

[0027] Figure 1A A perspective view of a linear actuator according to an embodiment is shown.

[0028] Figure 1B A cross-section of a linear actuator according to an embodiment is shown.

[0029] Figures 2A to 2C Different positional states of the linear actuator according to an embodiment are shown.

[0030] Figure 3 A cross-section of the ball joint of a linear actuator according to an embodiment is shown.

[0031] Figure 4A A rear view of a linear actuator according to an embodiment is shown.

[0032] Figure 4B A closer rear view of the ball joint of the linear actuator according to an embodiment is shown.

[0033] Figure 5 A linear actuator with an alternative construction according to an embodiment is shown.

[0034] Figures 6A to 6B A plan view of an exemplary aircraft according to an embodiment is depicted.

[0035] Figures 7A to 7C Examples of linear actuators coupled to or incorporated into a propulsion system according to some embodiments are shown. Detailed Implementation

[0036] Embodiments of the present invention pertain to linear actuators with ball joints. The ball joint provides rotational adjustment between the linear actuator and an external structure to which it is connected. Consequently, when the external structure connected to the linear actuator moves or shifts, the ball joint prevents external forces from impacting the linear actuator and / or prevents misalignment between components of the linear actuator.

[0037] According to an embodiment, the spherical joint can be configured such that it is parallel to the translational member of the linear actuator. For example, the axis of the hollow channel within the spherical joint can be parallel and / or coaxial with the translational member. When actuated, the translational member can pass through the hollow channel of the spherical joint. This configuration allows the linear actuator to be compact and has a good stroke-to-length ratio.

[0038] Linear actuators can include any suitable device configured to induce linear motion. A linear actuator can be configured to convert rotational motion into linear motion. A linear actuator can be a two-force-component actuator to provide force in either direction along the axis. According to embodiments, the linear actuator can take the form of any suitable type or style of linear actuator. The figure primarily depicts and describes herein an electric ball screw linear actuator. The ball screw can be a continuous ramp device providing mechanical advantages. The stator assembly rotates to drive a screw-type shaft in the desired direction. Embodiments are also applicable to wheel and handle actuators (e.g., belt, chain, rack, or cable attached to the shaft), cam actuators, or any other suitable type of linear actuator.

[0039] Figures 1A to 1B An example of a linear actuator 120 according to an embodiment is shown. Figure 1AA perspective view of the linear actuator 120 is shown, and Figure 1B A cross-section of the linear actuator 120 is shown. The linear actuator 120 may include a translation member 123, a drive member 124, a housing 126 for receiving a motor 127, a ball joint 122 with a hollow channel 150, a coupling 121, and / or any other suitable member.

[0040] Translation member 123 may be configured to translate (e.g., move linearly). For example, translation member 123 may translate relative to housing 126 and / or drive member 124. When actuated by drive member 124, translation member 123 may translate linearly along its longitudinal axis. Translation member 123 may take the form of a rod, shaft, lead screw, or any other suitable elongated object that may be cylindrical or have any suitable shape. Translation member 123 may be threaded and / or include ball grooves.

[0041] Drive member 124 may be configured to cause translation member 123 to translate. Drive member 124 may be coupled to housing 126 and / or translation member 123. Drive member 124 may surround translation member 123 such that translation member 123 moves through drive member 124 (e.g., through a hollow channel within drive member 124). In some embodiments, drive member 124 may include ball bearings recirculating on internal tracks within drive member 124. Some examples of drive member 124 include drive nut, slider, or lead nut.

[0042] The housing 126 may include any suitable structure for housing the components of the linear actuator 120. The housing 126 may be a structure configured to completely or partially enclose one or more components and / or provide structural support for the linear actuator 120. For example, the housing 126 may enclose, house, and / or connect to the drive component 124, motor 127, gearbox 139, and / or any other suitable component. The housing 126 may also be referred to as a body, support, or block. Figure 1A This includes an indication of housing 126 pointing to a cylinder. According to an embodiment, the cylinder may be part of housing 126, and housing 126 further includes additional structures (e.g., structures surrounding drive member 124). Figures 2A to 2C and Figure 3 The additional parts of housing 126 are indicated.

[0043] Motor 127 may be configured to operate drive member 124, and thereby operate translation member 123. Motor 127 may include a stator and / or a rotor. Motor 127 may be an electric motor. According to an embodiment, motor 127 may be coupled to one or more gears of a set referred to as gearbox 139. Gearbox 139 may also be coupled to drive member 124. Rotor may be configured to cause rotation of a first gear of gearbox 139. Final gear of gearbox 139 may contact drive member 124, or otherwise be configured to cause movement in or at drive member 124.

[0044] According to an embodiment, the translation member 123 may have a dynamic position relative to some or all of the other components of the linear actuator 120. For example, the translation member 123 may be configured to translate relative to the housing 126, the drive member 124, the motor 127, the gearbox 139, and / or the ball joint 122. Apart from the translation member 123, components housed within or connected to the housing 126 may be held in a fixed position relative to the housing 126. For example, the housing 126, the drive member 124, the motor 127, the gearbox 139, and / or the ball joint 122 may be configured to remain in a fixed position relative to each other.

[0045] Figures 2A to 2C The different positional states of the linear actuator 120 during operation are shown. Figure 2A A linear actuator 120 in its fully extended state is shown. Figure 2B A linear actuator 120 in a partially extended state is shown. Figure 2C A linear actuator 120 in a retracted (or almost fully retracted) state is shown. (As shown) Figure 2A As shown, when the linear actuator 120 is in its fully extended state, the ball joint 122 may be located near the second end 162 of the translation member 123, and the first end 161 may be located at the maximum distance from the ball joint 122. Figure 2C As shown, when the linear actuator 120 is in the retracted state, the ball joint 122 may be located relatively close to the first end 161 of the translation member 123, and the second end 162 of the translation member 123 may be located near or at the maximum distance from the ball joint 122.

[0046] According to an embodiment, the linear actuator 120 can be coupled to two structures. A ball joint 122 can be configured to connect the housing 126 of the linear actuator 120 to a first structure. A coupling 121 (provided at a first end of the translation member 123) can be configured to connect the translation member 123 of the linear actuator 120 to a second structure. As a result, the linear actuator 120 can be configured to cause movement of the second structure relative to the first structure, or otherwise actuate the second structure. This will be discussed in more detail below and as... Figures 6A to 6BAs depicted, examples of the first and second structures may be a support structure (e.g., a boom) for an aircraft and a tiltable propulsion system, respectively, wherein the linear actuator 120 is configured to cause the tiltable propulsion system to tilt relative to the support structure.

[0047] Return to reference Figures 1A to 1B The translation member 123 can be aligned with the drive member 124. For example, the longitudinal axis of the drive member 124 can be parallel to the longitudinal axis of the translation member 123. The translation member 123 can be centrally located within the drive member 124 (e.g., within the hollow channel of the drive member 124). The translation member 123 can be coaxial with the drive member 124.

[0048] The internal alignment of the linear actuator 120 enables the linear actuator 120 to operate, to actuate efficiently, to reduce wear and loss, and / or to otherwise achieve the desired effect. The internal alignment of the linear actuator 120 may include the alignment between two or more of the drive member 124, translation member 123, housing 126, gearbox 139, motor 127, and / or any other suitable component of the linear actuator 120.

[0049] According to an embodiment, the ball joint 122 (also referred to as a ball bearing) may be a flexible joint. The ball joint 122 may be configured to passively adjust its position or configuration in response to external forces. These external forces may be caused by changes in position or angle of one or more structures (e.g., a first or second structure) to which the linear actuator 120 is coupled. The adjustment and / or flexibility provided by the ball joint 122 prevents external forces from affecting other components of the linear actuator 120 (which could cause misalignment or other undesirable effects). For example, a bending load may cause a slight rotation of the ball joint 122 instead of applying additional load to the housing 126, thereby allowing the housing 126 to remain aligned with the drive member 124 and the translation member 123. The ball joint 122 may allow the linear actuator 120 as a whole to undergo changes in angle or position without any bending or torsion of any component (e.g., other than the ball joint 122). The ball joint 122 enables the linear actuator 120 to maintain internal alignment (e.g., between the translation member 123 and the drive member 124) and / or to move without experiencing additional load.

[0050] The ball joint 122 can be coupled to the housing 126. The ball joint 122 can also be configured for coupling to an external structure (e.g., a support structure discussed in more detail below). As mentioned above, the ball joint 122 can be dynamically positioned relative to the translation member 123, and / or the ball joint 122 can have a fixed position relative to the housing 126 (e.g., and other members).

[0051] The ball joint 122 may include a hollow channel 150 (also referred to as a space, gap, or opening). The hollow channel 150 may extend from a first end of the ball joint 122 to a second (e.g., opposite) end through the center of the ball joint 122. The hollow channel 150 may be cylindrical or any other suitable shape. The hollow channel 150 may include a longitudinal axis (also referred to as a central axis or centerline) that may intersect the center point of the ball joint 122.

[0052] According to an embodiment, the ball joint 122 may be oriented parallel to the translation member 123. For example, the longitudinal axis of the hollow channel 150 may be parallel and / or coaxial (also referred to as coincident or collinear) with the longitudinal axis of the translation member 123.

[0053] According to an embodiment, the translation member 123 may be at least partially disposed within the spherical joint 122. For example, the translation member 123 may be partially disposed within the hollow channel 150, and / or the spherical joint 122 may be configured to surround the translation member 123. The translation member 123 may be configured to translate within and / or through the hollow channel 150 during actuation of the linear actuator 120. As a result, different portions of the translation member 123 may be located within the hollow channel 150 at different times or at different actuation positions. Some or all of the translation members 123 may pass through and beyond the center point of the spherical joint 122. The translation member 123 may be configured to move linearly through the hollow channel 150 without contacting the walls of the hollow channel 150 or other portions of the spherical joint 122.

[0054] One or more dimensions of the ball joint 122 may be larger than the corresponding dimensions of the translation member 123. For example, the outer radial diameter of the spherical member (e.g., the inner ring) of the ball joint 122 may be larger than the radial diameter of the translation member 123. Additionally, the diameter of the hollow channel 150 of the ball joint 122 may be larger than the diameter of the translation member 123. In some embodiments, the diameters of the hollow channel 150 and the translation member 123 may be approximately equal, with a slight margin, to allow the translation member 123 to move frictionlessly within the hollow channel 150. In other embodiments, the diameter of the translation member 123 may be small enough to allow other structures (e.g., a portion of the housing 126) to also fit within the hollow channel 150.

[0055] As mentioned above, the linear actuator 120 may include a coupling 121 for coupling the translation member 123 to the second structure. According to an embodiment, the coupling 121 may be located at a first end 161 of the translation member 123, coupled to, and / or fixedly connected to, the first end 161. Therefore, the coupling 121 may have a fixed position relative to the translation member 123.

[0056] The connecting member 121 can be any suitable connecting mechanism. For example... Figures 1A to 1B As shown, in some embodiments, the connector 121 may take the form of a second spherical joint. As an example, the second spherical joint can be bolted to an external structure via a hollow channel in the center of the spherical joint. The second spherical joint may be oriented perpendicular to (e.g., rather than parallel to) the translation member 123 and / or the spherical joint 122 (also referred to as the first spherical joint). For example, the axis 182 of the hollow channel in the second spherical joint may be perpendicular to the longitudinal axis 181 of the translation member 123 and / or the hollow channel 150 of the first spherical joint. In some embodiments, the connector 121 may have an outer diameter similar to or the same as the diameter of the translation member 123 (e.g., a spherical structure).

[0057] The ball joint 122 and the coupling 121, which takes the form of a second ball joint, together provide complete capability to prevent internal misalignment between the components of the linear actuator 120 caused by movement of the two external structures. In some embodiments, the linear actuator 120 may move or rotate as a whole. However, the linear actuator 120 may remain internally aligned and not experience large loads or forces internally.

[0058] like Figures 1A to 1B As shown, in some embodiments, the ball joint 122 may be larger than the coupling 121. For example, both the outer diameter (e.g., of the spherical member) and the inner diameter (e.g., of the hollow channel 150) of the ball joint 122 may be larger than the corresponding diameter of the coupling 121. The larger size of the ball joint 122 can advantageously provide greater strength at the ball joint 122.

[0059] By design, the ball joint has greater strength (e.g., load capacity) in the radial direction (e.g., perpendicular to the longitudinal axis) compared to the axial direction. Therefore, the connector 121 can be oriented to experience loads in the radial (e.g., stronger) direction. The ball joint is typically not positioned and oriented to receive loads in the axial direction. However, in embodiments, the ball joint 122 can be positioned and oriented to receive loads in the axial (e.g., weaker) direction. Embodiments utilize a larger size to compensate for these axial loads. The increased size provides greater load capacity in all directions, including the axial direction. According to embodiments, due to the larger size, the ball joint 122 may be able to axially carry the same or similar loads as the connector 121 can radially carry.

[0060] Furthermore, due to its larger size, the ball joint 122 can be made of lightweight materials (e.g., lighter than those used for smaller connectors, such as connector 121) while still providing sufficient load-bearing capacity. Additionally, as discussed above, the larger size allows the ball joint 122 to accommodate the translation member 123 within the hollow channel 150, enabling the ball joint 122 to have a dynamic position relative to the translation member 123.

[0061] Figure 3 A closer cross-section view of the ball joint 122 and other nearby components is shown. The ball joint 122 may include an inner ring 125, an outer ring 128, a bracket 129, and any other suitable components.

[0062] The bracket 129 may include any suitable structure configured to support the outer ring 128. For example, the bracket 129 may include an opening, gap, or hollow channel configured to mate with the outer ring 128. Additionally, the bracket 129 may be configured for attachment to an external structure. For example, the bracket 129 may include one or more attachment points 177, such as threaded screw holes or bolt slots, for secure attachment to an external structure. Thus, the bracket 129 may attach the ball joint 122 and thereby the linear actuator 120 to an external structure.

[0063] The outer ring 128 may be approximately annular, having an opening, gap, or hollow channel, wherein a concave spherical inner surface is configured to receive the inner ring 125. The outer ring 128 may be disposed within and / or coupled to the bracket 129. For example, the size and shape of the outer ring 128 may be configured to fit tightly within the bracket 129. Additionally, a threaded ring 142 may be provided for securing the outer ring 128 to the bracket 129. The threaded ring 142 may apply pressure to a first side of the outer ring 128, and a second side of the outer ring 128 may contact a flange or another portion of the bracket 129. As a result, the outer ring 128 may be securely connected to the bracket 129. The threaded ring 142 may also provide additional load-bearing capacity (e.g., in the axial direction) for the ball joint 122.

[0064] The inner ring 125 may be disposed within the outer ring 128. For example, the size and shape of the inner ring 125 may be configured to fit snugly within the outer ring 128. The inner ring 125 may have a convex spherical shape. The convex spherical shape of the inner ring 125 may have a matching curvature or otherwise conform to the concave spherical surface of the outer ring 128. The inner ring 125 may also be referred to as a spherical joint 122 or a spherical component of a spherical bearing. Additionally, the inner ring 125 may include a hollow channel 150, which is discussed in more detail above.

[0065] The inner ring 125 may be rotatably coupled to the outer ring 128. In other words, the inner ring 125 may be configured to rotate within the outer ring 128 while remaining housed within it. The inner ring 125 may be rotatable in multiple directions. For example, embodiments allow the contact surfaces of the inner ring 125 and / or the outer ring 128 to slide or glide with relatively low friction. Sliding contact can be achieved through lubrication. In some embodiments, movement may be facilitated by providing ball bearings, rollers, and / or any other suitable components between the inner ring 125 and the outer ring 128.

[0066] The inner ring 125 can be connected to the housing 126. For example... Figure 3 As shown, a portion of the housing 126 (e.g., an extension or flange) may extend into the hollow channel 150 of the inner ring 125. This may be attached to a portion of the translation member 123, which may surround a portion of the housing 126 such that both the translation member 123 and the housing 126 are at least partially disposed within the hollow channel 150. The size and shape of the portion of the housing 126 may be configured to fit snugly within the hollow channel 150. Additionally, a nut 141, etc., may be provided for securing the inner ring 125 to the housing 126. The nut 141 may apply pressure on a first side of the inner ring 125, and a second side of the inner ring 125 may contact a side, flange, or another portion of the housing 126. As a result, the inner ring 125 may be securely connected to the housing 126 and / or positioned near the body of the housing 126. Thus, the inner ring 125 may be coupled to the ball joint 122 (and thus the external structure) to the remainder of the linear actuator 120. The embodiments allow the inner ring 125 (and ball joint 122) to be positioned on either side of the housing 126 (e.g., rear or front).

[0067] Therefore, in some embodiments, the inner ring 125 may be fixedly attached to the housing 126, and thus to other components of the linear actuator 120, while the outer ring 128 may be fixedly attached to the bracket 129, which may be fixedly attached to the external structure. Thus, different portions of the ball joint 122 can be connected to the linear actuator 120 and the external structure respectively, while the outer ring 128 and the inner ring 125 of the ball joint 122 can move and rotate relative to each other. This flexible connection allows the remaining parts of the linear actuator 120 (e.g., housing 126, translation member 123, drive member 124, and other components) to displace and move relative to the external structure while remaining connected to it. When the external structure moves or otherwise transmits external forces to the ball joint 122, the ball joint 122 can passively adjust by rotation between the outer ring 128 and the inner ring 125 to absorb the force.

[0068] In an alternative embodiment, the outer ring 128 may be coupled to the housing 126 (instead of the bracket 129 and / or external structure), and the inner ring 125 may be coupled to the bracket 129 and / or external structure (instead of the housing 126).

[0069] According to an embodiment, the ball joint 122 may be configured to provide three rotational degrees of freedom. For example, the inner ring 125 may be able to rotate about each of three axes perpendicular to each other.

[0070] In some embodiments, the ball joint 122 may be configured to restrict or inhibit rotation in one or more rotational directions. For example, one or more anti-rotation members may be included to limit certain movement of the ball joint 122. Figure 3 As shown, in some embodiments, the bracket 129 may include a notch 131 (also referred to as a groove), and the housing 126 may include a tab 132 (e.g., a cylindrical pin or nut). The notch 131 and the tab 132 may be configured to constrain the housing 126 to rotate about the longitudinal axis of the translation member 123 and / or the linear actuator 120.

[0071] Figures 4A to 4B A rear view of the linear actuator 120 and the ball joint 122 is shown. Figures 4A to 4B As shown, tab 132 can be positioned within notch 131 and can have a width similar to and / or slightly smaller than notch 131. As a result, if housing 126 begins to rotate about its longitudinal axis, tab 132 can contact one or more walls of notch 131, such that tab 132 (and thus housing 126) can be constrained by retainer 129. Notch 131 can extend in a direction parallel to the longitudinal axis, allowing tab 132 to move freely in that direction. Notch 131 can also be deeper than tab 132, allowing tab 132 to move upward and downward within notch 131. As a result, rotational movement about the longitudinal axis can be constrained, while rotational movement in other directions (e.g., two other rotational directions) can be permitted.

[0072] As discussed above, housing 126 can be attached to inner ring 125. Therefore, constraining movement of housing 126 causes inner ring 125 to be constrained within outer ring 128, and causes the entire linear actuator 120 to be constrained in a predetermined rotational direction. Inner ring 125, and thus ball joint 122 and / or linear actuator 120, can maintain at least two rotational degrees of freedom.

[0073] Therefore, one of the three rotational degrees of freedom can be largely or completely suppressed. This prevents undesirable rotation as a byproduct of an actuation mechanism (e.g., a gear acting on drive member 124). In some embodiments, a small gap may exist between tab 132 and notch 131, such that ball joint 122 is not completely suppressed and can still rotate in the other two directions, and / or may also allow rotation about the suppressed direction by a predetermined amount (e.g., a small amount). Tab 132 and / or notch 131 may be positioned directly vertically above the longitudinal axis of translation member 123.

[0074] In some embodiments, the notch 131 and tab 132 may be positioned on other components to provide a similar anti-rotation effect. For example, the notch 131 may be included on the inner ring 125, and the tab 132 may be included on the outer ring 128 or the support 129.

[0075] Return to reference Figures 1A to 1B As discussed above, connector 121 may be in the form of a ball joint. Connector 121 may be connected to a corresponding connecting member of an external structure to connect linear actuator 120 to the external structure. In some embodiments, one or more members may be included to restrict certain movements of connector 121. For example, connector 121 may include one or more tabs or pins protruding away from connector 121 in a direction perpendicular to the longitudinal axis of translation member 123. The tabs may be configured to contact the corresponding connecting member and / or one or more spacers (e.g., disposed between connector 121 and the corresponding connecting member of the external structure) in the event of rotation about the longitudinal axis of translation member 123. As a result, rotation of connector 121, and thus linear actuator 120, about the longitudinal axis of translation member 123 is prevented. In other words, one of the three rotational degrees of freedom may be largely or completely suppressed. This prevents undesirable rotation as a byproduct of the actuation mechanism. In some embodiments, a small gap may exist between the tab and the spacer, such that connector 121 is not completely suppressed and can still rotate in the other two directions.

[0076] Compared to alternatives, the embodiments advantageously provide the ability to maintain linear actuator alignment in a compact, less complex, lighter, and more robust manner. For example, Figure 5 An alternative configuration of the linear actuator 170 is shown. This linear actuator 170 includes a first spherical connector 172 oriented perpendicular to the longitudinal axis of the linear actuator 170 and fixedly positioned to the structural tube 174 at a distance beyond the second end of the linear actuator 170, which is consistent with... Figures 1A to 1BThe ball joint 122 shown in the diagram forms a contrast. A first ball joint 172 can be fixedly connected to a first structure (e.g., via a bolt passing through an opening in the first ball joint 172), while a second ball joint 171 can be fixedly connected to a second structure. A structural tube 174 is provided to maintain a rigid structure while allowing translational movement of the translation member 173. When the linear actuator 170 operates, the translation member 173 moves into and out of the structural tube 174 as shown by the dashed lines.

[0077] Using ball joints at both ends, the linear actuator 170 may be able to passively adjust its position and / or maintain internal alignment in response to external forces. However, because the structural tube 174 elongates the overall structure, the linear actuator 170 is less efficient than... Figures 1A to 1B The linear actuator 120 is compact.

[0078] The stroke-to-length ratio can be described as the linear stroke distance provided by the linear actuator compared to the total length of the linear actuator when fully extended. Figure 5 The linear actuator 170 provides a stroke-to-length ratio greater than 2:1. In contrast, Figures 1A to 1B The linear actuator 120 provides an improved stroke-to-length ratio that is closer to 1:1. In some embodiments, Figures 1A to 1B The linear actuator 120 may have a stroke-to-length ratio of approximately 1.2:1 or less. A smaller stroke-to-length ratio is preferred because the device occupies less space to achieve the same actuation distance.

[0079] Figures 1A to 1B The linear actuator 120 achieves an improved stroke-to-length ratio by connecting the ball joint 122 to the housing 126 and orienting the ball joint 122 parallel to the translation member 123, allowing the translation member 123 to travel through the hollow channel 150. As a result, the ball joint 122 becomes dynamically positioned along the translation member 123, rather than being fixedly positioned to the structure at a distance beyond the translation member 124 (e.g., Figure 5 (structural tube). In some embodiments, by placing the motor and housing 126 in opposite directions (e.g., in...) Figure 2A Oriented to the left (from the perspective of the left), the stroke-to-length ratio can be further improved (or reduced) to about 1.1:1, so that the housing 126 does not overhang outside the translation member 123 when it extends.

[0080] Therefore, for the same amount of travel, Figures 1A to 1B The linear actuator 120 is more compact. (Comparison) Figure 5 The extended position shown is the same as Figure 2A The difference in the ratio of stroke to length can be seen in the extended position shown. Figure 5In the middle, the retracted position is not very compact because the first spherical connector 172 and the structural tube 174 extend to the right further outward than the translation member 173.

[0081] Additionally, due to the weight of the extra components from structural tube 174, therefore Figure 5 The linear actuator 170 is relatively heavy. This is a significant disadvantage in applications where the total weight of the structure incorporating the linear actuator is strictly limited (e.g., aircraft or other aerospace applications).

[0082] In addition, with Figures 1A to 1B Compared to the linear actuator 120 shown, Figure 5 The linear actuator 170 shown has lower compressive strength and is more prone to buckling. The distance between the connection points (e.g., the first spherical connector 172 and the second spherical connector 171) is relatively long, and this can create a "long column" effect when the translation member 173 extends. At full extension, the connection points are spaced approximately twice the length of the translation member 173. In contrast, Figures 1A to 1B The linear actuator 120 is configured such that the two connection points (e.g., connector 121 and ball joint 122) are closer together at any given point of actuation. For example, the maximum distance between the two connection points is approximately the length of the translation member 123 during extension (e.g., ...). Figure 2A As shown in the diagram), the minimum distance between the two connection points is approximately the length of the drive member 124 when it is retracted (e.g., Figure 2C As shown in the image). Figures 1A to 1B The linear actuator 120 is more robust, stiffer, and less susceptible to buckling.

[0083] According to an embodiment, the ball joint 122 can be used with any suitable type of linear actuator. Although a ball screw linear actuator is depicted in the figure, any type of linear actuator that can physically accommodate the ball joint as shown (e.g., oriented around the rod and parallel to the rod) can be used instead of a ball screw linear actuator.

[0084] As mentioned above, according to an embodiment, the linear actuator 120 can be coupled to two structures. The linear actuator 120 can cause movement of one or more external structures. For example, the first structure may have a fixed position, and the second structure may be configured to move or tilt relative to the first structure when the linear actuator 120 is operated. The embodiment allows the linear actuator 120 to be used in any suitable context for any suitable structure. In one example, the linear actuator 120 can be used to actuate aircraft components.

[0085] Figure 6A and Figure 6BA plan view of an exemplary aircraft 100 according to an embodiment is depicted. The aircraft 100 may be any suitable type of flight vehicle, such as an airplane, helicopter, drone, or hybrid-powered aircraft. In some embodiments, the aircraft 100 may be capable of vertical takeoff and landing (VTOL). The aircraft 100 may be configured for manual piloting, remote piloting, and / or autonomous flight.

[0086] In the example shown, the aircraft 100 includes a fuselage 104, which may include cabin sections for carrying passengers and / or cargo (e.g., facing the nose). One or more wings (including a first wing 102 and a second wing 103) may be mounted on or otherwise attached to the fuselage 104.

[0087] The aircraft 100 may include support structures 106(A)-(F) that can be coupled to wings 102, 103. For example... Figures 6A to 6B As shown, each of the support structures 106(A)-(F) may take the form of a boom, but the embodiments include any other suitable structures. Figures 6A to 6B The diagram shows six support structures 106(A)-(F), of which three support structures 106(A)-(F) are provided below each of the paired wings 102, 103. The support structures 106(A)-(F) are connectable to the underside of the paired wings and may include a forward portion extending beyond the front of the wing and a rear portion extending behind the wing.

[0088] The aircraft 100 may also include propulsion systems 101(A)-(L). Each of the propulsion systems 101(A)-(L) may be configured to provide thrust to the aircraft 100. One or more of the propulsion systems 101(A)-(L) may be mounted on support structures 106(A)-(F). For example, a pair of propulsion systems 101(A)-(L) may be mounted on opposite ends of respective support structures 106(A)-(F), with one propulsion system mounted forward of the wing and the other propulsion system mounted aft of the wing. In other embodiments, one or more of the propulsion systems 101(A)-(L) may be directly coupled to the wing.

[0089] One or more of the propulsion systems 101(A)-(L) can be configured to change orientation. For example, one or more of the propulsion systems 101(A)-(L) can be constructed and / or installed in a manner that allows for tilting of angles and orientations relative to the respective wings 102 or 103, the respective support structures 106(A)-(F), and / or the aircraft 100. As a result, the tilting propulsion system can be configured to provide thrust relative to the aircraft 100 in more than one direction.

[0090] The tilt propulsion system can be configured to switch between forward flight configuration (e.g., horizontal orientation) and vertical flight configuration (e.g., vertical orientation) (e.g., rotation or tilt). Figure 6A The tilt propulsion systems 101(A), 101(B), 101(C), 101(G), 101(H) and / or 101(I) are shown as currently configured for forward flight (also known as the second tilt configuration or second tilt angle). Figure 6B The tilt propulsion systems 101(A), 101(B), 101(C), 101(G), 101(H) and 101(I) are shown as currently configured in a vertical flight configuration (also known as a first tilt configuration or a first tilt angle).

[0091] The propulsion system 101 can be controlled to switch between tilt configurations depending on the aircraft's current movement requirements to provide additional thrust in any suitable direction. For example, during takeoff, landing, and / or hovering, the propulsion system 101 can be configured for vertical flight to provide additional vertical thrust. During forward cruise, the propulsion system 101 can be configured for forward flight to provide horizontal thrust. During phases of forward acceleration, deceleration, altitude gain, and / or altitude loss, the propulsion system 101 can be configured with an intermediate tilt angle to provide both horizontal and vertical thrust components.

[0092] The tilting propulsion system can be coupled to a corresponding support structure via a linear actuator, one or more rotatable joints, and / or any other suitable component to provide a rotatable connection. For example, the linear actuator can be configured to cause the tilting propulsion system to tilt.

[0093] Figures 7A to 7C An example of a linear actuator 120 coupled to a support structure 106 (e.g., a first structure) and a propulsion system 101 (e.g., a second structure) is shown. The linear actuator 120 may be configured to tilt or otherwise actuate the propulsion system 101 relative to the support structure 106. The linear actuator 120 may be anchored in position to the support structure 106, which may also be referred to as a fixed structure. The linear actuator 120 may be configured to extend and / or retract a translational member from the support structure 106 to tilt (e.g., upward and / or downward) the propulsion system 101, which may also be referred to as a movable structure.

[0094] The support structure 106 may surround the linear actuator 120. A representative portion (e.g., a bracket) of the support structure 106 is located in... Figures 7A to 7C As shown in the figure. To illustrate the linear actuator 120, Figures 7A to 7COther components and / or enclosures of the support structure 106 are not shown. The support structure 106 may be a continuous structure surrounding the linear actuator 120. In some embodiments, the support structure 106 may be formed by a plurality of components at least partially surrounding the linear actuator 120.

[0095] exist Figure 7A In this configuration, the propulsion system 101 is set to a vertical (or near-vertical) position. Figure 7B In this configuration, when the linear actuator 120 is actuated (e.g., retracts the translation member), the propulsion system 101 tilts to an angular position. Figure 7C As the linear actuator 120 continues to actuate (e.g., retract the translation member), the propulsion system 101 tilts to a further angular position to approach the forward flight configuration.

[0096] During the operation of the aircraft and / or tilting mechanism, various aircraft structures (e.g., booms, propulsion systems, supports, etc.) undergo a certain amount of deformation (e.g., torsion, deflection, bending) and / or positional movement due to large forces from drag, heavy components, etc. This can then cause the fixedly attached linear actuator (e.g., without a ball joint) to experience bending loads, shear loads, torsion, and / or other undesirable forces. According to embodiments, these bending loads can instead cause a slight rotation (e.g., passive adjustment and / or automatic angular change) between a portion of the ball joint (e.g., the outer ring) and the housing of the linear actuator, and thus the bending load can be absorbed by the ball joint. As a result, alignment is maintained between the housing, motor, gears, drive components, and translational components, and additional loads are prevented on the linear actuator.

[0097] In an alternative configuration, the linear actuator 120 may include a trunnion mount instead of a ball joint for coupling to the support structure 106 and providing rotational adjustment capability. The trunnion mount can be another type of flexible joint, typically having one degree of freedom and capable of absorbing misalignment in one direction. However, trunnion mounts typically cannot absorb misalignment in other directions. Furthermore, trunnion mounts are undesirably heavy, large, complex, and expensive. Therefore, embodiments preferably utilize a ball joint instead of a trunnion mount to provide additional capabilities to prevent misalignment, reduce weight, decrease complexity, and / or reduce cost.

[0098] Although this article primarily discusses linear actuators in the context of tilt propulsion systems on aircraft, the embodiments can be applied to any other suitable linear actuator applications on aircraft as well as other non-aircraft applications.

[0099] For simplicity, various active and passive circuit system components are not shown in the figures. In the foregoing description, numerous specific details have been described with reference to embodiments of this disclosure, which may vary from implementation to implementation. Therefore, the description and figures are to be considered illustrative rather than restrictive. The unique and exclusive indication of the scope of this disclosure, and what the applicant intends to be within the scope of this disclosure, is the literal and equivalent scope of the set of claims set forth in this application, in the specific form set forth by these claims (including any subsequent amendments). Specific details of particular embodiments may be combined in any suitable manner without departing from the spirit and scope of the embodiments of this disclosure.

[0100] Additionally, spatially relative terms such as “front” or “rear” may be used to describe the relationship of an element and / or feature to another element and / or feature, as illustrated in the figures. It will be understood that spatially relative terms are intended to cover different orientations of the device in use and / or operation, other than those depicted in the figures. For example, if the device in the figures is flipped, an element described as the “front” surface may be oriented as “rear” relative to other elements or features. The device may be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and the spatially relative descriptive language used herein will be interpreted accordingly.

[0101] Although this disclosure has been described with reference to specific embodiments, those skilled in the art will recognize upon reviewing this disclosure that variations and modifications are possible.

[0102] It should be understood that all numerical values ​​used in this document are for illustrative purposes and are subject to change. In some cases, ranges are specified to provide a sense of scale, but this does not preclude numerical values ​​from being published outside of such ranges.

[0103] It should also be understood that all figures and diagrams herein are intended to be illustrative. Unless otherwise expressly indicated, the figures are not intended to represent any particular physical arrangement of the elements shown, or that all elements shown in the figures are necessary. Those skilled in the art will understand upon review of this disclosure that elements shown in the figures or otherwise described in this disclosure may be modified or omitted, and that other elements not shown or described may be added.

[0104] The above description is illustrative only and not restrictive. Many variations of the invention will become clear to those skilled in the art upon reading this disclosure. Therefore, the scope of patent protection should not be determined by reference to the above description, but rather by reference to the following claims and their full scope or equivalents. Claims (as amended under Article 19 of the Treaty) 1. A linear actuator, comprising: case; Translational components; and A spherical joint connected to the housing and oriented parallel to the longitudinal axis of the translation member, wherein the translation member is configured to translate relative to the spherical joint and the housing, wherein the spherical joint comprises: Outer ring; Inner circle; and Notches and tabs are configured to constrain the inner ring from rotating about the longitudinal axis of the translation member. 2. The linear actuator of claim 1, wherein the spherical joint includes a hollow channel, and the translation member is at least partially disposed within the hollow channel, wherein the translation member is configured to translate through the hollow channel when the linear actuator is operated. 3. The linear actuator according to claim 2, wherein the longitudinal axis of the translation member is a first longitudinal axis, wherein the hollow channel has a second longitudinal axis, and the first longitudinal axis is parallel to the second longitudinal axis. 4. The linear actuator of claim 2, wherein a portion of the housing is disposed within the hollow channel, and the translation member is at least partially disposed within the portion of the housing within the hollow channel. 5. The linear actuator according to claim 1, further comprising: A connector attached to a first end of the translation member, wherein the ball joint and the housing are positioned between the first end of the translation member and a second end provided opposite to the first end. 6. The linear actuator according to claim 5, wherein the spherical joint is a first spherical joint, the connecting member is a second spherical joint oriented perpendicular to the longitudinal axis of the translation member, the second spherical joint has a fixed position relative to the translation member, and the second spherical joint is oriented perpendicular to the first spherical joint. 7. The linear actuator of claim 5, wherein the ball joint is configured to connect the housing to the first structure, and the coupling is configured to connect the translation member to the second structure, such that the linear actuator is configured to cause the second structure to move relative to the first structure. 8. The linear actuator according to claim 1, further comprising: A drive member, coupled to the housing and provided around the translation member, and configured to cause translation of the translation member; and An electric motor is provided within the housing and configured to operate the drive component. 9. The linear actuator of claim 8, wherein the translation member is configured to translate relative to the ball joint, the housing, the drive member, and the electric motor, and wherein the ball joint, the housing, the drive member, and the electric motor are configured to remain in a fixed position relative to each other. 10. The linear actuator of claim 1, further comprising: A drive member is coupled to the housing and provided around the translation member, wherein the translation member is coaxial with the drive member. 11. The linear actuator of claim 10, further comprising: A connector is attached to the translation member, wherein the ball joint is configured to connect the housing to a first structure, wherein the connector is configured to connect the translation member to a second structure, and wherein the ball joint is configured to passively adjust its positioning in response to a change in position of the first structure or the second structure, thereby maintaining alignment between the translation member and the drive member. 12. The linear actuator according to claim 1, wherein the ball joint comprises: A support structure is configured to connect to the first structure. The outer ring is connected to the bracket, and The inner ring is disposed within the outer ring and connected to the housing, the inner ring having a spherical shape with a hollow channel, a portion of the housing being disposed within the hollow channel, and the translational member being disposed at least partially within the portion of the housing within the hollow channel. 13. The linear actuator of claim 12, wherein the inner ring is configured to rotate within the outer ring such that the spherical joint is configured to passively adjust its position in response to an external force. 14. The linear actuator of claim 13, wherein the inner ring has at least two rotational degrees of freedom. 15. (Deleted). 16. The linear actuator of claim 1, wherein the linear actuator has a stroke-to-length ratio equal to or less than 1.2 to 1. 17. An aircraft comprising a tiltable propulsion system coupled to a linear actuator according to claim 1. 18. A system comprising: Linear actuators, comprising: case; Translational components, including: The first end; and A second end is provided opposite to the first end; and A spherical joint is coupled to the housing and oriented parallel to the longitudinal axis of the translation member, wherein the translation member is configured to translate relative to the spherical joint and the housing, and wherein the spherical joint and the housing are positioned between the first end and the second end; The first structure connected to the housing via the ball joint; and A second structure connected to the translation member, wherein the translation member is configured to cause the second structure to move relative to the first structure when the translation member is actuated. 19. The system of claim 18, wherein the first structure is a support structure for an aircraft, the second structure is a tiltable propulsion system for the aircraft, and the translation member is configured to cause the tiltable propulsion system to tilt when the translation member is actuated. 20. The system of claim 18, wherein the ball joint is configured to passively adjust in response to a change in position or angle of the first or second structure, thereby maintaining the internal alignment of the linear actuator.

Claims

1. A linear actuator, comprising: case; A translational member configured to translate relative to the housing; as well as A spherical joint is connected to the housing and oriented parallel to the longitudinal axis of the translation member, wherein the translation member is configured to translate relative to the spherical joint and the housing.

2. The linear actuator according to claim 1, wherein, The spherical joint includes a hollow channel, and the translation member is at least partially disposed within the hollow channel, wherein the translation member is configured to translate through the hollow channel when the linear actuator is operated.

3. The linear actuator according to claim 2, wherein, The longitudinal axis of the translational member is a first longitudinal axis, wherein the hollow channel has a second longitudinal axis, and the first longitudinal axis is parallel to the second longitudinal axis.

4. The linear actuator according to claim 2, wherein, A portion of the housing is disposed within the hollow channel, and the translational member is at least partially disposed within the portion of the housing within the hollow channel.

5. The linear actuator according to claim 1, further comprising: A connector is attached to a first end of the translation member, wherein the translation member is configured to translate relative to the ball joint and the housing, and wherein the ball joint and the housing are positioned between the first end of the translation member and a second end provided opposite to the first end.

6. The linear actuator according to claim 5, wherein, The spherical joint is a first spherical joint, and the connecting member is a second spherical joint oriented perpendicular to the longitudinal axis of the translation member. The second spherical joint has a fixed position relative to the translation member, and the second spherical joint is oriented perpendicular to the first spherical joint.

7. The linear actuator according to claim 6, wherein, The ball joint is configured to connect the housing to the first structure, and the connector is configured to connect the translation member to the second structure, such that the linear actuator is configured to cause the second structure to move relative to the first structure.

8. The linear actuator according to claim 1, further comprising: A drive member, which is coupled to the housing and provided around the translation member, and configured to cause the translation member to translate; as well as An electric motor is provided within the housing and configured to operate the drive component.

9. The linear actuator according to claim 8, wherein, The translational member is configured to translate relative to the spherical joint, the housing, the drive member, and the electric motor, wherein the spherical joint, the housing, the drive member, and the electric motor are configured to remain in a fixed position relative to each other.

10. The linear actuator of claim 1, further comprising: A drive member is coupled to the housing and provided around the translation member, wherein the translation member is coaxial with the drive member.

11. The linear actuator of claim 10, further comprising: A connector is attached to the translation member, wherein the ball joint is configured to connect the housing to a first structure, wherein the connector is configured to connect the translation member to a second structure, and wherein the ball joint is configured to passively adjust its positioning in response to a change in position of the first structure or the second structure, thereby maintaining alignment between the translation member and the drive member.

12. The linear actuator according to claim 1, wherein, The spherical joint includes: A support structure is configured to connect to the first structure; Connected to the outer ring of the bracket; and An inner ring disposed within the outer ring and connected to the housing, the inner ring having a spherical shape with a hollow channel, wherein a portion of the housing is disposed within the hollow channel, and the translational member is at least partially disposed within the portion of the housing within the hollow channel.

13. The linear actuator according to claim 12, wherein, The inner ring is configured to rotate within the outer ring, such that the spherical joint is configured to passively adjust its position in response to an external force.

14. The linear actuator according to claim 13, wherein, The inner ring has at least two rotational degrees of freedom.

15. The linear actuator of claim 14, further comprising: Notches and tabs are configured to constrain the inner ring from rotating about the longitudinal axis of the translation member.

16. The linear actuator according to claim 1, wherein, The linear actuator has a stroke-to-length ratio equal to or less than 1.2 to 1.

17. An aircraft comprising a tiltable propulsion system coupled to a linear actuator according to claim 1.

18. A system comprising: Linear actuators, comprising: case; Translational members configured to translate relative to the housing; and A spherical joint connected to the housing and oriented parallel to the longitudinal axis of the translation member, wherein the translation member is configured to translate relative to the spherical joint and the housing; The first structure connected to the housing via the ball joint; and A second structure connected to the translation member, wherein the translation member is configured to cause the second structure to move relative to the first structure when the translation member is actuated.

19. The system according to claim 18, wherein, The first structure is a support structure for the aircraft, the second structure is a tiltable propulsion system for the aircraft, and the translation member is configured to cause the tiltable propulsion system to tilt when the translation member is actuated.

20. The system according to claim 18, wherein, The ball joint is configured to passively adjust in response to changes in position or angle of the first or second structure, thereby maintaining the internal alignment of the linear actuator.

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