LINEAR ACTUATOR WITH DAMPING MECHANISM

Abstract

Linear actuator that includes: an actuator body (10) comprising a motor (13), a guide screw (151), an outer tube (152) and a retractable tube (153), wherein the guide screw (151) is driven by the motor (13) to rotate, the outer tube (152) encloses an outside of the retractable tube (153) and the retractable tube (153) comprises a screw nut (157) which is screwed to the guide screw (151) for transmission; a quick-release mechanism (30) arranged on the guide screw (151) to release a drive relationship between the motor (13) and the guide screw (151); and a damping mechanism (50) arranged in the actuator body (10) comprising an elastic element (51) and a deceleration structure (53); wherein, when the quick-release mechanism (30) is in a released state, the guide screw (151) rotates under a load from the retractable tube (153), the screw nut (157) compresses the elastic element (51) to cause the deceleration structure (53) to be driven to perform a braking action in order to slow down the rotational speed of the rotating guide screw (151) via the deceleration structure (53).

Description

BACKGROUND OF THE REVELATION Technical Area

[0001] The present disclosure relates to the technical field of linear actuators, in particular to a linear actuator with a damping mechanism. Description of the state of the art

[0002] A prior art linear actuator is arranged in an electric care bed, a treadmill or a wheelchair and is used to adjust and change the elevation angle and height; consequently, the prior art linear actuator is generally known to consumers and manufacturers.

[0003] US Patent No. US5329657 discloses a quick-release coupling for the head section of a hospital bed, which includes a coupling carrier. The carrier has a Fowler section that is movable between a horizontal and an inclined position relative to a bed frame. The bed frame has an electric reversing drive motor that, via a reduction gear arrangement and a disengageable coupling mechanism, can rotatably drive a threaded shaft. A nut engages with the shaft and is prevented from rotating with it. A linkage arrangement couples the nut to the Fowler section to allow a reciprocating motion of the Fowler section in response to a reciprocating motion of the nut along the shaft. A manual release is provided on the Fowler section.When activated, the releasable clutch mechanism is released, consequently the threaded shaft can rotate independently of the motor and gearbox arrangement.

[0004] US Patent No. US5346045 discloses a linear actuator comprising an electric reversing motor that drives a threaded screw shaft engaging a roller nut. A tubular housing, rigidly connected to the nut, features an internal seat element and load-retaining lugs at its distal ends. A hydraulic shock absorber unit, providing linear deceleration, is normally held in its most relaxed state between the seat element and one end of a spacer tube abutting the nut. When the nut is within the shock absorber stroke distance from the driven end of the shaft, the free end of the shaft compresses the shock absorber unit against the bearing surface.When the nut is within the shock absorber stroke distance from the free end of the shaft, a ring with a stop collar engages, holding the shock absorber body at a fixed distance from the free end of the shaft, with the spacer tube compressing the shock absorber unit. A centrifugal brake is attached to a drive clutch pulley and limits the rotation of the shaft above a predetermined speed.

[0005] US Patent Publication No. US2012240696A1 discloses a linear actuator with an electric reversing motor that drives, via a gearbox, a non-self-locking spindle. This spindle axially moves a tubular positioning element, which is connected at one end to a spindle nut on a spindle. The actuator includes a quick-release mechanism for disengaging the tubular positioning element from the electric motor and the portion of the gearbox located between the motor and the quick-release mechanism, such that the spindle is rotated by the load on the tubular positioning element. The actuator further includes braking means to control the speed of the tubular positioning element under external load when the quick-release mechanism is activated.The braking system consists of a centrifugal brake, which makes it possible to create a design in which the lowering speed is controlled automatically when the quick release is activated.

[0006] DE 10 2014 019 729 A1 describes a linear actuator comprising a gearbox housing, a motor assembly, a guide screw, a telescopic tube, a quick-release mechanism and a buffer mechanism.

[0007] DE 20 2021 101 750 U1 describes an electric push rod with a dual braking mechanism. DE 20 2022 100 838 U1 describes an industrial electric linear heavy-duty actuator. DE 11 2020 005 715 T5 describes an actuator whose overall length can be reduced. SUMMARY OF THE REVELATION

[0008] The present disclosure provides a linear actuator with a damping mechanism, wherein the rotational speed of a rotating guide screw is reduced by a deceleration structure, thereby reducing a shock force generated when a retractable tube is retracted into an outer tube.

[0009] Accordingly, the present disclosure provides a linear actuator with a damping mechanism, comprising an actuator body, a quick-release mechanism, and a damping mechanism. The actuator body includes a motor, a guide screw, an outer tube, and a retractable tube. The guide screw is driven by the motor to rotate. The outer tube encloses the outside of the retractable tube. The retractable tube has a nut that is screwed to the guide screw for power transmission. The quick-release mechanism is located on the guide screw and is used to disengage the drive relationship between the motor and the guide screw. The damping mechanism is located within the actuator body and includes an elastic element and a deceleration structure.When the quick-release mechanism is in a released state, the guide screw rotates when the retractable tube is subjected to a load, with the screw nut compressing the elastic element to cause the deceleration structure to be driven to generate braking; consequently, the rotational speed of the rotating guide screw is reduced via the deceleration structure.

[0010] Accordingly, the present disclosure provides a linear actuator with a damping mechanism, comprising an actuator body, a quick-release mechanism, and a damping mechanism. The actuator body includes a motor, a guide screw, and a retractable tube. The guide screw is driven by the motor to rotate. The retractable tube has a nut that is screwed to the guide screw for power transmission. The quick-release mechanism is located on the guide screw and is used to disengage the drive relationship between the motor and the guide screw. The damping mechanism is located within the actuator body and includes an elastic element and a deceleration structure. The deceleration structure includes a rotary gear driven by the guide screw and a braking structure arranged corresponding to the rotary gear.Whereas when the screw nut compresses the elastic element and the elastic element is deformed to cause the rotary gear to be mechanically connected to the brake structure, the rotational speed of the rotating guide screw via the brake structure, which brakes the rotary gear, is reduced.

[0011] Accordingly, the present disclosure provides a linear actuator with a damping mechanism, comprising an actuator body and a damping mechanism. The actuator body includes a motor, a guide screw, and a retractable tube. The guide screw is driven by the motor to rotate. The retractable tube has a nut that is screwed to the guide screw for transmission. The damping mechanism is arranged within the actuator body and includes an elastic element and a deceleration structure. The deceleration structure includes a rotary gear driven by the guide screw and a braking structure arranged corresponding to the rotary gear.Whereas when the screw nut compresses the elastic element and the elastic element is deformed to cause the rotary gear to be mechanically connected to the brake structure, the rotational speed of the rotating guide screw via the brake structure, which brakes the rotary gear, is reduced.

[0012] The advantages achieved by the present disclosure are as follows. The engagement between the rotary gear and the rotation stop element is resolved by a recovery element. A screw cap ensures that the impact force from the nut is evenly distributed to the elastic element. A front and a rear position limiting ring provide stable positioning and fastening for the elastic element. The engagement stability between the rotary gear and the rotation stop element is improved by the presence of a first concave / convex surface and a second concave / convex surface on both the rotary gear and the rotation stop element. The manufacturing process and the complex assembly process are simplified by the use of an internal mounting block for the rotary gear, which engages with a U-shaped notch in the directional guide unit.An axial bearing prevents relative friction between a distal surface of the elastic element and the rotating gear, thus avoiding unacceptable situations that could generate scratches or noise. By arranging an offset gear and the rotation stop element in parallel, the invalid stroke of the retractable tube is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The features of the disclosure that are considered novel are set forth in detail in the attached claims. However, the disclosure itself can best be understood by referring to the following detailed description of the disclosure, which describes a number of exemplary embodiments of the disclosure, to be considered in conjunction with the attached drawings; these show: Fig. 1 a perspective view showing the arrangement according to the first embodiment of the present disclosure; Fig. 2 a schematic view showing the arrangement of some of the components according to the first embodiment of the present disclosure; Fig. 3 an exploded view showing some of the components according to the first embodiment of the present disclosure; Fig. 4 a cross-sectional view showing the arrangement according to the first embodiment of the present disclosure; Fig. 5 a cross-sectional view showing an operating state according to the first embodiment of the present disclosure; Fig. 6 a schematic view showing the arrangement of some of the components according to the second embodiment of the present disclosure; Fig. 7 a cross-sectional view showing the arrangement according to the second embodiment of the present disclosure; Fig. 8 a cross-sectional view showing an operating state according to the second embodiment of the present disclosure; Fig. 9 a cross-sectional view showing the arrangement according to the third embodiment of the present disclosure; Fig. 10 a cross-sectional view showing an operating state according to the third embodiment of the present disclosure; Fig. 11 a cross-sectional view showing the arrangement according to the fourth embodiment of the present disclosure; Fig. 12 a perspective view showing the arrangement according to the fifth embodiment of the present disclosure; Fig. 13 a schematic view showing the arrangement of some of the components according to the fifth embodiment of the present disclosure; Fig. 14 an exploded view showing the arrangement of some of the components according to the fifth embodiment of the present disclosure; Fig. 15 a cross-sectional view showing the arrangement according to the fifth embodiment of the present disclosure; Fig. 16 a cross-sectional view showing an operating state according to the fifth embodiment of the present disclosure; Fig. 17 a perspective view showing the arrangement according to the sixth embodiment of the present disclosure; Fig. 18 a schematic view showing the arrangement of some of the components according to the sixth embodiment of the present disclosure; Fig. 19 an exploded view showing the arrangement of some of the components according to the sixth embodiment of the present disclosure; Fig. 20 a cross-sectional view showing the arrangement according to the sixth embodiment of the present disclosure; and Fig. 21 a cross-sectional view showing an operating state according to the sixth embodiment of the present disclosure. DETAILED DESCRIPTION OF THE REVELATION

[0014] The technical content of this disclosure becomes apparent through the detailed description of the embodiments, accompanied by the illustration of the associated drawings, as follows. The embodiments and drawings disclosed herein are to be regarded as illustrative rather than limiting.

[0015] In Fig. 1, Fig. 2, Fig. 3, Fig. 4 to Fig. 5. The present disclosure provides a linear actuator with a damping mechanism. The linear actuator with the damping mechanism is mainly used in a nursing bed or a medical bed (not shown in the figures), wherein a front section of the nursing bed or medical bed generates an elevating or horizontal lying motion when actuated by the linear actuator. In particular, when a patient must be in a supine position to be treated with an emergency rescue operation, such as an electric shock, the linear actuator reduces the shock force generated when the front section of the nursing bed or medical bed rapidly lowers, consequently minimizing injury to the patient and providing the patient with a more comforting sensation.

[0016] The linear actuator mainly contains an actuator body 10, a quick-release mechanism 30 and a damping mechanism 50.

[0017] In Fig. The actuator 10 mainly comprises a housing 11, a motor 13, and a transmission mechanism 15. The housing 11 mainly contains a lower housing element 111 and an upper housing element 115. The upper housing element 115 and the lower housing element 111 are made of a plastic material. The lower housing element 111 consists of a round tubular segment 112 and a half housing cover 113, which is formed from and extends from one end of the round tubular segment 112. The end of the round tubular segment 112 furthest from the half housing cover 113 is sealed. The upper housing element 115 is a half housing cover that engages with the half housing cover 113 of the lower housing element 111. Fastening components, e.g., screws, are located between the lower housing element 111 and the upper housing element 115.Screws provided for assembly and fastening.

[0018] The motor 13 is arranged in the round, tubular segment 112 of the lower housing element 111. The motor 13 has a worm gear 131. The worm gear 131 generates normal and opposite rotations through the combination and operation of the components, e.g., the magnetic poles of a coil and a current, in the motor 13.

[0019] In Fig. 2, Fig. 4 and Fig. The transmission mechanism 15 mainly comprises a guide screw 151, an outer tube 152, and a retractable tube 153. A rear section of the guide screw 151 is supported in the lower housing element 111 by the casing of a front bearing 154 and a rear bearing 155, as shown in Fig. 4 and Fig. Figure 5 shows the remaining section of the guide screw 151 protruding from the housing 11. A worm gear 156, which engages reciprocally with and corresponds to the worm 131, encases the guide screw 151 and is located on the rear side of the front bearing 154. According to this embodiment, the threaded screw 151 is a non-self-locking guide screw; in other words, when the retractable tube 153 is restricted to generate rotations, the guide screw 151 rotates freely with respect to the retractable tube 153 in a situation where the retractable tube 153 is subjected to an axial thrust or a compressive force, consequently generating a linear movement of the retractable tube 153 to retract into the outer tube 152.

[0020] The outer tube 152 is a hollow tube element. The outer tube 152 encloses an outer circumference of the guide screw 151 and carries the retractable tube 153. One end of the outer tube 152 is enclosed and secured by the lower housing element 111 and the upper housing element 115.

[0021] The retractable tube 153 encases the outer circumference of the guide screw 151 and is located inside the outer tube 152. One end of the retractable tube 153 is connected to a nut 157, with the retractable tube 153 and the guide screw 151 being mutually screwed together via the nut 157 for power transmission. An outer circumference of the nut 157 is provided with a groove and a block (not shown in the figures) that are alternately attached to the outer tube 152; consequently, the nut 157 and the retractable tube 153 can only move linearly within the outer tube 152 and cannot rotate.

[0022] In Fig. 4 and Fig. The quick-release mechanism 30 mainly comprises a positioning gear 31, a clutch gear 33, and a guide unit 35. The positioning gear 31, the clutch gear 33, and the guide unit 35 are essentially designed as a single round, tubular element. The positioning gear 31 surrounds and is attached to the guide screw 151; consequently, the positioning gear 31 rotates with the guide screw 151. The clutch gear 33 surrounds the guide screw 151 via the guide unit 35 and is located on one side of the positioning gear 31, with the clutch gear 33 moving axially on it by a guiding action provided by the guide unit 35.Several claw grooves (not shown in the figures) are arranged in one side of the clutch gear 33, while several convex claw projections (not shown in the figures) are arranged on an outer circumference of the position gear 31; according to the same principle, each of the convex claw projections and each of the claw grooves can be interchangeably arranged between the position gear and the clutch gear. Each of the convex claw projections is fitted in each of the claw grooves; consequently, the clutch gear 33 is actuated to produce an engagement or disengagement movement corresponding to that of the position gear 31.

[0023] According to this embodiment, the quick-release mechanism 30 further comprises a pull unit 37 which is pivotably connected to an outer surface of the upper housing element 115, as shown in Fig. Figure 1 shows that the pull unit 37 is connected to the clutch gear 33 by a connecting component (not shown in the figures) located in the upper housing element 115. Actuating the pull unit 37 causes the clutch gear 33 to slide on the guide unit 35 and perform the engagement or disengagement movement corresponding to the positioning gear 31.

[0024] The guide screw 151 is driven by the engagement between the worm 131 of the motor 13 and the worm gear 156. When the clutch gear 33 and the position gear 31 are engaged, the guide screw 151 is driven to rotate by the position gear 31, the clutch gear 33, and the guide unit 35. When the clutch gear 33 and the position gear 31 are disengaged, the guide screw 151 and the position gear 31 rotate freely under a load applied to the retractable tube 153, at which time the clutch gear 33, the guide unit 35, and the worm gear 156 are restrained by the worm 131, and no rotation is generated.

[0025] In Fig. In this embodiment, the damping mechanism 50 is arranged on the guide screw 151. According to this embodiment, the damping mechanism 50 is located between the nut 157 and the worm gear 156. The damping mechanism 50 mainly comprises an elastic element 51 and a deceleration structure 53. According to this embodiment, the elastic element 51 is a compression spring. According to this embodiment, the deceleration structure 53 comprises a rotary gear 531, a rotation stop element 533, and a brake element 535. According to this embodiment, the rotation stop element 533 and the brake element 535 are defined as a brake structure. According to this embodiment, the shape of the rotary gear 531 and that of the rotation stop element 533 are essentially round and tubular, which is not considered a limiting factor here. The rotary gear 531 is arranged close to the nut 157.The rotation stop element 533 is arranged on one side of the rotary gear 531, away from the screw nut 157. The brake element 535 encloses an outer circumference of the rotation stop element 533. According to this embodiment, the brake element 535 is a spring, which is not intended to be restrictive, with one end of the brake element 535 attached to the housing 11 of the actuator body 10.

[0026] According to some embodiments, several convex claw projections 5313 are arranged on a distal surface of the rotary gear 531, facing towards the rotary stop element 533. Several claw grooves 5331 are formed in a distal surface of the rotary stop element 533, also facing towards the rotary gear 531. Each claw groove 5331 corresponds to each of the convex claw projections 5313. Each claw groove 5331 and each convex claw projection 5313 are actuated to engage or disengage. Following the same principle, each convex claw projection 5313 and each claw groove 5331 can be arranged interchangeably between the rotary stop element 533 and the rotary gear 531.

[0027] According to this embodiment, the delay structure 53 further comprises a directional guidance unit 537, which encases the guide screw 151 and rotates with it. The rotary gear 531 and the rotation stop element 533 encase the directional guidance unit 537. The directional guidance unit 537 mainly comprises a lower housing 5371 and an upper housing 5373. The upper housing 5373 engages with the lower housing 5371 to jointly encase the guide screw 151. A first positioning surface 1511 is arranged on a circumferential surface of the guide screw 151. A second positioning surface 5377 is arranged on both the upper housing 5373 and the lower housing 5371. The directional guidance unit 537 rotates with the guide screw 151 through the first positioning surface 1511 and the second positioning surface 5377, which are alternately mounted and positioned.

[0028] Several guide strips 5375 extend from a circumferential surface of the directional guidance unit 537. Several guide slots 5311 are formed in an inner wall of the rotary gear 531. Each of the guide strips 5375 is accordingly positioned in each of the guide slots 5311. The directional guidance unit 537, as such, drives the rotary gear 531 through each of the guide strips 5375 of the directional guidance unit 537, which is positioned in each of the guide slots 5311, so that it rotates with the directional guidance unit 537. The rotation stop element 533 encloses a zone of the directional guidance unit 537 where the guide strips 5375 are not located.When the rotary gear 531 is not actuated by the elastic element 51, the rotation stop element 533 is not mechanically connected to the rotary gear 531. At this point, the rotation stop element 533 is held back by the brake element 535 and does not rotate with the guide screw 151 and the direction guide unit 537. Only after the rotary gear 531 has been pushed by the elastic element 51 is it mechanically connected to the rotation stop element 533 (the mechanical connection is defined when each of the convex claw projections 5313 is appropriately positioned and combined with each of the claw grooves 5331; a combination generated by some other means, such as friction, can also be provided according to the same principle). The rotation stop element 533 stops the rotation of the gear 531 by being held back by the brake element 535.The amount of guide slot and guide strip can be one.

[0029] According to this embodiment, the delay structure 53 further includes a recovery element 539, which is arranged between the rotary gear 531 and the rotation stop element 533. The recovery spring 539 releases the engagement between the rotary gear 531 and the rotation stop element 533 when the rotary gear 531 is not being pushed through the elastic element 51. Following the same principle, the recovery element 539 can be in a state where it is located on the inside or outside of the rotary gear 531 or the rotation stop element 533.

[0030] According to this embodiment, the damping mechanism 50 further includes a screw cap 55 that encloses one end of the elastic element 51 away from the deceleration structure 53. When the screw nut 157 impacts directly onto the elastic element 51, an impact force is transmitted uniformly to the elastic element 51 via the screw cap 55.

[0031] According to this embodiment, the damping mechanism 50 further includes a thrust bearing 57 that encircles an outer circumference of the rotary gear 531. Because the rotary gear 531 rotates with the guide screw 151, the elastic element 51 does not generate any rotation via the thrust bearing 57. After the elastic element 51 has been compressed and deformed by the screw nut 157, the thrust bearing 57 prevents relative friction between a distal surface of the elastic element 51 and the rotary gear 531, thus avoiding unacceptable situations that could generate scratches or noise. The thrust bearing 57 can be replaced by a cushion, based on the same principle.

[0032] According to some embodiments, at least one position limiting element 60 is also provided. The at least one position limiting element 60 penetrates the outer tube 152 and is attached to it in order to limit the stroke of movement of the screw cap 55 and / or the elastic element 51.

[0033] The linear actuator with the damping mechanism provided by the present disclosure further comprises a rear support 70 and a front support 75. The rear support 70 is arranged on a rear side of the rear bearing 155 and is clamped and secured by the upper housing element 115 and the lower housing element 111. The front support 75 encloses a distal section of the retractable tube 153 away from the screw nut 157.

[0034] When, in use with the weight of the patient or a pressure force exerted by medical personnel on the front section of the nursing bed or hospital bed, the clutch gear 33 and the position gear 31 are separated by actuating the pull unit 37, the screw nut 157 drives the guide screw 151 to generate rotations after the retractable tube 153 has been subjected to the aforementioned load, the retractable tube 153 then retracts into the outer tube 152, the elastic element 51 producing a compressed deformation at a distal point of the stroke of the retractable tube 153 by the screw nut 157, which presses on the screw cap 55 and the elastic element 51;The rotary gear 531 is then pushed by the compressive force generated after the elastic element 51 has been deformed to move towards the rotation stop element 533, with each of the convex claw projections 5313 of the rotary gear 531 being engaged in each of the claw grooves 5331 of the rotation stop element 533 at this point, and consequently the rotary gear 531 driving the rotation stop element 533 to rotate with the rotary gear 531. With the braking element 535, which tightens and restrains the rotation stop element 533, the rotation stop element 533 stops the rotation of the rotary gear 531 and the guide screw 151, consequently slowing the rotational speed of the guide screw 151 and reducing the speed of movement of the retractable tube 153, which retracts into the outer tube 152.

[0035] In Fig. 6, Fig. 7 to Fig. 8. The structure of the linear actuator with the damping mechanism disclosed in this embodiment is essentially the same as that of the linear actuator with the damping mechanism disclosed in the first embodiment. The differences between this embodiment and the first embodiment are as follows. According to this embodiment, a deceleration structure 53A mainly comprises a rotary gear 531A, a rotary stop element 533A, and the brake element 535. A first friction surface 5314 is formed on a distal surface of the rotary gear 531A, facing towards the rotary stop element 533A. A second friction surface 5334 is formed on a distal surface of the rotary stop element 533A, facing towards the rotary gear 531A. The drive and rotation are provided by the friction between the first friction surface 5314 and the second friction surface 5334.

[0036] In Fig. 9 and Fig. 10. The structure of the linear actuator with the damping mechanism disclosed in this embodiment is essentially the same as that of the linear actuator with the damping mechanism disclosed in the aforementioned embodiments. The differences between this embodiment and the aforementioned embodiments are as follows. According to this embodiment, a deceleration structure 53B mainly comprises a rotary gear 531B, a rotary stop element 533B, and the braking element 535. A first magnet 5315 is arranged in the rotary gear 531B, while a second magnet 5333 is arranged in the rotary stop element 533B. According to this embodiment, a recovery element is composed of the first magnet 5315 and the second magnet 5333. The drive and rotation between the rotary gear 531B and the rotary stop element 533B are provided by a frictional action generated between their distal surfaces.Based on the same magnetic pole repulsion principle between the first magnet 5315 and the second magnet 5333, the rotary gear 531B is not mechanically connected to the rotation stop element 533B unless pressed against it by the elastic element 51. According to some embodiments, the corresponding distal surfaces of the rotary gear 531B and the rotation stop element 533B are driven to rotate by a combination of a convex and concave structure or by claw projections and claw grooves.

[0037] In Fig. 11 The structure of the linear actuator with the damping mechanism disclosed in this embodiment is essentially the same as that of the linear actuator with the damping mechanism disclosed in the aforementioned embodiments. The differences between this embodiment and the aforementioned embodiments are as follows. According to this embodiment, a deceleration structure 53C mainly comprises a rotary gear 531C and a rotary stop element 533C. According to this embodiment, the rotary stop element 533C is defined as a braking structure. One end of the elastic element 51 is tightened to an outer circumference of the rotary gear 531C. A positioning surface (not shown in the figures) is formed on the rotary stop element 533C to be reciprocally attached to the surface of the guide screw 151. The rotary gear 531C is driven by the guide screw 151 to rotate with the guide screw 151.A compressive force generated after the elastic element 51 has been deformed pushes the rotation stop element 533C to mechanically engage with the rotary gear 531C. The braking effect, generated by friction between the first friction surface 5314 of the rotary gear 531C and the second friction gear 5334 of the rotation stop element 533C, reduces the rotational speed of the guide screw 151, which is in a rotating state, or stops the rotation.

[0038] In Fig. 12, Fig. 13, Fig. 14, Fig. 15 to Fig. 16. The differences between the linear actuator with the damping mechanism disclosed in this embodiment and that disclosed in the first embodiment are as follows. According to this embodiment, a deceleration structure 53D mainly comprises a rotary gear 531D, a rotary stop element 533D, and a braking element 535. A first concave / convex surface 5317 is formed on a distal surface of the rotary gear 531D, facing in the direction of the rotary stop element 533D. A second concave / convex surface 5335 is formed on a distal surface of the rotary stop element 533D, facing in the direction of the rotary gear 531D. The first concave / convex surface 5317 and the second concave / convex surface 5335 are actuated to engage or disengage, thereby improving the engagement stability between the rotary gear 531D and the rotary stop element 533D.

[0039] A directional guidance unit 537D has a U-shaped notch 5379 which surrounds the first positioning surface 1511 of the guide screw 151, causing the directional guidance unit 537D to rotate with the guide screw 151. An inner mounting block 5319 is arranged on the rotary gear 531D, the inner mounting block 5319 being movably connected to the U-shaped notch 5379, causing the rotary gear 531D to move axially with respect to the directional guidance unit 537D and to rotate with the directional guidance unit 537D. The rotary stop element 533D encloses the direction guide unit 537D, wherein, if the rotary gear 531D is not mechanically connected to the rotary stop element 533D, the rotary stop element 533D is not rotatable, thereby simplifying the manufacturing process and also simplifying the complicated assembly process.

[0040] According to this embodiment, a damping mechanism 50D further comprises a front position limiting ring 56 and a rear position limiting ring 58. The front position limiting ring 56 and the rear position limiting ring 58 each enclose two ends of the elastic element 51, thus providing a stable positioning and fastening effect for the elastic element 51.

[0041] According to this embodiment, several position limiting elements 60 are provided. Each of the position limiting elements 60 runs along the outer tube 152 and is attached to it, thereby limiting the stroke of movement of the front position limiting ring 56. The number of position limiting rings 60 can be one.

[0042] In Fig. 17, Fig. 18, Fig. 19, Fig. 20 to Fig.The differences between the linear actuator with the damping mechanism disclosed in this embodiment and the one disclosed in the fifth embodiment are as follows. According to this embodiment, a deceleration structure 53E mainly comprises a rotary gear 531E, a rotary stop element 533E, the brake element 535, and an offset gear 536. According to this embodiment, the rotary stop element 533E, the brake element 535, and the offset gear 536 are defined as a brake structure. The rotary gear 531E is connected to the guide screw 151 via a direction guide unit 537E and rotates with the direction guide unit 537E. The rotary stop element 533E encloses the direction guide unit 537E. When the rotary gear 531E is not mechanically connected to the rotary stop element 533E, the rotary stop element 533E is not rotatable. The offset gear 536 is rotatably arranged in the housing 11 of the actuator body 10 and is connected to the rotation stop element 533E.The brake element 535 encases the offset gear 536, with one end of the brake element 535 being attached to the housing 11 of the actuator body 10. An invalid stroke of the retractable tube 153 is thus shortened.

[0043] According to some embodiments, the delay structure 53E further includes a recovery element 539, which is arranged between the rotary gear 531E and the rotation stop element 533E. When the elastic element 51 does not press on the rotary gear 531E, the rotary gear 531E can be moved, with the engagement of the rotary gear 531E and the rotation stop element 533E being disengaged.

[0044] In some embodiments, a block projection 5316 is arranged on a distal surface of the rotary gear 531E, facing towards the rotary stop element 533E. A block slot 5336 is formed on a distal surface of the rotary stop element 533E, also facing towards the rotary gear 531E. The block projection 5316 and the block slot 5336 are operated to engage or disengage. Several first teeth 5337 extend from a circumferential surface of the rotary stop element 533E. Several second teeth 5361 extend from a circumferential surface of the offset gear 536. The driving and rotational action is provided by the first teeth 5337 engaging with the second teeth 5361.

[0045] While this disclosure has been described by means of specific embodiments, numerous modifications and variations could be made by those skilled in the field without deviating from the scope of protection and inventive concept of this disclosure as set out in the claims.

Claims

[1] Linear actuator comprising: an actuator body (10) comprising a motor (13), a guide screw (151), an outer tube (152) and a retractable tube (153), wherein the guide screw (151) is driven by the motor (13) to rotate, the outer tube (152) encloses an outside of the retractable tube (153) and the retractable tube (153) comprises a screw nut (157) which is screwed to the guide screw (151) for transmission; a quick-release mechanism (30) arranged on the guide screw (151) to release a drive relationship between the motor (13) and the guide screw (151); and a damping mechanism (50) arranged in the actuator body (10) comprising an elastic element (51) and a deceleration structure (53); wherein, when the quick-release mechanism (30) is in a released state, the guide screw (151) rotates under a load from the retractable tube (153), the screw nut (157) compresses the elastic element (51) to cause the deceleration structure (53) to be driven to perform a braking action in order to slow down the rotational speed of the rotating guide screw (151) via the deceleration structure (53). [2] Linear actuator according to claim 1, wherein the deceleration structure (53) comprises a rotary gear (531) and a rotation stop element (533) arranged accordingly on the rotary gear (531), wherein the rotary gear (531) is arranged on the guide screw (151) and rotates with the guide screw (151), wherein the rotation stop element (533) is arranged on the guide screw (151) and is mechanically connected to the rotary gear (531) to perform the braking on the rotary gear (531). [3] Linear actuator according to claim 2, wherein the deceleration structure (53) further comprises a braking element (535) arranged on the rotation stop element (533). [4] Linear actuator according to claim 3, wherein the braking element (535) is a spring and one end of the spring is attached to the actuator body (10). [5] Linear actuator according to claim 2, wherein the rotary gear (531) comprises at least one convex claw projection (5313) and the rotary stop element (533) comprises at least one claw groove (5331) which can engage with or be disengaged from the convex claw projection (5313). [6] Linear actuator according to claim 2, wherein the delay structure (53) further comprises a direction guidance unit (537), the rotary gear (531) is connected to the guide screw (151) via the direction guidance unit (537), the direction guidance unit (537) comprises at least one guide strip (5375), the rotary gear (531) comprises at least one guide slot (5311) which engages with the guide strip (5375) accordingly, and the rotation stop element (533) is arranged on the direction guidance unit (537). [7] Linear actuator according to claim 6, wherein the directional guidance unit (537) comprises a lower housing (5371) and an upper housing (5373), the upper housing (5373) engaging with the lower housing (5371) to enclose the guide screw (151), the guide screw (151) comprising a first positioning surface (1511), the upper housing (5373) and the lower housing (5371) each comprising a second positioning surface (5377) attached to and positioned on the first positioning surface (1511). [8] Linear actuator according to claim 2, wherein the delay structure (53) further comprises a recovery element (539) arranged on the rotary gear (531), on the rotary stop element (533) or between the rotary gear (531) and the rotary stop element (533). [9] Linear actuator according to claim 8, wherein the recovery element (539) is a spring or a magnet (5315, 5333). [10] Linear actuator according to claim 2, wherein the damping mechanism (50) further comprises an axial bearing (57) arranged on the rotary gear (531). [11] Linear actuator according to claim 2, wherein the rotary gear (531A) comprises a first friction surface (5314) and the rotation stop element (533A) comprises a second friction surface (5334) which is driven by the first friction surface (5314) to rotate. [12] Linear actuator according to claim 2, wherein the rotary gear (531D) comprises a first concave / convex shaped toothing (5317) and the rotary stop element (533D) comprises a second concave / convex toothing (5335) which can be engaged with or disengaged from the first concave / convex toothing (5317). [13] Linear actuator according to claim 12, wherein the delay structure (53D) further comprises a direction guidance unit (537D), the rotary gear (531D) is connected to the guide screw (151) via the direction guidance unit (537D), the direction guidance unit (537D) comprises a U-shaped notch (5379), the rotary gear (531D) comprises an inner mounting block (5319) which is movably connected to the U-shaped notch (5379), and the rotation stop element (533D) is arranged on the direction guidance unit (537D). [14] Linear actuator according to claim 12, wherein the damping mechanism (50D) further comprises a front position limiting ring (56) and a rear position limiting ring (58) and the front position limiting ring (56) and the rear position limiting ring (58) are arranged at two ends of the elastic element (51). [15] Linear actuator according to claim 14, further comprising at least one position limiting element (60) that limits a stroke of the front position limiting ring (56), wherein the position limiting element (60) is attached to the outer tube (152). [16] Linear actuator according to claim 1, further comprising at least one position limiting element (60) that limits a stroke of the elastic element (51), wherein the damping mechanism (50) further comprises a screw cap (55) arranged at an end of the elastic element (51) located away from the deceleration structure (53), and the position limiting element (60) is attached to the outer tube (152). [17] Linear actuator according to claim 2, wherein the deceleration structure (53C) tightens and secures the rotation stop element (533C) via the elastic element (51) to perform braking. [18] Linear actuator according to claim 2, wherein the deceleration structure (53E) further comprises a brake element (535) and an offset gear (536), wherein the offset gear (536) is pivotably arranged in the actuator body (10) and is connected to the rotation stop element (533E), wherein the brake element (535) encases the offset gear (536) and one end thereof is fixed in the actuator body (10). [19] Linear actuator according to claim 18, wherein the delay structure (53E) further comprises a recovery element (539) arranged between the rotary gear (531E) and the rotary stop element (533E). [20] Linear actuator according to claim 18, wherein the rotary gear (531E) comprises a block projection (5316), the rotary stop element (533E) comprises a block slot (5336) and several first teeth (5337), the offset gear (536) comprises several second teeth (5361) which engage with the first teeth (5337) and are rotatable, and the block projection (5316) can be engaged with and released from the block slot (5336) accordingly. [21] Linear actuator comprising: an actuator body (10) comprising a motor (13), a guide screw (151) and a retractable tube (153), wherein the guide screw (151) is driven by the motor (13) to rotate, and the retractable tube (153) comprises a screw nut (157) which is screwed to the guide screw (151) for transmission; a quick-release mechanism (30) arranged on the guide screw (151) to release a drive relationship between the motor (13) and the guide screw (151); and a damping mechanism (50) arranged in the actuator body (10) comprising an elastic element (51) and a deceleration structure (53), wherein the deceleration structure (53) comprises a rotary gear (531) driven by the guide screw (151) and a brake structure arranged corresponding to the rotary gear (531); wherein, when the screw nut (157) compresses the elastic element (51) and the elastic element (51) is deformed to cause the rotary gear (531) to be mechanically connected to the brake structure, the rotational speed of the rotating guide screw (151) is slowed down via the brake structure, which brakes the rotary gear (531). [22] Linear actuator according to claim 21, wherein the brake structure comprises a rotation stop element (533, 533D) and a brake element (535), wherein the brake element (535) is arranged on the rotation stop element (533, 533D) and wherein the rotation stop element (533, 533D) is arranged according to the rotary gear (531, 531D) and is operationally engaged with it or disengaged from it. [23] Linear actuator according to claim 21, wherein the brake structure comprises a rotation stop element (533C), one end of the rotation stop element (533C) is attached to the elastic element (51) and another end of the rotation stop element (533C) is arranged according to the rotary gear (531C) and is operationally engaged with it or released from it. [24] Linear actuator according to claim 21, wherein the brake structure comprises a rotation stop element (533E), a brake element (535) and an offset gear (536), the rotation stop element (533E) being arranged correspondingly to the rotary gear (531E) and being engaged with it or disengaged from it during operation, the brake element (535) being arranged on the offset gear (536) and the offset gear (536) being rotatably arranged in the actuator body (10) and being connected to the rotation stop element (533E). [25] Linear actuator comprising: an actuator body (10) comprising a motor (13), a guide screw (151) and a retractable tube (153), wherein the guide screw (151) is driven by the motor (13) to rotate, and the retractable tube (153) comprises a screw nut (157) which is screwed to the guide screw (151) for transmission; and a damping mechanism (50) arranged in the actuator body (10) comprising an elastic element (51) and a deceleration structure (53), wherein the deceleration structure (53) comprises a rotary gear (531) driven by the guide screw (151) and a brake structure arranged corresponding to the rotary gear (531); wherein, when the screw nut (157) compresses the elastic element (51) and the elastic element (51) is deformed to cause the rotary gear (531) to be mechanically connected to the brake structure, the rotational speed of the rotating guide screw (151) is slowed down via the brake structure, which brakes the rotary gear (531).

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