Linear actuating device with buffering mechanism

Abstract

The linear actuating device with the buffering mechanism comprises an actuating body, a quick release mechanism and the buffering mechanism, the actuating body comprises a motor, a guide screw, an outer pipe and a telescopic pipe, the guide screw is driven by the motor to rotate, the telescopic pipe is sleeved with the outer pipe, and the telescopic pipe is provided with a nut to be in threaded connection transmission with the guide screw; the quick release mechanism is arranged on the driving screw and is used for releasing the driving of the motor and the driving screw; the buffer mechanism is arranged on the actuating main body and comprises an elastic body and a speed reducing structure; when the quick release mechanism is released, the guide screw rotates under the load of the telescopic pipe, the elastic body is compressed through the nut, the speed reduction structure is driven to generate braking, and therefore the rotating guide screw is decelerated through the speed reduction structure. Therefore, the impact force generated when the telescopic pipe retracts into the outer pipe can be reduced.

Description

[0001] This application claims priority to U.S. patent application filed on July 25, 2023, with application number 63528669 and invention name “LINEAR ACTUATOR WITH BUFFER MECHANISM”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of a linear actuator, and in particular to a linear actuator with a buffer mechanism. Background Art

[0003] The linear actuator is installed in electric beds, treadmills or wheelchairs to adjust the elevation angle or height, which is quite common and accepted by the public.

[0004] For example, U.S. Patent Publication No. US5329657 discloses a hospital bed, including an articulated support having a backrest portion that can move between a horizontal position and an inclined position relative to the frame of the bed. The bed frame supports a reversible electric drive motor that can rotatably drive a threaded shaft through a reduction gear device and a detachable coupling mechanism. The nut is engaged with the shaft and is held so as not to rotate with the shaft, and a linkage device connects the nut to the backrest portion to achieve reciprocating motion of the backrest portion in response to the reciprocating motion of the nut along the shaft. A manual release device is provided on the backrest portion, and disengages from the releasable connection mechanism when actuated so that the threaded shaft can rotate freely independently of the motor and the gear device.

[0005] In addition, U.S. Patent Publication No. US5346045 discloses a linear actuator having a reversible motor driving a threaded shaft engaged with a roller nut. A tubular housing connected to the nut has a base member and a load securing lug at its distal end. The hydraulic shock absorber providing linear deceleration is usually maintained in its most relaxed state, located between the base member and the end of the spacer tube abutting the nut. When the nut is within the shock absorber travel distance of the driven end of the shaft, the free end of the shaft presses the shock absorber against the base. When the nut is within the shock absorber travel distance of the free end of the shaft, the ring engages with the stop ring, thereby maintaining the shock absorber body at a fixed distance from the free end of the shaft, and the spacer tube compresses the shock absorber. A centrifugal brake is provided on the drive coupling pulley and limits the rotation of the shaft from exceeding a predetermined rate.

[0006] Again, US Patent Publication No. US2012240696A1 discloses a linear actuator having a reversible electric motor, which drives a non-self-locking spindle through a transmission device, by which a tubular positioning assembly can be axially moved because one end of it is connected to a spindle nut on a spindle. The actuator includes a transmission device for moving the tubular positioning assembly from the motor and a portion from the motor to a quick release device so that the spindle is set to rotate through a load on the tubular positioning assembly. The actuator also includes a brake device, when the quick release device is activated, for controlling the speed of the tubular positioning assembly during external load. The brake device consists of a centrifugal brake, wherein the descent speed is self-controlled when the quick release device is activated. Summary of the invention

[0007] One object of the present application is to provide a linear actuator with a buffer mechanism, which can reduce the impact force of the telescopic tube when it is retracted into the outer tube by decelerating the rotating lead screw through a deceleration structure.

[0008] In order to achieve the above-mentioned purpose, the present application provides a linear actuator with a buffer mechanism, including an actuator body, a quick release mechanism and a buffer mechanism, wherein the actuator body includes a motor, a lead screw, an outer tube and a telescopic tube, the lead screw is driven by the motor to rotate, the outer tube is sleeved on the outside of the telescopic tube, the telescopic tube has a nut and is used to be threadedly connected with the lead screw for transmission; the quick release mechanism is provided on the lead screw and is used to release the drive of the motor and the lead screw; the buffer mechanism is configured on the actuator body and includes an elastic body and a deceleration structure; when the quick release mechanism is released, the lead screw rotates under the load of the telescopic tube, the nut compresses the elastic body and drives the deceleration structure to brake, so that the rotating lead screw can be decelerated by the deceleration structure.

[0009] In one embodiment, the deceleration structure includes a rotating wheel and a stopper configured corresponding to the rotating wheel, the rotating wheel is provided on the lead screw and rotates with it, the stopper is provided on the lead screw and brakes the rotating wheel through a mechanical connection with the rotating wheel.

[0010] In one embodiment, the deceleration structure further includes a brake assembly, and the brake assembly is disposed on the anti-rotation member.

[0011] In one embodiment, the brake assembly is a spring, and one end of the spring is fixed to the actuating body.

[0012] In one embodiment, the rotating wheel is provided with at least one convex key, and the anti-rotation member is provided with at least one key groove capable of engaging with or disengaging from the convex key.

[0013] In one embodiment, the deceleration structure also includes a guide member, the rotating wheel is connected to the lead screw via the guide member, the guide member is provided with at least one guide strip, the rotating wheel is provided with at least one guide groove that can correspond to the guide strip, and the stop member is provided on the guide member.

[0014] In one embodiment, the guide member includes a lower shell and an upper shell, the upper shell corresponds to the lower shell cover and is combined with the lead screw, the lead screw is provided with a first positioning plane, and the upper shell and the lower shell are respectively provided with a second positioning plane that can be embedded and positioned with the first positioning plane.

[0015] In one embodiment, the deceleration structure further includes a reset member, and the reset member is disposed at one of the rotating wheel, the anti-rotation member, and between the rotating wheel and the anti-rotation member.

[0016] In one embodiment, the reset member is a spring or a magnet.

[0017] In one embodiment, the buffer mechanism further includes a thrust bearing disposed on the rotating wheel.

[0018] In one embodiment, the rotating wheel is provided with a first friction surface, and the anti-rotation member is provided with a second friction surface which can be driven to rotate by the first friction surface.

[0019] In one embodiment, the rotating wheel is provided with a first concave-convex surface, and the anti-rotation member is provided with a second concave-convex surface capable of engaging with or disengaging from the first concave-convex surface.

[0020] In one embodiment, the deceleration structure also includes a guide member, the rotating wheel is connected to the lead screw through the guide member, the guide member is provided with a U-shaped opening, the rotating wheel is provided with an embedded block movably connected to the U-shaped opening, and the stop member is provided on the guide member.

[0021] In one embodiment, the buffer mechanism further includes a front positioning ring and a rear positioning ring, and the front positioning ring and the rear positioning ring are respectively arranged at two ends of the elastic body.

[0022] In one embodiment, it further comprises at least one limiter for limiting the travel of the front positioning collar, and the limiter is fixed to the outer tube.

[0023] In one embodiment, it further includes at least one limiter for limiting the travel of the elastic body, and the buffer mechanism also includes a cap, which is arranged at one end of the elastic body away from the deceleration structure, and the limiter is fixed to the outer tube.

[0024] In one embodiment, the deceleration structure generates braking by tightening and fixing the anti-rotation member by the elastic body.

[0025] In one embodiment, the deceleration structure further includes a brake assembly and an offset wheel, wherein the offset wheel is pivotally mounted on the actuating body and connected to the anti-rotation member, and the brake assembly is sleeved on the offset wheel and one end of the brake assembly is fixed to the actuating body.

[0026] In one embodiment, the deceleration structure further includes a reset member, which is disposed between the rotating wheel and the anti-rotation member.

[0027] In one embodiment, the rotating wheel is provided with a clamping block, the anti-rotation member is provided with a clamping slot and a plurality of first protruding teeth, the offset wheel is provided with a plurality of second protruding teeth that can engage and rotate with each of the first protruding teeth, and the clamping block can engage or disengage corresponding to the clamping slot.

[0028] In order to achieve the above-mentioned purpose, the present application provides another linear actuator device with a buffer mechanism, including an actuator body, a quick release mechanism and a buffer mechanism, wherein the actuator body includes a motor, a lead screw and a telescopic tube, the lead screw is driven by the motor to rotate, and the telescopic tube has a nut and is used to be threadedly connected with the lead screw for transmission; the quick release mechanism is arranged on the lead screw and is used to release the drive of the motor and the lead screw; the buffer mechanism is arranged on the actuator body and includes an elastic body and a deceleration structure, the deceleration structure includes a rotating wheel driven by the lead screw and a stopping member corresponding to the rotating wheel; wherein when the nut compresses the elastic body, the elastic body is deformed to actuate the rotating wheel and the stopping member to generate a mechanical connection, and the lead screw is decelerated by the braking of the rotating wheel by the stopping member.

[0029] In one embodiment, the stopping member includes a stopper and a brake assembly, wherein the brake assembly is disposed on the stopper, and the stopper is configured to correspond to the rotating wheel and can be operatively engaged or disengaged.

[0030] In one embodiment, the stopping member includes a stopper, one end of which is fixed to the elastic body, and the other end of which is configured to correspond to the rotating wheel and can be operatively engaged or disengaged.

[0031] In one embodiment, the stopping member includes a stopper, a brake assembly and an offset wheel, wherein the stopper is configured corresponding to the rotating wheel and can be operably engaged or disengaged, the brake assembly is arranged on the offset wheel, and the offset wheel pivotally mounts the actuating body and is connected to the stopper.

[0032] In order to achieve the above-mentioned purpose, the present application provides another linear actuator with a buffer mechanism, including an actuator body and a buffer mechanism, the actuator body includes a motor, a lead screw and a telescopic tube, the lead screw is driven by the motor to rotate, the telescopic tube has a nut and is used to be threadedly connected with the lead screw for transmission; the buffer mechanism is arranged on the actuator body and includes an elastic body and a deceleration structure, the deceleration structure includes a rotating wheel driven by the lead screw and a stopping member corresponding to the rotating wheel; when the nut compresses the elastomer, the elastic body is deformed to actuate the rotating wheel and the stopping member to generate a mechanical connection, and the lead screw is decelerated by the braking of the rotating wheel by the stopping member.

[0033] The present application also has the following effects: by setting a reset component, it is convenient to disengage the rotating wheel and the anti-rotation member. By using the cap setting, the impact force of the nut can be evenly transmitted to the elastomer. By means of the front positioning ring and the rear positioning ring, a stable holding effect is formed on the elastomer. By setting the first concave-convex surface and the second concave-convex surface of the rotating wheel and the anti-rotation member, the bite stability between the two can be improved. By matching the built-in block of the rotating wheel and the U-shaped mouth of the guide component, the assembly procedure can be simplified and the ease of assembly can be improved. By setting a thrust bearing, the relative friction between the end face of the elastomer and the rotating wheel can be avoided, which can avoid scratches or abnormal noises. By arranging the offset wheel and the anti-rotation member in parallel, the ineffective stroke of the telescopic tube can be shortened. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a perspective view of the first embodiment of the present application.

[0035] Figure 2 This is an appearance diagram of some components of the first embodiment of the present application.

[0036] Figure 3 This is a partial component exploded view of the first embodiment of the present application.

[0037] Figure 4 This is a combined cross-sectional view of the first embodiment of the present application.

[0038] Figure 5 A state cross-sectional view is used for the first embodiment of the present application.

[0039] Figure 6 This is an appearance diagram of some components of the second embodiment of the present application.

[0040] Figure 7 This is a combined cross-sectional view of the second embodiment of the present application.

[0041] Figure 8 A state cross-sectional view is used for the second embodiment of the present application.

[0042] Fig. 9 This is a combined cross-sectional view of the third embodiment of the present application.

[0043] Fig.10 A state cross-sectional view is used for the third embodiment of the present application.

[0044] Fig.11 This is a combined cross-sectional view of the fourth embodiment of the present application.

[0045] Fig.12 This is a combined perspective view of the fifth embodiment of the present application.

[0046] Fig.13 This is an appearance diagram of some components of the fifth embodiment of the present application.

[0047] Fig.14 This is a partial component exploded view of the fifth embodiment of the present application.

[0048] Fig.15 This is a combined cross-sectional view of the fifth embodiment of the present application.

[0049] Fig.16 A state cross-sectional view is used for the fifth embodiment of the present application.

[0050] Fig.17 This is a combined perspective view of the sixth embodiment of the present application.

[0051] Fig.18 This is an appearance diagram of some components of the sixth embodiment of the present application.

[0052] Fig.19 This is a partial component exploded view of the sixth embodiment of the present application.

[0053] Fig. 20 This is a combined sectional view of the sixth embodiment of the present application.

[0054] Fig.21 A state cross-sectional view is used for the sixth embodiment of the present application.

[0055] Description of reference numerals:

[0056] 10: Actuating body;

[0057] 11: Shell seat;

[0058] 111: lower housing;

[0059] 112: round tube section;

[0060] 113: half shell;

[0061] 115: upper shell;

[0062] 13: Electric motor;

[0063] 131: worm;

[0064] 15: transmission mechanism;

[0065] 151: lead screw;

[0066] 1511: first positioning plane;

[0067] 152: external pipe;

[0068] 153: telescopic tube;

[0069] 154: front bearing;

[0070] 155: rear bearing;

[0071] 156: worm gear;

[0072] 157: nut;

[0073] 30: quick release mechanism;

[0074] 31: positioning wheel;

[0075] 33: Clutch wheel;

[0076] 35: guide assembly;

[0077] 37: pull assembly;

[0078] 50, 50D, 50E: buffer mechanism;

[0079] 51: elastomer;

[0080] 53, 53A, 53B, 53C, 53D, 53E: speed reduction structure;

[0081] 531, 531A, 531B, 531C, 531D, 531E: rotating wheels;

[0082] 5311: guide groove;

[0083] 5313: convex key;

[0084] 5314: first friction surface;

[0085] 5315: first magnet;

[0086] 5316: card block;

[0087] 5317: first concave-convex surface;

[0088] 5319: embedded block;

[0089] 533, 533A, 533B, 533C, 533D, 533E: anti-rotation parts;

[0090] 5331: keyway;

[0091] 5333: second magnet;

[0092] 5334: second friction surface;

[0093] 5335: second concave-convex surface;

[0094] 5336: card slot;

[0095] 5337: first convex tooth;

[0096] 535: brake assembly;

[0097] 536: offset wheel;

[0098] 5361: second convex tooth;

[0099] 537, 537D, 537E: guide member;

[0100] 5371: lower shell;

[0101] 5373: upper shell;

[0102] 5375: guide strip;

[0103] 5377: second positioning plane;

[0104] 5379: U-shaped mouth;

[0105] 539: Reset component;

[0106] 55: cap;

[0107] 56: front positioning ring;

[0108] 57: thrust bearing;

[0109] 58: rear positioning ring;

[0110] 60: limiter;

[0111] 70: rear support;

[0112] 75: front support. DETAILED DESCRIPTION

[0113] The detailed description and technical contents of the present application are described as follows in conjunction with the accompanying drawings. However, the attached drawings are only provided for reference and explanation and are not intended to limit the present application.

[0114] See also Figures 1 to 5As shown, the present application provides a linear actuator with a buffer mechanism, which is mainly used in nursing beds or medical beds (not shown). Through the operation of the linear actuator, the front section of the nursing bed or medical bed can be raised or swung horizontally, especially when the patient must lie flat to perform electric shocks during first aid. Through the setting of this linear actuator, the impact force of the front section of the nursing bed or medical bed when it descends rapidly can be slowed down, thereby reducing the damage to the patient and improving the user's comfort.

[0115] The aforementioned linear actuating device mainly includes an actuating body 10 , a quick-release mechanism 30 and a buffer mechanism 50 .

[0116] Please read first Figure 1 As shown, the actuator body 10 mainly includes a housing base 11, a motor 13 and a transmission mechanism 15. The housing base 11 mainly includes a lower housing 111 and an upper housing 115. The upper housing 115 and the lower housing 111 can be made of plastic or other materials. The lower housing 111 is composed of a circular tube section 112 and a half-shell cover 113 extending from one end of the circular tube section 112. The end of the circular tube section 112 away from the half-shell cover 113 is closed; the upper housing 115 is also a half-shell cover, which is correspondingly covered with the half-shell cover 113 of the lower housing 111. The lower housing 111 and the upper housing 115 can be combined by screws or other screw-fastening components.

[0117] The motor 13 is installed inside the circular tube section 112 of the lower housing 11 and has a worm 131. The motor 13 can make the worm 131 rotate in positive and negative directions through the combination and operation of internal magnetic poles, coils, current and other related components.

[0118] Please also read Figure 2 , Figure 4 and Figure 5 As shown, the transmission mechanism 15 mainly includes a lead screw 151, an outer tube 152 and a telescopic tube 153, wherein the lead screw 151 is sleeved by a front bearing 154 and a rear bearing 155, so that the rear section of the lead screw 151 is supported inside the lower housing 111 (see Figure 4 and Figure 5 ), the rest of the lead screw 151 extends out of the housing 11; a worm wheel 156 corresponding to the aforementioned worm 131 and meshing with each other is sleeved on the lead screw 151 on the rear side of the front bearing 154, wherein the lead screw 151 of this embodiment is a non-self-locking lead screw, that is: when the telescopic tube 153 is constrained or restricted and cannot rotate, the telescopic tube 153 is subjected to axial thrust or pressure, which will enable the lead screw 151 to rotate freely relative to the telescopic tube 153, so that the telescopic tube 153 can produce linear displacement and retract into the interior of the outer tube 152.

[0119] The outer tube 152 is a hollow body, which is sleeved along the outer periphery of the lead screw 151 and is used to provide support for the telescopic tube 153 . One end of the outer tube 152 is covered and fixed by the lower shell 111 and the upper shell 115 .

[0120] The telescopic tube 153 is sleeved on the outer periphery of the lead screw 151 and formed inside the outer tube 152. A nut 157 is connected to one end of the telescopic tube 153, and the nut 157 is threadedly connected with the aforementioned lead screw 151 for transmission. The outer periphery of the nut 157 is provided with a groove and a block (not shown) that are interlocked with the outer tube 152, so that the nut 157 and the telescopic tube 153 can only make linear movement inside the outer tube 152, but cannot make rotational movement.

[0121] See also Figure 4 and Figure 5 As shown, the quick release mechanism 30 mainly includes a positioning wheel 31, a clutch wheel 33 and a guide assembly 35. The positioning wheel 31, the clutch wheel 33 and the guide assembly 35 are generally cylindrical, wherein the positioning wheel 31 is sleeved on the lead screw 151 and fixed, so that the positioning wheel 31 can rotate with the lead screw 151. The clutch wheel 33 is sleeved on the lead screw 151 through the guide assembly 35 and is formed on the side of the positioning wheel 31. The clutch wheel 33 can move axially thereon with the help of the guiding effect of the guide assembly 35. A plurality of key slots (not shown in the figure) are arranged on one side of the clutch wheel 33, and a plurality of convex keys (not shown in the figure) are arranged on the outer periphery of the positioning wheel 31; similarly, each convex key and each key slot can also be interchangeably arranged between the positioning wheel and the clutch wheel. Each convex key can be embedded in each key slot, so that the clutch wheel 33 can be operatively engaged or disengaged corresponding to the positioning wheel 31.

[0122] Please refer to Figure 1 As shown, the quick release mechanism 30 of this embodiment further includes a pull assembly 37, which is pivotally connected to the outside of the upper housing 115 (eg, Figure 1 As shown), and connected to the aforementioned clutch wheel 33 through a connecting member (not shown) disposed inside the upper shell 115, so that by operating the pulling assembly 37, the clutch wheel 33 can slide on the guide assembly 35 and can engage or disengage corresponding to the positioning wheel 31.

[0123] The lead screw 151 is driven by the meshing of the worm 131 of the motor 13 and the worm wheel 156. When the clutch wheel 33 and the positioning wheel 31 are engaged, the lead screw 151 is rotated by the positioning wheel 31, the clutch wheel 33 and the guide assembly 35. When the clutch wheel 33 and the positioning wheel 31 are disengaged, the lead screw 151 rotates freely together with the positioning wheel 31 under the load of the telescopic tube 153. At this time, the clutch wheel 33, the guide assembly 35 and the worm wheel 156 are restrained by the worm 131 and do not rotate.

[0124] Please also read Figure 3 As shown, the buffer mechanism 50 is arranged on the lead screw 151. The buffer mechanism 50 of this embodiment is located between the nut 157 and the worm gear 156, and the buffer mechanism 50 mainly includes an elastic body 51 and a deceleration structure 53. The elastic body 51 of this embodiment is a compression spring. The deceleration structure 53 of this embodiment mainly includes a rotating wheel 531, a stopper 533 and a brake assembly 535, wherein the stopper 533 and the brake assembly 535 together constitute the stop member of this embodiment. The shape of the rotating wheel 531 and the stopper 533 of this embodiment is generally cylindrical, but not limited to this shape; the rotating wheel 531 is arranged adjacent to the nut 157, and the stopper 533 is arranged on the side of the rotating wheel 531 away from the nut 157. The brake assembly 535 is sleeved on the outer periphery of the stopper 533. The brake assembly 535 of this embodiment is a spring, but not limited to this type. One end of the spring is fixed on the shell seat 11 of the actuator body 10.

[0125] In one embodiment, the end surface of the rotating wheel 531 facing the stopper 533 is provided with a plurality of convex keys 5313, and the end surface of the stopper 533 facing the rotating wheel 531 is provided with a plurality of key slots 5331, each key slot 5331 is configured corresponding to each convex key 5313, and can be operatively engaged or disengaged. Similarly, each convex key 5313 and each key slot 5331 can also be interchangeably arranged between the stopper 533 and the rotating wheel 531. The number of the convex key 5313 and the key slot 5331 can be one.

[0126] The deceleration structure 53 of this embodiment further includes a guide member 537, which is sleeved on the lead screw 151 and rotates with the lead screw 151, and the rotating wheel 531 and the stop member 533 are sleeved on the guide member 537. The guide member 537 mainly includes a lower shell 5371 and an upper shell 5373, and the upper shell 5373 corresponds to the lower shell 5371 and is sleeved on the lead screw 151 together, wherein a first positioning plane 1511 is provided on the circumference of the lead screw 151, and a second positioning plane 5377 is provided inside the upper shell 5373 and the lower shell 5371, so that the first positioning plane 1511 and the second positioning plane 5377 are mutually engaged and positioned, so that the guide member 537 can rotate with the lead screw 151.

[0127] In addition, a plurality of guide strips 5375 extend from the circumference of the guide member 537, and a plurality of guide grooves 5311 are provided on the inner wall of the rotating wheel 531. Each guide strip 5375 is engaged with a corresponding guide groove 5311. Each guide groove 5311 is embedded in the guide strips 5375 of the guide member 537 so that the guide member 537 can drive the rotating wheel 531 to rotate. The stop member 533 is sleeved on the area of ​​the guide member 537 where there is no guide strip 5375. Therefore, when the rotating wheel 531 is not actuated by the elastomer 51, there is no mechanical connection between the stop member 533 and the rotating wheel 531. At this time, the stop member 533 is restricted by the brake assembly 535 and does not rotate with the lead screw 151 and the guide member 537. Only when the rotating wheel 531 is pushed by the elastic body 51, the rotating wheel 531 and the anti-rotation member 533 are forced to be mechanically connected (the so-called "mechanical connection" refers to the engagement of the aforementioned convex keys 5313 corresponding to the respective key slots 5331; similarly, it can also be a connection generated by friction, etc.), and the anti-rotation member 533 is restrained by the brake assembly 535, so that the rotating wheel 531 is stopped from rotating by the anti-rotation member 533. The number of the aforementioned guide groove 5311 and guide bar 5375 can also be one.

[0128] The deceleration structure 53 of this embodiment further includes a reset member 539, which is disposed between the rotating wheel 531 and the anti-rotation member 533, so as to push the rotating wheel 531 away when the rotating wheel 531 is not pushed by the elastic body 51, so as to disengage the rotating wheel 531 and the anti-rotation member 533. Similarly, the reset member 539 can also be disposed inside or outside the rotating wheel 531 or the anti-rotation member 533.

[0129] The buffer mechanism 50 of this embodiment further includes a cap 55 which is sleeved on an end of the elastic body 51 away from the deceleration structure 53 , so that when the nut 157 directly hits the elastic body 51 , the impact force is evenly transmitted to the elastic body 51 through the cap 55 .

[0130] The buffer mechanism 50 of this embodiment further includes a thrust bearing 57, which is sleeved on the outer periphery of the rotating wheel 531. Since the rotating wheel 531 rotates following the lead screw 151, the setting of the thrust bearing 57 can prevent the elastic body 51 from rotating. After the elastic body 51 is squeezed and deformed by the nut 157, the setting of the thrust bearing 57 can prevent the end face of the elastic body 51 from being relatively rubbed against the rotating wheel 531, thereby preventing scratches or abnormal noises. Similarly, the thrust bearing 57 can also be replaced by a gasket.

[0131] In one embodiment, at least one limiting member 60 is further included, which is passed through and fixed on the outer tube 152 and is used to limit the movement of the cap 55 and / or the elastic body 51 .

[0132] The linear actuator with a buffer mechanism of the present application also includes a rear support 70 and a front support 75. The rear support 70 is sleeved on the rear side of the rear bearing 155 and is clamped and fixed by the upper shell 115 and the lower shell 111. The front support 75 is sleeved on the end of the telescopic tube 153 away from the nut 157.

[0133] When in use, the clutch wheel 33 and the positioning wheel 31 are disengaged by operating the pull assembly 37, and the patient's own weight or medical staff applies pressure to the front section of the nursing bed or medical bed. The telescopic tube 153 is subjected to the aforementioned load, so that the nut 157 drives the lead screw 151 to rotate, and the telescopic tube 153 is retracted into the outer tube 152. At the end of the movement of the telescopic tube 153, the nut 157 pushes the cap 55 and the elastic body 51 to compress and deform the elastic body 51; then, the elastic body 51 The compression force generated after deformation pushes the rotating wheel 531 to move toward the stop member 533. At this time, the convex keys 5313 of the rotating wheel 531 will be embedded in the key grooves 5331 of the stop member 533, so that the rotating wheel 531 drives the stop member 533 to rotate together. The brake assembly 535 tightens and restricts the stop member 533, so that the stop member 533 can stop the rotation of the rotating wheel 531 and the lead screw 151, thereby reducing the rotation speed of the lead screw 151 and slowing down the movement speed of the telescopic tube 153 retracting into the outer tube 152.

[0134] See also Figures 6 to 8 As shown, the linear actuator with a buffer mechanism in this embodiment is roughly the same in structure as the aforementioned first embodiment, with the difference being that the deceleration structure 53A in this embodiment mainly includes a rotating wheel 531A, a stopper 533A and a brake assembly 535, wherein a first friction surface 5314 is provided on the end surface of the rotating wheel 531A facing the stopper 533A, and a second friction surface 5334 is provided on the end surface of the stopper 533A facing the rotating wheel 531A, and the rotation is driven by the friction between the first friction surface 5314 and the second friction surface 5334.

[0135] See also Fig. 9 and Fig.10As shown, the difference between the linear actuator with a buffer mechanism of this embodiment and the aforementioned embodiments is that the deceleration structure 53B of this embodiment mainly includes a rotating wheel 531B, a stopper 533B and a brake assembly 535, wherein a first magnet 5315 is provided on the rotating wheel 531B, and a second magnet 5333 is provided on the stopper 533B, wherein the first magnet 5315 and the second magnet 5333 together constitute the reset member of this embodiment. The rotating wheel 531B and the stopper 533B are also driven to rotate by the friction of their end faces; the first magnet 5315 and the second magnet 5333 utilize the repulsion of the same polarity of their magnetic poles to enable the rotating wheel 531B to be separated from the mechanical connection with the stopper 533B when it is not pushed by the elastic body 51. In one embodiment, the corresponding end faces of the rotating wheel 531B and the stopper 533B can also be driven to rotate by a concave-convex structure or a combination of a key and a groove.

[0136] See also Fig.11 As shown, the difference between the linear actuator with a buffer mechanism of this embodiment and the aforementioned embodiments is that the deceleration structure 53C of this embodiment mainly includes a rotating wheel 531C and a stopper 533C, wherein the stopper 533C constitutes the stop member of this embodiment. One end of the elastic body 51 is tightly bound and fixed to the outer periphery of the stopper 533C, and a positioning plane (not shown) is provided inside the rotating wheel 531C to interlock with the plane of the lead screw 151, so that the rotating wheel 531C is driven by the lead screw 151 to rotate together, and the compression force generated by the deformation of the elastic body 51 pushes the stopper 533C and the rotating wheel 531C to be mechanically connected, and the friction between the first friction surface 5314 of the rotating wheel 531C and the second friction surface 5334 of the stopper 533C is used to generate a braking effect, so that the rotating lead screw 151 reduces the rotation speed or stops rotating.

[0137] See also Figures 12 to 16 As shown, the difference between the linear actuator with a buffer mechanism of this embodiment and the first embodiment is that the deceleration structure 53D of this embodiment mainly includes a rotating wheel 531D, a stopper 533D and a brake assembly 535, wherein a first concave-convex surface 5317 is provided on the end surface of the rotating wheel 531D facing the stopper 533D, and a second concave-convex surface 5335 is provided on the end surface of the stopper 533D facing the rotating wheel 531D. The first concave-convex surface 5317 and the second concave-convex surface 5335 can be operably engaged or disengaged, thereby enhancing the engagement stability between the two.

[0138] The guide member 537D is provided with a U-shaped opening 5379, which is sleeved corresponding to the first positioning plane 1511 of the lead screw 151, so that the guide member 537D can rotate with the lead screw 151. In addition, an embedded block 5319 is provided inside the rotating wheel 531D, which is movably connected to the aforementioned U-shaped opening 5379, so that the rotating wheel 531D can move axially relative to the guide member 537D and can rotate with it. The stopper 533D is sleeved on the guide member 537D. When the rotating wheel 531D and the stopper 533D are not mechanically connected, the stopper 533D does not rotate, which can simplify the assembly process and improve the ease of assembly.

[0139] The buffer mechanism 50D of this embodiment further includes a front positioning ring 56 and a rear positioning ring 56 . The front positioning ring 56 and the rear positioning ring 56 are respectively sleeved on two ends of the elastic body 51 to form a stable holding effect on the elastic body 51 .

[0140] This embodiment further includes a plurality of limit members 60, each of which is passed through and fixed on the outer tube 152 to limit the movement of the front positioning ring 56. The number of the limit member 60 can be one.

[0141] See also Figures 17 to 21 As shown, the difference between this embodiment and the aforementioned fifth embodiment is that the deceleration structure 53E of this embodiment mainly includes a rotating wheel 531E, a stopper 533E, a brake assembly 535 and an offset wheel 536, wherein the stopper 533E, the brake assembly 535 and the offset wheel 536 together constitute the stop member of this embodiment. The rotating wheel 531E is also connected to the lead screw 151 through the guide member 537E and rotates with it, and the stopper 533E is sleeved on the guide member 537E. When the rotating wheel 531E and the stopper 533E are not mechanically connected, the stopper 533E does not rotate. The offset wheel 536 is pivotally arranged on the housing seat 11 of the actuator body 10 and connected to the stopper 533E, and the brake assembly 535 is sleeved on the offset wheel 536 and one end of the brake assembly 535 is fixed in the housing seat 11 of the actuator body 10; in this way, the invalid stroke of the telescopic tube 153 can be shortened.

[0142] In one embodiment, the deceleration structure 53E also includes a reset member 539, which is arranged between the rotating wheel 531E and the stop member 533E, so that when the rotating wheel 531E is not pushed by the elastic body 51, the rotating wheel 531E can be pushed away to disengage the rotating wheel 531E and the stop member 533E.

[0143] In one embodiment, the end surface of the rotating wheel 531E facing the stopper 533E is provided with a slot 5336, and the end surface of the stopper 533E facing the rotating wheel 531E is provided with a block 5316, and the block 5316 and the slot 5336 can be operatively engaged or disengaged. A plurality of first protruding teeth 5337 extend from the circumference of the stopper 533E, and a plurality of second protruding teeth 5361 extend from the circumference of the offset wheel 536, and the rotation is driven by the engagement of each first protruding tooth 5337 and each second protruding tooth 5361.

[0144] The above description is only a preferred embodiment of the present application and is not intended to limit the patent scope of the present application. Other equivalent changes that apply the patent spirit of the present application should all fall within the patent scope of the present application.

Claims

1. A linear actuator with a buffer mechanism, characterized in that: include: The actuator body includes a motor, a lead screw, an outer tube and a telescopic tube, wherein the lead screw is driven by the motor to rotate, the outer tube is sleeved outside the telescopic tube, and the telescopic tube has a nut and is used for threaded connection with the lead screw for transmission; a quick release mechanism, disposed on the lead screw and used to release the drive of the motor and the lead screw; as well as A buffer mechanism, disposed on the actuating body and comprising an elastic body and a deceleration structure; When the quick release mechanism is released, the lead screw rotates under the load of the telescopic tube, the nut compresses the elastic body and drives the deceleration structure to brake, so that the rotating lead screw can be decelerated by the deceleration structure.

2. The linear actuator with a buffer mechanism according to claim 1, characterized in that: The deceleration structure includes a rotating wheel and a stopper corresponding to the rotating wheel. The rotating wheel is arranged on the lead screw and rotates with it. The stopper is arranged on the lead screw and brakes the rotating wheel through a mechanical connection with the rotating wheel.

3. The linear actuator with a buffer mechanism according to claim 2, characterized in that: The deceleration structure further includes a brake assembly, and the brake assembly is arranged on the anti-rotation member.

4. The linear actuator with a buffer mechanism according to claim 3, characterized in that: The brake assembly is a spring, one end of which is fixed to the actuating body.

5. The linear actuator with a buffer mechanism according to claim 2, characterized in that: The rotating wheel is provided with at least one convex key, and the anti-rotation component is provided with at least one key groove capable of engaging with or disengaging from the convex key.

6. The linear actuator with a buffer mechanism according to claim 2, characterized in that: The deceleration structure also includes a guide component, the rotating wheel is connected to the lead screw through the guide component, the guide component is provided with at least one guide bar, the rotating wheel is provided with at least one guide groove that can be correspondingly engaged with the guide bar, and the stopper is provided on the guide component.

7. The linear actuator with a buffer mechanism according to claim 6, characterized in that: The guide component includes a lower shell and an upper shell, the upper shell corresponds to the lower shell cover and is sleeved with the lead screw, the lead screw is provided with a first positioning plane, and the upper shell and the lower shell are respectively provided with a second positioning plane that can be embedded and positioned with the first positioning plane.

8. The linear actuator with a buffer mechanism according to claim 2, characterized in that: The deceleration structure further includes a reset member, which is disposed at one of the rotating wheel, the rotation stopper, and between the rotating wheel and the rotation stopper.

9. The linear actuator with a buffer mechanism according to claim 8, characterized in that: The reset member is a spring or a magnet.

10. The linear actuator with a buffer mechanism according to claim 2, characterized in that: The buffer mechanism further includes a thrust bearing disposed on the rotating wheel.

11. The linear actuator with a buffer mechanism according to claim 2, characterized in that: The rotating wheel is provided with a first friction surface, and the anti-rotation member is provided with a second friction surface which can be driven to rotate by the first friction surface.

12. The linear actuator with a buffer mechanism according to claim 2, characterized in that: The rotating wheel is provided with a first concave-convex surface, and the anti-rotation member is provided with a second concave-convex surface which can be engaged with or disengaged from the first concave-convex surface.

13. The linear actuator with a buffer mechanism according to claim 12, characterized in that: The deceleration structure also includes a guide member, the rotating wheel is connected to the lead screw through the guide member, the guide member is provided with a U-shaped opening, the rotating wheel is provided with an embedded block movably connected to the U-shaped opening, and the stopper is provided on the guide member.

14. The linear actuator with a buffer mechanism according to claim 12, characterized in that: The buffer mechanism further comprises a front positioning collar and a rear positioning collar, and the front positioning collar and the rear positioning collar are respectively arranged at two ends of the elastic body.

15. The linear actuator with a buffer mechanism according to claim 14, characterized in that: It also includes at least one limiting member for limiting the travel of the front positioning collar, and the limiting member is fixed to the outer tube.

16. The linear actuator with a buffer mechanism according to claim 1, characterized in that: It also includes at least one limiter for limiting the travel of the elastic body. The buffer mechanism also includes a cap, which is arranged at one end of the elastic body away from the deceleration structure. The limiter is fixed to the outer tube.

17. The linear actuator with a buffer mechanism according to claim 2, characterized in that: The deceleration structure generates braking by the elastic body tightening and fixing the anti-rotation member.

18. The linear actuator with a buffer mechanism according to claim 2, characterized in that: The deceleration structure further includes a brake assembly and an offset wheel. The offset wheel is pivotally mounted on the actuating body and connected to the anti-rotation member. The brake assembly is sleeved on the offset wheel and one end of the brake assembly is fixed to the actuating body.

19. The linear actuator with a buffer mechanism according to claim 18, characterized in that: The deceleration structure further includes a reset member disposed between the rotating wheel and the rotation stopper.

20. The linear actuator with a buffer mechanism according to claim 18, characterized in that: The rotating wheel is provided with a clamping block, the anti-rotation member is provided with a clamping slot and a plurality of first protruding teeth, the offset wheel is provided with a plurality of second protruding teeth that can mesh and rotate with each of the first protruding teeth, and the clamping block can engage or disengage corresponding to the clamping slot.

21. A linear actuator with a buffer mechanism, characterized in that: include: The actuator body comprises a motor, a lead screw and a telescopic tube, wherein the lead screw is driven by the motor to rotate, and the telescopic tube has a nut and is used for threaded connection with the lead screw for transmission; a quick release mechanism, disposed on the lead screw and used to release the drive of the motor and the lead screw; as well as A buffer mechanism, disposed on the actuating body and comprising an elastic body and a deceleration structure, wherein the deceleration structure comprises a rotating wheel driven by the lead screw and a stop member disposed corresponding to the rotating wheel; When the nut compresses the elastic body, the elastic body is deformed to actuate the rotating wheel and the stopping member to generate a mechanical connection, and the stopping member brakes the rotating wheel to decelerate the lead screw.

22. The linear actuator with a buffer mechanism according to claim 21, characterized in that: The stopping member includes a stopper and a brake assembly, wherein the brake assembly is disposed on the stopper, and the stopper is configured corresponding to the rotating wheel and can be operatively engaged or disengaged.

23. The linear actuator with a buffer mechanism according to claim 21, characterized in that: The stopping member includes a stopper, one end of which is fixed to the elastic body, and the other end of which is configured to correspond to the rotating wheel and can be operatively engaged or disengaged.

24. The linear actuator with a buffer mechanism according to claim 21, characterized in that: The stopping member includes a stopper, a brake assembly and an offset wheel. The stopper is configured corresponding to the rotating wheel and can be operatively engaged or disengaged. The brake assembly is disposed on the offset wheel. The offset wheel pivotally mounts the actuating body and is connected to the stopper.

25. A linear actuator with a buffer mechanism, characterized in that: include: an actuating body, comprising a motor, a lead screw and a telescopic tube, wherein the lead screw is driven by the motor to rotate, and the telescopic tube has a nut and is used for threaded connection with the lead screw for transmission; and A buffer mechanism, disposed on the actuating body and comprising an elastic body and a deceleration structure, wherein the deceleration structure comprises a rotating wheel driven by the lead screw and a stop member disposed corresponding to the rotating wheel; When the nut compresses the elastic body, the elastic body is deformed to actuate the rotating wheel and the stopping member to generate a mechanical connection, and the stopping member brakes the rotating wheel to decelerate the lead screw.

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