WO2021249447A1

WO2021249447A1 - One-way driving linear actuator

Info

Publication number: WO2021249447A1
Application number: PCT/CN2021/099260
Authority: WO
Inventors: 许欣; 赵新星
Original assignee: 浙江捷昌线性驱动科技股份有限公司
Priority date: 2020-06-09
Filing date: 2021-06-09
Publication date: 2021-12-16
Also published as: CN111810603A

Abstract

A one-way driving linear actuator, relating to the technical field of linear transmission, and comprising a driving motor, a transmission assembly, a rotating lead screw (20), a transmission nut (21), an inner tube (12), and an outer tube (13). The driving motor drives the rotating lead screw (20) to rotate by means of the transmission assembly; the rotating lead screw (20) rotates to drive the transmission nut (21) to move axially along the rotating lead screw (20); the transmission nut (21) drives the inner tube (12) to move relative to the outer tube (13); a connecting sleeve (22) is arranged on the transmission nut (21); the connecting sleeve (22) and the transmission nut (21) are axially fixed; the connecting sleeve (22) is separated from the inner tube (12); when the rotating lead screw (20) rotates in a forward direction, the end of the connecting sleeve (22) is abutted against the end of the inner tube (12) so as to drive the inner tube (12) to stretch out relative to the outer tube (13). The linear actuator only allows one-way pushing and thus has high safety, and moreover, the structure is relatively simple, and the cost is saved.

Description

One-way drive linear actuator

【Technical Field】

The invention relates to a unidirectional drive linear actuator, which belongs to the technical field of linear transmission.

【Background technique】

Linear actuators, also called electric push rods, are widely used in furniture, medical equipment, solar power generation and other fields. Its main structure includes drive motors, transmission worms, worm gears, screws, and nuts. The working principle is that the drive motor drives the transmission worm. When it rotates, the transmission worm meshes with the worm wheel to drive the worm wheel to rotate, the worm wheel rotates to drive the screw to rotate, and the screw to rotate drives the nut to move axially. The nut is generally connected with an inner tube to realize the telescopic movement of the inner tube.

In traditional linear actuators, both the extension and retraction are driven by the drive motor, but this drive mode makes the drive motor reverse to drive the inner tube to retract, and it won’t stop when it encounters a foreign object, which can easily cause damage or damage to the object. Human body injury, especially for children with heavier curiosity, who like to touch and explore with their hands, they are easily pinched, with high risk and low safety performance. Therefore, it is also necessary to develop this kind of anti-pinching linear actuator, so linear actuators that can only be driven in one direction are also beginning to appear on the market, but such linear actuators are usually more complicated in structure.

[Summary of the invention]

The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a one-way drive linear actuator, so that the linear actuator only has one-way push, has better safety, and is relatively simple in structure. , More cost-saving.

To solve the above technical problems, the present invention adopts the following technical solutions:

A one-way drive linear actuator includes a drive motor, a transmission assembly, a rotating screw and a transmission nut, an inner tube and an outer tube. The drive motor drives the rotating screw to rotate through the transmission assembly, and the rotation of the rotating screw drives the transmission The nut moves axially along the rotating screw rod. The transmission nut drives the inner tube to move relative to the outer tube. The inner tube is separated. When the rotating screw rod rotates in the forward direction, the end of the connecting sleeve abuts against the end of the inner tube to drive the inner tube to extend relative to the outer tube.

The beneficial effects of the present invention:

In the linear actuator of the present invention, a connecting sleeve is arranged on the transmission nut, and the connecting sleeve and the transmission nut are kept relatively fixed in the axial direction, but the connecting sleeve and the inner tube are separated from each other and do not have a connection relationship. When the rotating screw rod rotates in the forward direction, the end of the connecting sleeve will abut against the end of the inner tube, so that the connecting sleeve generates an axial thrust on the inner tube, that is, when the rotating screw is rotated in the forward direction, the transmission nut can normally push the inner tube. When the rotating screw rod rotates in the reverse direction, the transmission nut drives the connecting sleeve to retract, but because the connecting sleeve and the inner tube are separated, the inner tube will not retract with the connecting sleeve at this time, which will reduce the gripping Circumstances, improve safety.

In addition, in the present invention, the connection sleeve is provided on the transmission nut because the transmission nut itself is usually made of injection molded products or non-wear-resistant materials. If the transmission nut itself is pushed against the inner tube, it will obviously affect the transmission. The nut itself is relatively damaged. Therefore, a separate connecting sleeve is designed in the present invention. Therefore, the interaction force generated with the inner tube is mainly borne on the connecting sleeve. The connecting sleeve itself can be made of higher-strength materials, such as metals, such as alloys. Of course It can also be made of plastic with better strength, so that the strength and accuracy requirements of the transmission nut itself do not need to be changed, the cost control is better, and it is relatively convenient for assembly.

Preferably, the transmission nut is provided with an external thread, the connection sleeve is provided with an internal thread matching the external thread, and the transmission nut and the connection sleeve are fixed by a threaded connection.

Preferably, the inner tube is provided with an annular groove, a guide ring is provided in the annular groove, at least one guide protrusion is provided on the guide ring, and the inner wall of the outer tube is provided with the guide protrusion With matching guide grooves.

Preferably, the outer diameter of the connecting sleeve is consistent with the outer diameter of the inner tube.

Preferably, the transmission assembly includes a transmission worm and a transmission worm, the transmission worm is connected with a driving motor, the transmission worm gear is sleeved outside the rotating screw, and a clutch device is provided between the transmission worm and the rotating screw.

Preferably, the clutch device includes a coupling gear sleeve and a return spring, the coupling gear sleeve is sleeved on the rotating screw rod and can move axially relative to the rotating screw rod, and the coupling gear sleeve is drivingly connected with the transmission worm gear.

Preferably, the linear actuator further includes a housing and a pull release assembly mounted on the housing, a swing rod is rotatably mounted on the housing, and the pull release assembly includes an axially movable arrangement relative to the rotating screw rod. A pull rod, the pendulum rod is connected with the pull rod, and when the pull rod is pulled, the pendulum rod swings to axially push the clutch device.

Preferably, the linear actuator further includes a first friction sleeve and a second friction sleeve sleeved on the rotating screw rod, the first friction sleeve and the second friction sleeve axially abut each other, and the first friction sleeve outer sleeve is provided with A self-locking torsion spring, a release torsion spring is sleeved on the second friction sleeve. When the rotating screw is subjected to an axial load, the rotating screw transmits the axial force to the first friction sleeve and the second friction sleeve. In the housing, no axial force is transmitted between the coupling gear sleeve and the first friction sleeve and the second friction sleeve in the axial direction.

Preferably, the first friction sleeve is arranged at the end of the rotating screw rod, and the housing includes a tail pull head at the end, and the tail pull head and the second friction sleeve are axially limited.

Preferably, the linear actuator further includes a push block, the push block is provided with a guide surface, the release torsion spring includes a radially extending pin, and the housing is provided with an axial movement relative to the rotating screw rod. A pull rod is provided, the pull rod is connected with the push block, and the pull rod is pulled, and the guide surface on the push block is in contact with the pin, so that the release torsion spring expands outward.

The features and advantages of the present invention will be disclosed in detail in the following specific embodiments and drawings.

【Explanation of the drawings】

The present invention will be further explained below in conjunction with the accompanying drawings:

Fig. 1 is an overall schematic diagram of a linear actuator according to an embodiment of the present invention;

2 is a schematic diagram of the internal structure of a linear actuator according to an embodiment of the present invention;

3 is a partial cross-sectional schematic diagram of a linear actuator according to an embodiment of the present invention;

4 is a schematic partial cross-sectional view of a linear actuator according to the first embodiment of the present invention;

Fig. 5 is an exploded schematic diagram of internal parts in a linear actuator according to an embodiment of the present invention.

【detailed description】

The technical solutions of the embodiments of the present invention are explained and described below in conjunction with the accompanying drawings of the embodiments of the present invention, but the following embodiments are only preferred embodiments of the present invention, not all of them. Based on the examples in the implementation manners, other examples obtained by those skilled in the art without creative work shall fall within the protection scope of the present invention.

In the following description, terms such as "inner", "outer", "upper", "lower", "left", "right" and other indicating orientation or positional relationship are based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments and simplifying the description, rather than indicating or implying that the pointed device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

Example one:

As shown in Figures 1 to 5, this embodiment is a one-way drive linear actuator, which includes a housing 11, a drive motor, a transmission assembly, a rotating screw rod 20 and a transmission nut 21, an inner tube 12 and an outer tube 13 The housing 11 in this embodiment includes an upper housing and a lower housing 112, and the transmission assembly includes a transmission worm 35 and a transmission worm gear 34. The driving motor drives the rotating screw rod 20 to rotate through the transmission assembly. The rotation of the rotating screw rod 20 drives the transmission nut 21 to move axially along the rotating screw rod 20. The transmission nut 21 drives the inner tube 12 to move relative to the outer tube 13, and The end of the tube 12 is usually connected with a driven object, so as to achieve the purpose of pushing the driven object.

The main improvement in this embodiment is that the transmission nut 21 is provided with a connecting sleeve 22, the connecting sleeve 22 is axially fixed with the transmission nut 21, the connecting sleeve 22 is separated from the inner tube 12, and the rotating wire When the rod 20 rotates in the forward direction, the end of the connecting sleeve 22 abuts against the end of the inner tube 12 to drive the inner tube 12 to extend relative to the outer tube 13.

In the linear actuator of the present invention, a connecting sleeve 22 is provided on the transmission nut 21. The connecting sleeve 22 and the transmission nut 21 are kept relatively fixed in the axial direction, but the connecting sleeve 22 and the inner tube 12 are separated from each other, and There is no connection relationship. When the rotating screw 20 rotates in the forward direction, the end of the connecting sleeve 22 will abut the end of the inner tube 12, so that the connecting sleeve 22 generates an axial thrust on the inner tube 12, that is, when the screw 20 is rotated When rotating in the forward direction, the transmission nut 21 can normally push the inner tube 12 out, and when the rotating screw 20 rotates in the reverse direction, the transmission nut 21 drives the connecting sleeve 22 to retract, but because the connecting sleeve 22 and the inner tube 12 are separated Therefore, the inner tube 12 will not retract with the connecting sleeve 22 at this time, thereby reducing the gripping situation and improving the safety.

In addition, in the present invention, the connection sleeve 22 is provided on the transmission nut 21 because the transmission nut 21 itself is usually made of injection molded products or non-wear-resistant materials. If the transmission nut 21 itself abuts the inner tube 12 Pushing obviously damages the transmission nut 21 itself. Therefore, a separate connecting sleeve 22 is designed in the present invention. Therefore, the interaction force with the inner tube 12 is mainly borne on the connecting sleeve 22. The connecting sleeve 22 itself can be made of higher strength. The material, such as metal, such as alloy, of course, can also be plastic with better strength. In this way, the strength and accuracy requirements of the transmission nut 21 do not need to be changed, the cost control is better, and it is relatively convenient for assembly.

Regarding the specific connection structure of the transmission nut 21 and the connecting sleeve 22, in this embodiment, it is preferable that the two are connected by a thread. The transmission nut 21 is provided with an external thread, and the connecting sleeve 22 is provided with a matching external thread. The inner thread of the drive nut 21 and the connecting sleeve 22 are fixed by a threaded connection. This kind of fixed connection method, because the transmission nut 21 and the connecting sleeve 22 are realized by tightly fitting threads, when a force is generated between the connecting sleeve 22 and the inner tube 12, the force of the inner tube 12 on the connecting sleeve 22 will be shared. To a plurality of screw teeth, so that the force will not be too concentrated, and the connecting sleeve 22 and the transmission nut 21 can be better protected.

In order to avoid changing the original structure due to the design of the connecting sleeve 22, in this embodiment, it is preferable that the outer diameter of the connecting sleeve 22 and the outer diameter of the inner tube 12 remain the same. The cavity, the connecting sleeve 22 can be moved in the original outer tube 13, and the cost of improvement is very low.

In addition, since the inner tube 12 itself is separated from the connecting sleeve 22, in order to allow the inner tube 12 to move in the outer tube 13 more guiding, the inner tube 12 is provided with an annular groove, and a guide ring is provided in the annular groove. 121, the guide ring 121 is provided with at least one guide protrusion, the inner wall of the outer tube 13 is provided with a guide groove matching the guide protrusion, the guide ring 121 is a split ring in this embodiment, The guide ring 121 can not only play a guiding role, but also prevent the inner tube 12 from being completely separated from the outer tube 13.

In order to enable the linear actuator in this embodiment to have a release function, a release function, that is, when the drive motor fails or other abnormal conditions, the user can manually adjust the telescopic function of the inner tube 12, in this embodiment The transmission worm 35 is connected to a driving motor, the transmission worm gear 34 is sleeved outside the rotating screw 20, and a clutch device is provided between the transmission worm 34 and the rotating screw 20. The clutch device is used to connect or cut off the power connection between the transmission worm gear 34 and the rotating screw 20.

The specific structure of the clutch device in this embodiment is as follows: the clutch device includes a ball sleeve 31, a spline sleeve 32, and a coupling gear sleeve 33. The ball sleeve 31 is sleeved on the rotating screw 20 through a flat position and rotates synchronously with the rotating screw 20 , The ball sleeve 31 is provided with a plurality of balls on the outer circumference of one end, the spline sleeve 32 is sleeved outside the ball sleeve 31, the spline sleeve 32 is always meshed with the transmission worm gear 34, and the spline sleeve 32 and the ball sleeve 31 are not directly connected, The coupling gear sleeve 33 is used to connect or disconnect the spline sleeve 32 and the ball sleeve 31, and the coupling gear sleeve 33 can move axially relative to the rotating screw 20.

As shown in Figure 5, the inner wall of the coupling gear sleeve 33 in this embodiment is provided with a spline groove 331 matching the spline sleeve 32, that is, the coupling gear sleeve 33 always rotates synchronously with the spline sleeve 32, and the coupling The inner wall of the shaft gear sleeve 33 is also provided with a ball groove 332 that matches the balls on the ball sleeve 31. When the coupling gear sleeve 33 moves axially toward the balls on the ball sleeve 31, the balls are butted into the ball groove 332. As a result, the coupling gear sleeve 33 is matched with the ball groove 332 to complete the torque transmission between the coupling gear sleeve 33 and the ball sleeve 31. Therefore, the coupling gear sleeve 33 at this time is equivalent to connecting the rotating screw 20 and the transmission worm gear 34 As shown in Figs. 3 and 4, the coupling gear sleeve 33 and the ball sleeve 31 have been butt-connected. When the coupling gear sleeve 33 moves away from the ball, the coupling gear sleeve 33 is separated from the ball sleeve 31, so that the torque transmission between the coupling gear sleeve 33 and the rotating screw 20 is disconnected.

In this embodiment, the linear actuator further includes a self-locking device. When the rotating screw rod 20 is reversed, frictional resistance is generated on the rotating screw rod 20. The structure of the self-locking device in this embodiment includes: A friction sleeve 41, a second friction sleeve 42, a release torsion spring 43, and a self-locking torsion spring 44. The second friction sleeve 42 is sleeved outside the first friction sleeve 41. The inner end surfaces of the two friction sleeves 42 abut, and the first friction sleeve 41 and the rotating screw 20 are positioned by a flat position, that is, in the circumferential direction, the first friction sleeve 41 and the rotating screw 20 rotate synchronously. , And the second friction sleeve 42 is free to rotate relative to the rotating screw rod 20. In the axial direction, the outer end surface of the first friction sleeve 41 and the inner end surface of the second friction sleeve 42 abut. At the same time, the torsion release spring 43 is sleeved on the second friction sleeve 42, the torsion release spring 43 always hugs the second friction sleeve 42 in the initial state, and the first friction sleeve 41 is sleeved with a self-locking torsion spring 44. The advantage of this self-locking device is that the installation space is smaller, mainly that the axial space will be smaller, which is beneficial to reduce the volume of the entire linear actuator.

When the inner tube 12 in the linear actuator is normally extended, the driving motor drives the rotating screw rod 20 to rotate forward through the clutch device. When the inner tube 12 extends to a predetermined position, the driving motor stops. In this position, when the inner tube 12 has a tendency to retract, the axial end faces of the first friction sleeve 41 and the second friction sleeve 42 abut, because the self-locking torsion spring 44 has a holding resistance effect on the first friction sleeve 41, and at the same time The second friction sleeve 42 is also held tightly by the release torsion spring 43 in a normal state. When the end surfaces of the first friction sleeve 41 and the second friction sleeve 42 abut against each other, frictional resistance is generated between the two, and this frictional resistance produces an impact on the rotating screw 20 The resistance to prevent it from reversing to complete the self-locking force.

When the linear actuator needs to be retracted normally, the drive motor drives the rotating screw 20 to rotate in the reverse direction through the clutch device. At this time, the rotating torque of the rotating screw 20 will overcome the self-locking force provided by the self-locking device, and the rotating screw 20 will Continue to reverse.

When the linear actuator is extended to a predetermined position and needs to be retracted quickly, this embodiment can unlock the self-locking device to achieve the purpose of quick release. In this embodiment, the unlocking is mainly performed by the second drive member. The specific structure is as follows: the second drive member includes a push block 52, the push block 52 is provided with a guide surface 521, the release torsion spring 43 includes a radially extending pin 431, and the guide surface 521 is provided on the push block On the side of 52, the push block 52 is integrated with the pull rod 51, that is, the self-locking device and the clutch device in this embodiment share the same pull rod 51. When the pull rod 51 is pulled, the guide surface 521 on the push block 52 and the pull rod 51 are integrated. The pin 431 conflicts, so that the release torsion spring 43 expands outward. When the release torsion spring 43 expands outward, the resistance between the release torsion spring 43 and the second friction sleeve 42 will decrease accordingly. In this state When the end faces of the first friction sleeve 41 and the second friction sleeve 42 abut, the second friction sleeve 42 will rotate synchronously with the first friction sleeve 41, so that the first friction sleeve 41 will not generate resistance to the rotating screw 20, so that it is convenient The goal of no resistance to the rotating screw 20 is achieved. At this time, if the clutch device is disconnected and the self-locking device is also unlocked, the rotating screw 20 is basically in a free idling state in this state, and the transmission nut 21 can be quickly retracted.

In addition, in this embodiment, the guide surface 521 is used to gradually push the release method of the torsion spring 43, which can achieve the purpose of gradually reducing the self-locking force, so that the self-locking force will not disappear immediately, so as to produce a stepless adjustment. Purpose.

It should be noted that for the linear actuators of other embodiments, the self-locking device may not be provided.

In this embodiment, in order to optimize the transmission of axial force, an axial limit kit is specially provided in this embodiment. Maintain the position. When the rotating screw rod 20 is subjected to an axial load, the rotating screw rod 20 transmits the axial force to the housing 11 through the axial limiting kit, and the coupling gear sleeve 33 is in contact with the axial limiter. No axial force is transmitted between the kits in the axial direction.

The axial limit kit itself and the rotating screw 20 are axially limited. Secondly, the axial limit kit is also axially limited with the housing 11. This installation method makes the axial limit on the rotating screw 20 The force can be transmitted to the housing 11 through the axial limit set, but the axial force is not transmitted between the coupling gear sleeve 33 and the axial limit set, so the coupling gear sleeve 33 will not receive from the rotating screw 20 When the user uses the drive member to toggle the coupling gear sleeve 33, it will save effort. At the same time, the strength requirements of the coupling gear sleeve 33 itself are also reduced. In addition, this is also conducive to prolonging the service life of the clutch device. The specific composition of the axial limit kit will be described in detail below.

In view of the presence of a clutch device and a self-locking device in this embodiment, the axial force transmission of this embodiment is as follows:

When the inner tube 12 of the linear actuator extends to a predetermined position and has a tendency to retract, the axial force of the inner tube 12 is transmitted to the connecting sleeve 22, and the connecting sleeve 22 transmits the axial force to the transmission nut 21, and the transmission nut 21 The axial force is transmitted to the rotating screw rod 20, the rotating screw rod 20 will receive the axial force, and the ball sleeve 31 is against the shoulder position of the rotating screw rod 20, so the axial force of the rotating screw rod 20 is transmitted to the ball for the first time On the sleeve 31, the end surface of the ball sleeve 31 is against the end surface of the first friction sleeve 41, that is, the ball sleeve 31 and the first friction sleeve 41 are axially limited, so the axial force will be transmitted to the first friction sleeve 41, and The rear end surface of the first friction sleeve 41 is opposed to the inner end surface of the second friction sleeve 42, so the axial force is transmitted to the second friction sleeve 42, and the rear end surface of the second friction sleeve 42 and the tail pull head 15 A tapered roller bearing 25 is arranged in between, so the axial force is finally transmitted to the tail pull head 15 through the tapered roller bearing 25.

In this embodiment, the ball sleeve 31, the first friction sleeve 41, and the second friction sleeve 42 together form an axial limit set, and the rotating screw 20 transmits the axial force to the tail pull through the axial limit set. On the head 15, from the perspective of the entire axial force transmission process, the coupling gear sleeve 33 in this embodiment will never be affected by the axial force, so it is also very labor-saving when the coupling gear sleeve 33 is toggled .

At the same time, since the clutch device does not receive the axial force from the rotating screw rod 20, the service life of the clutch device can be greatly improved. Of course, it should be noted that if there is no self-locking device in the linear actuator, it is also possible to additionally add a shaft sleeve-like structure to the rotating screw rod 20 as an axial limit kit.

For the first friction sleeve 41, this embodiment preferably includes a front sleeve and a rear sleeve. The axial middle of the front sleeve and the rear sleeve is abutted by a thrust bearing. In other embodiments, the first friction sleeve 41 It can be in the form of an integral shaft sleeve.

As described above, the hand-pulled release assembly, the hand-pulled release assembly includes a first drive member and a second drive member, the first drive member is connected to the clutch device, and the second drive member is used to connect the self Lock device, the pull release assembly includes an initial state and a fully released state, from the initial state to the fully released state, the first drive member drives the clutch device to disconnect the power connection, and the second drive member drives The release torsion spring 43 is released. In this embodiment, the user only needs to operate one pull release assembly to control the two devices, which is very convenient to operate.

The structure of the first driving member of this embodiment: The first driving member includes a swing rod 53 that is rotatably mounted on the housing 11, and the pull release assembly further includes a pull rod 51 that is axially movably arranged relative to the rotating screw rod 20, The pendulum rod 53 is connected with the pull rod 51. When specifically installed, the upper end of the pendulum rod 53 is rotatably connected with the pull rod 51, the pendulum rod 53 is rotatably connected to the housing in the middle, and the lower end of the pendulum rod 53 is connected with the coupling gear sleeve 33. When 51 is pulled, the swing rod 53 swings, pushing the coupling gear sleeve 33 to move axially.

In order to better optimize the operation of the clutch device and the self-locking device, the operation sequence of the clutch device and the self-locking device is optimized in this embodiment:

As shown in Figure 2, in the initial state, the guide surface 521 of the push block 52 needs to move a certain stroke before it comes into contact with the pin 431 of the release torsion spring 43. This stroke can be understood as the push block 52 Idle stroke. During this idle stroke, the clutch device is operating normally. The purpose of this formation is that the coupling gear sleeve 33 will be toggled first. At the same time, when resetting, the self-locking device locks first, and then the clutch device Then power connection, the advantage of this is that when the self-locking device generates self-locking force, the rotation speed of the rotating screw rod 20 will be reduced, so that the coupling gear sleeve 33 will not be damaged when the coupling gear sleeve 33 is engaged with the ball sleeve 31 33 and ball sleeve 31, can greatly extend the service life.

In addition, in order to enable the user to better perceive the magnitude of the release range, in this embodiment, a toothed bar 511 is provided on the pull rod 51, and a movable tooth 54 is provided on the housing 11, and the movable tooth 54 is connected with When the pull rod 51 is pulled by the spring, the movable teeth 54 are locked into the rack 511 one by one, and the position of the movable teeth 54 on the rack 511 can be used to sense the pulling stroke of the pull rod 51.

It should be noted that the structure of the self-locking device and the clutch device is not limited to the structure shown in this embodiment. Taking the self-locking device as an example, the self-locking device may only include a single third friction sleeve. The three friction sleeves rotate synchronously with the rotating screw 20, and the release torsion spring 43 is sleeved on the third friction sleeve. In the initial state, the release torsion spring 43 tightly embraces the third friction sleeve to generate resistance to the rotating screw 20, which is equivalent to releasing The torsion spring 43 is a self-locking torsion spring 44. When the release torsion spring 43 is pushed by the push block 52, the resistance of the release torsion spring 43 to the third friction sleeve disappears. Taking the clutch device as an example, the clutch device can be another spline sleeve 32 It can be realized in combination with spline.

The above are only specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that the present invention includes but is not limited to the drawings and the description in the above specific embodiments. content. Any modification that does not deviate from the functional and structural principles of the present invention will be included in the scope of the claims.

Claims

A one-way drive linear actuator includes a drive motor, a transmission assembly, a rotating screw and a transmission nut, an inner tube and an outer tube. The drive motor drives the rotating screw to rotate through the transmission assembly, and the rotation of the rotating screw drives the transmission The nut moves axially along the rotating screw rod, and the transmission nut drives the inner tube to move relative to the outer tube. It is characterized in that a connection sleeve is provided on the transmission nut, and the connection sleeve is axially fixed with the transmission nut, and the connection The sleeve is separated from the inner tube, and when the rotating screw rod rotates in the forward direction, the end of the connecting sleeve abuts against the end of the inner tube to drive the inner tube to extend relative to the outer tube.
The one-way drive linear actuator according to claim 1, wherein the transmission nut is provided with an external thread, the connecting sleeve is provided with an internal thread matching the external thread, and the transmission nut is connected with the The sleeves are fixed by threaded connection.
The one-way drive linear actuator according to claim 1, wherein the inner tube is provided with an annular groove, the annular groove is provided with a guide ring, and the guide ring is provided with at least one guide protrusion Therefore, the inner wall of the outer tube is provided with a guide groove matching the guide protrusion.
The one-way linear actuator according to claim 1, wherein the outer diameter of the connecting sleeve is consistent with the outer diameter of the inner tube.
The one-way drive linear actuator according to claim 1, wherein the transmission assembly comprises a transmission worm and a transmission worm, the transmission worm is connected with a driving motor, and the transmission worm is sleeved outside the rotating screw, A clutch device is arranged between the transmission worm wheel and the rotating screw rod.
The one-way drive linear actuator according to claim 5, wherein the clutch device includes a coupling gear sleeve and a return spring, and the coupling gear sleeve is sleeved on the rotating screw rod and can be relative to the rotating screw. The rod moves axially, and the coupling gear sleeve is in transmission connection with the transmission worm gear.
The one-way drive linear actuator of claim 5, wherein the linear actuator further comprises a housing and a pull release assembly mounted on the housing, and a swing rod is rotatably mounted on the housing, so The pull release assembly includes a pull rod axially movably arranged relative to the rotating screw rod, the swing rod is connected with the pull rod, and when the pull rod is pulled, the swing rod swings to axially push the clutch device.
The one-way drive linear actuator according to claim 5, wherein the linear actuator further comprises a first friction sleeve and a second friction sleeve sleeved on the rotating screw rod, and the first friction sleeve Abutting against the second friction sleeve axially, the first friction sleeve is sleeved with a self-locking torsion spring, and the second friction sleeve is sleeved with a release torsion spring. When the rotating screw is axially loaded, the rotating screw passes through the The first friction sleeve and the second friction sleeve transmit axial force to the housing, and the coupling gear sleeve and the first friction sleeve and the second friction sleeve do not transmit axial force in the axial direction.
The one-way drive linear actuator according to claim 8, wherein the first friction sleeve is arranged at the end of the rotating screw rod, and the housing includes a tail puller at the end, and the tail puller The axial limit between the head and the second friction sleeve.
The one-way drive linear actuator according to claim 8, wherein the linear actuator further comprises a push block, the push block is provided with a guide surface, and the release torsion spring includes a radially extending guide Feet, the housing is provided with a pull rod movably arranged axially relative to the rotating screw rod, the pull rod is connected with the push block to pull the pull rod, and the guide surface on the push block is in contact with the pin to make The release torsion spring expands outward.