CN112583198A - Linear driver for electric furniture and electric furniture - Google Patents

Abstract

The invention relates to the field of furniture and discloses a linear driver for electric furniture and the electric furniture, wherein the linear driver for the electric furniture comprises a shell, a worm wheel and a lead screw, wherein one end of the worm extends into the shell, the worm wheel is arranged in the shell and is meshed with the worm, the lead screw penetrates through the worm wheel and is in threaded connection with the worm wheel, at least one end of the lead screw penetrates out of the shell to be connected with a movable part of the electric furniture, and the worm wheel is matched to limit the axial movement of the lead screw relative to the lead screw; at least one end of the worm wheel is provided with a guide structure, the guide structure is sleeved outside the lead screw and is in clearance fit with the lead screw, and the guide structure is fixed relative to the worm wheel or the shell. According to the invention, the guide structure is additionally arranged at least one end of the worm wheel, the guide structure is fixed relative to the shell or the worm wheel, the guide structure is sleeved outside the lead screw and is in clearance fit with the lead screw, and the guide structure is utilized to guide the movement of the lead screw relative to the worm wheel, so that the coaxiality of the lead screw and the worm wheel is improved, and the influence on the normal movement of the lead screw due to the inclination of the lead screw relative to the worm wheel is avoided.

Description

Linear driver for electric furniture and electric furniture

Technical Field

The invention relates to the field of furniture, in particular to a linear driver for electric furniture and the electric furniture.

Background

In order to provide furniture such as tables, chairs and sofas with folding and lifting functions, drivers are usually provided. The drivers commonly used in the furniture industry at present are linear drivers, the linear drivers are mainly of two types, one linear driver comprises a lead screw, a worm wheel sleeved on the lead screw and a worm meshed with the worm wheel, and the worm wheel is in threaded connection with the lead screw. The worm rotates to drive the worm wheel to rotate, so that the lead screw moves axially relative to the worm wheel.

However, in the process of the rotation of the worm wheel, once the relative inclination occurs between the screw rod and the worm wheel, the power source for driving the rotation of the worm will be dead.

Disclosure of Invention

The invention aims to provide a linear driver for electric furniture and the electric furniture, which guides the movement of a lead screw relative to a worm wheel so as to ensure the coaxiality between the lead screw and the worm wheel.

In order to achieve the purpose, the invention adopts the following technical scheme:

a linear driver for electric furniture comprises a shell, a worm with one end extending into the shell, a worm wheel arranged in the shell and meshed with the worm, and a lead screw, wherein the lead screw penetrates through the worm wheel and is in threaded connection with the worm wheel, at least one end of the lead screw penetrates out of the shell to be connected with a movable part of the electric furniture, and the worm wheel is matched to limit the axial movement of the worm wheel relative to the lead screw; at least one end of the worm wheel is provided with a guide structure, the guide structure is sleeved outside the lead screw and is in clearance fit with the lead screw, and the guide structure is fixed relative to the worm wheel or the shell.

As a preferable technical solution of the linear actuator for the electromotive furniture, the guide structure is integrally provided with the worm wheel;

or, the guide structure is arranged on the shell;

or the guide structure and the shell are arranged separately and fixed relative to the shell.

As a preferable technical solution of the linear actuator for electric furniture, one or both ends of the worm wheel in the axial direction are provided with a smooth edge portion integrally formed with the worm wheel, the smooth edge portion is provided with a guide hole, the screw rod penetrates through the guide hole and is in clearance fit with the inner wall of the guide hole, and the guide structure is the guide hole.

As a preferable technical solution of the linear actuator for electric furniture, the housing includes a first housing and a second housing that are connected to each other, the first housing and the second housing are both provided with arc-shaped grooves, the arc-shaped grooves on the first housing and the arc-shaped grooves on the second housing are in one-to-one correspondence and have opposite openings, the arc-shaped grooves having opposite openings enclose a guide, the screw rod passes through the guide hole and is in clearance fit with an inner wall of the guide hole, and the guide structure is the guide hole.

As a preferable technical solution of the linear actuator for electromotive furniture, the screw rod is sleeved with a sleeve fixed relative to the housing, and an inner wall of the sleeve is in clearance fit with the screw rod to form the guide structure.

As a preferable technical solution of the linear actuator for the electromotive furniture, a first oil storage groove is provided on an inner wall of a hole where the guide structure is in clearance fit with the lead screw.

As a preferable technical solution of the linear actuator for the electric furniture, one or two axial ends of the worm wheel are provided with a smooth edge connected thereto, each smooth edge is sleeved with a support, and the smooth edge can rotate relative to the housing through the support; the support member is any one of a bearing and a sleeve.

As a preferable technical solution of the linear actuator for the electric furniture, the inner wall of the shaft sleeve is provided with a second oil storage tank.

As a preferable aspect of the linear actuator for electromotive furniture, the boss is fixed to the housing, and an elastic element is interposed between the boss and the worm wheel.

As a preferable technical solution of the linear actuator for electromotive furniture, the linear actuator further includes a braking member connected to the housing and sleeved outside the worm, and the braking member is capable of elastically deforming and is used for providing a braking force opposite to the rotation direction of the worm for the worm.

As a preferable technical solution of the linear actuator for electromotive furniture, a U-shaped portion is provided on the housing for connecting a fixing portion of the electromotive furniture.

As a preferable technical solution of the linear actuator for electric furniture, the linear actuator for electric furniture further includes a limiting component for limiting a limit position of the screw rod.

As a preferable technical solution of the linear actuator for electromotive furniture, the limit component includes:

the two ends of the screw rod are provided with first limiting parts fixed relative to the screw rod;

the second locating part is arranged on the shell and corresponds to the first locating part one by one, one of the first locating part and the corresponding second locating part is a limit switch electrically connected with a power source connected with the worm, and the other can enable the limit switch to control and stop the power source.

As a preferable technical solution of the linear actuator for the electromotive furniture, an end of the screw rod penetrating out of the housing is provided with a connecting hole for connecting a movable portion of the electromotive furniture, or a connecting portion fixed to the screw rod and for connecting the movable portion of the electromotive furniture.

The invention also provides electric furniture, which comprises the linear driver for the electric furniture.

The invention has the beneficial effects that: according to the linear driver for the electric furniture, the guide structure is additionally arranged at least one end of the worm gear, the guide structure is fixed relative to the shell or the worm gear, the guide structure is sleeved outside the lead screw and is in clearance fit with the lead screw, the guide structure is used for guiding the movement of the lead screw relative to the worm gear, the coaxiality of the lead screw and the worm gear is improved, and the influence on the normal movement of the lead screw due to the inclination of the lead screw relative to the worm gear is avoided.

The electric furniture comprises the linear driver for the electric furniture, and the coaxiality of the worm wheel and the lead screw can be effectively improved, so that the folding or lifting work of the electric furniture can be normally used.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the contents of the embodiments of the present invention and the drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a linear actuator for electromotive furniture according to an embodiment of the present invention;

fig. 2 is an exploded view of a linear actuator for electromotive furniture according to an embodiment of the present invention;

fig. 3 is a sectional view of a linear actuator for electromotive furniture according to an embodiment of the present invention;

FIG. 4 is a cross-sectional view of a worm gear provided in accordance with one embodiment of the present invention;

FIG. 5 is an enlarged partial schematic view at A in FIG. 3;

FIG. 6 is an enlarged partial schematic view at B in FIG. 3;

fig. 7 is a schematic structural diagram of a second housing according to an embodiment of the present invention;

FIG. 8 is a schematic view of a brake according to an embodiment of the present invention;

fig. 9 is an exploded view of a linear actuator for electromotive furniture according to a second embodiment of the present invention;

fig. 10 is a sectional view of a linear actuator for electromotive furniture according to a second embodiment of the present invention;

FIG. 11 is an enlarged partial schematic view at C of FIG. 10;

fig. 12 is an exploded view of a linear actuator for electromotive furniture according to a third embodiment of the present invention.

In the figure:

11. a motor; 12. a worm; 13. a worm gear; 131. a light edge portion; 132. an annular groove; 14. a lead screw;

21. a first housing; 22. a second housing; 23. a U-shaped portion; 24. a second positioning member; 25. a motor front end cover; 250. a through hole; 251. a limiting step; 252. a boss;

3. a guide structure; 31. a third positioning member; 32. a guide hole; 321. an arc-shaped slot;

41. a bearing; 42. a shaft sleeve; 421. a first positioning member; 43. a gasket; 44. an elastic element;

5. a first limit piece;

6. a wire rod;

7. a stopper; 71. a notch; 72. cutting; 73. friction surface.

Detailed Description

In order to make the technical problems solved, the technical solutions adopted and the technical effects achieved by the present invention clearer, the technical solutions of the present invention are further described below by way of specific embodiments with reference to the accompanying drawings. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some but not all of the elements associated with the present invention are shown in the drawings.

Example one

As shown in fig. 1 to 3, the present embodiment provides a linear actuator for electromotive furniture, which includes a housing, a worm 12 having one end extending into the housing, a worm wheel 13 disposed in the housing and engaged with the worm 12, and a lead screw 14, wherein the lead screw 14 penetrates the worm wheel 13 and is in threaded connection with the worm wheel 13, at least one end of the lead screw 14 penetrates the housing for connecting with a movable portion of the electromotive furniture, and the worm wheel 13 is configured to limit axial movement thereof relative to the lead screw 14.

The worm 12 rotates to drive the worm wheel 13 engaged with the worm to rotate, so that the screw 14 moves axially, and the mounting rack of the electric furniture is driven by the screw 14 to move.

The electric furniture can be an electric sofa, an electric table and chair or an electric bed, and the linear driver is usually directly fixed on a fixed part of the electric furniture. Specifically, the housing is formed with a U-shaped portion 23 for connecting a fixing portion of the electric sofa frame or the electric bed frame, or the like.

In order to connect the threaded spindle 14 to the movable part of the electrical furniture, in the present embodiment, one end of the threaded spindle 14 penetrates the housing and is connected to a connection part fixed relative thereto for connecting the movable part of the electrical furniture. The connecting portion may be formed integrally with the screw 14, or may be provided separately and fixed to the screw 14, which is not limited herein.

In other embodiments, both ends of the lead screw 14 may also penetrate through the housing and be connected to a connection portion fixed relative thereto.

In another embodiment, at least one end of the screw 14 penetrating through the housing may be provided with a connecting hole, and the screw 14 is connected to the movable portion of the electric furniture through the connecting hole, preferably, an oil-containing shaft sleeve or a bearing made of plastic is arranged in the connecting hole, and may be specifically arranged according to actual requirements.

The electric household linear driver further comprises a power source, in this embodiment, the power source is a motor 11, and an output shaft of the motor 11 is integrally formed or connected with the worm 12 into a whole. The motor 11 is connected with a wire 6, the wire 6 is used for connecting a power supply and a control switch, and the power supply is electrically connected with the motor 11 through the wire 6 so as to supply power to the motor 11; the control switch is electrically connected with the motor 11 through the wire 6, and the motor 11 is controlled to rotate forwards or backwards through the control switch. In other embodiments, the power source may also be an electric motor.

Further, in order to limit the stroke of the lead screw 14, the linear driver for the electromotive furniture further includes a limit component for limiting the limit position of the movement of the lead screw 14. Specifically, the limiting assembly includes a first limiting member 5 and a second limiting member, two ends of the screw 14 both penetrate through the housing and are connected with the first limiting member 5, and the first limiting member 5 is sleeved outside the screw 14 and penetrates through the first limiting member 5 and the screw 14 through an elastic pin shaft, so that the first limiting member 5 is fixed relative to the screw 14. The housing is provided with a second limiting part which is a limiting switch, preferably a micro switch, and the limiting switch is electrically connected with the motor 11. During the movement of the lead screw 14 relative to the housing, once the second limit switch contacts the first limit member, the motor will stop rotating, and the lead screw 14 will be kept in the current state. In other embodiments, the first limiting member may be a limit switch.

In order to improve the stability of the lead screw 14 when moving relative to the worm wheel 13, at least one end of the worm wheel 13 is provided with the guide structure 3, the guide structure 3 is sleeved outside the lead screw 14 and is in clearance fit with the lead screw 14, and the guide structure 3 is fixed relative to the worm wheel 13. Preferably, the worm wheel 13 is provided with a guide structure 3 at both ends to improve the stability of the lead screw 14 when moving. The specific size of the clearance between the guiding structure 3 and the lead screw 14 can be determined by repeated experiments, and is not limited in detail.

In the present embodiment, the guide structure 3 is provided integrally with the worm wheel 13. Specifically, as shown in fig. 3 to 5, both axial ends of the worm wheel 13 are provided with a smooth edge portion 131 integrally formed therewith, the smooth edge portion 131 is provided with a guide hole 32, the guide hole 32 is a smooth hole, the lead screw 14 passes through the guide hole 32, and an inner wall of the guide hole 32 is in clearance fit with the lead screw 14 to form the above-mentioned guide structure 3. The guide structure 3 is used for guiding the movement of the lead screw 14 relative to the worm wheel 13, the coaxiality of the lead screw 14 and the worm wheel 13 is improved, and the phenomenon that the lead screw 14 inclines relative to the worm wheel 13 to cause the motor 11 to block rotation is avoided.

Preferably, the inner wall of the guide hole 32 of the present embodiment is provided with a first oil storage groove (not shown in the figure) for storing lubricating oil to lubricate the screw 14, so as to ensure the smoothness of the rotation of the screw 14.

Further, in order to facilitate the installation and replacement of the worm wheel 13, the housing includes a first housing 21 and a second housing 22, and the first housing 21 and the second housing 22 are detachably connected. In the present embodiment, the first housing 21 and the second housing 22 are connected by a plurality of screws arranged circumferentially. In other embodiments, the first housing 21 and the second housing 22 may be clamped or bolted.

Further, in order to axially limit and support the worm wheel 13, a support is provided on at least one of the optical edge portions 131, and the optical edge portion 131 can rotate relative to the housing through the support. In this embodiment, each of the optical edge portions 131 is provided with a supporting member, one of which is a bearing 41, and the other of which is a sleeve 42, so as to improve the stability of the worm wheel 13. In other embodiments, a support member may be sleeved on only one of the optical edge portions 131, and the support member may be the bearing 41 or the shaft sleeve 42. In order to axially restrain the worm wheel 13, an end surface of the optical edge portion 131, on which the support is not fitted, is required to be in contact with the inner wall of the housing.

Specifically, a bearing 41 is sleeved outside one of the plain edge portions 131, an inner ring of the bearing 41 is fixed relative to the plain edge portion 131, and an outer ring of the bearing 41 is fixed relative to the housing; a sleeve 42 is fitted around the other flange portion 131, and the sleeve 42 is fixed to the housing. Preferably, the bearing 41 is a ball bearing, and the inner ring of the bearing 41 may be fixed relative to the smooth edge 131 by interference fit.

Since the outer ring of the bearing 41 is fixed relative to the housing, and the inner ring and the outer ring of the bearing 41 are not axially movable, the function of axially limiting the worm wheel 13 is indirectly achieved. The worm wheel 13 is supported and axially limited through the bearing 41 and the shaft sleeve 42, and the stability of the lead screw 14 is improved.

Specifically, as shown in fig. 2, 3 and 6, the outer peripheral wall of the shaft sleeve 42 is provided with a first positioning member 421, the inner wall of the housing is provided with a second positioning member 24, and the first positioning member 421 and the second positioning member 24 are in plug-in fit to limit the axial movement and the circumferential rotation of the shaft sleeve 42. In this embodiment, the first positioning element 421 is a protrusion, and the second positioning element 24 is a groove. Preferably, the first positioning members 421 are provided in plural, the plural first positioning members 421 are uniformly distributed along the circumferential direction of the outer wall of the shaft sleeve 42, and the first positioning members 421 correspond to the second positioning members 24 one by one. In other embodiments, the first positioning element 421 can be a groove, and the second positioning element 24 can be a protrusion.

Further, in order to avoid axial play during rotation of the worm wheel 13, in the present embodiment, the bushing 42 is fixed relative to the housing, and an elastic element 44 is disposed between the bushing 42 and the worm wheel 13. Specifically, one side of the worm wheel 13 facing the sleeve 42 is provided with an annular groove 132, the elastic element 44 is installed in the annular groove 132, a gasket 43 is arranged between the worm wheel 13 and the sleeve 42, and the outer diameter of the gasket 43 is larger than the maximum outer diameter of the annular groove 132, so that the gasket 43 can abut against the axial end face of the worm wheel 13. The spacer 43 is pressed by the boss 42 so that the elastic member 44 is pressed into the annular groove 132, and vibration is damped by deformation of the elastic member 44, thereby preventing the worm wheel 13 from moving axially. Preferably, the gasket 43 is a wave-shaped gasket, and the elastic member 44 is a rubber member.

In other embodiments, two bushings 42 may be used to support and axially limit the worm wheel 13, one bushing 42 is sleeved outside each optical edge 131, and the bushings 42 are fixed relative to the inner wall of the housing. Specifically, a gasket 43 is arranged between each shaft sleeve 42 and the axial end face of the worm wheel 13, so that the phenomenon of dead jacking when the worm wheel 13 and the shaft sleeve 42 are assembled is prevented. An axial end face of the worm wheel 13 is provided with an annular groove 132, an elastic element 44 is installed in the annular groove 132, the elastic element 44 is abutted to the gasket 43, one side of the worm wheel 13 is limited by the aid of the shaft sleeve 42, and the other side of the worm wheel 13 is limited by the aid of the elastic element 44 matched with the shaft sleeve 42, so that axial movement is prevented from occurring in the rotating process of the worm wheel 13.

In other embodiments, two bearings 41 may be used to support and axially retain the worm gear 13. Specifically, the plain rim portions 131 at two ends of the worm wheel 13 may be respectively sleeved with one bearing 41, an inner ring of the bearing 41 is fixed relative to the plain rim portion 131, an outer ring of the bearing 41 is fixed relative to the housing, and the two bearings 41 simultaneously have an axial limiting effect on the worm wheel 13, so as to prevent the worm wheel 13 from moving axially during rotation.

Further, a second oil storage groove (not shown) is formed in an inner wall of the sleeve 42 to store lubricating oil for lubricating the flange 131 and ensuring smooth rotation of the worm wheel 13.

Further, as shown in fig. 7 and 8, the linear actuator for electromotive furniture further includes a stopper 7, the stopper 7 is connected to the housing and sleeved outside the worm 12, and the stopper 7 can be elastically deformed to provide a braking force to the worm 12 opposite to the rotation direction of the worm 12. Specifically, the outer side of the second housing 22 is connected with a motor front end cover 25, a through hole 250 is formed in the motor front end cover 25, a plurality of circumferentially arranged limiting steps 251 are arranged on the inner wall of the through hole 250, and a boss 252 is arranged on at least one limiting step 251. The peripheral wall of the braking member 7 is provided with a plurality of notches 71, and the notches 71 correspond to the bosses 252 one by one and are mutually inserted and matched, so that the braking member 7 is fixed on the motor front end cover 25 in a non-rotatable manner.

The outer wall of one end of the worm 12 close to the motor 11 is a cylindrical surface without worm teeth, the free end of the worm 12 penetrates through the braking member 7 and extends into the second housing 22, the braking member 7 is provided with a plurality of notches 72, the notches 72 and the notches 71 are alternately arranged along the circumferential direction of the braking member 7, space is provided for elastic deformation of the braking member 7 by arranging the notches 72 and the notches 71, the surface of the braking member 7, which is in contact with the worm 12, forms a friction surface 73, and the friction surface 73 is matched with the cylindrical surface without the worm teeth on the worm 12 in the rotation process of the worm 12 so as to provide braking force for the worm 12. The specific structure of the braking member 7 and how the braking member 7 brakes the worm 12 are prior art and will not be described in detail herein.

In order to avoid that the stop 7 damages the surface of the worm 12 during the rotation of the worm 12, it is required that the hardness of the material from which the stop 7 is made is lower than the hardness of the material from which the worm 12 is made.

The embodiment also provides an electric furniture, which comprises the linear driver for the electric furniture, and can improve the coaxiality of the screw rod 14 and the worm wheel 13, effectively prevent the motor 11 from being locked due to the inclination of the screw rod 14 relative to the worm wheel 13, and further ensure the normal use of the folding or lifting work of the electric furniture.

Example two

As shown in fig. 9 to 11, the present embodiment is different from the first embodiment in the structure of the guide structure 3. In this embodiment, the guiding structure 3 is disposed on the housing. Specifically, the arc-shaped grooves 321 are formed in the first casing 21 and the second casing 22, the arc-shaped grooves 321 in the first casing 21 and the arc-shaped grooves 321 in the second casing 22 correspond to each other in a one-to-one manner and have opposite openings, the arc-shaped grooves 321 with the opposite openings enclose a guide hole 32, and the inner wall of the guide hole 32 is in clearance fit with the lead screw 14 to form the guide structure 3. The lead screw 14 is guided by the clearance fit of the inner wall of the guide hole 32 and the lead screw 14, so that the lead screw 14 is prevented from inclining, and the stability of movement and rotation of the lead screw 14 is ensured. In this embodiment, there are two guide holes 32, the two guide holes 32 are located at two axial ends of the worm wheel 13, and two ends of the lead screw 14 penetrate out of the housing through the two guide holes 32.

Preferably, the inner wall of the guide hole 32 is provided with a first oil storage groove for storing lubricating oil to lubricate the screw 14, thereby ensuring the smoothness of the rotation of the screw 14.

In order to limit the worm wheel 13, two ends of the worm wheel 13 are provided with a smooth edge 131, and each smooth edge 131 is sleeved with a support member, which is a shaft sleeve 42 fixed relative to the housing. Specifically, the peripheral wall of the shaft sleeve 42 is provided with a first positioning member 421, the inner wall of the housing is provided with a second positioning member 24, and the first positioning member 421 and the second positioning member 24 are in plug-in fit to limit the axial movement and the circumferential rotation of the shaft sleeve 42. In this embodiment, the first positioning element 421 is a protrusion, and the second positioning element 24 is a groove. Preferably, the first positioning members 421 are provided in plural, the plural first positioning members 421 are uniformly distributed along the circumferential direction of the outer wall of the shaft sleeve 42, and the first positioning members 421 correspond to the second positioning members 24 one by one. In other embodiments, the first positioning element 421 can be a groove, and the second positioning element 24 can be a protrusion.

Further, in order to prevent the shaft sleeve 42 and the worm wheel 13 from being jammed in the assembling process, a gasket 43 is arranged between each shaft sleeve 42 and the axial end face of the worm wheel 13 opposite to the shaft sleeve. Preferably, the shim 43 is a wave shim.

Further, in order to prevent the axial play of the worm wheel 13 during rotation, an elastic member 44 is disposed between one of the bushings 42 and the end surface of the worm wheel 13 opposite thereto. Specifically, an annular groove 132 is formed in one axial end face of the worm wheel 13, the elastic element 44 is mounted in the annular groove 132, the gasket 43 abuts against the elastic element 44, the bushing 42 abuts against the gasket 43, and vibration is damped by deformation of the elastic element 44, so that axial movement of the worm wheel 13 is prevented.

Preferably, the inner wall of the sleeve 42 is provided with a second oil storage groove for storing lubricating oil to lubricate the outer wall of the flange 131 and ensure the smooth rotation of the worm wheel 13.

In other embodiments, a bearing 41 may be sleeved on each of the flange portions 131, an inner ring of the bearing 41 is fixed to the worm wheel 13, and an outer ring of the bearing 41 is fixed to the housing, instead of the bushing 42.

In other embodiments, the bearing 41 may be sleeved on one of the flange portions 131, an inner ring of the bearing 41 is fixed to the worm wheel 13, and an outer ring of the bearing 41 is fixed to the housing. A sleeve 42 fixed to the housing is fitted around the other flange 131. And a gasket 43 is arranged between the shaft sleeve 42 and the axial end face of the worm wheel 13 opposite to the shaft sleeve, so that the shaft sleeve 42 and the worm wheel 13 are prevented from being deadlocked in the assembling process. An annular groove 132 is formed in one axial end face of the worm wheel 13, the elastic element 44 is mounted in the annular groove 132, the gasket 43 abuts against the elastic element 44, the bushing 42 abuts against the gasket 43, and vibration is damped by deformation of the elastic element 44, so that axial movement of the worm wheel 13 is prevented.

EXAMPLE III

As shown in fig. 12, the present embodiment is different from the other embodiments in the structure of the guide structure 3. In this embodiment, the guide structure 3 is provided separately from the housing and the worm wheel 13 and fixed to the housing. Specifically, the guiding structure 3 is a sleeve, the sleeve is sleeved outside the screw 14, and the inner wall of the sleeve is in clearance fit with the screw 14. The peripheral wall of the sleeve is provided with a third positioning piece 31, the inner wall of the shell is provided with a fourth positioning piece, and the third positioning piece 31 and the fourth positioning piece are matched in an inserted mode to limit axial movement and circumferential rotation of the sleeve. In this embodiment, the third positioning element 31 is a protrusion, and the fourth positioning element is a groove. Preferably, the third positioning element 31 is provided in plurality, the plurality of third positioning elements 31 are uniformly distributed along the circumferential direction of the outer wall of the sleeve, and the fourth positioning elements correspond to the third positioning elements 31 one to one. In other embodiments, the third positioning element 31 may be a groove, and the fourth positioning element may be a protrusion.

Preferably, the inner wall of the sleeve is provided with a first oil storage groove to lubricate the screw 14, so as to ensure the smoothness of the rotation of the screw 14.

Further, the two axial ends of the worm wheel 13 are provided with the smooth edge portions 131 connected with the worm wheel, a support is sleeved outside each smooth edge portion 131, the support is a bearing 41, the inner ring of the bearing 41 is fixed relative to the smooth edge portions 131, the outer ring of the bearing 41 is fixed relative to the housing, and the worm wheel 13 is supported and axially limited by the two bearings 41. The two bearings 41 are used for axially limiting the worm wheel 13 so as to prevent the worm wheel 13 from axially moving in the rotating process.

In other embodiments, a sleeve 42 fixed relative to the housing may be sleeved on each of the light edge portions 131; one of the plain edge portions 131 may be fitted with a sleeve 42 fixed to the housing, the other plain edge portion 131 may be fitted with a bearing 41, an inner ring of the bearing 41 may be fixed to the plain edge portion 131, and an outer ring of the bearing 41 may be fixed to the housing. The two specific ways of supporting and axially retaining the worm wheel 13 are the same as described above, and the description thereof is not repeated here.

Example four

In this embodiment, two guide structures 3 are provided, and are respectively located at two ends of the worm wheel 13. The present embodiment is different from the other embodiments in that one of the guiding structures 3 adopts the guiding hole 32 which is in clearance fit with the lead screw 14 and is positioned on the light edge 131 in the first embodiment, and the other guiding structure 3 adopts the guiding hole 32 which is in clearance fit with the lead screw 14 and is arranged on the shell in the second embodiment.

In other embodiments, one of the guiding structures 3 may be the guiding hole 32 in the first embodiment which is in clearance fit with the screw 14 and is located on the smooth edge 131, and the other guiding structure 3 may be the sleeve in the third embodiment which is in clearance fit with the screw 14.

In another embodiment, one of the guiding structures 3 may be a guiding hole 32 provided on the housing in the second embodiment and in clearance fit with the lead screw 14, and the other guiding structure 3 may be a sleeve in the third embodiment and in clearance fit with the lead screw 14.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Wherein the terms "first position" and "second position" are two different positions.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Claims (15)

1. A linear driver for electric furniture comprises a shell, a worm (12) with one end extending into the shell, a worm wheel (13) arranged in the shell and meshed with the worm (12), and a lead screw (14), wherein the lead screw (14) penetrates through the worm wheel (13) and is in threaded connection with the worm wheel (13), at least one end of the lead screw (14) penetrates out of the shell to be used for connecting a movable part of the electric furniture, and the worm wheel (13) is matched to limit the axial movement of the lead screw (14); the worm gear is characterized in that at least one end of the worm gear (13) is provided with a guide structure (3), the guide structure (3) is sleeved outside the lead screw (14) and is in clearance fit with the lead screw (14), and the guide structure (3) is fixed relative to the worm gear (13) or the shell.

2. Linear drive for electromotive furniture items according to claim 1, characterised in that the guide structure (3) is provided integrally with the worm wheel (13);

or, the guide structure (3) is arranged on the shell;

or the guide structure (3) is arranged separately from the housing and fixed relative to the housing.

3. Linear actuator for electric furniture according to claim 2, characterized in that the worm wheel (13) is provided with a smooth edge (131) at one or both axial ends, the smooth edge (131) is provided with a guide hole (32), the screw (14) passes through the guide hole (32) and is in clearance fit with the inner wall of the guide hole (32), and the guide structure (3) is the guide hole (32).

4. The linear actuator for electric furniture according to claim 2, characterized in that the housing comprises a first housing (21) and a second housing (22) which are connected with each other, the first housing (21) and the second housing (22) are provided with arc-shaped grooves (321), the arc-shaped grooves (321) on the first housing (21) and the arc-shaped grooves (321) on the second housing (22) are in one-to-one correspondence and are opposite in opening, the arc-shaped grooves (321) which are opposite in opening enclose a guide hole (32), the lead screw (14) passes through the guide hole (32) and is in clearance fit with the inner wall of the guide hole (32), and the guide structure (3) is the guide hole (32).

5. Linear drive for electromotive furniture items according to claim 2, characterised in that the screw (14) is sheathed with a sleeve fixed relative to the housing, the inner wall of the sleeve being in clearance fit with the screw (14) to form the guide structure (3).

6. Linear drive for an electromotive furniture piece according to one of claims 1 to 5, characterized in that the inner wall of the hole of the guide structure (3) which is clearance-fitted with the threaded spindle (14) is provided with a first oil reservoir.

7. Linear drive for an electrically powered furniture item according to any of claims 1 to 5, characterised in that the worm wheel (13) is provided with a light edge (131) attached to one or both axial ends thereof, each light edge (131) being provided with a support by means of which the light edge (131) is rotatable relative to the housing; the support member is any one of a bearing (41) and a sleeve (42).

8. Linear drive for an electrically powered furniture item according to claim 7 characterised in that the inner wall of the sleeve (42) is provided with a second oil reservoir.

9. Linear drive for electrically powered furniture according to claim 7, characterized in that the bushing (42) is fixed with respect to the housing, an elastic element (44) being interposed between the bushing (42) and the worm wheel (13).

10. Linear drive for electric furniture according to any of claims 1 to 5, characterized in that it further comprises a stop member (7) connected to the housing and fitted outside the worm (12), said stop member (7) being elastically deformable for providing the worm (12) with a braking force opposite to the direction of rotation of the worm (12).

11. Linear drive for an electromotive furniture according to any of claims 1 to 5, characterized in that the housing is provided with a U-shaped portion (23) for connecting a fixed portion of the electromotive furniture.

12. Linear drive for electric furniture according to any of claims 1 to 5, characterized in that it further comprises a limiting assembly for limiting the extreme position of the movement of the lead screw (14).

13. The linear actuator for electromotive furniture according to claim 12, wherein the limit stop assembly comprises:

the two ends of the lead screw (14) are provided with first limiting parts (5) fixed relative to the lead screw;

the second locating part is arranged on the shell and corresponds to the first locating part (5) one by one, one of the first locating part and the corresponding second locating part is a limit switch electrically connected with a power source connected with the worm (12), and the other can enable the limit switch to control the power source to stop acting.

14. Linear drive for an electromotive furniture according to one of claims 1 to 5, characterized in that the end of the threaded spindle (14) that protrudes out of the housing is provided with a connection hole for connecting a movable part of the electromotive furniture or with a connection part that is fixed relative to the threaded spindle (14) and is used for connecting a movable part of the electromotive furniture.

15. An electromotive furniture piece, characterized by comprising the linear actuator for electromotive furniture piece according to any one of claims 1 to 14.

Images