CN112062036A

CN112062036A - Lifting device

Info

Publication number: CN112062036A
Application number: CN201910499181.XA
Authority: CN
Inventors: 翁佳伟; 王鑫; 邹晓辰; 夏喆
Original assignee: Hangzhou Hikrobot Technology Co Ltd
Current assignee: Hangzhou Hikrobot Co Ltd
Priority date: 2019-06-10
Filing date: 2019-06-10
Publication date: 2020-12-11
Anticipated expiration: 2039-06-10
Also published as: CN112062036B

Abstract

The embodiment of the invention discloses a lifting device, relates to the technical field of automatic guided vehicles, and can prolong the service life of a lead screw. The lifting device comprises: the lifting execution assembly and the lifting driving assembly; the lifting driving assembly comprises a driving motor, a vertically arranged lead screw, a nut sleeved on the lead screw and a nut limiting assembly for limiting the nut to move up and down, and the driving motor is connected with the nut through a transmission mechanism; the top end of the lead screw is rotatably connected with the lifting execution assembly. The invention is suitable for occasions where goods are lifted by utilizing the automatic guide transport vehicle.

Description

Lifting device

Technical Field

The invention relates to the technical field of automatic guided vehicles, in particular to a lifting device on an automatic guided vehicle.

Background

An Automated Guided Vehicle (AGV) is a Vehicle equipped with an electromagnetic or optical automatic guide device, which can travel along a predetermined guide path, and has safety protection and various transfer functions, and belongs to the category of a Wheel Mobile Robot (WMR).

In order to realize the carrying and lifting of the goods, some AGVs are provided with lifting devices. The lifting device generally comprises a lifting execution assembly and a lifting driving assembly; the lifting driving component adopts screw-nut pair transmission, and the top end of the screw is rigidly connected with the lifting executing component.

In the prior art, the screw rod in the lifting driving assembly is rigidly connected with the lifting executing assembly, and when a lifting platform of the lifting executing assembly generates unbalance load under the action of load, the unbalance load can be directly applied to the screw rod, so that the stress working condition of the screw rod nut pair is severe, and the service life of the screw rod nut pair is shortened.

Disclosure of Invention

In view of this, an embodiment of the present invention provides a lifting device, which can prolong the service life of a lead screw.

An embodiment of the present invention provides a lifting device, including: the lifting execution assembly and the lifting driving assembly; the lifting driving assembly comprises a driving motor, a vertically arranged lead screw, a nut sleeved on the lead screw and a nut limiting assembly for limiting the nut to move up and down, and the driving motor is connected with the nut through a transmission mechanism; the top end of the lead screw is rotatably connected with the lifting execution assembly.

According to a specific implementation manner of the embodiment of the invention, the lifting execution assembly comprises: the lifting platform is arranged above the base, and an auxiliary lifting mechanism is arranged between the lifting platform and the base; the lifting driving assembly is arranged on the base; wherein the lead screw in the lifting drive assembly is positioned below the lifting platform; a first through hole is formed in the lifting platform; and a second through hole is formed in the position, close to the top end of the lead screw, corresponds to the first through hole, and a pin shaft penetrates through the first through hole and the second through hole in the horizontal direction.

According to a specific implementation manner of the embodiment of the present invention, the first through hole and/or the second through hole are vertically arranged elongated holes, or the diameter of the first through hole and/or the second through hole is larger than the diameter of the pin.

According to a specific implementation manner of the embodiment of the invention, a ball socket is arranged on the lifting platform; the lead screw comprises a lead screw body and a ball head arranged at the top end of the lead screw body, and the ball head is positioned in the ball socket.

According to a specific implementation manner of the embodiment of the invention, the lifting platform is provided with a ball socket, and the ball socket is arranged on the ball socket.

According to a specific implementation manner of the embodiment of the invention, the lead screw comprises a lead screw body and a joint bearing arranged at the top end of the lead screw body; the second through hole is formed in the center hole of the inner sleeve of the joint bearing, and the pin shaft is inserted into the center hole of the inner sleeve of the joint bearing.

According to a specific implementation manner of the embodiment of the invention, a bearing seat is fixed at the top end of the lead screw body, a bearing mounting hole is formed in the bearing seat, and the joint bearing is mounted in the bearing mounting hole; a limiting plate is mounted on the outer side of the bearing mounting hole, a third through hole is formed in the limiting plate and corresponds to a central hole of the inner sleeve of the joint bearing, and the pin shaft penetrates through the third through hole and is inserted into the central hole of the inner sleeve of the joint bearing; the third through hole is a vertically arranged elongated hole, or the diameter of the third through hole is larger than that of the pin shaft.

According to a specific implementation manner of the embodiment of the invention, the lifting platform comprises a bearing plate, a bridge-shaped block is connected onto the bearing plate, and the ball socket is positioned in a groove in the middle of the bridge-shaped block.

According to a specific implementation manner of the embodiment of the invention, the lifting platform comprises a bearing plate, a bridge-shaped block is connected to the bearing plate, and the first through holes are formed in wing plates on two sides of the bridge-shaped block; the joint bearing is positioned in a groove in the middle of the bridge-shaped block.

According to a specific implementation mode of the embodiment of the invention, the bearing plate is provided with a notch, the bridge-shaped block is arranged at the notch, and the ear parts at two sides of the bridge-shaped block are connected to the lower surface of the bearing plate; wherein, the ear of bridge type piece both sides is located the tip of the pterygoid lamina of bridge type piece both sides.

According to a specific implementation manner of the embodiment of the invention, the nut limiting assembly comprises: the base body is fixedly connected to the base of the lifting execution assembly, a through hole is formed in the base body, a bearing is arranged in the through hole, and the bearing is fixed in the through hole along the axial direction of the through hole; the nut comprises a first end part, a second end part and a middle part positioned between the first end part and the second end part, and the outer ring of the middle part of the nut is sleeved and fixed in the central hole of the bearing; a transition joint of the first end part and the middle part of the nut is provided with a limiting step, and the limiting step is abutted against one end of the bearing; the second end part of the nut extends out of the central hole of the bearing and is connected with the limiting blocking piece; the first end of the nut is connected with the driving motor through the transmission mechanism.

According to a specific implementation manner of the embodiment of the invention, the auxiliary lifting mechanism comprises a first connecting arm, a second connecting arm, a third connecting arm and a fourth connecting arm; the arm body between the two ends of the first connecting arm is hinged with the arm body between the two ends of the second connecting arm; the first end of the first connecting arm is hinged or slidably connected with the base, and the second end of the first connecting arm is slidably connected with the lifting platform; the first end of the second connecting arm is hinged or slidably connected with the lifting platform, and the second end of the second connecting arm is slidably connected with the base; the arm body between the two ends of the third connecting arm is hinged with the arm body between the two ends of the fourth connecting arm; the third connecting arm and the first connecting arm are arranged at intervals and in parallel, and the fourth connecting arm and the second connecting arm are arranged at intervals and in parallel; a cross rod is connected between the first connecting arm and the third connecting arm and/or between the second connecting arm and the fourth connecting arm; the first end of the third connecting arm is hinged or slidably connected with the base, and the second end of the third connecting arm is slidably connected with the lifting platform; the first end of the fourth connecting arm is hinged or connected with the lifting platform in a sliding mode, and the second end of the fourth connecting arm is connected with the base in a sliding mode.

According to a specific implementation manner of the embodiment of the invention, the driving motor is vertically arranged on one side of the screw rod; the transmission mechanism comprises a speed reducer connected with an output shaft of the driving motor, and a belt transmission mechanism, a chain transmission mechanism or a gear transmission mechanism is arranged between the output shaft of the speed reducer and the nut.

According to the lifting device provided by the embodiment of the invention, the top end of the lead screw is rotatably connected with the lifting execution assembly, so that even if unbalance loading exists in the lifting process, unbalance loading force generated by the unbalance loading cannot be directly transmitted to the lead screw, namely, component force which forms a certain included angle (larger than 0 DEG) with the central axis of the lead screw cannot be generated on the lead screw, so that the eccentric wear phenomenon between the lead screw and the nut caused by the deflection of the lead screw under the action of the component force can be avoided, the stress condition of the lead screw can be improved, and the service life of the lead screw is prolonged.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, 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 drawings without creative efforts.

FIG. 1 is a schematic diagram of an exemplary lift device in accordance with one embodiment of the present invention;

FIG. 2 is a partial cross-sectional view of the structure of FIG. 1;

FIG. 3 is a schematic view of a ball head at the top of the lead screw of FIG. 2 and a ball socket matching structure on the ball socket seat;

FIG. 4 is a schematic diagram of another exemplary lift device in accordance with the present invention;

FIG. 5 is a schematic view of a connection structure between the lift driving assembly and the bridge block of the lift actuating assembly in FIG. 4;

FIG. 6 is a schematic view of the lift drive assembly of FIG. 4;

FIG. 7 is a schematic structural diagram of a bearing seat for mounting a joint bearing connected to the top of the screw rod in FIG. 4;

fig. 8 is a schematic structural view of the stopper plate mounted outside the bearing mounting hole in fig. 4.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

It should be understood that the described embodiments are only some embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The present embodiment provides a lifting device for an apparatus for lifting a load to a certain height, such as an AGV, which includes a chassis having wheels at a lower portion thereof, and on which an electromagnetic or optical automatic guidance device for allowing the AGV to travel along a guidance path may be mounted, and on which the lifting device may be mounted. The lifting device is applied to an AGV as an example.

Referring to fig. 1 to 3, an exemplary lifting apparatus according to an embodiment of the present invention includes: the lifting execution assembly 1 and the lifting driving assembly 2; the lifting driving assembly 2 comprises a driving motor 21, a vertically arranged screw rod 22, a nut 23 sleeved on the screw rod 22 and a nut limiting assembly 24 limiting the up-and-down movement of the nut 23, and the driving motor 21 is connected with the nut 23 through a transmission mechanism 25; the top end of the lead screw 22 is rotatably connected with the lifting execution assembly 1.

In this embodiment, the lifting performing assembly 1 is used for performing a lifting operation, and can lift the goods to be lifted by a predetermined distance. It should be understood that the lifting implement assembly 1 may have a loading platform on which the cargo to be lifted is placed prior to lifting.

Referring to fig. 2, the screw 22 and the nut 23 in the lifting drive assembly 2 constitute a screw-nut pair. Alternatively, balls may be provided between the screw 22 and the nut 23, in which case the screw-nut pair may also be referred to as a ball screw.

In one embodiment, a screw limiting bottom plate may be disposed at the bottom of the screw 22 to serve as a mechanical limit for the screw 22, which prevents the screw 22 from being screwed out upward, and the mechanical limit may be used together with an electrical limit to ensure safe operation of the lifting driving assembly 2.

When lifting operation is executed, when the driving motor 21 in the lifting driving assembly 2 rotates, the nut 23 is driven to rotate through the transmission mechanism 25, the nut 23 rotates to drive the lead screw 22 to rotate, the lead screw is driven by the nut 23 to perform jacking motion, and therefore the lifting executing assembly 1 is driven to complete lifting action. It should be understood that when the nut 23 rotates, in order to push the lead screw to perform the jacking motion, a limiting component, such as a latch, a detent, a block, etc., for limiting the rotation of the lead screw 22 along with the nut 23 needs to be arranged between the lead screw 22 and the lifting actuator assembly 1.

Because the lifting executing assembly may have manufacturing or assembling errors, the lifting executing assembly can generate the situation of shaking back and forth or left and right if an unbalance load exists in the lifting process. If the lead screw 22 is directly and rigidly connected with the lifting execution assembly 1, during the lifting process, the top of the lead screw 22 will be subjected to left and right component forces, and the lead screw 22 will also deflect left and right under the action of the component forces, which is easy to generate adverse effects on the lead screw, such as eccentric wear, increase local wear, and reduce the service life of the lead screw 22 and the nut 23. Therefore, in the embodiment, the top end of the lead screw 22 is rotatably connected with the lifting executing component 1 to avoid rigid connection between the top end of the lead screw 22 and the lifting executing component 1, so that even if an offset load exists in the lifting process, an offset load force generated by the offset load cannot be directly transmitted to the lead screw, that is, a component force forming a certain included angle (greater than 0 degree) with the central axis of the lead screw cannot be generated on the lead screw, thereby avoiding an eccentric wear phenomenon between the lead screw and the nut caused by the deflection of the lead screw under the action of the component force, improving the stress condition of the lead screw 22 and the nut 23, and prolonging the service life of the lead screw 22 and the nut 23.

Referring to fig. 1 and 2, or fig. 4 and 5, in an embodiment, the lift actuating assembly 1 includes: the lifting platform 12 is arranged above the base 11, and an auxiliary lifting mechanism 13 is arranged between the lifting platform 12 and the base 11; the lifting driving component 2 is arranged on the base 11; wherein the lead screw 22 in the lifting drive assembly 2 is located below the lifting platform 12; a first through hole 123 is formed in the lifting platform 12; a second through hole 124 is formed in the position, close to the top end of the lead screw, of the lead screw 22, the second through hole 124 corresponds to the first through hole 123, and a pin shaft 3 penetrates through the first through hole 123 and the second through hole 124 along the horizontal direction.

In this embodiment, the first through hole is formed in the lifting platform, the second through hole is formed in the screw rod, and the pin shaft penetrates through the first through hole and the second through hole in the horizontal direction, so that the lifting platform can rotate relative to the top end of the screw rod, and thus even if unbalance loading occurs in the lifting process, unbalance loading force generated by the unbalance loading cannot be directly transmitted to the screw rod, namely, component force which forms a certain included angle (larger than 0 degree) with the central axis of the screw rod cannot be generated on the screw rod, and therefore the eccentric wear phenomenon between the screw rod and the nut due to the fact that the screw rod deflects under the action of the component force can be avoided.

In an embodiment, the first through hole and/or the second through hole are vertically arranged elongated holes, or the diameter of the first through hole and/or the second through hole is larger than that of the pin shaft, so that the lifting platform can rotate relative to the screw rod in two degrees of freedom directions (such as the front-back direction and the left-right direction), adaptability to different unbalance loading conditions can be improved, the screw rod can be prevented from being inclined in more degrees of freedom directions, and the eccentric wear phenomenon between the screw rod and the nut can be effectively reduced or prevented. The front-rear direction may be a direction coinciding with the travel route of the AGV in the horizontal plane, and the left-right direction may be a direction perpendicular to the travel route of the AGV in the horizontal plane.

The first through hole 123 shown in fig. 1 is a circular hole, and the second through hole 124 shown in fig. 3 is a vertically-arranged elongated hole, so that the left-right direction inclination of the lifting platform 12 (the rotation inclination is performed by taking the rotation center line parallel to the axis of the pin shaft 3 as a rotation shaft) can be realized, and the front-back direction inclination of the lifting platform 12 (the rotation inclination is performed by taking the rotation center line perpendicular to the axis of the pin shaft 3 as a rotation shaft) can also be realized, thereby better relieving the adverse effect on the screw rod 22 when the unbalance load exists in the lifting process. Moreover, the first through hole 123, the second through hole 124 and the pin 3 are mutually matched, so that the rotation of the lifting platform 12 in the horizontal direction can be avoided, and the lifting stability is provided.

The pin shaft 3 inserted into the first through hole 123 and the second through hole 124 can prevent the lifting execution assembly 1 from being separated from the lifting driving assembly 2, and can limit the lead screw 22, so as to limit the lead screw 22 from rotating together with the nut 23 when the nut 23 rotates.

Referring to fig. 2 and 3, in an embodiment, the top end of the lead screw 22 is connected with the lifting actuating assembly 1 by a ball-and-socket joint. In this embodiment, the lifting platform 12 is provided with a ball socket 121; the lead screw 22 comprises a lead screw body and a ball head 221 arranged at the top end of the lead screw body, the ball head 221 is located in the ball socket 121, and the ball head 221 at the top end of the lead screw body is matched with the ball socket 121 on the lifting platform 12, so that even if unbalance loading exists in the lifting executing assembly 1 in the lifting process, adverse effects of the unbalance loading on the lead screw 22 and the nut 23 can be reduced or avoided through relative rotation between the ball head 221 and the ball socket 121, the stress condition of the lead screw 22 and the nut 23 is improved, and the service life of the lead screw 22 and the nut 23 is prolonged.

Referring to fig. 1 and 2, in order to facilitate the machining and the arrangement of the ball socket 121 and the replacement of the ball socket after wear, a ball socket 122 may be provided on the lifting platform 12, and the ball socket 121 may be provided on the ball socket 122. Thus, the socket 121 can be easily preformed on the socket 122, and the socket 121 can be easily disposed on the lifting platform 12 through the socket 122. After the ball socket 121 is worn, the ball socket 122 can be removed from the lifting platform 12 and replaced with a new ball socket 122. The embodiment of the invention is not limited to this, and the ball socket may be directly machined at the bottom of the lifting platform. The ball socket can also be arranged at the top end of the screw rod, and correspondingly, the ball head is arranged on the lifting platform.

In this embodiment, when the lifting platform 12 is tilted left and right or front and back under the action of an unbalance load, the ball head 221 and the ball socket 121 are connected by a spherical pair, so that the lead screw 22 is not affected by the unbalance load, the stress condition of the lead screw nut can be improved, and the service life of the lead screw nut is prolonged.

In order to facilitate the arrangement of the ball socket 121 on the lifting platform 12 and provide protection for a spherical pair formed by the ball head 221 and the ball socket 121 in a matching manner, and reduce interference of foreign matters on free rotation between the ball head 221 and the ball socket 121, further, the lifting platform 12 comprises a bearing plate 124, a bridge-shaped block 125 is connected to the bearing plate 124, and the first through holes 123 are opened on wing plates at two sides of the bridge-shaped block 125; the ball socket 121 is positioned in a groove in the middle of the bridge-shaped block 125, and a spherical pair formed by the matching of the ball head 221 and the ball socket 121 can be protected by wing plates on two sides of the bridge-shaped block 125.

Referring to fig. 1, in an embodiment, a notch is formed on the bearing plate 124, the bridge block 125 is embedded in the notch, and the ears at two sides of the bridge block 125 are connected to the lower surface of the bearing plate 124; wherein, the ear parts at both sides of the bridge block 125 are located at the end parts of the wing plates at both sides of the bridge block 125. The bridge-shaped block 125 is embedded in the notch formed on the bearing plate 124, so that the structure is relatively compact; the ear portions on both sides of the bridge-shaped block 125 are connected to the lower surface of the bearing plate 124, so that the connection reliability can be improved, and the ear portions can lift the bearing plate 124, thereby stably transmitting the lifting force of the screw rod 22 to the bearing plate 124.

When the AGV moves on a hollow or bumpy ground, the lifting actuator 1 is easily affected by the road condition and separated from the lifting drive assembly 2, so that an impact phenomenon may occur on the lead screw 22 in the lifting drive assembly 2, and to avoid this, referring to fig. 4 to 7, in another embodiment, a joint bearing connection manner is adopted between the top end of the lead screw 22 and the lifting actuator 1. Specifically, in this embodiment, the lead screw 22 includes a lead screw body and a joint bearing 4 provided at a top end of the lead screw body; the second through hole is formed in the center hole of the inner sleeve of the joint bearing 4, and the pin shaft 5 is inserted into the first through hole 123 and the center hole of the inner sleeve. The inner sleeve of the joint bearing 4 is sleeved in the outer sleeve and can rotate relative to the outer sleeve.

In this embodiment, the pin 5 is inserted into the first through hole 123 and the inner sleeve of the joint bearing 4, so as to connect the lifting platform 12 and the lead screw 22 together in a relatively compact manner, and when the lifting platform 12 encounters a hollow or bumpy ground, the impact between the lifting platform 12 and the lead screw 22 can be reduced or avoided. In addition, when the lifting platform 12 has an offset load in the lifting process, the adverse effect of the offset load on the lead screw 22 and the nut 23 can be reduced or avoided through the relative rotation between the inner sleeve and the outer sleeve of the joint bearing 4, the stress condition of the lead screw 22 and the nut 23 is improved, and the service life of the lead screw 22 and the nut 23 is prolonged.

To facilitate the installation of the joint bearing 4, in an embodiment, a bearing seat 6 may be fixed at the top end of the lead screw body of the lead screw 22, the bearing seat 6 has a bearing installation hole, and the joint bearing 4 is installed in the bearing installation hole;

a limiting plate 7 is mounted on the outer side of the bearing mounting hole, a third through hole 71 is formed in the limiting plate 7, the third through hole 71 corresponds to the central hole 41 of the inner sleeve of the knuckle bearing 4, and the pin 5 penetrates through the third through hole 71 and is inserted into the central hole 41 of the inner sleeve of the knuckle bearing 4; the third through hole 71 is a vertically arranged elongated hole.

In this embodiment, the first through hole 123 shown in fig. 4 and 5 is a circular hole, and the third through hole 71 shown in fig. 6 and 8 is a vertically-arranged elongated hole, so that the left and right inclination of the lifting platform 12 (the rotation inclination is performed by using the rotation center line parallel to the axis of the pin 5 as a rotation axis) can be realized, and the front and back inclination of the lifting platform 12 (the rotation inclination is performed by using the rotation center line perpendicular to the axis of the pin 5 as a rotation axis) can also be realized, which better relieves the adverse effect on the lead screw 22 when there is unbalance loading during the lifting process. Moreover, the first through hole 123, the third through hole 71 and the pin 5 are mutually matched, so that the rotation of the lifting platform 12 relative to the lead screw in the horizontal direction can be avoided, and the lifting stability is provided.

In an embodiment, the diameter of the third through hole 71 may be larger than the diameter of the pin 5, and it may also be convenient to tilt the lifting platform 12 left and right or front and back.

In this embodiment, the third through hole 71 is a vertically arranged elongated hole, or the diameter of the third through hole 71 is larger than the diameter of the pin 5, so that when the lifting platform 12 has an unbalanced load during the lifting process, the inner sleeve and the outer sleeve of the joint bearing 4 can rotate relatively. The pin 5 inserted into the third through hole 71 and the first through hole 123 can limit the rotation of the lead screw, that is, the lead screw 22 is limited to rotate together with the nut 23 when the nut 23 rotates.

In order to provide protection for the knuckle bearing 4, further, the lifting platform 12 includes a bearing plate 124, a bridge block 125 is connected to the bearing plate 124, and the first through hole 123 is opened on the wing plates at two sides of the bridge block 125; the knuckle bearing 4 is located in a groove in the middle of the bridge block 125, and the knuckle bearing 4 can be protected by wing plates on two sides of the bridge block 125.

In this embodiment, a notch may be formed on the carrier plate 124, the bridge block 125 is embedded in the notch, and the ears at two sides of the bridge block 125 are connected to the lower surface of the carrier plate 124; wherein, the ear parts at both sides of the bridge block 125 are located at the end parts of the wing plates at both sides of the bridge block 125. The bridge-shaped block 125 is embedded in the notch formed on the bearing plate 124, so that the structure is relatively compact; the ear portions on both sides of the bridge-shaped block 125 are connected to the lower surface of the bearing plate 124, so that the connection reliability can be improved, and the ear portions can lift the bearing plate 124, thereby facilitating the transmission of the lifting force of the screw rod 22 to the bearing plate 124.

In the foregoing embodiment, an auxiliary lifting mechanism 13 is disposed between the lifting platform 12 and the base 11 to improve the lifting stability. The auxiliary lifting mechanism may also be a screw-nut pair, and may also be a scissor-fork mechanism, referring to fig. 1 and 4, in an embodiment, the auxiliary lifting mechanism 13 may include a first connecting arm 131, a second connecting arm 132, a third connecting arm 133, and a fourth connecting arm 134;

wherein, the arm body between the two ends of the first connecting arm 131 is hinged with the arm body between the two ends of the second connecting arm 132, preferably, the middle part of the arm body of the first connecting arm 131 is hinged with the middle part of the arm body of the second connecting arm 132; the first end of the first connecting arm 131 is hinged or slidably connected to the base 11, and the second end is slidably connected to the lifting platform 12.

The arm body between the two ends of the third connecting arm 133 is hinged to the arm body between the two ends of the fourth connecting arm 134, preferably, the middle part of the arm body of the third connecting arm 133 is hinged to the middle part of the arm body of the fourth connecting arm 134; the third connecting arm 133 and the first connecting arm 131 are spaced and arranged in parallel, and the fourth connecting arm 134 and the second connecting arm 132 are spaced and arranged in parallel; a cross bar 8 is connected between the first connecting arm 131 and the third connecting arm 133 and/or between the second connecting arm 132 and the fourth connecting arm 134;

a first end of the third connecting arm 133 is hinged or slidably connected to the base 11, and a second end is slidably connected to the lifting platform 12; the first end of the fourth connecting arm 134 is hinged or slidably connected to the lifting platform 12, and the second end is slidably connected to the base 11.

In this embodiment, the cross bar 8 is connected between the first connecting arm 131 and the third connecting arm 133, and/or between the second connecting arm 132 and the fourth connecting arm 134, so that the lifting motions of the first connecting arm 131 and the third connecting arm 133, and/or the lifting motions of the second connecting arm 132 and the fourth connecting arm 134 are synchronized, which can improve the strength and stability of the auxiliary lifting mechanism 13.

Referring to fig. 2, in one embodiment, the nut limit assembly 24 includes: the base body 241 is fixedly connected to the base of the lifting execution assembly, a through hole is formed in the base body 241, a bearing 242 is arranged in the through hole, and the bearing 242 is axially fixed in the through hole along the through hole through an end cover 243; the nut 23 comprises a first end part, a second end part and a middle part between the first end part and the second end part, and the outer ring of the middle part of the nut is sleeved and fixed in the central hole of the bearing 242; the transition joint of the first end part and the middle part of the nut 23 is provided with a limiting step which is abutted against one end of the bearing 242; the second end of the nut 23 extends from the central hole of the bearing 242 and is connected to a limit stop 244, which may be a bayonet or a fastening nut; the first end of the nut is connected with the driving motor through the transmission mechanism.

Referring to fig. 1, 2 and 4, in an embodiment, the driving motor 21 is vertically disposed at one side of the lead screw 22, and when the height of the lifting implement assembly 1 is constant, the remaining part is the lifting stroke except for the necessary thread engagement length (the engagement length is determined by the lifting load weight) occupied by the nut 23, so that the lifting implement assembly 1 has a larger lifting stroke. That is to say, in this embodiment, it is realized that under the working condition that the lead screw nut is lifted vertically, the same lifting execution assembly height can have a larger lifting stroke.

The transmission mechanism 25 comprises a speed reducer 251 connected with the output shaft of the driving motor 21, and a belt transmission mechanism, a chain transmission mechanism or a gear transmission mechanism is arranged between the output shaft of the speed reducer 251 and the nut 23. In one embodiment, a pulley 253 may be fixed to the output shaft of the reducer 251 and the outer circumference of the nut 23, and the two pulleys may be connected to each other by a timing belt 252.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. The term "comprising", without further limitation, means that the element so defined is not excluded from the group consisting of additional identical elements in the process, method, article, or apparatus that comprises the element.

All the embodiments in the present specification are described in a related manner, and the same and similar parts among the embodiments may be referred to each other, and each embodiment focuses on the differences from the other embodiments.

For convenience of description, the above devices are described separately in terms of functional division into various units/modules. Of course, the functionality of the units/modules may be implemented in one or more software and/or hardware implementations of the invention.

The above description is only for the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A lifting device, comprising: the lifting execution assembly and the lifting driving assembly; the lifting driving assembly comprises a driving motor, a vertically arranged lead screw, a nut sleeved on the lead screw and a nut limiting assembly for limiting the nut to move up and down, and the driving motor is connected with the nut through a transmission mechanism; the top end of the lead screw is rotatably connected with the lifting execution assembly.

2. The lift apparatus of claim 1, wherein the lift performing assembly comprises:

the lifting platform is arranged above the base, and an auxiliary lifting mechanism is arranged between the lifting platform and the base;

the lifting driving assembly is arranged on the base; wherein the lead screw in the lifting drive assembly is positioned below the lifting platform;

a first through hole is formed in the lifting platform; and a second through hole is formed in the position, close to the top end of the lead screw, corresponds to the first through hole, and a pin shaft penetrates through the first through hole and the second through hole in the horizontal direction.

3. The lifting device as claimed in claim 2, wherein the first through hole and/or the second through hole is a vertically disposed elongated hole, or a diameter of the first through hole and/or the second through hole is larger than a diameter of the pin.

4. The lifting device as recited in claim 2, wherein the lifting platform is provided with a ball socket; the lead screw comprises a lead screw body and a ball head arranged at the top end of the lead screw body, and the ball head is positioned in the ball socket.

5. The lifting device as recited in claim 2, wherein the lead screw includes a lead screw body and a knuckle bearing disposed at a top end of the lead screw body;

the second through hole is formed in the center hole of the inner sleeve of the joint bearing, and the pin shaft is inserted into the first through hole and the center hole of the inner sleeve of the joint bearing.

6. The lifting device as claimed in claim 5, wherein a bearing seat is fixed to the top end of the screw body, a bearing mounting hole is formed in the bearing seat, and the knuckle bearing is mounted in the bearing mounting hole;

a limiting plate is mounted on the outer side of the bearing mounting hole, a third through hole is formed in the limiting plate and corresponds to a central hole of the inner sleeve of the joint bearing, and the pin shaft penetrates through the third through hole and is inserted into the central hole of the inner sleeve of the joint bearing;

the third through hole is a vertically arranged elongated hole, or the diameter of the third through hole is larger than that of the pin shaft.

7. The lifting device according to claim 4, wherein the lifting platform comprises a carrying plate, a bridge-shaped block is connected to the carrying plate, and the first through hole is formed in wing plates on two sides of the bridge-shaped block; the ball socket is positioned in a groove in the middle of the bridge-shaped block.

8. The lifting device according to claim 5, wherein the lifting platform comprises a carrying plate, a bridge-shaped block is connected to the carrying plate, and the first through hole is formed in wing plates on two sides of the bridge-shaped block; the joint bearing is positioned in a groove in the middle of the bridge-shaped block.

9. The lifting device according to claim 7 or 8, wherein the bearing plate is provided with a notch, the bridge-shaped block is arranged at the notch, and the ear parts at two sides of the bridge-shaped block are connected to the lower surface of the bearing plate; wherein, the ear of bridge type piece both sides is located the tip of the pterygoid lamina of bridge type piece both sides.

10. The lifting device of claim 2, wherein the nut limiting assembly comprises: the base body is fixedly connected to the base of the lifting execution assembly, a through hole is formed in the base body, a bearing is arranged in the through hole, and the bearing is fixed in the through hole along the axial direction of the through hole;

the nut comprises a first end part, a second end part and a middle part positioned between the first end part and the second end part, and the outer ring of the middle part of the nut is sleeved and fixed in the central hole of the bearing;

a transition joint of the first end part and the middle part of the nut is provided with a limiting step, and the limiting step is abutted against one end of the bearing; the second end part of the nut extends out of the central hole of the bearing and is connected with the limiting blocking piece;

the first end of the nut is connected with the driving motor through the transmission mechanism.

11. The lifting device as claimed in claim 2, wherein the auxiliary lifting mechanism comprises a first connecting arm, a second connecting arm, a third connecting arm and a fourth connecting arm;

the arm body between the two ends of the first connecting arm is hinged with the arm body between the two ends of the second connecting arm; the first end of the first connecting arm is hinged or slidably connected with the base, and the second end of the first connecting arm is slidably connected with the lifting platform; the first end of the second connecting arm is hinged or slidably connected with the lifting platform, and the second end of the second connecting arm is slidably connected with the base;

the arm body between the two ends of the third connecting arm is hinged with the arm body between the two ends of the fourth connecting arm; the third connecting arm and the first connecting arm are arranged at intervals and in parallel, and the fourth connecting arm and the second connecting arm are arranged at intervals and in parallel; a cross rod is connected between the first connecting arm and the third connecting arm and/or between the second connecting arm and the fourth connecting arm;

the first end of the third connecting arm is hinged or slidably connected with the base, and the second end of the third connecting arm is slidably connected with the lifting platform; the first end of the fourth connecting arm is hinged or connected with the lifting platform in a sliding mode, and the second end of the fourth connecting arm is connected with the base in a sliding mode.

12. The lifting device as claimed in claim 1, wherein the driving motor is vertically disposed at one side of the screw rod;

the transmission mechanism comprises a speed reducer connected with an output shaft of the driving motor, and a belt transmission mechanism, a chain transmission mechanism or a gear transmission mechanism is arranged between the output shaft of the speed reducer and the nut.