CN218960355U

CN218960355U - Electric lifting system for seat

Info

Publication number: CN218960355U
Application number: CN202223113061.8U
Authority: CN
Inventors: 熊兵
Original assignee: Dongguan Keken Mechanical And Electrical Technology Co ltd
Current assignee: Dongguan Keken Mechanical And Electrical Technology Co ltd
Priority date: 2022-11-23
Filing date: 2022-11-23
Publication date: 2023-05-05
Anticipated expiration: 2032-11-23

Abstract

The utility model discloses a seat electric lifting system which comprises a seat foot, an outer connecting sleeve, an inner connecting sleeve, a screw rod nut, a screw rod, a motor and a seat mounting device, wherein the outer connecting sleeve is arranged on the seat foot; the chair leg is provided with a first through hole, the outer connecting sleeve is vertically fixed on the chair leg, and a second through hole is arranged in the outer connecting sleeve; the lower end of the inner connecting sleeve is connected with the screw rod nut, the inner connecting sleeve and the screw rod nut are arranged in the second through hole of the outer connecting sleeve in a lifting manner, and the upper end of the inner connecting sleeve is connected with the seat mounting device; the inner connecting sleeve is internally provided with a third through hole, the screw rod vertically penetrates through the screw rod nut and is in transmission fit with the screw rod nut, the lower end of the screw rod downwards and movably penetrates through the first through hole, and the upper end of the screw rod upwards and movably stretches into the third through hole of the inner connecting sleeve; the motor is arranged at the lower side of the chair leg, and the power output end of the motor is connected with the lower end of the screw rod to drive the screw rod to rotate. The utility model has the advantages of high degree of automation, high safety, high reliability, good visual effect and good use effect.

Description

Electric lifting system for seat

Technical Field

The utility model relates to the technical field of seats, in particular to an electric lifting system of a seat.

Background

Currently, the lifting chair is increasingly widely applied to offices and other places. The basic principle of the air pressure lifting chair is that high-pressure nitrogen is filled in the air pressure lifting chair, as the through holes are formed in the piston, the air pressure at two ends of the piston is equal, the sectional areas at two sides of the piston are different, one end is connected with a piston rod, the other end is not, the lifting shaft slowly descends under the action of the air pressure, the speed is uniform, and the lowest point can be reached; the lifting shaft is not externally forced, and the lifting shaft is lifted to the highest point. Pneumatic lifting chairs are typically filled with high purity nitrogen at a pressure of about two atmospheres. However, the air pressure elevating chair has two disadvantages: (1) The automation degree is low, the lifting process of the air pressure lifting chair needs to be manually operated, when the air pressure lifting chair descends, a person is required to sit on the chair, then the control rod is pulled, when the air pressure lifting chair ascends, the person is required to stand up, and then the control rod is pulled, so that the air pressure lifting chair is inconvenient to use; (2) The safety is lower, because the high-pressure nitrogen gas with about two atmospheres is filled in the air pressure rod, when the damage problem occurs at the upper end of the air pressure rod, or when the air pressure lifting chair is impacted severely, the high-pressure nitrogen gas is easy to fry the chair upwards, thereby causing serious injury to the buttocks of a human body.

Chinese patent document CN114451712a discloses an office chair with a rotatable seat plate, comprising a fixed plate, on which a lifting assembly is arranged; the lifting assembly comprises a motor A arranged on the fixed plate and a supporting column penetrating through the fixed plate, a worm is arranged at the output end of the motor A, a rotating rod is arranged above the worm, worm wheels meshed with the worm are sleeved on the rotating rod, bearings with seats for the rotating rod to rotate are arranged on both sides of the worm wheels, racks meshed with the worm wheels are arranged on one side of a supporting column, a sliding block is arranged on the fixed plate, and a sliding rail for the sliding block to slide is arranged on one side, away from the racks, of the supporting column; the seat is arranged above the support column, and the support column is connected with the seat through a rotating assembly. The patent document CN114451712a can drive the seat up and down by the motor a.

However, the lifting assembly disclosed in the above patent document CN114451712a has the following drawbacks: (1) The safety is poor, and because the transmission components such as the motor A, the worm, the rotating rod, the worm wheel, the rack, the sliding block, the sliding rail and the like are all positioned on the fixed plate and exposed outside to directly face a user, the transmission components are easy to touch by the user in the use process, and the safety hidden trouble is great; (2) The reliability is poor, as the lifting assembly is provided with more transmission parts such as a motor A, a worm, a rotating rod, a worm wheel, a rack, a sliding block, a sliding rail and the like, the more the transmission parts are, the poorer the reliability is, and particularly, all the transmission parts are exposed outside, and external dust and oil dirt easily enter the transmission parts, so that the reliability is further reduced; (3) The visual effect is poor, and the result of use is not good, because lifting assembly installs on the fixed plate, exposes outside, so its visual effect is relatively poor to lifting assembly occupation space is big, and the user uses the seat that interferes easily.

Disclosure of Invention

The utility model aims to solve the technical problems of the prior art and provides the electric seat lifting system with high automation degree, high safety, high reliability, good visual effect and good use effect.

In order to solve the technical problems, the technical scheme of the utility model is as follows: an electric lifting system of a seat comprises a seat foot, an outer connecting sleeve, an inner connecting sleeve, a screw nut, a screw rod, a motor and a seat mounting device; the outer connecting sleeve is vertically fixed on the chair leg, a second through hole is arranged in the outer connecting sleeve, and the second through hole is communicated with the first through hole up and down; the lower end of the inner connecting sleeve is connected with the screw rod nut, and the inner connecting sleeve and the screw rod nut are arranged in the second through hole of the outer connecting sleeve in a lifting manner; the screw rod vertically penetrates through the screw rod nut and is in transmission fit with the screw rod nut, the lower end of the screw rod downwards movably penetrates through the first through hole, and the upper end of the screw rod upwards movably stretches into the third through hole of the inner connecting sleeve; the motor is arranged on the lower side of the chair leg, and the power output end of the motor is connected with the lower end of the screw rod so as to drive the screw rod to rotate; the upper end of the inner connecting sleeve extends out of the second through hole of the outer connecting sleeve upwards, and the upper end of the inner connecting sleeve is connected with the seat mounting device.

Preferably, the first through hole is vertically arranged in the middle of the chair leg, and the lower end of the outer connecting sleeve is inserted into the upper end of the first through hole; the lower side of the chair leg is provided with a motor seat, and the lower end of the motor seat is connected with the motor; the middle part of the motor base is provided with a motor base connecting sleeve, and the upper end of the motor base connecting sleeve is inserted into the lower end of the first through hole; the motor base connecting sleeve is provided with a fourth through hole, and a first bearing is arranged in the fourth through hole; the lower end of the screw rod passes through the first bearing and is positioned through the first bearing.

Preferably, a first clamping ring is further arranged at the upper end of the fourth through hole of the motor base connecting sleeve, and the first clamping ring is used for preventing the first bearing from loosening upwards; a second clamping ring is arranged at the lower end of the fourth through hole of the motor base connecting sleeve and is used for preventing the screw rod from loosening downwards; the motor is transversely arranged, the motor is provided with a speed reducer, and the motor can drive the screw rod to rotate through the speed reducer.

Preferably, the second through hole is vertically arranged, a chute is vertically arranged on the wall of the second through hole, a slide bar is vertically arranged on the outer wall of the inner connecting sleeve, and the slide bar can be installed in the chute in a vertical sliding manner.

Preferably, the inner wall of the outer connecting sleeve is a polygonal inner wall with a polygonal cross section, the outer wall of the inner connecting sleeve is a corresponding polygonal outer wall, and the polygonal outer wall is in sliding fit with the polygonal inner wall.

Preferably, the screw nut comprises an upper nut portion and a lower nut portion which are integrally connected, the overall external shapes of the upper nut portion and the lower nut portion are cylindrical, the diameter of the upper nut portion is smaller than that of the lower nut portion, an annular step surface is arranged at the joint between the upper nut portion and the lower nut portion, the upper nut portion is connected into the lower end of the third through hole of the inner connecting sleeve, and the lower end face of the inner connecting sleeve is abutted against the annular step surface.

Preferably, an external thread is arranged on the upper nut part of the screw rod nut, an internal thread is arranged at the lower end of the third through hole, and the upper nut part is in threaded connection with the lower end of the third through hole.

Preferably, the seat mounting device comprises a lower connecting shaft, a second bearing and an upper connecting shaft, wherein the lower end of the lower connecting shaft is connected inside the upper end of the third through hole of the inner connecting sleeve, the second bearing is sleeved outside the upper end of the lower connecting shaft, the lower end of the upper connecting shaft is sleeved outside the second bearing, and the upper end of the upper connecting shaft is used for mounting the seat. The two bearings are arranged in parallel, the lower end of the upper connecting shaft is provided with a bearing sleeve, and the bearing sleeve is sleeved outside the two bearings.

Preferably, the outer connecting sleeve, the inner connecting sleeve, the lower connecting shaft and the upper connecting shaft are respectively made of plastic or hardware materials.

Preferably, the chair legs are multi-claw chair legs, disc-shaped chair legs or wheel-shaped chair legs.

The beneficial effects of the utility model are as follows: (1) The utility model drives the screw rod to rotate through the motor, drives the screw rod nut to lift through the screw rod, drives the inner connecting sleeve to lift through the screw rod nut, and finally drives the seat mounting device to lift through the inner connecting sleeve, the lifting process does not need manual operation, and the motor can be controlled to rotate through the arrangement of the control button, so that the automatic lifting of the seat is controlled, and the degree of automation is high. (2) Compared with the traditional pneumatic lifting mode, the utility model has the advantages that the problem that the seat is fried by high-pressure nitrogen is avoided, and the safety is high; in addition, the motor is arranged at the lower side of the chair leg, the screw rod and the screw rod nut are hidden in the inner connecting sleeve, and the inner connecting sleeve is slidably arranged in the outer connecting sleeve, so that a user cannot touch the lifting transmission part, and the safety of the electric lifting system is greatly improved. (3) According to the utility model, the motor drives the screw rod to rotate, and then the screw rod drives the screw rod nut to lift, so that the inner connecting sleeve and the seat mounting device are driven to lift, the lifting transmission mode has fewer parts, and the reliability of the transmission mode is high; and the inner connecting sleeve and the screw rod nut are arranged in the second through hole of the outer connecting sleeve in a lifting manner, and the outer connecting sleeve is fixed on the chair leg, so that the inner connecting sleeve, the screw rod nut and the screw rod can be stably and reliably supported through the outer connecting sleeve, and the lifting process is very high in stability. (4) Because the motor is arranged at the lower side of the chair leg, and the screw rod, the screw rod nut and the inner connecting sleeve are positioned in the outer connecting sleeve, the lifting transmission assembly occupies little space above the chair leg, has good visual effect, and is not easy to interfere a user to use the chair, and has good use effect.

Drawings

Fig. 1 is one of the overall construction diagrams of a seat electric lift system according to the first embodiment.

Fig. 2 is a second overall configuration diagram of the electric lifting system for a seat according to the first embodiment.

Fig. 3 is a dispersion structure view and a partial enlarged view of the electric seat lifting system according to the first embodiment.

Fig. 4 is another decentralized configuration diagram of the electric seat lifting system according to the first embodiment.

Fig. 5 is a longitudinal sectional view of the electric lifting system for a seat according to the first embodiment.

Fig. 6 is an overall construction diagram of a seat electric lifting system of the second embodiment.

Fig. 7 is an overall construction diagram of a seat electric lifting system of the third embodiment.

In the figure: 1. chair legs; 11. a first through hole; 2. an outer connecting sleeve; 22. a chute; 21. a second through hole; 3. an inner connecting sleeve; 31. a third through hole; 32. a slide bar; 4. a screw nut; 41. an upper nut portion; 42. a lower nut portion; 43. an annular step surface; 5. a screw rod; 6. a motor; 61. a speed reducing device; 7. a seat mounting device; 71. a lower connecting shaft; 72. a second bearing; 73. an upper connecting shaft; 8. a motor base; 81. the motor base connecting sleeve; 82. a fourth through hole; 83. a first bearing.

Detailed Description

The structural and operational principles of the present utility model will be described in further detail below with reference to the accompanying drawings.

In the description of the present utility model, it should be understood that the directions or positional relationships indicated by the terms "upper", "lower", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of description and simplification of the description, and do not indicate or imply that the apparatus or element in question must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the utility model.

Example 1

As shown in fig. 1 to 5, the present embodiment is a seat electric lifting system, which comprises a seat foot 1, an outer connecting sleeve 2, an inner connecting sleeve 3, a screw nut 4, a screw rod 5, a motor 6 and a seat mounting device 7; the chair leg 1 of the embodiment is a five-claw chair leg, and can also be a multi-claw chair leg with other claw numbers; the chair leg 1 is provided with a first through hole 11, the outer connecting sleeve 2 is vertically fixed on the chair leg 1, a second through hole 21 is arranged in the outer connecting sleeve 2, and the second through hole 21 is communicated with the first through hole 11 up and down; the lower end of the inner connecting sleeve 3 is connected with the screw nut 4, and the inner connecting sleeve 3 and the screw nut 4 are arranged in the second through hole 21 of the outer connecting sleeve 2 in a lifting manner; the inner connecting sleeve 3 is internally provided with a third through hole 31, the screw rod 5 vertically penetrates through the screw rod nut 4 and is in driving fit with the screw rod nut 4, the lower end of the screw rod 5 downwards movably penetrates through the first through hole 11, the upper end of the screw rod 5 upwards movably stretches into the third through hole 31 of the inner connecting sleeve 3, and the upper end of the screw rod 5 is not in contact with the inner wall of the third through hole 31; the motor 6 is arranged at the lower side of the chair leg 4, and the power output end of the motor 6 is connected with the lower end of the screw rod 5 to drive the screw rod 5 to rotate; the upper end of the inner connecting sleeve 3 extends out of the second through hole 21 of the outer connecting sleeve 2, and the upper end of the inner connecting sleeve 3 is connected with the seat mounting device 7.

The operation process of the utility model is as follows: (1) an automatic ascent process: the motor 6 drives the screw rod 5 to rotate positively, and the screw rod 5 drives the screw rod nut 4 to ascend in the rotating process, the screw rod nut 4 further pushes the inner connecting sleeve 3 to ascend along the second through hole 21, and the inner connecting sleeve 3 finally pushes the seat mounting device 7 to ascend; the ascending process and the ascending travel can be controlled by buttons or remote control; (2) an automatic descent process: the motor 6 drives the screw rod 5 to reversely rotate, the screw rod 5 drives the screw rod nut 4 to descend in the rotating process, the screw rod nut 4 drives the inner connecting sleeve 3 to descend along the second through hole 21, and the inner connecting sleeve 3 finally drives the seat mounting device 7 to descend; the descending process and the descending stroke can be controlled by buttons or remote control.

According to the utility model, the motor 6 drives the screw rod 5 to rotate, the screw rod 5 drives the screw rod nut 4 to lift, the screw rod nut 4 drives the inner connecting sleeve 3 to lift, and finally the inner connecting sleeve 3 drives the seat mounting device 7 to lift, so that the motor 6 can be controlled to rotate without manual operation in the lifting process, and the automatic lifting of the seat is controlled, so that the degree of automation is high. Compared with the traditional pneumatic lifting mode, the utility model has the advantages that the problem that the seat is fried by high-pressure nitrogen is avoided, and the safety is high; in addition, the motor 6 is arranged at the lower side of the chair leg 1, the screw rod 5 and the screw rod nut 4 are hidden in the inner connecting sleeve 3, and the inner connecting sleeve 3 is slidably arranged in the outer connecting sleeve 2, so that a user cannot touch the lifting transmission part, and the safety of the electric lifting system is greatly improved. According to the utility model, the motor 6 drives the screw rod 5 to rotate, and then the screw rod 5 drives the screw rod nut 4 to lift, so that the inner connecting sleeve 3 and the seat mounting device 7 are driven to lift, so that the parts of a lifting transmission mode are fewer, and the reliability of the transmission mode is high; in addition, the inner connecting sleeve 3 and the screw nut 4 are installed in the second through hole 21 of the outer connecting sleeve 2 in a lifting manner, and the outer connecting sleeve 2 is fixed on the chair leg 1, so that the inner connecting sleeve 3, the screw nut 4 and the screw 5 can be stably and reliably supported through the outer connecting sleeve 2, and the lifting process is very high in stability. Because the motor 6 is arranged at the lower side of the chair leg 1, and the screw rod 5, the screw rod nut 4 and the inner connecting sleeve 3 are positioned in the outer connecting sleeve 2, the lifting transmission component occupies very little space above the chair leg 1, has good visual effect, and is not easy to interfere a user to use the chair, and has good use effect.

As shown in fig. 1-5, the first through hole 11 is vertically opened in the middle of the chair leg 1, the lower end of the outer connecting sleeve 2 is inserted into the upper end of the first through hole 1, and the lower end of the outer connecting sleeve 2 is fixed by the first through hole 11 more firmly and reliably. The lower side of the chair leg 1 is provided with a motor seat 8, and the lower end of the motor seat 8 is connected with the motor 6; the middle part of the motor base 8 is provided with a motor base connecting sleeve 81, and the upper end of the motor base connecting sleeve 81 is inserted into the lower end of the first through hole 11; the motor base connecting sleeve 81 is provided with a fourth through hole 82, and a first bearing 83 is installed in the fourth through hole 82; the lower end of the screw 5 passes through the first bearing 83 and is positioned by the first bearing 83. The first bearing 83 of the utility model can play a role in stabilizing lateral support on the lower end of the screw rod 5, so that the lower end of the screw rod 5 is stably positioned.

As shown in fig. 1-5, a first snap ring 84 is further disposed at the upper end of the fourth through hole 82 of the motor base connecting sleeve 81, and the first snap ring 84 is used for preventing the first bearing 83 from loosening upwards; a second clamping ring 85 is arranged at the lower end of the fourth through hole 82 of the motor base connecting sleeve 81, and the second clamping ring 85 is used for preventing the screw rod 5 from loosening downwards; the motor 6 is transversely arranged, so that the motor 6 can be better hidden, the motor is prevented from occupying a larger space, the motor 6 is provided with a speed reducer 61, and the motor 6 can drive the screw rod 5 to rotate through the speed reducer 61.

As shown in fig. 1-5, the second through hole 21 is vertically arranged, a chute 22 is vertically arranged on the wall of the second through hole 21, a sliding strip 32 is vertically arranged on the outer wall of the inner connecting sleeve 3, and the sliding strip 32 is slidably installed in the chute 22 up and down. The sliding fit of the sliding strip 32 and the sliding groove 22 can prevent the inner connecting sleeve 3 from rotating in the outer connecting sleeve 2, so that the lifting process of the inner connecting sleeve 3 is smoother. The number of the sliding strips 32 and the sliding grooves 22 is one or two respectively. It should be noted that, the inner wall of the outer connecting sleeve 2 may be a polygonal inner wall with a polygonal cross section, and the outer wall of the inner connecting sleeve 3 is a corresponding polygonal outer wall, and the polygonal outer wall is slidably matched with the polygonal inner wall, so that the structures of the sliding strip 32 and the sliding chute 22 may be omitted.

As shown in fig. 1 to 5, the screw nut 4 includes an upper nut portion 41 and a lower nut portion 42 integrally connected, the overall external shape of the upper nut portion 41 and the lower nut portion 42 is cylindrical, the diameter of the upper nut portion 41 is smaller than that of the lower nut portion 42, an annular step surface 43 is provided at the connection portion between the upper nut portion 41 and the lower nut portion 42, the upper nut portion 41 is connected within the lower end of the third through hole 31 of the inner connecting sleeve 3, and the lower end surface of the inner connecting sleeve 3 abuts against the annular step surface 43. The upper nut portion 41 of the screw nut 4 is provided with an external thread, the lower end of the third through hole 31 is provided with an internal thread, and the upper nut portion 41 is in threaded connection with the lower end of the third through hole 31.

As shown in fig. 1 to 5, the seat mounting device 7 includes a lower connection shaft 71, a second bearing 72, and an upper connection shaft 73, wherein the lower end of the lower connection shaft 71 is connected to the inside of the upper end of the third through hole 31 of the inner joint 3, the second bearing 72 is sleeved outside the upper end of the lower connection shaft 71, the lower end of the upper connection shaft 73 is sleeved outside the second bearing 72, and the upper end of the upper connection shaft 73 is used for mounting a seat (not shown in the drawings). The seat mounting device 7 of the present utility model can be fixed at the upper end of the inner joint sleeve 3 by the lower joint shaft 71, and the arrangement of the second bearing 72 and the upper joint shaft 73 can rotate the upper joint shaft 73 above the lower joint shaft 71; when the seat is mounted on the upper connection shaft 73, the seat can be rotated with the rotation of the upper connection shaft 73; it can be seen that the seat mounting device 7 of the present utility model can perform the function of a swivel seat, and is more suitable for users.

As shown in fig. 1-5, the second bearings 72 are arranged in parallel, the lower end of the upper connecting shaft 73 is provided with a bearing sleeve 731, and the bearing sleeve 731 is sleeved outside the two second bearings 72. The outer connecting sleeve 2, the inner connecting sleeve 3, the lower connecting shaft 71 and the upper connecting shaft 73 are respectively made of plastic or hardware materials; the hardware material is preferably aluminum profile, steel material and stainless steel material.

Example two

As shown in fig. 6, a seat electric lifting system with another structure according to the present utility model is different from the seat electric lifting system in the first embodiment in that the seat leg 1 is a disc-shaped seat leg, and other technical features are the same as those of the first embodiment, and are not described herein.

Example III

As shown in fig. 7, a seat electric lifting system with another structure according to the present utility model is different from the seat electric lifting system in the first embodiment in that the seat leg 1 is a wheel-shaped seat leg, and other technical features are the same as those of the first embodiment and are not described herein.

In the foregoing, only the preferred embodiment of the present utility model is described, and any minor modifications, equivalent changes and modifications made to the above embodiments according to the technical solutions of the present utility model fall within the scope of the technical solutions of the present utility model.

Claims

1. An electric seat lifting system is characterized in that: comprises a chair leg, an outer connecting sleeve, an inner connecting sleeve, a screw nut, a screw rod, a motor and a chair mounting device; the outer connecting sleeve is vertically fixed on the chair leg, a second through hole is arranged in the outer connecting sleeve, and the second through hole is communicated with the first through hole up and down; the lower end of the inner connecting sleeve is connected with the screw rod nut, and the inner connecting sleeve and the screw rod nut are arranged in the second through hole of the outer connecting sleeve in a lifting manner; the screw rod vertically penetrates through the screw rod nut and is in transmission fit with the screw rod nut, the lower end of the screw rod downwards movably penetrates through the first through hole, and the upper end of the screw rod upwards movably stretches into the third through hole of the inner connecting sleeve; the motor is arranged on the lower side of the chair leg, and the power output end of the motor is connected with the lower end of the screw rod so as to drive the screw rod to rotate; the upper end of the inner connecting sleeve extends out of the second through hole of the outer connecting sleeve upwards, and the upper end of the inner connecting sleeve is connected with the seat mounting device.

2. The seat electric lift system of claim 1 wherein: the first through hole is vertically formed in the middle of the chair leg, and the lower end of the outer connecting sleeve is inserted into the upper end of the first through hole; the lower side of the chair leg is provided with a motor seat, and the lower end of the motor seat is connected with the motor; the middle part of the motor base is provided with a motor base connecting sleeve, and the upper end of the motor base connecting sleeve is inserted into the lower end of the first through hole; the motor base connecting sleeve is provided with a fourth through hole, and a first bearing is arranged in the fourth through hole; the lower end of the screw rod passes through the first bearing and is positioned through the first bearing.

3. The seat electric lift system of claim 2 wherein: the upper end of the fourth through hole of the motor base connecting sleeve is also provided with a first clamping ring, and the first clamping ring is used for preventing the first bearing from loosening upwards; a second clamping ring is arranged at the lower end of the fourth through hole of the motor base connecting sleeve and used for preventing the screw rod from loosening downwards; the motor is transversely arranged, the motor is provided with a speed reducer, and the motor can drive the screw rod to rotate through the speed reducer.

4. The seat electric lift system of claim 1 wherein: the second through hole of outer adapter sleeve is vertical to be set up, and the spout has been seted up vertically to the pore wall of second through hole, the outer wall of interior adapter sleeve is vertical to be provided with the draw runner, the draw runner can install in the spout with sliding from top to bottom.

5. The seat electric lift system of claim 1 wherein: the inner wall of the outer connecting sleeve is a polygonal inner wall with a polygonal cross section, the outer wall of the inner connecting sleeve is a corresponding polygonal outer wall, and the polygonal outer wall is in sliding fit with the polygonal inner wall.

6. The seat electric lift system of claim 1 wherein: the screw rod nut comprises an upper nut portion and a lower nut portion which are integrally connected, the whole external shapes of the upper nut portion and the lower nut portion are cylindrical, the diameter of the upper nut portion is smaller than that of the lower nut portion, an annular step surface is arranged at the joint between the upper nut portion and the lower nut portion, the upper nut portion is connected into the lower end of the third through hole of the inner connecting sleeve, and the lower end face of the inner connecting sleeve is abutted to the annular step surface.

7. The seat electric lift system of claim 6 wherein: the upper nut part of the screw rod nut is provided with external threads, the lower end of the third through hole is provided with internal threads, and the upper nut part is in threaded connection with the lower end of the third through hole.

8. The seat electric lift system of claim 1 wherein: the seat mounting device comprises a lower connecting shaft, a second bearing and an upper connecting shaft, wherein the lower end of the lower connecting shaft is connected into the upper end of a third through hole of the inner connecting sleeve, the second bearing is sleeved outside the upper end of the lower connecting shaft, the lower end of the upper connecting shaft is sleeved outside the second bearing, and the upper end of the upper connecting shaft is used for mounting a seat.

9. The seat electric lift system of claim 8 wherein: the two bearings are arranged in parallel, the lower end of the upper connecting shaft is provided with a bearing sleeve, and the bearing sleeve is sleeved outside the two bearings at the same time; the outer connecting sleeve, the inner connecting sleeve, the lower connecting shaft and the upper connecting shaft are respectively made of plastic or hardware materials.

10. The seat electric lift system of claim 1 wherein: the chair legs are multi-claw chair legs, disc-shaped chair legs or wheel-shaped chair legs.