CN112401511A

CN112401511A - Lifting bookshelf device convenient for book storage and taking

Info

Publication number: CN112401511A
Application number: CN202011214748.3A
Authority: CN
Inventors: 赵梦
Original assignee: Foshan Chopsticks Technology Co ltd
Current assignee: Foshan Chopsticks Technology Co ltd
Priority date: 2020-11-03
Filing date: 2020-11-03
Publication date: 2021-02-26

Abstract

The invention discloses lifting bookshelf equipment convenient for books to be stored and taken, which comprises a box body, wherein a reading area is arranged in the box body, a working cavity positioned on the lower side of the reading area is arranged in the box body, a motor cavity positioned on the lower side of the working cavity is arranged in the box body, an inlet is rotatably arranged in the left side wall of the reading area, a bookshelf is arranged between the reading area and the working cavity in a sliding manner, and three book cavities are arranged in the bookshelf.

Description

Lifting bookshelf device convenient for book storage and taking

Technical Field

The invention relates to the technical field of elevators, in particular to lifting bookshelf equipment convenient for book storage and taking.

Background

The traditional bookshelf is fixed, books at a high position are inconvenient to take, the books are often taken only by using a ladder, the ladder is not beneficial to people to find the books due to the limitation of the ladder, unsafe factors are increased while time is spent, and the books cannot be paid back.

Disclosure of Invention

In order to solve the problems, the embodiment designs a lifting bookshelf device convenient for book access, which comprises a box body, wherein a reading area is arranged in the box body, a working cavity is arranged in the box body and is positioned on the lower side of the reading area, a motor cavity is arranged in the box body and is positioned on the lower side of the working cavity, an inlet is rotationally arranged in the left side wall of the reading area, a bookshelf is slidably arranged between the reading area and the working cavity, three book cavities are arranged in the bookshelf, the book cavities are vertically arranged, a supporting sliding plate and a supporting plate are fixedly arranged on the bottom wall of the working cavity, the supporting sliding plate is positioned on the left side of the supporting plate, a supporting sliding groove which is communicated from front to back is arranged on the supporting sliding plate, a supporting sliding rod is slidably arranged in the supporting sliding groove, a hydraulic lifting rod is, the lower end of the bookshelf is fixedly provided with a lifting plate positioned in the bookshelf, the lower end of the lifting plate is fixedly provided with a lifting sliding plate, the lifting sliding plate is provided with a lifting sliding groove which is communicated from front to back, a lifting sliding rod is arranged in the lifting sliding groove in a sliding manner, the lower end of the lifting plate is fixedly provided with a moving rod positioned on the right side of the lifting sliding plate, the hydraulic lifting rod is hinged with the moving rod, the hydraulic lifting rod is hinged with the lifting sliding rod, a threaded rod is rotatably arranged between the working cavity and the motor cavity, a firewall is arranged between the reading area and the working cavity in a sliding manner and is in threaded connection with the threaded rod, the threaded rod is fixedly provided with a transmission bevel gear positioned in the motor cavity, the bottom wall of the motor cavity is fixedly provided with a motor, and the left end of the motor, the power bevel gear is fixedly installed on the first power shaft and meshed with the transmission bevel gear, a top block is arranged on the left side wall of the reading area in a sliding mode, the upper end of the top block is fixedly connected with the upper side wall of the reading area through a reset spring, a fire extinguishing partition is fixedly arranged at the right end of the top block, three through grooves are formed in the fire extinguishing partition and are communicated up and down, three fire extinguishing tubes are fixedly arranged on the upper side wall of the reading area, fire extinguishing cavities are formed in the fire extinguishing tubes and are communicated with the outside of the box body, the fire extinguishing tubes are in sliding fit with the fire extinguishing partition, spring cavities which are symmetrical left and right with the fire extinguishing tubes as symmetrical centers are formed in the fire extinguishing partition, openings of the spring cavities face the fire extinguishing tubes, wedge blocks are arranged between the spring cavities and the fire extinguishing cavities in a sliding mode and are fixedly connected with the spring cavities through springs, and the two wedge-shaped blocks are contacted to close the fire extinguishing cavity.

Beneficially, a second power shaft is connected to the upper end of the motor in a power mode, the second power shaft is rotatably connected with a wall body between the motor cavity and the working cavity, a main bevel gear is fixedly mounted on the second power shaft, a connecting shaft is rotatably mounted on the right side wall of the working cavity, a transmission gear and an auxiliary bevel gear are fixedly mounted on the connecting shaft, the transmission gear is located on the left side of the auxiliary bevel gear, the auxiliary bevel gear is meshed with the main bevel gear, rotating shafts are rotatably arranged on the left side wall and the right side wall of the book cavity, a moving block is arranged in the book cavity in a threaded mode and located at the rotating shaft, a cleaning brush is fixedly arranged at the lower end of the moving block, a driven gear is fixedly arranged on a part, extending rightwards, of the rotating shaft, the transmission gear is driven to rotate by the main bevel gear, the driven gear moves downwards along with the bookshelf and, the driven gear drives the rotating shaft to rotate, so that the moving block and the cleaning brush are driven to move.

Beneficially, books intracavity slip is equipped with the book board of propping of two longitudinal symmetries, two prop the book board pass through compression spring with lateral wall fixed connection about the books chamber, be equipped with opening arc wall left around the books chamber on the lateral wall, it is equipped with the connecting axle to prop the book board left end rotation, the fixed dwang that is equipped with on the connecting axle, the fixed handle that is equipped with on the dwang, the handle drives the dwang rotates and drives the dwang with it removes to prop the book board, the compression spring compression, the handle card is gone into in the arc wall.

Beneficially, a lifting shaft is rotatably mounted in the lifting plate, a movable bevel gear located on the left side of the lifting plate is fixedly mounted on the lifting shaft, a movable worm gear located on the right side of the lifting plate is fixedly mounted on the lifting shaft, a spline sleeve is connected to the second power shaft through a spline, a connecting block is fixedly arranged on the spline sleeve and fixedly connected with the lifting plate, the movable worm gear is connected with the spline sleeve worm gear, a driven bevel gear located on the lower side of the firewall is fixedly mounted on the threaded rod, and the second power shaft drives the movable worm gear to rotate through the spline sleeve, so that the movable bevel gear is driven to rotate.

Beneficially, a groove with a downward opening is formed in the side wall of the working cavity, an ultraviolet lamp is arranged in the groove in a sliding mode and fixedly connected with the groove through a telescopic spring, and a pushing block located on the lower side of the ultraviolet lamp is fixedly arranged on the lifting plate.

Beneficially, fixed exhaust fan case that is equipped with on the wall of working chamber right side, exhaust fan case rotates and is equipped with exhaust fan axle, the epaxial fixed mounting of exhaust fan is located the worm wheel of working chamber, the worm wheel with second power shaft worm gear is connected, the epaxial fixed mounting of exhaust fan is located exhaust fan in the exhaust fan case, second power shaft drives the worm wheel rotates, thereby passes through the exhaust fan axle drives the exhaust fan rotates.

The invention has the beneficial effects that: the invention has simple structure and convenient operation, does not need people to climb to the upper layer to take books, can automatically descend to facilitate people to take the books on the upper layer, stores the bookshelf and the books in a closed space when not used for a long time, cleans and sterilizes the books, can automatically align the books in the ascending and descending process, prevents the books from falling off, can quickly extinguish fire when a fire happens, and reduces property loss.

Drawings

In order to more clearly illustrate the embodiments of the 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, and it is obvious that the drawings in the following description are only some embodiments of the invention, and it is obvious for those skilled in the art that other drawings can be obtained based on these drawings without creative efforts.

The invention is further illustrated with reference to the following figures and examples.

Fig. 1 is a schematic view illustrating an overall structure of a lifting bookshelf apparatus for facilitating book access according to the present invention.

Fig. 2 is a schematic view of the structure a-a in fig. 1.

Fig. 3 is an enlarged schematic view of B in fig. 1.

Fig. 4 is an enlarged schematic view of C in fig. 1.

Detailed Description

The invention will now be described in detail with reference to fig. 1-4, wherein for ease of description the orientations described hereinafter are now defined as follows: the up, down, left, right, and front-back directions described below correspond to the up, down, left, right, and front-back directions in the projection relationship of fig. 1 itself.

The invention relates to lifting bookshelf equipment convenient for book access, which comprises a box body 11, wherein a reading area 15 is arranged in the box body 11, a working cavity 21 positioned on the lower side of the reading area 15 is arranged in the box body 11, a motor cavity 66 positioned on the lower side of the working cavity 21 is arranged in the box body 11, an inlet 16 is rotationally arranged in the left side wall of the reading area 15, a bookshelf 37 is arranged between the reading area 15 and the working cavity 21 in a sliding manner, three book cavities 36 are arranged in the bookshelf 37, the book cavities 36 are vertically arranged, a supporting sliding plate 61 and a supporting plate 65 are fixedly arranged on the bottom wall of the working cavity 21, the supporting sliding plate 61 is positioned on the left side of the supporting plate 65, a supporting sliding groove 62 which is penetrated in front and back is arranged on the supporting sliding plate 61, a supporting sliding rod 63 is arranged in the supporting sliding groove 62 in, the hydraulic lifting rod 64 is hinged with the supporting sliding rod 63, the lower end of the bookshelf 37 is fixedly provided with the lifting plate 26 positioned in the motor cavity 21, the lower end of the lifting plate 26 is fixedly provided with the lifting sliding plate 58, the lifting sliding plate 58 is provided with a lifting sliding groove 59 which is through from front to back, the lifting sliding groove 59 is internally provided with the lifting sliding rod 60 in a sliding manner, the lower end of the lifting plate 26 is fixedly provided with the moving rod 35 positioned on the right side of the lifting sliding plate 58, the hydraulic lifting rod 64 is hinged with the moving rod 35, the hydraulic lifting rod 64 is hinged with the lifting sliding rod 60, the threaded rod 22 is rotatably arranged between the working cavity 21 and the motor cavity 66, the fireproof wall 17 is slidably arranged between the reading area 15 and the working cavity 21, the fireproof wall 17 is in threaded connection with the threaded rod 22, and the transmission bevel gear 30 positioned in the motor cavity 66 is fixedly arranged on the threaded, a motor 68 is fixedly installed on the bottom wall of the motor cavity 66, a first power shaft 27 is dynamically connected to the left end of the motor 68, a power bevel gear 29 is fixedly installed on the first power shaft 27, the power bevel gear 29 is meshed with the transmission bevel gear 30, a top block 14 is slidably installed on the left side wall of the reading area 15, the upper end of the top block 14 is fixedly connected with the upper side wall of the reading area 15 through a reset spring 12, a fire extinguishing partition plate 13 is fixedly installed at the right end of the top block 14, three through grooves 69 are formed in the fire extinguishing partition plate 13, the through grooves 69 are vertically communicated, three fire extinguishing pipes 38 are fixedly installed on the upper side wall of the reading area 15, a fire extinguishing cavity 45 is formed in each fire extinguishing pipe 38, the fire extinguishing cavity 45 is communicated with the outside of the box body 11, the fire extinguishing pipes 38 are in sliding fit with the fire extinguishing partition plate 13, spring cavities 47 are formed in the fire extinguishing partition plate 13 and, spring chamber 47 opening orientation fire extinguishing pipe 38, spring chamber 47 with it is equipped with wedge 46 to slide between the chamber 45 of putting out a fire, wedge 46 through spring 48 with spring chamber 47 fixed connection, two wedge 46 contacts the closure chamber 45 of putting out a fire.

Beneficially, a second power shaft 31 is connected to the upper end of the motor 68 in a power manner, the second power shaft 31 is rotatably connected to a wall body between the motor cavity 66 and the working cavity 21, a main bevel gear 54 is fixedly mounted on the second power shaft 31, a connecting shaft 52 is rotatably mounted on the right side wall of the working cavity 21, a transmission gear 53 and a secondary bevel gear 51 are fixedly mounted on the connecting shaft 52, the transmission gear 53 is located on the left side of the secondary bevel gear 51, the secondary bevel gear 51 is engaged with the main bevel gear 54, rotating shafts 49 are rotatably mounted on the left and right side walls of the book cavity 36, a moving block 55 is disposed on the rotating shaft 49 in the book cavity 36 in a threaded manner, a cleaning brush 56 is fixedly disposed at the lower end of the moving block 55, a driven gear 50 is fixedly disposed on a portion of the rotating shaft 49 extending rightward, and the transmission gear 53 is driven by the main bevel gear 54 through the secondary bevel gear 51, the driven gear 50 moves downwards along with the bookshelf 37 and is meshed with the transmission gear 53, and the driven gear 50 drives the rotating shaft 49 to rotate, so that the moving block 55 and the cleaning brush 56 are driven to move.

Beneficially, book chamber 36 slides and is equipped with book board 39, two of two longitudinal symmetries book board 39 through compression spring 40 with lateral wall fixed connection about book chamber 36, be equipped with opening arc 41 to the left on the lateral wall of book chamber 36 front and back, book board 39 left end rotates and is equipped with connecting axle 42, the fixed dwang 43 that is equipped with on the connecting axle 42, the fixed handle 44 that is equipped with on the dwang 43, the handle 44 drives dwang 43 rotates and drives dwang 43 with book board 39 removes, compression spring 40 compresses, handle 44 card is gone into in the arc 41.

Beneficially, a lifting shaft 25 is rotatably mounted in the lifting plate 26, a moving bevel gear 23 located on the left side of the lifting plate 26 is fixedly mounted on the lifting shaft 25, a moving worm gear 67 located on the right side of the lifting plate 26 is fixedly mounted on the lifting shaft 25, a spline sleeve 70 is connected to the second power shaft 31 through a spline, a connecting block 71 is fixedly arranged on the spline sleeve 70, the connecting block 71 is fixedly connected to the lifting plate 26, the moving worm gear 67 is connected to the spline sleeve 70 through a worm gear, a driven bevel gear 57 located on the lower side of the firewall 17 is fixedly mounted on the threaded rod 22, and the second power shaft 31 drives the moving worm gear 67 to rotate through the spline sleeve 70, so as to drive the moving bevel gear 23 to rotate.

Advantageously, a groove 18 with a downward opening is formed in the upper side wall of the working chamber 21, an ultraviolet lamp 20 is slidably disposed in the groove 18, the ultraviolet lamp 20 is fixedly connected with the groove 18 through a telescopic spring 19, and a pushing block 24 positioned on the lower side of the ultraviolet lamp 20 is fixedly disposed on the lifting plate 26.

Beneficially, fixed exhaust fan case 32 that is equipped with on the wall of working chamber 21 right side, exhaust fan case 32 rotates and is equipped with exhaust fan axle 33, fixed mounting is located on the exhaust fan axle 33 worm wheel 34 in the working chamber 21, worm wheel 34 with second power axle 31 worm gear is connected, fixed mounting is located on the exhaust fan axle 33 exhaust fan 28 in the exhaust fan case 32, second power axle 31 drives worm wheel 34 rotates, thereby passes through exhaust fan axle 33 drives exhaust fan 28 rotates.

The following will describe in detail the use steps of the lifting bookshelf device for facilitating book access in the present document with reference to fig. 1 to 4:

in the initial state, the hydraulic lifting rod 64 lifts the bookshelf 37 into the reading area 15 through the lifting plate 26, the compression spring 40 pushes the book supporting plate 39 to clamp the book in the book cavity 36, the pushing block 24 pushes the ultraviolet lamp 20 into the groove 18, the expansion spring 19 compresses, the return spring 12 and the spring 48 are in the initial state, the left wedge-shaped block 46 and the right wedge-shaped block 46 are in contact with each other,

when the book taking device is used, the motor 68 is started, the motor 68 drives the second power shaft 31 to rotate, the second power shaft 31 drives the worm wheel 34 to rotate, the worm wheel 34 drives the exhaust fan shaft 33 to rotate, the exhaust fan 28 is driven to rotate, the working cavity 21 is kept ventilated and dry, the second power shaft 31 drives the main bevel gear 54 to rotate, the main bevel gear 54 drives the auxiliary bevel gear 51 to rotate, the auxiliary bevel gear 51 drives the connecting shaft 52 to rotate, the transmission gear 53 is driven to rotate, a user starts the hydraulic lifting rod 64 to enable the lifting plate 26 to drive the bookshelf 37 to descend according to requirements, an upper-layer book is taken, the compression spring 40 pushes the book supporting plate 39 to clamp the book in the book cavity 36, when a librarian needs to put the book into the book cavity 36, the handle 44 is pulled to the front side and the rear side to pull the handle 44 into the arc-shaped groove 41, the compression spring 40 is compressed, the book is placed and pulled out after the, the compression spring 40 pushes the book supporting plate 39 to press a book tightly, meanwhile, the lifting plate 26 drives the pushing block 24 to descend, the pushing block 24 is separated from the ultraviolet lamp 20, the expansion spring 19 pushes the ultraviolet lamp 20 into the working chamber 21, ultraviolet irradiation disinfection is carried out on the book descending into the working chamber 21, meanwhile, the first power shaft 27 drives the rotating shaft 49 and the driven gear 50 to descend, the driven gear 50 is meshed with the transmission gear 53, the transmission gear 53 drives the driven gear 50 to rotate, the driven gear 50 drives the rotating shaft 49 to rotate, the rotating shaft 49 drives the moving block 55 and the cleaning brush 56 to move right, the cleaning brush 56 cleans dust on the book, the motor 68 is reversed, the cleaning brush 56 moves left to an initial position, and the motor 68 is halted;

when a fire breaks out in the reading area 15, the motor 68 is started to drive the first power shaft 27 to rotate, the first power shaft 27 drives the power bevel gear 29 to rotate, the power bevel gear 29 drives the transmission bevel gear 30 to rotate, the transmission bevel gear 30 drives the threaded rod 22 to rotate, the threaded rod 22 drives the fire-fighting wall 17 to move upwards in the reading area 15, the fire-fighting wall 17 pushes the ejector block 14 to move upwards, the reset spring 12 compresses, the ejector block 14 drives the fire-fighting partition plate 13 to move upwards, the wedge-shaped block 46 is compressed into the spring cavity 47, the spring 48 compresses, the fire-fighting cavity 45 is communicated with the reading area 15, extinguishing a fire in the reading area 15, after the fire is extinguished, the motor 68 rotates the first power shaft 27 reversely to drive the firewall 17 to descend, the reset spring 12 pushes the top block 14 to move downwards for resetting, the top block 14 drives the fire extinguishing partition plate 13 to move downwards, the spring 48 pushes the two wedge-shaped blocks 46 to contact and separate the fire extinguishing cavity 45 and the reading area 15, and the motor 68 stops;

when books are needed to be stored, the hydraulic lifting rod 64 is started to completely lower the bookshelf 37 into the ultraviolet lamp 20, the lifting plate 26 drives the lifting shaft 25 and the movable bevel gear 23 to descend, the movable bevel gear 23 is meshed with the driven bevel gear 57, the motor 68 drives the second power shaft 31 to rotate, the second power shaft 31 drives the movable worm gear 67 to rotate through the spline sleeve 70, the movable worm gear 67 drives the lifting shaft 25 to rotate, the lifting shaft 25 drives the movable bevel gear 23 to rotate, the movable bevel gear 23 drives the driven bevel gear 57 to rotate, the driven bevel gear 57 drives the threaded rod 22 to rotate, the threaded rod 22 drives the firewall 17 to move upwards to block the inlet 16 without touching the top block 14, and the motor 68 stops.

The above embodiments are merely illustrative of the technical ideas and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. The utility model provides a lift bookshelf equipment convenient to books access which characterized in that: comprises a box body, a reading area is arranged in the box body, a working cavity positioned on the lower side of the reading area is arranged in the box body, a motor cavity positioned on the lower side of the working cavity is arranged in the box body, an inlet is rotationally arranged in the left side wall of the reading area, a bookshelf is slidably arranged between the reading area and the working cavity, three book cavities are arranged in the bookshelf, the book cavities are vertically arranged, a supporting sliding plate and a supporting plate are fixedly arranged on the bottom wall of the working cavity, the supporting sliding plate is positioned on the left side of the supporting plate, a supporting sliding groove which is communicated with the front and the back is arranged on the supporting sliding plate, a supporting sliding rod is slidably arranged in the supporting sliding groove, a hydraulic lifting rod is hinged on the upper side of the supporting plate and is connected with the supporting sliding rod, a lifting plate positioned in the lower end, a lifting sliding groove which is communicated with the front and the back is arranged on the lifting sliding plate, a lifting sliding rod is arranged in the lifting sliding groove in a sliding manner, a moving rod which is positioned on the right side of the lifting sliding plate is fixedly arranged at the lower end of the lifting plate, the hydraulic lifting rod is hinged with the moving rod, the hydraulic lifting rod is hinged with the lifting sliding rod, a threaded rod is rotatably arranged between the working cavity and the motor cavity, a fireproof wall is slidably arranged between the reading area and the working cavity and is in threaded connection with the threaded rod, a transmission bevel gear which is positioned in the motor cavity is fixedly arranged on the threaded rod, a motor is fixedly arranged on the bottom wall of the motor cavity, the left end of the motor is in power connection with a first power shaft, a power bevel gear is fixedly arranged on the first power shaft and is meshed with the transmission bevel gear, and a jacking block is slidably arranged on the left, the kicking block upper end through reset spring with read district lateral wall fixed connection, the fixed baffle of putting out a fire that is equipped with of kicking block right-hand member, be equipped with three logical groove on the baffle of putting out a fire, it link up from top to bottom to lead to the groove, read and to go up fixed three fire extinguishing pipe that is equipped with on the district lateral wall, be equipped with the chamber of putting out a fire in the fire extinguishing pipe, the chamber of putting out a fire with the outer intercommunication of box, put out a fire with put out a fire baffle sliding fit, be equipped with in the baffle of putting out a fire with the spring chamber that the fire extinguishing pipe is symmetry center bilateral symmetry, spring chamber opening orientation the fire extinguishing pipe, the spring chamber with it is equipped with the wedge to slide between the chamber of putting out a fire, the wedge pass through the spring.

2. An elevated bookshelf apparatus for facilitating book access as claimed in claim 1 wherein: the utility model discloses a book structure, including book chamber, motor upper end power connection, second power shaft, motor chamber and wall body between the working chamber rotate to be connected, fixed mounting has main bevel gear on the second power shaft, rotate on the working chamber right side wall and install and link up the axle, link up epaxial fixed mounting have drive gear and vice bevel gear, drive gear is located vice bevel gear left side, vice bevel gear with main bevel gear meshes, it is equipped with the rotation axis to rotate on the lateral wall about the book chamber, the rotation axis is located book intracavity screw thread is equipped with the movable block, the fixed cleaning brush that is equipped with of movable block lower extreme, the rotation axis is the fixed driven gear that is equipped with of right extending portion.

3. An elevated bookshelf apparatus for facilitating book access as claimed in claim 2 wherein: book intracavity slides and is equipped with the book board of propping of two front and back symmetries, two prop the book board pass through compression spring with lateral wall fixed connection about the books chamber, be equipped with opening arc wall left around the books chamber on the lateral wall, it is equipped with the connecting axle to prop the book board left end rotation, the fixed dwang that is equipped with on the connecting axle, the fixed handle that is equipped with on the dwang.

4. A lifting bookshelf apparatus for facilitating book access as claimed in claim 3 wherein: the lifter comprises a lifter plate, a lifter shaft, a movable bevel gear, a movable worm gear, a spline sleeve, a connecting block, a worm rod, a driven bevel gear, a movable bevel gear, a worm gear shaft, a worm gear and a worm gear, wherein the lifter shaft is rotatably arranged in the lifter plate, the movable bevel gear is fixedly arranged on the lifter shaft and positioned on the left side of the lifter plate, the movable worm gear is fixedly arranged on the lifter shaft and positioned on the right side of the lifter plate, the spline sleeve is connected to a second power shaft through a spline, the spline sleeve is fixedly provided with the.

5. An elevated bookshelf apparatus for facilitating book access as claimed in claim 4 wherein: be equipped with the recess that the opening is decurrent in the lateral wall on the working chamber, it is equipped with ultraviolet lamp to slide in the recess, ultraviolet lamp pass through expanding spring with recess fixed connection, the fixed promotion piece that is located of ultraviolet lamp downside that is equipped with on the lifter plate.

6. An elevated bookshelf apparatus for facilitating book access as claimed in claim 5 wherein: the exhaust fan box is fixedly arranged on the right side wall of the working cavity, the exhaust fan box is rotatably provided with an exhaust fan shaft, a worm wheel in the working cavity is fixedly mounted on the exhaust fan shaft, the worm wheel is connected with a worm gear of a second power shaft, and an exhaust fan in the exhaust fan box is fixedly mounted on the exhaust fan shaft.