CN210195942U

CN210195942U - Expansion type driving device

Info

Publication number: CN210195942U
Application number: CN201920525278.9U
Authority: CN
Inventors: Zhixiong Chen; 陈志雄
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-04-17
Filing date: 2019-04-17
Publication date: 2020-03-27
Anticipated expiration: 2029-04-17

Abstract

The utility model relates to a drive arrangement's technical field discloses inflation formula drive arrangement, including the gear structure that has power take off end and power input end, receive the temperature influence inflation or the inflation piece of shrink, annotate the chamber of placing and remove the chamber of full liquid, remove the chamber have with place the intercommunication mouth of chamber intercommunication, the inflation piece is arranged in and is placed the chamber, removes the chamber and is equipped with the moving member, the one end shutoff intercommunication mouth of moving member, the moving member is the meshing with gear structure's power input end and arranges. When the expansion piece is affected by high temperature and gradually takes an expansion state, the liquid in the placing cavity is extruded, the liquid is discharged to the moving cavity, the moving piece is pushed to move, power input is provided for the gear structure, and the gear structure is enabled to provide driving force to the outside; when the temperature is reduced, the expansion piece contracts, the liquid resets, the moving piece moves and resets, and the moving piece provides power input for the gear structure again; according to the change of temperature, the moving part reciprocates, realizes providing driving force to the outside automatically, greatly improves drive arrangement's autonomy.

Description

Expansion type driving device

Technical Field

The patent of the utility model relates to a drive arrangement's technical field particularly, relates to inflation formula drive arrangement.

Background

Mechanical products such as mechanical clocks, watches and clockwork spring toys are all provided with clockwork springs, and the starting and running of the mechanical products are realized through the clockwork springs.

In the application of clockwork spring, often through the manual winding, complex operation, and often need specific instrument just can realize the winding.

In the prior art, when a spring is wound, the autonomy of the existing driving device is poor, and the driving force cannot be automatically generated, so that the operation is complicated.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide an inflation formula drive arrangement aims at solving prior art, and drive arrangement's the poor problem of autonomy.

The utility model discloses a realize like this, inflation formula drive arrangement, including the gear structure that has power take off end and power input end, receive the temperature influence inflation or the inflation piece of shrink, annotate full of liquid place the chamber and remove the chamber, remove the chamber have with place the intercommunication mouth of chamber intercommunication, the inflation piece is arranged in place the chamber, it is equipped with the moving member that receives hydraulic pressure reciprocating motion to remove the chamber, the one end shutoff of moving member the intercommunication mouth, the moving member with gear structure's power input end is the meshing and arranges.

Further, place the chamber including the main cavity and divide the chamber, the main cavity with divide the chamber to be the intercommunication and arrange, the inflation piece is arranged in the main cavity, remove the chamber through the intercommunication mouth with divide the chamber intercommunication.

Further, the moving part comprises a hose which is expanded or contracted by hydraulic pressure and a rack, an inlet is formed at one end of the hose, the inlet of the hose is arranged corresponding to the sub-cavity, and liquid is pressed into the hose; the other end of the hose and the rack are fixedly arranged, and the rack and the power input end of the gear structure are arranged in a meshed mode.

Further, the moving part comprises a hard pipe which is fixedly arranged, the hard pipe is arranged in the moving cavity, and the hard pipe surrounds and surrounds the hose.

Further, the hard tube is provided with an inner end face facing the hose, and the inner end face of the hard tube is provided with a plurality of balls; the hose has an outer end face facing the hard tube, the outer end face of the hose abutting against the ball.

Furthermore, one end of the hose is provided with a blocking ring, the movable cavity comprises two movable walls which are arranged in an array mode, the hose is arranged between the two movable walls, and two ends of the blocking ring respectively abut against the two movable walls.

Further, the inflatable driving means comprises a housing, the housing forming the placement chamber and the moving chamber inside; the shell comprises a bottom shell wall, the placing cavity is provided with a placing wall arranged in a surrounding mode, the placing wall forms a bottom opening, and the bottom shell wall closes the bottom opening of the placing wall; the expansion member abuts the bottom housing wall.

Further, the expansion piece comprises a paraffin material and a telescopic sleeve, the paraffin material is arranged inside the telescopic sleeve, and the telescopic sleeve is arranged in a sealing manner; the telescopic sleeve is abutted against the wall of the bottom shell.

Further, the gear structure comprises an input gear, an output gear, a first gear set, a second gear set, a transmission wheel, a forward gear set and a reverse gear set, wherein the input gear forms the power input end, and the output gear forms the power output end; the input gear is meshed with the first gear set, the output gear is meshed with the second gear set, and the second gear set is meshed with the driving wheel; when the expansion piece is in an expansion state, the input gear rotates anticlockwise, the first gear set rotates clockwise, the forward gear set is respectively meshed with the first gear set and the transmission wheel, and the reverse gear set is in an idle rotation state; when the expansion piece is in a contraction state, the input gear rotates clockwise, the first gear set rotates anticlockwise, the reverse gear set is respectively meshed with the first gear set and the transmission wheel, and the forward gear set is in an idle rotation state.

Further, the gear structure comprises a fixed shell, the fixed shell is provided with a forward installation groove and a reverse installation groove, the forward gear set is movably installed in the forward installation groove, one end of the forward installation groove is close to the first gear set, the other end of the forward installation groove extends in the direction away from the first gear set, when the forward gear set is located at one end of the forward installation groove, the forward gear set is respectively meshed with the first gear set and the transmission wheel, and when the forward gear set is located at the other end of the forward installation groove, the forward gear set is in an idle running state; the reverse gear set is movably arranged on the reverse installation groove, one end of the reverse installation groove is close to the first gear set, the other end of the reverse installation groove extends in the direction deviating from the first gear set, when the reverse gear set is located at one end of the reverse installation groove, the reverse gear set is respectively meshed with the first gear set and the transmission wheel, and when the reverse gear set is located at the other end of the reverse installation groove, the reverse gear set is in an idle state.

Compared with the prior art, the expansion type driving device provided by the utility model has the advantages that when the expansion piece is affected by high temperature and the temperature is higher than a set value, the expansion piece is gradually in an expansion state, so that liquid in the cavity is extruded and placed, the liquid is discharged to the moving cavity, and the moving piece is pushed to move during liquid fluid, so that power input is provided for the gear structure, and further the gear structure provides driving force to the outside through the power output end; when the temperature is reduced to be below a set value, the expansion piece contracts, the liquid resets, the moving piece moves and resets, and at the moment, the moving piece provides power input for the gear structure again; like this, according to the change of temperature, make moving member reciprocating motion, realize that automatic externally provides drive power, greatly improve drive arrangement's autonomy.

Drawings

Fig. 1 is a schematic perspective view of an expansion drive apparatus provided by the present invention;

fig. 2 is an exploded schematic view of a moving member of the expansion actuator provided by the present invention;

fig. 3 is a schematic perspective view of another embodiment of the expansion-type driving device provided by the present invention

Fig. 4 is a schematic perspective view of another embodiment of an expansion drive provided by the present invention;

fig. 5 is an exploded schematic view of another embodiment of an expansion drive provided by the present invention;

fig. 6 is an exploded schematic view of another embodiment of an expansion drive provided by the present invention;

fig. 7 is a schematic perspective view of a gear structure of an expansion type driving device provided by the present invention;

fig. 8 is a schematic perspective view of a gear structure of an expansion type driving apparatus provided by the present invention;

fig. 9 is a schematic perspective view of a first gear set of the expansion drive provided by the present invention;

fig. 10 is a schematic perspective view of a blocking portion of an expansion-type driving device according to the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The following describes the implementation of the present invention in detail with reference to specific embodiments.

The same or similar reference numerals in the drawings of the present embodiment correspond to the same or similar components; in the description of the present invention, it should be understood that if there are the terms "upper", "lower", "left", "right", etc. indicating the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, it is only for convenience of description and simplification of the description, but it is not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and therefore the terms describing the positional relationship in the drawings are only for illustrative purposes and are not to be construed as limitations of the present patent, and those skilled in the art can understand the specific meanings of the terms according to specific situations.

Referring to fig. 1-10, the preferred embodiment of the present invention is shown.

The utility model provides an inflation formula drive arrangement for solve the poor problem of drive arrangement's autonomy.

Expansion drive arrangement, including gear structure 10, inflation piece 20, place chamber 40 and remove chamber 50, gear structure 10 has power take off end and power input end, inflation piece 20 receives temperature influence expansion or shrink, it fills with liquid to place the inside notes in chamber 40, it has and places the intercommunication mouth 51 that chamber 40 communicates to remove chamber 50, inflation piece 20 is arranged in and is placed chamber 40, it is equipped with moving member 30 to remove chamber 50, moving member 30 receives hydraulic pressure influence reciprocating motion, the one end shutoff intercommunication mouth 51 of moving member 30, moving member 30 is the meshing with gear structure 10's power input end and arranges.

In the expansion type driving device, when the expansion piece 20 is affected by high temperature and the temperature is greater than a set value, the expansion piece 20 gradually takes an expansion state, so that liquid in the placing cavity 40 is extruded, the liquid is discharged to the moving cavity 50, and the moving piece 30 is pushed to move when the liquid is fluid, so that power input is provided for the gear structure 10, and further the gear structure 10 provides driving force to the outside through a power output end; when the temperature is reduced to be below the set value, the expansion piece 20 contracts, the liquid resets, the moving piece 30 moves and resets, and at the moment, the moving piece 30 provides power input for the gear structure 10 again; thus, according to the change of the temperature, the moving member 30 reciprocates, the driving force is automatically provided to the outside, and the autonomy of the driving device is greatly improved.

The placing cavity 40 comprises a main cavity 41 and a sub-cavity 42, the main cavity 41 is communicated with the sub-cavity 42, the expansion part 20 is placed in the main cavity 41, and the sub-cavity 42 is communicated with the moving cavity 50; thus, when the expansion member 20 expands due to temperature, the extruding liquid flows from the main chamber 41 to the sub-chamber 42, and then the moving member 30 is driven to move, so that the moving member 30 moves more quickly and stably.

The volume of the main chamber 41 is greater than the volume of the subchamber 42, which helps to increase the flow rate of the liquid and to make the drive more sensitive.

The expansion member 20 is larger than the sub-cavity 42, so that the main cavity 41 limits the expansion member 20, and the expansion member 20 is prevented from separating from the main cavity 41 to influence the use of the driving device.

The moving part comprises a hose 33 and a rack 35, the hose 33 is expanded or contracted under hydraulic pressure, when liquid is filled into the hose 33, the hose 33 is expanded, the liquid flows back to the sub-cavity, and the hose 33 is contracted; expansion or contraction of the hose 33 is achieved.

Furthermore, an inlet is formed at one end of the hose 33, the inlet of the hose 33 is arranged corresponding to the sub-cavity, and the liquid is pressed into the hose 33; the other end of the hose 33 is fixedly arranged with the rack 35, and the rack 35 is meshed with the power input end of the gear structure; when the hose 33 is expanded, the driving rack 35 is moved to output the driving force to the other side.

The moving part comprises a hard pipe 34 which is fixedly arranged, the hard pipe 34 is arranged in the moving cavity, and the hard pipe 34 surrounds the flexible pipe 33; under the action of the hard pipe 34, the flexible pipe 33 is limited and guided, so that when the flexible pipe 33 expands, the transverse expansion is reduced, the longitudinal expansion is realized, the sensitivity is improved, and the flexible pipe 33 drives the rack 35 to move.

The hard tube 34 has an inner end surface facing the flexible tube 33, and the inner end surface of the hard tube 34 is provided with a plurality of tubes 36; hose 33 has an outer end face facing hard tube 34, the outer end face of hose 33 abutting ball 36; under the action of the balls 36, the friction force between the hose 33 and the hard tube 34 is reduced, and the resistance of the hard tube 34 to the expansion of the hose 33 is reduced, so that the hose 33 drives the rack 35 to move.

One end of the hose 33 is provided with a plugging ring, the movable cavity comprises two movable walls which are arranged in an array manner, the hose 33 is arranged between the two movable walls, and two ends of the plugging ring respectively abut against the two movable walls; under the effect of shutoff ring, effectively avoid liquid mistake to get into and remove the chamber, make liquid can the full effect fill hose 33.

The rack 35 has a connecting section, by which the rack 35 is fixedly connected to the hose 33, so that the hose 33 drives the rack 35.

Furthermore, the connecting section is provided with an external thread, the hose 33 is provided with an internal thread, and the hose 33 and the rack 35 are fixedly connected through screwing.

The connecting section is provided with a first trapezoid part which is arranged from outside to inside in a trapezoid shape from small outside to large inside; the hose 33 is formed with a second trapezoidal portion, which is arranged from inside to outside in a trapezoidal shape with a small inside and a large outside; this has the advantage of improving the stability of the connection of the hose 33 to the rack 35.

Specifically, the expansion-type driving means comprises a housing 60, the housing 60 internally forming a placement chamber 40 and a movement chamber 50; the housing 60 comprises a bottom shell wall 61, the placing cavity 40 is provided with a placing wall arranged in a surrounding manner, the placing wall forms a bottom opening, and the bottom shell wall 61 closes the bottom opening of the placing wall; the expansion member 20 abuts against the bottom housing wall 61; under the action of the bottom wall 61, a closed space is formed to ensure the installation of the expansion member 20 and the storage of the liquid, and the external temperature is transferred to the expansion member 20 through the bottom wall 61, thereby realizing the expansion or contraction of the expansion member 20.

In addition, the bottom shell wall 61 and the placing cavity 40 are integrally formed and enclosed to be in a closed state, and the placing cavity is communicated only through the communication port.

The bottom case wall 61 may be made of a heat conductive silicon or a heat conductive metal such as aluminum, so that external heat is easily transferred to the expansion member 20.

The expansion piece 20 comprises paraffin material and a telescopic sleeve, the paraffin material is arranged in the telescopic sleeve, and the telescopic sleeve is arranged in a sealing manner; the telescopic sleeve is abutted against the bottom shell wall 61; thereby achieving expansion and contraction of the expansion member 20.

The expansion sleeve can be a rubber sleeve to realize expansion or contraction, and can also be made of latex materials to realize expansion or contraction.

In this embodiment, the gear structure 10 includes an input gear 11, an output gear 12, a first gear set 13, a second gear set 14, a transmission wheel 15, a forward gear set 16 and a reverse gear set 17, where the input gear 11 forms a power input end, and the output gear 12 forms a power output end; the input gear 11 is meshed with the first gear set 13, the output gear 12 is meshed with the second gear set 14, and the second gear set 14 is meshed with the driving wheel 15; when the expansion member 20 is in an expanded state, the input gear 11 rotates anticlockwise, the first gear set 13 rotates clockwise, the forward gear set 16 is respectively meshed with the first gear set 13 and the transmission wheel 15, and the reverse gear set 17 is in an idle state; when the expansion member 20 is in the contracted state, the input gear 11 rotates clockwise, the first gear set 13 rotates counterclockwise, the reverse gear set 17 engages with the first gear set 13 and the transmission wheel 15, respectively, and the forward gear set 16 is in an idle state.

In this way, the input gear 11, the output gear 12, the first gear set 13, the second gear set 14, the transmission wheel 15, the forward gear set 16, and the reverse gear set 17 cooperate with each other to output power.

The moving member moves to transmit the driving force to the input gear 11, so that the input gear 11 rotates to drive the first gear set 13 to rotate clockwise or counterclockwise, thereby driving the forward gear set 16 or the reverse gear set 17 to rotate, rotating the driving wheel 15, and rotating the output gear 12 to output power externally.

Furthermore, the gear structure 10 includes a fixed case, the fixed case is formed with a forward installation groove 19 and a reverse installation groove 18, the forward gear set 16 is movably installed with the forward installation groove 19, one end of the forward installation groove 19 is close to the first gear set 13, the other end of the forward installation groove 19 extends in a direction away from the first gear set 13, when the forward gear set 16 is at one end of the forward installation groove 19, the forward gear set 16 is respectively engaged with the first gear set 13 and the transmission wheel 15, and when the forward gear set 16 is at the other end of the forward installation groove 19, the forward gear set 16 is in an idle state; the reverse gear set 17 movably mounts the reverse installation slot 18, one end of the reverse installation slot 18 is close to the first gear set 13, the other end of the reverse installation slot 18 extends in a direction away from the first gear set 13, when the reverse gear set 17 is at one end of the reverse installation slot 18, the reverse gear set 17 respectively engages with the first gear set 13 and the transmission wheel 15, and when the reverse gear set 17 is at the other end of the reverse installation slot 18, the reverse gear set 17 is in an idle state.

Therefore, no matter the expansion part 20 expands or contracts, the moving part 30 moves back and forth along with the expansion part, the gear structure 10 can output power, the efficiency is improved, and the power waste is effectively avoided.

The reverse gear set 17 comprises a first gear body and a second gear body, and the first gear body and the second gear body are arranged in a meshing manner; when the expansion part 20 is in a contraction state, the input gear 11 rotates clockwise, the first gear set 13 rotates anticlockwise, the first tooth body is meshed with the first gear set 13, and the second tooth body is meshed with the transmission wheel 15; in this way, the rotation direction of the transmission wheel 15 is consistent no matter the expansion member 20 extends or contracts, and it is ensured that the driving force is output no matter the expansion member 20 extends or contracts.

When the expansion member 20 is in an extended state, the power input wheel 11 is driven to rotate clockwise, so that the first gear set 13 rotates anticlockwise, the first gear set 13 is meshed with the first gear body, and the second gear body is meshed with the transmission wheel 15; in this way, the rotation direction of the transmission wheel 15 is consistent no matter the expansion member 20 extends or contracts, and it is ensured that the driving force is output no matter the expansion member 20 extends or contracts.

The first gear set 13 is provided with a torsion spring 70, and the moving member 30 is conveniently reset when the expansion member 20 is contracted under the action of the torsion spring 70.

The power output end may be connected to the clockwork spring 90 to realize the winding of the clockwork spring 90, so that power is output externally autonomously according to a temperature change.

Under the effect of clockwork spring 90, play the energy storage, store the drive power of power take off output, be convenient for utilize it.

The rack 35 has an inner end surface facing the power input end of the gear structure, and the power input wheel presses against the inner end surface of the rack 35, so that when the rack 35 moves, the power input wheel is driven to rotate, and the power input wheel rotates to generate friction with the rack 35, thereby realizing power input to the power input wheel.

Another embodiment of the moving part:

the moving member 30 comprises a moving part 31 and a blocking part 32, the moving part 31 and the blocking part 32 are fixedly arranged, the moving part 31 and the power input end of the gear structure 10 are arranged in a meshed manner, and the blocking part 32 blocks the communication port 51; under the action of the blocking part 32, the liquid can drive the moving part 30 to move conveniently, and the liquid is prevented from exerting acting force on the moving part 30 to enter the moving cavity 50, so that the moving part 30 is prevented from being influenced.

Furthermore, the front end of the plugging part 32 is arranged opposite to the sub-cavity 42; thus, when the expansion member 20 contracts, the front end of the moving member 30 moves to the sub-chamber 42, so that the moving member 30 has a larger moving space, thereby increasing the moving range of the moving member 30 and increasing the power input of the moving member 30 to the power input end.

The displacement chamber 50 is arranged in a spiral configuration such that the displacement member 30 has a greater displacement area to increase the power input to the power input of the displacement member 30.

The plugging part 32 comprises a plugging rod and a plurality of plugging rings, the plugging rings surround the plugging rod, and the plugging rings are arranged at intervals along the axial direction of the plugging rod; the movable cavity 50 comprises two movable walls which are arranged in an array, the plugging rod and the plugging ring are respectively arranged between the two movable walls, and two ends of the plugging ring respectively abut against the two movable walls; under the effect of shutoff ring, guarantee the shutoff effect to liquid, the at utmost guarantees that the extrusion force of liquid is applyed to moving member 30, guarantees that moving member 30 possesses enough power of moving.

Moreover, each plugging ring comprises a tail plugging ring, the tail plugging ring is positioned in the movable cavity 50, and the tail plugging ring is positioned in the movable cavity 50 no matter the expansion piece 20 is in an expansion state or a contraction state, so that the tail plugging ring is guaranteed to plug liquid; thus, when the moving member 30 reciprocates, the tail plugging ring plays a plugging role in plugging liquid.

In addition, because each plugging ring is arranged at intervals, liquid enters between the adjacent plugging rings, and the moving member 30 is conveniently pushed by the liquid.

The sub-cavity 42 has a longitudinal length, the plugging rod has an axial length, and the axial length of the plugging rod is greater than the longitudinal length of the sub-cavity 42, so that the phenomenon that the tail plugging ring is separated from the movable cavity 50 to cause liquid to flow to the movable cavity 50 by mistake is effectively avoided.

The moving member 30 is arranged in an arc shape; thus, the moving member 30 has a larger moving range, and the reciprocating movement of the moving member 30 is more stable.

The moving part 31 is provided with an inner end surface facing the power input end, the inner end surface of the moving part 31 forms meshing teeth, and the inner end surface of the moving part 31 is in meshing arrangement with the power input end; thereby realizing power output when the moving member 30 moves.

The rack can be provided with meshing teeth or not, and the power input wheel rotates to generate friction force with the rack, so that power input of the power input wheel is realized.

The above description is only exemplary of the present invention and should not be taken as limiting the scope of the present invention, as any modifications, equivalents, improvements and the like made within the spirit and principles of the present invention are intended to be included within the scope of the present invention.

Claims

1. Expansion type drive arrangement, its characterized in that is including the gear structure that has power take off end and power input end, the inflation piece that expands or contracts by the temperature influence, fill with the chamber and remove the chamber of placing of liquid, remove the chamber have with place the intercommunication mouth of chamber intercommunication, the inflation piece is arranged in place the chamber, it is equipped with the moving member that receives hydraulic pressure reciprocating motion to remove the chamber, the shutoff of the one end of moving member the intercommunication mouth, the moving member with the power input end of gear structure is the meshing and arranges.

2. The expansion drive apparatus according to claim 1, wherein the placement chamber includes a main chamber and a branch chamber, the main chamber is disposed in communication with the branch chamber, the expansion member is placed in the main chamber, and the moving chamber is in communication with the branch chamber through the communication port.

3. The expansion drive apparatus according to claim 2, wherein the moving member includes a hose that is hydraulically expanded or contracted, an inlet port is formed at one end of the hose, the inlet port of the hose is arranged in correspondence with the sub-chamber, and the fluid is pressurized into the hose; the other end of the hose and the rack are fixedly arranged, and the rack and the power input end of the gear structure are arranged in a meshed mode.

4. An inflatable drive as claimed in claim 3 wherein said moveable member comprises a rigid tube in a fixed arrangement, said rigid tube being disposed in said moveable chamber, said rigid tube surrounding said flexible tube.

5. An expansion drive according to claim 4, wherein said rigid tube has an inner end face directed towards said flexible tube, said inner end face of said rigid tube being provided with a plurality of balls; the hose has an outer end face facing the hard tube, the outer end face of the hose abutting against the ball.

6. An inflatable actuating device according to any of claims 3 to 5, wherein one end of the flexible tube is provided with a blocking ring, the moving chamber comprises two moving walls arranged in a row, the flexible tube is arranged between the two moving walls, and two ends of the blocking ring abut against the two moving walls respectively.

7. An inflatable drive according to any of claims 1 to 5, comprising a housing, the housing defining the placement chamber and the displacement chamber therein; the shell comprises a bottom shell wall, the placing cavity is provided with a placing wall arranged in a surrounding mode, the placing wall forms a bottom opening, and the bottom shell wall closes the bottom opening of the placing wall; the expansion member abuts the bottom housing wall.

8. The inflatable drive according to claim 7, wherein the inflatable member comprises a paraffin material and a telescoping sleeve, the paraffin material being disposed inside the telescoping sleeve, the telescoping sleeve being in a sealed arrangement; the telescopic sleeve is abutted against the wall of the bottom shell.

9. An inflatable drive according to any of claims 1 to 5, wherein the gear arrangement comprises an input gear forming the power input, an output gear forming the power output, a first gear set, a second gear set, a drive wheel, a forward gear set and an inverse gear set; the input gear is meshed with the first gear set, the output gear is meshed with the second gear set, and the second gear set is meshed with the driving wheel; when the expansion piece is in an expansion state, the input gear rotates anticlockwise, the first gear set rotates clockwise, the forward gear set is respectively meshed with the first gear set and the transmission wheel, and the reverse gear set is in an idle rotation state; when the expansion piece is in a contraction state, the input gear rotates clockwise, the first gear set rotates anticlockwise, the reverse gear set is respectively meshed with the first gear set and the transmission wheel, and the forward gear set is in an idle rotation state.

10. The expansion drive in accordance with claim 9, wherein the gear structure comprises a stationary housing formed with a forward-set groove and a reverse-set groove, the forward-gear set movably mounted in the forward-set groove, one end of the forward-set groove being close to the first gear set, the other end of the forward-set groove extending in a direction away from the first gear set, the forward-gear set respectively engaging the first gear set and the drive wheel when the forward-gear set is at one end of the forward-set groove, the forward-gear set being in a freewheeling state when the forward-gear set is at the other end of the forward-set groove; the reverse gear set is movably arranged on the reverse installation groove, one end of the reverse installation groove is close to the first gear set, the other end of the reverse installation groove extends in the direction deviating from the first gear set, when the reverse gear set is located at one end of the reverse installation groove, the reverse gear set is respectively meshed with the first gear set and the transmission wheel, and when the reverse gear set is located at the other end of the reverse installation groove, the reverse gear set is in an idle state.