CN220470563U - Gear box - Google Patents

Abstract

The application relates to a gear box, and relates to the technical field of gear boxes, wherein the gear box comprises a box body, a power input shaft and a power output shaft are rotatably connected to the box body, a transmission mechanism is arranged in the box body, the transmission mechanism comprises a primary transmission assembly and a speed change assembly, the primary transmission assembly comprises a driving worm wheel, a driving worm and a driving shaft, the driving worm is coaxially connected with the power input shaft, the driving worm wheel is meshed with the driving worm, and the driving shaft is coaxially connected with the driving worm wheel; the speed change assembly comprises a first speed change gear and a second speed change gear, the first speed change gear and the second speed change gear are meshed with each other, the second speed change gear is coaxially connected with the power output shaft, and the first speed change gear is in transmission connection with the driving shaft. The application adopts worm gear to replace gear drive, can let the noise of gear box lower.

Description

Gear box

Technical Field

The application relates to the technical field of gearboxes, in particular to a gearbox.

Background

Gearboxes are an important mechanical component that is widely used in wind power plants. The main function is to transmit the power generated by the wind wheel under the action of wind power to the generator and to make the generator obtain corresponding rotating speed.

The gearbox receives the force from the wind wheel and the gear is transferred to the generator and gets the corresponding rotational speed.

The gearbox bears the counter force generated when the acting force from the wind wheel moves, and has enough rigidity to bear the action of force and moment, so that the deformation is prevented, and the transmission quality is ensured. The design of the gearbox body is carried out according to the requirements of layout arrangement, processing and assembly conditions, convenience in inspection and maintenance and the like of the power transmission of the wind turbine generator. With the continuous rapid development of the gear box industry, more and more industries and different enterprises apply to the gear box, and more enterprises develop in the gear box industry.

The gear box is an important part widely used in mechanical transmission, when a pair of gears are meshed, due to the unavoidable errors of tooth pitch, tooth shape and the like, meshing impact can be generated in the running process, noise corresponding to the meshing frequency of the gears can be generated, and friction noise can also be generated between tooth surfaces due to relative sliding. Since gears are the fundamental component in the transmission of a gearbox, reducing gear noise is necessary to control gearbox noise. In general, the cause of gear system noise occurs mainly in the following ways:

1. gear design aspects. Improper parameter selection, too small overlap ratio, improper tooth profile modification or no modification, unreasonable gear box structure and the like. The basic joint error and the tooth form error are overlarge in gear machining, the tooth side clearance is overlarge, the surface roughness is overlarge, and the like.

2. Gear trains and gearboxes. The assembly is eccentric, the contact precision is low, the parallelism of the shaft is poor, the rigidity of the bearing and the support is insufficient, the rotation precision of the bearing is not high, the clearance is improper, and the like.

3. Other aspects input torque. Fluctuation of load torque, torsional vibration of a shafting, balance conditions of a motor and other transmission pairs and the like.

Disclosure of Invention

The present application provides a gearbox with the purpose of reducing noise in operation of the gearbox.

The application provides a gear box adopts following technical scheme:

the gearbox comprises a box body, wherein a power input shaft and a power output shaft are rotatably connected to the box body, a transmission mechanism is arranged in the box body, the transmission mechanism comprises a primary transmission assembly and a speed change assembly, the primary transmission assembly comprises a driving worm wheel, a driving worm and a driving shaft, the driving worm is coaxially connected with the power input shaft, the driving worm wheel is meshed with the driving worm, and the driving shaft is coaxially connected with the driving worm wheel;

the speed change assembly comprises a first speed change gear and a second speed change gear, the first speed change gear and the second speed change gear are meshed with each other, the second speed change gear is coaxially connected with the power output shaft, and the first speed change gear is in transmission connection with the driving shaft.

Through adopting above-mentioned technical scheme, through setting up the cooperation of initiative worm wheel and initiative worm in the one-level drive assembly for adopt the transmission mode of worm gear to carry out the transmission of power in the gear box, because the transmission of worm gear is similar to helical gear meshing transmission, gradually go out gradually, the transmission is more steady, consequently this application adopts worm gear to replace gear drive, can let the noise of gear box lower.

Optionally, an intermediate transmission assembly is arranged between the first speed change gear and the driving shaft, the intermediate transmission assembly comprises an auxiliary worm wheel, an auxiliary worm and an auxiliary shaft, the auxiliary worm wheel and the auxiliary worm are meshed with each other, the auxiliary shaft is coaxially connected with the auxiliary worm wheel, the auxiliary worm is coaxially connected with the driving shaft, and the auxiliary shaft is coaxially connected with the first speed change gear.

Through adopting above-mentioned technical scheme, the setting of middle drive assembly, on giving the power take off shaft with the power transmission in the one-level drive assembly through auxiliary worm wheel and auxiliary worm, realize the transmission of power through worm wheel worm, further reduce the noise in the gear box.

Optionally, a gear replacement mechanism is arranged between the power input shaft and the driving shaft, the gear replacement mechanism comprises a gear transmission assembly, the gear transmission assembly comprises a driving gear, an intermediate transmission gear set and a driven gear, the driving gear is coaxially connected with the power input shaft, the driven gear is coaxially connected with the driving shaft, the intermediate transmission gear set is arranged between the driven gear and the driving shaft, and the intermediate transmission gear set can transmit power of the driving gear to the driven gear.

Through adopting above-mentioned technical scheme, gear replacement mechanism's setting can realize through the driving gear in the gear drive subassembly, middle drive gear group and driven gear that power between driving shaft and the power input shaft passes through gear drive's mode and transmits for under the operating mode under the great load, can ensure that the gear box can normally work through gear drive.

Optionally, the intermediate drive gear group includes auxiliary gear, connecting axle and switching-over gear, the auxiliary gear with the driving gear intermesh, the connecting axle both ends respectively with auxiliary gear with switching-over gear coaxial coupling, switching-over gear with driven gear intermesh, switching-over gear with driven gear is the conical gear.

Through adopting above-mentioned technical scheme, through auxiliary gear, connecting axle and reversing gear cooperation driving gear and driven gear in the intermediate drive subassembly, can change the power transmission direction of power input axle, ensure that the power of power input axle can transmit to the driving shaft.

Optionally, the gear replacement mechanism further includes a switching assembly, the switching assembly includes a mounting seat, the mounting seat includes a rotating sleeve, the rotating sleeve is coaxially disposed with the driving shaft, and an inner wall of the rotating sleeve is disposed with an outer side wall of the driving shaft at intervals; the driving worm wheel and the driven gear are fixedly connected with the corresponding outer wall of the rotating sleeve, and the inner wall of the rotating sleeve is provided with a meshing groove in a penetrating way along the axial direction of the driving shaft; the switching assembly comprises a switching long gear, the switching long gear is sleeved on the driving shaft and axially connected with the driving shaft in a sliding mode, the switching long gear is arranged between the driving worm gear and the driven gear, meshing teeth are arranged on the outer side wall of the switching long gear, and the meshing grooves are in plug-in fit with the meshing teeth axially of the driving shaft and are slidably connected with the inner wall of the meshing grooves.

Through adopting above-mentioned technical scheme, rotate telescopic setting on the mount pad, with initiative worm wheel and driven gear and driving shaft spaced apart, also ensure simultaneously initiative worm wheel and driven gear can normally rotate. The matching arrangement of the meshing teeth on the rotating sleeve inner meshing groove and the switching long gear enables the switching long gear to be matched with the corresponding rotating sleeve, and then the power on the power input shaft can be transmitted to the driving shaft in a worm gear transmission or gear transmission mode, so that switching of two states is achieved.

Optionally, the mount pad still includes first mounting panel and second mounting panel, first mounting panel with the coaxial mounting hole that has seted up that runs through of second mounting panel, the rotation sleeve sets up along self axial between first mounting panel and the second mounting panel just rotation sleeve both ends respectively with corresponding the mounting hole grafting cooperation, rotation sleeve lateral wall with correspond be provided with the bearing between the mounting hole inner wall.

Through adopting above-mentioned technical scheme, the setting of first mounting panel and second mounting panel is used for fixed rotation sleeve, rotates the bearing between sleeve and the mounting hole, ensures to rotate the sleeve and can normally rotate.

Optionally, the switching long gear is provided with a first connecting long groove, the driving shaft is provided with a second connecting long groove, the first connecting long groove is mutually communicated with the second connecting long groove, a connecting pin block is arranged between the switching long gear and the driving shaft, and the connecting pin block is arranged in the first connecting long groove and the second connecting long groove.

Through adopting above-mentioned technical scheme, the cooperation setting of first connection elongated slot, second connection elongated slot and connecting pin piece for when the rotation sleeve rotates for the driving shaft, the connecting pin piece can conflict the inner wall of first connection elongated slot and second connection elongated slot, ensures that rotation sleeve and driving shaft can synchronous rotation.

Optionally, the length direction of the first connecting long groove and the second connecting long groove is along the axial direction of the driving shaft, the connecting pin block is in plug-in fit with the second connecting long groove, and the connecting pin block is in sliding connection with the inner wall of the first connecting long groove along the length direction of the driving shaft.

Through adopting above-mentioned technical scheme, the connecting pin piece is installed to in the second installation elongated slot, and the inner wall of first connecting elongated slot and connecting pin piece follow the length direction sliding connection of first connecting elongated slot to make the switching long gear can follow the axial of driving shaft and slide on the driving shaft.

Optionally, the switching assembly further includes a switching driving member, the switching driving member is disposed between the driving worm gear and the driven gear along an axial direction of the driving shaft, and the switching driving member is connected with the switching long gear and the switching driving member can drive the switching long gear to slide on the driving shaft.

By adopting the technical scheme, the automatic driving of the switching long gear is realized by setting the switching driving piece, so that the transmission between the driving shaft and the power input shaft can be automatically selected between worm gear transmission and gear transmission.

1. According to the gear box, the first-stage transmission assembly and the middle transmission assembly are arranged in the gear box, and the worm and gear transmission mode is adopted, so that noise generated during operation of the gear box can be reduced.

2. The gear replacement mechanism is additionally arranged in the gear box, so that the gear box can be switched between gear transmission and worm and gear transmission, and the gear box can meet transmission requirements under various working conditions.

3. The driving worm wheel is driven by the driving worm, the driven gear is driven by the driving gear, and the driving worm and the driven gear can synchronously rotate, so that the long gear can be conveniently switched between the driving worm wheel and the driven gear.

Drawings

Fig. 1 is a schematic view of the overall structure of the gear box of embodiment 1 of the present application.

Fig. 2 is a schematic diagram of the overall structure of the transmission mechanism of embodiment 1 of the present application.

Fig. 3 is a schematic view of the overall structure of the gear case of embodiment 2 of the present application.

Fig. 4 is a schematic view showing the overall structure of the inside of the gear case of embodiment 2 of the present application.

Fig. 5 is a schematic view showing the overall structure of a gear assembly according to embodiment 2 of the present application.

Fig. 6 is a schematic diagram of the overall structure of the switching assembly of embodiment 2 of the present application.

In the figure, 1, a box body; 2. a power input shaft; 3. a power output shaft; 4. a transmission mechanism; 41. a primary transmission assembly; 411. a driving worm; 412. a driving worm wheel; 413. a driving shaft; 42. an intermediate transmission assembly; 421. an auxiliary worm wheel; 422. an auxiliary worm; 423. an auxiliary shaft; 43. a speed change assembly; 431. a first speed change gear; 432. a second speed change gear; 433. a variable speed shaft; 5. a gear replacement mechanism; 51. a gear drive assembly; 511. a drive gear; 512. an intermediate drive gear set; 5121. an auxiliary gear; 5122. a connecting shaft; 5123. a reversing gear; 513. a driven gear; 52. a switching assembly; 521. a mounting base; 5211. a first mounting plate; 5212. a second mounting plate; 5213. a mounting hole; 5214. rotating the sleeve; 5215. a meshing groove; 522. switching the long gear; 5221. meshing teeth; 5222. a first connecting elongated slot; 5223. a second connecting elongated slot; 5224. a connecting pin block; 5225. installing a sleeve seat; 5226. the driving member is switched.

Detailed Description

The present application is described in further detail below with reference to fig. 1-6.

Example 1:

the utility model provides a gear box, referring to fig. 1, includes box 1, is provided with power input shaft 2 and power output shaft 3 on the box 1, and power input shaft 2 and the even end of power output shaft 3 extend to in the box 1, and the other end is located outside box 1, and power input shaft 2 and power output shaft 3 all correspond the lateral wall rotation with box 1 through the bearing and be connected.

Referring to fig. 1 and 2, a transmission mechanism 4 is disposed in the case 1, the transmission mechanism 4 includes a primary transmission assembly 41, the primary transmission assembly 41 includes a driving worm 411, a driving worm wheel 412 and a driving shaft 413, the driving worm 411 is coaxially connected with the power input shaft 2, the driving worm 411 is meshed with the driving worm wheel 412, and the driving worm wheel 412 is coaxially connected with the driving shaft 413. Therefore, when the power input shaft 2 is connected to the drive motor, the power of the power input shaft 2 can be transmitted to the drive shaft 413 by the engagement of the drive worm wheel 412 and the drive worm 411.

Referring to fig. 1 and 2, the transmission mechanism 4 further includes a plurality of intermediate transmission assemblies 42, and the intermediate transmission assemblies 42 include an auxiliary worm wheel 421, an auxiliary worm 422, and an auxiliary shaft 423, the auxiliary worm wheel 421 is engaged with the auxiliary worm 422, and the auxiliary worm wheel 421 is coaxially connected with the auxiliary shaft 423. The intermediate transmission assemblies 42 are sequentially connected in a transmission manner, and the auxiliary worm 422 is coaxially connected with an auxiliary shaft 423 in the adjacent last intermediate transmission assembly 42. The worm gear 422 in the first intermediate drive assembly 42 is coaxially connected to the drive shaft 413 in the drive direction of the intermediate drive assembly 42. Thus, by the arrangement of the transmission mechanism 4 and the several intermediate transmission assemblies 42, transmission of power on the power input shaft 2 can be achieved. The number of intermediate drive assemblies 42 in this application is preferably 1.

Referring to fig. 1 and 2, the transmission mechanism 4 further includes a speed change assembly 43, the speed change assembly 43 includes a first speed change gear 431, a second speed change gear 432, and a speed change shaft 433, the first speed change gear 431 is intermeshed with the second speed change gear 432, the second speed change gear 432 is coaxially connected with the power output shaft 3, and the first speed change gear 431 is coaxially connected with the speed change shaft 433. The shift shaft 433 is coaxially coupled to the auxiliary shaft 423 in the final intermediate transmission assembly 42 in the transmission direction of the intermediate transmission assembly 42. Thus, by the arrangement of the transmission mechanism 4, the power input shaft 2 is enabled to sequentially transmit power to the primary transmission assembly 41, the plurality of intermediate transmission assemblies 42, and the speed change assembly 43, and finally output power from the power output shaft 3. The rotational speed relationship between the power input shaft 2 and the power output shaft 3 can be achieved by adjusting the first speed change gear 431 and the second speed change gear 432.

The implementation principle of the embodiment of the application is as follows: according to the gear box, through the transmission mode of the worm gear and the worm, the size of the box body 1 can be reduced, and noise generated during the working process of the gear box is reduced by replacing the gear transmission mode.

A process for designing a gearbox, comprising the steps of:

s1: determining initial parameters: and determining initial design parameters of the gear and the worm gear, and establishing an initial model.

S2: performing intensity checking calculation and CAE intensity simulation analysis;

s3: according to the actual requirements, parameters are adjusted, intensity checking is conducted again, and a final model is determined;

s4: determining acceptance criteria;

s5: determining the size of each part, the tolerance level of installation and the sealing requirement;

s6: determining a welding mode of the box body;

s7: and determining a final scheme, and carrying out production.

The implementation principle of the embodiment of the application is as follows: and setting the structure of the gear box according to the data of the definite test requirement of the gear box so as to meet the test requirement.

Example 2:

this embodiment differs from embodiment 1 in that: a gear box, referring to fig. 3 and 4, a gear replacement mechanism 5 is also provided in the box 1.

Referring to fig. 4 and 5, the gear replacement mechanism 5 is provided in plurality, and the plurality of gear replacement mechanisms 5 are provided between the power input shaft 2 and the driving shaft 413, between the driving shaft 413 and the auxiliary shafts 423 in the corresponding intermediate transmission assemblies 42, and between the auxiliary shafts 423 in the adjacent two intermediate transmission assemblies 42, respectively. The gear replacement mechanism 5 has the same structure, and the gear replacement mechanism 5 between the power input shaft 2 and the drive shaft 413 will be described below.

Referring to fig. 4 and 5, the gear replacement mechanism 5 includes a gear transmission assembly 51, the gear transmission assembly 51 includes a driving gear 511, an intermediate transmission gear set 512 and a driven gear 513, the driving gear 511 is coaxially connected with the power input shaft 2, the intermediate transmission gear set 512 includes an auxiliary gear 5121, a connecting shaft 5122 and a reversing gear 5123, both ends of the connecting shaft 5122 are coaxially connected with the auxiliary gear 5121 and the reversing gear 5123, the auxiliary gear 5121 is meshed with the driving gear 511, the driven gear 513 is meshed with the reversing gear 5123, the driven gear 513 is coaxially connected with the driving shaft 413, and the driven gear 513 and the reversing gear 5123 are conical gears. Accordingly, by providing the gear train assembly 51, the power of the power input shaft 2 can be transmitted to the driving shaft 413 through the engagement between the gears.

Referring to fig. 5 and 6, the gear replacing mechanism 5 further includes a switching assembly 52, the switching assembly 52 includes a mounting base 521, the mounting base 521 is provided with two along the axial interval of the driving shaft 413, the mounting base 521 includes a first mounting plate 5211 and a second mounting plate 5212, a mounting hole 5213 is coaxially and penetratingly provided on the first mounting plate 5211 and the second mounting plate 5212, the first mounting plate 5211 and the second mounting plate 5212 are provided along the axial interval of the mounting hole 5213, the driving shaft 413 is inserted into the mounting hole 5213 and the mounting hole 5213 is coaxially provided with the driving shaft 413, a rotating sleeve 5214 is provided between the first mounting plate 5211 and the second mounting plate 5212, two ends of the rotating sleeve 5214 are respectively inserted into the mounting holes 5213 on the first mounting plate 5211 and the second mounting plate 5212, and a bearing is provided between the outer side wall of the rotating sleeve 5214 and the inner wall of the corresponding mounting hole 5213, so the mounting base 521 can fix the rotating sleeve 5214, and simultaneously the rotating sleeve 5214 can rotate with the driving shaft 413 as a central line.

Referring to fig. 5 and 6, the worm gear 412 is sleeved outside the rotating sleeve 5214 of the corresponding mounting seat 521, and the worm gear 412 is fixedly connected with the corresponding rotating sleeve 5214, so that the worm gear 412 can normally rotate. The driven gear 513 is sleeved outside the rotating sleeve 5214 of the corresponding mounting seat 521, and the driven gear 513 is fixedly connected with the corresponding rotating sleeve 5214, so that the driven gear 513 can normally rotate.

Referring to fig. 5 and 6, a plurality of engagement grooves 5215 are provided in an inner wall of the rotating sleeve 5214, the engagement grooves 5215 penetrate the rotating sleeve 5214 in an axial direction of the rotating sleeve 5214 and the plurality of engagement grooves 5215 are provided at uniform intervals in a circumferential direction of the rotating sleeve 5214. The switching assembly 52 further comprises a switching long gear 522, a plurality of engaging teeth 5221 are arranged on the outer side of the switching long gear 522, the engaging teeth 5221 and the engaging grooves 5215 are arranged in a one-to-one correspondence, the engaging teeth 5221 and the corresponding engaging grooves 5215 are mutually inserted and matched along the axial direction of the main shaft, the engaging teeth 5221 are slidably connected with the inner wall of the corresponding engaging grooves 5215, the switching long gear 522 is sleeved on the driving shaft 413, the switching long gear 522 is arranged between the driving worm gear 412 and the driven gear 513 along the axial direction of the driving shaft 413, the switching long gear 522 is slidably connected with the outer side wall of the driving shaft 413 along the axial direction of the driving shaft 413, and when one end of the switching long gear 522 is inserted into the rotating sleeve 5214 corresponding to the driving worm gear 412, the rotating sleeve 5214 corresponding to the driven gear 513 at the other end of the switching long gear 522 is mutually arranged at intervals along the axial direction of the driving shaft 413; when one end of the switching long gear 522 is inserted into the rotating sleeve 5214 corresponding to the driven gear 513, the rotating sleeves 5214 corresponding to the worm gear 412 at the other end of the switching long gear 522 are disposed at intervals in the axial direction of the driving shaft 413.

Referring to fig. 5 and 6, the switching long gear 522 is disposed, so that after the switching long gear 522 is in plug-in fit with the corresponding rotating sleeve 5214, the switching long gear 522 can be driven to rotate by the driven gear 513 or the driving worm gear 412, so as to realize power transmission between the driving shaft 413 and the power input shaft 2. Thus, by selecting the rotating sleeve 5214 to which the switching long gear 522 is to be socket-fitted, the gear box can be made to select either through worm gear or through gear.

Referring to fig. 5 and 6, a first connection long groove 5222 is formed in an inner wall of the switching long gear 522, a corresponding second connection long groove 5223 is formed in the driving shaft 413, the first connection long groove 5222 and the second connection long groove 5223 are mutually communicated along a radial direction of the switching long gear 522, a connection pin block 5224 is arranged between the switching long gear 522 and the driving shaft 413, the connection pin block 5224 is arranged in the first connection long groove 5222 and the second connection long groove 5223, and when the switching long gear 522 and the driving shaft 413 relatively rotate, the connection pin block 5224 is mutually abutted against the inner walls of the first connection long groove 5222 and the second connection long groove 5223, so that the switching long gear 522 can drive the driving shaft 413 to rotate, and therefore power transmission between the switching long gear 522 and the driving shaft 413 is achieved.

Referring to fig. 5 and 6, the first and second connection long grooves 5222 and 5223 are provided in the longitudinal direction of the driving shaft 413 in the axial direction thereof, the connection pin blocks 5224 are inserted into the corresponding second connection long groove 5223 in the radial direction of the driving shaft 413, the first connection long groove 5222 penetrates the switching long gear 522 in the axial direction of the driving shaft 413, and the outer side wall of the connection pin block 5224 is slidably connected to the inner wall of the first connection long groove 5222 in the axial direction of the driving shaft 413. Therefore, the switching long gear 522 can slide on the driving shaft 413.

Referring to fig. 5 and 6, the switching long gear 522 is externally sleeved with a mounting socket 5225, and a bearing is provided between the inner wall side of the mounting socket 5225 and the outer side wall of the switching long gear 522, thereby enabling the switching long gear 522 to normally rotate.

Referring to fig. 5 and 6, a switching driving member 5226 is provided on the mounting socket 5225, the switching driving member 5226 is a cylinder, a linear module or a linear push rod, the switching driving member 5226 is disposed between the two mounting sockets 521 along the axial direction of the driving shaft 413, and the switching driving member 5226 is connected with the switching long gear 522. The switching long gear 522 can be slid on the driving shaft 413 in the axial direction of the driving shaft 413 by the switching driver 5226, so that the switching long gear 522 can be connected to the corresponding driven gear 513 or the driving worm gear 412 in a driving manner.

The implementation principle of the embodiment of the application is as follows: the driving of the switching driving piece 5226 is realized through the driving of the switching driving piece 5226 in the gear replacement mechanism 5, so that the switching long gear 522 can be in transmission connection with a corresponding worm gear or a gear, and the transmission mode between the power output shaft 3 and the power input shaft 2 can be switched between gear transmission and worm gear transmission under the cooperation of a plurality of switching driving pieces 5226, so that the transmission requirements of the gearbox under different working conditions can be met.

The embodiments of this embodiment are all preferred embodiments of the present application, and are not intended to limit the scope of the present application, in which like parts are denoted by like reference numerals. Therefore: all equivalent changes in structure, shape and principle of this application should be covered in the protection scope of this application.

Claims (8)

1. The gearbox comprises a box body (1), and is characterized in that a power input shaft (2) and a power output shaft (3) are rotatably connected to the box body (1), a transmission mechanism (4) is arranged in the box body (1), the transmission mechanism (4) comprises a primary transmission assembly (41) and a speed change assembly (43), the primary transmission assembly (41) comprises a driving worm wheel (412), a driving worm (411) and a driving shaft (413), the driving worm (411) is coaxially connected with the power input shaft (2), the driving worm wheel (412) is meshed with the driving worm (411), and the driving shaft (413) is coaxially connected with the driving worm wheel (412);

the speed change assembly (43) comprises a first speed change gear (431) and a second speed change gear (432), the first speed change gear (431) and the second speed change gear (432) are meshed with each other, the second speed change gear (432) is coaxially connected with the power output shaft (3), and the first speed change gear (431) is in transmission connection with the driving shaft (413);

the power input shaft (2) with be provided with gear replacement mechanism (5) between driving shaft (413), gear replacement mechanism (5) include gear drive subassembly (51), gear drive subassembly (51) include driving gear (511), intermediate drive gear group (512) and driven gear (513), driving gear (511) with power input shaft (2) coaxial coupling, driven gear (513) with driving shaft (413) coaxial coupling, intermediate drive gear group (512) set up driven gear (513) with between driving shaft (413) and intermediate drive gear group (512) can with driving gear (511) power transmission to driven gear (513).

2. A gearbox according to claim 1, characterised in that an intermediate transmission assembly (42) is arranged between the first change gear (431) and the driving shaft (413), the intermediate transmission assembly (42) comprising an auxiliary worm wheel (421), an auxiliary worm (422) and an auxiliary shaft (423), the auxiliary worm wheel (421) and the auxiliary worm (422) being intermeshed, the auxiliary shaft (423) being coaxially connected with the auxiliary worm wheel (421), the auxiliary worm (422) being coaxially connected with the driving shaft (413), the auxiliary shaft (423) being coaxially connected with the first change gear (431).

3. A gearbox according to claim 1, characterized in that the intermediate transmission gear set (512) comprises an auxiliary gear (5121), a connecting shaft (5122) and a reversing gear (5123), the auxiliary gear (5121) is meshed with the driving gear (511), two ends of the connecting shaft (5122) are respectively connected with the auxiliary gear (5121) and the reversing gear (5123) coaxially, the reversing gear (5123) is meshed with the driven gear (513), and the reversing gear (5123) and the driven gear (513) are conical gears.

4. A gearbox according to claim 1, wherein the gear replacement mechanism (5) further comprises a switching assembly (52), the switching assembly (52) comprising a mounting (521), the mounting (521) comprising a rotating sleeve (5214), the rotating sleeve (5214) being arranged coaxially with the driving shaft (413) and the rotating sleeve (5214) inner wall being arranged spaced from the driving shaft (413) outer side wall;

the driving worm gear (412) and the driven gear (513) are fixedly connected with the outer wall of the corresponding rotating sleeve (5214), and an engagement groove (5215) is formed in the inner wall of the rotating sleeve (5214) in a penetrating manner along the axial direction of the driving shaft (413);

the switching assembly (52) comprises a switching long gear (522), the switching long gear (522) is sleeved on the driving shaft (413) and is connected with the driving shaft (413) in a sliding mode along the axial direction of the driving shaft (413), the switching long gear (522) is arranged between the driving worm gear (412) and the driven gear (513), meshing teeth (5221) are arranged on the outer side wall of the switching long gear (522), and the meshing grooves (5215) are matched with the meshing teeth (5221) in an inserting mode along the axial direction of the driving shaft (413) in a sliding mode, and the inner wall of the meshing grooves (5215) is connected with the outer side wall of the meshing teeth (5221) in a sliding mode.

5. The gearbox of claim 4, wherein the mounting base (521) further comprises a first mounting plate (5211) and a second mounting plate (5212), the first mounting plate (5211) and the second mounting plate (5212) are coaxially provided with mounting holes (5213) in a penetrating manner, the rotating sleeve (5214) is axially arranged between the first mounting plate (5211) and the second mounting plate (5212) along the self axis, two ends of the rotating sleeve (5214) are respectively in plug-in fit with the corresponding mounting holes (5213), and a bearing is arranged between the outer side wall of the rotating sleeve (5214) and the inner wall of the corresponding mounting hole (5213).

6. The gearbox of claim 4, wherein the switching gear (522) is provided with a first connecting slot (5222), the driving shaft (413) is provided with a second connecting slot (5223), the first connecting slot (5222) is mutually communicated with the second connecting slot (5223), a connecting pin block (5224) is arranged between the switching gear (522) and the driving shaft (413), and the connecting pin block (5224) is arranged in the first connecting slot (5222) and the second connecting slot (5223).

7. The gearbox as recited in claim 6, wherein the first connecting slot (5222) and the second connecting slot (5223) are disposed along the axial direction of the driving shaft (413), the connecting pin block (5224) is in plug-in fit with the second connecting slot (5223), and the connecting pin block (5224) is slidably connected with the inner wall of the first connecting slot (5222) along the length direction of the driving shaft (413).

8. A gearbox according to claim 4, wherein the switching assembly (52) further comprises a switching drive (5226), the switching drive (5226) being arranged between the worm gear (412) and the driven gear (513) in the axial direction of the driving shaft (413), the switching drive (5226) being interconnected with the switching gear (522) and the switching drive (5226) being capable of driving the switching gear (522) to slide on the driving shaft (413).