CN211901467U - Gear box - Google Patents

Abstract

The invention discloses a gearbox, which comprises a bracket, a box body, wheels, a driving device and a shell, wherein the driving device is used for driving the wheels to rotate; the driving device is arranged in the box body and comprises a driving motor, a driving shaft, a driven shaft and an output shaft, wherein the driving motor is used for driving the driving shaft to rotate; the driving shaft is positioned above the driven shaft, the output shaft is positioned below the driven shaft, and the axial leads of the driving shaft, the driven shaft and the output shaft are positioned on the same vertical plane; the transmission structure of the gearbox is compact, the occupied space is small, and therefore the driving force provided by the gearbox is increased, and the electric forklift bears larger carrying capacity.

Description

Gear box

Technical Field

The invention relates to the technical field of forklifts, in particular to a gearbox.

Background

The existing electric forklift is widely applied due to no noise, no exhaust, simple maintenance, easy operation and excellent traction performance, but the electric forklift needs a plurality of power supplies to provide energy, so the space utilization of the whole transmission system of the body of the electric forklift is very critical compared with that of a fuel forklift.

However, the electric three-wheel forklift in the prior art has unreasonable transmission structure and large occupied space of the reduction gearbox. Therefore, the energy supply of the electric forklift is limited, and the forklift cannot bear larger transportation capacity due to insufficient counter weight.

Therefore, chinese patent publication No. CN202952821 discloses a forklift reduction gearbox assembly, which comprises a box body, wherein an input gear shaft and an output gear shaft are arranged in the box body, the box body is rotatably arranged on a support, a rotating motor is arranged on the support, and the rotating motor is in transmission connection with a steering gear on the box body and drives the box body to rotate; a wheel driving shaft is arranged below the box body, wheels are arranged on the wheel driving shaft, and the wheel driving shaft is connected with an output gear shaft through bevel gear transmission; the output gear shaft is vertical to the wheel driving shaft; the invention has the advantages that: the controllable steering driving gearbox is realized, and the characteristics of reasonable transmission structure arrangement, high space utilization rate, in-situ rotation realization and the like are realized.

And chinese patent publication No. CN205836534U discloses a steering variable-speed drive device, which includes a box body and a tire, wherein an inner ring and a rotary fluted disc of a rotary bearing are fixedly mounted on the box body, the rotary fluted disc is engaged with an external rotary power output gear, a pinion is mounted on an upper end cover and the box body through two bearings, an external power device is connected with the pinion and drives the pinion to rotate, a large gear engaged with the pinion is mounted on an upper end of a bearing sleeve through a bearing and connected with a lower angular gear shaft through a spline, the bearing sleeve is fixed on the box body, a lower end of the angular gear shaft is fixed on a lower end of the bearing sleeve through a bearing, the angular gear shaft is engaged with a basin gear, the basin gear is mounted on the box body through a bearing, the drive shaft is mounted on the box body through a bearing, the basin gear is connected with a drive shaft spline, and the pneumatic tire is, Can carry out steering drive of various angles and has the characteristics of simple and reliable structure.

However, those skilled in the art find that the above invention has the following technical problems in the process of use:

1) the existing steering speed-changing driving device can only select one of an electric steering device and a manual steering device due to the installation position, the installation space and the like, and the installation positions of the electric steering device and the manual steering device are the same and the installation structures are different;

2) the oil seal on the wheel driving shaft belongs to a quick-wear part, the replacement frequency is high, but the end cover, the driving shaft and other gear parts need to be detached during replacement, and the replacement is very inconvenient;

3) the transmission structures of the forklift speed reduction box assembly and the steering variable-speed driving device have improved spaces.

Disclosure of Invention

In order to solve the technical problem, the invention provides the gearbox, which has a very compact transmission structure, effectively reduces the occupied space of the gearbox on the forklift, further increases the driving force provided by the gearbox, and enables the electric forklift to bear larger carrying capacity.

In order to achieve the first object, the invention adopts the following technical scheme:

a gearbox comprises a bracket, a box body which is rotatably arranged below the bracket, wheels which are arranged at the lower half part of the box body, a driving device for driving the wheels to rotate, and a shell which is arranged at the side surface of the box body; the wheel comprising a hub and a tyre mounted on the hub,

the driving device is arranged in the box body and comprises a driving motor, a driving shaft, a driven shaft and an output shaft, wherein the driving motor is used for driving the driving shaft to rotate;

the driving shaft is located above the driven shaft, the output shaft is located below the driven shaft, and the axial leads of the driving shaft, the driven shaft and the output shaft are located on the same vertical plane.

Preferably, the following is also provided:

a first connecting shaft; the upper end of the first connecting shaft is fixedly connected with the bracket, and the box body is rotatably arranged on the first connecting shaft;

a second mounting hole positioned at the top end of the box body, the first connecting shaft is mounted in the second mounting hole,

the first cover plate is fixedly connected with the lower end face of the first connecting shaft or integrally formed, and the outer diameter of the first cover plate is larger than that of the first connecting shaft;

the two tapered roller bearings which are arranged in pairs and matched up and down are positioned in a gap between the second mounting hole and the first connecting shaft, the inner surfaces of the two tapered roller bearings are tightly matched with the first connecting shaft, and the outer surfaces of the two tapered roller bearings are tightly matched with the inner surface of the second mounting hole;

the first retainer ring is positioned in a gap between the second mounting hole and the first connecting shaft and above the two tapered roller bearings;

the second mounting hole at least comprises a third inner surface, a fourth inner surface and a fifth inner surface from top to bottom, the third inner surface and the fifth inner surface are cylindrical surfaces, the fourth inner surface is a horizontal surface and is used for connecting the third inner surface and the fifth inner surface, and the inner diameter of the fifth inner surface is larger than that of the third inner surface;

the first check ring abuts against the fourth inner surface, the outer surface of the first check ring is in tight fit with the fifth inner surface, and the inner diameter of the first check ring is smaller than that of the third inner surface.

Preferably, the following is also provided:

a first connecting shaft; the lower end of the first connecting shaft is fixedly connected with the box body, and the upper end of the first connecting shaft is rotatably arranged on the bracket;

the first connecting shaft is positioned in the first mounting hole;

the two tapered roller bearings which are arranged in pairs and matched up and down are positioned in a gap between the third mounting hole and the first connecting shaft, the inner surfaces of the two tapered roller bearings are tightly matched with the first connecting shaft, and the outer surfaces of the two tapered roller bearings are tightly matched with the inner surface of the third mounting hole;

the second retainer is positioned in a gap between the third mounting hole and the first connecting shaft and above the two tapered roller bearings;

and the second cover plate is fixed on the upper end surface of the first connecting shaft through a bolt, and the outer diameter of the second cover plate is larger than the inner diameter of the second mounting hole.

Preferably, the driving shaft is a stepped shaft, the driving shaft comprises a first shaft body, a second shaft body and a third shaft body, the outer diameters of the first shaft body, the second shaft body and the third shaft body are sequentially reduced along the direction away from the driving motor, the first shaft body is in transmission fit with the driving motor, the third shaft body is in transmission fit with the pinion through a flat key, a first mounting hole is further formed in the outer end face of the third shaft body, and the driving shaft is rotatably mounted on the inner side of the shell through the first mounting hole.

Preferably, the first deep groove ball bearing is further provided with a first mounting seat, a first deep groove ball bearing, a first O-shaped ring, a first check ring and a first oil seal, the first deep groove ball bearing, the first check ring and the first oil seal are sequentially sleeved on the second shaft body along the direction away from the driving motor and are tightly matched with the outer surface of the second shaft body and the inner surface of the first mounting seat, the first mounting seat is clamped inside the box body through the first deep groove ball bearing and the first shaft body, and the first O-shaped ring is arranged between the first mounting seat and the box body.

Preferably, the driven shaft is a stepped shaft and sequentially comprises a fourth shaft body, a fifth shaft body and a sixth shaft body along the direction far away from the driving motor, the outer diameter of the fifth shaft body is larger than that of the fourth shaft body and that of the sixth shaft body, the fifth shaft body is a gear portion and is meshed with the output gear, and the sixth shaft body is provided with a large gear through a flat key.

Preferably, a second deep groove ball bearing and a third deep groove ball bearing are arranged at two ends of the driven shaft in a sleeved mode respectively, the inner surface of the second deep groove ball bearing is in tight fit with the fourth shaft body, the outer surface of the second deep groove ball bearing is in tight fit with the box body, the inner surface of the third deep groove ball bearing is in tight fit with the sixth shaft body, and the outer surface of the third deep groove ball bearing is in tight fit with the shell.

Preferably, the gearbox is further provided with a second mounting seat and a second oil seal positioned between the second mounting seat and the output shaft, the second mounting seat is fixedly connected with the box body or integrally formed with the box body, a stepped hole is formed in the second mounting seat, the output shaft is installed in the stepped hole, the stepped hole at least comprises a first inner surface, the output shaft is a stepped shaft and at least comprises a seventh shaft body, the inner surface of the second oil seal is tightly matched with the seventh shaft body, the outer surface of the second oil seal is tightly matched with the first inner surface, the output shaft is closer to the shaft body of the hub than the seventh shaft body, and the outer diameter of the output shaft is not larger than the seventh shaft body; the inner surface of the hub is closer to the stepped hole than the first inner surface, and has a diameter not smaller than the first inner surface.

Preferably, the output shaft further comprises an eighth shaft body and a ninth shaft body along the direction away from the hub, the ninth shaft body is provided with an external spline, the ninth shaft body is provided with an output gear through the spline, the outer diameter of the eighth shaft body is larger than that of the ninth shaft body, the inner surface of one conical roller bearing is in tight fit with the output gear, the outer surface of the other conical roller bearing is in tight fit with the eighth shaft body, and the outer surface of the other conical roller bearing is in tight fit with the second mounting seat.

Preferably, the output gear comprises a second gear part and a second mounting part, the second mounting part is a shaft body and is provided with a shaft hole, an internal spline is arranged in the shaft hole, the second mounting part is sleeved on the output shaft through the spline, the second gear part is meshed with the driven shaft, and the inner diameter of the second gear part is larger than the outer diameter of the second mounting part;

the inner end cover is fixed on the end face, far away from one end of the hub, of the output shaft through bolts, and the outer diameter of the inner end cover is smaller than the inner diameter of the second gear part and larger than the outer diameter of the second mounting part.

The invention has the technical effects that:

1) the driving shaft, the driven shaft and the output shaft are transversely arranged, the assembly is convenient, the transmission structure is very compact, the occupied space of the gearbox on the forklift is effectively reduced, the driving force provided by the gearbox is increased, and the electric forklift can bear larger carrying capacity.

2) According to the invention, the driving device is arranged in the box body, so that the gearbox has a space for installing the electric steering structure and the manual steering structure.

3) When the second oil seal of the gearbox is replaced, the second oil seal can be taken out only by detaching the wheel hub, and the gearbox is very convenient.

Drawings

FIG. 1 is a schematic structural view of the transmission of the present invention;

FIG. 2 is a front view of FIG. 1;

FIG. 3 is a cross-sectional view A-A of FIG. 2;

FIG. 4 is a partial enlarged view at O of FIG. 3;

FIG. 5 is an enlarged view of a portion of FIG. 3 at P;

FIG. 6 is an enlarged view of a portion of FIG. 4 at Q;

FIG. 7 is a cross-sectional view of the drive shaft;

FIG. 8 is a cross-sectional view of the driven shaft;

FIG. 9 is a cross-sectional view of the output shaft;

FIG. 10 is a cross-sectional view of the output gear;

fig. 11 is a cross-sectional view of the second mount.

Description of reference numerals: 1. a support; 2. a box body; 3. a wheel; 4. a drive device; 5. a housing; 41. a drive motor; 42. a drive shaft; 43. a driven shaft; 44. an output shaft; 45. a pinion gear; 46. a bull gear; 47. an output gear; 6. a first connecting shaft; 91. a first cover plate; 92. a first retainer ring; 21. a third inner surface; 22. a fourth inner surface; 23. a fifth inner surface; 421. a first shaft body; 422. a second shaft body; 423. a third shaft body; 24. a first mounting seat; 94. a first O-ring; 95. a first oil seal; 96. a third retainer ring; 431. a fourth shaft body; 432. a fifth shaft body; 433. a sixth shaft body; 31. a tire; 32. a hub; 25. a second mounting seat; 99. a second oil seal; 251. a first inner surface; 441. a seventh shaft body; 442. an eighth shaft body; 443. a ninth shaft body; 471. a second gear portion; 472. a second mounting portion.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be considered as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, unless otherwise specified, "a plurality" means two or more unless explicitly defined otherwise.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

A gearbox as shown in fig. 1, 2 and 3 comprises a bracket 1, a box body 2 which is rotatably arranged below the bracket 1, wheels 3 which are arranged at the lower half part of the box body 2, a driving device 4 for driving the wheels 3 to rotate, and a shell 5 which is arranged at the side surface of the box body 2;

the driving device 4 is installed inside the box body 2 and comprises a driving motor 41, a driving shaft 42, a driven shaft 43 and an output shaft 44, wherein the driving motor 41 is used for driving the driving shaft 42 to rotate, a pinion 45 is connected to the driving shaft 42 through a key, a bull gear 46 is connected to the driven shaft 43 through a key, an output gear 47 is connected to the output shaft 44 through a key, the output shaft 44 is fixedly connected with the wheels 3, the pinion 45 is in transmission fit with the bull gear 46, and the output gear 47 is in transmission fit with the driven shaft 43;

the driving shaft 42, the driven shaft 43 and the output shaft 44 are all arranged transversely, the driving shaft 42 is located above the driven shaft 43, the output shaft 44 is located below the driven shaft 43, and the axial leads of the driving shaft 42, the driven shaft 43 and the output shaft 44 are all located on the same vertical plane.

So set up, all adopt spur gear transmission in being arranged in driving wheel 3 pivoted drive arrangement 4 for this gearbox's simple to operate, long service life.

In the embodiment of the present application, as shown in fig. 4 and 6, a first connecting shaft 6 is further provided;

the upper end of the first connecting shaft 6 is fixedly connected with the bracket 1, and the box body 2 is rotatably arranged on the first connecting shaft 6;

or the lower end of the first connecting shaft 6 is fixedly connected with the box body 2, and the upper end of the first connecting shaft 6 is rotatably arranged on the bracket 1.

Further preferably, when the first connecting shaft 6 is fixedly connected with the bracket 1, there are further provided:

a second mounting hole positioned at the top end of the box body 2, wherein the first connecting shaft 6 is mounted in the second mounting hole,

the first cover plate 91 is fixedly connected with the lower end face of the first connecting shaft 6 or integrally formed, and the outer diameter of the first cover plate 91 is larger than that of the first connecting shaft 6;

the two tapered roller bearings which are arranged in pairs and matched up and down are positioned in a gap between the second mounting hole and the first connecting shaft 6, the inner surfaces of the two tapered roller bearings are tightly matched with the first connecting shaft 6, and the outer surfaces of the two tapered roller bearings are tightly matched with the inner surface of the second mounting hole;

a first retainer ring 92 located in a gap between the second mounting hole and the first connecting shaft 6 and above the two tapered roller bearings;

the second mounting hole at least comprises a third inner surface 21, a fourth inner surface 22 and a fifth inner surface 23 from top to bottom, the third inner surface 21 and the fifth inner surface 23 are cylindrical surfaces, the fourth inner surface 22 is a horizontal surface and is used for connecting the third inner surface 21 and the fifth inner surface 23, and the inner diameter of the fifth inner surface 23 is larger than that of the third inner surface 21;

the first retainer ring 92 abuts against the fourth inner surface 22, the outer surface of the first retainer ring 92 is tightly fitted with the fifth inner surface 23, and the inner diameter of the first retainer ring 92 is smaller than that of the third inner surface 21.

In other embodiments, when the first connecting shaft 6 is fixedly connected with the box body 2, there are further provided:

the third mounting hole is positioned on the bracket 1, and the first connecting shaft 6 is positioned in the third mounting hole;

the two tapered roller bearings which are arranged in pairs and matched up and down are positioned in a gap between the third mounting hole and the first connecting shaft 6, the inner surfaces of the two tapered roller bearings are tightly matched with the first connecting shaft 6, and the outer surfaces of the two tapered roller bearings are tightly matched with the inner surface of the third mounting hole;

the second retainer is positioned in a gap between the third mounting hole and the first connecting shaft 6 and above the two tapered roller bearings;

and the second cover plate is fixed on the upper end surface of the first connecting shaft 6 through bolts, and the outer diameter of the second cover plate is larger than the inner diameter of the second mounting hole.

By improving the transmission mechanism of the gearbox, a space is reserved in the box body 2 to accommodate the driving motor 41, and the driving motor 41 is not required to be arranged on the bracket 1, so that the forklift can realize electric steering by arranging a steering motor and a steering gear, and can also realize manual steering by arranging a tiller on the box body 2;

the device is characterized by further comprising a steering gear, an intermediate gear and a rotating motor, wherein the rotating motor is mounted on the support 1, the steering gear is fixedly connected with the box body 2, the intermediate gear is driven to rotate by the rotating motor, and the intermediate gear is meshed with the steering gear; and then the forklift is driven to steer by rotating the motor.

It is worth to be noted that the rotary motor is directly replaced by a handle rudder, and further the intermediate gear is driven to rotate manually, so that manual steering can be realized; the existing gearbox can be switched between manual steering and electric steering in the mode, but only one of the manual steering and the electric steering can be selected, and in the embodiment of the application, a handle rudder can be directly installed on the box body 2 to achieve steering, so that a steering gear, an intermediate gear and a rotating motor are not needed, and the structure is simple.

It is worth to be noted that, under the condition that the steering gear, the intermediate gear and the rotating motor are installed, the steering can be realized by directly installing a handle rudder on the box body 2, namely, the electric steering device and the manual steering device are installed at the same time; further preferably, when the electric power steering and the manual steering are installed simultaneously, a switching device is provided to ensure that the electric power steering and the manual steering cannot be performed simultaneously.

In the embodiment of the present application, as shown in fig. 7, the driving shaft 42 is a stepped shaft, the driving shaft 42 includes a first shaft body 421, a second shaft body 422, and a third shaft body 423, the outer diameters of which become smaller in sequence along a direction away from the driving motor 41, the first shaft body 421 is in transmission fit with the driving motor 41, the third shaft body 423 is in transmission fit with the pinion 45 through a flat key, a first mounting hole is further provided on an outer end surface of the third shaft body 423, and the driving shaft 42 is rotatably mounted inside the housing 5 through the first mounting hole.

Further preferably, the first mounting seat 24, the first deep groove ball bearing, the first O-ring 94, the third retainer ring 96 and the first oil seal 95 are further arranged, the first deep groove ball shaft, the third retainer ring 96 and the first oil seal 95 are sequentially sleeved on the second shaft 422 along the direction away from the driving motor 41 and are tightly matched with the outer surface of the second shaft 422 and the inner surface of the first mounting seat 24, the first mounting seat 24 is clamped inside the box body 2 through the first deep groove ball bearing and the first shaft body 421, and the first O-ring 94 is arranged between the first mounting seat 24 and the box body 2. With the arrangement, the friction distance between the first O-shaped ring 94 and the box body 2 in the installation process can be reduced, and the sealing performance of the first O-shaped ring 94 is ensured.

In the embodiment of the present application, as shown in fig. 8, the driven shaft 43 is a stepped shaft, and sequentially includes a fourth shaft body 431, a fifth shaft body 432 and a sixth shaft body 433 in a direction away from the driving motor 41, the outer diameter of the fifth shaft body 432 is larger than that of the fourth shaft body 431 and the sixth shaft body 433, the fifth shaft body 432 is a gear portion and is engaged with the output gear 47, and the sixth shaft body 433 is provided with the large gear 46 through a flat key; further preferably, a second deep groove ball bearing and a third deep groove ball bearing are arranged at two ends of the driven shaft 43 in a sleeved mode respectively, the inner surface of the second deep groove ball bearing is in tight fit with the fourth shaft body 431, the outer surface of the second deep groove ball bearing is in tight fit with the box body 2, the inner surface of the third deep groove ball bearing is in tight fit with the sixth shaft body 433, and the outer surface of the third deep groove ball bearing is in tight fit with the shell 5.

In the present embodiment, the wheel 3 includes a tire 31 and a hub 32, which are fixedly connected, and the hub 32 is fixedly connected with an output shaft 44.

In the embodiment of the present application, as shown in fig. 5, 9 and 11, a second mounting seat 25 and a second oil seal 99 located between the second mounting seat 25 and the output shaft 44 are further provided, the second mounting seat 25 is fixedly connected to or integrally formed with the casing 2, the second mounting seat 25 is provided with a stepped hole, the output shaft 44 is mounted in the stepped hole, the stepped hole at least includes a first inner surface 251, the output shaft 44 is a stepped shaft and at least includes a seventh shaft body 441, the second oil seal 99 has an inner surface tightly fitted with the seventh shaft body 441 and an outer surface tightly fitted with the first inner surface 251, the first inner surface 251 is a cylindrical surface, wherein the output shaft 44 is closer to the hub 32 than the seventh shaft body 441 and has an outer diameter not greater than the seventh shaft body 441; the inner surface of the hub 32, which is closer than the first inner surface 251 in the stepped hole, has a diameter not smaller than the first inner surface 251. So configured, when the second oil seal 99 is damaged and needs to be replaced, the oil seal can be removed by simply removing the hub 32.

In the embodiment of the present application, two tapered roller bearings are further provided between the second mounting seat 25 and the output shaft 44, the output shaft 44 further includes at least an eighth shaft body 442 and a ninth shaft body 443 along a direction away from the hub 32, the ninth shaft body 443 is provided with an external spline, the ninth shaft body 443 is mounted with the output gear 47 through the spline, the eighth shaft body 442 has an external diameter larger than the ninth shaft body 443, an inner surface of one of the tapered roller bearings is tightly fitted with the output gear 47 and an outer surface thereof is tightly fitted with the second mounting seat 25, and an inner surface of the other tapered roller bearing is tightly fitted with the eighth shaft body 442 and an outer surface thereof is tightly fitted with the second mounting seat 25; further preferably, the inner surface of the second mounting seat 25 is provided with a circle of second protruding portions, and the second protruding portions are located between the two tapered roller bearings.

In another embodiment, the seventh shaft body 441 is the shaft body on the output shaft 44 closest to the hub 32.

In the embodiment of the present application, the output shaft 44 further includes at least a tenth shaft body, the tenth shaft body is closer to the hub 32 than the seventh shaft body 441, and the outer diameter of the tenth shaft body is not greater than the outer diameter of the seventh shaft body 441.

In the embodiment of the present application, the first inner surface 251 is the inner surface of the stepped hole closest to the hub 32.

In another embodiment, the stepped bore further includes at least a second inner surface therein, the second inner surface being closer to the hub 32 than the first inner surface 251, the second inner surface having a diameter no smaller than the diameter of the first inner surface 251.

In the embodiment of the present application, as shown in fig. 10, the output gear 47 includes a second gear portion 471 and a second mounting portion 472, the second mounting portion 472 is a shaft body and is provided with a shaft hole, an internal spline is arranged in the shaft hole, the second mounting portion 472 is arranged on the output shaft 44 through a spline sleeve, the second gear portion 471 is engaged with the driven shaft 43, and an inner diameter of the second gear portion 471 is larger than an outer diameter of the second mounting portion 472; further preferably, an inner end cover is further provided, the inner end cover is fixed on the end face of the output shaft 44, which is far away from the end of the hub 32, through bolts, and the outer diameter of the inner end cover is smaller than the inner diameter of the second gear part 471 and larger than the outer diameter of the second mounting part 472; further preferably, the length of the second mounting part 472 differs from the length of the ninth shaft body 443 by no more than 1 mm. This is provided to facilitate mounting of the output shaft 44 and the output gear 47.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made in the above embodiments by those of ordinary skill in the art without departing from the principle and spirit of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. A gearbox comprises a bracket (1), a box body (2) which is rotatably arranged below the bracket (1), wheels (3) which are arranged on the lower half part of the box body (2), a driving device (4) which is used for driving the wheels (3) to rotate, and a shell (5) which is arranged on the side surface of the box body (2); said wheel (3) comprising a hub (32) and a tyre (31) mounted on the hub (32), characterized in that,

the driving device (4) is installed inside the box body (2) and comprises a driving motor (41), a driving shaft (42), a driven shaft (43) and an output shaft (44), the driving motor (41) is used for driving the driving shaft (42) to rotate, a small gear (45) is connected to the driving shaft (42) through a key, a large gear (46) is connected to the driven shaft (43) through a key, an output gear (47) is connected to the output shaft (44) through a key, the output shaft (44) is fixedly connected with the hub (32), the small gear (45) is in transmission fit with the large gear (46), and the output gear (47) is in transmission fit with the driven shaft (43);

the driving shaft (42), the driven shaft (43) and the output shaft (44) are transversely arranged, the driving shaft (42) is located above the driven shaft (43), the output shaft (44) is located below the driven shaft (43), and the axial lines of the driving shaft (42), the driven shaft (43) and the output shaft (44) are located on the same vertical plane.

2. A gearbox according to claim 1, characterised in that there is further provided:

a first connecting shaft (6); the upper end of the first connecting shaft (6) is fixedly connected with the bracket (1), and the box body (2) is rotatably arranged on the first connecting shaft (6);

a second mounting hole is positioned at the top end of the box body (2), the first connecting shaft (6) is mounted in the second mounting hole,

the first cover plate (91) is fixedly connected with the lower end face of the first connecting shaft (6) or integrally formed, and the outer diameter of the first cover plate (91) is larger than that of the first connecting shaft (6);

the two tapered roller bearings which are arranged in pairs and matched up and down are positioned in a gap between the second mounting hole and the first connecting shaft (6), the inner surfaces of the two tapered roller bearings are tightly matched with the first connecting shaft (6), and the outer surfaces of the two tapered roller bearings are tightly matched with the inner surface of the second mounting hole;

a first retainer ring (92) located in a gap between the second mounting hole and the first connecting shaft (6) and above the two tapered roller bearings;

the second mounting hole at least comprises a third inner surface (21), a fourth inner surface (22) and a fifth inner surface (23) from top to bottom, the third inner surface (21) and the fifth inner surface (23) are cylindrical surfaces, the fourth inner surface (22) is a horizontal surface and is used for connecting the third inner surface (21) and the fifth inner surface (23), and the inner diameter of the fifth inner surface (23) is larger than that of the third inner surface (21);

the first retainer ring (92) abuts against the fourth inner surface (22), the outer surface of the first retainer ring (92) is in tight fit with the fifth inner surface (23), and the inner diameter of the first retainer ring (92) is smaller than that of the third inner surface (21).

3. A gearbox according to claim 1, characterised in that there is further provided:

a first connecting shaft (6); the lower end of the first connecting shaft (6) is fixedly connected with the box body (2), and the upper end of the first connecting shaft (6) is rotatably arranged on the bracket (1);

the third mounting hole is positioned on the bracket (1), and the first connecting shaft (6) is positioned in the third mounting hole;

the two tapered roller bearings which are arranged in pairs and matched up and down are positioned in a gap between the third mounting hole and the first connecting shaft (6), the inner surfaces of the two tapered roller bearings are tightly matched with the first connecting shaft (6), and the outer surfaces of the two tapered roller bearings are tightly matched with the inner surface of the third mounting hole;

the second retainer is positioned in a gap between the third mounting hole and the first connecting shaft (6) and above the two tapered roller bearings;

and the second cover plate is fixed on the upper end surface of the first connecting shaft (6) through a bolt, and the outer diameter of the second cover plate is larger than the inner diameter of the second mounting hole.

4. A gearbox according to claim 1, characterised in that the drive shaft (42) is a stepped shaft, the drive shaft (42) comprises a first shaft body (421), a second shaft body (422) and a third shaft body (423) which are sequentially reduced in outer diameter in the direction away from the drive motor (41), the first shaft body (421) is in transmission fit with the drive motor (41), the third shaft body (423) is in transmission fit with the pinion (45) through a flat key, a first mounting hole is further formed in the outer end surface of the third shaft body (423), and the drive shaft (42) is rotatably mounted inside the housing (5) through the first mounting hole.

5. The gearbox according to claim 1, further comprising a first mounting seat (24), a first deep groove ball bearing, a first O-ring (94), a first retainer ring (92) and a first oil seal (95), wherein the first deep groove ball shaft, the first retainer ring (92) and the first oil seal (95) are sequentially sleeved on the second shaft body (422) along a direction away from the driving motor (41) and are tightly matched with the outer surface of the second shaft body (422) and the inner surface of the first mounting seat (24), the first mounting seat (24) is clamped inside the box body (2) through the first deep groove ball bearing and the first shaft body (421), and the first O-ring (94) is arranged between the first mounting seat (24) and the box body (2).

6. A gearbox according to claim 1, characterised in that the driven shaft (43) is a stepped shaft comprising in sequence, in the direction away from the drive motor (41), a fourth shaft body (431), a fifth shaft body (432) and a sixth shaft body (433), the fifth shaft body (432) having a larger outer diameter than the fourth shaft body (431) and the sixth shaft body (433), the fifth shaft body (432) being a gear wheel part and being in mesh with the output gear (47), the sixth shaft body (433) being fitted with a gearwheel (46) by means of a flat key.

7. The gearbox according to claim 6, further comprising a second deep groove ball bearing and a third deep groove ball bearing respectively sleeved at two ends of the driven shaft (43), wherein the inner surface of the second deep groove ball bearing is tightly matched with the fourth shaft body (431), the outer surface of the second deep groove ball bearing is tightly matched with the box body (2), the inner surface of the third deep groove ball bearing is tightly matched with the sixth shaft body (433), and the outer surface of the third deep groove ball bearing is tightly matched with the housing (5).

8. A gearbox according to claim 1, characterised in that a second mounting seat (25) and a second oil seal (99) between the second mounting seat (25) and the output shaft (44) are provided, the second mounting seat (25) being fixedly connected to or integrally formed with the housing (2), the second mounting seat (25) being provided with a stepped bore in which the output shaft (44) is mounted, the stepped bore comprising at least a first inner surface (251), the output shaft (44) being a stepped shaft and comprising at least a seventh shaft body (441), the second oil seal (99) having an inner surface in close fit with the seventh shaft body (441) and an outer surface in close fit with the first inner surface (251), wherein the output shaft (44) is provided with a shaft body closer to the hub (32) than the seventh shaft body (441) and having an outer diameter not greater than the seventh shaft body (441); the inner surface of the hub (32) is closer to the stepped hole than the first inner surface (251) and has a diameter not smaller than the first inner surface (251).

9. A gearbox according to claim 8 characterised in that there are two tapered roller bearings in a mating relationship between the second mounting seat (25) and the output shaft (44), the output shaft (44) further comprises at least an eighth shaft body (442) and a ninth shaft body (443) in a direction away from the hub (32), the ninth shaft body (443) is provided with external splines, the ninth shaft body (443) is splined to the output gear (47), the eighth shaft body (442) has an external diameter greater than the ninth shaft body (443), one of the tapered roller bearings has an internal surface in close fit with the output gear (47) and an external surface in close fit with the second mounting seat (25), and the other tapered roller bearing has an internal surface in close fit with the eighth shaft body (442) and an external surface in close fit with the second mounting seat (25).

10. A gearbox according to claim 1, characterised in that the output gear (47) comprises a second gear part (471) and a second mounting part (472), the second mounting part (472) being a shaft and being provided with a shaft hole, the shaft hole being provided with internal splines, the second mounting part (472) being provided on the output shaft (44) via a spline housing, the second gear part (471) being in engagement with the driven shaft (43), the second gear part (471) having an internal diameter which is larger than the external diameter of the second mounting part (472);

the inner end cover is fixed on the end face, far away from one end of the hub (32), of the output shaft (44) through bolts, and the outer diameter of the inner end cover is smaller than the inner diameter of the second gear part (471) and larger than the outer diameter of the second mounting part (472).

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