CN221023274U

CN221023274U - Transmission device and vehicle

Info

Publication number: CN221023274U
Application number: CN202322710054.4U
Authority: CN
Inventors: 陈祥; 孙玉章; 韩明坤; 张宗杰; 赵金龙; 杨金亮
Original assignee: China National Heavy Duty Truck Group Jinan Power Co Ltd
Current assignee: China National Heavy Duty Truck Group Jinan Power Co Ltd
Priority date: 2023-10-10
Filing date: 2023-10-10
Publication date: 2024-05-28
Anticipated expiration: 2033-10-10

Abstract

The application provides a transmission device and a vehicle, comprising a driving assembly, a speed reducing assembly, a differential mechanism and a power output assembly; the driving assembly comprises a hollow shaft and a motor, the hollow shaft and the motor are coaxially arranged, a rotor of the motor is fixedly connected with the hollow shaft, the speed reducing assembly comprises an input gear and an output gear, the input gear is in transmission connection with the output gear, the input gear is fixed on the hollow shaft and coaxially rotates with the hollow shaft, and the output gear is connected with the input end of the differential mechanism; the power output assembly comprises two output shafts, the output shafts are connected with the output end of the differential mechanism, the output shafts and the hollow shafts are coaxially arranged, and each output shaft is configured to be connected with a corresponding travelling wheel and drive the travelling wheel to rotate. The application provides a transmission device and a vehicle, which have better gravity center state and smaller unsprung mass and can improve the strength and the control performance of an electric drive axle.

Description

Transmission device and vehicle

Technical Field

The application relates to the field of new energy automobiles, in particular to a transmission device and a vehicle.

Background

The pure electric light truck is used as a main urban vehicle, the demand of the pure electric light truck is increased year by year, the driving axle is used as a core component of the pure electric light truck, the endurance, the bearing capacity and the driving operability of the pure electric light truck are all indistinguishable from those of the pure electric light truck, and the quality of the pure electric light truck influences the service life of the automobile and the personal safety of a driver.

Currently, electric drive axles are divided into motor-reducer vertical, motor-reducer parallel and coaxial. The parallel electric drive axle adopts a mode that the motor main shaft and the transmission half shaft are arranged in parallel, the speed regulation can be directly carried out through the motor, the efficiency is higher, the development and manufacturing cost is lower, and the electric drive axle has higher integration level, and the automobile body has enough space for placing a battery pack, so that the electric drive axle has been widely applied to the field of new energy automobiles.

However, the parallel electric drive axle has a relatively large unsprung weight, the center of gravity of the rim is biased outwards, and the vehicle can shake during instantaneous acceleration, so that the strength of the whole axle is relatively low, and the steering performance is poor.

Disclosure of utility model

The application provides a transmission device and a vehicle, which have better gravity center state and smaller unsprung mass and can improve the strength and the control performance of an electric drive axle.

In a first aspect, the present application provides a transmission comprising a drive assembly, a reduction assembly, a differential, and a power take off assembly; the driving assembly comprises a hollow shaft and a motor, the hollow shaft and the motor are coaxially arranged, a rotor of the motor is fixedly connected with the hollow shaft, the speed reducing assembly comprises an input gear and an output gear, the input gear is in transmission connection with the output gear, the input gear is fixed on the hollow shaft and coaxially rotates with the hollow shaft, and the output gear is connected with the input end of the differential mechanism; the power output assembly comprises two output shafts, the output shafts are connected with the output end of the differential mechanism, the output shafts and the hollow shafts are coaxially arranged, and each output shaft is configured to be connected with a corresponding travelling wheel and drive the travelling wheel to rotate.

As with the transmission described above, optionally, the rotor of the motor is connected to the outside of the hollow shaft by an interference fit or a transition fit.

The above-mentioned transmission device, optionally, the speed reducing assembly further comprises a transmission gear, the transmission gear is meshed with the input gear, and the output gear and the transmission gear are coaxially connected and synchronously rotate.

As in the transmission described above, optionally, the axes of rotation of the drive gear and the output gear are parallel to the hollow shaft.

As with the transmission described above, the number of teeth in the transmission gear is optionally greater than the number of teeth in the input gear.

The transmission device as described above, optionally, the differential comprises a planet gear carrier, a sun gear and a planet gear, the planet gear being meshed between the sun gear and the output shaft.

As mentioned above, optionally, the two output shafts include a first output shaft and a second output shaft, and the travelling wheels respectively connected with the first output shaft and the second output shaft form a travelling wheel pair.

As with the transmission described above, optionally, the output shaft and the hollow shaft are located on opposite sides of the differential respectively, a first end of the output shaft is connected to the differential, and a second end of the output shaft passes through the hollow shaft and is connected to the corresponding road wheel.

The transmission device is characterized in that the input gear, the output gear and the sun gear are cylindrical gears;

the planetary gears are all conical gears.

In a second aspect, the application provides a vehicle comprising a transmission as described above.

The construction of a transmission and a vehicle of the present utility model, as well as other objects and advantages thereof, will be more apparent from the description of the preferred embodiments taken in conjunction with the accompanying drawings.

Drawings

Fig. 1 is a schematic structural diagram of a transmission device according to an embodiment of the present application.

Reference numerals illustrate:

101-left travelling wheels;

102-right walking wheels;

200-a drive assembly;

201-a motor;

202-a hollow shaft;

300-a deceleration assembly;

301-input gear;

302-a transmission gear;

303-an output gear;

304-a first support bearing;

305-an intermediate shaft;

306-a second support bearing;

400-differential;

401-sun gear;

402-a planet carrier;

403-first planetary gears;

404-a second planetary gear;

405-third planetary gear;

406-fourth planetary gear;

500-a power take-off assembly;

501-a first output shaft;

502-a left wheel end first bearing;

503-a left wheel end second bearing;

504-right wheel end first bearing;

505-a second output shaft;

506-right wheel end second bearing.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

However, the parallel electric drive axle has larger unsprung weight, the center of gravity of the wheel rim is biased outwards, the center of gravity of the wheel rim is not good in balance state, shake can occur during instantaneous acceleration, the strength of the whole axle is lower, and meanwhile, the larger unsprung weight can cause larger inertia and is unfavorable for control.

The application provides a transmission device and a vehicle, wherein a main shaft of a motor and an output shaft of a travelling wheel are coaxially arranged by adopting the design of a coaxial electric drive bridge of single reduction transmission, and the motor is distributed on one side of the travelling wheel so as to adjust the gravity center position of the motor to be on the shaft; the internal structure of the electric drive axle is simplified, components such as a gear shifting mechanism and the like are omitted, and stepless speed change is realized through a single motor; in addition, the transmission mechanism and the power output mechanism are arranged in parallel, so that the transmission torque is shortened, and the internal space is enlarged. Compared with the traditional parallel electric drive bridge, the electric drive bridge has better gravity center state and smaller unsprung mass, and can improve the strength and the control performance of the electric drive bridge.

A transmission device and a vehicle according to this embodiment are further described below.

Fig. 1 is a schematic view of a transmission device according to an embodiment of the present application.

As shown in fig. 1, an embodiment of the present application provides a transmission device and a vehicle. As can be seen in fig. 1, the transmission includes a drive assembly 200, a reduction assembly 300, a differential 400, and a power take-off assembly 500; the driving assembly 200 comprises a hollow shaft 202 and a motor 201, the hollow shaft 202 and the motor 201 are coaxially arranged, a rotor of the motor 201 is fixedly connected with the hollow shaft 202, the speed reduction assembly 300 comprises an input gear 301 and an output gear 303, the input gear 301 is in transmission connection with the output gear 303, the input gear 301 is fixed on the hollow shaft 202 and coaxially rotates with the hollow shaft 202, and the output gear 303 is connected with an input end of the differential 400; the power take-off assembly 500 includes two output shafts, each coupled to an output of the differential 400, and coaxially disposed with the hollow shaft 202, each configured to couple to a corresponding road wheel and rotate the road wheel.

So that the main shaft of the motor 201 and the output shaft of the travelling wheel are coaxially arranged, and the gravity center position of the main shaft is adjusted to be on the shaft; in addition, the internal structure of the electric drive axle is simplified, components such as a gear shifting mechanism and the like are omitted, and stepless speed change is realized through a single motor; in addition, the transmission mechanism and the power output mechanism are arranged in parallel, so that the transmission torque is shortened, and the internal space is enlarged. Compared with the traditional parallel electric drive bridge, the electric drive bridge has better gravity center state and smaller unsprung mass, and can improve the strength and the control performance of the electric drive bridge.

Specifically, the drive assembly 200 may include a hollow shaft 202 and a motor 201, wherein the motor rotor may be a permanent magnet or a squirrel cage type, and different types of rotors are selected according to power requirements, and the motor rotor provides power for the entire transmission system. Wherein, the motor 201 is distributed on one side of the speed reducing assembly 300, and the number is 1.

In some embodiments, the reduction assembly 300 includes an input gear 301 and an output gear 303, wherein the input gear 301 may be disposed outside the hollow shaft 202 or integrally connected to the inside of the reduction assembly 300.

The number of the input gears 301 and the output gears 303 is 1, and the input gears 301 and the output gears 303 are respectively connected to the hollow shaft 202 and the intermediate shaft 305 through a spline manner.

In some embodiments, the rotor of the motor 201 and the hollow shaft 202 are connected to the outer side of the hollow shaft 202 by an interference fit or a transition fit, which is configured to drive the hollow shaft 202 to rotate synchronously while the rotor of the motor 201 rotates.

In some embodiments, the reduction assembly 300 further includes a transfer gear 302, the transfer gear 302 and the input gear 301 intermesh, and the output gear 303 and the transfer gear 302 are coaxially coupled and synchronously rotate.

Wherein the output gear 303 and the transfer gear 302 are connected to the intermediate shaft 305 by a first support bearing 304 and a second support bearing 306. The support bearing is connected to the intermediate shaft 305 by means of a transition or interference fit, which acts to maintain a certain rotational accuracy of the output gear 303 and the transfer gear 302, reducing friction and wear caused by rotation.

Specifically, the rotation of the transmission gear 302 will drive the intermediate shaft 305 to rotate synchronously, and the intermediate shaft 305 transmits torque to the output gear 303, so as to drive the output gear 303 to rotate, wherein the diameter of the output gear 303 is smaller than that of the transmission gear 302.

In some embodiments, the rotation axes of the transmission gear 302 and the output gear 303 are parallel to the hollow shaft 202, so that the transmission mechanism is arranged transversely, and compared with the transmission shaft of the conventional longitudinal electric drive axle, the transmission device of the embodiment can shorten the longitudinal distance and expand a larger space longitudinally. Meanwhile, the transmission chain can be effectively shortened by adopting the arrangement mode, and the transmission efficiency is obviously improved.

In some embodiments, the number of teeth of the transfer gear 302 is greater than the input gear 301. This is because the rotational speed of the rotor of the motor 201 is much greater than that required when the vehicle is traveling normally, and therefore, the rotational speed of the motor cannot be directly used for power supply to the vehicle, and the rotational speed of the motor needs to be redistributed.

According to the principle of deceleration, the reduction ratio=the number of driven gears/the number of driving gears, and the purpose of deceleration is achieved by utilizing gear transmission so as to meet the working requirement.

In some embodiments, differential 400 includes a planet carrier 402, a sun gear 401, and first through fourth planet gears 403-406, with first through fourth planet gears 403-406 meshed between sun gear 401 and an output shaft.

Specifically, the planet gear carrier 402 is mounted on the sun gear 401, and the sun gear 401 and the planet gear carrier 402 may be designed as a whole, or may be connected through a spline, and the sun gear 401 rotates to drive the planet gear carrier 402 to rotate synchronously, where the sun gear 401 is mounted on the hollow shaft 202.

In some embodiments, the number of the planetary gears is 4, the first planetary gear 403 to the fourth planetary gear 406 are wrapped in a shell, wherein the first planetary gear 403 and the third planetary gear 405 are oppositely arranged, the second planetary gear 404 and the fourth planetary gear 406 are oppositely arranged and perpendicular to the first planetary gear 403 and the third planetary gear 405, the movement between the planetary gears is mutually restricted, each planetary gear is correspondingly connected on the shell through a bolt, and 1 hole is reserved on the left side and the right side of the outer part of the shell. The first output shaft 501 and the second output shaft 505 are solid shafts, and the first output shaft 501 and the second output shaft 505 are inserted into the housing of the differential 400.

Specifically, the housing is externally connected to the planetary gear carrier 402, wherein the first planetary gear 403 and the third planetary gear 405 are internally provided with splines respectively connected to the first output shaft 501 and the second output shaft 505.

When the vehicle is traveling straight, the resistance to the left traveling wheel 101 and the right traveling wheel 102 is the same, the first output shaft 501 and the second output shaft 505 are rigidly connected, the rotation of the sun gear 401 transmits torque to the carrier 402, the carrier 402 is driven to rotate, and the first to fourth planetary gears 403 to 406 revolve around the sun gear 401, and at this time, the first to fourth planetary gears 403 to 406 do not rotate, and the rotation speeds of the left traveling wheel 101 and the right traveling wheel 102 are the same.

When the vehicle turns, the resistances to the left traveling wheel 101 and the right traveling wheel 102 are different, and the first planetary gear 403 to the fourth planetary gear 406 revolve while rotating, so that the planetary gears rotate around the planetary gear shaft, which causes an increase in the rotational speed of the output shaft gear on one side and a decrease in the rotational speed of the output shaft gear on the other side, and the traveling wheels on both sides rotate at different rotational speeds. At this time, the speeds of the left traveling wheel 101 and the right traveling wheel 102 are made different, thereby ensuring that the vehicle turns smoothly.

The first planetary gear 403 is connected to the first output shaft 501, and transmits power to the left traveling wheel 101. The third planetary gear 405 is connected to the second output shaft 505, and the third planetary gear 405 rotates to drive the second output shaft 505 to rotate, so as to transmit power to the right travelling wheel 102.

The upper and lower ends of the carrier 402 and the interiors of the first to fourth planetary gears 403 to 406 may be provided with 1 inner hole, respectively.

In some embodiments, the differential 400 may be internally provided with 1 mounting shaft longitudinally through the apertures of the second and fourth planet gears 404, 406, connected to the planet gear carrier 402.

It should be noted that, two bearings, which are tapered roller bearings, are disposed inside the differential 400 and located on the left and right sides of the differential housing (not shown in the drawings), and serve to bear and transmit the driving forces of the differential and the reducer, reduce the transmission friction resistance, and improve the transmission efficiency and reliability. The inner diameter of the bearing is in interference fit with the journal of the differential case.

In some embodiments, the mounting of the input gear 301 coaxially with the sun gear 401 comprises a first output shaft 501 and a second output shaft 505, wherein, as an alternative embodiment, the first output shaft 501 is connected to the left road wheel 101 and the second output shaft 505 is connected to the right road wheel 102. The road wheels to which the first output shaft 501 and the second output shaft 505 are respectively connected constitute a road wheel pair. Wherein, output shaft passes through spline connection with the walking wheel.

In some embodiments, the input gear 301, the output gear 303 and the sun gear 401 are all cylindrical gears, which has advantages of stable transmission ratio, high efficiency and the like, and the first planetary gear 403 to the fourth planetary gear 406 are conical gears, wherein the first planetary gear 403 and the fourth planetary gear 406 are meshed with each other and can rotate independently of the housing of the differential 400. In particular, the type of drive gear 302 is also a spur gear.

Wherein, both ends of the output shaft are respectively provided with two bearings for supporting the rotation of the output shaft. The first output shaft 501 is provided with a left wheel end first bearing 502 and a left wheel end second bearing 503 at two ends respectively, and the second output shaft 505 is provided with a right wheel end first bearing 504 and a right wheel end second bearing 506 at two ends respectively, wherein the bearings are tapered roller bearings.

In some embodiments, the first output shaft 501, the second output shaft 505, and the hollow shaft 202 are located on opposite sides of the differential, respectively, with a first end of the output shaft connected to the differential and a second end of the output shaft passing through the hollow shaft 202 and connected to corresponding road wheels.

In some embodiments, sun gear 401 meshes with output gear 303, and output gear 303 transmits power to sun gear 401.

Specifically, the diameter of the sun gear 401 is larger than that of the output gear 303, and the number of teeth of the sun gear 401 and the output gear 303 can be adjusted according to the rotational speed and torque requirements of the wheel end of the travelling wheel.

In some embodiments, the middle of the left traveling wheel 101 and the right traveling wheel 102 forms a housing cavity, the driving assembly 200, the decelerating assembly 300 and the differential 400 are distributed inside the housing cavity, and the outside of the housing cavity is surrounded by iron sheets.

In some embodiments, the transmission device can be applied to the fields of light pick-up cards, light commercial vehicles and the like, stepless speed change can be realized through motor control, the highest speed of a vehicle adopting the transmission device can reach 160-170km/h, the speed is higher than that of pure electric vehicles of other transmission devices, the running of the vehicle under different working conditions can be met, the transmission device is not only limited to short-distance transportation in cities, but also the transportation range of the vehicle can be enlarged.

In some embodiments, the transmission is further provided with a locking mechanism (not shown) that can weaken or make the differential 400 lose its differential action when the traction of the road wheels of the automobile is lost, so that the road wheels on both the left and right sides can obtain the same torque. Preventing the phenomenon that the walking wheel on one side slips and the walking wheel on the other side is fixed in place.

It should be noted that, the transmission device of this embodiment includes the electric drive axle, and the design of highly integrating saves many high strength parts and connecting pieces that link up, and this also saves a lot of weight, has alleviateed the weight of car greatly, and the biggest loading capacity of car can be promoted in the lightweight design, simultaneously, can improve the duration of car.

It should be noted that, the transmission device of this embodiment has a simple structure, the reduction assembly 300 adopts single-stage reduction, the weight of the transmission device is lighter, the frictional resistance between the tire and the ground is smaller, the service life of the transmission device is prolonged, the transportation work can be completed efficiently, and because of the small weight, the transmission device has smaller inertia, is convenient for flexibly controlling the running of the automobile under different working conditions, and has better maneuverability of the automobile.

It should be noted that, the assembly process between the gears of the transmission device of the embodiment is simple, and the used part structures are all common national standard parts, so that the transmission device is easy to detach and replace, convenient for later maintenance, capable of greatly reducing production cost and maintenance cost, saving labor and beneficial to popularization.

The operation of the transmission will be explained below.

First, the motor is started, the rotor of the motor 201 outputs power to drive the hollow shaft 202 to rotate, then the hollow shaft 202 drives the input gear 301 to rotate, the input gear 301 transmits torque to the transmission gear 302, the input gear 301 is meshed with the transmission gear 302, the transmission gear 302 is driven to rotate while the input gear 301 rotates, and the transmission gear 302 transmits torque to the output gear 303. The output gear 303 is meshed with the sun gear 401, the sun gear 401 is driven to rotate while the output gear 303 rotates, the sun gear 401 transmits torque to the planet gear carrier 402, the planet gear carrier 402 is driven to rotate, the first planet gear 403 to the fourth planet gear 406 in the differential 400 revolve along with the planet gear carrier 402 and simultaneously rotate, and power is transmitted to the left travelling wheel 101 and the right travelling wheel 102 through the first output shaft 501 and the second output shaft 505 respectively.

In this embodiment, the device comprises a driving assembly 200, a speed reducing assembly 300, a differential 400 and a power output assembly 500; the driving assembly 200 comprises a hollow shaft 202 and a motor 201, the hollow shaft 202 and the motor 201 are coaxially arranged, a rotor of the motor 201 is fixedly connected with the hollow shaft 202, the speed reduction assembly 300 comprises an input gear 301 and an output gear 303, the input gear 301 is in transmission connection with the output gear 303, the input gear 301 is fixed on the hollow shaft 202 and coaxially rotates with the hollow shaft 202, and the output gear 303 is connected with an input end of the differential 400; the power take-off assembly 500 includes two output shafts, each coupled to an output of the differential 400, and coaxially disposed with the hollow shaft 202, each configured to couple to a corresponding road wheel and rotate the road wheel. The motor and the travelling wheel are coaxially arranged, and the gravity center position of the motor is adjusted to be on the shaft; the internal structure of the electric drive axle is simplified, components such as a gear shifting mechanism and the like are omitted, and stepless speed change is realized through a single motor; and the transmission mechanism and the power output mechanism are arranged in parallel, so that the transmission torque is shortened, and the internal space is enlarged. Compared with the traditional parallel electric drive bridge, the electric drive bridge has better gravity center state and smaller unsprung mass, and can improve the strength and the control performance of the electric drive bridge.

The terms "first," "second," and the like in embodiments of the present application are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate in order to describe embodiments of the application herein. Furthermore, the terms "comprise" and "have," as well as any variations thereof, are intended to cover a non-exclusive inclusion.

In the embodiments of the present application, the terms "upper", "lower", "inner", "middle", "outer", "front", "rear", and the like indicate the azimuth or the positional relationship based on the azimuth or the positional relationship shown in the drawings. These terms are only used to better describe the present application and its embodiments and are not intended to limit the scope of the indicated devices, elements or components to the particular orientations or to configure and operate in the particular orientations. Also, some of the terms described above may be used to indicate other meanings in addition to orientation or positional relationships, for example, the term "upper" may also be used to indicate some sort of attachment or connection in some cases. The specific meaning of these terms in embodiments of the present application will be understood by those of ordinary skill in the art in view of the specific circumstances.

In addition, the terms "disposed," "connected," "secured" and "affixed" are to be construed broadly. For example, "connected" may be in a fixed connection, a removable connection, or a unitary construction; may be a mechanical connection, or an electrical connection; may be directly connected, or indirectly connected through intervening media, or may be in internal communication between two devices, elements, or components. The specific meaning of the above terms in the embodiments of the present disclosure may be understood by those of ordinary skill in the art according to specific circumstances.

It should be noted that references in the specification to "one embodiment," "an example embodiment," "some embodiments," etc., indicate that the embodiment may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

Generally, terms should be understood at least in part by use in the context. For example, the term "one or more" as used herein may be used to describe any feature, structure, or characteristic in a singular sense, or may be used to describe a combination of features, structures, or characteristics in a plural sense, at least in part depending on the context. Similarly, terms such as "a" and "an" may also be understood to convey a singular usage or a plural usage, depending at least in part on the context.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present application, and not for limiting the same; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the application.

Claims

1. The transmission device is characterized by comprising a driving assembly, a speed reducing assembly, a differential mechanism and a power output assembly;

The driving assembly comprises a hollow shaft and a motor, wherein the hollow shaft and the motor are coaxially arranged, a rotor of the motor is fixedly connected with the hollow shaft, the speed reduction assembly comprises an input gear and an output gear, the input gear is in transmission connection with the output gear, the input gear is fixed on the hollow shaft and coaxially rotates with the hollow shaft, and the output gear is connected with an input end of the differential mechanism;

The power output assembly comprises two output shafts, the output shafts are connected with the output end of the differential mechanism, the output shafts and the hollow shafts are coaxially arranged, and each output shaft is configured to be connected with a corresponding travelling wheel and drive the travelling wheel to rotate.

2. The transmission of claim 1, wherein the rotor of the motor is connected to the outside of the hollow shaft by an interference fit or a transition fit.

3. The transmission of claim 1, wherein the reduction assembly further comprises a drive gear, the drive gear and the input gear intermesh, and the output gear and the drive gear are coaxially coupled and synchronously rotate.

4. A transmission according to claim 3, wherein the axes of rotation of the drive gear and the output gear are parallel to the hollow shaft.

5. A transmission according to claim 3, wherein the number of teeth of the transmission gear is greater than the input gear.

6. The transmission of claim 1, wherein the differential comprises a planet carrier, a sun gear, and a planet gear, the planet gear meshing between the sun gear and the output shaft.

7. A transmission according to any one of claims 1 to 6, wherein both said output shafts include a first output shaft and a second output shaft, said road wheels to which said first output shaft and said second output shaft are respectively connected forming a road wheel pair.

8. The transmission defined in any one of claims 1 to 6, wherein the output shaft and the hollow shaft are located on opposite sides of the differential, respectively, a first end of the output shaft being connected to the differential, and a second end of the output shaft passing through the hollow shaft and being connected to the corresponding road wheel.

9. The transmission of claim 6, wherein the input gear, the output gear, and the sun gear are all spur gears;

The planetary gear is a conical gear.

10. A vehicle comprising a transmission according to any one of claims 1-6.