Disclosure of Invention
The primary object of the present invention is to provide a double planetary transmission aimed at reducing the overall weight of the transmission.
In order to achieve the purpose, the invention provides a double-planetary-row transmission which comprises a motor, a first planetary row, a second planetary row, a left half shaft and a right half shaft;
the first planet row comprises a first sun gear, a first planet carrier and a first gear ring;
the second planet row comprises a second sun gear, a second planet gear and a second planet carrier, and the second planet gear comprises a first planet gear and a second planet gear which are meshed with each other;
the motor is in transmission connection with the first sun gear;
the first gear ring is in transmission connection with the second sun gear;
the first planet carrier is in transmission connection with the left half shaft;
the second planet carrier is in transmission connection with the right half shaft.
Optionally, the second planet row further includes a second ring gear, the first planet wheel is externally engaged with the second sun wheel, and the second planet wheel is internally engaged with the second ring gear.
Optionally, the first planet gear and the second planet gear are both mounted on the second planet carrier.
Optionally, the second planet row further includes a second planet shaft fixed to the second planet carrier, and the first planet wheel and the second planet wheel are both mounted on the second planet carrier through the second planet shaft.
Optionally, the second ring gear is connected with a stationary portion of the double row transmission.
Optionally, the first planet carrier further comprises a first planet gear, the first sun gear is externally engaged with the first planet gear, the first planet gear is internally engaged with the first ring gear, and the first planet gear is mounted on the first planet carrier.
Optionally, the first planet row further comprises a first planet axle fixed to the first planet carrier, the first planet wheel being mounted to the first planet carrier by the first planet axle.
Optionally, the motor includes a rotor shaft, and the motor is in transmission connection with the first sun gear through the rotor shaft.
Optionally, the rotor shaft is a hollow shaft, and the left half shaft passes through the rotor shaft.
The invention also provides a vehicle comprising the double-planetary-row transmission.
According to one technical scheme, a first planet row and a second planet row which are connected through a first gear ring and a second sun gear are arranged in a double-planet-row speed changer, a motor is connected with the first sun gear to achieve power input, a first planet carrier is connected with a left half shaft, and a second planet carrier is connected with a right half shaft to achieve power output, so that the double-planet-row speed changer can achieve speed changing and differential functions at the same time. So, on the one hand, compare in the derailleur structure that adopts parallel axis plus bevel gear among the prior art, reduced the required part quantity of derailleur to make the whole weight reduction of double planetary row derailleur, make the weight of double planetary row derailleur lighter, improved the power density of double planetary row derailleur, and then be favorable to the lightweight of vehicle. On the other hand, compared with a transmission structure with a parallel shaft and a bevel gear in the prior art, the axial size of the double-planetary-row transmission is reduced, the overall size of the double-planetary-row transmission is reduced, the occupied space of the double-planetary-row transmission is reduced, and the structure of the double-planetary-row transmission is more compact. On the other hand, compared with the arrangement of a single planet wheel, the first planet wheel and the second planet wheel which are meshed with each other are arranged in the second planet row, the speed ratio range of the double-planet-row speed changer can be further expanded, the double-planet-row speed changer can be allowed to be provided with a light-weight motor with high rotating speed and low torque, the overall weight of the double-planet-row speed changer can be further reduced, the requirements of speed changing and differential functions of the double-planet-row speed changer are met, meanwhile, the light weight of the double-planet row is further facilitated, and the light weight of a vehicle is further facilitated.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that all the directional indicators (such as up, down, left, right, front, and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the movement situation, etc. in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indicator is changed accordingly.
In addition, the descriptions related to "first", "second", etc. in the present invention are 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 at least one such feature. In addition, "and/or" in the whole text includes three schemes, taking a and/or B as an example, including a technical scheme, and a technical scheme that a and B meet simultaneously; in addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.
At present, with the development of new energy vehicle industry, electric vehicles have become a development trend. Under the trend of increasing sales of electric vehicles, the development of light weight of the electric vehicles is imperative.
In order to ensure the endurance mileage of an electric vehicle, a large battery is generally provided in the electric vehicle to meet the endurance requirement. As such, there is an increasing demand for weight reduction of other components in the electric vehicle.
At present, the transmission of the electric vehicle adopts a parallel shaft type layout, and meanwhile, the traditional bevel gear differential is used for power output. However, this transmission has a problem of heavy weight.
In view of this, the present invention proposes a double planetary transmission.
Referring to fig. 1, in the embodiment of the present invention, the double planetary transmission includes a motor 10, a first planetary gear 100, a second planetary gear 200, a left half shaft 20, and a right half shaft 30. The first planetary row 100 includes a first sun gear 110, a first carrier 140, and a first ring gear 130; the second planet row 200 comprises a second sun gear 210, a second planet gear 220 and a second planet carrier 240, wherein the second planet gear 220 comprises a first planet gear 221 and a second planet gear 222 which are meshed with each other; the motor 10 is in transmission connection with the first sun gear 110; the first gear ring 130 is in transmission connection with the second sun gear 210; the first planet carrier 140 is in transmission connection with the left half shaft 20; the second planet carrier 240 is in transmission connection with the right half shaft 30.
Specifically, the motor 10 is a power source of a double planetary transmission for inputting power to the double planetary transmission, and the power of the motor 10 is sequentially transmitted to the first planetary row 100 and the second planetary row 200. The first ring gear 130 of the first planetary row 100 is connected with the second sun gear 210 of the second planetary row 200, and in an embodiment, the first ring gear 130 and the second sun gear 210 are respectively connected with two ends of a connecting shaft through splines, so that the first ring gear 130 is in transmission connection with the second sun gear 210, and further, the first planetary row 100 is in transmission connection with the second planetary row 200. More specifically, the power of the motor 10 is transmitted to the first planetary row 100 through the first sun gear 110 and then transmitted to the second sun gear 210 of the second planetary row 200 through the first ring gear 130 of the first planetary row 100, and thus, the power transmission from the first planetary row 100 to the second planetary row 200 is achieved.
The half shafts are used to transmit power between the double planetary transmission and the drive wheels. The left half shaft 20 serves to transmit the power of the motor 10 to left wheels of the vehicle, and the right half shaft 30 serves to transmit the power of the motor 10 to right wheels of the vehicle. That is, the left and right half shafts 20, 30 are the power output shafts of the double planetary transmission. The left half shaft 20 is connected with the first planet carrier 140 of the first planet row 100, the right half shaft 30 is connected with the second planet carrier 240 of the second planet row 200, the power of the motor 10 is transmitted to the left half shaft 20 through the first planet row 100, and the power of the motor 10 is transmitted to the right half shaft 30 through the first planet row 100 and the second planet row 200, so that the driving of the vehicle wheels is realized.
The second planet wheel 220 comprises a first planet wheel 221 and a second planet wheel 222 which are meshed with each other, the first planet wheel 221 and the second planet wheel 222 are meshed with each other, namely the second planet wheel 220 is of a double-planet structure. Thus, compared with the arrangement of a single planet wheel, the speed ratio range of the double-planet-row transmission can be further expanded by arranging the first planet wheel 221 and the second planet wheel 222 which are meshed with each other, so that the double-planet-row transmission can be allowed to be configured with the light-weight motor 10 with high rotating speed and low torque, the overall weight of the double-planet-row transmission is further reduced, the requirements of speed changing and differential functions of the double-planet-row transmission are met, meanwhile, the light weight of the double-planet-row transmission is further facilitated, and the light weight of a vehicle is further facilitated.
Of course, the power source of the double-planetary-row transmission can also be a fuel engine, a methanol engine and the like, namely the double-planetary-row transmission can be applied to different types of vehicles such as fuel vehicles, pure electric vehicles, hybrid vehicles, new energy vehicles and the like.
So, through set up the first planet row 100 and the second planet row 200 that are connected in double planetary row transmission, can realize the function of variable speed, differential simultaneously, on the one hand, compare in the derailleur structure that adopts parallel axis plus bevel gear among the prior art, reduced the required part quantity of derailleur to make double planetary row transmission's whole weight reduce, make double planetary row transmission's weight lighter, improved double planetary row transmission's power density, and then be favorable to the lightweight of vehicle. On the other hand, compared with a transmission structure with a parallel shaft and a bevel gear in the prior art, the axial size of the double-planetary-row transmission is reduced, the overall size of the double-planetary-row transmission is reduced, the occupied space of the double-planetary-row transmission is reduced, and the structure of the double-planetary-row transmission is more compact. On the other hand, compared with a transmission structure adopting parallel shafts and bevel gears in the prior art, the speed change is realized by utilizing double planetary rows, and the speed ratio range is expanded, so that the rotating speed range of the motor 10 is expanded, different design requirements are further met, and the application range of the transmission is expanded.
In one embodiment of the present invention, a first planetary gear train 100 and a second planetary gear train 200 connected to each other via a first ring gear 130 and a second sun gear 210 are disposed in a double planetary gear train, a motor 10 is connected to a first sun gear 110 to implement power input, a first carrier 140 is connected to a left axle shaft 20, and a second carrier 240 is connected to a right axle shaft 30 to implement power output, so that the double planetary gear train simultaneously implements speed change and differential functions. So, on the one hand, compare in the derailleur structure that adopts parallel axis plus bevel gear among the prior art, reduced the required part quantity of derailleur to make the whole weight reduction of double planetary row derailleur, make the weight of double planetary row derailleur lighter, improved the power density of double planetary row derailleur, and then be favorable to the lightweight of vehicle. On the other hand, compared with a transmission structure with a parallel shaft and a bevel gear in the prior art, the axial size of the double-planetary-row transmission is reduced, the overall size of the double-planetary-row transmission is reduced, the occupied space of the double-planetary-row transmission is reduced, and the structure of the double-planetary-row transmission is more compact. On the other hand, compared with the arrangement of a single planet wheel, the arrangement of the first planet wheel 221 and the second planet wheel 222 which are meshed with each other in the second planet row 200 can further expand the speed ratio range of the double-planet-row transmission, and further can allow the double-planet-row transmission to be provided with the light-weight motor 10 with high rotating speed and low torque, so that the overall weight of the double-planet-row transmission is further reduced, the requirements of speed changing and differential functions of the double-planet-row transmission are met, meanwhile, the light weight of the double-planet-row transmission is further facilitated, and the light weight of a vehicle is further facilitated.
Further, the second planetary row 200 further includes a second ring gear 230, the first planetary gear 221 is externally engaged with the second sun gear 210, and the second planetary gear 222 is internally engaged with the second ring gear 230. Specifically, the second planetary gear 220 includes a first planetary gear 221 and a second planetary gear 222 that are meshed with each other, the first planetary gear 221 and the second planetary gear 222 are meshed with each other, the first planetary gear 221 is meshed with the second sun gear 210, and the second planetary gear 222 is meshed with the second ring gear 230. More specifically, the second ring gear 230 is an internal tooth structure, that is, meshing teeth are provided on the inner peripheral wall of the second ring gear 230, and are used for meshing connection with the second planet gears 222.
Further, the first planet gears 221 and the second planet gears 222 are both mounted to the second planet carrier 240. Specifically, the second sun gear 210 is located at the center of the second planet row 200, the second planet gears 220 are meshed with the outer ring of the second sun gear 210, and in the circumferential direction of the second sun gear 210, a plurality of groups of the second planet gears 220 may be provided, where the number of the groups of the second planet gears 220 is not limited. More specifically, the second planetary gear 220 includes a first planetary gear 221 and a second planetary gear 222 that are meshed with each other, the first planetary gear 221 is meshed with an outer ring of the second sun gear 210, and the second planetary gear 222 is meshed with an inner ring of the second ring gear 230, that is, the first planetary gear 221 and the second planetary gear 222 are in a state of constant mesh with the adjacent second sun gear 210 and the adjacent second ring gear 230, so as to realize transmission of power in the second planetary row 200. The first planet gears 221 and the second planet gears 222 are both mounted on a second planet carrier 240, and the second planet carrier 240 provides a fixed and supporting part for the second planet gears 220.
Further, the second planet row 200 further comprises a second planet shaft fixed to the second planet carrier 240, and the first planet wheel 221 and the second planet wheel 222 are both mounted to the second planet carrier 240 through the second planet shaft. Specifically, a second planetary gear shaft is fixed to the second planetary gear carrier 240, and the second planetary gear 220 is mounted on the second planetary gear carrier 240 through the second planetary gear shaft. The second planet gears 220 may be provided with multiple sets in the circumferential direction of the second sun gear 210, and the number of the second planet gear shafts is consistent with that of the second planet gears 220, so that each set of second planet gears 220 is mounted on the second planet carrier 240 through the corresponding second planet gear shaft, thereby realizing the connection between the second planet gears 220 and the second planet carrier 240. More specifically, the second planetary gear 220 includes a first planetary gear 221 and a second planetary gear 222, and correspondingly, the second planetary gear shaft also includes a first planetary gear shaft and a second planetary gear shaft two, so that the first planetary gear 221 is mounted to the second planet carrier 240 through the first planetary gear shaft, and the second planetary gear 222 is mounted to the second planet carrier 240 through the second planetary gear shaft two.
Further, the second ring gear 230 is connected with the stationary portion of the double planetary transmission. Specifically, the second ring gear 230 is connected to a stationary portion of the double planetary transmission, so that the rotation of the second ring gear 230 is restricted, making the second ring gear 230 a stationary member. Meanwhile, the second ring gear 230 is fixed to provide positioning and supporting for the double-row planetary transmission, so that the structural strength of the double-row planetary transmission is improved compared with the problem of insufficient structural strength of the planetary row in the prior art. In one embodiment, the second ring gear 230 is splined to the housing of the double planetary transmission, so that the stability and reliability of the connection between the second ring gear 230 and the housing of the double planetary transmission are ensured. Of course, the second ring gear 230 may be connected to the casing of the double planetary transmission by means of rectangular teeth or the like. Of course, the stationary portion of the double planetary transmission may be a stationary member such as a motor stator or a brake hub.
Further, the first planetary row 100 further includes a first planet gear 120, the first sun gear 110 is externally engaged with the first planet gear 120, the first planet gear 120 is internally engaged with the first ring gear 130, and the first planet gear 120 is mounted on the first carrier 140. Specifically, the first sun gear 110 is located at the center of the first planetary row 100, the first planetary gears 120 are engaged with the outer ring of the first sun gear 110, and the first planetary gears 120 may be provided in multiple groups in the circumferential direction of the first sun gear 110, where the number of the groups of the first planetary gears 120 is not limited. The first planet gear 120 is mounted on a first planet carrier 140, and the first planet carrier 140 provides a fixed support for the first planet gear 120. Meanwhile, the first planet gear 120 is also meshed with the inner ring of the first ring gear 130, that is, the first planet gear 120, the adjacent first sun gear 110 and the adjacent first ring gear 130 are in a constantly meshed state, so that transmission among the first planet gear 120, the adjacent first sun gear 110 and the adjacent first ring gear 130 is realized.
Further, the first planetary row 100 further includes a first planetary wheel shaft fixed to the first carrier 140, and the first planetary wheel 120 is mounted to the first carrier 140 by the first planetary wheel shaft. Specifically, a first planetary gear shaft is fixed to the first carrier 140, and the first planetary gear 120 is mounted on the first carrier 140 via the first planetary gear shaft. The first planetary gears 120 may be provided with a plurality of sets along the circumferential direction of the first sun gear 110, and the number of the first planetary gear shafts is consistent with that of the first planetary gears 120, so that each set of the first planetary gears 120 is mounted on the first planet carrier 140 through the corresponding first planetary gear shaft, thereby realizing connection between the first planetary gears 120 and the first planet carrier 140.
Further, the motor 10 includes a rotor shaft 11, and the motor 10 is drivingly connected to the first sun gear 110 through the rotor shaft 11. Specifically, the motor 10 and the first sun gear 110 are splined through the rotor shaft 11 of the motor 10, and thus, the power of the motor 10 is transmitted to the first sun gear 110 through the rotor shaft 11, and thus to the first planetary row 100, the second planetary row 200, and further to the left half shaft 20 and the right half shaft 30. Of course, the rotor shaft 11 of the motor 10 may also be splined to a high-speed shaft, which is in turn splined to the first sun gear 110, so as to transmit the power of the motor 10 to the first sun gear 110 and then to the first planetary row 100. In addition, the motor 10 may be integrated with the first planetary gear set 100, and the rotor shaft 11 may be spline-connected to a rotor of the motor 10.
Further, the rotor shaft 11 is a hollow shaft, and the left half shaft 20 passes through the rotor shaft 11. Specifically, the rotor shaft 11 of the motor 10 is a hollow shaft, and the left half shaft 20 passes through the middle hollow of the rotor shaft 11 and is freely rotatable with respect to the rotor shaft 11, thereby transmitting power to the left wheel. Therefore, the overall structure of the double-planetary-row transmission is more compact.
In one embodiment, the electric machine 10 is the power source of a double planetary transmission for powering the double planetary transmission. More specifically, the electric machine 10 includes a stator and a rotor that outputs torque to the double planetary transmission via a rotor shaft 11. The torque of the motor 10 is transmitted to the second planetary row 200 through the first planetary row 100, and the first planetary row 100 and the second planetary row 200 rotate under the action of the torque of the motor 10, so as to drive the left half shaft 20 and the right half shaft 30 to rotate, thereby driving the left wheel and the right wheel of the vehicle. In this way, the first planetary row 100 and the second planetary row 200 realize speed reduction and differential speed so as to meet the requirement of the rotating speed at the wheel end of the vehicle.
Thus, the torque transmission path of the left half shaft 20 is: electric machine 10 (positive) -first sun gear 110 (positive) -first planet gear 120 (negative) -first planet carrier 140 (positive) -left half shaft 20 (positive); the torque transfer path for the right half-shaft 30 is: motor 10 (positive) -first sun gear 110 (positive) -first planet gear 120 (negative) -first ring gear 130 (negative) -second sun gear 210 (negative) -second planet gear one 221 (positive) -second planet gear two 222 (negative) -second planet carrier 240 (positive) -right half shaft 30 (positive). It is noted that, when the motor 10 outputs a torque in a positive direction, the torque in the positive direction is transmitted through the first planetary row 100 and the second planetary row 200, so that the left half shaft 20 and the right half shaft 30 obtain a torque in the positive direction.
When the vehicle is running straight, the left and right wheels need to have the same rotational speed and torque. By adjusting the tooth ratio of the first planetary row 100 and the second planetary row 200, the rotation speed of the first planet carrier 140 is made to be the same as the rotation speed of the second ring gear 230, so that the rotation speed and the torque output by the left half shaft 20 and the right half shaft 30 are made to be the same.
When the vehicle left output speed is high, the left wheel speed and torque are higher than the right wheel speed and torque. Specifically, when the vehicle turns right, the rotation speed of the left wheel is higher than that of the right wheel, and after being transmitted through the left and right half shafts 20 and 30, the larger rotation speed is transmitted to the first carrier 140, and the smaller rotation speed is transmitted to the second carrier 240. At this time, the gear ratio of the first planetary gear set 100 and the second planetary gear set 200 is such that the speed value of the first carrier 140 rising is equal to the speed value of the second carrier 240 falling, so that the left half shaft 20 outputs a higher rotation speed and a higher torque, and the right half shaft 30 outputs a lower rotation speed and a lower torque.
When the vehicle right output speed is high, the right wheel speed and torque are higher than the left wheel speed and torque. Specifically, when the vehicle turns left, the rotation speed of the left wheel is lower than that of the right wheel, and after being transmitted through the left and right half shafts 20 and 30, a smaller rotation speed is transmitted to the first carrier 140 and a larger rotation speed is transmitted to the second carrier 240. At this time, the gear ratio of the first planetary row 100 and the second planetary row 200 is such that the speed value of the first carrier 140 descending is equal to the speed value of the second carrier 240 ascending, so that the left half shaft 20 outputs a lower rotation speed and a smaller torque, and the right half shaft 30 outputs a higher rotation speed and a larger torque.
The present invention further provides a vehicle, which includes a double planetary transmission, and the specific structure of the double planetary transmission refers to the above embodiments, and since the vehicle adopts all the technical solutions of all the above embodiments, the vehicle at least has all the beneficial effects brought by the technical solutions of the above embodiments, and details are not repeated herein.
The above description is only an alternative embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.