CN108859706A - A kind of electricity drives axle assembly and vehicle - Google Patents

Abstract

The invention relates to an electric drive axle assembly and a vehicle, wherein the electric drive axle assembly includes a motor, a casing, a planetary gear reduction mechanism, a hypoid gear and a differential arranged in the casing, and the casing is fixed to the motor ; The driving shaft of the motor, the planetary gear reduction mechanism and the driving gear shaft of the hypoid gear are coaxially transmitted, and the passive gear of the hypoid gear is connected to the half shaft gear of the differential; the output half shaft of the differential is extended Out of the housing and perpendicular to the drive gear shaft. The electric drive axle assembly can improve the stability of gear transmission and the operability of installation, and at the same time can also improve the adaptability of the casing to the speed ratio of different gears and reduce the cost.

Description

An electric drive axle assembly and vehicle

technical field

The invention relates to the technical field of vehicles, in particular to an electric drive axle assembly and a vehicle.

Background technique

The input shaft and output shaft of the traditional electric drive axle are all parallel, and all of them use cylindrical helical gears. This parallel-axle drive axle poses a challenge to the conventional rear axle. The coincidence degree of cylindrical main teeth is small, and the size required to transmit high torque is large. The number of gear teeth is less than 17, which is prone to undercutting. Therefore, the number of teeth is rarely less than 17. At the same time, the transmission stability is poor and the noise is large.

In addition, there are currently two types of structures commonly used in pure electric vehicles, the parallel offset electric drive axle structure or the coaxial electric drive axle structure. Among them, the input shaft of the parallel offset axis electric drive axle is parallel to the output shaft, and the There is a distance, the motor is decelerated by two-stage cylindrical helical gears, and the torque is transmitted through the side gears in the differential, but the shell of this structure is basically divided into two parts, and the two parts need to be combined during installation. At the same time, at this time, the parallelism guarantee ability of each axis is relatively high, and the operation is more complicated; the motor shaft of the coaxial electric drive axle is coaxial with the output shaft, and the motor is decelerated by two-stage cylindrical helical planetary gears. The half-shaft gear transmits the torque, but this structure takes up a lot of space along the left and right directions of the vehicle, resulting in a shorter length of the constant velocity transmission shaft and higher requirements for the swing angle of the universal joint, especially for those with higher requirements for the swing angle of the universal joint Front-wheel drive electric vehicles may be more difficult to match.

In addition, whether it is a parallel off-axis electric drive axle structure or a coaxial electric drive axle structure, if the speed ratio of the gear needs to be changed, the adaptability of the shell is poor, and the shell needs to be recast, which is costly.

Therefore, how to improve the stability of gear transmission, the operability of installation and the adaptability of the casing to the speed ratio of different gears to reduce the cost is a technical problem to be solved by those skilled in the art.

Contents of the invention

The purpose of the present invention is to provide an electric drive axle assembly and a vehicle, which can improve the stability of gear transmission and the operability of installation, and can also improve the adaptability of the housing to the speed ratio of different gears and reduce the cost.

In order to solve the above technical problems, the present invention provides an electric drive axle assembly, which includes a motor, a housing, a planetary gear reduction mechanism, a hypoid gear and a differential arranged in the housing, the housing and The motor is fixed; the drive shaft of the motor, the planetary gear reduction mechanism and the driving gear shaft of the hypoid gear are coaxially transmitted, and the driven gear of the hypoid gear and the half shaft gear of the differential Transmission connection; the output half shaft of the differential extends out of the housing and is perpendicular to the drive gear shaft.

The hypoid gear is used on the electric drive axle, and the drive shaft of the motor is perpendicular to the output half shaft. Since the tooth line of the hypoid gear is curved, due to the increase of the helix angle, at least two or more teeth are in contact at the same time during the transmission process, overlapping and alternating contact, increasing the overlap coefficient, and also increasing The contact ratio is improved, on the one hand, the impact is reduced, the transmission is more stable, and the noise is reduced; on the other hand, the load is stronger than the pressure (that is, the pressure per unit area) is lower, and the wear is more uniform, which increases the load of the gear accordingly. ability, effectively extending the service life of the hypoid gear; and, in the case of achieving the same transmission ratio, the hypoid gear can have a relatively small number of teeth, that is, the volume is relatively small, and the goal of light weight can be achieved, and at the same time , due to the offset of the axis of the small wheel, the helix angle of the small wheel can be increased to about 50 degrees, resulting in a significant increase in the length of the contact line of the small wheel, which can further enhance the strength and rigidity of the small wheel.

The electric drive axle assembly has only one shell, which is fixed with the motor, and has a good overall integration. It can be assembled by one-time clamping, which is easy to install, has good operability, and is easy to ensure the positional accuracy of each component installation. . Moreover, the space occupied by the electric drive axle assembly along the left and right directions of the vehicle is small, and only the diameter of the motor can reduce the occupied space and facilitate the arrangement. At the same time, the speed ratio of the hypoid gear can be greatly changed under the same installation size, such as 2.5-5.5, the total speed ratio can be easily changed from 7.5 to 16.5, with the change of the speed ratio of the planetary gear reduction mechanism, the total speed ratio The tuning range will be wider, making it ideal for low-speed commercial EVs that require low revs but exceptionally high torque. That is to say, the speed ratio can be greatly changed without changing the size of the casing, and one type of casing can be adapted to change a larger speed ratio, thereby improving the applicability of the casing and reducing costs.

Optionally, it also includes a limit assembly arranged in the housing, the limit assembly includes a roller bearing, the inner ring of the roller bearing is adapted to the drive gear shaft, and the roller bearing The outer ring is fixed with the housing.

Optionally, the number of the roller bearings is two, and the size of the roller bearing facing the side of the driven gear is larger than the size of the roller bearing facing the side of the motor.

Optionally, the roller bearing is a tapered roller bearing, and the limiting assembly further includes a limiting nut and an elastic spacer, and the elastic spacer is arranged between the two tapered roller bearings, the Limiting nuts are arranged on the outside of the tapered roller bearings, and are used to limit the axial positions of the inner rings of the two tapered roller bearings.

Optionally, the planetary gear reduction mechanism includes a sun gear, an inner ring gear, a planet carrier and a planetary gear; the sun gear, the ring gear and the planet carrier are arranged coaxially, and the sun gear and the planet carrier Among the ring gears, one is fixed with the housing, and the other is coaxially transmitted with the drive shaft of the motor; the planetary gear is meshed and connected between the sun gear and the ring gear, so The planetary carrier is connected with the driving gear shaft through transmission, and the planetary carrier can rotate under the drive of the planetary gear.

Optionally, the planet carrier includes a transmission member and a drive claw, the transmission member is connected to the drive gear shaft in transmission, the number of the drive claws is the same as the number of the planetary gears, and each of the drive claws One end is connected with the transmission member, and the other end is connected with the corresponding planetary gear.

Optionally, a fixing ring is provided on the outer side of the housing for fixing with the sub-frame or vehicle body of the vehicle.

In addition, the present invention also provides a vehicle, which includes the electric drive axle assembly as described above.

The technical effect of the vehicle with the above-mentioned electric drive axle assembly is similar to that of the above electric drive axle assembly, so it will not be repeated here to save space.

Description of drawings

Fig. 1 is a schematic structural view of an electric drive axle assembly provided by an embodiment of the present invention;

Figure 2 is an enlarged view of A in Figure 1;

Fig. 3 is a schematic structural view of the planetary gear reduction mechanism in Fig. 1;

FIG. 4 is a side view of FIG. 3 .

In the accompanying drawings 1-4, reference numerals are explained as follows:

1-motor; 2-shell, 21-fixed ring; 3-planetary gear reduction mechanism, 31-sun gear, 32-inner ring gear, 33-planet carrier, 34-planetary gear, 35-planetary gear shaft, 36-bearing ; 4-hypoid gear, 41-driving gear shaft, 42-passive gear; 5-differential, 51-side shaft gear, 52-output half shaft; 6-limiting assembly, 61-tapered roller bearing, 62-limit nut, 63-elastic spacer sleeve.

Detailed ways

In order to enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Please refer to Figures 1-4, Figure 1 is a schematic structural view of the electric drive axle assembly provided by the embodiment of the present invention; Figure 2 is an enlarged view of A in Figure 1; Figure 3 is a schematic structural view of the planetary gear reduction mechanism in Figure 1 ; FIG. 4 is a side view of FIG. 3 .

An embodiment of the present invention provides an electric drive axle assembly and a vehicle. The vehicle includes an electric drive axle assembly, wherein, as shown in FIG. 1 , the electric drive axle assembly includes a motor 1, a housing 2 and a Planetary gear reduction mechanism 3, hypoid gear 4 and differential gear 5 in 2, one end of housing 2 is fixed with motor 1. Specifically, in this embodiment, the drive shaft of the motor 1 is in transmission connection with the planetary gear reduction mechanism 3 and the driving gear shaft 41 of the hypoid gear 4 (specifically, it can be connected by a spline to realize power transmission), and the hypoid gear The driven gear 42 of 4 is in drive connection with the side gear 51 of the differential 5, wherein the planetary gear reduction mechanism 3 forms the first stage of reduction, the hypoid gear 4 forms the second stage of reduction, and the driven gear of the hypoid gear 4 42 transmits the power to the differential 5, and the side gear 51 of the differential 5 transmits the power to the half shaft, which is connected to the wheel through the constant velocity half shaft, so as to realize the power transmission from the motor 1 to the wheel.

In this embodiment, the hypoid gear 4 is used on the electric drive axle, and the drive shaft of the motor 1 is perpendicular to the output half shaft 52 of the differential 5 . The tooth line of the hypoid gear 4 is a curve. Due to the increase of the helix angle, at least two or more teeth are in contact at the same time during the transmission process, overlapping and alternating contact, which increases the overlap coefficient and increases the The contact ratio, on the one hand, reduces the impact, makes the transmission more stable, and reduces the noise; on the other hand, the load is stronger than the pressure (that is, the pressure per unit area) is lower, and the wear is more uniform, which increases the load capacity of the gear accordingly. , effectively prolonging the service life of the hypoid gear 4; and, in the case of achieving the same transmission ratio, the hypoid gear 4 can have a relatively small number of teeth, that is, the volume is relatively small, and the weight reduction goal can be achieved, At the same time, due to the offset of the axis of the small wheel, the helix angle of the small wheel can be increased to about 50 degrees, resulting in a significant increase in the length of the contact line of the small wheel, which can further enhance the strength and rigidity of the small wheel.

The electric drive axle assembly is only provided with a shell 2, which is fixed with the motor 1, has a good overall integration, can be assembled by one-time clamping, is easy to install, has good operability, and is easy to ensure the installation of various components position accuracy. Moreover, the electric drive axle assembly occupies a small space along the left and right directions of the vehicle, and only has the diameter of the motor 1, which can reduce its occupied space and facilitate layout. At the same time, the speed ratio of the hypoid gear 4 can be greatly changed under the same installation size, such as 2.5-5.5, the total speed ratio can be easily changed from 7.5 to 16.5, and the speed ratio of the planetary gear reduction mechanism 3 can be adjusted. The adjustment range of the ratio will be larger, which is very suitable for low-speed commercial electric vehicles that require low speed but particularly large torque. That is to say, the speed ratio can be greatly changed without changing the size of the casing 2 , and a casing 2 can be adapted to change a larger speed ratio, thereby improving the applicability of the casing 2 and reducing costs.

In the above embodiment, as shown in FIG. 2 , it also includes a limit assembly 6 arranged in the housing 2 , the limit assembly 6 includes a roller bearing, and the inner ring of the roller bearing is adapted to the driving gear shaft 41 And sleeved on the outside of the driving gear shaft 41, the outer ring of the roller bearing is fixed with the housing 2. That is to say, the roller bearing is arranged between the inner wall of the housing 2 and the driving gear shaft 41 to support the driving gear shaft 41, and at the same time limit the radial position of the driving gear shaft 41 to avoid deviation during rotation. To ensure the coaxiality and the stability of power transmission.

In the above embodiment, the number of roller bearings is two to further ensure the coaxiality and the stability of power transmission. Since the driven gear 42 needs to be connected with the side gear 51, the side facing the driven gear 42 is stressed. Therefore, in this embodiment, two roller bearings are arranged at intervals and the size of the roller bearing on the side facing the driven gear 42 is larger than the size of the roller bearing on the side facing the motor 1, that is to say, the force The roller bearing on the larger side has a larger size. Correspondingly, the diameter of the side of the driving gear shaft 41 facing the driven gear 42 is also relatively larger, and is compatible with the inner ring of the larger roller bearing, which can ensure the quasi-double Curved surface gear 4 stability of power transmission. Of course, in this embodiment, the number of roller bearings can also be set to three or more, and the size of each roller bearing can also be set to be the same, and two roller bearings are set and face the driven gear 42. The larger size of the roller bearing on one side can simplify the overall structure and reduce the cost while ensuring the stability of power transmission.

The roller bearings in the above embodiments are tapered roller bearings 61. At this time, the limit assembly 6 also includes a limit nut 62 and an elastic spacer 63. The elastic spacer 63 is arranged between the two tapered roller bearings 61. The limit nut 62 is arranged on the outside of the tapered roller bearing 61 (that is, the side away from the other tapered roller bearing 61), and is used to limit the axial position of the inner rings of the two tapered roller bearings 61, so as to prevent the two from moving along Axial movement occurs, affecting the support and restriction of the driving gear shaft 41 .

Specifically, as shown in FIG. 2 , in this embodiment, the outer side of the tapered roller bearing 61 on the side facing the driven gear 42 abuts against the driven gear 42 , and the number of limit nuts 62 is one, which is located on the side facing the motor 1 . On the outside of the tapered roller bearing 61 on one side, the limit nut 62 and the driven gear 42 limit the position of the two tapered roller bearings 61 from both ends respectively, preventing the two tapered roller bearings 61 from moving along the axis of the driving gear shaft 41. At the same time, the elastic spacer 63 between the two tapered roller bearings 61 is in a compressed state and has a tendency to push the inner rings of the two tapered roller bearings 61 outward, which plays a role in predicting the position of the two tapered roller bearings. The function of tightness provides adjustment margin for the limit nut 62, and the elastic spacer 63 combines the limit nut 62 and the driven gear 42 to limit the inner rings of the two tapered roller bearings 63. Of course, in this embodiment, the positions of the two tapered roller bearings 61 can also be limited by setting limit nuts 62 on the outer sides of the two tapered roller bearings 61. At this time, the number of limit nuts 62 There are two, and the solution shown in FIG. 2 can simplify the overall structure, and only operate one limit nut 62, which simplifies the operation process.

In the foregoing embodiment, as shown in Fig. 3 and Fig. 4, the planetary gear reduction mechanism 3 includes a sun gear 31, an inner ring gear 32, a planetary carrier 33 and a planetary gear 34, and the planetary gear 34 is meshed and connected between the sun gear 31 and the inner ring gear 32 between. Wherein, the sun gear 31, the ring gear 32 and the planet carrier 33 are arranged coaxially. As shown in FIG. When the drive shaft of the motor 1 drives the sun gear 31 to rotate, each planetary gear 34 rotates synchronously around the axis of the sun gear 31 while each planetary gear 34 rotates around its axis, and can drive the planetary carrier 33 to rotate, and the planetary carrier 33 and the quasi The hypoid gear 4 is coaxially connected, so that the drive shaft of the motor 1 transmits power to the hypoid gear 4 through the planetary gear reduction mechanism 3 .

Certainly, in this embodiment, the sun gear 31 and the housing 2 may also be relatively fixed, and the inner ring gear 32 is connected to the driving shaft of the motor 1 through transmission, and there is no limitation here. As shown in Figure 4, in the present embodiment, the quantity of planetary gear 34 is three, also can be set to four or more all can be, and setting three planetary gear 34 can satisfy the stable rotation of driving planetary carrier 33 In the case of , the overall structure of the planetary gear reduction mechanism 3 is simplified to achieve the goal of weight reduction. In addition, in this embodiment, the specific structure of the planetary gear reduction mechanism 3 is not limited, as long as it can transmit the power of the drive shaft of the motor 1 to the driving gear shaft 41 of the hypoid gear 4 and form the first stage of deceleration That's it.

In the above-mentioned embodiment, the planet carrier 33 includes a transmission member and a drive claw, the transmission member is in transmission connection with the driving gear shaft 41 (can be realized by a spline connection), the number of the drive claw is the same as that of the planetary gear 34, and each drive claw One end of it is connected with the transmission member, and the other end is connected with the planetary gear 34 corresponding thereto. Specifically, the transmission part is located in the middle, and it is provided with a drive claw outward, and one end of the drive claw is connected with the planetary wheel 34, and the claw is fixed with the planetary wheel shaft 35, and a bearing 36 is arranged between the planetary wheel shaft 35 and the planetary wheel 34. When each planetary gear 34 rotates synchronously, each driving pawl drives the driving member to rotate, and then drives the driving gear shaft 41 to rotate.

Of course, the planet carrier 33 can also be set as a disc structure, wherein the disc structure is connected with each planetary gear 34 at the same time, and can rotate under the drive of each planetary gear 34, and at the same time, the central part of the disc structure It is transmission connected with the driving gear shaft 41 to transmit the power to the hypoid gear 4 . However, setting the planetary carrier 33 as a structural solution including transmission parts and driving claws can simplify the overall structure of the planetary carrier 33, reduce the overall weight of the electric drive axle assembly, and achieve the goal of light weight.

The electric drive axle assembly in the above embodiment is suitable for both the structure of the disconnected rear axle and the structure of the integral rear axle. When it is suitable for the structure of the disconnected rear axle, there is also a There is a fixing ring 21, through which the sub-frame or vehicle body of the vehicle is fixed, that is, the electric drive axle assembly becomes a sprung mass, which improves the comfort of the occupants.

The above are only preferred embodiments of the present invention, and it should be pointed out that for those of ordinary skill in the art, some improvements and modifications can also be made without departing from the principle of the present invention, and these improvements and modifications should also be considered Be the protection scope of the present invention.

Claims (8)

1. a kind of electricity drives axle assembly, which is characterized in that including motor (1), shell (2) and the row being set in the shell (2) Star wheel reducer structure (3), hypoid gear (4) and differential mechanism (5), the shell (2) and the motor (1) are fixed；

The driving gear of the drive shaft of the motor (1), the planet gear reducing mechanism (3) and the hypoid gear (4) Axis (41) coaxial transmission, the driven gear (42) of the hypoid gear (4) and the axle shaft gear (51) of differential mechanism (5) are driven Connection；

It is outside and vertical with the driving gear shaft (41) that the output axle shaft (52) of the differential mechanism (5) stretches out the shell (2).

2. electricity according to claim 1 drives axle assembly, which is characterized in that further include the limit in the shell (2) Component (6), the limit assembly (6) includes roller bearing, the inner ring of the roller bearing and the driving gear shaft (41) phase Adaptation, the outer ring of the roller bearing and the shell (2) are fixed.

3. electricity according to claim 2 drives axle assembly, which is characterized in that the quantity of the roller bearing is two, and court It is greater than the ruler towards the roller bearing of the motor (1) side to the size of the roller bearing of the side of the driven gear (42) It is very little.

4. electricity according to claim 3 drives axle assembly, which is characterized in that the roller bearing is tapered roller bearing (61), the limit assembly (6) further includes stop nut (62) and collapsible dist collar (63), and the collapsible dist collar (63) is set to two Between the tapered roller bearing (61), the stop nut (62) is set to the outside of the tapered roller bearing (61), is used for Limit the axial position of the inner ring of two tapered roller bearings (61).

5. electricity according to claim 1-3 drives axle assembly, which is characterized in that the planet gear reducing mechanism (3) Including sun gear (31), ring gear (32), planet carrier (33) and planetary gear (34)；

The sun gear (31), the ring gear (32) and the planet carrier (33) coaxial arrangement, and the sun gear (31) and In the ring gear (32), one and the shell (2) are fixed, the drive shaft coaxial transmission of another one and the motor (1)；

Planetary gear (34) engagement is connected between the sun gear (31) and the ring gear (32), the planet carrier (33) It is sequentially connected with the driving gear shaft (41), and the planet carrier (33) can rotate under the drive of the planetary gear (34).

6. electricity according to claim 5 drives axle assembly, which is characterized in that the planet carrier (33) includes driving member and driving Pawl, the driving member and the driving gear shaft (41) are sequentially connected, the quantity of the driving claw and the planetary gear (34) Quantity is identical, and one end of each driving claw is connect with the driving member, the other end and the corresponding planetary gear (34) it connects.

7. electricity according to claim 1-3 drives axle assembly, which is characterized in that the outside of the shell (2) is also set There are fixed ring (21), is fixed for the subframe or vehicle body with vehicle.

8. a kind of vehicle, which is characterized in that drive axle assembly including the described in any item electricity of such as claim 1-7.