CN114435122B - Electric vehicle and two-speed coaxial electric vehicle drive axle thereof - Google Patents

Abstract

The invention discloses an electric automobile and a two-gear coaxial electric automobile drive axle thereof, wherein the drive axle comprises: axle housing, motor, planetary gear speed change mechanism, planetary gear differential mechanism, right half axle and left half axle; the left-row speed change planetary gear and the right-row speed change planetary gear are both arranged on the differential planet carrier; a motor shaft of the motor is in transmission fit with the right row of variable speed sun gears; the left differential sun gear is in transmission fit with one end of the left half shaft, and the right differential sun gear is in transmission fit with one end of the right half shaft. In the scheme, motor power is input by a right row of speed change sun gear of a planetary gear speed change mechanism, then output by a differential planet carrier, power distribution is realized through a planetary gear differential mechanism, and finally power is transmitted and output by a half shaft; the design of this scheme can retrench the overall structure of transaxle, also makes the structure of transaxle compacter moreover, and then makes whole envelope space reduce to vehicle chassis's occupation space has been reduced.

Description

Electric vehicle and two-speed coaxial electric vehicle drive axle thereof

Technical Field

The invention relates to the technical field of electric vehicle driving, in particular to an electric vehicle and a two-speed coaxial electric vehicle driving axle thereof.

Background Art

Electric vehicles are vehicles that use an onboard power source as a driving force, use an electric motor to drive the wheels, and comply with various requirements of road traffic and safety regulations. The powertrain of general electric vehicles is realized by directly connecting the drive motor to a single-speed ratio reducer, and the drive motor and reducer are manufactured and assembled separately.

However, since the overall structure of the drive motor and reducer is relatively large, it will take up most of the space in the vehicle chassis; and a single reducer has only one gear, which cannot take into account the speed and torque requirements when climbing and at high speeds.

Summary of the invention

In view of this, an embodiment of the present invention provides a two-speed coaxial electric vehicle drive axle, which can simplify the overall structure of the drive axle and make the structure of the drive axle more compact, thereby reducing the overall envelope space and reducing the space occupied by the vehicle chassis.

The present invention also provides an electric vehicle using the two-speed coaxial electric vehicle drive axle.

To achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

A two-speed coaxial electric vehicle drive axle, comprising: an axle housing, a motor, a planetary gear speed change mechanism, a planetary gear differential mechanism, a right half shaft and a left half shaft;

The planetary gear differential mechanism comprises: a right row differential sun gear, a right row differential planetary gear, a left row differential sun gear, a left row differential planetary gear and a differential planet carrier;

The left differential sun gear is meshed with the left differential planetary gear, the right differential sun gear is meshed with the right differential planetary gear, the left differential planetary gear is meshed with the right differential planetary gear, and the left differential planetary gear and the right differential planetary gear are both mounted on the differential planet carrier;

The planetary gear speed change mechanism comprises: a speed change ring gear, a right speed change sun gear, a right speed change planetary gear, a left speed change planetary gear and a left speed change sun gear;

The left speed change sun gear is meshed with the left speed change planetary gear, the right speed change sun gear is meshed with the right speed change planetary gear, the left speed change planetary gear is meshed with the right speed change planetary gear, the right speed change planetary gear is meshed with the speed change ring gear, the speed change ring gear is fixedly connected to the bridge housing, and the left speed change planetary gear and the right speed change planetary gear are both mounted on the differential planet carrier;

The motor shaft of the motor is matched with the right speed-changing sun gear;

The left differential sun gear is in driving cooperation with one end of the left half shaft, and the right differential sun gear is in driving cooperation with one end of the right half shaft.

Preferably, it also includes: a B2 brake and a B1 brake;

The B2 brake is arranged between the axle housing and the left speed change sun gear, and the B1 brake is arranged between the axle housing and the speed change ring gear.

Preferably, the B2 brake and/or the B1 brake comprises: a wet diaphragm brake.

Preferably, the motor, the planetary gear speed change mechanism, the planetary gear differential mechanism, the right half shaft and the left half shaft are coaxially arranged.

Preferably, it also includes: a wheel hub assembly;

The other end of the right half shaft is in driving cooperation with the wheel hub assembly on the right side; the other end of the left half shaft is in driving cooperation with the wheel hub assembly on the left side.

Preferably, the hub assembly comprises: a hub gear ring, a hub planetary gear, a hub sun gear, a hub planetary carrier and a hub;

The wheel hub sun gear is meshed with the wheel hub planetary gear, the wheel hub planetary gear is meshed with the wheel hub ring gear, and the wheel hub ring gear is fixedly connected to the wheel hub;

The other end of the right half shaft is fixedly connected to the hub sun gear on the right side; the other end of the left half shaft is fixedly connected to the hub sun gear on the left side.

Preferably, the hub planet carrier is fixedly connected to the bridge housing.

Preferably, the hub gear ring is fixedly connected to the wheel hub via a spline; or, the hub gear ring is integrally formed with the wheel hub.

Preferably, the wheel hub assembly on the left side has the same structure as the wheel hub assembly on the right side.

An electric vehicle comprises a drive axle, wherein the drive axle is the two-speed coaxial electric vehicle drive axle as described above.

It can be seen from the above technical scheme that in the two-speed coaxial electric vehicle drive axle provided by the present invention, the motor power is input by the right-row speed change sun gear of the planetary gear transmission mechanism, and then output by the common differential planetary carrier, and then the power distribution is realized through the planetary gear differential mechanism, and finally the power is transmitted and output by the half-shaft; wherein, the planetary gear transmission mechanism and the planetary gear differential mechanism share the differential planetary carrier; the present scheme is designed in this way, which can simplify the overall structure of the drive axle, and also makes the structure of the drive axle more compact, thereby reducing the overall envelope space, thereby reducing the occupied space of the vehicle chassis.

The present invention also provides an electric vehicle, which has corresponding beneficial effects due to the adoption of the above-mentioned two-speed coaxial electric vehicle drive axle. The details can be referred to the above description, which will not be repeated here.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

FIG1 is a schematic diagram of a two-speed coaxial electric vehicle drive axle provided by an embodiment of the present invention;

FIG. 2 is a schematic diagram of gear meshing between a planetary gear speed change mechanism and a planetary gear differential mechanism provided in an embodiment of the present invention.

Among them, 10 is a wheel hub assembly, 11 is a wheel hub gear ring, 12 is a wheel hub planetary gear, 13 is a wheel hub sun gear, 14 is a wheel hub planetary carrier, and 15 is a wheel hub; 20 is a bridge housing; 31 is a motor stator, 32 is a motor stator, and 33 is a motor shaft; 40 is a B2 brake; 50 is a planetary gear speed change mechanism, 51 is a speed change gear ring, 52 is a right row of speed change sun gear, 53 is a right row of speed change planetary gear, 54 is a left row of speed change planetary gear, and 55 is a left row of speed change sun gear; 60 is a B1 brake; 70 is a planetary gear differential mechanism, 71 is a right row of differential sun gear, 72 is a right row of differential planetary gear, 73 is a left row of differential sun gear, 74 is a left row of differential planetary gear, and 75 is a differential planetary carrier; 80 is a right half shaft; 90 is a left half shaft.

DETAILED DESCRIPTION

The present invention discloses a two-speed coaxial electric vehicle drive axle, which can reduce the overall mass of a drive motor and a gearbox, reduce the overall envelope space, optimize the layout space of a vehicle powertrain, and realize two-speed shifting, thereby further reducing energy consumption.

The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

The two-speed coaxial electric vehicle drive axle provided by the embodiment of the present invention, as shown in FIG1 , comprises: an axle housing 20 , a motor, a planetary gear speed change mechanism 50 , a planetary gear differential mechanism 70 , a right half shaft 80 , and a left half shaft 90 ;

The planetary gear differential mechanism 70 includes: a right differential sun gear 71, a right differential planetary gear 72, a left differential sun gear 73, a left differential planetary gear 74 and a differential planet carrier 75;

As shown in FIG. 2 , the left differential sun gear 73 meshes with the left differential planetary gear 74, the right differential sun gear 71 meshes with the right differential planetary gear 72, the left differential planetary gear 74 meshes with the right differential planetary gear 72, and both the left differential planetary gear 74 and the right differential planetary gear 72 are mounted on the differential planet carrier 75;

The planetary gear speed change mechanism 50 includes: a speed change ring gear 51, a right speed change sun gear 52, a right speed change planetary gear 53, a left speed change planetary gear 54 and a left speed change sun gear 55;

As shown in FIG2 , the left speed change sun gear 55 meshes with the left speed change planetary gear 54, the right speed change sun gear 52 meshes with the right speed change planetary gear 53, the left speed change planetary gear 54 meshes with the right speed change planetary gear 53, the right speed change planetary gear 53 meshes with the speed change ring gear 51, the speed change ring gear 51 is fixedly connected to the bridge housing 20, and the left speed change planetary gear 54 and the right speed change planetary gear 53 are both mounted on the differential planet carrier 75;

The motor shaft 33 of the motor is in driving cooperation with the right speed-changing sun gear 52;

The left differential sun gear 73 is in driving cooperation with one end of the left half shaft 90 , and the right differential sun gear 71 is in driving cooperation with one end of the right half shaft 80 .

It can be seen from the above technical scheme that in the two-speed coaxial electric vehicle drive axle provided by the embodiment of the present invention, the motor power is input by the right-row speed change sun gear of the planetary gear transmission mechanism, and then output by the common differential planetary carrier, and then the power distribution is realized through the planetary gear differential mechanism, and finally the power is transmitted and output by the half-shaft; wherein, the planetary gear transmission mechanism and the planetary gear differential mechanism share the differential planetary carrier; the present scheme is designed in this way, which can simplify the overall structure of the drive axle, and also makes the structure of the drive axle more compact, thereby reducing the overall envelope space, thereby reducing the occupied space of the vehicle chassis.

In this solution, in order to realize the two-speed shifting of the drive axle, so as to select the corresponding gear according to the driving condition of the vehicle, so as to take into account the requirements of power and high speed; accordingly, as shown in FIG. 1 , the two-speed coaxial electric vehicle drive axle provided by the embodiment of the present invention also includes: a B2 brake 40 and a B1 brake 60;

The B2 brake 40 is arranged between the bridge housing 20 and the left speed sun gear 55, and is used to realize the connection or disconnection of the left speed sun gear 55 and the bridge housing 20; the B1 brake 60 is arranged between the bridge housing 20 and the speed ring gear 51, and is used to realize the connection or disconnection of the speed ring gear 51 and the bridge housing 20.

Furthermore, the B2 brake 40 and/or the B1 brake 60 include: a wet diaphragm brake. That is, the B2 brake 40 and/or the B1 brake 60 use a wet diaphragm brake, which can achieve power-uninterrupted shifting, thereby greatly improving the comfort and smoothness of the shifting.

In this solution, as shown in Fig. 1, the motor, the planetary gear transmission mechanism 50, the planetary gear differential mechanism 70, the right half shaft 80 and the left half shaft 90 are coaxially arranged. This solution is designed so as to make the overall structure of the drive axle more compact, which is conducive to saving the layout space of the structure and also helps to achieve coaxial power output.

In order to further optimize the above technical solution, as shown in FIG1 , the two-speed coaxial electric vehicle drive axle provided by the embodiment of the present invention further includes: a wheel hub assembly 10;

The other end of the right half shaft 80 is in driving cooperation with the right wheel hub assembly 10; the other end of the left half shaft 90 is in driving cooperation with the left wheel hub assembly 10. Specifically, the motor power is input by the right speed change sun gear 52 of the planetary gear speed change mechanism 50, then output by the common differential planet carrier 75, and then distributed through the planetary gear differential mechanism 70, and finally transmitted to the wheel hub assembly 10 by the half shaft, thereby realizing the power input of the wheel hub assembly 10.

In this solution, as shown in FIG1 , the hub assembly 10 includes: a hub gear ring 11 , a hub planetary gear 12 , a hub sun gear 13 , a hub planetary carrier 14 and a hub 15 ;

The hub sun gear 13 meshes with the hub planetary gear 12, the hub planetary gear 12 meshes with the hub ring gear 11, and the hub ring gear 11 is fixedly connected to the hub 15;

The other end of the right half shaft 80 is fixedly connected to the right wheel hub sun gear 13; the other end of the left half shaft 90 is fixedly connected to the left wheel hub sun gear 13. This scheme is designed in this way, that is, to realize the planetary gear reduction mechanism integrated into the wheel hub 15, so as to achieve the effect of transmitting the motor power to the wheel hub planetary gear reduction mechanism through the half shaft, so as to facilitate the reduction of the wheel hub 15 and increase the torque, that is, to facilitate the reduction design of the wheel hub end. In this way, the wheel hub assembly 10 has the characteristics of compact structure and high power density, which further makes the overall structure of the drive axle smaller, thereby reducing the overall mass, and optimizing the layout space of the vehicle powertrain; at the same time, it can also help to achieve coaxial output.

Furthermore, the hub planet carrier 14 is fixedly connected to the bridge housing 20. Specifically, the hub planet carrier 14 can be fixedly connected to the bridge housing 20 via a spline. This solution is designed in this way to make the structure of the bridge housing 20 more compact and also achieve the effect of optimizing the space layout.

Furthermore, the wheel hub gear ring 11 is fixedly connected to the wheel hub 15 via a spline; this solution is designed in this way and has the characteristics of simple structure and stable transmission; of course, in order to ensure the connection strength between the wheel hub gear ring 11 and the wheel hub 15, and to facilitate improving production efficiency; accordingly, the wheel hub gear ring 11 and the wheel hub 15 are integrally formed.

In this solution, as shown in FIG1 , the structure of the left wheel hub assembly 10 is the same as that of the right wheel hub assembly 10. This solution is designed in this way, which not only reduces the design workload of the wheel hub assembly 10, but also facilitates the mass production of the wheel hub assembly 10, thereby helping to reduce the production cost of the wheel hub assembly 10.

The embodiment of the present invention also provides an electric vehicle, including: a drive axle, wherein the drive axle is the above-mentioned two-speed coaxial electric vehicle drive axle. Since the present solution adopts the above-mentioned two-speed coaxial electric vehicle drive axle, it also has corresponding beneficial effects, which can be specifically referred to the above description and will not be repeated here.

The present invention is further described below in conjunction with specific embodiments:

The technical problems to be solved by the present invention are:

The present invention is based on a planetary gear mechanism and proposes a two-speed coaxial electric vehicle drive axle that can be applied to the field of new energy vehicles, which can reduce the overall mass, optimize the space layout, take into account both power and high speed, and improve energy consumption performance.

The technical solution of the present invention is described in detail:

As shown in FIG1 , the two-speed coaxial electric vehicle drive axle is composed of a wheel hub assembly 10 , a bridge housing 20 , a motor stator 31 , a motor rotor 32 , a motor shaft 33 , a B2 brake 40 , a planetary gear speed change mechanism 50 , a B1 brake 60 , a planetary gear differential mechanism 70 , a right half shaft 80 and a left half shaft 90 .

The hub assembly 10 is composed of a hub gear ring 11, a hub planetary gear 12, a hub sun gear 13, a hub planet carrier 14 and a hub 15. The hub sun gear 13 meshes with the hub planetary gear 12, the hub planetary gear 12 meshes with the hub gear ring 11, the hub gear ring 11 is fixedly connected to the hub 15 via a spline (or the hub gear ring 11 and the hub 15 are integrally formed), and the hub planet carrier 14 is fixedly connected to the bridge housing 20 via a spline. Further, the structures of the hub assemblies 10 on the left and right sides are the same.

In the planetary gear transmission mechanism 50, the left speed change sun gear 55 meshes with the left speed change planetary gear 54, the right speed change sun gear 52 meshes with the right speed change planetary gear 53, the left speed change planetary gear 54 meshes with the right speed change planetary gear 53, the right speed change planetary gear 53 meshes with the speed change ring gear 51, the speed change ring gear 51 is fixedly connected to the bridge housing 20 through a spline, and the left speed change planetary gear 54 and the right speed change planetary gear 53 are installed on the differential planet carrier 75, and share the planet carrier with the planetary gear differential mechanism 70. The B1 brake realizes the connection and disconnection of the speed change ring gear 51 and the bridge housing 20; the B2 brake realizes the connection and disconnection of the left speed change sun gear 55 and the bridge housing 20.

In the planetary gear differential mechanism 70, the left differential sun gear 73 meshes with the left differential planetary gear 74, the right differential sun gear 71 meshes with the right differential planetary gear 72, the left differential planetary gear 74 meshes with the right differential planetary gear 72, and the left differential planetary gear 74 and the right differential planetary gear 72 are mounted on the differential planet carrier 75. The planetary gear speed change mechanism 50 and the planetary gear differential mechanism 70 can realize the common use of sun gears and planetary gears according to the speed ratio requirements.

The motor stator 31 is fixedly connected to the bridge housing 20 by shrink fitting, and the motor shaft 33 is connected to the right speed change sun gear 52 of the planetary gear transmission mechanism 50 by splines. The left differential sun gear 73 and the right differential sun gear 71 of the planetary gear differential mechanism 70 are connected to the hub sun gear 13 of the hub assembly 10 by the left half shaft 90 and the right half shaft 80 respectively.

The motor power is input from the right speed change sun gear 52 of the planetary gear speed change mechanism 50, output from the common differential planet carrier 75, and then distributed through the planetary gear differential mechanism 70, and finally transmitted from the half shaft to the sun gear of the hub assembly to achieve power output. Its working mode is shown in Table 1:

B1 B2 Speed Ratio 1st gear ● ○ (1+k ₂ )·k ₃ 2nd gear ○ ● (k ₁ +k ₂ )·k ₃ /k ₁

Table 1

Wherein k ₁ , k ₂ , and k ₃ have the following specific meanings:

k ₁ : the speed ratio of the left planetary gear transmission mechanism 50, which is the number of teeth of the speed ring gear 51 / the number of teeth of the left speed sun gear 55;

k ₂ : right planetary gear ratio of the planetary gear transmission mechanism 50, which is the number of teeth of the speed ring gear 51 / the number of teeth of the right speed sun gear 52;

k ₃ : reduction ratio of the hub assembly 10 planetary gear, which is the number of teeth of the hub ring gear 11 / the number of teeth of the hub sun gear 13 .

The innovative features and beneficial effects of the present invention are as follows:

(1) The gear can be selected according to the vehicle's driving conditions, taking into account both power and high-speed requirements to improve efficiency; and the B1 brake and B2 brake are wet diaphragm brakes, which can achieve power-uninterrupted gear shifting, greatly improving the comfort and smoothness of gear shifting;

(2) The left and right drive axles use the same hub assembly, and the planetary gear transmission mechanism 50 and the planetary gear differential mechanism 70 can be used in conjunction with the sun gear and the planetary gear according to the speed ratio requirements, thereby reducing the cost of mass production;

(3) The planetary gear transmission mechanism, planetary gear differential mechanism and first-stage planetary gear reduction mechanism are used, and the first-stage planetary gear reduction mechanism is integrated into the wheel hub. The compact structure and high power density make the overall structure of the electric vehicle drive axle assembly smaller and more compact, achieving coaxial output and saving vehicle layout space.

The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims (9)

1. A two-speed coaxial electric vehicle drive axle, characterized by comprising: an axle housing (20), a motor, a planetary gear speed change mechanism (50), a planetary gear differential mechanism (70), a right half shaft (80) and a left half shaft (90); The planetary gear differential mechanism (70) comprises: a right row differential sun gear (71), a right row differential planetary gear (72), a left row differential sun gear (73), a left row differential planetary gear (74) and a differential planet carrier (75); The left differential sun gear (73) meshes with the left differential planetary gear (74), the right differential sun gear (71) meshes with the right differential planetary gear (72), the left differential planetary gear (74) meshes with the right differential planetary gear (72), and the left differential planetary gear (74) and the right differential planetary gear (72) are both mounted on the differential planet carrier (75); The planetary gear speed change mechanism (50) comprises: a speed change ring gear (51), a right speed change sun gear (52), a right speed change planetary gear (53), a left speed change planetary gear (54) and a left speed change sun gear (55); The left speed change sun gear (55) meshes with the left speed change planetary gear (54), the right speed change sun gear (52) meshes with the right speed change planetary gear (53), the left speed change planetary gear (54) meshes with the right speed change planetary gear (53), the right speed change planetary gear (53) meshes with the speed change ring gear (51), the speed change ring gear (51) is fixedly connected to the bridge housing (20), and the left speed change planetary gear (54) and the right speed change planetary gear (53) are both mounted on the differential planet carrier (75); The motor shaft (33) of the motor is in driving cooperation with the right speed-changing sun gear (52); The left differential sun gear (73) is in driving cooperation with one end of the left half shaft (90), and the right differential sun gear (71) is in driving cooperation with one end of the right half shaft (80); Also includes: a B2 brake (40) and a B1 brake (60); The B2 brake (40) is arranged between the axle housing (20) and the left-row speed change sun gear (55), and the B1 brake (60) is arranged between the axle housing (20) and the speed change ring gear (51). 2. The two-speed coaxial electric vehicle drive axle according to claim 1, characterized in that the B2 brake (40) and/or the B1 brake (60) comprises: a wet diaphragm brake. 3. The two-speed coaxial electric vehicle drive axle according to claim 1, characterized in that the motor, the planetary gear speed change mechanism (50), the planetary gear differential mechanism (70), the right half shaft (80) and the left half shaft (90) are coaxially arranged. 4. The two-speed coaxial electric vehicle drive axle according to claim 1, characterized in that it further comprises: a wheel hub assembly (10); The other end of the right half shaft (80) is in driving cooperation with the wheel hub assembly (10) on the right side; and the other end of the left half shaft (90) is in driving cooperation with the wheel hub assembly (10) on the left side. 5. The two-speed coaxial electric vehicle drive axle according to claim 4, characterized in that the wheel hub assembly (10) comprises: a wheel hub ring gear (11), a wheel hub planetary gear (12), a wheel hub sun gear (13), a wheel hub planetary carrier (14) and a wheel hub (15); The wheel hub sun gear (13) meshes with the wheel hub planet gear (12), the wheel hub planet gear (12) meshes with the wheel hub ring gear (11), and the wheel hub ring gear (11) is fixedly connected to the wheel hub (15); The other end of the right half shaft (80) is fixedly connected to the right wheel hub sun gear (13); and the other end of the left half shaft (90) is fixedly connected to the left wheel hub sun gear (13). 6. The two-speed coaxial electric vehicle drive axle according to claim 5, characterized in that the hub planet carrier (14) is fixedly connected to the axle housing (20). 7. The two-speed coaxial electric vehicle drive axle according to claim 5, characterized in that the wheel hub gear ring (11) is fixedly connected to the wheel hub (15) via a spline; or the wheel hub gear ring (11) and the wheel hub (15) are integrally formed. 8. The two-speed coaxial electric vehicle drive axle according to any one of claims 4 to 7, characterized in that the wheel hub assembly (10) on the left side has the same structure as the wheel hub assembly (10) on the right side. 9. An electric vehicle, comprising: a drive axle, characterized in that the drive axle is a two-speed coaxial electric vehicle drive axle as claimed in any one of claims 1 to 8.