One-gear coaxial electric drive axle system capable of being used for road light vehicle

Abstract

The utility model relates to a one-gear coaxial electric drive axle system capable of being used for a road light vehicle, which is mainly used for solving the technical problems that the contact fatigue strength of tooth surfaces of two groups of planet row structures of the existing electric drive axle system is large, the existing electric drive axle system cannot bear larger impact load, and a compact differential mechanism structure is insufficient in torque transmission capacity. The speed reducer comprises the driving mechanism, the first-stage speed reducing mechanism and the two second-stage speed reducing mechanisms, the two second-stage speed reducing mechanisms are located at the two ends of the shell respectively, electric driving systems are evenly distributed in the axial direction, and under the road impact load, damage caused by the fact that the shell bears too large stress can be avoided. The first-stage speed reducing mechanism is further connected with the differential mechanism, and differential rotation of the two output ends is achieved.

Description

Technical Field

[0001] The utility model relates to a vehicle electric drive axle system, in particular to a first-gear coaxial electric drive axle system for light road vehicles. Background Art

[0002] With the popularization of electrification and intelligence of current transportation tools, the electric drive axle system is the most advantageous technical solution in the current and future commercial vehicle fields. In recent years, due to the imperfect popularization of charging facilities, the electric drive axle system cannot be popularized in the fields of long-distance and large-tonnage vehicles. However, it has incomparable advantages in urban road vehicles or light short-distance transport vehicles, and can achieve the goal of vehicle charging at night and working during the day.

[0003] The electric drive axle system can replace the engine, transmission and complex transmission system of fuel vehicles, avoiding the problems of insufficient domestic engine technology and complex structures of the transmission and transmission system; at the same time, using electricity as the power source of the vehicle is more economical than traditional fuel vehicles; and the environmental protection characteristics of vehicles equipped with the electric drive axle system better meet national requirements.

[0004] Chinese Patent CN21830729U proposes a first-gear coaxial electric drive axle, which continuously uses two sets of planetary trains, making the torque of the second set of planetary trains relatively high, the tooth surface contact fatigue strength large, and the second planetary train prone to pitting failure.

[0005] Chinese Patent CN117755066A proposes a coaxial electric drive axle structure, but the differential sun gear used in it is a special modified tooth profile structure, which is compact and can be conveniently applied under the small torque of passenger cars; however, the tooth width of the sun gear is very small, the torque transmission capacity is limited, and there is no differential lock, so the torque transmission capacity is insufficient and the vehicle has no off-road ability. Summary of the Utility Model

[0006] The purpose of the utility model is to solve the technical problems that the tooth surface contact fatigue strength of the two sets of planetary train structures of the existing electric drive axle system is large, it cannot withstand large impact loads, and the compact differential structure has insufficient torque transmission capacity, and to propose a first-gear coaxial electric drive axle system for light road vehicles.

[0007] To solve the above technical problems, the technical solution provided by the utility model is as follows:

[0008] A first-gear coaxial electric drive axle system for light road vehicles, characterized in that it includes a housing, a driving mechanism, a differential, a first-stage reduction mechanism, two second-stage reduction mechanisms and two output half shafts;

[0009] The housing is a coaxial two-piece structure, including a first housing and a second housing connected coaxially; the first housing is used to carry a driving mechanism and a secondary reduction mechanism; the second housing is used to carry a differential, a primary reduction mechanism and another secondary reduction mechanism; the two secondary reduction mechanisms are respectively located at both ends of the housing;

[0010] The primary reduction mechanism adopts a compound planetary gear set and two primary reduction half shafts; the input end of the compound planetary gear set is connected to the output end of the driving mechanism, the output end of the compound planetary gear set is connected to the input end of the differential, and the output end of the differential is respectively connected to one end of the two primary reduction half shafts;

[0011] The other ends of the two primary reduction half shafts are respectively connected to the input ends of the two secondary reduction mechanisms, the output ends of the two secondary reduction mechanisms are respectively connected to the two output half shafts, and the two output half shafts are respectively used to connect to wheels;

[0012] The two primary reduction half shafts and the two output half shafts are coaxially arranged.

[0013] Further, the compound planetary gear set includes a primary reduction sun gear, a plurality of primary reduction planetary gears, and a primary reduction planetary carrier;

[0014] The primary reduction sun gear serves as the input end of the compound planetary gear set and is connected to the output end of the driving mechanism through a spline; the primary reduction sun gear meshes with the plurality of primary reduction planetary gears, the plurality of primary reduction planetary gears are connected to the primary reduction planetary carrier, and the primary reduction planetary carrier serves as the output end of the compound planetary gear set and is connected to the input end of the differential.

[0015] Further, the differential includes a differential housing, two planetary gears located in the differential housing, a first half shaft gear, a second half shaft gear, and a differential lock;

[0016] The differential housing is fixedly connected to the primary reduction planetary carrier, the two planetary gears are connected to the differential housing through a cross shaft, and the two planetary gears respectively mesh with the first half shaft gear and the second half shaft gear; the first half shaft gear and the second half shaft gear are respectively connected to one end of the two primary reduction half shafts through a spline; one end of the differential lock is connected to the differential housing, and the other end is connected to the first half shaft gear or the second half shaft gear.

[0017] Further, the two secondary reduction mechanisms adopt a first planetary gear set and a second planetary gear set with the same structure, the first planetary gear set is located in the first housing, and the second planetary gear set is located in the second housing;

[0018] The first planetary gear set includes a first sun gear, a plurality of first planetary gears meshing with the first sun gear, and a first planetary carrier connected to the plurality of first planetary gears; the second planetary gear set includes a second sun gear, a plurality of second planetary gears meshing with the second sun gear, and a second planetary carrier connected to the plurality of second planetary gears.

[0019] The first sun gear and the second sun gear serve as the input ends of two secondary reduction mechanisms and are respectively connected to the other ends of two primary reduction half shafts; the first planetary carrier and the second planetary carrier serve as the output ends of two secondary reduction mechanisms and are respectively connected to the two output half shafts.

[0020] Further, the differential lock adopts a wet clutch. One friction plate of the wet clutch is connected to the differential housing, and the other friction plate is connected to the first half shaft gear or the second half shaft gear.

[0021] Further, the drive mechanism adopts a drive motor, and the output shaft of the drive motor is connected to the primary reduction sun gear through a spline.

[0022] Advantages of the present utility model:

[0023] 1. The present utility model adopts a coaxial integrated electric drive axle structure. For the working conditions of light vehicle usage scenarios, a first gear electric drive axle system is adopted, making the electric drive axle system structure compact and the control simple.

[0024] 2. The present utility model is provided with a primary reduction mechanism and two secondary reduction mechanisms, achieving the secondary reduction ability of the electric drive axle system and improving the power performance of the vehicle; the two secondary reduction mechanisms are respectively located at both ends of the housing, and the electric drive system is evenly distributed along the axial direction, which helps to avoid damage due to excessive bearing stress of the housing under road impact loads.

[0025] 3. In the differential of the present utility model, one of the half shaft gears is integrated with a differential lock, improving the vehicle's self-rescue ability on muddy roads (sand and gravel roads).

[0026] 4. The housing of the present utility model adopts an integrated two-section structure. One side is used to carry the drive motor and a secondary reduction mechanism, and the other side is used to carry the primary reduction mechanism, the differential, and another secondary reduction mechanism. The coaxial structure of the housing can evenly bear the housing load and reduce the risk of eccentric load vibration damage.

[0027] 5. The advantage of the two-section housing in the present utility model is that it can use a set of cooling circulation system, and the integrated oil passage is cast (machined) in the housing, with good integration and high reliability. The housing has a relatively high torsional stiffness, meeting the demanding requirements of the complex working conditions of commercial vehicles for the torsional needs of the axle housing itself. Description of the Drawings

[0028] Figure 1 This is a schematic structural diagram of an embodiment of a first-gear coaxial electric drive axle system for light road vehicles according to the present utility model.

[0029] Description of reference numerals:

[0030] 1. First housing; 2. Second housing; 3. Driving motor; 4. First-stage reduction planetary gear; 5. First-stage reduction sun gear; 6. First-stage reduction planet carrier; 7. Differential; 8. Differential lock; 9. Second planetary gear set; 10. First planetary gear set; 11. First half shaft gear; 12. Second half shaft gear; 13. Second sun gear; 14. First-stage reduction half shaft; 16. First sun gear; 17. Output half shaft. Detailed implementation manners

[0031] The present utility model will be further described below in conjunction with the accompanying drawings and embodiments.

[0032] The present utility model provides a first-gear coaxial electric drive axle system for light road vehicles. As Figure 1 shown, it includes a housing, a driving mechanism, a differential 7, a first-stage reduction mechanism, two second-stage reduction mechanisms, and two output half shafts 17;

[0033] The housing is of a two-piece structure, including a first housing 1 and a second housing 2 arranged coaxially. The first housing 1 is used to carry the driving mechanism and one second-stage reduction mechanism, and the second housing 2 is used to carry the differential 7, the first-stage reduction mechanism, and the other second-stage reduction mechanism. The two second-stage reduction mechanisms are respectively located at both ends of the housing. The coaxial structure of the two-piece housing can evenly bear the housing load and reduce the risk of eccentric load vibration damage. The advantage of the two-piece structure of the housing is that it can share a set of cooling circulation systems, and the integral oil passage is cast (machined) in the housing, with good integration and high reliability. The housing has a relatively high torsional stiffness, meeting the demanding requirements of the complex working conditions of commercial vehicles for the torsional needs of the housing itself.

[0034] The driving mechanism adopts a driving motor 3, and its output shaft is connected to the input end of the first-stage reduction mechanism.

[0035] The first-stage reduction mechanism includes a compound planetary gear set and two first-stage reduction half shafts 14. The compound planetary gear set includes a first-stage reduction sun gear 5, first-stage reduction planet gears 4, and a first-stage reduction planet carrier 6. The first-stage reduction sun gear 5 serves as the input end of the first-stage reduction mechanism and is connected to the output shaft of the drive motor 3 through a spline. The first-stage reduction sun gear 5 meshes with the first-stage reduction planet gears 4, and the first-stage reduction planet gears 4 are connected to the first-stage reduction planet carrier 6. The first-stage reduction planet carrier 6 is connected to the input end of the differential 7, and the output ends of the differential 7 are respectively connected to one ends of the two first-stage reduction half shafts 14. The other ends of the two first-stage reduction half shafts 14 are respectively connected to two second-stage reduction mechanisms. The power output by the drive motor 3 is reduced at the first stage through the first-stage reduction mechanism, and the reduction ratio is a fixed value n1. The two first-stage reduction half shafts 14 and the two output half shafts 17 are coaxially arranged. The two output half shafts 17 are respectively used to connect to the wheels.

[0036] The differential 7 includes a differential housing, two planet gears located inside the differential housing, a first half shaft gear 11, a second half shaft gear 12, and a differential lock 8. The first-stage reduction planet carrier 6 is fixedly connected to the differential housing. The two planet gears are connected to the differential housing through a cross shaft. The two planet gears respectively mesh with the first half shaft gear 11 and the second half shaft gear 12. The first half shaft gear 11 and the second half shaft gear 12 are respectively connected to the other ends of the two first-stage reduction half shafts 14 through splines. The differential lock 8 uses a wet clutch and is connected to the first half shaft gear 11 or the second half shaft gear 12. When an external clutch engagement signal is released, the wet clutch locks the half shaft gear it is connected to as a differential lock to achieve synchronous rotation. Under other working conditions, the differential 7 enables the differential movement of the two wheels. The power is distributed to the two first-stage reduction half shafts 14 respectively after passing through the differential 7.

[0037] The two second-stage reduction mechanisms are respectively the first planetary gear set 10 and the second planetary gear set 9 with the same structure. The first planetary gear set 10 is located inside the first housing 1, and the second planetary gear set 9 is located inside the second housing 2. The first planetary gear set 10 includes a first sun gear 16, first planet gears meshing with the first sun gear 16, and a first planet carrier connected to the first planet gears. The first planet carrier is connected to one output half shaft 17. The second planetary gear set 9 includes a second sun gear 13, second planet gears meshing with the second sun gear 13, and a second planet carrier connected to the second planet gears. The first planet carrier is connected to the other output half shaft 17. The power on the two first-stage reduction half shafts 14 is respectively transmitted to the first planetary gear set 10 and the second planetary gear set 9. The first planetary gear set 10 and the second planetary gear set 9 serve as the second-stage reduction mechanisms to achieve a second-stage reduction with a reduction ratio of n2. After the first-stage reduction, the motor torque is amplified. The first planetary gear set 10 and the second planetary gear set 9 can evenly distribute the load and improve the contact fatigue strength of the gears under large torque.

[0038] The utility model discloses a first-gear coaxial electric drive axle system that can be used for light road vehicles, which realizes deceleration through a two-stage deceleration mechanism. The electric drive system under normal working conditions is in a constant meshing state, that is, a non-powered electric drive system with only one gear, which is suitable for light road vehicles. When the vehicle is stuck in a quagmire or other working conditions that require locking the differential 7, the differential lock 8 is locked, and the first half-shaft gear 11 rotates coaxially with the second half-shaft gear 12 to achieve vehicle escape.

Claims

1. A first gear coaxial electric drive axle system that can be used for light road vehicles, characterized in that: It comprises a housing, a driving mechanism, a differential (7), a primary reduction mechanism, two secondary reduction mechanisms and two output half shafts (17); The housing is a coaxial two-section structure, comprising a first housing (1) and a second housing (2) which are coaxially connected; the first housing (1) is used to carry a driving mechanism and a secondary reduction mechanism; the second housing (2) is used to carry a differential (7), a primary reduction mechanism and another secondary reduction mechanism; the two secondary reduction mechanisms are respectively located at two ends of the housing; The primary reduction mechanism adopts a compound planetary gear and two primary reduction half shafts (14); the input end of the compound planetary gear is connected to the output end of the driving mechanism, the output end of the compound planetary gear is connected to the input end of the differential (7), and the output end of the differential (7) is respectively connected to one end of the two primary reduction half shafts (14); The other ends of the two primary reduction half shafts (14) are respectively connected to the input ends of the two secondary reduction mechanisms, and the output ends of the two secondary reduction mechanisms are respectively connected to the two output half shafts (17), and the two output half shafts (17) are respectively used to connect to wheels; The two primary reduction half shafts (14) are coaxially arranged with the two output half shafts (17).

2. A first gear coaxial electric drive axle system for road light vehicles according to claim 1, characterized in that: The compound planetary gear comprises a primary reduction sun gear (5), a plurality of primary reduction planetary gears (4), and a primary reduction planet carrier (6); The primary reduction sun gear (5) serves as the input end of the compound planetary gear set and is connected to the output end of the driving mechanism via a spline; the primary reduction sun gear (5) is meshed with a plurality of primary reduction planetary gears (4), the plurality of primary reduction planetary gears (4) are connected to the primary reduction planet carrier (6), and the primary reduction planet carrier (6) serves as the output end of the compound planetary gear set and is connected to the input end of the differential (7).

3. A first gear coaxial electric drive axle system for road light vehicles according to claim 2, characterized in that: The differential (7) comprises a differential housing, two planetary gears located in the differential housing, a first side shaft gear (11), a second side shaft gear (12) and a differential lock (8); The differential housing is fixedly connected to the primary reduction planet carrier (6); the two planetary gears are connected to the differential housing via a cross shaft; the two planetary gears are respectively meshed with a first half-shaft gear (11) and a second half-shaft gear (12); the first half-shaft gear (11) and the second half-shaft gear (12) are respectively connected to one end of the two primary reduction half-shafts (14) via splines; one end of the differential lock (8) is connected to the differential housing, and the other end is connected to the first half-shaft gear (11) or the second half-shaft gear (12).

4. A first gear coaxial electric drive axle system for road light vehicles according to claim 3, characterized in that: The two two-stage reduction mechanisms adopt a first planetary row (10) and a second planetary row (9) of identical structure, wherein the first planetary row (10) is located in a first housing (1), and the second planetary row (9) is located in a second housing (2); The first planetary gear (10) comprises a first sun gear (16), a plurality of first planetary gears meshing with the first sun gear (16), and a first planet carrier connected to the plurality of first planetary gears; the second planetary gear (9) comprises a second sun gear (13), a plurality of second planetary gears meshing with the second sun gear (13), and a second planet carrier connected to the plurality of second planetary gears; The first sun gear (16) and the second sun gear (13) serve as input ends of two secondary reduction mechanisms and are respectively connected to the other ends of two primary reduction half shafts (14); the first planet carrier and the second planet carrier serve as output ends of the two secondary reduction mechanisms and are respectively connected to the two output half shafts (17).

5. A first gear coaxial electric drive axle system for road light vehicles according to claim 4, characterized in that: The differential lock (8) adopts a wet clutch, one friction plate of the wet clutch is connected to the differential housing, and the other friction plate is connected to the first half-shaft gear (11) or the second half-shaft gear (12).

6. A first gear coaxial electric drive axle system for road light vehicles according to claim 5, characterized in that: The driving mechanism adopts a driving motor (3), and the output shaft of the driving motor (3) is connected to the primary reduction sun gear (5) via a spline.

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