Active cell integrated electrically-driven powertrain

Abstract

The present invention relates to an active cell integrated electrically-driven powertrain, mainly consisting of a driving motor, a controller, a differential, a gear sleeve, a locking mechanism, a left half shaft, a right half shaft, a reduction gear and an output device assembly. According to the present invention, by using a single motor coaxially integrated with a differential, the setting of first differential and then deceleration, coaxial design of a driving motor and a drive wheel and axle based on the configuration of a planet to a wheel side planet, high-power-density oil-cooled motor technology, and four-in-one integrated design of driving, differential, deceleration and control, the most simplified envelope of a drivetrain is achieved. Compared with the prior art, a powertrain that is efficient, compact, light in weight, high in power density and high in reliability is achieved, which facilitates engineering design, so that the overall space utilization rate is greatly improved.

Description

An active battery cell integrated electric drive power assembly Technical Field

[0001] The present invention belongs to the field of electric transmission technology, and specifically relates to an active battery-integrated electric drive power assembly, and more particularly to an electric drive power assembly for high-power medium and heavy-duty wheeled special electric transmission vehicles. Background Art

[0002] With energy and environmental concerns, electric vehicles are gaining increasing attention. In modern, fully electrified and information-based special operations systems, electric drive has become a future development trend for special vehicles. Electric drive is currently developing rapidly, especially in the passenger car sector. However, in the field of high-power special vehicles, due to their harsh operating conditions and higher performance requirements, the development and application of electric drive systems lags behind that of passenger vehicles. For high-power medium- and heavy-duty vehicles, the most common way to achieve greater maneuverability and efficiency is through the use of hybrid powertrains. Various known hybrid and all-electric vehicles also strive to adopt simplified, high-power-density powertrains to increase the available space for passengers, cargo, and other vehicle components.

[0003] Existing electric drive systems for high-power wheeled vehicles primarily consist of dual motors, a differential, a reduction gear set, and a housing. This approach, where the dual motors first reduce speed and then differential, creates a complex transmission system and occupies a large longitudinal dimension of the vehicle, hindering overall and upper-mounted layout.

[0004] Future electric drive special vehicles will require electric drive systems with higher power density and more compact structures to support the power layout of the next generation of vehicles. To adapt to the evolution of future electric drive vehicles, the overall development goals of new electric drive units for medium and heavy-duty special vehicles are to achieve highly integrated, simplified drive system envelope, high power density with high efficiency, and high reliability that can be mass-produced. Currently, an effective method for achieving these goals in electric drive units is to use a coaxial integrated layout that integrates a high-power density, oil-cooled motor, a compact planetary gear train, a high-speed differential, and a multi-phase inverter controller.

[0005] A highly integrated coaxial drive unit recently announced aims to match a vehicle mass of approximately 2,000 kg. It uses a single planetary gearbox integrated with the motor rotor, inputs power to the differential, and then outputs it through the half-shaft. The device is also integrated with the motor controller.

[0006] Magna's new-generation coaxial electric axle solutions, as well as Schaeffler's, are also among the most advanced all-in-one drive units. These coaxial drives utilize a deceleration-first, differential-secondary approach. Neither the planetary gear train nor the differential are integrated into the motor cavity, occupying axial or radial space. While this technology is suitable for small sedans and passenger cars, achieving high-power drive for medium- and heavy-duty special vehicles with complex operating conditions requires a more powerful electric motor and a more complex power transmission route.

[0007] Summary of the Invention

[0008] The present invention provides a centralized electric drive powertrain for high-power medium and heavy-duty wheeled special vehicles, addressing the development needs of future high-power density electric drive systems - highly integrated, efficient, small and lightweight, and achieving a minimal power transmission system envelope.

[0009] The present invention provides an active battery integrated electric drive force assembly, which is characterized by: mainly consisting of a drive motor 2, a differential 4, a left half shaft 7, a right half shaft 8, a reduction device and an output device assembly; the drive motor 2 is an inner rotor permanent magnet synchronous motor, the differential is arranged in the cavity of the drive motor, the differential 4 is mainly composed of a cross shaft 23, a planetary gear 24, a half shaft gear 25, and a differential housing 26, wherein the differential housing 26 is a bidirectional shaft extension structure, a flange 27 is formed locally on the outer surface of the differential housing and is fixedly connected to the motor rotor bracket 13 of the drive motor, the cross shaft 23 is installed in the differential housing, and the cross shaft 23 is fixed to the motor rotor bracket 13 of the drive motor. Each of the four pin shafts 29 is provided with a planetary gear 24, the outer end face of the planetary gear is matched with the arc spherical surface in the differential housing, and the two half-shaft gears 25 are axially symmetrically arranged on both sides of the cross shaft 23, and are rotatably connected to the inner wall of the bidirectional axial extension of the differential housing 26; the half-shaft gears 25 are meshed with the external teeth of the planetary gears 24, and the bidirectional axial extension of the differential housing 26 is rotatably connected to the two ends of the drive motor respectively; the left half-shaft 7 and the right half-shaft 8 are respectively connected to the inner hole splines of the two half-shaft gears; the output ends of the left half-shaft 7 and the right half-shaft 8 are respectively connected to the corresponding output device assembly through a reduction device.

[0010] Beneficial effects: The centralized electric drive power assembly provided by the present invention is suitable for high-power wheeled special vehicles. It realizes the simplification of the power transmission system envelope by adopting a single-motor coaxial integrated differential, a setting of differential first and then deceleration, a configuration from planetary to wheel-side planetary to coaxial design of the drive motor and the drive wheel shaft, high-power density oil-cooled motor technology, and a four-in-one integrated design of drive, differential, deceleration, and control. Compared with the existing technology, it realizes a power assembly with high efficiency, compactness, lightweight, high power density, and high reliability, which is easy to carry out engineering design, and greatly improves the overall space utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG1 is a schematic diagram of the structure of the active battery cell integrated electric driving force assembly of the present invention;

[0012] Figure 2 is a schematic diagram of the drive motor structure;

[0013] Figure 3 is a schematic diagram of the oil cooling channel of the drive motor;

[0014] Figure 4 is a schematic diagram of the differential structure;

[0015] Figure 5 is a schematic diagram of the deceleration device and output assembly structure;

[0016] Figure 6 is a schematic structural diagram of the locking mechanism;

[0017] Figure 7 Schematic diagram of the installation structure of the cross shaft and planetary gears. DETAILED DESCRIPTION

[0018] As shown in FIG1 , the present invention provides an active battery integrated electric drive power assembly 1, which is mainly composed of a drive motor 2, a differential 4, a gear sleeve 5 with an end face key, a locking mechanism 6, a left half shaft 7, a right half shaft 8, a reduction gear 9, and an output device assembly 10;

[0019] The rotation of the drive motor 2 is controlled by the controller 3. The drive motor 2 is an inner rotor permanent magnet synchronous motor. The differential is arranged in the cavity of the drive motor. The motor rotor bracket of the drive motor is fixedly connected to the differential housing of the differential 4. The left half shaft 7 and the right half shaft 8 are respectively connected to the inner hole splines of the two differential half shaft gears; the output ends of the left half shaft 7 and the right half shaft 8 are respectively connected to the output device assembly 10 through a reduction device 9.

[0020] As shown in Figures 2 and 3, the drive motor 2 includes a motor rotor component 11, a motor winding core assembly 12, a motor rotor bracket 13, a casing 14, a motor left end cover 15, and a motor right end cover 16; the air gap between the motor rotor component 11 and the motor winding core assembly 12 is approximately 0.5-1mm, the motor winding core assembly 12 is interference fit connected to the casing 14, and the motor left end cover 15 and the motor right end cover 16 are fixedly connected to the casing 14 by bolts; the drive motor 2 is an oil-cooled motor, which adopts active oil cooling and spraying by an electronic oil pump, that is, the motor winding core assembly 12 adopts in-slot straight-through oil cooling, and the motor rotor component 11 adopts surface spray oil cooling.

[0021] The motor winding core assembly 12 adopts a concentrated winding fractional slot electromagnetic scheme, and its magnetic circuit and oil channel are integrated to form an inter-slot oil channel 17; the end of the motor winding core assembly 12 and the motor right end cover 15 form an end oil chamber 18, and the casing of the drive motor 2 is also provided with an oil inlet 19, a casing oil inlet channel 20, a casing oil return channel 21, and an oil return port 22. The electronic oil pump is actuated to allow the cooling oil to enter through the oil inlet and cool the winding core assembly through the casing oil inlet channel, and the oil that takes away the heat is returned to the oil return port through the casing oil return channel and enters the vehicle's cooling system, thereby realizing direct contact between the cooling medium oil and the heat source motor winding and core, thereby greatly improving the cooling efficiency, increasing the peak power, and achieving the requirements of high power density and lightweight.

[0022] As shown in Figures 4 and 1, the differential 4 is an inter-wheel differential, featuring high speed and heavy load characteristics. It can achieve active differential speed between the left and right wheels when the vehicle turns, and can be locked by a locking mechanism 6, achieving coaxial zero speed difference. The differential 4 is integrated with the drive motor 2 and primarily consists of a cross shaft 23, planetary gears 24, side gears 25, and a differential housing 26. The differential housing 26 is a biaxial extension structure. A flange 27 is formed on the outer surface of the differential housing and is fixedly connected to the motor rotor bracket 13 via bolts 28M10×30-10.9. The four planetary gears 24 are first radially connected to the four pins 29 of the cross shaft 23 and then spherically connected to the differential housing arc 30. The side gears 25 are meshed with the planetary gears 24. The side gears 25 are positioned and supported within the biaxial extension by bearings 31, meeting high-speed operation requirements. The bidirectional shaft extension of the differential housing 26 engages with the inner race of the drive motor bearing 32 through an interference fit. The outer race of the drive motor bearing 32 engages with the left and right motor end caps 15 and 16 through a transition fit, forming a support structure that combines the drive motor and differential support, maximizing functional, structural, and spatial overlap. A differential lock end key 33 is located on the right side of the bidirectional shaft. This key, coupled to the gear sleeve 5 of the locking mechanism, transmits power through end-face engagement, achieving differential lock. A weight-reducing hole is located in the center of the cross shaft.

[0023] As shown in Figure 6 , the locking mechanism 6 is located on the right side of the differential 4 and consists of a spring 50, a shift fork 56, a piston 54, two O-rings 55, a cylinder 52 with an air inlet 51, and a bolt 53. The gear sleeve 5 is splined to the right half-shaft 8, the shift fork 56 is positioned within the outer cylindrical groove of the gear sleeve 5, and the cylinder 52 is engaged with the inner flange hole of the motor's right end cover 16 and fixedly secured to the motor's right end cover 16 via bolts 53. The piston 54 is engaged with the inner bore of the cylinder 52 and is sealed therewith via two O-rings 55. The spring 50 passes through the piston 54 and is positioned within the inner wall cavity of the shift fork 56 and the motor's right end cover 16.

[0024] Its working principle is as follows: when the differential 4 needs to be locked, air is introduced through the air inlet 51, and the air pressure is not less than 0.8 MPa, pushing the piston 54 to the left in the cylinder, pushing the shift fork 56, and the shift fork 56 compresses the spring 50, driving the end face key of the gear sleeve 5 to engage with the end face key 33 for differential locking, thereby realizing the differential locking function. The above action is performed statically or at low speed.

[0025] When release is required, the air inlet 51 is deflated, the spring 50 returns to its original position, driving the shift fork 56. The shift fork 56 pushes the right side of the outer groove shaft hole of the gear sleeve 5, pushing the gear sleeve 5 to the right. The gear sleeve 5 slides on the right half-shaft 8 and disengages from the end face key 33 for differential locking. The differential 4 is in a disconnected state. The above actions are performed at a static or low speed.

[0026] As shown in FIG5 and FIG1, the reduction gear 9 adopts a single-row large helical angle helical gear planetary gear structure, and is placed on the left and right sides of the power assembly with the motor shaft, playing the role of reducing speed and increasing torque.

[0027] Taking the left side as an example, the reduction gear 9 is composed of a sun gear 34, a planetary gear 35, a combined frame 36, and a combined ring gear assembly 49. It has the characteristics of small size, light weight, low noise, and large torque transmission. The sun gear 34 of the reduction gear 9 adopts an integrated design with the left half-shaft 7. One end of the combined frame 36 is connected to the left end cover of the motor through a bearing 37. The combined ring gear assembly 49 is fixed to the end cover by bolts 38. The combined ring gear assembly 49 is made of high-strength lightweight aluminum material and a steel ring gear. The combined frame 36 adopts high-strength titanium alloy extrusion molding technology to meet the purpose of lightweighting. The reduction gear 9 adopts a lubrication method that combines splashing and centralized centrifugal types.

[0028] As shown in Figure 5, the output device 10 is located on the left and right sides of the electric drive powertrain and consists of a bearing 39, a bearing seat 40, a positioning sleeve 41, an output connecting plate 42, a locking cover 43, a support sleeve 44 connected to the vehicle body, and an oil seal 45. The positioning sleeve 41 is connected to the combined frame 36 of the reduction gear 9 via a spline with an inner diameter centering at the right end of the combined frame 36 shaft. The output connecting plate 42 is splined to the combined frame 36 at the left end of the combined frame 36 shaft. The output connecting plate 42 is connected to the inner ring of the bearing 39 using a js6 connection. The outer ring of the bearing 39 is connected to the bearing seat 40 using an H6 / h6 connection. The bearing seat 40 is fixedly connected to the support sleeve 44 and the combined ring gear assembly 37 via bolts 48. The output connecting plate 42 is provided with an end key 46, and the end of the output connecting plate 42 is fixed to the locking cover 43 via bolts 47. The oil seal 45 is a bidirectional oil seal that can seal 0.5 MPa of oil inwardly and 0.3 MPa of water outwardly. It is connected to the output connection plate 42 in an h8 fit and to the support sleeve 44 in an H7 fit.

[0029] As shown in Figures 1 and 5, the half-shafts are divided into a left half-shaft 7 and a right half-shaft 8. The left end of the left half-shaft 7 is integrated with the sun gear 34 of the reduction gear 9, and the right end of the left half-shaft 7 is spline-connected to the left half-shaft gear 25; the right end of the right half-shaft 8 is integrated with the sun gear 34 of the reduction gear 9, the left end of the right half-shaft 8 is spline-connected to the right half-shaft gear 25, and the middle part is spline-connected to the gear sleeve 5.

[0030] As shown in FIG1 , the controller 2 is integrated with the drive motor 2 , and is characterized by adopting multi-phase output, full SIC device motor controller technology, and a DC900V voltage platform to form a high power density and lightweight controller.

[0031] Working principle:

[0032] The controller in the active cell integrated electric drive powertrain controls the drive motor according to instructions from upper-level controllers such as the vehicle controller. The torque control mode is usually adopted. The vehicle controller provides torque instructions to the drive motor controller to control the drive motor torque.

[0033] Under driving conditions, the torque output by the drive motor is diverted through the differential, and then decelerated and torque-increased by the reduction device before the power is transmitted to the output assemblies on both sides, and directly transmitted to the wheel-side assemblies on both sides to drive the vehicle forward; under braking conditions, the braking torque of the electric drive force assembly can be coordinated and generated by the drive motor and the brake at the wheel-side assemblies on both sides according to the control instructions of the electromechanical composite braking, or it can be provided by one of the two separately.

[0034] In special circumstances, the electric drive powertrain can also be controlled in speed mode. In speed mode, the vehicle controller provides the target speed, and the electric drive powertrain controller autonomously adjusts the torque of the drive motor according to the requirements of target speed tracking.

[0035] The inter-wheel differential with power integration and diversion is characterized by high speed and heavy load, and can realize active differential between the left and right wheels when the vehicle is turning; when it is necessary to pass through special muddy, icy and snowy roads, climb slopes, overcome obstacles and other working conditions, it can be locked through the locking mechanism to achieve coaxial speed difference and meet the vehicle's power requirements.

[0036] The present invention adopts differential first and then deceleration, uses a planet-to-planet configuration, aligns the drive motor and the drive wheel coaxially, and realizes the most simplified power transmission system envelope.

Claims

1. An active battery cell integrated electric drive power assembly, characterized by: The invention mainly consists of a driving motor (2), a differential (4), a left half-shaft (7), a right half-shaft (8), a speed reducer and an output device assembly; the driving motor (2) is an inner rotor permanent magnet synchronous motor, the differential is arranged in the cavity of the driving motor, the differential (4) mainly consists of a cross shaft (23), a planetary gear (24), a half-shaft gear (25), and a differential housing (26), wherein the differential housing (26) is a bidirectional shaft extension structure, a flange (27) is formed locally on the outer surface of the differential housing and is fixedly connected to the motor rotor bracket (13) of the driving motor, the cross shaft (23) is installed in the differential housing, and four pins (29) of the cross shaft (23) are each provided with a There is a planetary gear (24), the outer end face of the planetary gear is matched with the arc spherical surface in the differential housing, and two half-shaft gears (25) are axially symmetrically arranged on both sides of the cross shaft (23) and are rotatably connected to the inner wall of the bidirectional shaft extension part of the differential housing (26); the half-shaft gears (25) are meshed with the outer teeth of the planetary gears (24), and the bidirectional shaft extension part of the differential housing (26) is rotatably connected to the two ends of the drive motor; the left half shaft (7) and the right half shaft (8) are respectively connected to the inner hole splines of the two half shaft gears; the output ends of the left half shaft (7) and the right half shaft (8) are respectively connected to the corresponding output device assembly through a reduction device.

2. The active battery cell integrated electric drive power assembly according to claim 1, characterized in that: The drive motor (2) comprises a motor rotor component (11), a motor winding core assembly (12), a motor rotor bracket (13), and a housing (14); the motor rotor bracket (13) is fixed in the motor rotor component (11), the motor rotor component (11) is arranged in the inner cavity of the motor winding core assembly (12), the motor winding core assembly (12) and the housing (14) are connected by interference fit, and a motor left end cover (15) and a motor right end cover (16) are respectively fixed at two ends of the housing (14).

3. The active battery cell integrated electric driving force assembly according to claim 2, characterized in that: The air gap between the motor rotor component (11) and the motor winding iron core assembly (12) is 0.5-1 mm.

4. The active battery cell integrated electric drive power assembly according to claim 2, characterized in that: The motor winding core assembly (12) adopts slot-through oil cooling, and the motor rotor component (11) adopts surface spray oil cooling.

5. The active battery cell integrated electric driving force assembly according to claim 4, characterized in that: The magnetic circuit and the oil passage of the motor winding core assembly (12) are integrated to form an inter-slot oil passage (17); the end of the winding core assembly (12) and the motor right end cover (15) form an end oil chamber (18); the housing of the drive motor (2) is also provided with an oil inlet (19), a housing oil inlet passage (20), a housing oil return passage (21), and an oil return passage (22); the electronic oil pump is operated to allow cooling oil to enter through the oil inlet, cool the winding core assembly through the housing oil inlet passage, and allow the oil that takes away heat to pass through the housing oil return passage to the oil return passage and enter the vehicle's cooling system.

6. The active battery cell integrated electric drive power assembly according to claim 2, characterized in that: The invention also includes a gear sleeve (5) with an end face key and a locking structure (6), wherein the locking structure (6) is arranged on the right side of the differential (4), the gear sleeve (5) is connected to the outer cylindrical spline of the middle part of the right side half shaft (8), and the locking structure is used to drive the gear sleeve (5) to slide relative to the right side half shaft (8); the right end of the bidirectional shaft extension part of the differential housing (26) is provided with an end face key (33) for differential locking, which is connected to the gear sleeve (5) through end face meshing to transmit power.

7. The active battery cell integrated electric drive power assembly according to claim 6, characterized in that: The locking structure (6) comprises a spring (50), a shift fork (56), a piston (54) and a cylinder (52) with an air inlet (51); the shift fork (56) is placed in the outer circular groove shaft hole of the gear sleeve (5); the piston (54) is matched with the inner hole of the cylinder (52), and the spring (50) passes through the piston (54) and is placed in the inner wall cavity of the shift fork (56) and the right end cover (16) of the motor.

8. The active battery cell integrated electric driving force assembly according to claim 7, characterized in that: The cylinder (52) is fixedly connected to the motor right end cover (16) of the drive motor (2).

9. The active battery cell integrated electric driving force assembly according to claim 1, characterized in that: The left side half shaft (7) is designed to be integrated with the sun gear of the reduction gear on the same side, and the right side half shaft (8) is designed to be integrated with the sun gear of the reduction gear on the same side.

10. The active battery cell integrated electric driving force assembly according to claim 1, characterized in that: Under driving conditions, the torque output by the drive motor is diverted through the differential, and then decelerated and torque-increased by the reduction device before the power is transmitted to the output device assemblies on both sides, and directly transmitted to the wheel side assemblies on both sides to drive the vehicle forward.

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