A dual-motor drive system

Abstract

The present invention discloses a dual-motor drive system, which includes a first motor, a second motor, two sets of gear reduction mechanisms, a differential lock and a parking mechanism; the first motor and the second motor are coaxially arranged, the primary gears of the two sets of gear reduction mechanisms are respectively arranged on the output shaft of the first motor and the output shaft of the second motor, and the differential lock mechanism is arranged at the ends of the output shaft of the first motor and the output shaft of the second motor; the differential lock mechanism includes a movable toothed disc assembly, a fixed toothed disc assembly and a fixed armature assembly, and when the relative rotation between the dual motors needs to be locked, the movable toothed disc assembly and the fixed toothed disc assembly are meshed and locked in the axial direction; when parking is required, the differential lock mechanism and the parking mechanism can be combined to realize the parking function. The structure of the dual-motor drive system can shorten the axial size of the gearbox, and realize the coupling of the output power of the dual motors through the differential lock mechanism, thereby improving the maximum output power and the vehicle's escape ability.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy vehicles, and in particular relates to a dual-motor drive system. Background Art

[0002] The drive systems of pure electric vehicles are currently divided into two types: single-motor centralized drive and multi-motor distributed drive. Most of the pure electric vehicles on the market currently use centralized drive solutions. The motor driving force is connected to the differential through gears, shafts, etc., and is roughly evenly distributed to the left and right half shafts. It is impossible to independently control a single wheel. Compared with electric vehicles with single-motor centralized drive, the advantages of using dual-motor distributed independent wheel drive are: compact structure, convenient layout, and strong vehicle driving flexibility.

[0003] The design of the dual-motor independent drive system needs to consider the spatial layout, the stress on each shaft system of the reducer, etc. As a core component of electric vehicles, it not only has high requirements for performance, but also has more stringent requirements for its safety and power. Especially when operating off-road vehicles, improving its escape ability and parking safety is an urgent problem that needs to be solved. Summary of the invention

[0004] In view of the above problems, the present invention discloses a dual-motor drive system to overcome the above problems or at least partially solve the above problems.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The embodiment of the present invention discloses a dual-motor drive system, which includes a first motor, a second motor, two sets of gear reduction mechanisms, a differential lock mechanism and a parking mechanism;

[0007] The first motor and the second motor are coaxially arranged, the first-stage pinions of the two groups of the gear reduction mechanisms are respectively arranged on the first motor output shaft and the second motor output shaft, and the differential lock mechanism is arranged at the ends of the first motor output shaft and the second motor output shaft; the parking mechanism is integrated with the differential lock mechanism and is arranged on one side of the differential lock mechanism;

[0008] The differential lock mechanism includes a movable gear plate assembly, a fixed gear plate assembly and a fixed armature assembly. The movable gear plate assembly is slidably connected to the output shaft of the first motor, and the fixed gear plate assembly is fixedly connected to the output shaft of the second motor. When the relative rotation between the dual motors needs to be locked, the fixed armature assembly is energized to generate electromagnetic force, so that the movable gear plate assembly moves toward the fixed gear plate assembly, and the end face teeth on the movable gear plate assembly and the fixed gear plate assembly are engaged with each other to lock.

[0009] Optionally, a return spring is provided between the movable toothed disc assembly and the first motor output shaft, for disconnecting the meshing connection between the movable toothed disc assembly and the fixed toothed disc assembly after the fixed armature assembly is powered off.

[0010] Optionally, the two gear reduction mechanisms include at least two stages of gear transmission, and the gears at each stage are coaxially arranged.

[0011] Optionally, each of the gear reduction mechanisms specifically includes a first-stage large gear, a second-stage small gear and a second-stage large gear, the first-stage large gear is meshed with the first-stage small gear and is close to the motor, the second-stage small gear is coaxially arranged with the first-stage large gear, the second-stage small gear is arranged away from the motor in the middle of the reduction box, and the second-stage small gear is meshed with the second-stage large gear, thereby reducing the axial size of the dual-motor drive system.

[0012] Optionally, the parking mechanism can perform a parking-in or parking-out action when the differential lock mechanism is in a locked state.

[0013] Optionally, the parking mechanism includes a parking gear, a parking pawl and a parking actuator, the parking gear and the fixed sprocket assembly are integrally arranged, the parking pawl and the parking gear are engaged, and the parking actuator is used to drive the parking pawl to switch between a parked position and an unparked position.

[0014] Optionally, a motor resolver rotor is further arranged between the differential lock mechanism and the primary gear, and the motor resolver stator is arranged on the reducer housing.

[0015] Optionally, rolling bearings are arranged on the housings on both sides of the first motor rotor and the second motor rotor, and the rolling bearings are located close to the outlet terminals of the first motor stator and the second motor stator, thereby shortening the axial distance between the first motor and the second motor.

[0016] Optionally, a first auxiliary bearing is provided on a side of the fixed gear plate assembly close to the second motor output shaft.

[0017] Optionally, a cylindrical groove is provided at the front end of the first motor output shaft, a cylindrical protrusion is provided at the end of the second motor output shaft, and a second auxiliary bearing is provided between the groove and the protrusion.

[0018] The advantages and beneficial effects of the present invention are:

[0019] The above-mentioned dual-motor drive system solution disclosed in the embodiment of the present invention can independently adjust the operating state of each drive wheel to provide driving flexibility; the differential lock function is realized by the differential lock mechanism, and the dual-motor driving force can be reasonably coupled during escape or extreme off-roading to improve the escape ability.

[0020] Furthermore, the parking function (P gear) is realized by the parking mechanism, which can improve parking safety and reliability; the axial size of the dual-motor drive system can be reduced, the space can be reasonably utilized, and the motor resolver can be installed inside the reducer housing to achieve a more compact structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0022] Figure 1 A schematic diagram of the structure of a dual-motor drive system in one embodiment of the present invention;

[0023] Figure 2 for Figure 1 Schematic diagram of the structure of the center differential lock mechanism.

[0024] In the figure: 11 is the rear bearing of the first motor; 12 is the stator of the first motor; 13 is the rotor of the first motor; 14 is the main bearing of the first motor; 15 is the resolver rotor of the first motor; 16 is the resolver stator of the first motor;

[0025] 21 is the second motor rotary transformer rotor; 22 is the second motor rotary transformer stator; 23 is the second motor main bearing; 24 is the second motor stator; 25 is the second motor rotor; 26 is the second motor rear bearing;

[0026] 31 is a first auxiliary bearing; 32 is a second auxiliary bearing;

[0027] 41 is a movable toothed disc assembly; 42 is a return spring; 43 is a fixed armature assembly; 44 is a fixed toothed disc assembly;

[0028] 51 is a first-stage pinion gear; 52 is a first-stage large gear; 53 is a second-stage pinion gear; 54 is a second-stage large gear;

[0029] 61 is a first-stage pinion gear; 62 is a first-stage large gear; 63 is a second-stage pinion gear; 64 is a second-stage large gear. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. 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.

[0031] It should be understood that the terms "include / comprise", "consist of..." or any other variations are intended to cover non-exclusive inclusion, so that a product, device, process or method that includes a series of elements includes not only those elements, but also may include other elements not explicitly listed when necessary, or also includes elements inherent to such product, device, process or method. In the absence of more restrictions, the elements defined by the sentence "include / comprise...", "consist of..." do not exclude the presence of other identical elements in the product, device, process or method that includes the elements.

[0032] For ease of understanding, the present invention will be attached to the specification Figure 1 The right side direction is defined as the rear end, and the left side direction is defined as the front end, but the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device, component or structure must have a specific direction, be constructed or operate in a specific direction, and should not be understood as a limitation on the present invention.

[0033] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] The technical solutions provided by various embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0035] See also Figure 1 The structural schematic diagram of the dual-motor drive system shown in the figure, a dual-motor drive system disclosed in an embodiment of the present invention, the dual-motor drive system includes a first motor, a second motor, two sets of gear reduction mechanisms, a differential lock mechanism and a parking mechanism;

[0036] The first motor and the second motor are coaxially arranged, the first pinion gears (51, 61) of the two sets of the gear reduction mechanisms are respectively arranged on the first motor output shaft and the second motor output shaft, the differential lock mechanism is arranged at the ends of the first motor output shaft and the second motor output shaft, according to Figure 1 It can be seen that the end position is a central position, which facilitates the installation and fixation of the differential lock mechanism.

[0037] The parking mechanism is integrated with the differential lock mechanism, for example, some parts of the parking mechanism are integrally arranged with some parts of the differential lock mechanism, and the parking mechanism is arranged on one side of the differential lock mechanism, and can be linked with the differential lock mechanism as needed.

[0038] See also Figure 2 The schematic diagram of the differential lock mechanism structure is shown, and the differential lock mechanism includes a movable toothed disc assembly 41, a fixed toothed disc assembly 44 and a fixed armature assembly 43. The movable toothed disc assembly 41 is slidably connected to the output shaft of the first motor, the fixed toothed disc assembly 44 is fixedly connected to the output shaft of the second motor, and the fixed armature assembly 43 is fixed to the housing of the reducer. When the relative rotation between the dual motors needs to be locked, the fixed armature assembly 43 is energized to generate electromagnetic force, so that the movable toothed disc assembly 41 moves toward the fixed toothed disc assembly 44, and the two can be attracted together. At the same time, the end face teeth on the movable toothed disc assembly and the fixed toothed disc assembly are meshed with each other, thereby locking the two output shafts of the dual motors together and providing power to the wheels as a power source.

[0039] The embodiment of the present invention can shorten the axial size of the gearbox through the coaxial arrangement of dual motors and the reasonable layout of the gear reduction mechanism, and realizes the coupling of the output power of the dual motors through the differential lock mechanism, thereby improving the maximum output power and the vehicle's escape ability.

[0040] In one embodiment, see Figure 2 A return spring 42 is arranged between the movable toothed disc assembly 41 and the first motor output shaft, and is used to compress the return spring 42 when the fixed armature assembly 43 is energized. When the power is off, the return spring is used to reset the movable toothed disc assembly 41, thereby disconnecting the meshing connection between the movable toothed disc assembly 41 and the fixed toothed disc assembly 44.

[0041] The function of the return spring 42 is to maintain the reliability of the differential lock mechanism being disconnected when locking is not required. The force required to be provided by the return spring 42 is determined by factors such as the weight of the movable sprocket assembly, its impact resistance, and the corresponding reset time.

[0042] In one embodiment, continue to see Figure 1 The two gear reduction mechanisms respectively arranged include at least two stages of gear transmission, and the gears at each stage can be optionally coaxially arranged.

[0043] Specifically, each of the gear reduction mechanisms further comprises a primary large gear (52, 62), a secondary small gear (53, 63) and a secondary large gear (54, 64). Figure 1It can be seen that the first-stage large gear meshes with the first-stage small gear and is close to the motor, and the second-stage small gear is coaxially arranged with the first-stage large gear, and the second-stage small gear is arranged away from the motor in the middle of the reduction box, and the second-stage small gear meshes with the second-stage large gear, thereby reducing the axial size of the dual-motor drive system. And because the second-stage gear is arranged away from the motor side, there is a large axial space between the left and right first-stage small gears; this space can be used to arrange the following differential lock mechanism and the following resolver and parking mechanism.

[0044] In one embodiment, the parking mechanism can perform a parking in or parking out action when the differential lock mechanism is in a locked state.

[0045] Specifically, the parking mechanism includes a parking gear, a parking pawl and a parking actuator (not shown in the figure), and the parking gear and the fixed sprocket assembly are integrally arranged, and the parking gear is preferably arranged on the outer circumference of the fixed sprocket assembly; then the parking pawl and the parking gear are engaged, and the parking actuator is used to drive the parking pawl to change between the parked position and the parked position. The above-mentioned parking pawl and parking actuator can be any structure that can achieve parking, and no specific limitation is made here.

[0046] In one embodiment, a motor resolver rotor (15, 21) is further arranged between the differential lock mechanism and the primary gear, and a motor resolver stator (16, 22) is arranged on the reducer housing.

[0047] Specifically, the first-stage pinion 51 and the first-stage pinion 61 are arranged close to the main bearing of the motor respectively, and the resolvers of the first motor and the second motor are close to the first-stage pinion 51 and the first-stage pinion 61 respectively, which can be far away from the motor stator, thereby reducing the influence of the motor stator on the resolver.

[0048] In one embodiment, rolling bearings are arranged on the housings on both sides of the first motor rotor 13 and the second motor rotor 25. The rolling bearings specifically include a first motor main bearing 14, a first motor rear bearing 11, a second motor main bearing 23, and a second motor rear bearing 26. The positions of the above rolling bearings are close to the outlet ends of the first motor stator 12 and the second motor stator 24. For details, see Figure 1 It can be seen that the length range of the stator of the first motor overlaps with the axial position of the rolling bearing. The purpose of this arrangement is to shorten the axial distance occupied by the first motor and the second motor.

[0049] In one embodiment, the fixed gear plate assembly 44 is provided with a first auxiliary bearing 23 on one side close to the second motor output shaft. In addition, a cylindrical groove is provided at the front end of the first motor output shaft, a cylindrical protrusion is provided at the end of the second motor output shaft, and a second auxiliary bearing is provided between the groove and the protrusion. According to the above structure, the coaxiality and stability of the end face gear meshing are guaranteed.

[0050] A first auxiliary bearing 23 and a second auxiliary bearing 31 are respectively arranged on the first motor output shaft and the second motor output shaft as auxiliary supports, thereby improving the support stiffness of the motor output shaft and the first-stage pinion (51, 61).

[0051] The above description is only an embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, expansion, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A dual-motor drive system, characterized in that: The dual-motor drive system includes a first motor, a second motor, two sets of gear reduction mechanisms, a differential lock mechanism and a parking mechanism; The first motor and the second motor are coaxially arranged, the first-stage pinions of the two groups of the gear reduction mechanisms are respectively arranged on the output shaft of the first motor and the output shaft of the second motor, and the differential lock mechanism is arranged at the ends of the output shaft of the first motor and the output shaft of the second motor; the parking mechanism is integrated with the differential lock mechanism and is arranged on one side of the differential lock mechanism; The differential lock mechanism includes a movable toothed disc assembly, a fixed toothed disc assembly and a fixed armature assembly, wherein the movable toothed disc assembly is slidably connected to the output shaft of the first motor, and the fixed toothed disc assembly is fixedly connected to the output shaft of the second motor. When the relative rotation between the dual motors needs to be locked, the fixed armature assembly is energized to generate electromagnetic force, so that the movable toothed disc assembly moves toward the fixed toothed disc assembly, and the end face teeth on the movable toothed disc assembly and the fixed toothed disc assembly are meshed and locked with each other, so that the two output shafts of the dual motors are locked together as a power source to provide power for the wheels; A reset spring is arranged between the movable gear disc assembly and the first motor output shaft, which is used to disconnect the meshing connection between the movable gear disc assembly and the fixed gear disc assembly after the fixed armature assembly is powered off. When the power is off, the reset spring resets the movable gear disc assembly, thereby disconnecting the meshing connection between the movable gear disc assembly and the fixed gear disc assembly.

2. The dual-motor drive system according to claim 1, characterized in that: The two groups of gear reduction mechanisms each include at least two stages of gear transmission, and the gears at each stage are coaxially arranged.

3. The dual-motor drive system according to claim 2, characterized in that: Each of the gear reduction mechanisms specifically includes a primary large gear, a secondary small gear and a secondary large gear. The primary large gear is meshed with the primary small gear and is close to the motor. The secondary small gear is coaxially arranged with the primary large gear. The secondary small gear is arranged away from the motor in the middle of the reduction box, and the secondary small gear is meshed with the secondary large gear, thereby reducing the axial size of the dual-motor drive system.

4. The dual-motor drive system according to claim 1, characterized in that: The parking mechanism can perform a parking in or parking out action when the differential lock mechanism is in a locked state.

5. The dual-motor drive system according to claim 3, characterized in that: The parking mechanism includes a parking gear, a parking pawl and a parking actuator. The parking gear and the fixed sprocket assembly are integrally arranged. The parking pawl is engaged with the parking gear. The parking actuator is used to drive the parking pawl to change between a parking position and an unparked position.

6. The dual-motor drive system according to any one of claims 1 to 5, characterized in that: A motor rotary transformer rotor is also arranged between the differential lock mechanism and the primary gear, and the motor rotary transformer stator is arranged on the reducer housing.

7. The dual-motor drive system according to any one of claims 1 to 5, characterized in that: Rolling bearings are arranged on the housings on both sides of the first motor rotor and the second motor rotor. The rolling bearings are located close to the first motor stator and the second motor stator outlet terminals, thereby shortening the axial distance between the first motor and the second motor.

8. The dual-motor drive system according to any one of claims 1 to 5, characterized in that: A first auxiliary bearing is disposed on a side of the fixed gear plate assembly close to the second motor output shaft.

9. The dual-motor drive system according to any one of claims 1 to 5, characterized in that: A cylindrical groove is arranged at the front end of the first motor output shaft, a cylindrical protrusion is arranged at the end of the second motor output shaft, and a second auxiliary bearing is arranged between the groove and the protrusion.

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