Time-sharing parallel wheel hub drive system

Abstract

This invention discloses a time-sharing parallel hub drive system, including a hub, a first motor, a first planetary gear set, and a second motor. The rotor of the first motor is connected to the hub, and the first planetary gear set is connected to either the hub or the rotor of the first motor. The first planetary gear set is also connected to the stator of the first motor. The system also includes an automatic disconnection and engagement device, which is connected to both the first planetary gear set and the second motor. When the first motor is operating and directly providing torque to the hub, the hub or the rotor of the first motor drives the first planetary gear set to rotate. The automatic disconnection and engagement device is in an automatically disconnected state, idling, while the second motor is stationary. When the second motor is operating, it transmits torque to the first planetary gear set through the automatic disconnection and engagement device, thus driving it in parallel with the first motor. This invention has the advantages of simplified structure and reduced cost.

Description

Technical Field

[0001] This invention relates to hub drive systems, and more specifically to a time-sharing parallel hub drive system. Background Technology

[0002] CN112838711A discloses a hub motor with dual motors operating in parallel. The technical solution includes a direct-drive motor and a low-torque motor. The direct-drive motor directly drives the wheels. The direct-drive motor and the low-torque motor share a cooling system. The power input of the low-torque motor is to a first-stage planetary reduction mechanism. The engagement and disengagement of the clutch determine whether power is transmitted from the first-stage planetary reduction mechanism to the second-stage planetary reduction mechanism. The power from the third-stage planetary reduction mechanism is coupled to the outer rotor housing 3 of the direct-drive motor via an outer transmission cover 33, achieving parallel operation of the two motors. When the vehicle needs power, the direct-drive motor runs continuously. When climbing hills or accelerating at low to medium speeds, the low-torque motor transmission system intervenes, providing higher peak torque. When the vehicle speed is high, the low-torque motor disengages to avoid being dragged and generating a high back electromotive force.

[0003] The above scheme uses two motors, three planetary gear sets, and one clutch. The direct-drive motor directly drives the wheels. The low-torque motor, after being reduced in speed and increased in torque by the first planetary gear set, then transmits power to the second and third planetary gear sets via the clutch for further reduction and torque increase, and finally drives the direct-drive motor in parallel. The above scheme has the following drawbacks:

[0004] To achieve the aforementioned direct drive and torque enhancement, a separate control system is required to engage or disengage the clutch. This separate clutch control system requires both electrical control and hydraulic drive components, resulting in a complex structure. Furthermore, the use of three planetary gear sets not only complicates the structure and increases costs, but also leads to high speeds for the low-torque motor at high vehicle speeds, resulting in poor NVH performance. Summary of the Invention

[0005] This invention provides a time-sharing parallel hub drive system with a simplified structure and reduced cost.

[0006] The technical solution to the above problem is as follows:

[0007] The time-sharing parallel hub drive system includes a hub, a first motor, a first planetary gear set, and a second motor. The rotor of the first motor is connected to the hub, the first planetary gear set is connected to the hub or the rotor of the first motor, and the first planetary gear set is also connected to the stator of the first motor. The system also includes an automatic disconnection and engagement device, which is connected to the first planetary gear set and the second motor respectively.

[0008] When the first motor is working and directly provides torque to the hub, the hub or the rotor of the first motor drives the first planetary gear to rotate, the automatic disconnection and engagement device is in the automatic disconnection state, the automatic disconnection and engagement device is idling, and the second motor is in the stationary state.

[0009] When both the first motor and the second motor are working, the first motor directly provides torque to the hub, and the hub or the rotor of the first motor drives the first planetary gear set to rotate. After the second motor provides torque to the automatic disconnection and engagement device, the automatic disconnection and engagement device is automatically engaged. The torque output by the second motor is transmitted to the first planetary gear set through the automatic disconnection and engagement device. After the torque of the first motor and the torque of the second motor are coupled, they are transmitted to the hub through the first planetary gear set.

[0010] The advantages of this invention are:

[0011] 1. In this invention, when the first motor drives in the forward direction, all components of the first planetary gear set rotate freely without load, while the second motor remains stationary. The automatic disconnection and engagement device idles without transmitting torque. When the vehicle requires drive from both the first and second motors, the second motor increases its speed to synchronize the speed of the first planetary carrier of the first planetary gear set with that of the first motor. At this time, the automatic disconnection and engagement device transmits torque, achieving parallel drive of the two motors. Therefore, this invention determines the disconnection or engagement of the automatic disconnection and engagement device based on the speed provided by the first motor and / or the second motor. Consequently, this invention does not require a separate actuator control system for the automatic disconnection and engagement device, thus simplifying the vehicle structure and reducing vehicle production costs.

[0012] 2. When the vehicle's power demand is low, a single-motor drive mode is used; when the vehicle's power demand is high, a dual-motor drive mode is used. Attached Figure Description

[0013] Figure 1 This is the first time-sharing parallel hub drive system of the present invention;

[0014] Figure 2 A cross-sectional view of the automatic disconnection and connection device;

[0015] Figure 3 This is the second type of time-sharing parallel hub drive system of the present invention.

[0016] Labels in the attached diagram:

[0017] Hub 1, First motor 2, Rotor 2a, Stator 2b, Housing 3, First planetary gear set 4, First sun gear 4a, First planetary carrier 4b, First ring gear 4c, First planetary gear 4d, Second motor 5, Stator 5a, Rotor 5b, Automatic disconnection and engagement device 6, Outer ring 6a, Star gear 6b, Rolling element 6c, Push rod 6d, Spring 6e, Shaft 6f, Second planetary gear set 7, Second sun gear 7a, Second planetary carrier 7b, Second ring gear 7c, Second planetary gear 7d. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. The described embodiments are only some, not all, of the embodiments of the present invention. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be simply construed as limiting the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. The embodiments of the present invention will be described in detail below with reference to the accompanying drawings:

[0019] In the description of this invention, it should be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this invention.

[0020] As shown in Figure 1, the first time-sharing parallel hub drive system of the present invention includes a hub 1, a first motor 2, a first planetary gear set 4, a second motor 5, and an automatic disconnection and engagement device 6. The rotor 2a of the first motor 2 is connected to the hub 1, and the connection method is not limited to mechanical methods such as splines. The first planetary gear set 4 is connected to the hub 1 or the rotor 2a of the first motor 2. The first planetary gear set 4 is also connected to the stator 2b of the first motor 2 or the housing 3. The stator 2b of the first motor 2 is connected to the fixed housing 3, and the connection method is not limited to mechanical methods such as splines. The automatic disconnection and engagement device 6 is connected to the first planetary gear set 4 and the second motor 5 respectively. The stator 5a of the second motor 5 is connected to the fixed housing 3, and the connection method is not limited to mechanical methods such as splines.

[0021] When the first motor 2 directly provides torque to the hub 1, the hub 1 or the rotor 2a of the first motor 2 drives the first planetary gear 4 to rotate. The automatic disconnection and engagement device 6 is in an automatic disconnection state, the automatic disconnection and engagement device 6 idles, and the second motor 5 is in a stationary state.

[0022] When both the first motor 2 and the second motor 5 are working, the first motor 2 directly provides torque to the hub 1. The hub 1 or the rotor 2a of the first motor 2 drives the first planetary gear 4 to rotate. After the second motor 5 provides torque to the automatic disconnection and engagement device 6, the automatic disconnection and engagement device 6 automatically engages. The torque output by the second motor 5 is transmitted to the first planetary gear 4 through the automatic disconnection and engagement device 6. The torque of the first motor 2 and the torque of the second motor 5 are coupled and then transmitted to the hub 1 through the first planetary gear 4.

[0023] The first planetary gear set 4 includes a first sun gear 4a, a first planet carrier 4b, a first ring gear 4c, and first planet gears 4d. The first ring gear 4c is connected to the stator 2b of the first motor 2, and the connection method is not limited to splines or other mechanical methods. The first planet carrier 4b is connected to the hub 1 or the rotor 2a of the first motor 2, and the connection method is not limited to splines or other mechanical methods. The first planet carrier 4b is also connected to the first planet gears 4d, and the first planet gears 4d respectively mate with the first sun gear 4a and the first ring gear 4c. The first sun gear 4a is connected to the automatic disconnection and engagement device 6. The first ring gear 4c of the first planetary gear set 4 can also be connected to the fixed housing 3.

[0024] The automatic disconnection and connection device 6 includes an outer ring 6a, a star wheel 6b, a rolling element 6c, a push rod 6d, a spring 6e, and a shaft 6f. The star wheel 6b has an opening on its circumference and a mounting hole corresponding to the opening. After the star wheel 6b is fitted into the outer ring 6a, a wedge gap is formed between the star wheel 6b and the outer ring 6a. The rolling element 6c is fitted into the wedge gap. The spring 6e is located in the mounting hole on the star wheel 6b. One end of the push rod 6d is located in the mounting hole and abuts against the spring 6e. The other end of the push rod 6d is fitted with the rolling element 6c. The shaft 6f is fixed to the star wheel 6b. In this embodiment, the outer ring 6a is connected to the rotor 5b of the second motor 5, and the shaft 6f is connected to the first sun gear 4a.

[0025] With the above structural configuration, this embodiment has the following operating modes;

[0026] 1. Single motor drive mode

[0027] The rotor 2a of the first motor 2 rotates, driving the connected hub 1 to rotate as well, thereby driving the vehicle. At this time, the first planetary carrier 4b rotates together with the hub 1 and the rotor 2a. The torque of the first planetary carrier 4b is transmitted to the shaft 6f sequentially through the first planetary gear 4d and the first sun gear 4a, causing the shaft 6f to rotate. The shaft 6f and the driving planetary gear 6b ​​rotate counterclockwise (from...). Figure 2When viewed from above, because the rotational speed of the star wheel 6b is higher than that of the outer ring 6a, the rolling element 6c disengages from the wedge, and the outer ring 6a loses its connection with the star wheel 6b. Thus, the outer ring 6a and the star wheel 6b are in a disconnected state, meaning the automatic disconnection and engagement device 6 is in a disconnected state. The torque of the first planetary gear set 4 cannot be transmitted to the second motor 5 through the automatic disconnection and engagement device 6, and the first planetary gear set 4 idles without load. The automatic disconnection and engagement device 6 not transmitting torque allows a speed difference between the first sun gear 4a of the first planetary gear set 4 and the rotor 5b of the second motor 5, specifically keeping the rotor 5b of the second motor 5 stationary. This mode is suitable for low to medium load conditions, increasing the load rate of a single motor, allowing the motor to operate in its high-efficiency range, and reducing energy consumption.

[0028] 2. Dual-motor parallel drive mode

[0029] Both the first motor 2 and the second motor 5 are in an electrically driven state. The rotor 2a of the first motor 2 rotates, driving the connected hub 1 to rotate together, thereby driving the vehicle. The rotor 5b of the second motor 5 rotates. When the shaft 6f is driven to rotate by the first sun gear 4a, the shaft 6f and the drive star gear 6b ​​rotate counterclockwise (as shown in the figure). The outer ring 6a is driven to rotate counterclockwise by the rotor 5b of the second motor 5. When the speed of the outer ring 6a is greater than the speed of the star gear 6b, the rolling element 6c is clamped between the outer ring 6a and the star gear 6b ​​under the action of friction. At this time, the outer ring 6a and the star gear 6b ​​are in a coupled state, that is, the automatic disconnection and coupling device 6 is in a coupled state. The torque output by the second motor 5 is transmitted to the sun gear 4a of the first planetary gear set 4 through the automatic disconnection and coupling device 6. After the first planetary gear set 4 completes the deceleration and torque increase, it is output to the hub 1 through the first planet carrier 4b. At this time, the power of the first motor 2 and the second motor 5 is coupled, and the first motor 2 and the second motor 5 are in a parallel drive state. This operating condition is suitable for medium to high load conditions. The first planetary gear set 4 is used to achieve speed reduction and torque increase, enabling the second motor 5 to be miniaturized and optimizing the high-efficiency range, providing greater power while reducing energy consumption.

[0030] 3. Reversing working mode

[0031] The rotor 2a of the first motor 2 rotates in the opposite direction, causing the connected wheel hub 1 to rotate together, thereby driving the vehicle.

[0032] 4. Braking energy recovery working mode

[0033] When the vehicle decelerates or brakes, the first motor 2 switches from the driving state to the generating state to convert the kinetic energy loss during vehicle braking into electrical energy to charge the battery and reduce energy consumption.

[0034] 5. When the vehicle speed is high, the second motor 5 does not need to participate in driving and automatically disconnects from the coupling device 6 to idle, and the second motor 5 stops to avoid being dragged and generating a high back electromotive force.

[0035] This invention is not limited to the above embodiments, such as Figure 3 For example, to improve the system's power performance, the present invention may, based on the first embodiment described above, provide a speed change device on the first planetary carrier 4b or the first sun gear 4a.

[0036] Preferably, the transmission device is a second planetary gear set 7, which is located between the first planetary gear set 4 and the automatic disconnection and engagement device 6. The second planetary gear set 7 is connected to the housing 3 or the stator 2a of the first motor 2, the first planetary gear set 4 and the automatic disconnection and engagement device 6 respectively.

[0037] The second planetary gear set 7 includes a second sun gear 7a, a second planetary carrier 7b, a second ring gear 7c, and a second planetary gear 7d. The second ring gear 7c is connected to the stator 2b of the first motor 2. The second planetary carrier 7b is connected to the first planetary gear set 4. The second planetary carrier 7b is also connected to the second planetary gear 7d. The second planetary gear 7d is respectively engaged with the second sun gear 7a and the second ring gear 7c. The second sun gear 7a is connected to the automatic disconnection and engagement device 6.

[0038] The above is a detailed description of the present technical solution. It should be understood that, due to the limitations of language and the diversity of technical solutions, those skilled in the art can also implement the present technical solution by making equivalent substitutions in the text, syntax or other ways. Therefore, such substitutions should be considered within the scope of protection of this application.

Claims

1. A time-sharing parallel hub drive system, comprising a hub (1), a first motor (2), a first planetary gear set (4), and a second motor (5), wherein the rotor (2a) of the first motor (2) is connected to the hub (1), the first planetary gear set (4) is connected to either the hub (1) or the rotor (2a) of the first motor (2), and the first planetary gear set (4) is also connected to the stator (2b) or the housing (3) of the first motor (2), characterized in that, It also includes an automatic disconnection and engagement device (6), which is connected to the first planetary gear set (4) and the second motor (5) respectively, so that the time-sharing parallel hub drive system can operate in a single motor drive mode and a dual motor parallel drive mode: The automatic disconnection and connection device (6) includes an outer ring (6a), a star wheel (6b), a rolling element (6c), a push rod (6d), a spring (6e), and a shaft (6f). The star wheel (6b) has an opening on its circumference and a mounting hole corresponding to the opening. After the star wheel (6b) is fitted into the outer ring (6a), a wedge gap is formed between the star wheel (6b) and the outer ring (6a). The rolling element (6c) is fitted into the wedge gap. The spring (6e) is located in the mounting hole on the star wheel (6b). One end of the push rod (6d) is located in the mounting hole and abuts against the spring (6e). The other end of the push rod (6d) is fitted with the rolling element (6c). The shaft (6f) is fixed to the star wheel (6b). The first planetary gear set (4) includes a first sun gear (4a), a first planetary carrier (4b), a first ring gear (4c), and a first planetary gear (4d). The first ring gear (4c) is connected to the stator (2b) of the first motor (2). The first planetary carrier (4b) is connected to the hub (1) or the rotor (2a) of the first motor (2). The first planetary carrier (4b) is also connected to the first planetary gear (4d). The first planetary gear (4d) is engaged with the first sun gear (4a) and the first ring gear (4c) respectively. The first sun gear (4a) is connected to the automatic disconnection and engagement device (6). It also includes a second planetary gear set (7) for changing speed. The second planetary gear set (7) is located between the first planetary gear set (4) and the automatic disconnection and connection device (6). The second planetary gear set (7) is connected to the stator (2a) of the housing (3) or the first motor (2), the first planetary gear set (4) and the automatic disconnection and connection device (6). The single-motor drive operating mode is as follows: When the speed of the second motor (5) is lower than or equal to the speed of the first motor (2), the rolling element (6c) in the automatic disconnection and engagement device (6) is released from the wedge formed by the star wheel (6b) and the outer ring (6a), the star wheel (6b) and the outer ring (6a) are disconnected from the power association, the first planetary gear set (4) rotates without load, so that the automatic disconnection and engagement device (6) does not transmit torque, so as to avoid the second motor (5) being dragged and generating back electromotive force, protecting the motor and battery system while reducing energy consumption; The dual-motor parallel drive working mode is as follows: When the speed of the second motor (5) is higher than that of the first motor (2), the rolling element (6c) of the automatic disconnection and coupling device (6) automatically clamps and engages under the action of friction, so that the torque output by the second motor (5) can be transmitted to the sun gear (4a) of the first planetary gear (4) through the automatic disconnection and coupling device (6), so that the first motor (2) and the second motor (5) are coupled.

2. The time-sharing parallel hub drive system according to claim 1, characterized in that, The second planetary gear set (7) includes a second sun gear (7a), a second planetary carrier (7b), a second ring gear (7c), and a second planetary gear (7d). The second ring gear (7c) is connected to the stator (2b) or housing (3) of the first motor (2). The second planetary carrier (7b) is connected to the first planetary gear set (4). The second planetary carrier (7b) is also connected to the second planetary gear (7d). The second planetary gear (7d) is engaged with the second sun gear (7a) and the second ring gear (7c) respectively. The second sun gear (7a) is connected to the automatic disconnection and engagement device (6).

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