Four-speed wheel hub electric drive system for off-road vehicles

Abstract

The present application belongs to the field of new energy vehicle electric drive technology, and particularly relates to a four-gear hub electric drive system for off-road vehicles, comprising a hub motor and a planetary transmission. The hub motor comprises a hub motor stator and a hub motor rotor, and the planetary transmission comprises components 1-7, planetary gears PGS1, PGS2 and PGS3, brakes B1 and B2, and one-way clutches C1 and C2, and four forward gears can be achieved. The use of one-way clutches can reduce the volume and weight of the system to achieve lightweight, the four forward gears can be simply shifted to reduce the difficulty of the control system, the planetary gears PGS2 and PGS3 can adopt an equal k value structure to simplify the types of gears to improve the economy of the system, and the transmission ratio range of the four forward gears is wider.

Description

Technical Field

[0001] This invention belongs to the field of electric drive technology for new energy vehicles, and specifically relates to a four-speed wheel hub electric drive system for off-road vehicles. Background Technology

[0002] In-wheel electric drive systems place the powertrain inside the vehicle's wheel rim, representing a distributed drive system. Currently, in-wheel electric drive systems mainly employ three forms: in-wheel motor direct drive, in-wheel motor paired with a reducer, and in-wheel motor paired with a transmission. Off-road vehicles primarily use the in-wheel motor paired with a reducer form.

[0003] Off-road vehicles operate under complex conditions, requiring higher driving torque from the wheels. Existing in-wheel electric drive systems with in-wheel motors and reducers struggle to simultaneously meet the demands of maximum wheel speed and maximum output torque, resulting in excessive design margins for the in-wheel motors and low system power density. As in-wheel motor technology advances, their rotational speeds increase, exacerbating this contradiction. To fully utilize the performance of in-wheel motors and improve the technical specifications of in-wheel electric drive systems in terms of power density, cost, and lightweight design, it is necessary to develop in-wheel electric drive systems that combine in-wheel motors with a transmission. Summary of the Invention

[0004] (a) Technical problems to be solved

[0005] The technical problem this invention aims to solve is: how to provide a four-speed in-wheel electric drive system for off-road vehicles, employing an in-wheel motor matched with a transmission to achieve four forward gears. It offers a wide transmission ratio range; in first gear, it meets the maximum output torque requirement of the in-wheel electric drive system, while in fourth gear, it meets the maximum wheel speed requirement, thus solving the technical problem of simultaneously achieving maximum wheel speed and maximum drive torque in off-road vehicles. Simultaneously, it addresses the increased size and weight associated with multi-speed transmissions, and reduces the cost of the drive system.

[0006] (II) Technical Solution

[0007] To solve the above-mentioned technical problems, the present invention provides a four-speed wheel hub electric drive system for off-road vehicles, the four-speed wheel hub electric drive system for off-road vehicles includes: a wheel hub motor (①) and a planetary transmission (②);

[0008] The hub motor (①) includes: a hub motor stator (8) and a hub motor rotor (9);

[0009] The planetary transmission (②) includes: a transmission component assembly, a planetary gear set assembly, a brake assembly, and a one-way clutch assembly;

[0010] The transmission component assembly includes: a first component (1), a second component (2), a third component (3), a fourth component (4), a fifth component (5), a sixth component (6), and a seventh component (7);

[0011] The planetary array assembly includes: a first planetary array PGS1, a second planetary array PGS2, and a third planetary array PGS3;

[0012] The brake assembly includes: a first brake B1 and a second brake B2;

[0013] The one-way clutch assembly includes: a first one-way clutch C1 and a second one-way clutch C2;

[0014] The hub motor rotor (9) is connected to the first component (1);

[0015] The hub motor stator (8) is connected to the seventh component (7);

[0016] The first planetary gear set PGS1 includes a first sun gear S1, a first planet carrier CA1 and a first gear ring R1, which are connected to the seventh component (7), the first component (1) and the fifth component (5) respectively;

[0017] The second planetary gear set PGS2 includes a second sun gear S2, a second planet carrier CA2, and a second gear ring R2, which are connected to the sixth component (6), the third component (3), and the fourth component (4), respectively.

[0018] The third planetary gear set PGS3 includes a third sun gear S3, a third planet carrier CA3, and a third gear ring R3, which are connected to the fourth component (4), the third component (3), and the second component (2), respectively.

[0019] The first brake B1 is used to brake the third component (3);

[0020] The second brake B2 is used to brake the fourth component (4);

[0021] The first one-way clutch C1 is used to connect the fifth component (5) and the sixth component (6);

[0022] The second one-way clutch C2 is used to connect the third component (3) and the fifth component (5).

[0023] When the first one-way clutch C1 and the first brake B1 are engaged, the fifth component (5) and the sixth component (6) are connected and rotate as a whole, and the third component (3) brakes to achieve first gear.

[0024] When the first one-way clutch C1 and the second brake B2 are engaged, the fifth component (5) and the sixth component (6) are connected and rotate as a whole, and the fourth component (4) brakes, thus achieving second gear.

[0025] When the first one-way clutch C1 and the second one-way clutch C2 are engaged, the fifth component (5) and the sixth component (6) are connected and rotate as a whole, and the third component (3) and the fifth component (5) are connected and rotate as a whole, thus achieving three gears.

[0026] When the second one-way clutch C2 and the second brake B2 are engaged, the third component (3) and the fifth component (5) are connected and rotate as a whole, and the fourth component (4) brakes, thus achieving four gears.

[0027] The hub motor (①) is a permanent magnet synchronous inner rotor motor.

[0028] (III) Beneficial Effects

[0029] Compared to existing in-wheel electric drive systems for off-road vehicles that use in-wheel motors paired with reducers, the four-speed in-wheel electric drive system for off-road vehicles proposed in this invention employs an in-wheel motor paired with a four-speed transmission, including an in-wheel motor and a planetary transmission. The in-wheel motor includes an in-wheel motor stator and an in-wheel motor rotor. The planetary transmission includes first components 1 to seventh components 7, planetary gear sets PGS1, PGS2, and PGS3, brakes B1 and B2, and one-way clutches C1 and C2, enabling four forward gears. The one-way clutches are compact, small in size, and lightweight, reducing the system's size and weight for weight reduction. The four forward gear operation scheme allows for switching only one control component per gear change, all of which are simple shifts, reducing the difficulty of shift control. Simultaneously, it improves shift quality, ensuring smooth shifting and reducing shift shock. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the four-speed wheel hub electric drive system for off-road vehicles according to the present invention.

[0031] Among them, ① is the hub motor, and ② is the planetary gearbox;

[0032] 1~7——First component, second component, third component, fourth component, fifth component, sixth component, seventh component;

[0033] PGS1, PGS2, and PGS3 – First Planetary Sorting, Second Planetary Sorting, and Third Planetary Sorting;

[0034] B1, B2 – First brake, second brake;

[0035] C1, C2 – First one-way clutch, second one-way clutch;

[0036] S1, CA1, R1 – the first sun gear, the first planet carrier, and the first gear ring of the first planetary gear set PGS1; S2, CA2, R2 – the second sun gear, the second planet carrier, and the second gear ring of the second planetary gear set PGS2; S3, CA3, R3 – the third sun gear, the third planet carrier, and the third gear ring of the third planetary gear set PGS3.

[0037] 8 – Stator of hub motor; 9 – Rotor of hub motor. Detailed Implementation

[0038] To make the objectives, contents, and advantages of the present invention clearer, the specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples.

[0039] To solve the above-mentioned technical problems, the present invention provides a four-speed wheel hub electric drive system for off-road vehicles, the four-speed wheel hub electric drive system for off-road vehicles includes: a wheel hub motor (①) and a planetary transmission (②);

[0040] The hub motor (①) includes: a hub motor stator (8) and a hub motor rotor (9);

[0041] The planetary transmission (②) includes: a transmission component assembly, a planetary gear set assembly, a brake assembly, and a one-way clutch assembly;

[0042] The transmission component assembly includes: a first component (1), a second component (2), a third component (3), a fourth component (4), a fifth component (5), a sixth component (6), and a seventh component (7);

[0043] The planetary array assembly includes: a first planetary array PGS1, a second planetary array PGS2, and a third planetary array PGS3;

[0044] The brake assembly includes: a first brake B1 and a second brake B2;

[0045] The one-way clutch assembly includes: a first one-way clutch C1 and a second one-way clutch C2;

[0046] The hub motor rotor (9) is connected to the first component (1);

[0047] The hub motor stator (8) is connected to the seventh component (7);

[0048] The first planetary gear set PGS1 includes a first sun gear S1, a first planet carrier CA1 and a first gear ring R1, which are connected to the seventh component (7), the first component (1) and the fifth component (5) respectively;

[0049] The second planetary gear set PGS2 includes a second sun gear S2, a second planet carrier CA2, and a second gear ring R2, which are connected to the sixth component (6), the third component (3), and the fourth component (4), respectively.

[0050] The third planetary gear set PGS3 includes a third sun gear S3, a third planet carrier CA3, and a third gear ring R3, which are connected to the fourth component (4), the third component (3), and the second component (2), respectively.

[0051] The first brake B1 is used to brake the third component (3);

[0052] The second brake B2 is used to brake the fourth component (4);

[0053] The first one-way clutch C1 is used to connect the fifth component (5) and the sixth component (6);

[0054] The second one-way clutch C2 is used to connect the third component (3) and the fifth component (5).

[0055] When the first one-way clutch C1 and the first brake B1 are engaged, the fifth component (5) and the sixth component (6) are connected and rotate as a whole, and the third component (3) brakes to achieve first gear.

[0056] When the first one-way clutch C1 and the second brake B2 are engaged, the fifth component (5) and the sixth component (6) are connected and rotate as a whole, and the fourth component (4) brakes, thus achieving second gear.

[0057] When the first one-way clutch C1 and the second one-way clutch C2 are engaged, the fifth component (5) and the sixth component (6) are connected and rotate as a whole, and the third component (3) and the fifth component (5) are connected and rotate as a whole, thus achieving three gears.

[0058] When the second one-way clutch C2 and the second brake B2 are engaged, the third component (3) and the fifth component (5) are connected and rotate as a whole, and the fourth component (4) brakes, thus achieving four gears.

[0059] The hub motor (①) is a permanent magnet synchronous inner rotor motor.

[0060] Example 1

[0061] The four-speed in-wheel electric drive system for off-road vehicles proposed in this embodiment includes an in-wheel motor ① and a planetary transmission ②, arranged horizontally from left to right. The planetary gear set PGS1 of the planetary transmission ② is nested inside the in-wheel motor ①. Figure 1 As shown.

[0062] The hub motor ① includes a hub motor stator 8 and a hub motor rotor 9, and the planetary gearbox ② includes components 1 to 7, planetary gear sets PGS1 to PGS3, brakes B1 to B2, and one-way clutches C1 to C2.

[0063] The hub motor ① can be a permanent magnet synchronous internal rotor motor, with hub motor rotor 9 connected to component 1 and hub motor stator 8 connected to component 7.

[0064] Planetary gear set PGS1 includes a sun gear S1, a planet carrier CA1, and a ring gear R1, which are connected to components 7, 1, and 5, respectively; planetary gear set PGS2 includes a sun gear S2, a planet carrier CA2, and a ring gear R2, which are connected to components 6, 3, and 4, respectively; planetary gear set PGS3 includes a sun gear S3, a planet carrier CA3, and a ring gear R3, which are connected to components 4, 3, and 2, respectively.

[0065] Brake B1 is used to brake component 3, and brake B2 is used to brake component 4; one-way clutch C1 is used to connect component 5 and component 6, and one-way clutch C2 is used to connect component 3 and component 5.

[0066] When the one-way clutch C1 and the brake B1 are engaged, components 5 and 6 are connected and rotate as a whole, and component 3 is braked, thus achieving first gear.

[0067] When the one-way clutch C1 and the brake B2 are engaged, components 5 and 6 rotate as a whole after being connected, and component 4 brakes, thus achieving second gear.

[0068] When one-way clutch C1 and one-way clutch C2 are engaged, component 5 and component 6 are connected and rotate as a whole, and component 3 and component 5 are connected and rotate as a whole, thus achieving three gears;

[0069] When the one-way clutch C2 and the brake B2 are engaged, components 3 and 5 rotate as a whole after being connected, and component 4 brakes, thus achieving fourth gear.

[0070] like Figure 1 In the embodiment shown, when the k values ​​of the planetary gear set PGS1 to PGS3 are k1 = -1.073, k2 = 2.50 and k3 = 2.50 respectively, the parameters of the four gears can be obtained, as listed in the table below.

[0071]

[0072] Note: In the table, “〇” indicates that the control element is engaged, and “×” indicates that the control element is disengaged.

[0073] In this example, planetary gear sets PGS2 and PGS3 adopt equal k-value structural parameters. The gear tooth parameters of the sun gear, planet gears and ring gear of the two planetary gear sets can be designed uniformly, reducing the types of gears, lowering gear processing costs, and improving the system's economy. In this example, the transmission ratio range of the four forward gears is wider, reaching 8.75.

[0074] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principle of the present invention and without changing the connection relationship, such as changing the arrangement position of the planetary gear set and the one-way clutch, or modifying the first planetary gear set into a simple double-planet gear set. These improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An off-road vehicle four-gear hub electric drive system, characterized in that, The off-road vehicle four-gear hub motor driving system comprises a hub motor (①) and a planetary transmission (②); The hub motor (①) comprises a hub motor stator (8) and a hub motor rotor (9); The planetary transmission (②) comprises a transmission component assembly, a planetary gear set assembly, a brake assembly and a one-way clutch assembly; The transmission component assembly comprises a first component (1), a second component (2), a third component (3), a fourth component (4), a fifth component (5), a sixth component (6) and a seventh component (7); The planetary gear set assembly comprises a first planetary gear set PGS1, a second planetary gear set PGS2 and a third planetary gear set PGS3; The brake assembly comprises a first brake B1 and a second brake B2; The one-way clutch assembly comprises a first one-way clutch C1 and a second one-way clutch C2; The hub motor rotor (9) is connected to the first component (1); The hub motor stator (8) is connected to the seventh component (7); The first planetary gear set PGS1 comprises a first sun gear S1, a first carrier CA1 and a first ring gear R1, which are connected to the seventh component (7), the first component (1) and the fifth component (5) respectively; The second planetary gear set PGS2 comprises a second sun gear S2, a second carrier CA2 and a second ring gear R2, which are connected to the sixth component (6), the third component (3) and the fourth component (4) respectively; The third planetary gear set PGS3 comprises a third sun gear S3, a third carrier CA3 and a third ring gear R3, which are connected to the fourth component (4), the third component (3) and the second component (2) respectively; The first brake B1 is used to brake the third component (3); The second brake B2 is used to brake the fourth component (4); The first one-way clutch C1 is used to connect the fifth component (5) and the sixth component (6); The second one-way clutch C2 is used to connect the third component (3) and the fifth component (5); When the first one-way clutch C1 and the first brake B1 are combined, the fifth component (5) and the sixth component (6) rotate as a whole after being connected, the third component (3) is braked, and the first gear is realized.

2. An off-road vehicle four-speed hub electric drive system as in claim 1 wherein, When the first one-way clutch C1 and the second brake B2 are combined, the fifth component (5) and the sixth component (6) rotate as a whole after being connected, the fourth component (4) is braked, and the second gear is realized.

3. The off-road vehicle four-speed hub electric drive system of claim 2, wherein, When the first one-way clutch C1 and the second one-way clutch C2 are combined, the fifth component (5) and the sixth component (6) rotate as a whole after being connected, the third component (3) and the fifth component (5) rotate as a whole after being connected, and the third gear is realized.

4. The off-road vehicle four-speed hub electric drive system of claim 3, wherein, When the second one-way clutch C2 and the second brake B2 are combined, the third component (3) and the fifth component (5) rotate as a whole after being connected, the fourth component (4) is braked, and the fourth gear is realized.

5. The off-road vehicle four-speed hub electric drive system of claim 4, wherein, The hub motor (①) adopts a permanent magnet synchronous inner rotor motor.

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