Transmission, drive system, and vehicle

Abstract

The application belongs to the technical field of transmission mechanisms, and discloses a transmission mechanism, a driving system and a vehicle, which comprise a first gear, a first gear ring, a second gear and a second gear ring, the first gear is located on the inner side of the first gear ring and is engaged with the first gear ring, the second gear is located on the inner side of the second gear ring and is engaged with the second gear ring, and the first gear ring and the second gear are drivingly connected in a manner that they cannot rotate relative to each other. The application realizes the step-by-step transmission of power in the radial direction through a two-stage internal meshing gear structure, expands the speed ratio range under the premise of not increasing the outer contour size of the transmission device, significantly improves the torque density, and thus improves the power output performance of the vehicle.

Description

Technical Field

[0001] This application relates to the field of transmission mechanism technology, and in particular to a drive system and vehicle. Background Technology

[0002] Wheel-side drive systems in vehicles are typically required to have small dimensions due to space constraints. However, compact wheel-side drive systems in related technologies suffer from low torque density, limiting the output capacity of the vehicle's drivetrain. Utility Model Content

[0003] This application aims to solve one of the technical problems existing in the prior art. Therefore, one objective of this application is to provide a transmission device that can improve torque density and enhance the power output performance of a vehicle.

[0004] This application proposes a transmission mechanism including a first gear, a first gear ring, a second gear, and a second gear ring. The first gear is located inside the first gear ring and meshes with it, and the second gear is located inside the second gear ring and meshes with it. The first gear ring and the second gear are connected in a transmission manner that prevents them from rotating relative to each other.

[0005] This application utilizes a two-stage internal meshing gear structure to achieve radial, step-by-step power transmission, expanding the speed ratio range without increasing the external dimensions of the transmission device, significantly improving torque density, and thus enhancing vehicle power output performance.

[0006] In some embodiments of this application, the first gear ring and the second gear are connected by a key, or the first gear ring and the second gear are fixedly connected, or the first gear ring and the second gear are an integral part.

[0007] In some embodiments of this application, the first gear ring and the second gear are arranged radially on the first gear ring.

[0008] In some embodiments of this application, the first gear ring and the second gear are arranged coaxially, and the axis of the first gear, the axis of the second gear, and the axis of the second gear ring are located in the same plane.

[0009] In some embodiments of this application, the axis of the second gear ring, the axis of the second gear, and the axis of the first gear are arranged sequentially in a predetermined direction.

[0010] In some embodiments of this application, the axis of the second gear ring and the axis of the first gear are arranged sequentially in a first direction, and the angle between the first direction and the direction of gravity is not 0°.

[0011] In some embodiments of this application, the rotation direction of the teeth of the first gear is the same as that of the teeth of the second gear.

[0012] This application proposes a drive system including a transmission mechanism according to any of the above embodiments.

[0013] In some embodiments of this application, the drive system further includes a planetary mechanism, which is connected to a transmission mechanism. The transmission mechanism is adapted to be connected to a power source, and the planetary mechanism of the transmission mechanism is adapted to be connected to a wheel.

[0014] This application proposes a vehicle including the drive system of any of the above embodiments. Attached Figure Description

[0015] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0016] Figure 1 This is a schematic diagram of the transmission mechanism provided in an embodiment of this application.

[0017] Figure 2 This is a schematic diagram of the driving system provided in an embodiment of this application.

[0018] Figure label:

[0019] 1. Transmission mechanism; 11. First gear; 12. First gear ring; 121. First bearing; 13. Second gear; 14. Second gear ring; 141. Second bearing; 2. Planetary mechanism; 21. Sun gear; 22. Planet gears; 23. Planet carrier; 24. Connecting shaft; 25. Housing; 26. End cover; 3. Input shaft; 31. Input bearing; 4. Support bushing; 5. Hub; 51. Wheel end bearing Detailed Implementation

[0020] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0021] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application 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, and therefore should not be construed as a limitation of this application.

[0022] In the description of this application, "first feature" and "second feature" may include one or more of the features.

[0023] In the description of this application, "multiple" means two or more, and "several" means one or more.

[0024] Buses are a major mode of transportation in cities. Due to the need for large interior space and comfortable passenger capacity, they typically use wheel-side drive axles. The drive unit is located at the wheel end, and the limited installation space restricts the torque output capacity of traditional wheel-side drive axles.

[0025] This application proposes a transmission mechanism 1, including a first gear 11, a first gear ring 12, a second gear 13, and a second gear ring 14. The first gear 11 is located inside the first gear ring 12 and meshes with the first gear ring 12. The second gear 13 is located inside the second gear ring 14 and meshes with the second gear ring 14. The first gear ring 12 and the second gear 13 are connected in a transmission manner that prevents them from rotating relative to each other.

[0026] This application provides a transmission mechanism 1, such as... Figure 1 As shown, the transmission mechanism 1 includes a first gear 11, a first gear ring 12, a second gear 13, and a second gear ring 14. The first gear 11 is located inside the first gear ring 12 and meshes with it. The second gear 13 is located inside the second gear ring 14 and meshes with it. The first gear ring 12 and the second gear 13 are connected in a non-rotatable manner. The first gear 11 and the first gear ring 12 constitute the first stage of transmission, and the second gear 13 and the second gear ring 14 constitute the second stage of transmission. Power can be input from the first gear 11, transmitted through the first gear ring 12 to the second gear 13, then transmitted from the second gear 13 to the second gear ring 14, and finally output to the wheel end.

[0027] By using a two-stage internal meshing gear structure, power is transmitted radially step by step, expanding the speed ratio range without increasing the outer dimensions of the transmission mechanism 1, significantly improving torque density, and thus enhancing the vehicle's power output performance.

[0028] Torque density refers to the torque generated per unit volume or unit mass of a power device. It can be understood that for the same power input, a higher output torque, smaller volume, lighter mass, and higher torque density are all desirable. Compared to the single-stage transmission setup of common internal meshing wheel-side transmission devices, under the same profile dimensions, the transmission mechanism 1 of this application, employing a two-stage transmission, can achieve a wider speed ratio range, provide greater output torque, or reduce the input power of the power source, thereby reducing the size of the power source, such as the motor. Under the same speed ratio, the transmission mechanism 1 of this application, by distributing the total transmission ratio to two pairs of gears, can significantly reduce the size of the driven gear, resulting in a smaller profile dimension, a more compact structure, and a higher degree of lightweighting.

[0029] Comparative analysis shows that the wheel-side drive system using the transmission mechanism 1 of this application embodiment can achieve a 20% weight reduction.

[0030] On the other hand, compared with external meshing, internal meshing gear pairs have higher contact strength, which can improve the load-bearing capacity and transmission stability of the entire transmission system.

[0031] In actual production applications, the root of the teeth of at least one of the first gear 11, the first gear ring 12, the second gear 13, and the second gear ring 14 can be shot-peened to strengthen them. The size of the transmission mechanism 1 can be further reduced by reducing the size of these gears, thereby achieving the ultimate in small size and lightweight design.

[0032] In some embodiments of this application, the first gear ring 12 and the second gear 13 are connected by a key.

[0033] The first gear ring 12 and the second gear 13 can be connected by either a flat key or a spline. Compared to the flat key connection, the spline connection has better load-bearing capacity and also has a centering and guiding function, while causing less weakening of the strength of the first gear ring 12 or the second gear 13.

[0034] In one embodiment, the first gear ring 12 and the second gear 13 are splined and press-fitted to ensure the reliability of torque transmission. The spline tooth profile adopts an involute tooth profile, which effectively reduces meshing impact. The press-fitting interference is controlled at 0.03–0.05 mm. After press-fitting, low-temperature tempering is performed to eliminate residual stress and ensure that there is no loosening or creep during long-term service.

[0035] In some embodiments of this application, the first gear ring 12 and the second gear 13 are fixedly connected.

[0036] The first gear ring 12 and the second gear 13 can be fixedly connected by fasteners or welded into a single structure. This direct fixed connection method can, on the one hand, improve the connection rigidity, reduce mechanism deformation, and reduce transmission noise of the transmission mechanism 1, and on the other hand, reduce transmission efficiency loss.

[0037] In some embodiments of this application, the first gear ring 12 and the second gear 13 are integral parts.

[0038] In a preferred embodiment, such as Figure 1 The first gear ring 12 and the second gear 13 are integral parts. The first gear ring 12 and the second gear 13 can adopt an integral forging structure, and the material can be carburized and quenched alloy steel 20CrMnTiH. Through precision cold forging, assembly gaps are eliminated, avoiding the risk of fatigue fracture caused by stress concentration in the keyway. Compared with assembly and welding methods, the fatigue life is significantly improved by integral forming.

[0039] In some embodiments of this application, the first gear ring 12 and the second gear 13 are arranged radially on the first gear ring 12.

[0040] like Figure 2 As shown, the first gear ring 12 and the second gear 13 are arranged radially on the first gear ring 12. This arrangement achieves the smallest axial dimension compared to arranging them axially. That is, the axial dimension of the transmission mechanism 1 can depend only on the widest of the first gear 11, the first gear ring 12, the second gear 13, and the second gear ring 14. This arrangement allows the entire transmission chain to extend entirely radially, effectively compressing the axial dimension and facilitating integration into a compact wheel-side space.

[0041] In some embodiments, such as Figure 2 The first gear ring 12 and the second gear 13 are integrally formed. The teeth of the first gear ring 12 and the second gear 13 are respectively located on the radial inner and outer sides of the integral structure. The axial connecting section between the first gear ring 12 and the second gear 13 is eliminated. This layout increases the distance between the left and right wheel drive devices of the vehicle by compressing the axial dimension of the entire transmission system. For buses, this increased distance can directly increase the aisle width between the seats on both sides of the vehicle, improving the accessibility for wheelchairs and other vehicles. This layout also minimizes the gear load transmission path, with the torque transmission path only along the radial direction, reducing transmission efficiency loss.

[0042] In some embodiments, the first gear ring 12 and the second gear 13 are arranged coaxially, and the axis of the first gear 11, the axis of the second gear 13, and the axis of the second gear ring 14 are located in the same plane.

[0043] This design ensures that the meshing centers of all gears are located in the same plane, avoiding uneven load distribution caused by axial misalignment. The coplanarity of the three axes facilitates a self-balancing structure in the entire transmission system under radial force, reducing the probability of uneven force on any particular gear or gear ring, improving the transmission smoothness, reducing transmission noise, and extending the life of the bearings supporting the gears or gear ring.

[0044] In some embodiments, the axes of the second gear ring 14, the first gear 11, and the second gear 13 are arranged sequentially in a predetermined direction.

[0045] In other embodiments, the axis of the second gear ring 14, the axis of the second gear 13, and the axis of the first gear 11 are arranged sequentially in a predetermined direction.

[0046] The second arrangement method mentioned above, such as Figure 2Compared to the first arrangement (not shown), the meshing force from the first gear 11 on the first gear ring 12 and the meshing force from the second gear ring 14 on the second gear ring 14 are in opposite directions. This can offset some of the radial meshing force, optimize the force distribution on the first gear ring 12 and the second gear 13, resulting in smoother transmission of the transmission mechanism 1, better structural strength and load-bearing capacity, and lower meshing noise. Furthermore, the reduced force on the first gear ring 12 and the second gear 13 can also extend the lifespan of the corresponding support bearings.

[0047] In some embodiments of this application, the axis of the second gear ring 14 and the axis of the first gear 11 are arranged sequentially in a first direction, and the angle between the first direction and the gravity direction is not 0°.

[0048] The second gear ring 14 serves as the output element, and the first gear 11 serves as the input element. The input element is typically coaxially connected to a power source, such as a motor. This means that the axial position of the first gear 11 determines the vertical arrangement of the power source. When the second gear ring 14 and the first gear 11 are arranged sequentially in the direction of gravity, the height of the power source is at its lowest. Furthermore, since the output element is typically coaxially fixed to the wheel hub 5, meaning the second gear ring 14 itself is already quite low, if the axis of the first gear 11 is directly below the axis of the second gear ring 14, the height of the first gear 11 is already very low, further reducing the ground clearance of the vehicle's drive system. Excessively low ground clearance is detrimental to the vehicle's passability.

[0049] Therefore, the angle between the first direction and the direction of gravity is not 0°, which helps to increase the vehicle's ground clearance and thus improve the vehicle's passability.

[0050] The angle between the first direction and the direction of gravity can be 45°, 60°, 90°, 180°, etc.

[0051] Preferably, such as Figure 2 The cross-sectional view of the drive axle parallel to the ground shows that the angle between the first direction and the gravity direction is 90°, and the angle relative to the first gear 11 is 180° (directly above the axis of the second gear ring 14). This allows the vehicle to have a moderate ground clearance, which on the one hand improves the vehicle's passability, and on the other hand prevents the bus floor from being too high, thus improving the convenience of vehicle passengers.

[0052] In some embodiments of this application, the rotation direction of the teeth of the first gear 11 is the same as that of the teeth of the second gear 13.

[0053] Helical gears offer the advantage of high meshing overlap, significantly reducing transmission noise. The consistent helix direction of the first gear 11 and the second gear 13 allows the meshing radial force of the first gear 11 on the first gear ring 12 and the meshing radial force of the second gear ring 14 on the second gear 13 to partially cancel each other out. This reduces the stress on the first gear ring 12 and the second gear 13, improving the structural strength and transmission smoothness of the transmission mechanism 1, and reducing transmission vibration and noise. Furthermore, the partial cancellation of the meshing axial force of the first gear 11 on the first gear ring 12 and the meshing axial force of the second gear ring 14 on the second gear 13 reduces the selection requirements for the support bearings of the second gear 13 and the first gear ring 12, lowering shaft system costs and improving the lightweight level of the transmission mechanism 1.

[0054] In addition, the same helix design allows for the standardization of gear machining tools, reducing the number of tool changes and improving production efficiency.

[0055] This application also proposes a drive system including the transmission mechanism 1 of any of the above embodiments. The drive system can be a wheel-side drive assembly, a drive axle, or a chassis, and has all the beneficial technical effects of the transmission mechanism 1 of the above embodiments.

[0056] In some embodiments of this application, the drive system includes a planetary mechanism 2, which is connected to a transmission mechanism 1. The transmission mechanism 1 is adapted to be connected to a power source, and the planetary mechanism 2 is adapted to be connected to a wheel.

[0057] Figure 2 This is a partial cross-sectional view of the drive axle parallel to the ground. The drive system includes a transmission mechanism 1 and a planetary mechanism 2. Power is input from the power source via the first gear 11, output from the second gear ring 14, and then further reduced in speed and increased in torque by the planetary mechanism 2 before being transmitted to the wheels. The planetary mechanism 2 itself is characterized by its small size and high torque output capability. The combination of the transmission mechanism 1 and the new mechanism makes the drive axle structure more compact and lighter, which not only improves the vehicle's output performance but also helps to further increase the vehicle's driving range, especially for new energy vehicles.

[0058] Since the planetary mechanism 2 is roughly centrally symmetrical, it is perfectly matched and integrated into the wheel end of the vehicle and coaxially driven with the wheel hub 5 without occupying additional vehicle space. Therefore, this wheel-side drive axle layout of "transmission mechanism 1 - planetary mechanism 2" makes the drive axle structure highly compact and the torque density greatly improved.

[0059] In some embodiments, such as Figure 2 As shown, the drive axle includes an input shaft 3, a transmission mechanism 1, a planetary mechanism 2, a support bushing 4, and a wheel hub 5.

[0060] Specifically, the input shaft 3 and the first gear 11 are integrally formed to create a gear shaft, reducing transmission efficiency loss. The input shaft 3 is supported by a set of input bearings 31. The set of bearings can consist of two bearings for better economy, or three bearings for robust support and smooth transmission.

[0061] The first gear ring 12 and the second gear 13 are an integral structure. The two ends of the integral structure are supported by the first bearing 121. The inner side of the integral structure is provided with meshing teeth that mesh with the first gear 11, and the outer side of the integral structure is provided with meshing teeth that mesh with the second gear ring 14. The power of the input shaft 3 is transmitted to the second gear ring 14 through the integral structure of the first gear 11, the first gear ring 12 and the second gear 13.

[0062] The second gear ring 14 has meshing teeth on the inner side of one end that mesh with the second gear 13, and the other end is supported by the second bearing 141.

[0063] The transmission mechanism 1 and the planetary mechanism 2 are located on the two axial ends of the hub 5, respectively. The support bushing 4 passes through the hub 5 and is supported on the support bushing 4 by the wheel end bearing 51. The integrated structure of the first gear ring 12 and the second gear 13 is supported on the support bushing 4 by the second bearing 141.

[0064] Planetary mechanism 2 includes a sun gear 21, planet gears 22, and a planet carrier 23. The sun gear 21 and the second ring gear 14 are coaxially connected. Specifically, a connecting shaft 24 connects the sun gear 21 and the second ring gear 14. The connecting shaft 24 and the sun gear 21 are integrally formed to form a gear shaft, reducing efficiency loss. One end of the connecting shaft 24 has the teeth of the sun gear 21, and the other end has an external spline. The connecting shaft 24 and the second ring gear 14 are connected by a spline, which helps improve the load-sharing performance of the transmission mechanism 1 and the planetary mechanism 2.

[0065] The drive axle also includes a housing 25 and an end cap 26. The housing 25 is generally cylindrical, and the end cap 26 is located at one end of the housing 25. The other end of the housing 25 is fixedly connected to the wheel hub 5. The planetary mechanism 2 is located within the space enclosed by the end cap 26, the housing 25, and the wheel hub 5. The planetary mechanism 2 is located on the outside of the vehicle. The housing 25 and the end cap 26 provide structural support and protection for the planetary mechanism 2, placing it in a relatively sealed space to prevent environmental impurities, such as mud and sand, from entering the mechanism.

[0066] The planetary carrier 23 is fixed on the housing 25. The power transmitted from the second gear ring 14 passes through the connecting shaft 24, the sun gear 21, the planet gear 22, the planetary carrier 23, and the housing 25 to the hub 5. The hub 5 rotates to drive the vehicle.

[0067] This application also provides a vehicle that includes the drive system of any of the above embodiments, which has the beneficial technical effects of highly compact structure, strong output capability and high torque density, and also has other technical advantages of the drive system described above, which will not be repeated here.

[0068] This vehicle can be a pure electric bus, equipped with the aforementioned drive system, achieving independent four-wheel drive. During start-up and low-speed operation, transmission mechanism 1 provides high torque output, working with a planetary gear set to achieve torque superposition. During high-speed cruising, transmission mechanism 1 can reduce friction loss and improve system efficiency by optimizing gear tooth profiles. The elimination of traditional driveshafts and differentials in the vehicle chassis lowers the floor height, improving passenger ease of entry and exit. In extreme conditions, such as on icy or snowy roads, each drive assembly can independently control torque output, achieving precise electronic differential control and enhancing driving safety.

[0069] In the description of this specification, references to terms such as "specific embodiment," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0070] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A transmission mechanism (1), characterized in that, It includes a first gear (11), a first gear ring (12), a second gear (13), and a second gear ring (14). The first gear (11) is located inside the first gear ring (12) and meshes with the first gear ring (12). The second gear (13) is located inside the second gear ring (14) and meshes with the second gear ring (14). The first gear ring (12) and the second gear (13) are connected in a transmission connection that prevents relative rotation.

2. The transmission mechanism (1) according to claim 1, characterized in that, The first gear ring (12) and the second gear (13) are connected by a key, or the first gear ring (12) and the second gear (13) are fixedly connected, or the first gear ring (12) and the second gear (13) are an integral piece.

3. The transmission mechanism (1) according to claim 1, characterized in that, The first gear ring (12) and the second gear (13) are arranged radially on the first gear ring (12).

4. The transmission mechanism (1) according to claim 3, characterized in that, The first gear ring (12) and the second gear (13) are arranged coaxially, and the axis of the first gear (11), the axis of the second gear (13) and the axis of the second gear ring (14) are located in the same plane.

5. The transmission mechanism (1) according to claim 4, characterized in that, The axes of the second gear ring (14), the second gear (13), and the first gear (11) are arranged sequentially in a predetermined direction.

6. The transmission mechanism (1) according to claim 1, characterized in that, The axis of the second gear ring (14) and the axis of the first gear (11) are arranged sequentially in the first direction, and the angle between the first direction and the gravity direction is not 0°.

7. The transmission mechanism (1) according to claim 1, characterized in that, The direction of rotation of the teeth of the first gear (11) is the same as that of the teeth of the second gear (13).

8. A drive system, characterized in that, Includes the transmission mechanism (1) as described in any one of claims 1 to 7.

9. The drive system according to claim 8, characterized in that, It also includes a planetary mechanism (2), which is connected to the transmission mechanism (1) in a transmission connection. The transmission mechanism (1) is adapted to be connected to a power source, and the planetary mechanism (2) is adapted to be connected to a wheel.

10. A vehicle, characterized in that, Includes the drive system as described in claim 8 or 9.

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