A transmission, electric drive system and working machine

Abstract

The utility model relates to a kind of transmission, electric drive system and working machine, the transmission includes: housing;Input shaft;First gear, fixedly set on the input shaft;Second gear, fixedly set on second shaft and with the first gear meshing;Third gear, fixedly set on the second shaft;Fourth gear, fixedly set on third shaft and with the third gear meshing;Wherein the second shaft with the third shaft is parallel, the number of the first gear and the input shaft is two, and two the first gear and the input shaft are located the different side of the plane where the second shaft and the third shaft are located.The utility model reduces the maximum rated power of single motor, and the operation of two motors is more efficient;Meanwhile, the reliability of system is improved, can satisfy the requirement of large traction force at low speed and the requirement of working machine travel speed at high speed.

Description

Technical Field

[0001] This utility model belongs to the field of engineering machinery, specifically relating to a transmission device, an electric drive system, and a working machine. Background Technology

[0002] Traditional construction machinery, such as excavators, loaders, graders, and bulldozers, has long relied primarily on diesel engines as its power source. While fuel power offers advantages such as high energy density and convenient refueling, it also suffers from problems including high fuel consumption, severe emissions, high noise levels, and high maintenance costs. With the increasing global emphasis on energy conservation and emission reduction, and the advancement of carbon neutrality goals, the construction machinery industry is facing a need for the transformation and upgrading of its power systems.

[0003] In recent years, the rapid development of electric drive technology, power battery technology, and electronic control systems has made electrified construction machinery possible. Electrified drive systems can achieve zero-emission, low-noise operation and significantly reduce overall energy consumption and maintenance costs. Furthermore, electric drives offer fast response and high control precision, improving the overall operability and operational efficiency of the machine. Based on these advantages, more and more manufacturers are developing and promoting pure electric or hybrid power construction machinery to replace traditional fuel-powered equipment. Especially in urban construction, tunnels, mines, and ports, where emission and noise requirements are stringent, electric construction machinery demonstrates significant application advantages.

[0004] In one known technical solution for heavy-duty loaders, a single-motor drive is used. To simultaneously meet the requirements of maximum traction in low gear and maximum speed in high gear, the gearbox needs a two- or more-gear design, with a relatively large gear ratio in the low gear. Shifting between gears also requires an additional shifting mechanism. This results in a gearbox with complex structure, high cost, and frequent malfunctions. Furthermore, the single motor has limited energy; its power and torque reserves are insufficient for heavy-duty vehicles, leading to low operating efficiency. Utility Model Content

[0005] Based on the applicant's research and practical experience in this field, the following improved technical solutions are proposed.

[0006] A transmission device, the transmission device comprising:

[0007] case;

[0008] Input axis;

[0009] The first gear is fixedly mounted on the input shaft;

[0010] The second gear is fixedly mounted on the second shaft and meshes with the first gear.

[0011] The third gear is fixedly mounted on the second shaft;

[0012] The fourth gear is fixedly mounted on the third shaft and meshes with the third gear;

[0013] The second axis is parallel to the third axis, and there are two of each of the first gear and the input shaft, with the two first gears and the two input shafts located on different sides of the plane in which the second axis and the third axis are located.

[0014] According to one example of the present invention, the two first gears have the same structure.

[0015] According to one example of the present invention, the two first gears and the input shaft are arranged symmetrically about the plane in which the second shaft and the third shaft are located.

[0016] According to one example of the present invention, the diameter of the first gear is smaller than the diameter of the second gear, the diameter of the third gear is smaller than the diameter of the second gear, and the diameter of the third gear is smaller than the diameter of the fourth gear.

[0017] According to one example of the present invention, the second gear and the third gear are double gears.

[0018] This utility model also proposes an electric drive system, the electric drive system comprising:

[0019] First motor and second motor;

[0020] The aforementioned transmission device;

[0021] The first motor and one of the input shafts are fixedly connected, and the second motor and the other of the input shafts are fixedly connected.

[0022] According to one example of the present invention, the first motor and the second motor are located on the same side of the housing.

[0023] According to one example of the present invention, the first motor and the second motor are the same motor.

[0024] According to one example of the present invention, a braking device is also included, which is capable of applying braking force to the third shaft.

[0025] This utility model also proposes a working machine, including the above-mentioned electric drive system.

[0026] In this invention, "fixedly mounted" on the shaft means that the gear is connected to the shaft by a detachable method such as spline connection or by a non-detachable method such as welding or riveting, or the gear and shaft are integrally formed, so that the rotational angular velocities of the shaft and the gear are the same. That is to say, during normal operation, the rotation of the shaft will always drive the rotation of the gear, and the rotation of the gear will always drive the rotation of the shaft; that is, there is no relative rotation between the shaft and the gear.

[0027] According to the above scheme, this utility model adopts a parallel dual-motor configuration. Compared with a single-motor scheme, this reduces the maximum rated power of a single motor and makes the operation of both motors more efficient. It also improves system reliability, allowing the system to continue operating even if one motor fails. Furthermore, it meets the requirements of high traction at low speeds and the high-speed requirements of the working machinery. In addition, this utility model uses a single-speed gearbox design. Compared with multi-speed schemes, it eliminates the need for gear shifting, achieving stepless speed change through motor control, greatly simplifying driver operation. Moreover, the elimination of complex shifting logic and mechanisms reduces gearbox costs and minimizes malfunctions caused by gear shifting.

[0028] Other features and advantages of this utility model will be further described below in conjunction with the accompanying drawings. Attached Figure Description

[0029] Exemplary embodiments of the present invention are described with reference to the accompanying drawings, wherein:

[0030] Figure 1 A schematic diagram of the structure of an electric drive system according to this utility model is shown.

[0031] Figure 2 A schematic diagram of the transmission device of this utility model is shown. Detailed Implementation

[0032] Embodiments of the present invention are described below with reference to the accompanying drawings. In the following description, numerous specific details are set forth to enable those skilled in the art to more fully understand and implement the present invention. However, it will be apparent to those skilled in the art that implementations of the present invention may not include some of these specific details. Furthermore, it should be understood that the present invention is not limited to the specific embodiments described. Rather, the present invention can be conceived to be implemented with any combination of the features and elements described below, regardless of whether they relate to different embodiments. Therefore, the following aspects, features, embodiments, and advantages are for illustrative purposes only and should not be construed as features or limitations of the claims unless expressly set forth in the claims.

[0033] The descriptions of orientation used in the following description, such as "upper," "lower," "inner," "outer," "radial," and "axial," are for convenience only and are not intended to limit the technical solution of the utility model, unless explicitly stated otherwise. Furthermore, the terms "first," "second," etc., used below to describe elements of this application are only used to distinguish individual elements and are not intended to limit the nature, sequence, order, or number of these elements.

[0034] Figure 1 A schematic diagram of the structure of an electric drive system according to this utility model is shown. Figure 2 A schematic diagram of the transmission device of this utility model is shown. (Combined with...) Figure 1 and Figure 2 The drive system of this utility model is an electric drive system, using an electric motor as the power source. Furthermore, considering that a single motor requires larger output torque and other parameters in applications such as large-tonnage loaders, but the maximum speed cannot meet the requirements in high-speed scenarios, thus necessitating a two-speed or higher gearbox, leading to complex structure, high cost, and high failure rate, this application adopts a dual-motor parallel structure. Specifically, the motor M includes a first motor and a second motor, each with its own output shaft, which serves as the input shaft S1 of the transmission device. A first gear Z1 is provided on the input shaft S1. As a preferred embodiment, such as... Figure 2 As shown, the input shaft S1 includes a first input shaft and a second input shaft, and each of the first and second input shafts is fixedly mounted with its own input gear, namely a first gear Z1. The two first gears Z1 mesh with the second gear Z2 respectively, and are symmetrically arranged with respect to the axis of the second gear Z2. More preferably, the line connecting the centers of the two first gears Z1 does not intersect the axis of the second gear Z2.

[0035] As can be seen from the above, in this utility model, two motors M are used as power sources, and these two motors are connected in parallel. Each motor is connected to its corresponding input shaft to input power, and then their respective power is combined on the same gear, namely the second gear Z2. Compared with a single motor, this greatly reduces the rated power of the motor. For example, for a single motor, in order to meet the maximum power demand, with its maximum rated power being P, the dual-motor parallel scheme proposed in this utility model requires the maximum rated power of each motor to be only 60% of P or even lower. The two motors can be the same or different motors. When using the same motor, the complexity of selection and control can be further reduced. Furthermore, the two motors can be controlled differently, such as through power distribution and dynamic start-stop, so that the motors operate in the high-efficiency range while also meeting the torque and power reserve requirements. For example, under light load conditions, only one motor can be used, and the other motor can be stopped. Both motors are used for output only under heavy load conditions. Since the power of a single motor is reduced, its heat dissipation is also reduced accordingly, which also reduces the requirements of the transmission device.

[0036] Furthermore, using two motors can improve the reliability of the entire electric drive system. If one motor fails and cannot operate, the other motor can still run normally, and the machine itself can still operate within a certain range, unlike a single motor failure which would render it completely inoperable.

[0037] Furthermore, the two motors are arranged on the same side of the transmission. Compared to arranging them on both sides of the transmission, arranging them on the same side can reduce the axial dimension of the entire electric drive system.

[0038] The transmission device also includes a third gear Z3 and a fourth gear Z4 that meshes with the third gear Z3. For example... Figure 1 and Figure 2 As shown, the third gear Z3 and the second gear Z2 are arranged coaxially, both mounted on the second shaft S2. As an optional implementation, they can be configured as a double gear. The fourth gear Z4 is mounted on the third shaft S3. The first and second input shafts, the second shaft S2, and the third shaft S3 are arranged in parallel.

[0039] In a preferred embodiment, the first input shaft and the second input shaft are symmetrically arranged on both sides of the plane where the second input shaft S2 and the third input shaft S3 are located.

[0040] Preferably, the two first gears Z1 are identical, and their first diameter is smaller than the second diameter of the second gear Z2 with which they mesh. The third gear Z3, which is coaxially arranged with the second gear Z2, has a third diameter smaller than the second diameter of the second gear Z2. The fourth gear Z4, which meshes with the third gear Z3, has a fourth diameter larger than the third diameter of the third gear Z3.

[0041] The transmission device includes a housing, inside which are located the first gear Z1, second gear Z2, third gear Z3, fourth gear Z4, and their respective shafts. Each shaft is rotatably supported on the housing via bearings. Two motors are located outside the housing.

[0042] Furthermore, such as Figure 1 As shown, the electric drive system also includes a braking device B, which is connected to the housing or other fixed component on one side and to the third shaft S3 on the other. Thus, when the braking device B is activated, it can apply braking force to the third shaft S3, thereby slowing it down. The braking device B can be a multi-plate structure.

[0043] In the transmission device of this invention, all gears are fixedly mounted on their respective shafts. This simplifies the connection between the shaft and the gears, eliminates the need for bearings to support the gears, and thus eliminates the need for bearing lubrication, making installation very convenient.

[0044] Industrial applicability

[0045] The electric drive system of this invention can be applied to various types of machinery. For example, it can be used in excavators, loaders, graders, bulldozers, etc., and is especially suitable for large-tonnage loaders. Loaders are earthmoving machines widely used in construction, mining, ports, metallurgy, and highway construction, mainly for loading, transporting, and unloading bulk materials such as soil, sand, gravel, and coal.

[0046] A loader typically consists of a power system, transmission system, walking system, steering system, hydraulic system, and working device. Based on its mode of movement, loaders can be divided into wheeled loaders and tracked loaders.

[0047] When the electric drive system provided by this utility model is applied to loaders or other operating machinery, it can operate according to the specific working requirements of the machinery. For example, in no-load or light-load conditions, only one motor can be used to meet the needs of the machinery, while the other motor can be completely stopped. When the machinery is under medium load, both motors can operate, but different operating states can be assigned to each motor, such as the first motor outputting 60% of the total power and the second motor outputting 40% of the total power, thus reducing the thermal load on individual motors. When the machinery is under heavy load or full load, both motors can operate simultaneously and maintain a high power output to meet system requirements.

[0048] Through the above-mentioned multi-condition collaborative control, the dual-motor parallel system can intelligently adjust the power output according to the actual load, so that the motor is always in the high-efficiency working range. This not only improves the overall energy efficiency and response performance, but also reduces the heat load and maintenance costs, making it particularly suitable for machinery with large load fluctuations and varied operating modes.

[0049] The foregoing description is merely an exemplary embodiment relating to the spirit and principles of this utility model. Those skilled in the art will understand that various changes can be made to the described examples without departing from the spirit and principles, and such changes and their various equivalents are contemplated by those skilled in the art and fall within the scope defined by the claims of this utility model.

Claims

1. A transmission device, characterized in that, The transmission device includes: case; Input axis (S1); The first gear (Z1) is fixedly mounted on the input shaft (S1); The second gear (Z2) is fixedly mounted on the second shaft (S2) and meshes with the first gear (Z1); The third gear (Z3) is fixedly mounted on the second shaft (S2); The fourth gear (Z4) is fixedly mounted on the third shaft (S3) and meshes with the third gear (Z3); The second axis (S2) is parallel to the third axis (S3), and there are two of each of the first gear (Z1) and the input shaft (S1), with the two first gears (Z1) and the two input shafts (S1) located on different sides of the plane where the second axis (S2) and the third axis (S3) are located.

2. The transmission device according to claim 1, characterized in that, The two first gears (Z1) have the same structure.

3. The transmission device according to claim 2, characterized in that, The two first gears (Z1) and the input shaft (S1) are symmetrically arranged about the plane in which the second shaft (S2) and the third shaft (S3) are located.

4. The transmission device according to any one of claims 1-3, characterized in that, The diameter of the first gear (Z1) is smaller than the diameter of the second gear (Z2), the diameter of the third gear (Z3) is smaller than the diameter of the second gear (Z2), and the diameter of the third gear (Z3) is smaller than the diameter of the fourth gear (Z4).

5. The transmission device according to any one of claims 1-3, characterized in that, The second gear (Z2) and the third gear (Z3) are a double gear.

6. An electric drive system, characterized in that, The electric drive system includes: First motor and second motor; The transmission device according to any one of claims 1-5; One of the first motor and the input shaft (S1) is fixedly connected, and the other of the second motor and the input shaft (S1) is fixedly connected.

7. The electric drive system according to claim 6, characterized in that, The first motor and the second motor are located on the same side of the housing.

8. The electric drive system according to claim 6 or 7, characterized in that, The first motor and the second motor are the same motor.

9. The electric drive system according to claim 6 or 7, characterized in that, It also includes a braking device (B) that can apply braking force to the third shaft (S3).

10. A type of operating machinery, characterized in that, The operating machinery includes an electric drive system according to any one of claims 6-9.

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