A transmission and a transmission assembly

Abstract

The present application relates to a kind of transmission and transmission assembly, transmission includes: housing, the housing forms cavity;Gear set, the gear set is housed in the cavity;Switching element, the switching element is housed in the cavity;Formed with oil passage on the housing, the oil passage includes the oil passage for providing hydraulic oil for the switching element and the oil passage for providing lubricating and cooling oil for each element of the gear set.The present application is integrated by being provided with multiple oil passages on housing, reduces the number of parts, reduces the complexity of installation, improves assembly efficiency.

Description

Technical Field

[0001] This invention belongs to the field of vehicle technology, and specifically relates to a transmission and transmission assembly for use in vehicles. Background Technology

[0002] Electric vehicles have achieved widespread adoption, and their market share is gradually increasing. Many traditional automakers are also beginning to increase their investment in electric vehicles. Currently, the most common solution for electric drive assemblies on the market is a combination of a single reducer and a water-cooled motor. The cooling medium of the water-cooling system is water, which conducts electricity, so it cannot directly cool heat sources such as windings. It can only be cooled by liquid cooling of the motor housing. Under this cooling method, the heat generated by the heat source inside the motor needs to be conducted through layers of materials to be carried away by the water channels. This creates a temperature gradient and easily leads to localized heat accumulation, resulting in low cooling efficiency and less than ideal effects. Oil, on the other hand, is non-conductive and can be used as a medium to directly cool the inside of the motor, improving cooling efficiency and effectiveness, thereby increasing the efficiency and power density of the electric drive.

[0003] For example, Chinese patent application CN202011440601.6 discloses a combination scheme of a single-speed reducer and an oil-cooled motor. This scheme achieves oil-cooled electric drive functionality by adding an electric pump to the reducer side to provide cooling and lubricating oil to the oil-cooled motor. While oil cooling improves the efficiency and power density of the electric drive to some extent, the single-speed reducer cannot simultaneously handle both high-speed and low-speed conditions well. To meet the maximum vehicle speed requirement, the motor's peak speed often needs to be exceptionally high, resulting in poor efficiency and NVH performance. Summary of the Invention

[0004] Based on the applicant's research and practical experience in this field, the following improved technical solutions are proposed.

[0005] A transmission, comprising:

[0006] The housing forms a cavity;

[0007] A gear set, the gear set being housed within the cavity;

[0008] A switching element, wherein the switching element is housed in the cavity;

[0009] Oil passages are formed on the housing, including passages for supplying hydraulic oil to the switching element and passages for supplying lubricating and cooling oil to the various components of the gear set.

[0010] According to one aspect of the present invention, the gear set includes a first shaft and a second shaft arranged in parallel, a first gear and a second gear are disposed on the first shaft, and a third gear and a fourth gear are disposed on the second shaft, wherein the first gear and the third gear are constantly meshed, and the second gear and the fourth gear are constantly meshed.

[0011] According to one aspect of the invention, the switching element includes a first clutch and a second clutch, the first clutch being used to fix the first gear to the first shaft, and the second clutch being used to fix the second gear to the first shaft.

[0012] According to one aspect of the invention, the oil passage includes a first oil passage formed on a side of the housing perpendicular to the axial direction of the gear set.

[0013] According to one aspect of the invention, the oil passage further includes a second oil passage formed in the portion of the housing between two sides perpendicular to the axial direction of the gear set.

[0014] According to one aspect of the invention, the oil passage includes a third oil passage formed on the side of the housing for connection with the motor.

[0015] According to one aspect of the invention, the oil passage includes a fourth oil passage formed on the side of the housing opposite in the axial direction to the side where the third oil passage is located.

[0016] According to one aspect of the invention, the housing has a first interface and a second interface, the first interface providing a channel for oil to enter the stator of the motor, and the second interface providing a channel for oil to enter the rotor of the motor.

[0017] According to one aspect of the invention, the aperture of the first interface is larger than the aperture of the second interface.

[0018] The present invention also proposes a transmission assembly, including the transmission described above; and a first oil pump and a second oil pump located on the housing, the first oil pump being located between two sides of the transmission perpendicular to the axial direction, and the second oil pump being located on one side of the transmission perpendicular to the axial direction.

[0019] As can be seen from the above solutions, the present invention has the following advantages:

[0020] ① The first gear with a high speed ratio improves the vehicle's acceleration and hill-climbing performance, while the second gear with a low speed ratio reduces the need for the motor's maximum speed, improves high-frequency howling and dynamic balance vibration issues, and enhances NVH performance.

[0021] ② Two gears can take into account the needs of electric drive at low speeds for high torque and high speeds for high speeds, maximizing the motor's operation in the high-efficiency range;

[0022] ③ The wet clutch-controlled gear shifting scheme can achieve gear shifting without power interruption, improving the driving experience;

[0023] ④ By adopting a dual-pump strategy, the precise control requirements for high-pressure oil pressure and low-pressure oil flow can be achieved;

[0024] ⑤ High-pressure oil circuits generally require higher pressure but less flow, while low-pressure oil circuits do not require high pressure but have greater flow requirements. The solution of separating high and low-pressure oil circuits can minimize hydraulic system leakage and improve system efficiency.

[0025] ⑥ The oil cooler can reduce the temperature of the lubricating oil entering the motor and improve the cooling effect. The filter press can filter impurities in the lubricating oil entering the motor, improve cleanliness, and avoid the adverse effects of excessive impurities on motor operation.

[0026] ⑦ All oil passages are designed on the casing, avoiding complex piping and reducing structural complexity;

[0027] ⑧ The oil circuit on the gearbox that supplies oil to the motor has two outlets that can be used to lubricate the stator and rotor of the motor separately, allowing for precise flow control and improved cooling. Attached Figure Description

[0028] Exemplary embodiments of the present invention are described with reference to the accompanying drawings, wherein:

[0029] Figure 1 A schematic diagram of the transmission of the present invention is shown.

[0030] Figure 2 A perspective view of the transmission of the present invention is shown.

[0031] Figure 3 A perspective view of the transmission of the present invention is shown from another angle. 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 invention. However, it will be apparent to those skilled in the art that implementations of the invention may not include some of these specific details. Furthermore, it should be understood that the invention is not limited to the specific embodiments described. Rather, the invention can be conceived to be practiced 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 merely for convenience of description and are not intended to limit the technical solution of the invention unless explicitly stated otherwise. Furthermore, the terms “first,” “second,” and other similar terms used below to describe the 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 transmission of the present invention is shown. The transmission is connected to a motor and outputs power from the motor to the wheels. The transmission includes a housing containing multiple gears and two clutches. The output shaft 1 of the motor is connected to the input shaft of the transmission, and then the power is transmitted to the input gear 2 of the differential via the gear mechanism inside the transmission. Finally, the differential transmits the power to the axle of the vehicle, thereby driving the wheels to rotate.

[0035] The transmission includes two parallel shafts. A first gear 3 and a second gear 4, supported by bearings, are mounted on the first shaft. The transmission housing also contains two clutches: a first clutch C1 that fixes the first gear 3 to the first shaft, causing the first gear 3 and the first shaft to rotate at the same angular velocity; and a second clutch C2 that fixes the second gear 4 to the first shaft, causing the second gear 4 and the first shaft to rotate at the same angular velocity.

[0036] Two gears, the third gear and the fourth gear, are mounted on the second shaft 5 and are fixedly connected to the second shaft 5. The third gear is constantly meshed with the first gear 3, forming the first gear pair TG1, and the fourth gear is constantly meshed with the second gear 4, forming the second gear pair TG2. A fifth gear, fixed to the second shaft 5, is also mounted on the second shaft 5 and is constantly meshed with the input gear 2 of the differential, forming the third gear pair TG3.

[0037] Figure 1The diagram shows the gear ratios and the power flow in both gears.

[0038] When the motor operates, causing the output shaft 1 of the motor to rotate, the first shaft rotates accordingly. When neither clutch is engaged, there is no synchronous rotation between the first gear 3 and the second gear 4 and the first shaft. Therefore, the first gear 3 and the second gear 4 are only supported on the first shaft by bearings and will not rotate with the first shaft. As a result, power cannot be transmitted backward through the two gear pairs, thus forming the neutral gear of the transmission, i.e., N gear.

[0039] When the first clutch C1 is engaged and the second clutch C2 is disengaged, the motor operates, driving the first shaft to rotate via the output shaft 1. The first gear 3 is fixedly connected to the first shaft via the first clutch C1, thus rotating together with the first shaft. This, in turn, drives the third gear via the first gear pair TG1, which in turn drives the fifth gear, also located on the second shaft, to rotate. Power is then transmitted to the differential via the third gear pair TG3. Therefore, the transmission operates in the first gear.

[0040] When the first clutch C1 is disengaged and the second clutch C2 is engaged, the motor operates, driving the first shaft to rotate via the output shaft 1. The second gear 4 is fixedly connected to the first shaft via the second clutch C2, thus rotating together with the first shaft. This, in turn, drives the fourth gear via the second gear pair TG2, which in turn drives the fifth gear, also located on the second shaft, to rotate. Power is then transmitted to the differential via the third gear pair TG3. Therefore, the transmission operates in the second gear position.

[0041] When the first clutch C1 is engaged and the second clutch C2 is disengaged, the motor rotates in the reverse direction, thereby driving the first shaft to rotate via the output shaft 1. The first gear 3 is fixedly connected to the first shaft via the first clutch C1, thus rotating together with the first shaft. This, in turn, drives the third gear to rotate via the first gear pair TG1, which in turn drives the fifth gear, also located on the second shaft. Power is then transmitted to the differential via the third gear pair TG3. Therefore, the transmission operates in the same gear as the first gear, but because the motor rotates in the reverse direction, the vehicle moves backward.

[0042] The operation of the first clutch C1 and the second clutch C2 is achieved by hydraulic oil. Therefore, the transmission of the present invention is equipped with an oil pump to provide the hydraulic oil required for the operation of the two clutches, enabling uninterrupted shifting between a high-ratio first gear and a low-ratio second gear through the two clutches.

[0043] Figure 2 A perspective view of the transmission of the present invention is shown. Figure 2As can be seen, the transmission of the present invention is equipped with a first oil pump 14. The first oil pump 14 can be in the form of an electronic oil pump. In addition, in order to achieve lubrication of various parts within the transmission, the present invention also provides a second oil pump 13. The second oil pump 13 can be in the form of an electronic oil pump.

[0044] By using two electronic oil pumps to supply the high-pressure oil required by the two clutches and the low-pressure cooling lubricating oil required by the transmission and / or motor, the present invention achieves precise control of the pressure of the high-pressure oil and the precise control of the flow rate of the low-pressure oil.

[0045] Figure 3 A perspective view of the transmission of the present invention is shown from another angle. Figure 3 The diagram shows the input shaft of the transmission, which is connected to the input shaft 1 of the motor. The transmission housing 12 and the motor housing are connected via a mating surface. The connection between the two can be achieved using threaded fasteners or the like.

[0046] Combination Figure 2 and Figure 3 It can be seen Figure 2 The diagram shows the side of the transmission housing facing away from the motor. Here, the side where the transmission housing engages with the motor is referred to as the first side, and the side axially opposite the first side is referred to as the second side. From Figure 2 As can be seen, on the second side, the housing 12 has multiple supports for supporting the shaft, as well as multiple oil passages. A first oil passage 7 is provided on the housing 12, extending in a direction perpendicular to the axial direction of the transmission, to provide lubrication and cooling for multiple components inside the housing.

[0047] On the second side, a fourth oil passage 8-2 is also provided, which is used to supply pressurized oil to one of the two clutches. From Figure 3 As can be seen, a third oil passage 8-1 is provided on the first side, which is used to supply pressurized oil to the other of the two clutches. The first oil pump 14 is provided on the first side.

[0048] from Figure 2As can be seen, a second oil passage 9 is provided on the portion of the housing 12 located between the first and second sides for cooling the motor. Correspondingly, the invention also provides a first interface 11 and a second interface 10 on the first side for fluid connection with the stator and rotor of the motor, so that lubricating oil is delivered to the stator and rotor of the motor respectively through the second oil passage 9 under the action of the second oil pump 13, thereby achieving cooling and lubrication. Both the first interface 11 and the second interface 10 can be configured to have circular apertures, and the aperture of the first interface 11 is larger than the aperture of the second interface 10, preferably one or two times larger, to achieve better lubrication of the stator. The first interface 11 can be located radially outside the second interface 10. The oil passage for rotor lubrication on the motor extends from the second interface 10 through the oil passage on the motor housing to the rear end cover of the motor, and then enters the rotor shaft from the structure on the rear end cover.

[0049] In this invention, the lubrication circuit does not require a distribution valve; instead, flow distribution is achieved through the throttling orifice diameter of each lubrication port. Thus, this invention uses a separate second oil pump 13 to provide low-pressure lubricating oil for active lubrication of rotating components inside the transmission, as well as for the stator and rotor of the motor. Furthermore, the physical isolation of two low-pressure oil passages and two high-pressure oil passages achieves the separation of high and low pressure oil circuits.

[0050] A filter 15 and a cooler 16 are also provided on the housing 12 to ensure lower oil temperature and better cleanliness of the lubricating oil entering the motor. The filter 15 and cooler 16 are positioned between the first and second sides, so as not to increase the axial dimension of the transmission. For the same purpose, the second oil pump 13 is also positioned between the first and second sides, but closer to the second side.

[0051] As an improvement of this invention, all oil passages are located on the housing 12 and formed thereon through machining, eliminating the need for oil pipes. This reduces the number of parts, lowers the complexity of installation, and improves assembly efficiency.

[0052] The foregoing description is merely an exemplary embodiment relating to the spirit and principles of the present invention. 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 the inventors and fall within the scope defined by the claims of the present invention.

Claims

1. A transmission, comprising: The housing forms a cavity; A gear set, the gear set being housed within the cavity; A switching element, wherein the switching element is housed in the cavity; Its features are, Oil passages are formed on the housing, including oil passages for supplying hydraulic oil to the switching element and oil passages for supplying lubricating and cooling oil to the various components of the gear set; The gear set includes a first shaft and a second shaft arranged in parallel. A first gear and a second gear are arranged on the first shaft, and a third gear and a fourth gear are arranged on the second shaft. The first gear and the third gear are constantly meshed, and the second gear and the fourth gear are constantly meshed. The switching element includes a first clutch and a second clutch, wherein the first clutch is used to fix the first gear to the first shaft, and the second clutch is used to fix the second gear to the first shaft. The system is equipped with a first oil pump and a second oil pump. The first oil pump is used to provide high-pressure oil required by the first clutch and the second clutch, and the second oil pump is used to provide low-pressure cooling and lubricating oil required by the transmission. The oil passage includes a first oil passage formed on a side of the housing perpendicular to the axial direction of the gear set; The oil passage further includes a second oil passage formed between two sides of the housing perpendicular to the axial direction of the gear set; the oil passage includes a third oil passage formed on the side of the housing for connection with the motor; the oil passage includes a fourth oil passage formed on the side of the housing opposite to the side containing the third oil passage in the axial direction; the housing has a first interface and a second interface, the first interface providing a channel for oil to enter the stator of the motor, and the second interface providing a channel for oil to enter the rotor of the motor; the aperture of the first interface is larger than the aperture of the second interface.

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