Integrated transfer case for dual-mode power system

Abstract

The utility model discloses an integrated transfer case for a dual-mode power system, which comprises a case body, a main power input shaft and a power output shaft are mounted on the case body, a transfer gear component is arranged between the main power input shaft and the power output shaft, and an auxiliary power input shaft and an auxiliary power shifting shaft are further mounted on the case body. The auxiliary power input shaft is used for being connected with a power-assisted motor. A reduction gear set is arranged between the auxiliary power input shaft and the auxiliary power gear shifting shaft, a high-speed gear set and a low-speed gear set are arranged between the auxiliary power gear shifting shaft and the main power input shaft, and a gear shifting controller is installed on the box body. The assist motor includes a low torque output mode using a high speed gear set and a high torque output mode using a low speed gear set. According to the utility model, the speed change part of boosting power is directly integrated on the transfer case body, so that the volume is reduced and the boosting output efficiency is improved under the condition that the boosting motor power and the engine power are connected in parallel.

Description

Technical Field

[0001] This utility model relates to the field of transfer case technology, and in particular to an integrated transfer case for a dual-mode power system. Background Technology

[0002] In tractor-traction operations, engine power is distributed to both the traction and working machinery, and tractors have recently shown a trend towards new energy and intelligent development. During tractor-traction operations, sudden increases in resistance are inevitable due to various factors such as soil changes, encountering obstacles, or potholes. In these situations, the tractor automatically controls and increases the power output of the traction component to overcome the sudden increase in resistance and achieve continuous traction. However, in actual use, simply increasing the engine's own power output is difficult to overcome the sudden increase in resistance. Therefore, the power system controls the transmission to automatically downshift to generate stronger output torque on the wheel system while maintaining the same engine power output. However, the moment the transmission downshifts is the instant when power is completely cut off between the engine and the wheel system, which can cause the vehicle to stop abruptly. Even with the increased output torque after downshifting, restarting the vehicle with significant resistance is very difficult, becoming a significant factor affecting continuous operation.

[0003] To address this issue, the inventors proposed a dual-mode power system that utilizes a power assist motor connected in parallel with the engine to supplement torque output or temporarily substitute power for the engine's shifting output. Specifically, a transfer case is used to output power to the wheel system, while engine power is connected to the input of the transfer case via the main gearbox, and the power assist motor is connected to the input of the transfer case via an auxiliary gearbox, achieving parallel power connection. Based on this technical principle, and considering the space constraints of the tractor body and the power coordination function of the power assist motor, the power connection structure at the transfer case needs to be optimized. Therefore, the inventors proposed an integrated transfer case, thus giving rise to this invention. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide an integrated transfer case for a dual-mode power system that enables parallel connection of power from the assist motor and engine, while reducing size and improving the efficiency of assist output.

[0005] To solve the above-mentioned technical problems, the technical solution of this utility model is: an integrated transfer case for a dual-mode power system, including a housing, on which a main power input shaft and a power output shaft are mounted, and a transfer gear assembly is provided between the main power input shaft and the power output shaft. An auxiliary power input shaft and an auxiliary power shift shaft are also mounted on the housing, the auxiliary power input shaft being used to connect to an assist motor; a reduction gear set is provided between the auxiliary power input shaft and the auxiliary power shift shaft, and a high-speed gear set and a low-speed gear set are provided between the auxiliary power shift shaft and the main power input shaft; a shift controller for switching between using the high-speed gear set and the low-speed gear set is mounted on the housing; the assist motor includes a low-torque output mode using the high-speed gear set and a high-torque output mode using the low-speed gear set.

[0006] As a preferred technical solution, the overall transmission speed ratio between the reduction gear set and the high-speed gear set is 3.5:1 to 4.5:1.

[0007] As a preferred technical solution, the overall transmission speed ratio between the reduction gear set and the low-speed gear set is 11:1 to 13:1.

[0008] As a preferred technical solution, the auxiliary power shift shaft is axially slidably mounted on the housing, and the shift controller includes a shift control motor for driving the auxiliary power shift shaft to slide axially.

[0009] As a preferred technical solution, a shift fork is movably mounted on the housing. The shift fork is used to move the auxiliary power shift shaft axially. A shift transmission mechanism is provided between the power end of the shift control motor and the shift fork. A displacement sensor for detecting the sliding displacement of the auxiliary power shift shaft and a speed sensor for detecting the output speed of the shift control motor are mounted on the housing. The displacement sensor and the speed sensor are signal-connected to a control element, and the output end of the control element is signal-connected to the shift control motor.

[0010] As a preferred technical solution, the high-speed gear set, the low-speed gear set, and the reduction gear set are all spur gear sets.

[0011] As a preferred technical solution, an auxiliary reduction intermediate shaft is further provided between the auxiliary power input shaft and the auxiliary power shift shaft, and the reduction gear set includes a first reduction gear set between the auxiliary power input shaft and the auxiliary reduction intermediate shaft and a second reduction gear set between the auxiliary reduction intermediate shaft and the auxiliary power shift shaft.

[0012] Due to the adoption of the above technical solution, the dual-mode power system uses an integrated transfer case, including a housing. A main power input shaft and a power output shaft are mounted on the housing. A transfer gear assembly is provided between the main power input shaft and the power output shaft. An auxiliary power input shaft and an auxiliary power shift shaft are also mounted on the housing. The auxiliary power input shaft is used to connect to the power assist motor. A reduction gear set is provided between the auxiliary power input shaft and the auxiliary power shift shaft. A high-speed gear set and a low-speed gear set are provided between the auxiliary power shift shaft and the main power input shaft. A shift controller for switching between the high-speed and low-speed gear sets is mounted on the housing. The power assist motor includes a low-torque output mode using the high-speed gear set and a high-torque output mode using the low-speed gear set. This utility model directly integrates the power assist transmission part into the transfer case housing, which, while achieving parallel connection between the power assist motor and the engine power, helps to reduce size and improve power assist output efficiency. Attached Figure Description

[0013] The following figures are intended only to illustrate and explain the present invention and do not limit the scope of the present invention. Wherein:

[0014] Figure 1 This is a schematic diagram of the structure of the assist motor in low-torque output mode according to an embodiment of this utility model;

[0015] Figure 2 This is a schematic diagram of the structure of the power assist motor in high torque output mode according to an embodiment of this utility model.

[0016] In the diagram: 1-Box housing; 2-Main power input shaft; 3-Power output shaft; 4-Transfer gear assembly; 41-Transfer transmission gear; 42-Transfer transmission intermediate shaft; 5-Auxiliary power input shaft; 51-Power assist motor; 6-Auxiliary power shift shaft; 61-Shift controller; 62-Shift control motor; 63-Shift fork; 64-Shift transmission mechanism; 65-Displacement sensor; 7-Reduction gear set; 71-Auxiliary reduction intermediate shaft; 72-First reduction gear set; 73-Second reduction gear set; 8-High-speed gear set; 9-Low-speed gear set. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the following detailed description, only certain exemplary embodiments of the present invention are described by way of illustration. Undoubtedly, those skilled in the art will recognize that various modifications can be made to the described embodiments without departing from the spirit and scope of the present invention. Therefore, the drawings and description are illustrative in nature and not intended to limit the scope of the claims.

[0018] like Figure 1and Figure 2 As shown, the dual-mode powertrain uses an integrated transfer case, including a housing 1 on which a main power input shaft 2 and a power output shaft 3 are mounted. Conventionally, the main power input shaft 2 is used to connect to the engine's power supply; more specifically, when the engine's output is connected to a main gearbox, the output of the main gearbox is poweredly connected to the main power input shaft 2.

[0019] A transfer gear assembly 4 is provided between the main power input shaft 2 and the power output shaft 3. The power from the main power input shaft 2 is transmitted to the power output shaft 3 via the transfer gear assembly 4. The power output shaft 3 is then connected to the tractor's wheel system to transmit traction power. Conventionally, the transfer gear assembly 4 is mainly used to solve the power transmission problem between the main power input shaft 2 and the power output shaft 3 when their shaft spacings are different. When the distance between the main power input shaft 2 and the power output shaft 3 is small, the transfer gear assembly 4 can be directly engaged by the transfer transmission gears 41 respectively installed on the main power input shaft 2 and the power output shaft 3. When the distance between the main power input shaft 2 and the power output shaft 3 is large, the transfer gear assembly 4 includes a transfer transmission intermediate shaft 42 between the main power input shaft 2 and the power output shaft 3. Transfer transmission gears 41 are respectively installed on the main power input shaft 2, the transfer transmission intermediate shaft 42, and the power output shaft 3. Adjacent transfer transmission gears 41 mesh with each other, and depending on the shaft distance, the transfer transmission intermediate shaft 42 and the transfer transmission gears 41 thereon can be one, two, or even more sets. Furthermore, conventionally, the transmission speed ratio between the main power input shaft 2 and the power output shaft 3 is 1:1.

[0020] In this embodiment, the housing 1 is also equipped with an auxiliary power input shaft 5 and an auxiliary power shift shaft 6. The auxiliary power input shaft 5 is used to connect to the power assist motor 51. A reduction gear set 7 is provided between the auxiliary power input shaft 5 and the auxiliary power shift shaft 6 to achieve first-level speed reduction. A high-speed gear set 8 and a low-speed gear set 9 are provided between the auxiliary power shift shaft 6 and the main power input shaft 2. A shift controller 61 for switching between the high-speed gear set 8 and the low-speed gear set 9 is installed on the housing 1. The power assist motor 51 includes a low-torque output mode using the high-speed gear set 8 and a high-torque output mode using the low-speed gear set 9.

[0021] Under normal circumstances, engine power is connected to the main power input shaft 2 via the main gearbox, and the power assist motor 51 is not powered; its output shaft only rotates in response. In this embodiment, engine power is transmitted to the power output shaft 3 for traction drive.

[0022] When a sudden increase in resistance occurs during traction operations, the torque demand for traction drive increases. Based on this increased torque demand, the shift controller 61 controls the switching between the low-speed gear set 9 and the high-speed gear set 8; for example, when the vehicle speed exceeds a certain specified speed, such as 15 km / h, ... Figure 1 As shown, the shift controller 61 controls the switching to use the high-speed gear set 8, that is, the power assist motor 51 uses a low-torque output mode at this time, or when the vehicle speed is lower than a certain specified speed, such as 15 km / h. Figure 2 As shown, the shift controller 61 controls the switching to use the low-speed gear set 9, meaning the power assist motor 51 uses a high-torque output mode at this time. The power assist motor 51 is powered and outputs low or medium speeds accordingly, such as approximately 2000 r / min in low-torque output mode or approximately 6000 r / min in high-torque output mode, to compensate for the torque output at the main power input shaft 2, thus achieving a greater torque output at the power output shaft 3.

[0023] When torque demand increases significantly, such as Figure 2 As shown, the shift controller 61 directly controls the switching to use the low-speed gear set 9, and the booster motor 51 directly outputs a high speed, such as 12000 r / min. The booster motor 51 enters a high-torque output mode, temporarily taking over the traction power output. In this case, the reduction gear set 7 and the low-speed gear set 9 together form a large speed ratio reduction. The booster motor 51 can use a high-speed mode to form a low-speed, high-torque output at the main power input shaft 2. When the booster motor 51 takes over the traction power output, the main gearbox performs a downshift operation. After downshifting, the output end of the main gearbox is reconnected to the main power input shaft 2, and the torque output on the engine side increases after downshifting. The booster motor 51 stops supplying power, and the greater power that the engine side can output after downshifting overcomes the resistance for traction drive.

[0024] If the engine cannot meet the torque demand on its own after downshifting, repeat the above-mentioned operation of compensating for power or temporarily taking over traction power to downshift for output.

[0025] In the above-described operation, this embodiment employs a high-speed gear set 8 and a low-speed gear set 9 to assist the output speed of the power assist motor 51, thereby achieving two operating modes at the main power input shaft 2: torque compensation and temporary torque output replacement. Regardless of the operating mode, the transmission ratio is utilized to ensure that the power assist motor 51, while maintaining a higher speed, achieves the required torque output at the desired speed on the main power input shaft 2. Compared to the direct power connection of the power assist motor 51 to the main power input shaft 2, especially in the operating mode where it temporarily replaces the engine for full power output, this ensures a smaller current flow within the power assist motor 51, less energy loss, and a lower risk of motor burnout.

[0026] The high-speed gear set 8 has a smaller transmission speed ratio, while the low-speed gear set 9 has a larger transmission speed ratio. This is easily understood by those skilled in the art based on conventional knowledge and will not be elaborated further here. Preferably, the overall transmission speed ratio between the reduction gear set 7 and the high-speed gear set 8 is 3.5:1 to 4.5:1. The overall transmission speed ratio between the reduction gear set 7 and the low-speed gear set 9 is 11:1 to 13:1.

[0027] Preferably, the auxiliary power shift shaft 6 is axially slidably mounted on the housing 1, meaning that the auxiliary power shift shaft 6 has both rotational and axial sliding degrees of freedom. The shift controller 61 includes a shift control motor 62 for driving the axial sliding of the auxiliary power shift shaft 6.

[0028] Furthermore, a shift fork 63 is movably mounted on the housing 1. The shift fork 63 is used to move the auxiliary power shift shaft 6 axially. A shift transmission mechanism 64 is provided between the power end of the shift control motor 62 and the shift fork 63. Here, the shift transmission mechanism 64 can be implemented by a worm gear and helical transmission to convert the rotational motion of the output end of the shift control motor 62 into the linear motion of the shift fork 63.

[0029] Furthermore, the housing 1 is equipped with a displacement sensor 65 for detecting the sliding displacement of the auxiliary power shift shaft 6 and a speed sensor for detecting the output speed of the shift control motor 62. The displacement sensor 65 and the speed sensor are signal-connected to a control element, and the output of the control element is signal-connected to the shift control motor 62.

[0030] When the power assist motor 51 needs to output power, the speed of the high-speed and low-speed shifting action needs to be controlled according to the aforementioned possible operating conditions. Therefore, this embodiment adds the speed sensor and the displacement sensor 65. For example, when encountering resistance and the torque demand increases significantly, the power assist motor 51 needs to quickly take over the power output in a high-torque output mode. At this time, based on the feedback from the speed sensor, the control element controls the shift control motor 62 to output high speed. Correspondingly, the shift fork 63 moves the auxiliary power shift shaft 6 to quickly shift gears, and the displacement sensor 65 detects whether the shift is in place. As another example, when encountering resistance and the torque demand increases, and the speed is higher than a specified speed, based on the feedback from the speed sensor, the control element controls the shift control motor 62 to output at normal speed. Correspondingly, the shift fork 63 moves the auxiliary power shift shaft 6 to shift gears normally, achieving the purpose of torque compensation at high speeds. The displacement sensor 65 detects whether the shift is in place. Similarly, when the torque demand increases while the speed is lower than the specified speed, the control element controls the shift control motor 62 to output normal speed for normal shifting, thereby achieving torque compensation at low speeds.

[0031] Under the above structural principle, the high-speed gear set 8, the low-speed gear set 9, and the reduction gear set 7 are all spur gear sets to meet the meshing requirements under axial movement. Furthermore, when the auxiliary power shift shaft 6 moves axially, only the high-speed gear set 8 or the low-speed gear set 9 meshes at any given time, while the reduction gear set 7 remains constantly meshed. Therefore, at least one gear in the reduction gear set 7 is a wide gear.

[0032] Since there is always a set of gears meshing between the auxiliary power shift shaft 6 and the main power input shaft 2 at any given time, and the reduction gear set 7 is also meshing between the auxiliary power input shaft 5 and the auxiliary power shift shaft 6, the main power input shaft 2 can still drive the output shaft of the auxiliary power motor 51 to rotate even when the power assist motor 51 is not driven. Therefore, when the power assist motor 51 is needed to compensate for or replace power, based on the real-time rotational speed of the main power input shaft 2, it is preferable to make the power assist motor 51 reach the corresponding rotational speed under reverse gear transmission. This means that both the auxiliary power shift shaft 6 and the main power input shaft 2 have active driving action, and the two driving actions cause the two shafts to maintain the meshing relationship of the gear sets between them. Thus, when the shift motor drives the auxiliary power shift shaft 6 to slide axially, the other set of gears can smoothly mesh. Of course, the gears that need to mesh during the axial sliding process of the auxiliary power shift shaft 6 should preferably have chamfers or similar features on the corresponding sides of their teeth to further promote smooth shifting.

[0033] Preferably, an auxiliary reduction intermediate shaft 71 is further provided between the auxiliary power input shaft 5 and the auxiliary power shift shaft 6. The reduction gear set 7 includes a first reduction gear set 72 between the auxiliary power input shaft 5 and the auxiliary reduction intermediate shaft 71, and a second reduction gear set 73 between the auxiliary reduction intermediate shaft 71 and the auxiliary power shift shaft 6, to further optimize the reduction gear configuration and provide more space for the installation of the power assist motor 51 and the shift motor at the position of the auxiliary power input shaft 5 on the housing 1. In this configuration, the second reduction gear set 73 is a spur gear set, and the first reduction gear set 72 can be a spur gear set or a helical gear set, without limitation. Similarly, the gears in the transfer gear assembly 4 can be spur gears or helical gears, without limitation.

[0034] In this embodiment, the transmission part of the power assist motor 51 is directly integrated into the housing 1 of the transfer case, realizing the parallel connection of the power assist motor 51 and the engine power. This high degree of integration facilitates size reduction and allows for convenient arrangement within the limited space of the tractor body. With this high level of integration, the instantaneous response characteristics of the power assist motor 51 can be fully utilized through gear transmission, enabling torque compensation or temporary power replacement in conjunction with the engine power. Furthermore, this embodiment uses a shift motor to control the axial movement of the auxiliary power shift shaft 6 for high- and low-speed gear shifting, improving the level of automation.

[0035] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. An integrated transfer case for a dual-mode power system, comprising a housing, wherein a main power input shaft and a power output shaft are mounted on the housing, and a transfer gear assembly is provided between the main power input shaft and the power output shaft, characterized in that: The housing is also equipped with an auxiliary power input shaft and an auxiliary power shift shaft. The auxiliary power input shaft is used to connect to the power assist motor. A reduction gear set is provided between the auxiliary power input shaft and the auxiliary power shift shaft. A high-speed gear set and a low-speed gear set are provided between the auxiliary power shift shaft and the main power input shaft. A shift controller for switching between using the high-speed gear set and the low-speed gear set is installed on the housing. The power assist motor includes a low-torque output mode using the high-speed gear set and a high-torque output mode using the low-speed gear set.

2. The integrated transfer case for a dual-mode powertrain as described in claim 1, characterized in that: The overall transmission speed ratio between the reduction gear set and the high-speed gear set is 3.5:1 to 4.5:

1.

3. The integrated transfer case for a dual-mode powertrain as described in claim 1, characterized in that: The overall transmission speed ratio between the reduction gear set and the low-speed gear set is 11:1 to 13:

1.

4. The integrated transfer case for a dual-mode powertrain as described in claim 1, characterized in that: The auxiliary power shift shaft is axially slidably mounted on the housing, and the shift controller includes a shift control motor for driving the auxiliary power shift shaft to slide axially.

5. The integrated transfer case for a dual-mode powertrain as described in claim 4, characterized in that: A shift fork is movably mounted on the housing. The shift fork is used to move the auxiliary power shift shaft axially. A shift transmission mechanism is provided between the power end of the shift control motor and the shift fork. A displacement sensor for detecting the sliding displacement of the auxiliary power shift shaft and a speed sensor for detecting the output speed of the shift control motor are mounted on the housing. The displacement sensor and the speed sensor are signal-connected to a control element. The output of the control element is signal-connected to the shift control motor.

6. The integrated transfer case for a dual-mode powertrain as described in claim 4, characterized in that: The high-speed gear set, the low-speed gear set, and the reduction gear set are all spur gear sets.

7. The integrated transfer case for a dual-mode powertrain as described in any one of claims 1 to 6, characterized in that: An auxiliary reduction intermediate shaft is also provided between the auxiliary power input shaft and the auxiliary power shift shaft. The reduction gear set includes a first reduction gear set between the auxiliary power input shaft and the auxiliary reduction intermediate shaft, and a second reduction gear set between the auxiliary reduction intermediate shaft and the auxiliary power shift shaft.

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