Transfer case

Abstract

The invention discloses a transfer case, which relates to the technical field of vehicle engineering and comprises a case body, a double-output-shaft reducing mechanism, a steering driving mechanism, two planetary gear mechanisms and two output transmission mechanisms, gear rings in the planetary gear mechanisms are fixedly connected with the corresponding output shafts; a third gear is fixedly arranged on a sun gear shaft in each planetary gear mechanism, and the two third gears are meshed with each other; each output transmission mechanism comprises a door bridge input shaft coaxially and fixedly connected with a planet carrier in the corresponding planet gear mechanism and a door bridge output shaft in transmission connection with the door bridge input shaft, one door bridge output shaft is used for driving wheels on one side of the vehicle to rotate, and the other door bridge output shaft is used for driving wheels on the other side of the vehicle to rotate. The steering driving mechanism is used for driving a sun wheel shaft to rotate. Zero steering of the vehicle and steering in the running process can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle engineering, and in particular to a transfer case. Background Art

[0002] Amphibious vehicles, capable of operating both on land and in water, are now widely used in emergency rescue, geological exploration, military operations, and other fields. As a key component of an amphibious vehicle's transmission system, the transfer case is responsible for distributing engine power to the land-based drive wheels and the aquatic propulsion system (such as the turbine).

[0003] Existing transfer cases for amphibious vehicles mostly utilize a traditional mechanical transmission structure, splitting power transmission through components such as gear sets and clutches. However, these transfer cases present numerous practical challenges. For one thing, conventional transfer cases struggle to meet the requirements for on-site steering in confined spaces, limiting their maneuverability and flexibility in complex terrain and aquatic environments. For example, in rescue scenarios involving narrow river channels, the vehicle's inability to quickly adjust its position on the spot can delay rescue efforts. When operating in complex land environments such as crowded urban streets, the lack of flexible steering also impacts vehicle efficiency. Furthermore, due to limitations in the transmission structure design, vibration and shock are prone to occur during power transmission, resulting in poor transmission stability. This not only reduces driving comfort but also increases wear on the transfer case's internal components, shortening its service life and increasing maintenance costs. Summary of the Invention

[0004] The purpose of the present invention is to provide a transfer case to solve the problems existing in the above-mentioned prior art, realize the zero-steering function of the vehicle while ensuring the driving and steering of the vehicle while moving, and improve the transmission stability.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a transfer case, comprising:

[0007] Box;

[0008] A dual-output shaft reduction mechanism is provided in the housing, wherein the input shaft of the dual-output shaft reduction mechanism is used for transmission connection with the output end of the gearbox of the vehicle;

[0009] Two planetary gear mechanisms are provided in the housing and correspond one-to-one with the output shafts of the dual-output shaft reduction mechanism, wherein the ring gears in the planetary gear mechanisms are fixedly connected to the corresponding output shafts; a third gear is fixedly provided on the sun gear shaft of each planetary gear mechanism, and the two third gears are meshed, and the pitch circle diameters of the two third gears are equal;

[0010] An output transmission mechanism is disposed in the housing and corresponds one-to-one with the planetary gear mechanisms. Each of the output transmission mechanisms includes a gate bridge input shaft coaxially fixedly connected to the planet carrier in the corresponding planetary gear mechanism and a gate bridge output shaft drivingly connected to the gate bridge input shaft. The gate bridge input shaft and the gate bridge output shaft are respectively rotatably connected to the housing. The gate bridge input shaft is rotationally matched with the sun gear shaft in the corresponding planetary gear mechanism. One gate bridge output shaft is used to drive the wheels on one side of the vehicle to rotate, and the other gate bridge output shaft is used to drive the wheels on the other side of the vehicle to rotate. All of the gate bridge input shafts and all of the gate bridge output shafts are distributed in parallel and at intervals.

[0011] A steering drive mechanism is used to drive one of the sun gear shafts to rotate.

[0012] Preferably, the dual-output shaft reduction mechanism includes the input shaft, a first gear, two output shafts and two second gears respectively meshing with the first gear. The input shaft and the two output shafts are respectively rotatably connected to the box body. The first gear is fixedly sleeved on the input shaft, the output shaft corresponds to the second gear one-to-one, and the second gear is fixedly sleeved on the corresponding output shaft; the input shaft and the two output shafts are distributed in parallel and at intervals.

[0013] Preferably, the steering drive mechanism includes a drive device fixedly connected to the box and a steering transmission mechanism arranged in the box, the steering transmission mechanism includes a first transmission shaft, a second transmission shaft, a fourth gear fixedly mounted on the first transmission shaft, and a fifth gear and a sixth gear respectively fixed on the second transmission shaft, the first transmission shaft is coaxial with and fixedly connected to the output shaft of the drive device, the fourth gear is engaged with the fifth gear, and the sixth gear is engaged with one of the third gears.

[0014] Preferably, the driving device adopts a hydraulic motor.

[0015] Preferably, the fixed sleeve on the portal bridge input shaft is provided with a portal bridge input gear, and the fixed sleeve on the portal bridge output shaft is provided with a portal bridge output gear meshing with the portal bridge input gear; the pitch circle diameter of the portal bridge output gear is larger than the pitch circle diameter of the portal bridge input gear.

[0016] Preferably, the two gate bridge output shafts are parallel and both are located below the input shaft of the dual output shaft reduction mechanism.

[0017] Preferably, the pitch circle diameter of the second gear is larger than the pitch circle diameter of the first gear.

[0018] Preferably, the pitch circle diameter of the fourth gear is smaller than the pitch circle diameter of the fifth gear, and the pitch circle diameter of the sixth gear is smaller than the pitch circle diameter of the third gear.

[0019] Preferably, both ends of each of the portal bridge output shafts extend out of the box and serve as first power output ends.

[0020] Preferably, both ends of the input shaft of the dual-output shaft reduction mechanism extend out of the box respectively, one end of the input shaft of the dual-output shaft reduction mechanism is used for transmission connection with the output end of the gearbox, and the other end is used as the second power output end; the second power output end is used for transmission connection with the input shaft of the propeller.

[0021] Compared with the prior art, the present invention has achieved the following technical effects:

[0022] The transfer case of the present invention is equipped with two planetary gear mechanisms that divide power through a dual-output shaft reduction mechanism. The power is then transmitted through the two planetary gear mechanisms and finally driven by two portal axle output shafts to rotate the wheels on both sides of the vehicle. The wheels on both sides are driven synchronously, resulting in smooth transmission. Furthermore, the sun gear in one planetary gear mechanism is driven by a steering mechanism, enabling the two sides of the vehicle to rotate in opposite directions when engine power is cut off, thereby achieving zero-steering. When engine power is not cut off, the rotation speed of the planetary carrier in one planetary gear mechanism is increased while that of the other planetary gear mechanism is reduced, thereby increasing the rotation speed of the wheels on one side of the vehicle and reducing the rotation speed of the wheels on the other side, thereby achieving on-the-go steering. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 It is a schematic structural diagram of the transfer case of the present invention;

[0025] Figure 2 Schematic diagram of the partial structure of the transfer case of the present invention Figure 1 ;

[0026] Figure 3 Schematic diagram of the partial structure of the transfer case of the present invention Figure 2 ;

[0027] Figure 4 Schematic diagram of the partial structure of the transfer case of the present invention Figure 3 ;

[0028] Figure 5 Schematic diagram of the partial structure of the transfer case of the present invention Figure 4 ;

[0029] In the figure: 1. Housing; 2. Input shaft; 3. First gear; 4. Second gear; 5. Output shaft; 6. Ring gear; 7. Planet carrier; 8. Gate axle input shaft; 9. Gate axle input gear; 10. Gate axle output gear; 11. Gate axle output shaft; 12. Planetary gear; 13. Sun gear shaft; 14. Third gear; 15. Drive unit; 16. First transmission shaft; 17. Fourth gear; 18. Fifth gear; 19. Second transmission shaft; 20. Sixth gear; 21. Sun gear. DETAILED DESCRIPTION

[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] The purpose of the present invention is to provide a transfer case to solve the problems existing in the above-mentioned prior art, realize the zero-steering function of the vehicle while ensuring the driving and steering of the vehicle while moving, and improve the transmission stability.

[0032] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] like Figures 1 to 5 As shown, this embodiment provides a transfer case, comprising:

[0034] Box 1;

[0035] A dual output shaft 5 reduction mechanism is provided in the housing 1, and an input shaft 2 of the dual output shaft 5 reduction mechanism is used for transmission connection with the output end of the gearbox of the vehicle;

[0036] Two planetary gear mechanisms are disposed within the housing 1 and correspond one-to-one with the output shafts 5 of the dual-output shaft 5 reduction mechanism. The ring gear 6 in the planetary gear mechanism is fixedly connected to the corresponding output shaft 5. A third gear 14 is fixedly disposed on the sun gear shaft 13 in each planetary gear mechanism, and the two third gears 14 are meshed, with the pitch circle diameters of the two third gears 14 being equal.

[0037] Output transmission mechanisms are disposed within the housing 1 and correspond one-to-one with the planetary gear mechanisms. Each output transmission mechanism includes a portal bridge input shaft 8 coaxially fixedly connected to the planet carrier 7 in the corresponding planetary gear mechanism and a portal bridge output shaft 11 drivingly connected to the portal bridge input shaft 8. The portal bridge input shaft 8 and the portal bridge output shaft 11 are respectively rotationally connected to the housing 1. The portal bridge input shaft 8 rotates in conjunction with the sun gear shaft 13 in the corresponding planetary gear mechanism. One portal bridge output shaft 11 is used to drive the wheels on one side of the vehicle, and the other portal bridge output shaft 11 is used to drive the wheels on the other side of the vehicle. All portal bridge input shafts 8 and all portal bridge output shafts 11 are arranged in parallel and spaced apart.

[0038] The steering drive mechanism is used to drive a sun gear shaft 13 to rotate.

[0039] In an alternative embodiment of this embodiment, a preferred dual-output shaft 5 reduction mechanism includes an input shaft 2, a first gear 3, two output shafts 5, and two second gears 4, each meshing with the first gear 3. The input shaft 2 and the two output shafts 5 are rotatably connected to the housing 1. The first gear 3 is fixedly sleeved on the input shaft 2. The output shafts 5 correspond one-to-one with the second gears 4, and the second gears 4 are fixedly sleeved on the corresponding output shafts 5. The input shaft 2 and the two output shafts 5 are spaced apart and arranged in parallel. Furthermore, the pitch circle diameter of the second gears 4 is larger than the pitch circle diameter of the first gear 3.

[0040] In an optional solution of this embodiment, it is more preferred that the steering drive mechanism includes a drive device 15 fixedly connected to the housing 1 and a steering transmission mechanism disposed within the housing 1. The steering transmission mechanism includes a first transmission shaft 16, a second transmission shaft 19, a fourth gear 17 fixedly sleeved on the first transmission shaft 16, and a fifth gear 18 and a sixth gear 20 respectively fixed to the second transmission shaft 19. The first transmission shaft 16 is coaxial with and fixedly connected to the output shaft 5 of the drive device 15. The fourth gear 17 meshes with the fifth gear 18, and the sixth gear 20 meshes with one of the third gears 14. In this embodiment, the pitch circle diameter of the fourth gear 17 is smaller than the pitch circle diameter of the fifth gear 18, and the pitch circle diameter of the sixth gear 20 is smaller than the pitch circle diameter of the third gear 14. This amplifies the torque of the output shaft 5 of the drive device 15, thereby providing the vehicle with greater power.

[0041] Among the alternatives of this embodiment, it is preferred that the drive device 15 utilize a hydraulic motor. A hydraulic motor can provide high torque upon startup, making it suitable for situations where high static friction needs to be overcome, and can provide sufficient torque for the vehicle's zero-position steering and steering during travel. It is worth noting that the zero-position steering mentioned in this embodiment refers to steering the vehicle in place.

[0042] In the optional scheme of this embodiment, it is more preferred that a fixed sleeve is provided on the portal bridge input shaft 8 with a portal bridge input gear 9, and a fixed sleeve is provided on the portal bridge output shaft 11 with a portal bridge output gear 10 that meshes with the portal bridge input gear 9; the pitch circle diameter of the portal bridge output gear 10 is larger than the pitch circle diameter of the portal bridge input gear 9; in this way, when the power of the portal bridge input shaft 8 is transmitted to the portal bridge output shaft 11, the torque is amplified, thereby enabling the wheels to obtain stronger driving force.

[0043] In the optional scheme of this embodiment, it is more preferred that the two gate bridge output shafts 11 are parallel and are both located below the input shaft 2 of the dual output shaft 5 reduction mechanism; from the cross section (i.e. the cross section perpendicular to the axial direction of the two gate bridge output shafts 11 and the input shaft 2 of the dual output shaft 5 reduction mechanism), the axes of the two gate bridge output shafts 11 and the input shaft 2 of the dual output shaft 5 reduction mechanism are located at the three vertices of the same triangle. This layout makes the transfer case compact in structure and high in space utilization, so that the force in the transmission process can be more evenly distributed on each shaft; when power is transmitted from the input shaft 2 to the two gate bridge output shafts 11, due to the three shafts The triangular structure allows force to be transmitted and distributed along the three sides of the triangle, avoiding the concentration of force on a single shaft or a section of the transmission path, thereby reducing the force burden on individual components and the risk of component damage due to overload. Secondly, the triangle is stable and is a stable structural form in mechanics. Arranging the three shafts in a triangle enhances the structural rigidity of the entire transmission system. Compared with layouts of other shapes, the triangular structure can better resist interference and deformation from external forces, reducing shaft offset, distortion, or loosening of transmission components caused by factors such as vibration and impact, thereby ensuring the accuracy and stability of the transmission. In addition, when the input shaft 2 transmits torque, the triangular structure allows the torque to be distributed relatively evenly to the two gate bridge output shafts 11, avoiding the problem of overloading one output shaft 5 or reduced transmission efficiency due to uneven torque distribution. This balanced torque effect can make the entire transmission system operate more stably and extend the service life of the transmission components.

[0044] In the optional scheme of this embodiment, it is more preferred that both ends of each gate bridge output shaft 11 extend out of the box body 1 and serve as the first power output end, so that the transfer case of this embodiment has four first power output ends, which can drive more wheels to actively rotate, thereby facilitating the realization of all-wheel drive of the vehicle.

[0045] In the optional scheme of this embodiment, it is more preferred that the two ends of the input shaft 2 of the dual output shaft 5 reduction mechanism extend out of the box body 1 respectively, one end of the input shaft 2 of the dual output shaft 5 reduction mechanism is used for transmission connection with the output end of the gearbox, and the other end is used as the second power output end; the second power output end is used for transmission connection with the input shaft 2 of the propeller; this makes the transfer case of this embodiment suitable for amphibious vehicles. Of course, the propeller is preferably a propeller propeller.

[0046] The working principle of the transfer case of this embodiment is as follows:

[0047] When driving in a straight line, the hydraulic motor is turned off. Under the action of the pressure of the hydraulic oil in the hydraulic motor, the sun gear shaft 13 and the sun gear 21 in the two planetary gear mechanisms are fixed; the power of the engine is transmitted to the input shaft 2 of the dual output shaft 5 reduction mechanism through the gearbox power. The input shaft 2 transmits the power to the two output shafts 5 through the first gear 3 and the second gear 4. The output shaft 5 drives the corresponding ring gear 6 in the planetary gear mechanism to rotate. The ring gear 6 drives the planetary gear 12 and the planetary carrier 7 to rotate, and then drives the portal axle input shaft 8 to rotate. The portal axle input shaft 8 drives the portal axle output shaft 11 to rotate through the portal axle input gear 9 and the portal axle output gear 10. One portal axle output shaft 11 drives the wheels on one side of the vehicle to rotate, and the other portal axle output shaft 11 drives the wheels on the other side of the vehicle to rotate.

[0048] When zero-steering is required, the engine power output is first cut off via the clutch, so that the ring gears 6 in the two planetary gear mechanisms are stationary. The hydraulic motor is then turned on to rotate the first transmission shaft 16. The first transmission shaft 16 drives the second transmission shaft 19 to rotate via the fourth gear 17 and the fifth gear 18. The second transmission shaft 19 drives the third gear 14 meshing with the sixth gear 20 to rotate via the sixth gear 20. The third gear 14 meshing with the sixth gear 20 drives another third gear 14 to rotate. Since the two third gears 14 are directly meshed, the two third gears 14 rotate in opposite directions, thereby driving the sun gear shafts 13 in the two planetary gear mechanisms to rotate at the same speed but in opposite directions. This in turn causes the planet carriers 7 in the two planetary gear mechanisms to rotate in opposite directions, resulting in opposite directions of rotation of the two portal axle input shafts 8 and the two portal axle output shafts 11. This drives the wheels on both sides of the vehicle to rotate in opposite directions, thereby achieving zero-steering of the vehicle. It is worth noting that the direction of zero-steering can be changed simply by changing the rotation direction of the output shaft 5 of the hydraulic motor.

[0049] When steering is required during travel, power transmission is maintained among the engine, transmission, and dual-output shaft 5 reduction mechanism, and the hydraulic motor is turned on. The hydraulic motor drives the first transmission shaft 16 to rotate. The first transmission shaft 16 drives the second transmission shaft 19 to rotate via the fourth gear 17 and the fifth gear 18. The second transmission shaft 19 drives the third gear 14 meshing with the sixth gear 20 to rotate via the sixth gear 20. The third gear 14 meshing with the sixth gear 20 drives the other third gear 14 to rotate. Since the two third gears 14 are directly meshed, the two third gears 14 rotate in opposite directions, thereby driving the sun gear shafts 13 in the two planetary gear mechanisms to rotate at the same speed but in opposite directions. This causes the speed of the planet carrier 7 in one planetary gear mechanism to increase, while the speed of the planet carrier 7 in the other planetary gear mechanism to decrease. This in turn causes the speed of one of the two portal axle output shafts 11 to increase and the speed of the other to decrease. However, the two portal axle output shafts 11 have the same direction of rotation, resulting in the wheels on both sides of the vehicle having the same direction of rotation but different speeds, thus achieving steering of the vehicle during travel. Likewise, the direction of steering during travel can be changed simply by changing the rotation direction of the output shaft 5 of the hydraulic motor.

[0050] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A transfer case, characterized in that: include: Box; A dual-output shaft reduction mechanism is provided in the housing, wherein the input shaft of the dual-output shaft reduction mechanism is used for transmission connection with the output end of the gearbox of the vehicle; Two planetary gear mechanisms are provided in the housing and correspond one-to-one with the output shafts of the dual-output shaft reduction mechanism, wherein the ring gears in the planetary gear mechanisms are fixedly connected to the corresponding output shafts; a third gear is fixedly provided on the sun gear shaft of each planetary gear mechanism, and the two third gears are meshed, and the pitch circle diameters of the two third gears are equal; An output transmission mechanism is disposed in the housing and corresponds one-to-one with the planetary gear mechanisms. Each of the output transmission mechanisms includes a gate bridge input shaft coaxially fixedly connected to the planet carrier in the corresponding planetary gear mechanism and a gate bridge output shaft drivingly connected to the gate bridge input shaft. The gate bridge input shaft and the gate bridge output shaft are respectively rotatably connected to the housing. The gate bridge input shaft is rotationally matched with the sun gear shaft in the corresponding planetary gear mechanism. One gate bridge output shaft is used to drive the wheels on one side of the vehicle to rotate, and the other gate bridge output shaft is used to drive the wheels on the other side of the vehicle to rotate. All of the gate bridge input shafts and all of the gate bridge output shafts are distributed in parallel and at intervals. A steering drive mechanism is used to drive one of the sun gear shafts to rotate.

2. The transfer case according to claim 1, characterized in that: The dual-output shaft reduction mechanism includes the input shaft, a first gear, two output shafts and two second gears respectively meshing with the first gear. The input shaft and the two output shafts are respectively rotatably connected to the box body. The first gear is fixedly sleeved on the input shaft, the output shaft corresponds to the second gear one-to-one, and the second gear is fixedly sleeved on the corresponding output shaft; the input shaft and the two output shafts are distributed in parallel and at intervals.

3. The transfer case according to claim 1, characterized in that: The steering drive mechanism includes a drive device fixedly connected to the box body and a steering transmission mechanism arranged in the box body. The steering transmission mechanism includes a first transmission shaft, a second transmission shaft, a fourth gear fixedly mounted on the first transmission shaft, and a fifth gear and a sixth gear respectively fixed on the second transmission shaft. The first transmission shaft is coaxial with and fixedly connected to the output shaft of the drive device. The fourth gear is engaged with the fifth gear, and the sixth gear is engaged with one of the third gears.

4. The transfer case according to claim 3, characterized in that: The driving device adopts a hydraulic motor.

5. The transfer case according to claim 1, characterized in that: The fixed sleeve on the portal bridge input shaft is provided with a portal bridge input gear, and the fixed sleeve on the portal bridge output shaft is provided with a portal bridge output gear meshing with the portal bridge input gear; the pitch circle diameter of the portal bridge output gear is larger than the pitch circle diameter of the portal bridge input gear.

6. The transfer case according to claim 1, characterized in that: The two gate bridge output shafts are parallel and are both located below the input shaft of the dual-output shaft reduction mechanism.

7. The transfer case according to claim 2, characterized in that: The pitch circle diameter of the second gear is larger than the pitch circle diameter of the first gear.

8. The transfer case according to claim 3, characterized in that: The pitch circle diameter of the fourth gear is smaller than the pitch circle diameter of the fifth gear, and the pitch circle diameter of the sixth gear is smaller than the pitch circle diameter of the third gear.

9. The transfer case according to claim 1, characterized in that: Both ends of each of the portal bridge output shafts extend out of the box and serve as first power output ends.

10. The transfer case according to claim 1, characterized in that: Both ends of the input shaft of the dual-output shaft reduction mechanism extend out of the box body respectively, one end of the input shaft of the dual-output shaft reduction mechanism is used for transmission connection with the output end of the gearbox, and the other end is used as the second power output end; the second power output end is used for transmission connection with the input shaft of the propeller.

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