A transfer case for special vehicles

Abstract

The present invention discloses a transfer case for special vehicles, which includes a first shaft for installing an input flange, a second shaft for installing a rear axle output flange, a third shaft drivingly connected to the first shaft, a fourth shaft drivingly connected to the third shaft, a fifth shaft for installing a front axle output flange, and a sixth shaft for transitional connection. A two-way lubricating pump is provided at the front end of the third shaft, and a differential is provided on the fourth shaft. The differential is drivingly connected to the third shaft. The fifth shaft is connected to the front output end of the differential, and the sixth shaft is connected to the rear output end of the differential. Moreover, both the second shaft and the sixth shaft are drivingly connected to the third shaft. The two-way lubricating pump is respectively communicated with the bearings of the first shaft, the second shaft, the third shaft, the fourth shaft, the fifth shaft and the sixth shaft. The transfer case of the present invention can reduce the included angle of the vehicle's drive shafts, reserve space under the vehicle body, facilitate the arrangement of special devices for existing vehicles, and improve the lubrication effect of the transfer case through a quantitative lubrication system to achieve precise lubrication.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle transmission design, and particularly relates to a transfer case for special vehicles. Background Art

[0002] In the design of vehicle chassis, transfer cases are generally installed on special multi-axle drive vehicles to distribute the power output by the transmission to each drive axle, so as to overcome the large driving resistance of the vehicle on poor roads and in areas without roads.

[0003] There are mainly two types of existing transfer cases. One is horizontally arranged. The structure of the horizontal transfer case is as follows: on one side of the front end of the transfer case is the input shaft, which is directly connected to the output shaft of the transmission. The rear end is the rear axle output shaft, which is connected to the rear axle through a universal transmission device. On the other side of the front end of the transfer case is the front axle output shaft, which is connected to the front axle through a universal transmission device. Due to its internal structure limitations, the size of this transfer case is small and the transmitted torque is small, and it is usually used in the passenger car field. The other is longitudinally arranged. Since its output shafts are all at the lower part of the box body, the included angle of the rear transmission shaft is too large, and the transmission shaft occupies and divides the lower space of the whole vehicle, resulting in the inability to arrange special devices such as integral snow sweeping brushes, cleaning racks, and special tool boxes. After the special devices are arranged on both sides of the vehicle, it causes high vehicle cost, complex structure, and chaotic pipelines. In addition, it also causes the vehicle to work reciprocally, with low efficiency. At the same time, there are two defects in the longitudinally arranged transfer case of another deformed structure. First, if the differential is not arranged, the front and rear axles cannot achieve differential of the inter-axle differential, which will accelerate tire wear and reduce the fuel efficiency of the whole vehicle. Second, the structure with the planetary differential arranged on the intermediate shaft will cause the rotation directions of the input shaft and the output shaft to be different, bringing unnecessary trouble to the layout of the whole vehicle. At the same time, the current lubrication method of the transfer case cannot control the lubrication amount of each component, and the lubrication effect is not good. At the same time, unnecessary gear oil agitation will increase power loss, resulting in phenomena such as heating and noise. And setting an oil receiving plate and an oil guiding groove on the box body, or casting and machining internal oil channels on the box body wall has high requirements for the casting and machining of the box body, low part yield, and it is not easy to control the quality and cost of the parts.

[0004] Therefore, how to optimize the structure of the transfer case for special vehicles and the lubrication effect of the transfer case is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0005] The purpose of the present invention is to provide a transfer case for special vehicles, which solves the problems of too large included angle of the transmission shaft arrangement and occupying the space of the whole vehicle during the multi-drive arrangement of special vehicles, and the inability to arrange integral special devices. At the same time, it improves the lubrication effect of the transfer case, realizes precise lubrication, and achieves the purpose of reducing system heating and extending the service life of the product.

[0006] In order to solve the above technical problems, the present invention provides a transfer case for special vehicles, comprising a first shaft for installing an input flange, a second shaft for installing a rear axle output flange, a third shaft drivingly connected to the first shaft, a fourth shaft drivingly connected to the third shaft, a fifth shaft for installing a front axle output flange, and a sixth shaft for transition connection, wherein a bidirectional lubrication pump is arranged at the front end of the third shaft, a differential is arranged on the fourth shaft, the differential is drivingly connected to the third shaft, the fifth shaft is connected to a front output end of the differential, the sixth shaft is connected to a rear output end of the differential, and the second shaft and the sixth shaft are both drivingly connected to the third shaft, and the bidirectional lubrication pump is respectively connected to the bearings of the first shaft, the second shaft, the third shaft, the fourth shaft, the fifth shaft and the sixth shaft.

[0007] Preferably, it also includes an external oil suction pipe and an internal oil suction pipe connected to the bidirectional lubrication pump.

[0008] Preferably, an oil suction filter is provided on the inner oil suction pipe.

[0009] Preferably, it also includes an oil outlet pipe connected to the bidirectional lubrication pump and an oil injection pipe connected to the oil outlet pipe.

[0010] Preferably, a front oil distribution valve is provided on the oil outlet pipe, and a rear oil distribution valve is provided on the oil injection pipe.

[0011] Preferably, the differential is a bevel gear differential or a planetary differential.

[0012] Preferably, the first shaft and the second shaft are arranged in series.

[0013] Preferably, two gears are arranged on the third shaft, and a bearing is provided between any one of the gears and the third shaft.

[0014] Preferably, it also includes a cooler oil inlet pipe connected to the oil outlet of the two-way lubrication pump, the cooler oil inlet pipe is connected to the cooler, and the cooler is provided with a cooler oil outlet pipe, and the cooler oil outlet pipe is connected to the front oil distribution valve.

[0015] Preferably, it also includes a temperature control valve arranged in parallel on the cooler oil inlet pipe and the cooler oil outlet pipe.

[0016] The transfer case for special vehicles provided by the present invention includes a first shaft for installing an input flange, a second shaft for installing a rear axle output flange, a third shaft drivingly connected to the first shaft, a fourth shaft drivingly connected to the third shaft, a fifth shaft for installing a front axle output flange, and a sixth shaft for transitional connection. A two-way lubricating pump is provided at the front end of the third shaft, a differential is provided on the fourth shaft, the differential is drivingly connected to the third shaft, the fifth shaft is connected to the front output end of the differential, the sixth shaft is connected to the rear output end of the differential, and both the second shaft and the sixth shaft are drivingly connected to the third shaft. The two-way lubricating pump is respectively communicated with the bearings of the first shaft, the second shaft, the third shaft, the fourth shaft, the fifth shaft and the sixth shaft. The transmission transfers power to the first shaft through the input flange and drives the first shaft to rotate. The first shaft transfers power to the third shaft to drive the third shaft to rotate. The third shaft drives the differential to work. The front output end of the differential transfers power to the fifth shaft. The fifth shaft transfers power to the front drive axle through the front axle drive flange to drive the wheels to rotate. At the same time, the rear output end of the differential transfers power to the sixth shaft. The sixth shaft transfers power to the second shaft through the third shaft gear and drives the second shaft to rotate. The second shaft transfers power to the rear drive axle through the rear axle drive flange to drive the wheels to rotate, so as to achieve the purpose of driving the vehicle. The differential plays the role of adjusting the output power of the transmission, enabling the vehicle to adapt to driving on different road conditions. At the same time, the third shaft drives the two-way lubricating pump to work, and the two-way lubricating pump lubricates the bearings of the first shaft, the second shaft, the third shaft, the fourth shaft, the fifth shaft and the sixth shaft to ensure the normal operation of the bearings of the first shaft, the second shaft, the third shaft, the fourth shaft, the fifth shaft and the sixth shaft. Through a gear reduction structure with three or more stages, the output position of the second shaft is increased, so that the application of the present invention can reduce the included angle of the transmission shaft, and at the same time leave a large amount of space under the whole vehicle, which is convenient for the layout of the integral special device of the existing vehicle. In addition, the lubrication effect of the transfer case is improved through a quantitative lubrication system to achieve precise lubrication, so as to reduce system heating and extend the service life of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0018] Figure 1 It is a schematic diagram of the overall structure of a specific embodiment provided by the present invention;

[0019] Figure 2 is Figure 1 a side view of the structure shown;

[0020] Figure 3 isFigure 1 The differential shown is a simplified transmission system diagram of a bevel gear type;

[0021] Figure 4 is Figure 1 The differential shown is a simplified transmission system diagram of a planetary type;

[0022] Figure 5 is Figure 1 The circulating oil circuit diagram of the overall structure shown;

[0023] Figure 6 is Figure 5 The side view of the structure shown;

[0024] Figure 7 is Figure 1 The gear lubricating oil circuit diagram of the overall structure shown;

[0025] Figure 8 is Figure 1 The bearing lubricating oil circuit diagram of the overall structure shown;

[0026] Figure 9 is Figure 1 The cooling lubricating oil circuit diagram of the overall structure shown.

[0027] Among them, Figures 1-9 in:

[0028] Input flange - 1, front oil distribution valve - 2, oil outlet pipe - 3, two-way lubricating pump - 4, front axle output flange - 5, oil temperature sensor - 6, rear oil distribution valve - 7, rear axle output flange - 8, breather - 9, speed sensor - 10, external oil suction pipe - 11, differential lock indicator switch - 12, differential lock - 13, air source interface - 14, oil suction filter - 15, internal oil suction pipe - 16, oil spray pipe - 17, first bearing lubricating pipe - 18, second bearing lubricating pipe - 19, third bearing lubricating pipe - 20, fourth bearing lubricating pipe - 21, fifth bearing lubricating pipe - 22, sixth bearing lubricating pipe - 23, seventh bearing lubricating pipe - 24, eighth bearing lubricating pipe - 25, cooler inlet pipe - 26, cooler - 27, cooler outlet pipe - 28, temperature control valve - 29, first transmission gear - Z1, second transmission gear - Z2, third transmission gear - Z3, fourth transmission gear - Z4, fifth transmission gear - Z5, sixth transmission gear - Z6, engagement sleeve - C1, differential - D1, first shaft - S1, second shaft - S2, third shaft - S3, fourth shaft - S4, fifth shaft - S5, sixth shaft - S6. Specific implementation manner

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention.

[0030] Please refer to Figures 1 to 9 , Figure 1 A schematic diagram of the overall structure of a specific implementation method provided by the present invention; Figure 2 for Figure 1 a side view of the structure shown; Figure 3 for Figure 1 The differential shown is a simplified diagram of the transmission system of the bevel gear type; Figure 4 for Figure 1 The differential shown is a simplified diagram of a transmission system of planetary type; Figure 5 for Figure 1 The oil circulation diagram of the overall structure is shown; Figure 6 for Figure 5 a side view of the structure shown; Figure 7 for Figure 1 The gear lubrication oil circuit diagram of the overall structure shown; Figure 8 for Figure 1 The bearing lubrication oil circuit diagram of the overall structure shown; Figure 9 for Figure 1 The cooling and lubrication oil circuit diagram of the overall structure is shown.

[0031] In a specific embodiment provided by the present invention, it mainly includes a first shaft S1 for installing an input flange 1, a second shaft S2 for installing a rear axle output flange 8, a third shaft S3 drivingly connected to the first shaft S1, a fourth shaft S4 drivingly connected to the third shaft S3, a fifth shaft S5 for installing a front axle output flange 5, and a sixth shaft S6 for transition connection. A bidirectional lubrication pump 4 is arranged at the front end of the third shaft S3, a differential D1 is arranged on the fourth shaft S4, the differential D1 is drivingly connected to the third shaft S3, the fifth shaft S5 is connected to the front output end of the differential D1, the sixth shaft S6 is connected to the rear output end of the differential D1, and the second shaft S2 and the sixth shaft S6 are both drivingly connected to the third shaft S3, and the bidirectional lubrication pump 4 is respectively connected to the bearings of the first shaft S1, the second shaft S2, the third shaft S3, the fourth shaft S4, the fifth shaft S5 and the sixth shaft S6.

[0032] The input flange 1 is installed at the front end of the first shaft S1, which transmits the power of the transmission to the first shaft S1 and drives the first shaft S1 to rotate. The first shaft S1 transmits the power to the third shaft S3 to drive the third shaft S3 to rotate. A two-way lubrication pump 4 is arranged at the front end of the third shaft S3. The third shaft S3 is used to drive the two-way lubrication pump 4 to work. The third shaft S3 is also used to drive the differential D1 to work. The fifth shaft S5 is connected to the front output end of the differential D1. The fifth shaft S5 is installed with the front axle output flange 5 to transmit the power to the front drive axle. The sixth shaft S6 is connected to the differential. The rear output end of D1 is connected, the second shaft S2 is installed with the rear axle output flange 8, and the second shaft S2 and the sixth shaft S6 are both transmission-connected with the third shaft S3, the sixth shaft S6, the third shaft S3 and the second shaft S2 are used to transmit power to the rear drive axle, and the two-way lubrication pump 4 is respectively connected with the bearings of the first shaft S1, the second shaft S2, the third shaft S3, the fourth shaft S4, the fifth shaft S5 and the sixth shaft S6, and the two-way lubrication pump 4 is used to lubricate the bearings of the first shaft S1, the second shaft S2, the third shaft S3, the fourth shaft S4, the fifth shaft S5 and the sixth shaft S6.

[0033] Specifically, in the actual application process, the transmission transmits power to the first shaft S1 through the input flange 1 and drives the first shaft S1 to rotate, the first shaft S1 transmits power to the third shaft S3 to drive the third shaft S3 to rotate, the third shaft S3 drives the differential D1 to work, the front output end of the differential D1 transmits power to the fifth shaft S5, the fifth shaft S5 transmits power to the front drive axle through the front axle drive flange 5 to drive the wheels to rotate, at the same time, the rear output end of the differential D1 transmits power to the sixth shaft S6, the sixth shaft S6 transmits power to the second shaft S2 through the third shaft gear and drives the second shaft S2 to rotate, the second shaft S2 transmits power to the rear drive axle through the rear axle drive flange 8 to drive the wheels to rotate, thereby achieving the purpose of driving the vehicle, and the differential D1 plays a role in adjusting the output power of the transmission. The purpose of force is to make the vehicle adapt to driving on different road conditions. At the same time, the third shaft S3 drives the two-way lubrication pump 4 to work, and the two-way lubrication pump 4 lubricates the bearings of the first shaft S1, the second shaft S2, the third shaft S3, the fourth shaft S4, the fifth shaft S5 and the sixth shaft S6 to ensure that the bearings of the first shaft S1, the second shaft S2, the third shaft S3, the fourth shaft S4, the fifth shaft S5 and the sixth shaft S6 work normally. Through the three-stage or more gear reduction structure, the output position of the second shaft S2 is raised, so that the application of the present invention can reduce the angle of the transmission shaft, and at the same time, a large amount of space is reserved at the bottom of the whole vehicle, which is convenient for the layout of the existing vehicle integral special device. In addition, the lubrication effect of the transfer case is improved by the quantitative lubrication system, and precise lubrication is achieved, so as to reduce the heat of the system and extend the service life of the product.

[0034] It should be noted that the first shaft S1 and the second shaft S2 are arranged in series, optimizing the structure of the drive shaft, raising the position of the second shaft S2 of the rear axle drive shaft, reducing the included angle of the drive shaft, and at the same time leaving a large amount of space under the whole vehicle to facilitate the arrangement of the integral special device of the existing vehicle.

[0035] It should also be noted that the connection relationships of the first shaft S1, the second shaft S2, the third shaft S3, the fourth shaft S4, the fifth shaft S5, the sixth shaft S6 and the differential D1 are as follows. The first shaft S1 and the third shaft S3 are meshed and connected through the first transmission gear Z1 and the second transmission gear Z2. A fifth transmission gear Z5 is also arranged on the third shaft S3. One of the second transmission gear Z2 or the fifth transmission gear Z5 on the third shaft S3 is installed with a bearing between it and the third shaft S3. A differential D1 is arranged on the fourth shaft S4. The fourth shaft S4 and the third shaft S3 are meshed and connected through the third transmission gear Z3 and the second transmission gear Z2. The fifth shaft S5 and the front output of the differential D1 are connected by splines. A sliding sleeve C1 is arranged on the fifth shaft S5. The sliding sleeve C1 adopts the conventional meshing technology. The inner sleeve of the sliding sleeve C1 and the fifth shaft S5 are connected by splines. According to the working needs, the outer sleeve of the sliding sleeve C1 and the differential D1 housing are combined or separated by splines. The front axle output flange 5 is installed at the front end of the fifth shaft S5, and its function is to transmit power to the front drive axle through the universal transmission device. The sixth shaft S6 and the rear output of the differential D1 are connected by splines. The sixth shaft S6 and the third shaft S3 are meshed and connected through the fourth transmission gear Z4 and the fifth transmission gear Z5. The second shaft S2 and the third shaft S3 are meshed and connected through the sixth transmission gear Z6 and the fifth transmission gear Z5. The rear axle output flange 8 is installed at the rear end of the second shaft S2, and its function is to transmit power to the rear drive axle.

[0036] To optimize the lubrication effect of the transfer case itself in the above embodiments, the transfer case for special vehicles further includes an external oil suction pipe 11 and an internal oil suction pipe 16 that communicate with the two-way lubricating pump 4. An oil suction filter 15 is provided on the internal oil suction pipe 16. The transfer case for special vehicles further includes an oil outlet pipe 3 that communicates with the two-way lubricating pump 4 and an oil injection pipe 17 that communicates with the oil outlet pipe 3. A front oil distribution valve 2 is provided on the oil outlet pipe 3, and a rear oil distribution valve 7 is provided on the oil injection pipe 17. The oil suction filter 15 is installed on the internal oil suction pipe 16, and the two are arranged together inside the box body and connected to one end of the external oil suction pipe 11. The other end of the external oil suction pipe 11 is connected to the oil suction port of the two-way lubricating pump 4. One end of the oil outlet pipe 3 is connected to the oil outlet of the two-way lubricating pump 4, and the other end is connected to the front oil distribution valve 2. One end of the oil injection pipe 17 is connected to the front oil distribution valve 2, and the other end is connected to the rear oil distribution valve 7. One end of the first bearing lubricating pipe 18, the second bearing lubricating pipe 19, and the third bearing lubricating pipe 20 is connected to the front oil distribution valve 2, and the other ends are respectively connected to the bearing lubrication points at various positions on the front box body. One end of the fourth bearing lubricating pipe 21, the fifth bearing lubricating pipe 22, the sixth bearing lubricating pipe 23, the seventh bearing lubricating pipe 24, and the eighth bearing lubricating pipe 25 is connected to the rear oil distribution valve 7, and the other ends are respectively connected to the bearing lubrication points at various positions on the rear box body. The two-way lubricating pump 4 operates by means of the power of the third shaft S3, pumps the lubricating oil filtered by the oil suction filter 15 in the box body through the internal oil suction pipe 16 and the external oil suction pipe 11 into the oil outlet pipe 3. The lubricating oil enters the front oil distribution valve 2 through the oil outlet pipe 3, and the lubricating oil is first distributed on the front oil distribution valve 2. A part of the lubricating oil is distributed according to the lubrication amount required by the bearings at each position. After passing through the first bearing lubricating pipe 18, the second bearing lubricating pipe 19, and the third bearing lubricating pipe 20, the lubricating oil lubricates the bearings at various positions on the front box body. Another part of the lubricating oil enters the oil injection pipe 17. The lubricating oil is secondarily distributed on the oil injection pipe 17. A part of the lubricating oil lubricates the corresponding gears through the oil injection holes on the oil injection pipe 17. Another part of the lubricating oil enters the rear oil distribution valve 7 through the oil injection pipe 17. The lubricating oil is finally distributed on the rear oil distribution valve 7. The lubricating oil is distributed according to the lubrication amount required by the bearings at each position. After passing through the fourth bearing lubricating pipe 21, the fifth bearing lubricating pipe 22, the sixth bearing lubricating pipe 23, the seventh bearing lubricating pipe 24, and the eighth bearing lubricating pipe 25, the lubricating oil lubricates the bearings at various positions on the rear box body.

[0037] It should be noted that the process of the lubricating oil quantity distribution method is as follows:

[0038] In the first step, according to the structural arrangement and application conditions of the transfer case, calculate the rotational speed n (r / min) and equivalent dynamic load F (N) of the bearings at each position, set the allowable temperature rise △T (°C) of the bearings, and according to the known conditions, according to the formula:

[0039] G = 0.19×10 -5 d·μ·n·F / ΔT

[0040] Calculate the required lubrication amount G1 (L / min) for the first bearing. In the formula: d is the nominal inner diameter of the bearing, μ is the bearing friction coefficient, n is the bearing speed, F is the equivalent dynamic load, and △T is the bearing temperature rise.

[0041] In the second step, test the actual lubrication amount of the bearings at each position. Fabricate a lubrication amount test tooling with reference to the structure of the target transfer case, simulate the no-load working conditions, adjust the throttle aperture sizes at each position by adjusting the front oil distribution valve 2 and the rear oil distribution valve 7, so that the lubrication amount at this bearing is consistent with the calculation result, lock the throttle aperture size, and repeat the above method for the lubrication amounts and throttle aperture sizes of the bearings at the remaining positions.

[0042] In the third step, verify the application effect of the product. Place the finished transfer case on the test bench, simulate the actual load conditions, measure the temperature of a certain bearing and the lubricating oil pressure, calculate the actual temperature rise △T of the bearing, and compare it with the initial set value. If the actual temperature rise of the bearing is greater than the set value and the lubricating oil pressure ≤ 3 bar, then increase the throttle aperture of the oil distribution valve; if the actual temperature rise of the bearing is greater than the set value and the lubricating oil pressure > 3 bar, then decrease the throttle aperture of the oil distribution valve; if the actual temperature rise of the bearing is less than the set value, then decrease the throttle aperture of the oil distribution valve; finally, according to the above method, comprehensively adjust the throttle aperture sizes at each position by adjusting the front oil distribution valve 2 and the rear oil distribution valve 7 to obtain the optimal lubrication amount for each bearing, ensure the required temperature rise of each bearing, so as to achieve precise lubrication of the bearings, reduce the oil level in the housing, and avoid heat generation due to gear oil agitation.

[0043] Based on this, the transfer case for special vehicles further includes an oil temperature sensor 6 for monitoring the oil temperature inside the transfer case. The oil temperature sensor 6 is used to monitor the oil temperature of the lubricating oil inside the transfer case to make the distribution of the lubricating oil amount more accurate.

[0044] It should be noted that the transfer case further includes a breather 9, an oil drain plug, and an oil filler port. The breather 9 is located above the rear axle drive flange 8 at the rear of the transfer case housing. The breather 9 uses a conventional breather, and its function is to ensure that the internal air pressure of the gearbox is communicated with the atmosphere. The oil drain plug is located at the lower part of the transfer case housing and is used for discharging the lubricating oil during oil change when the lubricating oil inside the transfer case reaches the oil change cycle during the use of the gearbox. The oil filler port is located at the upper part of the transfer case output housing and is used for filling the transfer case with oil.

[0045] It should be noted that the above transfer case further includes a speed sensor 10 for monitoring the speed of the transfer case. The speed sensor 10 is located at the middle position at the front end of the transfer case input housing and is used to monitor the speed of the transfer case.

[0046] Furthermore, the transfer case further includes a differential lock 13 for locking or disengaging the differential D1. The transfer case for special vehicles further includes an air source interface 14 for connecting to an air source to provide power for the differential lock 13. The transfer case for special vehicles further includes a differential lock indicating switch 12 for displaying the locked or disengaged state of the differential lock 13. The differential lock 13 is located on the front axle fork housing at the front end of the transfer case input housing and is used to lock and disengage the differential D1. The air source interface 14 is located in the upper left corner of the front axle fork housing. The air source interface 14 is a common threaded interface and is used to connect to an air source to provide power for the fork mechanism of the differential lock 13. The differential lock indicating switch 12 is located in the upper left corner of the front axle fork housing and is used to display the locked or disengaged state of the differential lock 13. When the vehicle is operating on rough roads (such as ice, sand, and off-road), compressed gas is introduced into the differential lock 13 through the air source interface 14 to lock the differential lock 13, and the front and rear outputs of the differential D1 are rigidly connected to provide sufficient power for the front and rear drive axles of the whole vehicle.

[0047] Furthermore, the differential D1 is a bevel gear differential or a planetary differential. The selection of the differential D1 can be determined according to the specific conditions of the vehicle, and it is subject to meeting the driving requirements of the vehicle. No specific limitation is made here.

[0048] Furthermore, the transfer case further includes a cooler inlet pipe 26 connected to the oil outlet of the two-way lubricating pump 4. The cooler inlet pipe 26 is connected to the cooler 27, and the cooler 27 is provided with a cooler outlet pipe 28. One end of the cooler inlet pipe 26 is connected to the oil outlet of the two-way lubricating pump 4, and the other end is connected to the inlet of the cooler 27. One end of the cooler outlet pipe 28 is connected to the outlet of the cooler 27, and the other end is connected to the front oil distribution valve 2. The cooler inlet pipe 26 transports lubricating oil to the cooler 27, and the cooler 27 cools the lubricating oil with a high temperature. The cooled lubricating oil is transported to the front oil distribution valve 2 through the cooler outlet pipe 28, and the front oil distribution valve 2 transports the cooled lubricating oil to each lubrication point of the transfer case.

[0049] It should be noted that the transfer case further includes a temperature control valve 29 connected in parallel to the cooler inlet pipe 26 and the cooler outlet pipe 28. The temperature control valve 29 is used to detect the oil temperature of the lubricating oil in real time so as to control and adjust the oil temperature cooling of the cooler 27, ensure that the lubricating oil is at a normal oil temperature, and ensure the cooling effect of the lubricating oil. The temperature control valve 29 is connected in parallel at both ends of the cooler 27 as required, or can be directly integrated on the cooler 27.

[0050] In summary, the transfer case for special vehicles provided in this embodiment mainly includes a first shaft for installing an input flange, a second shaft for installing a rear axle output flange, a third shaft drivingly connected to the first shaft, a fourth shaft drivingly connected to the third shaft, a fifth shaft for installing a front axle output flange, and a sixth shaft for transitional connection. A two-way lubricating pump is provided at the front end of the third shaft, and a differential is provided on the fourth shaft. The differential is drivingly connected to the third shaft. The fifth shaft is connected to the front output end of the differential, and the sixth shaft is connected to the rear output end of the differential. Both the second shaft and the sixth shaft are drivingly connected to the third shaft. The two-way lubricating pump is respectively communicated with the bearings of the first shaft, the second shaft, the third shaft, the fourth shaft, the fifth shaft, and the sixth shaft. The transmission transmits power to the first shaft through the input flange and drives the first shaft to rotate. The first shaft transmits power to the third shaft to drive the third shaft to rotate. The third shaft drives the differential to work. The front output end of the differential transmits power to the fifth shaft. The fifth shaft transmits power to the front drive axle through the front axle drive flange to drive the wheels to rotate. At the same time, the rear output end of the differential transmits power to the sixth shaft. The sixth shaft transmits power to the second shaft through the third shaft gear and drives the second shaft to rotate. The second shaft transmits power to the rear drive axle through the rear axle drive flange to drive the wheels to rotate, thereby achieving the purpose of driving the vehicle. The differential plays the role of adjusting the output power of the transmission, enabling the vehicle to adapt to driving on different road conditions. At the same time, the third shaft drives the two-way lubricating pump to work, and the two-way lubricating pump lubricates the bearings of the first shaft, the second shaft, the third shaft, the fourth shaft, the fifth shaft, and the sixth shaft to ensure the normal operation of the bearings of the first shaft, the second shaft, the third shaft, the fourth shaft, the fifth shaft, and the sixth shaft. Through a three-stage or more than three-stage gear reduction structure, the output position of the second shaft is raised, enabling the application of the present invention to reduce the included angle of the transmission shaft. At the same time, a large amount of space is left under the whole vehicle, facilitating the arrangement of the integral special device of the existing vehicle. In addition, the lubrication effect of the transfer case is improved through a quantitative lubrication system to achieve precise lubrication, thereby reducing system heat generation and extending the service life of the product.

[0051] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A transfer case for special vehicles, characterized in that, it includes a first shaft for installing an input flange, a second shaft for installing a rear axle output flange, a third shaft drivingly connected to the first shaft, a fourth shaft drivingly connected to the third shaft, a fifth shaft for installing a front axle output flange, and a sixth shaft for transitional connection. A two-way lubricating pump is provided at the front end of the third shaft, a differential is provided on the fourth shaft, the differential is drivingly connected to the third shaft, the fifth shaft is connected to the front output end of the differential, the sixth shaft is connected to the rear output end of the differential, and both the second shaft and the sixth shaft are drivingly connected to the third shaft. The two-way lubricating pump is respectively communicated with the bearings of the first shaft, the second shaft, the third shaft, the fourth shaft, the fifth shaft and the sixth shaft; it further includes an external suction oil pipe and an internal suction oil pipe communicated with the two-way lubricating pump; an oil suction filter is provided on the internal suction oil pipe; it further includes an oil outlet pipe communicated with the two-way lubricating pump and a spray oil pipe communicated with the oil outlet pipe; a front oil distribution valve is provided on the oil outlet pipe, and a rear oil distribution valve is provided on the spray oil pipe; One end of the first bearing lubricating pipe, the second bearing lubricating pipe and the third bearing lubricating pipe is connected to the front oil distribution valve, and one end of the fourth bearing lubricating pipe, the fifth bearing lubricating pipe, the sixth bearing lubricating pipe, the seventh bearing lubricating pipe and the eighth bearing lubricating pipe is connected to the rear oil distribution valve. The other ends of the first bearing lubricating pipe, the second bearing lubricating pipe, the third bearing lubricating pipe, the fourth bearing lubricating pipe, the fifth bearing lubricating pipe, the sixth bearing lubricating pipe, the seventh bearing lubricating pipe and the eighth bearing lubricating pipe are respectively connected to the lubrication points of the bearings.

2. The transfer case for special vehicles according to claim 1, characterized in that, the differential is a bevel gear differential or a planetary differential.

3. The transfer case for special vehicles according to any one of claims 1 to 2, characterized in that, the first shaft and the second shaft are arranged in series.

4. The transfer case for special vehicles according to claim 3, characterized in that, two gears are arranged on the third shaft, and a bearing is provided between any one of the gears and the third shaft.

5. The transfer case for special vehicles according to claim 4, characterized in that, it further includes a cooler inlet pipe communicated with the oil outlet of the two-way lubricating pump, the cooler inlet pipe is communicated with a cooler, and a cooler outlet pipe is provided on the cooler. The cooler outlet pipe is communicated with the front oil distribution valve.

6. The transfer case for special vehicles according to claim 5, characterized in that, it further includes a temperature control valve arranged in parallel on the cooler inlet pipe and the cooler outlet pipe.

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