Differential transmission device for vehicle pivot steering

Abstract

The invention relates to the technical field of vehicle transmission systems, in particular to a differential transmission device for vehicle pivot steering, which comprises a differential shell and an input shaft, one end of the input shaft is connected with a first gear, the other end of the input shaft is fixedly connected with a cross shaft of a first central differential, and the input shaft is used for receiving power transmitted by an engine; the central differential mechanism comprises a first central differential mechanism and a second central differential mechanism, and is used for realizing a differential function when the vehicle runs normally and a reverse rotation function of left and right wheels when the vehicle steers centrally; one end of the first combination sleeve is meshed with inner teeth of the second gear, and the other end of the first combination sleeve is connected with the transmission shaft and used for achieving power switching through the second meshing gear; the second combination sleeve is meshed with the third gear and used for adjusting the power transmission state of the second central differential mechanism; according to the central steering differential mechanism, the differential function and the central steering function are integrated through cooperation of the multiple differential mechanisms, and the applicability of a vehicle is improved.

Description

Technical Field

[0001] This invention relates to the field of vehicle transmission system technology, and in particular to a differential transmission device for vehicle stationary turning. Background Technology

[0002] In a vehicle's drivetrain, the differential is a key component for achieving smooth steering. Its core function is to allow the left and right drive wheels to rotate at different speeds during cornering, thereby preventing tire slippage and mechanical wear. Traditional differentials can only passively adapt to the speed difference between the left and right wheels and cannot actively control the wheels to rotate in opposite directions. For scenarios requiring extremely small turning radii, such as forklifts, heavy engineering vehicles, or military off-road vehicles, the vehicles must rely on complex multi-wheel steering systems or hydraulic auxiliary devices to achieve on-the-spot steering (center steering), resulting in complex structures and high costs.

[0003] Chinese Patent Application No. CN113785140A discloses a differential or transfer drive (10) for a vehicle, a method for manufacturing the differential or transfer drive (10), and its application. The differential or transfer drive (10) includes a differential housing (12), in which half-shaft gears (18, 20) and balance wheels (22, 24) are housed. The half-shaft gears (18) drive a first half-shaft (14) or a second half-shaft (16), respectively. Large gears (32, 60) are driven via a drive shaft (34) and are torsionally connected to the differential housing (12). The large gears (32, 60) are form-fitted to the differential housing (12) of the differential or transfer drive (10).

[0004] However, existing technologies still have the following problems: they cannot simultaneously achieve differential and center steering functions through a single differential transmission device, resulting in low functional integration; they have complex structures, requiring additional steering assistance systems, which increases vehicle weight, cost, and maintenance difficulty; and they have a single power transmission path, making it difficult to flexibly distribute torque under complex working conditions, affecting vehicle handling and passability. Summary of the Invention

[0005] To address these issues, the present invention provides a differential transmission device for vehicle stationary steering, which overcomes the problems of existing technologies that cannot simultaneously achieve differential and center steering functions through a single differential transmission device, resulting in low functional integration; complex structure requiring an additional steering assistance system, increasing vehicle weight, cost, and maintenance difficulty; and a single power transmission path making it difficult to flexibly distribute torque under complex operating conditions, thus affecting vehicle handling and passability.

[0006] To achieve the above objectives, the present invention provides a differential transmission device for vehicle stationary turning. It includes:

[0007] The differential housing serves as the support frame for the differential, housing and securing the internal transmission components.

[0008] The input shaft is fixed in the differential housing by bearings. One end is connected to the first gear, and the other end is fixedly connected to the cross shaft of the first central differential to receive power transmitted by the engine.

[0009] The first central differential includes...

[0010] A cross shaft, which is fixedly connected to the input shaft, is used to receive the power from the input shaft to drive the planetary gears to rotate.

[0011] The first planetary gear is fitted onto the surface of the cross shaft and meshes with the first half-shaft gear to drive the first half-shaft gear to rotate.

[0012] The first half-shaft gear meshes externally with the first planetary gear to receive the power transmitted by the first planetary gear;

[0013] The second center differential includes,

[0014] A cross shaft is fixedly connected to the first half-shaft gear of the first central differential to receive the power of the first half-shaft gear.

[0015] The second planetary gear is fitted onto the surface of the cross shaft and meshes with the second half-shaft gear to drive the second half-shaft gear to rotate.

[0016] The second half-shaft gear meshes with the second planetary gear to receive the power transmitted by the second planetary gear;

[0017] The first engagement sleeve has one end meshing with the internal teeth of the second gear and the other end connected to the drive shaft, so as to realize power switching through the second meshing gear.

[0018] The second engagement sleeve meshes with the third gear to adjust the power transmission status of the second central differential;

[0019] Gear sets, including,

[0020] The first gear meshes with the input shaft and transmits engine power to the input shaft;

[0021] The second gear meshes with the first half-shaft gear of the first central differential to connect the conventional right differential.

[0022] The third gear meshes with the second half-shaft gear of the second central differential to connect the fifth gear and the conventional left conventional differential;

[0023] The fourth gear meshes with the second gear to transmit power to the right conventional differential;

[0024] The fifth gear, which meshes with the third gear, is used to transmit power to the left conventional differential.

[0025] Furthermore, the first engagement sleeve disengages from the second gear under straight-line driving conditions, allowing the first central differential to distribute power normally; under center steering conditions, it engages with the second gear, forcing power to be transmitted to the right conventional differential through the second gear.

[0026] Furthermore, in straight-line operation, the second engagement sleeve meshes with the third gear, causing the second central differential to rotate as a whole, and power is transmitted to the left conventional differential; in center-steering operation, it locks with the differential housing, forcing the third gear to rotate in the opposite direction, causing the left and right conventional differentials to rotate in opposite directions.

[0027] Furthermore, a needle roller bearing is provided between the cross shaft and the half-shaft gear of the first and second central differentials to reduce friction loss, and a thrust bearing is provided between the differential housing and the half-shaft gear.

[0028] Furthermore, the differential housing is equipped with an optimized oil passage.

[0029] Furthermore, under straight-line driving conditions, the power transmission path includes,

[0030] The right path transmits power in the order of input shaft, first central differential, second gear, fourth gear, and right conventional differential;

[0031] The left path transmits power in the following order: input shaft, first central differential, first half-shaft gear, second central differential, third gear, fifth gear, and left conventional differential.

[0032] Furthermore, under center steering conditions, the power transmission path includes,

[0033] The right path transmits power in the following order: input shaft, first central differential, second gear, fourth gear, and right conventional differential (forward rotation).

[0034] The left path transmits power in the following order: input shaft, first central differential, first half-shaft gear, second central differential, third gear (reverse rotation), fifth gear, and left conventional differential (reverse rotation).

[0035] Furthermore, the differential transmission device for vehicle stationary turning also includes,

[0036] The drive shaft has one end connected to the first or second coupling sleeve, and the other end fixed to the output shaft.

[0037] The output shaft, which includes a left output shaft and a right output shaft, meshes with the half-shaft gears of the left and right conventional differentials, respectively, to transmit power to the left and right wheels.

[0038] Furthermore, the differential transmission device for vehicle stationary turning also includes,

[0039] The left conventional differential, which is connected to the fifth gear and the left output shaft, is used to distribute power to the left wheel and receive reverse power when the center turns;

[0040] The right conventional differential, which is connected to the fourth gear and the right output shaft, is used to distribute power to the right wheel and maintain positive rotation when the center turns.

[0041] Compared with the prior art, the beneficial effects of the present invention are as follows: In the straight-line driving condition, the first engagement sleeve separates from the second gear, allowing the first central differential to operate without interference. This enables precise and efficient distribution of the rotational speeds of the left and right wheels according to the actual driving needs of the vehicle, avoiding problems such as wheel slippage and wear during straight-line driving, and improving the stability of the vehicle and the service life of the tires. In the center-turning condition, the engagement of the first engagement sleeve and the second gear forces power to be transmitted to the right conventional differential along a specific path. This, combined with the counter-rotation of the left wheel, enables the vehicle to turn around its own center in place, greatly improving the vehicle's turning flexibility and passability in narrow spaces or complex terrain, and meeting the handling requirements of special-purpose vehicles and high-performance vehicles.

[0042] Furthermore, in straight-line driving conditions, the tight meshing of the second engagement sleeve and the third gear provides a stable and reliable path for power transmission from the second central differential to the left conventional differential, reducing shocks and vibrations during power transmission and making the power output of the vehicle smoother when driving straight. The second central differential rotates as a whole with the cooperation of the second engagement sleeve, working in conjunction with the first central differential. This allows for more precise adjustment of the speed difference between the left and right wheels according to road conditions and wheel load, further optimizing the vehicle's straight-line performance and improving its ability to pass through different road conditions. In center-steering conditions, the locking of the second engagement sleeve and the differential housing forces a change in the rotation direction of the third gear, achieving reverse rotation of the left and right conventional differentials. This design enables the vehicle to complete center-steering actions quickly and efficiently, significantly improving the vehicle's steering flexibility in narrow spaces and meeting the stringent steering performance requirements of special operating scenarios such as forklifts and engineering vehicles.

[0043] Furthermore, in traditional differentials, the cross shaft and half-shaft gears often have sliding contact, resulting in high frictional resistance and easy energy loss and component wear. The application of needle roller bearings significantly reduces the coefficient of friction between the two, reduces the heat generated by friction, avoids annealing, deformation, or even jamming of parts caused by high temperatures, extends the service life of the cross shaft and half-shaft gears, and improves power transmission efficiency while reducing vehicle fuel consumption. When the vehicle is running, the half-shaft gear will generate axial force due to power transmission and road resistance. If not controlled, it will cause axial movement of the half-shaft gear, affecting gear meshing accuracy, causing unstable power transmission, increased noise, and other problems. Thrust bearings can effectively bear and disperse axial force, keeping the half-shaft gear in the correct axial position, ensuring stable meshing with the planetary gears, and improving the smoothness and reliability of differential transmission.

[0044] Furthermore, the optimized oil circuit of this invention can precisely deliver lubricating oil to key friction parts such as needle roller bearings and thrust bearings. Compared with the traditional differential's reliance on splash lubrication, this greatly improves lubrication efficiency and reliability. It effectively avoids problems such as bearing dry friction and gear wear caused by insufficient lubrication, ensuring the differential maintains good operating condition under various working conditions and reducing the risk of failure due to poor lubrication. During circulation, the lubricating oil not only lubricates but also carries away a large amount of heat generated by friction inside the differential. Through the oil circuit design, the lubricating oil can quickly flow through high-temperature areas, transferring heat to the differential housing surface for dissipation. This prevents problems such as deterioration of component material properties and lubrication failure due to overheating, especially under conditions such as prolonged high-speed driving or frequent turning, significantly improving the differential's thermal stability and extending its continuous operating time.

[0045] Furthermore, in straight-line driving conditions, the dual-path power transmission combined with the differential function of the differential allows the vehicle to automatically adjust the speed of the left and right wheels according to road conditions, improving the vehicle's straight-line stability and tracking ability, reducing tire wear, and eliminating the need for frequent steering corrections by the driver, thus reducing driver fatigue. In center-steering conditions, the reverse rotation design of the left and right wheels allows the vehicle to complete a turn in place within a very small space, greatly improving the vehicle's steering flexibility. This is especially suitable for forklifts, engineering vehicles, and other scenarios that require operation in narrow spaces, effectively improving the vehicle's operating efficiency and passability.

[0046] Furthermore, the high-strength connection and precise transmission between the drive shaft and output shaft of this invention ensures rapid and stable power transmission to the wheels, making the vehicle responsive. In center-steering conditions, the precise distribution of reverse or forward power by the left and right traditional differentials enables the vehicle to turn on the spot, significantly improving maneuverability in narrow alleys, warehouses, and other spaces, reducing the turning radius, and increasing work efficiency. In straight-line driving conditions, the differential function of the traditional differential, in conjunction with the drive shaft and output shaft, allows the vehicle to automatically adjust wheel speeds according to road conditions, ensuring smooth driving. During center-steering, the components work together to achieve reverse wheel rotation, broadening the vehicle's application scenarios. Whether it's an engineering work vehicle or a high-performance racing car, this transmission device can ensure stable operation under different working conditions. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the differential transmission device for vehicle stationary turning according to the present invention.

[0048] In the diagram, 1 is the fourth gear; 2 is the right conventional differential; 3 is the first gear; 4 is the first engagement sleeve; 5 is the second gear; 6 is the third gear; 7 is the second engagement sleeve; 8 is the first central differential; 9 is the second central differential; 10 is the left conventional differential; and 11 is the fifth gear. Detailed Implementation

[0049] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0050] It should be noted that the data in this embodiment are all derived from a comprehensive analysis and evaluation of historical data from the six months prior to this determination and the corresponding historical determination results by the system described in this invention. Those skilled in the art will understand that the system described in this invention can determine the above-mentioned parameters for a single item by selecting the value with the highest proportion based on the data distribution as the preset standard parameter, using weighted summation to obtain the value as the preset standard parameter, substituting each historical data point into a specific formula and using the value obtained by that formula as the preset standard parameter, or other selection methods, as long as the system described in this invention can clearly define different specific situations in the single-item determination process through the obtained values.

[0051] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0052] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0053] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0054] Please see Figure 1 As shown, it is a structural schematic diagram of the differential transmission device for vehicle stationary turning according to the present invention.

[0055] The present invention relates to a differential transmission device for vehicle stationary turning, comprising:

[0056] The differential housing (not shown in the figure) serves as the support frame for the differential, housing and securing the internal transmission components.

[0057] The input shaft (not shown in the figure) is fixed in the differential housing by bearings. One end is connected to the first gear, and the other end is fixedly connected to the cross shaft of the first central differential to receive the power transmitted by the engine.

[0058] The first central differential 8 includes...

[0059] A cross shaft (not shown in the figure) is fixedly connected to the input shaft to receive power from the input shaft to drive the planetary gears to rotate.

[0060] The first planetary gear (not shown in the figure) is fitted on the surface of the cross shaft and meshes with the first half-shaft gear to drive the first half-shaft gear to rotate.

[0061] The first half-shaft gear (not shown in the figure) meshes externally with the first planetary gear to receive the power transmitted by the first planetary gear;

[0062] The second central differential 9 includes...

[0063] A cross shaft (not shown in the figure) is fixedly connected to the first half-shaft gear of the first central differential to receive the power of the first half-shaft gear.

[0064] The second planetary gear (not shown in the figure) is fitted on the surface of the cross shaft and meshes with the second half-shaft gear to drive the second half-shaft gear to rotate.

[0065] The second half-shaft gear (not shown in the figure) meshes with the second planetary gear to receive the power transmitted by the second planetary gear;

[0066] The first engagement sleeve 4 has one end meshing with the internal teeth of the second gear and the other end connected to the drive shaft, so as to realize power switching through the second meshing gear.

[0067] The second engagement sleeve 7 meshes with the third gear to adjust the power transmission status of the second central differential;

[0068] Gear sets, including,

[0069] The first gear 3 meshes with the input shaft and transmits engine power to the input shaft;

[0070] The second gear 5 meshes with the first half-shaft gear of the first central differential 8 to connect the conventional right conventional differential 2.

[0071] The third gear 6 meshes with the second half-shaft gear of the second central differential 9 to connect the fifth gear 5 and the conventional left conventional differential 10;

[0072] The fourth gear 1 meshes with the second gear 5 to transmit power to the right conventional differential 2;

[0073] The fifth gear 11 meshes with the third gear 6 to transmit power to the left conventional differential 10.

[0074] Specifically, the first engagement sleeve disengages from the second gear under straight-line driving conditions, allowing the first central differential to distribute power normally; under center steering conditions, it engages with the second gear, forcing power to be transmitted to the right conventional differential through the second gear.

[0075] In this embodiment of the invention, the first engaging sleeve is designed as an axially sliding gear sleeve structure. The inner ring has an internal gear ring that matches the external teeth of the second gear, and the outer ring is connected to the drive shaft via a spline. The differential housing is equipped with a drive mechanism (such as a hydraulic cylinder or electromagnetic coil) to push the first engaging sleeve to move axially, thereby achieving engagement or disengagement with the second gear. Simultaneously, the differential housing is equipped with a positioning groove and a limiting device to ensure that the engaging sleeve maintains a stable position under different operating conditions.

[0076] In straight-line driving conditions, the first engagement sleeve separates from the second gear, allowing the first central differential to operate without interference. This enables precise and efficient distribution of the left and right wheel speeds according to the actual driving needs of the vehicle, preventing wheel slippage and wear during straight-line driving, thus improving vehicle stability and tire lifespan. In center-steering conditions, the engagement of the first engagement sleeve and the second gear forces power to be transmitted to the right differential along a specific path. This, combined with the counter-rotation of the left wheel, enables the vehicle to turn around its center in place, greatly improving the vehicle's steering flexibility and passability in narrow spaces or complex terrain, meeting the handling requirements of special-purpose vehicles and high-performance vehicles.

[0077] Specifically, the second engagement sleeve meshes with the third gear in straight-line operation, causing the second central differential to rotate as a whole, and power is transmitted to the left conventional differential; in center steering operation, it locks with the differential housing, forcing the third gear to rotate in the opposite direction, causing the left and right conventional differentials to rotate in opposite directions.

[0078] In this embodiment of the invention, the second coupling sleeve adopts a cylindrical structure with nested inner and outer teeth. The inner ring has an internal gear ring that matches the external teeth of the third gear, and the outer ring has splines and grooves. A locking mechanism is provided at a corresponding position on the differential housing. This mechanism includes a retractable locking pin and an electromagnetic or hydraulic device to drive its movement. In addition, a guide rail is installed between the second coupling sleeve and the differential housing to ensure the stability and accuracy of the coupling sleeve during axial sliding. A scale marking is also provided on the housing to indicate the working status of the coupling sleeve.

[0079] In straight-line driving conditions, the tight meshing of the second engagement sleeve and the third gear provides a stable and reliable path for power transmission from the second central differential to the left conventional differential, reducing shocks and vibrations during power transmission and making the power output smoother when the vehicle is driving straight. The second central differential rotates as a whole with the cooperation of the second engagement sleeve, working in conjunction with the first central differential. This allows for more precise adjustment of the speed difference between the left and right wheels based on road conditions and wheel load, further optimizing the vehicle's straight-line performance and improving its ability to pass through different road conditions. In center-steering conditions, the locking of the second engagement sleeve and the differential housing forces a change in the rotation direction of the third gear, achieving reverse rotation of the left and right conventional differentials. This design enables the vehicle to complete center-steering actions quickly and efficiently, significantly improving the vehicle's steering flexibility in confined spaces and meeting the stringent steering performance requirements of forklifts, engineering vehicles, and other special operating scenarios.

[0080] Specifically, needle roller bearings are provided between the cross shaft and the half-shaft gear of the first and second central differentials to reduce friction loss, and thrust bearings are provided between the differential housing and the half-shaft gears.

[0081] In this embodiment of the invention, the needle roller bearing has the following characteristics: In the first and second central differentials, an annular groove is machined into the journal portion of the cross shaft, and a corresponding mounting groove is also provided on the inner wall of the shaft hole of the half-shaft gear. The needle roller bearing consists of multiple slender needle rollers and a cage. During installation, the needle roller bearing is embedded in the fit clearance between the cross shaft and the half-shaft gear. The cage restricts the movement range of the needle rollers, ensuring that the needle rollers are evenly distributed, so that the cross shaft and the half-shaft gear achieve rolling friction contact. The thrust bearing has an annular mounting seat machined inside the differential housing corresponding to the end face of the half-shaft gear, and a matching groove is also provided on the end face of the half-shaft gear. The thrust bearing adopts a planar thrust ball bearing structure, consisting of a bearing race, steel balls, and a cage. The thrust bearing is installed between the differential housing and the end faces of the half-shaft gear. The bearing races fit tightly against the housing mounting base and the half-shaft gear groove, respectively. Guided by the cage, the steel balls roll between them to withstand the axial force transmitted by the half-shaft gear. During vehicle operation, when engine power is transmitted to the center differential via the input shaft, the cross shaft drives the planetary gears to rotate. The planetary gears mesh with the half-shaft gears, causing them to rotate. At this time, the needle roller bearing rolls between the cross shaft and the half-shaft gear, converting the original sliding friction into rolling friction and reducing relative motion resistance. The axial force generated by the half-shaft gear during power transmission acts on the thrust bearing through its end faces. The rolling steel balls of the thrust bearing disperse the axial force to the differential housing, preventing axial movement of the half-shaft gear and ensuring stable power transmission. Under straight-line driving conditions, the differential adjusts the speed of the left and right wheels according to road conditions, and the needle roller bearing and thrust bearing operate continuously and stably. Under center steering conditions, although the power transmission path and gear direction change, the bearings can still effectively cope with high loads and complex stress conditions, ensuring the normal operation of the differential.

[0082] In traditional differentials, the cross shaft and half-shaft gears often have sliding contact, resulting in high frictional resistance and easy energy loss and component wear. The application of needle roller bearings significantly reduces the coefficient of friction between the two, reduces the heat generated by friction, avoids annealing, deformation, or even jamming of parts caused by high temperatures, extends the service life of the cross shaft and half-shaft gears, and improves power transmission efficiency while reducing vehicle fuel consumption. When the vehicle is running, the half-shaft gears will generate axial force due to power transmission and road resistance. If not controlled, this can lead to axial movement of the half-shaft gears, affecting gear meshing accuracy, causing unstable power transmission, increased noise, and other problems. Thrust bearings can effectively bear and disperse axial force, keeping the half-shaft gears in the correct axial position, ensuring stable meshing with the planetary gears, and improving the smoothness and reliability of the differential transmission.

[0083] Specifically, the differential housing is equipped with optimized oil passages.

[0084] The differential housing in this embodiment of the invention employs a composite oil circuit structure, comprising a main oil passage, branch oil passages, and an annular oil groove. The main oil passage is arranged along the axial centerline of the housing, with one end connected to an external oil pump, serving as the main input channel for lubricating oil. The branch oil passages extend radially from the main oil passage, leading to key lubrication points of the first and second central differentials, respectively. Annular oil grooves are provided at the connection between the cross shaft and the half-shaft gear, and at the end face of the half-shaft gear contacting the differential housing. The branch oil passages are connected to the annular oil grooves through small oil injection holes. Furthermore, an oil collection groove is provided at the bottom of the differential housing for recovering lubricating oil, and is connected to the oil pump inlet through a return oil pipe, forming a lubricating oil circulation system. During vehicle operation, the oil pump pressurizes the lubricating oil and injects it into the main oil passage, where it is then distributed to the branch oil passages under pressure. When the lubricating oil reaches the annular oil groove between the cross shaft and the half-shaft gear, it seeps into the needle roller bearing through the gap between the oil groove and the needle roller bearing, lubricating the contact surfaces between the needle rollers and the cross shaft and half-shaft gear. Simultaneously, the lubricating oil flowing towards the end face of the half-shaft gear is evenly distributed between the bearing race and the steel balls under the rotation of the thrust bearing, forming a lubricating film. Under high-speed operation or heavy-load conditions of the differential, the oil pump automatically adjusts the output pressure based on feedback from the pressure sensor to ensure that the lubricating oil fully covers all friction points. The recovered lubricating oil, after being filtered for impurities in the oil collection tank, re-enters the oil pump for reuse, ensuring the cleanliness and lubrication performance of the lubricating oil in the oil circuit.

[0085] This invention optimizes the oil circuit to precisely deliver lubricating oil to key friction components such as needle roller bearings and thrust bearings. Compared to traditional differentials that rely on splash lubrication, this significantly improves lubrication efficiency and reliability. It effectively avoids problems such as bearing dry friction and gear wear caused by insufficient lubrication, ensuring the differential maintains good operating conditions under various operating conditions and reducing the risk of failure due to poor lubrication. During circulation, the lubricating oil not only lubricates but also carries away a large amount of heat generated by friction within the differential. Through the oil circuit design, the lubricating oil can quickly flow through high-temperature areas, transferring heat to the differential housing surface for dissipation. This prevents problems such as deterioration of component material properties and lubrication failure due to overheating, especially under conditions such as prolonged high-speed driving or frequent turning, significantly improving the differential's thermal stability and extending its continuous operating time.

[0086] Specifically, under straight-line driving conditions, the power transmission path includes,

[0087] The right path transmits power in the order of input shaft, first central differential, second gear, fourth gear, and right conventional differential;

[0088] The left path transmits power in the following order: input shaft, first central differential, first half-shaft gear, second central differential, third gear, fifth gear, and left conventional differential.

[0089] Specifically, under center steering conditions, the power transmission path includes,

[0090] The right path transmits power in the following order: input shaft, first central differential, second gear, fourth gear, and right conventional differential (forward rotation).

[0091] The left path transmits power in the following order: input shaft, first central differential, first half-shaft gear, second central differential, third gear (reverse rotation), fifth gear, and left conventional differential (reverse rotation).

[0092] In this embodiment of the invention, the vehicle is driving normally on a straight road. Right path power transmission: After the engine starts, the output shaft drives the first gear to rotate at high speed. The first gear meshes with the input shaft, transmitting power to the input shaft. After the input shaft rotates, it drives the cross shaft of the first central differential to rotate. The cross shaft drives the first planetary gear to rotate, and the first planetary gear meshes with the first half-shaft gear, giving the first half-shaft gear power. At this time, the first engagement sleeve separates from the second gear, and the power of the first half-shaft gear is directly transmitted to the second gear. The second gear meshes with the fourth gear, transmitting power to the right conventional differential. The right conventional differential distributes power to the right wheel through the right output shaft. The right wheel rotates under the power drive, propelling the vehicle forward. During this process, the first central differential automatically adjusts the speed difference between the left and right wheels according to road conditions and wheel resistance to ensure the vehicle travels smoothly in a straight line. Left path power transmission: The power from the input shaft is also transmitted to the first central differential. After receiving the power, the first half-shaft gear transmits it to the cross shaft of the second central differential. The second engagement sleeve meshes with the third gear, causing the second central differential to rotate as a whole. The second half-shaft gear of the second central differential drives the third gear to rotate, and the third gear meshes with the fifth gear, transmitting power to the left conventional differential. The left conventional differential distributes power to the left wheel through the left output shaft, working in conjunction with the right wheel to achieve straight-line driving. When the vehicle needs to turn in place in narrow spaces, the power transmission is as follows: After the driver issues a steering command, the first engagement sleeve moves axially under the action of a hydraulic or electromagnetic drive mechanism and meshes with the second gear. Engine power is transmitted to the first central differential via the first gear and input shaft. Because the first engagement sleeve meshes with the second gear, the power is forced to the second gear, and then sequentially transmitted to the right conventional differential via the fourth gear, driving the right wheel to rotate forward. The power transmission is as follows: The second engagement sleeve locks with the differential housing, and the second half-shaft gear of the second central differential continuously receives power from the first half-shaft gear, but because the second engagement sleeve is locked, the third gear is forced to rotate in the opposite direction. The third gear rotates in the reverse direction, driving the fifth gear to rotate, which in turn transmits the reverse power to the left conventional differential. The left conventional differential drives the left wheel to rotate in the reverse direction via the left output shaft, enabling the vehicle to turn around its center. The driveshaft is made of high-strength alloy steel, with one end connected to the first or second coupling sleeve via a spline, and the other end welded to the output shaft. The output shaft is also made of high-strength material. The left and right output shafts are connected to the left and right conventional differentials via half-shaft gears, respectively. In straight-line driving conditions, the driveshaft stably transmits power to the output shaft according to the state of the coupling sleeve. In center-steering conditions, the driveshaft, in conjunction with the switching of the coupling sleeve, ensures that the left and right output shafts receive forward and reverse power respectively. The meshing design of the output shaft and half-shaft gears ensures the high efficiency and stability of power transmission, allowing the wheels to respond quickly to changes in power.

[0093] In straight-line driving conditions, the dual-path power transmission combined with the differential function of the differential allows the vehicle to automatically adjust the speed of the left and right wheels according to road conditions, improving the vehicle's straight-line stability and tracking ability, reducing tire wear, and eliminating the need for frequent steering corrections by the driver, thus reducing driver fatigue. In center-steering conditions, the reverse rotation design of the left and right wheels allows the vehicle to complete a turn in a very small space, greatly improving the vehicle's steering flexibility. It is especially suitable for forklifts, engineering vehicles, and other scenarios that require operation in narrow spaces, effectively improving the vehicle's operating efficiency and passability.

[0094] Specifically, the differential transmission device for vehicle in-situ turning also includes,

[0095] The drive shaft has one end connected to the first or second coupling sleeve, and the other end fixed to the output shaft.

[0096] The output shaft, which includes a left output shaft and a right output shaft, meshes with the half-shaft gears of the left and right conventional differentials, respectively, to transmit power to the left and right wheels.

[0097] In this embodiment of the invention, the drive shaft adopts a hollow tubular structure, made of high-strength alloy steel, with a surface hardened to enhance wear resistance. One end has an internal spline that tightly engages with the external spline of the first or second coupling sleeve, allowing for axial sliding connection. The other end is welded with a flange and fixed to the output shaft with bolts. The output shaft is a solid shaft, with the left and right output shafts being identical in material and manufacturing process to the drive shaft. Their ends have external splines that mesh with the internal splines of the left and right traditional differential half-shaft gears. Simultaneously, the output shaft is mounted on the axle housing via tapered roller bearings to ensure rotational accuracy and stability.

[0098] Specifically, the differential transmission device for vehicle in-situ turning also includes,

[0099] The left conventional differential, which is connected to the fifth gear and the left output shaft, is used to distribute power to the left wheel and receive reverse power when the center turns;

[0100] The right conventional differential, which is connected to the fourth gear and the right output shaft, is used to distribute power to the right wheel and maintain positive rotation when the center turns.

[0101] In this embodiment of the invention, both the left and right conventional differentials include a differential housing, half-shaft gears, planetary gears, and a cross shaft. The differential housing is bolted to either the fifth gear (left) or the fourth gear (right). The half-shaft gears are splined to the output shaft. Two planetary gears are mounted on the cross shaft and mesh with the half-shaft gears. The differential housing contains a lubricating oil groove, which communicates with the output shaft bearing through an oil hole for lubrication.

[0102] The high-strength connection and precise transmission between the drive shaft and output shaft of this invention ensure rapid and stable power transmission to the wheels, making the vehicle responsive. In center-steering conditions, the precise distribution of reverse or forward power by the left and right traditional differentials enables the vehicle to turn on the spot, significantly improving maneuverability in narrow alleys, warehouses, and other spaces, reducing the turning radius, and increasing work efficiency. In straight-line driving conditions, the differential function of the traditional differential, in conjunction with the drive shaft and output shaft, allows the vehicle to automatically adjust wheel speeds according to road conditions, ensuring smooth driving. During center-steering, the components work together to achieve reverse wheel rotation, broadening the vehicle's application scenarios. Whether it's an engineering work vehicle or a high-performance racing car, this transmission device can ensure stable operation under different working conditions.

[0103] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

[0104] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A differential transmission device for vehicle stationary turning, characterized in that, include: The differential housing serves as the support frame for the differential, housing and securing the internal transmission components. The input shaft is fixed in the differential housing by bearings. One end is connected to the first gear, and the other end is fixedly connected to the cross shaft of the first central differential to receive power transmitted by the engine. The first central differential includes... A cross shaft, which is fixedly connected to the input shaft, is used to receive the power from the input shaft to drive the planetary gears to rotate. The first planetary gear is fitted onto the surface of the cross shaft and meshes with the first half-shaft gear to drive the first half-shaft gear to rotate. The first half-shaft gear meshes externally with the first planetary gear to receive the power transmitted by the first planetary gear; The second center differential includes, A cross shaft is fixedly connected to the first half-shaft gear of the first central differential to receive the power of the first half-shaft gear. The second planetary gear is fitted onto the surface of the cross shaft and meshes with the second half-shaft gear to drive the second half-shaft gear to rotate. The second half-shaft gear meshes with the second planetary gear to receive the power transmitted by the second planetary gear; The first engagement sleeve has one end meshing with the internal teeth of the second gear and the other end connected to the drive shaft, so as to realize power switching through the second meshing gear. The second engagement sleeve meshes with the third gear to adjust the power transmission status of the second central differential; Gear set, include, The first gear meshes with the input shaft and transmits engine power to the input shaft; The second gear meshes with the first half-shaft gear of the first central differential to connect the conventional right differential. The third gear meshes with the second half-shaft gear of the second central differential to connect the fifth gear and the conventional left conventional differential; The fourth gear meshes with the second gear to transmit power to the right conventional differential; The fifth gear, which meshes with the third gear, is used to transmit power to the left conventional differential.

2. The differential transmission device for vehicle stationary turning according to claim 1, characterized in that, The first engagement sleeve separates from the second gear under straight-line conditions, allowing the first central differential to distribute power normally; under center steering conditions, it engages with the second gear, forcing power to be transmitted to the right conventional differential through the second gear.

3. The differential transmission device for vehicle stationary turning according to claim 1, characterized in that, When the second engagement sleeve is in straight-line operation, it meshes with the third gear, causing the second central differential to rotate as a whole, and power is transmitted to the left conventional differential; when the center steering is in operation, it locks with the differential housing, forcing the third gear to rotate in the opposite direction, causing the left and right conventional differentials to rotate in opposite directions.

4. The differential transmission device for vehicle stationary turning according to claim 1, characterized in that, The first and second central differentials are provided with needle roller bearings between the cross shaft and the half shaft gear to reduce friction loss, and the differential housing is provided with a thrust bearing between the differential housing and the half shaft gear.

5. The differential transmission device for vehicle stationary turning according to claim 1, characterized in that, The differential housing is equipped with an optimized oil passage.

6. The differential transmission device for vehicle stationary turning according to claim 1, characterized in that... Under straight-line driving conditions, the power transmission path includes: The right path transmits power in the order of input shaft, first central differential, second gear, fourth gear, and right conventional differential; The left path transmits power in the following order: input shaft, first central differential, first half-shaft gear, second central differential, third gear, fifth gear, and left conventional differential.

7. The differential transmission device for vehicle stationary turning according to claim 1, characterized in that, Under center steering conditions, the power transmission path includes, The right path transmits power in the order of input shaft, first central differential, second gear, fourth gear, and right conventional differential; The left path transmits power in the following order: input shaft, first central differential, first half-shaft gear, second central differential, third gear, fifth gear, and left conventional differential.

8. The differential transmission device for vehicle stationary turning according to claim 1, characterized in that, The differential transmission device for vehicle stationary turning also includes, The drive shaft has one end connected to the first or second coupling sleeve, and the other end fixed to the output shaft. The output shaft, which includes a left output shaft and a right output shaft, meshes with the half-shaft gears of the left and right conventional differentials, respectively, to transmit power to the left and right wheels.

9. The differential transmission device for vehicle stationary turning according to claim 1, characterized in that, The differential transmission device for vehicle stationary turning also includes, The left conventional differential, which is connected to the fifth gear and the left output shaft, is used to distribute power to the left wheel and receive reverse power when the center turns; The right conventional differential, which is connected to the fourth gear and the right output shaft, is used to distribute power to the right wheel and maintain positive rotation when the center turns.

Images