Final rotation assembly

Abstract

The final rotation assembly comprises a shell, a shaft head and a side cover, a through hole is formed in the shell, a transmission shaft is arranged in the through hole, and a planetary gear train set used for being in linkage fit with the transmission shaft to conduct speed reduction and torque increase on the transmission shaft is arranged in the through hole. The shell is provided with a heat dissipation structure used for absorbing part of heat in the shell and dissipating the heat and a first adjusting structure used for being in linkage fit with the heat dissipation structure so as to adaptively improve the heat dissipation efficiency of the heat dissipation structure according to the internal temperature of the shell. A sealing structure used for preventing part of external impurities from entering the through hole through a gap between the shaft head and the shell and a second adjusting structure used for being in linkage fit with the sealing structure to adjust the sealing strength of the sealing structure in a self-adaptive mode are arranged between the inner wall of the shaft head and the end wall of the shell. The problems that a traditional final transmission assembly is insufficient in heat dissipation efficiency, the heat dissipation capacity cannot be adjusted in a self-adaptive mode, the sealing performance is poor, the sealing strength cannot be adjusted in a self-adaptive mode, and external impurities easily invade the interior to affect the transmission reliability are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of final rotation assembly, and particularly discloses a final rotation assembly. BACKGROUND

[0002] In a vehicle walking system, a final transmission assembly is a core component for realizing speed reduction and torque increase and driving a wheel to rotate, and its performance directly affects the power output and operation reliability of the vehicle. At present, the existing final transmission assembly usually includes a shell, a shaft head, a transmission shaft and a planetary gear set, the shell is fixed to a vehicle frame, the shaft head is connected to a wheel hub, and the planetary gear set converts the power of a driving motor into a low-speed large torque required by the wheel.

[0003] However, the existing structure has two key defects: first, when the traditional final transmission assembly works, the planetary gear set meshes and the bearing rotates to generate a large amount of heat, the traditional shell relies on passive heat dissipation of fixed-form heat dissipation ribs, the heat dissipation efficiency is fixed and cannot be automatically improved with the increase of internal temperature, which easily leads to aging of lubricating oil due to high temperature, aggravation of wear due to thermal expansion of parts, and shortening of the service life of the assembly.

[0004] Secondly, the gap between the traditional shaft head and the shell is the main channel for the invasion of external impurities (such as dust and mud), and the sealing strength of the existing sealing structure (such as an O-ring) is fixed. When the gap is generated due to wear after long-term use, the sealing pressure cannot be automatically compensated, which leads to the invasion of impurities into the interior, pollutes the lubricating oil, aggravates the wear of gears and bearings, and even causes transmission failure, increases maintenance cost and fault risk. SUMMARY

[0005] In view of the deficiencies of the prior art, the present application provides a final rotation assembly to solve the problems of insufficient heat dissipation efficiency and inability to automatically adjust the heat dissipation capacity of the traditional final transmission assembly, poor sealing performance and inability to automatically adjust the sealing strength, and easy invasion of external impurities into the interior to affect the transmission reliability.

[0006] To achieve the above object, the application provides a final rotating assembly, which comprises a shell for connecting with an external automobile frame, a matched shaft head for connecting with an external wheel hub, and a side cover, the shaft head is movably arranged at the beginning end of the shell, the side cover is detachably connected with the end of the shell, a through hole is formed along the axial direction of the shell, the end of the shaft head is partially arranged in the through hole, a transmission shaft for linkage with the output end of an external driving motor is arranged in the through hole, a planetary gear train set for linkage with the transmission shaft to reduce the speed and increase the torque of the transmission shaft is arranged in the through hole, a heat dissipation structure for absorbing part of the heat inside the shell and dissipating the heat, and a first adjusting structure for linkage with the heat dissipation structure to adaptively improve the heat dissipation efficiency of the heat dissipation structure according to the temperature inside the shell are arranged on the shell, and a sealing structure for blocking the invasion of part of impurities from the gap between the shaft head and the shell into the through hole and a second adjusting structure for linkage with the sealing structure to adaptively adjust the sealing strength of the sealing structure are arranged between the inner wall of the shaft head and the end wall of the shell.

[0007] The above technical solution has the advantages that: in the above technology, the heat inside the shell is efficiently absorbed and dissipated by the heat dissipation structure, and the heat dissipation efficiency is adaptively improved according to the internal temperature by the first adjusting structure, so that the damage of components and the aging of lubricating oil caused by high temperature can be avoided, and the thermal stability of the assembly under different working conditions can be ensured; the sealing structure effectively blocks the invasion of part of impurities from the gap between the shaft head and the shell into the through hole, and the second adjusting structure adaptively adjusts the sealing strength, so that the wear gap of the sealing element after long-term use can be compensated, the erosion of impurities to the planetary gear train set and the transmission shaft can be reduced, and the risk of transmission failure can be reduced; through the adaptive adjustment of the overall structure of heat dissipation and sealing, the running reliability and service life of the assembly are improved, the maintenance frequency and cost are reduced, and the power transmission demand under complex driving conditions of the vehicle is adapted.

[0008] The application further provides that: the heat dissipation structure comprises a heat dissipation passage hollowly arranged in the shell and a plurality of heat dissipation grooves annularly arranged on the peripheral wall of the shell, the heat dissipation passage is arranged in a spiral line and is arranged along the length direction of the shell with the axis of the shell as the reference line, the plurality of heat dissipation grooves are arranged along the length direction of the shell, and the plurality of heat dissipation grooves are all in communication with the heat dissipation passage, and the radial cross section of the heat dissipation groove is arranged in a fish gill shape.

[0009] The advantages of adopting the above technical solution are as follows: the spiral heat dissipation channel is arranged along the length of the outer shell, which can extend the heat conduction path within the channel, fully absorb the heat inside the shell, and improve the heat exchange efficiency; the several circumferentially opened heat dissipation slots are connected to the heat dissipation channel, expanding the heat dissipation area. Combined with the gill-shaped radial cross-section design, it can guide the airflow to form an orderly flow, enhance the convective heat dissipation effect, and accelerate the outward dissipation of heat; at the same time, the combined structure of the heat dissipation channel and the gill-shaped heat dissipation slots does not require additional power drive, and achieves efficient passive heat dissipation by relying on its own structure, ensuring that the internal temperature of the shell is stable within a reasonable range, avoiding the misalignment of components due to thermal expansion, ensuring the smooth operation of the planetary gear train and the drive shaft, and improving the transmission stability and durability of the assembly.

[0010] The present invention further comprises: the first adjustment structure including a plurality of first adjustment plates disposed on the outer peripheral wall of the outer shell, the plurality of first adjustment plates being disposed one-to-one with a plurality of heat dissipation slots, the first adjustment plate being composed of a connecting plate and a sealing plate connected together, the connecting plate being connected to the outer peripheral wall of the outer shell, the sealing plate being made of shape memory alloy material, the sealing plate having a first shape in a first temperature range, the sealing plate having a second shape in a second temperature range, the sealing plate being disposed on the corresponding heat dissipation slot in the first shape and sealing the opening of the heat dissipation slot, the sealing plate being deformed and bent in the second shape and separated from the opening of the heat dissipation slot to expose the heat dissipation slot.

[0011] The advantages of adopting the above technical solution are as follows: The sealing plate of the first adjustment plate in the above technology is made of shape memory alloy. Under the first temperature range, it maintains the first form to cover the heat dissipation groove, which can prevent external dust, mud and water and other impurities from entering the heat dissipation passage and through hole, avoiding blockage of the heat dissipation structure and contamination of internal components. Under the second temperature range, it switches to the second form and deforms and bends, thereby exposing the heat dissipation groove to increase the heat dissipation area, thereby improving the heat dissipation efficiency and realizing temperature adaptive adjustment of heat dissipation capacity. Through the above technical settings, the heat dissipation mode can be automatically switched according to the internal temperature without manual intervention, balancing heat dissipation needs and protection needs, reducing the impact of the external environment on the heat dissipation structure, ensuring the long-term stable operation of the heat dissipation system, and further improving the assembly's ability to adapt to complex working conditions.

[0012] The present invention further comprises: the inner wall of the shaft head and the end wall of the outer shell are fitted with a clearance and form a rotational clearance; the sealing structure includes a first protrusion circumferentially disposed on the inner wall of the shaft head and a second protrusion circumferentially disposed on the end wall of the outer shell; the second protrusion is disposed around the first protrusion; the outer wall of the first protrusion is fitted with the inner wall of the shaft head and forms a first passage; the outer wall of the second protrusion is fitted with the end wall of the outer shell and forms a second passage; both the first protrusion and the second protrusion are disposed within the rotational clearance; the first passage, the second passage, and the rotational clearance combine to form a labyrinth groove.

[0013] The advantages of adopting the above technical solution are as follows: In the above technology, the rotational clearance formed by the clearance fit between the shaft head and the end wall of the housing, and the labyrinth groove constructed by the first protrusion and the second protrusion, utilize the combination structure of the first passage, the second passage and the rotational clearance to extend the path of external impurities into the through hole, forming multiple barrier layers to effectively prevent dust, mud and water and other impurities from entering the interior; the clearance fit design between the two protrusions and the corresponding walls does not affect the flexible rotation of the shaft head, ensuring smooth transmission; the above labyrinth groove structure achieves passive sealing by mechanical form, which can improve the sealing effect without the need for additional sealing components, avoids the problems of easy wear and aging of traditional sealing structures, enhances the reliability and durability of the seal, reduces the wear of impurities on the planetary gear train and the drive shaft, and ensures the transmission accuracy of the assembly.

[0014] The present invention further comprises: the second adjustment structure including a second adjustment plate disposed on the end wall of the outer shell, the second adjustment plate being composed of a fixed ring and a sealing ring connected together, the fixed ring being connected to the end wall of the outer shell, the sealing ring being made of shape memory alloy, the sealing ring having a third form in a first temperature range, the sealing ring having a fourth form in a second temperature range, the sealing ring being disposed at the opening of the labyrinth groove in the third form and the outer wall of the sealing ring being clearance-fitted with the inner wall of the shaft head, the sealing ring being deformed and bent towards the end wall of the outer shell until it is attached to the end wall of the outer shell to expose the labyrinth groove.

[0015] The advantages of adopting the above technical solution are as follows: The sealing ring of the second adjustment structure in the above technology is made of shape memory alloy bearing. In the first temperature range, it maintains the third form covering the labyrinth groove opening to enhance the sealing effect and further prevent external impurities from entering. In the second temperature range, it switches to the fourth form, bending and attaching towards the end wall of the outer shell to expose the labyrinth groove so as to facilitate the discharge of internal dust and liquid, realizing the self-cleaning of the labyrinth groove, while not affecting the operation of the shaft head. The temperature adaptive deformation design of the sealing ring takes into account both sealing protection and cleaning and maintenance needs. The labyrinth groove can be cleaned without disassembling the assembly, reducing maintenance difficulty and cost. At the same time, it avoids the aggravation of wear caused by long-term compression of the sealing components, extends the service life of the sealing structure, and ensures the sealing stability of the assembly under different temperature conditions.

[0016] The present invention further comprises: two mating blocks arranged opposite each other on the inner peripheral wall of the through hole; a mating groove is provided on the mating block; an oil replenishing head is provided in the mating groove; a bolt is detachably connected between the oil replenishing head and the mating block; an oil replenishing cavity is hollowly provided in the oil replenishing head; an oil outlet hole communicating with the oil replenishing cavity is provided on both sides of the oil replenishing head; and the oil replenishing cavity is filled with solid lubricating grease.

[0017] The advantages of adopting the above technical solution are: the oil replenishing head of the mating block inside the through hole is detachably connected by bolts, which facilitates the installation, replacement and maintenance of the oil replenishing head; the oil replenishing chamber is filled with solid lubricating grease, which can store the lubricating medium for a long time, and together with the oil outlet holes on both sides, it can achieve precise release of lubricating oil, providing continuous lubrication for the planetary gear train and the drive shaft. Through the setting of the above oil replenishing structure, there is no need for external oil pipes and power devices. It can achieve on-demand oil replenishment by relying on its own structure, avoiding the problems of lubricating oil leakage and waste in traditional lubrication methods. The detachable design makes it easy to replenish lubricating grease regularly, ensuring stable lubrication effect, reducing friction and wear during the meshing of the planetary gear train and the rotation of the drive shaft, improving the service life of components and transmission efficiency, and ensuring the long-term smooth operation of the assembly.

[0018] The present invention further includes: a sealing plate provided in the oil outlet hole, the sealing plate being made of shape memory alloy; the sealing plate having a fifth form in a first temperature range; and the sealing plate having a sixth form in a second temperature range; the sealing plate being bent and sealing the connection between the oil outlet hole and the oil replenishment chamber in the fifth form; and the sealing plate being flush with the inner wall of the oil outlet hole in the sixth form to allow the oil replenishment chamber to communicate with the oil outlet hole.

[0019] The advantages of adopting the above technical solution are as follows: The sealing plate inside the oil outlet is made of shape memory alloy. In the first temperature range, it maintains its fifth form and bends to seal the connection between the oil replenishment chamber and the oil outlet, preventing lubricating grease from flowing out randomly under unnecessary operating conditions, thus reducing grease waste and contamination. In the second temperature range, it switches to its sixth form and flattens against the inner wall of the oil outlet, connecting the oil replenishment chamber and the oil outlet, achieving precise release of lubricating grease and providing sufficient lubrication for components under high temperature and high load conditions. Through the temperature adaptive switch design of the sealing plate, the timing of oil replenishment is precisely matched with the working state of the assembly, ensuring efficient use of lubricating grease, avoiding increased transmission resistance caused by excessive grease under low temperature and low load conditions, while ensuring lubrication reliability under high temperature and high load conditions, and improving the stability and economy of assembly operation.

[0020] The present invention further includes a floating oil seal provided between the inner wall of the shaft head and the end wall of the outer casing.

[0021] The advantages of adopting the above technical solution are as follows: The floating oil seal installed between the inner wall of the shaft head and the end wall of the outer shell can further enhance the sealing effect at the gap between the two, forming a double sealing barrier, effectively preventing external dust, mud, water and other impurities from entering the through hole, while preventing internal lubricating oil leakage; the floating oil seal has good wear resistance and impact resistance, adapts to the slight displacement during the rotation of the shaft head, ensures tight sealing surface, and avoids sealing failure caused by vibration or assembly deviation; the above structure can achieve stable sealing without additional adjustment parts, and forms multiple protections with the labyrinth groove sealing structure, significantly improving the sealing reliability of the assembly, reducing the wear of internal components and lubricating oil consumption, extending the maintenance cycle and service life of the assembly, and adapting to complex and harsh driving environments.

[0022] The present invention further includes a bearing connecting the outer peripheral wall of the shaft end and the inner peripheral wall of the through hole.

[0023] The advantages of adopting the above technical solution are: the bearing connecting the outer peripheral wall of the shaft end and the inner peripheral wall of the through hole in the above technology can reduce the frictional resistance during the rotation of the shaft end, ensure the smooth and flexible operation of the shaft end, and improve the power transmission efficiency.

[0024] The invention further comprises: the planetary gear train is a three-stage linkage structure, sequentially divided into a primary planetary gear train, a secondary planetary gear train, and a tertiary planetary gear train along the power transmission direction. The primary planetary gear train includes a primary sun gear, primary planet gears, and a primary planet carrier; the secondary planetary gear train includes a secondary sun gear, secondary planet gears, and a secondary planet carrier; and the tertiary planetary gear train includes a tertiary sun gear, tertiary planet gears, and a tertiary planet carrier. The primary sun gear is connected to the drive shaft to drive the primary sun gear when the drive shaft rotates. The primary sun gear meshes with the primary planet gears, and the primary planet gears are linked to the primary planet carrier to drive the primary planet carrier when the primary planet gears rotate. The first-stage planetary carrier rotates in conjunction with the second-stage sun gear to drive the second-stage sun gear to rotate synchronously when the first-stage planetary carrier rotates. The second-stage sun gear meshes with the second-stage planetary gears. The second-stage planetary gears mesh with the second-stage planetary carrier to drive the second-stage planetary carrier to rotate when the second-stage planetary gears rotate. The second-stage planetary carrier meshes with the third-stage planetary gears. The third-stage planetary gears mesh with the third-stage planetary carrier to drive the third-stage planetary carrier to rotate when the third-stage planetary gears rotate. The third-stage planetary carrier is also meshed with the shaft head to transmit the amplified torque to the shaft head.

[0025] The advantages of adopting the above technical solution are as follows: The three-stage planetary gear train in the above technology transmits power step by step along the power transmission direction, realizing multiple reductions and torque increases in the power of the drive shaft. It can convert the high-speed, low-torque of the drive motor into the low-speed, high-torque required by the shaft head, meeting the traction requirements during vehicle operation. The meshing linkage of the sun gear, planet gears and planet carrier at each stage of the planetary gear train makes the power transmission path clear and stable. The multi-planet gear meshing design distributes the load, reduces the force on a single tooth, and reduces the risk of wear and breakage. The linkage between the planet carrier and the sun gear ensures efficient power transmission with no significant power loss, improving transmission efficiency. The three-stage structural design achieves a significant torque amplification within a limited space, making the assembly structure compact and adaptable to vehicle installation space constraints. At the same time, it improves transmission smoothness and load-bearing capacity, ensuring the reliability of power output under complex working conditions such as heavy loads and climbing. Attached Figure Description

[0026] Figure 1 This is a cross-sectional view of the present invention in a non-operating state or in a low-speed operating state. Figure 2 This is a cross-sectional view of the present invention in operation or at low speed. Figure 3 This is a simplified three-dimensional view of the outer casing in the non-operating state or low-speed operating state of the present invention; Figure 4 This is a simplified three-dimensional view of the outer casing in operation or low-speed operation in this invention. Detailed Implementation

[0027] This invention provides a final rotating assembly, comprising a housing 1 for connecting to an external vehicle frame, a shaft head 2 for connecting to an external wheel hub, and a side cover 21. The shaft head 2 is movably disposed at the beginning of the housing 1, and the side cover 21 is detachably connected to the end of the housing 1. The housing 1 has a through hole 11 along its axial direction, and the end of the shaft head 2 is partially inserted into the through hole 11. The through hole 11 is provided with a drive shaft 3 for linkage with the output end of an external drive motor. A planetary gear train is provided in the through hole 11 for linkage with the drive shaft 3 to reduce speed and increase torque. The housing 1 is provided with a heat dissipation structure for absorbing and dissipating part of the heat inside the housing 1, and a mechanism for linkage with the heat dissipation structure to... The first adjustment structure for adaptively improving the heat dissipation efficiency of the heat dissipation structure is provided between the inner wall of the shaft head 2 and the end wall of the outer shell 1. A sealing structure is provided to prevent external impurities from entering the through hole 11 through the gap between the shaft head 2 and the outer shell 1. A second adjustment structure is provided to work in conjunction with the sealing structure to adaptively adjust the sealing strength of the sealing structure. The heat dissipation structure includes a hollow heat dissipation passage 4 opened in the outer shell 1 and several circumferential heat dissipation grooves 41 opened on the outer peripheral wall of the outer shell 1. The heat dissipation passage 4 is spirally arranged and opened along the length of the outer shell 1 with the axis of the outer shell 1 as the reference line. Several heat dissipation grooves 41 are opened along the length of the outer shell 1, and all of the heat dissipation grooves 41 are connected to the heat dissipation passage 4. The heat dissipation grooves 41 are radially... The cross-section is arranged in a gill-like shape. The first adjustment structure includes several first adjustment plates disposed on the outer peripheral wall of the outer shell 1. Each of the first adjustment plates corresponds to a number of heat dissipation slots 41. Each first adjustment plate is composed of a connecting plate 42 and a closing plate 43 connected together. The connecting plate 42 is connected to the outer peripheral wall of the outer shell 1. The closing plate 43 is made of shape memory alloy. The closing plate 43 has a first shape in a first temperature range and a second shape in a second temperature range. In the first shape, the closing plate 43 covers the corresponding heat dissipation slot 41 and closes the opening of the heat dissipation slot 41. In the second shape, the closing plate 43 deforms and bends, separating from the opening of the heat dissipation slot 41 to expose the heat dissipation slot 41. The inner wall of the shaft head 2 is clearance-fitted with the end wall of the outer casing 1, forming a rotational gap 22. The sealing structure includes a first protrusion 23 circumferentially disposed on the inner wall of the shaft head 2 and a second protrusion 12 circumferentially disposed on the end wall of the outer casing 1. The second protrusion 12 is disposed around the first protrusion 23. The outer wall of the first protrusion 23 is clearance-fitted with the inner wall of the shaft head 2, forming a first passage. The outer wall of the second protrusion 12 is clearance-fitted with the end wall of the outer casing 1, forming a second passage. Both the first protrusion 23 and the second protrusion 12 are disposed within the rotational gap 22. The first passage, the second passage, and the rotational gap 22 combine to form a labyrinth groove 24. The second adjustment structure includes a second adjustment plate disposed on the end wall of the outer casing 1.The second adjusting plate is composed of a fixing ring 13 and a sealing ring 14. The fixing ring 13 is connected to the end wall of the outer shell 1. The sealing ring 14 is made of shape memory alloy. The sealing ring 14 has a third form in a first temperature range and a fourth form in a second temperature range. In the third form, the sealing ring 14 covers the opening of the labyrinth groove 24 and the outer wall of the sealing ring 14 is clearance-fitted with the inner wall of the shaft head 2. In the fourth form, the sealing ring 14 deforms and bends towards the end wall of the outer shell 1 until it adheres to the end wall of the outer shell 1 to expose the labyrinth groove 24. Two mating blocks 5 are arranged opposite each other on the inner peripheral wall of the through hole 11. The mating blocks 5 have mating grooves 51. An oil replenishing head 52 is provided in the groove 51. The oil replenishing head 52 is detachably connected to the mating block 5 by a bolt 53. The oil replenishing head 52 has an open oil replenishing cavity 521. Oil outlet holes 522 communicating with the oil replenishing cavity 521 are provided on both side walls of the oil replenishing head 52. The oil replenishing cavity 521 is filled with solid lubricating grease 523. A sealing plate 54 is provided in the oil outlet hole 522. The sealing plate 54 is made of shape memory alloy. The sealing plate 54 has a fifth form in a first temperature range and a sixth form in a second temperature range. In the fifth form, the sealing plate 54 is bent and blocks the connection between the oil outlet hole 522 and the oil replenishing cavity 521. In the sixth form… The oil supply chamber 521 is flush with the inner wall of the oil outlet 522 to allow communication between the oil supply chamber 521 and the oil outlet 522. A floating oil seal 25 is provided between the inner wall of the shaft head 2 and the end wall of the outer casing 1. A bearing 26 is connected between the outer peripheral wall of the end of the shaft head 2 and the inner peripheral wall of the through hole 11. The planetary gear train is a three-stage linkage structure and is divided into a first-stage planetary gear 311 system, a second-stage planetary gear 321 system, and a third-stage planetary gear 331 system along the power transmission direction. The first-stage planetary gear 311 system includes a first-stage sun gear 31, a first-stage planetary gear 311, and a first-stage planet carrier 312. The second-stage planetary gear 321 system includes a second-stage sun gear 32, a second-stage planetary gear 321, and a second-stage planet carrier 322. The third-stage planetary gear 331 system includes a third-stage sun gear 33, a third-stage planetary gear 33, and a third-stage planetary gear 331 system. The system comprises a primary sun gear 331 and a third-stage planetary carrier 332. The primary sun gear 31 is connected to the drive shaft 3 so that it rotates when the drive shaft 3 rotates. The primary sun gear 31 meshes with a primary planetary gear 311. The primary planetary gear 311 is linked to the primary planetary carrier 312 so that it rotates when the primary planetary gear 311 rotates. The primary planetary carrier 312 is linked to the secondary sun gear 32 so that it rotates synchronously when the primary planetary carrier 312 rotates. The secondary sun gear 32 meshes with a secondary planetary gear 321. The secondary planetary gear 321 is linked to the secondary planetary carrier 322 so that it rotates when the secondary planetary gear 321 rotates.The secondary planetary carrier 322 is linked with the tertiary sun gear 33 to drive the tertiary sun gear 33 to rotate synchronously when the secondary planetary carrier 322 is rotating. The tertiary sun gear 33 is meshed with the tertiary planet gear 331. The tertiary planet gear 331 is linked with the tertiary planetary carrier 332 to drive the tertiary planetary carrier 332 to rotate when the tertiary planet gear 331 is rotating. The tertiary planetary carrier 332 is linked with the shaft head 2 so that the tertiary planetary carrier 332 transmits the amplified torque to the shaft head 2.

[0028] Operating procedure of this device: 1. When the final drive assembly is running, the external drive motor outputs power to drive the drive shaft to rotate. The drive shaft drives the first-stage sun gear to rotate. The first-stage sun gear meshes with the first-stage planet gear, causing the planet gear to rotate on its own axis and revolve around a fixed gear ring, driving the first-stage planet carrier to rotate and complete the first reduction and torque increase. The first-stage planet carrier drives the second-stage sun gear to rotate synchronously. The second-stage sun gear meshes with the second-stage planet gear to repeat the transmission logic, achieving the second reduction and torque increase through the second-stage planet carrier. The second-stage planet carrier drives the third-stage sun gear to rotate. The third-stage sun gear meshes with the third-stage planet gear to transmit power. After the third-stage planet carrier completes the third reduction and torque increase, the amplified torque is transmitted to the shaft head. The shaft head rotates flexibly under the support of the bearing, driving the external wheel hub to rotate.

[0029] 2. During operation, the meshing of the planetary gear system and the rotation of the bearings inside the outer shell generate heat. The spiral heat dissipation channel absorbs the heat and dissipates it through the gill-shaped heat dissipation grooves. When the temperature is in the first range, the shape memory alloy sealing plate of the first adjustment structure covers the heat dissipation grooves to prevent impurities from entering. When the temperature rises to the second range, the sealing plate deforms and bends to expose the heat dissipation grooves, increasing the heat dissipation area and improving the heat dissipation efficiency.

[0030] 3. When the shaft head rotates, the labyrinth groove formed by the first protrusion and the second protrusion at the rotation gap between the shaft head and the end wall of the outer casing extends the path for impurities to enter, and forms a multi-layer seal in conjunction with the floating oil seal; when the temperature is in the first range, the sealing ring of the second adjustment structure covers the labyrinth groove to strengthen the seal; when the temperature rises to the second range, the sealing ring bends and adheres to the end wall of the outer casing, exposing the labyrinth groove to discharge accumulated dust and liquid.

[0031] 4. At the same time, when the temperature is within the first range, the solid grease in the oil filling head inside the through hole is sealed in the oil filling chamber by the shape memory alloy sealing plate; when the temperature rises to the second range, the sealing plate flattens and opens the oil outlet hole, and the grease is released to the planetary gear train and drive shaft to achieve precise lubrication; the side cover is connected to the end of the sealed outer shell through a detachable connection to ensure the stability of the internal structure's operating environment.

[0032] The shape memory alloy material described in the above technology is existing technology. It can preferably be a nickel-titanium based alloy, which is divided into standard NiTi binary alloy (phase transformation temperature 50-100°C), NiTiCu ternary alloy (phase transformation temperature 30-80°C), and NiTiHfNb quaternary alloy (phase transformation temperature >150°C). It can be selected and adjusted according to actual working conditions. Since shape memory alloy is existing technology, its structure and function will not be described in detail.

[0033] The specific meshing methods between the planetary gear trains and their linkage relationships with other components in the above-mentioned technologies are all existing technologies. Their operating principles and corresponding auxiliary structures are similar to the planetary gear trains in existing technologies, so they will not be elaborated further.

[0034] In the above technology, the shape memory alloy has two phase transformation modes. The terms "fifth mode" and "sixth mode" are only used to distinguish them from the phase transformation modes of other components. There are not five modes in total. This is for the purpose of understanding and differentiation.

[0035] The sealing system of the second adjustment structure and its linkage structure in the above technology is a double protection structure of "floating oil seal + labyrinth groove" (i.e., a structure in which "a floating oil seal is set between the inner wall of the shaft head and the end wall of the outer shell"). When the sealing ring opens the labyrinth groove at high temperature, the floating oil seal remains in a closed sealing state, which can completely block the intrusion of external mud, water, dust and other impurities. The labyrinth groove itself forms a multi-bent passage structure with the first protrusion and the second protrusion (corresponding to the design of "first passage, second passage and rotation gap" in the original text). Even if the sealing ring opens, the internal dust and liquid can be discharged along the bent passage, while external impurities are difficult to enter due to the narrow passage and tortuous path. Therefore, the design of "opening the labyrinth groove at high temperature" of the sealing ring discharges internal dirt on the basis of double sealing, without deviating from the fundamental purpose of "sealing". On the contrary, it avoids the corrosion of the sealing parts by the residual dirt, which is an optimized supplement to the sealing function.

[0036] In the aforementioned technology, the shape memory alloy components are selected from nickel-titanium-copper ternary alloys or NiTiHfNb quaternary alloys (i.e., "material selection for shape memory alloys"). The known properties of these materials are "fatigue cycle resistance ≥ [missing information]". The shape memory alloy sheets / plates are designed to withstand vibrations and load impacts in the final drive assembly. Furthermore, they are used in conjunction with fixed structures (such as the connection between sealing rings and fixed rings, and the connection between sealing plates and connecting plates, corresponding to "component connection relationships"). These fixed structures limit the deformation range of the alloy components, preventing fatigue wear caused by excessive stretching or bending. In addition, the heat dissipation, sealing, and lubrication functions of this solution do not entirely rely on the shape memory alloy: even if the alloy fails occasionally, the basic ventilation of the heat dissipation path, the physical sealing of the labyrinth groove, and the basic oil supply to the lubrication chamber can still maintain core functions, providing functional redundancy and ensuring long-term reliability.

[0037] The setting of the "first and second temperature ranges" in the above technology is achieved by selecting shape memory alloys with different phase transition temperatures (i.e., the description of "selectable phase transition temperature of shape memory alloys"). For the temperature response requirements of the three subsystems—heat dissipation, sealing, and lubrication—alloys with matching phase transition temperatures can be selected respectively. For example, the sealing plate of the heat dissipation system uses an alloy with a phase transition temperature of 70℃, the sealing ring of the sealing system uses an alloy with a phase transition temperature of 90℃, and the sealing plate of the lubrication system uses an alloy with a phase transition temperature of 80℃. Through this "differentiated material selection," the temperature response ranges of each subsystem can be made independent and non-conflicting, achieving coordinated control of multiple systems without relying on a unified "second temperature range."

[0038] The setting of the "first and second temperature ranges" in the above technology is achieved by selecting shape memory alloys with different phase transition temperatures (i.e., the description of "selectable phase transition temperature of shape memory alloys"). For the temperature response requirements of the three subsystems—heat dissipation, sealing, and lubrication—alloys with matching phase transition temperatures can be selected respectively. For example, the sealing plate of the heat dissipation system uses an alloy with a phase transition temperature of 70℃, the sealing ring of the sealing system uses an alloy with a phase transition temperature of 90℃, and the sealing plate of the lubrication system uses an alloy with a phase transition temperature of 80℃. Through this "differentiated material selection," the temperature response ranges of each subsystem can be made independent and non-conflicting, achieving coordinated control of multiple systems without relying on a unified "second temperature range."

[0039] In the above technology, the temperature response of each component is a "step-by-step" process of heat accumulation under operating conditions, and there is no physical or functional interference between the actions of each system: After the vehicle starts, the temperature of the final drive assembly gradually rises from room temperature. When it reaches 70°C (the second temperature range of the cooling system), the shape memory alloy sealing plate of the cooling system deforms and opens the gill-shaped heat dissipation grooves. This heat dissipation is "auxiliary cooling" and can only slow down the rate of temperature rise (rather than complete cooling). When the vehicle is under continuous high load conditions (such as heavy-load uphill driving or long-term high-speed driving), the rate of heat generation will exceed the rate of heat dissipation, and the temperature will continue to rise. When the temperature reaches 80°C (the second temperature range of the lubrication system), the shape memory alloy sealing plate of the lubrication system deforms and opens the oil outlet of the grease filler head to replenish grease to the gear meshing surface. If the load increases further, the heat continues to accumulate and the temperature rises to 90°C (the second temperature range of the sealing system). The shape memory alloy sealing ring of the sealing system deforms and opens the drainage passage of the labyrinth groove. Meanwhile, the operation of each component will not cause functional conflicts or physical interference due to temperature control: on the one hand, the start-up of the heat dissipation system only suppresses the temperature rise and will not drop the temperature below 70°C. Therefore, under subsequent high loads, the temperature can still gradually reach the response threshold of the lubrication and sealing systems. On the other hand, the heat dissipation system's sealing plate is located in the heat dissipation slot area, the lubrication system's sealing plate is located at the oil outlet of the oil replenishing head, and the sealing system's sealing ring is located outside the fixed ring of the labyrinth groove. The installation positions of the three components in the final drive assembly are independent of each other and there is no structural overlap. Moreover, the operation process (the sealing plate opens and closes the heat dissipation slot, the sealing plate opens and closes the oil outlet, and the sealing ring adjusts the labyrinth groove passage) corresponds to different functional areas. There will be no interference problems such as collision or jamming due to component deformation, which can realize orderly start-up and coordinated operation at different temperature stages.

[0040] In the above technology, there is no direct connection between the drive shaft and the shaft head.

[0041] The foregoing has shown and described the basic principles and main features of the present invention, as well as its advantages. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the present invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope. All such changes and modifications fall within the scope of the present invention as claimed, which is defined by the appended claims and their equivalents.

Claims

1. A final drive assembly, comprising a housing for connecting to an external vehicle frame, a mating axle head and a side cover for connecting to an external wheel hub, the axle head being movably disposed at the beginning of the housing, the side cover being detachably connected to the end of the housing, the housing having a through hole along its axial direction, the end of the axle head being partially inserted into the through hole, the through hole being provided with a drive shaft for linkage with the output end of an external drive motor, and a planetary gear train for linkage with the drive shaft to reduce speed and increase torque on the drive shaft being disposed in the through hole, characterized in that: The housing is provided with a heat dissipation structure for absorbing heat inside the housing and dissipating heat, and a first adjusting structure for cooperating with the heat dissipation structure to adaptively improve the heat dissipation efficiency of the heat dissipation structure according to the temperature inside the housing; a sealing structure for blocking impurities from the outside from entering the through hole through the gap between the shaft head and the housing is arranged between the inner wall of the shaft head and the end wall of the housing; and a second adjusting structure for cooperating with the sealing structure to adaptively adjust the sealing strength of the sealing structure is arranged.

2. A final drive assembly according to claim 1, wherein: The heat dissipation structure comprises a heat dissipation passage hollowed in the housing and a plurality of heat dissipation grooves annularly arranged on the peripheral wall of the housing; the heat dissipation passage is arranged in a spiral line and is arranged along the length direction of the housing with the axis of the housing as the reference line; the plurality of heat dissipation grooves are arranged along the length direction of the housing and are all in communication with the heat dissipation passage; and the radial cross section of the heat dissipation groove is arranged in a fish gill shape.

3. A final drive assembly according to claim 2, wherein: The first adjusting structure comprises a plurality of first adjusting plates arranged on the peripheral wall of the housing; the plurality of first adjusting plates are one-to-one corresponding to the plurality of heat dissipation grooves; the first adjusting plate is connected by a connecting plate and a closing plate; the connecting plate is connected with the peripheral wall of the housing; the closing plate is made of a shape memory alloy material; the closing plate has a first shape at a first temperature range; the closing plate has a second shape at a second temperature range; the closing plate is arranged on the corresponding heat dissipation groove in the first shape and closes the opening of the heat dissipation groove; and the closing plate is deformed and bent away from the opening of the heat dissipation groove in the second shape to expose the heat dissipation groove.

4. A final drive assembly according to claim 1, wherein: The inner wall of the shaft head and the end wall of the housing are gap-fitted and form a rotation gap; the sealing structure comprises a first protruding portion annularly arranged on the inner wall of the shaft head and a second protruding portion annularly arranged on the end wall of the housing; the second protruding portion is arranged outside the first protruding portion; the outer wall of the first protruding portion is gap-fitted with the inner wall of the shaft head and forms a first passage; the outer wall of the second protruding portion is gap-fitted with the end wall of the housing and forms a second passage; the first protruding portion and the second protruding portion are arranged in the rotation gap; and the first passage, the second passage and the rotation gap form a labyrinth groove.

5. A final drive assembly according to claim 4, wherein: The second adjusting structure comprises a second adjusting plate arranged on the end wall of the housing; the second adjusting plate is connected by a fixed ring and a sealing ring; the fixed ring is connected with the end wall of the housing; the sealing ring is made of a shape memory alloy material; the sealing ring has a third shape at a first temperature range; the sealing ring has a fourth shape at a second temperature range; the sealing ring is arranged at the opening of the labyrinth groove in the third shape and the outer wall of the sealing ring is gap-fitted with the inner wall of the shaft head; and the sealing ring is deformed and bent towards the end wall of the housing in the fourth shape until it is attached to the end wall of the housing to expose the labyrinth groove.

6. A final drive assembly according to claim 1, wherein: Two cooperating blocks are oppositely arranged on the inner wall of the through hole; a cooperating groove is arranged on the cooperating block; a oil supplement head is arranged in the cooperating groove; a bolt is detachably connected between the oil supplement head and the cooperating block; an oil supplement cavity is hollowed in the oil supplement head; oil outlet holes in communication with the oil supplement cavity are arranged on the two side walls of the oil supplement head; and solid lubricating grease is filled in the oil supplement cavity.

7. A final drive assembly according to claim 6, wherein: The oil outlet hole is provided with a blocking sheet made of shape memory alloy material, the blocking sheet has a fifth shape in a first temperature range and a sixth shape in a second temperature range, the blocking sheet is arranged at the bending position of the communication between the oil outlet hole and the oil supplement cavity in the fifth shape, and the blocking sheet is arranged flat with the inner wall of the oil outlet hole in the sixth shape to make the oil supplement cavity communicate with the oil outlet hole.

8. A final drive assembly according to claim 1, wherein: A floating oil seal is arranged between the inner wall of the shaft head and the end wall of the shell.

9. A final drive assembly as set forth in claim 1, wherein: A bearing is connected between the outer peripheral wall of the end of the shaft head and the inner peripheral wall of the through hole.

10. A final drive assembly according to claim 1, wherein: The planetary gear train set is a three-stage linkage structure and is sequentially divided into a first-stage planetary gear train, a second-stage planetary gear train and a third-stage planetary gear train along the power transmission direction, the first-stage planetary gear train comprises a first-stage sun gear, a first-stage planetary gear and a first-stage carrier, the second-stage planetary gear train comprises a second-stage sun gear, a second-stage planetary gear and a second-stage carrier, the third-stage planetary gear train comprises a third-stage sun gear, a third-stage planetary gear and a third-stage carrier, the first-stage sun gear is connected with the transmission shaft to drive the first-stage sun gear to rotate when the transmission shaft rotates, the first-stage sun gear is in meshing arrangement with the first-stage planetary gear, the first-stage planetary gear is in linkage cooperation with the first-stage carrier to drive the first-stage carrier to rotate when the first-stage planetary gear rotates, the first-stage carrier is in linkage cooperation with the second-stage sun gear to drive the second-stage sun gear to synchronously rotate when the first-stage carrier rotates, the second-stage sun gear is in meshing arrangement with the second-stage planetary gear, the second-stage planetary gear is in linkage cooperation with the second-stage carrier to drive the second-stage carrier to rotate when the second-stage planetary gear rotates, the second-stage carrier is in linkage cooperation with the third-stage sun gear to drive the third-stage sun gear to synchronously rotate when the second-stage carrier rotates, the third-stage sun gear is in meshing arrangement with the third-stage planetary gear, the third-stage planetary gear is in linkage cooperation with the third-stage carrier to drive the third-stage carrier to rotate when the third-stage planetary gear rotates, and the third-stage carrier is in linkage cooperation with the shaft head to make the third-stage carrier transmit the amplified torque to the shaft head.

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