A wet rear axle control system with multi-domain temperature awareness and dynamic heat dissipation

Abstract

This invention belongs to the technical field of wet rear axle assembly, specifically a wet rear axle control system with multi-domain temperature sensing and dynamic heat dissipation. The system includes an axle housing, within which a braking component is housed. This braking component includes a differential, which is also located within the axle housing. This wet rear axle control system with multi-domain temperature sensing and dynamic heat dissipation achieves adaptive and precise heat dissipation control based on real-time multi-domain temperature sensing through a detection system. This optimizes energy consumption and thermal management performance. The detection system, through an array of sensors deployed in multiple domains such as the differential, gears, and bearings, obtains for the first time real-time distribution data of the "temperature field" inside the rear axle, rather than just oil temperature information. The core control module and dynamic heat dissipation algorithm module of the intelligent heat dissipation control unit can integrate this data to accurately assess the overall and local thermal loads and dynamically and collaboratively adjust the speed of the drive motor and the pressure of the circulating pump.

Description

Technical Field

[0001] This invention relates to the field of wet rear axle assembly technology, and in particular to a wet rear axle control system with multi-domain temperature sensing and dynamic heat dissipation. Background Technology

[0002] As a key transmission component in heavy vehicles, construction machinery, and special vehicles, such as excavators, the wet-braking rear axle assembly integrates high-power-density moving parts such as differentials, main reduction gear pairs, and bearings. During operation, especially under heavy loads, continuous steering, or low-speed, high-torque conditions, these components generate a large amount of heat due to gear meshing friction, bearing rotational friction, and differential wear. If this heat cannot be dissipated in a timely and effective manner, the lubricating oil temperature inside the axle will rise sharply, and its viscosity will decrease, leading to lubrication failure, abnormal wear of components, aging of seals and oil leakage, and even failures such as gear or bearing seizure, seriously affecting the reliability and service life of the entire vehicle.

[0003] Currently, the industry mainly uses the following two technical solutions for heat dissipation in wet rear axles, but both have significant limitations. The core problems are low heat dissipation efficiency, poor uniformity, and lack of intelligent response:

[0004] 1. Splash lubrication and natural convection cooling (first-generation passive cooling)

[0005] This is the most basic traditional solution, relying on the rotation of gears inside the axle to agitate the lubricating oil, forming an oil mist or droplets that splash lubricates and roughly cools the components, while simultaneously relying on natural convection between the axle housing's outer wall and the air for heat dissipation. This solution has inherent drawbacks:

[0006] Passive and inefficient heat dissipation: The heat dissipation capacity depends entirely on the gear speed and the ambient temperature. Under low-speed, heavy-load conditions (such as construction machinery climbing hills or vehicles starting), the gear's oil churning effect is weak, resulting in insufficient heat dissipation and a tendency to form high-temperature hotspots.

[0007] Extremely poor uniformity: The oil mist distribution is random, and the cooling effect is weak in areas far from the gears (such as the top of the differential housing and the far end of the bearing), resulting in a severely uneven temperature field inside the axle. Heat tends to accumulate in local areas (such as the gear meshing area), forming a "heat island effect," while other areas are not adequately cooled, making it impossible to achieve precise directional heat dissipation.

[0008] 2. Fixed fuel injector pipe cooling (second-generation active cooling)

[0009] To improve the inadequacy of splash heat dissipation, a solution has emerged that involves installing a fixed oil injection line inside the axle housing, using an external oil pump to spray cooled lubricating oil in a directional manner onto heat source surfaces such as gears or differentials.

[0010] Although it's an active cooling method, its uniformity and adaptability are insufficient: while the solution improves heat dissipation intensity, its spray position and angle are fixed, resulting in a static spray area. This leads to:

[0011] Dead zone coverage: For complex differential assemblies and multiple bearings, fixed nozzles cannot achieve full coverage cooling without dead angles, and there are still heat dissipation blind spots.

[0012] Lack of dynamic adjustment: Fuel injection flow and pressure are usually constant or manually adjusted, and cannot be automatically adjusted according to the real-time and dynamic changes in the thermal load state inside the rear axle (such as temperature differences between components and heat generation rates under different operating conditions). This may cause energy waste and overcooling under light loads, and insufficient cooling intensity under heavy loads or local overheating.

[0013] Unable to handle local overheating: When the system detects an abnormal temperature rise at a certain point (such as a bearing), the fixed oil injection mode cannot enhance the cooling intensity of that specific area. The real-time matching degree between the heat dissipation action and the heat source state is low, and it is essentially still an "open-loop" control. Summary of the Invention

[0014] Based on the existing technical problems of passive and inefficient heat dissipation, extremely poor uniformity, and lack of dynamic adjustment in wet rear axle assemblies, this invention proposes a wet rear axle control system with multi-domain temperature sensing and dynamic heat dissipation.

[0015] The present invention proposes a wet rear axle control system with multi-domain temperature sensing and dynamic heat dissipation, including an axle housing, wherein a braking component is disposed inside the axle housing, and the braking component includes a differential, wherein the differential is disposed inside the axle housing.

[0016] The axle housing is equipped with a heat dissipation component, which dissipates heat from the braking component. The heat dissipation component includes a heat dissipation device and a drive device. The heat dissipation device includes a heat dissipation ring assembly, which sprays hydraulic oil to dissipate heat from the internal braking component. The drive device includes a rotating sleeve, which rotates to drive the heat dissipation ring assembly to reciprocate.

[0017] The heat dissipation device also includes a limiting sleeve, which is fixedly installed on the inner wall of the bridge housing. A ball bearing is rotatably connected to the inner wall of the limiting sleeve. The outer surface of the heat dissipation ring assembly is slidably inserted into the inner wall of the limiting sleeve. The outer surface of the ball bearing is in contact with the outer surface of the heat dissipation ring assembly. The heat dissipation ring assembly includes two heat dissipation annular pipes, a connecting pipe, and a nozzle with a one-way valve. The two heat dissipation annular pipes are connected to each other through the connecting pipe. The outer surfaces of the connecting pipe and the heat dissipation annular pipes are both fixedly connected to one end of the nozzle.

[0018] It also includes a detection system, which comprises a multi-domain temperature sensing unit, an intelligent heat dissipation control unit, an actuator drive and status feedback unit, and a system monitoring and early warning unit.

[0019] Preferably, the braking component further includes a drive gear, which is rotatably connected to the inner wall of the axle housing via a bearing. The inner wall of the axle housing is rotatably connected to a half-shaft via a bearing. A driven gear is fixedly installed on the outer shell of the differential. The driven gear meshes with the drive gear. One end of each of the two half-shafts meshes with the side gear of the differential. An oil drain valve and an oil inlet valve are fixedly connected to the outer surface of the axle housing.

[0020] Preferably, the driving device further includes a driving housing, the outer surface of which is fixedly installed to the outer surface of the bridge housing by bolts, an annular support frame is fixedly installed on the inner wall of the driving housing, a fixed gear ring is fixedly installed on the inner wall of the annular support frame, a driving motor is fixedly installed on the inner wall of the driving housing, a rotating frame is fixedly installed at one end of the output shaft of the driving motor, and a lifting gear is rotatably connected to the outer surface of the rotating frame through a bearing, the lifting gear meshing with the fixed gear ring.

[0021] Preferably, the inner wall of the drive housing is rotatably connected to one end of the rotating sleeve via a bearing, one end of the rotating sleeve extends into the interior of the bridge housing, an arc-shaped bevel gear ring is fixedly installed on the outer surface of the heat dissipation ring assembly, a drive bevel gear is fixedly installed on one end of the rotating sleeve, the drive bevel gear meshes with the arc-shaped bevel gear ring, an arc-shaped threaded groove is formed on the inner wall of the rotating sleeve, a lifting sleeve is slidably inserted into the inner wall of the rotating sleeve, one end of the lifting sleeve is slidably inserted into the inner wall of the arc-shaped threaded groove via a column, and one end of the lifting sleeve is hinged to the outer surface of the lifting gear via a pin.

[0022] Preferably, a hydraulic circulation subsystem is provided outside the drive housing. The hydraulic circulation subsystem includes an oil reservoir placed outside the drive housing. Two circulation pumps are placed on the outer surface of the oil reservoir. The inlet end of one circulation pump is fixedly connected to the inner wall of the oil reservoir, and one end of the outlet end of the circulation pump is fixedly connected to a delivery pipe via a three-way valve. One end of the outlet end of the other circulation pump is fixedly connected to one end of the inlet valve via a connecting pipe, and the connecting pipe is fixedly connected to one end of the three-way valve. The inlet end of the circulation pump is fixedly connected to one end of the drain valve via a filter and a radiator. One end of the delivery pipe is fixedly installed to the inner wall of the lifting sleeve, and one end of the delivery pipe is fixedly connected to the outer surface of the heat dissipation ring assembly via a hose. A sealing folding sleeve is rotatably connected to the lower end of the rotating sleeve, and one end of the sealing folding sleeve is fixedly installed to one end of the delivery pipe.

[0023] Preferably, the multi-domain temperature sensing unit includes a multi-domain sensor array and a signal acquisition and processing module;

[0024] The multi-domain sensor array includes a differential temperature sensor, a gear temperature sensor, a bearing temperature sensor, and a hydraulic oil temperature sensor, which are used to collect temperature data of different heat source domains inside the rear axle in real time.

[0025] The sensor probe of the differential temperature sensor is closely attached to a selected temperature measurement point on the outer surface of the differential housing.

[0026] The gear temperature sensor is installed on the housing near the back bearing seat of the driven gear (circular gear) to indirectly monitor heat conduction in the meshing area;

[0027] The bearing temperature sensor is installed on the outer surface of the bearing housing near the outer ring bearing area of ​​the drive gear bearing and the differential bearing;

[0028] The hydraulic oil temperature sensor is installed in the oil sump at the bottom of the axle housing;

[0029] The signal acquisition and processing module is used to filter, amplify, and convert analog-to-digital signals from multiple sensors to output a stable digital temperature signal.

[0030] Preferably, the intelligent heat dissipation control unit includes a core control module and a dynamic heat dissipation algorithm module;

[0031] The core control module receives temperature data from the multi-domain temperature sensing unit and executes control logic;

[0032] The dynamic heat dissipation algorithm module is used to calculate the real-time heat load level based on the fused multi-domain temperature data, and dynamically generate speed / reciprocating frequency control commands for the drive motor and output pressure / flow control commands for the circulating pump through the built-in heat dissipation strategy mapping model, so as to achieve precise and adaptive adjustment of heat dissipation intensity and range.

[0033] Preferably, the actuator drive and status feedback unit includes a drive motor drive control module and a circulating pump pressure closed-loop control module;

[0034] The drive motor drive control module is used to receive speed commands from the intelligent heat dissipation control unit, drive the drive motor to operate, and provide real-time feedback on the motor's speed, current, and operating status.

[0035] The circulating pump pressure closed-loop control module is used to receive pressure / flow commands, adjust the working power of the circulating pump, and monitor and provide feedback on the actual pressure or flow value of the hydraulic circuit in real time, forming a closed-loop control.

[0036] Preferably, the system monitoring and early warning unit includes a fault diagnosis module and an early warning indication module;

[0037] The fault diagnosis module is used to monitor faults such as sensor open circuit / short circuit, actuator communication timeout, or command execution abnormality, and generate fault codes;

[0038] The warning indication module is used to trigger an audible and visual alarm via a local indicator light, display screen, or vehicle bus when the temperature at any monitoring point exceeds a preset safety threshold or when a system malfunction occurs, and to send warning information to a higher-level vehicle controller.

[0039] The beneficial effects of this invention are as follows:

[0040] 1. By incorporating a heat dissipation device, uniform and dead-angle-free active jet cooling is achieved, significantly improving heat dissipation efficiency and uniformity. The "heat dissipation ring assembly," composed of a heat dissipation annular pipe, connecting pipes, and multiple nozzles, can reciprocate at a large angle under the drive of the drive device. This movement expands the spray coverage of the cooling oil from a fixed point or small fan-shaped area to a dynamically scanning wide area, thus uniformly covering key heat sources such as the differential housing, the sides of the gear meshing area, and surrounding bearings. This effectively eliminates the "cooling dead angles" present in traditional fixed nozzles and solves the problem of localized overheating caused by uneven heat dissipation. The problem is that the drive unit, through the unique design of the rotating sleeve and the lifting sleeve, converts the rotational motion of the drive motor into the reciprocating rotation of the cooling ring assembly. At the same time, hydraulic oil is delivered to the rotating cooling ring assembly through delivery pipes and hoses. The entire transmission and delivery system is integrated into the drive housing. All moving parts operate in a closed and controlled environment, without mechanical interference with core transmission components such as the differential and half shafts. This ensures the reliability of the rear axle body transmission and achieves stable delivery of the cooling medium to the motion actuators. This solves the technical problems of passive and inefficient cooling, extremely poor uniformity, and lack of dynamic adjustment in existing wet rear axle assemblies.

[0041] 2. By setting up a detection system, adaptive and precise heat dissipation control based on real-time multi-domain temperature sensing was achieved, optimizing energy consumption and thermal management performance. The detection system, through sensor arrays deployed in multiple domains such as the differential, gears, and bearings, obtained for the first time real-time distribution data of the "temperature field" inside the rear axle, rather than just oil temperature information. The core control module and dynamic heat dissipation algorithm module of the intelligent heat dissipation control unit can integrate this data to accurately assess the overall and local thermal loads, and dynamically and collaboratively adjust the drive motor speed (controlling the scanning frequency) and the circulation pump pressure (controlling the fuel injection intensity). This allows the heat dissipation intensity to precisely match the real-time thermal load, avoiding the risk of overheating while reducing unnecessary energy consumption under low thermal loads. This represents a leap from "extensive continuous heat dissipation" to "precise on-demand heat dissipation," possessing fault self-diagnosis and early warning capabilities, and improving the system's safety and maintainability. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of a wet rear axle control system with multi-domain temperature sensing and dynamic heat dissipation proposed in this invention.

[0043] Figure 2 This is a perspective view of the half-shaft structure of a wet rear axle control system with multi-domain temperature sensing and dynamic heat dissipation proposed in this invention.

[0044] Figure 3 This is a perspective view of the circulating pump structure of a wet rear axle control system with multi-domain temperature sensing and dynamic heat dissipation proposed in this invention.

[0045] Figure 4 This is a perspective view of the heat dissipation ring structure of a wet rear axle control system with multi-domain temperature sensing and dynamic heat dissipation proposed in this invention.

[0046] Figure 5 This is a perspective view of the limiting sleeve structure of a wet rear axle control system with multi-domain temperature sensing and dynamic heat dissipation proposed in this invention.

[0047] Figure 6 This is a perspective view of the ball bearing structure of a wet rear axle control system with multi-domain temperature sensing and dynamic heat dissipation proposed in this invention.

[0048] Figure 7 This is a perspective view of the fixed gear ring structure of a wet rear axle control system with multi-domain temperature sensing and dynamic heat dissipation proposed in this invention.

[0049] Figure 8 This is a perspective view of the arc-shaped threaded groove structure of a wet rear axle control system with multi-domain temperature sensing and dynamic heat dissipation proposed in this invention.

[0050] Figure 9This is a system block diagram of the detection system of a wet rear axle control system with multi-domain temperature sensing and dynamic heat dissipation proposed in this invention.

[0051] In the diagram: 1. Axle housing; 2. Differential; 21. Drive gear; 22. Half shaft; 23. Driven gear; 24. Oil drain valve; 25. Oil inlet valve; 3. Limit sleeve; 31. Ball bearing; 32. Cooling ring assembly; 4. Drive housing; 41. Annular support frame; 42. Fixed gear ring; 43. Drive motor; 44. Rotating frame; 45. Lifting gear; 5. Rotating sleeve; 51. Arc-shaped bevel gear ring; 52. Drive bevel gear; 53. Arc-shaped threaded groove; 54. Lifting sleeve; 6. Oil reservoir; 61. Circulating pump; 62. Delivery pipeline; 63. Sealing folding sleeve. Detailed Implementation

[0052] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0053] Reference Figures 1-9 A wet rear axle control system with multi-domain temperature sensing and dynamic heat dissipation includes an axle housing 1, and a braking component is provided inside the axle housing 1. The braking component includes a differential 2, which is located inside the axle housing 1.

[0054] like Figures 2-4 As shown, specifically, the braking components also include a drive gear 21, a driven gear 23, and a half-shaft 22; the drive gear 21 is rotatably connected to the inner wall of the axle housing 1 via a bearing; the driven gear 23 is fixedly mounted on the outer shell of the differential 2, and the driven gear 23 meshes with the drive gear 21; the inner wall of the axle housing 1 is rotatably connected to one end of the two half-shafts 22 via bearings, and one end of the two half-shafts 22 meshes with the two side gears of the differential 2 respectively; the outer surface of the axle housing 1 is fixedly connected to a drain valve 24 for discharging hot oil and an inlet valve 25 for injecting cooling oil.

[0055] like Figures 5-8 As shown, the axle housing 1 is equipped with a heat dissipation component, which includes a heat dissipation device and a drive device. The heat dissipation device includes a heat dissipation ring group 32 that can perform reciprocating rotational motion. The heat dissipation ring group 32 is configured to spray hydraulic oil onto the braking components around it during rotation to dissipate heat. The drive device includes a rotating sleeve 5, and the rotational motion of the rotating sleeve 5 is converted into the reciprocating rotational motion of the heat dissipation ring group 32.

[0056] Specifically, the heat dissipation device also includes a limiting sleeve 3 fixed to the inner wall of the bridge housing 1, and the inner wall of the limiting sleeve 3 is provided with a plurality of balls 31; the outer surface of the heat dissipation ring assembly 32 is slidably inserted into the inner wall of the limiting sleeve 3 and supported on the balls 31; the heat dissipation ring assembly 32 includes two coaxial and parallel heat dissipation annular pipes, at least one connecting pipe and a plurality of nozzles; the two heat dissipation annular pipes are fixedly connected to each other through the connecting pipe to form a closed loop; the nozzles are distributed on the heat dissipation annular pipes and the connecting pipe, and each nozzle is integrated with a one-way valve to prevent oil backflow in the bridge housing 1.

[0057] Specifically, the drive unit also includes a drive housing 4, a fixed gear ring 42, a drive motor 43, and a rotating frame 44; the drive housing 4 is fixedly installed on the outer surface of the axle housing 1; the fixed gear ring 42 is fixed inside the drive housing 4 by an annular support frame 41; the drive motor 43 is fixed inside the drive housing 4, and its output shaft is fixedly connected to the rotating frame 44; a lifting gear 45 is rotatably connected to the rotating frame 44 by a bearing, and the lifting gear 45 meshes with the fixed gear ring 42.

[0058] Specifically, the rotating sleeve 5 is rotatably connected to the drive housing 4 via a bearing, with one end extending into the axle housing 1; an arc-shaped bevel gear ring 51 is fixedly installed on the outer periphery of the heat dissipation ring assembly 32; a drive bevel gear 52 is fixedly installed at one end of the rotating sleeve 5 located inside the axle housing 1, and the drive bevel gear 52 meshes with the arc-shaped bevel gear ring 51; an arc-shaped threaded groove 53 is provided on the inner wall of the rotating sleeve 5; a lifting sleeve 54 is slidably inserted into the rotating sleeve 5, and a column is fixed on the lifting sleeve 54, which is slidably inserted into the arc-shaped threaded groove 53; one end of the lifting sleeve 54 is hinged to the lifting gear 45 via a pin.

[0059] Specifically, it also includes a hydraulic circulation subsystem, which includes an oil reservoir 6, two circulation pumps 61, a filter, a radiator, connecting pipes, a three-way valve, and a delivery pipe 62; the oil reservoir 6 is connected to the inlet of one circulation pump 61; the outlet of the circulation pump 61 is connected to the connecting pipe and the delivery pipe 62 through the three-way valve; the outlet of the other circulation pump 61 is connected to the connecting pipe and the oil inlet valve 25, and its inlet is fixedly connected to the oil drain valve 24 after passing through the radiator and the filter; one end of the delivery pipe 62 is fixedly connected to the lifting sleeve 54 and connected, and the other end is connected to the heat dissipation ring assembly 32 through a flexible hose; a sealing folding sleeve 63 is rotatably connected to the lower end of the rotating sleeve 5, and one end of the sealing folding sleeve 63 is fixedly installed to one end of the delivery pipe 62.

[0060] like Figure 9 As shown, it also includes a detection system, which comprises a multi-domain temperature sensing unit, an intelligent heat dissipation control unit, an actuator drive and status feedback unit, and a system monitoring and early warning unit.

[0061] The multi-domain temperature sensing unit is used to collect temperature data of multiple specified heat source domains inside the bridge housing 1 in real time.

[0062] Specifically, the multi-domain temperature sensing unit includes a multi-domain sensor array and a signal acquisition and processing module;

[0063] The multi-domain sensor array includes a differential temperature sensor, a gear temperature sensor, a bearing temperature sensor, and a hydraulic oil temperature sensor, which are used to collect temperature data of different heat source domains inside the rear axle in real time.

[0064] The sensor probe of the differential temperature sensor is closely attached to a selected temperature measurement point on the outer surface of the differential 2 housing. The preferred location is the middle of the housing or the area near the planetary gear shaft, which can directly reflect the core operating temperature of the differential 2 assembly.

[0065] Method 1 (Embedded): A blind hole is machined and installed in a non-critical stress area of ​​the differential 2 housing. The armored thermocouple or platinum resistance (PT100) probe is then cured into the hole with high-temperature thermally conductive adhesive to achieve tight contact and mechanical protection.

[0066] Method 2 (Surface Mount): Use a surface mount PTD with a stainless steel pressure plate or clamp, and use existing bolts (such as bearing cover bolts) on the differential 2 housing for fastening to ensure that the thermal interface is coated with high thermal conductivity silicone grease.

[0067] The gear temperature sensor is installed on the housing near the back bearing seat of the driven gear 23 (circular gear) to indirectly monitor heat conduction in the meshing area.

[0068] The bearing temperature sensor is installed on the outer surface of the bearing housing near the bearing bearing of the drive gear 21 and the bearing of the differential 2. A dedicated sensor integrated mounting base is designed at the bearing cover or the bearing housing of the bridge housing 1 to embed a miniaturized thermocouple or digital temperature chip (such as DS18B20) so that its temperature measuring end is in close contact with the metal body outside the outer ring of the bearing.

[0069] The hydraulic oil temperature sensor is installed in the oil sump at the bottom of the axle housing 1; a standard threaded oil temperature sensor is used, which is directly screwed into the NPT or M threaded hole preset on the side wall or bottom of the axle housing 1, so that its temperature measuring part is immersed in the oil.

[0070] All sensor cables must be routed along the inner wall or dedicated channel of static components such as bridge housing 1 and drive housing 4, and securely fixed with cable clips, cable ties or adhesive fasteners to ensure a safe distance of not less than 15mm from all rotating components such as differential 2, half shaft 22, and gears.

[0071] Centralized busbar principle: All sensor cables should be connected to a multi-core waterproof aviation plug or junction box in a safe static area within the bridge housing 1 (such as the inner cavity above the drive housing 4).

[0072] The signal acquisition and processing module is used to filter, amplify, and convert analog-to-digital signals from multiple sensors to output a stable digital temperature signal.

[0073] The intelligent heat dissipation control unit is connected to the multi-domain temperature sensing unit to calculate the heat load based on temperature data and generate dynamic heat dissipation control commands.

[0074] Specifically, the intelligent heat dissipation control unit includes a core control module and a dynamic heat dissipation algorithm module;

[0075] The core control module receives temperature data from the multi-domain temperature sensing unit and executes control logic;

[0076] The dynamic heat dissipation algorithm module is used to calculate the real-time heat load level based on the fused multi-domain temperature data, and dynamically generate speed / reciprocating frequency control commands for the drive motor 43 and output pressure / flow control commands for the circulating pump 61 through the built-in heat dissipation strategy mapping model, so as to achieve precise and adaptive adjustment of heat dissipation intensity and range.

[0077] The working logic of the dynamic heat dissipation algorithm module is described in the form of a step-by-step flowchart as follows:

[0078] Step 1: Data Acquisition and Preprocessing: Receive real-time temperature data from the multi-domain temperature sensing unit, including the temperature of differential 2. Temperature of driven gear 23 Bearing temperature Hydraulic oil temperature The raw temperature signals from the differential temperature sensor are processed sequentially. The raw temperature signal from the driven gear temperature sensor The raw temperature signal from the bearing temperature sensor and the raw temperature signal from the hydraulic oil temperature sensor. Perform the following processes in sequence:

[0079] 1. Validity verification: Determine whether the signal is within a physically reasonable range (e.g., -40°C to 200°C) and detect whether the sudden change between adjacent sampling points exceeds the preset limit rate of change in order to eliminate outliers;

[0080] 2. Filtering and noise reduction: The verified signal is processed using a moving average filter or Kalman filter algorithm to obtain a stable and reliable temperature value. , , , .

[0081] Step Two: Feature Fusion and Index Calculation Steps: Based on the preprocessed temperature data, the following steps are performed:

[0082] 1. Rate of change calculation: Calculate the instantaneous rate of change at key temperature points, for example... , and .

[0083] 2. Integration of Comprehensive Heat Load Indicators: A weighted fusion algorithm is used to calculate the comprehensive temperature index reflecting the overall heat load. The calculation formula is as follows:

[0084] ,in , , To meet the preset weighting coefficients based on the heat capacity and thermal failure risk of the differential, gears, bearings, and fluids. ,and , This represents the average bearing temperature. This indicates the higher of the differential 2 temperature and the driven gear 23 temperature, used to track the core heat source.

[0085] 3. Calculation of thermal imbalance index: The maximum temperature difference between the core heat source and the cooling medium is calculated using the following formula: .

[0086] Step 3: Dynamic Classification of Heat Load Levels: Based on the comprehensive temperature index calculated in Step 2. Thermal imbalance index And the rate of temperature change at each point, dynamically classifying the current heat load level. ( ).

[0087] The division rules are as follows:

[0088] Level 0: When < And the rate of change at each major temperature point When the load is below the set threshold, it is determined to be in standby / low load state.

[0089] Level 1: When ≤ < When this occurs, it is determined to be in a normal adjustment state.

[0090] Level 2: When satisfied ≤ < or ≥ Under any of these conditions, the system is determined to be in an active enhanced heat dissipation state.

[0091] Level 3: When ≤ < When this occurs, it is determined to be a high load / peak heat dissipation state.

[0092] Level 4: When ≥ Or any single point temperature ≥ When this occurs, it is determined to be in critical / protection mode.

[0093] in, This is the normal temperature threshold, the upper limit of the system temperature when under low heat load or in standby mode. To monitor the temperature threshold, the starting point at which the system enters the active temperature control range, To enhance the trigger point of the heat dissipation mode, a high-load temperature threshold is established. The critical temperature threshold is the limit boundary for the safe operation of the system. A threshold is set for thermal imbalance, serving as a criterion for determining whether the temperature difference between the core heat source and the cooling medium is too large. The single-point limit temperature threshold is the absolute maximum temperature allowed at any single measurement point (such as a bearing or gear), which is a preset threshold based on the system's safe operation requirements.

[0094] Step 4: Level-based bivariate basic instruction mapping: Based on the heat load level determined in Step 3. Query the preset heat dissipation strategy basic mapping table to obtain the corresponding initial control command:

[0095] Drive motor base speed ;

[0096] Circulating pump base output pressure ;

[0097] This mapping table defines the baseline values ​​for scanning frequency and injection intensity required to maintain basic thermal balance at different levels.

[0098] The "preset heat dissipation strategy basic mapping table" built into the dynamic heat dissipation algorithm module is based on the heat load level ( ~ The base speed of the drive motor and the base pressure of the circulating pump are predefined, as follows:

[0099]

[0100] in, To adjust the speed of the drive motor at low speed, For low-pressure regulation of the circulating pump, This is a motor speed mapping function. This is the pump pressure mapping function.

[0101] The following is a pre-defined mapping example based on the characteristics of a typical wet rear axle system (the values ​​are for illustrative purposes only and need to be calibrated according to the specific system):

[0102]

[0103] Note: For levels 0 and 1, linear or proportional adjustment is used to achieve a smooth transition.

[0104] For Level 2 and above, a fixed high value is used to quickly respond to high heat loads.

[0105] Level 4 and Limited by the rated capacity of the drive motor and circulating pump, and the system safety boundaries.

[0106] In step four of the dynamic heat dissipation algorithm module, the calling logic of the mapping table is as follows:

[0107] 1. Determine the query index: Use the current heat load level determined in step three. As a query index for the mapping table.

[0108] 2. Obtain the baseline value: based on Query the mapping table to obtain the corresponding:

[0109] ,in, This is the basic mapping function for the heat dissipation strategy.

[0110] 3. Level 1 linear interpolation processing: If =1, further needs to be determined according to The linear interpolation calculation is performed at a specific location within the interval, using the following formula:

[0111] ,in, This is the lowest speed for level 1. The reference speed for level 2, and These are the attention threshold and the high load threshold, respectively.

[0112] 4. Transfer to the correction step: Transfer the acquired baseline value The process is then moved to step five for fine-tuning to address special situations such as localized hotspots and rapid temperature rises.

[0113] The baseline values ​​of this mapping table are predetermined through thermal simulation analysis and bench calibration tests of the rear axle assembly to ensure basic heat dissipation capabilities under different heat load levels.

[0114] Step 5: Refined Instruction Correction Based on Thermal State Profile: Based on the detailed thermal state profile constructed in Step 2, the basic instructions obtained in Step 4 are dynamically corrected to optimize heat dissipation and energy efficiency.

[0115] 1. Correction of scanning frequency for local hotspots: If The command to increase the drive motor speed by 43 is then corrected using the following formula:

[0116] ,in, The average temperature at all monitoring points. Threshold for hotspot determination This is the speed correction factor.

[0117] 2. Injection intensity correction for rapid overall temperature rise: If the hydraulic oil temperature change rate > If the pressure command of circulating pump 61 is increased first, the correction formula is as follows:

[0118] ,in, The threshold for oil temperature rise rate. This is the pressure correction factor.

[0119] 3. Predictive advance adjustment: If the overall temperature index change rate Then predictive control is activated, simultaneously increasing both speed and pressure commands:

[0120] , ,in, The critical rate of increase threshold. , This is the advance adjustment coefficient. If multiple corrections are triggered simultaneously, the maximum value among the correction results is taken as the final instruction.

[0121] Step Six: Control Command Output and Closed-Loop Iteration: Output the target speed command for drive motor 43 generated in Step Five. and circulating pump 61 target pressure command Send to the actuator driver and status feedback unit, waiting for a preset control cycle. (Typical values ​​range from 100 milliseconds to 1 second) After that, return to step one and start a new round of calculation and control based on the latest sensor data, thereby achieving continuous adaptive closed-loop dynamic heat dissipation management.

[0122] The actuator drive and status feedback unit is connected to the intelligent heat dissipation control unit, the drive motor of the drive device, and an external circulating pump 61. It is used to drive the drive motor 43 and the circulating pump 61 according to the control command and to provide feedback on their working status.

[0123] Specifically, the actuator drive and status feedback unit includes a drive motor drive control module and a circulating pump pressure closed-loop control module;

[0124] The drive motor control module is used to receive speed commands from the intelligent heat dissipation control unit, drive the drive motor 43 to operate, and provide real-time feedback on the motor's speed, current and operating status.

[0125] The circulating pump pressure closed-loop control module is used to receive pressure / flow commands, adjust the working power of the circulating pump 61, and monitor and provide feedback on the actual pressure or flow value of the hydraulic circuit in real time, forming a closed-loop control.

[0126] The system monitoring and early warning unit is connected to the intelligent heat dissipation control unit and other units for fault diagnosis and safety warning.

[0127] Specifically, the system monitoring and early warning unit includes a fault diagnosis module and an early warning indication module;

[0128] The fault diagnosis module is used to monitor faults such as sensor open circuit / short circuit, actuator communication timeout, or command execution abnormality, and generate fault codes;

[0129] The warning indicator module is used to trigger an audible and visual alarm via local indicator lights, displays, or the vehicle bus when the temperature at any monitoring point exceeds a preset safety threshold or when a system malfunction occurs, and to send warning information to a higher-level vehicle controller.

[0130] Working principle: Step 1: Multi-domain temperature sensing and status monitoring

[0131] The multi-domain sensor array (including differential temperature sensor, gear temperature sensor, bearing temperature sensor, and hydraulic oil temperature sensor) starts working and collects the temperature simulation signals of each key heat source domain inside the axle housing 1 (differential housing 2, gear meshing area, bearing position, and oil sump).

[0132] The signal acquisition and processing module filters, amplifies, and performs analog-to-digital conversion on the above multiple raw signals, outputs a set of stable digital temperature values ​​that characterize the current thermal state, and sends them to the intelligent heat dissipation control unit.

[0133] Meanwhile, the fault diagnosis module of the system monitoring and early warning unit continuously monitors the effectiveness and communication status of each sensor signal;

[0134] Step 2: Intelligent Decision Making and Dynamic Control Command Generation: The core control module of the intelligent heat dissipation control unit receives temperature data.

[0135] The dynamic heat dissipation algorithm module is activated and executes the following logic:

[0136] Data fusion: Calculating the comprehensive temperature index and thermal imbalance .

[0137] Status assessment: , and the temperature rise rate at each point and the preset threshold ( , , , , By comparing and dynamically classifying the current heat load level, (Levels 0 to 4).

[0138] Instruction mapping and modification: based on level Query the basic mapping table to obtain the basic speed of the drive motor 43. and the basic pressure of the circulating pump 61 Subsequently, based on the local hot spot temperature difference and the overall temperature rise trend, fine-tuning is performed to generate the final target speed command for the drive motor 43. and circulating pump 61 target pressure command If any temperature data exceeds the safety threshold If a fault is diagnosed, the warning indication module of the system monitoring and early warning unit will immediately trigger local and remote alarms.

[0139] Step 3: Actuator driving and heat dissipation actions are executed.

[0140] The actuator drive and status feedback unit receives control commands from the intelligent heat dissipation control unit. , The drive motor drive control module is based on The corresponding PWM signal is output to drive the drive motor 43 located inside the drive housing 4 in the drive device to rotate. The output shaft of the drive motor 43 drives the rotating frame 44 to rotate. The circulating pump pressure closed-loop control module controls the rotation according to the signal output. Adjust the motor power or valve opening of the circulating pump 61 in the hydraulic circulation subsystem.

[0141] Mechanical transmission and heat dissipation:

[0142] The rotation of the drive motor 43 is transmitted to the lifting gear 45, which is hinged to it, through the rotating frame 44. Since the lifting gear 45 meshes with the fixed gear ring 42, it is forced to rotate while revolving, thereby driving the lifting sleeve 54 to generate axial reciprocating motion in the rotating sleeve 5 through the pin shaft. The reciprocating motion of the lifting sleeve 54 is converted into the reciprocating rotation motion of the rotating sleeve 5 through the engagement of the column on it with the arc-shaped threaded groove 53 on the inner wall of the rotating sleeve 5. The reciprocating rotation of the rotating sleeve 5 is driven by the engagement of the drive bevel gear 52 at its end with the arc-shaped bevel gear ring 51 fixed on the heat dissipation ring assembly 32, and finally drives the entire heat dissipation ring assembly 32 (including two heat dissipation ring pipes, connecting pipes and multiple nozzles) to perform a large-angle reciprocating rotation scanning motion in the limiting sleeve 3, supported by the ball bearings 31.

[0143] Hydraulic jet cooling:

[0144] One circulating pump 61 pumps cooling oil from the oil reservoir 6. One path, via a three-way valve, is used to replenish and cool the oil sump of the axle housing 1 through the connecting pipe inlet valve 25. The other path is used to deliver the oil to the reciprocating cooling ring assembly 32 through the delivery pipe 62, the rotating sealing folding sleeve 63, the lifting sleeve 54, and the hose. Under pressure, the cooling oil is atomized or jetted from multiple nozzles (with one-way valves) distributed on the cooling ring assembly 32. Another circulating pump 61 draws hot oil from the oil sump of the axle housing 1, filters it, and after being cooled by the radiator, it is delivered back into the axle housing 1 through the inlet valve 25. This provides uniform and active spray cooling to the braking components such as the differential 2, driven gear 23, and drive gear 21 bearings within the rotational scanning range. The hot oil, after absorbing heat, is discharged through the drain valve 24, filtered, and returned to the inlet of the circulating pump 61, completing one cooling cycle.

[0145] Step 4: State Feedback and Closed-Loop Adjustment

[0146] The actuator drive and status feedback unit collects the actual speed and current of the drive motor 43 and the actual pressure of the hydraulic circuit in real time, and sends these status feedback signals back to the intelligent heat dissipation control unit. The intelligent heat dissipation control unit compares the actual status feedback from the actuator with the target command, evaluates the control effect, and dynamically adjusts the control command in the next control cycle by combining the latest collected temperature data (returning to step one), thereby achieving continuous adaptive and closed-loop optimization control.

[0147] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A wet rear axle control system with multi-domain temperature sensing and dynamic heat dissipation, comprising an axle housing (1), characterized in that: The axle housing (1) is provided with a braking component, which includes a differential (2) and is located inside the axle housing (1). The bridge housing (1) is provided with a heat dissipation component inside, which dissipates heat from the braking component. The heat dissipation component includes a heat dissipation device and a drive device. The heat dissipation device includes a heat dissipation ring group (32). The heat dissipation ring group (32) sprays hydraulic oil to dissipate heat from the internal braking component. The drive device includes a rotating sleeve (5). The rotation of the rotating sleeve (5) drives the heat dissipation ring group (32) to reciprocate. The heat dissipation device also includes a limiting sleeve (3), which is fixedly installed on the inner wall of the bridge housing (1). A ball bearing (31) is rotatably connected to the inner wall of the limiting sleeve (3). The outer surface of the heat dissipation ring assembly (32) is slidably inserted into the inner wall of the limiting sleeve (3). The outer surface of the ball bearing (31) is in contact with the outer surface of the heat dissipation ring assembly (32). The heat dissipation ring assembly (32) includes two heat dissipation annular pipes, a connecting pipe, and a nozzle with a one-way valve. The two heat dissipation annular pipes are connected to each other through the connecting pipe. The outer surfaces of the connecting pipe and the heat dissipation annular pipes are both fixedly connected to one end of the nozzle. It also includes a detection system, which comprises a multi-domain temperature sensing unit, an intelligent heat dissipation control unit, an actuator drive and status feedback unit, and a system monitoring and early warning unit.

2. The wet rear axle control system with multi-domain temperature sensing and dynamic heat dissipation according to claim 1, characterized in that: The braking component also includes a drive gear (21), which is rotatably connected to the inner wall of the axle housing (1) via a bearing. The inner wall of the axle housing (1) is rotatably connected to a half shaft (22) via a bearing. The outer shell of the differential (2) is fixedly mounted with a driven gear (23), which meshes with the drive gear (21). One end of each of the two half shafts (22) meshes with the side gear of the differential (2). The outer surface of the axle housing (1) is fixedly connected to an oil drain valve (24) and an oil inlet valve (25).

3. A wet rear axle control system with multi-domain temperature sensing and dynamic heat dissipation according to claim 2, characterized in that: The drive device also includes a drive housing (4), the outer surface of which is fixedly installed to the outer surface of the bridge housing (1) by bolts. An annular support frame (41) is fixedly installed on the inner wall of the drive housing (4), and a fixed gear ring (42) is fixedly installed on the inner wall of the annular support frame (41). A drive motor (43) is fixedly installed on the inner wall of the drive housing (4), and a rotating frame (44) is fixedly installed at one end of the output shaft of the drive motor (43). A lifting gear (45) is rotatably connected to the outer surface of the rotating frame (44) through a bearing, and the lifting gear (45) meshes with the fixed gear ring (42).

4. A wet rear axle control system with multi-domain temperature sensing and dynamic heat dissipation according to claim 3, characterized in that: The inner wall of the drive housing (4) is rotatably connected to one end of the rotating sleeve (5) through a bearing. One end of the rotating sleeve (5) extends into the interior of the bridge housing (1). An arc-shaped bevel gear ring (51) is fixedly installed on the outer surface of the heat dissipation ring assembly (32). A drive bevel gear (52) is fixedly installed on one end of the rotating sleeve (5). The drive bevel gear (52) meshes with the arc-shaped bevel gear ring (51). An arc-shaped threaded groove (53) is opened on the inner wall of the rotating sleeve (5). A lifting sleeve (54) is slidably inserted into the inner wall of the rotating sleeve (5). One end of the lifting sleeve (54) is slidably inserted into the inner wall of the arc-shaped threaded groove (53) through a column. One end of the lifting sleeve (54) is hinged to the outer surface of the lifting gear (45) through a pin.

5. A wet rear axle control system with multi-domain temperature sensing and dynamic heat dissipation according to claim 4, characterized in that: A hydraulic circulation subsystem is provided outside the drive housing (4). The hydraulic circulation subsystem includes an oil reservoir (6). The oil reservoir (6) is placed outside the drive housing (4). Two circulation pumps (61) are placed on the outer surface of the oil reservoir (6). The oil inlet of one circulation pump (61) is fixedly connected to the inner wall of the oil reservoir (6). One end of the oil outlet of the circulation pump (61) is fixedly connected to a delivery pipe (62) through a three-way valve. One end of the oil outlet of the other circulation pump (61) is fixedly connected to one end of the oil inlet valve (25) through a connecting pipe. The connecting pipe is fixedly connected to one end of the three-way valve. The oil inlet of the circulating pump (61) is fixedly connected to one end of the oil drain valve (24) through a filter and a radiator. One end of the conveying pipe (62) is fixedly installed on the inner wall of the lifting sleeve (54). One end of the conveying pipe (62) is fixedly connected to the outer surface of the heat dissipation ring assembly (32) through a hose. The lower end of the rotating sleeve (5) is rotatably connected to a sealing folding sleeve (63). One end of the sealing folding sleeve (63) is fixedly installed on one end of the conveying pipe (62).

6. A wet rear axle control system with multi-domain temperature sensing and dynamic heat dissipation according to claim 5, characterized in that: The multi-domain temperature sensing unit includes a multi-domain sensor array and a signal acquisition and processing module; The multi-domain sensor array includes a differential temperature sensor, a gear temperature sensor, a bearing temperature sensor, and a hydraulic oil temperature sensor, which are used to collect temperature data of different heat source domains inside the rear axle in real time. The sensor probe of the differential temperature sensor is closely attached to a selected temperature measurement point on the outer surface of the differential (2) housing. The gear temperature sensor is installed on the housing near the back bearing seat of the driven gear (23) to indirectly monitor heat conduction in the meshing area; The bearing temperature sensor is installed on the outer surface of the bearing housing near the outer ring bearing area of ​​the bearing of the drive gear (21) and the bearing of the differential (2); The hydraulic oil temperature sensor is installed in the oil sump at the bottom of the axle housing (1); The signal acquisition and processing module is used to filter, amplify, and convert analog-to-digital signals from multiple sensors to output a stable digital temperature signal.

7. A wet rear axle control system with multi-domain temperature sensing and dynamic heat dissipation according to claim 6, characterized in that: The intelligent heat dissipation control unit includes a core control module and a dynamic heat dissipation algorithm module; The core control module receives temperature data from the multi-domain temperature sensing unit and executes control logic; The dynamic heat dissipation algorithm module is used to calculate the real-time heat load level based on the fused multi-domain temperature data, and dynamically generate speed / reciprocating frequency control commands for the drive motor (43) and output pressure / flow control commands for the circulating pump (61) through the built-in heat dissipation strategy mapping model, so as to realize precise and adaptive adjustment of heat dissipation intensity and range.

8. A wet rear axle control system with multi-domain temperature sensing and dynamic heat dissipation according to claim 7, characterized in that: The actuator drive and status feedback unit includes a drive motor drive control module and a circulating pump pressure closed-loop control module. The drive motor drive control module is used to receive speed commands from the intelligent heat dissipation control unit, drive the drive motor (43) to operate, and provide real-time feedback on the motor speed, current and working status. The circulating pump pressure closed-loop control module is used to receive pressure / flow commands, adjust the working power of the circulating pump (61), and monitor and provide feedback on the actual pressure or flow value of the hydraulic circuit in real time to form a closed-loop control.

9. A wet rear axle control system with multi-domain temperature sensing and dynamic heat dissipation according to claim 8, characterized in that: The system monitoring and early warning unit includes a fault diagnosis module and an early warning indication module; The fault diagnosis module is used to monitor sensor open circuit / short circuit, actuator communication timeout or instruction execution abnormality, and generate fault codes; The warning indication module is used to trigger an audible and visual alarm via a local indicator light, display screen, or vehicle bus when the temperature at any monitoring point exceeds a preset safety threshold or when a system malfunction occurs, and to send warning information to a higher-level vehicle controller.

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