Power loss analysis method and device for vehicle comprehensive transmission
阅读说明：本技术 一种用于车辆综合传动的功率损失分析方法和装置 (Power loss analysis method and device for vehicle comprehensive transmission ) 是由 吴维 高鑫 苑士华 李鑫勇 于 2021-09-02 设计创作，主要内容包括：本发明公开一种用于车辆综合传动的功率损失分析方法和装置,包括：划分综合传动工作模式；统计各个综合传动工作模式的使用占比,在占比较大的工作模式中选取频次较高的综合传动使用工况；根据所述综合传动使用工况下的功率损失部件及对应功率损失方式,得到工况参数和结构参数；对所述结构参数划分为主导参数、被动参数和需要协调的参数,分别对应于综合传动效率匹配优化的不同阶段。采用本发明的技术方案,可以针对综合传动不同工作模式下功率损失的差异,实现所有工作模式的适用。(The invention discloses a power loss analysis method and a device for vehicle comprehensive transmission, which comprises the following steps: dividing a comprehensive transmission working mode; counting the use ratio of each comprehensive transmission working mode, and selecting a comprehensive transmission use working condition with higher frequency in the working modes with larger ratio; obtaining working condition parameters and structural parameters according to the power loss component under the comprehensive transmission use working condition and the corresponding power loss mode; and dividing the structural parameters into a leading parameter, a passive parameter and a parameter needing coordination, and respectively corresponding to different stages of the comprehensive transmission efficiency matching optimization. By adopting the technical scheme of the invention, the application of all working modes can be realized aiming at the difference of power loss under different working modes of comprehensive transmission.)
1. A power loss analysis method for a vehicle integrated transmission, comprising:
step S1, dividing the comprehensive transmission working mode
S2, counting the use ratio of each comprehensive transmission working mode, and selecting the comprehensive transmission use working condition with higher frequency in the working mode with larger ratio;
step S3, obtaining working condition parameters and structural parameters according to components contained in the power loss under the comprehensive transmission use working condition and the corresponding power loss mode;
and step S4, dividing the structural parameters into a leading parameter, a passive parameter and a parameter needing coordination, and respectively corresponding to different stages of the comprehensive transmission efficiency matching optimization.
2. A power loss analysis method for an integrated transmission for a vehicle as claimed in claim 1, wherein the integrated transmission operating mode comprises: a straight-driving mechanical mode, a straight-driving hydraulic mode, a straight-driving steering mechanical mode, a straight-driving steering hydraulic mode, a center steering mechanical mode, a center steering hydraulic mode, a neutral mechanical mode, and a neutral hydraulic mode.
3. The method of claim 1 wherein the integrated transmission use conditions include engine speed, gear and lubricant temperature to characterize input and output power and operating conditions of each transmission of the integrated transmission system.
4. A power loss analysis method for an integrated transmission of a vehicle according to claim 1, wherein the power loss containing means includes: the device comprises a front transmission, a hydraulic element, a clutch, a brake, a control lubrication hydraulic system, a steering pump motor, a planetary mechanism, an oil seal and a dynamic seal; wherein, the power loss mode of the front drive comprises the following steps: gear meshing loss, gear oil stirring loss, sealing friction loss and bearing friction loss; the power loss mode of the hydraulic element comprises the following steps: flow loss, mechanical loss, oil churning loss, lockup clutch band loss; the power loss mode of the planetary mechanism comprises the following steps: gear engagement loss, gear and other oil stirring loss, seal friction loss and bearing friction loss; the power loss mode of the dynamic seal comprises the following steps: friction and churning losses, leakage losses; the method for controlling the power loss of the lubrication hydraulic system comprises the following steps: volumetric mechanical losses, valve and line leakage losses, flow resistance losses, throttling losses, overflow losses; the power loss modes of the clutch and the brake comprise: friction loss, belt row loss, slip loss; the power loss mode of the steering pump motor comprises the following steps: mechanical loss of a pump motor, leakage loss of the pump motor, power loss of an oil supplementing pump, overflow loss of a constant pressure valve and oil stirring loss; the power loss mode of the oil seal comprises the following steps: friction and churning losses.
5. The power loss analysis method for an integrated transmission of a vehicle according to claim 1, wherein the operating condition parameters describe an operating environment and an operating state of the integrated transmission, including an input rotation speed, a torque, a temperature, an operating mode, a gear, an oil parameter, and a depth of oil immersion; the structural parameters describe relevant parameters of parts participating in comprehensive transmission, and the parts comprise gears, bearings, clutches, pump motors, hydraulic elements and sealing rings; relevant parameters of the gear include: tooth number, modulus, tooth width, material parameters; relevant parameters of the bearing include: pitch circle diameter, roller size, roller number, material parameters, bearing width; relevant parameters of the clutch include: inner and outer diameters, friction pair number, friction pair clearance, material parameters and surface groove type; relevant parameters of the pump motor include: cylinder size, plunger size, displacement, material parameters; relevant parameters of the hydraulic element include: overall dimension, blade dimension, circle dimension, circumferential spacing, material parameters; relevant parameters of the seal ring include: inner and outer diameters, working pressure, dimensional tolerance, material parameters and groove type.
6. A power loss analyzing apparatus for a vehicle integrated transmission, characterized by comprising:
the dividing module is used for dividing the comprehensive transmission working mode;
the selection module is used for counting the use ratio of each comprehensive transmission working mode and selecting the comprehensive transmission use working condition with higher frequency in the working mode with larger ratio;
the analysis module is used for obtaining working condition parameters and structural parameters according to components contained in the power loss under the comprehensive transmission use working condition and the corresponding power loss mode;
and the classification module is used for dividing the structural parameters into dominant parameters, passive parameters and parameters needing coordination, and respectively corresponds to different stages of comprehensive transmission efficiency matching optimization.
7. A power loss analysis apparatus for an integrated transmission for a vehicle as claimed in claim 6, wherein the integrated transmission operating mode comprises: a straight-driving mechanical mode, a straight-driving hydraulic mode, a straight-driving steering mechanical mode, a straight-driving steering hydraulic mode, a center steering mechanical mode, a center steering hydraulic mode, a neutral mechanical mode, and a neutral hydraulic mode.
8. The power loss analysis apparatus for an integrated transmission of a vehicle of claim 6, wherein the integrated transmission use conditions include engine speed, gear and lubricant temperature to characterize input and output power and operating conditions of each transmission of the integrated transmission system.
9. A power loss analyzing apparatus for an integrated transmission of a vehicle as set forth in claim 6, wherein the power loss containing means includes: the device comprises a front transmission, a hydraulic element, a clutch, a brake, a control lubrication hydraulic system, a steering pump motor, a planetary mechanism, an oil seal and a dynamic seal; wherein, the power loss mode of the front drive comprises the following steps: gear meshing loss, gear oil stirring loss, sealing friction loss and bearing friction loss; the power loss mode of the hydraulic element comprises the following steps: flow loss, mechanical loss, oil churning loss, lockup clutch band loss; the power loss mode of the planetary mechanism comprises the following steps: gear engagement loss, gear and other oil stirring loss, seal friction loss and bearing friction loss; the power loss mode of the dynamic seal comprises the following steps: friction and churning losses, leakage losses; the method for controlling the power loss of the lubrication hydraulic system comprises the following steps: volumetric mechanical losses, valve and line leakage losses, flow resistance losses, throttling losses, overflow losses; the power loss modes of the clutch and the brake comprise: friction loss, belt row loss, slip loss; the power loss mode of the steering pump motor comprises the following steps: mechanical loss of a pump motor, leakage loss of the pump motor, power loss of an oil supplementing pump, overflow loss of a constant pressure valve and oil stirring loss; the power loss mode of the oil seal comprises the following steps: friction and churning losses.
10. The power loss analysis apparatus for an integrated transmission of a vehicle according to claim 6, wherein the operating condition parameters describe an operating environment and an operating state of the integrated transmission, including an input rotation speed, a torque, a temperature, an operating mode, a gear, an oil parameter, and a depth of oil immersion; the structural parameters describe relevant parameters of parts participating in comprehensive transmission, and the parts comprise gears, bearings, clutches, pump motors, hydraulic elements and sealing rings; relevant parameters of the gear include: tooth number, modulus, tooth width, material parameters; relevant parameters of the bearing include: pitch circle diameter, roller size, roller number, material parameters, bearing width; relevant parameters of the clutch include: inner and outer diameters, friction pair number, friction pair clearance, material parameters and surface groove type; relevant parameters of the pump motor include: cylinder size, plunger size, displacement, material parameters; relevant parameters of the hydraulic element include: overall dimension, blade dimension, circle dimension, circumferential spacing, material parameters; relevant parameters of the seal ring include: inner and outer diameters, working pressure, dimensional tolerance, material parameters and groove type.
Technical Field
The invention belongs to the technical field of vehicle transmission, and particularly relates to a power loss analysis method and device for vehicle comprehensive transmission.
Background
The power loss is one of important parameters of the service performance of a transmission system, which not only causes the waste of the output power of an engine, but also causes the rise of oil temperature, and influences the working efficiency and the service life of a transmission part, thereby influencing the performance of the whole vehicle. At present, most of the traditional power loss analysis methods separately calculate the transmission efficiency of each component from the perspective of a transmission component, and finally multiply to obtain the efficiency of a transmission system. From the opposite perspective, one considers the transmission system and divides the system into a plurality of assemblies according to functions, and the power loss of each component in the assemblies is calculated by a traditional method. However, the tracked vehicle adopting the comprehensive transmission needs to adapt to various different working conditions, and the working modes need to be switched under different working conditions. Both analysis methods default that power loss exists in all parts in the comprehensive transmission, the difference of parts participating in work in different working modes is not considered, and the difference of loss types of the same part in different modes is not considered, so that the method cannot be applied to all working modes and has limitation.
Disclosure of Invention
The invention aims to solve the technical problem of providing a power loss analysis method and a power loss analysis device for vehicle comprehensive transmission, aiming at the difference of power loss in different working modes of the comprehensive transmission and realizing the applicability of all the working modes.
In order to achieve the purpose, the invention adopts the following technical scheme:
a power loss analysis method for a vehicle integrated transmission, comprising:
step S1, dividing the comprehensive transmission working mode
S2, counting the use ratio of each comprehensive transmission working mode, and selecting the comprehensive transmission use working condition with higher frequency in the working mode with larger ratio;
step S3, obtaining working condition parameters and structural parameters according to components contained in the power loss under the comprehensive transmission use working condition and the corresponding power loss mode;
and step S4, dividing the structural parameters into a leading parameter, a passive parameter and a parameter needing coordination, and respectively corresponding to different stages of the comprehensive transmission efficiency matching optimization.
Preferably, the integrated transmission operating modes include: a straight-driving mechanical mode, a straight-driving hydraulic mode, a straight-driving steering mechanical mode, a straight-driving steering hydraulic mode, a center steering mechanical mode, a center steering hydraulic mode, a neutral mechanical mode, and a neutral hydraulic mode.
Preferably, the comprehensive transmission use conditions comprise engine speed, gear and lubricating oil temperature so as to represent input and output power and operation states of each transmission element of the comprehensive transmission system.
Preferably, the power loss-containing components include: the device comprises a front transmission, a hydraulic element, a clutch, a brake, a control lubrication hydraulic system, a steering pump motor, a planetary mechanism, an oil seal and a dynamic seal; wherein, the power loss mode of the front drive comprises the following steps: gear meshing loss, gear oil stirring loss, sealing friction loss and bearing friction loss; the power loss mode of the hydraulic element comprises the following steps: flow loss, mechanical loss, oil churning loss, lockup clutch band loss; the power loss mode of the planetary mechanism comprises the following steps: gear engagement loss, gear and other oil stirring loss, seal friction loss and bearing friction loss; the power loss mode of the dynamic seal comprises the following steps: friction and churning losses, leakage losses; the method for controlling the power loss of the lubrication hydraulic system comprises the following steps: volumetric mechanical losses, valve and line leakage losses, flow resistance losses, throttling losses, overflow losses; the power loss modes of the clutch and the brake comprise: friction loss, belt row loss, slip loss; the power loss mode of the steering pump motor comprises the following steps: mechanical loss of a pump motor, leakage loss of the pump motor, power loss of an oil supplementing pump, overflow loss of a constant pressure valve and oil stirring loss; the power loss mode of the oil seal comprises the following steps: friction and churning loss
Preferably, the working condition parameters describe the working environment and the running state of the comprehensive transmission, and comprise input rotating speed, torque, temperature, working mode, gear, oil parameters and oil immersion depth; the structural parameters describe relevant parameters of parts participating in comprehensive transmission, and the parts comprise gears, bearings, clutches, pump motors, hydraulic elements and sealing rings; relevant parameters of the gear include: tooth number, modulus, tooth width, material parameters; relevant parameters of the bearing include: pitch circle diameter, roller size, roller number, material parameters, bearing width; relevant parameters of the clutch include: inner and outer diameters, friction pair number, friction pair clearance, material parameters and surface groove type; relevant parameters of the pump motor include: cylinder size, plunger size, displacement, material parameters; relevant parameters of the hydraulic element include: overall dimension, blade dimension, circle dimension, circumferential spacing, material parameters; relevant parameters of the seal ring include: inner and outer diameters, working pressure, dimensional tolerance, material parameters and groove type.
The present invention also provides a power loss analysis apparatus for a vehicle integrated transmission, comprising:
the dividing module is used for dividing the comprehensive transmission working mode;
the selection module is used for counting the use ratio of each comprehensive transmission working mode and selecting the comprehensive transmission use working condition with higher frequency in the working mode with larger ratio;
the analysis module is used for obtaining working condition parameters and structural parameters according to components contained in the power loss under the comprehensive transmission use working condition and the corresponding power loss mode;
and the classification module is used for dividing the structural parameters into dominant parameters, passive parameters and parameters needing coordination, and respectively corresponds to different stages of comprehensive transmission efficiency matching optimization.
Preferably, the integrated transmission operating modes include: a straight-driving mechanical mode, a straight-driving hydraulic mode, a straight-driving steering mechanical mode, a straight-driving steering hydraulic mode, a center steering mechanical mode, a center steering hydraulic mode, a neutral mechanical mode, and a neutral hydraulic mode.
Preferably, the comprehensive transmission use conditions comprise engine speed, gear and lubricating oil temperature so as to represent input and output power and operation states of each transmission element of the comprehensive transmission system.
Preferably, the power loss-containing components include: the device comprises a front transmission, a hydraulic element, a clutch, a brake, a control lubrication hydraulic system, a steering pump motor, a planetary mechanism, an oil seal and a dynamic seal; wherein, the power loss mode of the front drive comprises the following steps: gear meshing loss, gear oil stirring loss, sealing friction loss and bearing friction loss; the power loss mode of the hydraulic element comprises the following steps: flow loss, mechanical loss, oil churning loss, lockup clutch band loss; the power loss mode of the planetary mechanism comprises the following steps: gear engagement loss, gear and other oil stirring loss, seal friction loss and bearing friction loss; the power loss mode of the dynamic seal comprises the following steps: friction and churning losses, leakage losses; the method for controlling the power loss of the lubrication hydraulic system comprises the following steps: volumetric mechanical losses, valve and line leakage losses, flow resistance losses, throttling losses, overflow losses; the power loss modes of the clutch and the brake comprise: friction loss, belt row loss, slip loss; the power loss mode of the steering pump motor comprises the following steps: mechanical loss of a pump motor, leakage loss of the pump motor, power loss of an oil supplementing pump, overflow loss of a constant pressure valve and oil stirring loss; the power loss mode of the oil seal comprises the following steps: friction and churning losses.
Preferably, the working condition parameters describe the working environment and the running state of the comprehensive transmission, and comprise input rotating speed, torque, temperature, working mode, gear, oil parameters and oil immersion depth; the structural parameters describe relevant parameters of parts participating in comprehensive transmission, and the parts comprise gears, bearings, clutches, pump motors, hydraulic elements and sealing rings; relevant parameters of the gear include: tooth number, modulus, tooth width, material parameters; relevant parameters of the bearing include: pitch circle diameter, roller size, roller number, material parameters, bearing width; relevant parameters of the clutch include: inner and outer diameters, friction pair number, friction pair clearance, material parameters and surface groove type; relevant parameters of the pump motor include: cylinder size, plunger size, displacement, material parameters; relevant parameters of the hydraulic element include: overall dimension, blade dimension, circle dimension, circumferential spacing, material parameters; relevant parameters of the seal ring include: inner and outer diameters, working pressure, dimensional tolerance, material parameters and groove type.
The power loss analysis method and the power loss analysis device provided by the invention aim at the difference of power loss under different working modes of comprehensive transmission, and realize the applicability of all working modes. On one hand, the invention considers the difference of the parts participating in the work under different working conditions and the loss types thereof, so that the power loss calculation is more accurate; on the other hand, the power loss type is divided according to each stage of vehicle design, and a foundation is laid for efficiency improvement work.
Drawings
FIG. 1 is a flow chart of a power loss analysis method for a vehicle integrated drive according to the present invention;
FIG. 2 is a schematic structural diagram of a power loss analyzing apparatus for a vehicle integrated transmission according to the present invention;
FIG. 3 is a schematic diagram of the vehicle integrated transmission.
Detailed Description
To better illustrate the objects and advantages of the present invention, the following further description is made with reference to the accompanying drawings and examples.
The invention provides a power loss analysis method for vehicle integrated transmission, which comprises the following steps:
step S1, dividing the comprehensive transmission working mode
The overall transmission is divided into 8 operating modes based on the direction of travel, transmission mode and gear, depending on the usage of the overall transmission, in combination with the power flow characteristics and loss patterns in the different power flow paths. The method specifically comprises the following steps: the straight driving and steering functions in the comprehensive transmission are respectively controlled by the straight driving branch and the steering branch, so that the vehicle has more steering modes, and power flow paths in different driving directions are different, so that the driving directions need to be distinguished when the working modes are divided. Compared with the traditional mechanical transmission, the hydraulic torque converter is added into the comprehensive transmission system, and the smoothness of the vehicle is improved. The power flow path is different between when the torque converter is in operation and when the torque converter is locked.
The comprehensive transmission working modes are divided into the following 8 types, as shown in table 1:
TABLE 1 Integrated Transmission operating modes
Step two, selecting the comprehensive transmission use working condition
And counting the use ratio of each working mode, and selecting the comprehensive transmission use working condition with higher frequency in the working modes with larger ratio.
The frequency ratio calculation method comprises the following steps:
the frequency ratio of each working mode is expressed as the average power of each mode multiplied by the time sequence, and the calculation formula is as follows:
wherein R isiRatio of frequency, PiMean power, tiRefers to the time that the pattern is used.
The average power calculation method of various working modes is different, and the formula is as follows:
straight-driving mechanical mode and straight-driving hydraulic mode:
the ground running resistance borne by the tracks on the two sides is as follows:
wherein f is the road surface deformation resistance coefficient; g is the gravity of the whole vehicle and the unit is N.
The average power is obtained by multiplying the running resistance and the average speed:
wherein P is the average power in kW; v is the average vehicle speed in km/h.
Straight-driving steering mechanical mode and straight-driving steering hydraulic mode:
the ground running resistance borne by the tracks on the two sides is respectively as follows:
wherein μ is the steering resistance coefficient; l is the grounding length of the crawler belt and is unit m; and B is the center distance of the crawler belt in m.
The average power is:
in differential-type integrated transmission, the steering kinematic coefficient qk＝0
Relative turning radius
Where R is the turning radius in m.
Center steering mechanical mode and center steering hydraulic mode:
where v is 0 and ρ is 0
Neutral mechanical mode and neutral hydraulic mode:
the power is not output from the wheels in neutral and the average power is expressed as the average power at the output of the engine.
Wherein T iseIs the engine output torque, in Nm; n iseIs the engine output speed in rpm.
In the working mode with larger ratio, the same method is used for selecting the comprehensive transmission working condition with higher frequency.
The comprehensive transmission use working condition comprises the engine speed, the gear and the lubricating oil temperature so as to represent the input and output power and the running state of each transmission part of the comprehensive transmission system.
For example, the operating conditions of the straight-driving steering mechanical mode are shown in table 2, and the operating ratios of the operating conditions of the straight-driving steering mechanical mode in table 2
Step three, power loss classification based on simulation result
And analyzing the related parameter types based on different power loss types and components, and extracting working condition parameters and structural parameters.
The method comprises the steps of firstly analyzing parts contained in the comprehensive transmission power loss, wherein the parts comprise 8 parts, namely a front transmission part, a hydraulic element, a clutch and a brake part, a control lubrication hydraulic system, a steering pump motor, a planetary mechanism, an oil seal and a dynamic seal. And respectively analyzing power loss modes of all parts, such as flow loss and oil stirring loss of a hydraulic element, gear meshing loss of a planetary mechanism and 28 power loss modes in total. The 28 power loss modes are classified into 4 major categories according to types: mechanical friction loss, oil churning loss, hydraulic loss and power extraction, wherein the mechanical friction loss can be divided into rolling friction loss and sliding friction loss according to the friction principle, and the hydraulic loss can be divided into flow resistance loss and hydraulic leakage loss according to the flow direction, and the total of the types of the mechanical friction loss, the oil churning loss, the hydraulic loss and the power extraction are 4 types and 6 types of the power loss. As shown in table 3.
TABLE 3 Power loss modes
The parameters involved in power loss are divided into two categories based on different power loss types and components: working condition parameters and structural parameters. The working condition parameters mainly describe the working environment and the running state of the comprehensive transmission, and comprise input rotating speed, torque, temperature, working mode, gear, oil parameters and oil immersion depth; the structural parameters are related to parts participating in comprehensive transmission, and specifically, as shown in table 4, the total number of the parts is 6, and 28 structural parameters are provided.
TABLE 4 structural parameters
Step four, power loss analysis based on working conditions
And obtaining working condition parameters and structural parameters according to components contained in the power loss under the comprehensive transmission use working condition with high frequency and the corresponding power loss mode.
Firstly, selecting a comprehensive transmission using working condition with higher frequency in a larger working mode, such as a working condition of six gears, a rotating speed of 2200r/min and a temperature of 90 ℃ in a direct driving mechanical mode. And then analyzing the power loss component and the corresponding power loss mode under the working condition, if the steering branch of the integrated transmission does not work under the straight-driving mechanical mode, the hydraulic torque converter is locked, so that the flow loss and the mechanical loss of the hydraulic torque converter and the leakage loss and the overflow loss of a steering pump motor do not exist.
After analyzing the power loss parts and the working modes of the parts under the working conditions, the parameter system can be analyzed from two layers of the working conditions and the structure. From the aspect of the working condition parameters, the working condition parameters under different working modes are different, for example, the straight-driving mechanical mode is suitable for several high gears, and the neutral mechanical mode is only suitable for neutral. And in terms of structural parameters, each power loss component is divided into the parts at the bottommost layer, the same parts are recombined, and the power loss parameters of the parts are analyzed. If the planetary speed change mechanism and the front transmission both have gears, the influence parameters of the gear power loss under the working condition can be analyzed uniformly.
Step five, classifying power loss based on working conditions
The structural parameters are divided into leading parameters, passive parameters and parameters needing coordination, and the leading parameters, the passive parameters and the parameters correspond to different stages of comprehensive transmission efficiency matching optimization respectively.
The structural parameters are divided into three categories: dominant parameters, passive parameters, and parameters that require coordination. The passive parameters refer to parameters that cannot be adjusted after the parts are machined, such as the number of teeth and the modulus of the gear, and need to be determined in the design stage of the comprehensive transmission so as to achieve the goal of improving the efficiency of the transmission system. The parameters to be coordinated refer to parameters determined by the installation position and relative movement among a plurality of parts, such as the circumferential spacing of hydraulic elements and the clearance of a friction pair in the clutch, and can be adjusted in real time during the installation process. Active parameters refer to parameters that can still be adjusted during operation of the integrated drive train, such as the properties of the lubricating oil and the oil immersion area.
When the comprehensive transmission efficiency improvement is considered, parameters needing to be adjusted in different stages are different. Passive parameters need to be considered in the design and manufacturing stage of the parts, parameters needing to be adjusted are considered in the installation stage, and active parameters need to be considered in the use stage. The parameters considered for the three phases are also related to the operating conditions.
As shown in fig. 2, the present invention further provides a power loss analysis apparatus for vehicle integrated transmission, which implements the power loss analysis method, including:
the dividing module is used for dividing the comprehensive transmission working mode;
the selection module is used for counting the use ratio of each comprehensive transmission working mode and selecting the comprehensive transmission use working condition with higher frequency in the working mode with larger ratio;
the analysis module is used for obtaining working condition parameters and structural parameters according to components contained in the power loss under the comprehensive transmission use working condition and the corresponding power loss mode;
and the classification module is used for dividing the structural parameters into dominant parameters, passive parameters and parameters needing coordination, and respectively corresponds to different stages of comprehensive transmission efficiency matching optimization.
Example 1:
the original vehicle is a hydraulic mechanical six-gear comprehensive transmission. For the straight-driving steering hydraulic mode, the power flow is shown in fig. 3. The power is output by the engine to the bevel gear mechanism for reversing, and then is divided into two paths by the shunting mechanism. The straight branch is shown as a solid line, passes through the hydraulic torque converter, is output to the planetary speed change mechanism, and is output to the gear rings of the two-side confluence planetary rows. The steering branch is transmitted to the sun gear of the collector planet via the steering pump motor, as indicated by the dashed line. The power of the steering branch and the straight driving branch is output to the driving wheels on two sides from the planet carrier after being converged.
Step one, dividing comprehensive transmission working modes
From the two aspects of mechanical/hydraulic and straight driving/steering, the comprehensive transmission working mode can be divided into 8 types: the straight-driving mechanical mode, the straight-driving hydraulic mode, the straight-driving steering mechanical mode, the straight-driving steering hydraulic mode, the center steering mechanical mode, the center steering hydraulic mode, the neutral mechanical mode and the neutral hydraulic mode are specifically shown in table 1.
Step two, selection of comprehensive transmission typical working condition
Firstly, the use ratio conditions of 8 working modes are counted, and then the ratios of different working conditions in each mode are counted.
The straight-driving mechanical mode and the straight-driving steering mechanical mode are applied to high-speed driving with high requirements on environment, the specific working conditions are shown in table 5,
TABLE 5 behavior of the straight-driving mechanical mode and the straight-driving steering mechanical mode
Four-gear high oil temperature
Five-gear high oil temperature
Six-gear high oil temperature
Four-gear low oil temperature
Five-gear low oil temperature
Six-gear low oil temperature
The straight driving hydraulic mode and the straight driving steering hydraulic mode are applied to low-speed driving with low environmental requirements, the specific working conditions are shown in table 6,
TABLE 6 operating conditions of the straight-driving hydraulic mode and the straight-driving steering hydraulic mode
High oil temperature at first gear
Second, high oil temperature
Three-gear high oil temperature
Reverse gear, high oil temperature
First gear, low oil temperature
Second, low oil temperature
Three-gear low oil temperature
Reverse gear, low oil temperature
The remaining 4 operating modes have no requirements on the gear, the specific operating conditions are shown in table 7,
TABLE 7 operating conditions for center steering mode and neutral mode
Three operating conditions with higher frequency were selected to analyze the overall transmission power loss, as shown in table 8,
TABLE 8 typical conditions
Serial number
Mode of operation
Input rotational speed
Gear position
Temperature of
1
Straight-driving machine
2200r/min
6
90℃
2
Neutral gear machine
800r/min
N
-43℃
3
Center steering hydraulic
1500r/min
PT
90℃
Step three, classifying power loss influence parameters based on simulation results
The components involved in the integrated transmission power loss were first analyzed, including class 8: front transmission, hydraulic elements, clutches and brakes, control lubrication hydraulic system, steering pump motor, planetary mechanism, oil seal and dynamic seal. And analyzing the power loss mode of each part, taking the power loss of a hydraulic element as an example.
The hydraulic element comprises a hydraulic torque converter and a lockup clutch, and the power loss comprises: 1) loss of flow
Including frictional drag losses and localized drag losses.
Frictional drag losses are a factor affecting torque converter performance. The calculation formula is as follows:
wherein, lambda is the on-way resistance coefficient of each working wheel; l is the length of each runner; rnThe hydraulic diameter of the runner of the working wheel; v is the average relative speed of the running wheels. The on-way drag coefficient is primarily related to blade roughness and reynolds number.
In addition to this, the frictional resistance loss is also related to the flow state of the fluid. When the flow velocity is small, laminar flow is mainly realized, and the viscosity of oil is a main factor influencing the friction resistance; the flow velocity is mainly turbulent when the flow velocity is high, and the flow velocity is a main factor influencing the magnitude of the frictional resistance. The impact loss is the main component of the local resistance loss, and the calculation formula is as follows:
wherein h iscIs an impact loss energy head;is the impact loss coefficient; omegacIs the loss velocity on impact.
2) Mechanical loss
The mechanical loss of the oil liquid in the flowing process is the bearing and sealing loss of a pump wheel shaft, the friction loss of the outer surface of a working wheel and liquid and the like. The friction loss can be expressed as:
MYP＝λYPρR5ω2
wherein λ isYPThe disc friction coefficient is related to the parameter between the disc and the shell; rho is the density of the working liquid; r is the kinematic viscosity coefficient of the working liquid; ω is the relative angular velocity between the disc and the housing.
3) Volume loss
In order to ensure that the working wheels are not contacted with each other in the working process, certain space and gap exist between the inner rings of the upstream outlet and the downstream inlet in the circulating flow process of oil, and certain pressure difference exists in the gap, so that the oil flows out of the annular gap, and the volume loss is caused.
4) Lockup clutch band loss
Under the working condition of non-engagement, speed difference exists between the friction plates, and then belt row loss is caused. The belt row loss is mainly related to the friction plate structure and contact area, the friction coefficient and the relative speed of the pump wheel and the turbine wheel.
The power loss pattern of the 8-type integrated transmission components is shown in table 4, and is totally 28.
Step four, power loss analysis based on working conditions
Three using conditions in the table 8 are selected, and the power loss mode and the parameter type under the conditions are analyzed.
In the working condition 1, the hydraulic torque converter is locked, the pump impeller and the turbine integrally rotate, the power loss is irrelevant to the blades, but the oil stirring loss of the torque converter shell still exists. Meanwhile, the steering branch does not work, the leakage loss of a steering pump motor and the overflow loss of a constant pressure valve do not exist, and the power loss is irrelevant to the displacement.
Analysis shows that the power loss of the working condition 1 does not comprise flow loss of a hydraulic element, mechanical loss, band discharge loss of a lockup clutch, leakage loss and overflow loss of a steering pump motor, and covers 82% of component loss types and 100% of working condition parameters.
In the working condition 2, the hydraulic torque converter is locked, and only the oil stirring loss of the shell of the torque converter exists. The straight driving branch does not work, and the power loss of the planetary mechanism and the leakage loss of the dynamic seal do not exist. The clutches of all gears are separated, so that the sliding friction loss of the clutches does not exist, but the friction loss and the belt discharge loss of the friction plates and the oil still exist.
Analysis shows that the power loss of the working condition 2 does not comprise the flow loss of a hydraulic element, the mechanical loss and the belt row loss of a lockup clutch, the power loss of a planetary mechanism, the leakage loss of a dynamic seal and the slip loss of the clutch, and covers 68 percent of component loss types. Meanwhile, the gear of the working condition 2 is fixed to be N gear, and no torque is output from two sides, namely the working condition parameters of the working condition 2 do not include the gear and the torque, and only 71% of the working condition parameters are covered.
In the working condition 3, the straight driving branch does not work, and the power loss of a planetary mechanism and a dynamic seal does not exist. And the clutches of all gears are separated, so that the slipping loss of the clutches does not exist.
Analysis shows that the power loss of the working condition 3 does not comprise the power loss of a planetary mechanism, the power loss of a dynamic seal and the friction loss of a clutch, and covers 75% of component loss types. Meanwhile, the gear of the working condition 3 is fixed as a PT gear, and working condition parameters do not include gears and cover 86% of working condition parameters.
Step five, classifying power loss based on working conditions
Driveline efficiency is an important indicator in vehicle design. And dividing the parameters under the working conditions divided in the step four into three types, so that the efficiency improvement requirement of each stage of vehicle design can be met.
The passive parameters cannot be adjusted after the parts are machined, and need to be considered in the design and manufacturing stage of the parts, as shown in table 9.
TABLE 9 Passive parameters
Number of gear teeth
Size of cylinder
Inner and outer diameters of friction plate
Gear module
Plunger size
Number of friction pairs
Width of gear teeth
Discharge capacity
Friction plate surface groove type
Bearing pitch diameter
External dimension of torque converter
Inner and outer diameters of sealing ring
Bearing roller size
Size of blade
Dimensional tolerance of sealing ring
Number of bearing rollers
Size of circle
Sealing ring groove type
Bearing width
Parameters of the material
The parameters to be coordinated refer to parameters determined by the installation position and relative movement among a plurality of parts, and mainly comprise: the circumferential distance of the hydraulic elements, the clearance of a friction pair in the clutch and the like can be adjusted in real time in the installation stage.
The active parameters refer to parameters which can still be adjusted in the operation process of the comprehensive transmission system, are mainly related to working conditions, comprise the characteristics of lubricating oil, the oil immersion area, the working pressure of a sealing ring and the like, and are parameters to be considered in the working stage.
In summary, the power loss analysis method and apparatus of the present invention is used to analyze the power loss of the integrated transmission. On one hand, the invention considers the difference of the parts participating in the work under different working conditions and the loss types thereof, so that the power loss calculation is more accurate; on the other hand, the power loss type is divided according to each stage of vehicle design, and a foundation is laid for efficiency improvement work.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.
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