Self-Generated Torque Induced by the Lockable and Self-Locking Differentials within the 4WD Drivetrain

2014 ◽  
Vol 659 ◽  
pp. 268-273
Author(s):  
Marian Truta ◽  
Marin Marinescu ◽  
Radu Vilau ◽  
Octavian Alexa ◽  
Constantin Ovidiu Ilie

This work is dealing with the self-generated torque that occurs within a 4WD military special automotive drivetrain. The mathematical model stated in this paper is confirmed by the means of multiple tests developed in real conditions. The tests were developed in order to reveal both transversal and longitudinal self-generated torque within the drivetrain, on different road surfaces. The present paper also introduces some new concepts, such is for instance the insensitive domain of a self-locking (or a progressively locking) differential. With the aid of this concept we can easier deal with the self-generated torque that is due to the increased internal friction of the differential. Moreover, a general, comprehensive theory can be further issued that could classify the self-locking differentials according to their internal friction and their locking coefficient variation.

Author(s):  
Jia Xiaohong ◽  
Ji Linhong ◽  
Jin Dewen ◽  
Zhang Jichuan

Abstract Clearance is inevitable in the kinematic joints of mechanisms. In this paper the dynamic behavior of a crank-slider mechanism with clearance in its tripod-ball sliding joint is investigated theoretically and experimentally. The mathematical model of this new-type joint is established, and the new concepts of basal system and active system are put forward. Based on the mode-change criterion established in this paper, the consistent equations of motion in full-scale are derived by using Kane method. The experimental rig was set up to measure the effects of the clearance on the dynamic response. Corresponding experimental studies verify the theoretical results satisfactorily. In addition, due to the nonlinear elements in the improved mathematical model of the joint with clearance, the chaotic responses are found in numerical simulation.


2012 ◽  
Vol 466-467 ◽  
pp. 951-955
Author(s):  
Jun Qing Zhan ◽  
Xiao Mei Feng ◽  
Li Shun Li ◽  
Xiang De Meng

The self-loading device used for side-crane is put forward. Its structure is presented. Based on the force analysis when the side-crane works at flat ground, the mathematical model is established when the crane working at uneven ground. And the design calculation is performed. The self-loading device’s optimal design is accomplished. Based on the above calculation results, the self-loading prototype is manufactured. And the design method can be adopted to the similar equipment’s structural design.


2013 ◽  
Vol 561 ◽  
pp. 54-58
Author(s):  
Xian Kui Zeng ◽  
Chang He Yang ◽  
Ze Shuai Song ◽  
Shu Hong Zhao

According to studying the mechanism of open mill mixing in low temperature and its intelligent mixing theory, based on the analysis of the experimental results getting from the self-developed XK-160E type open mill, we established a mathematical model for predicting the mix Mooney viscosity. The inspection and verification of mathematical model results showed that the predicted Mooney viscosity was very close to the practical value indicating a good predictive effect.


Author(s):  
Basil A. Housari ◽  
Sayed A. Nassar

This study provides an experimental and theoretical investigation of the effect of the bearing friction coefficient and the thread friction on the self-loosening of threaded fasteners that are subjected to cyclic transverse service loads. Coating and lubrication affect the thread and the underhead friction of the fastener, which affects the loosening rate when it is subjected to transverse loads. A mathematical model was developed to evaluate the self-loosening behavior in threaded fasteners when subjected to cyclic transverse loads. An experimental procedure and test set up are designed in order to collect real-time data on the rate of preload loss per cycle as well as the rotational angle of the bolt head during its gradual loosening. The values of the coefficients of friction under the bolt head and between the threads were changed in the mathematical model to monitor their effect on the loosening rate. Experimentally, the friction coefficients are modified by changing the coating or the lubrication applied to the fasteners. One coating and one solid film lubricant are used, namely, phosphate and oil coating and Olefin and Molydisulfide lubricated bolts. The theoretical and experimental results are presented and discussed.


Author(s):  
S. A. Nassar ◽  
B. A. Housari

A mathematical model and an experimental procedure are presented for studying the self-loosening phenomenon of threaded fasteners that are subjected to cyclic transverse loads. The effect of thread and underhead friction coefficients, the hole clearance, and the frequency and the amplitude of the transverse excitation are investigated. The experimental set up is made of a single-bolt joint, which is subjected to a cyclic transverse displacement or force. For each variable, the drop in the fastener tension and the joint clamp load versus the number of cycles is recorded and analyzed. In the mathematical model, the linear and angular motion of the bolt head is formulated in terms of the system properties and the external cyclic transverse excitation. The mathematical model provides the bolt rotation in the loosening direction, which causes the partial or full loss of the clamp load. An iterative MATLAB code is developed and used for the calculation of tension drop-off in the fastener tension due the self-loosening. Mathematical and experimental results are compared for various levels of system and external loading variables.


2020 ◽  
Vol 22 (3) ◽  
pp. 197
Author(s):  
P. Caputo ◽  
G.A. Ranieri ◽  
D. Miriello ◽  
A. Bloise ◽  
A.A. Abe ◽  
...  

The stones used for the construction of road surfaces have a complex mineralogical and hence chemical composition. They are made up of several types of minerals put together. This generates a significant difference in adhesion with the bituminous binder. The aim of this study is to create a mathematical model able to predict the adhesion between bitumen and stone on the basis of contact angle measurements made on different pure minerals. The mathematical model used was developed keeping in mind the exponential bond that the minerals have with the corresponding bond angle. This model also confirmed the established fact that the lower the value of Δ, the better the adhesion between the bitumen and the aggregate.


2019 ◽  
Vol 10 (3) ◽  
pp. 933-942
Author(s):  
Yuxin Pei ◽  
Nanlin Zhang ◽  
Huaxing Zhou ◽  
Shengchuan Zhang ◽  
Wei Zhang ◽  
...  

AbstractHydraulic fracturing is a key measure to increase production and transform oil and gas reservoirs, which plays an important role in oil and gas field development. Common hydraulic fracturing is of inevitable bottlenecks such as difficulty in sand adding, sand plugging, equipment wearing and fracturing fluid damage. To solve these problems, a new type of fracturing technology, i.e., the self-propping fracturing technology is currently under development. Technically, the principle is to inject a self-propping fracturing liquid system constituting a self-propping fracturing liquid and a channel fracturing liquid into the formation. Self-propping fracturing liquid changes from liquid to solid through phase transition under the formation temperature, replacing proppants such as ceramic particles and quartz sand to achieve the purpose of propping hydraulic fractures. The flow pattern, effective distance and filling ratio of the self-propping fracturing liquid system in the hydraulic fracture are greatly affected by the parameters such as the fluid leak-off rate, surface tension and injection velocity. In this paper, a set of mathematical models for the flow distribution of self-propping fracturing liquid system considering fluid leak-off was established to simulate the flow pattern, effective distance, as well as filling ratio under different leak-off rates, surface tensions and injection velocities. The mathematical model was verified by physical experiments, proving that the mathematical model established herein could simulate the flow of self-propping fracturing liquid systems in hydraulic fractures. In the meantime, these results have positive impacts on the research of interface distribution of liquid–liquid two-phase flow.


2014 ◽  
Vol 998-999 ◽  
pp. 704-707
Author(s):  
Shun Li Wang ◽  
Lian Sheng Li

ASR (Acceleration Slip Regulation) is the extension based on ABS. ABS and ASR are called by a joint name as slip regulation control system. Compared with two wheel drive car, four-wheel drive car has many defects, which is like snatch operation tedious and other defects. This paper has analyzed drive characteristic of four-wheel drive car and established drive simplify mathematical model. According to the mathematical model, we have established drive simulation model in MATLAB/SIMULINK environment, and made simulated analysis of different road surfaces for the model. The result indicated that slip regulation control system played preferable inhibiting effect for drive wheel spike of four-wheel drive car, and it can obtain a certain improvement of dynamic property. It verified feasibility of control algorithm and validity of control strategy at the same time.


Author(s):  
Olexandr Pavlenko ◽  
Serhii Dun ◽  
Maksym Skliar

In any economy there is a need for the bulky goods transportation which cannot be divided into smaller parts. Such cargoes include building structures, elements of industrial equipment, tracked or wheeled construction and agricultural machinery, heavy armored military vehicles. In any case, tractor-semitrailer should provide fast delivery of goods with minimal fuel consumption. In order to guarantee the goods delivery, tractor-semitrailers must be able to overcome the existing roads broken grade and be capable to tow a semi-trailer in off-road conditions. These properties are especially important for military equipment transportation. The important factor that determines a tractor-semitrailer mobility is its gradeability. The purpose of this work is to improve a tractor-semitrailer mobility with tractor units manufactured at PJSC “AutoKrAZ” by increasing the tractor-semitrailer gradeability. The customer requirements for a new tractor are determined by the maximizing the grade to 18°. The analysis of the characteristics of modern tractor-semitrailers for heavy haulage has shown that the highest rate of this grade is 16.7°. The factors determining the limiting gradeability value were analyzed, based on the tractor-semitrailer with a KrAZ-6510TE tractor and a semi-trailer with a full weight of 80 t. It has been developed a mathematical model to investigate the tractor and semi-trailer axles vertical reactions distribution on the tractor-semitrailer friction performances. The mathematical model has allowed to calculate the gradeability value that the tractor-semitrailer can overcome in case of wheels and road surface friction value and the tractive force magnitude from the engine. The mathematical model adequacy was confirmed by comparing the calculations results with the data of factory tests. The analysis showed that on a dry road the KrAZ-6510TE tractor with a 80 t gross weight semitrailer is capable to climb a gradient of 14,35 ° with its coupling mass full use condition. The engine's maximum torque allows the tractor-semitrailer to overcome a gradient of 10.45° It has been determined the ways to improve the design of the KrAZ-6510TE tractor to increase its gradeability. Keywords: tractor, tractor-semitrailer vehicle mobility, tractor-semitrailer vehicle gradeability.


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