Part Of Axle Research Articles

Effect of Rotary Swaging on Mechanical Behaviors of Axle Steel Rod.

The short-chain forming process using rotary swaging (RS) is an important method of achieving the manufacturing of lightweight axles. Axle steel, like 42CrMo, is widely used in many types of axles and shafts; however, there is no existing research on rotary-swaged axle steel's mechanical properties. It makes sense to carry out a comprehensive study on the effect of RS on the mechanical behaviors of axle steel rods. In this study, a 42CrMo steel rod was processed by RS through ten passes. The tensile properties, torsion properties, compression properties, and fatigue properties were tested. There was an overall improvement in the torsional and fatigue performance after RS. Combined with a finite element analysis (FEM), the uneven distribution of the dislocations and existence of the elongation material were inferred to have caused the different modes of the mechanical behaviors. Fracture surfaces were analyzed and the results showed that the fracture pattern had changed. There existed a competitive relation between the internal fatigue cracks and external cracks, which could be attributed to uneven strain hardening. This research proved the advantages of RS in the processing of axle parts, which mainly benefitted the torsional working conditions, and provided evidence for a new processing route for lightweight axles with RS.

FAILURE ANALYSIS OF A TRACTOR FRONT AXLE

Tractors, high-power, low-speed traction vehicles and power units are similar to trucks or automobiles but designed for use off-road. They are defined as motor vehicles with wheels that allow them to hold on to loose terrain and be fitted with trailers. Tractors operate in challenging operating conditions. Therefore, it is possible that they become damaged. In some cases the damage is due to disrupted engineering, but more frequently, it is due to failures in material processing and maintenance, raw material errors, design and manufacturing errors, and user-related errors. This study examined the fractured front axle of a tractor. Spectroscopic, metallographic and hardness measurements of the axle parts were made. Stress analyses were also performed using finite elements to determine the stress conditions in the renewed section. The finite element analysis showed that the broken region was exposed to maximum stresses. Stress analyses using finite elements were also carried out to determine the stress conditions in the repeated section. With the fracture surface analysis, mild fatigue was observed, and it was concluded that the fracture occurred suddenly.

Enhanced task parameterized dynamic movement primitives by GMM to solve manipulation tasks

PurposeUnder the development trend of intelligent manufacturing, the unstructured environment requires the robot to have a good generalization performance to adapt to the scene changes. The purpose of this paper aims to present a learning from demonstration (LfD) method (task parameterized [TP]-dynamic movement primitives [DMP]-GMR) that combines DMPs and TP-LfD to improve generalization performance and solve object manipulation tasks.Design/methodology/approachThe dynamic time warping algorithm is applied to processing demonstration data to obtain a more standard learning model in the proposed method. The DMPs are used to model the basic trajectory learning model. The Gaussian mixture model is introduced to learn the force term of DMPs and solve the problem of learning from multiple demonstration trajectories. The robot can learn more local geometric features and generalize the learned model to unknown situations by adding task parameters.FindingsAn evaluation criterion based on curve similarity calculated by the Frechet distance was constructed to evaluate the model’s interpolation and extrapolation performance. The model’s generalization performance was assessed on 2D virtual data sets, and first, the results show that the proposed method has better interpolation and extrapolation performance than other methods.Originality/valueThe proposed model was applied to the axle-hole assembly task on real robots, and the robot’s posture in grasping and placing the axle part was taken as the task parameter of the model. The experiment results show that The proposed model is competitive with other models.

A New Method of Manufacturing Hollow Shafts via Flexible Skew Rolling

The existing rolling process of large and long axle parts, such as the cross wedge rolling (CWR) process, requires special molds and larger equipment. Flexible skew rolling (FSR) hollow shafts with mandrel is a near net-shape rolling technology which can achieve the diversified production of rolled parts without special molds. It has significant advantages such as small equipment tonnage, small die size, low rolling load, simple process adjustment, and especially suitable for multi-variety and small-batch production. This paper proposes hollow train shafts formed by FSR with mandrel. Reasonable parameters were selected for experiments, and the forming process was calculated by finite element (FE) software. The experimental results are consistent with the simulation results, indicating that the FE model is reliable. The rolling force and rolling torque are analyzed by simulation. Finally, the microstructure of different positions of the rolled-piece is analyzed, and the microstructure of the rolled part is refined. It is provide a feasible scheme for the rolling of large hollow shaft parts.

Experimental study on the relationship between the friction coefficient and interference in locomotive axle press-fitting

PurposeTo address the lack of data in this field and determine the relationship between the coefficient of friction and the interference between locomotive wheels and axles, this study evaluates the theoretical relationship between the coefficient of friction and the interference under elastic deformation.Design/methodology/approachWhen using numerical analyses to study the mechanical state of the contacting components of the wheels and axle, the interference between the axle parts and the coefficient of friction between the axle parts are two important influencing factors. Currently, as the range of the coefficient of friction between the wheel and axle in interference remains unknown, it is generally considered that the coefficient of friction is only related to the materials of the friction pair; the relationship between the interference and the coefficient of friction is often neglected.FindingsA total of 520 press-fitting experiments were conducted for 130 sets of wheels and axles of the HXD2 locomotive with 4 types of interferences, in order to obtain the relationship between the coefficient of friction between the locomotive wheel and axle and the amount of interference. These results are expected to serve as a reference for selecting the coefficient of friction when designing axle structures with the rolling stock, research on the press-fitting process and evaluations of the fatigue life.Originality/valueThe study provides a basis for the selection of friction coefficient and interference amount in the design of locomotive wheels and axles.

EXPERIMENTAL ANALYSIS OF THE EFFECT OF MECHANICAL PROPERTIES AND MICROSTRUCTURE ON TOOL VIBRATION AND SURFACE QUALITY IN DRY TURNING OF HARDENED AISI 4340 STEELS

AISI 4340 (34CrNiMo6) steel is a difficult to machine steel material because of its high hardness and tendency to get strain hardened. These steels are mostly used in manufacturing of the axle parts, drive coupling, and rotating shafts due to their high mechanical properties. In this experimental study, the effects of mechanical properties and microstructure on tool vibration and surface quality in dry turning of hardened AISI 4340 steels were investigated. Test samples were classified as Raw Material (RM), Conventional Heat Treatment (CHT) and Tempering process (T). The experiments were carried out under dry cutting conditions by different cutting parameters on the CNC turning lathe. Three axes vibration amplitude values (along the [Formula: see text]-, [Formula: see text]- and [Formula: see text]-directions) were measured using accelerometers as online and surface roughness (Ra) values were measured with the surface roughness device. Tool vibrations and Ra values were found to be lower in T sample compared to the RM and CHT samples. When the samples were analyzed in terms of microstructure and mechanical properties, it was seen that the tensile strength increased as the hardness values increased. After the tempering process at 200∘C, pearlite and bainitic structures emerged along with the martensite structure. The surface quality that can be obtained on a cylindrical grinding lathe, has been reached with the dry turning process. Significant gains have been achieved in terms of cost and time.

Independent wheel control system design for highly automated driving

For L4 and above autonomous driving levels, the automatic control system has been redundantly designed, and a new steering control method based on brake has been proposed; a new dual-track model has been established through multiple driving tests. The axle part of the model was improved, the accuracy of the transfer function of the model was verified again through acceleration-slide tests; a controller based on interference measurement was designed on the basis of the model, and the relationships between the controller parameters was discussed. Through the linearization of the controller, the robustness of uncertain automobile parameters is discussed; the control scheme is tested and verified through group driving test, and the results prove that the accuracy and precision of the controller meet the requirements, the robustness stability is good. Moreover, the predicted value of the model fits well with the actual observation value, the proposal of this method provides a new idea for avoiding car out of control.

Study on Formation Mechanism of Axle Part in the New Cross-Wedge Rolling Process Based on Experiment and Simulation

Aiming at the concavity defects in the cross-wedge rolling (CWR) process, one new rolling method named as the twice closed–open joint CWR was presented to improve the use ratio of material in CWR of the axle parts. The new rolling method included three stages: the first closed rolling, the second closed rolling and the last open rolling. To investigate the flow of material in this rolling process, one 3D finite element model (FEM) of the twice closed–open joint CWR was established. The CWR process of one pump spindle part was simulated using the established 3D FEM. The formation, the flow law of metal materials and concavity defects of end were studied. In addition, the CWR experiments were carried out. The results of simulation agreed with the results of tests well. The results proved that the new method can decrease the extent of concavity and improve the material use ratio.

UNCONVENTIONAL MATERIAL PART FEM ANALYSIS

The article covers the usability of alternative materials in vehicle construction. The paper elaborates upon the setup of the process and analysis of the results of the carbon composite component FEM model. The 3D model, used for the examination, is a part of axle from an alternative small electric vehicle. The analysis was conducted with the help of MSC Adams and Ansys Workbench software. Color maps of von Mises stress in material and total deformations of the component are the results of calculation.

Characterization of the cytotoxic activity of [2]rotaxane (TRO-A0001), a novel supramolecular compound, in cancer cells.

Rotaxanes comprise a class of interlocked molecules containing a wheel threaded onto an axle with blocking groups on the ends to keep the wheel from sliding off. Here, we show that [2][bis(2-(3,5-dimethylphenylcarbonyloxy)ethyl) ammoniumtrifluoromethanesulfonate]-[dibenzo-24-crown-8] rotaxane (TRO-A0001), a rotaxane compound, exerted a growth inhibitory effect on several human cancer cell lines. An MTT assay revealed an IC50 of 14-830nM for TRO-A0001 in these cells. Neither the wheel nor the axle part alone inhibited tumor cell growth, suggesting that the complete rotaxane molecule with its unique "intramolecular mobility" is required to inhibit cell growth. Annexin-V/PI staining provided evidence of the induction of apoptosis, which was further confirmed by the observation of poly (ADP-ribose) polymerase cleavage. Furthermore, a cell cycle analysis using flow cytometry showed that TRO-A0001 treatment resulted in G1 arrest in glioblastoma T98G and melanoma G361 cells. An immunoblot analysis revealed that in both cell lines, TRO-A0001 treatment caused the induction of p21/Cip1, thereby down-regulating Cdks 2, 4 and 6 and reducing Cyclins D1 and E. The results presented in this study demonstrate cytotoxicity of the rotaxane compound and its potential as a lead compound for the development of a chemotherapeutic agent against cancer.

Based on 3D Virtual Prototype Technology and Finite Element Analysis of the Optimization of the Automobile Front Axle

The front axle is an important part of a car, directly affects the dynamic characteristics of car. Based on UG NX6.0 for automobile front axle parts 3D modeling, finite element analysis software ANSYS modal analysis was carried out on the front axle, and extract their first four order natural frequency and vibration mode shapes, the automobile front axle structure stress analysis and stress distribution nephogram of get parts. Analysis of the impact load condition and emergency braking conditions modal analysis, and further to fatigue analysis of the front axle bridge shell, for provide valuable reference data for the reasonable design of parts. For the kinetics of further research and improvement of front axle provides the theoretical basis, but also provides reference to the actual test.

Automotive stamped part fatigue design

Fatigue design of automotive axle parts is of prior concern because of these are high safety parts and they are expected to drive the overall vehicle mass reduction. In this framework, the stamping process is widely used to form axle parts, before assembling them by welding. Consequently, the mechanical and physical characteristics of the blank sheet are modified, having a strong influence on the fatigue behavior. In this paper, we address the consequences of the stamped process on the fatigue design and how they may be effectively taken into account in the automotive industry. Actually, the coupling between the stamping process and the fatigue design is under development at PSA Peugeot Citroën Company since several years. Such an analysis deals with some major topics: thickness variation, plastic hardening and deformation, and residual stress. All of these ingredients result in fatigue criteria evolutions: it is important to stress that the stamping process can have advantageous or disadvantageous consequences on the fatigue design. This is here highlighted on some examples, dealing with front and rear axles.

G1510204 全方向移動型生活支援ロボットの基礎研究([G151-02]ロボティクス・メカトロニクス部門一般セッション(2))

As part of the robot for field operation improved at the time of the accident of the Fukushima Daiichi nuclear power plant in the Great East Japan Earthquake, It designed as a next generation type basic robot which can respond by the function in which housekeeping support of the materials handling operation in everyday life besides dangerous business, such as the building trade and forestry with an insufficient successor, and dangerous object processing, etc., etc. were refined. Design and analysis were performed for the axle part mechanism of the robot which becomes important in various scenes on importance this time. The axle part mechanism model and analysis result of the robot which designed are introduced this time.

Research on the Microstructure and Tribological Properties of the Electroless Ni-P-PTFE Composite Repairing Coating on Gears

The abrasion of axle parts would shorten their useful life, which could be significantly ameliorated to improve the wear resistance of gears through surface repairing and lower production cost. In this work, preparation technology of electroless Ni-P-PTFE composite repairing coatings on 45# carbon steel was investigated by the method of cerium induced codeposition. Coatings with PTFE ranging of 0-10g/L and Ce2+ of 0-1.0g/L were obtained. SEM and XRD were employed to study the worn surface topography, wear mechanism and microstructure of the coatings, respectively. The results indicate that the PTFE particles uniformly distributed throughout the Ni-P matrix, on the edge position of Ni-P crystal cells, and small amounts of which were wrapped in the crystal cells. The wear mechanism manifested as adhesion and slight grain-abrasion, along with associated ploughed grooves. It was also demonstrated that the wear rate of deposits is 2×10-6mm3.N-1.m-1 in condition of dry sliding, which is smaller than it by 3 orders of magnitude. Obviously, electroless Ni-P-PTFE coating improves the wear resistance of gears significantly and can be used as repairing coating.

농업용 트랙터의 주요 농작업 소요동력 분석

The purpose of this study was to analyze power requirement of an agricultural tractor by major field operations. First a survey was conducted to obtain annual usage ratio of agricultural tractor by field operation. Plowing, rotary tillage, and loader operations were selected as major field operations of agricultural tractor. Second, a power measurement system was constructed with strain-gauge sensors to measure torque of four driving axles and a PTO axle, speed sensors to measure rotational speed of the driving axles and an engine shaft, pressure sensors to measure pressure of hydraulic pumps, an I/O interface to acquire the sensor signals, and an embedded system to calculate power requirement. Third, the major field operations were experimented under fields with different soil conditions following planned operation paths. Power requirement was analyzed during the total operation period consisted of actual operation period (plowing, rotary tillage, and loader operations) and period before and after the actual operation (3-point hitch operating, forward and reverse driving, braking, and steering). Power requirement of tractor major components such as driving axle part, PTO part, main hydraulic part, and auxiliary hydraulic part were measured and calculated to determine usage ratio of agricultural tractor power. Results of averaged power requirement for actual field operation and total operation were 23.1 and 17.5 kW, 24.6 and 19.1 kW, and 14.9 and 8.9 kW, respectively, for plowing, rotary tillage, and loader operations. The results showed that rotary tillage required the greatest power among the operations. Averaged power requirement of driving axles, PTO axle, main hydraulic part, and auxiliary part during the actual field operation were 8.1, 7.8, 3.4, and 1.5 kW, respectively, and the total requirement power was about 70 % (20.8 kW) of the rated power. Averaged power requirement of driving axles, PTO axle, main hydraulic, and auxiliary hydraulic for the total operation period were 6.5, 6.0, 2.1, 0.9 kW, respectively, and total requirement power was about 52 % (15.5 kW) of the rated power. Driving axles required the greatest amount of power among the components.

Dual Polyrotaxane: One-pot Synthesis of Topological Polymer by Using Metathesis Reaction

Abstract The topological polyrotaxane was built from an ammonium salt as an axle component bearing one olefin and one bulky unit at the end of chain and the derivative of dibenzo-24-crown-8 (DB24C8) as a wheel component having one terminal olefin. In this system, two kinds of reactions work at the same time as a driving force of the polymer construction. One is the inclusion reaction between the ammonium salt part of axle and the wheel, another is metathesis reaction between olefins of the axle and olefins of the wheel.

Probability of Improvement in Routine Inspection Work of Shinkansen Vehicle Axles.

Fracture mechanics calculation, fatigue test using a full scale axle and investigation on the accuracy of current ultrasonic test are performed to improve the efficiency of routine inspection work of Shinkansen vehicle axles without losing their safety. As allowable cracks, we propose a crack of 3 mm depth at the inner end of gear-side wheelseat, the most important part of an axle for inspection, and a crack of 2 mm depth at the central non-fitted part of axle which is apt to be damaged in running, because such cracks don't propagate for good. Finally, we discover that it is possible to omit the magnetic particle portion of the bogie inspection for Shinkansen vehicle axles provided the service stress and the residual stress are kept almost at the current level.

The analysis and prevention of failure in railway axles

Axles are one of the most important components in railway vehicle with regard to safety, since a fail-safe design is not available. To maintain the safety record of high speed railway systems, the fatigue strength of the axles has been extensively studied. The objective of the present paper is to review and analyse the causes of failure in railway axles, and to show how the results have been applied to improve axle manufacture and in-service inspection. The problems of fretting fatigue crack initiation at press-fitted axle parts is emphasized, however, these problems have not been completely solved even though up-to-date fatigue design methods are employed. The safety of the railway has been ensured by maintenance such as the regular inspection for fatigue cracks at critical parts.