Advanced Materials Research Vol. 1039

Abstract: To solve the interference problem during the grinding process of large lead ball nut, a new forming grinding system based on flexible shaft has been designed in this paper. The paper analyzed and compared with three grinding methods including reducing setting angle, deflecting setting angle and adopting flexible shaft grinding system to figure out their influence on possibility, precision and efficiency of grinding. The result shows that the flexible shaft grinding system designed can avoid interference effectively. Additionally, it can also meet the requirement of efficiency and precision when grinding the large lead ball nut.

Abstract: Recycling of End of Life Vehicle (ELV) is a coming social issue in China. For the purpose of establishing recycling enterprise rationally, all the aspect should be taken into account, especially the cost of recycling. In this paper a cost model of recycling process is presented and analyzed to the disassembly and recycling process. The configuration of equipment with different mode of disassembly is also discussed.

Abstract: This paper introduced a virtual roaming system which can be effectively used in studying ocean scenes based on 3ds max modeling tools and virtools development software. Establishing this system needs the following steps: building geometric model, making texture mapping, light treatment, importing model and designing interactive function. Taking jack-up offshore platform as an example, the system has three roaming modes including manual roaming with character, manual roaming without character and automatic roaming. Users can roam in this platform freely. The collision detection technology and the immersive technology were integrated into the system to improve the reality of it. The system also has a good visual effect and interactive function.

Abstract: The primary goal of concurrent engineering is to minimize the time spend and to reduce quality problems encountered between a product's conception and customer use, thereby minimizing cost and maximizing product quality. Tolerance is an important index of product design and manufacture. Although they are small as compared with part dimensions, tolerances can propagate and accumulate in an assembly affecting the product assimilability. Moreover, tolerance is inevitable because manufacturing exactly equal parts is known to be impossible. This paper presents a brief review of statistical tolerance and clearance analysis for the assembly, and proposes a method of tolerance analysis by a leading commercial computer-aided tolerance (CAT) analysis system, VisVSA. This method can ensure assembly precision requirements, and design optimally tolerance distribution based on Monte Carlo simulation, take a example of brake assembly to detailed introduce the use of this method. The purpose of this article is expected to make the following contributions: (i) to help the designers to evaluate products for assimilability, (ii) to provide a new perspective to tolerance problems, and (iii) to provide a tolerance analysis tool, VisVSA, which can be incorporated into a CAD or solid modeling system.

Abstract: With a brief introduction of basic concepts and characteristics of green manufacturing, the research status and development trend of green manufacturing is analyzed, and a number of key technologies on green manufacturing are briefly discussed, including green design, green simulation, and green monitoring. The application of green manufacturing in automobiles and machine tools are described to prove the good prospects.

Abstract: Looking at the high rates of production and the steep competition in the world market, it becomes quite essential that the fault control is done in a very efficient way. This article presents a summary on the maintenance, the monitoring techniques, and the diagnosis methods for the condition based maintenance of machine tools. The paper initially gives a brief introduction on the condition based maintenance of machine tools. In the next part, the various methods for the monitoring are discussed followed by the models for data mining. The paper concludes that most of the techniques have their own advantages and drawbacks, so a careful selection of the techniques is needed to form a proper monitoring system.

Abstract: To reduce error inspection rate of the brand inspection in enterprise logistics, this paper puts forward a inspection method which depends on template matching algorithm based on machine vision.This method identifies cigarette carton brand by image processing, first template matching, accurate template matching of real-time carton bar code, then sends message to industrial personal computer to does sorting operation. Practice has proved that the system is stable, fast, accurate to meet the site requirement.

Abstract: Condition monitoring (CM) and fault diagnosis of equipments has gained greater attention in recent years, due to the need to reduce the down time and enhance the life/ condition of the equipments. The rolling element bearings (REB) are the most critical components in rotary machines. Hence, bearing fault detection and diagnosis is an integral part of the preventive maintenance activity. Vibration signal analysis provides wide range of information for analysis. So in this paper, vibration signals for four conditions of a deep groove ball bearing namely Normal (N), bearing with defect on inner race (IR), bearing with defect on ball (B), and bearing with defect on outer race (OR) have been acquired from a customized bearing test rig under maximum speed and variable load conditions. Depending on the machinery operating conditions and the extent of bearing defect severity, the measured vibration signals are non-stationary in nature. Non-stationary signals are effectively analyzed by wavelet transform technique, which is a popular and widely used time-frequency technique. The focus of this paper is to select a best possible mother wavelet for applying WT on bearing vibration signals. The two selection criteria includes minimum Shannon entropy criteria (MSEC) and Maximum Energy to Shannon Entropy Ratio criteria R(s). This helps in effective bearing CM using WT.

Abstract: In recent years, researching the stability of the CNC machining process is a hotpot in CNC industry. Based on cDAQ and labVIEW, online monitoring system is presented, meanwhile, both software structure and hardware structure are introduced in detail. Researches show that vibration and pressure are the main factors for the quality of the flatness. By studying the relative vibration between the spindle and the platform in the Z axis direction, as well as the shifty pressure that tool works on the flatness of the workpiece, four experiments are designed in this paper under different technological conditions including free moving, Axial Depth of cut, speed and feed speed, which verify the reliability of the online monitoring system.

Abstract: Rolling element bearing is crucial for operation safety of modern mechanical equipment. Its poor damping and heavy load capacity usually makes it degrade faster than the shafts and the gear sets. In this paper, a recently proposed time-frequency (TF) representation tool, named the complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN), is introduced for the TF representation of helicopter bearing degradation data. Totally three sets of sequentially collected accelerometer data were included for the comparison study, with the first two data sets showing no signs of degradation and the third data set corresponds to totally scored bearing rollers. Facilitated by CEEMDAN method, no clear distinction can be observed on the TF plane as for the strong background noises. Thus we previously highlight the bearing signatures using spectral kurtosis (SK), a forth order statistics which is sensitive for impulsive components. Its fast algorithm, called the kurtogram, implements the detection of considerably weak bearing components and suppresses other background components, e.g., gear mesh components. With the preprocessing by kurtogram, the feature information on the TF plane can be easily characterized for the third data set.