The application of Acoustic Emission technology for monitoring rolling element or hydrodynamic plain bearings has been addressed by several authors in former times. Most of these investigations took place under idealized conditions, to allow the concentration on one single source of emission, typically recorded by means of a piezoelectric sensor. This can be achieved by either eliminating other sources in advance or taking measures to shield them out (e. g. by placing the acoustic emission sensor very close to the source of interest), so that in consequence only one source of structure-born sound is present in the signal. With a practical orientation this is often not possible. In point of fact, a multitude of potential sources of emission can be worth considering, unfortunately superimposing one another. The investigations reported in this paper are therefore focused on the simultaneous monitoring of both bearing types mentioned above. Only one piezoelectric acoustic emission sensor is utilized, which is placed rather far away from the monitored bearings. By derivation of characteristic values from the sensor signal, different simulated defects can be detected reliably: seeded defects in the inner and outer race of rolling element bearings as well as the occurrence of mixed friction in the sliding surface bearing due to interrupted lubricant inflow.
Knowledge about the relations between process steps or dependencies of materials, technologies, designs, tools and machines is mostly stored in the product developers mind. The same effect takes place when one talks about product related knowledge and the referring technological requirements It is lost if the person leaves the company. The following paper describes a knowledge management approach for a product independent description of Micro System processes and presents a software prototype for decision support in early product development phases.Keywords process knowledge management, design for X, decision support systems
Knowledge Management in MST IndustryPlanning development and production today means proceeding along economic and technical parameters, derived from product requirements and customer oriented business processes. During the last few years much effort has been made to push "Knowledge Management" in industry. At the least, the result often represented no more than a new type of document management with additional "meta" information on top to support the requirements of a company's quality management. Documentation of technological capabilities in Microsystems Technology (MST) often leads to a non-reusable, product specific documentation of a production design according to the quality management guidelines. Hence, a lot of information about the subjacent fabrication know-how -or relations between application requirements, physical effects, technological constraints and costs, -is so far not documented, or documented in an insufficient manner. Insufficient in this context means irretrievable or only customer project related so that it cannot be reused for new projects in terms of Nonaka and Takeuchi's Seci model [01]. Knowledge about Please use the following format when citing this chapter:
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