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The presented work is focused on the development of a comprehensive thermo-mechanical model for predicting the temperature rise in thermoplastic polymer spur gears with any desired profile geometry while running. The specific constitutional behavior of thermoplastics influences the gear-meshing pattern, which can deviate substantially from ideal gear meshing, as typically exhibited by metal gears
The temperature increase that occurs during running of a polymer gear pair can be divided into two components: the nominal and flash temperatures. The latter denotes the short-term temperature increase that takes place during a gear meshing cycle. A thorough analysis of the flash temperature yields an insight into the heat dissipation process, which also determines the nominal temperature increase
Aircraft maintenance and repair organizations (MROs) have to be competitive and attractive for both existing and new customers. The aircraft ground time at MROs should be as short as possible and cost effective without reducing the quality of the work. Process optimization in MROs requires the continuous improvement of processes and the elimination of non-value-added activities during maintenance
This paper presents a new accelerated testing procedure for plastic gears that is based on several different levels of testing. The iterative testing procedure fulfils requests from the product development process. The following criteria are considered for testing: reduced number of tests, shorter test time and reliable results for different applications. The proposed method was applied over the f
The parameters necessary for the reliable design of PEEK gears were determined. The effect of a steel gear's surface on the polymer gear's wear was investigated. Values for the wear coefficient of a steel/PEEK gear pair in dry and lubricated conditions are proposed. Testing showed that, on average, grease lubrication extends the lifespan of PEEK gears by a factor of 1.23, while the additional trea
Supplier relationships in the automotive industry have changed fundamentally in recent decades owing to trends such as less verticalintegration, global sourcing, simultaneous engineering, and theInternet. Suppliers have become much more important in terms ofboth production and development. The ability to manage engineeringchanges (EC) efficiently and reliably reflects the capability of thewhole su
Conventionally, a technical system is defined in the design phase and considers all important requirements and aspects. The expected operations and the circumstances of operations are to be known in advance. If these are known, then the designed system can even be validated before it is produced or launched on the market. Validation is typically based on predictive analyses or simulations. However
Beliefs, expectations and values are often assumed to drive decisions about climate change adaptation. We tested hypotheses based on this assumption using survey responses from 508 European forest professionals in 10 countries. We used the survey results to identify communication needs and the decision strategies at play, and to develop guidelines on adequate communications about climate change adBeliefs, expectations and values are often assumed to drive decisions about climate change adaptation. We tested hypotheses based on this assumption using survey responses from 508 European forest professionals in 10 countries. We used the survey results to identify communication needs and the decision strategies at play, and to develop guidelines on adequate communications about climate change ad
The robust engineering seeks for design of products and processes insensitive to changes in the work environment and to the variation of the components. The robust process has built-in mechanisms to detect potential errors on time, to eliminate them and to initiate all the necessary measures to ensure the same error does not occur again. One-of-a-kind production is characterised by unique products
The paper presents an application of job process planning and scheduling into the production of turned parts. Both planning and scheduling are controlled by the genetic algorithm (GA) approach in order to achieve optimum plans. Genetic algorithms are one of the artificial intelligence methods. With GA we are searching in an iterative manner for possible schedules taking into account the limitation
The topic of this paper is the application of abrasive flow machining (AFM) to gear tool inserts polishing. Polished surface on plastic gear teeth improves surface geometry stability, and it increases the lifespan, which was proved on the gear testing rig. Experiments have shown that it is an efficient alternative to the hand polishing procedure. Besides significant cost and processing time saving
ABSTRACT Increased competition in the global market has forced companies to diversify their product ranges to meet the customers? changing needs and adopt product development strategies for mass customization or even one-of-a-kind production, which inevitably requires designing modular products. Product modularity is achieved via platform-based systems, in which various combinations of different m
The nonlinear material properties of thermoplastics like polyoxymethylene (POM) can influence the thermo-mechanical response of polymer gears to applied running loads. In the presented study, the non-elastic strain rate- and temperature-dependent mechanical characteristics of POM are examined, along with their influence on the mechanical response of the polymer gear at the tooth root and contact i
The study conducts research on lean product development (PD) methodology and presents a case study of its practical application into a specific one-of-a-kind development of large power transformers. The demonstrated framework is the result of a 5-year intensive research that led to an extensive transformation of a traditional PD environment into a highly efficient process according to lean princip
The development of innovative and competitive products and mastery of IT&T technologies are crucial for a company's long-term success in the global market. The main flag bearers for development are product developers, but it is questionable whether the existing systems are appropriate for the education of such professionals. For example, one study found large deficiencies concerning their skil
This paper presents a systematic discussion of the specifics of communication and work within a virtual development team, which is of crucial importance for competitiveness in the course of globalization. With advances in technology, work within virtual teams is gaining ever-greater importance. However, in this process, special knowledge and skills of virtual team members are a greater obstacle th
Achieving high quality standards and 100% defect-free deliverables is becoming a trend among manufacturers of household appliances. In that respect, thorough and reliable end-tests represent an important step towards this goal. This paper deals with the design of end-test procedures for vacuum cleaner motors based on sound analysis. It is well known that sound carries important information about t
The ability to manage engineering changes (ECs) efficiently reflects the agility of an enterprise. A large majority of products become gradually improved and perfected through the developmental-design process, during which the set design requirements are met or even upgraded, thus prolonging the product life cycle. The concept of product improvement was based on the activation and tracking of (ECs
This paper addresses the problem of the detailed quality end-test of vacuum cleaner motors at the end of the manufacturing cycle. For the prototyping purposes a test rig has been constructed and is presented in short. The diagnostic system built hereto takes advantage of vibration, sound and commutation analysis as well as parity relation checks. The paper focuses on the sound analysis module and
