¡@¡@The countershaft transmission is a device connected between engine and driving wheel for transferring power. This device can provide variable gear ratios to maintain engine speed in certain operating range and is well applied for vehicle transmission systems for its high performance. In this thesis, the systematic design methodology for dual-clutch countershaft automatic transmission (DCT) is proposed. This methodology can provide a systematic design procedure for the gear box prototype, number of teeth, computer-aid program and preliminary layout. First, the fundamentals and gear-shifting operations for DCT are illustrated to establish the design requirements. Secondly, 12 kinds and 8 kinds for 7-speed DCT prototype are synthesized for the gear mechanism with FR type and FF type respectively. Then, according to both FR and FF types, calculate the proper number of teeth for ideal gear ratio and build the computer-aided calculating interface. Finally, the preliminary layouts of the above prototypes and number of teeth are built by CAD models. The result of this research will be beneficial for further newly DCT designs.

Controlled Start Transmissions (CST) can be described as a mechanical transmission combined with a wet clutch for controlled torque output. CST:s are commonly used to start up heavy loads for example mining conveyors. Several CST:s can work together to share the load. The transferred torque is controlled by a hydraulic wet clutch which is a proven technology for high torque transfer and low wear. This thesis is a part of a project to increase the knowledge and improve the CST design and control performance. The heat generation in the wet clutch is the focus of this thesis. Literature review shows that most research is done in order to get high accuracy for smaller clutches and most of the high torque engagements have very short transients.Models for the CST clutch heat generation together with thermal behavior have been developed and investigated. This includes a temperature model together with a kinetic model of the gearbox and a clutch torque model. Validation of separate model components and sensitivity analysis of the parameters are made. The developed model is then analyzed by comparing measurements from a commission site and simulations to get an idea of how much heat is generated.

No description available.

No description available.

No description available.

No description available.

No description available.

Esse estudo tem como tese que o comportamento de recém nascidos e bebês é ativo, ou seja, guiado a uma meta específica e baseado no conhecimento a respeito do ambiente ao seu redor. Também é assumido que essa capacidade de adaptação se fortaleça ao longo dos 4 primeiros meses após o nascimento. Foram investigadas as atividades manuais de recém nascidos e bebês, tendo em vista que as mãos são uma importante ferramenta de percepção e interação com o ambiente. Assim, os objetivos do estudo foram: a) descrever o comportamento de apertar ao longo dos 4 primeiros meses após o nascimento; e b) identificar acoplamentos entre apertos manuais e o contexto ambiental durante os quatro primeiro meses após o nascimento. Os resultados mostraram que os bebês alteraram a organização temporal dos apertos diferentemente nas situações de contingência e não contingência, um indicativo inicial do comportamento ativo nos apertos manuais / This thesis searched for evidences that newborns and infants behaviour are active, in the other words, intentional, guide by a goal and based in environment knowledge. Also, it is suggested that the adaptation capacity improve around the first 4 months of age Thereunto, the manual activities were investigate, because the hand is an important font of perception and interaction with the environment. So, the goals of the study were: a) to describe neonate and infant clutches around four first months after birth; and b) to verify the coupling between clutches and environmental outcomes during the first four months after birth. The results showed that infants could alter the temporal organization of clutches differently in contingent and no contingent conditions, an initial indicative of active clutch behaviour in young infants

The rapid release of energy in mechanisms is often limited by conversion of potential energy to kinetic energy. The use of a flywheel to store energy over time eliminates this constraint. Using this principle, a lightweight and compact energy transmission mechanism has been developed for robotic combat applications. The purpose of the proposed design is to throw an opposing robot ten or more feet into the air. This design incorporates a flywheel, a self-resetting dog clutch with built in shock absorbing rubber for impact mitigation, and an optimized four-bar linkage to deliver the energy. A mathematical model of the dynamic system has been developed to analyze and aid in the design process. Testing of subsystems was performed to validate the design. A final design is proposed with the recommendation that it be built and tested. A validated design is applicable to many real-world problems that require rapid kinetic energy release including reconnaissance robots required to hop high fences.

Esse estudo tem como tese que o comportamento de recém nascidos e bebês é ativo, ou seja, guiado a uma meta específica e baseado no conhecimento a respeito do ambiente ao seu redor. Também é assumido que essa capacidade de adaptação se fortaleça ao longo dos 4 primeiros meses após o nascimento. Foram investigadas as atividades manuais de recém nascidos e bebês, tendo em vista que as mãos são uma importante ferramenta de percepção e interação com o ambiente. Assim, os objetivos do estudo foram: a) descrever o comportamento de apertar ao longo dos 4 primeiros meses após o nascimento; e b) identificar acoplamentos entre apertos manuais e o contexto ambiental durante os quatro primeiro meses após o nascimento. Os resultados mostraram que os bebês alteraram a organização temporal dos apertos diferentemente nas situações de contingência e não contingência, um indicativo inicial do comportamento ativo nos apertos manuais / This thesis searched for evidences that newborns and infants behaviour are active, in the other words, intentional, guide by a goal and based in environment knowledge. Also, it is suggested that the adaptation capacity improve around the first 4 months of age Thereunto, the manual activities were investigate, because the hand is an important font of perception and interaction with the environment. So, the goals of the study were: a) to describe neonate and infant clutches around four first months after birth; and b) to verify the coupling between clutches and environmental outcomes during the first four months after birth. The results showed that infants could alter the temporal organization of clutches differently in contingent and no contingent conditions, an initial indicative of active clutch behaviour in young infants