Energy efficient drive train for a high-performance battery chain saw
Up to today, small two-stroke gasoline engines are the major power source for professional outdoor power equipment such as hedge trimmers, chain saws, blowers, cut-off saws.
New compact high-torque drive for mobile outdoor power equipment
Due to the development of a high efficient drive train based on a direct drive brushless DC motor (BLDC) powered by a Lithium-Ion battery, STIHL has the possibility to provide professional mobile outdoor power equipment with high output power and sufficient operating time. The requirements of the different products like chain saws, trimmers, blowers, lawn movers or hedge trimmers are very specific due to the different fields of application. Therefore STIHL decided to develop a motor kit specially designed to meet the requirements of all applications but also to be optimized in terms of production cost. This paper describes the development process of the motor kit, which powers the new STIHL rechargeable battery driven products.
Mechanics of deformable directed surfaces
Abstract The paper develops a simple, yet complete and consistent non-linear dynamic thermo-elastic shell theory based on the concepts of a two-dimensional directed continuum. The constitutive equations are postulated in a general form. Stress-strain relations are derived using the equation of energy balance and the two entropy production inequalities, which are rewritten in a special form. The linear theory is discussed in detail. The structure of the stress-strain relations is presented in the most general form and then specialized to concrete examples, in particular, to the classical shell theory, using their invariance properties with respective to certain symmetry groups. The elastic moduli are determined by demanding the coincidence of the frequency dispersion surfaces obtained using the two-dimensional theory with the lowest foils of the corresponding surfaces resulting from the three-dimensional theory of elasticity.