摘要:
The invention is directed to a process for manufacture of fine precious metal containing particles, specifically silver-based particles and silver-based contact materials via an intermediate silver(+1)-oxide species. The process comprises in a first step the formation of a thermally instable silver (+1)-oxide species by adding a base to an aqueous silver salt solution comprising an organic dispersing agent. Due to the presence of the organic dispersing agent, the resulting silver (+1)-oxide species is thermally instable, thus the species is decomposing to metallic silver at temperature lower than 100° C. The process optionally may comprise the addition of a powdered compound selected from the group of inorganic oxides, metals, and carbon-based compounds. Furthermore the process may contain additional separating and drying steps. The process is versatile, cost efficient and environmentally friendly and is used for the manufacture of silver-based particles and electrical contact materials. Silver nanoparticles made according to the process are characterized by a narrow particle size distribution. Electrical contact materials manufactured according to the process reveal improved contact welding properties.
摘要:
The present invention relates to a method for manufacture of silver-based composite powders for electrical contact materials. The invention relates also to electrical contact materials made from such composite powders. The process comprises a high energy dispersing process of wet silver oxide (Ag2O) with additional second oxide components in aqueous suspension. The high energy dispersing process can be conducted by high shear mixing or by high energy milling. Preferably high speed dispersing units working at rotating speeds in the range of 5,000 to 30,000 rpm or high energy mills such as attritor mills are used. The new process is versatile, economical and offers access to a broad spectrum of contact materials. The silver-based composite powders made according to the new process yield contact materials with a highly dispersed microstructures and superior material characteristics.
摘要:
A forage harvester is equipped with a safety device which incorporates controls that monitor various operating conditions including an operator's presence and apply a brake for stopping any possible rotation of the cutting drum whenever an unsafe condition for the operator exists.
摘要:
A shaped, activated metal, fixed-bed catalyst with a pore volume of 0.05 to 1 ml/g and an outer activated layer consisting of a sintered, finely-divided, catalyst alloy and optionally promoters. The catalyst alloy has metallurgical phase domains, resulting from the method of preparation of the alloy, in which the largest phase by volume has a specific interface density of more than 0.5 &mgr;m−1.
摘要:
The invention concerns a drive arrangement of a crop conveying and/or processing mechanism of a harvesting machine with an internal combustion engine (25) that is arranged to drive the crop conveying and/or processing mechanism through power transmission elements in a first operating mode in a first direction at a first speed, and a reversible motor (86) that is arranged to drive the crop conveying and/or processing mechanism in a second operating mode at a second speed in a second direction that differs from the first direction. The drive arrangement is also able to be driven in one or both of third and fourth operating modes. In the third operating mode the reversible motor (86) drives the crop conveying and/or processing mechanism in the first direction at a third speed, that is lower than the first speed and in the fourth operating mode the drive of the crop conveying and/or processing mechanism is separated from the internal combustion engine (25) and the reversible motor (86) operates as a brake for the crop conveying and/or processing mechanism.
摘要:
The invention is directed to a process for manufacture of fine precious metal containing particles, specifically silver-based particles and silver-based contact materials via an intermediate silver(+1)-oxide species. The process comprises in a first step the formation of a thermally instable silver (+1)-oxide species by adding a base to an aqueous silver salt solution comprising an organic dispersing agent. Due to the presence of the organic dispersing agent, the resulting silver (+1)-oxide species is thermally instable, thus the species is decomposing to metallic silver at temperature lower than 1000° C. The process optionally may comprise the addition of a powdered compound selected from the group of inorganic oxides, metals, and carbon-based compounds. Furthermore the process may contain additional separating and drying steps. The process is versatile, cost efficient and environmentally friendly and is used for the manufacture of silver-based particles and electrical contact materials. Silver nanoparticles made according to the process are characterized by a narrow particle size distribution. Electrical contact materials manufactured according to the process reveal improved contact welding properties.
摘要:
A mechanism for powering a combine header unit at infinitely variable speeds. A primary motor is coupled to a primary input shaft via a clutch, a variable-speed secondary motor is directly coupled to a secondary input shaft, and the header unit coupled to a header output shaft. A planetary gear-train couples the primary input shaft, the secondary input shaft, and the header output shaft to each other. A primary brake is coupled to the primary input shaft, and a secondary brake coupled to the secondary input shaft. A control circuit is employed to command the operation of the clutch, the secondary motor, the primary brake, and the secondary brake in response to operator commands.
摘要:
A drive system for a crop processing device and for a crop transport device of a forage harvester, can be operated at least in a first operational mode and in a second operational mode. In the first operational mode, the crop processing device is driven by a first drive power supplying device, and at least part of the drive power is made available to the crop transport device by a second drive power supplying device. The second drive power supplying device is a reversible, variable speed device and is solely coupled to the crop processing device when the drive system is in a second operational mode. In order to prevent a movement of the crop transport device in the second operational mode, in which, e.g., the crop processing device can be worked with a sharpening device, a stop device is suggested that stops the crop transport device in the second operational mode.