The authors propose in this paper testing of materials used in dental constructions and dental cutters used for their processing on an electric stand, made by the authors. The stand will be equipped with a transmission that ensures variation of the rotation speed of the cutter from 3000 to 30000 rpm, variation of the sample rotation speed of the tested material from 10 to 300 rpm, vertical and horizontal plane and horizontal rotation mechanisms. The operation of the stand is considered to be simple. In order to carry out the tests, it is necessary and obligatory that the sample preparation operation is carried out in accordance with the validation standards, namely, the knowledge of the sample material, the mechanical properties, the dimensions and their weight. After mounting the samples and the cutter on the stand, the pressing force is established by adding additional weights, the rotation speed of the sample is set and the rotation speed of the cutter is also set to the horizontal movement speed to the cutter (measured in microns) by means of a micrometric screw mounted on the table stand acting on the sample holder.It measures the test time, determines the shape, dimensions and the weight of the samples after each period of time. Following the determinations we can observe the proportionality of the friction force with normal reaction, the connection between the coefficient of friction and the rotation speed during the test, the quality of the sample surfaces and the milling cutter subjected to the test.The study was conducted to determine the wear properties of dental cutters used in dental laboratories, where many materials with different mechanical and technological properties are used.
Therefore the specialists must to recommend to the workers that use thermal engines that equip the motor vehicle, to use revolution regime that leads to values determining , in the same time with the obtaining of the full power of the engine and using more of it. It was taken in study two situations of using (in our case) thermal engines that equip agricultural machines. Stationing work, when the engine power is used to action the work equipment, hydraulic installation, wheels of a the most frequent thing power price; Work during moving, when is made traction work and traction work combined with the action of the equipment of work. The experiments were made on tractor in the experimental field of S.D.E.B.M. on plan soil.For measuring the motor moment at the power plug it was used a voltage meter with moment motor. For revolution measuring were used a intensity translator. For determining, traction force were used a double . The same results were made in field are populated in table no.1. Depending on the efficiency of traction r\= 0.7...0.75 and of the transmission mechanical efficiency of the final shaft of the power plug r|p = 0.91 ^ 0.95, the real power sent for auto moving is approximate 25% from the engine power respective approximate 18kw, staying free for the work percent approximate 60kw , that means a big capacity of work. (table 1). It is recommend too the workers that use thermal engines that equip the motor vehicle, to use revolution regime that leads to values determining , in the same time with the obtaining of the full power of the engine and using more of it.
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