STUDY OF PHYSICAL PROCESSES IN A TURBOGENERATOR END ZONE AT THE MECHANICAL DAMAGES OF STATOR CORE FASTENING

With the help of mathematical simulation of mechanical processes in the stator core fastening system of a powerful turbogenerator end zone obtained appropriateness of basic parameters changes at the break of clamp prisms heads of the stator core. It is determined that the sudden break of one or more clamp prisms leads to longitudinal oscillation of their other working heads and stiff connected with them press plate, accordingly. Although such oscillation is insignificant but propagates along the entire surface of the press plate with a maximum value in the break zone and subsequent decrease with distance from this zone and therefore can be detected with the help of existing vibration sensors by installing them on the press plate. It is possible to use a limited number of sensors due to the propagation of vibration along the entire surface of the plate. But because the vibration changes are insignificant, in this case, there is a complexity of control that requires the use of high-sensitivity sensors and great informative computing equipment. According to the sensors indices, it is possible to determine the number of breaks for clamp prisms heads of the stator core and the number of them working heads, accordingly. Besides, this effect can be used to diagnose the un-compression of the stator core tooth zone. Since one of the important ways to improve the control and diagnostics of turbogenerators is the detection, the presence of such knowledge will allow making the optimal decision for further measures. References 8, figures 8, tables 2.

Influence of the modes of shaping of sand-resin shellis on quality of the produced castings

Resin in sand-resin mixes in the course of heating at production of casting shell molds undergoes changes of a state: solid – liquid – solid. For the purpose of increase in durability and decrease in contents of binding (pulverbakelit) in mix when forming a shell, along with thermal influence, the static pressure, the resines changing in compliance with change of aggregate state was used. Basic pressure is 0.25 MPas and moves through a press plate right after filling of mix on heated up to 230 °C model plate. In 10 seconds pressure increases up to 0.35 MPas. And in 10 seconds pressure goes down to 0.2 MPas. It is experimentally defined that the castings received in the shell forms made with use of variable pressure have the minimum and uniform internal tension. Also researches showed that such castings have high purity of a surface (Rz 70–80) and lack of internal defects.

Study and Design of Sheet Metal Bending Springback Adjustable Die

A kind of U type 90°or V type 90°bending springback testing die was set up to discuss the bending springback . The springback of material can be masteried through setting up of bending springback adjusting test die without prior calculation . In order to adjust the bending angle , the T type slide seat and bending press plate were used and the adjusting of bending radii was implemented by replacing the adjusting axis of bending radii. At first, if the springback value of the sheet metal made sure for the die design , then the die was designed , the large of works for repaired and tested die were reduced and it will be the `most convenient for the die designer.