Vol 39, No 7 (2019)

Methods are considered for analysis of the kinematic and dynamic errors in reproducing programmed tool trajectories in mechatronic manipulators with control loops.

A formula for the theoretical tolerance in fitting is derived by analysis of the components in the model of parametric failure for joints with interference. The formula takes account of the life of the joint and the specified probability of fault-free operation. It is found that selection of the fit without a margin of precision does not ensure the necessary reliability of the joint, while correct selection of the margin of precision extends the fault-free operation of the joint.

The flow of viscous liquid in highly efficient commercial axial pumps is hydrodynamically analyzed. Design recommendations are made regarding the flow sections of the pump, so as to ensure a pressure characteristic with no descending section and efficient coolant circulation in a fast-neutron reactor.

A new method has been developed for the corrosion protection of steel parts: gas-phase coating application. The resulting coating is characterized by high density, chemical resistance to aggressive media, and good surface adhesion. This method may be used for parts of complex shape. The static and fatigue failure of БСт.3сп, 40, and Э10 steel is investigated, in the presence of nickel coatings of different thickness, applied at different temperatures.

The development and practical introduction of a robot hot-stamping system for compressor blades in gas-turbine engines is discussed. The benefits of this system are noted.

The finishing of the flow sections of compressor blades is considered. A sequence of operations for this purpose in an automated cycle is proposed. The development of control programs for the grinding of flow sections of the blades is discussed, with allowance for the nonuniform distribution of the margin over the blade surface.

The actual cutter geometry in precision cutting is described, and the corresponding model of the mechanical characteristics of cutting is presented.

The basing of parts is analyzed. The contact relations between the surfaces of parts are found to play a basing role. That leads to redundant basing. If that redundancy is taken into account, many problems affecting the quality, precision, and performance of machines may be eliminated.

Methods of calculating the cutting temperature in two- and three-dimensional formulations are compared. In the calculations, the variation in source intensity with increasing depth beneath the surface is taken into account.

The possibility of improving the manufacture of high-precision products by means of virtual assembly is considered. Such technology is found to significantly improve the assembly process and to reduce the associated costs.