The processing of the piece surfaces involves the transformation of the blank into a piece, the defining characteristics of the surfaces (the form, dimensions, deviations, etc.), depending to a large extent on the parameters of the generated processes of the surfaces. Generating surfaces by enveloping represents a complex problem, this mode of generating being a constant concern of researchers due to its advantages. A very important issue is the cutting edge profiling of the future tool, which will generate the wanted profile of the piece. Throughout time, researchers have studied the problems of enveloping surfaces and stated theorems related to them, based on which practical solutions have been conceive to determine the generating and generated surfaces form. The paper presents an overview on study methods for reciprocally enwrapping surfaces, as well as methods for profiling tools for generating helical surfaces by the kinematic method and by the method of decomposing the helical movement. This review can represent a basis for future research articles and projects.

The paper presents a new deep drawing sheet metal method in which, due to the complex geometric shape of the part, there are significant variations in the level of deformation in different areas of the piece. The method aims to im-prove the quality in the deep drawing process by reducing the variation of the wall thickness of the part, caused by the different degree of stretching of the sheet in different areas of it. In the proposed method the vertical movement of the punch is completed by two vertical rotational movements of it which will have the effect the increasing the flexibility of the deformation process, the active elements occupying the most favorable position dictated by the material flow in the die. It results an improved material deformability and a higher degree of deformation. Also, the new method offers a relatively simple constructive solution of the press and does not require long auxiliary times for assembly-disassembly.

The reliability of hydrostatic installations depends on the low level of impurities in an environment with pressure at an allowable value, which avoids an accentuated wear of the individual elements of the installations. Hydraulic filters are elements that have a role in protecting the hydrostatic installations from the particles that are found in the hydraulic oil. The paper aims to present some of the elements underlying the construction of hydraulic environment filtration equipment, certain conditions that are imposed on them, as well as the main problems related to the calculation and sizing of filters.

Recently, 3D measurement systems have developed more and more in various fields. With the help of 3D measuring systems, the measurement time in design, manufacture, assembly and production is substantially reduced. In this paper, it is proposed to redesign two pieces of a helical pump (driver and driven screws) based on numerical models obtained by scanning. These models are obtained based on the processing of point clouds resulting from the 3D scanning of the respective pieces. After completing the actual scanning process, the numerical models were measured using specific software to determine the dimensional characteristics and their modeling was performed in a computer-aided design program. Subsequently, the inspection was performed by overlapping the scanned model and the CAD model of each piece, in order to be able to compare the analytical models with the real pieces. This comparison allows to appreciate the degree to which the analytical model obtained by redesign corresponds to the real piece. In this way, the ability of future pieces obtained based on the analytical model to be able to accomplish the desired functional role can be appreciated.

This paper presents the profiling of the hob mill designed to generate the active surface of the cam of a cycloidal reducer. The algorithm allows determining the active surface of the generating rack gear, which is reciprocally enveloping with the active surface of the cycloidal disk. The novelty of the algorithm, based on the determination of the intermediate surface, consists in the fact that an innovative method of determining this surface is used, called the “virtual pole” method. The method allows determining the enwrapping curve of an ordered curl of surfaces, generated in the rolling movement of two conjugated centrodes. Using the “virtual pole” method, the calculation time for tool profiling is significantly reduced and the disadvantage of the resulting error, small enough to be neglected from a technical point of view, is fully compensated by this reduction in calculation time.