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The conical rotary compressor represents a solution for gases compression, for relatively small flow, in conditions of a superior energetic efficiency. Although the theoretical solution for the helical conical compressor was elaborated decades ago, a viable technology solution become possible at industrial level only after the development of machine tools with numerically controlled axes. In this paper is proposed a study, analytical and graphical, concerning the geometry of conical rotary compressor’s rotors, modelled by rapid prototyping technology. The propose modelling allow to elaborate various constructive forms for conical compressor’s rotors.

The problematic concerning the generating process uniformity, in the specific case of machining involute gear teeth with a rack shaped cutter provided by a single tooth is one of the notable challenges from gear teeth machining domain. In previous work, it has already been presented a solution of this problem, based on a graphical application in CATIA. The solution involves the modification of enveloping process ongoing, such as the circular feed motion takes place with variable speed. The variation law of feed motion speed that should be followed for smoothing the detached chip area is, obviously, different for each gear-type specific case. This paper is aiming to study the influence of generated tooth features onto this law form. Graphical and numerical applications addressing different cases of teeth numbers for the generated gear are presented and analyzed.

The hob mill is a cutting tool with a wide application for generation in machining of splined shafts. A method for profiling the hob mill for generation of square splines is presented in this paper. The analytical development was done based on a complementary theorem of surface enwrapping — the method of generating trajectories. A numerical application for a standardized spline shaft is presented. Based on the same theorem is presented a graphical application, developed in the CATIA design environment, for profiling the hob mill which generated standardised square splines.

The method of generating the gear tooth with a rack tool is applied on MAAG machine tools. Their specific cutting scheme leads to an irregular energetic loading of the tool cutting edge, during the rolling process. In this paper, we present a new method for analyzing the energetic load along the cutting edges of the rack shaped cutter, based on graphical modelling of the cutting process performed in CATIA. The energetic load smoothing is proposed to be obtained by finding an appropriate variation law for the circular feed communicated to the workpiece by toothing machine kinematical chain, during the rolling motion that permanently respects the rolling condition established between the centrodes attached to both tool and workpiece. A numerical solution in a concrete case of analysis is also included.

The modelling of a curl of surfaces associated with a pair of rolling centrodes, when it is known the profile of the rack-gear's teeth profile, by direct measuring, as a coordinate matrix, has as goal the determining of the generating quality for an imposed kinematics of the relative motion of tool regarding the blank. In this way, it is possible to determine the generating geometrical error, as a base of the total error. The generation modelling allows highlighting the potential errors of the generating tool, in order to correct its profile, prior to using the tool in machining process. A method developed in CATIA is proposed, based on a new method, namely the method of "relative generating trajectories". The analytical foundation is presented, as so as an application for knows models of rack-gear type tools used on Maag teething machines. [ABSTRACT FROM AUTHOR]

In this paper, we present a graphical method, developed in CATIA environment, based on the method of substituting circles family and dedicated to profile pinion cutters for generating interior surfaces. Hereby, the family of substituting circles associated to the worked piece (the profile to be generated) is determined at the same time to the curve transposed, in the rolling motion, to the tool centrode. After finding the position of the contact points between the generated profile and the family circles, we can determine, in the transposed family, the locus of the points from the reciprocal enwrapping profile -- the pinion cutter profile. The paper also includes two method applications, for generating a hole with square transversal section, and a pump stator with trapezoidal profile. Comparisons between the profiling results when using the graphical method, versus an analytical method have also been realized. The results are proving the coincidence between the two profiles determined as above, on one hand, and both rapidity and precision of the graphical method, on the other hand. [ABSTRACT FROM AUTHOR]

Decrease of the unitary energetic load along the cutting edge with variable working angle, by increasing of the number of cutting edges in the construction of the helical drill, and, in the same time, the accomplishment of an evenness unitary energetic load may be assumptions for decreasing of the temperature of the tool cutting edge at its periphery. This will leads to the decreasing of the tool wear rate, hence the increasing of the tool's durability. In this paper, we present experimental research on curved cutting edge drills, regarding the speed-durability dependence in processing carbon steel. We observed that durability of curved cutting edge drills is superior to durability of standard drills for the same working conditions. [ABSTRACT FROM AUTHOR]

This paper presents a simplified algorithm for the profiling of the rack gear tool to generate the active profile associated with rolling centrodes. The algorithm is based on the enveloping surfaces principles and reduces the computational problem by proposing an approximate representation of tool’s profile using only three or four points on the profile to be generated by using Bezier representations of the surfaces. The algorithm computes the coefficients of a Bezier substitution polynomial instead of computing hundreds of points on the active profile. This simplifies the solution methodology and requires only a limited number of points along the profile to be generated. The algorithm is computationally efficient and can also be used in the case when the active profile to be generated is physically measured at a few points. Examples include mill tools, splined shafts, and gears. [ABSTRACT FROM AUTHOR]