Open Access
Access granted
Subscription Access
Vol 36, No 12 (2016)
- Year: 2016
- Articles: 18
- URL: https://journal-vniispk.ru/1068-798X/issue/view/14011
Article
Optimal technological base for long workpieces
Abstract
A method is proposed for calculating the technological base in the case of long stepped workpieces, each step of which is a solid of revolution. The method is based on contactless measurement of the cross sections of the cylindrical segments. Optimization of the axial base ensures the most uniform distribution of the margin over the cylindrical surface.
991-994
Torsional rigidity of harmonic gear drives
Abstract
A model is proposed for harmonic gear drives. The model takes into account that harmonic engagement involves multiple pairs and multiple zones and also takes account of the manufacturing and assembly errors, the deformation of the drive components, and the adjustment of the gaps in the engagement under load. By means of the model, harmonic gear drives with high torsional rigidity may be designed.
995-998
999-1000
Design of heavy-duty bearings with oil–air lubrication
Abstract
Analytical formulas are obtained for the thermal state of a bearing with oil–air lubrication; the viscosity class of the lubricant is taken into account. Recommendations are made regarding the structure of the oil-supply channels and the sealing of the frictional module.
1001-1003
Surface microgeometry after selective laser sintering of metal powder
Abstract
A multifactorial model is proposed for the surface microgeometry after selective laser sintering of metal powder. The dependence of the microgeometry on the following dominant factors is established: the laser power, the speed of the laser beam, and the scanning increment.
1004-1007
1008-1011
1012-1016
Diamond cutting of granite
Abstract
The cutting of granite by a polycrystalline diamond tool is studied, so as to determine the force required in the process. This information is needed in the design of a test bench that may be used in certification of rock-cutting tools.
1017-1019
1020-1024
Multifunctional equipment for machining gas-turbine components
Abstract
A multipurpose grinding and milling center for machining the blades of gas-turbine engines is described. The characteristics of a prototype Russian SXS735TC2 multifunctional system are presented. The individual components of the system are analyzed.
1025-1029
Composite hard-alloy end mills
Abstract
One-piece hard-alloy end mills are characterized by excellent wear resistance but they are too expensive, on account of the frequent shaft failure. Multicomponent hard-alloy end mills are even more expensive. In many operating conditions, however, composite hard-alloy end mills are competitive with onepiece and multicomponent mills and are much less expensive.
1030-1032
Parametric self-excitation of a dynamic end-milling machine
Abstract
The parametric self-excitation of a dynamic end-milling machine is considered. Parametric selfexcitation, accompanied by stability loss, significantly impairs the properties of the system. The factors affecting parametric self-excitation include the cutting conditions—in particular, the tool speed—and the tool geometry, which determines the orientation of the cutting forces. Some regions of stability during parameter variation are noted.
1033-1039
Cutting-force components in turning by tools with no cutting tip
Abstract
Turning by tools that are characterized by a linear or curved cutting blade but have no cutting tip is studied experimentally. The influence of the depth and cutting speed, the supply, and the cutter inclination on the components Pz and Py of the cutting force is investigated in inverse and direct cutting.
1040-1043
Fast drilling of small-diameter holes by core flat drills
Abstract
Attention focuses on the fast drilling of small-diameter holes by core flat drills, hard-alloy drills, and unidirectional drills with the supply of working fluid to the cutting zone. Means of improving the productivity are discussed. The best approach to drilling small-diameter holes is outlined.
1044-1047
Model of formation of processing errors intragrinding
Abstract
A model is proposed for the errors in internal grinding. It may be used in a system for optimizing the automatic cycles so as to ensure specified precision and surface quality. The model takes account of all the basic types of errors observed in internal grinding: the error in the diameter, noncircularity, radial runout, noncylindrical form, fluctuation of the longitudinal profile, and total radial runout. The margin actually removed in the internal grinding of circular and noncircular workpieces is considered. The renumbering of the radius of cross section g from which machining begins in pass i of step z is described.
1048-1053
1054-1055
1056-1057
Uncertainties in measuring the compressor-blade profile in a gas-turbine engine
Abstract
The proposed mathematical model permits assessment of the uncertainties in measuring the profile of compressor blades in a gas-turbine engine. The following geometric parameters may be calculated by means of the model: the radius of the input and output edges; the maximum profile thickness; the profile thickness at the input and output edges; and the chord width. The model may be used to determine the probability characteristics of the uncertainties in measuring the compressor-blade profile in a gas-turbine engine.
1058-1065