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卷 36, 编号 5 (2016)
- 年: 2016
- 文章: 21
- URL: https://journals.rcsi.science/1068-798X/issue/view/13959
Article
Self-braking of free-wheel mechanisms
摘要
Static self-braking of wedge-based free-wheel mechanisms is investigated by means of a nonconservative boundary-element model. The distribution of the contact characteristics in the kinematic pairs of the self-braking mechanisms is established. Their stress–strain state is determined.
339-344
Increasing the load capacity and rigidity of roller–screw mechanisms by adjusting the screw surfaces
摘要
A method is proposed for increasing the load capacity and rigidity of roller–screw mechanisms by adjusting the screw surfaces. That permits the design of compact mechanisms such as automobile steering assemblies.
345-351
Optimization of stays for the machining of long stepped shafts
摘要
Special stays must be used to increase the precision and productivity in the machining of long stepped shafts. Recommendations are made for optimization of the design of a mobile stay by means of special mobile supporting rods.
352-354
Taking account of the contact-layer pliability in end clip design
摘要
An approach is proposed for taking account of various factors in the analysis of permanent and removable end clips. The factors considered are the pliability of the contact layer between the shaft and the sleeve, the diametric gap, and the pliability of the hinge section in a permanent end clip. Formulas are presented for the clamping forces and hinge dimensions. An algorithm is outlined for calculating the component transmitting the torque and axial force.
355-359
Thermal conditions in the additive manufacture of metallic parts in vacuum
摘要
Thermal conditions for the additive manufacture of components by melting metal and alloy wire are presented. In an experiment, a prototype 3D printer is used to print components in vacuum.
360-363
Lubricator casings for locomotive wheel rims
摘要
A laboratory system is developed for selecting the best casing in the wheel-rim lubricator of an electric locomotive. Casings made of high-pressure polyethylene are found to match the wear resistance of the lubricant.
364-365
Calibration of thin-walled precision pipe by transverse compression and expansion using a multisector tool
摘要
An experimental system is developed for the calibration of thin-walled precision pipe by transverse compression and expansion using a multisector tool. Formulas are derived for the basic parameters of the system.
366-370
Polymer composites based on polytetrafluoroethylene modified with motor oil
摘要
The production of wear-resistant polymer composites from polytetrafluoroethylene modified with motor oil is considered. Porous polymer blanks are steeped with motor oil and then heated.
371-375
Machining polymer workpieces on a lathe after preliminary surface deformation
摘要
Preliminary surface deformation (rolling) is proposed in the turning of polymers. The dependence of the surface roughness on the rolling and cutting conditions is derived.
376-378
Burnishing of holes with the application of a soft-metal antifrictional coating
摘要
The vibrational burnishing of holes is considered. In this technology, for which appropriate equipment is proposed, a solution of antifrictional mixture activated by ultrasound is supplied to the machining zone.
379-382
Turret head for numerically controlled machine tools with a pneumatic rotary drive for the tool disk
摘要
A simple turret head has been developed for numerically controlled machine tools. This system has a pneumatic rotary drive for the tool disk and pneumatic clamps. It may be used to replace imported models.
383-385
Automated design of machine-tool attachments
摘要
The creation of an automated information system for the design of attachments used in the machining of aviation engines is considered.
386-391
New roughing method for external surfaces of revolution of hard-to-machine workpieces
摘要
Roughing methods for the external surfaces of revolution of hard-to-machine workpieces are analyzed. On that basis, a new roughing method is proposed, with the use of both a cutter and a mill.
392-393
Analysis of the forces in the combined cutting and deforming of non-rigid shafts with tangential oscillations
摘要
The motion of the floating cutter elements in a combined tool for the machining of non-rigid shafts is considered.
394-396
Simulation of multicutter milling with tool vibration
摘要
Simulation of multitooth milling reveals the shortcomings of current CAM systems. An example illustrates the potential for expanding CAM systems so as to take account of vibration in developing the control software for numerically controlled machine tools.
397-399
Producing cylindrical gears by high-speed grinding
摘要
Continuous grinding of cylindrical gears for planetary transmissions by means of highly porous worm grinding wheels is considered. A model is developed for the interaction of the radial, axial, and tangential supply motion, permitting tooth grinding with high precision and productivity. The use of highly porous grinding wheels significantly reduces the thermal stress and improves the cutting conditions.
400-403
Hardening curves for materials with strain hardening
摘要
Experimental hardening curves are plotted for the analysis of the cutting process in strain-hardening materials. As examples, approximate formulas for specific carbon steels are presented.
404-406
Resultant cycloid trajectory in plane finishing
摘要
The formation of cycloid trajectories in plane finishing is considered. Some of their properties are described. The grid density of the cycloid trajectory is inversely proportional to the speed of the workpiece and its radial position on the lap. For free rotation of the part in the same direction as the lap, the grid density does not depend on the workpiece’s radial position at the lap.
407-409
Spark plasma sintering of cutting plates
摘要
Numerical modeling of the spark plasma sintering of square plates from aluminum-oxide and tungsten-carbide powder is considered. The rounding radius of the plates is 0.8, 1.2, or 1.6 mm. The distribution of the temperature and mechanical stress within each sample and also within the mold is determined. The results are used for preliminary assessment of the possibility of spark plasma sintering of cutting plates.
410-413
Flash formation in the pulsed laser cutting of thin-walled workpieces
摘要
A model of flash formation based on the secondary melting of the cut’s lower edge by superheated melt supplied by a turbulent gas flux is discussed.
414-416
Solving parametric assembly problems
摘要
A method is proposed for matching components in the selective assembly of bearings. The method involves selecting paths associated with redistribution of the flux. This is a procedure with a finite number of steps.
417-421