卷 36, 编号 7 (2016)

By kinematic analysis of a planetary roller screw and analysis of the relative amplitudes and phase shifts of the harmonics of its kinematic error as a function of their relative frequencies, additional requirements may be imposed on the manufacture and operation of the screw components so as to reduce the kinematic error and increase the precision.

The manufacture of sand–polymer shaping mandrels for the production of composite components by coiling is considered.

The stress state of a unilaterally reinforced hole in a plate under axial extension is analyzed. Such reinforcement does not effectively reduce the maximum stress.

A method is developed for the computer simulation of the disk concentrator in a system for the modification of screw threads by ultrasonic surface plastic deformation.

An atomic approach to chip deformation and failure in cutting is outlined. The relation of the shear strength and the type of chip to the energy characteristics of the crystal lattice, its packing-defect energy, and the latent heat of fusion is established. The constancy of the shear with variation in the cutting conditions is related to the limiting dislocation density and the formation of an amorphous–liquid state.

Neural-network modeling permits the determination of the instantaneous extremum for a set of parameters used in predicting the optimal machining precision.

The patent activity of high-tech enterprises in the Republic of Udmurtia is analyzed. The strategies adopted at those enterprises for the legal protection of industrial property are evaluated by analysis of the patents secured in the past fifteen years.

The benefits of coordinated motion are considered. A method of determining the initial point of the positioning unit is proposed. A relation is established between the directional vectors of the positioning unit’s coordinate system and the Euler angles of the robot’s coordinate system, which are used in adjusting the coordinated motion.

The internal abrasive machining of thermoprotective rubber coatings with constant retaining force on the grinding wheel is studied, theoretically and experimentally. A model of rubber failure in abrasive machining is proposed on the basis of the work of a single abrasive grain in contact with the machined surface. A relation is established between the components of the grinding force and the normal and tangential contact stresses at the working surfaces of a single grain of the wheel.

In mining, it is important to improve the precision of geophysical instruments in mineral prospecting, especially in the exploration of oil and gas fields. The possibility of creating instruments for monitoring the neutron yield of a borehole neutron generator in neutron–neutron logging systems is considered. One possibility is to employ detectors based on natural diamonds, which are a valuable resource. Their use in hightech geophysical instruments for prospecting may be regarded as a valuable step in the efficient utilization of natural resources, which is an important goal at this time. Experience shows that Russian-made diamond detectors of the proposed design are satisfactory replacements for the instruments currently used to monitor the yield of a borehole neutron generator in neutron–neutron logging systems. Tests of the detectors in the AINK-43M pulsed neutron–neutron logging system demonstrate the improved productivity and precision of the measurement system.