Features of the Transportation Capsules with the Ground by Means of the Inflatable Shell in the Suction Head of the SPACECRAFT "Phobos-Grunt"
Engineering Education # 05, May 2016
Challenging Issues for Predicting and Validating Reliability of Sustained Spacecraft Operation
Engineering Education # 06, June 2015
Features of Running Brush Motors in Dry Nitrogen Environment When Using in Electrohydraulic Actuators
Engineering Education # 11, November 2014
Explosive Device of Conduit Using Ti Ni Alloy
Engineering Education # 04, April 2014
By the present time a great number of compounds and alloys with a shape memory effect has been known. The alloys based on titanium nickelide are the most widely spread. In space engineering there is a task of breaking a fuel conduit when separating the spacecraft from the rocket in space technology.The paper examines a procedure for design calculation of separating device of conduit using the Ti-Ni alloy (nitinol). This device can be used instead of the pyro-knives.The device contains two semi-rings from Ti-Ni alloy. In the place of break on the conduit an annular radius groove is made. At a temperature of martensite passage the semi-rings undergo deformation and in the strained state are set in the device. With heating to the temperature of the austenitic passage of bushing macro-deformation the energy stored by the nitinol bushing is great enough to break the conduit on the neck. The procedures for design calculation and response time of device are given.
Pipe couplings for shaft connection
Engineering Education # 07, July 2013
Elastic pipe couplings are used in low power drives because their application is limited due to loss of section stability under loading of comparatively low rotational moment. This results in significant performance degradation of properties of such couplings. In order to improve section stability and, therefore, to increase the transfer moment, it was proposed to fill the pipe’s internal space (between shafts to be connected) with narrow metallic rings which were mounted with some tension. Changing the number and height of rings could lead to changes of the coupling properties. A coupling with an elastic metallic assembly mounted in the pipe’s hole was developed for operation under high dynamic loads. A patent for invention of the Russian Federation was received for this coupling.
Supports for resisting axial forces in centrifugal mechanisms with heavy rotors
Engineering Education # 04, April 2013
Heavy rotating shafts with radial bearings require an additional axial support. Axial support in some mechanisms is designed poorly. This article describes a developed design of an axial support and results of its structural analysis. This design is patented in the Russian Federation. The proposed support is designed for installation on the free end of the shaft and does not interfere with the shaft’s radial float and rotation of its axis. The admissible lateral displacement of the shaft in the axial installation is 1-2 mm, and the maximum rotation of the shaft axis is 30 arc minutes. The support is suitable for the shaft of an oil turbo pump unit. This shaft is mounted with bearings; its axis has radial and angular displacements during the operation.
77-30569/315087 Form error of thin-walled workpiece fixed with cams considering the size of contact area between mating parts.
Engineering Education # 02, February 2012
The case of thin-walled workpiece fixing with n cams was considered. Algorithm of calculation of main parameters when fixing the thin-walled workpiece. Proposed algorithm differs from known algorithms because it takes the size of contact area and diagram of contact pressure into account. Dimensionless graphics were plotted for the case when the workpiece is fixed with three cams. These graphics allowed to determine contact half-angle, form error of workpiece when it’s fixed with three cams and movement of median surface’s points of workpiece under the cam and strictly between cams. The example of the calculation was included in this article.
77-30569/264652 Development of the method for calculating the cylindrical joints with a small gap for a thin-walled external member
Engineering Education # 11, November 2011
Methods of mechanical machine creating became the foundation of the developing method for calculating a thin-walled external member with all constraints taken in the account. Dimensionless parameters were used in that method to provide the engineering generality. The most important parameter is a radial gap. The final system of equations was obtained in the article; this system can be solved only by computer.
Engineering Methods of Calculations of the Connection of Details on Cylindrical Surfaces with Small Gap (if Details with Hole Are Considered Boundless). Examples.
Engineering Education # 06, June 2011
Engineering methods of calculation of the connection of details were defined with the usage of the theory of elasticity. Several graphs were acquired. The methods described in the article are easy to employ and have much in common due to the usage of dimensionless forms. The main parameter is radial gap. The methods are probabilistic, for size of the details can vary.
Definition of Tension and Travel in Covering Details on Cylindrical Surfaces with Small Gap (if Details with Hole Are Considered Boundless).
Engineering Education # 06, June 2011
The methods of definition of contact pressure affecting the hole of covering details were described in the previous article. The research was held in accordance with the theory of elasticity’s flat deformation problem. The dependencies obtained can be used to calculate tensions, travels and deformations in covering details. Several graphs for calculations of the late parameters were built.
Definition of the Distribution Diagram of Contact Pressure in the Connections of Details on Cylindrical Surfaces with Small Gap (if Details with Hole Are Considered Boundless).
Engineering Education # 05, May 2011
The lack of reliable and comfortable methods of engineering calculations of connections of the details on cylindrical surfaces with accounting of radial gap, that is somewhat of a key component in such calculation, is becoming more and more obvious. The following group of articles has to improve this situation. The calculation can generally be divided into three parts in accordance with rigidity of the detail with hole. This article is dedicated to the development of methods of engineering calculations of connections of the details on cylindrical surfaces with small gap, that can be considered as boundless in radial direction
Developing the New Construction of the Planetary Roller Screws with Flexible Nut
Engineering Education # 02, February 2011
The article is dedicated to the development of the new construction for the planetary roller screws with flexible nut. The deformation of nut gives the possibility to compensate the gaps between the details’ thread. The newly-presented feature of the construction is the installation of two collets between nut and the assembly frame. Each collet transforms axial force into redial force to press the nut.
Nutless roller screws
Engineering Education # 10, October 2010
Further adoption of the prospective roller screws is complicated because of the difficulties one can find in the process of its production. The most complicated part of a roller screw is its nut’s high-precise threading. This complication gave birth to the idea of the whole subclass of roller screws – the nutless ones. The article represents the two general designs of nutless roller screws and its analysis. Being compared to the common screws, the nutless ones proved to have a number of shortcomings and a number of advantages at the same time. That is why one can easily find some applications for the newly-invented nutless roller screws. The absence of nuts makes the technology of production much more quick, easy and cheap, and thus gives an opportunity to start production in Russia. After the successful adoption of the nutless roller screws, Russian machine-building plants will easily continue with the common ones
On the Modification of the Threading in the Details of the Planetary Roller Screws
Engineering Education # 07, July 2010
In latest time planetary screw drive mechanisms to avoid edge contact mating thread turns their details have modified the thread on rollers. Profile revolutions shaped rollers are made, performed along the arc of a circle. Most of the details after the production exposed process ofbreaking-in , which changes its initial profile. On the profile loop of roller’s thread is formed straight section approximately in the middle, the starting and ending points are the points of the initial contact of mating thread turns. A similar profile loop of roller’s thread formed in process of exploitation by reason by deterioration. This article describes the mechanisms of the new, proposed modification of the thread of their parts. They differ from the known simplification of manufacturing technology, increased load capacity and axial stiffness, which remained stable throughout the resource.
Measuring the Points of the Primary Contact Between the Details of the Planetary Roller Screws: an Experience of Development
Engineering Education # 05, May 2010
This article is dedicated to the description of the process of development of the interaction between the contacting turns of threads in the planetary roller screws. The following cases are investigated: the interaction between roller and screw; and the interaction between roller and nut. The model serves as a basis for all further calculations of the wear resistance of the roller screws, that is a major criterion for their outage. The result was achieved in accordance with the outcome of the high-accuracy measuring of roller screws’ thread shapes and some theoretical development. The derived model permits to account for the intensive tear and wear of the turns of the threading in the details of the roller screws
Spacecraft▓s Landing Devices on the Basis of Polyfoams and Cellular Designs
Engineering Education # 04, April 2010
The article describes questions of designing space vehicles landing devices which have energy absorbers constructed on the basis of polyfoams and cell structures.