Vasilenko Anatoliy Vitaljevich

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Abstract

1. Actuality and purpose of work.

    Pressing out of pressure couplings of a type «shaft - bushing» can be done by two methods: «Dry» pressing out and hydropressing out.
     «Dry» pressing out of bushings is carried out by the pullers of various constructions.
    We can choose a puller with the proper developed effort for pressing out of majority of pressure couplings of a type «shaft - bushing» and we can apply him, if the construction of this knot allows. Pullers are wide-spread, because they are convenient to operate, simple in design and ease to transport. The increase of using press fits in machine building which have a member of advantages comparing to pin and slotted joints contributes to the wide-spread usage of pullers.
    The purpose of the work is to develop the recommendations on metal consumption lowering of hydraulic puller with an outward capture at providing required power and strength descriptions of this device for diminishing the financial expenses on its manufacturing.

2. Supposed scientific novelty.

    It is assumed to decide the followings problems to achieve within the framework of master's degree work the defined purpose:
- to define forces, operating on the components;
- to create the solid models of basic knots of a hydropuller;
- to explore the stress-deformed state of components;
- to develop recommendation on optimization of construction of knots details of hydropuller in order to decrease their metal consumption.
    This work can become the example of decision of a problem of puller components (and other mechanisms) through the FEM and unique certificated programmatic complex ANSYS.

3. Estimated practical result.

    In this master's degree work it is assumed to attain the decrease of a hydropuller components metal consumption, and thus, decrease of metal consumption of the whole device without the change of its power descriptions.

4. Review of information about pullers.

     A lot of printing materials and internet sources have been searched to get acquainted with existent information about application, constructions and designs of pullers. The result of these searches are the following.
    In a general case a hydraulic puller consists of two elements:
1) a knot of capture, intended to catch the bushing, which is taken off, and allows to change the diameter of capture and length of captures;
2) hydraulic jack, creating force of pressing out.
     The scheme of the rolling bearing pressing out with the help of a hydraulic puller is shown on a fig. 1.

     The analysis of different illustrations of pullers, conducted mainly on internetsources, has shown that there are a large variety of constructions of this device, which change depending on a firm-producer.
    I haven’t succeeded in finding the definite procedures of puller designing (a search has been conducted in the Russian, Ukrainian and English languages). Therefore the conclusion must be drawn that while of probability it is possible to draw conclusion, that while a puller designing one point is followed: whether it is capable of fulfilling its function to press out of pressure couplings of a type «shaft - bushing». The variety of constructions is explained by the distinction in achieving other aims which can be: simplicity of construction, specialization on pressing out of certain components or, vice versa, standardization of application, realization of some innovations and other.
    A text file, devoted to a design of puller, has been found in the Internet. The research of the possibility designs the puller components with their laying out by different eventual elements and possibility to determine the forces, operating on the components of a device is conducted in this work [1].

5. Theoretical basis of calculations.

    Depending on the construction of puller capture knot components are undergone bending tensions, squeezing tensions & cutting.
     Jaw’s are subject to the clean direct bending.
    The radius of curvature of neutral layer is determined from the following equation:

    where is a radius of neutral layer,
          is a bending moment, causing the bend of beam along the plane of z,
          is the module of Jung, ,
          is an axial moment of inertia of area of section.
    Calculation formula for normal tensions at the clean direct bend of prismatic beams:

    where is the shortest distance from a point tension determined in which, to the neutral axis [2].
    The axes of knot of capture work on a cut. A cut is similar to a change.
     Tangent tensions of a change (cut) are determined from equation [3]:

    where is cutting force in a transversal section,
           is an area of cut.
    Calculations on durability of hydrocylinder imply determination of thickness of wall of cylinder, thicknesses of lids (heads) of cylinder, diameter of plunger, diameter of hairpins or screw-bolts for fastening of lids.
    The thickness of wall of the onelayer thick-walled cylinder is determined on a formula:

    where is conditional pressure, equal (1,2.1,3) P ;
          is the assumed tension on tension, Pa;
          is a coefficient of transversal deformation (coefficient of Puasson).
     The thickness of wall of the thin-walled cylinder is determined on a formula [4]:

6. Conclusion.

    Master's degree work on a theme "Development of design recommendations on metal consumption lowering of hydraulic puller Q=10t based on the analysis of the stress-deformed condition of components using method of finite elements and ANSYS program" has the definite orientation on practical application of its results.
    The review of information on the theme of work allows to say that pullers are a widespread device dismantling of pressure couplings of a type «shaft - bushing», however it’s difficult to find information concerning the puller design.
    Master's degree work results can become the basis for creation of method on optimization of puller components design.

List of references:

1.  Department of Mechanical, Materials and Aerospace Engineering // Final project: pulley puller. - http://www-mae.engr.ucf.edu/eml4535/samplefinal.pdf
2. Agamyrov Levon Vladymyrovich // Íîðìàëüíûå íàïðÿæåíèÿ ïðè ÷èñòîì ïðÿìîì èçãèáå (Íàâüå, 1826 ã.) - http://www.mysopromat.ru/cgi-bin/index.cgi
3. Agamyrov Levon Vladymyrovich // Îïðåäåëåíèå âíóòðåííèõ ñèë, íàïðÿæåíèé è äåôîðìàöèé ïðè ñäâèãå - http://www.mysopromat.ru/cgi-bin/index.cgi
4. A.A. Kononov, D.J. Kobzov, J.N. Kulakov, S.M. Yermashonok // Ãèäðîöèëèíäðû - http://gidravl.narod.ru/gidrocil.html#14

     This abstract of thesis is not final, because master's degree work is on the stage of development and will be ready to November, 2006. If you want to familiarize with its materials, you can write to author.