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Pozycja Teoria i praktyka eksploatacji przekładni ślimakowych(Wydawnictwo Politechniki Łódzkiej, 2006) Sabiniak, Henryk Grzegorz; Red. nauk. Wydziału: Urban, Tadeusz; Lawrowski, Zbigniew; Wilk, AndrzejWorm gears are used for drive transrnission as reducers. They are practically not applicable as intensifiers. Worm gears are characterised by great compactness of structure, which is a consequence of the capability of achieving very large ratios, up to 70, at one degree. Still cases of greater speed reductions at one degree are also known. The gears can transrnit quite heavy loads, which results from the number of pairs of teeth in a worm and a worm wheel working subsequently. The minimum number of pairs of teeth in continuous cooperation in cylindrical worm gears usually does not fall below 2 (Fig. 2), whereas in globoidal worm gears the number of pairs of teeth being at the same time in the mesh can reach 5 (Fig. 2) or more. Moreover they are silent-running. Among the problems most frequently occurring in the process of the gear exploitation there is a proper selection of lubricator, its amount, and the way of complementing it as well as the frequency of its replacement. This problem results from a serious fault characteristic for worm gears. Due to a specificity of their teeth geometry a great amount of heat is ernitted during the work. Thus the exploitation of the gears consists mainly in quick reception of the losses of thermal energy in the mesh and in dissipating it as quickly as possible. In order to offer a solution to the above problems mathematical relations, graphs, tables and appendant drawings supported by specific examples have been included in the paper. . This short description already gives a clue of the difficulty of decisionmaking on the selection of proper worm gear for drive transrnission in a given machine or a mechanical device. A description of the course of action when selecting a worm gear also offered in the paper can be helpful in such cases. The paper provides a complete idea of the elastothermohydrodynarnic lubricating theory in worm teeth as well as a complete description of mathematical and physical relations. The whole theory has been illustrated with an example. The considerations have also been supported by a description of numerous experiments made on models as well as on real gears and devoted to the type of friction taking place in the worm teeth in various exploitation conditions. The contents of the paper also include a complete selection of lubricating agents, with oils and greases. The influence of the assembling and of the gear running-in on the further exploitation parameters has been described, with a stress placed on an important feature of self-locking. The current state and the perspectives of worm gears development have been presented and further tendencies and directions in the research have been introduced.Pozycja Obciążalność i trwałość przekładni ślimakowych(Wydawnictwo Politechnika Łódzka, 2007) Sabiniak, Henryk Grzegorz; Red. nauk. Wydziału: Urban, Tadeusz; Pytko, Stanisław; Wróbel, JerzyVerification calculations are indispensable in the design process of any type of structure. Their aim is predominantly to determine whether the exploitation and load capacity limits have not been crossed in the designed structure. They are also applied in worm gears design. The results of verification calculations are the basis for determining the exploitation characteristics of a future gear. If in the design process more than one version of a worm gear has been designed, verification calculations enable carrying out elimination by resigning from the versions that do not meet the predetermined requirements. Basing on the analysis of verification calculations it is possible to decide about the choice of the finał version, the best one out of the versions developed in the design stage. In case of difficulty with taking any of the above mentioned decisions ( elimination or final choice) it is possible to return to -the stage of design calculations and draft of construction of the designed worm gear, being already equipped with the knowledge about where the "barriers" lie within the limits of the gear strain and where the safety "reserve" is excessive in its elements. Concurrent performance of two stages of design and verification calculations during gear design is widely practised and recommended, even for a single item, not mentioning a series or a type series of worm gears. Verification calculations also have other advantages. Having performed a number of experimental researches on real and model gears and having gained experiences in industry it is possible to differentiate empirical relationships, the basis for verification calculations, enabling evaluating explicitly the safety and strain of work of a given worm gear, which constitutes a good corrector of previously made calculations and drafts and of final construction solutions of worm gears based on them. The described method of joining together two stages: preliminary design works on worm gear and verification calculations is particularly effective and advantageous in toothed gears construction. It can be concluded from the above considerations that verification calculations are the finał stage of all mechanical structures design, as they confirm or deny the fact of meeting the predetermined strength and exploitation requirements by the installations. In case of worm gears design verification calculations are to determine if the following values have not been exceeded: mesh resistance to pitting, tooth root resistance to destruction, early abrasive wear of the working surface of teeth, temperature of the gear work, deflection of wormshaft. V erification calculations also include determining the finał efficiency of worm teeth mesh and of the whole gear as well as the degree of its self-locking. The paper provides numerous examples of such calculations.