NUT FOR THREAD STOP
Yu. V. Rodionov
Penza State University of Architecture and Construction, Penza, Russia
e-mail: dekauto@pguas.ru
S. V. Sumenkov
Penza State University, Penza, Russia
e-mail: tm@pnzgu.ru
A. S. Sumenkov
Penza State University of Architecture and Construction, Penza, Russia
e-mail: dekauto@pguas.ru
Abstract. In engineering products, a significant part of the connections are formed using threaded connections, the functioning of which largely determines the reliability of mechanisms and assemblies. To preserve the invariability of the tightening of threaded connections during the operation of vehicles, a nut is presented, in which the internal thread is divided into two parts with different geometric parameters. Nut thread profiles made with different profile heights are described. The first profile height is equal to the height of the initial contour with sharp vertices, and the other one is equal to the standardized height and rounded vertices. When assembling the connection between the increased working height of the nut thread profile and the internal diameter of the bolt thread, the necessary tightness is provided. In the zone of the upper section of the outer diameter of the thread of the nut, the metal is elastically deformed, therefore, when the bolt and nut are connected, an interference is formed with an increase in the coefficient of friction, which determines the operational reliability of the connection.
The optimal ratio of the lengths of sections with different profile heights has been determined to ensure the necessary increase in the locking properties of threaded connections, depending on the specific operating conditions of vehicles.
Conducted laboratory studies on a specially made stand showed the reliability of the initial scientific hypothesis, suggesting that the stability of tightening a threaded connection depends on changes in physical parameters associated with the distortion of the crystal lattice and changes in the density of dislocations that occur in the process of thread formation using a particular technology and during its operation. .
A technique for accelerated testing based on the creation of an additional unscrewing torque has been developed, which can significantly reduce the amount of testing and predict the time after which it is necessary to re-tighten the connection.
The nut is designed for repeated use during reassembly with retention of locking properties during the repair of various technical devices, including cars.
The technology for the production of the proposed nut is simple and economical and involves the use of universal screw-cutting equipment available at any repair company.
In further studies, it is planned to conduct long-term operational tests of vehicles in order to confirm the reliability of the proposed nut for thread locking at the same time as achieving the simplicity of the product and high manufacturability.
Key words: nut, threaded connection, tightening stability, thread profile.
Cite as: Rodionov, Yu. V., Sumenkov, S. V., Sumenkov, A. S. (2022) [Nut for thread stop]. Intellekt. Innovatsii. Investitsii [Intellect. Innovations. Investments]. Vol. 1, pp. 147–155, https://doi.org/10.25198/2077-7175-2022-1-147.
