Research of evaluation criteria quality control of the worked oil, charged into the main gearbox of «VR-14»

Abstract

The main unit of the helicopter transforming torque from the motor shaft to the rotor and to the drives of the helicopter units is the main gearbox. The operating conditions of the reducer relate to the field of high-cycle fatigue. Oil is supplied by the gearbox lubrication system, to reduce the main gearbox mechanisms kinematic connection working parts friction coefficient and it necessary cooling. The reliability of the lubrication system largely depends on the quality of the oil used in accordance with the regulatory requirements for it, which regulate the properties of fresh oil. Regulatory requirements contain indicators that characterize its reliability, but do not reflect the requirements imposed on the properties of oils that are in use. The working oil requirements are presented by the product developer. It is used and indicated in the chemotological map of the design documentation with the reflection of these requirements and in the operational documentation. The quality control evaluation criteria of the «BP-14» main gearbox of Mi-8AMT / MTV (Mi-8) helicopters is discussed in the article. The measures aimed at improving the reliability, preserving the quality of the used oil and evaluating its parameters, as well as ensuring the durability of the whole mechanism. It was found in the course of studying the requirements for fresh oils and workers that the existing requirements do not allow us to estimate the real state of the oil and the technical condition of the system as a whole due to its partial replacement with fresh oil for different ones. The characteristics of the oil deteriorate, and at the during operation there are no requirements for oil having a working life in the design and operational documentation. The article proposes to define the following indicators for determining the quality of working oil and deciding on further operation: “determining the amount of mechanical impurities” according to GOST 10577 and “determining the purity class” according to GOST 17216