SLIDING BEARING APPLICATIONS IN AIRCRAFT AND SPACE ENGINEERING

Abstract

Examples and prospects of various types of sliding bearings applications in power elements of aircraft engines and in turbopump units (TPU) of liquid propellant rocket engines (LPRE) are discussed in this article.

In the second half of the last century, piston aircraft engines were replaced by turboprop (TPE) and turbojet (TJE) engines. Almost all leading manufacturers of these motors use rolling bearings as rotor supports for the main power units. The use of sliding bearings is extremely rare and is the exception rather than the rule. These exceptions include the company Pratt & Whitney, which has been using sliding bearings since the 1950s (engine PT6A). The sliding bearings are also used in modern turbofan engines Pratt & Whitney PW1000G series. The use of sliding bearings as a support for planetary gearbox elements has a number of advantages over rolling bearings, since under normal operating conditions such supports have a significantly longer service life.

In rocketry, sliding bearings are used as supports for a LPRE TPU. Examples of such supports are hydrodynamic sliding bearings of the first German missiles during the Second World War (one of them was the FAU-2) and Soviet missiles developed by S.P. Korolev and V.P. Glushko. As our analysis has shown, in the 50s the use of sliding bearings in LPRE was abandoned due to a number of advantages of rolling bearings over sliding bearings, especially taking into account the very short service life of these engines (hundreds of seconds). Recently, however, sliding bearings as supports for a TPU have been attracting more attention again due to the development of reusable missile systems with a sharp increase in required service life. Although the results achieved for TPU with rolling bearings still provide the required durability, studies of the sliding bearings for TPU design with increased service life are relevant.

The data obtained as the result of the analysis describe existing practice of using sliding bearings in units of aircraft and rocket engines, as well as the prospects for their further use.