RU2228470C1 - Combined support - Google Patents

Abstract

FIELD: mechanical engineering; rotary machines requiring development of high speed and repeated starts/stops. SUBSTANCE: proposed combined support has housing with anti-friction and sliding bearings arranged inside it; mounted on inner surface of shaft are flexible metal plates which are deformable under action of centrifugal forces and are used as mounting and fastening members for outer race of anti-friction bearing during starts and stops and working surfaces of sliding bearing at main operating modes. EFFECT: increased service life and enhanced reliability of "rotor- supports" system due to separation and duplication of functions of anti- friction and sliding bearings. 1 dwg

Description

The invention relates to the field of mechanical engineering and can be used in rotary machines, which are subject to increased requirements for speed and the possibility of multiple starts (stops) of the machine.

Known combined support, which is the closest in technical essence to the proposed invention, containing a housing and placed in it a sliding bearing and a rolling bearing. In such a support, in the normal mode, one sliding bearing works, and in the “start-stop” modes, the rolling bearing takes up the load [1]. This support design allows speed separation between the hydrostatodynamic bearing and the rolling bearing. However, in the considered case, there is a deterioration in dynamic properties at transient conditions (shock loads, contact of the surfaces of the shaft and the sliding bearing during unstable motion), in addition, there is a deterioration in the structural parameters of the bearing due to the need for a lubricant supply system for the sliding bearing, which complicates the design of the bearing .

The problem to which the invention is directed is to increase the resource and reliability of the rotor-support system by separating and duplicating the functions of rolling and sliding bearings.

The problem is achieved in that in the combined support containing the housing and the rolling bearing and the sliding bearing, unlike the prototype, elastic metal plates are installed on the inner surface of the hollow shaft, which can be deformed by centrifugal forces, which serve as elements for installation and fastening the outer ring of the rolling bearing at start-ups and shutdowns and the bearing surfaces of the sliding bearing in the main operating modes.

The invention is illustrated by the drawing, which shows a combined support. The combined support consists of a housing 1 in which a rolling bearing 2, a shaft 3 and elastic metal plates 4 located therein are mounted.

The device operates as follows: when the machine starts, the shaft 3 is rotated and the load is transferred to the housing 1 through the rolling bearing 2. Torque is transmitted from the shaft to the outer ring of the rolling bearing due to the adhesion forces between the elastic metal plates and the outer ring of the rolling bearing. When the shaft rotational speed increases under the action of centrifugal forces, the elastic metal plates bend, thereby forming one of the surfaces of the sliding bearing on the inner surface of the shaft with an axial supply of lubricant. The rolling bearing is switched off from work, its outer ring rotates under the action of the friction moment of the sliding bearing. When stopped, reverse processes occur. This increases the stability of rotation of the rotor due to increased damping from the side of elastic metal plates. Under shock loads and unstable operation, the susceptibility of the bearing to damage is reduced due to the additional rotation of the shaft in the rolling bearing.

This device allows to increase the reliability and durability of the support node due to the separation and duplication of the functions of the rolling bearing and the sliding bearing of a hydrodynamic bearing in various operating modes of the turbomachine.

Sourse of information

1. RU 2073801, publ. 02/20/97 - a prototype.

Claims (1)

A combined support comprising a housing and a rolling bearing and a sliding bearing housed therein, characterized in that elastic metal plates are installed as one of the bearing surfaces of the sliding bearing in the main operating modes and mounting elements for fixing the outer ring of the rolling bearing during start-up and shutdown periods fixed on the inner surface of the hollow shaft and forming wedge gaps with the outer ring of the rolling bearing.