RU21941U1 - SLIDING BEARING INSERT - Google Patents

Description

g-0, (G1D2 - T546

MPK7 F16C / 1702, F01D25 / 16

SLIDING BEARING INSERT

The proposed utility model relates to the field of mechanical engineering, specifically the field of turbine construction, namely, the manufacture of inserts of medium-frequency, heavily loaded thrust plain bearings, which are used in the production of sliding bearings of powerful turbine units and turbogenerators and can also be used in the field of metallurgical equipment, shipbuilding and automotive industry.

A known design of a sliding bearing shell including a steel base with a polymetallic antifriction layer deposited on the inner surface, for example, of lead bronze, to which an additional thin layer of aluminum-tin alloy is applied by vacuum ion-plasma spraying with a variable layer that grows to the surface and reaches the surface values of not less than 25% wt. tin. (RF patent No. 2154754, IPC 7 F 16 C 33/04, BI 23 2000).

The disadvantages of the known design of the liner is the lack of antifriction properties, reduced running time, which can lead to uneven distribution of load on the bearing, local increase in pressure and failure of the bearing, especially during running-in.

A known design of a plain bearing liner comprising a steel base with a polymetallic antifriction layer deposited on the inner surface, for example, of porous aluminum bronze, to which a thin layer of antifriction material, for example polytetrafluoroethylene, is additionally applied by vacuum ion-plasma spraying. (Anli Patent No. 1584842, IPC 7 F 16 C 33/04, Inventions Abroad, VNIIIPI publication, publication No. 4794 dated 02/18/1981).

The disadvantages of the known design of the liner is not high enough operational stability of the bearing shell under conditions of high loads and rotational speeds.

Closest to the claimed device, of a similar purpose for the totality of problems, is a sliding bearing shell device, in which an antifriction layer of a metal alloy is applied to the inner surface of the body of the liner made of cast iron or steel, the most common of which is babbitt alloy, for example, grades B-83. To ensure reliable adhesion of the babbitt layer to the body of the insert, grooves are usually cut in the latter to form a dovetail-type compound. (Gaevik D.T. Bearing bearings of modern machines. M .: Mechanical Engineering, 1985, adopted as a prototype)

The reasons that impede the achievement of the technical result indicated below when using the known device adopted as a prototype include the fact that a significant amount of expensive babbitt alloy is spent on the manufacture of the known device, as well as the peeling of the babbit layer from the semi-dry and dry friction modes body liner and significant wear is observed.

The desired technical result is to increase the operational stability of the plain bearing shell by increasing the hardness and strength of its adhesion to the base, reduce residual stresses in the coatings, and reduce the degree of wear of the shell and the moment of friction.

The specified technical result is achieved in the design of the plain bearing shell, which includes the body of the shell, made in the form of a hollow metal cylinder and deposited on its inner surface by thermal spraying, an antifriction layer consisting of a bimetallic alloy, for example, tin and aluminum, taken in the ratio of May. %:

Tin - 80.0 - 70.0; Aluminum -20.0 - 30.0.

The analysis of the prior art by the applicant, including a search by patent and scientific and technical sources of information, and the identification of sources containing information about analogues of the claimed invention, allowed to establish that the applicant did not find an analogue characterized by features identical to the indicated essential features of the claimed invention. The definition from the list of identified analogues of the prototype, as the closest in the set of essential features, allowed to identify the set of essential distinguishing features in relation to the technical result perceived by the applicant in the claimed device set forth in the claims. Consequently,

claimed technical solution

novelty.

The drawing shows a sketch of a longitudinal section of the liner of the thrust bearing, showing the design of the liner according to the claimed technical solution.

The design of the liner of the thrust bearing includes a body 1 made of steel. An antifriction bimetallic layer 2 with a thickness of not more than 5.0 mm was applied to the inner surface of the body 1 by a thermal spray method.

When using a bimetallic alloy as the only anti-friction layer, it contains aluminum and tin, taken in the mass% ratio: 20 ... 30 and 80 ... 70, respectively, which allows to increase the adhesion of the antifriction layer and prevent its peeling from the body the liner, to increase the reliability of the liner at elevated temperatures, arises: them under the conditions of semi-dry and dry friction.

Within these limits, the variation in the amount of the added molybdenum disulfide additive does not have a drying effect; it does not significantly affect the quality and achievement of the optimal physical and mechanical characteristics of the antifriction layer.

The manufacture of the proposed design of the liner is drained according to the well-known technology: after the fine machining of the inner surface of the body 1 of the liner, an anti-friction layer is applied by thermal spraying 2. Before spraying, the surface of the steel body 1 is preferably machined by cutting with the formation of small ragged grooves to ensure adhesion reliability anti-friction layer 2 with the body 1 of the liner. In the manufacture of the body of the liner from cast iron, such processing is not required. Spraying is carried out by spraying a powder or wire materials corresponding to the desired composition of the sprayed layer.

In the process of spraying a mixture of powders on the body of the liner in a high-temperature and high-speed gas stream, they melt and thereby provide good mechanical adhesion with the hot surface of the body of the liner and, at the same time, with each other.

The operation of the bearing block bearing is explained below in the example.

// 0 9I meets the patentability criterion

1 .. .3 MPa (10 .. .30 kgf / cm), rotor speed n 3000 .. .3600 rpm and

temperature in an oil wedge t 70 ... 88 ° С. For comparative bench tests, several liner samples were made with a bearing surface diameter of 300 mm and a length of 250 mm. These samples were made with a steel body 1 and with a variation in the composition of the substrate 2 and the antifriction babbitt layer 3 within the stated ratios of the components of the metal alloy. The test results are presented in the table.

As can be seen from the above data, the adhesion strength of the intermediate and antifriction layers between themselves and with the body of the liner of the proposed design, has significantly increased compared with the liner devices known from the prior art. In addition, due to the increased content of the molybdenum disulfide additive in the babbit layer and the implementation of the intermediate substrate layer of an aluminum-tin alloy in the sample of the proposed design, the liner hardness and strength increased, which, as a result, reduced the friction moment and wear by 18 ... 25% between shaft and plain bearing shell. The latter effect on improving the reliability of the liner under conditions of elevated temperatures that occur under conditions of semi-dry and dry friction.

W) t C

Table

Claims (2)

1. The plain bearing shell, consisting of a body in the form of a hollow metal cylinder and deposited on its inner surface by the method of thermal spraying of an antifriction layer representing a metal alloy - babbit, characterized in that the antifriction layer is made of a bimetallic alloy. 2. The plain bearing according to claim 1, characterized in that the bimetallic alloy contains the following components, taken in the ratio, wt. %:
Tin - 80.0 - 70.0
Aluminum - 20.0 - 30.0