RU2336441C1 - Taper plain bearing - Google Patents

Abstract

FIELD: mechanics.

SUBSTANCE: invention relates to machine building and can be used in most industries for production of machine and mechanism shaft bearing supports operated under axial and radial loads. The taper hydro-static-and-dynamic taper-thrust surface plain bearing incorporates the shaft journal external bush with grooves on its inner surfaces. One of the said grooves, representing a circular groove, is arranged across the bearing taper generating lines and shifted relative the bearing central transverse axis towards the taper smaller base by 0.25 to 0.35 of its length. Note that working fluid is forced via the radial hole into the aforesaid groove. The bearing inner surface facing the larger base opposite the said circular groove is furnished with lengthwise recesses to form a multi-wedge inner surface of the bearing. The proposed taper plain bearing feature consisting in separating and duplicating the bearing smooth and multi-wedge functions serves to simplify its design and operation.

EFFECT: higher reliability and longer life, ease of manufacture and operation.

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Description

The invention relates to mechanical engineering and can be used in all sectors of the economy as bearings of machine shafts and mechanisms loaded with radial and axial loads and increasing the reliability and durability of machines.

A conical hydrostatodynamic support is known, comprising a sleeve spanning a shaft journal with cameras located on its inner surface transversely forming the sleeve cone with a displacement relative to its average transverse axis towards the smaller base of the cone by a value from 0.15 to 0.2 of its generatrix length, and the width of the chambers made 0.1-0.3 lengths of the generatrix of the cone [1].

A disadvantage of the known conical hydrostatodynamic support is that it remains possible to break the lubricating film in the expanding part of the support, which reduces the bearing capacity of the surface and requires significant centrifugal forces to restore the lubricating layer, as well as the use of a high viscosity lubricant, while reducing durability, reliability and service life the entire bearing assembly

The objective of the invention is to increase the reliability and durability of the bearing assembly, simplifying its design, increasing the service life, driving stability and suppressing beats of shafts and rotors.

The problem is solved using the proposed conical hydrostatodynamic sliding bearing with a conical bearing surface, which comprises a sleeve spanning a shaft pin with recesses located on its inner surface, one recess being made annular, located across the bearing cone generators with a shift relative to its middle transverse axis to a smaller side the base of the cone by a value of 0.25 to 0.35 of the length of its generatrix and through a radial hole it is brought under pressure p At the same time, longitudinal recesses are made on the inner surface of the bearing, located toward the larger base from the said annular undercut, forming a multi-ribbed inner surface of the bearing.

Design features of the proposed bearing are illustrated by drawings.

Figure 1 schematically shows a conical hydrostatodynamic plain bearing, a longitudinal section; figure 2 is a cross section aa in figure 1; figure 3 is a transverse section bB in figure 1; figure 4 is a transverse section bb in figure 1; figure 5 - bearing housing, a longitudinal section; in Fig.6 is a view of D in Fig.5; in Fig.7 - element E in Fig.4.

The proposed conical hydrostatodynamic sliding bearing is a hydrostatodynamic support and consists of a housing 1 in the form of a sleeve with an inner conical surface and a shaft 2.

The housing 1 covers the journal of the shaft 2 and on the inner surface has longitudinal 3 and transverse 4 grooves. The recess 4 is made circular, located across the generatrices of the bearing cone with an offset from the middle transverse axis to the smaller base of the cone by an amount from 0.25 to 0.35 of the length of its generatrix L, and a working fluid is supplied through the radial hole 5 to it. This inner surface, located between the end face of the smaller base of the cone and the annular recess 4, is a smooth hydrostatodynamic sliding bearing.

On the inner surface of the bearing, located toward the larger base from the annular recess 4, longitudinal recesses 3 are made having a wedge profile in cross section and forming a multi-wedge inner surface of the bearing. This part of the housing, located between the end face of the larger base of the cone and the annular recess 4, is a multi-wedge hydrostatodynamic sliding bearing.

The proposed conical hydrostatodynamic bearing operates as follows.

During transient modes of operation (start, stop), when the shaft frequency is small, the axial and radial load is transmitted to the housing through a multi-V-plain bearing, in the lubricating layer of the working clearance of which excessive pressure arises and the shaft floats due to the free passage of the working fluid along the longitudinal grooves with a wedge cross-sectional profile.

With an increase in the shaft rotation frequency in the lubricating layer of the working clearance of a smooth plain bearing, an excess pressure also arises that exerts a pop-up effect on the shaft.

Thus, a smooth plain bearing provides greater load-bearing capacity, while multi-V-bearings provide greater stability.

The proposed design allows the use of a low viscosity working fluid for lubricating the bearings, which eliminates the use of rolling bearings, which have a limited life and require lubrication with mineral oils.

Reducing the viscosity of the lubricant leads to a decrease in bearing capacity, and therefore, to a decrease in the reliability of the bearing. These features eliminate this drawback and allow for the relatively low pressure of the lubricant entering the annular undercut to provide the necessary values of the bearing capacity.

One of the disadvantages of the known conical hydrostatodynamic support [1] is the limited vibration resistance. Replacing the smooth surface with a multi-wedge one can radically change the characteristics of the support: the bearing capacity decreases, but the stability of the shaft movement increases sharply due to the appearance of additional hydrodynamic wedges in the unloaded zone. With a correctly selected lubricant supply pressure and geometric characteristics, multi-v-ribbed bearings can almost completely suppress the whirlwind and runout of rotor shafts.

The high level of bearing capacity and vibration stability can provide the proposed bearing, including multi-wedge and smooth conical sections. To a certain extent, this design can be considered as a combination of a bearing and a seal. In this case, the supply of lubricant is carried out from the wedge end, and the smooth conical part acts as a gap seal. It is advisable to use this type of support in pump units in which the lubrication and cooling of the bearing assemblies are carried out by working bodies and the medium can flow between the high and low pressure cavities.

The proposed conical hydrostatodynamic sliding bearing increases the reliability and durability of the support unit by separating and duplicating the functions of smooth and multi-v-ribbed sliding bearings, simplifies its manufacture and operation due to the simplicity of design and increases the service life.

Information sources

1. A.S. SU No. 1191638, IPC F16C 21/00. Conical hydrostatodynamic support. I.Ya. Tokar et al. Application 3786390 / 25-27, 09.09.84, 11.15.85 - prototype.

Claims (1)

A conical hydrostatodynamic sliding bearing with a conical bearing surface, comprising a sleeve spanning a shaft pin with recesses located on its inner surface, characterized in that one recess is made annular, located across the bearing cone generators with an offset relative to its transverse axis toward the smaller base of the cone by an amount from 0.25 to 0.35 of the length of its generatrix and to it through a radial hole a working fluid is supplied under pressure, while on the inner surface ti bearing located towards the larger base of said annular recesses are formed longitudinal groove forming the inner bearing surface pumps.

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