The thrust bearing with fluid pivot

Along with significant advantages, bearings with self-aligning thrust pads on a mechanical support and bearings with an alignment system have many disadvantages, such as the lack of damping of axial vibrations, axial subsidence of the supports under the action of axial forces, axial subsidence from mechanical wear of the supports of the bearing elements.

To solve these problems, the company “TRIZ” has developed thrust damper bearing PUD TRIZ with fluid pivot using the hydrodynamic pressure of the oil wedge to form a liquid (hydrostatic) support of the bearing pads. Such a bearing has the main advantages of thrust bearings with self-aligning pads and bearings with a compensating alignment system. These advantages are realized due to the flow of a part of the lubricant from the hydrodynamic wedge into the cavity on the back side of the thrust pad (surfaces of the housing), which ensures the formation of a hydrostatic pressure buffer on the back side of the pad. Thanks to this, the pad floats and is installed in space in such a way, until the balance of forces and moments occurs for the given mode of operation (similar to a pad with a mechanical support).

Thrust damper bearing allows you to eliminate the phenomenon of axial force subsidence of the node, eliminate mechanical supports from the bearing structure, thereby eliminating additional axial subsidence when the bearing surfaces in contact are crushed, and also reduce the axial dimension of the node. The formation of a hydrostatic layer of lubricant on the rear side of the pad will provide the bearing with additional noise suppression and damping, which will reduce axial vibration and rotor rocking.

The thrust damper bearing – PUD

To ensure more stable operation of the rotor, under the condition of uneven load on the bearing elements, the company “TRIZ” has developed a thrust bearing with a spherical abutment (PUDS) of the bearing ring on the bearing housing through hydrostatic support – PUDS TRIZ with a liquid support.

Between the spherical surfaces of the thrust ring and the housing, lubricant is supplied from the cavity (pocket) on the back side of each pad. When the bearing receives an axial load, part of the lubricant from the hydrodynamic wedge flows through the hydrostatic pocket of the pad into the annular groove on the spherical surface of the thrust ring. A hydrostatic pressure circuit is formed between the spherical surfaces, which allows the spherical surface of the thrust ring to float on the layer of lubricant and settle (turn) in the desired position under the influence of an uneven load on the pads. This design allows for an even greater reduction of noise and damping, and also has the ability to equalize the load between the load-bearing pads, which has no analogues.

The thrust damper bearing PUDS – with fluid pivot and a spherical abutment

Thrust bearing with alignment on a spherical surface
(after bench tests)

ADVANTAGES OF BEARINGS WITH LIQUID SUPPORT:

• -high leveling and compensating ability;

• -provision of double bearing capacity;

• -ensuring highly efficient leveling of the load on the load-bearing elements;

• -minimization of axial subsidence from the influence of axial forces;

• -absence of axial subsidence from mechanical wear of supports of bearing elements;

• -redistribution of the force on the bearing blocks in case of uneven axial load;

• -long service life, guaranteed six-year mileage;

• -reducing the number of parts;

• -built-in electroerosive destruction protector;

• -scrapers provide supply, removal and removal of oil;

• -TRIZ tangential and radial cooling is used in the pads;

• -low power losses;

• -compact;

• -adhesion of the anti-friction layer with the substrate is 30% higher;

• -a standard lubrication system is used;

• -ease of maintenance.

Comparison of the number of elements:
a) thrust bearing on a liquid basis; b) thrust bearing with an alignment system

Bench tests of thrust bearings on a liquid basis showed effective damping in modes of increased vibration with high axial load.

Bearing test mode