JPS61236916A - Sliding pad bearing - Google Patents

Abstract

PURPOSE:To obtain the bearing characteristic and increase load capacity by setting a bearing housing to be opposed in slidable ways to the plane vertical to the nearly center line of a bearing pad, thus preventing the generation of the force for inducing the swing turn of the shaft. CONSTITUTION:Two sliding pads 2 having the plain back surface are accommodated into a lower housing 3' so as to be slidable between a slidable surface 7 through a plurality of rollers 5. Further, the sliding pad 2 is position-held into the lower housing 3' by a spring 8. The hydraulic pressure for supporting a shaft 1 by the wedge action of an oil film Z during the revolution of the shaft 1 is generated, and the sliding pad 2 moves freely along the slidable surface 7. Therefore, the swing turn of the sliding pad 2 is suppressed in order to suppress the reaction force in the vertical direction for the nearly center line OM of the sliding pad 2 onto the shaft 1, and the stable characteristic can be obtained, and high load can be supported.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a sliding pad bearing in which a bearing pad rotatably supporting a shaft can slide within a housing.

<Prior Art> Tailing pad bearings are generally used as bearings that support the rotors of high-speed rotating machines such as compressors and turbines.

As shown in FIG. 7, which shows the cross-sectional structure of this tailing pad bearing, and FIG. 8, which shows its cross-sectional shape as seen from the Stored and each tailing pad 02
is configured to be tiltable about the support seat X as a fulcrum. Further, an oil supply hole 04 is bored in the upper housing 03.

Oil supply hole 04 during rotation of +11101? The oil supplied through the shaft 01 forms an oil film Yt- between the shaft 01 and the tailing pad 02, and the kernel oil 8! ! Axis 0 in Y due to wedge action
Hydraulic pressure necessary to support 1 is generated.

Such a tilting pad bearing has the advantage of exhibiting stable operating characteristics without producing unstable phenomena such as oil whirl or oil whip that are seen in gastrointestinal bearings. That is, each tailing pad 02 has its support seat
Since it is freely tiltable about the support seat X, it cannot bear a moment and tilts so that the resultant force of the pressure distribution in the oil films Y on the left and right sides of the support seat X balances the rotation of the support seat X. Therefore, only the resultant force in the direction connecting the center of the shaft 01 and the support seat X acts on each tailing pad 02, and the supporting reaction force from both tailing pads 02 is always directed toward the center of the shaft 01. . As a result, even if the eccentricity of the shaft 01 changes with respect to the dynamic load applied to the shaft 01, no force in a direction that causes it to swing around is generated, and the tailing pad bearing exhibits extremely stable characteristics.

<Problem to be solved by the invention> Although the tailing pad bearing has better dynamic characteristics than other bearings, the support seat X of the tailing pad 02
has a small circumferential width b (see Fig. 7), and this width b''
ft: If it is too large, it will not be able to tilt freely and will be subject to a moment load, making it impossible to exhibit its original characteristics.

If @b of the support seat X of the tailing pad 02 is small, the surface pressure of the lower housing 03' that receives the support seat Xt will be high. If the shafts are rounded and brought into contact with each other, the surface pressure will be excessive and elastic deformation will occur in the contact area.As a result, the contact area will increase and the tilting movement of the tailing butt 02 will be restricted. The tailing butt bearing will not be able to fully demonstrate its original function. Furthermore, since the tailing pad 02 is supported at the center, it may deform due to bending, especially when supporting a large load.

Problems such as changes in the curvature of the sliding surface with '@01 also occur.

The present invention relates to such conventional tailing pad bearings as described above. , due to some minor problems, the passenger load was reduced to 11Lt.
- It is an object of the present invention to provide a sliding pad bearing that can maintain stable performance even when subjected to shocks.

Means for Solving the Problems> The present invention provides a bearing comprising a plurality of bearing pads for rotatably holding an @ in a bearing housing, in which a contact between the inside of the bearing housing and the back surface of the bearing pad is provided. The opposing surface is a plane perpendicular to the approximate center line of this bearing pad.

The bearing pad is slidably provided on the plane.

Function: The back surface of the bearing pad is in contact with the bearing housing approximately evenly over its entire area, and as a result of the surface pressure being distributed approximately evenly, it is possible to stably support a large load. Furthermore, the bearing pad slides in a direction that eliminates the force that causes the shaft to swing, resulting in extremely stable operating characteristics.

<Embodiment> As shown in FIG. 1 showing the cross-sectional structure of an embodiment of the sliding pad bearing according to the present invention, and FIG. 2 showing the cross-sectional structure in the direction of the A sliding pad 2 is housed therein, and an oil supply hole 4 is bored in the upper housing 3 as in the conventional model. The back surface of each of the sliding pads 2 is made of a flat surface,
The sliding surface 7 of the lower housing 3' is also formed of a flat surface, and the sliding surface 7 of the lower housing 3' is parallel to the central axis O of the sliding pad 2.
It is perpendicular to M. Each sliding pad 2 is configured to be able to slide along the sliding surface 7 via a plurality of levers 5 interposed between its back surface and the sliding surface 7, and has the strength to support its own weight. It is held in position within the lower housing 3' by a spring 8. In addition, ζru5
Their positional relationship is maintained normally by the retainer 6.

The oil supplied through all the oil supply holes 4 while the shaft 1 is rotating is
an oil film 21 is formed between the sliding pad 2 and the sliding pad 2;
Hydraulic pressure necessary to support the shaft 1 is generated in the kernel oil@2 by a wedge action.

By the way, the sliding pad 2 is attached to the lower housing 3.
Since it can freely slide along the sliding surface 7 of
The bearing cannot carry a load in the direction parallel to shaft 1, so no reaction force is applied in the same direction to shaft 1, and the oil film 2
The resultant force of pressure is always directed toward the center 0 of axis 1. In this way, no matter what the relative displacement of %4111 with respect to the sliding pad 2 is, the sliding pad 2 does not exert a reaction force on the axis 1 in the direction perpendicular to its approximate center line OM, so the deflection of the axis 1 is reduced. Rotation is suppressed, and the sliding pad bearing exhibits extremely stable characteristics.

In addition, since the sliding pad 2 is supported almost uniformly on the sliding surface 7 over its entire back surface, it is not subject to the locally high surface pressure that occurs on the support seat of conventional tailing pad bearings. The oil film 2 is not formed and can support a high load, and the sliding pad 2 is not deformed by bending, and the formation of the oil film 2 is stabilized.

As shown in FIG. 3, which shows the cross-sectional structure of another embodiment of the present invention, there is a hole on the back surface of the sliding pad 102.
105t- provided, oil supply hole 107 and throttle 106 here
This is also possible by supplying high-pressure oil through the pad 1 to hydrostatically lift the sliding pad 102 from the lower housing 103', thereby minimizing the frictional resistance between the sliding pad 102 and the lower housing 103'.

Furthermore, in this embodiment, a plurality of thin plate springs 108t'' having a small wave shape as shown in FIG. A damping effect is provided by the squeezing effect of the oil interposed between the springs 108. In FIG. 1, 101 is a shaft, 103 is an upper housing, and 104 is an oil supply hole.

Furthermore, as shown in FIG. 5 showing the cross-sectional structure of another embodiment of the present invention and FIG. 6 showing the cross-sectional structure taken along the arrows 1--2, a pocket 205 is provided on the back surface of the sliding pad 202, and a pocket 205 is provided on the back surface of the sliding pad 202, and a pocket 205 is provided on the back surface of the sliding pad 202. Pocket 2 through 207 and diaphragm D 2061
In order to floatingly support the sliding pad 202fc by the high-pressure oil supplied to the sliding pad 202f, the back surface of the sliding pad 202 may be set in a cylindrical shape centered on an axis parallel to this to provide a self-aligning effect. It is possible. In the figure, 201 is a shaft, 203 is an upper housing, 203' is a lower housing, and 204 is an oil supply hole, and these functions are the same as in the previous embodiment.

<Effects of the Invention> According to the present invention, the facing surfaces of the bearing housing and the back surface of the bearing pad are made into a plane perpendicular to the approximate center line of the bearing pad, and the bearing pad can be slid on the plane. This prevents the generation of forces that would cause the shaft to sink and whirl, resulting in stable bearing characteristics. Furthermore, since there are no localized excessive surface pressure points, the load capacity t can be increased.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of one embodiment of a sliding pad bearing according to the present invention, FIG. 2 is a cross-sectional view taken along arrows -■, and FIG. 4 is a perspective view of the thin plate spring, FIG. 5 is a sectional view of a sliding pad bearing according to another embodiment of the present invention, FIG. The figure is a cross-sectional view of a conventional tailing pad bearing, and FIG. In the figure, 1.101, 201 are shafts, 2, 102, 202 are sliding pads Th, 31103.203 are upper housings, 3', 103', 203' are lower housings, 5 is rollers, °7 is sliding surface , 8,108 are springs.

Claims (1)

[Claims] A bearing comprising a plurality of bearing pads for rotatably holding a shaft within a bearing housing, wherein the opposing surfaces of the inside of the bearing housing and the back surface of the bearing pads are aligned with respect to the approximate center line of the bearing pads. A sliding pad bearing, characterized in that the bearing pad is slidably provided on a perpendicular plane.