JPS5947164B2 - Self-adjusting gap bearing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of a tailing pad type bearing used for a light-load, high-speed rotating shaft.

Generally, tilting pad type bearings are used for light-load, high-speed rotating shaft bearings to prevent vibrations caused by oil whip, oil whirl, etc. However, this bearing cannot prevent vibrations caused by rotor imbalance. The present invention aims to reduce the vibrations generated by the rotor. Its structure includes a piston that is inserted into a hole in the pad holding ring and moves toward the axis of the rotor, and its head is spherical to support the tailing pad.

This piston receives pressure from lubricating oil from an oil hole provided in the pad retaining ring, and a check valve is placed in this oil hole on the side of the piston, and a spring is placed between the check valve and the piston. impose. Here, lubricating oil enters from the shaft hole of the bearing box, passes through the oil groove, and is divided into the following two paths. One side is squeezed through the oil hole in the pad holding ring, flows between the pads, and is injected into the gap between the rotor shaft and the pads.

The other oil passes through a check valve against a spring through an oil hole located coaxially with the piston in the pad holding ring, and acts to move the piston in the rotor axial direction and press the pad against the shaft. Next, this will be explained using figures. FIG. 1 shows a cross section perpendicular to the axis of the bearing, FIG. 2 shows a view taken along arrows A and A in FIG. 1, and FIG. 3 shows details of the pad portion.

1 is the shaft of the rotor, and 2 is the tailing pad that supports it.

A piston 3 is fitted into a hole 6a provided in a pad holding ring 6 and moves toward the axis 1 of the rotor. The piston 3 has a spherical head 3a and a spherical recess 2a in the pad 2.
The pad retaining ring 6 is fitted with a pressure P1 caused by lubricating oil from the oil hole 15 provided in the pad retaining ring 6. This oil hole 1
5 is provided with a valve seat 15a, and a check valve 4 is placed on the piston side. Between this check valve 4 and the piston 3, the inside 3b of the piston 3
A spring 5 is applied. Next, the operation of the bearing of the present invention will be explained.

The lubricating oil for forced lubrication enters from the oil hole 10 in the bearing box at a pressure P1 and passes through the oil groove 11, and on the other hand, the lubricating oil passes through the oil hole 12 in the pad holding ring and the throttle hole 12a provided in this hole, and the pressure decreases to P2, and the pressure is reduced to P2. 2 and into the gap 13 between the pad 2 and the pad 2. Then, it passes through the gap between the rotor shaft 1 and the pad 2 and emerges from the pad side surface 14 (FIG. 2). One side enters from the oil hole provided in the pad holding ring 6 as described above with the pressure P1, and the spring 5
The check valve is pushed against this force, and the fluid flows into the hole 6a of the pad retaining ring 6, pushing the piston 3 in the direction of the rotor axis, and the pad 2 is pressed in the direction of the shaft 1 with a force F, as shown in FIG. The force generated by the circumferential speed of the shaft and the viscosity of the oil acts in a wedge shape and becomes a force F that pushes the pad 2 away (Fig. 3), and becomes stable when this force F1 and the force F2 that pushes the pad 2 up are balanced.
When the oil pressure P is increased, the pressure difference between P1 and P2 becomes larger, so the gap between the shaft 1 and the pad 2 becomes smaller, and the effect of suppressing vibration increases. Further, although the pad 2 approaches the shaft 1 side quickly, it takes time because there is a check valve 4 in the direction away from the shaft. Therefore, it is possible to prevent the shaft from moving due to vibration or the like. That is, according to the present invention, 1). Even if the dimensional accuracy of the shaft, the dimensional accuracy of the pads, etc. are uneven, the gap force t is automatically adjusted, so the work is easy and the interchangeability of spare parts is also good. 2). The gap between the bearing and the shaft is automatically adjusted based on the circumferential speed and load of the shaft, and the pressure and viscosity of the oil.

3). If vibrations occur in the shaft, increasing the oil pressure will reduce the gap and increase the effect of suppressing vibrations.

[Brief explanation of drawings]

Figure 1 shows a cross section perpendicular to the axis of the bearing, and Figure 2 shows the section A of Figure 1.
, A arrow view, and FIG. 3 shows details of the pad part. 1... Rotor shaft, 2... Tilting pad, 3
... Piston, 4... Check valve, 5... Spring, 6... Pad retaining ring, 10, 12, 15... Oil hole, 11... Oil groove, 13... Pad and the gap between the pads, 14...the side of the pads.

Claims (1)

[Claims] 1 In a tailing pad type bearing, a piston is inserted into a hole provided in a pad retaining ring and moves toward the axis of the rotor, and its head is made spherical to support the tailing pad. receives pressure from lubricating oil from an oil hole provided in the pad retaining ring, a check valve is placed in this oil hole on the side of the piston, and a spring is placed between the check valve and the piston. Self-adjusting gap bearing.