JPS58142014A - floating bush bearing - Google Patents

Abstract

PURPOSE:To prevent seizure and damage of a floating bush, by forming grooves, communicated to openings of oil supply passages in the radial direction further for generating a lubricating film of dynamic pressure fluid by a wedge-shaped clearance, to the peripheral surface of the floating bush. CONSTITUTION:A floating bush 3 is rotatably mounted between a rotary shaft 2 and bearing housing 1, and lubricating oil from the housing 1 is supplied to the periphery of the bush 3 and the internal periphery of the bush 3 by oil supply passages 4 radially provided to th bush 3. Grooves 5, which are communicated to openings of the passages 4 in the radial direction further for generating a lubricating film of dynamic pressure fluid by a wedge-shaped clearance, are formed to the peripheral surface of the bush 3 in this floating bush bearing. That is, lubricating oil provided with dynamic pressure in a bearing clearance in the inside of the bush 3 stably holds to lubricate the shaft 2 and suppress vibration caused in the shaft 2 together with lubricating oil provided with static pressure forcibly fed from the passage 4. As a result, seizure and damage of the floating bush can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to floating bush bearings, particularly floating bush bearings used in superchargers.

Conventional floating bush bearings have a floating bush rotatably interposed between the rotating shaft and the bearing housing, and pressurized lubricating oil from the bearing housing.

In addition to supplying oil to the gaps on the outer circumference of the floating bushing, oil is also supplied to the gaps on the inner circumference of the floating bushing through the radial oil supply path provided in the floating bushing, and the rotating shaft is stabilized by the damping effect of the lubricating oil film generated in these gaps. It supports the following.

In this type of floating bush bearing, the floating bush is equipped with a plurality of oil supply passages extending in the 4' radial direction as described above, but the opening on the outer circumferential side of the floating bushing of this oil supply passage is When the lubricating oil is communicated with the oil supply hole provided in the bearing housing, the lubricating oil from the oil supply hole is supplied to the bearing gap inside the floating bush through the oil supply path. However, if the opening on the outer circumferential side of the oil supply path deviates from the position of the oil supply hole, lubricating oil is no longer supplied to the bearing gap on the inside of the floating bush, but instead is pushed back into the bearing gap on the outside of the floating bush by the centrifugal force caused by rotation. This causes oil leaks in the bearing gap inside the floating bush.

As a result, the rotating shaft and the floating bushing may seize.

The present invention has been made based on the above-mentioned problems, and an object of the present invention is to provide a floating push bearing that can prevent damage due to wear and tear.

The present invention is characterized in that a floating bush is rotatably mounted between the rotating shaft and the bearing housing, and lubricating oil from the bearing housing is supplied to the outer periphery of the floating bush and through a radial oil supply path provided in the floating bush. In a floating push bearing of a type that is supplied to the inner circumference of a floating push, a dynamic pressure fluid lubrication film is created on the circumferential surface of the floating bush by a horizontal space S communicating with an opening of a radial oil supply passage. ``1. The first groove tube is formed□.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of the floating bush bearing of the present invention. In the figure, 1 is the bearing nozzle 1, 2 is the rotating shaft,
is a floating bush provided between the rotating shaft 2 and the bearing nose 1. The bearing housing 1 is equipped with an oil supply hole IA that supplies pressurized lubricating oil. The floating bush 3 is provided with a plurality of oil supply passages 4 extending in the radial direction. In this example, a groove 5 is formed that passes slowly through the inner opening of the oil supply path 4 and forms a horizontal gap 11 with respect to the outer circumferential surface of the rotating shaft 2. In this example, the shape of this groove 5 is Although the groove has an arcuate shape in which the groove depth becomes narrower along the direction of rotation, it is also possible to form it with an inclined surface, etc.
The development of A and the hydraulic pressure generation state 111t-11 are shown in 211. My own figures 2 and 1
The operation of an example of the floating push bearing of the present invention described above will be explained with reference to the drawings.

When the rotating shaft 2 rotates in the direction of the arrow, the lubricating oil that has flowed through the entire oil supply path 4 into the bearing clearance inside the floating bush 3 generates dynamic pressure noise due to the wedge-shaped clearance formed by the groove 5. This dynamic pressure generation state is shown in FIG. This lubricating oil with dynamic pressure holds and lubricates the rotating shaft 2 stably in the bearing clearance inside the floating bush 3 together with the lubricating oil with a static pressure supplied under pressure from the oil supply path, and also lubricates the rotating shaft 2 due to vibrations generated in the rotation @2. can be suppressed.

FIG. 3 shows another example of the floating bush bearing of the present invention, in which the same reference numerals as in FIG. 1 indicate the same parts. In this embodiment, a groove 6 forming a wedge gap is formed on the outer peripheral surface of the floating bush 3. The groove 6 is formed by cutting off the outer peripheral surface 3Bt of the floating bush 3, as shown in FIG. The opening of the oil supply passage 4 provided in the floating bush 3 is located in the rear portion of the groove 6 with respect to the rotation axis 20 rotations. The hydraulic pressure Ft generated by this groove 6 is shown in FIG.

The operation of another example of the floating bush bearing of the present invention described above will be explained based on FIGS. 5 and 3.

When one of the plurality of oil supply passages 4 and grooves 6 is located at the oil supply hole IA as shown in FIG.
The pressurized lubricating oil passes through the groove 6 and the oil supply passage 4 to the inner bearing of the floating bush 3'f! There was an influx of
Lubricate this area. After that, rotate the rotating shaft 20 times,
When the floating bushings 3 rotate in the same direction, the lubricating oil accumulated in the grooves 6 has a relative velocity in the opposite direction to the rotation of the floating bushings 3 due to shear force.
Hydraulic pressure F? shown in Figure 5? Occur. The lubricating oil with the hydraulic pressure F lubricates the outer circumference of the floating bush 3, and also overcomes the centrifugal force caused by rotation by the oil supply passage 4 whose opening is off the center of the groove 6, and lubricates the inner bearing of the floating bush 3. It is supplied every 1k hours. This can prevent oil from running out in the bearing clearance inside the floating bush.

In addition, when the rotating shaft 2 vibrates as shown by the dotted line in FIG. Vibration of the rotating shaft 2 is suppressed through.

In the embodiment shown in FIG. 3, the groove 6 is formed into a rectangular shape when viewed from the entire outer circumference, but it is also possible to form the groove into a circular groove 6A as shown in FIG. It is not limited to the shape.

As described above, according to the present invention, lubricating oil can be sufficiently supplied to the bearing clearance between the inner and outer peripheries of the floating bushing, thereby preventing seizure and damage to the floating bushing. As a result, it is possible to increase the speed of a rotating machine using this bearing metal.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an embodiment of the floating bush bearing of the present invention, FIG. 2 is a developed view of the inner surface of the floating bush of the bearing shown in FIG. 1 and a state in which dynamic pressure is generated, and FIG. 1 is a cross-sectional view showing another embodiment of the floating bush bearing of the present invention. FIG. 4 is a perspective view of the floating bush used in the bearing shown in FIG. 3, and FIG. FIG. 6 is a perspective view showing another example of the floating bush used in the present invention. 1... Bearing housing, IA... Oil supply hole, 2...
Rotating shaft, 3... Floating bush, 4... Oil supply path, 5.
6...Groove. Figure 1 Figure 2 Figure 5 Figure T4

Claims (1)

[Claims] 1. A floating bush is rotatably installed between the rotating shaft and the bearing housing, and lubricating oil from the bearing housing is supplied to the floating bush through the outer periphery of the floating bush and a radial oil supply path provided in the floating bush. In a floating bush bearing that is supplied to the inner periphery of the bush, a groove is formed on the surface of the floating bush to communicate with the opening of the radial oil supply path and to generate a dynamic pressure fluid lubrication film due to a wedge-shaped clearance. A floating bush bearing featuring: 2. The floating bush bearing according to claim 1, wherein the groove for generating a dynamic pressure fluid lubrication film is formed on the inner circumferential surface of the floating bush. 1. The floating bush bearing according to claim 1, wherein the groove for generating a dynamic pressure fluid lubrication film is formed on the outer peripheral surface of the floating bush.