JPH06129432A - Oil lubrication radial bearing device - Google Patents

Abstract

PURPOSE:To improve a bearing characteristic, long-term reliability and safety by providing on the inner periphery surface of a bearing to support a rotary shaft a cylindrical fluoric resin material provided with plural penetration holes in the axial direction of a circumferential groove, providing in addition a stop ring at a bearing end portion. CONSTITUTION:When a rotary shaft 1 is in stop state, a lubricant 4 is supplied, then it flows through an outer periphery groove 10b and is guided into an inner periphery groove 10a through a penetration hole 13. Thus, the lubricant is supplied to the slide surfaces of a rotary side bearing opening 7a and a bearing side bearing opening 7b. Meanwhile, when the rotary shaft 1 starts to rotate, the slide surfaces of the rotary side bearing opening 7a and the bearing side bearing opening 7b fall into a boundary lubrication (the middle of fluid lubrication and solid lubrication) state. At this time, by the elastic deformation of a fluoric resin material 9, the slide surfaces of the rotary side bearing opening 7a and the bearing side bearing opening 7b fall rather into a state near to fluid lubrication out of the boundary lubrication. That is, the state of elastic fluid lubrication is brought on.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing device for supporting a rotary shaft of a rotary machine, and more particularly, to a bearing device that contacts the rotary shaft even in a wide range from a stopped state to a high speed rotation of the rotary machine. The present invention relates to an oil-lubricated radial bearing device capable of preventing burning and burning of a bearing, improving bearing characteristics, and improving long-term reliability and safety.

[0002]

2. Description of the Related Art In recent years, bearings are also regarded as important as the performance of various rotary machines in each technical field is increasing. In particular, in rotating machines of power plants, demands for long-term reliability, safety, and maintenance-free are increasing.

By the way, since a bearing used in a large-scale rotating machine having a horizontal shaft has a large load capacity (a weight of the rotating shaft which can be supported by the pressure of the lubricant in the bearing), the bearing is not used when the rotating shaft is started or stopped or when the rotating shaft is rotated. During a so-called transient when an external force is applied, there is a problem that the rotating shaft and the bearing member are likely to come into contact with each other and the lubricating film in the bearing is easily damaged. For this reason, the bearing may be burnt and burned, resulting in an accident. The problems of the conventional bearing device will be described below with reference to the conventional representative example. FIG. 5: is sectional drawing which shows the structural example of the conventional bearing device. Note that FIG. 5 shows an example of a bearing device used in a large rotating machine.

In FIG. 5, the rotary shaft 1 is supported by a bearing 2, and the bearing 2 is housed in a bearing bracket 3. The lubricant 4 in the bearing bracket 3 is supplied to the sliding surface (bearing gap) by the pump 5 installed outside, and is cooled by the cooler 6 as necessary.

Further, when the rotating shaft 1 rotates at high speed in the bearing gap 7, a lubricating film is formed by a dynamic action and a film pressure 8 as shown in FIG. 6 is generated, so that the rotating shaft 1 and the bearing 2
Will not be in direct contact. However, when the rotary shaft 1 is started or stopped, the rotary shaft 1 rotates at a low speed, so that the membrane pressure 8 cannot be expected, and the rotary shaft 1 and the bearing 2 come into contact with each other. Therefore, the bearing member is made of a material that can withstand contact with the rotating shaft 1. That is, for example, a metal material such as white metal 12 is used.

Since the sliding surface between the rotary shaft 1 and the bearing 2 is a boundary lubrication region (between fluid lubrication and solid lubrication), in the case of a metal material such as the white metal 12, whether the bearing 2 seizes or not depends on the lubricant. The effect of 4 is also quite dominant. Further, since the bearings are in contact with each other, the wear of the bearing 2 cannot be avoided, and the friction coefficient is large because it is a metal material. Therefore, there is a problem that the rotational torque at the time of starting or stopping the rotary shaft 1 becomes large. Further, when the metal material such as the white metal 12 is worn away, the bearing base material itself comes into contact with the rotating shaft 1, and there is a great risk of an accident due to the burning and burning of the bearing 2.

[0007]

As described above, in the conventional bearing device, the seizure and burning due to the contact between the rotating shaft and the bearing occurs in the low speed rotation region when the rotating shaft of the rotating machine is started or stopped. There were problems in bearing characteristics, reliability and safety.

The object of the present invention is to prevent the burning and burning of the bearing due to the contact between the rotating shaft and the bearing even in the wide range of the rotating shaft of the rotating machine from the stopped state to the high speed rotation, thereby improving the bearing characteristics and long-term reliability. Another object of the present invention is to provide an oil-lubricated radial bearing device capable of improving safety.

[0009]

In order to achieve the above object, an oil lubricated radial bearing device of the present invention is provided with a cylindrical fluororesin material on an inner peripheral surface of a bearing for supporting a rotary shaft of a rotary machine. A circular groove for supplying lubricating oil to the bearing sliding surface and the rotary shaft sliding surface is provided on the outer and inner circumferences of the cylindrical fluororesin material, and a plurality of through holes are provided in the axial direction of the circumferential groove. Further, a stop ring is provided at the end of the bearing to prevent the cylindrical fluororesin material from moving in the axial direction. Here, in particular, the inner peripheral surface and the outer peripheral surface of the cylindrical fluororesin material are machined so that the clearance on the rotating shaft side and the clearance on the bearing side are almost the same at room temperature.

[0010]

Therefore, in the oil-lubricated radial bearing device of the present invention, a circumferential groove for supplying lubricating oil to the bearing sliding surface and the rotary shaft sliding surface is provided on the outer circumference and the inner circumference, and the shaft of the circumferential groove is provided. A cylindrical fluororesin material with a plurality of through holes in the direction is provided on the inner peripheral surface of the bearing that supports the rotating shaft, and the end of the bearing is fixed so that the cylindrical fluororesin material does not move in the axial direction. By providing a stop ring on the fluororesin material, the elastic deformation of the fluororesin material, the reduction of the friction coefficient in the lubricating oil, and the difference in the coefficient of linear expansion from the rotating shaft cause the rotating shaft to start or stop at low speeds, and thus the rated Bearing lubrication characteristics are improved at high speed rotation, wear resistance can be effectively exhibited, and long-term reliability and safety of the bearing device can be significantly improved.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a sectional view showing a structural example of an oil-lubricated radial bearing device according to the present invention. The same elements as those in FIG. 5 are designated by the same reference numerals, and the description thereof will be omitted. Here, only different portions will be described. Describe.

That is, in the oil lubricated radial bearing device of this embodiment, as shown in FIG. 1, a cylindrical fluororesin material 9 is provided on the inner peripheral surface of the bearing 2 to support the rotary shaft 1. Also,
In order to supply the lubricant 4 to the sliding surfaces of the rotation side bearing gap 7a and the bearing side bearing gap 7b, the inner peripheral groove 10a and the outer peripheral groove 10b are formed in the central portion of the fluororesin material 9, and the inner peripheral groove 1
0a and the outer circumferential groove 10b in the axial direction at several through holes 1
3 is provided. Further, a stop ring 11 is provided at the end of the bearing 2 so that the cylindrical fluororesin material 9 does not move extremely in the axial direction. Furthermore, fluororesin material 9
Has its inner peripheral surface and outer peripheral surface machined so that the rotation-side bearing clearance 7a and the bearing-side bearing clearance 7b have substantially the same clearance at room temperature. Here, as the fluororesin material 9, for example, Teflon (trade name of DuPont) material can be used. Next, the operation of the oil-lubricated radial bearing device of the present embodiment configured as described above will be described with reference to FIGS.

In FIG. 1, when the rotary shaft 1 is in a stopped state,
When the lubricant 4 is supplied, it flows through the outer peripheral groove 10b and is guided to the inner peripheral groove 10a by the through hole 13 as shown in FIG. 2. In this way, the rotation side bearing gap 7a and the bearing side bearing gap 7b are separated from each other. The lubricant 4 is supplied to the sliding surface.

On the other hand, when the rotary shaft 1 starts to rotate, the lubricant 4 causes the sliding surface of the bearing gap 7a on the rotary side and the bearing gap 7b on the bearing side to be in a boundary lubrication (intermediate between fluid lubrication and solid lubrication) state. At this time, due to the elastic deformation of the fluororesin material 9,
The sliding surfaces of the rotation side bearing gap 7a and the bearing side bearing gap 7b are
Of the boundary lubrication described above, the state is more like fluid lubrication. That is, the elastic fluid lubrication is achieved. FIG. 3 is a schematic diagram showing the distribution of the film pressure 8 when a lubricating film is generated in the rotation side bearing gap 7a and the bearing side bearing gap 7b.

FIG. 4 shows the rotary shaft 1 and the fluororesin material 9
FIG. 7 is a schematic diagram showing a relationship between a rotation-side bearing gap 7a and a bearing-side bearing gap 7b due to a difference in linear expansion coefficient between and. As shown in FIG. 4, the temperature of the lubricant 4 rises as the rotation speed increases, and the temperature of the lubricant 4 becomes constant at the rated rotation speed. The rotary shaft 1 and the bearing 2 have a small thermal expansion with respect to the temperature, but the fluororesin material 9 has a large thermal expansion, so that the rotary side bearing gap 7a becomes wide and one bearing side bearing gap 7b becomes narrow. That is, since the fluororesin material 9 is processed so that the rotation-side bearing gap 7a and the bearing-side bearing gap 7b are substantially the same at room temperature, the relationship shown in FIG. 4 is obtained.

Next, when the rotation speed of the rotating shaft 1 increases, the loss in the bearing 2 increases, but the loss in the bearing 2 does not increase because the bearing gap 7a on the rotating side increases. In addition, even when an external force is applied to the rotating shaft 1, even during a so-called transient, the lubricant film is less likely to be damaged due to elastic deformation of the fluororesin material 9 and the galling phenomenon between the materials is eliminated, so that the bearing 2 is prevented from being burned and burned. Don't get up

On the other hand, when the rotating shaft 1 is rotating at a low speed, the temperature does not rise so much, so that the bearing gap 7a on the rotating side and the bearing gap 7b on the rotating side are almost the same. On the sliding surface of the side bearing gap 7b, the one with smaller contact resistance rotates. That is, with respect to the bearing 2, whether only the rotating shaft 1 rotates, or the rotating shaft 1 and the fluororesin material 9 simultaneously rotate, or the rotating shaft 1 and the fluororesin material 9 rotate together, but the rotation speed is In any case, the rotation torque becomes small because it rotates at the place where the contact resistance is small. Further, due to the elastic deformation of the fluororesin material 9, galling due to contact with the rotating shaft 1 or the bearing 2 is eliminated, and a lubricating film is easily formed.

As described above, in the oil-lubricated radial bearing device of this embodiment, the cylindrical fluororesin material 9 is provided on the inner peripheral surface of the bearing 2 which supports the rotating shaft 1, and the center portion of the fluororesin material 9 is provided. , The inner peripheral groove 10a and the outer peripheral groove 1 for supplying the lubricant 4 to the sliding surfaces of the rotation side bearing gap 7a and the bearing side bearing gap 7b.
0b, and the inner peripheral groove 10a and the outer peripheral groove 10b.
Are provided with several through holes 13 in the axial direction, and a stop ring 11 is provided at the end of the bearing 2 so that the cylindrical fluororesin material 9 does not move extremely in the axial direction. The inner peripheral surface and the outer peripheral surface of the fluororesin material 9 are processed so that the bearing gap 7a and the bearing-side bearing gap 7b are substantially the same.

Therefore, the bearing lubrication characteristics are improved in a wide range of the high speed operation region from the stopped state of the rotating shaft 1,
It is possible to prevent burning and burning due to contact between the bearing and the bearing 2, and it is possible to obtain an oil-lubricated radial bearing device having extremely high performance and long-term reliability and safety.

That is, even in the low-speed rotation region when the rotary shaft 1 is started or stopped, elastohydrodynamic lubrication is used to prevent burning and burning due to the contact between the rotary shaft 1 and the bearing 2, and at the same time, friction is caused. By reducing the coefficient, it becomes possible to reduce the rotational torque, improve the bearing characteristics, and improve the long-term reliability and safety.

In the above embodiment, the cylindrical fluororesin material is processed such that the inner peripheral surface and the outer peripheral surface thereof are machined so that the clearance on the rotary shaft side and the clearance on the bearing side are almost the same at room temperature. However, this is not an essential requirement of the present invention.

[0023]

As described above, according to the present invention, a cylindrical fluororesin material is provided on the inner peripheral surface of a bearing that supports a rotary shaft of a rotary machine, and the outer and inner peripheries of the cylindrical fluororesin material are provided. The bearing sliding surface and the rotating shaft sliding surface are provided with a circumferential groove for supplying lubricating oil, a plurality of through holes are provided in the axial direction of the circumferential groove, and a cylindrical fluorine is provided at the end of the bearing. Since a stop ring is provided to prevent the resin material from moving in the axial direction, even if the rotating shaft of the rotating machine is in a wide range from the stopped state to high speed rotation, the bearing is prevented from burning and burning due to contact between the rotating shaft and the bearing. However, it is possible to provide an oil-lubricated radial bearing device capable of improving bearing characteristics, long-term reliability, and safety.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of an oil lubricated radial bearing device according to the present invention.

FIG. 2 is a vertical cross-sectional view for explaining the operation of the oil lubricated radial bearing device in the same embodiment.

FIG. 3 is a schematic diagram showing a state of pressure distribution generated in a bearing direction of a shaft of the oil lubricated radial bearing device in the embodiment.

FIG. 4 is a schematic view showing the relationship between the rotational shaft side and the bearing side clearance with respect to the rotational speed of the oil lubricated radial bearing device in the embodiment.

FIG. 5 is a cross-sectional view showing a configuration example of a conventional bearing device.

FIG. 6 is a schematic diagram showing the distribution of pressure generated in the bearing direction of the shaft in the bearing device of FIG.

[Explanation of symbols]

1 ... Rotary shaft, 2 ... Bearing, 3 ... Bearing bracket, 4 ... Lubricant, 5 ... Pump, 6 ... Cooler, 7 ... Bearing gap, 7a ...
Rotor shaft side bearing gap, 7b ... Bearing side bearing gap, 8 ... Membrane pressure, 9 ... Fluorine resin material, 10a ... Inner circumferential groove, 10b ... Outer circumferential groove, 11 ... Stop ring, 12 ... White metal, 13 ...
Through hole

Claims (2)

[Claims] 1. A cylindrical fluororesin material is provided on an inner peripheral surface of a bearing for supporting a rotary shaft of a rotary machine, and a bearing sliding surface and a rotary shaft slide are provided on an outer circumference and an inner circumference of the cylindrical fluororesin material. A circular groove for supplying lubricating oil is formed on the moving surface, and a plurality of through holes are provided in the axial direction of the circumferential groove, and the cylindrical fluororesin material is axially provided at the end of the bearing. An oil-lubricated radial bearing device, characterized in that a stop ring is provided so as not to move. 2. The inner peripheral surface and the outer peripheral surface of the cylindrical fluororesin material are machined so that the clearance on the rotating shaft side and the clearance on the bearing side are substantially the same at room temperature. The oil-lubricated radial bearing device described in 1.