JPS6252199B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to a bearing device that supports a radial load and a thrust load, and particularly to a self-lubricating type bearing device using an oil disc. [Technical background of the invention and its problems] Disc oil disc oil bearings are often used in rotating electric machines such as large-capacity electric motors and generators. Oil disc oil-filled bearings have a great advantage in that the shaft and disk rotate as one, compared to oil ring oil-filled bearings which require monitoring of the movement of the ring. However, on the other hand, if the oil disk exceeds a certain circumferential speed, the lubricating oil will scatter, so there is a dissatisfaction that the self-cooling range in which a desired amount of oil can be obtained is narrow. For example, FIG. 5 shows the relationship between rotational speed and pumping amount for a bearing with a diameter of 140 mm and an oil disk diameter of 290 mm. As is clear from this figure, when the circumferential speed of the oil disk exceeds approximately 4 m/sec, the pumped amount begins to decrease due to scattering.
Therefore, in the case of a rotating machine that is trying to obtain the desired oil flow rate of 2.5/min, the rotation speed range is 120 to 500 rpm.
limited to. In order to convey this scattered oil as far above the oil disk as possible, various proposals have been made in the past in which an oil guide cover is provided to cover the outer periphery of the oil disk (Japanese Utility Model Publication No. 55-82596). However, the rate of increase in the pumped amount was at most 10 to 20%, which was not satisfactory. Additionally, there is a problem in that the bearing device becomes larger due to the attachment of the oil guide cover. On the other hand, it has also been adopted to use this oil disk as an oil supply means and to support the thrust force applied to the rotating shaft on the stationary side by using the oil disk as a thrust collar. There are generally two types of configurations of this thrust bearing, one of which is shown in the example shown in Fig. 6, in which Babbitt metal 2 is attached to the side surface of the bearing 1 to form a thrust surface A, which slides into contact with the oil disk 3 for comparison. It is designed to support light loads. However, since such a bearing forms a thrust sliding contact surface on the side surface of the bearing 1, there is an increase in working time due to changing the cutting process, and the Babbitt metal in this part must be attached in a different way from the cylindrical part. For these reasons, this part is disadvantageous in terms of productivity as it occupies 35 to 40% of the bearing manufacturing time. Another example, as shown in FIG. 7, is one in which thrust pads 5, 5 are provided on both sides of the bearing box 4 to support the thrust force via oil disks 3a and 3b. In this example, the lubricating oil pumped up by the right disk 3a is introduced into the bearing 1 by the oil paddle 6, and the left disk 3b is used only as a thrust collar. In such a configuration, the pad and its supporting member occupy a large space, which is an obstacle to downsizing the bearing device. Bearing devices equipped with these sliding thrust bearings suffer from large losses in the thrust bearings, resulting in low bearing efficiency, which is a major drawback in improving the efficiency of rotating machines. By making the rotation speed of the oil pumping part of the oil disk lower than the rotation speed of the shaft, it is possible to suppress the scattering of the pumped oil and expand the self-cooling range of the bearing to high-speed areas. An object of the present invention is to provide a bearing device that can reduce thrust bearing loss. [Summary of the Invention] In order to achieve the above object, the bearing device of the present invention has the following features:
a rotating shaft; a journal bearing that supports the rotating shaft and is housed in a bearing box; a flange portion having a diameter larger than the bearing diameter disposed adjacent to the bearing on the rotating shaft; A plurality of rolling elements arranged in the circumferential direction with their lower parts immersed in the lubricating oil of the bearing box, inscribed in these rolling elements and locked with the stationary side member with some play, and receiving the thrust force of the rotating shaft on the side surface. Even if the rotary shaft rotates at high speed, the oil disc is slowed down to a speed lower than that, effectively supplying lubricating oil to the bearing, and thrust force is supported by rolling friction with low loss. It is intended to do so. [Embodiment of the Invention] An embodiment of the present invention will be described with reference to the drawings. 1st
The bearing device shown in the figures and FIG. It supplies lubricating oil to the bearing surface and transmits the thrust force shown by arrow B between the stationary outer ring (described later) that forms part of the oil disk 8 and the thrust receiving seat 9 of the bearing box. It is. Next, the oil disc 8 will be explained with reference to FIG. A protruding flange portion 10 is formed on a part of the rotating shaft 7. An annular inner ring 11 is provided on the outer periphery of this collar portion 10.
is fitted by shrink fitting. A concave raceway 11a is formed on the outer periphery of this inner ring 11. An outer ring 13 is provided on the outside of the inner ring 11 with a rolling layer 12 in between. A concave raceway 13a is also formed on the inner circumferential side of the outer ring 13.
is formed. The annular layer 12 is disposed between the inner and outer rings 11 and 13 and has a plurality of rolling elements 14 formed of balls fitted into raceways and capable of rolling in the circumferential direction.
and an annular retainer 15 that slidably envelops the retainer 15 from both sides. A groove 16 extending in the axial direction is provided in the upper part of the outer ring 13, and a pin 17 protruding from the oil paddle 6 described above is loosely inserted into this groove to prevent the outer ring 13 from rotating. The immersion positional relationship between the oil disk 8 and the lubricating oil configured as described above is such that the oil level OL is set to be at or slightly lower than the outer peripheral surface of the lowest part of the inner ring 11. In addition, as shown in Fig. 1, the oil disk 8
It is preferable to interpose an elastic body 18 such as a spring or rubber at the contact portion between the outer ring and the thrust receiving seat 9 of the bearing box to suppress minute vibrations of the outer ring 13. Next, the action will be explained. As the rotating shaft 7 rotates, the inner ring 11 also rotates at the same rotational speed. When the inner ring 11 rotates, the rolling elements 14 in contact with the inner ring 11 rotate on their own axis and revolve around the orbit at a rotation speed slower than that of the rotating shaft. As the rolling elements 14 revolve, the cage 15 attached thereto also revolves at the same rotational speed as the rolling elements 14. In other words, since the lower part of the rolling layer 12 composed of the rolling elements 14 and the retainer 15 is immersed in lubricating oil, the rolling layer 12 pumps up oil at a rotation speed slower than the rotation speed of the rotating shaft 7. This number of revolutions can be expressed by an equation for determining the number of revolutions of the rolling elements in a rolling bearing. In other words, if the number of revolutions is n, then n=(1-dcosα/dm)N/2(rpm)...(1) where d: Diameter of rolling element (mm) α: Contact angle of rolling element (°) dm : Pitch diameter of rolling element (mm) N: Number of rotations of rotating shaft (rpm). By using the above-mentioned rolling elements, the rotational speed of the rolling layer 12 can be suppressed to about 40% of the rotational speed of the rotating shaft. FIG. 4 shows the relationship between the amount of lubricating oil pumped up and the rotational speed of the rotating shaft in an experiment using the oil disk according to this embodiment. For comparison, the pumping characteristics a of a conventional integral disk-shaped oil disk are also shown, and the dimensions of the oil disk are set to be the same. (In this experiment, the inner diameter of the outer ring was approximately the same as the outer diameter of a conventional oil disk, 290 mm, and the rolling elements were 8 balls arranged at equal intervals.)
As is clear from this figure, the pumping characteristic b greatly exceeds the high speed region. For example, now 2.5/min
Regarding bearings that require a pumping amount of oil, according to the conventional disc mentioned above, it is 120 to
The disc of this embodiment, which was previously limited to a range of 500 rpm, can be used for a range of 230 to 1200 rpm. Although some unusable range in the low speed region is unavoidable due to the characteristics of the revolution number,
The expansion range in the high-speed region is large, and therefore it is extremely effective in greatly expanding the range in which the bearing can be operated with self-lubrication. The structure of the rolling layer 12 in this embodiment is the same as that of an angular ball bearing of a rolling bearing.
Therefore, when a thrust force is applied in the direction of arrow B in FIG. can support. Therefore, the thrust force becomes rolling friction, which is a very small amount of friction loss, and is effective in reducing bearing loss and, in turn, mechanical loss of the rotating machine. Further, since the slide bearing 1 only needs to support the radial load of the rotating shaft 7, there is no need to form a Babbitt sliding surface on the side surface which is difficult to work with. Furthermore, since this oil disk 8 has both an oil supply function and a thrust bearing function, there is no need to provide a space-occupying thrust pad as in the past, and the bearing device can be easily miniaturized. . In the above embodiment, the inner ring 11 is fitted to the flange 10 of the rotary shaft 7, but the flange 10 and the inner ring 11 may be integrated. Pin 17 of oil paddle 6 in groove 16
However, it is also possible to provide a round hole in the upper part of the outer ring 13 and allow the pin 17 to pass freely through this round hole to prevent the outer ring from rotating. Furthermore, the structure of the rolling layer can be modified in various ways. That is, the rolling elements 14 are not limited to balls, but rollers can also be used. The table shows combinations based on the type of rolling layer and load conditions, and is an example that can be selected as appropriate depending on the direction of thrust load and the rotation speed of the rotating shaft. (The angular balls on the left end are those of the above embodiment.) In the case where the thrust force acts in both directions, the support structure of the outer ring 13 is the same as that of the above embodiment, such as supporting the outer ring 13 by sandwiching it between the bearing box 4 and the bearing 1. Of course, the present invention is not limited to this and can be implemented in various ways.

[Table] [Effects of the Invention] According to the present invention, the oil disk for lubricating the bearing is provided between the non-rotating outer ring and the outer ring and the rotating shaft, and thrust force can be transmitted between the two, and the rotating shaft It consists of a rolling layer that rotates at a rotational speed slower than the rotational speed of It is possible to expand the bearing capacity and reduce thrust bearing loss.

[Brief explanation of the drawing]

Fig. 1 is a front view of a bearing device showing an embodiment of the present invention, Fig. 2 is a sectional view taken along the - line in Fig. 1 and seen in the direction of the arrow, and Fig. 3 is an oil disk of Fig. 1. Figure 4 is a characteristic curve diagram showing the relationship between the rotational speed of the rotating shaft and the amount of pumped oil in comparison with a conventional oil disc. Figure 5 is a diagram showing a conventional oil disc. A curve diagram showing the relationship between rotational speed and pumped oil amount, and FIGS. 6 and 7 are sectional views of a conventional bearing device, respectively. 1...bearing, 4...bearing box, 7...rotating shaft, 8
...Oil disc, 9...Thrust receiver, 1
1... Inner ring, 12... Rolling layer, 13... Outer ring, 1
4...Rolling element, 15...Cage.

Claims (1)

[Claims] 1. A rotating shaft, a journal bearing that supports this rotating shaft and is housed in a bearing box, a flange portion having a diameter larger than the bearing diameter disposed adjacent to the bearing on the rotating shaft, and an exterior covering on this flange portion. and a plurality of rolling elements arranged in the circumferential direction and having their lower portions immersed in lubricating oil of the bearing box;
A bearing device comprising an outer ring that is inscribed in these rolling elements, locks with the stationary side member with play, and receives the thrust force of the rotating shaft on its side surface.