JPH0554563B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a sliding bearing device in, for example, a small-diameter, oil-free motor, etc. The rotary shaft is supported by an integral bearing that is assembled in one place at the same time.

[Conventional technology]

Fig. 3 is a sectional view showing an example in which a conventional bearing device is adopted for an axial gap type DC rotating machine. These are an upper bearing and a lower bearing that bear both the radial load and the thrust load applied to the shaft 1, 4 is a bearing housing that holds these upper and lower bearings 8 and 9, 5 is a rotor in the DC rotating machine, and 6 is this rotor. 5 is a hub for coupling with the rotating shaft 1, and 7 is a stator of a DC rotating machine.

In the above configuration, while the rotating shaft 1 is rotating, the upper bearing 8 and the lower bearing 9 bear the thrust load caused by the rotating shaft 1, the rotor 5, and the hub 6, and the radial load caused by the rotation of the rotor 5 and the hub 6.

[Problem that the invention seeks to solve]

Since the conventional bearing device is configured as described above, it is necessary to use an expensive ball bearing in order to have at least either the upper bearing 8 or the lower bearing 9 bear the thrust load. There was a problem with the high cost. Furthermore, in order to solve this problem, there have been some models in which a thrust receiver 10 as shown in FIG. 4 is added in addition to the upper bearing 8 and the lower bearing 9. However, with this structure, it is natural that a thrust receiver must be prepared separately, and in this case, there are problems such as the assembly of the DC rotating machine becoming more complicated. This invention aims to solve these problems.

[Means for solving problems]

In the case of this invention, a thrust support sintered bearing part made of a sintered alloy having a smaller porosity than the sintered alloy of this bearing part is added in a superposed state to the lower surface of a radial support sintered bearing part made of a sintered alloy. However, these are integrated and supported by a bearing housing.

[Function] In the case of this invention, the radial load is simultaneously received by the radial support sintered bearing located at the upper part, and the thrust load is simultaneously received by the thrust support sintered bearing located at the lower part. The porosity of the bearing part is smaller than the porosity of the sintered alloy in the radial support sintered bearing part, so lubricating oil seeped from the upper radial support sintered bearing part is retained in the thrust support sintered bearing part. This can be used as a lubricant for this part, and since both bearings are integrated, the lubricating oil circulation efficiency is also good.

〔Example〕

An embodiment of this invention will be described below. That is, Fig. 1 is a cross-sectional view of an axial gap type DC rotating machine in which the sliding bearing device of the present invention is implemented. 3a is an upper radial support sintered bearing part which, like this upper stage bearing 2, takes charge of the radial load applied to the rotating shaft 1, and 3b is the lower surface of this bearing part. The lower thrust support sintered bearing part has an L-shaped side cross section and is placed in an overlapping state with the thrust surface facing upward. It constitutes a lower stage bearing 3. 4
is a bearing housing that holds these upper stage bearings 2 and lower stage bearings 3.

In the above configuration, the radial load acting on the central axis of the rotating shaft 1 is received by the radial support sintered bearing portion 3a located above the upper stage bearing 2 and the lower stage bearing 3. On the other hand, the thrust load acting on the central axis of the rotating shaft 1 is received by the thrust support sintered bearing portion 3b located at the lower part of the lower stage bearing 3. In the radial support sintered bearing part 3a, as the rotating shaft 1 rotates, the impregnated lubricating oil seeps out onto the inner circumferential surface of the bearing, and then most of it flows from the negative pressure part of the bearing part to the porous part in the center. However, the remaining lubricating oil flows downward along the rotating shaft 1 due to gravity. At this time, the thrust support sintered bearing part 3b located below has a smaller porosity than the upper radial support sintered bearing part 3a, so the lubricating oil flowing down is retained in this part, and therefore the rotating shaft 1 Lubricating oil is sufficiently distributed between the lower surface of the thrust support sintered bearing portion 3b and wear on the thrust surface is reduced.

In the embodiment shown in FIG. 1 described above, the thrust support sintered bearing part 3b has an L-shaped side cross section, but as shown in another embodiment shown in FIG. 2, it is formed into a cup shape. It may be something. In addition, in the embodiments shown in FIGS. 1 and 2 above, the axial
Although an example of application of the bearing device of the present invention to a gap-type DC rotating machine has been shown, the application of the bearing device of the present invention is not limited to this; for example, it can be used as a bearing device for a capstan motor of a VTR, a spindle motor of a floppy disk, etc. It's okay. Other Examples In each of the above examples, the rotating shaft is supported by both the upper bearing and the lower bearing, but the rotating shaft can be supported by design changes such as extending the bearing part of the upper radial support sintered bearing. It may be supported only by the lower stage bearing.

〔Effect of the invention〕

As described above, in this invention, the thrust support sintered bearing part with a lower porosity is provided in an overlapping state on the lower surface of the radial support sintered bearing part, and these parts are integrated into a single body and supported by the bearing housing. So,
This integrated bearing can simultaneously receive the radial load and thrust load applied to the rotating shaft. This eliminates the need to use expensive ball bearings or provide a separate thrust receiver, making it an inexpensive and easy-to-assemble sliding system. Not only can a bearing device be obtained, but also the lubricating oil circulation efficiency is good, so wear resistance is good, and the load capacity is increased.

[Brief explanation of drawings]

1 and 2 are cross-sectional views showing each embodiment of the sliding bearing device of the present invention, FIG. 3 is a cross-sectional view showing a conventional bearing device using ball bearings, and FIG. 4 is a sintered bearing and a thrust bearing device. FIG. 2 is a cross-sectional view showing a conventional bearing device using a saucer. In addition, in the figure, 1 is a rotating shaft, 3a is a radial support sintered bearing part, 3b is a thrust support sintered bearing part, and 4
indicates the bearing housing. In other figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1 A rotating shaft installed in the vertical direction, a radial supporting sintered bearing made of a sintered alloy that takes charge of the radial load applied to the rotating shaft, and the radial supporting sintered bearing part that takes charge of the thrust load applied to the rotating shaft. and a thrust support sintered bearing made of a sintered alloy having a smaller porosity than the sintered alloy of the sintered bearing, and the radial support sintered bearing and the thrust support sintered bearing are integrated into one unit. A sliding bearing device characterized by being supported by a bearing housing.