JPS6346290B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tapered land bearing for thrust use, and particularly to improvements in the bearing surface thereof.

Tapered land bearings for thrust use have a flat circular bearing surface with a plurality of tapered surfaces sequentially formed in the circumferential direction. When lubricating oil is supplied from the inner circumference of the bearing, this As the rotary shaft rotates, it is drawn into the tapered surface to generate a wedge-shaped oil film between the rotary shaft end surface and the thrust load of the rotary shaft is supported by the pressure of this oil film.

In this conventional tapered land bearing, when the rotating shaft rotates at high speed, the lubricating oil supplied to the tapered surface is affected by centrifugal force and is scattered outward from the bearing surface. Oil film breakage occurs on the outer circumference of the bearing surface, resulting in metal-to-metal contact and unstable friction.
This had the disadvantage of causing a decrease in seizure resistance.

The present invention has been made in order to eliminate the above-mentioned drawbacks, and the bearing surface is configured such that the tapered surface has a slope with the apex at the outer peripheral side in the forward direction of the rotational shaft and the lowest point at the inner peripheral side at the rear in the rotational direction. By forming the bearing surface on a solid annular flat plate and making the outer circumferential side of the tapered surface higher than the inner circumferential side, the lubricating oil supplied to the bearing surface is discharged to the outside due to the influence of centrifugal force. In addition to the above structure, an oil groove is provided on the lower circumferential side of the tapered surface where the outer circumference is wider than the inner circumference. To provide a thrust tapered land bearing capable of supplying sufficient lubricating oil even to the outer peripheral side of the bearing surface.

Hereinafter, the present invention will be explained with reference to illustrated embodiments. 1 to 3 show an embodiment of the present invention. Reference numeral 1 denotes a tapered land bearing, which is made of an annular flat plate. A tapered surface 2 is formed which is divided by rays at intervals. Reference numeral 3 denotes an oil groove provided on the lower side of each tapered surface 2, that is, on the rear side in the rotational direction of the rotating shaft.

While conventional tapered land bearings have an inclination only in the circumferential direction, the tapered surface 2 has an inclination in the radial direction in addition to the inclination in the circumferential direction, as shown in FIGS. 2 and 3. It also has a slope of . In other words, the inner circumferential side at the rear in the rotational direction of the rotating shaft is the lowest point 4, and the outer circumferential side at the front in the rotational direction is the apex 5.
A tapered surface 2 is formed with a slope of . The taper amount h of this tapered surface 2 is 5 to 7 μm
However, the taper amount h is approximately 2 to 100 μm.
It can be applied depending on the purpose.

Therefore, each tapered surface 2 has its front side in the rotational direction higher than its rear side, and its outer circumferential side is higher than its inner circumferential side. This prevents the lubricating oil supplied onto the tapered surface 2 from scattering outward from the bearing surface due to centrifugal force, increases the pressure generation ability of the bearing surface, maintains frictional stability, and prevents seizure. It is possible to improve sexual performance.

The bearing 1 according to this embodiment supports a rotating shaft at the apex 5 of each tapered surface 2, and is particularly suitable for high-speed rotation and light loads such as turbo chargers.

4 to 6 show a second embodiment. Since the basic configuration is the same as that of the first embodiment, the explanation thereof will be omitted.

Similar to the first embodiment, the tapered surface 2 of the tapered land bearing 1 according to this embodiment has an upward slope from the inner circumferential side at the rear in the rotational direction of the rotating shaft to the outer circumferential side at the front in the rotational direction. , sometimes there is a land surface 6 on the outer circumferential side of each tapered surface and on the forward side in the rotational direction of the rotating shaft.
is provided. As shown in FIG. 4b, this land surface 6 spans the entire width on the front side in the direction of rotation of the rotating shaft.
From there, along the outer periphery, the width becomes gradually narrower toward the rear side in the rotational direction.

As described above, according to this embodiment, the land surface 6 extending over the entire length is formed on the outer periphery of the bearing 1, so that the lubricating oil supplied to the tapered surface 2 through the oil groove 3 is
It is possible to prevent oil from being discharged to the outside of the bearing surface due to the influence of centrifugal force generated by the rotation of the rotating shaft, and it is possible to further increase the ability of the bearing surface to generate oil film pressure.

Note that the shapes of the tapered surface 2 and the land surface 6 are as follows.
As shown in Figures a to d, various embodiments are possible. In other words, figure a shows a land surface 6 that gradually becomes narrower from the approximate center of the tapered surface 2 in the rotational direction of the rotational axis outward to the approximate center of the outer periphery, and figure b shows the tapered surface 2. The land surface 6 is formed over the entire length in the radial direction at the front in the rotation direction of the rotation shaft of the tapered surface 2, and in FIG. In the case where a land surface 6 having a narrow width is formed, or in figure d, the tapered surface 2 is shaped like an arc centered on the inner peripheral side at the rear in the rotational direction of the rotating shaft, and the land surface is formed on the outer part of the arc. This is what I did. Each of these tapered surfaces 2
Of course, the shape of the land surface 3 may be selected depending on the rotational speed, load, etc. of the rotating shaft to be supported.

FIG. 8 shows a third embodiment. The tapered surface 2 of the tapered land bearing 1 according to this embodiment has an upward slope from the inner circumferential side at the rear in the rotational direction of the rotating shaft to the outer circumferential side at the front in the rotational direction, as in each of the above embodiments. Furthermore, a land surface 6 is provided on the outer peripheral side of each tapered surface and on the forward side in the rotational direction of the rotating shaft. This land surface 6 is formed to span the entire width on the front side in the rotational direction of the rotational shaft, and gradually become narrower from there along the outer periphery toward the rear side in the rotational direction. Further, an oil groove 3 is provided on the lower side in the circumferential direction of the tapered surface 2, and the outer circumferential side is wider than the inner circumferential side, and the outer circumferential side of the oil groove 3 is located at the front in the rotational direction of the rotating shaft with respect to the radial direction. In other words, the width is widened toward the tapered surface 2 side.

By providing the oil groove 3 according to the above configuration,
Enough lubricating oil can be supplied to the tapered surface 2 and land surface 6, increasing the cooling effect, stabilizing friction,
The effect of improving seizure resistance can be obtained.

Note that the oil groove 3 may have a fan shape with both sides of the groove inclined at equal angles with respect to the radiation. It goes without saying that the land surface 6 may have various shapes as shown in FIGS. 7a to 7d.

Next, the effects of the present invention will be explained based on experimental results.
The tapered land bearings according to the second and third embodiments were compared with a conventional tapered land bearing in which a tapered surface and a land surface were sequentially formed in the circumferential direction of the bearing surface under the experimental conditions shown in the table. be.

Table: Rotation speed: 500 rpm Oil type: SEA #30 Oil temperature: 100°C Load: 20 minute incremental increase method every 10 kg As a result of comparing the seizure pressure under the above conditions, as shown in Fig. 8, the bearing of the present invention is superior to the conventional bearing. It is recognized that the seizure surface pressure is higher than that of the

As described above, according to the present invention, the ability to generate oil film pressure can be improved by preventing lubricating oil from being discharged outward from the bearing surface due to the influence of centrifugal force caused by the rotation of the rotating shaft. has. In addition, in the present invention, a tapered surface that is inclined in the radial and circumferential directions, with the apex at the outer circumferential side at the front in the rotational direction of the rotating shaft and the lowest point at the inner circumferential side at the rear in the rotational direction, is formed in a compact structure forming the bearing surface. It is formed on an annular flat plate, and in conventional devices, for example, by providing a cavity connected to the oil groove below the bearing pad surface, and decreasing the height of this cavity sequentially from the inner circumferential side to the outer circumferential side. , compared to the case where the pad surface of the cavity is bent to form a gradient with the inner circumferential side at the rear in the direction of rotation formed on the pad surface during shaft operation. An extremely rigid and stable sloped bearing surface can be uniformly constructed. As in the above conventional example, the slope is formed by the bending of the pad surface during operation, so there is a risk that the slope will not exist at the time of startup, resulting in oil film formation and seizing. There is a risk that the slope of the bearing surface will not be uniform on each pad surface and the load distribution will vary, resulting in jamming or seizure of the bearing surface, and furthermore, there is a risk that cavitation erosion may occur due to the oil flow passing through the cavity. According to the present invention, the bearing slope surface formed firmly and uniformly on a solid annular flat plate prevents the gap between the shaft end surface formed from the time of startup and the slope surface. The oil film is formed by being guided through the wedge-shaped gap, and the evenly sloped surface distributes the load evenly, which has the effect of maintaining good oil film generation ability without causing seizure or jamming. Furthermore, in the present invention, in addition to the above-mentioned configuration, an oil groove is provided on the bottom side in the circumferential direction of the tapered surface, so that the outer circumferential side is wider than the inner circumferential portion, so that there is no corner on the outer circumferential side of the bearing surface. By ensuring oil flow, wear resistance and seizure resistance can be further improved.

[Brief explanation of drawings]

1 to 3 show an embodiment of the present invention, in which FIG. 1 is a plan view, FIGS. 2 and 3 are sectional views taken along lines - and - in FIG. 1, respectively, and FIG. ~ Figure 6 shows another embodiment, Figure 4a is a plan view, Figure 4b is an enlarged view showing a section of the tapered surface and land surface, and Figures 5 and 6 are respectively Figure 4. of-
7A to 7D are enlarged views showing other examples of the same parts as in FIG. 4B, FIG. 8 is a plan view showing the third embodiment, and FIG. It is a graph showing the results of a friction test performed on bearings according to a second example and a third example of the present invention and a conventional bearing. 1... Tapered land bearing, 2... Tapered surface, 3... Oil groove, 4... Lowest point of tapered surface, 5...
...Apex of tapered surface, 6...Land surface.

Claims (1)

[Scope of Claims] 1. A tapered land bearing in which a plurality of tapered surfaces are sequentially formed in the circumferential direction of a bearing surface that supports a rotating shaft, and the tapered surface has an apex at the outer circumferential side in front of the rotating shaft in the rotational direction. , for thrust, characterized in that it is formed on a solid annular flat plate constituting the bearing surface, maintaining a gradient inclined in the radial direction and circumferential direction with the lowest point on the inner circumferential side at the rear in the rotational direction. Tapered land bearing. 2. The tapered land bearing for thrust according to claim 1, characterized in that a land surface is formed on the inclined upper side of the tapered surface. 3. The thrust tapered land bearing according to claim 2, wherein a land surface is formed on the front side of the tapered surface in the rotational direction of the rotating shaft. 4. The tapered land bearing for thrust according to claim 2, wherein a land surface is formed on the front side in the rotational direction of the rotating shaft and on the outer peripheral side of the tapered surface. 5. A thrust device according to claim 2, characterized in that the tapered surface has an arc shape centered on the inner peripheral side at the rear in the rotational direction of the rotating shaft, and a land surface is formed on the outer side of the arc. Tapered land bearing. 6 In a tapered land bearing in which a plurality of tapered surfaces are sequentially formed in the circumferential direction of a bearing surface that supports a rotating shaft, the tapered surface has an apex at the outer circumferential side at the front in the rotational direction of the rotating shaft, and an inner surface at the rear in the rotational direction. It is formed on the solid annular flat plate constituting the bearing surface, maintaining a slope inclined in the radial and circumferential directions with the lowest point on the circumferential side, and on the lower side of the tapered surface in the circumferential direction. A thrust tapered land bearing characterized by having an oil groove wider on the outer circumference than on the inner circumference. 7. The tapered land bearing for thrust according to claim 6, characterized in that the outer peripheral side of the oil groove is widened toward the front side in the rotational direction of the rotating shaft. 8. Claim 6 or 7, characterized in that a land surface is formed on the inclined upper side of the tapered surface.
Tapered land bearing for thrust as described in section.