JPS6377345A - Lubricating device for bearing - Google Patents

Abstract

PURPOSE:To improve the state of the lubrication of a fluid by alternately forming contact sections and groove sections to sections in specified length in a shaft and a bearing and shaping oil holding sections having prescribed outer diameters on both sides of the contacting sections and the groove sections. CONSTITUTION:A shaft 11 is rotated in an oil impregnated metal powder sintered bearing 10 with a cylindrical inner surface. A plurality of contact sections 12, which have width in sections corresponding to 70-85% of the length of the bearing 10 and where the shaft 11 and the inner surface of the bearing 10 are brought into contact and turned, and groove sections 13 having outer diameters made thinner than those of the contact sections 12 are shaped alternately to the intermediate section of the bearing 10. Oil holding sections 14 having outer diameters made thinner than the inner surface of the bearing 10 by 150-300mum are each formed on the sides further outer than both ends of the contact sections 12.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a small-sized, light-loaded sintered oil-impregnated bearing lubrication device.

BACKGROUND OF THE INVENTION Conventionally, a lubricating device for a bearing of this type has generally been constructed as shown in FIGS. 3 and 4. That is, the shaft 2 rotates on the inner surface of the sintered oil-impregnated bearing 1, and when the shaft 2 is stopped, the inner surface of the bearing 1 and the surface of the shaft 2 form a contact portion 3 that is in metal contact. When the shaft 2 rotates in this state, the temperature of the contact part 3 increases due to frictional heat due to metal contact, and the oil contained inside the bearing 1 is drawn out to the contact part 3, causing an oil film to form between the bearing 1 and the shaft 2. This forms a state of fluid lubrication. The oil drawn out from the bearing 1 flows from the contact part 3 to the end 4 of the bearing 1, and
It is sucked into the inside of the bearing 1 and then drawn out to the contact portion 3, where the circulation is repeated to provide lubrication. When the shaft 2 stops rotating, the temperature of the bearing 1 decreases and the oil returns to the bearing 1 to return to its initial state.

Problems to be Solved by the Invention In such a conventional configuration, it is difficult to connect the contact portion 3 from the inside of the bearing 1.
The oil drawn out flows out of the bearing 1 and toward the end 4 of the bearing 1 while maintaining a state of fluid lubrication between the bearing 1 and the shaft 2. Oil is sucked into the bearing 1 from the end 4, but the amount of oil drawn out from the contact portion 3 exceeds the amount of oil sucked into the end 4, causing oil to flow further outside from the end 4. The oil will flow out and cannot return to the bearing 1, resulting in a decrease in the amount of oil in the bearing 1. As this phenomenon continues, the oil contained in the bearing 1 is extremely reduced, and the metal-to-metal contact state persists at the contact portion 3, leading to seizure of the bearing 1 and a serious failure.

The present invention solves these problems, and aims to provide a bearing lubrication device that prevents the oil contained in the bearing from flowing out and maintains a good fluid lubrication state.

Means for Solving the Problem In order to solve this problem, the present invention provides a shaft rotating inside a sintered oil-impregnated bearing with a shaft that is 70 to 80% of the length of the bearing in the middle of the bearing. A plurality of contact parts that contact the inner surface of the bearing and rotate with a width of 150 mm, and groove parts whose outer diameter is narrower than this contact part are arranged alternately, and further on both sides from the contact parts at both ends by 150 mm from the diameter of this contact part. This is a bearing lubricating device having an oil retaining portion thinned by ~300 μm.

Effect: With this configuration, the contact area between the bearing and the shaft is divided into multiple parts and the contact area is reduced, so the amount of oil drawn from the contact area is reduced, and this drawn oil is transferred to the shaft. This groove retains the oil and sucks the oil into the inside of the bearing. The oil sucked into the bearing is repeatedly circulated to the contact area to lubricate it. The oil flowing further outward from the contact portions at both ends is retained by capillary action between the inner surface of the bearing and the shaft, and almost no oil flows out to the ends of the bearing. Then, the small amount of oil that has leaked out is sucked into the bearing from the end, preventing oil from leaking to the outside of the bearing, and eliminating the phenomenon of oil shortage.

EXAMPLE Below, an example for use on the skin will be described based on FIGS. 1 and 2.

A shaft 11 that rotates inside a bearing 1o whose inner surface is cylindrical and is made of sintered oil-impregnated material has a contact portion 12 that rotates in contact with the inner surface of the bearing 1o with a width equivalent to 70 to 85 inches of the length of the bearing 10. A plurality of groove portions 13 having an outer diameter narrower than the contact portion are alternately provided in the intermediate portion of the bearing 1o, and the inner surface of the bearing is 150~
The oil retaining portion 14 is formed with a thickness of 300 μm. End 1
6 is a surface perpendicular to the inner cylinder of the bearing 1o, and the surface has a porous structure as sintered material.

In the above configuration, when the shaft 11 starts rotating, the temperature of the contact parts 12 increases due to frictional heat at the plurality of contact parts 12 where the shaft 11 and the bearing 10 are in contact, and the inner surface of the bearing 10 of the contact part 12 increases. Although the oil contained inside is drawn out, the amount of oil drawn out is reduced because the area of the contact portion 12 is narrower than in the past. Even if the amount of oil decreases, since the area of the contact portion 12 is narrowed, the shaft 11 will rotate with the contact portion 12 in a fluid lubricated state. The oil flowing out from the contact part 12 is
The bearing 1 is divided into a groove 13 provided in the middle part of the bearing 1 and an oil retaining part 14 on both sides.
Oil is sucked into the inside of the bearing 10 in the latter oil retaining part 14.
The oil is retained by capillary action between the inner surface of the bearing 10 and the outer surface of the shaft 11, and the oil is sucked into the bearing 10, and then drawn out to the contact portion 12, where the circulation is repeated to provide lubrication. Therefore, almost no oil leaks from the oil retaining part 14 to the end 15, but even so, the very small amount of oil that flows out is sufficiently sucked into the bearing 10 from the end 15, and no oil flows out of the bearing 10. There's nothing left to do.

As described above, according to this embodiment, the shaft 11 is provided with a plurality of grooves 13 in the middle part of the bearing 1o, and the oil retaining parts 14 are provided on both sides of the contact part 12 at both ends. The area becomes narrower, and the amount of oil drawn out from the contact portion 12 decreases.

The shaft flowing out from the contact part 12 is connected to the groove part 13 and the oil retaining part 1.
4 and is held by the groove 13 and the oil retaining part 14, and oil is sucked into the inside of the bearing 1o from the groove 13 and the oil retaining part 14.

Therefore, very little oil flows out to the end portion 15, so that the oil does not decrease.

Effects of the Invention As is clear from the above description of the embodiments, according to the present invention, a plurality of grooves for retaining oil and a contact portion that contacts the shaft are provided in the intermediate portion of the bearing, and oil retaining portions are provided on both sides of the grooves. This reduces the amount of oil drawn out from the contact area, retains the oil in the groove and oil retaining area, and sucks the oil into the bearing, so that almost no oil flows to the end, which prevents the bearing from running out of oil. This has the effect of eliminating burn-in and eliminating problems that could lead to serious failures.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of a bearing in a bearing lubrication device according to an embodiment of the present invention, FIG. 2 is a sectional view taken along line AA in FIG. 1, and FIG. 3 is a side sectional view of a bearing in a conventional bearing lubrication device. cross section,
FIG. 4 is a sectional view taken along line BB in FIG. 3. 10...Bearing, 11...Shaft, 12...
...Contact part, 13...Groove part, 14...
...Oil storage department. Name of agent: Patent attorney Toshio Nakao and 1 other person f0
- Bearing 13 - Skin 14 - Yupaku 3?

Claims (1)

[Claims] A shaft that rotates inside a sintered oil-impregnated bearing is provided with a contact portion in the middle of the bearing that rotates in contact with the inner surface of the bearing with a width equivalent to 70 to 85% of the length of the bearing, and a contact portion that rotates in contact with the inner surface of the bearing, and A lubricating device for a bearing, in which a plurality of grooves each having a narrow outer diameter are alternately formed, and oil retaining portions each having an outer diameter 150 to 300 μm thinner than the contact portion at both ends are further formed on both sides of the contact portion at both ends.