JP2668594B2 - Grease lubrication structure - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grease lubrication structure for plain bearings.

Conventional technology Sliding bearings for linear motion that slide (reciprocate) along an axis are provided with a grease reservoir at a position in contact with the sliding surface, and the grease is stored in the gap between the shaft and the sliding bearing from the grease reservoir. Lubrication is performed by supplying a small amount.

In addition, in order to prevent foreign matters such as dust and chips from entering the gap between the shaft and the sliding bearing, seals may be provided in contact with the outer peripheral surface of the shaft near the front and rear ends of the sliding bearing.

Then, when the plain bearing moves along the shaft, the grease in the grease reservoir adheres to the surface of the shaft and remains, so that the grease is supplied to the gap between the shaft and the plain bearing. Since the grease of (1) cannot enter the gap, it is scraped off at the end of the plain bearing.

Therefore, when the slide bearing is provided with the seal and repeatedly slides along the shaft as described above, the grease is unilaterally supplied from the grease reservoir to the gap inside the seal arranged near both ends of the slide bearing. It fills, gradually increases the pressure, and eventually leaks out of the seal.

Such a situation is a big problem as a sliding bearing of a mechanical device such as an injection molding machine that does not like oil stains.

SUMMARY OF THE INVENTION An object of the present invention is to provide a grease lubrication structure in which the grease filled in the gap inside the seal is returned to the grease reservoir of the sliding bearing and the grease does not leak from the seal portion.

Means for Solving the Problems A shaft and a slide bearing for linear motion that slides along the shaft are provided, and the slide bearing includes a grease reservoir shielded around the shaft.

Seals that contact the outer peripheral surface of the shaft are provided near both ends of the slide bearing, and a shielded gap is formed between both ends of the slide bearing and the inside of the seal.

A communication passage for returning the grease accumulated in the gap to the grease reservoir is formed between the gap inside the seal and the grease reservoir of the plain bearing.

When sliding the sliding bearing along the shaft, the grease inside the grease reservoir of the sliding bearing adheres to the outer peripheral surface of the shaft, and the seals near both ends of the sliding bearing scratch the grease that adheres to the outer peripheral surface of the shaft. take.

The grease in the grease reservoir of the plain bearing fills the gap inside the seal, and the grease filled in the gap inside the seal returns to the grease reservoir of the plain bearing through the communication passage and circulates as the internal pressure increases.

Embodiment FIG. 1 shows a first embodiment.
A shaft 1 and a sliding bearing 2 for linear motion sliding along the shaft 1
And the sliding bearing 2 has a grease reservoir 4 shielded around the shaft 1.

Seals 5 and 5 contacting the outer peripheral surface of the shaft 1 are provided near both ends of the slide bearing 2, respectively, and a shielded gap 8 and 9 is provided between both ends of the slide bearing 2 and the insides of the seals 5 and 5. Are formed respectively.

Between the gaps 8 and 9 inside the seals 5 and 5 and the grease reservoir 4 at the center of the slide bearing 2, a communication passage 16 for returning the grease accumulated in the gaps 8 and 9 to the grease reservoir 4, 17 are formed respectively.

A slide bearing 2 is mounted on a shaft 1, and a housing 3 is fixed to the slide bearing 2. The plain bearing 2 linearly reciprocates in the longitudinal direction of the shaft 1. A space is provided between the front part and the rear part, and the space is shielded by a housing 3 to form a grease reservoir 4 around the shaft 1. ing.

Seals 5, 5 are attached to the inner circumference of both ends of the housing 3 near the front and rear ends of the slide bearing 2, and the tips of the seals 5, 5 are in contact with the outer peripheral surface of the shaft 1. An injection hole 6 communicating with the grease reservoir 4 of the plain bearing 2 is provided in the center of the housing 3 in a vertical direction intersecting the longitudinal direction of the shaft 1. The injection hole 6 of the housing 3 has a top end opening for non-return. A nipple 7 equipped with a ball valve is attached. On both sides of the injection hole 6 of the housing 3, two vertical straight holes 10, 1 communicating with the grease reservoir 4 of the plain bearing 2 in the vertical direction intersecting the longitudinal direction of the shaft 1.
1 is formed respectively, and two vertical holes 12 and 13 are formed near both ends of the housing 3 so as to communicate with gaps 8 and 9 inside the seals 5 and 5 parallel to the vertical holes 10 and 11, respectively. . The housing 3 is formed with a horizontal hole 14 communicating the vertical hole 10 and the vertical hole 12 and a horizontal hole 15 communicating the vertical hole 11 and the vertical hole 13 in the longitudinal direction of the shaft 1. Vertical straight hole 12, horizontal straight hole 1
4, the vertical straight hole 10 constitutes a communication passage 16 that connects the gap 8 inside the one seal 5 and the grease reservoir 4 of the slide bearing 2 to each other.
The vertical hole 13, the horizontal hole 15, and the vertical hole 11 of the housing 3 constitute a communication passage 17 for communicating the gap 9 inside the other seal 5 and the grease reservoir 4 of the slide bearing 2.

Check valves 18 and 19 for preventing the reverse flow of grease from the grease reservoir 4 of the plain bearing 2 to the communication passages 16 and 17 are provided at the lower end openings of the vertical straight holes 10 and 11 of the housing 3 facing the grease reservoir 4, respectively. It is installed.

When the sliding bearing 2 is repeatedly slid along the shaft 1, the grease in the grease reservoir 4 of the sliding bearing 2 is accumulated and filled in the gaps 8 and 9 inside the seals 5 and 5. When the grease is further fed into the gaps 8 and 9 inside the seals 5 and 5, the grease filled in the gap 8.9 inside the seals 5 and 5 slips through the communication passages 16 and 17 as the internal pressure increases. Bearing 2
Return to grease reservoir 4.

When grease is injected from the nipple 7 into the injection hole 6 of the housing 3, the internal pressure of the grease reservoir 4 of the sliding bearing 2 increases, and the grease inside the grease reservoir 4 of the sliding bearing 2 will flow back into the communication passages 16 and 17. , But plain bearing 2
The reverse flow of grease from the grease reservoir 4 to the communication passages 16 and 17 is blocked by the check valves 18 and 19.

In this way, the internal pressure in the gaps 8 and 9 inside the seals 5 and 5 is removed, and the grease does not leak out from the seals 5 and 5 to the outside. Also, the grease returns to the grease reservoir 4 of the sliding bearing 2 through the communication passages 16 and 17 from the gaps 8 and 9 inside the seals 5 and 5 while lubricating the sliding surface between the shaft 1 and the sliding bearing 2. And slowly circulate.

FIG. 2 shows a second embodiment, in which the housing 3 in the first embodiment is formed with horizontal straight holes 14, 15 which connect the vertical straight holes 10, 11 and the vertical straight holes 12, 13. In this embodiment, the vertical straight holes 10, 11 and the vertical straight holes 12, 13 are connected to each other by the tubes 20, 20 outside the housing 3, and the outer circumference of the shaft 1 provided near both ends of the plain bearing 2 Seals 5,5 that contact the surface are O
It is in the form of a ring.

The vertical straight hole 12, the tube 20, and the vertical straight hole 10 of the housing 3 constitute a communication passage 16 which communicates the gap 8 inside the one seal 5 and the grease reservoir 4 of the sliding bearing 2 with each other. The straight hole 13, the tube 20, and the vertical straight hole 11 constitute a communication passage 17 that communicates the gap 9 inside the other seal 5 and the grease reservoir 4 of the slide bearing 2.

The communication passages 16 and 17 can be easily formed, and one end of each of the tubes 20 and 20 can be
The used grease in the gaps 8 and 9 inside the seals 5 and 5 extruded from the tubes 20 and 20 can be recovered by removing the grease from the upper end openings of 0 and 11.

FIG. 3 shows a third embodiment, in which communication passages 16 and 17 are constituted by grooves provided on the outer peripheral surface of the slide bearing 2 and short vertical holes reaching the grease reservoir 4 from the ends thereof. The seals 5, 5 provided in the vicinity of both ends of the slide bearing 2 and in contact with the outer peripheral surface of the shaft 1 are in the form of packing. Communication passage 16,
17 is completed by attaching the housing 3 to the plain bearing 2.

 Other configurations are the same as those of the first embodiment.

Since the communication passages 16 and 17 can be formed more easily and there is no need to process the housing 3 side, it can be used when the housing 3 is difficult to process.

FIG. 4 shows a fourth embodiment, in which the plain bearing 2 is provided with horizontal straight holes for directly communicating the grease reservoir 4 and the gaps 8, 9 inside the seals 5, 5 to form the communication passages 16, 17. Is.

 Other configurations are the same as those of the first embodiment.

The communication passages 16 and 17 are the shortest and are not bent, so that they are easy to process.

Advantages of the Invention By sliding the slide bearing along the shaft, the grease in the grease reservoir of the slide bearing adheres to the outer peripheral surface of the shaft. The grease in the grease reservoir of the plain bearing fills the gap inside the seal. The grease filled in the gap inside the seal can be prevented from leaking to the outside from the seal portion, and the grease inside the grease pool of the slide bearing can be prevented from decreasing.

In addition, since the grease is always present in the gap inside the seal, the lip of the seal is always sufficiently lubricated by the grease, and the wear of the lip of the seal is small. Grease consumption is reduced.

[Brief description of the drawings]

1 is a sectional view of the first embodiment, FIG. 2 is a sectional view of the second embodiment, FIG. 3 is a sectional view of the third embodiment, and FIG. 4 is a sectional view of the fourth embodiment. 1 ... shaft, 2 ... sliding bearing, 3 ... housing, 4 ...
Grease pool, 5 …… Seal, 8,9 …… Gap, 16,17 ……
Communication passage.

Claims (1)

(57) [Claims] 1. A shaft bearing and a slide bearing for linear motion that slides along the shaft. The slide bearing has a grease reservoir shielded around the shaft, and the shaft bearing is provided near both ends of the shaft bearing. Seals that contact the outer peripheral surface are provided, and a shielded gap is formed between both ends of the slide bearing and the inside of the seal, and the inside of the gap is formed between the gap inside the seal and the grease reservoir of the slide bearing. A grease lubrication structure characterized in that a communication passage is formed to return the grease accumulated in the grease reservoir to the grease reservoir.