JP2577669B2 - Bearing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing device, and more particularly to a bearing device for a vertical rotary machine.

[0002]

2. Description of the Related Art In general, a so-called vertical rotary machine in which the axis of a rotary shaft of a rotor is positioned in a vertical direction, the rotor is supported by upper and lower bearings, and the rotor is configured to be rotatable around the vertical axis. ing. Although the upper and lower bearings reduce the dynamic friction by lubrication, the upper bearings are usually grease lubricated because oil lubrication is difficult. Since this grease lubrication does not have a simple mechanism for reliably preventing the grease from leaking, a method such as using a grease-sealed rolling bearing has been adopted.

[0003]

However, the above-described grease filling method has a problem in that the amount of grease to be filled is small, and the grease leaks out within a short period of time and lubrication cannot be performed. Was. Further, there is a disadvantage that leaked grease enters the inside of a rotary machine such as a pump.

[0004] The present invention has been made in view of the above-mentioned point, and an object thereof is to increase the amount of grease sealed in a rolling bearing, to sufficiently lubricate the bearing, and to improve the grease. It is an object of the present invention to provide a bearing device which does not mix with the fluid handled by the rotating machine and does not leak the handling fluid of the rotating machine to the bearing side.

[0005]

In order to achieve the above-mentioned object, a bearing device according to the present invention is a bearing for a vertical rotating machine which supports a rotor with upper and lower bearings and rotates the rotor about a vertical axis. In the device, the upper rolling bearing is lubricated with grease, and a collar that rotates with the rotating shaft is attached below the rolling bearing, a flange is provided on the outer ring portion of the collar, a recess is formed, and the collar is provided outside the collar. The bearing housing is provided with a recess for storing grease, and a lower surface of the collar forms a labyrinth with the bearing housing.

[0006]

According to the present invention having the above-described structure, the upper rolling bearing is filled with grease, and a collar that rotates together with the rotating shaft is attached below the rolling bearing. The grease that has been formed and comes out of the rolling bearing during rotation is pressed into this recess, and the bearing housing outside the collar is provided with a recess for accumulating grease. The grease can be reliably supplied to the rolling bearing. Even if grease leaks from the collar, the grease that has leaked can be stored in the bearing housing, so that the grease does not mix with the fluid handled by the rotating machine. further,
Since the lower surface of the collar and the bearing housing form a labyrinth, the grease vapor is prevented from entering the inside of the pump, and the fluid handled by the rotating machine is prevented from leaking to the bearing side. Therefore, even if a sufficient amount of grease is sealed, the operation can be performed for a long time without leakage, and at the same time, since the grease does not enter the inside of the rotating machine, the handled fluid is not contaminated.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a bearing device according to the present invention will be described below with reference to FIG.

FIG. 1 is a sectional view of a two-axis vacuum pump which is a three-dimensional rotary machine including the bearing device of the present invention. In the figure, reference numeral 1 denotes a vacuum pump, and the vacuum pump 1 is connected to an electric motor M via a gear box 15. The vacuum pump 1 includes a pump casing 2, and a pump rotor 3 is rotatably disposed in the pump casing 2. The rotating shaft 3a of the pump rotor 3 is housed in a bearing housing 4 and a bearing cover 5 attached to the upper end of the pump casing 2. The rotating shaft 3a is rotatably supported by an upper rolling bearing 6 provided in the bearing cover 5.

Immediately below the rolling bearing 6, a collar 7 is provided.
Are arranged so as to rotate integrally with the rotating shaft 3a. The collar 7 has a collar outer ring portion 7a, a collar portion 7b is formed at an upper end of the collar outer ring portion 7a, and a concave portion 7c is formed in the collar outer ring portion 7a and the collar portion 7b.

On the other hand, the bearing housing 4 outside the collar 7
Is provided with a grease reservoir 8 having a concave shape, and a labyrinth 1 is provided on an opposing surface of the collar 7 and the bearing housing 4.
0 is formed. Reference numeral 11 denotes a pump suction port, and reference numeral 12 denotes a pump discharge port.

Next, the operation of the bearing device of the present invention configured as described above will be described.

Grease is supplied from the upper part of the rolling bearing 6, and a sufficient amount of grease is put into the rolling bearing 6. If the amount of grease is large, use a rolling bearing 6
Accumulates in the recess 7c inside the collar 7 below the
When the rotating shaft 3a is rotated in this state, the grease is pushed to the outer ring portion 7a side of the collar 7 by centrifugal force, but accumulates in the concave portion 7c of the collar 7 and does not leak outside. Also,
The grease that has flowed downward from the rolling bearing 6 during operation is accumulated in the concave portion 7c of the collar 7 and does not leak outside. Nevertheless, grease that has leaked to the outside of the collar 7 for some reason accumulates in the grease pool 8 at the bottom of the bearing housing 4 and does not leak further inside. Further, since the lower surface of the collar 7 and the bearing housing 4 form a labyrinth 10 on the opposing surfaces, the grease vapor is prevented from entering the pump.

Next, another embodiment of the present invention will be described with reference to FIG. 2, components having the same functions and functions as those of FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, a configuration for injecting an inert gas is added to the above embodiment. That is, an inert gas inlet 13 is provided in the bearing housing 4, and a gas supply path 14 communicating with the inlet 13 is provided, so that the inert gas is supplied to a gap between the rotating shaft 3 a and the bearing housing 4. ing. By injecting the inert gas, the bearing portion and the inside of the pump are shut off by the inert gas, thereby preventing the grease vapor from entering the inside of the pump and preventing the fluid handled by the vacuum pump 1 from entering the bearing portion. In.

[0015]

As is apparent from the above description, according to the present invention, the amount of grease to be sealed can be increased since the collar having the concave portion is provided below the rolling bearing.
Grease can be reliably supplied to the rolling bearing, and even if grease leaks from the collar, the grease that has leaked can be stored in the bearing housing, so that the grease mixes with the fluid handled by rotating machines such as pumps. Nothing. In addition, the lower surface of the collar and the bearing housing form a labyrinth, which prevents grease vapor from entering the inside of a rotating machine such as a pump, and at the same time prevents fluid handled by the rotating machine from leaking to the bearing side. I have. Therefore, even if a sufficient amount of grease is sealed, the grease can be operated for a long time without leaking, and at the same time, since the grease does not enter the inside of the rotating machine, the handled fluid is not contaminated.

Further, when the bearing device according to the present invention is applied to a vacuum pump, an inert gas can be injected into a gap between the rotating shaft below the collar and the bearing housing. It is shut off by an inert gas, preventing the grease vapor from entering the pump and creating a clean vacuum.Also, it prevents the handling fluid from entering the bearing, preventing the grease from deteriorating. Thus, the bearing life can be extended.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a bearing device according to the present invention.

FIG. 2 is a sectional view showing another embodiment of the bearing device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum pump 2 Electric motor 3 Rotor 3a Rotating shaft 4 Bearing housing 5 Bearing cover 6 Rolling bearing 7 Collar 8 Grease reservoir 10 Labyrinth 13 Inert gas inlet 14 Gas supply path

 ──────────────────────────────────────────────────続 き Continued from the front page (56) References JP-A-55-119221 (JP, A) JP-A 62-149250 (JP, U) JP-A 61-131521 (JP, U) JP-A 1-131521 165821 (JP, U)

Claims (2)

(57) [Claims] In a bearing device for a vertical rotating machine that supports a rotor with upper and lower bearings and rotates the rotor about a vertical axis, the upper rolling bearing is lubricated with grease, and a lower portion of the rolling bearing is provided below the rolling bearing. A collar that rotates with the rotating shaft is attached, a collar is provided on the outer ring portion of the collar to form a recess, and a bearing housing provided outside the collar is provided with a recess for storing grease, and the lower surface of the collar is A bearing device, wherein a labyrinth is formed with a bearing housing. 2. The bearing device according to claim 1, wherein an inert gas is injected into a gap between the rotating shaft below the collar and the bearing housing.