JPH1061671A - Sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent leakage of fine lubricating droplets by forming a labyrinth diameter in such a manner that the inside is made larger than the outside toward the inside of a bearing support device. SOLUTION: An offset type labyrinth 1 is formed between a bearing support device 7 and a rotor 2. Plural circumferential annular grooves 5 gradually increasing in height from the outside 3 toward the inside 4 and plural radial projecting parts 6 are alternately formed on the outer periphery of the rotor 2, and circumferential annular grooves 8 and radial projecting parts 9 are alternately formed on the inner periphery of the bearing support device 7 in such a manner as to stagger to mesh with the annular grooves 5 and the projecting parts 6. A difference in circumferential speed due to a diametral difference of the labyrinth produces an atmospheric pressure difference, whereby the air flows from the outside toward the inside, so that the fine lubricant is pushed back by the air current. Accordingly, prevention of leakage of lubricating oil can be improved remarkably.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing device for forming a labyrinth between a bearing supporting device for lubricating and a rotating body fixed to a shaft.

[0002]

2. Description of the Related Art Conventionally, this type of sealing device is a sealing device for forming a labyrinth 400 between a bearing support device 100 for lubricating and a rotating body 300 fixed to a shaft 200 as shown in FIG. Therefore, a labyrinth seal having the same labyrinth diameter between the outer side 401 and the inner side 402 is used to prevent the lubricating oil from leaking out of the bearing support device 100.

[0003]

However, when the bearing 500 rotates at a higher speed, more fine lubricating droplets are generated than droplets. In such a case, in the above-mentioned conventional labyrinth structure, the finely divided lubricating droplets are subjected to the bearing support device 10.
0 Leakage may occur to the outside, contaminating mechanical devices, and such leakage of lubricating droplets may cause problems such as the need for short-term replenishment of lubricant in oil bath lubrication. there were.

The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to reduce labyrinth between a bearing support device for lubrication and a rotating body fixed to a shaft. An object of the present invention is to provide a highly accurate sealing device capable of preventing leakage of finely divided lubricating droplets. Another object of the present invention is to provide a sealing device that does not require replenishment of lubricant for a long period of time by preventing the leakage.

[0005]

In order to achieve the above-mentioned object, a technical means of the present invention is to provide a seal for forming a labyrinth between a bearing supporting device for lubricating and a rotating body fixed to a shaft. In the device, the labyrinth diameter is configured so that the inside is larger than the outside toward the inside of the bearing support device.

[0006]

According to the above technical means, the sealing device in which a labyrinth is formed between the rotating body fixed to the shaft and the bearing support has a larger diameter toward the inside of the bearing support than on the outside. Therefore, the difference in the circumferential speed due to the diameter difference creates a pressure difference, and the air flows from the outside to the inside, and the finely divided lubricant (lubricating droplets) is pushed back inside the bearing support device by this air flow.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the sealing device of the present invention will be described below with reference to the drawings. INDUSTRIAL APPLICABILITY The sealing device of the present invention is used for a bearing support device that lubricates various mechanical devices.

In the figure, reference numeral 1 denotes a bearing support device 7 for lubricating,
The labyrinth formed between the rotating body 2 fixed to the shaft 15 and the labyrinth 1 is shown in FIG.
The diameter of the inner side 4 is larger than the diameter of the outer side 3 toward the inner side 10. In the figure, reference numeral 11 denotes a bearing.

For example, referring to FIG. 1, an embodiment of the labyrinth 1 will be described. A labyrinth 1 having a different shape is formed between the bearing support device 7 and the rotating body 2, and the labyrinth 1 is formed on the outer periphery of the rotating body 2. A plurality of circumferential annular grooves 5 and a plurality of radial protrusions 6, which gradually increase in height from the outer side 3 to the inner side 4, are alternately formed. A circumferential annular groove 8 is formed on the inner periphery of the bearing support device 7 so as to be difficult to mesh with the annular groove 5 and the protrusion 6.
.. And the radial projections 9 are alternately formed.

Therefore, the labyrinth 1 is formed between the bearing support device 7 and the rotating body 2 by the configuration described above, and the labyrinth 1 is directed toward the inner side 10 of the bearing support device 7 from the diameter of the outer side 3. Since the diameter of 4 is configured to be larger, the difference in circumferential speed due to this diameter difference creates a pressure difference, and the air flows from the outside to the inside, and the finely divided lubricant The (lubricating droplets) are not pushed back inside the bearing support device by this airflow and leak.

The illustrated example is merely an embodiment, and various known staggered types can be applied to the labyrinth constituting the sealing device of the present invention within the scope of the present invention. In addition, the heights of the protruding portions 6, 9 and the depths of the annular grooves 5, 8 and the numbers thereof are not limited, and can be appropriately changed within the scope of the present invention. The labyrinth clearance (radial clearance, axial clearance) is preferably as small as possible, but is not particularly limited to the illustrated example.

The sealing device of the present invention (FIG. 1) and the sealing device of the prior art (FIG. 3) were implemented under the same conditions as described below, and the amount of leakage of the lubricant in that case was compared. Leakage of lubricating droplets was confirmed from the labyrinth at the stage when about 4 hours had passed since the first rotation at high speed, whereas leakage of lubricating droplets was not confirmed after about 24 hours with the sealing device of this embodiment. . (Operating conditions) Shaft diameter: 150 mm (large diameter side) Number of revolutions: 2560 rpm Lubricant: ISO VG36 Temperature: room temperature Machine used: centrifuge

In FIG. 2, reference numeral 12 denotes a cover provided on the inner side 10 of the bearing support device 7 in order to prevent the lubricant from directly contacting the labyrinth 1 to reduce the transfer of the lubricant in the labyrinth direction. Can be. The cover 12
Is formed in an annular shape so as to protrude in the axial direction from the shaft fixing portion 12a.

In the figure, reference numeral 13 denotes a weir provided on the upper inside of the bearing support device 7 to prevent lubricant from entering the labyrinth 1 along the inner wall.

A labyrinth 1 is provided on the bearing support device 7 side.
Notches (or oil holes) 14... Communicating from the labyrinth 1 side to the inside of the bearing support device 10 may be provided so that the lubricant received by the bearing can be returned inside. As a result, leakage of the lubricant can be further eliminated, and shortening of the lubricant supply cycle can be prevented. The number, diameter, and length of the cutouts (or oil holes) 14 are not limited in number, diameter, and length, and are optional.

An air breather (air vent) 16 is provided at an upper portion on the outer side of the bearing support device so as to prevent the flow of air between the inside of the bearing support device and the outside air.

[0017]

As described above, the present invention uses a labyrinth seal having a larger diameter on the inside than on the outside toward the inside of the bearing support device. Since a pressure difference is created and the air flows from the outside to the inside, the finely divided lubricant is not pushed back by this air flow and leaks out of the apparatus. Therefore, the prevention of leakage of the lubricating oil is remarkably improved as compared with the prior art, and as a result, the replenishment cycle of the lubricating oil is lengthened as compared with the prior art, and the cost of this type of sealing device is reduced. Was completed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional front view showing a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional front view showing a second embodiment of the present invention.

FIG. 3 is a vertical sectional front view showing a conventional technique.

[Explanation of symbols]

 1: labyrinth 2: rotating body 3: outside 4: inside 7: bearing support device 10: inside bearing support device 15: shaft

Claims (1)

[Claims] 1. A sealing device for forming a labyrinth between a bearing supporting device for lubricating and a rotating body fixed to a shaft, wherein a diameter of the labyrinth is larger toward the inside of the bearing supporting device than inside the bearing supporting device. A sealing device, characterized in that the sealing device is configured to: