JP4785220B2 - Bearing device used to support vertical rotating shaft in underwater rotating machine - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a bearing device mainly used for supporting a rotating shaft in an underwater rotating machine such as an underwater electric pump and an aeration / stirring device.
[0002]
[Prior art and its problems]
In an underwater rotating machine such as an underwater electric pump or an aeration / stirring device, corrosion is particularly likely to occur in the vicinity of a wetted part or a gap between a rotating part and a stationary part. It has already been elucidated that the cause of corrosion is due to the action of the corrosion cell formed on the metal surface. If the potential difference between the anode and cathode of the corrosion cell can be eliminated, the corrosion current flows. The corrosion will stop after it disappears.
[0003]
However, the rotating shafts of submersible rotary machines, such as submersible electric pumps and aeration / stirring devices, are supported by bearings, and the inner ring and outer ring of the bearing are in contact with each other almost in a point contact manner via balls. In addition, the gap between the opposing surfaces of the inner and outer rings is filled with lubricating grease, and the grease is non-conductive. Therefore, when the rotary shaft rotates, an insulating oil film is formed on the contact portion between the inner and outer rings and the ball. Thus, the inner ring of the bearing and the rotating part connected to the inner ring are completely insulated from the outer part of the bearing and the stationary part connected thereto, and it is inevitable that corrosion occurs due to a potential difference.
[0004]
As a means for electrically connecting the inner and outer rings of the bearing, an attempt has been made to slidably contact the metal spring plate led out from the inner periphery of the outer ring to the outer peripheral surface of the inner ring, but the wear coefficient during rotation has increased. As a result, the power loss increases and the spring plate is severely worn and poor in durability, and cannot be put to practical use.
[0005]
OBJECT OF THE INVENTION
An object of the present invention is to provide a bearing device that has a permanent and effective electrolytic corrosion prevention function without reducing the potential difference generated between the rotating body portion and the stationary body portion when driving an underwater rotating machine, and without increasing the wear coefficient. It is to provide.
[0006]
[Structure of the invention]
In Bearing device for use in supporting a vertical rotary shaft in water rotary machine according to the present invention is to FutaSo the bearing cover from the outside of the bearing bracket engaged static bearing outer ring, the vertical type in which engaged static bearing inner ring the gap formed between the axial end portion and the bearing cover the inner surface of the rotary shaft, is filled with a conductive grease by Rukoto were electrically conduction between the bearing cover and a vertical axis of rotation, underwater rotating When driving the machine, the potential difference generated between the vertical rotary shaft and the rotating body portion connected to the vertical rotating shaft and the bearing bracket and the stationary body portion is reduced to eliminate the flow of corrosion current, and the outer wall of the stationary body portion A current-carrying anode made of a low-potential metal is attached so as to be electrically connected to the wetted part, and the flow of anticorrosion current is formed by eluting the current-carrying anode. It has electrolytic corrosion prevention function and annexed grease replenishing means from the outside of the bearing cover leading to the gap portion.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The following describes an example of a submersible pump used for vertical rotary shaft support.
[0008]
In FIG. 2, reference numeral 1 denotes a vertical rotation shaft fitted to the motor rotor 2, and an impeller 3 is attached to a load side lead-out end below the shaft. Reference numeral 4A denotes an anti-load side bearing at the upper part of the vertical rotating shaft 1, and as shown in detail in FIG. 1, a bearing inner ring 5 that fits to the vertical rotating shaft 1 and a bearing outer ring 7 that fits to the bearing bracket 6 are shown. Are opposed to each other through the ball 8. Reference numeral 10b denotes a bearing cover that is superposed on the center of the bearing bracket 6 to cover the anti-load side bearing 4A, and is formed between the inner surface of the bearing cover 10b and the anti-load side end face of the vertical rotary shaft 1. by the gap portion 9b of filling the conductive grease 11, and a bearing cover 10b and the bearing bracket 6 and a vertical rotary shaft 1 is moved electrically conductive, the rotor 2 and by extension continuous with the vertical rotary shaft 1 And the rotating body portion such as the impeller 3 and the stationary body portion such as the motor outer body 12 and the head cover 13 connected to the bearing bracket 6 are electrically connected. 14 is attached to the grease replenishing means so that leads from the outside of the bearing cover 10b to the gap portion 9b, may be of the grease cup form as shown, or have been the grease injection pipe form derived on the head cover 10b It may be a thing. Reference numeral 16 denotes a galvanic anode made of a low-potential metal such as an aluminum alloy, and is attached to a wetted part such as the head cover 13.
[0009]
[Action]
Since the rotating part and the stationary part can be electrically connected as described above, the potential difference generated between the two parts during driving is reduced, corrosion current does not flow, and corrosion prevention due to elution of the galvanic anode. A current flow is formed to produce an anticorrosive action.
[0010]
【The invention's effect】
By using the bearing device of the present invention, a potential difference between the rotating body portion and the stationary body portion when driving an underwater rotating machine is reduced, and a permanent and effective electric corrosion prevention function is provided without increasing the wear coefficient. Will be allowed.
[Brief description of the drawings]
FIG. 1 is a longitudinal side view of a bearing device of the present invention.
FIG. 2 is a longitudinal side view of a submersible electric pump using the bearing device of the present invention.
[Explanation of symbols]
1 vertical rotary shaft 5 bearing inner ring 6 bearing bracket 7 gap portion 10b bearing cover 11 conductive grease 14 grease means between the axial end and the bearing cover the inner surface of the bearing outer ring 9b vertical rotation axis
16 galvanic anode

Claims (1)

And FutaSo the bearing cover from the outside of the bearing bracket engaged static bearing outer ring, the gap formed between the axial end portion and the bearing cover the inner surface of the vertical rotating shaft engaged static bearing inner ring by isosamples filled with conductive grease is electrically conducting and the bearing cover and a vertical rotary shaft, a rotary body part connected to it a vertical rotation axis and in the drive water rotary machine, connected to the bearing bracket and which A galvanic anode made of a low-potential metal to reduce the potential difference between the stationary body part and wipe away the flow of the corrosion current and to be electrically connected to the outer wall wetted part of the stationary body part the mounting has that flow is formed electrolytic corrosion prevention function of protective current by eluting the fluid conductive anode and grease from the outside of the bearing cover leading to the air gap Characterized by being attached to feed means, journalled device used in support of the vertical rotary shaft in water rotary machine.

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