JP4618924B2 - Electric corrosion prevention method and apparatus for rotating spindle in underwater rotating machine - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and apparatus for preventing electrolytic corrosion of a main shaft in an underwater rotating machine such as an underwater electric pump and an aeration / stirring device.
[0002]
[Prior art and its problems]
Conventionally, with respect to the prevention of electrolytic corrosion of the main shaft in an underwater rotating machine such as an underwater electric pump, a method has been adopted in which an electroplating anode is attached to the load side lead-out portion of the main shaft or an anticorrosion current is supplied using an external power source. . However, with the method of attaching the galvanic anode to the load side lead-out part of the main shaft, the rotational balance is lost as the galvanic anode is worn over time, causing vibration, and excessive eccentric load may be applied to the main shaft, leading to shaft breakage. In addition, it is difficult to predict the life of the galvanic anode, and there is a problem that maintenance and replacement work must be frequently performed by lifting the underwater rotating machine from seawater. In addition, in order to flow an anti-corrosion current using an external power supply, an onshore facility where an external power supply facility is installed is necessary, and many difficult problems that must be cleared such as securing the site, maintaining and maintaining the power supply, increasing power energy consumption, etc. Furthermore, when moving the use site of the underwater rotating machine to the next use site, the entire power supply facility must be moved, which requires a large movement cost.
[0003]
OBJECT OF THE INVENTION
The object of the present invention is to provide an underwater water source that does not require an external power supply facility, does not increase power energy consumption, and can respond quickly to movement at the site of use. An object of the present invention is to provide a method and an apparatus for preventing electrolytic corrosion of a rotating spindle in a rotating machine.
[0004]
[Structure of the invention]
In the method for preventing galvanic corrosion of a main shaft in an underwater rotating machine according to the present invention, a direct current is obtained by rectifying and smoothing an alternating current extracted by inserting one power supply line introduced into the underwater rotating machine into a current transformer. The current is converted into an electric current, and the negative side is caused to flow around the axis of the rotation spindle, and the positive side is caused to flow into the insoluble counter electrode. Further, in the apparatus for preventing electrolytic corrosion of the main shaft in the submersible rotary machine according to the present invention, the peripheral surface and the upper side of the non-load-side bearing housing of the motor, which is the prime mover of the submersible rotary machine, are covered with a head cover and introduced into the motor circuit. Install a current transformer to be inserted in one line in the head cover of the power supply line and a rectifying base for smoothing the alternating current in the head cover, and provide an insoluble counter electrode that is supported by a stationary body such as the head cover and contacts the outside. And the negative side of the direct current taken out from one of the power supply lines and smoothed by the rectifying base is caused to flow around the axis of the rotating spindle and the positive side is allowed to flow into the insoluble counter electrode.
[0005]
【Example】
Examples of submersible electric pumps will be described below.
[0006]
In the drawings of the embodiment, reference numeral 1 denotes a motor that serves as a prime mover for the submersible electric pump, 2 denotes a rotating main shaft made of stainless steel, and an impeller (not shown) is attached to a lower end of the load side. 3 is an upper bearing housing that supports the end of the shaft opposite to the load side of the rotating main shaft 2, 4 is a head cover that covers the peripheral surface and upper part of the upper bearing housing 3, and 5 is a power supply line that is introduced into the circuit of the motor 1, Reference numeral 6 denotes a rectifying base mounted in the head cover 4, and reference numeral 7 denotes a current transformer. The rectifying base 6 smoothes the alternating current extracted by inserting one line of the motive power 5 into the current transformer 7. Process. 8 is a conductive washer for electrically connecting the rotating main shaft 2 and the bearing outer ring 9, and 10 is an insoluble counter electrode which is supported by a stationary body such as the head cover 4 and is in contact with liquid. A magnetic oxide, a ceramic compound, or platinum or titanium coated with platinum is preferable. Then, the negative side of the DC power source smoothed by the rectifying base is caused to flow around the axis of the rotary main shaft 2 and the positive side is allowed to flow into the insoluble counter electrode.
[0007]
[Action]
The AC current extracted by inserting one line of the power supply line 5 into the current transformer is smoothed by the rectifying base 6 and converted into a DC current. Current is passed to the insoluble counter electrode 10 to form an anticorrosion current circuit, and the anticorrosion effect of the rotating spindle 2 is maintained throughout the operation and stop of the pump. In addition, if it is set as the structure which connects the rotation main shaft 2 and the bearing outer ring | wheel 9 with the conduction | electrical_connection washer 8, etc., the anticorrosion effect by an anticorrosion electric current will affect not only the rotation main shaft 2 but a stationary body part.
[0008]
【The invention's effect】
According to the present invention, since no external power supply facility is required, power energy consumption is not increased, and it is possible to immediately respond to the movement of the use site, the anticorrosion effect is semi-permanent, no cause of shaft runout, and excellent maintainability. ing.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing the principle of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Motor 2 Rotating spindle 3 Upper bearing housing 4 Head cover 5 Power supply line 6 Rectification base 7 Current transformer 10 Insoluble counter electrode

Claims (2)

One of the power supply wires introduced to the underwater rotating machine is inserted into a current transformer, and the AC current taken out is converted to DC current by rectifying and smoothing, and the minus side flows around the axis of the rotating spindle. In addition, a method for preventing electrolytic corrosion of a rotating spindle in an underwater rotating machine, wherein the plus side is caused to flow into an insoluble counter electrode. A current transformer and an alternating current that are inserted into one line in the head cover of the power supply line that covers the peripheral surface and upper side of the bearing housing on the anti-load side of the motor, which is the prime mover of the submersible rotating machine, with a head cover and is introduced into the motor circuit. The rectifying base for smoothing is mounted in the head cover, provided with an insoluble counter electrode that is supported by a stationary body such as the head cover and is in contact with the outside, and is taken out from one of the power supply lines and smoothed by the rectifying base. An apparatus for preventing galvanic corrosion of a main shaft in an underwater rotating machine, wherein the negative side of the direct current flows in around the axis of the rotating main shaft and the positive side flows into an insoluble counter electrode.

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