JP2002139066A - Electrolytic corrosion preventing device of underwater rotary machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrolytic corrosion preventing device for underwater rotary machine capable of giving a low-cost electrolytic corrosion preventive effect permanently by decreasing the potential difference generated between a rotor part and stator part when a prime mover is put in operation. SOLUTION: A vertical hole 7 is bored in the center of the end face of a rotary shaft 1 fitted in a bearing inner ring 4a, and in this hole 7 the lower part of an electroconductive coil spring 6 is fitted, and the rear surface of the central part lid wall 8 of a bearing housing 5 is contacted with the top of the coil spring 6, and thereby the rotary shaft 1 and the rotor part continued thereto are put in electric continuity to the housing 5 and the stator part continued thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a submersible electric pump,
The present invention relates to a device for preventing electric corrosion of a submersible rotating machine such as a stirring device.

[0002]

2. Description of the Related Art In a submersible rotary machine such as an underwater electric pump or an aeration / stirring device, corrosion is particularly likely to occur near a liquid contact part or a gap between a rotating part and a stationary part. It has already been clarified that the cause of the corrosion is due to the action of the corrosion battery formed on the metal surface, and if the potential difference between the anode and cathode of the corrosion battery could be eliminated, corrosion current would flow. It will disappear and the corrosion will stop.

However, the rotating shaft of a submersible rotating machine, such as a submersible electric pump or aeration / stirring device, is supported by a bearing such as a ball bearing, and the gap between the opposing surfaces of the inner and outer rings of the bearing is filled with grease for lubrication. Since the grease is non-conductive, an insulating oil film is formed on the contact portion between the inner and outer rings and the ball when the rotating shaft rotates, and the bearing inner ring and the rotating body portion connected thereto, and the bearing outer ring and the stationary body connected thereto It is completely insulated from the part,
It is inevitable that a potential difference causes corrosion.

Various coatings and coatings have been attempted to protect against corrosion. However, coatings and coatings on rotating parts and the like are easily peeled off due to abrasion and cavitation phenomena. Even in the case of partial exfoliation, once it is exfoliated, the electrolytic corrosion prevention function is lost and corrosion proceeds. Also, an electrical anticorrosion method has been attempted to obtain an anticorrosion effect by a sacrificial dissolution action of the anode material. However, this method requires that the entire mechanical structure be in an electrically conductive state, and even a part thereof is non-conductive. There is no effect in the conductive state, and the most bottleneck is that the rotating body portion and the stationary body portion are separated by the bearing portion when the motor is driven as described above.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to reduce the potential difference between a rotating body portion and a stationary body portion during driving of a motor without requiring painting or expensive coating on a rotating portion or the like, thereby making permanent and low cost. An object of the present invention is to provide an anti-corrosion effect of a submersible rotating machine that can obtain an anti-corrosion effect.

[0006]

In the apparatus for preventing electrolytic corrosion of a submersible rotary machine according to the present invention, a vertical hole is formed at the center of the end face of a rotating shaft fitted to an inner ring of a bearing, and a conductive coil spring is provided in the vertical hole. The lower surface is fitted, the back surface of the center cover wall of the bearing housing with the bearing outer ring fitted thereon is brought into contact with the upper end of the coil spring, and the rotating shaft and the rotating body part connected to it, the bearing housing and the stationary stationary connected thereto It was configured to be electrically connected to the body part. Preferably, the upper end of the conductive coil spring is vertically raised to form a contact piece that comes into contact with the back surface of the center cover wall of the bearing housing, and a recess is formed on the back surface of the center cover wall of the bearing housing. The upper end of the conductive coil spring is vertically formed so as to be formed into a contact piece which is engaged with the recess.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A description will be given below of an example in which an underwater electric pump is implemented.

In FIG. 1, reference numeral 1 denotes a motor rotation shaft, and an impeller 3 is mounted on a load-side lead-out end.
Reference numeral 4 denotes a bearing for supporting the end of the rotating shaft 1 on the non-load side. As shown in detail in FIGS. 2 to 5, a bearing inner ring 4a statically fitted to the rotating shaft 1 and a bearing outer ring statically fitted to the bearing housing. 4b is opposed via the ball 4c. Reference numeral 6 denotes a conductive coil spring, and reference numeral 7 denotes a vertical hole formed in the center of the end face of the non-load-side lead-out end of the rotating shaft 1, and a lower portion of the conductive coil spring 6 fits in the vertical hole 7. Be mounted. Numeral 8 denotes a central lid wall of the bearing housing 5. As shown in FIG. 2, when the lid is mounted from the outside of the bearing housing 5, the vicinity of the center of the rear surface of the central lid wall 8 is located at the upper end of the conductive coil spring 6. Contact. When the upper end of the conductive coil spring 6 is formed on a vertically raised contact piece 6a as shown in FIG. 3, the contact piece 6a comes into contact with the back surface of the central lid wall 8 of the bearing housing 5. I do. Further, as shown in FIG. 4, if the recess 9 is formed in the back surface of the central lid wall 8 of the bearing housing 5 so that the touch piece 6 a is engaged in the recess 9, the driving of the motor can be performed. , The lateral deflection of the conductive coil spring 6 due to the action of the centrifugal force can be suppressed. FIG.
If a conductive sphere 6b is attached to the tip of the contact piece 6a as shown in FIG. 7, an effect is obtained that the sliding contact with the back surface of the central lid wall 8 becomes smooth. In any of the above embodiments, the conductive coil spring 6 fitted in the vertical hole 7 of the rotating shaft 1
Is pressed against the back surface of the central lid wall 8 by its elasticity, and the rotating shaft 1 and the bearing housing 5 are electrically connected to each other via the conductive coil spring 6, and are thus connected to the rotating shaft 1. A rotating body portion such as an impeller 3, a bearing housing 5, and a motor outer shell 1 connected thereto.
0 and a stationary body portion such as the head cover 11 are electrically connected to each other. Reference numeral 12 denotes a galvanic anode made of a metal having a low potential such as an aluminum alloy, which is mounted on a liquid-contacting portion outside a stationary body such as the head cover 11, for example.

[0009]

By electrically connecting the rotating shaft and the bearing housing with a conductive coil spring in the above-described manner, the rotating shaft and the rotating body portion connected to the rotating shaft and the bearing housing and the rotating shaft when the underwater rotating machine is driven are driven. The potential difference between the continuous stationary body portion is reduced, the corrosion current does not flow, and the flow of the anticorrosion current due to the elution of the galvanic anode is formed, so that the anticorrosion action is produced.

[0010]

According to the apparatus of the present invention, for underwater rotating machines such as underwater electric pumps and aeration / stirring devices, there is no need for painting or expensive coating on rotating parts and the like.
By reducing the potential difference generated between the rotating body portion and the stationary body portion at the time of driving the prime mover, a permanent and low-cost electrolytic corrosion prevention effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a vertical side view of a submersible electric pump to which the device of the present invention has been applied.

FIG. 2 is a longitudinal sectional side view of a main part of the device of the present invention, showing a state in which the upper end of a conductive coil spring is in contact with the back surface of a central lid wall of a bearing housing in a normal form.

FIG. 3 is a vertical sectional side view of a main part of the device of the present invention, in which an upper end of a conductive coil spring is formed in a vertically raised contact piece and is in contact with a back surface of a central lid wall of a bearing housing; Indicates the status.

FIG. 4 is a vertical sectional side view of a main part of the device of the present invention, in which an upper end of a conductive coil spring is formed in a vertically raised contact piece and engages in a recess on the back surface of a central lid wall. Indicates a state in which

FIG. 5 is a vertical sectional side view of a main part of the device of the present invention, showing a state in which an upper end of a conductive coil spring is vertically raised and a conductive sphere is attached to the end thereof.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotating shaft 4a Bearing inner ring 4b Bearing outer ring 5 Bearing housing 6 Conductive coil spring 6a Contact piece 7 Vertical hole 8 Central lid wall 9 Depression

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F16C 19/00 F16C 19/00 F-term (Reference) 3H022 AA01 BA06 BA07 CA01 CA48 CA50 CA56 DA12 DA14 3H034 AA01 BB01 BB06 BB12 CC03 CC06 CC07 DD01 DD28 DD30 EE11 EE15 3J101 AA02 AA42 AA52 AA62 BA77 BA80 EA72 FA11 GA29 GA60

Claims (3)

[Claims] 1. A vertical hole (7) is formed at the center of the end face of a rotating shaft (1) fitted to a bearing inner ring (4a).
The lower part of the conductive coil spring (6) is fitted to the
The back surface of the central lid wall (8) of the bearing housing (5) fitted with the bearing outer ring (4b) is brought into contact with the upper end of the coil spring (6), and the rotating shaft (1) and the rotating body part connected to the rotating shaft (1) And a bearing housing (5) and a stationary body portion connected to the bearing housing (5) are electrically connected to each other. 2. An upper end of a conductive coil spring (6) is formed vertically on a contact piece (6a) which comes into contact with the back surface of a central lid wall (8) of a bearing housing (5). The apparatus for preventing electrolytic corrosion of a submersible rotating machine according to claim 1, characterized in that: 3. A recess (9) is formed on the back surface of the central lid wall (8) of the bearing housing (5), and the upper end of the conductive coil spring (6) is vertically raised to form the recess. The device for preventing electrolytic corrosion of a submersible rotary machine according to claim 1, characterized in that it is formed on a contact piece (6a) engaged in the fossa (9).