JP2542995Y2 - Bearing support device for canned motor pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a bearing support device for a canned motor pump belonging to a non-leakage (non-seal) pump used for transferring dangerous chemical liquids, expensive chemical liquids, and the like.

[Conventional technology]

As described above, in the leak-free pump, the motor rotor is immersed in the pumping liquid together with the rotating part of the pump, and the impeller is supported by the overhanged motor shaft by two bearings in the liquid. There is a canned motor type pump in which a thin corrosion-resistant cylindrical can (can) is attached to the rotor to isolate the rotor and insulate the stator from liquid.

FIG. 3 is a longitudinal sectional view showing a conventional example of the above-mentioned canned motor pump. A motor shaft 2 having a cantilever support of an impeller 1 at a shaft end is provided by two bearings A and B in the liquid. The motor is supported, and a thin corrosion-resistant cylindrical can (can) 4 is inserted inside the motor stator 3 to insulate the stator 3 from the liquid, and the rotor 5 is similarly wrapped in a thin can. ing. A part of the pump discharge liquid sent to the opening 7 at the end opposite to the pump side of the motor via the cooling pipe 6 branched from the pump discharge port is used as the two bearings A and B.
Are lubricated and cooled by the circulating flow guided to the impeller suction portion through the gaps between the sliding surfaces of the can, the inside of the can, the motor rotor gap g and the submerged bearing B sliding gap. Therefore, there is no shaft sealing device in the pump section (non-sealing), the pump handling liquid does not leak to the outside, and the motor stator 3 and the rotor 5 are isolated and protected from the liquid by the corrosion-resistant can. And the ability to transfer expensive chemical liquids and the like without leakage.

As shown in FIG. 2 (a), the submerged bearing A is provided with a slide bearing and a thrust bearing which are connected to each other so that the cooling liquid flows continuously between opposed sliding surfaces. ,
The sliding bearing portion includes a rotating sliding member 13 attached to the motor shaft 2 inside a fixed sliding member 12 supported by a bearing case 11.
The thrust bearing portion is provided at the end of the rotary sliding member 13 with a thrust bearing (sliding member) 14.
Are sandwiched between the nut 15 at the shaft end and the step portion 2a of the shaft 2, and are mounted so as to rotate integrally. As shown in FIG. 2 (b), an end face groove 12a in the radial direction is formed on the end face of the fixed sliding member 12.

During the operation of the pump, the cooling liquid sent from the opening 7 is radially discharged through the end face groove 12 a through the sliding gap between the fixed sliding member 12 and the rotating sliding member 13 in the direction of the arrow, and is discharged to the stator can 4. After the collision, the direction was changed and sent to the pump side.

[Problems to be solved by the invention]

As described above, in a canned motor pump having a conventional can, in order to cool and lubricate the bearing,
Pressure fluid is supplied to the submerged bearing from the pump discharge port.
After passing through the sliding gap between the sliding members of the fixed bearing and the rotating bearing, the coolant flows radially outward through the space between the end face groove 12a provided in the fixed bearing and the thrust bearing 14, It collides with the stator can 4 and changes direction to the pump side.

As described above, since the pressure liquid after leaving the fixed bearing 12 always collides with the same position of the stator can 4, when a small amount of slurry is mixed, the pressure liquid of the stator can 4 collides. There is a problem that a hole is formed at the position and the motor is damaged.

The present invention solves the above-mentioned problems, prevents lubrication of the bearing released from the thrust bearing, wear and breakage of the stator can by the cooling pressure fluid, and detects wear of the sliding bearing portion. It is an object of the present invention to provide an improved bearing support device.

[Means for solving the problem]

In order to achieve the above object, in the present invention, the pump portion and the drive motor portion are separated by a partition wall (can) so that the pump has a leak-free structure, and the impeller and the motor rotor are rotatably supported by submerged bearings. In the canned motor pump, the bearing case for supporting the fixed sliding member of the slide bearing is extended to a position covering the outer peripheral portion of the thrust bearing connected to the rotary sliding member.

Further, a gap between the bearing case and the outer peripheral portion of the thrust bearing is formed to be smaller than a gap between the inside of the can of the canned motor pump and the motor rotor.

[Action]

Since the present invention is configured as described above, during pump operation, a part of the pump discharge liquid is introduced into the submerged bearing portion as a cooling liquid, and the sliding gap and the thrust bearing of the sliding bearing supported by the bearing case are provided. The lubrication and cooling of these two bearing parts while passing through the sliding gap is the same as the conventional one, but the cooling fluid having the pressure discharged radially outward through the thrust bearings However, it collides with the inner surface of the extension of the bearing case that supports the outer sliding member of the slide bearing, changes its direction in the axial direction, and flows toward the pump.

Therefore, there is no breakage point unlike the stator can of the conventional canned motor pump.

In addition, by forming the gap between the bearing case and the outer peripheral portion of the thrust bearing or a member integral with the outer peripheral portion smaller than the gap between the inside of the can of the canned motor pump and the motor rotor, when the sliding bearing portion wears out. Since the bearing case and the outer peripheral portion of the thrust bearing come into contact with each other before the motor rotor and the stator come into contact via the can, bearing wear is detected by a change in the motor current value at that time.

〔Example〕

 Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view of a bearing support device in a canned motor pump showing one embodiment of the present invention,
The same reference numerals as those shown in FIG. 2 (a) indicate the same or similar parts.

In the figure, fixed (bearing) supported by bearing case 21
The inner side in the radial direction of the sliding member 12 slides with a rotating (bearing) sliding member 13 fixed to the motor shaft 2, and the end face on the pump side (right side in the figure) is as shown in FIG. 2 (b). The radial end face groove 12a is formed, and the thrust bearing 14 is connected to the nut 15 at the shaft end and the step 2a of the shaft 2 so as to face the end face groove 12a.
This is the same as the conventional one (FIG. 2 (a)) in that it is sandwiched by and rotates integrally with the rotary sliding member 13.

However, in the present embodiment, the end 21a of the bearing case 21 supporting the fixed sliding member 12 is extended to a position covering the outer peripheral portion of the thrust bearing 14, and the inner surface of the extended end 21a has
A groove 21b reaching the end face groove 12a of the fixed sliding member 12 is provided to be open on the pump side, and the depth of the groove 21b, that is, the inner surface of the end portion 21a of the bearing case 21 and the outer circumferential surface of the thrust bearing 14 are provided. Is formed smaller than the gap g (FIG. 3) between the inside of the can attached to the motor stator 3 and the rotor 5 and the rotor 5. In the figure, 4 is a motor stator can, and 7 is a coolant inlet opening.

With the above configuration, during pump operation, a part of the pump discharge liquid is introduced as a cooling liquid from the opening 7 of the bearing case 21 as shown by the arrow, and the fixed sliding member 12 and the rotating sliding member Thrust bearing 14
Flows radially as shown by the arrow in the end face groove 12a opposite to the inner surface of the bearing case end 21a, and changes its direction at a right angle. ).

According to this embodiment, the cooling pressure liquid radially passing through the thrust bearing 14 is applied to the extended end 21 of the bearing case 21.
Since it collides with the inner surface of a and changes its direction in the axial direction and flows toward the pump side, the pressurized liquid does not directly collide with the stator can 4, so that the stator can 4 is not damaged. Normally, the thickness of the bearing case 21 is usually about 5 mm, and the stator can 4
Compared to the thickness of about 0.4 mm, the bearing case end 21a is not damaged by the pressure liquid because it is sufficiently thick and durable.

Also, the gap G between the inner surface of the bearing case end 21a and the outer peripheral surface of the thrust bearing 14 is formed smaller than the gap g between the inside of the can 4 attached to the motor stator 3 and the rotor 5. During bearing wear, before the stator of the motor comes into contact with the can, the inner surface of the bearing case end 21a and the outer periphery of the thrust bearing 14 come into contact, so it is possible to detect bearing wear by a change in the motor current value at that time. it can.

[Effect of the invention]

As described above, according to the present invention, in the canned motor pump belonging to the non-leakage pump, the outer peripheral portion of the thrust bearing connected to the inner sliding member is provided with the bearing case for supporting the outer sliding member of the slide bearing. After extending to the position to cover, lubricating and cooling the slide bearing and thrust bearing, the pressure liquid radially discharged from the thrust bearing collides with the inner surface of the bearing case and changes its direction in the axial direction to pump. As a result, the motor stator can is protected from the pressure flow flowing out of the thrust bearing.

Also, the gap between the bearing case and the outer periphery of the thrust bearing is
By forming the gap smaller than the gap between the inside of the can of the canned motor pump and the motor rotor, bearing wear can be detected by a change in the motor current value before the can and the motor rotor contact when the bearing is worn. .

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a bearing support device used in a canned motor pump showing one embodiment of the present invention, and FIGS. 2 (a) and (b) are longitudinal sectional views and essential parts of a bearing support device showing a conventional example. FIG. 3 is a longitudinal sectional view of a conventional canned motor pump. 3 ... motor stator, 4 ... stator can, 5 ... motor rotor, 7 ... coolant inlet opening, 12 ... fixed sliding member, 13 ... rotating sliding member, 14 ... thrust bearing ,twenty one……
Bearing case.

Claims (2)

(57) [Scope of request for utility model registration] A pump section and a drive motor section partitioned by a partition wall;
In a canned motor pump in which a pump has a leak-free structure and an impeller and a motor rotor are rotatably supported by submerged bearings, a bearing case for supporting a fixed sliding member of a sliding bearing is connected to a rotating sliding member. A bearing support device for a canned motor pump, wherein the bearing support device extends to a position covering an outer peripheral portion of a thrust bearing. 2. The bearing support for a canned motor pump according to claim 1, wherein a gap between the bearing case and the outer peripheral portion of the thrust bearing is formed smaller than a gap between the inside of the can of the canned motor pump and the motor rotor. apparatus.