JPS60167644A - Mechanical seal pump - Google Patents

Abstract

PURPOSE:To prevent the performance of a mechanical seal pump from deteriorating due to the moisture of a bearing by coating air flow of atmosphere having relatively low humidity on the bearing. CONSTITUTION:Since an air flow produced by the fact that air in a winding chamber 20 is drawn by a rotary plate 25 with blades has relatively low humidity and preventes steam leaked from a mechanical seal 10 from contacting a bearing 12, it can prevent the deterioration in the performance due to the moisture of the bearing 12. The steam from the seal 10 is externally exchausted by an air hole 22 by the air flow, and a dew partly condensed on the wall of a pump casing is transmitted on the wall, exhausted from an air hole 22, thereby preventing the corrosion due to the moisture in a space 21 in which the plate 25 is disposed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mechanical seal pump that seals the shaft with a mechanical seal, particularly to a draining device for the shaft seal portion.

A conventional mechanical seal pump for this scale is shown in FIG. The rotor 1 of the electric motor includes a rotor 2 and a rotating shaft 3 that supports it.
An impeller 4 is fixed to one end of a rotating shaft 3, and the impeller 4 is rotated within a pump casing 6 formed separately from the motor casing 5 to direct fluid from the suction lower to the discharge port 8. Transport. In the opening 9 through which the rotating shaft 3 passes through the pump casing 6, the rotating shaft 3 is sealed with a mechanical seal portion 1o. Furthermore, the rotation axis 3 (lj.

Bearing A1 using ball bearings on both sides of rotor 2
1 and B12.

The bearing A11 is attached to a holding rib A14 on one side wall 13 of the motor casing 5, and the other bearing B12 is similarly attached to a holding rib B16 provided on the partition wall 15 of the motor casing 5. Retaining ribs A14 and B16
There are a plurality of air holes A17 and B18 around the membrane, respectively, so that the air in the winding chamber 2o that houses the winding 19 flows, cooling the winding 19 and the like. A space 21 between the mechanical part 10 and the bearing B12 communicates with the outside air through an air hole C22.

By the way, ball bearings are often used as bearings in general mechanical seal pumps, but it is clear that the steam generated from the mechanical seals leaks, and that the durability of ball bearings is significantly impaired by moisture. However, in order to make the external dimensions of the five pumps as small as possible, they must be arranged close to each other in terms of construction.

This caused the following problem.

During pump operation, a small amount of fluid vapor leaks through a small 1° gap in the mechanical seal, and the vapor flows into the bearing B12, which is a ball bearing, promoting corrosion of the bearing B12 and reducing its durability. As a result, the performance of the bearing B12 deteriorated due to corrosion due to moisture, and defects such as water leakage from the mechanical seal portion 10 caused large wobbling of the rotating shaft 3, resulting in defective problems.

The present invention aims to solve the above-mentioned conventional problems.

The present invention provides an impeller that is located in a pump casing and transfers fluid, a rotating shaft that connects the impeller and a rotor of an electric motor, and a mechanical shaft that seals a portion of the rotating shaft that passes through the pump casing. A rotary plate with blades is provided on the rotary shaft and is located between the mechanical seal portion and the bearing, and the rotating plate with blades rotates to rotate the electric motor. It is configured to generate an airflow flowing around the bearing from the winding chamber,
This prevents performance deterioration of the bearing due to moisture.

An embodiment of the present invention will be described below based on the drawings. The explanation of the same components as those of the conventional example will be omitted, and the main parts of this embodiment will be explained.
A guide portion 23 is formed to guide the airflow that has passed through the bearing B12 so that it passes around the bearing B12. In this embodiment, the guide portion 23 is formed integrally with the partition wall 15, but
It may be a separate body. A rotary plate 2 with vanes that sucks air through the aperture 24 in a part of the rotating shaft 3 located between the aperture 24 of the guide portion 23 and the aperture 9 of the pump casing 6
5 will be provided.

In the above configuration, when the pump is operated, the vaned rotating plate 26 fixed to the rotating shaft 3 rotates together with the rotating shaft 3,
The area around the opening 24 of the guide portion 23 becomes negative pressure, and the air in the winding chamber 2o is drawn through the air hole B18 of the partition wall 15, around the bearing B12, and further through the opening 24 to the bladed rotary plate 25. Further, the air is discharged to the outside from the air hole C22 by the bladed rotary plate 26. The air flow generated when the air in the winding chamber 2o is drawn by the vaned rotary plate 25 has relatively low humidity and prevents steam leaking from the mechanical seal portion 1o from contacting the bearing B12.
Performance deterioration of the bearing B12 due to moisture can be prevented. In addition, the steam from the mechanical seal part 10 is discharged to the outside from the air hole C22 by the air current, and some of the dew that has condensed on the wall surface of the pump casing is also drained from the air hole C22 through the wall surface, and the bladed rotating plate 25 Corrosion due to moisture within a certain space 21 is prevented.

As described above, according to the present invention, the bearing part is covered with an airflow having a relatively low humidity atmosphere, and furthermore, this airflow is used to release steam, water, etc. from the mechanical seal part to the outside, so that the area around the bearing part is always protected from moisture. However, it is possible to prevent performance deterioration of the bearing portion and improve its durability, thereby extending the service life of the pump. In addition, the airflow inside the winding chamber becomes more intense than before, lowering the room temperature and extending the life of the winding.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional mechanical seal pump, and FIG. 2 is a sectional view of essential parts showing an embodiment of the present invention. 2...Rotor, 3...Rotating shaft, 4...
... Impeller, 6 ... Pump casing, 1
0...Mechanical seal part, 11.12...
... Bearing, 16 ... Partition wall, 17.18.2
2...Air hole, 2o...Winding chamber, 23
...Guide part, 24 ... Hole, 25.
... Rotating plate with blades. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2

Claims (3)

[Claims] (1) An impeller that is located inside the pump casing and transfers fluid, a rotating shaft that connects the impeller and the rotor of the electric motor, and a mechanical seal that seals the portion of the rotating shaft that passes through the pump casing. and a bearing for supporting the rotary shaft, a rotary plate with blades is provided on the rotary shaft between the mechanical seal portion and the bearing, and rotation of the rotary plate with blades causes the electric motor to rotate. A mechanical seal pump configured to generate an airflow flowing from inside the winding chamber to around the bearing. (2) A bearing is held in a partition wall forming a winding chamber of the electric motor, an air hole is formed, and a guide portion is provided opposite to the air hole to guide passing air to the vicinity of the bearing, and the winding chamber 2. The mechanical seal pump according to claim 1, wherein the airflow flowing from the guide portion to the opening in the guide portion is generated by a rotary plate with vanes. (3) The mechanical seal pump according to claim 1 or 2, wherein a plurality of air holes are provided in the wall surface of the motor casing located in the discharge direction of the rotary plate with vanes.