JPS6146680B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Object of the Invention The present invention relates to a shaft seal protection device for a submersible pump or a blower that utilizes the pumping action of a submersible pump.

In conventional submersible pumps, etc., as shown in Figure 3, the lower wall 1' of the motor casing 2', which is integrally cast, also serves as the upper wall of the oil chamber A' and is constructed as a rigid body. The volume of A′ remains constant. Therefore, when the pump is in use, the pressure in the oil chamber A' increases, causing pressurization of the shaft sealing portion 6', which impairs the sealing effect, and there is a fear that oil may infiltrate into the motor chamber B'.

An object of the present invention is to reduce the increase in internal pressure by expanding the volume of the oil chamber to accommodate the increase in pressure in the shaft seal lubricating oil chamber, so as to prevent oil from entering the motor chamber when a pump or the like is used.

(2) Structure of the Invention In the shaft seal protection device for a submersible pump or blower according to the present invention, there is a By bringing the inner periphery of the annular membrane body into close contact with the fixed body around the bearing housing, and by bringing the outer periphery into close contact with the joint between the motor casing and the oil chamber peripheral wall, the lower wall of the motor casing and A flexible diaphragm also serves as the upper wall of the oil chamber, and the oil chamber is formed on the outer periphery of the shaft seal adjacent to the motor chamber partitioned by the flexible diaphragm. It is configured so that it can be adapted to expand its volume.

Referring to FIGS. 1 and 2, which illustrate embodiments, reference numeral 1 denotes a flexible diaphragm that serves as both the lower wall of the motor casing 2 and the upper wall of the oil chamber A, and is made of rubber or a thin metal plate. The inner periphery 3a of the flexible annular membrane 3 is brought into close contact with the fixed body 4 around the bearing housing, and the outer periphery 3b is brought into close contact with the joint between the motor casing 2 and the oil chamber peripheral wall 5. The shaft sealing portion 6 is adjacent to the motor chamber B partitioned by the flexible diaphragm 1.
The oil chamber A formed on the outer periphery of the oil chamber A is constructed so that its volume can be expanded in accordance with the increasing tendency of the internal pressure.

When using a pump, etc., the flexible diaphragm 1 prevents the oil chamber A from increasing, depending on the tendency of pressure increase in the oil chamber A.
The internal volume is expanded and the increase in internal pressure is reduced.

(3) Effects of the Invention In the device of the present invention, the oil chamber A has a structure in which the volume can be changed by the flexible diaphragm 1. The volume within the oil chamber A is expanded by the flexible diaphragm 1, and an increase in internal pressure is reduced. Therefore, the sealing effect is not impaired due to pressurization of the shaft seal portion 6, and oil can be prevented from entering the motor chamber B. Further, the flexible diaphragm 1 brings the inner peripheral part 3a of the annular membrane body 3 into close contact with the fixed body 4 around the bearing housing, and also brings the outer peripheral part 3b into close contact with the fixed body 4 around the bearing housing.
Since it is clamped at the joint between the oil chamber peripheral wall 5 and the motor casing 2, there is no need to manufacture it integrally with the motor casing 2. Therefore, the motor casing 2 can be made of a thin steel pipe or the like to make it lightweight. It has the advantage that it can be constructed robustly and can be manufactured at low cost.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional side view of the main part of a submersible pump having the device of the present invention, Fig. 2 is a longitudinal sectional side view of the main part showing another embodiment, and Fig. 3 is a longitudinal sectional side view of the main part of a conventional submersible pump. be. DESCRIPTION OF SYMBOLS 1... Flexible diaphragm, 2... Motor casing, 3... Annular membrane body, 3a... Inner peripheral part, 3b...
Outer peripheral part, 4... Fixed body around the bearing housing, 5... Oil chamber peripheral wall, 6... Shaft sealing part, A...
Oil room, B...Motor room.

Claims (1)

[Claims] 1. Between the opposing surfaces of the oil chamber A formed on the outer periphery of the shaft sealing portion 6 and the motor chamber B facing the oil chamber A, the inner circumferential portion 3b of the flexible annular membrane 3 is placed around the bearing housing. By bringing the outer peripheral part 3b into close contact with the fixed body 4 and the joint part between the motor casing 2 and the oil chamber peripheral wall 5, a flexible structure that serves as the lower wall of the motor casing 2 and the upper wall of the oil chamber A is formed. with and without flexible diaphragm 1;
The oil chamber A, which is formed on the outer periphery of the shaft sealing part 6 adjacent to the motor chamber B divided by the flexible diaphragm 1, is configured so that its volume can be expanded in accordance with the tendency of increase in internal pressure. A shaft seal protection device for a submersible pump or blower.