JP4614615B2 - Shaft seal device for submersible pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shaft sealing device suitable for a submersible pump, in particular, having low cost and good assembling workability without manufacturing a special shaft, and holding its sealing performance without the abnormal wear of a shaft even in liquid including sand and slurry, the residence of the liquid in a circular gap on the outer periphery of a shaft guide-down portion and the face roughness and opening due to the accumulation of deposits resulting in the poor start of the pump or biting between sliding faces. <P>SOLUTION: A fixed sealing ring 6 is supported by a housing 1, the shaft guide-down portion 7 is loosely fitted to the fixed sealing ring 6 and a shaft through-hole 4, a rotary sealing ring 9 which is rotated right over the fixed sealing ring 6 together with the shaft and has slide contact with the fixed sealing ring 6 with spring energization is fitted to the shaft guide-down portion 7 to hold an circular gap 8 on its outer periphery, and a stirring edge 13 formed declining to the rotating direction of the shaft is held on the inner peripheral face of the rotary sealing ring 9 facing the circular gap 8. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shaft seal device mounted on a submersible pump or the like.
[0002]
[Prior art]
As is well known, in a submersible pump, a shaft through hole is generally formed in the center of a partition wall interposed between a pump vortex chamber and an oil chamber, and an annular groove recessed in the outer periphery of the upper end of the through hole is provided in the ring groove. A fixed seal ring of the shaft seal device is fitted, and an annular gap is held on the outer periphery of the shaft guide lower part that is loosely fitted in the fixed seal ring and the shaft through hole, and rotates with the shaft directly above the fixed seal ring and with a spring. The rotary seal ring is fitted to the shaft guide lower part so as to be in sliding contact with the fixed seal ring due to the force, but the liquid retained in the annular gap precipitates solid matter due to sliding heat generation, and the precipitate is fixed. It adheres to the inner circumference of the seal ring and shaft through-hole, and it accumulates and causes the start failure of the pump, and the deposit is caught between the sliding contact surfaces of the fixed seal ring and the rotary seal ring. Sealing performance by causing roughing and face opening It will be inhibited. In order to solve such a problem, a spiral groove is formed on the outer periphery of the shaft guide lower part, and a precipitate is pushed out to the pump chamber side by a screw pump action accompanying the rotation of the shaft (for example, patent document) 1).
[0003]
[Patent Document 1]
JP 2000-274380 A (FIG. 1)
[0004]
[Problems to be solved by the invention]
However, in the structure of Patent Document 1, a general-purpose shaft cannot be used, and it is necessary to manufacture a dedicated one. Therefore, the cost is increased, and the strength of the shaft also remains a problem. In addition, there is a difficulty in assembling that an accessory member such as an O-ring is easily damaged by the spiral groove when the rotary seal ring is assembled. Furthermore, according to the structure of Patent Document 1, it is suitable for use in a viscous liquid such as oil, but if used in a liquid containing sand or slurry as in a construction site, the shaft is used. The engraved spiral groove causes abnormal wear, which causes an early breakage of the shaft. Further, the repair work associated with the wear of the spiral groove is a large repair of replacing the entire shaft, and requires a great repair cost.
[0005]
The present invention solves the above-mentioned problems, does not require the production of a dedicated shaft, uses a general-purpose shaft, does not reduce the strength, can be easily assembled at low cost, and is made of sand, slurry, etc. There is no abnormal wear of the shaft due to, the liquid in the annular gap at the outer periphery of the lower part of the shaft is agitated to prevent retention, the pump does not start poorly due to deposits, and the above precipitation between the sliding surfaces An object of the present invention is to provide a shaft seal device that can maintain sealing performance without causing surface roughening or surface opening due to biting of foreign substances in liquids or liquids, and is particularly suitable for a submersible pump.
[0006]
[Structure of the invention]
In the shaft seal device of the submersible pump according to the present invention, in the outside type shaft seal device configured in the housing for fixed seal ring support by forming a ring groove on the outer side of the upper end of the shaft through hole, the fixed seal ring is provided. Rotation that fits in the ring groove, loosely fits the shaft guide portion of the prime mover into the fixed seal ring and the shaft through hole, rotates with the shaft directly above the fixed seal ring, and slides in contact with the fixed seal ring by spring bias A seal ring is attached to the shaft guide lower part, and an annular gap is held between the inner periphery of the rotary seal ring and the outer periphery of the shaft guide lower part, and the inner diameter of the shaft through hole (4) is the same as the inner diameter of the fixed seal ring (6). Alternatively, it has a slightly larger diameter, and has an agitation edge formed in a descending gradient toward the rotation direction of the shaft inward from the inner peripheral surface of the fixed seal ring on the inner peripheral surface of the rotary seal ring facing the annular gap. I let you.
[0007]
【Example】
Hereinafter, description will be made with reference to the examples of FIGS. 1 and 2 in which the submersible pump is implemented.
[0008]
Reference numeral 1 denotes a partition wall interposed between the pump chamber 2 and the oil chamber 3, and a ring groove 5 is recessed outside the upper end of the shaft through-hole 4 drilled in the center to constitute a housing for fixed sealing ring support. In the outside type shaft seal device, the fixed sealing ring 6 is fitted into the ring groove 5. Reference numeral 7 denotes a shaft guide lower part of the prime mover, and a rotary seal ring 9 that is loosely fitted into the fixed seal ring 6 and the shaft through-hole 4 and rotates together with the shaft via the bellows 10 and the retainer 11 is mounted immediately above the fixed seal ring. An annular gap 8 is held on the inner periphery of the rotary seal ring 9 and the outer periphery of the shaft guide lower portion 7. The rotary seal ring 9 is in sliding contact with the fixed seal ring 6 by the spring force of the coil spring 12, and the inner diameter of the shaft through hole 4 is the same as the inner diameter of the fixed seal ring 6 on the inner peripheral surface of the rotary seal ring 9. Alternatively, a stirring edge 13 formed in a descending gradient toward the rotational direction of the shaft is provided inward from the inner peripheral surface of the fixed sealing ring 6 which is formed to have a slightly larger diameter .
[0009]
[Action]
When the shaft rotates and the submersible pump is driven, the liquid in the annular gap 8 in which the inner diameter of the shaft through hole 4 is the same as or slightly larger than the inner diameter of the fixed sealing ring 6 Since the swirling flow stirred by the stirring edge 13 provided inward from the peripheral surface is pushed out to the pump chamber 2 side without being shielded and does not stay in the annular gap 8, precipitates in the liquid are not Not only is it prevented from adhering to and depositing on the inner peripheral surface of the fixed sealing ring 6 and the shaft through-hole 4, but also the solid matter itself is prevented by the cooling action. Further, the auxiliary member such as the bellows 10 is not damaged when the rotary seal ring 9 is assembled.
[0010]
【The invention's effect】
According to the present invention, it is not necessary to produce a dedicated shaft, a general-purpose shaft is used, and the assembly work is easily performed at a low cost without reducing the strength, and is fixed to the inner peripheral surface of the rotary seal ring 9. Since the swirl flow stirred by the stirring edge 13 formed in a descending gradient toward the rotation direction of the shaft inward from the inner peripheral surface of the seal ring 6 acts to push out to the pump chamber 2 side without being shielded, In the outer periphery of the shaft guide lower portion 7, the liquid in the annular gap 8 is prevented from staying, and a cooling action is generated, so that the start failure of the pump due to deposit accumulation does not occur. Sealing performance is maintained without causing surface roughening or crevice due to the inclusion of the above precipitates or foreign matter in the liquid between the sliding contact surfaces, and the shaft performance is maintained against liquids containing sand, slurry, etc. No abnormal wear, There is an advantage that a suitable shaft seal device is obtained as a water pump.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional side view of an essential part of a shaft seal device of the present invention mounted on a submersible pump.
FIG. 2 is a longitudinal side view of a rotary seal ring in the device of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Housing for fixed sealing ring support 4 Shaft through-hole 5 Ring groove 6 Fixed sealing ring 7 Shaft guide lower part 8 Annular gap 9 Rotating sealing ring 13 Stirring edge

Claims (1)

In the outside type shaft seal device configured in the housing (1) for supporting the stationary seal ring by recessing the ring groove on the outer side of the upper end of the shaft through hole of the submersible pump , the fixed seal ring (6) is connected to the ring groove. (5) Fit into the shaft, loosely engage the shaft guide lower part (7) of the prime mover with the fixed seal ring (6) and the shaft through hole (4), and rotate with the shaft directly above the fixed seal ring (6). A rotary seal ring (9) that is in sliding contact with the fixed seal ring (6) by a bias spring is attached to the shaft guide lower part (7), and an annular gap (8) is formed between the inner periphery of the rotary seal ring and the outer periphery of the shaft guide lower part (7). The inner diameter of the shaft through hole (4) is the same as or slightly larger than the inner diameter of the fixed seal ring (6), and the shaft is formed inward from the inner peripheral surface of the fixed seal ring (6). The stirring edge (13) formed in a downward slope toward the rotational direction of Shaft seal device of the submersible pump, characterized in that is held on the inner peripheral surface of the rotary seal ring facing the Jo gap (8) (9).

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