JPH07243396A - Synthetic resin pump - Google Patents

Abstract

PURPOSE:To prevent the rubber-based elastic ring of a mechanical seal from turning together in spite of the use of a casing cover made of synthetic resin. CONSTITUTION:A pump casing made of synthetic resin is provided with a casing cover made of synthetic resin. A driving shaft is introduced through a driving shaft introducing hole 27 formed in the casing cover. An impeller 40 is mounted on the driving shaft. A mechanical seal 50, which is provided with a rotating ring 51 pressed by a spring 52, a fixed ring 54, and a rubber-based elastic ring 55, is disposed at the driving shaft introducing hole. The rubber-based elastic ring is pressed against an accommodating stage part 56, which is formed in the casing cover, to form an integral part of the casing cover. A non-circular part is formed at the driving shaft introducing hole so that a part of rubber- based elastic ring is caught in it to prevent itself from turning.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pump made of synthetic resin in which a pump casing and a casing cover are made of synthetic resin, and a drive shaft introducing hole is sealed by a mechanical seal.

[0002]

2. Description of the Related Art In a centrifugal pump for handling seawater or chemical liquids, when the liquid contacting parts such as a pump casing, a casing cover and a centrifugal impeller are made of metal material such as cast iron or stainless steel, the liquid contacting parts are There is a problem that it touches the liquid and causes rust or corrosion. Therefore, the pump case
There is known a spiral pump in which a single casing, a casing cover, and a centrifugal impeller are made of synthetic resin such as PPE resin.

Generally, in various pumps, a drive shaft introducing hole is opened in a casing cover that closes the back surface of the pump, and a drive shaft rotated by an electric motor is introduced from the drive shaft introducing hole, and an impeller is provided on the drive shaft. Is installed. Then, in order to liquid-tightly seal the drive shaft introducing hole opened in the casing cover, a mechanical seal is installed in the drive shaft introducing hole.

Although various structures of the mechanical seal 50 are known, basically, as shown in FIG. 6 as a typical example, the drive shaft 26 to which the impeller 40 is attached is made of a metal rotation that also serves as a spring bearing. The ring 51 is inserted, and this rotating ring 5
1, a spring 52 is bridged between the impeller 40 and the impeller 40, a sliding ring 53 made of metal or carbon is fitted into the rotating ring 51, and a fixed ring 54 is brought into contact with the sliding ring 53. The fixing ring 54 is configured to press the rubber elastic ring 55 made of rubber or synthetic rubber.

The rubber elastic ring 55 is adapted to be fitted into a housing step portion 56 which surrounds the drive shaft introducing hole 27 formed in the casing cover 3, and receives the pressing force of the spring 52 to be housed in the housing step portion 56. It is pressed in close contact.

The accommodating step portion 56 is made of a rubber-based elastic ring 5.
5 is composed of a circumferential surface 56a to which the outer peripheral surface of the rubber member 5 is fitted and closely contacted, and a contact surface 56b to which the end surface of the rubber elastic ring 55 is pressed and closely contacted. The introduction hole 27 is opened.

When the casing cover 3 is made of metal, the accommodating step portion 56 is formed by cutting, and therefore the circumferential portion 56a and the drive shaft introducing hole 2 are formed.
Both 7 are formed in a perfect circle. Therefore, the contact surface between the end surface of the rubber elastic ring 55 and the contact surface 56b of the housing step portion 56 has an annular shape.

In this case, this type of mechanical seal 50
Then, a predetermined surface pressure is applied to the contact surfaces of the sliding ring 53 and the fixed ring 54 to maintain liquid tightness, and a predetermined surface pressure is applied to the contact surfaces of the rubber elastic ring 55 and the housing step portion 56. It is designed to maintain close contact with each other and to perform liquid-tight sealing,
The sliding ring 53 is fixed by the spring 52 to the fixed ring 54.
And the rubber elastic ring 55 is pressed against the accommodating step portion 56 by this pressing force to keep the adhesion, and the rubber elastic ring 55 is accommodating the accommodating step portion 56 with a predetermined friction force.
It is stationary inside. In response to such a pressing force, the central portion of the rubber elastic ring 55 contacts the contact surface 56b of the accommodation step 56b.
It protrudes from the outside and bites into the inside of the drive shaft introducing hole 27. The biting portion 57 has an annular shape along the inner surface shape of the drive shaft introducing hole 27, as shown in FIG. 6B.

[0009]

However, in the case of a metal pump in which the casing cover 3 is made of metal, the casing cover 3 has a large rigidity and thus is less likely to be deformed. In the case of a pump in which the casing cover 3 is made of a synthetic resin such as PPE resin for the sake of improvement, the storage stepped portion 56 of the casing cover 3 may be deformed due to strain or thermal expansion due to heat generation of the sliding portion.

When such deformation occurs, the fitting force between the rubber elastic ring 55 and the circumferential surface 56a of the accommodating step portion 56 becomes weak, and the rubber elastic ring 55 and the contact surface 56b of the accommodating step portion 56 become. Of the rubber-based elastic ring 55 and the inner surface of the drive shaft introducing hole 27 are weakened. Therefore, the rubber-based elastic ring 55
The frictional force between the storage step portion 56 and the storage step portion 56 decreases, and the fixed ring 54 and the rubber elastic ring 55 rotate together with the rotation of the rotating ring 51, so that the sealing performance between the rubber elastic ring 55 and the storage step portion 56 is increased. Is worried that it will drop significantly.

In order to prevent the above-described deformation of the storage step portion 56, a means for making a metal storage step portion by inserting it into the synthetic resin casing cover 3 may be considered, but the manufacturing is troublesome and the cost is high. In addition, there is a concern that stress concentration may occur in the synthetic resin around the insert metal and a crack may occur at this location.

The present invention has been made in view of the above circumstances. An object of the present invention is to prevent a rubber-based elastic ring of a mechanical seal from co-rotating although a casing cover made of synthetic resin is used. It is an object of the present invention to provide a synthetic resin pump that is prevented and that maintains a highly reliable liquid-tight seal.

[0013]

According to a first aspect of the present invention, a pump casing made of synthetic resin is attached with a casing cover made of synthetic resin, and a drive shaft introducing hole is formed in the casing cover. The drive shaft is introduced through the hole, the impeller is attached to the drive shaft, and the mechanical seal is installed in the drive shaft introduction hole. The mechanical seal is fixed by the rotation ring pressed by the spring and the rotation ring. A synthetic resin comprising a ring and a rubber elastic ring pressed by the fixed ring, the rubber elastic ring being pressed against a housing step portion surrounding the drive shaft introducing hole formed on the inner surface of the casing cover. In the pump manufactured by the present invention, a special feature is that a non-circular portion is formed in the drive shaft introducing hole, into which a part of the rubber elastic ring is deformed and bites. To.

According to a second aspect of the present invention, a casing cover made of synthetic resin is attached to a pump casing made of synthetic resin, a drive shaft introducing hole is opened in the casing cover, and the drive shaft is introduced from the drive shaft introducing hole. Then, an impeller is attached to the drive shaft, and a mechanical seal is installed in the drive shaft introduction hole. The mechanical seal is attached to the rotary ring pressed by the spring, the fixed ring that makes sliding contact with the rotary ring, and the fixed ring. A rubber-made elastic ring that has been pressed, and the rubber-based elastic ring is pressed against an accommodating step portion that surrounds the drive shaft introducing hole formed on the inner surface of the casing cover, A part of the rubber elastic ring is deformed and bites into the contact surface against which the end surface of the rubber elastic ring of the step is pressed. Parts characterized by being formed.

[0015]

According to the invention of claim 1, a non-circular portion is formed in the drive shaft introducing hole, and a part of the rubber elastic ring is deformed and bites into the non-circular portion. Is prevented from rotating. Therefore, the rubber-based elastic ring does not rotate together, and the sealing performance between the rubber-based elastic ring and the housing step portion is maintained.

Further, according to the invention of claim 2, since the uneven portion is formed on the contact surface of the accommodating step portion, a part of the end portion of the rubber elastic ring is deformed to engage with the uneven portion, and the rubber is The rotation of the system elastic ring is prevented. Therefore, the rubber-based elastic ring does not rotate together, and the sealing performance between the rubber-based elastic ring and the housing step portion is maintained.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the first embodiment shown in FIGS. The present embodiment shows an example applied to a centrifugal pump made of synthetic resin.
Is a pump casing made of synthetic resin such as PPE resin. In this synthetic resin pump casing 1, a suction port 2 is opened in the center of the front surface, and a casing cover 3 is attached to the opening of the back surface. The casing cover 3 is also made of synthetic resin such as PPE resin. The casing cover 3 shown in FIG. 1 has a guide vane 4 integrally formed inside and a bracket 5 integrally formed outside. Such a casing cover 3 is fixed to the pump casing 1 by using mounting bolts 6 ...

A flange pipe joint 7 is attached to the front surface of the pump casing 1 so as to face the suction port 2. The flange pipe joint 7 is fixed to the pump casing 1 by fixing bolts 8 ... And a suction pipe (not shown) is connected to the flange pipe joint 7. A valve seat 9 is formed on an inner end surface of the flange pipe joint 7, and a valve body 10 that constitutes a one-way valve is formed on the valve seat 9.
Is designed so that it can be attached and detached. The valve body 10 is integrally provided with a packing portion 11 on the periphery thereof, and the packing portion 11 is sandwiched between the flange pipe joint 7 and the pump casing 1. The valve body 10 is adapted to come into contact with and separate from the valve seat 9 by elastically deforming a base portion connected to the packing portion 11. When the fluid pressure is applied from the inside of the pump casing 1, the valve body 10 is seated on the valve seat 9. Then, the suction port 2 is closed.

A partition wall 14 is formed inside the pump casing 1, and an introduction passage 15 that communicates with the suction port 2 is formed inside the partition wall 14. The end of the partition wall 14 is butt-connected to the guide vane 4 via an O-ring 16. Partition wall 1
A gas-liquid separation chamber 17 surrounded by the pump casing 1 is formed on the outer peripheral portion of the nozzle 4. And the pump casing 1
A discharge port 18 is opened on the upper wall of the device, and a suction pipe (not shown) is connected to the discharge port 18.

A priming port 19 is opened on the upper wall of the pump casing 1, and the priming port 19 is closed by a priming port closing plug 20. In addition, a drain port 21 is opened in the lower wall of the pump casing 1,
The drain port 21 is closed by a drain port closing plug 22.

The bracket 5 formed integrally with the casing cover 3 has an electric motor 25 through a connecting bolt 24.
Are linked to. The electric motor 25 includes a drive shaft 26 integral with the electric motor shaft, and the drive shaft 26 is introduced into the pump casing 1 through a drive shaft introduction hole 27 opened at the center of the casing cover 3.

A centrifugal impeller 4 is attached to the tip of the drive shaft 26.
0 is fixed via a fixing nut 48. The centrifugal impeller 40 is also made of synthetic resin such as PPE resin, and in this embodiment, an impeller having a semi-open structure is used.

A fixed leg 28 is formed integrally with the bracket 5, and the fixed leg 28 is attached to a fixed base 30 by fixing bolts 29. The electric motor 25 is also supported by the support legs 31 with respect to the fixed base 30.

A mechanical seal 50 is provided between the centrifugal impeller 40 and the casing cover 3. With this mechanical seal 50, the drive shaft introducing hole 27 and the drive shaft 2 are provided.
Liquid-tightness with 6 is maintained. Mechanical seal 50
Will be explained in detail later.

The drive shaft 26 includes a casing cover 3
If a liquid leaks from the mechanical seal 50 by any chance, the water draining plate 34 is attached to the portion derived from the above. It is designed to prevent the electric motor 25 from being shaken off and entering.

Further, at the lower part of the bracket 5, a discharge port 35 for discharging the liquid shaken off by the draining plate 34 is opened. The mechanical seal 50 will be described with reference to FIGS. 2 and 3. The drive shaft 26 that drives the impeller 40 includes a metal rotating ring 5 that also serves as a spring receiver.
1 is inserted, and the rotating ring 51 and the impeller 40
A spring 52 is stretched between the back plate and the back plate.
The rotating ring 51 has a metal sliding ring 53.
The sliding ring 53 is in contact with the fixed ring 54. A rubber elastic ring 55 made of rubber or synthetic rubber is in contact with the fixing ring 54.

The rubber elastic ring 55 is adapted to be fitted into a housing step portion 56 surrounding the drive shaft introducing hole 27 formed in the casing cover 3. This storage step 56 is
As shown in the drawing of the entire casing cover 3 in FIG. 3,
It is composed of a circumferential surface 56a with which the outer peripheral surface of the rubber elastic ring 55 is fitted and in close contact, and a contact surface 56b with which the end surface of the rubber elastic ring 55 is pressed. The drive shaft introducing hole 27 is opened in the. In the present embodiment, the drive shaft introducing hole 27 has a non-circular shape, for example, a polygonal shape such as a quadrangle, as shown in FIG.

The casing cover 3 shown in FIG. 3 has a structure in which the guide vane and the bracket are not integrally provided. Mechanical seal 5 configured as above
0, the rotating ring 51 contacts the sliding ring 53 by the spring 52, and the sliding ring 53 and the fixed ring 54
Are pressed against each other, and the rubber-based elastic ring 55 is pressed against the housing step 56 by this pressing force. Therefore,
The rubber elastic ring 55 is engaged with the housing step portion 56 by a frictional force, and is stationary inside the housing step portion 56. In response to this pressing force, the central portion of the rubber elastic ring 55 protrudes from the contact surface 56b of the housing step portion 56, and the drive shaft introduction hole 2
It will start to bite inside 7. This bite 57
2 has a non-circular outer surface, for example, a polygonal shape such as a quadrangle, along the inner surface shape of the drive shaft introducing hole 27, as shown in FIG.

The operation of the embodiment having such a structure will be described. Since the casing cover 3 is made of synthetic resin, if the storage step portion 56 is distorted or thermally deformed, the contact frictional force between the rubber elastic ring 55 and the storage step portion 56 may be reduced. The central portion of the rubber-based elastic ring 55 bites into the inside of the drive shaft introducing hole 27, and this biting portion 57 follows the inner surface shape of the drive shaft introducing hole 27 as shown in FIG. For example, since it has a quadrangular shape, it is locked to the inner surface of the drive shaft introducing hole 27 to prevent the rubber elastic ring 55 from rotating.

Therefore, the fixed ring 54 and the rubber elastic ring 55 are prevented from rotating together with the rotation of the rotating ring 51 and the sliding ring 53, and the rubber elastic ring 55 and the accommodating step portion 56 are brought into contact with each other. The adhesion of the surface is maintained, and the liquid-tight sealing is reliably maintained.

In the case of the first embodiment, the entire drive shaft introducing hole 27 has a non-circular shape such as a quadrangle.
The present invention is not limited to this, and as shown in FIG. 4 as a second embodiment, the casing cover 3 in the drive shaft introducing hole 27.
A non-circular recess 58 such as a quadrangle may be formed only on the inner end of the. The rubber elastic ring 5 is inserted into the non-circular recess 58.
The central portion of the bit 5 bites, and the biting portion 57 prevents the rubber elastic ring 55 from rotating.

Further, in the first and second embodiments,
Although the inner surface of the drive shaft introducing hole 27 has a non-circular shape, the present invention can be implemented by the means as described in claim 2. That is, an example of this case is shown as a third embodiment in FIG. In the case of the third embodiment, the contact surface 56 of the housing step portion 56 formed on the casing cover 3
In FIG. 5A, one or a plurality of recesses (or protrusions) 60 ... Are formed as shown in FIG.
In the case of such a structure, the end surface of the rubber-based elastic ring 55 that receives the force of the spring 52 has the contact surface 56 of the housing step portion 56.
The rubber-based elastic ring 55 is partly deformed by the pressing force at this time and bites into the concave portions 60 of the contact surface 56a. Since the biting portion 61 engages with the recess 60, the rubber elastic ring 55 is prevented from rotating.

Therefore, also in this case, the fixed ring 54 and the rubber elastic ring 55 are prevented from rotating together with the rotation of the rotary ring 51 and the sliding ring 53, and the rubber elastic ring 55 and the accommodating step portion 56 are prevented. The close contact with and the liquid tightness is maintained.

Incidentally, as in the third embodiment, the accommodation step 5
When the concavo-convex portion 60 ... Is formed on the contact surface 56a of No. 6, the concavo-convex portion may have a circular shape or another shape, as shown by an imaginary line in FIG.

Further, the pump of the present invention is not limited to the centrifugal pump described in the embodiment, and in short, is a pump having a structure in which the casing cover is made of synthetic resin and a mechanical seal is attached to the drive shaft introducing hole. It can be applied to any type of pump as long as it is available. Further, the structure of the mechanical seal is not limited to that of the embodiment, and the structure can satisfy the gist described in the claims.

[0036]

As described above, according to the present invention, since the biting portion of the rubber-based elastic ring is locked to the casing cover side to prevent rotation, the rubber-based elastic ring is rotated as the rotation ring rotates. Are prevented from co-rotating, the adhesion between the rubber-based elastic ring and the housing step portion is maintained, and liquid tightness is maintained. Therefore, highly reliable sealing performance is exhibited.

[Brief description of drawings]

FIG. 1 is a sectional view of a centrifugal pump showing a first embodiment of the present invention.

FIG. 2 is an enlarged view of a mechanical seal of the same embodiment, in which (A) is a longitudinal sectional view and (B) is II- of (A).
Sectional view of line II.

FIG. 3 shows an example of a casing cover (A)
The figure shows the inner surface, and the figure (B) is a sectional view taken along the line III-III in the figure (A).

FIG. 4 is an enlarged view of a mechanical seal according to a second embodiment of the present invention, where (A) is a vertical sectional view, (B) is a sectional view taken along line IVB-IVB in (A), (C) figure is sectional drawing of the IVC-IVC line of (A) figure.

FIG. 5 is an enlarged view of a mechanical seal according to a third embodiment of the present invention, in which (A) is a longitudinal sectional view and (B) is a contact along line VV in (A). Face drawing.

6A and 6B are enlarged views of a conventional mechanical seal, in which FIG. 6A is a vertical sectional view, and FIG. 6B is VI-VI in FIG.
Sectional view of the line.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Synthetic resin pump casing 2 ... Suction port 3 ... Casing cover 18 ... Discharge port 25 ... Electric motor 26 ... Drive shaft 27 ... Drive shaft introduction hole 40 ... Centrifugal impeller 50 ... Mechanical seal 51 ... Rotating ring 52 ... Spring 53 ... Sliding ring 54 ... Fixed ring 55 ... Rubber-based elastic ring 56 ... Accommodation step 56a ... Circumferential surface 56b ... Abutting surface 57, 61 ... Bite portion 58 ... Non-circular recess 60 ... Concave surface recess

Claims (2)

[Claims] 1. A pump casing made of synthetic resin is attached with a casing cover made of synthetic resin, a drive shaft introducing hole is opened in this casing cover, and a drive shaft is introduced from this drive shaft introducing hole. An impeller is attached to the drive shaft, and a mechanical seal is installed in the drive shaft introduction hole. The mechanical seal includes a rotating ring pressed by a spring, a fixing ring slidingly contacting the rotating ring, and a rubber system pressed by the fixing ring. An elastic ring, wherein the rubber-based elastic ring is pressed against an accommodating step portion that surrounds the drive shaft introduction hole formed on the inner surface of the casing cover, in the synthetic resin pump, the drive shaft introduction hole, A synthetic resin pump characterized in that a non-circular portion is formed in which a part of the rubber elastic ring is deformed and bites. 2. A casing cover made of synthetic resin is attached to a pump casing made of synthetic resin, a drive shaft introducing hole is opened in this casing cover, and a drive shaft is introduced from this driving shaft introducing hole. An impeller is attached to the drive shaft, and a mechanical seal is installed in the drive shaft introduction hole. The mechanical seal includes a rotating ring pressed by a spring, a fixing ring slidingly contacting the rotating ring, and a rubber system pressed by the fixing ring. An elastic ring, wherein the rubber elastic ring is pressed against a housing step portion surrounding the drive shaft introducing hole formed on the inner surface of the casing cover, wherein the rubber of the housing step portion is On the contact surface against which the end surface of the system elastic ring is pressed, a concave and convex portion is formed that partially deforms the rubber elastic ring. Plastic pump according to claim.