JPH0828710A - High pressure seal with layered structure and air chamber - Google Patents

Abstract

PURPOSE:To make a high pressure seal, which is mounted between a cyl-inder and a plunger for a high pressure plunger pump, compact and prolong the service life thereof by laminating and adhering outer and inner elastomer rings between plastic rings to partition annular air chambers therewith. CONSTITUTION:A high pressure seal 10 which is mounted between a cylinder 1 and a plunger 2, or a high pressure room 3 and the back pressure side (a), has plural outer elastomer rings 12 and plural inner elastomer rings 13 concentrically laminated and adhered each other between plural plastic rings 11 to partition air chambers 14 therewith. It is sealed with both elastomer rings 12, 13 when pressure varied with the operation of a pump is low, while it is sealed with the air chambers 14 compressed and deformed in the axial line direction and the plastic rings 11 deformed inward and outward of the radial direction following inner pressure when it is high.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high pressure seal having a laminated structure and an air chamber interposed between a cylinder and a plunger of a high pressure plunger pump.

[0002]

2. Description of the Related Art As shown in FIG. 2, a high-pressure plunger pump is configured so that a plunger 2 that reciprocates in a cylinder 1 supplies water from a water supply pipe 4 to a high-pressure chamber 3 and drains it from a drain pipe 5. A high pressure seal 6 is provided on the back pressure side between the cylinder 1 and the plunger 2 to seal high pressure water in the high pressure chamber 3.

As shown in FIG. 3, the high-pressure seal 6 is constructed by combining an O-ring 7 and a plastic seal 8 in which the O-ring 7 is housed in an annular groove 9.

[0004]

In the above high-pressure plunger pump, the pressure greatly changes during the water supply process and the drainage process. Therefore, in the conventional high-pressure seal 6, the O-ring 7 is twisted due to pressure fluctuation, and is pushed out between the cylinder 1 and the plunger 2 on the back pressure side a at the time of high pressure, and a protrusion phenomenon occurs to shorten the life. .

On the other hand, when the high-pressure seals 6 are provided in multiple stages to disperse the pressure, the length increases in the axial direction, and the plunger 2
There is a problem that the stroke is shortened.

An object of the present invention is to provide a high pressure seal having a laminated structure and an air chamber which are compact and have a long life.

[0007]

SUMMARY OF THE INVENTION According to the present invention, in a high pressure seal interposed between a cylinder and a plunger of a high pressure plunger pump, a plurality of outer elastomer rings and an inner ring are provided between a plurality of plastic rings. The elastomer ring and the elastomer ring are concentrically laminated and adhered to each other, and an annular air chamber is defined by the plastic ring and the outer elastomer ring and the inner elastomer ring.

[0008]

In the high-pressure seal having the laminated structure and the air chamber configured as described above, the low pressure of the pressure fluctuation is sealed by the elastomer ring, and the high pressure causes the air chamber to be axially compressed and deformed. The ring is deformed inward and outward in the radial direction and sealed.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, a cylinder 1 and a plunger 2
Between the high-pressure chamber 3 and the back pressure side a, a high-pressure seal indicated by reference numeral 10 is provided as a whole.

The high-pressure seal 10 is provided between a plurality of plastic rings 11 (four in the illustrated example).
A plurality (three in the illustrated example) of outer elastomer rings 1
2 and inner elastomer ring 1 concentric with the ring 12
3 and 3 are laminated and adhered to each other to form an air chamber 14 inside.
It is composed by defining. This bonding is firmly performed by ultrasonic bonding or an adhesive. Therefore, it is formed compact in the axial direction.

As the material of the plastic ring 11 of the present invention, high molecular polyethylene, polyacetal and the like are preferable. Further, as the material of the elastomer ring, chloroprene rubber, ethylene propylene rubber, acrylic rubber, urethane rubber, chlorosulphonated polyethylene rubber and the like are preferable.

Next, the operation will be described.

In the high-pressure plunger pump, the pressure greatly changes during the water supply process and the drainage process. The low pressure is sealed by both elastomer rings 12, 13. On the other hand, the high pressure causes the air chamber 14 to be compressed and deformed in the axial direction by the high pressure, and the internal pressure thereof causes the plastic ring 1 to move.
1 is sealed by deforming radially inward and outward.
At this time, since the plastic ring 11 and the two elastomer rings 12 and 13 are firmly adhered to each other, the plastic ring 11 returns to its original shape even when the pressure is repeatedly changed at high and low pressures.
Therefore, unlike the conventional case, it does not protrude to the back pressure side. Therefore, damage is prevented and the life is extended. Further, by changing the number of laminated layers, it is possible to obtain the pressure dispersion effect and appropriately cope with the pressure fluctuation range.

[0015]

Since the present invention is constructed as described above, it is made compact by the laminated structure and
The life can be extended.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an embodiment of the present invention.

FIG. 2 is a side sectional view showing an example of a conventional high pressure plunger pump.

FIG. 3 is a side sectional view showing an example of a conventional high pressure seal.

[Explanation of symbols]

 1 ... Cylinder 2 ... Plunger 3 ... High pressure chamber 4 ... Water supply pipe 5 ... Drain pipe 6, 10 ... High pressure seal 7 ... O-ring 8 ... Plastic seal 9. ..Annular groove 11 ... plastic ring 12 ... outer elastomer ring 13 ... inner elastomer ring 14 ... air chamber

Claims (1)

[Claims] 1. In a high pressure seal interposed between a cylinder and a plunger of a high pressure plunger pump, a plurality of outer and inner elastomer rings are concentrically laminated and bonded between a plurality of plastic rings. A high-pressure seal having a laminated structure and an air chamber, characterized in that an annular air chamber is defined by the plastic ring, the outer elastomer ring and the inner elastomer ring.