CN2811687Y - Dynamic seal structure for high pressure fluid - Google Patents

Abstract

A dynamic sealing structure for high-pressure fluid, which has a cylinder body 1 with a built-in piston rod 2, one end of the piston rod 2 is connected to the cylinder body and the other end is sequentially equipped with an outer seal ring 4, an inner seal ring 6 and a seal that prevents the inner seal The circlip 10 for the ring 6 to move outward is characterized in that the outer sealing ring 4 and the inner sealing ring 6 are wedgingly connected by an axial tapered concave hole and a corresponding tapered convex head. The utility model can effectively realize the sealing of high-pressure fluid below 300 MPa without increasing the manufacturing cost of the sealing material, and can be widely used in the sealing of high-pressure fluid of hydraulic oil cylinders, pumps, motors and the like.

Description

A dynamic sealing structure for high-pressure fluid

technical field

The utility model relates to a high-pressure fluid sealing device.

Background technique

The sealing devices on hydraulic cylinders, pumps and motors currently used generally rely on a small gap formed between the sealing element and the rigid body of the hydraulic cylinder, the pump body and the motor body to prevent the passage of hydraulic oil, thereby realizing the hydraulic oil. seal. This sealing method can achieve good sealing when the hydraulic oil pressure is not greater than 20Mpa; when the pressure is increased to above 20Mpa, there will be problems with the material of the sealing element, the leakage is serious, and the sealing effect is not good.

Utility model content

The technical problem to be solved by the utility model is to propose a dynamic sealing structure for high-pressure fluid, which can seal the fluid well when the fluid pressure reaches 300MPa. .

In the technical solution of the utility model, the dynamic sealing structure for high-pressure fluid is that it has a cylinder body with a built-in piston rod, one end of the piston rod is connected with the cylinder body and the other end is sequentially equipped with an outer sealing ring, an inner The circlip that seals and prevents the inner sealing ring from moving outward has a structural feature that the outer sealing ring and the inner sealing ring are wedgingly connected by an axial tapered concave hole and a corresponding tapered convex head.

Further explanation is given below.

Referring to Fig. 1, the utility model has a cylinder body 1 with a built-in piston rod 2, and one end of the piston rod 2 is connected with the cylinder body and the other end (sealed end) is equipped with an outer seal ring 4 in sequence (that is, from left to right in Fig. 1 ). , the inner seal ring 6 and the snap ring 10 that prevents the inner seal ring 6 from moving to the outside (that is, the right side in Fig. 1 ), its structural feature is that an axial The tapered concave hole and the corresponding tapered convex head are wedgingly connected.

The working principle of the present utility model is (see Fig. 1), the cavity between the cylinder body 1 and the piston rod 2 on one side of the seal ring (left side in Fig. 1) is filled with high-pressure fluid (such as hydraulic oil) 3, And there is a gap 5 between the outer seal ring 4 and the cylinder body 1, a gap 8 between the outer seal ring 4 and the piston rod 2, a gap 7 between the inner seal ring 6 and the piston rod 2, and a gap 7 between the inner seal ring 6 and the cylinder body. There is a gap 9 between 1, the size of the gap 5 and the gap 7 is generally between 0.004 mm and 0.01 mm, and the size of the gap 8 and the gap 9 is obviously larger than the gap 5 and the gap 7, about 0.1 mm. The outer sealing ring 4 is on the left side of the inner sealing ring 6 , and the outer sealing ring 4 and the inner sealing ring 6 are in contact with each other through the oblique surface of the cone, and they are closely matched.

When the pressure of the high-pressure fluid is low, the fluid cannot pass because the gap 5 and the gap 7 are relatively small, and the tight fit between the inner and outer seal rings makes the high-pressure fluid sealed on the left side of the outer seal ring.

When the pressure of the high-pressure fluid rises, the fluid has a horizontal thrust to the right on the outer seal ring 4, and the outer seal ring 4 transmits this force to the inner seal ring 6, and the inner seal ring 6 is blocked by the retaining spring 10, so that The inner sealing ring 6 cannot move to the right. Therefore, the inner seal ring 6 will give the outer seal ring 4 a force perpendicular to the contact surface. The diameter expands, reducing the gap 5 . Due to the force of the circlip 10 to the inner sealing ring 6 and the action of the outer sealing ring 4 to the inner sealing ring 6, the diameter of the inner sealing ring 6 will be reduced, so that the gap 7 will be reduced. Due to the reduction of the gaps 5 and 7, high-pressure fluid cannot pass through, thereby achieving sealing.

When the pressure continues to rise (within 300Mpa), the gaps 5 and 7 continue to decrease, which can achieve a good sealing effect, and its dynamic sealing effect is very reliable.

Therefore, when the pressure of the high-pressure fluid increases, this structure can still achieve the sealing effect.

The structure of the utility model can realize the sealing of any pressure below 300Mpa without increasing the manufacturing cost of the sealing material.

It can be seen from the above that the utility model is a dynamic sealing structure for high-pressure fluid, which can effectively realize the sealing of high-pressure fluid below 300MPa without increasing the manufacturing cost of sealing materials, and can be widely used in hydraulic cylinders, pumps, motors, etc. High pressure fluid seal.

Description of drawings

Fig. 1 is a schematic cross-sectional structure diagram of an embodiment.

In the picture:

1-cylinder, 2-piston rod,

3-High pressure fluid, 4-Outer sealing ring,

5, 7, 8, 9-gap, 6-inner sealing ring,

10-circlip.

Detailed ways

According to the sealing structure of the present utility model shown in Fig. 1, there is a cylinder body 1 with a built-in piston rod 2, and one end of the piston rod 2 is connected with the cylinder body and the other end (sealed end) is installed in sequence (that is, from left to right in Fig. 1 ). There is an outer seal ring 4, an inner seal ring 6 and a snap ring 10 that prevents the inner seal ring 6 from moving to the outside (that is, the right side in Fig. 1 ), and an axial seal is adopted between the outer seal ring 4 and the inner seal ring 6 The tapered concave hole and the corresponding tapered convex head are wedgingly connected. The sealing structure of the utility model is used for the sealing of the hydraulic oil cylinder. The conical inclined surface of the conical concave hole at one end of the outer sealing ring 4 is in the form of the axis line of the piston rod 2 (that is, the angle between the generatrix and the axis of the conical body). 30° included angle, the tapered slope of the tapered convex head of the inner seal ring 6 and the axis line of the piston rod 2 also form the same 30° included angle (the range of the included angle may be 20°-60°).

Claims (1)

1, a kind of dynamic seal (packing) structure that is used for high-pressure liquid, the cylinder body (1) that built-in piston rod (2) are arranged, one end of piston rod (2) jump ring (10) that the other end is equipped with outer seal ring (4), inner seal ring (6) successively and stops this inner seal ring (6) to move laterally with the cylinder body connection, it is characterized in that, adopt axial taper shrinkage pool to be connected between described outer seal ring (4) and the inner seal ring (6) with corresponding taper plush copper wedging.