JPH0217719B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a sealing device for preventing leakage between an impeller and a non-rotating part.

(Prior art) A pump having a rotating impeller, such as a centrifugal pump, takes in the pump medium at the center of the impeller,
Eject from the surrounding area. It is therefore important that the impeller inlet closely mates with the housing inlet and that the pump medium is prevented from flowing back to the inlet side. Such backflow causes turbulence at the inlet and reduces pump efficiency.

In order to obtain the necessary seal between the impeller and the non-rotating part, a U-shaped seal ring made of rubber is placed on the non-rotating part as shown in Japanese Patent Publication No. 28-2080, and the impeller is rotated while the impeller is rotating. Normally, it is in direct contact with this.

This type of seal ring has the problem of wear due to contact pressure, and as long as it is intact, an effective sealing effect can be expected, but the pumping liquid may be exposed to substances that easily cause wear, such as sand or mines. When the seal ring contains muddy cuttings, etc., the life of the seal ring is very short and requires a lot of maintenance.

The present invention provides a sealing device that does not require such rubber consumable parts and has a long life and requires less maintenance.

(Disclosure of the Invention) In order to reduce the wear of the impeller and the seal rings of the non-rotating parts as described above, one method is to equip the seal ring with a wear-resistant material such as metal or ceramics. However, it is effective to reduce the contact pressure of the seal ring.

In other words, it is undesirable for the seal surface to have a large contact pressure, not only from the point of view of wear but also from the point of view of loss of power. It is extremely effective to restrict the movement of the ring.

However, if this regulation is applied in a manner that exerts a force on the contact surface pressure, the contact surface pressure may warp and cause wear, which is particularly problematic in a device where the pump medium is the source of wear.

Therefore, it is preferable to restrict the movement by a force perpendicular to the contact surface. The present invention attempts to solve this problem by applying appropriate compressive deformation to the O-ring and placing it in contact with the upper or lower surface of the seal ring.

However, if the O-ring itself were to move toward the contact surface and be pulled out, this would be extremely undesirable in terms of stability of this regulation. For this reason, in the present invention, the axial opening of the groove or slot into which the O-ring enters is made so shallow that the O-ring cannot pass through it unless it is subjected to considerable compressive deformation (which never occurs during operation). By doing so,
The purpose is to restrict the movement of this O-ring. This method restricts the movement of the seal ring towards the contact surface. However, it is also necessary to deal with the problem of followability at the contact surface that occurs when using a large-sized seal ring with poor dimensional accuracy, and for this problem, regulating only by the radial force of the O-ring is not sufficient. Not.

In the present invention, the shape of the slot, which is the fixed position of the O-ring, has a slope in which the dimension gradually decreases from the inner side toward the entrance side, and the shallow dimension is selected appropriately, so that the O-ring can be easily attached to the slot. This is done by giving some degree of freedom to deal with the followability. Further, by interposing the O-ring, the seal ring can be easily replaced.

(Example) The present invention will be explained in detail with reference to the drawings.

In the figure, 1 is a part of the impeller, 2 is a part of the pump housing, 3 is a seal ring attached to the impeller, 4 is a seal ring attached to the housing, 5 is an O-ring, and 6 is a slot for the O-ring. show.

The seal rings 3 and 4 are mounted on the impeller and the housing, respectively, facing each other, and one of them, for example, an O-ring 5 is disposed on the upper surface of the seal ring 3.

The O-ring 5 is also disposed deep in a slot 6 extending axially along the outer periphery of the seal ring 3. The shape of this slot 6 is such that the O-ring cannot pass through it unless the dimension of its axial opening, that is, the distance between the opening and the upper surface of the set seal ring, causes considerable deformation of the O-ring 5. The depth dimension in the radial direction of the inner part, which is a shallow dimension of the range and the fixed position of the O-ring 5, is the compressive pressure that acts in the direction perpendicular to the contact surface that restricts the axial movement of the seal ring. The O-ring 5 is formed in such a size that the O-ring 5 is provided with an incline, and furthermore, the slot 6 is formed to have an inclined shape that tapers smoothly from the back toward the opening side, for example, in a tapered shape. The shallow opening size and the inclined shape synergistically have the effect of restricting the axial movement of the seal ring by the O-ring 5, and at the same time have the effect of giving the seal ring a slight degree of freedom in axial followability. be.

To attach seal ring 3 to impeller 1,
First, the O-ring 5 is placed in the slot 6, and then the seal ring 3 is pushed into the slot 6 against the compression pressure of the O-ring 5. By doing this, the O-ring 5 is deformed and the seal ring 3 is locked in a predetermined position, and together with the shape of the slot, the axial movement of the seal ring 3 is restricted and the seal ring 3 is slightly moved against the sealing surface. You can have a degree of freedom. In addition, as mentioned above, the O-ring cannot pass through the opening unless the dimensions of the opening and the distance between the opening and the upper surface of the set seal ring cause considerable deformation to the O-ring 5 (which never occurs during operation). The size of the slot is such that there is no possibility that the O-ring 5 will come out of the slot 6, and stable operation can be expected to continue.

The locking action of the O-ring 5 in the radial direction of the seal ring 3 becomes stronger as the seal ring is exposed to higher pressure, and its action is not diminished by high pressure.

Although the case where the O-ring 5 is disposed on the seal ring 3 has been described above, it is of course possible that the O-ring 5 may be disposed on the seal ring 4.

Although the basics of the present invention have been described above with respect to one embodiment, this does not limit the technical scope of the present invention as described in the purpose of the invention and the scope of the claims.

(Effects of the Invention) The effects of the present invention are that the impeller and the housing do not form a direct sliding surface, which is an economical effect that prevents wear and tear on the expensive impeller and housing, and that the seal ring has a longer lifespan and maintenance. Cost reduction can be expected. Moreover, various problems caused by the seal ring not being sufficiently flat can be solved.

[Brief explanation of drawings]

The drawing is a sectional view of a sealing device according to an embodiment of the present invention. 1; impeller, 2; pump housing, 3,
4; Seal ring, 5; O-ring, 6; Slot.

Claims (1)

[Claims] 1. A sealing device in which a seal ring provided on a rotating impeller or its surrounding housing forms a mechanical seal device between a rotating part and a non-rotating part together with other seal rings, at least one seal ring. 3 is O-ring 5
The O-ring 5 deforms in a slot 6 extending in the axial direction along the outer periphery of the seal ring 3 to lock the seal ring 3, and the O-ring 5 is held in the inner part of the slot 6. In order to block the removal of the ring 5 and at the same time give the O-ring a degree of freedom such that the seal ring can follow the seal ring in the axial direction, the axial opening of the slot 6 is opened in the radial direction from the inner side thereof. A sealing device characterized in that the depth is shallow, and the opening and the inner side are smoothly connected by an inclined surface. 2. The sealing device according to claim 1, wherein the sealing surface between the two sealing rings 3 and 4 is radial to the rotation axis.