JPH0231637Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to an improvement of a mechanical seal that seals the rotating shaft of a body such as a water pump.

[Conventional technology]

Conventionally, in this type of mechanical seal,
As illustrated in FIG. 5, the housing 2 of the fuselage 1
In order to seal the rotating shaft 3 inserted therein, a sleeve 4 is fitted around the periphery of the rotating shaft 3, and a floating seat 6, which is a rotating ring, is provided on the outer periphery of the sleeve 4 via a buffer rubber 5. A seal ring 7, which is a fixed ring, is brought into sliding contact with this floating sheet 6, and this seal ring 7 is attached to a casing 8 fixed to the housing 2 side via a bellows-shaped packing 9, and the seal ring 9
A pair of spring suppressing members 10, 10 bent into an L-shaped cross section between the outer circumferential flanges 9a, 9b at both ends.
The seal ring 7 is pressed against the floating seat 6 by a spring 11 elastically loaded through the spring 11, and the extension part 8 of the casing 8 is inserted into the engagement recess 7a formed in the inner diameter part of the seal ring 7.
Some have a structure in which they are assembled into a unit by engaging the parts a and preventing rotation.

[Problem that the invention attempts to solve]

However, in such a conventional mechanical seal, at least one of the contact surfaces between the packing 9 and the seal ring 7 or the casing 8, which are members forming the seal portion, are coated with adhesive A or B. The seal ring 7 has an assembly structure in which the seal ring 7 is fixed with adhesive.
Since the rotation is prevented by engaging the extension part 8a of the casing 8 with the engagement recess 7a formed in the inner diameter part of the seal ring 7, a clearance is created between the two, which prevents sliding. The seal body is twisted by the clearance due to the dynamic torque, and torsional repulsion force is accumulated in the bonded areas between the seal ring 7, the casing 8, and the packing 9, and is thus accumulated in the seal body. Due to the correlation between the torsional repulsion force and the lubrication properties of the sliding surface, abnormal noises are often generated due to the stay-slip motion. Also, during assembly, adhesive may adhere to other parts or dust may This not only makes the bonding work troublesome, but also causes the seal to tear or malfunction. Moreover,
For example, under high-temperature conditions, such as water pumps that operate at high temperatures and high speeds, adhesive A or B deteriorates and becomes more likely to peel off, resulting in leaks and stable sealing that may not last for a long time. There were also various problems in terms of durability, such as the inability to maintain it.

[Purpose of invention]

The present invention was developed under the above circumstances, and its purpose is to provide a mechanical seal in which each seal component can be assembled integrally without adhesive. There is a particular thing.

[Means for solving problems]

In order to solve the above-mentioned problems, the mechanical seal of the present invention is provided on the inner circumferential surface of the bellows-like packing, at a position corresponding to the fitting surface with the inner diameter bent part of the spring suppressing member, and on the outer circumference of the rear end of the fixed ring. A rib is provided to protrude into pressure contact with at least one of the surface and the outer peripheral surface of the rear end of the inner cylindrical portion of the casing, and the spring suppressing member is press-fitted onto the outer peripheral surface of the packing with an appropriate tightening margin. This is what I did.

[Effect]

That is, in the present invention, by having the above-mentioned configuration, the ribs on the inner circumferential surface of the packing receive the tightening load from the inner bent portion of the spring suppressing member and escape to the outside in the axial direction of the inner bent portion. In this way, it comes into close contact with the outer peripheral surface of the rear end of the fixed ring or the outer peripheral surface of the rear end of the inner cylindrical portion of the casing, so that good sealing can be achieved even if the contact load is relatively small. In addition, the close contact load on the inner peripheral surface of the packing can be made relatively small, and since no adhesive is used, even if the fixed ring is twisted by the clearance of the rotation stopper part with the casing due to the sliding torque with the rotating ring, the above-mentioned The packing easily slips in the circumferential direction, and no repulsive force against twisting is accumulated.

〔Example〕

Next, the present invention will be explained with reference to the embodiments shown in FIG. 1 and below. In the illustrated embodiment of the present invention, the same reference numerals are used for the parts having the same structure as the mechanical seal of the conventional structure shown in FIG. 3, and the explanation thereof will be omitted.

1 and 2 show a first embodiment of the mechanical seal according to the present invention, in which the inner peripheral surface of the packing 9 is connected to the inner diameter bent portion 10a of the spring suppressing member 10 on the side of the seal ring 7. A rib 91 is formed at a position corresponding to the fitting surface and pressed against the outer peripheral surface 7b of the rear end of the seal ring 7, and this gasket 9 is provided with an appropriate tightening margin between the seal ring 7 and the spring suppressing member 10. They are arranged in a press-fitted state and assembled integrally in a non-adhesive state.

Furthermore, FIGS. 3 and 4 show a second embodiment of the mechanical seal according to the present invention, in which the rib 91 formed on the seal 9 in the first embodiment is replaced by a spring retainer on the housing 2 side. The rear end outer circumferential surface 8 of the inner cylindrical portion of the casing 8 is located at a position corresponding to the fitting surface with the inner diameter bent portion 10b of the member 10.
b, and the gasket 9 is placed in a press-fitted state with an appropriate tightening margin between the spring suppressing member 10 and the casing 8, and assembled integrally in a non-adhesive state. It has the following configuration.

In each of the above embodiments, the rib 91 of the packing 9
is deformed so as to face outward in the axial direction of the inner diameter bent portions 10a, 10b due to the compressive force from the inner diameter bent portions 10a, 10b of the spring suppressing member 10 fitted on the outer periphery with appropriate interference. It is in close contact with the rear end outer circumferential surfaces 7b and 8b.

In addition, it goes without saying that the present invention can be modified in various ways without departing from the gist of the invention.

[Effect of idea]

As is clear from the above explanation, according to the present invention, the rib provided on the inner peripheral surface of the packing receives the tightening load from the inner diameter bent portion of the spring suppressing member.
Since the inner diameter bent portion is deformed toward the axially outer side and comes into close contact with the rear end outer peripheral surface of the fixed ring or the rear end outer peripheral surface of the inner cylindrical portion of the casing, the contact load is relatively small. Has a sealing function,
Moreover, since no adhesive is used, even if the fixed ring is twisted by the amount of clearance between the rotation stopper and the casing due to sliding torque, the gasket easily slips in the circumferential direction, thereby preventing torsional repulsion from accumulating. This does not cause abnormal noises (squeaks).
It is possible to reliably prevent the occurrence of
Since no adhesive is used even under high-temperature conditions, it has the excellent effect of maintaining stable sealing properties over a long period of time.

[Brief explanation of the drawing]

Figure 1 shows the first mechanical seal according to the present invention.
2 is an enlarged sectional view of the main part of the packing in part A of FIG. 1; FIG. 3 is a schematic sectional view of the main part showing the second embodiment of the present invention; FIG. FIG. 4 is an enlarged sectional view of the main part of the seal in the ro part of FIG. 3, and FIG. 5 is a schematic sectional view of the main part of a conventional mechanical seal. 1... Body, 3... Rotating shaft, 4... Sleeve,
6...Floating seat (rotating ring), 7...
Seal ring (fixed ring), 7a... recess, 8...
Casing, 8a...extending part, 9...packing,
91...Rib, 10...Spring suppressing member, 1
1...Spring.

Claims (1)

[Scope of utility model registration request] A fixed ring that is in sliding contact with a rotating ring provided on the periphery of the rotating shaft via a sleeve is attached to a casing fixed to the housing via a bellows-shaped packing, and a cross section L is formed between the outer peripheral flanges at both ends of the packing. In a mechanical seal equipped with a spring that presses the stationary ring against the rotating ring via a pair of spring suppressing members bent into a letter shape, an inner diameter bent portion of the spring suppressing member and an inner diameter bent portion of the spring suppressing member are provided on the inner circumferential surface of the seal. The position corresponds to the mating surface of
A rib is provided to protrude into pressure contact with at least one of the outer peripheral surface of the rear end of the fixed ring and the outer peripheral surface of the rear end of the inner cylindrical portion of the casing, and the spring suppressing member is provided with an appropriate tightening margin on the outer peripheral surface of the packing. A mechanical seal characterized by press-fitting.