JPH0632527Y2 - mechanical seal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a mechanical seal suitable for shaft-sealing of a sealing liquid such as a hot-melt fluid, a slurry liquid or a high-viscosity liquid.

[Prior Art] Conventionally, in this type of mechanical seal, as shown in FIG. 5, when the rotary shaft 2 inserted into the inner diameter of the machine body 1 is sealed, a tightening screw 3 is attached to the machine body 1 side. Baffle sleeve 5 fixed to the seal cover 4 mounted via
Is arranged on the outer circumference of the rotary shaft 2, and a retainer 7 backed up by a metal bellows 6 is provided on the outer circumference of the baffle sleeve 5.
Assemble the stationary seal part consisting of the mating ring 8 and the mating ring.

Then, on the mating ring 8 of the stationary side seal portion, a rotating side seal portion including a seal ring 12 assembled by a knock pin 10 and an O ring 11 via a sleeve 9 on the rotating shaft 2 side is provided with a metal bellows 6. It is possible to make sliding contact by utilizing the elasticity of.

On the other hand, the seal cover 4 is provided with a quenching hole 13 which communicates with the inside of the metal bellows 6.
Quenching is performed by injecting the cooling fluid W into the stationary seal portion and discharging it from the stationary fluid seal portion.

[Problems to be Solved by the Invention] However, in the above-described mechanical seal having the conventional structure, in particular, since the tip end portion 6a of the metal bellows 6 transmits torque by the rotation stop of the stationary side seal portion, the bellows is transmitted. Not only is the load applied to 6 easily damaged, but also when stainless steel or the like is used as the bellows material, it easily gets worn out, and the surface pressure may be insufficient during operation to cause leakage.

Further, in order to compensate for the settling of the metal bellows 6, it is conceivable to interpose a coil spring 14 inside the metal bellows 6, as shown in FIG. It is not a countermeasure.

Further, in FIG. 6, in the structure in which the stationary side seal portion is prevented from rotating by the clutching action of the tip end portion 5a of the baffle sleeve 5 and the retainer 8, when the coil spring 14 extends, the bellows 6 also moves. Since the bellows 6 is deformed by extension, the flexure of the bellows 6 becomes large, and a load larger than that at the time of mounting acts on the sliding surface, and the surface pressure tends to be excessive.

In addition, the retainer 7 and the mating ring 8 that is a sliding material
Since it has an integral structure by shrink fitting, it is often impossible to replace it if the mating ring 8 is damaged.

Furthermore, since such a conventional structure does not have a steady rest of the bellows 6, there is a problem that the bellows 6 may be damaged due to runout of the bellows 6 during long-term use due to metal fatigue.

[Object of the Invention] The present invention has been made under the circumstances described above, and its purpose is to reliably prevent insufficient or excessive surface pressure on the sliding surface and damage to the bellows, and An object of the present invention is to provide a mechanical seal in which moving materials can be easily repaired and replaced.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention comprises a seal cover mounted on the side of the machine body, which is fixed to the outer periphery of a rotary shaft inserted through the inner diameter of the machine body. A baffle sleeve is arranged, and a stationary seal part consisting of a retainer backed up by a metal bellows and a mating ring is attached to the outer periphery of this baffle sleeve, while the mating ring of this stationary seal part is attached to the rotary shaft side. In a mechanical seal in which a rotary side seal part made up of a seal ring assembled to the above is slidably contacted and a coil spring is interposed inside the metal bellows, the retainer and the mating ring of the stationary side seal part are mutually connected. Assembling in a separable manner and allowing the tip of the baffle sleeve to face the inside diameter of the mating ring. In the meanwhile, the notch groove formed in the inner diameter portion of the mating ring is engaged with the rising portion higher than the inner diameter of the retainer formed in the tip end portion of the baffle sleeve to prevent rotation, while the baffle sleeve is provided. A damper is provided between the outer periphery of the retainer and the inner periphery of the retainer.

In this case, in order to prevent rotation by forming a rising portion at the tip portion of the baffle sleeve and engaging with a notch groove formed in the inner diameter portion of the mating ring, a standing piece is caulked at the tip portion of the baffle sleeve. To form a rising part by integrally forming a key groove at the tip of the baffle sleeve and implanting a key member in this key groove to form a rising part, or the tip of the baffle sleeve is L-shaped It is preferable that the flange is formed into a rising portion, and a knock pin that engages with a notch groove formed in the inner diameter portion of the mating ring is planted on the side opposite to the sliding surface of the rising portion.

[Operation] That is, according to the present invention, the tip of the baffle sleeve is made to face the inner diameter side of the mating ring, and the notch groove formed in the inner diameter of the mating ring is provided with a rising edge formed at the tip of the baffle sleeve. Since the parts are engaged and prevented from rotating, the torque transmission of the sliding torque is performed between the baffle sleeve and the mating ring, and the sliding torque does not act on the bellows.

In addition, since the rising portion formed at the tip of the baffle sleeve is higher than the inner diameter of the retainer, it acts as a stopper so that the retainer abuts against the rising portion when the bellows is stretched and deformed. The bellows load of the value set in is always applied to the sliding surface.

Further, since the damper is provided between the outer circumference of the baffle sleeve and the inner circumference of the retainer, the bellows can be steady.

Furthermore, since the retainer of the stationary side seal portion and the mating ring are separably assembled from each other, the sliding member can be easily repaired and replaced.

[Embodiment] Hereinafter, the present invention will be described in detail with reference to each embodiment shown in FIGS. 1 to 4. In the illustrated embodiment according to the present invention, the same reference numerals will be used for parts having the same constructions as those of the conventional mechanical seal shown in FIGS. 5 and 6.

1 and 2 show a first embodiment of the mechanical seal according to the present invention.

That is, as shown in FIGS. 1 and 2, the coil spring 14 is provided inside the metal bellows 6 as shown in FIG.
In the mechanical seal formed by interposing, the retainer 7 and the mating ring 8 forming the stationary side seal portion are separably assembled via a packing 15 such as an O-ring.

On the other hand, the leading end portion 5a of the baffle sleeve 5 faces the inner diameter portion 8a of the mating ring 8, and the rising portion includes a standing piece 51 that is integrally formed on the leading end portion 5a of the baffle sleeve 5 by caulking. 50 is a notch groove 81 formed in the inner diameter portion 8a of the mating ring 8.
It is possible to prevent rotation by engaging with.

Reference numeral 16 in the drawing denotes a damper having heat resistance and elasticity such as tetrafluoroethylene resin interposed between the outer circumference of the baffle sleeve 5 and the inner circumference 7a of the retainer 7.

In this case, the height of the rising portion 50 formed on the tip portion 5 a of the baffle sleeve 5 is equal to the inner circumference 7 of the retainer 7.
It is higher than the inner diameter of a, so that when the bellows 6 is stretched and deformed, it serves as a stopper by bringing the retainer 7 into contact with the rising portion 50, thereby preventing the bellows 6 from stretched and deformed. Thus, the bellows load of the initially set value can always be applied to the sliding surface.

Further, FIG. 3 shows a second embodiment according to the present invention. In forming the rising portion 50 on the tip portion 6a of the baffle sleeve 5, a key groove 52 is formed on the tip portion 5a of the baffle sleeve 5. The key member 53 is provided in the key groove 52.

Furthermore, FIG. 4 shows a third embodiment according to the present invention, in which the tip portion 5a of the baffle sleeve 5 is L-shaped.
The rising portion 50 is formed in a V-shaped flange shape, and a knock pin 54 that engages with the notch groove 81 formed in the inner diameter portion 8a of the mating ring 8 is planted on the opposite sliding surface side of the rising portion 50. It has the following configuration.

[Effect of the Invention] As is apparent from the above description, the present invention allows the tip of the baffle sleeve to face the inner diameter side of the mating ring, and the notch groove formed in the inner diameter of the mating ring. Since the rising portion formed at the tip of the baffle sleeve is engaged and prevented from rotating, the sliding torque is transmitted between the baffle sleeve and the mating ring. Does not work, which prevents the bellows from settling.

In addition, since the rising portion formed at the tip of the baffle sleeve is higher than the inner diameter of the retainer, it acts as a stopper so that the retainer abuts against the rising portion when the bellows is stretched and deformed. The bellows load of the value set in is always applied to the sliding surface.

Further, since the damper is provided between the outer circumference of the baffle sleeve and the inner circumference of the retainer, the runout of the bellows can be suppressed and fatigue damage can be prevented.

Furthermore, since the retainer of the stationary side seal portion and the mating ring are separably assembled from each other, the sliding member can be easily repaired and replaced, which is an excellent effect.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view showing an essential part of a mechanical seal according to a first embodiment of the present invention, FIG. 2 is a sectional view showing an overall structure of the mechanical seal in an assembled state, and FIG. 3 is related to the present invention. An enlarged sectional view of an essential part showing a second embodiment of a mechanical seal, FIG. 4 is an enlarged sectional view of an essential part showing a second embodiment of a mechanical seal according to the present invention, and FIGS. 5 and 6 are conventional mechanical seals. FIG. 3 is a cross-sectional view of a main part showing each of the assembled states of the above to the machine body. 1 ... Airframe, 2 ... Rotating shaft, 4 ... Seal cover, 5 ... Baffle sleeve, 5a ... Tip part, 50 ... Standing part, 6 ... Metal bellows, 7 ... Retainer, 7a ... Inside Perimeter, 8 ... mating ring, 8a ... inner diameter part, 81 ... notch groove, 12 ... seal ring, 14 ... coil spring, 15 ... packing, 16 ... damper.

Claims (4)

[Scope of utility model registration request] 1. A baffle sleeve fixed to a seal cover attached to the machine body is arranged on the outer circumference of a rotary shaft inserted through an inner diameter portion of the machine body, and a metal bellows is backed up on the outer circumference of the baffle sleeve. While the stationary side seal portion including the retainer and the mating ring is assembled, the rotating side seal portion including the seal ring assembled on the rotating shaft side is slidably contacted with the mating ring of the stationary side seal portion. At the same time, in a mechanical seal formed by interposing a coil spring inside the metal bellows, the retainer and the mating ring of the stationary side seal portion are assembled so as to be separable from each other, and the tip portion of the baffle sleeve is attached to the mating ring. While facing the inner diameter side of the ring, in the notch groove formed in the inner diameter part of this mating ring, Note that while a rising portion higher than the inner diameter of the retainer formed at the tip of the baffle sleeve is engaged to prevent rotation, a damper is provided between the outer circumference of the baffle sleeve and the inner circumference of the retainer. Characteristic mechanical seal. 2. The mechanical seal according to claim 1, wherein a rising piece is integrally formed by crimping at the tip of the baffle sleeve to form a rising portion. 3. The mechanical seal according to claim 1, wherein a key groove is provided at the tip of the baffle sleeve, and a key member is planted in the key groove to form a rising portion. 4. A knock pin that engages with a notch groove formed in an inner diameter portion of the mating ring on the side opposite to the sliding surface of the rising portion by forming the leading end portion of the baffle sleeve into an L-shaped flange shape to form a rising portion. The mechanical seal according to claim 1, wherein the mechanical seal is planted.