JPH0247319Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to the improvement of a mechanical seal used to seal the rotating shaft of a machine body such as a compressor for a car air conditioner.

[Prior Art] Conventionally, in mechanical seals used in this type of car air conditioner compressors, etc.
As shown in the figure, a rotating shaft 3 is inserted through a mating ring 2, which is a fixed ring fixed to the housing 1 side of the machine body, and the rotating shaft 3 is inserted into the mating ring 2 in advance and rotates together. When assembling the seal ring 4, which is a rotating ring made of carbon material, the seal ring is normally backed up integrally by the elastic holding mechanism 5 before being assembled.

Elastic holding mechanism 5 of such a seal ring 4
As shown in FIG. 4, the body part 8a is inserted into the casing 6 via the drive ring 7 on the periphery of the rotary shaft 3 in a press-fastened state, and the tip part 8b is inserted into the casing 6. A rubber bellows 8 that is in close contact with the back side of the seal ring 4, and a coil spring 10 that urges the tip end 8b of the rubber bellows 8 in the axial direction toward the mating ring 2 via a spring suppressing member 9. consisting of, and
The distal end locking piece 6a of the casing 6 is fitted into the groove 4a formed on the outer periphery of the seal ring 4 to prevent rotation, and is incorporated into the rotating shaft 3. The mating ring 2 is moved by the biasing force of the coil spring 10.
The seal ring 4 is elastically biased to slide, thereby preventing leakage of sealing fluid to the outside.

However, in the case of the mechanical seal of the conventional structure described above, the so-called main body rotation type mechanical seal, the rubber bellows 8 is designed to have a cross-sectional shape with a bent neck portion 8c so as to be able to withstand pressure from the back side. is the current situation.

[Problems to be solved by the invention] For this reason, when assembling the elastic retaining mechanism 5 together with the seal ring 4 to the rotating shaft 3, it is necessary to
When the body 8a of the rubber bellows 8 is inserted, the insertion resistance at that time causes the rubber bellows 8 to deform, and in the assembled state shown in FIG. This increases the variation in the pressing load of the seal ring 4 to the mating ring 2 side, which places unnecessary stress on the rubber bellows during operation. In order to join
There was a problem that the durability of the rubber bellows decreased and stable sealing performance could not be obtained.

[Purpose of the invention] The present invention was made under the above circumstances, and its purpose is to eliminate fluctuations in the pressing load of the seal ring against the mating ring side during assembly. Our goal is to provide a mechanical seal that enables

[Means for solving the problems] In order to solve the above problems, the present invention has the following features:
The rotating ring fixed to the rotating shaft side is attached to the fixed ring fixed to the housing side of the fuselage via an elastic holding mechanism that integrally holds the rotating ring in the axial direction, so that it can slide freely. and a casing which is inserted into and fixed to the rotating shaft and is engaged with the rotating ring so that the rotation of the rotating shaft can be transmitted, and a body of the holding mechanism is inserted into the casing together with a drive band of the rotating shaft. A rubber bellows is built into the circumference of the shaft so that it can be inserted in a compressed state, and its tip is in close contact with the back side of the rotating ring. a coil spring that presses and biases in the axial direction of the ring side, the tip end of the drive band extends toward the rotating ring side and is brought into contact with and locked with the spring suppressing member, and the tip end of the rubber bellows The structure is such that the distance between the body and the body can be maintained constant at all times.

[Function] That is, the present invention has the above-mentioned configuration, so that the tip end of the drive band extends toward the rotating ring side and is brought into contact with the spring suppressing member, and also engages the tip end of the rubber bellows. Since the distance between the seal ring and the body is always constant, the rubber bellows will not be deformed due to insertion resistance when assembling the seal ring onto the rotating shaft. The bent neck part does not come into contact with the back surface of the seal ring, which prevents fluctuations in the pressing load of the seal ring toward the mating ring side, and also prevents the rubber bellows from coming into contact with the rubber bellows during operation. Substantially only the pressing load of the coil spring acts,
Since no unnecessary stress is applied to the rubber bellows, the durability of the rubber bellows increases and stable sealing performance can be obtained.

[Example] Hereinafter, the present invention will be described in detail with reference to an example shown in FIGS. 1 and 2. In the illustrated embodiment of the present invention, parts having the same structure as the conventional mechanical seal shown in FIGS. 3 and 4 will be described using the same reference numerals.

That is, the present invention provides an elastic holding mechanism 5 for backing up the seal ring 4, as shown in FIG.
, a drive band 71 is used in place of the conventional drive band 7 shown in FIGS. 3 and 4,
The tip end 71a of the drive band 71 is extended toward the seal ring 4 side to serve as a stopper, and the rubber bellows 8 The structure is such that the distance between the tip portion 8b and the body portion 8a is always maintained constant, and thereby, as shown in FIG. Eliminates deformation of the rubber bellows 8 due to insertion resistance during attachment,
The bent neck portion 8c of the rubber bellows 8 in the assembled state is prevented from coming into contact with the back surface of the seal ring 4.

It should be noted that the present invention is not limited to the above-described embodiments in any way, and it goes without saying that various modifications can be made without changing the gist of the present invention.

[Effects of the invention] As is clear from the above explanation, according to the invention, the rotary ring fixed to the housing side of the fuselage
A rotating ring fixed to the rotating shaft side is assembled so as to be slidable by being elastically pressed in the axial direction via an elastic holding mechanism that integrally holds the rotating ring, and the holding mechanism is inserted into the rotating shaft. a casing that is fixedly attached and engaged with the rotating ring so as to transmit rotation of the rotating shaft; and a body portion of the casing together with a drive band that can be inserted into the periphery of the rotating shaft in a compressed state. a rubber bellows whose tip end is in close contact with the back side of the rotating ring; and a coil which presses the tip end of the rubber bellows from the back side in the axial direction of the rotating shaft ring side via a spring restraining member. and a spring, and the distal end of the drive band extends toward the rotating ring side and is brought into contact with and locked to the spring suppressing member, so that the distance between the distal end of the rubber bellows and the body is always maintained constant. Since the seal ring is not deformed due to insertion resistance when the seal ring is assembled to the rotating shaft, the bent neck of the rubber bellows does not bend around the seal ring in the assembled state. There is no contact with the back surface, which prevents fluctuations in the pressing load of the seal ring to the mating ring side. Since only the pressing load acts and no unnecessary stress is applied to the rubber bellows,
This has the excellent effect of increasing the durability of the rubber bellows and providing stable sealing performance.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part showing an embodiment of a seal ring elastic holding mechanism used in a mechanical seal according to the present invention before assembly; FIG. Figure 3 is a schematic cross-sectional view of the main parts of a conventional mechanical seal.
FIG. 4 is a sectional view of a main part of the conventional seal ring elastic holding mechanism before assembly. DESCRIPTION OF SYMBOLS 1... Body housing, 2... Fixed ring (mating ring), 3... Rotating shaft, 4... Rotating ring (seal ring), 5... Elastic holding mechanism, 6... Casing, 71... Drive Band, 71a...
Tip (stopper), 8...Rubber bellows, 8
a...Body part, 8b...Tip part, 8c...Bent neck part, 9...Spring suppressing member, 91...Stopper piece part, 10...Coil spring.

Claims (1)

[Scope of utility model registration request] The rotating ring fixed to the rotating shaft side is attached to the fixed ring fixed to the housing side of the fuselage via an elastic holding mechanism that integrally holds the rotating ring in the axial direction, so that it can slide freely. and a casing which is inserted into and fixed to the rotating shaft and is engaged with the rotating ring so that the rotation of the rotating shaft can be transmitted, and a body of the holding mechanism is inserted into the casing together with a drive band of the rotating shaft. A rubber bellows is built into the circumference of the shaft so that it can be inserted in a compressed state, and its tip is in close contact with the back side of the rotating ring. a coil spring that presses and biases in the axial direction of the ring side, the tip end of the drive band extends toward the rotating ring side and is brought into contact with and locked with the spring suppressing member, and the tip end of the rubber bellows A mechanical seal that is characterized by the fact that the distance between the body and the body can always be maintained constant.