JPS5836931Y2 - Shaft sealing device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a shaft sealing device, and is effective when used, for example, in a refrigerant compressor of an air conditioner.

Conventionally, this type of shaft sealing device includes a fixed ring through which a rotating shaft passes through the central part and whose outer peripheral part is fixed to the housing, and a fixed ring whose one side is in sliding contact with the fixed ring and is located inward from the fixed ring. It consisted of a sliding ring whose inner peripheral end was fixed to a rotating shaft.

The contact and sliding surfaces between the fixed ring and the sliding ring were kept sealed by lubricating oil flowing from inside the compressor.

However, since the lubricating oil that lubricates the inside of the compressor needs to be mixed into the refrigerant and circulated inside the compressor and the refrigerant cycle, it must be compatible with the refrigerant.

As a result, a problem arose in that the refrigerant got mixed into the lubricating oil layer formed on the contact sliding surface between the fixed ring and the sliding ring, deteriorating the sealing performance.

In view of the above-mentioned problems, it is an object of the present invention to prevent the destruction of the lubricating oil layer caused by the mixing of refrigerant into the lubricating oil layer, and to prevent the deterioration of sealing performance.

In order to achieve this objective, the present invention takes the following measures.

A storage chamber is formed between the fixing ring, the oil seal, the housing button, and the rotating shaft, and this storage chamber is filled with seal oil that has a low affinity for the refrigerant.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An m-embodiment of the present invention applied to a swash plate compressor for an automobile air conditioner will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a rotating shaft, which rotates under the driving force of an engine (not shown).

Reference numeral 2 denotes a swash plate keyed to the rotating shaft 1, which swings and rotates in response to the rotation of the rotating shaft 1.

This rocking rotation of the swash plate 2 is transmitted to the piston 5 via the shoe 3 and the ball 4, and the piston 5 reciprocates within the silling portion 6.

Reference numeral I designates a center housing that rotatably supports the rotary shaft 1 via a bearing 8, and has a cylinder portion 6 formed therein.

Reference numerals 9 and 10 denote side housings disposed to cover the ends of the center housing 7, and the cylinder portion 6
Suction chamber 11 forming a passage for refrigerant (Freon) to be sucked into
and a discharge chamber 12 forming a passage for the refrigerant discharged from the cylinder portion 6.

In the compressor having this configuration, lubricating oil is mixed into the refrigerant, and the circulating oil that circulates together with the refrigerant is used to create spaces between the piston 5 and the cylinder part 6, and between the rotating shaft 1 and the bearing 8.
It is designed to lubricate areas where lubrication is required, such as between the

Of the side housings 9 and 10, the side housing 9 on the side through which the rotating shaft 1 passes has a shaft sealing device 50 between the rotating shaft 1 and the surface of the side housing 9 facing the rotating shaft 1. This prevents the refrigerant and lubricant inside the compressor from leaking outside the compressor.

This shaft sealing device 50 has a shape as shown in FIG. 2. In FIG. It is in close contact with the side housing 9 and fixed by a circlip 53.

Reference numeral 59 denotes a ring-shaped oil seal made of a highly flexible material such as nitrile rubber, and the outer periphery 59a is inserted and fixed into a groove 9a provided in the side housing 9, and the inner periphery 59c is fixed. It has a thick wall and a button, and is adapted to contact and fit onto the rotating shaft 1 to form a seal between the rotating shaft 1 and the rotating shaft 1.

59b is a small hole with a diameter of about 1wn provided in the oil seal 59 of the cigarette to equalize the pressure on both sides of the oil seal 59.

A storage chamber 510 is formed by a space surrounded by the oil seal 59, the fixing ring 51, the side housing 9, and the rotating shaft 1. , and is filled with a sealing oil 511 having excellent sealing properties, such as silicone oil and polyoxypropylene triol.

This storage chamber 510 prevents the refrigerant and lubricating oil that have flowed from inside the compressor along the housings 7 and 9 from flowing out to the outside of the compressor (A4JI!I in the figure).

Further, 54 is a sliding ring made of a material with excellent sliding properties such as carbon, which is connected via a cover plate 55 to a position of the rotating shaft 1 facing the storage chamber 510, and rotates integrally with the rotating shaft 1. It looks like this.

The sliding ring 54 is a rubber seal ring 5.
6, and prevents the seal oil 511 in the storage chamber 510 from flowing out to the outside of the compressor (side A) along the rotary shaft 1, and at the same time, the sealing oil 511 in the storage chamber 510 is in close contact with the rotating shaft 1 through This prevents the seal oil 511 in the storage chamber 510 from flowing out along the fixing ring 51 to the outside of the compressor (Aill!l).

57 is a spring that connects the seal ring 5 via the holding plate 58.
6 sliding ring 5411! Press the seal ring 5.
6 and the sliding ring 54, and at the same time press the sliding ring 54 toward the fixed ring 51 to increase the contact pressure between the sliding ring 54 and the fixed ring 51. It is.

Therefore, in the device having the above configuration, the refrigerant and lubricating oil inside the compressor are transferred to the seal oil 511 in the storage chamber 510 as described above.
Furthermore, since the seal oil 511 in the storage chamber 510 is sealed by the seal ring 56, the sliding ring 54, and the fixed ring 51, the compressor is well sealed.

A small hole 59b is formed in the oil seal 59 so that the pressure on both sides of the oil seal 59 is equalized, so the pressure in the suction chamber 11 in the compressor (usually 3
The oil seal 59 is pushed to the left in the figure due to the pressure difference between the atmospheric pressure outside the compressor (atmospheric pressure) and the atmospheric pressure outside the compressor, and as a result, the seal oil 511 in the storage chamber 510 leaks to the suction chamber 11 side.
This can prevent the occurrence of such problems.

Here, considering the case where the oil seal 59 is not provided and therefore the storage chamber 510 and seal oil 511 are not provided, in such a case, refrigerant and lubricating oil flowing from inside the compressor along the housing 7.9 The refrigerant and lubricant flowing along the rotating shaft 1 from inside the compressor housing are blocked by the fixed ring 51, and the refrigerant and lubricating oil are blocked by the sliding ring 54 button and the seal ring 5.
The refrigerant and lubricating oil that are blocked by 6 and further blocked by the fixed ring 51 flow out to the outside of the compressor (A side) along the fixed ring 51 due to the sliding contact between the sliding ring 54 and the fixed ring. It will be blocked.

In the case where the storage chamber 510 does not include the seal oil 511, the contact sliding surface between the sliding ring 54 and the fixed ring 51 is kept sealed by the lubricating oil flowing from inside the compressor.

However, the lubricating oil that lubricates the inside of the compressor must be mixed with the refrigerant and circulated inside the compressor and within the refrigerant cycle, so it is necessary to use an oil that is compatible with the refrigerant. Therefore, in the case where the seal between the sliding ring 54 and the fixed ring 51 is maintained with lubricating oil, it is easy to cause a situation where the refrigerant gets mixed into the lubricating oil layer and deteriorates the sealing performance. Storage room 51
According to research conducted by the present inventors, especially when the compressor is stopped, the refrigerant liquefies and accumulates around the shaft sealing device, causing damage to the sliding ring 54 and the fixed ring. It has been recognized that the lubricating oil retained on the contact surface with the 51 is also immersed in the liquid refrigerant, which reduces the viscosity of the lubricating oil and significantly deteriorates the sealing effect. It was done.

However, in the shaft sealing device having the above configuration, the sliding surface of the sliding ring 54 that contacts the fixed ring 51 is located in the storage chamber 510.
Since the seal is maintained by the seal oil 511 inside the sliding ring 54, there is no risk of refrigerant getting mixed in.
The sealing oil always provides a good seal between the fixed ring 51 and the fixing ring 51.

In particular, since the seal oil 511 is made of silicone oil or polyoxypropylene triol, which has a low affinity with the refrigerant (Freon), the refrigerant does not seep into the seal oil 511, and therefore the refrigerant improves the sealing properties of the seal oil 511. There is no fear that it will get worse.

In the above-mentioned embodiment, an example was shown in which the device was used as a shaft sealing device for a swash plate type compressor, but it goes without saying that the device of the present invention is not limited to use in this swash plate type compressor.
It is also applicable to other types of compressors such as vane type compressors and screw compressors, and furthermore, it is widely applicable to general rotating machines other than compressors.

Therefore, the fluid inside the rotating machine is not limited to Freon, and therefore the seal oil 511 filled in the storage chamber 510 is not limited to silicone oil or polyoxypropylene triol, which have a small affinity for Freon. Depending on your needs, you can choose from oils with excellent sealing properties.

As explained above, the shaft sealing device of the present invention includes the fixing ring 51,
A storage chamber 510 is formed from the oil seal 59, the spring ring 9, and the rotating shaft 1, and the storage chamber 510 is filled with seal oil 511 having excellent sealing properties.
The fluid inside the rotating machine can be sealed very well by this seal oil 511, and the sliding ring 54
is closely fixed to the rotating shaft 1 in the storage chamber 510 via a seal ring 56, and the sliding ring 54 is closely fixed to the rotating shaft 1 via the seal ring 56.
Since the seal oil 511 in the storage chamber 510 is made to slide in contact with the sliding ring 54 and the seal ring 56,
This can prevent leakage from inside the storage chamber 510 to the outside of the rotating machine.

Therefore, the shaft sealing device of the present invention has an excellent effect of significantly improving sealing performance.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of the device of the present invention used as a shaft sealing device 50 of a swash plate type compressor, and FIG. 2 is a sectional view of the shaft sealing device 50 shown in FIG. 1. 1...Rotating shaft, 9...Side housing, 50...Shaft sealing device, 51...Fixing ring, 54...Sliding Ring, 56...
・Seal ring, 59...Oil seal, 51
0...Storage room, 511...Seal Y circle

Claims (1)

[Scope of utility model registration request] A shaft sealing device that seals between a rotating shaft of a refrigerant compressor that compresses and discharges refrigerant and lubricating oil as one unit and a nozzle housing that incorporates this rotating shaft, the shaft sealing device facing the rotating shaft of the housing. fixing a fixing ring to the surface, and fixing the outer periphery of a ring-shaped oil seal to a surface of the housing facing the rotating shaft that is on the inner side of the rotating machine from the surface to which the fixing ring is fixed; The inner periphery of this ring-shaped oil seal is fitted in contact with the rotating shaft, and a storage chamber is formed by the oil seal, the fixed ring, the housing, and the rotating shaft, and the refrigerant is not allowed to flow into the storage chamber. a sealing oil having a lower affinity than the lubricating oil, and a sliding ring is closely fixed to a portion of the rotating shaft facing the storage chamber, and the sliding ring and the fixed ring are brought into contact with each other. A shaft sealing device characterized by sliding.