JPH07247958A - Shaft seal device - Google Patents

Abstract

PURPOSE:To easily provide a shaft seal device to meet the purpose of the use without executing the surface working on a rotary shaft by providing a first shaft seal device arranged on the outer circumferential part of the rotary shaft, and a second shaft seal device which is provided between the first shaft seal device and the rotary shaft, and driven by the rotary shaft. CONSTITUTION:In a compressor to be used for the refrigeration cycle, a plurality of pistons 23 are reciprocatingly slid with the time difference in a cylinder 40, and the fluid such as a gaseous refrigerant in a suction chamber 32 is discharged in a discharge chamber 33 by swaying a swaying plate 19 around a rigid ball 21 along the inclined surface of a rotor 24. The sealing between a rotary main shaft 2 and a boss part 1 of a front housing 10b is realized by a lip seal 11 which is a first shaft seal device. An auxiliary shaft seal device 26 provided with a hollow part where the rotary main shaft 2 is penetrated, and a thick wall part 26a for fixing the shaft on one end is provided as a second shaft seal device through an O-ring, and the second seal shaft device is driven by the rotary main shaft 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaft seal device for a rotating shaft, and more particularly to a shaft seal auxiliary device for a shaft seal device for a rotating main shaft of a compressor used in a refrigeration cycle.

[0002]

2. Description of the Related Art Conventionally, as a shaft sealing device for preventing leakage of refrigerant gas or lubricating oil in a compressor or the like, Japanese Patent Laid-Open No.
The mechanical seals disclosed in No. 101754 or No. 50-101755 are known. That is, referring to FIG. 3, the seal sheet 4 mounted on the rotary main shaft 2, the pressing snap ring 14 for preventing the rotation of the seal sheet, and the seal retainer 8 are pressed against the seal surface of the seal sheet. The rotation of the seal sheet 4 attached to the rotary spindle 2 is prevented by a shaft seal 6 including a spring 9 and an O-ring, and the leakage of refrigerant gas and the like from the rotary spindle is prevented.

Further, as a shaft sealing device using a lip seal, for example, a structure shown in Japanese Patent Publication No. 58-10586 is known. That is, referring to FIG.
A ring-shaped lip body 1 made of a flexible thin plate is attached to a rotary main shaft 2 extending in a boss portion 1 of a compressor casing.
No. 1 is used, and the inner diameter portion thereof is pressed against the outer peripheral surface of the rotating main shaft 2 to prevent leakage of the refrigerant gas and the like. In order to support the thin plate ring-shaped lip body 11, two holding bodies 12 and 13 each having a substantially L-shaped cross section are used.
It is sandwiched between these holders 12 and 13 via an O-ring 16 for sealing with 1. An O-ring 14 seals between the shaft sealing device and the boss portion 1, and a snap ring 15 is inserted into the bore of the boss portion 1.

Similarly, a shaft sealing device having a structure shown in Japanese Patent Laid-Open No. 61-58985 is known as a device utilizing a lip body. Referring to FIG. 5, the boss portion 1 of the open type compressor
The flexible lip piece 11a that is pressed by the rotating main shaft 2 protruding from the outside and the holding portion 11b that holds the flexible lip piece 11a and is mounted in the bore of the boss portion 1 of the compressor casing are made of the same synthetic resin. It is integrally molded with the material.

[0005]

As a refrigerant used for heat exchange in a refrigeration cycle, CFC (Chloro Fluoro Carbon) or HCFC has conventionally been used from the viewpoint of stability and the like.
(Hydro Chloro Fluoro Carbon) is widely used, and CFC-12 or HC is used as the refrigerant for the air conditioner.
FC-22 and the like are used. However, from the viewpoint of protection of the global environment in recent years, the practical use of alternative substances that do not affect the ozone layer has been promoted. Therefore, HFC (Hydro Fluoro C
arbon) or a mixture of HFCs such as HFC-13
4a, HFC-32 / 134a and other alternative refrigerants have come into use. However, when these alternative refrigerants are used as refrigerants for air conditioners, in particular, abnormal wear of the friction surface of the sliding portion of the shaft seal device installed inside the compressor, which is one of the components of the air conditioner, is prevented. There is a problem that it will occur. That is, some of the lubricating oils that have been conventionally used in the above-mentioned alternative refrigerants have low compatibility (for example, refrigerating machine oils such as naphthene-based, paraffin-based, and alkylbenzene-based), and the lubricating oil is applied to the sliding portion. Since it didn't reach, it caused poor lubrication. Therefore, the abrasion of the sliding portion causes leakage of the refrigerant gas and the like.

Further, the CFC (eg CFC-12 etc.) or HCFC (eg HC
Chlorine, which is a part of the composition of FC-22, etc., forms a certain compound (for example, chloride film, chloride compound, etc.) by thermal decomposition of the sliding surface of sliding parts of metal in sliding contact. It is known that this has an effect of reducing friction or the amount of damage on the contact surface (so-called extreme pressure effect). For this reason, when these refrigerants are used for heat exchange, they have a lubricating action to prevent wear of sliding parts of the compressor, etc., and therefore, in combination with lubricating oil introduced from the outside to the compressor, It helped prevent abnormal wear of sliding parts. However, the above alternative refrigerant, HFC or a mixture thereof (for example, HFC-134a, HFC-32 / 134a, etc.) does not contain chlorine in its composition, and the above-mentioned extreme pressure action is not included. Therefore, the lubrication ability is lower than before.

By the way, in the mechanical seal type shaft sealing device described above, the structure is complicated and the cost is high, and the sealing surface (the sliding surface between the seal sheet 4 and the rotary main shaft 2 in the figure and the seal sheet 4 is used. Since the sliding surface between the shaft seal 6 and the shaft seal 6 is relatively wide), when the above-mentioned alternative refrigerant is used, abnormal wear of the sliding surface of the sliding component is likely to occur due to poor lubrication. Occurred. Therefore, instead of the mechanical seal, a lip seal type shaft sealing device having a simple structure and being easy to use has come to be used. However, since this type of shaft sealing device has a smaller sealing point than the case where a mechanical seal is used, it is necessary to make the surface finish of the sliding portion of the rotary spindle 2 with the lip piece 11a highly precise. . For this reason, the refrigerant of the compressor using the mechanical seal already on the market is replaced with the above-mentioned alternative refrigerant HFC or its mixture (for example, HFC-134).
a, HFC-32 / 134a, etc.)
Merely replacing the shaft sealing device with a lip seal type is insufficient to prevent leakage of refrigerant gas or the like from the compressor due to wear of the lip piece 11a due to poor machining accuracy of the rotary main shaft 2. .

In view of the above problems, the present invention relates to a compressor shaft sealing device used in a refrigeration cycle, and by using an auxiliary shaft sealing device without performing new processing or the like on an existing product, a substitute refrigerant can be obtained. It is to provide a compressor that can be continuously used even after being changed.

[0009]

In order to achieve the above object, in the invention according to claim 1, the rotary shaft and the outer peripheral surface of the rotary shaft are slidably contacted with each other to divide in the longitudinal direction of the rotary shaft. In the shaft sealing device that seals between the two areas,
A first shaft sealing device fixedly installed on the outer side of the rotary shaft; and an outer peripheral surface that is installed between the first shaft sealing device and the rotary shaft and is in sliding contact with the first shaft sealing device. A shaft sealing device for a rotary shaft body having a structure including a second shaft sealing device which has a second shaft sealing device that rotates following the rotation of the rotary shaft.

According to a second aspect of the present invention, the second shaft sealing device has a hollow portion through which the rotary shaft penetrates, and is a shaft sealing device for a rotary shaft body integrally fixed to the rotary shaft. can get. Further, in the invention according to claim 3, the second shaft sealing device is a shaft sealing device for a rotary shaft body having a structure in which a part of the inner diameter of the hollow portion is reduced.

[0011]

In the present invention, in addition to the first shaft sealing device, the second shaft sealing device is interposed on the rotary shaft, and the outer peripheral portion of the second shaft sealing device is sealed with the first shaft sealing device. Therefore, the first shaft sealing device does not come into direct sliding contact with the outer peripheral portion of the rotary shaft.

Further, since the second shaft sealing device has a hollow portion through which the rotary shaft can pass, the second shaft sealing device can be easily mounted. Furthermore, since a part of the inner diameter of the hollow portion is made small, the fixing to the rotary shaft becomes strong.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings.

In FIG. 1, a cylindrical casing 10 has a drive mechanism for transmitting a drive force to a piston 23 between a cylinder block 10a fitted and fixed at one end and a front housing 10b fixed at the other end. In addition, a crank chamber 22 that also serves as an oil storage chamber for lubricating oil for each part of the drive mechanism is formed. The rotor 24 arranged in the crank chamber is fixed by press-fitting or the like to the rotary main shaft 2 that is rotatably inserted through the bearing 15 in the central portion of the front housing 10b, and is driven by the rotation of the rotary main shaft 2. Rotate. One side of the rotor 24 faces the front housing 10b via the thrust needle bearing 17, and the other side of the rotor 24 has a ring-shaped rocking plate 19 facing the inclined face via the thrust needle bearing 18. There is. This swing plate 19 is swingably provided at the tip of the swing center shaft body 20 via a rotatable rigid ball 21, and the bevel gear 20b at the tip of the swing center shaft body 20 is swing plate 19. The rotation of the rocking plate 19 is prevented by meshing with the bevel gear 25 fixed to the.

A plurality of cylinders 40 are formed in the cylinder block 10a, and a piston 23 is slidably inserted in each of them. These pistons 23 are connected by rods 23a to connection holes 19a provided in the vicinity of the periphery of the oscillating plate 19. Also, cylinder block 1
A cylinder head 30 is superposed on one end of 0a through a gasket (not shown) and a valve plate assembly 29,
A suction chamber 32 and a discharge chamber 33 are formed.

In the above structure, when the rotary main shaft 2 is rotated by an appropriate rotary drive means (for example, an engine of an automobile), the rotor 24 rotates in the crank chamber 22, and the rotor 24 runs along the inclined surface of the rotor 24. Since the rocking plate 19 rocks around the hard sphere 21 without rotating, a plurality of pistons 23 reciprocally slide in the cylinder 40 with a time difference based on the rocking plate 19, and as a result, the refrigerant gas in the suction chamber 32, etc. The fluid is sucked into the cylinder through the suction port 32a and compressed by sliding of the piston 23 while the discharge port 3 is being compressed.
It is discharged to the discharge chamber 33 through 3a. In practice, the suction port 38 and the discharge port 39 provided on the cylinder head 30
Since a cooling circuit is used between the cooling circuit and the cooling circuit, the refrigerant gas in this cooling circuit circulates in the circuit while repeating condensation and evaporation.

In the compressor having such a structure, the rotary main shaft 2 and the boss portion 1 of the front housing 10b are sealed by a lip seal 11 which is a first shaft sealing device. Reference numeral 11b is a holding portion of a lip seal that has been conventionally used, and 11a is a lip piece. The O-ring 14 seals the outer peripheral portion of the lip seal and the inner peripheral surface of the boss portion 1. Reference numeral 26 denotes an auxiliary shaft sealing device as a second shaft sealing device according to the present invention. In the present embodiment, the auxiliary shaft sealing device has a hollow portion through which the rotary spindle 2 penetrates and is formed in a cylindrical shape whose cross section is concentric with the rotary spindle. Has been done. The inner diameter of the hollow portion is reduced by providing a thick wall portion 26a for fixing the shaft on one end side of the auxiliary shaft sealing device 26 in order to strengthen the connection with the rotating main shaft. In the embodiment shown in FIG. 2, the thick wall portion for fixing the shaft has a two-face width structure,
When the rotary main shaft 2 penetrates the hollow portion and is fixed by fitting the rotary main shaft at the shaft fixing two-face width portion, the rotary main shaft can rotate concentrically with the rotary main shaft. At this time, a guide groove for receiving the thick wall portion for fixing the shaft may be provided on the outer peripheral surface of the rotating main shaft. An O-ring 27 is provided on the inner peripheral surface of the auxiliary shaft sealing device to seal the gap between the auxiliary shaft sealing device and the rotating main shaft.

As the auxiliary shaft sealing device in this embodiment,
Although either synthetic resin or metal material can be used, it is more preferably formed of engineering plastic such as ABS, polypropylene, Teflon, vinyl chloride, polyamide, polyacetal, polycarbonate. As the metal, stainless steel, phosphor bronze, etc. are effective. Since the surface finishing of the outer peripheral surface can be performed at the time of processing the auxiliary shaft sealing device, the number of processed parts can be reduced and the work is simple.

Further, the fixing to the rotary main shaft is performed by the thick wall portion for fixing the shaft provided at the one end of the hollow portion, but the hollow portion may be fixed by press-fitting to the rotary main shaft. The seal between the auxiliary shaft sealing device and the boss 1 is
In view of the small sliding area with the rotating main shaft, the lip seal is generally used.

With the above construction, the auxiliary shaft sealing device 26 is integrally fixed to the rotating main shaft 2 and rotates in accordance with the rotation of the rotating main shaft. Further, the lip seal 11 directly contacts and seals the outer peripheral surface of the auxiliary shaft sealing device, and the lip piece 11a does not slide directly on the outer peripheral surface of the rotary spindle 2.

[0021]

As described above in detail, according to the present invention, the first shaft sealing device fixedly installed on the outer peripheral portion of the rotary shaft and installed between the first shaft sealing device and the rotary shaft. Since the structure is provided with the second shaft sealing device that rotates following the rotation of the rotary shaft, when the new shaft sealing device is adopted instead of the existing shaft sealing device, the existing rotary shaft It is not necessary to improve the surface treatment of the above, and it is possible to easily provide the shaft sealing device according to the intended purpose. Therefore, for example, when changing to an alternative refrigerant while maintaining the specifications of an existing air conditioner, the shaft sealing device can be easily changed. Therefore, the shaft sealing device according to the present invention can be used as an alternative refrigerant corresponding kit for an air conditioner (so-called, It can be used as a retrofit kit).

Furthermore, since the second shaft sealing device according to the present invention does not need to improve the surface finish of the rotary shaft machined for the ready-made shaft sealing device, it can be manufactured by simply improving the structure. The product can be used continuously.

Further, since it has a hollow portion for penetrating the rotary shaft, it can be easily mounted on the rotary shaft. Further, the hollow portion has a structure in which a part of the inner diameter of the hollow part is made small, so that the hollow shaft is firmly fixed to the rotary shaft. Therefore, even if the centrifugal force generated at the time of rotation acts, it is hard to come off.

[Brief description of drawings]

FIG. 1 is a sectional view of a product in which a shaft sealing device according to the present invention is used.

FIG. 2 is an enlarged sectional view of a second shaft sealing device.

FIG. 3 is a sectional view of an example of a conventional shaft sealing device.

FIG. 4 is a sectional view showing another example of a conventional shaft sealing device.

FIG. 5 is a sectional view showing another example of a conventional shaft sealing device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Boss part, 2 ... Rotating main shaft, 11 ... 1st shaft sealing device (lip seal), 11a ... Lip piece, 11b ... Lip body,
14 ... O-ring, 26 ... Second shaft sealing device (auxiliary shaft sealing device), 26a ... Shaft fixing thick portion, 27 ... O-ring

Claims (3)

[Claims] 1. A shaft sealing device for slidingly contacting a rotating shaft and an outer peripheral surface of the rotating shaft to seal between two regions divided in the longitudinal direction of the rotating shaft, the device being fixedly installed outside the rotating shaft. A first shaft sealing device, and an outer peripheral surface that is installed between the first shaft sealing device and the rotating shaft and is in sliding contact with the first shaft sealing device. A shaft seal device for a rotating shaft body, comprising: a second shaft seal device that is driven and rotated. 2. The shaft of the rotary shaft body according to claim 1, wherein the second shaft sealing device has a hollow portion through which the rotary shaft penetrates, and is integrally fixed to the rotary shaft. Sealing device. 3. The shaft sealing device for a rotating shaft body according to claim 1, wherein a part of an inner diameter of the hollow portion of the second shaft sealing device is reduced.