JPH01200073A - Mechanical seal of compressor - Google Patents

Abstract

PURPOSE:To secure the high gas sealing performance by the simple constitution by interposing a magnetic fluid seal between a sealing ring which constitutes the mechanical seal of a refrigeration cycle compressor and a sealing plate. CONSTITUTION:The titled mechanical seal has a cylindrical seal plate 21 arranged in a through hole on a compressor casing and a sealing ring 23. and O-rings 7 and 9 are fitted in a groove 32 formed on the outer peripheral surface of the sealing plate 21 and a stepped part 36 formed on the inner peripheral surface of the sealing ring 23. The O-ring 9 is nipped between a seat metal 15 which receives a spring 13 and the sealing ring 23. In this case, a magnetic fluid deal 24 is interposed between the sealing plate 21 and the sealing ring 23. The magnetic fluid seal 24 is constituted by accommodating a magnetic fluid 25 into the space formed between an inner cylinder 27 fixed onto the sealing ring 23 and an outer cylinder 29. Further, a pole piece 47 consisting of a permanent magnet is fixed onto the magnetic fluid seal 24 side on the seal plate 21.

Description

[Detailed description of the invention] [Industrial use! I'F] The present invention relates to a compressor that operates a refrigeration circuit in cycles, and particularly to a mechanical seal thereof.

[Prior Art] This type of compressor generally includes a compression mechanism section inside a casing, and drives the compression mechanism section by rotating a main shaft passing through gauging. In that case, in addition to the bearing, the part where the main shaft penetrates the casing is provided with a mechanical seal that seals the inside and outside of the gauging (for example, Japanese Patent Publication No. 6J-43 et al. 55
(Refer to Publication No. ″).

In a conventional mechanical seal, as shown in FIG. 4, a cylindrical seal plate 1 and a felt ring 3 arranged in a through hole of a casing (not shown) are butted against each other with the same axis. There is. A groove 5 is formed on the outer peripheral surface of the seal plate 1. This groove 5 has an 0 ring 7
is embedded. 0 ring 7 is seal plate 1'
This is for sealing between the hole wall of the gauging through hole and the hole wall of the gauging through hole. A stepped portion 9 is formed on the inner surface of the felt ring 3. An O-ring 11 is provided on this stepped portion. The O-ring 11 is a washer 15 that receives the spring 13.
and felt ring 3. Spring 13 is held between washer 15 and case 17. The case 17 is fixed to the felt ring 3 at a portion extending along the outer peripheral surface of the felt ring 3.

[Problems to be solved by the invention] In the above mechanical seal, the seal plate 1
Since the contact portion 18 of the felt ring 3 wears out over time, there is a problem that, for example, oil inside the compressor may leak. Therefore, it is strongly required to improve the assembly accuracy and finishing accuracy of the seal plate 1. Further, when the compressor is vertically driven downward by the shaft, the mechanical seal is constantly immersed in oil, making it more likely that oil will leak.

Therefore, the problem of the present invention is to solve the problem of r! No damage due to J rubbing,
An object of the present invention is to provide a mechanical seal that has excellent airtightness and is easy to process.

[Means for Solving the Problems] According to the present invention, in a mechanical seal provided around the main shaft of a compressor for cycling a refrigeration circuit, seal rings are fitted on the outside of the main shaft and are opposed to each other in the axial direction. A mechanical seal for a compressor is obtained, which includes a sealing plate, a magnetic fluid interposed between the seal ring and the sealing plate, and a permanent magnet that holds the magnetic fluid.

[Function] According to the mechanical seal of the present invention, the magnetic fluid is held between the seal ring and the sealing plate by the permanent magnet. As a result, the gap between the seal ring and the sealing plate I is filled with the magnetic fluid.

Embodiment] FIG. 1 shows a mechanical seal according to an embodiment of the present invention. Note that the same parts as in FIG. 4 are designated by the same reference numerals, and their explanation will be omitted.

The illustrated mechanical seal has a cylindrical seal plate 21 and a seal ring 23. Seal plate 21
and the seal ring 23 are provided with the same axis. A main shaft (not shown) is inserted inside the seal plate 21 and the seal ring 23.

A magnetic fluid seal 24 is interposed between the seal plate 21 and the seal ring 23. Magnetic fluid seal 24
Referring also to FIG. 2, the inner cylinder 27 fixed to the seal ring 23 and the outer cylinder f! ! A magnetic fluid 25 is housed in a case 30 formed by i29. A pole piece 47 made of a permanent magnet is fixed to the seal plate 21 on the side facing the magnetic fluid 25. The magnetic fluid 25 is made of ferrite, magnetite, or the like. As a result, the magnetic fluid 25 is
The air is sucked towards the area and airtightly seals the gap.

A ring-shaped stopper 32 is formed on the outer peripheral surface of the seal plate 21 . An O-ring 7 is fitted into this gap 32. A step portion 36 is formed on the inner wall surface of the seal ring 23 on the opposite side from the magnetic driftwood 25. This stepped portion 36 is provided with an O-ring 9.

According to the above-mentioned mechanical seal, even if the O-ring 7 is damaged due to wear, oil such as lubricating oil or refrigerating machine oil is prevented from flowing out from inside the compressor.

FIG. 3 shows another embodiment of the seal plate 21. This sea plate 21 is entirely made of permanent magnets.

[Effects of the Invention] As explained above with reference to the embodiments, according to the mechanical seal of the present invention, a magnetic fluid is interposed between the seal ring and the seal plate, and the gap is sealed by the magnetic fluid. It has excellent airtightness and can prevent oil from flowing out from inside the compressor, regardless of the installation state of the compressor, even if the O-ring etc. are damaged due to wear. Additionally, the seal ring can be easily processed.

[Brief explanation of the drawing]

FIG. 1 shows a mechanical seal according to an embodiment of the present invention.
PI sectional view, Figure 2 is a front view showing the magnetic driftwood seal used in the mechanical seal in Figure 1, Figure 3 is a side sectional view showing another example of the seal plate, and Figure 4 is a conventional mechanical seal. FIG. 1; Seal plate, 3; Felt ring, 5; Eraser, 7
; 0 ring, 21: seal plate, 23; seal ring, 24; magnetic fluid seal, 25; magnetic fluid.

Claims (1)

[Claims] 1. A mechanical seal provided around the main shaft of a compressor that operates a refrigeration circuit in cycles, including a seal ring and a sealing plate that fit on the outside of the main shaft and face each other in the axial direction, and an intervening between the seal ring and the sealing plate. 1. A mechanical seal for a compressor, comprising: a magnetic fluid that has a magnetic fluid and a permanent magnet that holds the magnetic fluid.