JPH0131819Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement of a mechanical seal for sealing a rotating shaft portion of a device.

[Conventional technology]

Traditionally, it has been used as a type of mechanical seal, for example in car air conditioner compressors.
A structure as shown in FIG. 3 is known that seals freon gas, refrigerating machine oil, etc., and this mechanical seal is located on the inner circumference of the shaft hole 2 of the equipment housing 1 and on the outer circumferential surface of the rotating shaft 5. A spring retainer 9 and a rubber-like elastic material are connected to each other by a coil spring 8 which is airtightly inserted through an O-ring 15 made of a rubber-like elastic material and whose one end abuts against a metal case 7 that is fitted and fixed to a stepped portion 6 of the shaft 5. Torque is generated by being pressed in the axial direction via an annular damper 16 made of an elastic material, and by engaging with an engaging protrusion 10 extending from the peripheral end of the metal case 7 in a direction parallel to the shaft 5. The seal ring 11 on the rotating side to which the
The floating sheet 4 on the stationary side, which is airtightly fitted and fixed via the ring 3, is configured to closely slide against each other on the opposing sliding surfaces 4' and 11'.

[Problem that the invention attempts to solve]

In the above configuration, the damper 16 is connected to the shaft 5
However, if the damper 16 is eccentric due to the vibration due to some other cause, the coil spring 8 Sliding surface 4', 1
There was a problem in that the load applied to 1' was uneven in the circumferential direction, making the sealing performance unstable.

[Means for solving problems]

The mechanical seal according to the present invention was developed based on the above-mentioned circumstances, and includes a rubber-like elastic material packing interposed between the seal ring and the shaft for the purpose of maintaining airtightness, and the seal ring and the shaft. A damper interposed between the seal ring and the elastic means for pressing the seal ring is integrally formed.

[Effect]

That is, according to the present invention, since the damper is integrated with the packing that is in close contact with the outer circumferential surface of the shaft, it does not become eccentric due to vibration etc. as in the conventional structure, and therefore, the damper is The load applied from the elastic means to the sliding surface of the mechanical seal does not become unstable.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. In this embodiment, the same reference numerals are given to the parts having the same structure as those of the conventional structure shown in FIG. 3 described above, and the explanation thereof will be omitted, and only the different parts will be explained.

In the mechanical seal of this embodiment shown in FIG. 1, an annular elastic body 12 having an approximately quarter-note cross section is installed between a rotary-side seal ring 11, a shaft 5, and a spring retainer 9. The elastic body 12 has a shape that integrates the O-ring 15 and the damper 16 in the conventional mechanical seal shown in FIG. The O-ring part 13 has the function of holding the O-ring part 13, and the O-ring part 13 expands from the O-ring part 13 in the outer radial direction and is located between the rear surface of the rotary side seal ring 11 and the spring retainer 9. A damper portion 14 is provided which functions to eliminate adverse effects on the sliding surfaces 4' and 11'. Therefore, the damper portion 14 is always held in a concentric position with respect to the shaft 5, and does not become eccentric due to vibration or the like, so that the load from the coil spring 8 is stably transmitted to the rotating side seal ring 11. As a result, a good sliding condition of the sliding surfaces 4', 11' can be maintained. In addition, the spring retainer 9 is designed such that the pressure received from the coil spring 8 in the elastic body 12 is limited to the damper portion 14 to obtain an appropriate load, and the pressure received from the coil spring 8 in the elastic body 12 is limited to the damper portion 14 by the axial sliding of the O-ring portion 13. In order to eliminate this influence, the stepped portion 9a is formed so that its inner diameter portion 9b is separated from the O-ring portion 13.

Next, Figure 2 is a graph showing the results of a seal performance comparison test between the mechanical seal of this embodiment and the conventional mechanical seal under the following conditions.As is clear from this graph, the sample with the conventional structure Whereas large variations occurred in the amount of leakage, all of the samples of this example showed stable sealing performance. Furthermore, as a result of examining the post-test conditions of samples with conventional structures in which a large amount of leakage occurred, it was confirmed that the damper was eccentric in all cases, and the flatness of the sliding surface of the rotating side seal ring was impaired. Ta.

<Test conditions> Test machine: Actual car air conditioner compressor Rotation speed: 5500rpm Intermittent conditions: 25sec.ON/5sec.OFF Discharge pressure: 20Kg/cm ² Suction pressure: 2Kg/cm ² Liquid to be sealed: Freezer oil, Freon R- 12 Test time: 500 hours [Effects of the invention] As described above, the mechanical seal of this invention, by integrating the seal and the damper, prevents eccentricity of the damper due to vibrations, etc., and absorbs the load from the elastic means by sliding the seal. It can be applied stably to surfaces and ensure good sealing properties, and its practical effects are extremely large.

[Brief explanation of the drawing]

FIG. 1 is a half-cut sectional view showing an embodiment of the present invention;
FIG. 2 is a graph showing the test results, and FIG. 3 is a half-cut sectional view showing the conventional structure. 4... Stationary side floating seat, 4', 1
1'...Sliding surface, 5...Shaft, 8...Coil spring, 9...Spring retainer, 11...
...Rotating side seal ring, 12...Elastic body, 13...
...O-ring part, 14...damper part.

Claims (1)

[Scope of utility model registration request] A mechanical seal having a structure in which a rotating side seal ring that slides and rotates closely with a stationary side floating seat is axially biased by an elastic means such as a coil spring via a damper made of a rubber-like elastic material. A mechanical seal characterized in that the damper is integrally molded with a packing such as an O-ring made of a rubber-like elastic material that is interposed between the seal ring and the shaft for the purpose of maintaining airtightness.