JPH0540661U - mechanical seal - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] To provide a mechanical seal with a high degree of verticality of the sealing surface. [Structure] By changing the coefficient of thermal expansion or the coefficient of thermal contraction of the material of the rotating shaft X and the rotating ring 2, the rotating ring is brought into close contact with the rotating shaft under the use environment temperature, and the minute gap is eliminated. Therefore, the accuracy of the verticality of the end face of the rotary ring is improved, and the seal between the rotary ring and the rotary shaft is not necessary.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 This invention relates to a mechanical seal.

[0002]

[Prior Art]

 Mechanical seals are widely used in various fields as a sealing device around an axis of a device equipped with a rotary shaft. The mechanical seal makes sliding contact between the end face of the rotating ring that is directly or indirectly inserted through the collar and the like on the rotating shaft and the end face of the non-rotating ring that is mounted on the casing side, and seals at the sliding face. It is configured to do. Therefore, it is important that the end faces of the rotating ring and the non-rotating ring have the same angle, and normally, the faces are perpendicular to the axis, and the accuracy of the verticality of the end face is directly linked to the sealing performance. Also, it is necessary to seal between the rotary ring and the rotary shaft, and normally an O-ring is used to prevent leakage from the shaft periphery. The mechanical seal part can be cooled, but the shaft temperature is higher than that of other parts due to heat conduction from the main body side, so the O-ring cannot be used in a high temperature environment.

[0003]

[Problems to be solved by the device]

 However, there is a slight gap between the rotary ring and the rotary shaft, and when the rotary ring is fixed to the shaft, it is fixed with a set screw, so the rotary ring may tilt in the axial direction. There is a problem that the verticality of the sealing surface becomes out of order. Also, the gap between the rotary ring and the rotary shaft is usually sealed by the O-ring, but as described above, the temperature between the rotary shaft and the rotary ring becomes higher than other parts, so the turbine motor is In some cases, the O-ring cannot be used in high temperature environments such as when it is used. In such a case, as shown in FIG. 3, it is necessary to use a material that withstands high temperatures such as carbon fiber 53 instead of the O-ring, and use a packing retainer 54 or the like to hold down the structure, which makes the structure extremely complicated. There is a drawback. The present invention aims to solve such conventional problems.

[0004]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a mechanical seal including a rotary ring fitted and fixed to a rotary shaft and a non-rotary ring fitted to a casing side, wherein the material of the rotary ring is the material of the rotary shaft. It is characterized by using a material having a smaller coefficient of thermal expansion. According to a second aspect of the present invention, in a mechanical seal having a rotary ring fitted and fixed to the rotary shaft and a non-rotary ring fitted and fitted to the casing side, the material of the rotary ring shrinks more than the material of the rotary shaft. It is characterized by using a material with a high rate.

[0005]

[Action]

 By changing the coefficient of thermal expansion or contraction of the material of the rotating shaft and the rotating ring, the rotating ring is brought into close contact with the rotating shaft at the operating environment temperature, and the minute gap is eliminated. Therefore, the accuracy of the verticality of the end face of the rotary ring is improved, and the seal between the rotary ring and the rotary shaft is unnecessary. Even if the set screw is loosened due to mechanical vibration during operation, the rotary ring does not move in the axial direction and the sealing function is not impaired.

[0006]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, a collar 1 is mounted on a rotating shaft X, and a rotary seal ring 2 is fitted in and attached to a vertical surface 10 of the collar 1. That is, the verticality of the rotary seal ring 2 is defined as the verticality of the vertical surface 10, and the accuracy of the verticality of the collar 1 is the same as that of the rotary seal ring 2. The collar 1 is provided with a set screw 15 to restrict the movement of the collar 1 in the axial direction. The non-rotating seal ring 3 is fitted on the casing Y side, is configured to be driven in the axial direction, and is pressed in the direction of the rotating seal ring 2 by the spring receiver 4. The rotary seal ring 2 and the non-rotary seal ring 3 are in sliding contact with each other to form a seal surface S.

The material of the collar 1 has a smaller coefficient of thermal expansion than the material of the rotating shaft X. Under a high temperature environment, the expansion difference between the two causes the outer periphery of the rotating shaft X and the inner periphery of the collar 1 to be different. Are configured to be closely attached. Therefore, no seal is required between the inner circumference of the collar 1 and the outer circumference of the rotary shaft X, and it is not necessary to use a heat-resistant seal as shown in FIG. As the material of the rotary shaft X and the collar 1, specifically, the following combinations can be considered. That is, when the rotation axis X is an iron-based S45C, SCM material, SNC material, or the like, a low expansion material is used as the collar 1. When corrosion resistance is required, SUS304 SUS304, SUS316, SUS316C, etc. may be used as the material of the rotating shaft X, and Ti or Hastelloy may be used for the color 1.

In the embodiment shown in FIG. 1, the collar 1 is used and the rotary seal ring 2 is fitted on the collar 1. However, the collar 1 is not used and the rotary seal ring 2 is directly mounted on the rotation axis X. It is also possible to insert the rotary seal ring 2. An example of this is shown in FIG. In this embodiment, the rotary seal ring 2'is directly inserted into the rotary shaft X, and its movement in the axial direction is regulated by the set screw 15 '. As the material of the rotary seal ring 2 ′, the material of the collar 1 described above may be used in relation to the rotation axis X. In this configuration, as in the case of the collar 1, the inner circumference of the rotary seal ring 2'and the outer circumference of the rotary shaft X are brought into close contact with each other in a high temperature environment, and the accuracy of the seal surface S of the rotary seal ring 2 is increased. Further, since the rotary seal ring 2'and the rotary shaft X are in close contact with each other, no seal is required between them.

Although the material of the collar 1 has a smaller coefficient of thermal expansion than that of the rotation axis X in the above-described embodiment, conversely, if the coefficient of thermal contraction of the material of the collar 1 is larger than that of the rotation axis X, a low temperature is obtained. In the environment, there is an effect that the color 1 and the rotation axis X are brought into close contact with each other.

As described above, in the above-described embodiment, since the material of the collar 1 or the rotary seal ring 2'has a coefficient of thermal expansion smaller than that of the rotation axis X, the color 1 is used in a high temperature environment. Alternatively, the rotary seal ring 2 ′ and the rotary shaft X are brought into close contact with each other, and the accuracy of the verticality of the sealing surface is improved. Further, there is an effect that a seal is not required between the collar 1 or the rotary seal ring 2 ′ and the rotary shaft X, and it is not necessary to use a high temperature resistant seal or the like.

[0011]

[Effect of the device]

 As described above, according to the present invention, in the mechanical seal having the rotary ring fitted and fixed to the rotary shaft and the non-rotary ring fitted and inserted on the casing side, the material of the rotary ring is made of the material of the rotary shaft. Since the material has a low coefficient of thermal expansion, the accuracy of the verticality of the sealing surface is improved, and the sealing performance is improved. Further, there is an effect that the seal between the rotary shaft and the rotary ring becomes unnecessary.

[Brief description of drawings]

FIG. 1 is a half sectional view showing an embodiment of the present invention.

FIG. 2 is a half sectional view showing another embodiment of the present invention.

FIG. 3 is a half cross-sectional view showing the configuration when a high temperature resistant seal is used.

[Explanation of symbols]

1: Color, 2: Rotating sealed ring, 3: Non-rotating sealed ring, 4:
Spring receiver, 10: vertical surface, 15: set screw, 50: rotating ring, 51: non-rotating ring, 5: 0 ring,
53: carbon fiber, 54: packing retainer.

Claims (4)

[Scope of utility model registration request] 1. A mechanical seal comprising a rotating ring fitted and fixed to a rotating shaft and a non-rotating ring fitted to the casing side, wherein the material of the rotating ring has a smaller thermal expansion coefficient than the material of the rotating shaft. Mechanical seal characterized by the material. 2. A mechanical seal comprising a rotating ring fitted and fixed to a rotating shaft and a non-rotating ring fitted to the casing side, wherein the material of the rotating ring has a thermal contraction rate higher than that of the material of the rotating shaft. Mechanical seal characterized by the material. 3. The mechanical seal according to claim 1, wherein the rotary ring is a collar, and the rotary seal ring is attached to the collar. 4. The rotary ring is a rotary seal ring.
Or mechanical seal of 2.