JPH0139972Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to shaft sealing technology, and in particular to improvement of a floating sheet for mechanical seals that has excellent high pressure resistance and vibration resistance.

[Conventional technology]

Conventionally, as a floating seat a of a mechanical seal, as shown in FIG. It is inserted airtightly through an O-ring d, the rear end is brought into contact with the bottom wall surface of the annular step c, and the knock pin d provided upright on the bottom wall surface is engaged with the notch e in the rotating direction. The sliding protrusion f slides closely against the sliding surface of a seal ring g that is airtightly supported on the shaft side, thereby sealing the shaft.

[Problem that the invention attempts to solve]

As described above, the floating seat a has its rear end surface in direct contact with the housing b, so that it does not perform a buffering action in the axial direction. With this configuration, it is possible to achieve excellent high pressure resistance so that the sealing function does not deteriorate even when the sealing fluid becomes high pressure. That is, a sealed fluid pressure is acting on the outer portion of the front end surface of the floating sheet a, pushing the floating sheet a rearward in the axial direction. Therefore, floating sheet a
If a buffer member is provided between the rear end surface and the housing b to perform a buffering action on the floating seat a, when the sealing fluid becomes high pressure, the floating seat a will be moved rearward in the axial direction by this sealing fluid. This causes the contact pressure on the sliding surfaces to drop significantly, resulting in a large amount of leakage.

However, in such a configuration, when the rotating shaft vibrates in the axial direction, the contact pressure on the sliding surface becomes excessive, causing chips and cracks on the sliding surface, resulting in large amounts of leakage, or extremely low contact pressure, resulting in leakage. It had the disadvantage that the amount was large, and there was a problem with vibration resistance.

Therefore, an object of the present invention is to provide a floating sheet for mechanical seals that has excellent high pressure resistance and vibration resistance.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention includes a cylindrical case fitted into the inner periphery of the support member, and a sliding protrusion formed on the inner part of the front end surface. a floating seat body disposed inside the cylindrical body case; a radial buffer ring provided between the outer peripheral surface of the floating seat body and the cylindrical body case; an axial buffer ring provided between the inner part of the rear end surface and the cylindrical case, and the cylindrical case introduces a sealing fluid to the outer part of the rear end surface of the floating seat body. A communication path is formed.

[Effect]

In the present invention, an axial buffer ring is provided between the inner part of the rear end surface of the floating seat body and the cylindrical body case, so that the floating seat body performs a buffering operation in the axial direction.

In addition, since the cylindrical case has a communication path that guides the sealing fluid on the outer side of the rear end surface of the floating seat body, the floating seat body may be moved in the axial direction by the sealing fluid. This makes it possible to prevent

〔Example〕

An embodiment of the floating sheet of the present invention will be described below with reference to FIG. The floating seat is comprised of a cylindrical floating seat body 1 that is fitted around the rotating shaft 15 and a cylindrical body case 2 that is airtightly inserted and supported in the shaft hole 16a on the housing 16 side via an O-ring 17. A notch 3 formed at the rear end of the cylindrical body case 2 is engaged with a knock pin 18 protruding from the front surface of the shaft hole 16a to prevent rotation. 4 is floating sheet body 1
It is an annular sliding protrusion formed on the front end surface of the cylindrical body case 2, and constitutes a small diameter part 1b continuous to the large diameter part 1a, and the large diameter part 1a is connected to the large diameter part 2a of the cylindrical body case 2.
It is inserted and supported in the radial direction via an O-ring 6, which is a radial buffer ring that fits into a circumferential groove 5 formed in the groove. Further, the small diameter portion 1b is inserted into the small diameter portion 2b of the cylindrical case 2, and an O-ring 7, which is an axial buffer ring, is placed in an annular space formed between both walls thereof and by the front end surface 2c and the rear end surface 1c. The structure is such that an axial buffer ring is provided between the inner part of the rear end surface 1c of the floating seat body 1 and the cylindrical body case 2, and the floating seat body 1 is fitted in the axial and radial directions. It is supported airtightly, and 8 is a back-up spring for adjusting the length in the axial direction. The above cylindrical body case 2
A dowel pin 9 is provided protrudingly on the inner diameter of the floating seat body 1 inserted into the cylindrical body case 2.
It engages with a notch 10 formed at the rear end of the small diameter portion 1b to prevent rotation. Reference numeral 11 denotes a communication hole that communicates the annular space between the O-rings 6 and 7 with the sealed fluid chamber 12, which forms a communication path together with the groove on the outer peripheral surface of the cylindrical body case 2, A sealing fluid is introduced into the outer portion of the rear end face 1c.

Note that 19 is a seal ring that closely slides on the sliding protrusion 4 of the floating sheet body 1 on the sliding surface 19a.

In the mechanical seal having the above configuration, the floating seat main body 1 is supported by two O-rings 6 and 7 provided in the radial direction and the axial direction with respect to the cylindrical case 2 supported on the housing 16 side. Therefore, the O-rings 6 and 7 have a degree of freedom in three-dimensional directions, and the vibrations of the rotating shaft 15 are absorbed by the O-rings 6 and 7. Therefore, the influence of vibration on the sliding surface of the floating sheet main body 1 is small, and stable and close sliding with the seal ring 19 is maintained.

Further, the sealing fluid is introduced into the annular chamber formed by the O-rings 6, 7, the floating seat body 1, and the cylindrical body case 2 through the communication hole 11, and the back pressure of the floating seat body 1 against the sealing fluid is Since the pressure is balanced by increasing the pressure, the O-ring 7 will not be crushed even if the sealing fluid is under high pressure, and the contact pressure on the sliding surface will not drop significantly, resulting in a stable shaft sealing effect. will be able to demonstrate this.

[Effect of idea]

As explained above, in the floating sheet for mechanical seals of the present invention, the floating sheet main body acts as a buffer in the axial direction, and can also prevent the floating sheet from moving in the axial direction due to the sealing fluid. It has excellent high pressure resistance and vibration resistance.

[Brief explanation of the drawing]

FIG. 1 is a half cut sectional view showing an embodiment of the floating sheet of the present invention, and FIG. 2 is a half cut sectional view showing a conventional floating sheet. 1... Floating sheet body, 1a, 2a
...Large diameter part, 1b, 2b... Small diameter part, 1c... Rear end surface, 2... Cylindrical body case, 2c... Front end surface,
3, 10... Notch, 5... Circumferential groove, 6, 7, 17,
24...O ring, 9, 18...Knock pin, 1
1...Communication hole, 12...Fluid chamber, 15...Rotation shaft, 16...Housing, 16a...Shaft hole, 19
……Seal ring.

Claims (1)

[Scope of utility model registration request] a cylindrical body case fitted into the inner periphery of the support member;
a floating seat body having a sliding protrusion formed on the inner side of the front end face and disposed inside the cylindrical body case; and a floating seat body provided between the outer circumferential surface of the floating seat body and the cylindrical body case. It consists of a radial buffer ring and an axial buffer ring provided between the inner part of the rear end surface of the floating seat main body and the cylindrical body case, and the floating seat body is attached to the cylindrical body case. A floating sheet for a mechanical seal, characterized in that a communication path for guiding a sealing fluid is formed in an outer portion of the rear end surface of the floating sheet.