JPS6234055Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a mechanical seal device used in various pumps and the like.

The conventional mechanical seal device generally includes a stationary ring and a rotating ring that form a sealing sliding surface.
Since the casing and the rotating shaft are each fixedly attached to each other, relative fluctuations between the rotating shaft and the casing, temperature rise inside the machine, etc. may cause surface runout or pressure force on the sealed sliding surface. This has the disadvantage that the sealing performance becomes unstable.

The present invention relates to an idea to eliminate the above-mentioned drawbacks of conventional mechanical seal devices, and includes a stationary ring disposed on the side of the casing that surrounds the rotating shaft, and one side surface abutting the stationary ring. a rotating ring having a rectangular cross section and a sealed sliding surface; a holder fixed to the rotating shaft and having an annular recess having a rectangular cross section on an inner end surface; The rotating ring is elastically supported independently from the holder by interposing O-rings between the outer peripheral surface of the rotating ring and the annular recess and between the other side of the rotating ring and the annular recess. It is characterized in that the space formed between the two O-rings, the rotary ring, and the holder is communicated with the atmosphere through a communication path formed in the holder. The purpose of this invention is to provide a mechanical seal device that allows its constituent members to follow the surface runout of the seal sliding surface, eliminates the influence of internal temperature rise, etc., and stabilizes the sealing performance.

The present invention has the above-mentioned configuration, in which a rotating ring with a rectangular cross section whose one side is in contact with a stationary ring to form a sealed sliding surface is attached to the inner end surface of a holder fixed to the rotating shaft side. The rotary ring is arranged in an annular recess having a rectangular cross section, and an O-ring is interposed between the outer peripheral surface of the rotary ring and the annular recess and between the other side of the rotary ring and the annular recess. Elastically supported independently from the holder,
In addition, the cavity formed between both O-rings, the rotating ring, and the holder is communicated with the atmosphere through a communication path provided in the holder, so even if relative fluctuations occur between the rotating shaft and the casing, The sliding surface of the rotating ring moves to follow the sliding surface of the stationary ring, preventing surface runout on the sealing sliding surface, keeping the pressure contact approximately constant, and furthermore, reducing the pressure between the rotating ring and the holder. Due to the cavity formed in the chamber and communicated with the atmosphere, fluctuations in the pressure contact force at the sealing sliding surface due to temperature rise inside the machine, leakage of fluid inside the machine, etc. are significantly reduced, and stable high sealing performance can be obtained.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In the figure, 1 is a rotating shaft, 2 is a shaft sleeve, and 3 is a holder for a rotating ring that is equipped with an O-ring 4 for sealing the shaft and is fixed to the rotating shaft 1. The inner end surface of the holder 3 (left side in the figure) An annular recess 3' having a rectangular cross section is formed in the annular recess 3', and a rotating ring 5 is disposed and supported in the annular recess 3' as will be described later. Reference numeral 16 denotes a casing surrounding the rotating shaft 1, in which a flushing water introduction ring 15 and a bellows support ring 14 are fixed, and are connected to the support ring 14 via the bellows 13. A stationary ring 11 is fixedly disposed on a holder 12.

Further, the rotating ring 5 has one side surface (the left side surface in the drawing) in contact with the sliding surface (the right side surface in the drawing) of the stationary ring 11 to form a sealed sliding surface a, and the other side An O-ring 9 is interposed between the side surface (the right side surface in the figure) and the inner surface of the annular recess 3' of the holder 3, which elastically supports the rotating ring 5 on the stationary ring 11 side and has a sealing function on the side surface side. The O-ring 9 is disposed in an O-ring groove formed on the inner surface of the recess 3'. Also, the outer circumferential surface (upper side shown)
and an O-ring 8 having an elastic support and sealing function is interposed between the inner upper surface of the annular recess 3' of the holder 3,
Furthermore, a pin 7 screwed from above the holder 3 is inserted into the ring 6 that is shrink-fitted to the outside of the outer circumferential surface.
The rotating ring 5 is rotated together with the holder 3,
In addition, the rotary ring 5 is movably disposed on the holder 3 toward the stationary ring 11 side.

In addition, both the O-rings 8 and 9 and the rotating ring 5
A cavity b is formed between the inner surfaces of the annular recess 3' of the holder 3, and the cavity b is communicated with the atmosphere through a communication passage 10.

In addition, 18 in the figure is the flushing water introduction chamber, 1
Reference numeral 9 denotes an in-machine compartment in which the in-machine fluid c exists.

The illustrated embodiment has the above-described structure, so that the stationary ring 11 receives the fluid pressure in the introduction chamber 18 and the interior chamber 19, while the rotating ring 5 receives the fluid pressure on the other side and the outer peripheral side. Elastically supported by both O-rings 9 and 8, the stationary ring 11 and the rotating ring 5 are brought into contact with each other with a predetermined pressing force, and as the rotating shaft 1 rotates, the rotating ring 5 also contacts the stationary ring 11 via the holder 3. The sealing sliding surface a portion is formed by pressing against the sliding surface of the sealing surface and rotating. Therefore, the fluid c in the cabin 19 is sealed against the atmosphere side A.

Even if a relative displacement occurs between the rotating shaft 1 and the casing 16 when the rotating shaft 1 is driven to rotate, the rotating ring 5 is movably attached to the holder 3 and is elastically supported by both O-rings 8 and 9. Since the sliding surface of the stationary ring 11 is
The sliding surfaces of the slider move accordingly, preventing surface runout, and the pressure contact force between the two sliding surfaces remains almost unchanged.
The sealing function of the sealing sliding surface a section is stable.

Furthermore, a cavity b is formed by both O-rings 8 and 9 between the rotating ring 5 and the annular recess 3' of the holder 3, and the cavity b is communicated with the atmosphere side A through a communication passage 10. , the cavity b reduces the temperature rise near the rotating ring 5 and the local pressure increase due to leakage of the fluid c inside the machine, stabilizes the contact force on the sealing sliding surface a, and allows the rotating ring 5 to slide smoothly. , rotated. Therefore, stable and high sealing performance can be obtained.

[Brief explanation of the drawing]

The drawing is a longitudinal sectional view of a mechanical seal device showing an embodiment of the present invention. 1: rotating shaft, 3: holder, 3': annular recess,
5: rotating ring, 6: ring, 7: pin, 8,
9: O-ring, 10: Communication path, 11: Stationary ring, 12: Stationary ring holder, 13: Bellows, 14: Support ring, 15: Introduction ring, 1
6: Casing, a: Sealed sliding surface, b: Vacant room.

Claims (1)

[Scope of utility model registration request] a stationary ring disposed on the casing side surrounding the rotating shaft; a rotating ring with a rectangular cross section whose one side is in contact with the stationary ring to form a sealed sliding surface; Equipped with a holder that is fixed and has an annular recess with a rectangular cross section formed on the inner end surface.
The rotating ring is arranged in the annular recess of the holder, and O-rings are interposed between the outer circumferential surface of the rotating ring and the annular recess and between the other side of the rotating ring and the annular recess, and the rotating The ring is elastically supported independently of the holder, and the hollow space formed between the O-ring, the rotary ring, and the holder is communicated to the atmosphere through a communication path formed in the holder. Mechanical seal device.