JPH0138365Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to shaft sealing technology for rotating equipment, and the fluid to be sealed is sealed by close sliding between a rotating ring driven by a shaft and a fixed ring fixed to a housing. This relates to the improvement of mechanical seals for sealing.

[Conventional technology]

Conventionally, as shown in FIG. 6, a rotating ring b is fixed to a rotating shaft a side and driven by the shaft a, and a fixed ring d is fixed to a housing c side as a fixed member, and a spring e is used. Accordingly, the sliding rings b, d are changed to the sliding surfaces f, f of the sliding rings b, d.
A mechanical seal that slides closely and seals the fluid A to be sealed is known.

[Problem that the invention attempts to solve]

In this type of mechanical seal, the pressure of the fluid A to be sealed is directly applied to the outer peripheral side ends of both sliding surfaces f, f, and therefore, both sliding surfaces f, f
It was not uncommon for the fluid A to be sealed to leak from between the two. Therefore, a spiral groove is formed on the outer peripheral surface of the rotary ring b to cause the fluid to be sealed to flow outward. However, in order to sufficiently reduce the pressure of the sealed fluid A around the sliding surfaces f and f due to this outward flow, it is necessary to create a narrow fluid gap between the outer circumferential surface of the rotating ring b and the inner circumferential surface of the housing C. A passage must be formed. In other words, if the rotating ring b is placed outside the housing C, or if there is a large gap between the outer circumferential surface of the rotating ring b and the inner circumferential surface of the housing C, even if a spiral groove is formed, it will not be sealed. The pressure of fluid A cannot be lowered sufficiently.

Therefore, an object of the present invention is to provide a mechanical seal that can sufficiently reduce the pressure of the fluid to be sealed around the sliding surfaces f, regardless of the installation location of the rotating ring or the inner diameter of the housing. do.

[Means for solving problems]

In order to achieve this objective, the present invention is an inward flow type system that is comprised of a rotating ring attached to the shaft side and a stationary ring attached to the housing side and closely sliding with the rotating ring, and seals the fluid to be sealed. In the mechanical seal, an annular box is formed on a front end surface of one of the rotating ring or the stationary ring, and the box extends until it surrounds at least a part of the outer peripheral surface of the other of the rotating ring or the stationary ring. A fluid passage is formed in the fluid passage, and in the fluid passage, a spiral groove causes the fluid to be sealed to flow outward, that is, an inner circumferential surface of a box forming the fluid passage and an inner circumferential surface of this box. A spiral groove is formed on at least one of the outer circumferential surfaces facing the .

[Effect]

In this invention, the fluid passage where the spiral groove should be formed is not formed between the inner peripheral surface of the housing and the outer peripheral surface of the rotating ring, but on the front end surface of one of the rotating ring or the fixed ring. is formed between the annular box and the other outer peripheral surface of the rotating ring or the stationary ring.

〔Example〕

Hereinafter, embodiments of the mechanical seal according to the present invention will be described in detail with reference to the drawings.

First, in FIGS. 1 to 3, 1 is a rotating shaft, 2 is a rotating ring fixed to the shaft 1 side and driven by this, and 3 is a fixed ring fixed to the non-rotating housing 4 side, and the housing A spring 6 disposed on the case 5 fitted in the stepped portion of the four-axis hole presses the rear surface through a washer 7, and its tip comes into sliding contact with the rotating ring 2, and the sliding surfaces 8, 8 are pressed against each other through the washer 7. I am doing it. Further, an annular box 10 is formed on the outer periphery of the fixed ring 3 so as to surround the outer periphery of the sliding end 9 of the rotating ring 2, and the inner circumferential surface of the box 10 and the opposing rotating ring 2 The sliding surfaces 8, 8 are formed on the outer peripheral surface of the sliding end portion 9 by the rotation of the rotating ring 2 and the accompanying rotational flow of the sealed fluid A'.
Spiral grooves 11 and 12 are formed so that the fluid A' to be sealed, which has reached the outer circumference of the seal, is discharged by its pumping action.

Since this embodiment is configured as described above,
When the rotating ring 2 rotates following the rotating shaft 1, the outer periphery of the sliding surfaces 8, 8 is pumped by the pumping action of the spiral groove 11 carved on the outer peripheral surface of the sliding end 9 of the rotating ring 2. Sealed fluid entering the
Pressure is generated in a direction that causes the rings 2 and 3 of A' to be discharged to the outside. Further, in the fluid A' to be sealed that comes into contact with the outer circumferential surface of the sliding end 9 of the rotating ring 2, rotational flow occurs as the rotating ring 2 rotates due to the frictional force with the outer circumferential surface. The sealing fluid A' attempts to make a helical movement in a direction in which it is discharged along a helical groove 12 formed in the inner circumferential surface of the box 10 at a portion that contacts the inner circumferential surface of the box 10. Therefore, the sliding surfaces 8, 8
The pressure of the sealed fluid A' applied to the outer periphery of
This has the effect of reducing the amount of leakage of A'.

In addition, in FIGS. 1 to 3, the spiral groove 1
1 and 12 are each carved into a small single-thread shape of a lead, but as shown in FIGS. ', 12', . . . may be carved, and in this case, the pumping action will be even greater.

Further, in the above embodiment, the annular box was provided on the fixed ring, but the box may not be provided on the fixed ring but may be provided on the rotating ring. Although the spiral grooves are carved on both the inner circumferential surface and the outer circumferential surface of the sliding end, the above effects can be sufficiently achieved even if the spiral grooves are carved on only one of them. .

〔effect〕

As explained above, the mechanical seal of the present invention forms a fluid passage between the annular box formed on the front end surface of one of the rotating ring or the fixed ring and the outer peripheral surface of the other rotating ring or the fixed ring, Since this fluid passage causes the fluid to be sealed to flow outward through the spiral groove, the pressure of the fluid to be sealed around the sliding surface can be reduced regardless of the installation location of the rotating ring or the inner diameter of the housing. This can be lowered sufficiently to prevent its leakage.

[Brief explanation of the drawing]

Fig. 1 is a half-cut sectional view showing one embodiment of the mechanical seal according to the present invention, Fig. 2 is a front view of the rotary ring, Fig. 3 is a sectional view of the fixed ring, and Fig. 4 is a mechanical seal other than the present invention. FIG. 5 is a sectional view of the fixed ring, and FIG. 6 is a half-cut sectional view showing an example of a conventional mechanical seal. 1... Shaft, 2... Rotating ring, 3... Fixed ring, 4... Housing, 5... Case, 6... Spring, 7... Washer, 8, 8... Sliding surface, 9...
...Sliding end, 10...Box, 11, 11',
12, 12'...Spiral groove, A'...Fluid to be sealed.

Claims (1)

[Scope of utility model registration request] In an inward flow type mechanical seal that seals the fluid to be sealed, the seal is composed of a rotating ring attached to the shaft side and a fixed ring attached to the housing side and closely slides with the rotating ring. An annular box is formed on the front end surface of one of the rings, and the box extends to surround at least a part of the other outer peripheral surface of the rotating ring or the stationary ring to form a fluid passage. The mechanical seal is characterized in that a spiral groove causes the fluid to be sealed to flow outward.