JPH067221Y2 - mechanical seal - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a static type / inward flow type mechanical seal used for axially sealing a rotating shaft of a machine body.

[Conventional technology]

Conventionally, in this type of mechanical seal, as illustrated in FIG. 3, a mating ring (3), which is a rotary ring, is provided around the circumference of a rotary shaft (2) inserted in a seal box (1) of an airframe. The mating ring (3) is fitted and held by the collar (5) which is tightened by the set screw (4), and the knock pin (6) protruding from the collar (5) is attached to the mating ring (5). While fixing by engaging with (3), attach the seal cover (9) fixed to the atmosphere side (A) of the seal box (1) with the bolt (8) via the intermediate seal cover (7). (9) and the intermediate seal cover (7), the coil spring (10) in the inner diameter portion formed.
And the biasing force of this coil spring (10) to the retainer (11).
Arranged with the compression ring (13) that is transmitted to the seal ring (12) which is a fixed ring via, the knock pin (14) projected on this compression ring (13) is engaged with the retainer (11), And, the compression ring (13), the seal cover (9) and the intermediate seal cover (7)
By locking the long drive pin (15) bridged along the axial direction of the inner diameter formed by
There is a structure in which the seal ring (12) is assembled in a cartridge type so as to be pressed and slidably contacted with the mating ring (3) and integrated.

And, in such a conventional mechanical seal, the sliding portion between the mating ring (3) and the seal ring (12) from the flushing hole (not shown) facing the seal box (1) of the machine body. Flushing is performed by injecting and extracting the self-liquid into.

[Problems to be solved by the device]

However, in the above-described conventional structure, in particular, as the coil spring (10) arranged in the inner diameter portion formed by the seal cover (9) and the intermediate seal cover (7), a long coil spring of equal diameter is used. Was used, so that the mounting length of the seal cover was lengthened in the axial direction, and it was not possible to assemble it compactly.

Also, since the compression ring (13) must be axially movable, this compression ring (1
The knock pin (15) for stopping the rotation of 3) requires a certain length, and the moment arm becomes long. Therefore, for example, if the liquid to be sealed is a liquid containing a large amount of slurry or a liquid with high viscosity and high pressure, the seal ring (1
When the sliding torque transmitted from 2) was large, the resistance of the knock pin (15) was a problem.

Further, since the leaked liquid is likely to collect in the inner diameter portion of the seal cover, there is a problem in that the leakable liquid easily solidifies by entering the coil spring and causing malfunction.

[Means for Solving the Problems]

In order to solve the above-mentioned problems, the mechanical seal of the present invention fixes a rotary ring around the axis of a rotary shaft inserted in a seal box of an airframe, while fixing a case to the atmosphere side of the seal box, In this case, a fixed ring that is in sliding contact with the rotating ring, a conical coil spring that urges the fixed ring toward the rotating ring, and a fixed ring that is interposed between the conical coil spring and the fixed ring and is circumferentially formed with the fixed ring. The engaged compression ring is incorporated, and a projection formed on the outer circumference of the compression ring is axially movably engaged with a notch extending in the axial direction formed in the case.

[Action]

In the present invention, a conical coil spring is used as a spring for urging the fixed ring, so that the mounting length of the mechanical seal on the stationary side is shortened to achieve compactness. In addition, the protrusion formed on the outer circumference of the compression ring that engages with the fixed ring engages with the notch of the case that is integrally fixed to the seal box of the machine body so that it can move in the axial direction. It has sufficient resistance to torque increase in the case of slurry, high viscosity or high pressure liquid. Moreover, since the notch for preventing the rotation formed in the case also has a function of promptly discharging the leaked liquid to the outside, it is possible to prevent malfunction of the coil spring due to solidification of the leaked liquid.

〔Example〕

Hereinafter, the mechanical seal of the present invention will be described with reference to FIGS.
Description will be given with reference to an embodiment shown in the drawing.

In the figure, (21) is a seal box of the fuselage, the rotary shaft (22) is inserted through the inner periphery thereof, the mating ring (23) is a rotary ring around the rotary shaft (22) Seal Box (2
It is located in the part located in 1). This mating ring (23) consists of a set screw (24) and the rotary shaft (22).
The collar (26), which is fastened and fixed to the shaft circumference of the shaft through the first O-ring (25), is fitted and held from the outside in a loosely fitted state through the second O-ring (27), and The first knock pin (28) protruding from the collar (26) is attached to the mating ring.
By engaging with (23), rotation is prevented, and these mating ring (23), set screw (24), first screw
The O-ring (25), the collar (26), the second O-ring (27) and the first knock pin (28) constitute a moving side assembly operation part.

On the other hand, a case (30) is fixed to the inner diameter portion of the seal box (21) of the airframe on the atmosphere side (A) via a gasket (29), and the case (30) is fixed to the inner periphery as described later. A small diameter mouth portion (30a) supporting a seal ring (34) as a ring via a third O-ring (35) and a large diameter extending from this small diameter mouth portion (30a) to the atmosphere side (A) in a cylindrical shape. It consists of a caliber (30b).

A coil spring (31) wound in a conical shape is arranged in the large-diameter mouth portion (30b).
(31) has one end (31a) on the large diameter side positioned on the atmosphere side (A) and is assembled and held by a snap ring (32), while the other end (31b) is a compression ring (33). Is in contact with. The seal ring (34) has a second knock pin (36) projecting from the end surface of the compression ring (33).
Is engaged with. Also, projections extending in the radial direction are provided at evenly distributed locations on the outer peripheral surface of the compression ring (33).
(37) is formed, and the large-diameter mouth portion (30) of the case (30) is formed.
In the axially extending notch (38) formed in b) corresponding to this projection (37) in a topological manner, the axially movable portion is engaged,
This prevents the seal ring (34) from rotating. Then, these cases (30) and coil springs (3
1), snap ring (32), compression ring (3
3), the seal ring (34) and the third O-ring (35) constitute a stationary side assembly operation part.

That is, the present invention elastically presses the stationary side seal ring (34) against the moving side mating ring (23) assembled around the rotary shaft (22) in the seal box (21) of the airframe. As the coil spring (31) to be brought into sliding contact, a conical spring wound in a conical shape is used, and the end on the atmosphere side of this conical spring is locked by the snap ring (32) to perform another assembly operation. By assembling together with the parts in the case (30),
The stationary side assembly is made compact, its mounting length is shortened, and the use of retainers such as the conventional mechanical seal is not required, and the radial volume of the seal ring (34) is reduced, thereby It can be installed in a narrow shaft seal.

The compression ring (33), which presses the seal ring (34) and engages with the seal ring (34) in the circumferential direction, has the projection (37) formed on the outer peripheral surface thereof, and the case (30). Since it is prevented from rotating by engaging with the notch (38) formed in the large-diameter mouth portion (30b), unlike the conventional rotation stopper using an axially long knock pin, the sealed space ( When the fluid of B) is a high slurry, high viscosity or high pressure liquid, it is possible to sufficiently cope with a large torque transmitted from the seal ring (34) through the compression ring (33). Moreover, the notch (3
8) promptly discharges the liquid leaked from the sealing sliding surface (39) between the mating ring (23) and the seal ring (34) to the inner circumference of the case (30) to the outside of the case (30). If the liquid to be sealed is a liquid that is easily solidified, the leaked liquid will stay in the inner circumference of the case (30) and the coil spring (3
It is also possible to prevent the problem that the operation on the stationary side is hindered by the adhesion and solidification to 1).

[Effect of device]

As is apparent from the above description, according to the present invention, the mounting length on the stationary side can be shortened by using the coil spring wound in a conical shape as the means for urging the seal ring in the axial direction. In addition, since the compression ring to which the sliding torque from the seal ring is transmitted is stopped by the notch formed in the case, it has sufficient resistance to large torque, and therefore high slurry, high viscosity or It can be used even under the condition that high-pressure liquid is sealed, and the notch for preventing rotation that is formed in the case quickly discharges the leaked liquid to the outside of the case and operates by sticking the leaked liquid to the coil spring. It prevents the deterioration of sex.

[Brief description of drawings]

FIG. 1 is a half sectional view showing an embodiment of a mechanical seal according to the present invention, FIG. 2 is a sectional view taken in the direction of the arrow X in FIG. 1, and FIG. 3 is a half sectional view showing an example of a conventional mechanical seal. is there. (21) Aircraft seal box, (22) Rotating shaft, (23) Rotating ring (Mating ring), (30) Case, (31) Coil spring, (33) Compression ring, (34) Fixed ring (Seal ring) ), (37) protrusion, (38) notch

Claims (1)

[Scope of utility model registration request] 1. A fixing means for fixing a rotary ring around an axis of a rotary shaft inserted in a seal box of a machine body, a case fixed to the atmosphere side of the seal box, and slidingly contacting the rotary ring in the case. A ring, a conical coil spring that urges the fixed ring toward the rotating ring, and a compression ring that is interposed between the conical coil spring and the fixed ring and that engages with the fixed ring in the circumferential direction are incorporated into the case. A mechanical seal characterized in that a projection formed on the outer circumference of the compression ring is engaged with a notch extending in the axial direction so as to be movable in the axial direction.