JPS6039580Y2 - Fixed part structure of fixed sealing ring in mechanical seal - Google Patents

Description

[Detailed Description of the Invention] (1) Purpose of the Invention The present invention relates to a fixed part structure of a fixed sealing ring in a mechanical seal such as a submersible pump.

Conventionally, the fixed part of the fixed sealing ring in a mechanical seal is the gap between the outer circumferential surface I'd of the metal fixed sealing ring 1' and the inner circumferential surface 3'c of the ring groove, as shown in FIG. 9A. by interposing an O-ring 6', or as shown in Fig. 9B,
It has a structure in which an L-shaped rubber backing 6'' is adhered from the back end surface 1''b of the fixed sealing ring 1'' to the outer peripheral surface 1''d.

However, the one in which an O-ring 6' is interposed as shown in FIG. 9A has the disadvantage that the sealing portion is a line contact and the sealing effect of the gap G is poor.

Further, although it can be applied to metal objects, it is difficult to apply to fired crystals due to molding considerations.

On the other hand, when the L-shaped rubber backing 6' is adhered as shown in Fig. 9B, the back side of the fixed sealing ring 1'' becomes a heat insulating layer, so the heat dissipation property of the heat generated on the sliding surface is poor, and it does not last for a long time. If used, there is a risk that heat will accumulate and cause seizure on the sliding surface.

The object of the present invention is to eliminate such conventional drawbacks and provide a fixed part structure of a fixed sealing ring that has a perfect sealing effect, excellent heat dissipation, and is highly durable.

(2) Structure of the invention In the fixing part structure of the fixed sealing ring in the mechanical seal according to the invention, the front end surface is a sliding surface that contacts the rotating sealing ring, and the back end surface is a non-sliding surface.The fixing part is made of silicon carbide. The sealing ring is housed in an annular groove recessed in the inner wall of the seal box along the outer periphery of the rotating shaft so that the non-sliding surface faces the bottom of the groove, and the outer circumferential surface of the fixed sealing ring and the inside of the annular groove A buffer backing having an annular bottomed groove bored from the front end face so that the back end face becomes the groove bottom is interposed in the gap between the circumferential surface and a core ring made of a hard material. The structure is such that the ring is held between the annular bottomed groove and the outer circumferential surface of the fixed sealing ring and the annular inner circumferential surface are tightly aligned with each other.

To explain the drawings illustrating the embodiment, reference numeral 1 denotes a fixed sealing ring whose front end surface 1a is a sliding surface that contacts the rotary sealing ring 2, and whose back end surface 1b is a non-sliding surface, and is made of silicon carbide. It is being

Reference numeral 3 denotes an annular groove recessed in a fixed body 5 such as the inner wall of a seal box along the outer periphery of the rotating shaft 4, and is a ring groove recessed in the fixed body 5 such as the inner wall of the seal box.
The stationary sealing ring 1 is housed in such a manner that it comes into contact with the groove bottom surface 3b, and a buffer backing 6 (described later) is press-fitted into the gap between the outer circumferential surface 1d of the stationary sealing ring 1 and the ring groove inner circumferential surface 3C.

The buffer backing 6 is molded from rubber or soft synthetic resin, and has a front end surface 6a with a back end surface 6b as a groove bottom.
It has an annular bottomed groove 7 bored from the annular bottomed groove 7.
By press-fitting a core ring 8 made of a hard material therein, the outer circumferential surface 1d of the fixed sealing ring 1 and the ring groove inner circumferential surface 3C are tightly aligned.

In order to make this alignment even tighter, the cross-sectional shape of the core ring 8 is formed into a wedge shape as shown in FIG. 4, or the inner peripheral surface 6C of the buffer backing and the outer periphery of the fixed seal ring are The surface in contact with the surface 1d is formed in an inclined shape, or as shown in FIG. If they are forcefully press-fitted, a wedge effect will be generated in the circumferential direction, and the adhesion effect between the contact surfaces can be significantly enhanced.

As for the fitting procedure, when using a wedge-shaped core ring as shown in FIG. 4, the embodiments shown in FIGS. In the case of a casing, it is desirable to use the embodiments shown in FIGS. 8A to 8C.

Reference numeral 9 designates a holding plate for preventing rotation and escape of the buffer backing 6, reference numeral 10 a bellows for supporting the rotary sealing ring 2 from the back side, reference numeral 11 a retainer, and reference numeral 112 a pressing spring.

(3) Effects of the invention According to the structure of the invention, the outer circumferential surface 1d of the fixed seal ring 1 and the inner circumferential surface 3 of the ring groove are
Due to the surface contact with C, the alignment is tight and the sealing effect is perfect.

Unlike the conventional structure in which an O-ring is interposed, this structure can also be applied to baked products, and since the fixed sealing ring 1 is made of silicon carbide, it has excellent wear resistance.

Also, unlike the conventional structure in which an L-shaped rubber backing is attached, the back end surface 1b of the fixed sealing ring 1 is the ring bottom surface 3 of the ring groove 3.
Since it is in direct contact with b, the heat dissipation is extremely good, and there is an advantage that the sliding surface will not seize even if used for a long time.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional side view of the main part of the mechanical seal according to the inventive structure, Fig. 2 is a half-sectional view of the buffer backing in the inventive structure, Fig. 3 is a half-sectional view of the core ring in the inventive structure, and Fig. 4 5 is a half-sectional view showing an example in which the cross-sectional shape of the core ring in the structure of the present invention is formed into a wedge shape, and FIG. Main part vertical side view showing an example of formation, No. 6
The figure is a longitudinal cross-sectional side view of the main part showing an example in which the contact surface between the inner circumferential surface of the ring groove and the outer circumferential surface of the buffer backing is formed in an inclined shape in the structure of the present invention, and A-C in Fig. 7 uses a wedge-shaped core ring. A vertical cross-sectional side view of the main part illustrating the procedure for forming the structure of the present invention in the case of
A-C in FIG. 8 are vertical sectional side views of main parts illustrating the fitting procedure when the contact surface with the buffer backing in the annular groove is formed in an inclined shape in the structure of the present invention, and A and B in FIG. 9
FIG. 2 is a longitudinal cross-sectional side view of a main part illustrating a fixed part structure of a fixed sealing ring in a conventional mechanical seal. 1...Fixed sealing ring made of turmeric carbide, 1a.
...Front side end surface, 1b... Back side end surface, 1d
...Outer peripheral surface, 2...Rotating sealing ring, 3.
...Ring groove, 3b...Ring groove bottom surface, 3c.
...Inner circumferential surface of ring groove, 4...Rotating shaft, 6...
...Buffer backing, 6a... Front end surface,
6b... Back side end surface, 7... Annular bottomed groove, butt... Core ring.

Claims (1)

[Scope of utility model registration request] A fixed sealing ring 1 made of silicon carbide, whose front end surface 1a is a sliding surface that contacts the rotating sealing ring 2 and whose back end surface 1b is a non-sliding surface, is recessed in the inner wall of the seal box along the outer periphery of the rotating shaft 4. The outer peripheral surface 1 of the fixed sealing ring 1 is accommodated in the provided ring groove 3 so that the non-sliding surface faces the groove bottom surface 3b.
In the gap between d and the annular groove inner circumferential surface 3c, there is a back end surface 6b.
A buffer backing 6 having an annular bottomed groove 7 bored from the front end surface 6a such that the groove bottom is interposed therebetween, and a core ring 8 made of a hard material is sandwiched in the annular bottomed groove 7. A fixed part structure of a fixed sealing ring in a mechanical seal, characterized in that the fixed sealing ring outer circumferential surface 1d and the ring groove inner circumferential surface 3C are tightly aligned with each other by this structure.