JPH0122510B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a narrow passage at least near the outer side of the sealed end surface in the radial direction outward and inner, and a radial single or A mechanical seal characterized in that multiple spiral grooves are provided, and the other side wall is provided with a radial single or multiple spiral groove whose unwinding direction is different from that of the above spiral grooves. The purpose is to obtain a mechanical seal with extremely high sealing performance and low frictional torque.

The mechanical seal of the present invention will be explained with reference to illustrative drawings.

A cover 2 is fixed to the end of the casing 1. The shaft 3 passes through these casings and covers. The sealing ring 4 is fitted onto the inner circumference of the cover 2 via a packing 5. This sealing ring 4 prevents relative rotation with the cover 2 by appropriate means.

The sides of the sealing ring 4 are provided with surfaces 6. The sealing ring 7 is fitted onto the outer periphery of the shaft 3 via a packing 8 so as to be movable in the axial direction. The sides of this sealing ring are provided with surfaces 9. The retaining ring 10 is fitted around the outer periphery of the shaft 3 and fixed to the shaft. The retaining ring 10 and the sealing ring 7 are prevented from relative rotation by appropriate means. A spring 11 is interposed between the seal ring 7 and the stop ring 10. The surface 9 of the sealing ring 7 is brought into close contact with the surface 6 of the sealing ring 4 to form a sealed end surface S. Spring 1
1 presses the sealing ring 7 against the sealing ring 4 to increase the strength of the close contact pressure of the sealing end surface S.

A baffle passage is provided in the vicinity of the sealed end face S, for example, at least in the radially outward and inward vicinity of the sealed end face. In this embodiment, they are provided on both sides. That is, the outward narrow passage 1
2, and a narrow passage 13 that gradually expands inward is provided radially inward. One side wall 14 of the narrow passageway 12 is provided with a radial single or multiple spiral groove 15, and the other side wall 16 is provided with a radial single or multiple spiral groove 15 with a different unwinding direction from the spiral groove 15. Alternatively, multiple spiral grooves 17 may be provided. The side wall 14 is constituted by the seal ring 7, and the side wall 16 is constituted by the seal ring 4. In addition,
In the figures shown, the spiral grooves 15 and 17 are shown as multiple spiral grooves.

Similarly, one side wall 18 of the narrow passage 13 is provided with a spiral groove 19, and the other side wall 20 is provided with a spiral groove 21.

With this configuration, in Figure 3, Y4−
When the spiral groove 15 of the sealing ring 7 in the Y4 projection is shown by a chain line, it is relative to the spiral groove 17 of the sealing ring 4 shown by a solid line so as to intersect with each other, as shown in the example. are doing. At the same time, a spiral groove 19, indicated by a chain line, faces the spiral groove 21 of the sealing ring 4, indicated by a solid line, so as to intersect with each other.

Next, an explanation will be given of the function of this embodiment for preventing fluid radially outward from the sealed end surface S from leaking inward.

When the shaft 3 is rotated, the sealing ring 7 rotates and the sealing ring 4 does not rotate, so that the sealing end surface S becomes a meeting surface of relatively rotating surfaces and limits the flow rate of fluid.

In the vicinity of the radially outer side of the sealed end surface S, there are spiral grooves 15 and 17, each of which generates a screw-shaped viscous pumping action to push the fluid radially outward. act. In this embodiment, as described above, these spiral grooves are provided so as to intersect with each other at the portion outward from the sealed end surface S, which is the meeting portion.
Therefore, due to the synergistic effect of the pumping action of both spiral grooves 15 and 17, a significantly high pressure is generated.
This is because the fluid at the intersection of the grooves is sandwiched from both sides by both grooves and moves outward as the groove rotates. Therefore, the sealing fluid that is located near the radially outer side of the sealing end face and tries to flow radially inward encounters a large resistance due to this pumping action, and is prevented from flowing radially inwardly, thus sealing the sealing fluid. Flow into the end surface S is also prevented. This makes it possible to obtain a mechanical seal with significantly less leakage.

Furthermore, in this embodiment, the sealing fluid that tends to leak inward from the sealed end surface S is pushed back into this sealed end surface by the strong pumping action of the spiral grooves 19 and 21 in the same way as described above. Since it is possible to obtain a mechanical seal with even higher sealing performance.

In implementing the mechanical seal of the present invention,
The spiral groove can also be constructed with an inclined straight line.

In the mechanical seal of the present invention, the spiral grooves on both sides of the narrow passageway, which reduce leakage, only face each other and do not touch each other, so there is little power loss and overall friction torque. This makes it possible to create a mechanical seal that is small and has high sealing performance.

Since the present invention is constructed and operates in this manner, in a mechanical seal that has a rotating and sliding sealing end face to prevent fluid from leaking inward in the radial direction, This provides effects such as reliably preventing fluid from flowing toward the end face, reliably preventing leakage, and reducing power loss.

[Brief explanation of drawings]

The drawings show an embodiment of the mechanical seal of the present invention, and FIG. 1 is a half-part longitudinal sectional side view, in which the portion of the spiral groove is schematically indicated by a chain line. FIG. 2 is a portion of the Y2-Y2 projection of FIG. 1, in which one of the spiral grooves is schematically indicated by a single solid line.
Figure 3 is a part of the Y3-Y3 projection in Figure 1,
One of the spiral grooves is schematically shown as a single solid line, and only the other spiral groove in the Y4-Y4 projection is shown as a chain line. 1...Casing. 2...Hippo. 3...Shaft. 4...Sealed ring. 5... Patsukin. 6...face.
7...Sealed ring. 8...Patsukin. 9... side. 10
...stop ring. 11...Spring. 12...Sebamari passage. 13...Sebamari passage. 14...Side wall.
15...Spiral-shaped groove. 16...Side wall. 17...
spiral groove. 18...Side wall. 19...Spiral-shaped groove. 20...Side wall. 21...Spiral-shaped groove. S
... Sealed end surface.

Claims (1)

[Claims] 1. A narrow passageway is provided at least in the vicinity of the outer side of the sealed end surface in the radial direction outward and inside, a radial single or multiple spiral groove is provided on one side wall forming the narrowed passageway, and the other side wall is provided with a radial single or multiple spiral groove. A mechanical seal characterized in that a radial single or multiple spiral groove is provided on the side wall of the spiral groove, the direction of which is different from that of the spiral groove described above.