JPH0652102B2 - Seal parts - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a seal part used for a seal of a fluid machine having a sliding surface such as a pump device.

[Prior Art] Conventionally, as a seal component of this type, as shown in FIG. 12, a ring-shaped elastic seal body 1 is used to reduce sliding resistance.
There is known an O-ring 103 in which a tetrafluoroethylene resin (hereinafter referred to as PTFE) sheet 102 is joined to a sliding surface constituted by the inner peripheral surface of 01.

Further, conventionally, for the purpose of imparting a self-lubricating property by a sealing fluid, as shown in FIG. 13, a sliding surface of a ring-shaped elastic seal body 105 having a lip portion 105a to which a garter spring 104 is mounted is partially Notched grooves 110 are formed at a plurality of positions on an oil seal 108 to which a PTFE sheet 107 having a notch groove 106 is joined, or as shown in FIG. The formed mechanical seal ring 111 is known.

[Problems to be Solved by the Invention] Of the above-mentioned conventional seal parts, the PT shown in FIG.
If the FE sheet 102 is attached, it is generally PTFE.
Since the sheet 102 is inferior in load bearing property, it has a difficulty in abrasion resistance, and particularly when the temperature is raised to about 120 ° C. to 180 ° C. by sliding heat, the PTFE sheet 102 is softened and wear is easily promoted. .

In this regard, there is also an unsintered PTFE having lipophilicity, but this has low mechanical strength and is uneasy in terms of pressure resistance. In addition, there is a fired PTFE having high mechanical strength, but on the contrary, since it has no lipophilicity, it has a drawback that it is inferior in lubricating property and is easily worn.

Further, as shown in FIG. 13, a notch groove 106 may be provided,
In the case where the recesses 110 are radially formed as shown in FIG. 4, the original sealing performance may be deteriorated.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a highly reliable seal component in which good slidability is ensured without deteriorating the sealing performance.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a porous PT.
A PTFE sheet obtained by partially heating and pressurizing an FE base material and leaving a porous part partially is joined to the sliding surface of the seal body.

[Operation] According to such a configuration, since the fluid is stored in the porous portion of the PTFE sheet, the lubricity is improved,
Moreover, since the PTFE base material is heated, it is less likely to be affected by sliding heat and durability is improved. Moreover, since the porous portion is partially formed, the other impervious portion causes fluid to flow. Leakage is suppressed and the original sealing function is effectively secured.

Embodiments Embodiments of the present invention will be described below with reference to the drawings.

1a and 1b are a sectional view and a side view, respectively, showing a gland packing to which a sealing component according to the present invention is applied.

In the figure, reference numeral 1 denotes a ring-shaped member that constitutes the seal body, which is formed of, for example, a mixture of graphite, wax and asbestos or aramid, and contains a lubricating oil. It is also possible to use fine particles of PTFE and oil contained in a cord-like body in which aramid fibers or the like are braided. Reference numeral 2 is a PTFE sheet formed in a ring shape having an L-shaped cross section. In this sheet 2, a cylindrical portion 2a is partially formed, for example, as a porous portion, and a collar portion 2b is an impermeable portion having no internal void. The gland packing 3 is configured by fitting the sliding surface of the seal body 1 to the gland packing 3.

The PTFE sheet 2 having the porous portion 2a is manufactured as follows.

That is, a tetrafluoroethylene resin base material made into a porous material by removing the liquid lubricant or solvent while making a sheet by mixing PTFE powder with a liquid lubricant or solvent is there. For example, a GORE-TEX sheet (trade name: manufactured by Japan GORE-TEX Co., Ltd.) is prepared, and this is heated at about 370 ° C. while being pressurized at about 200 kg / cm ² using a heating plate partially having holes. As a result, the porous base material is brought into a molten state corresponding to the non-perforated portion of the heating plate, and the voids are crushed and solidified to form the impermeable portion 2b. In other words, the PTFE sheet 2 having the porous portion 2a and the impermeable portion 2b is formed.

The gland packing 3 configured as described above is fitted onto the rotary shaft 21 of the shaft sealing device and elastically pressed against the fixed ring 22 by the movable ring 23 as shown in FIG.

Regarding the point that the sliding surface of the PTFE sheet 2 is inferior in load bearing characteristics, since lubricating oil is stored in the porous portion 2a forming the cylindrical portion, lubricity is improved and wear is suppressed. In particular, even if the normal use temperature of the gland packing 3 is 100 ° C. and the temperature is raised to 120 to 180 ° C. by sliding heat, the PTFE sheet 2 still has the porous portion 2a.
Since the PTFE sheet 2 is heated to 327 ° C. or higher in the heating step for leaving, the PTFE sheet 2 is not likely to be softened, and the mechanical strength is strengthened, so that the abrasion resistance is remarkably improved.

Further, since the collar portion 2b of the PTFE sheet 2 is configured as the impermeable portion 2b which is baked and solidified by heating, permeation leakage from the side surface is prevented, and good sealing performance can be maintained.

FIG. 3 shows the operating time / leakage amount characteristics in the operating state of the shaft sealing device using the PTFE sheet 2, and FIG. 4 shows the leakage amount / dynamic torque characteristics.

The measurement conditions are as follows: water as the fluid is 3 kg / cm ² , the rotation speed of the rotating shaft 21 is 3600 RPM, and the number of samples is 4.

This measurement result also revealed that the oil content of the seal body 1 in the gland packing 3 was transferred to the porous portion 2a of the PTFE sheet 2 to ensure the sealability with excellent lubricity.

In addition, since the leakage decreased and became stable, the dynamic torque did not increase, and the operation could be continued with a leakage of about 1/10 of GP.

By the way, although the gland packing 3 has been described as an example in the above example, the present invention can also be applied to the O-ring 31 shown in FIG. That is, the GORE-TEX sheet is used as a base material, and the PTFE sheet 32 having the porous portion 32a and the impermeable portion 32b is partially heated to slide the rubber ring-shaped seal body 33 on the PTFE sheet 32. 4 on the moving surface (inner surface)
It is integrated by vulcanization molding through a fluoroethylene / hexafluoropropylene polymer (FEP).

FIG. 6 shows still another embodiment, which is applied to the rectangular ring 41. For example, a PTFE sheet 42 formed so that the boundary between the porous portion 42a and the impermeable portion 43 changes gently in the axial direction is integrated with the sliding surface of the rubber ring-shaped seal body 43. is there. By using such a square ring 41 in a shaft sealing device for a rotary shaft 44 as shown in FIG. 7, for example, excellent slidability can be exhibited without impairing the sealing performance as described above. It will be possible.

FIG. 8 shows another example of application to the oil seal 51, in which a plurality of triangular porous parts 52 are formed in the central part by using the porous base material made of the Gore-tex sheet described above.
a is left, and the other parts are made into impermeable parts 52b. P
The TFE sheet 52 is integrally formed on the inner peripheral surface of the lip seal 53, and has the same effect as that of the above embodiment.
In the figure, 54 is a garter spring.

As another embodiment, FIGS. 9a and 9b show an example of application to a mechanical seal 61, which is a ring-shaped PTFE sheet having porous portions 62a and impermeable portions 62b formed at a plurality of locations on the outer peripheral side. 62 is adhered and fixed to a ring-shaped seal body 63 made of SUS via FEP.

Further, FIGS. 10a and 10b show an application example to another mechanical seal 71, which has a plurality of porous portions 72a and impermeable portions 72b which are formed by being equally arranged in the circumferential direction.
The TFE sheet 72 is adhered to the SUS ring body 73 so that the porous portion 72 a corresponds to the gas filling hole 74.

Such a mechanical seal 71 is fitted onto the rotary shaft 75 of the shaft sealing device as shown in FIG. 11, and is elastically pressed toward the fixed ring 77 side by the movable ring 76, so that an appropriate sealing is achieved. Liquid effect and abrasion resistance are exhibited.

[Advantages of the Invention] As described above, according to the present invention, porous PTF is used.
Since the PTFE sheet made by partially heating and pressurizing the E base material to partially leave the porous portion bonded to the sliding surface of the seal body, the sealing function can be effectively maintained and is excellent. Lubricity can be exhibited to improve durability.

[Brief description of drawings]

1a and 1b are a sectional view and a half-side view showing a gland packing to which a sealing component according to the present invention is applied, respectively, and FIG. 2 is an explanatory view of an example of use of the gland packing of FIG. 1, and FIG. Is a characteristic diagram showing the measurement results of the operating time and the leakage amount of the one shown in FIG. 2, FIG. 4 is a characteristic diagram showing the measurement results of the leakage amount and the dynamic torque of the one shown in FIG. 2, and FIG. FIG. 6 is a sectional view showing an O-ring which is an embodiment, FIG. 6 is a sectional view showing a square ring which is still another embodiment of the present invention, and FIG. Is a sectional view showing an oil seal according to another embodiment of the present invention, and FIGS. 9a and 9b are sectional views showing a mechanical seal according to yet another embodiment of the present invention and a semi-cut side view, FIG. 10a. And FIG. 10b respectively show another embodiment of the present invention. FIG. 11 is an explanatory view of a usage example of the mechanical seal shown in FIG. 10a and FIG. 10b, FIG. 12, FIG. 13, FIG. 13 and FIG. 14 are different conventional seals. It is sectional drawing which shows a component. 1, 33, 43, 53, 63, 73 ... Seal body,
2, 32, 42, 52, 62, 72 ... Tetrafluoride ethylene resin sheet, 2a, 32a, 52a, 62a, 72a ...
… Porous part.

Claims (1)

[Claims] 1. A porous tetrafluoroethylene resin substrate is partially heated and pressed to partially leave a porous portion.
A seal part characterized in that a fluoroethylene resin sheet is joined to the sliding surface of the seal body.