JP6411035B2 - Method for manufacturing rotary shaft seal - Google Patents

Description

The present invention relates to a method for manufacturing a rotary shaft seal.

As a conventional rotary shaft seal, there are three parts, that is, an outer metal (outer case), a seal member, and an inner metal (inner case) (see, for example, Patent Document 1). However, there was a limit when cost reduction was attempted with the number of parts remaining at 3.
Therefore, as a technique for reducing the number of parts, a rotary shaft seal having a structure in which a metal thin plate material is bent and a seal member is sandwiched has been proposed (for example, see Patent Document 2).

  However, there is a drawback that the bending process for holding the seal member between the metal fittings is complicated.

Japanese translation of PCT publication No. 5-500780 JP 2012-149725 A

  The problem to be solved is that the rotary shaft seal with the number of parts reduced to two complicates the manufacturing process. Furthermore, it is difficult to obtain high dimensional accuracy by bending a thin metal plate material, and the holding force of the seal member varies.

Therefore, the production method of the rotation shaft seal of the present invention, one from a resin sealing element and one of the fitting At a manufacturing method of forming Ru rotation shaft seal, the fitting comprises a cylindrical wall portion, a radial inside direction A first projecting wall and a second projecting wall projecting radially inwardly to form an annular concave groove having a hemispherical opening; A step of forming a small groove or a small ridge and installing the metal fitting in a mold, and a seal element creating step of producing a base part in the groove and an extending part extending from the base part by injection molding It is a method to have .

In addition, after the injection molding, the method further includes a step of reinforcing the seal element by crimping a part of the first projecting wall and the second projecting wall.
Further, the seal element is polyphenylene sulfide in PTFE resin powder, and those obtained by blending the carbon fibers, or, PTFE resin powder polyethersulfone, and a method consisting of those obtained by blending the carbon fibers.

According to the method of manufacturing the rotary shaft seal of the present invention, the manufacturing process is not complicated while the number of parts is two. And it can manufacture at low cost.

It is principal part sectional drawing which shows the use condition of the 1st Embodiment of this invention. It is principal part sectional drawing which shows a manufacturing method. It is principal part sectional drawing. It is a figure which shows 2nd Embodiment, Comprising: (A) is principal part sectional drawing, (B) is an effect | action explanatory drawing. It is principal part sectional drawing which shows 3rd Embodiment. It is principal part sectional drawing which shows 4th Embodiment. It is principal part sectional drawing which shows the manufacturing method of the reference example deeply related to this invention . It is principal part sectional drawing which shows a manufacturing method, Comprising: (A) shows principal part sectional drawing of an intermediate | middle product, (B) shows principal part sectional drawing of a finished product. It is principal part sectional drawing which shows the manufacturing method of the other reference example deeply related to this invention , (A) shows principal part sectional drawing of an intermediate product, (B) shows principal part sectional drawing of a finished product. It is principal part sectional drawing which shows 5th Embodiment. It is principal part sectional drawing which shows 6th Embodiment.

Hereinafter, the present invention will be described in detail based on the illustrated embodiment.
FIG. 1 shows a use state of the first embodiment of the present invention. This rotary shaft seal is used by being mounted between the rotary shaft 10 and the housing 20. The rotary shaft seal is retained by a retaining ring 19. The right side of FIG. 1 is the high pressure side H that contains the sealed fluid, and the left side is the low pressure side L.

  As shown in FIGS. 1 to 3, a resin sealing element 3 and a metal fitting 4 are provided. The seal element 3 is made of, for example, polyphenylene sulfide blended with PTFE resin powder and carbon fiber.

The metal fitting 4 has a cylindrical wall portion 5 and a first projecting wall 1 and a second projecting wall 2 projecting radially inward to form an annular concave groove 6 opening radially inward. Small concave grooves 7 (small concave grooves 7a and 7b) having the same diameters D ₁ and D ₂ are formed at positions corresponding to the radial directions of the opposing surfaces 14 and 15 of the first and second protruding walls 1 and 2. . The outer peripheral edge 9 of the sealing element 3 is filled and held in the concave groove 6 by injection molding.

  The manufacturing method of the rotating shaft seal of 1st Embodiment is demonstrated. First, the small groove 7 is formed in the groove 6 of the metal fitting 4 by cutting or grinding. Next, as shown in FIG. 2, the molten resin is caused to flow into the mold M and the groove 6 is filled with the molten resin. In order to prevent the metal fitting from moving to the left in FIG. 2, it is preferable to support and press the outer peripheral surface of the cylindrical wall portion 5 with a support member (not shown). Thereafter, the resin is solidified by cooling. Although the seal element 3 contracts somewhat, the seal element 3 and the metal fitting 4 are locked at positions A and B or C and D in FIG.

FIG. 4 shows a second embodiment. The small groove 7a of the first projecting wall 1 and the small groove 7b of the second projecting wall 2 are formed at positions not corresponding to the radial direction. Specifically, the diameter D ₁ of the first protruding wall 1 of the small concave groove 7a is set larger than the diameter D ₂ of the second protruding wall 2 of the small recess groove 7b. Other configurations are the same as those of the first embodiment.
In the manufacturing process, the molten resin shrinks when solidified, but the portion shown by the solid line in FIG. 4B (the inner peripheral side of the small groove 7a of the first protruding wall 1 and the second protruding wall 2). Since the seal element 3 and the metal fitting 4 are engaged with each other on the outer peripheral side of the small concave groove 7b, in the range Y, there is an advantage that contraction of the seal element 3 is suppressed.

FIG. 5 shows a third embodiment. Diameter D ₁ of the first protruding wall 1 of the small concave groove 7a is set smaller than the diameter D ₂ of the second protruding wall 2 of the small recess groove 7b. Other configurations are the same as those of the second embodiment.

FIG. 6 shows a fourth embodiment. In the radial direction corresponding position of the first projecting wall 1 and a second protruding wall 2 of the opposing surfaces 14, 15 (the diameter D _3, D ₄₎ the small protrusion 8 (small protrusion 8a, 8b) are formed . Other configurations are the same as those of the first embodiment.

7 and 8 show reference examples that are closely related to the present invention . The seal element 3 is prevented from being pulled out by caulking by pressing and plastically deforming a part 11 of the first protruding wall 1. Other configurations are the same as those of the first embodiment.

A method for producing a rotary shaft seal of a reference example closely related to the present invention will be described. First, as shown in FIG. 7, the metal fitting 4 is installed in the mold M, and the concave groove (in the state where the opposing surfaces 14 and 15 of the first protruding wall 1 and the second protruding wall 2 are flat surfaces). 6 is filled with the outer peripheral edge 9 of the sealing element 3 by injection molding. Thereafter, as shown in FIG. 8B, a part 11 of the first projecting wall 1 is caulked.

FIG. 9 shows another reference example closely related to the present invention . A portion 11 (tip portion 12) of the first projecting wall 1 is crimped by bending to prevent the sealing element 3 from being removed. Other configurations are the same as those of the first embodiment.

A method for producing a rotary shaft seal of another reference example closely related to the present invention will be described. First, as shown in FIG. 9A, a notch 13 having a depth dimension v is formed in the non-facing surface 16 of the first projecting wall 1, and then the groove 6 is filled with molten resin by injection molding. Next, as shown in FIG. 9B, the distal end side (the distal end portion 12) is caulked by bending from the notch 13 of the first projecting wall 1.
The depth dimension v and the thickness dimension t of the first protruding wall 1 are set to 0.6 × t ≦ v ≦ 0.8 × t. When the depth dimension v is less than the lower limit value, it cannot be caulked sufficiently, and the seal element 3 may be detached from the metal fitting 4. When the depth dimension v exceeds the upper limit value, the force for pressing and holding the seal element 3 is insufficient, and there is a risk of damage due to insufficient strength.

FIG. 10 shows a fifth embodiment. Small concave grooves 7 are formed in the opposing surfaces 14 and 15 of the first and second protruding walls 1 and 2, and the outer peripheral edge 9 of the seal element 3 is filled and held in the concave grooves 6 by injection molding. Thereafter, a part 11 of the first protruding wall 1 is caulked by pressing to reinforce the sealing element 3. Other configurations are the same as those of the first embodiment and the above-mentioned “reference example deeply related to the present invention”.

FIG. 11 shows a sixth embodiment. Small concave grooves 7 are formed in the opposing surfaces 14 and 15 of the first and second protruding walls 1 and 2, and the outer peripheral edge 9 of the seal element 3 is filled and held in the concave grooves 6 by injection molding. A portion 11 (tip portion 12) of the first protruding wall 1 is caulked by bending to reinforce the sealing element 3. Other configurations are the same as those of the first embodiment and the above-mentioned “other reference examples deeply related to the present invention”.

  The design of the present invention can be changed. For example, in FIG. 8 or FIG. 10, a part 11 of the second projecting wall 2 may be caulked to prevent the sealing element 3 from being removed. 10 or 11, small protrusions 8 are formed on the opposing surfaces 14 and 15 of the first projecting wall 1 and the second projecting wall 2, and the first projecting wall 1 and the second projecting wall. It is also possible to reinforce the sealing element 3 by crimping a part 11 of 2.

  As described above, the present invention includes the resin sealing element 3 and the metal fitting 4, and the metal fitting 4 forms a circular inward groove 6 that is open in the radial inner direction and the cylindrical wall portion 5. A first projecting wall 1 and a second projecting wall 2 projecting to the side, and a small groove 7 or a small projecting strip 8 is formed on the opposing surfaces 14 and 15 of the first projecting wall 1 and the second projecting wall 2. Since the outer peripheral edge 9 of the sealing element 3 is filled and held in the concave groove 6 by injection molding, the manufacturing process is simple while the number of parts is two. And a high-quality rotating shaft seal can be manufactured at low cost by mass production.

  Moreover, the resin sealing element 3 and the metal fitting 4 are provided, and the metal fitting 4 protrudes radially inward to form a cylindrical wall portion 5 and an annular concave groove 6 opening radially inward. A wall 1 and a second projecting wall 2, the outer peripheral edge 9 of the seal element 3 is filled in the concave groove 6 by injection molding, and the first projecting wall 1 and the second projecting wall 2 Since the part 11 is crimped to prevent the sealing element from being removed, the manufacturing process is simple while the number of parts is two. And a high-quality rotating shaft seal can be manufactured at low cost by mass production.

  Moreover, the resin sealing element 3 and the metal fitting 4 are provided, and the metal fitting 4 protrudes radially inward to form a cylindrical wall portion 5 and an annular concave groove 6 opening radially inward. A small groove 7 or a small ridge 8 is formed on the opposing surfaces 14 and 15 of the first and second protruding walls 1 and 2, and the groove 6 The outer peripheral edge portion 9 of the seal element 3 is filled and held by injection molding, and the seal element 3 is prevented from being reinforced by caulking part 11 of the first projecting wall 1 and the second projecting wall 2. Therefore, the manufacturing process is simple while the number of parts is two. And a high-quality rotating shaft seal can be manufactured at low cost by mass production. Furthermore, the sealing element 3 can be prevented from being pulled out more reliably.

  The sealing element 3 is a thermoplastic resin composition, specifically, PTFE resin powder blended with polyphenylene sulfide and carbon fiber, or PTFE resin powder blended with polyethersulfone, and Since the carbon fiber is blended, the wear resistance is good, and the shrinkage rate after injection molding is small. Therefore, it is suitable for a rotary shaft seal in which the seal element 3 is integrated with the metal fitting 4.

DESCRIPTION OF SYMBOLS 1 1st protrusion wall 2 2nd protrusion wall 3 Seal element 4 Metal fitting 5 Cylindrical wall part 6 Concave groove 7 Small concave groove 8 Small protrusion 9 Outer peripheral edge part
11 part
14 Opposite surface
15 Opposite surface
M mold

Claims (3)

A method of manufacturing a resin sealing element (3) and a metal fitting (4) and Ru color formed rotation shaft seal Te at,
The metal fitting (4) has a cylindrical wall portion (5) and a radially inward projecting first projecting wall (1) / second projecting projecting radially inward groove (6). An integral one having a wall (2);
A small groove (7) or a small protrusion (8) is formed on the opposing surfaces (14) and (15) of the first protruding wall (1) and the second protruding wall (2),
Installing the metal fitting (4) in the mold (M);
A method for producing a rotary shaft seal , comprising: a seal element creating step of producing a base part in the concave groove (6) and an extending part extending from the base part by injection molding. 2. The rotation according to claim 1, further comprising a step of, after the injection molding, further comprising a step of reinforcing the seal element (3) by crimping a part (11) of the first projecting wall (1) and the second projecting wall (2). Manufacturing method of shaft seal. The said sealing element (3) consists of what mix | blended PTFE resin powder and carbon fiber with polyphenylene sulfide, or what mix | blended PTFE resin powder and carbon fiber with polyether sulfone. The manufacturing method of the rotating shaft seal of description .

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