JP5897693B2 - Shaft sealing structure - Google Patents

Description

      The present invention relates to a shaft sealing structure.

  Conventionally, shaft seals have been widely used for rotation as shown in FIG. That is, the outer case 30 and the inner case 31 are configured to hold the seal element 32 and the gasket 33 together. The outer case 30 has an inner flange portion 34, the seal element 32 is brought into contact with the inner surface thereof, and is held by the inner flange portion 35 of the inner case 31 via the gasket 33. By bending the one end 30A, the seal element 32 and the gasket 33 are firmly attached to form a shaft seal 40, and such a shaft seal 40 is mounted on various fluid devices (for example, patents). Reference 1).

JP 2009-103264 A

  However, in recent fluid equipment, there is a strong demand for downsizing and cost reduction, and there is a limit to the conventional shaft seal structure. That is, it is difficult to reduce the size because the axial direction dimension is the axial direction dimension of the outer case 30, and further, the bending process of the one end 30A is necessary for manufacturing, resulting in an increase in cost and a large number of parts. It was.

Therefore, the present invention assembles the first housing part and the second housing part that constitute the housing of the fluid device and has the shaft insertion hole, and fixes the outer case and the inner case together by fixing means. the sealing element of the omitted naked state, 挾着 held in alone, form configured to seal between the shaft and the shaft insertion hole portion, the second housing part is a cylindrical sliding bearing The first housing part has a hole for fitting the cylindrical sliding bearing, the sliding bearing is fitted into the hole, and the inner end surface of the bearing and the back step of the hole are stepped. The sealing element was held tightly on the surface.

Also, the first housing part and the second housing part, which constitute the housing of the fluid device and having the shaft insertion hole, are assembled and fixed to each other by a fixing means, and the outer case and the inner case are omitted. the sealing element of, via a gasket, and挾着held, and configured to seal between the shaft and the shaft insertion hole portion, the second housing part is a cylindrical sliding bearing, the The first housing part has a hole for fitting the cylindrical sliding bearing, the sliding bearing is fitted into the hole, and the inner end surface of the bearing and the back stepped surface of the hole are The sealing element was held in place.

Also, the first housing part and the second housing part, which constitute the housing of the fluid device and having the shaft insertion hole, are assembled and fixed to each other by a fixing means, and the outer case and the inner case are omitted. the sealing element of, and 挾着 held in alone, a shaft sealing structure configured to seal between the shaft and the shaft insertion hole, the first to contact the sealing element in the above naked state the挾圧end face of the housing part product or the second housing part, viewed from the axial direction, the eccentric pattern, elliptical pattern, sealability improving be any shape of a polygonal pattern, and, ridges for detent or Has a groove.

Also, the first housing part and the second housing part, which constitute the housing of the fluid device and having the shaft insertion hole, are assembled and fixed to each other by a fixing means, and the outer case and the inner case are omitted. The shaft sealing structure is configured such that the seal element is held tightly via a gasket and the space between the shaft and the shaft insertion hole is sealed, and is in contact with the bare seal element or gasket. For the compression end face of the first housing part or the second housing part, as viewed from the axial direction, the shape is any of an eccentric pattern, an elliptical pattern, and a polygonal pattern for improving sealing performance and for preventing rotation Has ridges or grooves.

  According to the shaft sealing structure of the present invention, one part (or two parts) having a minimum sealing portion is sufficient, and the size and cost can be reduced.

It is principal part sectional drawing which shows the 1st Embodiment of this invention. It is principal part sectional drawing which shows the 2nd Embodiment of this invention. It is principal part sectional drawing which shows the 3rd Embodiment of this invention. It is principal part sectional drawing which shows the 4th Embodiment of this invention. It is principal part sectional drawing which shows the 5th Embodiment of this invention. It is principal part sectional drawing which shows the 6th Embodiment of this invention. It is principal part sectional drawing which shows the 7th Embodiment of this invention. It is principal part sectional drawing which shows the specific example to which the 7th Embodiment of this invention is applied. It is a figure for demonstrating the various specific examples about the plane for soot pressure. It is a figure which shows another specific example about the plane for soot pressure. It is principal part sectional drawing which shows a prior art example.

Hereinafter, the present invention will be described in detail based on the illustrated embodiment.
1 to 7 show first to seventh embodiments, each having a first housing part H ₁ and a second housing part H ₂ constituting a housing H of a fluid device, and The first housing part H ₁ and the second housing part H ₂ have shaft insertion holes 11 and 12 into which the shaft 2 is inserted, and are assembled so that both the holes 11 and 12 are concentric. In addition, they are fixed to each other by the fixing means 5. In the present invention, the shaft 2 has a circular cross section and is a rotating shaft or a rocking shaft or a (reciprocating) linear motion axis.

Reference numeral 8 denotes a bare seal element. The bare state refers to a state in which the outer case 30 and the inner case 31 in the shaft seal 40 as illustrated in FIG. 11 are omitted.
As shown in FIG. 1, FIG. 4 and FIG. 7, this bare seal element 8 is singly held by fixing the first housing part H ₁ and the second housing part H ₂ together. The shaft 2 and the holes 11 and 12 are sealed by sliding contact (pressure contact) in a J-shaped curved posture of the bare seal element 8.
Alternatively, as shown in FIGS. 2, 3, 5, and 6, the gasket 3 is made to correspond to the proximal end portion near the outer peripheral edge of the bare seal element 8, and the first housing component H ₁ and the second housing It is also desirable to maintain the pressure by holding the parts H ₂ together. At this time, the seal element 8 and the gasket 3 are bonded together in the state before holding the negative pressure by the first housing part H ₁ and the second housing part H _2, that is, in the unassembled state. It is also desirable to integrate by, for example, or integrate by baking (vulcanization).

  As a specific example, it is possible to integrate with a chemically reactive adhesive containing cyanoacrylate or the like, or with vinylidene fluoride fluororubber (FKM) when the material of the seal element 8 and the gasket 3 is polytetrafluoroethylene (PTFE). The integration by vulcanization adhesion (baking) can be mentioned. By adopting such an integrated structure, the rigidity and strength of the pressure-holding holding portion can be increased, and the sealing element 8 can be maintained in a stable posture at a highly accurate position, the sealing performance is improved, and the life is extended. .

In the following, each embodiment will be specifically described. First, from the seventh embodiment shown in FIG. 7 and FIG. 8, a butterfly valve for a vehicle exhaust gas recirculation system (hereinafter referred to as an EGR system) is illustrated as the fluid device 10. In FIG. 8, the butterfly valve disc 15 is fixed to a shaft 2 as a swingable valve shaft so as to open and close the flow path 16. The shaft 2 is a first housing part H ₁ having a flow path 16. Further, it is arranged in a direction orthogonal to the flow path 16.

7 and 8 show the case where the second housing part H ₂ is a cylindrical sliding bearing 17, and the bearing 17 is fitted into the left and right holes 18, 18 of the first housing part H ₁ and fixed. The means 5 includes a concave groove 19 formed in the hole 18 and a C-shaped retaining ring 20. Reference numeral 21 denotes a valve opening / closing operation lever fixed to one end of a shaft (valve shaft) 2. The shaft (valve shaft) 2 has a stepped portion 21, and the inner end surface 22 of the bearing 17 (second housing part H ₂ ) corresponds to (slidably contacts with) the stepped portion 21, so that the shaft (valve The movement of the shaft 2 in the left-right axial direction is prevented. Thus, in FIGS. 7 and 8, the hole 11 of the first housing part H ₁ has a large diameter, and the hole 12 of the second housing part H ₂ has a small diameter.

The inner diameter dimension of the hole 18 is set to be larger than the inner diameter dimension of the hole 11, and in the first housing part H ₁ , a bare seal is formed at the stepped corners of the hole 11 and the hole 18. A seal element base end storage space 23 having a shaft center dimension L ₁ slightly smaller than the thickness of the element 8 is formed, a stepped surface 24 forming one side surface of the storage space 23, and an inner end surface 22 of the bearing 17. Then, the sealing element 8 is pressed and held (fixed).

Incidentally, 25, as edge inner and curved in a J-shape do not interfere, a cutaway formed relief space into the first hole portion 11 of the housing part H _1. The space 25 and the storage space 23 are continuously formed in a stepped shape (step shape).
Although not shown, the fixing means 5 for preventing the second housing part H ₂ (bearing 17) from coming off is formed with a female screw portion near the outer end of the hole 18 and a male screw on the outer peripheral surface. It is also desirable to configure with an annular nut formed with a portion (not shown).

  In each embodiment shown in FIGS. 1 to 6, the fluid device may be a butterfly valve for the EGR system similar to that in FIGS. 7 and 8, but other than that, a vacuum pump, a compressor A swing motor (rotary actuator), a fluid pressure cylinder (moving linearly), a valve (having a spool), etc. are also free.

Next, additional description will be given of each embodiment of FIGS.
The shaft insertion hole 11 of the first housing part H _{1 has} an inner diameter that is slightly larger than the outer diameter of the shaft 2 (with a circular cross section) and is formed in a region close to the right space 7 in FIG. A large-sized hole 13 is formed through the surface 24 up to the left space 6 in FIG. The second housing part H ₂ has an insertion cylindrical part 14 that fits into the hole 13 of the first housing part H ₁ . An example of the fixing means 5 is a bolt 26. That is, the bolt 26 is screwed from the left space 6 side to fix the second housing part H ₂ to the first housing part H ₁ . And the distal end surface 14A of the insertion cylindrical portion 14, the first housing part stepped surface 24 of the H _1, the sealing element 8 is挾着. FIG. 1 shows a case where only the bare seal element 8 is clamped and held between the stepped surface 24 and the tip surface 14A, and the gasket is omitted.

In contrast, in FIG. 2, the gasket 3 is interposed between the tip surface 14 </ b> A and the seal element 8.
In FIG. 3, the gasket 3 is interposed between the stepped surface 24 and the seal element 8.
In FIG. 2, the fixing means 5 exemplifies a bolt 26 screwed from the right space 7 side, and FIG. 3 exemplifies a bolt / nut coupling 27.

  Next, FIGS. 4, 5 and 6 show cases where the bending direction of the seal element 8 in FIGS. Other configurations are the same as those in FIGS. 1, 2, and 3.

By the way, it is desirable that the radial position of the seal element 8 is set with high accuracy in a state in which the seal element 8 is clamped and held, and its axis is completely aligned with the axis L ₂ of the shaft 2. Therefore, in FIGS. 1 to 7, the hole 13, the outer peripheral end surface 8 A of the seal element 8 is fitted to the holes 13 and 18 of the first housing part H ₁ with high precision (tight fitting). The inner diameter dimension of 18 and the outer diameter dimension of the seal element 8 are set to be the same.
The shaft center L is formed by the stepped surface 24 of the first housing part H ₁ and the front end face 14A or the inner end face 22 of the second housing part H ₂ with the seal element 8 alone or with the gasket 3 interposed. Hold (fix) in a direction parallel to ₂ . Moreover, with the stepped surface 24 for挾圧(挾着),挾圧end surface 28, such as the distal end surface 14A · the end face 22 is a flat shape orthogonal to the axis L ₂ of the shaft 2.

Figure 9 is an explanatory view of the above stepped surface 24 or the distal end surface 14A · the end face 22 as挾圧plane (end face) 28 from the axis L ₂ parallel direction, FIG. 9 (A)挾A plurality of small protrusions 42 project from the pressure end surface 28, and as shown by the dotted lines in FIG. 1, the small protrusions 42 enter the seal element 8, and the seal element 8 rotates about the axis of the shaft 2. Or moving in the radial inward direction is prevented. The small protrusions 42 may be provided on the stepped surface 24 side (not shown). Alternatively, instead of the small protrusion 42 in FIG. 9A, a small concave portion is formed on the compression end face 28, and a part of the seal element 8 enters the small concave portion in the clamped state and rotates. May be prevented (not shown).

As shown in FIG. 9 (B), a plurality of ridges 43 are provided radially, and as shown by the dotted lines in FIG. 2, the ridges 43 enter the gasket 3 to rotate or radially inward. It is also preferable to prevent movement. The protrusion 43 can be provided on the stepped surface 24 side, and the radial protrusions 43 in FIG. 9B can be formed as radial grooves.
As shown in FIG. 9C, radial short ridges 44 that are shorter than those in FIG. 9B are provided, and as shown by the dotted lines in FIG. It is also preferable to prevent rotation or movement in the radial inward direction. It is also preferable to provide the short protrusion 44 on the stepped surface 24 side. Further, the radial short ridges 44 may be radial short grooves.
Next, as shown in FIG. 9 (D), it is desirable that the pressing end surface 28 be a knurled surface 45 or the pressing end surface 28 be a blast roughened surface 46 as shown in FIG. 9 (E).

Further, as shown in FIG. 10 (A), an eccentric pattern 47 constituted by circular ridges or concave grooves eccentric with respect to the axis L ₂ may be provided on the compression end face 28. Alternatively, as shown in FIG. 10B, it is also preferable to apply an elliptical pattern 48 to the compression end face 28 with a ridge or a groove. Alternatively, as shown in FIG. 10C, it is also preferable to apply a polygonal pattern 49 to the compression end face 28 with a ridge or a groove.
In FIGS. 10 (A) to 10 (C), the function and effect for preventing rotation and improving the sealing performance are exhibited.
In this way, the pressure end face 28 (one or both) such as the tip end face 14A, the stepped face 24, the inner end face 22 and the like on which the seal element 8 is attached is shown in FIGS. Forming as in A) to (C) prevents the sealing element 8 from being rotated, or prevents displacement in the radial inward direction, and also improves the sealing performance.

In the present invention, as described above, the first housing part H ₁ and the second housing part H ₂ having the shaft insertion holes 11 and 12 constituting the housing H of the fluid device are assembled to the fixing means 5. The bare seal element 8 with the outer case and the inner case being omitted is fixedly held by itself or via the gasket 3 so that the shaft 2 and the holes 11 and 12 are connected to each other. Since the gap is sealed, the number of sealing materials can be minimized (one or two), so that downsizing can be achieved and the cost can be reduced. Further, the in interfitting sufficiently large first housing part H ₁ and the second housing part H ₂ holes 13 and 18 such as the seal element 8 (which挾圧the sealing element 8)挾圧endface 28 , 28 has a plane shape orthogonal to the axis L ₂ with high accuracy, and the sealing performance is also stabilized by ensuring a stable posture. Further, as illustrated in FIG. 9, there is an advantage that _one portion (the compression end surface 28) of the large first and second housing parts H ₁ and H ₂ can be easily sealed and processed to prevent rotation. There is also.

In addition, since the sealing element 8 and the gasket 3 are integrated in the state before being held tightly, the portion held by the first housing part H ₁ and the second housing part H _{2 is} held. The rigidity and strength of the seal element 8 is improved, and the sealing element 8 (although it is a small part) maintains a highly accurate position and orientation stably, has excellent sealing performance, prevents uneven wear, etc. Withstand use for a period (extends life).

2 shaft 3 gasket 5 fixing means 8 seal element
10 Fluid equipment
11, 12 shaft insertion hole
17 Cylindrical sliding bearing
18 holes
22 Inner end face
24 Stepped surface
28 Pressure end face
47 Eccentric pattern
48 Ellipse pattern
49 Polygon pattern H Housing H ₁ First housing part H ₂ Second housing part

Claims (4)

The first housing part (H ₁ ) and the second housing part (H ₂ ) having the shaft insertion holes (11) and (12) constituting the housing (H) of the fluid device are assembled, and the fixing means (5) fixed to each other by a sealing element bare state is omitted outer case and the inner case (8), and 挾着 held in alone, the shaft (2) and the shaft insertion hole portion (11) (12 ) configured to seal between the,
The second housing part (H ₂ ) is a cylindrical sliding bearing (17), and the first housing part (H ₁ ) has a hole (18) for fitting the cylindrical sliding bearing (17). The sliding bearing (17) is fitted into the hole (18), and the inner end surface (22) of the bearing (17) and the back side stepped surface (24) of the hole (18) A shaft sealing structure characterized in that the sealing element (8) is attached and held . The first housing part (H ₁ ) and the second housing part (H ₂ ) having the shaft insertion holes (11) and (12) constituting the housing (H) of the fluid device are assembled, and the fixing means (5) fixed to each other by a sealing element bare state is omitted outer case and the inner case (8), via a gasket (3), and挾着holding the shaft (2) and the hole for the shaft insertion Configured to seal between the parts (11) and (12),
The second housing part (H ₂ ) is a cylindrical sliding bearing (17), and the first housing part (H ₁ ) has a hole (18) for fitting the cylindrical sliding bearing (17). The sliding bearing (17) is fitted into the hole (18), and the inner end surface (22) of the bearing (17) and the back side stepped surface (24) of the hole (18) A shaft sealing structure characterized in that the sealing element (8) is attached and held. The first housing part (H ₁ ) and the second housing part (H ₂ ) having the shaft insertion holes (11) and (12) constituting the housing (H) of the fluid device are assembled, and the fixing means (5) fixed to each other by a sealing element bare state is omitted outer case and the inner case (8), and 挾着 held in alone, the shaft (2) and the shaft insertion hole portion (11) (12 A shaft sealing structure configured to seal between
The first housing part (H ₁₎ or the second housing part挾圧end face of the (H ₂₎ (28) for contact with the sealing element (8) of the bare state, viewed from the axial direction, the eccentric pattern (47), A shaft sealing structure characterized by having a shape of either an elliptical pattern (48) or a polygonal pattern (49) with improved sealing performance and a protrusion or groove for preventing rotation. A first housing component (H) having a shaft insertion hole (11) (12) constituting a housing (H) of the fluid device ₁  ) And second housing part (H ₂  ) Are fixed to each other by the fixing means (5), and the bare seal element (8), in which the outer case and the inner case are omitted, is clamped and held via the gasket (3). A shaft sealing structure configured to seal between (2) and the shaft insertion hole (11) (12),
A first housing part (H) in contact with the bare seal element (8) or gasket (3); ₁  ) Or second housing part (H ₂  ) Of the compression end face (28) of the eccentric pattern (47), elliptical pattern (48), or polygonal pattern (49) as seen from the axial direction, improving sealing performance and preventing rotation. A shaft sealing structure characterized by having a protrusion or a concave groove.

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