JP4736394B2 - Seal ring - Google Patents

Description

  The present invention relates to a seal ring.

  In a hydraulic system for automobiles, in particular, a drive system represented by AT (automatic transmission), a seal ring that seals a gap between a shaft and a housing is used.

  FIG. 5 is a schematic view showing a conventional seal ring 101.

  The seal ring 101 is for sealing an annular gap between the housing 200 provided with the shaft hole and the shaft 300 inserted into the shaft hole, and is attached to the annular groove 301 provided in the shaft 300. Has been used.

  The seal ring 101 is made of a resin material. The seal ring 101 is provided in the housing 200 and the first seal portion 102 for sealing the non-sealing target fluid side A side wall surface of the annular groove 301 provided in the shaft 300. And a second seal portion 103 for sealing the inner peripheral surface of the shaft hole formed.

  When the pressure is applied in the direction of the arrow P in FIG. 5 from the sealing target fluid side O toward the non-sealing target fluid side A, the seal ring 101 is pressed against the non-sealing target fluid side A. 102 presses the side wall surface of the annular groove 301, and the second seal portion 103 presses the inner peripheral surface of the shaft hole facing the annular groove 301 and seals it at each position.

  In this way, leakage of the sealing fluid to the non-sealing target fluid side A was prevented. Here, the fluid to be sealed is, for example, lubricating oil, and particularly refers to ATF (automatic transmission oil) when used in an automobile transmission.

  FIG. 6 is a diagram for explaining problems when the seal ring 101 is mounted. FIG. 6A shows a state in which the seal ring 101 is mounted eccentrically with respect to the shaft 300. b) is an enlarged view of a portion corresponding to the dotted line portion when the shaft 300 is inserted into the housing 200 in FIG. 5A, and FIG. 5C shows the seal ring 101 being extremely eccentric with respect to the shaft 300. The case where it is mounted in a state is shown.

  Below, the problem at the time of mounting | wearing with the seal ring 101 is demonstrated.

  The seal ring 101 is attached to the annular groove 301 while expanding a cut portion provided on the circumference thereof. After the mounting, the seal ring 101 is held on the bottom surface of the annular groove 301 with the bottom surface of the annular groove 301 temporarily tightened.

  In this state, the shaft 300 is moved in the direction of the arrow in FIG. 6B and inserted into the housing 200. However, when the seal ring 101 cannot maintain the state of tightening the bottom surface of the annular groove 301, the shaft 300 There is a concern that the seal ring 101 may come into contact with the opening edge of the housing 200 at the portion X shown in FIG.

Therefore, conventionally, the annular groove 301 is filled with glycerin or the like and the diameter of the seal ring 101 is reduced, so that the seal ring 101 is temporarily fixed and held in the annular groove 301, or paraffin is applied to the seal ring 101. Means for temporarily fixing and holding the seal ring 101 in the annular groove 301 has been used. However, these means are inconvenient and troublesome.

  Furthermore, because of the function of the seal ring (because the outer diameter of the seal ring during operation is the inner diameter of the housing), especially when the annular gap is large, the degree of freedom of the seal ring is large relative to the annular groove. Since the seal ring is easily eccentric with respect to the shaft, this problem is likely to occur (see FIG. 6C).

  In recent years, along with the reduction in sliding resistance and downsizing, the cross-sectional shape of the seal ring tends to be deformed and reduced in cross-section, and therefore, seal rings having a substantially T-shaped cross section have become mainstream.

As a document disclosing related conventional examples, there is Patent Document 1.
International Publication No. 03/100301 Pamphlet

  However, the above problem may occur even in a seal ring having a T-shaped cross section.

  FIG. 7 is a schematic cross-sectional view showing a seal ring 100 having a T-shaped cross section, and FIG. 8 is a schematic cross-sectional view for explaining problems of the conventional seal ring 100.

  By the way, in the seal ring 101, a clearance (clearance) is formed on the side surface and the bottom of the groove for introducing hydraulic pressure. In addition, in the seal ring 100 having a substantially T-shaped cross section, in addition to this, The side wall of the seal ring 100 has a lightening portion 41 (an oil groove portion, a relief portion, a portion provided for reducing sliding resistance, and this portion is provided with respect to a seal ring having a substantially rectangular cross section so that the cross section is substantially T A character shape). As described above, the seal ring 100 having a substantially T-shaped cross section has a gap also formed between the side wall surface of the annular groove 301 and the thinned portion 41, and therefore, the annular groove compared to the seal ring 101 having a substantially rectangular cross section. The degree of freedom within 301 is great.

  Therefore, as shown in FIG. 8, after the seal ring 100 is attached to the shaft 300, the seal ring 100 is easily moved in the annular groove 301 when the shaft 300 is inserted into the housing. There is a concern that 100 may fall out of the annular groove 301. In particular, when the annular gap is large, this appears more conspicuously than the seal ring 101 having a substantially rectangular cross section.

  Therefore, the equipment is assembled by temporarily fastening the cutting portion using a high-viscosity fluid such as “grease” or “petrol” that does not affect the operation of the equipment.

  However, with the temporary fixing method, the assembly workability (assembly efficiency) of the equipment is reduced, or foreign matter adheres to grease or petroleum jelly, so that the foreign matter flows into the hydraulic circuit of the equipment, and the operation and durability of the equipment There are concerns about adverse effects on sex.

  The present invention has been made in view of the above-described circumstances, and the axial width on the groove bottom side of the first seal portion that seals the side wall surface of the annular groove on the non-sealing target fluid side is set to the first width. It is an object of the present invention to provide a technique capable of improving the assemblability in a seal ring in which sliding resistance is reduced by providing the seal portion smaller than the axial width.

In order to achieve the above object, the present invention provides:
A first seal portion that seals the side wall surface on the non-sealing target fluid side of the annular groove provided in one of the two members concentrically and relatively rotatably assembled;
A second seal portion for sealing the surface of the other member of the two members;
A seal ring that seals the annular gap between the two members by these seal portions,
A separation part is provided at one place in the circumferential direction of the ring body,
The sliding resistance is reduced by providing the axial width of the ring body on the groove bottom side of the annular groove with respect to the first seal portion smaller than the axial width of the ring body in the first seal portion. In the seal ring,
A protruding portion that protrudes toward the side wall surface of the annular groove is provided on the groove bottom side of the first seal portion over the entire circumference .
The projecting portion is provided so as not to contact the side wall surface of the annular groove even when a fluid to be sealed acts on the annular gap between the two members .

  With this configuration, the seal ring can be made difficult to move in the annular groove. Therefore, when one member fitted with the seal ring is inserted into the other member, the seal ring is dropped from the annular groove. Can be prevented. Thereby, it becomes possible to improve the assembly property (assembly efficiency) of the apparatus to which the seal ring is applied.

Further, since the projecting portion is provided so as not to contact the side wall surface of the annular groove even when a fluid to be sealed acts on the annular gap between the two members, the sealing performance is affected. Without giving, it is possible to improve the assemblability of the device to which the seal ring is applied.

  Here, the shape of the projecting portion may be a shape that is symmetrical with respect to an axis (plane) hypothesized in the radial direction (a direction orthogonal to the axial direction) in consideration of assembly.

  According to the present invention, the axial width on the groove bottom side of the first seal portion that seals the side wall surface of the annular groove on the non-sealing target fluid side is smaller than the axial width of the first seal portion. Thus, it is possible to provide a technique capable of improving the assemblability of the seal ring with reduced sliding resistance.

  The best mode for carrying out the present invention will be exemplarily described in detail below with reference to the drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in this embodiment should be appropriately changed according to the configuration of the apparatus to which the invention is applied and various conditions. It is not intended to limit the scope to the following embodiments.

(Embodiment 1)
FIG. 1 is a plan view showing a seal ring 1 according to Embodiment 1 of the present invention, and FIG. 2 is a schematic cross-sectional view showing the seal ring 1 according to this embodiment, corresponding to the AA cross section of FIG. FIG. 3 and FIG. 3 are schematic sectional views showing a state in which the seal ring 1 according to the present embodiment is mounted on the shaft 30.

  The seal ring 1 is for sealing an annular gap between the housing 20 as the other member provided with the shaft hole and the shaft 30 as one member inserted into the shaft hole. It is used by being mounted in an annular groove 31 provided in the 30.

The seal ring 1 is made of a resin material, and the first seal portion 2 for sealing the side wall surface 32 on the non-sealing target fluid side A of the annular groove 31 provided in the shaft 30 and the housing 20 And a second seal portion 3 for sealing the inner peripheral surface 21 of the provided shaft hole.

Then, when pressure is applied in the direction of arrow P in FIG. 2 from the sealing target fluid side O toward the non-sealing target fluid side A, the seal ring 1 is pressed against the non-sealing target fluid side A, so the first seal portion 2 presses the side wall surface 32 of the annular groove 31, and the second seal portion 3 presses the inner peripheral surface 21 of the shaft hole facing the annular groove 31 and seals it at each position.

  In this way, leakage of the sealing fluid to the non-sealing target fluid side A was prevented. Here, the fluid to be sealed is, for example, lubricating oil, and particularly refers to ATF (automatic transmission oil) when used in an automobile transmission.

  The seal ring 1 is provided with a separation portion (cutting portion, joint portion) S at one place in the circumferential direction for the purpose of improving assemblability. The shape of the separation portion S is not particularly limited, but from the viewpoint of sealing properties, a so-called special step cut that can maintain the sealing performance against ambient temperature changes is preferable. The special step cut is a separation structure in which a step-like separation part is formed on both of two seal surfaces (the first seal part 2 side and the second seal part 3 side) in the seal ring. This special step cut is provided with a pair of left and right (axial direction) projections and recesses on the outer peripheral side on one side through a separated part, and a pair of left and right recesses and projections on the other side. . And it is comprised so that the convex part of one side and the recessed part of the other side may fit, and the concave part of one side and the convex part of the other side may fit.

  The features of this embodiment will be described below.

  The seal ring 1 has a substantially T-shaped cross section. Thereby, the outer circumferential side and the inner circumferential side of the seal ring are provided with different axial widths (lengths).

  That is, the width of the ring body in the axial direction on the groove bottom 33 side of the annular groove 31 relative to the first seal portion 2 (in the seal ring 1, the width of the inner peripheral surface of the seal ring 1) B is the first seal. The width of the ring body in the axial direction of the portion 2 is smaller than the width C (in the seal ring 1, the width of the outer peripheral surface of the seal ring 1) C.

  Further, the substantially T-shaped cross section of the seal ring 1 shown in FIG. 1 is a shape in which the inner peripheral side (groove bottom 33 side) portion of the side surface of the seal ring having a substantially rectangular cross section is hollowed out. Yes. Here, for the sake of convenience of explanation, the portion that has been thinned is referred to as a thinned portion (oil groove portion, escape portion) 4.

  As a characteristic configuration of the present embodiment, the seal ring 1 includes a protrusion 5 as a protruding portion protruding in the axial direction in the lightening portion 4.

  The protrusion 5 is provided in the axial direction in a range in which the seal ring 1 is provided between the two members and pressure P is applied and does not contact the side wall surface 32 of the annular groove 31, that is, in a range that does not affect the sealing performance. Is provided to protrude. Here, in the seal ring 1 (its cross-sectional shape, in particular, the protrusion 5), as shown in FIG. It has a symmetrical shape (a left-right symmetrical shape in FIG. 2).

Further, the protrusion 5 is that provided over the entire circumference in the lightening portion 4 of the seal ring 1.

  As described above, since the seal ring 1 is provided with a substantially T-shaped cross section, the contact area (pressure receiving area) with the side wall surface 32 of the annular groove 31 in the first seal portion 2 can be reduced. , Sliding resistance can be reduced.

  In the present embodiment, the protrusion 5 is provided on the thinned portion 4 so that the seal ring 1 can hardly move in the annular groove 31. The protrusion 5 contacts the side wall surface 32 of the annular groove 31 even if it is greatly decentered, and this functions as a drop-off prevention. Therefore, when the shaft 30 fitted with the seal ring 1 is inserted into the housing 20, the seal ring 1 It can prevent falling off from the annular groove 31 (see FIG. 3). Thereby, it becomes possible to improve the assembly property of the apparatus to which the seal ring 1 is applied.

  In addition, since it is no longer necessary to use high-viscosity fluids such as grease and petroleum jelly, foreign matter adheres to grease and petroleum jelly, which has been a concern in the past, and the foreign matter flows into the hydraulic circuit of the equipment, causing operation and durability of the equipment. There is no adverse effect on sex.

  In the above description, the seal ring 1 is attached to the annular groove 31 formed in the shaft 30 as one of the two members. However, the seal ring 1 is not limited to this and is provided on the housing 20 side. It may be attached to the annular groove and slidably contact the outer peripheral surface of the shaft 30.

(Embodiment 2)
FIG. 3 is a schematic cross-sectional view showing a seal ring 10 according to Embodiment 2 of the present invention. In addition, about the component similar to the seal ring 1 shown in FIG. 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  In the seal ring 1 shown in FIG. 1, the cross-sectional shape is substantially T-shaped, but in the seal ring 10, the cross-sectional shape is substantially trapezoidal as shown in FIG.

  By providing the seal ring 10 with a substantially trapezoidal cross section, the axial width (for example, the width of the inner peripheral surface of the seal ring 10) B on the groove bottom 33 side of the annular groove 31 with respect to the first seal portion 2 is The axial width of the first seal portion 2 (the width on the outer peripheral surface side of the seal ring 10) C is provided.

  In the seal ring 10, the contact state of the first seal portion 2 for sealing the side wall surface 32 of the annular groove 31 is linear (a contact state that is elongated and continuous with the side wall surface 32, actually slightly. Since the pressure receiving area can be reduced, the sliding resistance can be reduced.

  In such a seal ring 10 as well, the projection 5 protruding in the axial direction is provided on the inner peripheral side (the groove bottom 33 side of the annular groove 31) with respect to the first seal portion 2. An effect can be obtained.

It is a top view which shows the seal ring which concerns on Embodiment 1 of this invention. It is a schematic sectional drawing which shows the seal ring which concerns on Embodiment 1 of this invention. It is a schematic sectional drawing which shows the state which mounted | wore the shaft with the seal ring which concerns on Embodiment 1 of this invention. It is a schematic sectional drawing which shows the seal ring which concerns on Embodiment 2 of this invention. It is a schematic sectional drawing which shows the conventional seal ring. It is a figure for demonstrating the problem at the time of mounting | wearing with the conventional seal ring. It is a schematic sectional drawing which shows the conventional seal ring. It is a schematic sectional drawing for demonstrating the problem of the conventional seal ring.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,10 Seal ring 2 1st seal part 3 2nd seal part 4 Thickening part 5 Protrusion 20 Housing 21 Inner peripheral surface 30 Shaft 31 Annular groove 32 Side wall surface 33 Groove bottom

Claims (1)

A first seal portion that seals the side wall surface on the non-sealing target fluid side of the annular groove provided in one of the two members concentrically and relatively rotatably assembled;
A second seal portion for sealing the surface of the other member of the two members;
A seal ring that seals the annular gap between the two members by these seal portions,
A separation part is provided at one place in the circumferential direction of the ring body,
The sliding resistance is reduced by providing the axial width of the ring body on the groove bottom side of the annular groove with respect to the first seal portion smaller than the axial width of the ring body in the first seal portion. In the seal ring,
A protruding portion that protrudes toward the side wall surface of the annular groove is provided on the groove bottom side of the first seal portion over the entire circumference .
The projecting portion is provided so as not to contact the side wall surface of the annular groove even when a fluid to be sealed acts on the annular gap between the two members .

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