JP2013155846A - Seal ring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seal ring having excellent sealability, low friction properties and low wear without being affected the shape of a sidewall of a mounting groove despite its simple shape.SOLUTION: A seal ring 1 is mounted to an annular groove provided in a rotation axis inserted through an axis hole of a housing, slidably contact with the sidewall surface of a non-sealing fluid side of the annular groove, contacts with an inner circumferential surface of the axis hole and seals an annular gap between the rotation axis and the axis hole. The seal ring 1 has an abutment joint 1a. An entire ring side surface 4 contacting with an upper sidewall surface is a surface having a tilt angle α so that a width of the surface is smaller in an outer circumference side than an inner circumference side. A ring outer circumferential surface 3 is a surface parallel to in an axis center of the seal ring and the inner circumferential surface of the axis hole. The tilt angle α is an angle within a range of 1 to 3° or smaller with respect to an angle perpendicular to the seal ring in its axis center direction.

Description

  The present invention relates to a seal ring that is mounted on a rotating shaft of a device such as an automatic transmission (hereinafter referred to as AT), a continuously variable transmission (hereinafter referred to as CVT), and holds a hydraulic pressure necessary for the operation of the device. .

  In devices such as AT and CVT, an oil seal ring for sealing hydraulic oil is attached to a key point. For example, the working oil supplied from the oil passage between the two annular grooves is attached to a pair of spaced annular grooves provided on the rotation shaft inserted through the shaft hole of the housing, and the side surfaces and inner peripheral surfaces of both seal rings. The side wall of the annular groove and the inner peripheral surface of the housing are sealed by the opposite side surface and the outer peripheral surface. Each seal surface in the seal ring holds the hydraulic pressure of the hydraulic oil between the seal rings while being in sliding contact with the side wall of the annular groove and the inner peripheral surface of the housing.

  Such a seal ring requires little oil loss and sufficient oil sealability. Moreover, in order to maintain performance over a long period of time, it is also required that the amount of wear be small. Particularly in recent years, improvement in fuel efficiency has been an important issue from the viewpoint of improving vehicle performance and reducing environmental burden. In equipment such as AT and CVT, a good seal is provided between the seal ring and the side wall of the annular groove. It is desired to further reduce friction and wear while maintaining the properties. The seal ring in CVT is used in a region where the PV value (value multiplied by load (P) and sliding speed (V)) is higher than that in AT, so higher wear resistance is required. It is done.

  A conventional general seal ring has a rectangular ring cross section. In such a seal ring, the contact area between the side surface of the seal ring and the side wall of the annular groove is large, and the friction loss increases. Further, due to variations in the processing accuracy of the annular groove, there is a risk that the sealing performance may be inferior when the groove opens outward. In order to cope with such a problem, the side surface of the ring that contacts the side wall surface of the annular groove on which the seal ring is mounted is a surface provided with an inclination angle such that the width on the inner peripheral side is smaller than the width on the outer peripheral side. Various techniques have been proposed (the following patent documents 1 to 4 and the like).

  For example, in Patent Document 1, in a seal ring that is mounted in a mounting groove having a tapered side wall, a taper portion or a step portion corresponding to the taper of the side wall is provided on an end surface in the axial direction. A seal ring is disclosed in which an annular close contact portion is provided in close contact with the side wall at the stepped portion. Further, Patent Document 2 discloses a seal ring in which the side surface of the seal ring has a tapered surface with an inclination angle of 2 to 10 degrees so that the width on the inner peripheral side is smaller than the width on the outer peripheral side, and the outer peripheral surface has an arc shape. Is disclosed.

  In Patent Document 3, the side surface which is a tapered surface inclined so as to reduce the ring width toward the radially inner side of the seal ring, and the outer diameter on one side surface is larger than the outer diameter on the other side surface side. Thus, a seal ring having an outer peripheral surface having a partially or entirely tapered or stepped cross-sectional shape is disclosed. Further, in Patent Document 4, in a seal ring formed on a tapered surface such that the inner circumferential width between both side surfaces of the seal ring is smaller than the outer circumferential width, the taper surface on both side surfaces of the seal ring has two steps. There is disclosed a seal ring that is formed in (or multi-stages) and whose taper surface has an inclination angle of the taper surface on the inner peripheral surface side larger than that of the taper surface on the outer peripheral surface side.

JP-A-8-28709 JP-A-8-219292 Japanese Patent Laid-Open No. 9-217836 JP 2004-28273 A

  Each of the seal rings of Patent Documents 1 to 4 deals with a sealing property that is generated when the side wall of the annular groove serving as the mounting groove is formed in a tapered shape. However, the sidewall shape of the mounting groove is not necessarily formed in a tapered shape. In this case, the desired effect may not be obtained with these conventional seal rings.

  Since the seal ring of Patent Document 3 is also provided with a taper on the outer peripheral surface, the outer peripheral surface of the seal ring and the inner peripheral surface of the housing slide depending on use conditions, or the outer peripheral surface of the seal ring is worn or the housing The inner peripheral surface may be worn out. Moreover, in this structure, in order to generate a wedge effect on the outer peripheral surface, it is necessary to manage the direction of assembly into the mounting groove.

  Since the seal ring of Patent Document 4 has a complicated structure in which the ring side surface is a multi-step tapered surface, the inclination angle of each tapered surface and the selection of the multi-step boundary line position can be selected by reducing the shape of the mounting groove and the pressing pressure. It is necessary to make a detailed determination in relation to the above, and is complicated.

  Further, the slight difference in the inclination angle of the ring side surface (taper surface) tends to affect the frictional force, the wear amount, and the sealing performance. However, in these conventional seal rings, the relationship between the inclination angle and each characteristic has not been sufficiently studied. In addition to the shape of the cross section of the seal ring, it is also important to combine the shape of the abutment, the material of the ring, etc., so that the desired characteristics of the seal ring as a whole are exhibited.

  The present invention has been made to cope with such problems, and has a simple shape but is excellent in sealing properties, low friction properties, and low wear properties regardless of the shape of the side wall of the mounting groove. The purpose is to provide a ring.

  The seal ring of the present invention is attached to an annular groove provided in a rotating shaft inserted through the shaft hole of the housing, slidably contacts the side wall surface of the annular groove on the non-sealed fluid side, and the shaft A seal ring that contacts an inner peripheral surface of a hole and seals an annular gap between the rotary shaft and the shaft hole, the seal ring having an abutment and contacting at least the side wall surface The entire side surface is a surface provided with an inclination angle such that the inner peripheral side width is smaller than the outer peripheral side width, and the ring outer peripheral surface is in the axial direction of the seal ring and the inner peripheral surface of the shaft hole. It is a parallel plane, and the inclination angle is an angle in a range of more than 1 degree and less than 3 degrees with respect to a plane perpendicular to the axial direction of the seal ring. In particular, the inclination angle is 1.5 to 2.5 degrees with respect to a plane perpendicular to the axial direction of the seal ring.

  The abutment of the seal ring is a compound step cut type abutment.

  The seal ring is a molded body formed by injection molding of a resin composition.

  The base resin of the resin composition is a polyether ether ketone (hereinafter referred to as PEEK) resin or a polyphenylene sulfide (hereinafter referred to as PPS) resin. Moreover, the said resin composition contains 5-30 weight% of carbon fibers with respect to this whole resin composition, It is characterized by the above-mentioned.

  The molded article has a flexural modulus of 5000 to 12000 MPa. The “flexural modulus” in the present invention refers to a flexural modulus measured by ASTM D790, and the measurement temperature is room temperature (23 ° C.).

  The outer diameter of the seal ring is φ50 mm to φ60 mm. Further, the seal ring is used for an AT or CVT hydraulic device of an automobile.

  The seal ring of the present invention has an abutment and at least the entire ring side surface contacting the side wall surface of the annular groove to be mounted is provided with an inclination angle such that the inner peripheral side width is smaller than the outer peripheral side width. The ring outer peripheral surface is a surface parallel to the axial direction of the seal ring, etc., and the inclination angle is in the range of more than 1 degree and less than 3 degrees with respect to the surface perpendicular to the axial direction of the seal ring. Therefore, the sealing property, the low friction property, and the low wear property are comprehensively excellent. In particular, when the tilt angle is set to an angle of 1.5 to 2.5 degrees, the sealing property, the low friction property, and the low wear property are remarkably excellent overall.

  Since the joint of the seal ring is a composite step cut type joint, the sealing performance is particularly excellent.

  Since the seal ring is a molded body formed by injection molding of a resin composition, it is easy to provide a composite step-cut mold joint, and the rotational torque is lower and more stable than a machined seal ring. .

  Since the base resin of the resin composition is a PEEK resin or a PPS resin, it has excellent bending elastic modulus, heat resistance, etc., and does not crack even when expanded in diameter when incorporated in a groove, and the oil temperature of the working oil to be sealed Can be used even when the For this reason, it can utilize suitably as a seal ring used for the hydraulic device of AT or CVT of the car where oil temperature becomes high.

  Since the resin composition contains 5 to 30% by weight of carbon fiber with respect to the entire resin composition, and the bending elastic modulus of the molded body is particularly 5,000 to 12000 MPa, the resin composition is incorporated in the groove while maintaining the sealing property. Even if the diameter is expanded, it will not crack.

It is the perspective view and sectional drawing which show an example of the seal ring of this invention. It is sectional drawing which shows the state which integrated the seal ring of FIG. 1 in the annular groove of the hydraulic apparatus of CVT. It is a perspective view which shows the joint of a composite step cut type | mold. It is the schematic of the testing machine of a seal ring. It is a figure which shows the test result of the amount of oil leaks. It is a figure which shows the test result of rotational torque. It is a figure which shows the test result of wear amount.

An example of the seal ring of the present invention will be described with reference to FIGS. 1A is a perspective view of the seal ring, FIG. 1B is a partially enlarged sectional view in the axial direction of the seal ring of FIG. 1A, and FIG. 2 is a view of the CVT hydraulic device. Cross-sectional views in a state of being incorporated in the annular groove are respectively shown. As shown in FIG. 1, the seal ring 1 has one joint 1 a. In the seal ring 1, the ring side surface 4 is a surface (tapered surface) provided with an inclination angle α such that the width W _{2 in} the ring axis direction on the inner peripheral side is smaller than the width W _{1 in} the ring axis direction on the outer peripheral side. It is symmetrical. The ring outer peripheral surface 3 and the ring inner peripheral surface 2 are surfaces parallel to the axial direction of the seal ring 1. In addition, the corner | angular part of the ring internal peripheral surface 2 and the ring side surface 4 may be provided with chamfering, and the step part may be provided.

  As shown in FIG. 2, the seal ring 1 is mounted in an annular groove 7 a provided in the rotary shaft 7 inserted through the shaft hole 6 b of the housing 6. The arrow in the figure is the direction in which the pressure from the hydraulic oil is applied, and the right side in the figure is the unsealed fluid side. The seal ring 1 is slidably in contact with the side wall surface 7b on the non-sealed fluid side of the annular groove 7a at the ring side surface 4a. The outer peripheral surface 3 is in contact with the inner peripheral surface 6a of the shaft hole 6b. With this sealing structure, the annular gap between the rotating shaft 7 and the shaft hole 6b is sealed.

  When used in an AT or CVT hydraulic device of an automobile, ATF or CVTF is used as the hydraulic fluid, the oil temperature is about 50 to 80 degrees, the hydraulic pressure is about 1 to 2 MPa, and the rotational speed of the rotating shaft is 1000 to 1000. Used under conditions of about 3000 rpm.

  As shown in FIG. 1B, in the seal ring 1 of the present invention, the inclination angle α of the ring side surface 4 is more than 1 degree and less than 3 degrees with respect to the surface 5 perpendicular to the axial direction of the seal ring. It is characterized by being set in a range (1 <α <3). In each figure, for the sake of explanation, the actual angle is exaggerated. When the inclination angle α is 1 degree or less, the sealing performance is excellent, but the rotational torque is increased. On the other hand, when the inclination angle α is 3 ° or more, the rotational torque is low, but the sealing performance is poor. Furthermore, with regard to the wear amount of the seal ring, if there is a slight inclination angle, the wear amount can be suppressed more than when the inclination angle α is 0 degree, and the wear amount decreases as the inclination angle α decreases. As described above, in the aspect in which the inclined ring side surface and the annular groove are in contact with each other, the inclination angle of the ring side surface and the sealing property, the low friction property, and the low wear property have a complicated correlation. In the present invention, based on the knowledge shown in the examples and the like described later, by setting the inclination angle α in the above range (1 <α <3), it has both sealing properties, low friction properties, and low wear properties. It is

  The range of the inclination angle α is more preferably set to a range of 1.5 to 2.5 degrees (1.5 ≦ α ≦ 2.5) with respect to the plane 5 perpendicular to the axial direction of the seal ring. . Most preferably, the inclination angle α is set to 2 degrees. As shown in Examples and the like to be described later, when the inclination angle α is 2 degrees, the sealing property, the low friction property, and the low wear property are most excellent overall. Further, even in the range of 1.5 to 2.5 degrees considering the dimensional tolerance (0.5 degrees), the sealing performance, the low friction characteristics, and the low wear characteristics are comprehensively excellent.

  The inclination angle α may be set at least on the ring side surface 4a contacting the side wall surface 7b of the annular groove 7a (see FIG. 2), but it is not necessary to manage the direction of assembly into the mounting groove. As shown in FIG. 2, it is preferable that the both side surfaces 4a and 4b of the seal ring 1 be symmetrical with respect to a tapered surface having the same predetermined inclination angle α.

  Further, the ring side surfaces 4a and 4b are not constituted by two or more tapered surfaces having different inclination angles, but are entirely tapered surfaces having a predetermined inclination angle α. For this reason, the side surface shape is simple and can be used without being influenced by the side wall shape of the annular groove to be mounted. However, the corners of the ring inner peripheral surface 2 and the ring side surface 4 may be provided with straight or curved chamfers. When the seal ring is manufactured by injection molding, the ring protrudes from the mold to the inner diameter side of the ring. A stepped portion may be provided.

  The side wall surface 7b of the annular groove 7a shown in FIG. 2 is slightly inclined (about 1 degree) from the surface perpendicular to the rotational axis direction for discharging chips generated during cutting or due to sagging during polishing. It may become a tapered surface. Even in this case, the seal ring of the present invention is applicable. A particularly preferable aspect of the present invention is a case where the side wall surface 7b of the annular groove 7a is a surface (no taper) perpendicular to the rotation axis direction. In this case, the inclination angle α of the ring side surface 4a is in the range of more than 1 degree and less than 3 degrees (1 <α <3) with respect to the side wall surface 7b of the annular groove 7a.

  As shown in FIG. 2, the ring outer peripheral surface 3 is a surface parallel to the axial center direction of the seal ring 1 and the inner peripheral surface 6 a of the shaft hole 6 b of the housing 6 that is a sliding partner. The outer peripheral surface 3 is a surface perpendicular to the surface 5 perpendicular to the axial direction of the seal ring. Since the ring outer peripheral surface 3 has no axial taper and has a shape parallel to the inner peripheral surface 6a of the shaft hole 6b, each of the outer peripheral surface 3 and the inner peripheral surface 6a is in sliding contact. Hard to wear. Further, since the ring outer peripheral surface 3 is a surface parallel to the inner peripheral surface 6a of the shaft hole 6b of the housing 6 and both surfaces are in close contact with each other, the posture of the seal ring within the annular groove is maintained without being inclined. Be drunk. As a result, the positional relationship (inclination angle) of the ring side surface 4a with respect to the side wall surface 7b of the annular groove 7a can be maintained constant, and excellent sealing properties, low friction properties, and low wear properties can be maintained over a long period of time. Can do. A slight difference in the inclination angle of the ring side surface, more specifically, the positional relationship between the side wall surface of the annular groove and the ring side surface affects the frictional force, the amount of wear, and the sealing performance. Is limited to a very narrow range (1 <α <3), and the shape of the outer peripheral surface of the ring is also set as described above, so that a change in characteristics due to a change in the positional relationship can be prevented.

  The seal ring 1 is a cut-type ring having one joint 1a (see FIG. 1), and is expanded in diameter by elastic deformation and attached to the annular groove 7a. Since the seal ring 1 has the abutment 1a, the diameter of the seal ring 1 is increased by the hydraulic pressure of the hydraulic oil during use, and the outer peripheral surface 3 is in close contact with the inner peripheral surface 6a of the shaft hole 6b. The shape of the abutment la can be a straight cut type, an angle cut type, or the like, but it is preferable to employ a composite step cut type as shown in FIG. In particular, in the present invention, since the ring side surface is a tapered surface having a predetermined inclination angle, it may be inferior to the case of providing no taper in terms of sealing performance. By using in combination with the mouth shape, the taper surface improves friction and wear characteristics and also has excellent sealing properties.

  The joint of the composite step cut type will be described with reference to FIG. FIG. 3 is a perspective view of the state in which the joint 1a of FIG. The mating port 1a of the seal ring is formed by mating port ends 8 and 8 'facing each other. When the end 8 of the seal ring is divided into two parts, a ring inner peripheral surface side 8a and a ring outer peripheral surface side 8b, by connecting two side surfaces in a substantially rectangular cross section of the seal ring (a trapezoidal surface with a tapered ring side surface) A butting surface 9 is formed at the tip of the rectangular cross section on the peripheral surface side 8a. Further, the rectangular cross-section portion 8b on the outer peripheral surface side of the ring has a lip 10 projecting a predetermined length (L) from the butting surface 9 into one rectangular cross-section portion that further divides this portion into two in the radial direction, and the other lip 10 A pocket 11 that is recessed from the abutting surface 9 by removing the rectangular cross section is formed. The inner and outer peripheral surfaces of the lip 10 and the pocket 11 are formed to have a predetermined curvature of the seal ring. On the other hand, the other end 8 'has an abutting surface 9, a lip 10 and a pocket 11, and an abutting surface 9', a pocket 11 'and a lip 10' formed so as to be complementarily fitted. ing. That is, when the abutting surfaces 9 and 9 ′ meet each other, the lip 10 and the pocket 11 ′ are fitted into the pocket 11 and the lip 10 ′, respectively. The length of the lip 10 and the pocket 11 'and the length of the pocket 11 and the lip 10' are formed to be substantially the same. When the mating port is fitted, the lip 10 of the mating end portion 8 is fitted into the pocket 11 'of the mating end portion 8', and the seal ring is substantially circular (see FIG. 1A).

  The material of the seal ring of the present invention is not particularly limited, but considering the fact that the diameter may be expanded by elastic deformation and attached to the groove, or there may be a composite step-cut mold joint, etc., the molded body of the resin composition (Resin seal ring) is preferable.

  As a synthetic resin used as a base resin of a resin composition forming a seal ring, a thermosetting polyimide resin, a thermoplastic polyimide resin, a polyether ketone ether ketone ketone (hereinafter referred to as PEKEKK) resin, a polyether ketone (hereinafter referred to as PEK) resin, PEEK resin, wholly aromatic polyester resin, polytetrafluoroethylene (hereinafter referred to as PTFE) resin, polytetrafluoroethylene / perfluoroalkyl vinyl ether copolymer resin, tetrafluoroethylene / hexafluoropropylene copolymer Examples thereof include a polymer resin, an ethylene-tetrafluoroethylene copolymer resin, a PPS resin, a polyamideimide (hereinafter referred to as PAI) resin, and a polyamide (hereinafter referred to as PA) resin. These resins may be used alone or as a polymer alloy in which two or more kinds are mixed.

  The seal ring is injection-molded with a resin composition because it is easy and low cost to manufacture a seal ring having a composite step-cut joint, and the rotational torque is lower and more stable than when machined. It is preferable to form an injection molded body. For this reason, it is preferable to use a thermoplastic resin that can be injection-molded as the synthetic resin. Of these, crystalline polyimide resins such as thermoplastic polyimide resin, PEKKK resin, PEK resin, PEEK resin, PPS resin, PAI resin, and PA resin are particularly preferable because of excellent frictional wear characteristics.

  Among such crystalline thermoplastic resins, it is particularly preferable to use PEEK resin or PPS resin because of excellent bending elastic modulus, heat resistance, and slidability. These resins have a high elastic modulus and do not crack even when they are expanded in diameter when incorporated in a groove, and can be used even when the temperature of the hydraulic fluid to be sealed becomes high, and there is no concern about solvent cracks.

  The PEEK resin is a crystalline thermoplastic resin having a polymer structure represented by the following formula (1) in which the benzene ring is linked to the para position by a carbonyl group and an ether bond. The PEEK resin having the structure of the following formula (1) has a melting point of about 343 ° C. and a glass transition point of 143 ° C., and has excellent heat resistance, creep resistance, load resistance, wear resistance, sliding properties, etc. In addition, it has excellent moldability.

  The PPS resin is a crystalline thermoplastic resin having a polymer structure represented by the following formula (2) in which a benzene ring is connected at a para position by a sulfur bond. The PPS resin having the structure of the following formula (2) has a melting point of about 280 ° C. and a glass transition point of 90 ° C., extremely high rigidity, excellent heat resistance, dimensional stability, wear resistance, sliding characteristics, etc. Have Depending on the molecular structure of the PPS resin, there are types such as a crosslinked type, a semi-crosslinked type, a linear type, and a branched type. In the present invention, the PPS resin can be used without being limited to these molecular structures and molecular weights. It is preferable to use a semi-bridging type having a relatively high toughness or a branching type having the highest toughness because the diameter is increased when incorporated into the groove.

  In addition, if necessary, the resin composition may include a fibrous reinforcing material such as carbon fiber, glass fiber, and aramid fiber, a spherical filler such as spherical silica and spherical carbon, a scale-like reinforcing material such as mica and talc, and potassium titanate. Can contain fine fiber reinforcement such as whisker. Moreover, solid lubricants such as PTFE resin, graphite and molybdenum disulfide, sliding reinforcing materials such as calcium phosphate and calcium sulfate, carbon black and the like can also be blended. These can be blended alone or in combination.

  As the above resin composition, a PEEK resin or a PPS resin is used as a base resin, and a carbon fiber as a fibrous reinforcing material and a PTFE resin as a solid lubricant are required for the seal ring of the present invention. It is preferable because it is easy to obtain the characteristics. By blending carbon fiber, mechanical strength such as flexural modulus can be improved, and sliding characteristics can be improved by blending PTFE resin.

  The carbon fiber may be either a pitch type or a PAN type classified from raw materials. Moreover, the average fiber diameter of carbon fiber is 20 micrometers or less, Preferably it is 5-15 micrometers. A thick carbon fiber exceeding this range is not preferable because the wear damage of the sliding counterpart material becomes large. The carbon fiber may be either chopped fiber or milled fiber. In addition, in order to improve the adhesion between the carbon fiber and the base resin and improve the mechanical properties of the seal ring, the surface of these carbon fibers is treated with a treatment agent containing an epoxy resin, a polyamide resin, etc. Surface treatment may be performed with a coupling agent or the like.

  The blending ratio of the carbon fibers is preferably 5 to 30% by weight with respect to the entire resin composition. More preferably, it is 10 to 20% by weight. When the blending ratio of the carbon fiber is less than 5% by weight, the reinforcing effect is poor and desired creep resistance and wear resistance may not be obtained. On the other hand, when the blending ratio of the carbon fiber exceeds 30% by weight, the melt fluidity is remarkably lowered, it becomes difficult to form the shape of the mating portion of the composite step-cut mold, and the sliding partner material is worn and damaged There is a fear.

  As the PTFE resin, any of molding powder by suspension polymerization, fine powder by emulsion polymerization, and recycled PTFE may be used. In order to stabilize the fluidity of the PEEK resin or the like, it is preferable to employ recycled PTFE that is difficult to be fiberized by shearing at the time of molding and hardly increases the melt viscosity.

  Regenerated PTFE is a powder that has been irradiated with a heat-treated powder (heated history added), γ-rays or electron beams. For example, a powder obtained by heat-treating molding powder or fine powder, a powder obtained by further irradiating this powder with γ-rays or an electron beam, a powder obtained by pulverizing a molding powder or a molded product of fine powder, and then a γ-ray or electron beam. There are types such as irradiated powder, molding powder or fine powder irradiated with gamma rays or electron beams. Among the regenerated PTFE, it does not aggregate, does not fiberize at the melting temperature of the PEEK resin, etc., has an internal lubricating effect, and can improve the fluidity of the PEEK resin stably. It is more preferable to employ PTFE resin irradiated with a beam or an electron beam.

  The blending ratio of the PTFE resin is preferably 5 to 35% by weight with respect to the entire resin composition. More preferably, it is 10 to 25% by weight. If the blending ratio of the PTFE resin is less than 5% by weight, desired sliding characteristics may not be obtained. On the other hand, when the blending ratio of the PTFE resin exceeds 35% by weight, the creep resistance and the like may be lowered.

  The means for mixing and kneading the above raw materials is not particularly limited, and the powder raw material is dry-mixed with a Henschel mixer, ball mixer, ribbon blender, ladyge mixer, ultra Henschel mixer, etc., and further biaxially extruded. It can be melt-kneaded by a melt extruder such as a machine to obtain molding pellets (granules). Further, for feeding the reinforcing material or the like, a side feed may be employed when melt kneading with a twin screw extruder or the like. As the molding method, injection molding is preferable as described above. Moreover, you may employ | adopt treatments, such as an annealing process, for physical property improvement.

  When the seal ring is manufactured by injection molding, the gate position is not particularly limited, but it is preferably provided on the inner peripheral side of the ring from the viewpoint of ensuring sealing performance and the need for post-processing. Further, as shown in FIG. 1 (a), it is preferable that the gate position 1b is provided at the mating facing portion on the inner peripheral side of the ring from the viewpoint of flow balance in injection molding.

  When the seal ring of the present invention is a resin molded body, the flexural modulus is preferably 5000 to 12000 MPa. More preferably, it is 6000-9000 MPa. When the bending elastic modulus is within this range, there is no fear of creep deformation during use, and the inclination angle of the ring side surface can be kept constant. If the flexural modulus is less than 5000 MPa, there is a risk of cracking when the diameter is increased when the groove is incorporated into the groove, and there is a risk of creep deformation during use. On the other hand, if it exceeds 12000 MPa, the sealing performance may be reduced.

  The seal ring of the present invention can be of any size. In particular, the effect is remarkable when the outer diameter is φ50 mm to φ60 mm. Moreover, ring thickness (diameter direction thickness) is about 1.5-2.5 mm.

Example (Inclination angle 2 degrees on both sides of the ring)
A seal ring (outer diameter φ52 mm, inner diameter φ48 mm, ring width 2...) Using a resin composition (made by NTN Precision Resin Co., Ltd .: BEAREE PK5301) containing PEEK resin as a main material and carbon fiber and PTFE resin is blended. 5 mm, ring thickness 2.0 mm) was manufactured by injection molding to obtain a resin seal ring.

Comparative example (inclination angles of 0 °, 1 °, 5 ° on both sides of the ring)
Resin seal rings with different inclination angles α were manufactured using the same materials as in the examples and the same manufacturing method. The shapes of these seal rings are the same as those of the example except that the inclination angles α on both side surfaces of the rings are 0 degree, 1 degree, and 5 degrees, respectively.

  About the characteristic of the obtained seal ring, the oil leak, the rotational torque, and the amount of wear were each evaluated with the testing machine shown in FIG. FIG. 4 is a schematic view of the testing machine. Seal rings 13 and 13 ′ were mounted in the annular groove of the counterpart shaft 12. The seal rings 13 and 13 ′ are configured to be in sliding contact with the annular groove side wall of the counterpart shaft 12 and the inner peripheral surface of the shaft hole of the housing 14 (see FIG. 2). The side wall of the annular groove that is in sliding contact with each seal ring is a surface (no taper) perpendicular to the axial direction. Oil was pumped from the right side of the apparatus and supplied to the annular gap between the seal rings 13 and 13 '. Detailed test conditions are as shown in Table 1 below.

  With this testing machine, the amount of oil leak (ml / min), the rotational torque (N · m) of the mating shaft, and the wear amount (wear depth, μm) of the side surface of the seal ring were measured. The oil leak amount and the rotational torque are values measured at the start of the test and after 300 hours of the test, and the wear amount is the amount after 300 hours of the test. The results are shown in FIGS.

  As shown in FIG. 5, in the oil leak test, (small) inclination angle 1 degree <inclination angle 0 degree <inclination angle 2 degree << inclination angle 5 degrees (large). As shown in FIG. 6, in the rotational torque test, (low) inclination angle 5 degrees = inclination angle 2 degrees <inclination angle 1 degree <inclination angle 0 degree (high). As shown in FIG. 7, the amount of wear on the side surface of the seal ring was (small) inclination angle 1 degree <inclination angle 2 degrees <inclination angle 5 degrees << inclination angle 0 degree (large). From this result, the seal ring with an inclination angle of 2 degrees according to the example is less in oil leak (sealability) and rotational torque (lower than the seal ring with an inclination angle of 0 degree, 1 degree and 5 degrees as a comparative example. (Friction) and wear on the side of the seal ring (low wear) are excellent overall, and the seal ring characteristics are considered to be the best.

  Since the seal ring of the present invention has a simple shape and is excellent in sealability, low friction and low wear, it can be used as a seal ring that requires these characteristics between the rotating shaft and the housing. In particular, it can be suitably used as a seal ring for a rotary shaft used under high PV conditions in hydraulic equipment such as AT and CVT.

DESCRIPTION OF SYMBOLS 1 Seal ring 1a Abutment 1b Gate position 2 Ring inner peripheral surface 3 Ring outer peripheral surface 4, 4a, 4b Ring side surface 5 Surface perpendicular to the axial direction of the seal ring 6 Housing 6a Inner peripheral surface 6b Shaft hole 7 Rotating shaft 7a Annular Groove 7b Side wall surface 8, 8 'Mating end 9, 9' Abutting surface 10, 10 'Lip 11, 11' Pocket 12 Mating shaft 13, 13 'Seal ring 14 Housing

Claims (9)

Attached to an annular groove provided on the rotating shaft inserted through the shaft hole of the housing, slidably contacts the side wall surface of the annular groove on the non-sealed fluid side, and contacts the inner peripheral surface of the shaft hole. A seal ring for sealing an annular gap between the rotating shaft and the shaft hole,
The seal ring has an abutment, and at least the entire ring side surface in contact with the side wall surface is a surface provided with an inclination angle such that the width on the inner peripheral side is smaller than the width on the outer peripheral side, The surface is a surface parallel to the axial center direction of the seal ring and the inner peripheral surface of the shaft hole,
The seal ring according to claim 1, wherein the inclination angle is an angle in a range of more than 1 degree and less than 3 degrees with respect to a plane perpendicular to the axial direction of the seal ring.   The seal ring according to claim 1, wherein the inclination angle is an angle of 1.5 to 2.5 degrees with respect to a plane perpendicular to the axial direction of the seal ring.   The seal ring according to claim 1 or 2, wherein the abutment of the seal ring is a compound step cut type abutment.   The seal ring according to claim 1, 2 or 3, wherein the seal ring is a molded body formed by injection molding of a resin composition.   The seal ring according to claim 4, wherein the base resin of the resin composition is a polyether ether ketone resin or a polyphenylene sulfide resin.   The seal ring according to claim 5, wherein the resin composition contains 5 to 30% by weight of carbon fiber with respect to the entire resin composition.   The seal ring according to claim 4, 5, or 6, wherein the molded article has a flexural modulus of 5000 to 12000 MPa.   The seal ring according to any one of claims 1 to 7, wherein an outer diameter of the seal ring is φ50 mm to φ60 mm.   The seal ring according to any one of claims 1 to 8, wherein the seal ring is used for an automatic transmission of an automobile or a hydraulic device of a continuously variable transmission.

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