JP2008014462A - Constant velocity universal joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple and inexpensive constant velocity universal joint preventing circumferential and radial movement of a rolling element in a pocket when rotating torque occurs. <P>SOLUTION: A shock absorbing material 10 formed of a porous solid lubricant is sealed in a space between the pocket 5a of a cage 5 and a ball 4. The porous solid lubricant uses a lubricating component containing lubricating oil and a resin component, as essential components. The lubricant is a solid product in a porous form with the resin component foamed, and it is formed with the lubricating component stored in a resin. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a constant velocity universal joint that is used in a drive shaft of an automobile and various industrial machines to transmit rotational torque.

  In recent years, technological improvements for higher performance, compactness, and weight reduction of automobiles and industrial machines have progressed, and constant velocity universal joints used for drive transmission of automobile parts and industrial machines have also been reduced in size, weight, and performance. There is an increasing demand for (long life).

  That is, the constant velocity universal joint is applied in a direction in which a high load is applied by reducing the size and weight in the same manner as the entire machine, and it may be difficult to achieve a long life with lubrication with conventional grease. Therefore, there is a demand for a constant velocity universal joint that has a long life and excellent maintainability even under severe conditions such as high temperature and high load.

  Here, in general, lubricants are used in sliding parts and rotating parts of machines such as automobiles and industrial machines, and grease or liquids that have been provided with shape retention by increasing the lubricating oil. There are known solid lubricants that can hold the lubricant and prevent its scattering and dripping.

  For example, there is a solid lubricant in which ultra-high molecular weight polyolefin or urethane resin and its curing agent are mixed with lubricating oil and grease, and a liquid lubricant component is held between the resin molecules to gradually exude physical properties. Known (see Patent Documents 1, 2, and 3).

  Also known is a polyurethane elastomer having self-lubricating properties by reacting a polyol, which is a polyurethane raw material, with a diisocyanate in a lubricating component in the presence of a lubricant (see Patent Document 4).

  Such a solid lubricant, for example, gradually precipitates the lubricating oil when it is sealed in a bearing and solidified. If this is used, maintenance for replenishing the lubricating oil becomes unnecessary, and there is a lot of moisture. It is often useful for extending the life of bearings even in environments where they are used or in environments where strong inertial forces are applied.

  However, if such a solid lubricant is used in a portion where expansion (sliding) or bending, such as a drive part of a constant velocity universal joint, is repeatedly applied at a high frequency, it follows the expansion (sliding) or bending. A very large force is required for the deformation, or a very large stress is applied to the solid lubricant, and a mechanical strength is also required for a portion holding the solid lubricant.

  However, since the strength and filling rate of the solid lubricant are usually compensatory, it is difficult to keep the lubricant at a high filling rate, which may hinder the extension of the service life.

  Therefore, there is a demand for a solid lubricant that can be applied to a constant velocity universal joint in which expansion (sliding), bending, and the like repeatedly occur.

  By the way, as the solid lubricant, there is an oil-containing solid lubricant in which a soft resin foamed to form continuous air holes is impregnated with lubricating oil, and the lubricating oil is retained in the pores. It is known to fill and use the entire interior of the constant velocity universal joint (see Patent Document 5).

  Next, FIG. 7A shows another conventional technique aimed at extending the life of the constant velocity universal joint.

  The constant velocity universal joint shown in FIG. 7A is a Barfield type constant velocity universal joint (BJ) which is one of fixed type constant velocity universal joints. The constant velocity universal joint includes an outer ring 70 that is an outer joint member, an inner ring 72 that is an inner joint member, a ball 73, and a cage 74. A track groove 70 a is formed on the spherical inner peripheral surface of the outer ring 70. In the inner ring 72, a shaft 75 is inserted into the center hole by spline fitting, and a track groove 72a that is paired with the track groove 70a of the outer ring 70 is formed on the spherical outer peripheral surface. A ball 73 is interposed between the track groove 70 a of the outer ring 70 and the track groove 72 a of the inner ring 72, and the ball 73 is held in a pocket 74 a of the cage 74.

7B and 7C are a cross-sectional view and a top cross-sectional view of the cage 74, respectively. At both ends of the pocket 74a, a crescent-shaped regulating member 76 made of synthetic resin is provided. A ball 73 is provided between the regulating member 76 in the pocket 74a so as to form a slight gap with the regulating member 76. As a result, the restriction member 76 restricts the circumferential movement of the ball 73 in the cage pocket 74a, thereby restricting relative rotation of the cage 74 with the outer ring 70 and the inner ring 72 to prevent backlash ( (See Patent Document 6).
JP-A-6-41569 JP-A-6-172770 JP 2000-319681 A Japanese Patent Laid-Open No. 11-286601 JP-A-9-42297 Japanese Utility Model Publication No. 4-126025

  Now, with the constant velocity universal joint described above, a slight gap is formed between the regulating member 76 and the ball 73, so that the circumferential movement of the ball 73 within the cage pocket 75a occurs slightly. However, there is a risk that noise due to backlash may occur without restricting radial movement. In addition, there is a problem that stable torque transmission becomes difficult. Further, since the regulating member 76 is provided as a separate part and it is necessary to perform this design strictly, there are problems in terms of work efficiency and manufacturing cost.

  If it is the prior art of patent documents 1-5, if oil-containing solid lubricant has the flexible deformability according to an external force, it can also follow the deformation by expansion / contraction (sliding) and bending of a constant velocity universal joint. However, when the lubricating oil retention force is small and the lubricating oil is used under high-speed rotation conditions, the lubricating oil is likely to be exhausted due to rapid precipitation.

  Oil-containing solid lubricants can be used in parts that operate for long periods of time, or when used in open spaces, the lubricating oil will precipitate, and this lubricant will repeatedly release and absorb from the pores and will not endure and flow in the space. To do.

  When such excessively precipitated lubricating oil comes into contact with the boot attached to the shaft and the outer joint member in the constant velocity universal joint, the component of the lubricating oil may deteriorate the boot material.

  Further, in the manufacturing process of the solid lubricant, many processes are required to surely impregnate the lubricating oil and grease, so that it is difficult to manufacture a constant velocity universal joint at a low cost.

  Therefore, the object of the present invention is to solve the above-mentioned problems, improve the lubricating oil retention force of the solid lubricant, and efficiently use the lubricating oil while keeping the amount of lubricating oil precipitated by deformation due to external force to the minimum necessary. Long life, little deterioration of boot, stable position of rolling elements in cage, and stable relative position of cage outer joint member and inner joint member to prevent noise due to backlash etc. An object of the present invention is to provide a constant velocity universal joint that is a speed universal joint and is useful for reducing manufacturing costs.

  The constant velocity universal joint of the present invention for solving the above-mentioned problems is an outer joint member in which a track groove is formed on the inner peripheral surface, and an inner surface in which the track groove is formed on the outer peripheral surface disposed inside the outer joint member. A joint member, a rolling element interposed between the track groove of the outer joint member and the track groove of the inner joint member, and the rolling element disposed between the outer joint member and the inner joint member. And a cage having a pocket to be accommodated, and a cushioning material is sealed in a space between the cage pocket and the rolling element (claim 1). The term “occlusion” as used in the present invention is the same as the meaning of occlusion in the scientific term, and indicates that a liquid lubricant is contained in a solid resin without becoming a compound.

  In the case of the constant velocity universal joint described above, the cushioning material is sealed in the space between the rolling element in the cage pocket and the cushioning material effectively restrains the rolling element when rotational torque is generated in the constant velocity universal joint. This restricts the circumferential and radial movements in the pocket of the rolling element to stabilize the position of the rolling element in the cage, and also stabilizes the relative position of the outer joint member and inner joint member of the cage. Can be made.

  Next, the buffer material is a solid material in which a lubricating component including a lubricating oil and a resin component are essential components, the resin component is foamed and made porous, and the lubricating component is occluded inside the resin. A solid lubricant (claim 2).

  In the case of the above constant velocity universal joint, a porous solid lubricant is sealed as a cushioning material in the space between the rolling element in the cage pocket, so that when the rotational torque is generated in the constant velocity universal joint, the porous solid lubricant The body effectively restrains the rolling element to regulate the circumferential movement and radial movement in the pocket of the rolling element to stabilize the position of the rolling element in the cage, and the outer joint member of the cage And the relative position with the inner joint member can also be stabilized. Moreover, since the rolling element is lubricated by the lubricating component contained in the porous solid lubricant, torque transmission of the rolling element can be made smooth.

  Next, the cushioning material was an elastic member (claim 3).

  In the case of the constant velocity universal joint, an elastic member is enclosed as a cushioning material in the space between the rolling element in the cage pocket, so that when the rotational torque is generated in the constant velocity universal joint, the elastic member By effectively restraining, the circumferential movement and radial movement in the pocket of the rolling element are regulated to stabilize the position of the rolling element in the cage, and the outer joint member and the inner joint member of the cage The relative position of can also be stabilized. Further, when rotational torque is generated in the constant velocity universal joint by the elastic force of the elastic member, it can be elastically deformed in accordance with torque transmission of the rolling elements.

  The present invention can be applied to various constant velocity universal joints. For example, the outer peripheral surface of the outer joint member and the outer peripheral surface of the inner joint member are spherical, and there are three between the inner peripheral surface of the outer joint member and the track groove formed on the outer peripheral surface of the inner joint member. Barfield type constant velocity universal joint (BJ) which is one of fixed type constant velocity universal joints with any number of balls (rolling elements) of 5, 6, 6, 7 or 8 Applicable. The undercut-free type constant velocity universal joint is interpreted as being included in the same classification as the Barfield type constant velocity universal joint, and is described in the present invention.

  Further, according to the present invention, a plurality of linear track grooves extending in the axial direction are formed on the cylindrical inner peripheral surface of the outer joint member, and a pair of track grooves of the outer joint member is formed on the spherical outer peripheral surface of the inner joint member. A plurality of linear track grooves are formed, and any of three, four, five, six, seven, or eight is provided between the track grooves of these outer joint members and the track grooves of the inner joint members. The present invention can be applied to a double offset type constant velocity universal joint (DOJ) which is one of sliding type constant velocity universal joints in which such a number of balls (rolling elements) are interposed.

  Alternatively, a plurality of linear track grooves are formed on the inner peripheral surface of the outer joint member, and a plurality of linear track grooves that are paired with the track grooves of the outer joint member are formed on the outer peripheral surface of the inner joint member, and The track groove of the outer joint member and the track groove of the inner joint member are inclined at a predetermined angle in opposite directions with respect to the axis, and the track groove of these outer joint member and the track groove of the inner joint member Cross groove type constant velocity universal joint (LJ) which is one of sliding type constant velocity universal joints with any number of balls (rolling elements) of 4, 6, 8 or 10 at the crossing part ).

  Since the constant velocity universal joint of the present invention encloses a cushioning material in the space between the rolling element in the cage pocket, when rotational torque is generated in the constant velocity universal joint, the circumferential movement in the pocket of the rolling element By restricting the radial movement, the position of the rolling element in the cage can be stabilized, and the relative position of the cage with the outer joint member and the inner joint member can also be stabilized. As a result, the play of the cage and rolling elements can be prevented easily and at low cost.

  In the constant velocity universal joint of the present invention, when the shock absorbing material is a porous solid lubricant or an elastic member, the shock absorbing material is elastically deformed in accordance with the movement of the rolling element when torque is transmitted. As a result, the position of the rolling element in the cage is stabilized by restricting circumferential movement and radial movement in the pocket of the rolling element without hindering normal torque transmission of the rolling element, and the outside of the cage. The relative position between the joint member and the inner joint member can also be stabilized, and abnormal noise due to backlash can be prevented.

  In addition, when the cushioning material is a porous solid lubricant, excessive lubrication components do not precipitate due to external force, so it is possible to prevent the boot from deteriorating due to excessive lubrication components, and if the boot breaks Even in this case, the lubrication inside the outer joint member can be maintained.

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

  FIG. 2A shows an embodiment in which the present invention is applied to a Barfield type constant velocity universal joint (BJ) which is one of fixed type constant velocity universal joints as a first embodiment of the present invention.

  The constant velocity universal joint includes an outer ring 1 that is an outer joint member, an inner ring 3 that is an inner joint member, a ball 4, and a cage 5. The outer ring 1 has a plurality of track grooves 1a formed on a spherical inner peripheral surface. The inner ring 3 has a plurality of track grooves 3 a that are paired with the track grooves 1 a of the outer ring 1 on the spherical outer peripheral surface, and is interposed between the track grooves 1 a of the outer ring 1 and the track grooves 3 a of the inner ring 3. Three, four, five, six, seven or eight balls 4 are interposed, and these balls 4 are pockets 5a of the cage 5 disposed between the outer ring 1 and the inner ring 3. Held in.

  A bellows-like boot 7 made of an elastomer such as rubber, resin, etc. having heat resistance, oil resistance, and wear resistance is attached from the opening end of the outer ring 1 to the shaft 6. , 9 and fixed. The boot 7 completely seals the inside of the outer ring 1.

  The outer ring 1 has a solid component in which a lubricating component including a lubricating oil and a resin component are essential components, the resin component is foamed and made porous, and the lubricating component is occluded in the resin. The cushioning material 10 made of the porous solid lubricant is sealed in the space between the cage 5 and the ball 4 in the pocket 5a.

  That is, the cushioning material 10 is placed in the space between the ball 4 in the pocket 5a of the cage 5 as shown in the transverse sectional view of the cage 5 in FIG. 1A and the upper sectional view of the cage 5 in FIG. Enclosed without gaps. The cushioning material 10 may be enclosed in a space other than the above, that is, a part or the entire area of the outer ring 1. In particular, when the buffer material 10 is sealed only in the above-described space, it is desirable to seal a lubricant such as grease in addition to the buffer material 10.

  In the porous solid lubricant as the buffer material 10, any one or both of an elastomer and a plastomer among plastics and rubbers can be used as an alloy or copolymer component.

  In the case of rubber, various rubbers such as natural rubber, isoprene rubber, butadiene rubber, styrene butadiene rubber, chloroprene rubber, butyl rubber, nitrile rubber, ethylene propylene rubber, silicone rubber, urethane elastomer, fluorine rubber, and chlorosulfone rubber can be employed.

  In the case of plastic, polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyacetal, polyamide 4,6 (PA4,6), polyamide 6,6 (PA6,6), polyamide 6T (PA6T), polyamide 9T (PA9T) General-purpose plastics and engineering plastics.

  Moreover, it is not restricted to said plastics etc., Polyurethane foams, such as a flexible urethane foam, a rigid urethane foam, a semi-rigid urethane foam, a polyurethane elastomer, etc. can be used. Various adhesives such as urethane adhesives, cyanoacrylate adhesives, epoxy resin adhesives, polyvinyl acetate adhesives, polyimide adhesives, and the like can also be used after being foamed and cured.

  Various additives such as pigments, antioxidants, metal deactivators, antistatic agents, flame retardants, antifungal agents and fillers can be added to the resin component as necessary.

  The porous solid lubricant as the cushioning material 10 used in the present invention has a lubricating component and a resin component as essential components, and requires a lubricating component by the action of external force such as expansion, contraction, centrifugal force, and expansion of bubbles accompanying a temperature rise. It can be supplied to the site.

  The air bubbles generated when being made porous by foaming are preferably continuous pores, and the lubricating component can be directly supplied from the surface of the resin component to the necessary portions via the continuous pores by the action of external force. In the case of the independent holes, the entire amount of the lubricating component in the resin component may be temporarily taken into the bubbles and may not be sufficiently supplied to the necessary part when necessary.

  In order to occlude the lubricating component inside the resin, it is desirable to employ a reactive impregnation method in which a foaming reaction and a curing reaction are simultaneously performed in the presence of a lubricant. In this way, it is possible to highly fill the inside of the resin with the lubricant, and thereafter, the post-impregnation step of impregnating and replenishing the lubricant can be omitted.

  On the other hand, if the foamed solid is molded in advance and only the impregnation method after impregnation with the lubricant is employed, a sufficient amount of lubricant does not penetrate into the resin, so that the lubricant holding power is not sufficient. If the lubricant is deposited in a short time and used for a long time, the lubricant may be insufficiently supplied. For this reason, the post-impregnation step is preferably employed as an auxiliary means for the reactive impregnation method.

  The reactive impregnation method is preferably performed by using a surfactant such as a commercially available silicone-based foam stabilizer and dispersing each raw material molecule uniformly. Further, it is possible to control the surface tension according to the type and amount of the foam stabilizer, and to control the type of bubbles (continuous type / independent type) and the size of the bubbles. Examples of the surfactant include an anionic surfactant, a nonionic surfactant, a cationic surfactant, an amphoteric surfactant, a silicone surfactant, and a fluorine surfactant.

  The ratio of the lubricating oil (100% by weight) of the lubricating oil is preferably 1% by weight to 95% by weight, and more preferably 5% to 80% by weight. When the ratio of the lubricating oil is less than 1% by weight, it is difficult to sufficiently supply the lubricating oil to a necessary portion. In addition, when the amount is more than 95% by weight, the specific function of the solid lubricant may not be achieved.

  As the lubricating component used in the present invention, any type can be used as long as it does not dissolve the solids forming the foam. For example, lubricating oil, grease, wax, etc. can be used alone or in combination. May be.

  As the lubricating oil used in this invention, paraffinic and naphthenic mineral oils, ester synthetic oils, ether synthetic oils, hydrocarbon synthetic oils, GTL base oils, fluorine oils, silicone oils and the like are generally used. Lubricating oils or mixed oils thereof.

  Examples of the thickener for grease used in the present invention include soaps such as lithium soap, lithium complex soap, calcium soap, calcium complex soap, aluminum soap and aluminum complex soap, and urea compounds such as diurea compounds and polyurea compounds. However, it is not particularly limited.

  Examples of the urea thickener include, but are not limited to, diurea compounds and polyurea compounds.

  The diurea compound is obtained, for example, by reaction of diisocyanate and monoamine. Diisocyanates include phenylene diisocyanate, diphenyl diisocyanate, phenyl diisocyanate, diphenylmethane diisocyanate, octadecane diisocyanate, decane diisocyanate, hexane diisocyanate, and monoamines include octylamine, dodecylamine, hexadecylamine, octadecylamine, oleylamine, aniline, p-Toluidine, cyclohexylamine and the like can be mentioned.

  The polyurea compound can be obtained, for example, by reacting diisocyanate with a monoamine or diamine. Examples of the diisocyanate and monoamine include those similar to those used for the production of the diurea compound. Examples of the diamine include ethylenediamine, propanediamine, butanediamine, hexanediamine, octanediamine, phenylenediamine, tolylenediamine, and xylenediamine. Is mentioned. As the base oil of the grease, the same lubricant oil as described above can be used.

  The wax used in the present invention may be any hydrocarbon synthetic wax, polyethylene wax, fatty acid ester wax, fatty acid amide wax, ketone / amines, hydrogenated oil, and the like. As the oil component used for these waxes, the same oil components as those described above can be used.

  Lubricating components as described above include solid lubricants such as molybdenum disulfide and graphite, friction modifiers such as organic molybdenum, oily agents such as amines, fatty acids, and fats, and antioxidants such as amines and phenols. Agents, rust inhibitors such as petroleum sulfonate, dinonyl naphthalene sulfonate, sorbitan ester, extreme pressure agents such as sulfur and sulfur-phosphorus, antiwear agents such as organic zinc and phosphorus, benzotriazole, sodium nitrite, etc. Various additives such as viscosity index improvers such as metal deactivators, polymethacrylates and polystyrenes may be included.

  As a means for foaming the resin component, a well-known foaming means may be employed. For example, a physical method for heating and vaporizing an organic solvent having a relatively low boiling point such as water, acetone, hexane, etc. A mechanical foaming method that blows active gas from the outside, such as azobisisobutyronitrile (AIBN) or azodicarbonimide (ADCA), which uses a decomposable foaming agent that decomposes by temperature or light and generates nitrogen gas, etc. And the like. Moreover, when it has a highly reactive isocyanate group as a raw material, you may use the chemical foaming by the carbon dioxide produced by the chemical reaction with it and a water molecule.

  In order to use foaming accompanied by such a reaction, it is desirable to use a catalyst as necessary. For example, a tertiary amine catalyst or an organometallic catalyst is used.

  Examples of the tertiary amine catalyst include monoamines, diamines, triamines, cyclic amines, alcohol amines, ether amines, imidazole derivatives, and acid block amine catalysts.

  In addition, as organometallic catalysts, stanaoctate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin marker peptide, dibutyltin thiocarboxylate, dibutyltin maleate, dioctyltin dimarkaptide, dioctyltin thiocarboxylate, lead octenoate, etc. Is mentioned. Moreover, you may mix and use these multiple types for the purpose of adjusting the balance of reaction.

  The expansion ratio of the resin component is desirably 1.1 times or more and less than 200 times. When the expansion ratio is 1.1 times or less, the bubble volume is small, and deformation is not allowed when an external force is applied, or the solid matter is too hard to deform. In addition, when it is 200 times or more, it is difficult to obtain a strength that can withstand external force, which may cause breakage or destruction during use.

  The porous solid lubricant as the buffer material 10 may be cast into a mold and molded, or after solidifying at normal pressure, it can be post-processed into a desired shape by cutting or grinding. Also, the inside of the outer joint member of the constant velocity universal joint, usually between the inner joint member and the outer joint member, may be filled with foam to cause a curing reaction, and then the boot is assembled to produce the constant velocity universal joint. it can.

  As described above, in this constant velocity universal joint, the buffer material 10 is enclosed in the space between the pocket 5a of the cage 5 and the ball 4, so that the ball 4 is more effectively transferred to the buffer material 10 when the torque of the ball 4 is transmitted. Because of restraint, the circumferential movement and radial movement of the ball 4 in the pocket 5a are restricted to stabilize the position of the ball 4 in the cage 5, and relative to the outer ring 1 and the inner ring 3 of the cage 5 The position can also be stabilized. Further, the friction component between the outer ring 1 and the inner ring 3 of the ball 4 can be suppressed by the lubricating component of the cushioning material 10, and torque transmission can be made smooth.

  As shown in FIG. 2B, as a second embodiment of the present invention, the present invention is applied to a Barfield type constant velocity universal joint as in FIG. Note that in this embodiment, parts having the same parts, functions, and forms as those in FIG. 2A are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the second embodiment, a lubricating component containing a lubricating oil and a resin component are essential components, the resin component is a solid material foamed and made porous, and the lubricating component is occluded inside the resin. The cushioning material 10a made of a conductive solid lubricant is placed between the ball 4 in the pocket 5a of the cage 5 in the space including the track groove 1a of the outer ring 1 and / or the space including the track groove 3a of the inner ring 3. Enclosed including space. As a result, since the ball 4 is effectively restrained by the cushioning material 10a when the torque of the ball 4 is transmitted, the ball 4 in the cage 5 is regulated by restricting the circumferential movement and radial movement of the ball 4 in the pocket 5a. 4 can be stabilized, and the relative positions of the cage 5 to the outer ring 1 and the inner ring 3 can also be stabilized. Further, the lubricating component of the cushioning material 10a can suppress the frictional resistance between the ball 4 and the track groove 1a of the outer ring 1 in which the ball 4 moves and the track groove 3a of the inner ring 3, thereby making it possible to transmit torque smoothly.

  Now, the application of the porous lubricant according to the present invention shown in FIGS. 2A and 2B can be applied to various other constant velocity universal joints. 3 (A) and 3 (B) show a double offset type constant velocity universal joint (DOJ) as one of sliding type constant velocity universal joints as third and fourth embodiments of the present invention. 5 (A) and FIG. 5 (B) show a cross groove type constant velocity universal joint (LJ) as one of sliding type constant velocity universal joints as fifth and sixth embodiments of the present invention. In the above embodiment, in the embodiment using the same type of constant velocity universal joint, parts having the same parts, functions, and forms are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 3A shows an embodiment in which the present invention is applied to a double offset constant velocity universal joint (DOJ), which is one of sliding type constant velocity universal joints, as a third embodiment of the present invention.

  The constant velocity universal joint includes an outer ring 15 that is an outer joint member, an inner ring 17 that is an inner joint member, a ball 18, and a cage 19. A plurality of linear track grooves 15 a extending in the axial direction are formed on the cylindrical inner peripheral surface of the outer ring 15, and a plurality of linear tracks paired with the track grooves 15 a of the outer ring 15 are formed on the spherical outer peripheral surface of the inner ring 17. A groove 17a is formed. Between the track groove 15a of the outer ring 15 and the track groove 17a of the inner ring 17, there are three, four, five, six, seven or eight balls 18 interposed. The ball 18 is held in a pocket 19 a of the cage 19. In this constant velocity universal joint, when a rotational torque is generated and the outer shaft 20 is rotated, the shaft 21 is rotated via the ball 18 following the rotation.

  In the present embodiment, the outer ring 15 has a solid component in which a lubricating component including a lubricating oil and a resin component are essential components, the resin component is foamed and made porous, and the lubricating component is As shown in the cross-sectional view of the cage 19 in FIG. 4A and the upper cross-sectional view of the cage 19 in FIG. It is enclosed in a space with the ball 18 in the pocket 19a. Note that the operation and effect of this embodiment are the same as those of the first embodiment shown in FIG.

  FIG. 3B shows, as a fourth embodiment, an embodiment in which the present invention is applied to a double offset type constant velocity universal joint, as in FIG. 3A.

  In the present embodiment, the resin containing the lubricating component and the resin component containing the lubricating oil as essential components in the space including the track groove 15a of the outer ring 15 and the space including the track groove 17a of the inner ring 17 or any one of the spaces is provided. The cushioning material 22a made of a porous solid lubricant that is a solid material foamed and made porous and has the lubricating component occluded inside the resin includes the space between the ball 19 in the pocket 19a of the cage 19 And enclosed. Note that the operation and effect of this embodiment are the same as those of the second embodiment shown in FIG.

  FIG. 5A shows an embodiment in which the present invention is applied to a cross-groove type constant velocity universal joint (LJ), which is one of sliding type constant velocity universal joints, as a fifth embodiment of the present invention.

  The constant velocity universal joint includes an outer ring 31 that is an outer joint member, an inner ring 32 that is an inner joint member, a ball 33, and a cage 34. A stub shaft 36 is spline-fitted in the center hole 35 of the inner ring 32, and torque transmission between the inner ring 32 and the stub shaft 36 is possible by this spline fitting. The stub shaft 36 is prevented from coming off by a snap ring 37.

  A plurality of linear track grooves 31 a are formed on the inner peripheral surface of the outer ring 31, a plurality of linear track grooves 32 a are formed on the outer peripheral surface of the inner ring 32, and the track grooves 31 a of the outer ring 31 and the tracks of the inner ring 32 are formed. The groove 32a forms a structure inclined at a predetermined angle with respect to the axis in opposite directions. Four, six, eight, or ten balls 33 are interposed at the intersections of the track grooves 31a of the outer ring 31 and the track grooves 32a of the inner ring 32. The balls 33 are connected to the outer ring 31 and the inner ring. 32 is held in a pocket 34a of the cage 34 positioned between the two.

  In addition, an end plate 38 for preventing leakage of grease filled in the joint and preventing entry of foreign matters is provided at one end side in the axial direction of the outer ring 31 with bolts (not shown) from the insertion side of the stub shaft 36. It is fixed by tightening. On the other hand, a sealing device is mounted between the other axial end of the outer ring 31 and the stub shaft 36.

  This sealing device includes a boot 39 and a metal boot adapter 40. The boot 39 has a small end portion and a large end portion, and has a shape folded back into a U shape in the middle. However, the present invention is not limited to this shape, and various things such as a boot having a bellows shape can be applied. The boot adapter 40 has a cylindrical shape, has a flange fitted to the outer peripheral surface of the outer ring 31 at one end, and is fixed by bolting from the insertion side of the stub shaft 36 together with the end plate 38. The small end portion of the boot 39 is fitted to the stub shaft 36 and further fixed by the boot band 41, and the large end portion is fixed by crimping to the end opposite to the flange side of the boot adapter 40. The However, it is not restricted to this fixing method, For example, you may fix with a boot band.

  Now, in the present embodiment, the outer ring 31 has a lubrication component including a lubricating oil and a resin component as essential components, and the resin component is a solid material foamed and made porous, and the lubrication component is contained in the outer ring 31. As shown in the cross-sectional view of the cage 34 in FIG. 6A and the upper cross-sectional view of the cage 34 in FIG. It is enclosed in a space with the ball 33 in the pocket 34a. Note that the operation and effect of this embodiment are the same as those of the first embodiment shown in FIG.

  FIG. 5B shows an embodiment in which the present invention is applied to a cross-groove constant velocity universal joint, as in FIG. 5A, as a sixth embodiment of the present invention.

  In the present embodiment, the resin containing the lubricating component and the resin component containing lubricating oil as essential components in the space including the track groove 31a of the outer ring 31 and the space including the track groove 32a of the inner ring 32, or any one of them, is used. The cushioning material 42a made of a porous solid lubricant, which is a solid material whose component is foamed and made porous, and has the lubricating component occluded inside the resin, includes the space between the ball 33 in the pocket 34a of the cage 34. And enclosed. Note that the operation and effect of this embodiment are the same as those of the second embodiment shown in FIG.

  In the first to sixth embodiments, a porous solid lubricant is used as a buffer material. In the first, third, and fifth embodiments, an elastic member such as rubber is used as the buffer material. Can be used. However, in this case, a lubricant such as a porous solid lubricant or grease can be separately sealed and applied to other parts. In the second, fourth, and sixth embodiments, an elastic member such as rubber cannot be used as a cushioning material.

  When an elastic member is used as a cushioning material, the elastic member elastically deforms with the movement of the ball when the ball torque is transmitted. Directional movement and radial movement can be restricted.

  As mentioned above, although embodiment of this invention was described, these embodiment is an illustration to the last, and includes all the matters within the meaning and range as described in a claim.

  The raw materials used in the examples and comparative examples are listed below, and the composition and measurement results of the solid lubricant are shown in Table 1.

(A) Urethane prepolymer (Daicel Chemical Industries, Plaxel EP-1130)
(B) Amine-based curing agent (Ihara Chemical Co., Ltd .: Iharacamine MT)
(C) Water (ion exchange water)
(D) Silicone type foam stabilizer (manufactured by Toray Dow Co., Ltd .: SRX298)
(E) Urea grease (Shin Nippon Oil Co., Ltd .: Pyronock Universal N6C)
(F) Isocyanate (manufactured by Nippon Polyurethane Co., Ltd .: Coronate T80)
(G) Polyether polyol (Asahi Glass Co., Ltd .: Preminol SX4004)
(H) Amine-based catalyst (Tosoh Corporation: TOYOCAT DB2)
(I) Lubricating oil (manufactured by Nippon Oil Corporation: Turbine 100)

[Example 1]
As shown in FIG. 2A, the inner ring 3, the cage 5 and the ball 4 were assembled to the outer ring 1 of a constant velocity universal joint (NTN Corporation: EBJ82). Separately, silicone foam stabilizers and urea grease were added to the urethane prepolymer in the amount (composition) shown in Table 1, and the mixture was well stirred at 120 ° C. The amine-based curing agent was added to this, and after stirring, water as a foaming agent was added to fill and foam the solid lubricant in the space between the balls 5 in the pockets 5a of the cage 5, and this was set to 120 ° C. The constant velocity universal joint holding the porous solid lubricant as the buffer material 10 was obtained by allowing it to stand for 1 hour in a thermostatic bath and curing.

[Example 2]
In the component amount (composition) shown in Table 1, polyether foam polyol with silicone foam stabilizer, mineral oil,
An amine catalyst and water as a blowing agent were added, and the mixture was heated at 90 ° C. and stirred well. Isocyanate is added to this, and the mixture is well stirred. A solid lubricant is filled and foamed in the space between the pocket 5a of the cage 5 and left standing in a thermostatic bath set at 90 ° C. for 15 minutes to form a porous material as the cushioning material 10. A constant velocity universal joint holding a porous solid lubricant was obtained.

[Comparative Example 1]
A constant velocity universal joint holding a solid lubricant was obtained in the same manner as in Example 1 except that the non-foamed lubricant was used in the amount (composition) shown in Table 1.

[Comparative Example 2]
Of the components (compositions) shown in Table 1, a foam was synthesized in the same manner as in Example 2 except for the mineral oil. The oil was impregnated later to obtain a constant velocity universal joint holding a post-impregnation type foaming lubricant. With respect to the foams obtained in Examples 1 and 2 and Comparative Examples 1 and 2, the value obtained by dividing the volume after foaming by the volume before foaming was determined as the foaming ratio and shown in Table 1.

  About the constant velocity universal joint of the obtained Example and a comparative example, a durability test was performed on the conditions of torque 245Nm, angle 6deg, and rotation speed 1000r / min, and the degree of damage or destruction of solid lubricant after rotating for 10 hours Was evaluated by visual observation and observation using an optical microscope. The results are as follows: ◯: No damage or breakage and continuous use was possible, △: Solid lubricant was not destroyed but the oil separation was excessive, x: Solid lubricant It was evaluated that it was damaged or destroyed and could not be used continuously.

  As is apparent from the results shown in Table 1, the lubricant in Example 1 having the same composition and filled with the foamed solid lubricant was more broken than the Comparative Example 1 filled with the non-foamable solid lubricant. It has durability that can be used continuously for a long time without damage.

  Further, Comparative Example 2 using a solid lubricant in which mineral oil was retained only in the post-impregnation step even in the foamed resin of the same composition was used in Example 2 using a solid lubricant in which mineral oil was occluded in the resin simultaneously with foaming. It can be seen that the amount of oil separated under the same centrifugal force was larger than that, and excess oil that did not contribute to lubrication was supplied. On the other hand, in the constant velocity universal joint of Example 2, the lubrication component is sufficiently occluded inside the resin in the reaction type solid lubricant, and the oil separation speed is appropriate even if centrifugal force acts, and the long time It turns out that it has the durability which can be used.

  Also, from these examples and comparative examples, the lubricating component is occluded inside the resin by the reactive impregnation simultaneously with foaming, and the lubricating oil is retained in the bubbles simply by impregnating the foamed resin molding into the lubricating oil. It can be seen that the oil retention by occlusion is higher than that of the case.

(A) is a cross-sectional view of the cage of FIG. 2 (A). FIG. 2B is an upper cross-sectional view of the cage of FIG. The present invention is applied to a Barfield type constant velocity universal joint which is one of fixed type constant velocity universal joints, and FIG. 5A is a sectional view showing a first embodiment. (B) is sectional drawing which shows 2nd Embodiment. The present invention is applied to a double offset type constant velocity universal joint, which is one of sliding type constant velocity universal joints, and (A) is a cross-sectional view showing a third embodiment. (B) is sectional drawing which shows 4th Embodiment. (A) is a cross-sectional view of the cage of FIG. 3 (A). FIG. 3B is a top sectional view of the cage of FIG. The present invention is applied to a cross-groove type constant velocity universal joint which is one of sliding type constant velocity universal joints, and (A) is a cross-sectional view showing a fifth embodiment. (B) is sectional drawing which shows 6th Embodiment. (A) is a cross-sectional view of the cage of FIG. 5 (A). FIG. 6B is a top sectional view of the cage of FIG. (A) is sectional drawing of the barfield type constant velocity universal joint which is one of the conventional sliding type constant velocity universal joints. (B) is a cross-sectional view of the cage of (A). (C) is a top sectional view of the cage of (A).

Explanation of symbols

1, 15, 31 Outer ring (outer joint member)
3, 17, 32 Inner ring (inner joint member)
4, 18, 33 balls (rolling elements)
5, 19, 34 Cage 5a, 19a, 34a Pocket 1a, 3a, 15a, 17a, 31a, 32a Track groove 10, 10a, 22, 22a, 42, 42a

Claims (8)

An outer joint member having a track groove formed on the inner peripheral surface, an inner joint member having a track groove formed on the outer peripheral surface disposed inside the outer joint member, the track groove of the outer joint member, and the inner joint member. A rolling element interposed between a track groove and a cage having a pocket disposed between the outer joint member and the inner joint member and accommodating the rolling element;
A constant velocity universal joint, wherein a cushioning material is sealed in a space between the cage pocket and the rolling element.   The cushioning material comprises a solid component in which a lubricating component including a lubricating oil and a resin component are essential components, the resin component is foamed and made porous, and the lubricating component is occluded inside the resin. The constant velocity universal joint according to claim 1, comprising an agent.   The constant velocity universal joint according to claim 1, wherein the cushioning material is an elastic member.   The outer joint member is formed with a plurality of track grooves on the spherical inner peripheral surface, and the inner joint member is formed with a plurality of track grooves paired with the track grooves of the outer joint member on the spherical outer peripheral surface. The rolling element is a ball interposed between the track groove of the outer joint member and the track groove of the inner joint member, and a cage for holding the ball is interposed between the outer joint member and the inner joint member. The constant velocity universal joint according to any one of claims 1 to 3, wherein the constant velocity universal joint is provided.   The outer joint member is formed with a plurality of linear track grooves extending in the axial direction on a cylindrical inner peripheral surface, and the inner joint member is paired with a track groove of the outer joint member on a spherical outer peripheral surface. A plurality of linear track grooves are formed, and the rolling elements are balls interposed between the track grooves of the outer joint member and the track grooves of the inner joint member, and between the outer joint member and the inner joint member. The constant velocity universal joint according to any one of claims 1 to 3, wherein a cage for holding the ball is interposed.   The outer joint member has a plurality of linear track grooves formed on the inner peripheral surface, and the inner joint member has a plurality of linear track grooves paired with the track grooves of the outer joint member on the outer peripheral surface. In addition, the track groove of the outer joint member and the track groove of the inner joint member are inclined at a predetermined angle with respect to the axis, and the rolling element is formed of the track groove of the outer joint member and the inner groove. 4. A ball interposed at an intersection of a joint member with a track groove, and a cage for holding the ball interposed between the outer joint member and the inner joint member. Any of the constant velocity universal joints described.   6. The ball according to claim 4, wherein the number of balls is any number selected from 3, 4, 5, 6, 7, or 8. Fast universal joint.   The constant velocity universal joint according to claim 6, wherein the number of balls is any number selected from 4, 6, 8, or 10.