WO2009110593A1

WO2009110593A1 - Lubrication system, and universal joint and bearing that use said lubrication system

Info

Publication number: WO2009110593A1
Application number: PCT/JP2009/054294
Authority: WO
Inventors: 美香小原; 芳英姫野
Original assignee: Ntn株式会社
Priority date: 2008-03-06
Filing date: 2009-03-06
Publication date: 2009-09-11

Abstract

Provided are a long-lived, low-cost lubrication system that not only improves the holding strength of the lubricant components in foam solid lubricants but can also keep the amount of exuded lubricant to the minimum necessary, and can supplement lubricant function even when there are insufficient lubricant components from the foam solid lubricant, and a universal joint and bearing that use said lubrication system. Disclosed is a lubrication system wherein a foam solid lubricant, made by including lubricant components inside a resin that is foamed and cured to become porous, and a supplementary lubricant grease are both present at the lubrication site. The above supplementary lubricant grease comprises at least a wax A with a melting point of 70-150ºC. As an example of the application in a constant velocity universal joint, a foam solid lubricant (9) and a supplementary lubricant grease (10) made by blending a prescribed wax A are both present inside a universal joint provided with an inner member (1), an outer member (2), an inner member track groove (3), an outer member track groove (4), a steel ball (5), a cage (6), a shaft (7), and a boot (8).

Description

Lubrication system, universal joint and bearing using the lubrication system

The present invention relates to a lubrication system capable of supplying lubricating oil to a sliding part and a rotating part of a mechanical device, and a universal joint and a bearing using the lubrication system.

Generally, a lubricant is used in sliding parts and rotating parts of most machines represented by automobiles and industrial machines. Lubricants can be broadly divided into liquid lubricants and solid lubricants. Grease with increased lubricating oil and shape retention, and solids that retain liquid lubricant and prevent its splashing and dripping. Lubricants are also known.

In recent years, technical improvements for higher performance, compactness, and weight reduction of automobiles have progressed, and there is a demand for miniaturization, higher performance, and longer life of universal joints used for drive transmission of automobile parts and industrial machines. It is growing. Along with the progress of downsizing and weight reduction, a high load is also applied to the universal joint, and it may be difficult to achieve a long life with conventional grease lubrication. Since higher performance will be required in the future, it is difficult to completely address the above problems by simply optimizing the amount of grease and additives, and research and development of new lubricants and new lubrication mechanisms Is required.

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. It is known (see Patent Documents 1 to 3). Also known is a self-lubricating polyurethane elastomer obtained 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). When such solid lubricant is sealed in a bearing and solidified, it gradually exudes lubricating oil. If this is used, maintenance for replenishing the lubricating oil becomes unnecessary, and there is a lot of moisture. It is intended to be useful for extending the life of the bearing even in environments where it is used or where inertia is strong.

However, in the techniques according to Patent Document 1 to Patent Document 4 described above, the solid lubricant has a large lubricating oil retaining force, but lacks flexible deformability. For this reason, if such a solid lubricant is used at a site where external stress such as compression or bending is frequently applied, such as the drive part of a constant velocity joint, it is very difficult to deform following the compression and bending. A large force is required, or a very large stress is applied to the solid lubricant, and a mechanical strength is also required in a portion for holding the solid lubricant. 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 easily used even at sites where external stress such as compression and bending repeatedly occurs at a high frequency.

As this solid lubricant, an oil-containing foam obtained by foaming a solid component and filling it with a lubricating oil has been reported. For example, an oil-impregnated foam in which lubricating oil is impregnated with a soft resin that is foamed to form continuous air holes and the lubricating oil is retained in the pores is also used by filling the inside of the bearing or constant velocity joint. It is known (see Patent Document 5). This is because the oil-impregnated foam is compressed following the boot that is deformed by the bending of the constant velocity joint. Here, the liquid lubricant that has oozed out from the oil-containing foam is supplied to a necessary portion, and good lubrication is possible.

However, the oil-impregnated foam of Patent Document 5 is of an impregnated type after impregnating a foamed resin with a lubricating oil, and has flexible deformability according to external force and can follow compression and bending deformation, Since the lubricating oil is not contained in the solid component, the lubricating oil retention force is small, and when used under high speed conditions such as a bearing, there is a possibility that the lubricating oil will quickly escape and be depleted. This oil-impregnated foam can be used in a short period of lubrication or in a closed space, but if it is used in a part that requires a long period of lubrication or in an open space, the supply of lubricating oil will be insufficient, or the oil holding power will be weak. Then, the excess lubricating oil is repeatedly released and absorbed from the pores and constantly flows in the space.

When the lubricant exuded excessively from such a solid lubricant comes into contact with an exterior material such as a boot material or rubber in a universal joint, the lubricant or its additive may chemically corrode or deteriorate the material. is there. In addition, in the process of manufacturing the lubricant, many manufacturing processes are required for reliably impregnating the lubricant and grease, and it is difficult to meet the demand for cost reduction.

For the reasons described above, there is a demand for a lubricant for a constant velocity joint that has high retention of the lubricant and that allows large deformation. In particular, it is necessary to include a lubricant in the solid component to increase the retention of the lubricating component. In response to this requirement, for example, a foamed lubricant (see Patent Document 6) that has a simple manufacturing process, is flexible, and has a high lubricating component retention force, and a constant velocity joint (see Patent Document 7) using the same have been proposed.

However, depending on how the foamed lubricant disclosed in Patent Document 6 and the constant velocity joint disclosed in Patent Document 7 are used, the release of the lubricant due to external force or temperature rise may be small. In view of durability, it is desirable that the release of the lubricating component from the resin component is the minimum necessary. If the release speed of the lubricating component is small, the speed at which the necessary amount of lubricant reaches the sliding portion becomes slow. For this reason, the lubricant is depleted and wear and lubrication may be caused even in the sliding portion.

JP-A-6-41569 JP-A-6-172770 JP 2000-319681 A Japanese Patent Laid-Open No. 11-286601 Japanese Patent Laid-Open No. 9-42297 JP 2007-177226 A Japanese Patent Laid-Open No. 2007-247887

The present invention has been made in order to cope with such problems, and improves the lubricating component holding power of the foamed solid lubricant that holds the lubricating component, and the lubricant by deformation and external force of the foamed solid lubricant. A long-life, low-cost lubrication system that can keep the amount of oozing out to the minimum necessary and can supplement the lubrication function even when the lubrication component from the foamed solid lubricant is insufficient. The purpose is to provide universal joints and bearings.

The lubrication system of the present invention is a lubrication system in which a foamed solid lubricant containing a lubrication component in a resin that is foamed and cured to be porous, and a grease for auxiliary lubrication coexist in a site to be lubricated. The auxiliary lubricating grease contains at least wax A having a melting point of 70 to 150 ° C. The wax A is at least one selected from fatty acid amides and hydrogenated oil.

The lubricating component contains at least one selected from lubricating oils and greases, wax B having a melting point of 70 to 150 ° C., and the wax B is a fatty acid monoamide wax, a hydrogenated oil wax, and a hydrocarbon. It is characterized by being at least one wax selected from system waxes. Further, the fatty acid monoamide wax is at least one selected from stearic acid amide, erucic acid amide, and oleic acid amide.

The foamed solid lubricant is characterized in that the resin foamed and cured to become porous has rubber-like elasticity, and the lubricating component contained in the resin has exudability due to deformation of the rubber-like elastic body. To do. In addition, the foaming ratio of the resin that is made porous by curing and curing is 1.1 to 100 times. Also, the open cell ratio after foaming / curing of the resin foamed / cured to be porous is 50% or more.

The foamed solid lubricant is obtained by foaming and curing a mixture containing the lubricating component, the resin, a curing agent, and a foaming agent, and the lubricating component is at least one selected from lubricating oil and grease. The resin is a urethane prepolymer containing in the molecule 2 to 6% by weight of an isocyanate group in the molecule, the foaming agent is water, and the mixture contains 20 lubricant components with respect to the entire mixture. It is characterized by containing ˜80% by weight and having an open cell ratio of 50% or more after foaming. The urethane prepolymer is at least one urethane prepolymer selected from an ester urethane prepolymer, a caprolactone urethane prepolymer, and an ether urethane prepolymer.

The ratio between the isocyanate group and the functional group of the curing agent that reacts with the isocyanate group is an equivalent ratio of (functional group of the curing agent / NCO) = 1 / (1.1 to 2.5). . The ratio of the hydroxyl group of water to the functional group of the curing agent is an equivalent ratio (water hydroxyl group / functional group of the curing agent) = 1 / (0.7 to 2.0). The curing agent is an aromatic polyamino compound. Further, the aromatic polyamino compound is an aromatic polyamino compound having a substituent at a position adjacent to the amino group.

The foamed solid lubricant is obtained by foaming and curing a mixture containing the lubricating component, the resin, a curing agent, and a foaming agent, the resin is a polyether polyol, and the curing agent is a polyisocyanate. The foaming agent is water, and the lubricating component is contained in an amount of 60 to 80% by weight based on the entire mixture including the resin, the curing agent, the foaming agent, and the lubricating component. To do.

The above mixture is characterized in that it is foamed and cured after filling the periphery of the sliding member or in the molding die.

In the universal joint of the present invention, the rotational torque is transmitted by the engagement between the track groove and the torque transmission member, and the torque transmission member rolls along the track groove to move in the axial direction. The universal joint used is characterized in that the auxiliary lubricating grease and the foamed solid lubricant coexist in the universal joint. Further, the mixture is filled around the torque transmission member before foaming / curing is completed. The universal joint is a constant velocity universal joint.

The bearing of the present invention is a bearing using the lubrication system, and is characterized in that the auxiliary lubricating grease and the foamed solid lubricant coexist in the bearing.

The lubrication system of the present invention is a lubrication system in which a foamed solid lubricant containing a lubrication component in a resin that is foamed and cured to be porous, and a grease for auxiliary lubrication coexist in a site to be lubricated. Since the prescribed wax A component is added to the auxiliary lubricating grease, the auxiliary lubricating grease is difficult to move from the sliding part even when an external force such as centrifugal force is applied, and the lubricating oil that exudes from the foamed solid lubricant Even when the components are insufficient, the auxiliary lubricating grease can provide a lubricating function. In addition, even if the sliding part is in a metal contact state due to a temporary lack of lubricant locally, the temperature rises due to the metal contact, so that the wax A component in the auxiliary lubrication grease melts and the auxiliary lubrication Since the fluidity of the grease is improved, the grease is quickly supplied to the sliding portion, and a smooth lubrication state can be maintained. For this reason, the lubrication function can be satisfactorily performed continuously without a shortage of the lubricant (because it does not flow out) in a sliding portion or the like in a mechanical element such as a bearing or a universal joint in which the solid foam lubricant is enclosed. .

The lubricating component contains at least one selected from a lubricating oil and a grease B having a melting point of 70 to 150 ° C., and the wax B includes a fatty acid monoamide wax, a hydrogenated oil wax, and By using at least one wax selected from hydrocarbon-based waxes, the amount of the lubricating component released from the foamed solid lubricant can be maintained at the required amount, and even if an external force such as centrifugal force is applied, the lubricating component Can be held in a state where it is difficult to move from the sliding portion. Further, even if the sliding portion is in a metal contact state due to a temporary lack of lubricant locally, the temperature rises due to the metal contact, so that the wax B component in the lubricating component of the foamed solid lubricant is melted. Since the fluidity is improved, the lubricant is quickly supplied to the sliding portion, and a smooth lubrication state can be maintained.

In the lubricating system of the present invention, the foamed solid lubricant is formed by foaming and curing a mixture containing a lubricating component, a resin that is foamed and cured to become porous, a curing agent, and a foaming agent. It is held in the foamed and cured resin. By foaming, free deformation with respect to external stress is possible, and in particular, flexibility can be improved. This lubricating component is mainly present in the resin, and can be gradually released to the necessary site while keeping the amount of the lubricating component that exudes due to external factors such as compression, bending, twisting, and expansion, for example, to a necessary minimum.

As a result of the above, by applying the lubrication system of the present invention to machine elements such as bearings and universal joints, cost reduction by reducing the amount of conventional grease, load on boot materials, weight reduction and compactness of constant velocity joints The technology is highly socially important not only from economically advantageous industrial aspects, but also from a plurality of viewpoints, such as environmental load reduction and design freedom.

It is sectional drawing which shows the constant velocity universal joint which is one Embodiment of the universal joint of this invention. It is sectional drawing which shows the constant velocity universal joint which is other embodiment of this invention. It is sectional drawing which shows the constant velocity universal joint which is other embodiment of this invention. It is sectional drawing which shows the constant velocity universal joint which is other embodiment of this invention. It is sectional drawing which shows the deep groove ball bearing which is one Embodiment of the bearing of this invention. It is sectional drawing of BJ which is other embodiment of the universal joint of this invention. It is sectional drawing of DOJ which is other embodiment of the universal joint of this invention. It is sectional drawing of TJ which is other embodiment of the universal joint of this invention. It is sectional drawing of the deep groove ball bearing which is other embodiment of the bearing of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inner member 2 Outer member 3 Inner member side track groove 4 Outer member side track groove 5 Steel ball 6 Cage 7 Shaft 8 Boot 9 Foamed solid lubricant 10 Grease for auxiliary lubrication 11 Deep groove ball bearing 12 Inner ring 13 Outer ring 14 Rolling element 15 Cage 16 Seal member 17 Foam solid lubricant 18 Auxiliary lubrication grease

The lubrication system of the present invention is characterized in that the foamed solid lubricant and the auxiliary lubricating grease containing the predetermined wax A coexist in the lubrication target portion. Auxiliary lubrication grease is responsible for lubrication until the lubricating component sufficiently oozes out of the foamed solid lubricant at the lubrication target site, and wax A added to the auxiliary lubrication grease suppresses the fluidity of the auxiliary lubrication grease. Thus, the lubrication function at the lubrication target part can be maintained for a long period of time.

The universal joint using the lubrication system of the present invention will be specifically described with reference to the drawings. FIG. 1 is a sectional view showing a constant velocity universal joint which is an embodiment of the universal joint of the present invention. As shown in FIG. 1, the constant velocity universal joint includes an inner member (also referred to as an inner ring) 1, an outer member (also referred to as an outer ring) 2, an inner member side track groove 3, an outer member side track groove 4, and a torque transmission member. (Also referred to as a steel ball) 5, cage 6, shaft 7, boot 8, foamed solid lubricant 9, auxiliary lubricating grease 10 in which a predetermined wax A is blended with grease, and other accessory parts . At this time, in the constant velocity universal joint, the auxiliary lubricating grease 10 is accommodated in the bottom portion of the outer member 2, and the foamed solid lubricant 9 is disposed in the vicinity of the torque transmission member 5, so The lubricating grease 10 coexists.

FIG. 2 is a sectional view showing a constant velocity universal joint according to another embodiment of the present invention. As shown in FIG. 2, the constant velocity universal joint includes an inner member (inner ring) 1, an outer member (outer ring) 2, an inner member side track groove 3, an outer member side track groove 4, and a torque transmission member (steel ball). 5, a cage 6, a shaft 7, a boot 8, a foamed solid lubricant 9, an auxiliary lubricating grease 10 in which a predetermined wax A is blended with grease, and other accessory parts. At this time, the auxiliary lubricating grease 10 is disposed in a space 7 a provided below the shaft hole of the inner member (inner ring) 1, and the foamed solid lubricant 9 is separated by the outer member side track groove 4 on which the torque transmitting member 5 slides. The foamed solid lubricant 9 and the auxiliary lubricating grease 10 coexist in a form arranged in a space surrounded by the rotation direction.

FIG. 3 is a cross-sectional view showing a constant velocity universal joint according to another embodiment of the present invention. As shown in FIG. 3, the constant velocity universal joint includes an inner member (inner ring) 1, an outer member (outer ring) 2, an inner member side track groove 3, an outer member side track groove 4, and a torque transmission member (steel ball). 5, a cage 6, a shaft 7, a boot 8, a foamed solid lubricant 9, an auxiliary lubricating grease 10 in which a predetermined wax A is blended with grease, and other accessory parts. At this time, the auxiliary lubricating grease 10 is arranged in the vicinity of the torque transmission member 5 in the track portion, and the foamed solid lubricant 9 is arranged in a space surrounded by the outer member side track groove 4 on which the torque transmission member 5 slides in the rotation direction. Thus, the foamed solid lubricant 9 and the auxiliary lubricating grease 10 coexist.

FIG. 4 is a cross-sectional view showing a constant velocity universal joint according to another embodiment of the present invention. As shown in FIG. 4, the constant velocity universal joint includes an inner member (not shown), an outer member (outer ring) 2, an inner member side track groove (not shown), an outer member side track groove 4, and torque transmission. It comprises a member 5, a cage 6 having eight cage windows 6 a, a shaft 7, a boot 8, a foamed solid lubricant 9, an auxiliary lubricating grease 10 in which a predetermined wax A is blended with grease, and other accessory parts. The At this time, the auxiliary lubricating grease 10 is accommodated in the vicinity of the torque transmission member 5 of the cage window 6a, and the foamed solid lubricant 9 is in a space surrounded by the outer member side track groove 4 in which the torque transmission member 5 slides in the rotation direction. The foamed solid lubricant 9 and the auxiliary lubricating grease 10 coexist in the form in which they are arranged.

The foamed solid lubricant 9 includes a resin component and a lubricant component, and by deforming the resin component, a deformation with respect to external stress is made possible. Among the foamed solid lubricant 9, the lubricating component is occluded not only in the open cells of the foam but also in the resin containing closed cells, and the retained amount of the lubricating component is larger than the retained amount by impregnation in the simply open cells. The lubricant is gradually released from the foamed solid lubricant due to the external force such as compression, bending, and expansion that occurs when the constant velocity universal joint takes an angle. It is. The auxiliary lubricating grease 10 is responsible for lubricating the inside of the universal joint together with a lubricating component that is gradually released from the foamed solid lubricant 9. In this case, the absolute amount of the lubricating component present in the universal joint is larger than that of the foamed solid lubricant alone. Therefore, a longer life can be achieved while maintaining the characteristics of reducing the amount of lubricant used, which is a great advantage when using a foamed solid lubricant, and reducing the load on boots and boot bands. Note that the fact that the lubricating component is occluded in the foamed / cured resin means that the liquid / semi-solid lubricating component such as lubricating oil and grease described below does not react with the foamed / cured resin or curing agent, and the compound It means that it is included without becoming.

An example in which the lubrication system of the present invention is applied to a rolling bearing will be specifically described with reference to the drawings. FIG. 5 is a sectional view of a deep groove ball bearing which is an embodiment of the bearing of the present invention. As shown in FIG. 5, the bearing 11 includes an inner ring 12, an outer ring 13 disposed concentrically with the inner ring 12, a plurality of rolling elements 14 interposed between the inner and outer rings, and the plurality of rolling elements 14. It is comprised by the holder | retainer 15 to hold | maintain and the sealing member 16 fixed to the outer ring | wheel 13 grade | etc.,. A foamed solid lubricant 17 is disposed in a space surrounded by the inner ring 12, the outer ring 13, the rolling elements 14, and the seal member 16, and an auxiliary lubricating grease 18 in which a predetermined wax A is blended with grease is provided. The foamed solid lubricant 17 and the auxiliary lubricating grease 18 coexist in the bearing so as to be disposed in the vicinity of the rolling elements 14 that are rolling portions.

6 is a cross-sectional view of BJ, which is another embodiment of the universal joint of the present invention, FIG. 7 is a cross-sectional view of DOJ, which is another embodiment of the present invention, and FIG. 8 is another embodiment of the present invention. A cross-sectional view of a certain TJ is shown.

As shown in FIG. 6, the BJ 21 has six or eight

track grooves

24, 25 in the axial direction formed at equal angles on the inner surface of the outer member 22 and the outer surface of the spherical inner member 23. , 25 is supported by a cage 27, the outer periphery of the cage 27 is a spherical surface 27a, and the inner periphery is a spherical surface 27b that conforms to the outer periphery of the inner member 23. Further, the outer periphery of the outer member 22 and the outer periphery of the shaft 28 are covered with a boot 29, and the outer member 22, the spherical inner member 23, the

track grooves

24 and 25, the torque transmission member 26, and the cage 27, A foamed solid lubricant 30 containing a lubricating component containing a predetermined wax B is enclosed in a space surrounded by the shaft 28. A lubrication system in which auxiliary lubrication grease formed by blending a predetermined wax A in a universal joint coexists is applied.

As shown in FIG. 7, the DOJ 31 is formed with six or eight

track grooves

34, 35 in the axial direction at equal angles on the inner surface of the outer member 32 and the outer surface of the spherical inner member 33. , 35 is supported by a cage 37, the outer periphery of the cage 37 is a spherical surface 37a, and the inner periphery is a spherical surface 37b that conforms to the outer periphery of the inner member 33, and each of the

spherical surfaces

37a, 37b The positions of the centers (A) and (B) are shifted in the axial direction on the axial center of the outer member 32. Further, the outer periphery of the outer member 32 and the outer periphery of the shaft 38 are covered with a boot 39, and the outer member 32, the spherical inner member 33, the

track grooves

34 and 35, the torque transmission member 36, and the cage 37, A foamed solid lubricant 40 containing a lubricating component containing a predetermined wax B is enclosed in a space surrounded by the shaft 38. A lubrication system in which auxiliary lubrication grease formed by blending a predetermined wax A in a universal joint coexists is applied.

As shown in FIG. 8, TJ 41 has three cylindrical track grooves 43 in the axial direction formed at equal angles on the inner surface of outer member 42, and three tripod members 44 incorporated inside outer member 42 have three Leg shafts 45, spherical rollers 46 serving as torque transmission members are fitted to the outer sides of the respective leg shafts 45, and needles 47 are incorporated between the spherical rollers 46 serving as torque transmission members and the leg shafts 45 to generate torque. A spherical roller 46 as a transmission member is supported so as to be rotatable and slidable in the axial direction, and the spherical roller 46 as a torque transmission member is fitted into the track groove 43. Further, the outer periphery of the outer member 42 and the outer periphery of the shaft 48 are covered with a boot 49, and a predetermined wax B is applied to a space surrounded by the outer member 42, the track groove 43, the tripod member 44, and the shaft 48. A foamed solid lubricant 50 containing the contained lubricating component is enclosed. A lubrication system in which auxiliary lubrication grease formed by blending a predetermined wax A in a universal joint coexists is applied.

For such TJ and DOJ, it is necessary to slide in the axial direction. Therefore, when an existing lubricant such as grease is used, the enclosed space volume is larger than that of the above-described fixed joint such as BJ. However, since the foamed solid lubricant (30 in FIG. 6, 40 in FIG. 7, 50 in FIG. 8) can be filled only in necessary portions, it is low when encapsulating the foamed solid lubricant in DOJ or TJ. The contribution to cost reduction and weight reduction becomes larger.

FIG. 9 is a cross-sectional view of a deep groove ball bearing which is another embodiment of the bearing of the present invention. As shown in FIG. 9, in the deep groove ball bearing 51, an inner ring 52 having an inner ring rolling surface 52a on the outer peripheral surface and an outer ring 53 having an outer ring rolling surface 53a on the inner peripheral surface are arranged concentrically, and the inner ring rolling surface 52a. A plurality of rolling elements 54 are arranged between the outer ring rolling surface 53a and the outer ring rolling surface 53a. The rolling element 54 is held by a cage 55, and a foamed solid lubricant 57 containing a lubricating component containing a predetermined wax B is enclosed at least around the rolling element 54. A lubrication system in which auxiliary lubrication grease formed by blending a predetermined wax A in a bearing coexists is applied. The seal member 56 is fixed to the outer ring 53 and the like at the axial end openings 58a and 58b of the inner ring 52 and the outer ring 53, respectively. The seal member 56 prevents leakage of a lubricating component that is gradually released from the foamed solid lubricant 57 and the like.

The foamed solid lubricant used in the present invention releases the lubricating component to the outside due to external stresses such as centrifugal force, compression, bending, and expansion, so that the lubricating component does not ooze out from the foamed solid lubricant. If the lubricating component is exhausted, the lubricating component may not be sufficiently present in the sliding portion. In the present invention, by using the auxiliary lubricating grease together, it is possible to make up for the shortage of the lubricating component that oozes out from the foamed solid lubricant.

Particularly, by using the auxiliary lubricating grease containing the predetermined wax A, it becomes easier to move the lubricant to the sliding portion. As a result, even if the lubrication component oozes out from the solid foam lubricant or the lubrication component is exhausted, the lubricating component oozes out from the solid foam lubricant by using the auxiliary lubricating grease. We can make up for the shortage. In addition, even if the sliding part is in a metal contact state due to a temporary lack of lubricant locally, the temperature rises due to the metal contact, so that the wax A component in the auxiliary lubrication grease melts and the auxiliary lubrication Since the fluidity of the grease is improved, the grease is quickly supplied to the sliding portion, and a smooth lubrication state can be maintained.

In the present invention, by adding the wax B component to the lubricating component of the foamed solid lubricant, the amount of the lubricating component released from the foamed solid lubricant can be maintained at a required amount, and an external force such as centrifugal force can be maintained. Even if added, the lubricating component can be held in a state in which it is difficult to move from the sliding portion. Further, even if the sliding portion is in a metal contact state due to a temporary lack of lubricant locally, the temperature rises due to the metal contact, so that the wax B component in the lubricating component of the foamed solid lubricant is melted. Since the fluidity is improved, the lubricant is quickly supplied to the sliding portion, and a smooth lubrication state can be maintained. For this reason, the lubrication function is continuously carried out without a shortage of lubricant (to improve the balance between outflow and supply) in the sliding portion of a mechanical element such as a bearing or universal joint in which a foamed solid lubricant is enclosed. Can fully fulfill.

The foamed solid lubricant used in the present invention requires much less energy when bent compared to non-foamed materials, and can be flexibly deformed while maintaining a high density of lubricating components such as lubricating oil. Therefore, even if the foamed solid lubricant shrinks in the process of cooling after solidifying the foamed solid lubricant inside the constant velocity universal joint, for example, it is necessary for bending and deformation even if the steel ball of the constant velocity universal joint is embraced Since the energy is small, it can be easily deformed and the problem of increased rotational torque can be prevented. Moreover, since it has many foamed parts, ie, a porous part, it is advantageous also at the point of weight reduction.

In addition, since the foamed solid lubricant used in the present invention only foams and cures a mixture containing a lubricating component and a resin component, no special equipment is required, and it can be filled and molded in any place. Is possible. Further, the density of the foamed solid lubricant can be changed by controlling the blending amount of the blending components of the mixture.

In the present invention, the foamed and hardened resin constituting the foamed solid lubricant is preferably a resin having rubber-like elasticity after foaming and curing and having a lubricating component exuding property due to deformation. Foaming / curing may be in a form in which foaming / curing is performed when the resin is produced, or in a form in which a foaming agent is blended with the resin and foaming / curing is performed in molding. Here, curing means a cross-linking reaction and / or a phenomenon in which a liquid is solidified. The rubber-like elasticity means rubber elasticity and means that deformation applied by an external force returns to the original shape by eliminating the external force.

For the resin component used in the foamed solid lubricant in the present invention, it is preferable to use a urethane prepolymer that is excellent in heat resistance and flexibility and can be reduced in cost. The foamed solid lubricant of the present invention is a foamed solid lubricant obtained by foaming and curing the urethane prepolymer or the like to make it porous, and having a lubricating component occluded inside the resin. This foamed solid lubricant has excellent lubricating component holding power, and can be manufactured at a low cost while suppressing the amount of the lubricating component oozed out even if it is deformed by an external force.

The urethane prepolymer that can be used in the present invention is obtained by a reaction between a compound having an active hydrogen group and a polyisocyanate, and the isocyanate group is contained at the end of the molecular chain or at the end of the side chain branched from within the molecular chain. It may be. The urethane prepolymer may have a urethane bond in the molecular chain.

Depending on the type of monomer (= compound having an active hydrogen group) to be reacted, it is classified into caprolactone, ester, ether and the like. Ether ethers include Takenate L-1170 (Mitsui Chemical Polyurethane), L-1158 (Mitsui Chemical Polyurethane), and Coronate 4090 (Nippon Polyurethane). Examples of the ester type include Coronate 4047 (manufactured by Nippon Polyurethane Co., Ltd.), and caprolactone type includes Takenate L-1350 (manufactured by Mitsui Chemical Polyurethane Co., Ltd.), Takenate L-1680 (manufactured by Mitsui Chemical Polyurethane Co., Ltd.), and Sianaprene 7-QM. (Manufactured by Mitsui Chemicals Polyurethane), Plaxel EP1130 (manufactured by Daicel Chemical Industries) and the like.

Also, oligomers or prepolymer compounds whose terminal groups are modified with isocyanate groups can be used. Examples of such a compound include a terminal isocyanate-modified polyether polyol and an isocyanate-modified product of a hydroxyl group-terminated polybutadiene. Examples of the terminal isocyanate-modified polyether polyol include Coronate 1050 (manufactured by Nippon Polyurethane Co., Ltd.). Examples of the isocyanate-modified product of hydroxyl-terminated polybutadiene include poly-bd MC50 (made by Idemitsu Kosan Co., Ltd.) and poly-bd HTP9 (made by Idemitsu Kosan Co., Ltd.).

These urethane prepolymers can be used in a mixture of 2 or more types depending on the desired mechanical properties.

In the present invention, a urethane prepolymer having an isocyanate group content of 2% by weight or more and less than 6% by weight or less can be used. If the content of isocyanate groups (-NCO) is less than 2% by weight, it becomes difficult to achieve both foaming and elasticity, and if it is more than 6% by weight, the hardness becomes too high and the resilience increases and deformation due to external force. It becomes easy to generate heat when receiving.

In addition, as the isocyanate group, a blocked isocyanate in which the isocyanate group is blocked with a blocking agent such as phenols, lactams, alcohols and oximes can be used.

The curing agent for curing the urethane prepolymer is preferably a compound having active hydrogen, and examples thereof include a polyamino compound having a functional group as an amino group and a polyol compound having a functional group as a hydroxyl group.

Polyamino compounds include 3,3'-dichloro-4,4'-diaminodiphenylmethane (hereinafter referred to as MOCA), 3,3'-dimethyl-4,4'-diaminodiphenylmethane, and 3,3'-dimethoxy-4. , 4'-diaminodiphenylmethane, 4,4'-diamino-3,3'-diethyl-5,5'-dimethyldiphenylmethane, trimethylene-bis- (4-aminobenzoate), bis (methylthio) -2,4- Aromatics typified by toluenediamine, bis (methylthio) -2,6-toluenediamine, methylthiotoluenediamine, 3,5-diethyltoluene-2,4-diamine, 3,5-diethyltoluene-2,6-diamine Examples include polyamino compounds.

Among the above polyamino compounds, aromatic amino compounds are preferable because of low cost and excellent physical properties, and aromatic diamino compounds having a substituent at the position adjacent to the amino group are particularly preferable. In the present invention, it is considered that the reactivity of the amino group is suppressed by the substituent at the adjacent position because it undergoes a step of curing together with foaming.

When the urethane prepolymer is cured with a polyamino compound, it becomes a foamed solid lubricant having urethane and urea bonds in the molecule. By generating urea bonds, the urethane bond density in the molecule is lowered, and elongation and impact resilience are improved. Moreover, rigidity can be provided by generating a urea bond.

Examples of the polyol compound include low molecular polyols such as 1,4-butane glycol and trimethylolpropane, polyether polyols, castor oil polyols, and polyester polyols. Of the polyol compounds, trimethylolpropane is preferred.

The ratio between the isocyanate group (—NCO) contained in the urethane prepolymer and the functional group of the curing agent that reacts with the isocyanate group is an equivalent ratio when the functional group is an amino group or a hydroxyl group (functional group of the curing agent). /NCO)=1/(1.1 to 2.5). The ratio of the isocyanate group contained in the urethane prepolymer, the amino group (—NH ₂ ) or hydroxyl group (—OH) of the curing agent, and the hydroxyl group of water (—OH) as the foaming agent, Flexibility, elasticity, etc. are determined. When the amino group (—NH ₂ ) or hydroxyl group (—OH) of the curing agent and the isocyanate group (—NCO) of the urethane prepolymer are reacted in an equivalent amount, an isocyanate group (—NCO) that reacts with water as the blowing agent is formed. Since it disappears, the range of (functional group of curing agent / NCO) = 1 / (1.1 to 2.5) is preferable. Further, the ratio of the hydroxyl group of water, which is a foaming agent, to the functional group of the curing agent is an equivalent ratio (hydroxyl group of water / functional group of the curing agent) = 1 / (0.7 to 2.0). If the amount of the curing agent is less than the above range, not only the physical properties such as the strength of the foamed solid lubricant are remarkably lowered, but also the urethane elastomer may not be cured.

Other examples of the resin component include polyether polyol. Examples of the polyether polyol include alkylene oxide (alkylene oxide having 2 to 4 carbon atoms, for example, ethylene oxide, propylene oxide, butylene oxide) adducts of low molecular polyols and ring-opening polymers of alkylene oxides. Polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol are included. As an example of polyether polyol, trade name Preminol manufactured by Asahi Glass Co., Ltd. may be mentioned. Preminol is a polyether polyol having a molecular weight of 5,000-12,000.

Examples of the polyisocyanate used as a curing agent for curing the polyether polyol include diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate and mixtures thereof, 1,5-naphthylene diisocyanate, 1, Examples include 3-phenylene diisocyanate and 1,4-phenylene diisocyanate. Examples of commercially available products include Nippon Polyurethane Co., Ltd .: Coronate T80.

The lubricating component that can be used in the present invention can be used as long as it does not dissolve the solid component forming the foam. As the lubricating component, for example, lubricating oil, grease, wax or the like can be used alone or in combination. Particularly preferred are hydrocarbon-based lubricants, hydrocarbon-based greases, or mixtures of hydrocarbon-based lubricants and hydrocarbon-based greases.

Examples of hydrocarbon-based lubricating oils include paraffinic and naphthenic mineral oils, hydrocarbon synthetic oils, GTL base oils, and the like. These can be used alone or as a mixed oil. In addition, ester synthetic oils, ether synthetic oils, fluorine oils, silicone oils and the like can also be used. These can be used alone or as a mixed oil.

The hydrocarbon grease is a grease having a hydrocarbon oil as a base oil, and examples of the base oil include the above-described hydrocarbon lubricants. Examples of the thickener include lithium soaps, lithium complex soaps, calcium soaps, calcium complex soaps, aluminum soaps, aluminum complex soaps, and other urea compounds such as diurea compounds and polyurea compounds. It is not a thing. The diurea compound is obtained by the reaction of diisocyanate and monoamine, and the polyurea compound is obtained by the reaction of diisocyanate and polyamine. In addition, greases based on ester-based synthetic oils, ether-based synthetic oils, GTL base oils, fluorine oils, silicone oils and the like can also be used.

By adding wax B to the above-mentioned lubricating component in the foamed solid lubricant, it is possible to suppress the fluidity at a relatively low temperature (normal temperature) and remain at the site where lubrication is necessary. When the temperature rises, the wax B dissolves, so that the fluidity of the lubricating component is improved and the lubricant is quickly supplied to the place where the lubricant is required.

The wax B added to the lubricating component of the foamed solid lubricant has a melting point of 70 to 150 ° C., and when the wax B has an amide bond in the molecule, the amide bond is a monoamide bond. If the melting point is less than 70 ° C., the temperature at which the softening (fluidity increases) is low, so the fluid may flow more than necessary and the lubricant may move from the place where it is necessary. If the melting point exceeds 150 ° C., the melting point is too high and the wax B may not melt when necessary, and the desired fluidity may not be improved, and supply of the lubricating component to the sliding portion may be delayed. Further, if the melting point of the wax B is high, it is necessary to raise the lubricating component to a high temperature when the wax B is melted / dispersed, which causes deterioration of the lubricating component itself. Also, those having two or more amide bonds in the wax molecule such as ethylene bis stearamide are not suitable. This is because the resin component is not cured when the foamed solid lubricant is produced. The reason for this is not clear, but it is considered that a wax having two or more amide bonds inevitably has a high molecular weight, and therefore compatibility with urethane molecules occurs.

The wax B added to the lubricating component is preferably at least one wax selected from fatty acid monoamide wax, hydrogenated oil wax, and hydrocarbon wax. As the fatty acid monoamide wax, either a saturated fatty acid monoamide or an unsaturated fatty acid monoamide can be used. Preferred fatty acid monoamides include stearic acid amide, oleic acid amide, erucic acid amide and the like. Examples of the hydrogen-cured oil-based wax include hardened castor oil, and examples of the hydrocarbon-based wax include paraffin wax. When the resin component of the foamed solid lubricant used in the present invention is polyurethane, fatty acid monoamide is particularly preferred among the waxes B. Among the fatty acid monoamides, at least selected from stearic acid amide, oleic acid amide, and erucic acid amide. Most preferably, one is used.

The amount of wax B added to the lubricating component of the foamed solid lubricant is from 1% to 15% by weight, more preferably from 2% to 10% by weight, based on the amount of the lubricating component. If it is less than 1% by weight, the fluidity at normal temperature cannot be lowered, and if it exceeds 15% by weight, the fluidity of the lubricating component is too low, and it is not preferable because it is difficult to reach the place where lubrication is required.

As a method of adding these waxes B to the lubricating component, it may be added as one of raw materials when preparing the foamed solid lubricant, or heated in advance to the melting point of the wax B in which all or part of the lubricating component is employed. In addition, they may be mixed uniformly. When the melting point of the wax B is equal to or higher than the production temperature of the foamed solid lubricant, the latter method is preferably used.

In the present invention, the means for foaming the foamed solid lubricant (foaming agent) uses an isocyanate compound as a raw material, and therefore preferably uses water that reacts with the isocyanate compound to generate carbon dioxide gas.

Further, it is preferable to use a catalyst as necessary, and 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. Examples of organometallic catalysts include stanaoctate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin mercaptide, dibutyltin thiocarboxylate, dibutyltin maleate, dioctyltin dimercaptide, dioctyltin thiocarboxylate, octenoate, etc. Is mentioned. Moreover, you may mix and use these multiple types for the purpose of adjusting the balance of reaction.

In the present invention, the foamed solid lubricant is a mixture containing the lubricating component (adding wax B as required), a resin component such as the urethane prepolymer or the polyether polyol, a curing agent, and a foaming agent. Obtained by foaming and curing.

When the resin component is a urethane prepolymer, the blending ratio of the lubricating component is 20 to 80% by weight, preferably 40 to 60% by weight, based on the entire mixture. When the lubricating component is less than 20% by weight, the supply amount of the lubricating oil or the like is so small that the function as the foamed solid lubricant cannot be exhibited.

When the resin component is a polyether polyol, the blending ratio of the lubricating component is 60 to 80% by weight with respect to the entire mixture. When the lubricating component is less than 60% by weight, the supply amount of the lubricating oil or the like is so small that the function as the foamed solid lubricant cannot be exhibited, and when it is more than 80% by weight, it may not solidify.

In the present invention, various additives such as pigments, antistatic agents, flame retardants, antifungal agents and fillers can be added to the solid foamed lubricant as necessary. In addition, solid lubricants such as molybdenum disulfide and graphite, friction modifiers such as organic molybdenum, oily agents such as amines, fatty acids, and fats, antioxidants such as amines and phenols, petroleum sulfonates, dinonylnaphthalene sulfone Rust inhibitors such as nates and sorbitan esters, extreme pressure agents such as sulfur and sulfur-phosphorus, antiwear agents such as organic zinc and phosphorus, metal deactivators such as benzotriazole and sodium nitrite, polymethacrylate, polystyrene Various additives such as a viscosity index improver such as

The method of mixing each component when producing the foamed solid lubricant is not particularly limited, and for example, mixing is performed using a commonly used stirrer such as a Henschel mixer, a ribbon mixer, a juicer mixer, a mixing head, or the like. be able to. The mixture preferably uses a surfactant such as a commercially available silicone foam stabilizer, and each raw material molecule is preferably dispersed uniformly. Further, the surface tension can be controlled by the type of the foam stabilizer, and the type of the generated bubbles can be controlled to open cells or closed cells. Examples of such surfactants include anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, silicone surfactants, and fluorine surfactants.

In the present invention, using a reactive impregnation method in which a foaming reaction and a curing reaction are simultaneously performed in the presence of a lubricating component such as a lubricating oil, in order to simultaneously achieve a high filling of the lubricating component and a high elongation of material properties at the same time. desirable. This is because the bubbles formed in the foam in the foam formation stage are uniformly impregnated with the lubrication component, and the lubrication component is occluded in the foamed / cured resin to increase the filling of the lubrication component and improve the material properties. High elongation is considered to be compatible. In contrast, the foam impregnated in advance and the impregnation method impregnating this with the lubricating component does not have sufficient lubricating component retention. The lubricant is released in a short period of time, and the lubricating component is supplied when used for a long time. It becomes insufficient.

In the present invention, the open cell ratio of the foamed solid lubricant after foaming is 50% or more, preferably 50% or more and 90% or less. When the open cell ratio is less than 50%, the ratio of the resin component (solid component) lubricating oil temporarily taken up in the closed cells increases and may not be supplied to the outside when necessary. In addition, if it exceeds 油 90%, there is a risk that it will be disadvantageous for long-term use due to a decrease in the oil retention of the lubricant and an increase in the amount of lubricant released, or the strength (durability) of the foamed solid lubricant itself may be reduced. I get out. The lubricating component taken into the closed cells is slowly released compared with the lubricating component taken into the open cells, and the sustained release can be continued for a long time.

In the present invention, the open cell ratio of the foamed solid lubricant can be calculated by the following procedure.
(1) The foamed solid lubricant that has been foam-cured is cut into an appropriate size to obtain sample A. The weight of sample A is measured.
(2) Soxhlet A is washed for 3 hours (solvent: petroleum benzine). Then leave it in a thermostatic bath at 80 ° C for 2 hours to completely dry the organic solvent and obtain Sample B. The weight of sample B is measured.
(3) The open cell ratio is calculated by the following procedure.
Open cell ratio = (1− (weight of resin component of sample B−weight of resin component of sample A) / weight of lubricating component of sample A) × 100
The resin component weight and the lubrication component weight of Samples A and B are calculated by multiplying the weights of Samples A and B by the composition charge ratio.
Lubricating components taken into discontinuous closed cells are not released to the outside by Soxhlet cleaning for 3 hours, so the weight of sample B is not reduced. The open cell ratio can be calculated as the release of the lubricating component.

The foaming ratio of the foamed solid lubricant should be at least 1.1 and less than 100 times. When the expansion ratio is 1.1 or less, the bubble volume is small and deformation cannot be allowed when external stress is applied. Moreover, when it is 100 times or more, it is difficult to obtain a strength that can withstand external stress. The expansion ratio is preferably 1.1 times to 10 times.

The foamed solid lubricant may be foamed and cured after pouring a mixture containing a lubricating component and resin into a lubrication target member such as a universal joint or a bearing, and after foaming and curing at normal pressure, cutting, grinding, etc. Then, it can be post-processed into the target shape and incorporated into the member to be lubricated. In the present invention, it is possible to easily fill any part of the member to be lubricated with a complicated shape, and there is no need for a molding die or a grinding process for obtaining a foamed molded product. It is preferable to employ a method of pouring the resin into the lubrication target member before foaming / curing and foaming / curing in the member. By adopting this method, the manufacturing process is simplified and the cost can be reduced. In addition, as a lubrication object member, a ball screw, a linear guide, a spherical bush, etc. other than the said constant velocity universal joint and a bearing are mentioned.

As the thickener and base oil of the auxiliary lubricating grease that can coexist with the foamed solid lubricant in the present invention, those exemplified as an example of the lubricating component in the foamed solid lubricant can be used. Similarly, various additives can be included.

In the present invention, by adding wax A to the auxiliary lubricating grease, it is possible to suppress the fluidity at a relatively low temperature (normal temperature) and to remain at the site where lubrication is required. When the temperature rises at the sliding portion of the element, the wax A melts, so that the fluidity of the auxiliary lubricating grease is improved, and the lubricant is quickly supplied to the place where the lubricant is required.

ワックス Wax A used for auxiliary lubricating grease has a melting point in the range of 70-150 ℃. If the melting point is less than ℃ 70 ° C, the temperature at which it softens (increases fluidity) is low, so there is a risk that it will flow more than necessary and the lubricant may move from where it is needed. . When the temperature exceeds 150 ° C., the melting point is too high and the wax A may not melt when necessary, and the target fluidity may not be improved, and the supply of the lubricating component to the sliding portion may be delayed. If the melting point of the wax A is high, it is necessary to raise the auxiliary lubricating grease to a high temperature when the wax A is melted / dispersed, which causes deterioration of the auxiliary lubricating grease itself.

The wax A used for the auxiliary lubricating grease is preferably selected from at least one of fatty acid amide and hydrogenated oil. The fatty acid amide may be a saturated fatty acid amide or an unsaturated fatty acid amide. Preferable fatty acid amides include stearic acid amide, oleic acid amide, erucic acid amide, and ethylenebisstearic acid amide. Examples of hydrogenated oil include hardened castor oil.

The amount of wax A used in the auxiliary lubricating grease is from 1% by weight to less than 15% by weight, more preferably from 2 to 10% by weight, based on the entire auxiliary lubricating grease. If the amount is less than 1% by weight, the fluidity at normal temperature cannot be lowered. If the amount is 15% by weight or more, the auxiliary lubricating grease becomes too hard to be supplied to a place requiring lubrication. When these waxes A are added to the auxiliary lubricating grease, it is preferable that the auxiliary lubricating grease is heated and uniformly mixed with the melting point of the selected wax A or higher.

In the present invention, the amount of auxiliary lubricating grease that can coexist with the foamed solid lubricant is preferably 1 to 60% by volume of the space volume to be lubricated. More preferably, it is 3 to 40% by volume. If the amount is less than 1% by volume, the amount of grease is insufficient. If the amount is more than 60% by volume, the amount of the foamed solid lubricant that contributes to lubrication over a long period of time decreases, resulting in a problem in durability.

In the present invention, the method of enclosing the auxiliary lubricating grease in the lubrication target portion is not limited. Before filling the lubrication target part with the foamed solid lubricant, auxiliary lubricating grease may be applied to the lubrication target part or its parts, or after filling the lubrication target part with the foamed solid lubricant, the syringe (or It is also possible to inject it to the target place with something similar to that.

Further, the place where the auxiliary lubricating grease is enclosed or applied in the lubrication system is not particularly limited, but it is preferable to enclose or apply it near the sliding portion of the lubrication target part. The auxiliary lubricating grease enclosed or applied can gradually move to the sliding portion of the lubrication target portion due to the centrifugal force or bending motion of the lubrication target portion, and can contribute to lubrication.

The place where the auxiliary lubricating grease is filled or applied in the universal joint is not particularly limited as long as it can reach the rolling part and the sliding part in the joint at the start of the universal joint. Preferably, it is the vicinity of the sliding part and rolling part in a universal joint. Specific parts of the constant velocity universal joint include the outer member bottom, the shaft of the inner member (inner ring), the torque transmission member of the track, the cage inner and outer surfaces, the cage window, and the outer The spherical portion of member-cage-inner member can be mentioned (see FIGS. 1 to 4). Further, as a method of enclosing the auxiliary lubricating grease in the universal joint, the auxiliary lubricating grease may be enclosed or applied in the universal joint or its parts before filling the universal joint with the foamed solid lubricant. Alternatively, after filling the universal joint with a foamed solid lubricant, it may be injected into a target location with a syringe (or similar one) (see FIGS. 1 to 4).

Examples of using the universal joint of the present invention for a constant velocity universal joint include an undercut free joint (hereinafter referred to as UJ) in addition to BJ. The number of torque transmitting members (balls) of such BJ and UJ may be 6 or 8. When a foamed solid lubricant is sealed in BJ or UJ, the lubricant is filled only in the necessary parts, which contributes to cost reduction and weight reduction, and because the operating angle used is large, it is compressed.・ It is easy to bend and the lubricant is easily supplied to the sliding part. In addition, examples of use for sliding type constant velocity universal joints include DOJ, TJ, and cross groove joint. Moreover, a cross joint etc. are mentioned as an inconstant velocity universal joint.

The bearing of the present invention is not limited to the bearing described in the embodiment, and can be widely applied to various types of rolling bearings. Examples include angular contact ball bearings, thrust ball bearings, cylindrical roller bearings, needle roller bearings, thrust cylindrical roller bearings, thrust needle roller bearings, tapered roller bearings, thrust tapered roller bearings, self-aligning ball bearings, and self-aligning rollers. Examples include bearings, thrust spherical roller bearings, and plain bearings.

<Preparation of auxiliary lubricating grease>
Auxiliary lubricating grease A to auxiliary lubricating grease H used in Examples 1 to 8 and Comparative Examples 1 to 4 were prepared by the following method.

Auxiliary lubrication grease A
Base grease by uniformly dispersing 9.16 g of diphenylmethane-4,4-diisocyanate and 7.84 g of p-toluidine in 83 g of mineral oil (manufactured by Nippon Oil Corporation: Turbine 100) Got. To this base grease, 10% by weight of stearamide (manufactured by Kao Corporation: fatty acid amide T melting point 97-102 ° C.) was added, heated to 110 ° C. and stirred well to obtain grease A for auxiliary lubrication.

Auxiliary lubrication grease B
Base grease by uniformly dispersing 9.16 g of diphenylmethane-4,4-diisocyanate and 7.84 g of p-toluidine in 83 g of mineral oil (manufactured by Nippon Oil Corporation: Turbine 100) Got. To this base grease, 3% by weight of stearic acid amide (manufactured by Kao Corporation: fatty acid amide T melting point 97-102 ° C.) was added, heated to 110 ° C. and stirred well to obtain auxiliary lubricating grease B.

Auxiliary lubrication grease C
Base grease by uniformly dispersing 9.16 g of diphenylmethane-4,4-diisocyanate and 7.84 g of p-toluidine in 83 g of mineral oil (manufactured by Nippon Oil Corporation: Turbine 100) Got. To this base grease, 5% by weight of ethylene bis-stearic acid amide (manufactured by Kao Corporation: fatty acid amide EB-G melting point 141.5-146.5 ° C) was added, heated to 150 ° C, stirred well, and supplementary lubricating grease C Got.

Auxiliary lubrication grease D
In 92 g of mineral oil (manufactured by Nippon Oil Corporation: Turbine 100), 3.94 g of diphenylmethane-4,4-diisocyanate and 4.07 g of octylamine were reacted, and the resulting diurea compound was uniformly dispersed to form a base grease. Obtained. To this base grease, 5% by weight of erucic acid amide (manufactured by Kao Corporation: fatty acid amide E melting point 79-85 ° C.) was added, heated to 100 ° C. and stirred well to obtain auxiliary lubricating grease D.

Auxiliary lubrication grease E
In 92 g of mineral oil (manufactured by Nippon Oil Corporation: Turbine 100), 3.94 g of diphenylmethane-4,4-diisocyanate and 4.07 g of octylamine were reacted, and the resulting diurea compound was uniformly dispersed to form a base grease. Obtained. To this base grease, 5% by weight of oleic acid amide (manufactured by Kao Corporation: fatty acid amide —N melting point 70-75 ° C) was added, and the mixture was heated to 100 ° C and stirred well to obtain auxiliary lubricating grease E It was.

Auxiliary lubrication grease F
In 92 g of mineral oil (manufactured by Nippon Oil Corporation: Turbine 100), 3.94 g of diphenylmethane-4,4-diisocyanate and 4.07 g of octylamine were reacted, and the resulting diurea compound was uniformly dispersed to form a base grease. Obtained. To this base grease, 5% by weight of hardened castor oil (manufactured by Kao Corporation: Kao wax 85-P melting point 85-87 ° C) was added, heated to 100 ° C and stirred well to obtain auxiliary lubricating grease F .

Auxiliary lubrication grease G
Base grease by uniformly dispersing 9.16 g of diphenylmethane-4,4-diisocyanate and 7.84 g of p-toluidine in 83 g of mineral oil (manufactured by Nippon Oil Corporation: Turbine 100) Got. To this base grease, 5% by weight of paraffin wax (manufactured by Nippon Seiwa Co., Ltd .: HNP-5 melting point 62 ° C.) was added, heated to 80 ° C. and stirred well to obtain auxiliary lubricating grease G.

Auxiliary lubrication grease H
Base grease by uniformly dispersing 9.16 g of diphenylmethane-4,4-diisocyanate and 7.84 g of p-toluidine in 83 g of mineral oil (manufactured by Nippon Oil Corporation: Turbine 100) Got. To this base grease, 15% by weight of stearamide (manufactured by Kao Corporation: fatty acid amide T melting point 97 to 102 ° C.) was added, heated to 110 ° C. and stirred well to obtain auxiliary lubricating grease H.

Examples 1 to 6, Comparative Example 1 and Comparative Example 3
First, as shown in FIG. 1, an outer member 2, an inner member 1, a cage 6 and a steel ball 5 which is a torque transmission member are assembled into a fixed eight ball joint sub-assy (manufactured by NTN: EBJ82 outer diameter size 72.6 mm), 5 g of auxiliary lubricating grease shown in Table 1 was sealed at the bottom of the outer member. Next, among the compositions shown in Table 1, (a), (d), (e), and (i) were mixed well at 80 ° C, and then dissolved at 120 ° C and (b) and (h) were quickly added. Mixed. Finally, (c) was added and stirred, and then 18.0 g was sealed in the joint subassembly with the auxiliary lubricating grease sealed therein. After a few seconds, the foaming reaction starts, and is allowed to stand for 30 minutes in a thermostatic bath set at 100 ° C to harden. The other parts such as boots and shafts are assembled, and the foamed solid lubricant and auxiliary lubricating grease coexist inside. A universal joint specimen was obtained. The obtained test piece was subjected to the durability test shown below. Further, the open cell ratio of the foamed solid lubricant was measured based on the above-mentioned method for calculating the open cell ratio. The results are also shown in Table 1.

<Durability test using constant velocity universal joint>
In order to evaluate whether or not the target durability has been improved, the constant velocity universal joint test piece was evaluated under the following conditions. If the outer member surface temperature exceeded 100 ° C during the test, the test was terminated due to an abnormal temperature rise. In addition, after the test, the inside of the test piece is inspected, and if there is no internal damage such as wear or peeling, it is judged as acceptable, “○” is judged, and if the damage is confirmed, judged as impossible, “×”. Record.
・ Torque 451 N ・ m
・ Angle 6 deg
・ Rotation speed 580 rpm
・ Test time 300 hours

Example 7, Example 8, Comparative Example 2 and Comparative Example 4
First, as shown in FIG. 1, an outer member 2, an inner member 1, a cage 6 and a steel ball 5 which is a torque transmission member are assembled into a fixed eight ball joint sub-assy (manufactured by NTN: EBJ82 outer diameter size 72.6 mm), 5 g of auxiliary lubricating grease shown in Table 1 was sealed at the bottom of the outer member. In the component amounts (composition) shown in Table 1, silicone-based foam stabilizer, mineral oil, amine-based catalyst, and water as a blowing agent were added to the polyether polyol, and the mixture was heated at 90 ° C. and stirred well. After adding isocyanate to this and stirring well, 16.0 g was sealed in the above-mentioned joint subassembly filled with auxiliary lubricating grease. After a few seconds, the foaming reaction starts, and it is left to cure for 15 minutes in a thermostatic chamber set at 90 ° C. Other parts such as boots and shafts are assembled, and the solid foam lubricant and auxiliary lubricating grease coexist in the interior. A test piece of a quick universal joint was obtained (see FIG. 1). About the obtained test piece and the foaming solid lubricant in a test piece, the item similar to Example 1 was measured. The results are also shown in Table 1.

In Examples 1 to 8, continuous operation was possible even after the test was completed, and good results were obtained. In Comparative Examples 1 and 2, the auxiliary lubricating grease containing wax A was enclosed, but the result was not possible. In Comparative Example 1, the outflow of the lubricating component to the boot side increased, and it was considered that the inside of the universal joint was deficient in the lubricant, resulting in damage (because the wax A に added to the auxiliary lubricating grease had a low melting point. I guess the effect did n’t appear). In Comparative Example 2 and Comparative Example 4, the open cell ratio of the foamed solid lubricant was less than 50%, so that the lubricant was sufficiently supplied to the necessary parts (sliding parts such as ball-track parts and cage spherical parts). I guess it didn't exist. In Comparative Example 3, since the amount of wax A added to the auxiliary lubricating grease was 15% by weight, there was little outflow of the lubricating component to the boot side. However, since the fluidity of the lubrication component is too low, it is difficult to move the lubrication component even in the joint, and the lubricant is not sufficiently supplied to the necessary part (sliding part such as ball-track part and cage spherical part). I guess.

Example 9 and Example 10
Of the compositions shown in Table 2, (a), (d), (e) and (i) were mixed well at 80 ° C, and then the amine curing agent (b) dissolved at 120 ° C was added and mixed quickly. . Finally, water (c) and an amine catalyst (h) were added and the mixture obtained by stirring was filled in the internal space of a taper bearing (NTN Corporation: 30204 outer diameter size 47 mm). After a few seconds, the foaming reaction started and allowed to stand at 100 ° C. for 30 minutes to cure. Then, 0.3 g of the auxiliary lubricating grease was injected into the vicinity of the rolling element with a syringe (see FIG. 5). A specimen was obtained. The obtained test piece was subjected to the following initial characteristic test and life test, and the state of appearance of the initial characteristic and the life time were measured. Further, the open cell ratio of the foamed solid lubricant was measured based on the above-mentioned method for calculating the open cell ratio. These results are also shown in Table 2.

<Initial characteristic test using bearings>
In order to evaluate whether or not the initial characteristics are obtained as one of the target auxiliary lubrications, the obtained bearing test piece was loaded with Fa = Fr = 67 N and rotated at 5000 rpm for 10 hours at 80 ° C. It was. Decompose after the test, and mark “◯” if no slip mark is observed at the roller large end, and mark “X” if no slip mark is observed.

<Life test using bearings>
A life test was subsequently conducted for those for which an initial characteristic test was possible. When a radial load of 67 N and a thrust load of 67 N were applied to the obtained specimen and rotated at 5000 rpm at 80 ° C, the input current of the motor driving the rotating shaft exceeded the limit current (the rotational torque was The lifetime was measured until it exceeded twice the starting torque.

Example 11 and Example 12
Add silicone-based foam stabilizer (d), lubricating oil (i), amine-based catalyst (h) and water (c) as blowing agent to polyether polyol (g) with the composition shown in Table 2, and heat at 90 ° C. Stir well. The mixture obtained by adding isocyanate to this and stirring well was filled in the internal space of a taper bearing (NTN Corporation: 30204 outer diameter size 47 mm). After a few seconds, the foaming reaction started. After standing for 15 minutes at 90 ° C. and curing, 0.3 g of the auxiliary lubricating grease was injected into the vicinity of the rolling element with a syringe (see FIG. 5). A specimen was obtained. The same items as in Example 9 were measured. The results are also shown in Table 2.

Comparative Example 5
Bearing test specimens having the compositions shown in Table 2 were prepared in the same procedure as in Example 9 and Example 10, but no auxiliary lubricating grease was enclosed. The same items as in Example 9 were measured. The results are also shown in Table 2.

Comparative Example 6
Bearing test specimens having the composition shown in Table 2 were prepared in the same manner as in Examples 11 and 12, but no auxiliary lubricating grease was enclosed. The same items as in Example 9 were measured. The results are also shown in Table 2.

Examples 13 to 16 and Comparative Example 7
First, as shown in FIG. 2, an outer member 2, an inner member 1, a cage 6 and a steel ball 5 which is a torque transmission member are assembled into a fixed eight ball joint sub-assy (manufactured by NTN: EBJ82 outer diameter size 72.6 mm) was prepared, and (a), (d), (e), (i) among the compositions shown in Table 3 were mixed well at 80 ° C. and then dissolved at 120 ° C. (b), (h) And mixed quickly. Finally, (c) was added and stirred, and then 15.0 g was sealed in the joint subassembly. After a few seconds, the foaming reaction started. The foamed solid lubricant in the constant velocity universal joint was cured by allowing it to stand for 30 minutes in a thermostatic bath set at 100 ° C. to cure. After that, 5 g of auxiliary lubricating grease is sealed in the space 7 a provided below the shaft hole of the inner member 1, and other sections such as boots and shafts are assembled, and the solid foam lubricant and auxiliary lubricating grease are contained inside. A test piece of a constant velocity universal joint coexisting with was obtained (see FIG. 2). About the obtained test piece and the foaming solid lubricant in a test piece, the item similar to Example 1 was measured. These results are also shown in Table 3.

In Examples 13 to 16, continuous operation was possible even after the test was completed, and good results were obtained. In Comparative Example 7, the outflow of the lubricating component to the boot side increased, and it was considered that the inside of the universal joint was deficient in the lubricant, resulting in damage (because the wax A added to the auxiliary lubricating grease had a low melting point. I guess the effect did n’t appear).

Reference Example 1 to Reference Example 6 and Reference Comparative Example 1
First, as shown in FIG. 6, an outer member 22, an inner member 23, a cage 27, and a fixed eight ball joint sub-assembly assembled with a steel ball 6 as a torque transmission member (manufactured by NTN: EBJ82 outer diameter size 72.6 mm). Next, among the compositions shown in Table 4, (e), (i), and (j) were mixed at a temperature equal to or higher than the melting point of (j) wax B, and once dissolved, the wax B was sufficiently dispersed in the lubricating component. Next, among the compositions shown in Table 4, the mixture of (a), (d) and the above (e), (i), (j) was mixed well at 80 ° C. and then dissolved at 120 ° C. ( b) and (h) were added and mixed rapidly. Finally, (C) was added and stirred, and then 18.0 g was sealed in the joint. After a few seconds, the foaming reaction started, left at 100 ° C for 30 minutes to cure the foamed solid lubricant in the joint, and assembled other sections such as boots and shafts to obtain a constant velocity universal joint specimen encapsulating the foamed solid lubricant. It was. The obtained test piece was subjected to the durability test described above. Further, the open cell ratio of the foamed solid lubricant was measured based on the above-mentioned method for calculating the open cell ratio. The results are also shown in Table 4.

Reference Example 7, Reference Example 8 and Reference Comparative Example 2
First, as shown in FIG. 6, a fixed eight ball joint sub-assembly (an NTN company: EBJ82 outer diameter size 72.6) in which an outer member 22, an inner member 23, a cage 27, and a steel ball 26 as a torque transmission member are assembled. mm). In the component amounts (composition) shown in Table 4, silicone foam stabilizer, mineral oil, amine catalyst, water as foaming agent were added to polyether polyol, heated at 90 ° C. and stirred well (in advance, with mineral oil) Wax B was thoroughly mixed at a temperature equal to or higher than the melting point of wax B, and wax B was dispersed in mineral oil). After adding isocyanate and stirring well, 16.0 g was sealed in the joint. After a few seconds, the foaming reaction started and allowed to stand for 15 minutes in a thermostat set at 90 ° C. to cure, and other parts such as boots and shafts were assembled to obtain a constant velocity universal joint specimen enclosing a foamed solid lubricant. The same items as in Reference Example 1 were measured for the obtained test pieces. The results are also shown in Table 4.

In Reference Example 1 to Reference Example 8, continuous operation was possible even after the test was completed, and good results were obtained. In Reference Comparative Example 1 and Reference Comparative Example 2, wax B was added to the lubricating component, but the result was not possible. In Reference Comparative Example 1, the foamed solid lubricant was not cured (solidified). In Reference Comparative Example 2, since the open cell ratio of the solid foamed lubricant was 50% or less, the lubricant was not sufficiently supplied to the necessary parts (steel balls-sliding parts such as track parts and cage spherical parts). I guess it.

Reference Example 9 and Reference Example 10
Of the compositions shown in Table 5, (e), (i), and (j) were mixed at a melting point or higher of the wax B, and the wax B was dissolved once and then sufficiently dispersed in the lubricating component. Next, among the compositions shown in Table 5, (a), (d), and a mixture of (e), (i), (j) are mixed well at 80 ° C., and then dissolved at 120 ° C. (B) The amine catalyst (h) was added and quickly mixed. Finally, water (c) was added and the mixture obtained by stirring was filled into the internal space of a taper bearing (NTN Corporation, 30204 outer diameter size 47 mm). After a few seconds, the foaming reaction started and allowed to stand at 100 ° C. for 30 minutes to be cured to obtain a bearing test piece in which a foamed solid lubricant was enclosed. The obtained bearing test piece and the foamed solid lubricant in the test piece were subjected to the initial characteristic test and the life test described above, and the appearance of the initial characteristic and the life time were measured. Further, the open cell ratio of the foamed solid lubricant was measured based on the above-mentioned method for calculating the open cell ratio. These results are also shown in Table 5.

Reference Example 11 and Reference Example 12
Add silicone-based foam stabilizer (d), lubricating oil (i), amine-based catalyst (h) and water (c) as blowing agent to polyether polyol (g) with the composition shown in Table 5, and heat at 90 ° C. Stir well. The mixture obtained by adding isocyanate to this and stirring well was filled in the internal space of a taper bearing (NTN Corporation: 30204 outer diameter size 47 mm). After a few seconds, the foaming reaction started, and it was left to cure at 90 ° C. for 15 minutes to obtain a bearing test piece in which a foamed solid lubricant was enclosed. The same items as in Reference Example 9 were measured. The results are also shown in Table 5.

Reference Comparative Example 3
Bearing test pieces were prepared in the same manner as in Reference Example 9 and Reference Example 10 with the compositions shown in Table 5, but the foamed solid lubricant was not cured (solidified).

Reference Comparative Example 4
Bearing test pieces were prepared in the same manner as in Reference Example 11 and Reference Example 12 with the compositions shown in Table 5, but wax B was not added to the lubricating component. The same items as in Reference Example 9 were measured. The results are also shown in Table 5.

The lubrication system of the present invention can improve the lubricating component retention of the foamed solid lubricant that retains the lubricating component, and can suppress the amount of lubricant oozing due to deformation of the foamed solid lubricant, and Even when the lubrication component from the foamed solid lubricant is insufficient, the lubrication function can be supplemented, and a long life and cost reduction can be met. Therefore, it can be suitably used as a lubrication system for various rolling bearings and universal joints used for various industrial machines and automobiles.

Claims

A lubrication system in which a foamed solid lubricant containing a lubricating component in a resin that is foamed and cured to become porous, and an auxiliary lubricating grease coexist in a lubrication target part.
The lubricating system according to claim 1, wherein the auxiliary lubricating grease contains at least wax A having a melting point of 70 to 150 ° C.
The lubricating system according to claim 1, wherein the wax A is at least one selected from fatty acid amides and hydrogenated oil.
The lubricating component contains at least one selected from lubricating oil and grease, wax B having a melting point of 70 to 150 ° C., and the wax B is a fatty acid monoamide wax, a hydrogenated oil wax, and a hydrocarbon. The lubricating system according to claim 1, wherein the lubricating system is at least one wax selected from system waxes.
4. The lubricating system according to claim 3, wherein the fatty acid monoamide wax is at least one selected from stearic acid amide, erucic acid amide, and oleic acid amide.
The foamed solid lubricant is characterized in that the resin foamed and cured to become porous has rubber-like elasticity, and the lubricating component contained in the resin has exudability due to deformation of the rubber-like elastic body. The lubrication system according to claim 1.
2. The lubrication system according to claim 1, wherein the foaming and curing resin has a foaming ratio of 1.1 to 100%.
2. The lubrication system according to claim 1, wherein the foamed / cured resin has a continuous cell ratio after foaming / curing of not less than 50%.
The foamed solid lubricant is obtained by foaming and curing a mixture containing the lubricating component, the resin, a curing agent, and a foaming agent.
The lubricating component is at least one selected from lubricating oil and grease;
The resin is a urethane prepolymer containing 2 wt% or more and less than 6 wt% of isocyanate groups in the molecule;
The blowing agent is water;
The lubricating system according to claim 1, wherein the mixture contains 20 to 80% by weight of the lubricating component with respect to the whole mixture, and the open cell ratio after foaming is 50% or more.
The lubrication system according to claim 8, wherein the urethane prepolymer is at least one urethane prepolymer selected from an ester urethane prepolymer, a caprolactone urethane prepolymer, and an ether urethane prepolymer.
The ratio of the isocyanate group to the functional group of the curing agent that reacts with the isocyanate group is an equivalent ratio (functional group of the curing agent / NCO) = 1 / (1.1 to 2.5). The lubrication system according to claim 8.
9. The ratio of the hydroxyl group of water to the functional group of the curing agent is an equivalent ratio (water hydroxyl group / functional group of the curing agent) = 1 / (0.7 to 2.0). The described lubrication system.
The lubricating system according to claim 8, wherein the curing agent is an aromatic polyamino compound.
The lubricating system according to claim 12, wherein the aromatic polyamino compound is an aromatic polyamino compound having a substituent at the position adjacent to the amino group.
The foamed solid lubricant is obtained by foaming and curing a mixture containing the lubricating component, the resin, a curing agent, and a foaming agent.
The resin is a polyether polyol, and the curing agent is a polyisocyanate,
The blowing agent is water;
The lubricating system according to claim 1, wherein the lubricating component is contained in an amount of 60 to 80% by weight based on the entire mixture including the resin, the curing agent, the foaming agent, and the lubricating component.
15. The lubrication system according to claim 8 or 14, wherein the mixture is foamed and hardened after being filled around a sliding member or in a molding die.
A universal joint using the lubrication system according to claim 1,
A rotational torque is transmitted by the engagement between the track groove and the torque transmission member, and the torque transmission member rolls along the track groove to move in the axial direction. The auxiliary lubricating grease, the foamed solid lubrication, and the like. A universal joint, characterized in that the agent coexists in the universal joint.
The universal joint according to claim 16, wherein the mixture is filled around the torque transmitting member before foaming and curing is completed.
The universal joint according to claim 16, wherein the universal joint is a constant velocity universal joint.
A bearing using the lubrication system according to claim 1,
A bearing characterized in that the auxiliary lubricating grease and the foamed solid lubricant coexist in the bearing.