Abstract: In a linear guide apparatus including an axially extending guide rail, a slider engaged with the guide rail, and a plurality of rolling elements loaded into the slider, the linear guide apparatus further includes a sealing device fixed to the slider in slidable contact with the guide rail for sealing a clearance existing between the guide rail and the slider, in which the sealing device includes: a lubricant-containing polymer member formed of a synthetic resin containing a lubricant, and having a contact portion contacting with the guide rail to surround the guide rail, both wing portions, a connecting portion connecting the wing portions to be C-shaped substantially, and a pair of first recesses formed in the respective wing portions for fixing the lubricant-containing polymer member to the slider; a first plate member fitted to the lubricant-containing polymer member opposed to the slider; and a pair of first cylindrical members inserted to the respective first recesses.

Abstract: In a seal for a rolling bearing, the seal has a molding member formed from a rubber material, the molding member including a lip portion, the molding member having 0.3 to 5.0 MPa of tensile stress at 10% strain and no less than 50% of elongation at break after the rubber material is subjected to an accelerated air aging at 130.degree. C. for 1000 hours. The rubber material includes the nitrile rubber compound containing a raw-material rubber, with respect to 100 weight parts of the raw-material rubber, 0.3 to 5.0 weight parts of an age resistor, and 0.3 to 5.0 weight parts of at least one secondary age resistor. The seal prevents grease enclosed in the rolling bearing from leaking out, the lip portion from being broken, and dust resistance from being lowered even in the case where the rolling bearing is used in a high-temperature environment.

Abstract: In a linear guide apparatus including a guide rail, a slider fitted movably to the guide rail, a plurality of rolling elements loaded to move the slider relative to the guide rail, and a seal device mounted on a side of the slider to seal a clearance existing between the guide rail and the slider, the seal device includes a reinforcement member that has a contact surface fixed to the slider and a recess formed in the contact surface to surround the outer surface of the guide rail, and a lubricant-containing polymer member that is fitted into the recess and has an inner sealing portion slidably contacting the guide rail and an outer surface opposed to the inner sealing portion and positioned at a predetermined clearance relative to the recess. The seal device assembling the lubricant-containing polymer member into the reinforcement member reduces a possibility of the occurrence of damage, cracking or other failures during fitting or use of the seal device.

Abstract: In a self-lubrication linear guide apparatus including a guide rail, a slider and a plurality of rolling elements, the apparatus further includes a plurality of lubricant-containing polymer spacer balls which are interposed between the rolling elements inside the slider. A lubricant gradually exudes from the lubricant-containing polymer spacer balls as time elapses to be automatically supplied to the rolling elements, so that satisfactory self lubrication can be achieved over a long period of time.

Abstract: In a linear guide apparatus including a guide rail, a slider and a plurality of rolling elements, the apparatus further includes a seal device fixed to the slider in slidable contact with an outer surface of the guide rail for sealing a clearance existing between the guide rail and the slider, the seal device including a reinforcement plate and a lubricant-containing polymer member, the reinforcement plate having a first surface fixed to the end face of the slider and a second surface which is formed of polyolefinic synthetic resin, the lubricant-containing polymer member being formed of a polyolefinic polymer and a lubricant, and joined to the second surface of the reinforcement plate by one-piece molding. The linear guide apparatus can supply automatically the lubricant from the seal device to the rolling elements in the slider consistently over an extended period of time while reducing a possibility of the occurrence of damage, cracking or other failures because of the reinforcement plate.

Abstract: A rolling bearing comprising an outer race having one track, an inner race having the other track, a plurality of rolling elements arranged between the both tracks, and a cage for retaining the plurality of rolling elements in such a way that the rolling elements can roll freely, wherein the cage is a lubricating oil-containing polymer member obtained by molding a synthetic resin containing 10 to 80% by weight of a lubricating oil. The cage retains a sufficient amount of a lubricating oil at a high rate of retention so that a lubricating action can be maintained in a stable manner for a prolonged period of time, and it is produced at low cost.

Abstract: A magnetic fluid composition comprising a low-volatile organic solvent as a carrier having dispersed therein ferromagnetic fine particles coated with a surface active agent having a lipophilic group having affinity to said low-volatile organic solvent, and a thixotropy-imparting agent is disclosed. The composition is prevented from splashing for an extended period of time even when used in a magnetic fluid-sealed apparatus operated at such a high speed that the rotational speed of the sealing part is 2 m/sec or higher.

Abstract: A heat-resistant, water-resistant, low-viscosity magnetic fluid and a process for producing same has a dispersion medium made of a low-volatile organic solvent, a low molecular weight dispersant having a lipophilic group and a polar group, the lipophilic group having an affinity for the organic solvent, ferromagnetic particles dispersed in the organic solvent, the surface of each of the ferromagnetic particles being covered with the dispersant, and an additive added to the dispersion medium having a lipophilic group and a polar group, the lipophilic group having a macromolecular chain. The process includes a step of adding the additive to the dispersion medium. The lipophilic group includes a macromolecular chain. The magnetic fluid is suitable for service, e.g., in a shaft seal.

Abstract: An electroconductive magnetic fluid composition is disclosed comprising a low volatility organic solvent as a carrier, a surface active agent having an lipophilic group with a strong affinity for the solvent, fine ferromagnetic particles coated at the surface thereof with the surface active agent and dispersed in the organic solvent, and a tertiary amine and an organic acid as an electrifying agent. The electroconductive magnetic fluid composition of the present invention is produced, preferably, including the steps of admixing fine ferromagnetic particles, a low boiling point organic solvent an surface active agent and separating to remove any fine particles of poor dispersibility.

Abstract: A magnetic fluid composition comprising a less volatile organic solvent as a dispersing medium, a dispersing agent having oleophilic groups exhibiting an affinity therewith, fine ferromagnetic particles coated at the surface thereof with the dispersing agent and dispersed in the less volatile organic solvent and a fluorocarbon surface active material having an organophobic portion and an organophilic portion together in a unitary molecular structure. The magnetic fluid is prepared by the steps of adding the low boiling organic solvent and the dispersant having oleophilic groups to fine ferromagnetic particles to obtain an intermediate medium, separating the fine particles of poor dispersibility from the intermediate medium and, then adding the less volatile organic solvent and heating the resulting material to evaporate the low boiling organic solvent thereby obtaining a magnetic fluid and, further, adding the fluorocarbon surface active material to the magnetic fluid.

Abstract: A ferrofluid composition is defined by fine particles of ferromagnetic material, a liquid carrier for dispersing the ferromagnetic material and a surfactant or surfactants acting as a dispersant. The surfactant is required to have such relation to the carrier that the surfactant has, as its hydrophobic group portion, a structure equivalent to the carrier, and the carrier is selected to be either an alkylpolyphenyl ether oil, an alkylnaphthalene oil or both. By virtue of this structural feature, fine ferromagnetic particles are uniformly and stably dispersed throughout the carrier which has low viscosity and is thermally very stable.

Abstract: An aqueous magnetic fluid composition comprising water as a dispersion medium and fine ferromagnetic particles as a dispersed phase, in which a coupling agent having a hydrophilic group and at least one hydrolyzable group is chemically bonded by way of the reaction product of the hydrolyzable group to the surface of the fine ferromagnetic particles. The magnetic fluid composition is prepared by way of obtaining an intermediate medium by chemically bonding the coupling agent by way of the hydrolysis product to the fine particles and separating fine particles of poor dispersibility and evaporating the composite product of the hydrolysis and at least a portion of water.