Abstract: A gear composed of a polymer blend or a copolymer of PA66 and PA6 which contains a part having a PA66 molecular structure and a part having a PA6 molecular structure in a weight ratio of PA66/PA6=99.9/0.1 to 95.0/5.0 is excellent in durability as well as heat resistance and dimensional stability. A speed reduction gear using the gear has a reduced size, and can be used under a higher torque without a torque increase due to dimensional change of the gear. An electric power steering apparatus using the speed reduction gear has a reduced size, and can be used for a larger automobile.

Abstract: After forming a primary powder bed at a toothed portion of an article, such as a gear or a spline shaft, by electrostatic powder coating process, the powder bed is removed from crests of teeth in the toothed portion by a specified thickness by scraping it off while sucking up the scraped powder. Next, the electrostatic powder coating process is performed again to form a secondary powder bed over the entire surface of the toothed portion. Then, the primary and secondary powder beds are melted or fused by induction heating to thereby form a coating film of a substantially uniform thickness.

Abstract: After forming a primary powder bed (i.e., powder layer) at a toothed portion of an article, such as a gear or a spline shaft, by electrostatic powder coating process, the powder bed/layer is removed from crests of teeth in the toothed portion by a specified thickness by scraping it off while sucking up the scraped powder. Next, the electrostatic powder coating process is performed again to form a secondary powder bed/layer over the entire surface of the toothed portion. Then, the primary and secondary powder beds/layers are melted or fused by induction heating to thereby form a coating film of a substantially uniform thickness.

Abstract: A worm wheel includes an annular metallic core portion and a resin rim portion which is fitted on an outer circumference of the core portion. The rim portion includes an annular main body portion which covers the outer circumference of the core portion and in which a toothed portion is formed on an outer circumference thereof and a pair of annular flanges which are made to extend from the main body portion in a radially inward direction X to thereby cover, respectively, outer edge portions of first and second sides of the core portion. The first annular flange 53 engages with a recess formed in the corresponding side of the core portion. A bottom portion of the recess includes an undercut portion in relation to a radially outward direction.

Abstract: The present invention relates to a resin gear to be meshed with a gear made of metal or the like, more particularly to a resin gear, wherein crystalline resin is used for a base material and reinforced fiber and further a crystalline nucleating agent are added as additives added to the base material.

Abstract: A press molding die capable of preventing a workpiece from moving is provided. The press molding die includes a punch for pressing a workpiece; a molding die having a molding surface on which the workpiece is placed and a concave portion which is formed on the molding surface and which has a shape corresponding to the punch; a pad for pressing a part of the workpiece placed on the molding surface and which is on the periphery of the concave portion; and a micro-rough layer which is formed by performing a particulate coating process on at least one of a portion of the pad, for pressing the workpiece, and a portion of the molding surface, corresponding to the portion of the pad. Preferably, the height of roughness of the micro-rough layer is 0.01 to 0.06 mm, and the particulate coating process is performed using a silicofluoric chrome plating solution.

Abstract: An electric power steering apparatus including a reduction mechanism 5 for transmitting an output of a steering assist motor 1 to a steering mechanism through a worm 3 and a worm wheel 4, in which the worm wheel 4 is formed by a thermosetting synthetic resin filled with a sheet 6 of aramid fibers having a low attacking property to a counter member and an effect of improving the abrasion resistance of the synthetic resin. Even when the reduction mechanism is used in an engine room or the temperature of the reduction mechanism is raised by frictional heat with heightening power, the reduction mechanism is durable, and further the gears have excellent abrasion resistance and toughness and improved durability.

Abstract: The invention relates to a worm wheel for use in a reduction gear, for example, and to a machine and a method for forming the same. The worm wheel includes a tooth having a tooth crest. At least the teeth are formed by injection molding a synthetic resin. The tooth crest includes a trace formed along a parting line as a result of the injection molding process. The trace does not exist on a surface of action of the tooth. The invention is suitable for applications demanding high contact gear accuracies.

Abstract: An electric steering apparatus comprises an annular tooth portion and a metal boss portion fitted in the inside of the annular tooth portion. The annular tooth portion has teeth for engaging with a worm. The annular tooth portion is made of synthetic resin material mixed with fibers having a length with an aspect ratio between 100 and 800 so that the fibers are arranged preferably in a direction crossing the direction of the torque, which is applied to the teeth, thereby to heighten a fatigue strength of the teeth and the teeth root portions.

Abstract: In an electric power steering device, a driven gear of a deceleration gear mechanism for transmitting rotation of an electric actuator for generating auxiliary steering power has a gear body made of a synthetic resin material. At least the outer periphery of a metal core ring is covered by the gear body. The gear body is molded and integrated with the core ring by injecting synthetic resin material into a mold, in which the core ring is inserted. A plurality of teeth, each of which has faces which run in the direction of the axis of rotation of the driven gear, are formed on the outer periphery of the core ring so as to be arranged at intervals in a circumferential direction. The synthetic resin material that constitutes the gear body is filled in the spaces between the teeth of the core ring.

Abstract: An electric power steering apparatus including a reduction mechanism 5 for transmitting an output of a steering assist motor 1 to a steering mechanism through a worm 3 and a worm wheel 4, in which the worm wheel 4 is formed by a thermosetting synthetic resin filled with a sheet 6 of aramid fibers having a low attacking property to a counter member and an effect of improving the abrasion resistance of the synthetic resin. Even when the reduction mechanism is used in an engine room or the temperature of the reduction mechanism is raised by frictional heat with heightening power, the reduction mechanism is durable, and further the gears have excellent abrasion resistance and toughness and improved durability.

Abstract: After forming a primary powder bed at a toothed portion of an article, such as a gear or a spline shaft, by electrostatic powder coating process, the powder bed is removed from crests of teeth in the toothed portion by a specified thickness by scraping it off while sucking up the scraped powder. Next, the electrostatic powder coating process is performed again to form a secondary powder bed over the entire surface of the toothed portion. Then, the primary and secondary powder beds are melted or fused by induction heating to thereby form a coating film of a substantially uniform thickness.

Abstract: An electric power steering apparatus including a reduction mechanism 5 for transmitting an output of a steering assist motor 1 to a steering mechanism through a worm 3 and a worm wheel 4, in which the worm wheel 4 is formed by a thermosetting synthetic resin filled with a sheet 6 of aramid fibers having a low attacking property to a counter member and an effect of improving the abrasion resistance of the synthetic resin. Even when the reduction mechanism is used in an engine room or the temperature of the reduction mechanism is raised by frictional heat with heightening power, the reduction mechanism is durable, and further the gears have excellent abrasion resistance and toughness and improved durability.

Abstract: In an electric power steering device, the rotation of an electric actuator for generating auxiliary steering power is transmitted to a vehicle wheel by way of a worm and a worm wheel. The worm wheel is molded from a synthetic resin material. The relative viscosity (VR) of the molded worm wheel is made greater than or equal to 100 and less than or equal to 300.

Abstract: An electric power steering apparatus includes a worm wheel having an annular tooth portion made of synthetic resin and a boss portion made of metal. The annular tooth portion has teeth that engage with a worm, and the boss portion is fitted to the annular tooth portion. One of an inside peripheral surface of the annular tooth portion and an outside peripheral surface of the boss portion has concaves disposed on both axial ends thereof, and the other has convexes fitted into the concaves. The radial length of these concaves and convexes is 1 to 2.5 times as large as the axial length of the concaves and convexes.

Abstract: The invention relates to a worm wheel for use in a reduction gear, for example, and to a machine and a method for forming the same. The worm wheel includes a tooth having a tooth crest. At least the teeth are formed by injection molding a synthetic resin. The tooth crest includes a trace formed along a parting line as a result of the injection molding process. The trace does not exist on a surface of action of the tooth. The invention is suitable for applications demanding high contact gear accuracies.

Abstract: An electric power steering device transmits rotation of an electric actuator for generating auxiliary steering power to a wheel via a worm and a worm wheel. The worm wheel is molded from pelletized synthetic resin material. A number average molecular weight of the pelletized synthetic resin material is greater than or equal to 30,000 and less than or equal to 60,000.

Abstract: In an electric power steering device, the rotation of an electric actuator for generating auxiliary steering power is transmitted to a vehicle wheel by way of a worm and a worm wheel. The worm wheel is molded from a synthetic resin material. The relative viscosity (VR) of the molded worm wheel is made greater than or equal to 100 and less than or equal to 300.

Abstract: In an electric power steering device, a driven gear of a deceleration gear mechanism for transmitting rotation of an electric actuator for generating auxiliary steering power has a gear body made of a synthetic resin material. At least the outer periphery of a metal core ring is covered by the gear body. The gear body is molded and integrated with the core ring by injecting synthetic resin material into a mold, in which the core ring is inserted. A plurality of teeth, each of which has faces which run in the direction of the axis of rotation of the driven gear, are formed on the outer periphery of the core ring so as to be arranged at intervals in a circumferential direction. The synthetic resin material that constitutes the gear body is filled in the spaces between the teeth of the core ring.

Abstract: An electric power steering apparatus including a reduction mechanism 5 for transmitting an output of a steering assist motor 1 to a steering mechanism through a worm 3 and a worm wheel 4, in which the worm wheel 4 is formed by a thermosetting synthetic resin filled with a sheet 6 of aramid fibers having a low attacking property to a counter member and an effect of improving the abrasion resistance of the synthetic resin. Even when the reduction mechanism is used in an engine room or the temperature of the reduction mechanism is raised by frictional heat with heightening power, the reduction mechanism is durable, and further the gears have excellent abrasion resistance and toughness and improved durability.