Abstract: A steering rack includes a rack shaft (10), a plurality of rack teeth (11a) formed on the rack shaft and each having a tooth trace inclined with respect to a first direction perpendicular to an axial direction of the rack shaft, and a dummy tooth (33a) aligned with the rack teeth and formed on the rack shaft. The dummy tooth (33a) is non-uniformly formed in a second direction parallel to the tooth trace of the rack tooth (11a).

Abstract: Each tooth of a worm wheel has a first tooth flank in which a helical surface portion is arranged on one side in a rotational axis direction of the worm wheel and a concavely curved surface portion is arranged on the other side in the rotational axis direction, and a second tooth flank in which a concavely curved surface portion is arranged on the one side in the rotational axis direction and the helical surface portion is arranged on the other side in the rotational axis direction.

Abstract: A gear blank is provided. It includes a disk having a first face and a second face. A first plurality of individual lugs formed on said first face circumferentially adjacent an outer circumferential edge of said disk. Each lug of said first plurality of individual lugs has a first inner circumferential edge formed on said first face along a first retaining diameter. Adjacent lugs of said first plurality of individual lugs have a first circumferential spacing therebetween.

Abstract: A transmission gear has a tooth surface formed of a free-form surface instead of an involute surface and a root area formed of a free-form surface instead of a trochoid surface. With such a transmission gear, the fatigue strength against contact pressure can be increased by reducing the Hertzian stress in the area around the meshing point of the tooth surface. The tooth surface is formed of a free-form surface in which the smallest radius of curvature in an area around a mating pitch point is maximized, and the fatigue strength against bending can be increased by reducing the bending stress at a tooth root portion of the bottom land. In addition, the gear noise can be reduced. The bottom land is formed of a free-form surface in which the smallest radius of curvature in an area around a tooth root is maximized.

Abstract: A method of improving working of grooves of a screw rotor, in particular, working of grooves side in working efficiency, a working apparatus, a working tool, and a method of manufacturing a screw compressor are provided. A method of controlling rotation of a work and turning of a tool at a time to form a screw tooth space based on a five-axis NC machine, and a special end mill having a cutting edge of a short length and a neck portion provided between the cutting edge and a shank portion to be made thin is used to perform working in grooves side finish working process.

Abstract: A hybrid spiroid and worm gear is formed as a gear body having an axis of rotation. The gear body has a plurality of spiroid gear teeth formed in opposing surfaces of the body formed generally radially relative to the axis of rotation. The gear body further has a plurality of worm gear teeth formed in a hub portion, between, separate and apart from the spiroid teeth. The worm gear teeth are formed generally longitudinally relative to the axis of rotation. A method for making the hybrid spiroid and worm gear is also disclosed.

Abstract: By finding a range of an allowable error of maximum meshing position of a worm shaft in an axial direction relative to a worm wheel, that is higher than that of a worm shaft of a conventional worm gear unit, a worm gear unit of the present invention is provided.

Abstract: A rack and pinion type steering device capable of reducing contact surface pressure, suppressing the wear of contact surfaces, and preventing a rack guide movable amount from being excessively increased by increasing the contact area of the outer peripheral surface of roller on the outer peripheral surface of a rack shaft in a rack guide, and method of manufacturing the steering gear.

Abstract: A gear blank is provided. It comprises a metal hub blank having an outer perimeter. A plurality of individual adjacent tabs extend radially from the outer perimeter of the metal hub blank. A polymeric ring overlaying a portion of the metal hub blank including the tabs is provided.

Abstract: In a process for the aligning of the tooth spaces of a workpiece with precut teeth, which is set up on the work spindle of a gear finishing machine, the workpiece (1) is brought into no-backlash double flank mesh with a pilot gear (6). The workpiece (1) is rotated, and during this rotation both the angular position of the tooth space centre lines of the pilot gear (6) and the centre distance between the pilot gear (6) and the workpiece (1) are measured. This allows the workpiece (1) to be tested with respect to radial run-out, flank material allowance, helix angle, and any possible irregularities.

Abstract: A method of forming a powder metal forging, which includes the steps of providing a preform including a sintered powder metal composition; inserting the preform in at least one part of a die set having a top die and a bottom die, at least one of the top die and the bottom die defining a helical forge form therewithin; closing the die set wherein the top die is contacting the bottom die; and compressing the preform in the forge form using an upper punch including a core rod and a lower punch, the compressing step occurring after the closing step, the compressing step resulting in a formed part having a helical outer surface. The method and apparatus of the present invention is particularly advantageous when forming a powder metal forging helical outer surface and an inner contour such as a cylindrical inside diameter.

Abstract: A method of improving working of grooves of a screw rotor, in particular, working of grooves side in working efficiency, a working apparatus, a working tool, and a method of manufacturing a screw compressor are provided. A method of controlling rotation of a work and turning of a tool at a time to form a screw tooth space based on a five-axis NC machine, and a special end mill having a cutting edge of a short length and a neck portion provided between the cutting edge and a shank portion to be made thin is used to perform working in grooves side finish working process.

Abstract: The invention relates to a plastic gear, particularly a worm gear, with teeth disposed side by side in circumferential direction. Provision is made according to the invention for the surface of at least one of the teeth to be structured in such a way as to constitute a grease depot. The invention additionally relates to a drive as well as to a method for introducing a structure, which constitutes a grease depot, into the surface of at least one tooth of a plastic gear.

Abstract: By finding a range of an allowable error of maximum meshing position of a worm shaft in an axial direction relative to a worm wheel, that is higher than that of a worm shaft of a conventional worm gear unit, a worm gear unit of the present invention is provided.

Abstract: A method for cutting worm and worm wheel in a worm-gear reduction unit (1) with circulation of bearing balls, comprising the steps of: (a) obtaining races (30) for the bearing balls (4) onto the worm wheel (3); and (b) obtaining races (20) for the bearing balls (4) onto the worm (2), wherein step (b) provides the cutting of the races (20) according to a cutting profile substantially corresponding to the envelope of the subsequent positions assumed by the bearing balls within the worm wheel races being formed.

Abstract: This method includes: a supporting process of supporting a worm wheel in a first supporting section of a supporting body; an engaging process of engaging a jig gear which corresponds to a worm with the worm wheel; a measuring process of measuring a distance between the centers of the worm wheel and the jig gear; a gear processing process of processing the worm based on the measured distance between the centers; and a supporting process of supporting the worm in a second supporting section of the supporting body after releasing the engagement between the worm wheel and the jig gear.

Abstract: The invention relates to a method for mounting a worm on an armature shaft of an armature for an electric motor. The invention proposes first mounting armature parts, such as an armature lamination packet with armature windings, a commutator, a bearing seat, and/or a bearing, on the armature shaft and then rolling the worm on the armature shaft. This has the advantage that the worm can have a greater diameter than does the armature shaft over its remaining length.

Abstract: In order that a worm 1 is rotated, a clearance (a region constituting a clearance portion between bearings and a worm gear) is formed (FIGS. 4(1) to (3)) in an upper surface of a base plate 3. A mold 12 for forming a lower half region of the worm therein is formed (FIG. 4(8)). A material 5 for the worm is deposited (FIG. 4(9)) to a height equal to that of a lower half region plus that of an upper half of the worm. An upper half of the worm is formed (FIGS. 4(10) to (12). Finally, the material 13 in the clearance between the base plate 3 and gear 1 is removed (FIG. 4(13)).

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: A drive gear engages a driven gear with non-intersecting axes of rotation making an angle of approximately 90° with respect to one another. A shaft has a first portion with a predetermined diameter, and a second portion has an enveloped worm gear with at least one roll-formed helical tooth formed thereon with an outer diameter greater than the diameter of the first portion of the shaft. The extra envelopment achieves an overall smaller package size for competitive advantage. When the shaft is rolled, the outside teeth exceed the shaft diameter by a predetermined amount allowing more teeth to be in contact with the driven gear. An outer bearing can be placed at the end of the shaft to allow the teeth to be of a larger diameter than the shaft. The pitch of the teeth can vary. Preferably, the bearing groove is roll formed simultaneously with the teeth of the worm gear since the centroid of the enveloped teeth must be located with the gear center line.