GEAR AND ELECTRIC ACTUATOR PROVIDED WITH SAME

• Main Authors: IKEDA, Yoshinori, KAWAGUCHI, Hayato
• Format: Patent
• Language: English; French; German
• Published: 23.12.2020
• Subjects: BLASTING; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; DYNAMO-ELECTRIC MACHINES; ELECTRICITY; ENGINEERING ELEMENTS AND UNITS; GEARING; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; GENERATION; HEATING; LIGHTING; MECHANICAL ENGINEERING; THERMAL INSULATION IN GENERAL; WEAPONS

An object of the present invention is to provide a sintered gear having improved quality which can prevent the tooth damage and deformation such as bow of the teeth during manufacturing steps of the sintered gear and an electric actuator provided with such a sintered gear. According to the present invention, there is provided a gear formed of sintered alloy comprising spur teeth formed on a circumference of the gear; a central hole on the center of the gear; a boss formed around the central hole; and a peripheral portion formed radially inner side of the teeth, a thickness of a region between the boss and the peripheral portion being thinner than that of the boss characterized in that the peripheral portion is formed on at least one side of the gear and has an axially large thickness, and also provided an electric actuator comprising a housing; an electric motor mounted on the housing; a speed reduction mechanism for transmitting rotational force of the motor to a ball screw mechanism; and the ball screw mechanism being able to convert the rotational motion of the electric motor to the axial linear motion of a driving shaft and comprising a nut and a screw shaft, the nut being formed with a helical screw groove on its inner circumference, secured on its outer circumference an output gear forming part of the speed reduction mechanism and supported rotationally but axially immovably relative to the housing by a pair of supporting bearings mounted on the housing, and the screw shaft formed with a helical screw groove on the outer circumference corresponding to the helical screw groove of the nut, adapted to be inserted into the nut via a large number of balls, and supported not rotationally but axially movably relative to the housing characterized in that an end face of an inner ring of one supporting bearing of the pair of supporting bearings and a side surface of the boss are closely contacted each other, and that the output gear is configured by a gear defined in any one of claims 1ˆ¼5.