Abstract: The protective cover having a cup shape is mounted to an outer ring of a bearing so as to seal an inward-side end portion of the bearing. A protective cover includes: a disc part made of a synthetic resin; and a sensor holder part that is made of the synthetic resin and protrudes inward from the disc part. The disc part is provided with a separation wall which separates the magnetic encoder and the magnetic sensor from each other. The separation wall has a surface facing the magnetic encoder and a surface facing the magnetic sensor, and one of the surfaces has a mark of a gas drainage pin of an injection molding die.

Abstract: A nut is used with being fixed to a sensor cap. The sensor cap is attached to an outer ring of a bearing in a wheel bearing device of an automobile. The sensor cap includes a sensor holder for holding a magnetic sensor. The nut is made of steel, and has a screw portion in which a bolt is screwed to attach the magnetic sensor to the sensor cap. A surface of the nut is coated with a zinc-nickel alloy plating layer with a nickel eutectic ratio of 8 to 18%.

Abstract: A nut is used with being fixed to a sensor cap. The sensor cap is attached to an outer ring of a bearing in a wheel bearing device of an automobile. The sensor cap includes a sensor holder for holding a magnetic sensor. The nut is made of steel, and has a screw portion in which a bolt is screwed to attach the magnetic sensor to the sensor cap. A surface of the nut is coated with a zinc-nickel alloy plating layer with a nickel eutectic ratio of 8 to 18%.

Abstract: A protective cover is molded through injection molding of a synthetic resin and includes a disc part, a sensor holder part protruding inward from the disc part, and a protruding part protruding inward from the disc part and being continuous with the sensor holder part. The disc part includes a separation wall which is thinner than other portions of the disc part and separates a magnetic encoder and a magnetic sensor from each other. The protruding part has, at the inward-side face thereof, a gate mark caused by the injection molding. The protruding part is provided with, at the outward-side face thereof, a thickness reduction part extending inward so as to be close to the gate mark.

Abstract: A radial-type magnetic encoder includes: an annular fixing member; and an annular plastic magnet attached to the annular fixing member. The annular fixing member includes the cylindrical portion, an outward flange portion extending outward in a radial direction from an edge of the cylindrical portion, and a sensor opposed portion bent from an edge of the outward flange portion and opposed to a magnetic sensor which detects rotation of the magnetic encoder, and the annular fixing member has a substantially U-shaped sectional shape along a plane including the radial direction and an axial direction. The annular plastic magnet has a shape that covers a front surface, a back surface, and an end edge of the sensor opposed portion, and an outer-diameter-side part of the outward flange portion.

Abstract: A protective cover is molded through injection molding of a synthetic resin and includes a disc part, a sensor holder part protruding inward from the disc part, and a protruding part protruding inward from the disc part and being continuous with the sensor holder part. The disc part includes a separation wall which is thinner than other portions of the disc part and separates a magnetic encoder and a magnetic sensor from each other. The protruding part has, at the inward-side face thereof, a gate mark caused by the injection molding. The protruding part is provided with, at the outward-side face thereof, a thickness reduction part extending inward so as to be close to the gate mark.

Abstract: A radial-type magnetic encoder includes: an annular fixing member; and an annular plastic magnet attached to the annular fixing member. The annular fixing member includes the cylindrical portion, an outward flange portion extending outward in a radial direction from an edge of the cylindrical portion, and a sensor opposed portion bent from an edge of the outward flange portion and opposed to a magnetic sensor which detects rotation of the magnetic encoder, and the annular fixing member has a substantially U-shaped sectional shape along a plane including the radial direction and an axial direction. The annular plastic magnet has a shape that covers a front surface, a back surface, and an end edge of the sensor opposed portion, and an outer-diameter-side part of the outward flange portion.