A ball screw device is provided, including a retainer that can properly retain balls. The difference between a diameter being the pitch circle diameter of the ball screw device and the outside diameter of the rack shaft is set to be equal to or larger than the difference between the bore diameter of a ball screw nut and the diameter. The thickness center diameter of the retainer is set to be smaller than the diameter. Even when the inclination angle is reduced, the clearance between the inclined surfaces of each retainer groove on the radial inside can be easily set to be smaller than the diameter of the balls because the bore diameter of the retainer is set to be smaller. Thus, even when the inclination angle of the inclined surfaces is set to be smaller, the balls can be properly retained.

A drive gear for a generally cylindrical imaging component. The drive gear includes a body for engaging the generally cylindrical imaging component; a cylindrical shaft attached to the body, the cylindrical shaft having an end surface; and lobes extending longitudinally outward from the end surface.

A drive gear for a generally cylindrical imaging component. The drive gear includes a body for engaging the generally cylindrical imaging component; a cylindrical shaft attached to the body, the cylindrical shaft having an end surface; and lobes extending longitudinally outward from the end surface.

The linear actuator comprises elongated first and second bands that cooperate to form an extractable and retractable column. Rotatable first and second band guide members respectively guide turns of the first and second bands into intertwined engagement. A power actuator causes rotation of the first and second band guide members such that the extractable and retractable column may be extracted or retracted. A base carries the power actuator, the first and second bands and the first and second band guide members. An anti-rotation mechanism comprises a first anti-rotation member attached to the base and a complementary second anti-rotation member attached to at least one of the first and second bands, with the first and second anti-rotation members engaging one another in the column to prevent rotation of the column relative to the base. The engagement of the first and second anti-rotation members is non-punctual about a periphery of the column.

The linear actuator comprises elongated first and second bands that cooperate to form an extractable and retractable column. Rotatable first and second band guide members respectively guide turns of the first and second bands into intertwined engagement. A power actuator causes rotation of the first and second band guide members such that the extractable and retractable column may be extracted or retracted. A base carries the power actuator, the first and second bands and the first and second band guide members. An anti-rotation mechanism comprises a first anti-rotation member attached to the base and a complementary second anti-rotation member attached to at least one of the first and second bands, with the first and second anti-rotation members engaging one another in the column to prevent rotation of the column relative to the base. The engagement of the first and second anti-rotation members is non-punctual about a periphery of the column.

The linear actuator comprises elongated first and second bands that cooperate to form an extractable and retractable column. Rotatable first and second band guide members respectively guide turns of the first and second bands into intertwined engagement. A power actuator causes rotation of the first and second band guide members such that the extractable and retractable column may be extracted or retracted. A base carries the power actuator, the first and second bands and the first and second band guide members. An anti-rotation mechanism comprises a first anti-rotation member attached to the base and a complementary second anti-rotation member attached to at least one of the first and second bands, with the first and second anti-rotation members engaging one another in the column to prevent rotation of the column relative to the base. The engagement of the first and second anti-rotation members is non-punctual about a periphery of the column.

The linear actuator comprises elongated first and second bands that cooperate to form an extractable and retractable column. Rotatable first and second band guide members respectively guide turns of the first and second bands into intertwined engagement. A power actuator causes rotation of the first and second band guide members such that the extractable and retractable column may be extracted or retracted. A base carries the power actuator, the first and second bands and the first and second band guide members. An anti-rotation mechanism comprises a first anti-rotation member attached to the base and a complementary second anti-rotation member attached to at least one of the first and second bands, with the first and second anti-rotation members engaging one another in the column to prevent rotation of the column relative to the base. The engagement of the first and second anti-rotation members is non-punctual about a periphery of the column.

A drive gear for a generally cylindrical imaging component. The drive gear includes a body for engaging the generally cylindrical imaging component; a cylindrical shaft attached to the body, the cylindrical shaft having an end surface; and lobes extending longitudinally outward from the end surface.

A drive gear for a generally cylindrical imaging component. The drive gear includes a body for engaging the generally cylindrical imaging component; a cylindrical shaft attached to the body, the cylindrical shaft having an end surface; and lobes extending longitudinally outward from the end surface.

A plane that contains a central axis of a worm shaft and that is orthogonal to a central axis of a worm wheel is arranged at a central position of the worm wheel in a tooth width direction thereof when no load is applied to a worm speed reducer. The worm wheel is formed by a cutting operation using a hob with a hob center offset from the central position toward an offset direction corresponding to a first direction along the tooth width direction. A pair of tooth flanks has different pressure angles at the central portion in the tooth width direction.