| 摘要 |
An electric linear motion actuator capable of accurately controlling the axial position of an outer ring member is provided. The electric linear motion actuator includes: a rotary shaft (10) to be driven by an electric motor (15); a plurality of planetary rollers (11) kept in rolling contact with the cylindrical surface formed on the outer periphery of the rotary shaft (10); a carrier (13) which retains the plurality of planetary rollers (11) such that the planetary rollers (11) are rotatable about axes of the respective planetary rollers (11) while revolving around the rotary shaft (10), and of which the axial movement is restricted; and an outer ring member (12) surrounding the plurality of planetary rollers (11) and supported so as to be slidable in the axial direction. Helical ribs (22) are formed on the inner periphery of the outer ring member (12); and circumferential grooves (23) are formed on the outer periphery of each planetary roller (11) so as to be engaged with the helical ribs (22). The rotation of the rotary shaft (10) is thus converted to the linear motion of the outer ring member (12). A revolution sensor (33) is provided which detects the rotation angle of the carrier (13). |
