Electric actuator

An electric actuator, comprising:

• a motor comprising a motor shaft that is rotatable about a motor axis;
• a speed reduction mechanism connected to the motor shaft;
• and
• a bearing fixed to the motor shaft,
• wherein the motor shaft comprises an eccentric axis portion centered on an eccentric axis that is eccentric with respect to the motor axis,
• the speed reduction mechanism comprises:
• an externally toothed gear connected to the eccentric axis portion via the bearing;
• an internally toothed gear that surrounds a radial outer side of the externally toothed gear and meshes with the externally toothed gear;
• an output flange portion arranged facing the externally toothed gear in an axial direction of the motor axis;
• a plurality of column members arranged so as to protrude from one member of the output flange portion and the externally toothed gear toward the other member and surround the motor axis;
• and
• at least one tube member surrounding the column members,
• the other member comprises a plurality of hole portions arranged so as to surround the motor axis,
• the plurality of column members are inserted into the plurality of hole portions respectively, and support the externally toothed gear to be swingable around the motor axis via an inner side surface of each of the hole portions,
• the at least one tube member surrounds the column members in the hole portions and is rotatable around a rotary axis passing through the hole portions,
• wherein the at least one tube member is attached to the column members,
• wherein each of the column members comprises:
• a column member body gap-fitted to an inner side of the tube member;
• and
• a flange portion protruding from the column member body toward an outer side in a radial direction centered on the rotary axis, and
• the flange portion is arranged facing a front end side of the at least one tube member in a protrusion direction of the column member.