Series elastic actuator

An elastic actuator comprising:

• a gear configured to transmit a rotational force;
• a mounting recess defined on a first side of the gear;
• a plurality of elastic wedges configured to be received in the mounting recess at positions spaced apart from each other in a circumferential direction of the mounting recess, each elastic wedge including a non-metal elastic material;
• an output body configured to cover the first side of the gear;
• at least one insertion wedge protruding from a first side of the output body toward the first side of the year and configured to be inserted between a pair of adjacent elastic wedges among the plurality of elastic wedges;
• and
• a shaft coupled to the output body and penetrating the gear,
• wherein a protrusion having an inner space through which the shaft passes is formed to extend from the mounting recess toward the output body,
• wherein the elastic actuator further comprises comprising a bearing to support the shaft in a radial direction of the shaft, and
• wherein the protrusion includes an inner circumferential surface that defines the inner space, and a bearing mounting recess is formed in the inner circumferential surface to receive the bearing.

A robot comprising:

• a main body;
• a connecting frame connected the main body;
• and
• an elastic actuator connected to the connecting frame and configured to be worn on an user's body, the elastic actuator comprising:
• a gear configured to transmit a rotational force;
• a mounting recess defined on a first side of the gear;
• a plurality of elastic wedges configured to be received in the mounting recess at positions spaced apart from each other in a circumferential direction of the mounting recess, each elastic wedge including a non-metal elastic material;
• an output body configured to cover the first side of the gear;
• and
• at least one insertion wedge protruding from a first side of the output body toward the first side of the gear and configured to be inserted between a pair of adjacent elastic wedges among the plurality of elastic wedges,
• wherein the first side of the output body is formed with a plurality of stepped portions that are recessed away from the gear and are arranged to align with the plurality of elastic wedges such that stepped portions form gaps between the elastic wedges and the output body.