Free-piston Stirling engine

A free-piston Stirling engine comprising:

• a cylinder;
• a reciprocating body capable of reciprocating inside the cylinder along an axial direction of the cylinder;
• an elastic body for controlling a reciprocating motion of the reciprocating body;
• a connection body for connecting the reciprocating body to a movable portion of the elastic body;
• a support body for fixing a fixation portion of the elastic body with the cylinder;
• a weight body for adjusting a movable mass including the reciprocating body and the connection body;
• and
• an attachment portion for attaching the weight body, wherein
• the connection body has a connection main body and a nut,
• the connection main body is fixed to the reciprocating body, the movable portion of the elastic body is sandwiched by the connection main body and the nut,
• the weight body is a male screw member that is provided on the side of the elastic body that is opposite to the reciprocating body,
• the attachment portion is a female screw member, the male screw member and the female screw member are capable of being screwed together, and
• any of multiple types of the male screw members with different weights is capable of being screwed to the female screw member.

A free-piston Stirling engine comprising:

• a cylinder;
• a reciprocating body capable of reciprocating inside the cylinder along an axial direction of the cylinder;
• an elastic body for controlling a reciprocating motion of the reciprocating body;
• a connection body for connecting the reciprocating body to a movable portion of the elastic body;
• a support body for fixing a fixation portion of the elastic body with the cylinder;
• and
• a weight body for adjusting a movable mass including the reciprocating body and the connection body,
• wherein
• the connection body has a rod and a first nut,
• the rod has a rod main body and a male screw, and is fixed to the reciprocating body,
• the first nut and a second nut are screwed to the male screw,
• the rod main body has an end portion that is opposite to the reciprocating body,
• the movable portion of the elastic body is sandwiched by the end portion of the rod main body and the first nut,
• the second nut is provided on the side of the elastic body that is opposite to the reciprocating body, and
• the weight body is sandwiched by the first nut and the second nut.