COUNTERWEIGHT

摘要

In a counterweight (2) according to the invention, a weight portion (8) has an outer-radius extended portion (8a) that is formed in an overlapping region between a piston-lower-end non-interference region (Sb) and a cylinder-block non-interference region (Sc) that are located radially outwardly of a reference non-interference region (Sa). Thus, the weight portion (8) is expanded radially outward from the reference non-interference region (Sa) without interfering with a cylinder block (16) and the lower end face (6a) of a piston (6). It is thus possible to effectively increase the moment of inertia without incurring a significant increase in the weight of the counterweight (2).