A linear compressor has a hollow piston with crown and sidewall. The piston reciprocates in a cylinder. A piston rod connects the piston to a spring. A connection between the piston rod and the piston transmits axial forces directly to the piston crown. The connection transmits lateral forces to the piston at an axial location away from the piston crown. The connection allows rotational flexibility between the piston and the piston rod transverse to and uniformly around the piston reciprocation axis.Other improvements in or relating to linear compressors are disclosed and claimed.