Machine with reduced cylinder friction

摘要

A machine 1010 with reduced cylinder friction is provided. The machine 101 has one or more cylinders 103. Each of the cylinders 103 has an inner surface 105 configured to engage a circumferential surface of a piston ring 107 of a piston 109 thereby defining a contact zone 111 between the inner surface (105) of the cylinder 103 and the circumferential surface of the piston ring 107. The inner surface 105 has at least one recess 129 indented therein. The ratio of the dimension of the recess 129 in the direction of travel of the piston 109 to the dimension of the contact zone 111 in the direction of travel of the piston 109 is in the range of approximately 1:5 to 3:5.