Double-headed swash type compressor and method for manufacturing cylinder block

A double-headed swash compressor comprising:

• a cylinder block including an annular array of piston bores formed through the cylinder block, a plurality of pistons reciprocatingly received in the piston bores, a suction space formed in the cylinder block, and a shaft bore formed through the cylinder block, the shaft bore communicating with a plurality of refrigerant supply holes formed in the cylinder block, the plurality of refrigerant supply holes communicating with a plurality of compression chambers defined by the piston bores and the plurality of pistons;
• a first housing coupled to a first side of the cylinder block, the first housing having a first discharge chamber formed therein;
• a second housing coupled to a second side of the cylinder block, the second housing having a second discharge chamber formed therein, the suction space formed between the first discharge chamber and the second discharge chamber;
• a shaft received in the shaft bore, the shaft including a passage in fluid communication with the suction space;
• a swash plate coupled to the shaft in an oblique position with respect to the shaft, the swash plate operatively coupled to the plurality of pistons;
• and
• a journal bearing disposed between an inner peripheral surface of the shaft bore and an outer peripheral surface of the shaft, the journal bearing formed entirely from a porous sintered material, wherein the outer peripheral surface of the shaft is spaced apart from the inner peripheral surface of the shaft bore by a first distance (a) when the shaft is inserted into the shaft bore, wherein oil contained in the refrigerant is introduced into or stored in a space defined by the distance (a) between the outer peripheral surface of the shaft and the inner peripheral surface of the shaft bore, the space in fluid communication with the suction space.

A method for manufacturing a cylinder block, comprising:

• preparing a cylinder block, the cylinder block including an annular array of piston bores formed through the cylinder block, a plurality of pistons reciprocatingly received in the piston bores, and a shaft bore formed through the cylinder block;
• inserting a journal bearing formed entirely of a porous sintered material into each of a first end of the shaft bore and a second end of the shaft bore;
• inserting a shaft in the shaft bore, an outer peripheral surface of the shaft spaced apart from an inner peripheral surface of the shaft bore by a distance (a) when the shaft is inserted in the shaft bore;
• and
• forming through-holes through the journal bearing, the through-holes in fluid communication with the piston bores when the journal bearing is inserted in each of the first end of the shaft bore and the second end of the shaft bore.