Patent ID: 8888475
Filing Date: 2014-11-18
Classification: F04C

Abstract:
1. A scroll compressor, comprising: a fixed scroll and an orbiting scroll, each having an end plate and a spiral wrap erected on the end plate; a compression chamber, formed by the fixed scroll and the orbiting scroll engaged with each other; a crankshaft, configured to make the orbiting scroll move orbitally; an orbiting bearing, provided in a boss portion on a back side of the orbiting scroll, and configured to support the orbiting scroll axially movably and rotatably relative to an eccentric pin portion of the crankshaft; a frame, disposed on a fixed side facing the back side of the orbiting scroll; a main bearing, attached to the frame, and configured to rotatably support the crankshaft; a sealing part, configured to seal between the back side of the orbiting scroll and the frame; and a high pressure hydraulic chamber formed in an inner peripheral portion, and a back pressure chamber formed in an outer peripheral portion, which are partitioned by the sealing part, wherein the high pressure hydraulic chamber is kept approximately at a discharge pressure with lubricating oil supplied thereto at approximately the discharge pressure, and wherein the back pressure chamber is kept at a pressure lower than the discharge pressure; an oil supply unit, including at least one small hole with a diameter not exceeding a seal ring width of the sealing part, wherein the at least one small hole is formed in a portion of the back side of the orbiting scroll or in the frame that faces the sealing part, and wherein the at least one small hole is caused to move, by the orbital motion of the orbiting scroll, across the sealing part such that the at least one small hole is alternately open to the high pressure hydraulic chamber and the back pressure chamber, thereby supplying oil in the high pressure chamber to the back pressure chamber; and at least one groove, formed on a boss end surface of the orbiting scroll opposing the frame, wherein each small hole of the at least one small hole is configured to communicate with the high pressure hydraulic chamber in the boss portion through a respective groove of the at least one groove, and wherein each of the at least one groove is narrower than the at least one small hole; wherein when a phase angle of the orbital motion of the orbiting scroll is within a predetermined phase angle range, each of the at least one groove is configured to intermittently communicate between the high pressure hydraulic chamber and the back pressure chamber, and configured to supply oil in the high pressure hydraulic chamber to the back pressure chamber, as a result of a differential pressure generated from the communication between the high pressure hydraulic chamber and the back pressure chamber; and wherein when the phase angle of the orbital motion of the orbiting scroll is not within the predetermined phase angle range, the at least one groove is located on the same side of the high pressure hydraulic chamber side partitioned by the sealing part, and configured to not supply oil from the high pressure hydraulic chamber to the back pressure chamber.