Scroll compressor

In a scroll compressor including

• a compression mechanism comprising a stationary scroll having a lap, an orbiting scroll having a lap, a compression chamber formed by engagement of said laps, a crankshaft for revolving said orbiting scroll through an orbiting bearing portion, and a main frame supporting said crankshaft through a main bearing portion;
• an electric motor portion for driving said compression mechanism, and
• a closed vessel containing said compression mechanism portion and said electric motor portion therein, adapted to be kept at a discharge pressure, and having a lubricating oil portion, the improvement comprising
• a first oil feed passage extending from said lubricating oil portion under said discharge pressure to a space, disposed adjacent to a distal end of a crank portion of said crankshaft, through said crankshaft;
• and
• a second oil feed passage extending from said space to be opened to sliding portions of end plates of said orbiting and stationary scrolls through the end plate of said orbiting scroll, and communicating with a lower pressure portion, said second oil feed passage having a throttle portion of a reduced flow passage area at said sliding portions of said end plates and said orbiting and stationary scrolls;
• and
• a third oil feed passage extending from midway said first oil feed passage to be opened to an outer peripheral surface of said crankshaft, and serving to supply a lubricating oil to said main bearing portion by the use of a centrifugal pumping action produced in accordance with the rotation of said crankshaft.

In a scroll compressor including

• a compression mechanism comprising a stationary scroll having an end plate and a lap of a spiral configuration provided upright on said end plate, an orbiting scroll having an end plate and a lap of a spiral configuration provided upright on said end plate, a compression chamber defined by engagement of said stationary scroll and said orbiting scroll with said laps inside, a crankshaft for revolving said orbiting scroll through an orbiting scroll bearing portion, and a main frame supporting said crankshaft through a main bearing portion,
• an electric motor portion for driving said compression mechanism,
• a closed vessel containing said compression mechanism and said electric motor portion therein, communicating with a discharge port of said compression mechanism to be kept at a discharge pressure, and having a lubricating oil portion provided at a lower end portion thereof, and
• a back pressure chamber defined by said orbiting scroll, said stationary scroll and said main frame to be disposed at a rear side of said orbiting scroll, and being kept at a pressure intermediate the discharge pressure and a suction pressure, the improvement comprising
• a seal member provided between said orbiting scroll and said main frame to isolate said back pressure chamber from said bearing portions, thereby keeping said bearing portions substantially under the discharge pressure;
• a first oil feed passage extending from said lubricating oil portion under said discharge pressure to a space, disposed adjacent to a distal end of a crank portion of said crankshaft, through said crankshaft;
• and
• a second oil feed passage extending from said space to be opened to sliding portions of said end plates of said orbiting and stationary scrolls through the end plate of said orbiting scroll, and further communicating with said back pressure chamber, said second oil feed passage having a throttle portion of a reduced flow passage area at said sliding portions of said end plates and said orbiting and stationary scrolls;
• and
• a third oil feed passage extending from midway said first oil feed passage to be opened to an outer peripheral surface of said crankshaft, and serving to supply a lubricating oil to said main bearing portion by the use of a centrifugal pumping action produced in accordance with the rotation of said crankshaft.

In a scroll compressor of the horizontal type including

• a stationary scroll,
• an orbiting scroll,
• a horizontally extending crankshaft for revolving said orbiting scroll,
• a main frame supporting a portion of said crankshaft toward a crank through a main bearing portion, and
• a closed vessel containing said two scrolls, said crankshaft, said main frame and said main bearing portion therein, adapted to be kept at a discharge pressure, and having a lubricating oil portion, the improvement comprising
• an auxiliary bearing portion mounted on said closed vessel, and supporting an end portion of said crankshaft opposite to said crank portion;
• a first oil feed passage extending from said lubricating oil portion under said discharge pressure to a space, disposed adjacent to a distal end of said crank, through an oil feed pipe, mounted on said closed vessel, and an oil feed passage portion formed in said crankshaft;
• a second oil feed passage extending from said space to a lower pressure portion through an end plate of said orbiting scroll, and having a throttle portion of a reduced flow passage area at sliding portions of said end plate of said orbiting scroll and an end plate of said fixed scroll;
• a third oil feed passage extending from midway said first oil feed passage to be opened to an outer peripheral surface of said crankshaft, and serving to supply a lubricating oil to said main bearing portion by the use of a centrifugal pumping action produced by the rotation of said crankshaft;
• and
• a fourth oil feed passage extending from midway said first oil feed passage to be opened to the outer peripheral surface of said crankshaft, and serving to supply the lubricating oil to said auxiliary bearing portion by the use of the centrifugal pumping action produced by the rotation of said crankshaft.

In a scroll compressor including

• a scroll compression mechanism housed in a closed vessel and comprising (i) an orbiting scroll having an end plate and a lap of a spiral configuration provided upright on said end plate, (ii) a stationary scroll having an end plate and a lap of a spiral configuration provided upright on said end plate, said orbiting scroll and said stationary scroll being engaged with their laps engaged with each other to form a compression space, and (iii) a frame fixedly secured to said stationary scroll to surround said orbiting scroll, said orbiting scroll being moved relative to said stationary scroll to centrally move said compression space to reduce a volume of said compression space, said closed vessel being communicated to a discharge port to be kept at a discharge pressure, a back pressure chamber being formed by said orbiting scroll, said stationary scroll and said frame to be disposed on an opposite side of said orbiting scroll to said lap thereof;
• the improvement comprising at least one seal member provided between said orbiting scroll and said frame to divide said back pressure chamber into a first space disposed at a central portion and a second space disposed at an outer peripheral portion of said back pressure chambers, said first space being kept at a pressure substantially equal to said discharge pressure, said second space being kept at a pressure intermediate a suction pressure and said discharge pressure, and said second space communicating through at least one communication passage with said compression space formed by said two scrolls during the compressing operation.