Electrically driven compressors and methods for circulating lubrication oil through the same

A method for circulating lubricating oil through the electric compressor having a compression mechanism arranged and constructed to draw in a refrigerant, compress and highly pressurize the refrigerant, and then discharge the pressurized refrigerant, the compression mechanism comprising a drive shaft and a bearing rotatably supporting the drive shaft, wherein a refrigerant flow channel is defined between a suction side of the compression mechanism and a discharge side of the compression mechanism, comprising:

• pressure-feeding lubricating oil to the bearing based upon a difference between the pressure at the discharge-side region of the refrigerant flow channel and the pressure at the area proximal to the bearing,
• storing the lubricating oil that has lubricated the bearing in an oil storage area defined proximal to the bearing,
• pressure-feeding lubricating oil from the oil storage area to the suction-side region of the refrigerant flow channel based upon a difference between the pressure at the oil storage area and the pressure at the suction-side region of the refrigerant flow channel, and
• returning the lubricating oil from the suction-side region of the refrigerant flow channel to the discharge-side region of the refrigerant flow channel by operating the compression mechanism.

An electrically driven compressor comprising:

• a compression mechanism arranged and constructed to draw in a refrigerant, compress and highly pressurize the refrigerant, and then discharge the pressurized refrigerant, the compression mechanism comprising a drive shaft, a movable scroll mounted on the drive shaft and a fixed scroll arranged and constructed to cooperate with the movable scroll,
• an electric motor rotatably driving the drive shaft,
• a bearing rotatably supporting the drive shaft, and
• a lubricating oil route arranged and constructed to transfer lubrication oil from a discharge-side region of the compression mechanism to a suction-side region of the compression mechanism via the bearing so as to lubricate the bearing as the refrigerant is compressed by the compression mechanism, wherein the lubricating oil route includes an oil supply route defined in the movable scroll, so that the lubrication oil is transferred from the discharge-side region to the bearing via the oil supply route.

A method for circulating lubricating oil within an electrically driven compressor, comprising:

• separating lubricating oil from compressed refrigerant in an area proximal to and communicating with a discharge port of the compressor,
• transferring the separated lubricating oil to a bearing that rotatably supports a drive shaft using a pressure-differential between the area proximal to and communicating with the discharge port and an area proximal to the bearing, wherein the bearing is lubricated with the lubricating oil,
• temporarily storing the lubricating oil that has lubricated the bearing,
• transferring the lubricating oil that has been temporarily stored to an area proximal to and communicating with a suction port of the compressor using a pressure-differential between the area proximal to the bearing and the area proximal to and communicating with the suction port,
• drawing the lubricating oil into a compression chamber of the compressor together with refrigerant supplied via the suction port and compressing the refrigerant and lubricating oil, and
• discharging the compressed refrigerant to the area proximal to and communicating with the discharge port.

An electrically driven compressor, comprising:

• means for separating lubricating oil from compressed refrigerant in an area proximal to and communicating with a discharge port of the compressor,
• means for transferring the separated lubricating oil to a bearing that rotatably supports a drive shaft using a pressure-differential between the area proximal to and communicating with the discharge port and an area proximal to the bearing, wherein the bearing is lubricated with the lubricating oil,
• means for temporarily storing the lubricating oil that has lubricated the bearing,
• means for transferring the lubricating oil that has been temporarily stored to an area proximal to and communicating with a suction port of the compressor using a pressure-differential between the area proximal to the bearing and the area proximal to and communicating with the suction port,
• means for drawing the lubricating oil into a compression chamber of the compressor together with refrigerant supplied via the suction port and compressing the refrigerant and lubricating oil, and
• means for discharging the compressed refrigerant to the area proximal to and communicating with the discharge port.