Motor-compressor unit

A motor-compressor unit comprising:

• a compressor including a rotatable crankshaft;
• a motor connected to the compressor crankshaft to rotate the crankshaft;
• a shell enclosing the compressor and the motor;
• a supply of lubricant located in the bottom of the shell;
• and
• a lubrication system for circulating lubricant through the compressor and including
• a first stage axial passage defined by and coaxial with the crankshaft, extending upward from a bottom thereof, in communication with the lubricant supply, and wherein surfaces of the crankshaft which define the first stage axial passage project around a first portion of the rotational axis of the crankshaft,
• a second stage axial passage defined by and coaxial with the crankshaft, extending upward from an upper portion of the first stage axial passage, and wherein surfaces of the crankshaft which define the second stage axial passage project around a second portion of the rotational axis of the crankshaft,
• a first stage radial passage defined by the crankshaft and extending radially outward from the first stage axial passage,
• a second stage radial passage defined by the crankshaft and extending radially outward from the second stage axial opening,
• means defining an interstage collection chamber for receiving lubricant directed outward through the first stage radial passage, and
• an interstage conduit having a first end in communication with the interstage collection chamber, and extending downward therefrom and then upward through the first stage axial passage and into the second stage axial passage;
• wherein rotation of the crankshaft draws lubricant from the lubricant supply, through the first stage axial passage, and into the first stage radial passage;
• forcibly directs the lubricant therethrough to increase the pressure of the lubricant and to direct the lubricant through the interstage collection chamber, the interstage conduit, the second stage axial passage, and into the second stage radial passage;
• and forcibly directs the lubricant therethrough to further increase the pressure of the lubricant.