Refrigerant cooled tapered roller bearing assembly

A process for cooling a tapered roller bearing including a cone having an outwardly presented tapered raceway, a cup having an inwardly presented tapered raceway surrounding the raceway of the cone, a thrust rib at the large end of one of the raceways, tapered rollers located between and contacting the raceways of the cone and cup and further having their large ends against the thrust rib, and a cage for maintaining the proper spacing between the rollers, the raceways and thrust rib all constituting surfaces against which the tapered rollers bear, said process comprising:

• directing a liquid mixture of refrigerant and oil toward at least one of the surfaces against which the tapered rollers bear, the boiling point of the oil being greater than the boiling point of the refrigerant;
• vaporizing the refrigerant with heat generated by friction between said one surface and the rollers which move along it, whereby heat is extracted from the bearing and the bearing operates at a relatively low temperature;
• leaving a film of oil on said one surface after the refrigerant vaporizes so that said one surface is well lubricated;
• thereafter collecting the oil and the vaporized refrigerant in the region of the larger ends of the tapered rollers;
• returning the collected oil through a channel to the location where the mixture of oil and refrigerant is directed toward the surfaces against which the tapered rollers bear;
• passing the collected vaporized refrigerant through a separate channel containing a condenser;
• condensing the vaporized refrigerant back to a liquid in the condenser;
• and returning the liquid refrigerant to the location where the mixture of oil and refrigerant is directed toward the surfaces against which the tapered rollers bear.

In combination with a spindle and a head in which the spindle revolves, an improved bearing assembly for supporting the spindle within the head to enable the spindle to rotate therein, said bearing assembly comprising:

• an inner race on the spindle and having an outwardly presented raceway;
• an outer race within the head and having an inwardly presented raceway located opposite to the raceway of the inner race;
• rolling elements arranged in a row between the two races and contacting the raceways so as to roll along the raceways when one race turns relative to the other;
• enclosing means for isolating from the surrounding atmosphere a generally annular space having first and second ends and including the space between the two raceways, so that the rolling elements are in the isolated space between the first and second ends of that space;
• a channel connecting the first and second ends of the isolated space outside of that space, the channel opening into the second end of the isolated space such that a liquid at that end will enter the channel to be transferred to the first end;
• a liquid mixture of refrigerant and oil which circulates through the isolated space and channel as the rolling elements move along the raceways, the refrigerant having a boiling point lower than that of the oil so that the refrigerant will evaporate in the isolated space when the temperature of the races and rolling elements exceeds the boiling point of the refrigerant to extract heat from the rollers and races;
• and a heat exchanger connected to and interposed between the two ends of the isolated space, with the connection at the second end being such that vaporized refrigerant will flow from the isolated space into the heat exchanger, the heat exchanger being of sufficient capacity to condense the vaporized refrigerant back to a liquid, whereby the refrigerant enters the isolated space at its first end as a liquid to be thereafter recirculated through the annular space between the raceways.