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A tapered roller bearing has a porous rib ring against which the large ends of its wrought steel tapered rollers bear so that the ring prevents the rollers from being expelled. The rib ring is formed from porous powdered steel that has been compacted to a density of about 70% to 85% of theoretical a

A tapered roller bearing has a porous rib ring against which the large ends of its wrought steel tapered rollers bear so that the ring prevents the rollers from being expelled. The rib ring is formed from porous powdered steel that has been compacted to a density of about 70% to 85% of theoretical and then sintered and machined. Thereafter, the machined rib ring is etched to expose the pores at the surface against which the large ends of the rollers bear. Finally, the rib ring is impregnated with oil. Should the bearing lose its normal supply of lubrication, the critical region of contact between the abutment face on the rib ring and the large ends of the rollers will nevertheless be adequately lubricated for a reasonable time by lubricant which escapes from the pores of the rib ring. The cage of the bearing may be piloted by the rib ring and by a ring-like cup insert that is formed in the same manner as the rib ring.

대표청구항 ▼

A tapered roller bearing capable of operation without significant damage for at least 30 minutes without external lubrication under a PV multiple of at least 22×106 where P is the contact stress between its rib ring and its rollers in units of psi and V is the relative velocity between its rib ring

A tapered roller bearing capable of operation without significant damage for at least 30 minutes without external lubrication under a PV multiple of at least 22×106 where P is the contact stress between its rib ring and its rollers in units of psi and V is the relative velocity between its rib ring and its rollers in units of ft/min, comprising: an inner race having an outwardly presented raceway that is tapered; an outer race having an inwardly presented raceway that is tapered and surrounds the raceway of the inner race; tapered rollers arranged in a row between the tapered raceways of the two races and contacting those raceways along their bodies, the tapered rollers being formed from wrought steel and having large and small ends; said rib ring normally mounted in a fixed position with respect to one of the races and projecting generally radially beyond the large end of the raceway for that race, the rib ring having a smooth abutment face free from “Beilby layer”and having open pores, said abutment face being presented toward the large ends of the tapered rollers and against which the rollers bear at their large ends, the rib ring being formed from a powdered steel having a density of about 70% to about 85% of its theoretical density, a liquid lubricant in the pores of the rib ring in an amount sufficient to provide emergency lubrication for at least said 30 minutes, said rib ring having a dynamic coefficient of friction in contact with said rollers which does not exceed 0.10 in the presence only of said emergency lubrication, and the rib ring being capable of sustaining a contact stress, constituting said P, of 40,000 lbs/in2 and when moved at said velocity V relative to said rollers being capable of enduring said PV multiple of 22×106 for 30 minutes in absence of lubrication other than the lubricant absorbed in the pores, where P is measured in lbs/in2 and V in ft/min.