US 5,667,157 A · Bearing clearance adjustment

Abstract

The comminution apparatus comprises a drive shaft having a roller bearing which is disposed in a housing. A temperature detector mounted in the housing monitors the temperature of the roller bearing. Hydraulic fluid is supplied to a circumferential groove in the housing to apply hydraulic pressure to the outer raceway. The hydraulic fluid pressure is monitored by a pressure detector and gage and may be vented by a manually operated relief valve. The drive shaft is rotated at normal operating speed and normal load with the bearing clearance at maximum until the bearing reaches an equilibrium temperature. Raising the hydraulic pressure develops a force on the rear surface of the outer raceway, biasing the outer raceway towards the shaft and reducing the bearing clearance. Reducing the bearing clearance reduces waste heat generated by skidding between the rollers and the raceway. When the bearing clearance is reduced to the optimum clearance, the skidding is eliminated and the bearing temperature reaches a minimum value. Further reduction of the bearing clearance imposes a preload on the rollers, increasing the friction between the rollers and the raceways and generating waste heat. The pressure is lowered to the pressure that correlates with the minimum temperature.

Claims18

Dependent claims

Comminution apparatus comprising:

a drive shaft, said drive shaft being rotatable about an axis for comminuting material;
housing means disposed around at least a portion of said drive shaft;
roller bearing means comprising first and second raceways and a plurality of rollers disposed intermediate said first and second raceways, wherein said first raceway and said rollers define a first clearance and said second raceway and said rollers define a second clearance, said first and second clearances defining a total clearance, said bearing means being disposed around said drive shaft and within said housing wherein said first raceway is adjacent a surface of said housing and said second raceway is adjacent said drive shaft;
temperature monitoring means for monitoring a temperature adjacent said bearing means, said temperature being commensurate with heat generated by friction between said raceways and said rollers;
and
adjustment means for radially moving one of said raceways whereby moving said raceway towards said rollers reduces said total clearance, said adjustment means being actuatable while said drive shaft is rotating;
wherein said total clearance is set at a maximum total clearance while said drive shaft is stationary, said drive shaft is rotated at a normal speed of rotation until said temperature stabilizes at a maximum temperature, said adjustment means is actuated to move said raceway towards said rollers until said temperature reaches a minimum temperature whereby said friction is minimized.

4 more elements

A method for optimizing total bearing clearance on a comminution apparatus having a drive shaft which is rotatable about an axis for comminuting material, a housing disposed around at least a portion of said drive shaft and at least one bearing comprising first and second raceways and a plurality of bearings disposed intermediate said first and second raceways, wherein said first raceway and said bearings define a first clearance and said second raceway and said bearings define a second clearance, said first and second clearances defining a total bearing clearance, said bearing means being disposed around said drive shaft and within said housing wherein said first raceway is adjacent a surface of said housing and said second raceway is adjacent said drive shaft, the comminution apparatus further having a temperature monitor for monitoring a temperature adjacent said bearing means, said temperature being commensurate with friction between said raceways and said bearings, a hydraulic pump for applying hydraulic pressure between said housing and said first raceway, a relief valve for venting said hydraulic pressure, and a pressure monitor for monitoring said hydraulic pressure, wherein said hydraulic pressure develops a hydraulic force which radially moves said first raceway, said pump being actuatable while said drive shaft is rotating, the method comprising the steps of:

A) setting said total bearing clearance at a maximum while said drive shaft is stationary;
B) rotating said drive shaft at a normal speed of rotation until said temperature stabilizes at a maximum temperature;
C) actuating said pump to radially move said first raceway to a position closer to said bearings;
D) monitoring a decreasing temperature and an increasing pressure as said first raceway is moved;
E) repeating steps C) and D) until said temperature stops decreasing and starts to increase;
F) stopping said pump;
and
G) venting said hydraulic pressure to a value which correlates with a minimum temperature.

5 more elements

Dependencies are inferred from the claim text.

Bearing clearance adjustment

Life of this patent

Bearing clearance adjustment

Life of this patent

Abstract

Claims18