Pit & Quarry, October 2017

MOTORS DRIVES BEARINGS sembly and disassembly happens when a force is applied against the unmounted race When mounting a bearing on a shaft with a tight fit pushing the outer race will exert an excessive thrust load and bring the rolling elements into sharp contact with the race causing brinelling Extremely heavy impact loads can also result in brinelling of the bearing races or even fracture the races and rolling elements FALSE BRINELLING False brinelling is fretting wear caused by slight axial rolling element movements while the bearing is stationary Vibration can make the rolling element slide back and forth across the race wearing a groove into it Roller bearings also exhibit false brinelling when used in positions that encounter very small reversing angular oscillation less than one complete rotation of the rolling element To distinguish false brinelling from true examine the depression or wear area False brinelling will wear away the surface texture whereas the original texture will remain in the depression of a true brinell BURNS FROM ELECTRIC CURRENT Arcing occurs when an electric current that passes through a bearing is broken at the contact surfaces between the races and rolling elements Each time the current is broken while passing between the ball or roller and race it produces a pit on both parts Eventually fluting develops Causes of arcing include static electricity from charged belts or processes that use calender rolls faulty wiring improper grounding welding inadequate or defective insulation loose rotor windings on an electric motor and short circuits P Q Information for this article provided by The Timken Co www timken com DECEMBER 7 REAL ESTATE NORTHERN WHITE SILICA SAND 645 MILLION TONS City of La Salle Illinois The Capital of Silica Sand Mining Minimum Bid 75 Million or 012 Ton Great Logistics via Interstate Rail Barge Meets API specs for frac sand Minimal overburden average 75 ft 14 20 40 56 40 70 26 70 140 Seam thickness 67 to 89 feet 240 acres with mineral rights Adjacent to operating silica mine Zoned M 1 Light Industrial This 240 Acre Property is Located on I 80 Only 90 Miles Southwest of Chicago 5 Miles North of Illinois River In cooperation with Jones Lang LaSalle 3122780600 FineAndCompany com 14 steps for bearing analysis success Consider following these steps when investigating any bearing damage 1 Gather operating data from bearing monitoring devices analyze service and maintenance records as well as charts and secure application diagrams graphics and engineering drawings 2 Prepare an inspection sheet to capture observations and take photographs throughout to document or describe damaged components 3 Extract any used lubricant samples from bearings housing and seal areas to determine lubricant conditions Package these separately and label them properly 4 Secure a sample of a new unused lubricant Record any specification batch information from the container and obtain the technical specifications and any related material safety data i e handling disposal toxicological documentation to accompany lubricant shipments 5 Check the bearing environment for external influences like other equipment problems that preceded or occurred at the same time bearing damage was reported 6 Disassemble the equipment and record an assessment of the mounted bearing condition 7 Inspect other machine elements including locknuts adapters seals and seal wear rings 8 Mark and record the mounted position of the bearings and components prior to removal 9 Measure and verify shaft and housing size roundness and taper using certified gauges 10 Following removal but before cleaning record observations of lubricant distribution and condition 11 Clean parts and record the manufacturers information from markings on the bearing rings i e part number serial number date code 12 Analyze the condition of the internal rolling contact surfaces load zones and the corresponding external surfaces 13 Apply preservative oil and repackage the bearings to avoid corrosion 14 Compile a summary report of all data for discussion with a trusted sales or service engineer 44 PIT QUARRY October 2017 pitandquarry com