GE GE752 manual Grinding, ±19771A

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GEK±91584D, Vertical Drilling Motor, Type GE752

2.Turn the feed control to back the stones away from the commutator before starting the ma- chine.

NOTE: If possible, use some method of collect- ing the copper chips and abrasive dust pro- duced by the grinding operation. For example, use a vacuum cleaning device with the suction wand set just behind the trailing edge of the stones.

Grinding

1.Apply power to the machine and gradually in- crease speed to 900±1000 rpm.

NOTE: Do not grind the commutator to a depth where no mica undercut remains, or to a diame- ter which is smaller than the minimum permis- sible diameter listed in the DATA section.

2.Begin grinding by radially feeding the stones lightly against the commutator. Then, slowly move the carriage back and forth longitudinally across the surface. When the cutting action of the stone ceases, again feed the stone lightly against the commutator and continue grinding. Use care to make a light cut and to avoid chatter. Cutting action should take place at the trailing edge of the stones. Heavy cuts will cause exces- sive copper drag.

3.Grind the commutator to obtain a uniformly smooth surface, but do not remove any more copper than necessary.

4.Lighten the cutting pressure on the stones near the end of the grinding operation. If medium± grade stones were used, stop the motor, change to finish±grade stones and repeat Steps 1, 2, 3 and 4. After the final cut, traverse the stones back and forth without changing the feed until cutting action ceases.

5.Remove power from the machine.

6.Check commutator runout with a dial indicator. Refer to the DATA section for concentricity limits.

FIG. 12. COMMUTATOR SLOT RAKING TOOL.

E±19771A.

7.If necessary, continue grinding to meet concen- tricity values listed in the DATA section.

8.Remove the grinder.

9.See Fig. 12 for slot raking tool. Rake the commu- tator slots to remove projecting mica fins or cop- per whiskers.

10.Run the machine again at 1000 rpm and polish the commutator with 00 sandpaper, crocus cloth or 400A Triemite* paper. The abrasive sheet should be mounted on a wooden block curved to fit the surface of the commutator.

CAUTION: Never use an emery cloth on this or any commutator. The abrasive particles on emery cloth scratch the commutator surface and lodge in the grooves between commuta- tor segments. This condition creates the pos- sibility of an eventual flashover which could seriously damage the machine.

11.Blow the dust from the commutator and the inte- rior of the motor with dry, compressed air. Hold the air nozzle one to two inches from the surface of the commutator and sweep nozzle longitudi- nally to dislodge copper chips and mica dust.

12.Air cure the commutator. See the following sec- tion for air curing instructions.

*Product of Minnesota Mining and Manufacturing Co.

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Contents Contents Vertical Drilling Motor Type GE752General Description IntroductionGEK±91584D, Vertical Drilling Motor, Type GE752 Vertical Drilling Motor, Type GE752, GEK±91584D Model DifferencesContd Model Differences DataData Contd Carbon BrushesPole Bore Diameter measured at center of pole Motors Min Max Motor Ratings Continuous Max. HP Shunt UP Special Tools Equipment Grounding InstructionsLubrication Grounding Procedures FigOverhaul Grease Tubes and Pipe PlugsInspection Monthly Covers, Seals, LatchesBrushholders Fig Brushholder Sleeves Brush Spring PressureCreepage Band BrushesCommutator Flash RingBasic Repairs Brush Replacement Brushholder ReplacementSEMI±ANNUALLY Installation Brushholder Clearance AdjustmentCommutator Resurfacing Sanding Procedure Hand Stoning ProcedureGrinder Installation Fixture GrindingCommutator GRINDER. E±18249 Grinding ±19771ATesting Before Disassembly Air Curing CommutatorBasic Overhaul Bar±To±Bar Resistance Test DisassemblyMegohmmeter Test Armature Removal From FrameCOMMUTATOR±END Bearing Pilot Longitudinal D732922 CHG. N. E±28621D Models See , Description Puller Tools 41D731569 CHG . E±14383C Puller TOOLS. E±18155A Models US1, AUT Longitudinal D735357, CHG. A. E±37949B Models See Table Cleaning Steam CleaningBearing Inspection Vapor DegreasingAnti±Friction Bearings/Shaft Tapers/Bearing Fits ArmatureCommutator Armature Shaft InspectionMotor Frame Armature Insulation 41D731545 CHG. F. E±18156A See Note Brushholders Lubrication of BoltsConnection Diagram 493A210 CHG . E±39092B Riser Width Creepage Band ReplacementRewinding Armature DiameterHydraulic Press Preferred Method ProcedureCommutator Tightening Torque Wrench Acceptable MethodSpin Seasoning Commutator Assembled On Armature Commutator ResurfacingTurning To Change Motor DirectionConnection Diagram 41A330278, CHG . E±38055B Connection Diagram 41A330179, CHG. A. E±37950A Raking ±4270BUsed Armature Resistance MeasurementTest After Repair Armature High Potential Test Rewound ArmatureProcedure for New Coil±Pole Assembly ReplacementCoil Installation Motor Frame Field CoilCoiled Frame Assembly 41D732353 CHG. N. E±39094A Models See , Coiled Frame Assembly 41D732345 CHG. V. E±39095A BOX Ground A1 and A2 View AT E Cables with P65 Coiled Frame Assembly 41D735440, CHG. A. E±38056B Description Magnet Frame Coiled Frame Assembly 41D735343, CHG. C. E±37951C Hardened Washer 1 1/4 Brazing Coil Terminals Gas Torch BrazingFlood Dipping Coiled Frame Test After RepairCoiled Frame Without Armature Reassembly Balancing ArmatureVarnish Treatment Armature Commutator±End Bearing Armature BearingsDrive±End Bearing Figs , 35, 36 All Models Except US2, UP6, AUT2 and AUP5DRIVE±END Bearing ASSEMBLY. E±18166E DRIVE±END Bearing ASSEMBLY. E±39301 Models US2, UP6, AUT2 and AUP5DRIVE±END Bearing Assembly 41B537821, CHG. B. E±37952B Armature Assembly Into Frame Models UP and AUPCOMMUTATOR±END Bearing Assembly 41B532745 CHG. F. E±39090A COMMUTATOR-END Bearing Assembly 41B538068 CHG . E-39300 Checking Internal Clearance Brush Installation HUB Mounting Hub FittingHub Mounting Testing After Overhaul Testing Series MachinesModels 5GE752AUP, AUT Ventilated 2300 cfm at 7.6 in. H2O at Commutator Chamber Testing Shunt Machines Models 5GE752UP and USMotor Operation UnventilatedLocking the Armature For Shipment Cleaning and SlushingRemoving Armature Locking Arrangement ShippingArmatures SkiddingProtection Preparation of BOXBoxing the Armature Storage Placing Into StorageRemoving from Storage Shipping BOX with Armature Less COVER. E±3784Vertical Drilling Motor, Type GE752, GEK±91584D OUTLINE, UP and AUP 41E903631 CHG. H. E±28755B Hole Grease Vent Tube Grease Tube Holes REF OUTLINE, US1, AUT 41E903745, CHG. A. E±37954B ºDº ºBº Vertical Drilling Motor, Type GE752, GEK±91584D GE Transportation Systems