GE GE752 manual ARMATURE Creepage Band Replacement, Rewinding Armature, Riser Width, Diameter

Vertical Drilling Motor, Type GE752, GEK±91584D

ARMATURE

Creepage Band Replacement

TABLE 3

STANDARD BOLT TORQUE VALUES

(For Lubricated Bolts)

Because of its superior adhesion qualities, the Teflon creepage band on the outer end of the commutator should be applied using the ªhot bondº process. A copy of this process is included in each Teflon Band Kit, Part No. 76518, which can be ordered from the following ad- dress:

General Electric Company

Insulating Materials Product Section

One Campbell Road

Schenectady, NY 12345

Attn: Customer Service

NOTE: The Teflon band is not included in the kit, but can be ordered through normal Renewal Parts channels.

Inspect the Band

1.There should be no gaps at the joint or between the edge of the Teflon band and the copper bars.

2.The band surface must be smooth, free of var- nish and bonded to the underlay material. There must not be any bubbles under the Teflon or buckling of the band.

3.The surface must be free of damage including scratches and cuts.

Rewinding Armature

The armature must be rewound if any coils are shorted or grounded.

Riser Width

During the rewinding procedure, the TIG welds on the commutator risers are machined to break the arma- ture coil connections. Machining reduces the width of the risers 1/32 to 1/16 in. each time, which in turn de- creases the current±carrying capacity of the risers.

If the calculated width of the risers (after machining) will be less than the Minimum Permissible Riser Width listed in the DATA section, a new commutator must be installed before new armature coils are assembled.

USE THE TORQUE VALUES IN THIS TABLE AS A GUIDE TO IN- SURE SATISFACTORY TIGHTENING OF BOLTS AND NUTS WHERE A SPECIFIC VALUE IS NOT GIVEN IN THE INSTRUC- TIONS.

*INCLUDES SOCKET HEAD SCREWS.

			TORQUE VALUES (LB./FT.)
			MEDIUM CARBON	ALLOY STEEL
			(SAE GRADE 5)	(SAE GRADE 8)*
	BOLT	THREADS
		PER
	DIAM.	INCH
1/4		20	5±8	10±12
		28	5±8	10±12
5/16		18	12±15	18±21
		24	12±15	20±23
3/8		16	20±25	30±36
		24	25±28	34±40
7/16		14	35±40	50±56
		20	40±45	60±65
1/2		13	55±60	80±90
		20	60±70	95±105
9/16		12	75±80	110±123
		18	90±100	130±145
5/8		11	105±115	152±169
		18	125±140	185±205
3/4		10	185±205	285±315
		16	220±245	340±370
7/8		9	300±330	440±490
		14	340±380	510±565
1		8	440±490	685±735
		12	530±570	790±8665
1±1/8		7	620±690	935±1040
		12	750±830	1115±1240
1±1/4		7	890±990	1250±1360
		12	1040±1160	1600±1750
1±3/8		6	1160±1290	1745±1940
		12	1420±1580	2125±2360
1±1/2		6	1570±1740	2300±2600
		12	1800±2000	2600±3020
				E±38274

Diameter

Refer to the DATA section for the Minimum Permissi- ble Commutator Diameter dimension. If the commutator brush±surface diameter will be less than the minimum permissible diameter after resurfacing operations are performed, replace the commutator before the new ar- mature coils are assembled.

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