MOTOR, ALTERNATING CURRENT (B3) (Continued)

TM 5-4120-359-14

(3) To replace bearings on Welco Industries, Inc. motors:

(a) Using screwdriver, remove four screws from each end bracket and carefully remove the end brackets.

(b) Note the position and number of springs, shims, and bearings as they are removed.

(d) Remove the bearings.

(e) Place the new bearings on the shafts.

(f) Place the spring and shim(s) back on shaft in same position as removed.

(g) Carefully place the rotor and shaft with bearings back in the motor housing.

(h) Using screwdriver, secure the end brackets to the motor with eight screws and washers. Before

tightening completely, spin shaft to see that it spins freely. If any rubbing is noted, adjust the end brackets slightly to

relieve rubbing. Finish tightening the eight screws.

(i) Check end play of shaft. End play should be 0020-0.005 inch (0.051-0.127 mm). If end play is not within

limits, disassemble motor and add or remove shims to adjust.

e. Installation (See figure 4-22.)

(1) Be sure the motor rotation is correct.

(2) Carefully slip motor into place with impellers and extension shafts loosely placed on motor shafts.

(3) Using socket and ratchet, secure the motor to the base with two each hex head cap screws, lock washers,

and flat washers. See figure 4-20 for holes to be used.

(4) Using a screwdriver, install fan inlet ring with three screws and flat washers.

(5) Check to see that the impellers are located an equal distance between the two walls of the blower housing.

(6) Using allen wrench, tighten the four extension shaft setscrews.

(7) Spin the impeller by hand to check for interference if impellers rub, see paragraph 4-23, for alinement

instructions.

Follow-on Procedure: Install fan and motor assembly. (See paragraph 4-21.)

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