TABLE OF CONTENTS Frequently, squirrel-cage fans will have pillow-block bearings outside the cage, one on each side as in FIGURE (1) .
A close inspection will reveal that the formulas found in the chapter: Armature To Field Coil Alignment will adapt to the arrangement shown in FIGURE (1) of this chapter. You simply plug the necessary measurements from FIGURE (1) from this chapter into the appropriate formulas from the above stated chapter and make the necessary moves, in either the vertical or lateral aspect. Further: If the rotating unit (shaft/fan assembly) is in its fixed/sacred position and the fan cage has to be adjusted to be correctly positioned around the fan, then the formulas from the chapter: Field Coil To Armature Alignment will apply.
| Note | In the rare event that seals of a close tolerance design (such as labyrinth seals) exist at the shaft entry ports to the fan housing, points A, B, C, and D would be at the two seals instead of at the rims of the fan wheel. (See A, B, C, and D written upside-down in FIGURE (1). Also, pay close attention to dimension E written upside-down in Figure(1). Providing such conditions prevail (labyrinth seals or equal) chances are slim to nil in correcting the fan wheel-to-housing clearance without wrecking one or both of the seals. Any clearance adjustment between the rim of the wheel and the mating fan housing would have to be done by physically altering the... |
