Cannon Instrument CT-1000 (Contant Temperature Bath) - Manual (Page 21)

19
CANNON ® CT-1000 Constant Temperature Bath Instruction & Operation Manual
Revision 3.1e—June, 2011; CANNON ® Instrument Company
2139 High Tech Road • State College, PA • USA 16803
B
APPENDIX B — CORRECTING
SHAFT & IMPELLER
MISALIGNMENT
Motor-stirrer units supplied by CANNON ® Instrument Company are
checked after assembly to ensure minimum run-out (deviation from
concentric rotation) at the impeller end of the shaft. The following
instructions are intended to assist those who may be experiencing exces-
sive vibration in the motor-stirrer because of shaft run-out or misalign-
ment of the impeller blades.
NOTE See the instructional video on the CT-1000 for a detailed description of
the procedure described below.
Set Screw Alignment The motor shaft contains a flat area. The coupling should be oriented in
such a way that the set screw is aligned with the flat. The stirrer shaft and
motor shaft should be inserted to approximately the same length in the
coupling.
You can test for shaft run-out and impeller blade alignment by placing
the motor on a soft surface with impeller facing up. Connect the motor to
the appropriate AC power source and observe the impeller and shaft. If
run-out is severe, the motor will vibrate and the shaft will flutter notice-
ably. The impeller will appear blurred if the impeller blades are not in the
same plane.
If necessary you can adjust the impeller blades by bending the large
horizontal sections of each of the four segments so that they lie in the
same plane. Since these segments are easily bent, check alignment
whenever the impeller is bumped, or if there is any suspicion that the
blade segments may have become misaligned.
Shaft run-out correction
The following procedure is suggested to correct shaft run-out:
Grasp the motor firmly with the left hand and touch the tip of a soft
crayon (a glass marking pencil, for example) momentarily to the side of
the shaft near the impeller end while the motor is running. It is advisable
to remove the impeller while carrying out this procedure. The mark
produced by the crayon will be evident as a line part way around the
shaft.