Cannon CT-500, Instruction & Operation Manual

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CANNON Instrument Company | Appendix I – Motor-Stirrer Problem Analysis 33
Appendix I – Motor-Stirrer Problem Analysis
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 excessive vibration in
the motor-stirrer because of shaft run-out or misalignment of the impeller blades. The motor stirrer
is picture outside of the instrument in Figure 17.
Figure 17: Motor Stirrer
Set Screw Alignment
The motor shaft contains a flat area. The coupling should be oriented so that the set screw is aligned
with the flat. The stirrer shaft and motor shaft should be inserted in approximately the same length
in the coupling.
Users 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 vibrates and the shaft flutters noticeably. The
impeller will appear blurred if the impeller blades are not in the same plane.
If necessary, 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