Brookfield BF35 - Manual (Page 20)

Brookfield Engineering Labs., Inc. Page 20 Manual No. M13-10000
Section 9 - Maintenance
Maintenance
From time to time, the bearings will need to be changed. Complete the following to
determine if it is time to perform this maintenance procedure:
1. The viscometer should have a zero dial reading when placed in an upright position
with the sleeve not immersed in fluid prior to running tests.
2. With the instrument in this position, rotate the sleeve at 600 RPM. The dial
reading in air should not exceed one.
3.
Place water in a suitable container and immerse the rotor sleeve to the fill line.
4. Rotate the sleeve at 600 RPM. The dial reading in water should be between 1.5
and 3.0.
5. At 300 RPM, the dial reading in water should be between 0.5 and 2.0.
If the viscometer fails to pass any one of the above tests, the bearings are bad and should
be replaced by a qualified instrument technician.
Bob Shaft Bearing and Torsion Spring Replacement:
Tools Required:
Allen Wrench, 1/16”
Torsion Spring Removal Tool
Retainer Ring Pliers (small)
External Retainer Ring Pliers
1. Unplug the power supply and remove the sleeve and bob.
2. With the appropriate allen wrench, loosen the set screw in the speed control
knob. Remove the speed control knob from the unit.
3.
Remove all four flat head screws on the outer housing cover and gently lift the
cover upward.
4. Use an allen wrench to loosen the set screw (one turn counter-clockwise) from
the aluminum bushing located inside the torsion spring. The set screw is located
at the top of the aluminum clamp sleeve used for the torsion spring.
5. Loosen the two screws and remove the stop block.
6. Loosen the top set screw (one turn counter-clockwise) on the dial.
7. Gently lift up on the torsion spring to remove it from the aluminum clamp sleeve
and dial.
Do not stretch the torsion spring.