Segmented sprockets disassemble upon normal operation of conveyor

Details

BE&E has received details from a single case in which sprocket failure has occurred. Some conveyors may exhibit a drive train failure from sprocket disassembly under normal operation of conveyor. This concern is caused from the improper torque from the supplier. Segmented sprocket bolts could become loose, which would allow segments to disassemble from their respectful sprocket hub. See the illustration below for reference of sprocket segments.

Corrective Action

Verify that all segmented sprocket bolts meet the outlined torque specifications below. Follow the procedure outlined in this bulletin for checking proper torque on bolts.

Standard Torque Specifications

Parts Information

Torque Check Procedure

1.  Tail Assembly 1. Reference the tail assembly as shown in the model below. Begin to remove spacer bar brace plates by loosening flanged nylock nuts (½”-13 UNC) on the face of the spacer bars or spacer angles. Pry spacer bars to expose screws as illustrated.

2. Pry the plastic wear strip bars until the following retaining hex bolts (⅜”-16 UNC) are exposed from the side panel. Loosen and remove the bolts from the side panel.

3. Remove the top/bottom panels from conveyor tail by loosening all fasteners (⅜”-16 UNC) as necessary.

4. Remove spacer box weldment and plastic wear strips as shown.

5. Using a combination wrench (1-½” UNC), secure a nut on the interior side of the sprocket assembly as shown.

6. Refer to the Standard Torque Specifications table with specified tightening torque. Using a properly set torque wrench tighten the screws (1″-8 UNC).

7. Continue the tightening sequence for all screws until ¼ turns can no longer be achieved.

8. Make sure each screw has been properly tightened until the screws are no longer turning at the specified torque wrench setting. Repeat the previous steps necessary.

9. Reassemble all components as necessary. Repeat these steps for the opposite side of conveyor.

Torque Check Procedure—Head Assembly

1.  Begin to loosen and remove the following hex head screws (⅜”-16 UNC) from the side panel.

2. Remove the top/bottom panels from conveyor head by loosening all fasteners (⅜”-16 UNC) as necessary.

3. Remove the spacer box weldment, ramp weldment, and wearstrips as shown.

4. Using a combination wrench (1-½” UNC), secure a nut on the interior side of the sprocket assembly as shown.

5. Refer to the Standard Torque Specifications table with specified tightening torque. Using a properly set torque wrench tighten the screws (1″-8 UNC).

6. Continue the tightening sequence for all screws until ¼ turns can no longer be achieved.

7. Make sure each screw has been properly tightened until the screws are no longer turning at the specified torque wrench setting. Repeat the previous steps necessary.

8. Reassemble all components as necessary. Repeat these steps for the opposite side of conveyor.