Endless conveyor drive monitoring system

Abstract

A drive load measuring system for a conveyor-type oven is disclosed. According to one embodiment, a drive load measuring system includes: a pair of mounting assemblies that support opposing end portions of a rotating drive shaft of an oven drive unit; and a PLC control unit operatively connected to the mounting assemblies. The mounting assemblies each include a pivot bracket mounted to the body of the oven and a force sensing fastener inserted into the pivot bracket and configured to generate an output signal representative of the load on the force sensing fastener. The PLC control unit can be configured to calculate load values of the force sensing fasteners and to detect rapid changes in the load values that may indicate jam-ups of conveyors driven by the oven drive unit. Alternatively, the PLC control unit can be configured to detect when load values of the force sensing fasteners exceed a threshold value, which may also indicate jam-ups of the conveyors. According to another embodiment, a drive load measuring system includes a pair of in-line torque sensors attached to a rotating drive shaft of an oven drive unit at or near end portions of the drive shaft; and a PLC control unit operatively connected to the mounting assemblies.

What is claimed: 
     
         1 . A monitoring system for monitoring a drive mechanism of an endless conveyor, the monitoring system comprising:
 a first sensor configured to sense a force applied to a first element of the drive mechanism and to output a first electrical signal reflective of the force; and   a programmable control system in communication with the first sensor, wherein the programmable control system is configured to continuously monitor the first electrical signal to detect a change in the force sensed by the first sensor, and wherein the programmable control system is configured to control the motion of the drive mechanism according to the change in the force sensed by the first sensor.   
     
     
         2 . The monitoring system of  claim 1 , wherein the force applied to the first element of the drive mechanism is indicative of a drive load experienced by the drive mechanism. 
     
     
         3 . The monitoring system of  claim 1 , wherein the drive mechanism further comprises a main drive shaft extending transversely across the endless conveyor and coupled to left side and right side conveyor stub shafts, the conveyor stub shafts being configured to drive the endless conveyor from the left side and the right side of the endless conveyor. 
     
     
         4 . The monitoring system of  claim 3 , wherein the first element of the drive mechanism comprises the main drive shaft of the drive mechanism. 
     
     
         5 . The monitoring system of  claim 4 , wherein the first sensor comprises a torque sensor mounted inline to the main drive shaft. 
     
     
         6 . The monitoring system of  claim 1 , wherein the first element of the drive mechanism comprises a portion of a mounting assembly supporting a main drive shaft of the drive mechanism. 
     
     
         7 . The monitoring system of  claim 6 , wherein the first sensor is a force sensing fastener. 
     
     
         8 . The monitoring system of  claim 6 , wherein the portion of the mounting assembly comprises a pivot bracket extending perpendicularly to a rotational axis of the main drive shaft and coupled to a mounting bracket of the mounting assembly, the mounting bracket having a first end and a second end. 
     
     
         9 . The monitoring system of  claim 8 , wherein the pivot bracket is coupled to the first end of the mounting bracket using a pivot connection and is coupled to the second end of the base mounting bracket using a force sensing connection that includes the first sensor. 
     
     
         10 . The monitoring system of  claim 1 , wherein the first element of the drive mechanism comprises a portion of a take-up assembly of the drive mechanism. 
     
     
         11 . The monitoring system of  claim 10 , wherein the first sensor is a load sensor. 
     
     
         12 . The monitoring system of  claim 1 , wherein the first sensor is selected from the list consisting of force sensing fastener, a strain pin, a load sensing clevis pin, a load sensor, and a circular load cell. 
     
     
         13 . The monitoring system of  claim 1 , further comprising:
 a second sensor configured to sense a force applied to a second element of the drive mechanism and to output a second electrical signal reflective of the force; and   the programmable control system in communication with the first and second sensors, wherein the programmable control system is configured to continuously monitor the first and second electrical signals to detect changes in the forces sensed by the first and second sensors and to control the motion of the drive mechanism according to the changes in the forces sensed by the first and second sensors.   
     
     
         14 . A monitoring system for monitoring a drive mechanism of an endless conveyor, the monitoring system comprising:
 a torque sensor mounted proximate an end portion of a drive shaft of the drive mechanism and configured to sense a torque applied to the drive shaft and to output an electrical signal reflective of the torque; and   a programmable control system in communication with the torque sensor, wherein the programmable control system is configured to continuously monitor the electrical signal to detect a change in the torque sensed by the torque sensor, and wherein the programmable control system is configured to control the motion of the drive mechanism according to the change in the torque sensed by the torque sensor.   
     
     
         15 . The monitoring system of  claim 14 , wherein the torque applied to the drive shaft is indicative of a drive load experienced by the drive mechanism. 
     
     
         16 . The monitoring system of  claim 14 , wherein the torque sensor is an in-line rotary torque sensor coupled to the drive shaft. 
     
     
         17 . A method for monitoring a drive mechanism of an endless conveyor, the method comprising:
 sensing a force applied to a first element of the drive mechanism with a first sensor;   outputting a first electrical signal reflective of the force sensed by the first sensor;   monitoring the first electrical signal with a programmable control system in communication with the first sensor;   detecting a change in the force sensed by the first sensor; and   controlling the motion of the drive mechanism according to the change in the force sensed by the first sensor.   
     
     
         18 . The method of  claim 17 , wherein the first element of the drive mechanism comprises a portion of a mounting assembly supporting a main drive shaft of the drive mechanism. 
     
     
         19 . The method of  claim 17 , wherein the first element of the drive mechanism comprises a portion of a take-up assembly of the drive mechanism. 
     
     
         20 . The method of  claim 17 , further comprising:
 sensing a force applied to a second element of the drive mechanism with a second sensor;   outputting a second electrical signal reflective of the force sensed by the second sensor;   monitoring the first and second electrical signals with a programmable control system in communication with the first and second sensors;   detecting changes in the forces sensed by the first and second sensors; and   controlling the motion of the drive mechanism according to the changes in the forces sensed by the first and second sensors.