Roller grate with hydraulic drive and a method for operating the roller grate

Abstract

A roller grate consists of rollers disposed one behind the other by means of which the material to be burned is moved, and of a drive for the rollers that constitutes a hydraulic motor for driving one or several rollers. A method for operating the roller grate consists of operating the hydraulic motor in angular steps. The roller grate has the advantage that roller grates having low-weight drive units can be operated with high reliability and with little wear of the drive units.

1 . A roller grate, comprising:
 a plurality of rollers disposed one behind the other for moving material to be burned; and   at least one hydraulic motor for driving at least one of the rollers.   
   
   
       2 . The roller grate as set forth in  claim 1 , wherein the hydraulic motor is a hydraulic roller actuator. 
   
   
       3 . The roller grate as set forth in  claim 2 , further comprising a target value indicator for prescribing a target value for the roller actuator. 
   
   
       4 . The roller grate as set forth in  claim 2 , wherein the hydraulic roller actuator is coupled with an angular position metering device and further comprising a proportional two-way valve and a controller for measuring a difference from a prescribed position target value and for zeroing said difference. 
   
   
       5 . The roller grate as set forth in  claim 1 , wherein a gear is interposed between the hydraulic motor and one of the rollers. 
   
   
       6 . The roller grate as set forth in  claim 1 , wherein a pressure limiting valve is disposed in a hydraulic train of the motor. 
   
   
       7 . The roller grate as set forth in  claim 6 , wherein the pressure limiting valve is an overflow valve. 
   
   
       8 . A method of operating a roller grate having rollers disposed one behind the other for moving material to be burned and at least one hydraulic motor comprising a hydraulic roller actuator for driving at least one of the rollers, comprising the step of rotating the rollers in angular steps via the hydraulic roller actuator. 
   
   
       9 . The method as set forth in  claim 8 , further comprising the step of prescribing a target value for the hydraulic roller actuator with a target value indicator by adding angular positions of the rollers. 
   
   
       10 . The method as set forth in the  claim 8 , wherein the angular steps of the rollers range between 1 and 10 degrees. 
   
   
       11 . The method as set forth in  claim 10 , wherein the angular steps of the rollers are of 5 degrees. 
   
   
       12 . The method as set forth in  claim 8 , wherein the hydraulic actuator is operated at a pressure ranging between 50 and 300 bar. 
   
   
       13 . The method as set forth in  claim 12 , wherein the hydraulic actuator is operated at a pressure ranging between 150 and 250 bar. 
   
   
       14 . The method as set forth in  claim 8 , wherein the rpm of the hydraulic actuator is reduced to a reduction gear ratio of 500 to 1.