Air compressor control

Abstract

Controlling air compressors based on a temperature of air compressed by the air compressor. A temperature of air compressed by the air compressor is sensed. The sensed compressed air temperature is compared with a predetermined threshold temperature. The air compressor is deactivated when the sensed temperature exceeds the threshold temperature. The threshold temperature may be selected to inhibit carbon formation caused by oil thermal breakdown.

1 . A method of controlling an air compressor, comprising: 
 a) sensing a temperature of air compressed by an air compressor;    b) comparing a sensed temperature of compressed air with a predetermined threshold temperature;    c) deactivating the air compressor when the sensed temperature exceeds the threshold temperature.    
   
   
       2 . The method of  claim 1  wherein the temperature of air compressed by the air compressor is sensed in a compressor port.  
   
   
       3 . The method of  claim 1  wherein the temperature of air compressed by the air compressor is sensed at a compression chamber.  
   
   
       4 . The method of  claim 1  wherein the temperature of air compressed by the air compressor is sensed by a temperature sensor mounted in a compressor unloader valve that is in fluid communication with a compression chamber.  
   
   
       5 . The method of  claim 1  wherein the threshold temperature is selected to inhibit carbon formation caused by oil breakdown.  
   
   
       6 . The method of  claim 1  wherein the air compressor is deactivated by bypassing a governor.  
   
   
       7 . The method of  claim 1  wherein the air compressor is deactivated by providing a shutdown air control signal to the compressor when the sensed temperature exceeds the threshold temperature.  
   
   
       8 . An apparatus for sensing a temperature of air compressed by an air compressor, comprising: 
 a) a valve assembly for selectively opening and closing a passage to a compression chamber; and    b) a temperature sensor supported by a component of the valve assembly for sensing a temperature of air in the valve assembly.    
   
   
       9 . The apparatus of  claim 8  wherein the valve assembly is an unloader control valve assembly.  
   
   
       10 . An air compressor, comprising: 
 a) a housing;    b) a head mounted to the housing such that the head and the housing define a compression chamber and a fluid passage in communication with the compression chamber;    c) a piston disposed in the compression chamber for compressing air in the compression chamber; and    d) a temperature sensor positioned to measure a temperature of air compressed by the piston.    
   
   
       11 . The air compressor of  claim 10  wherein the temperature sensor is substantially isolated from the head and the housing.  
   
   
       12 . The air compressor of  claim 10  wherein the temperature sensor is disposed in the fluid passage.  
   
   
       13 . The air compressor of  claim 10  further comprising a valve assembly disposed in the fluid passage, wherein the temperature sensor is supported by a component of the valve assembly.  
   
   
       14 . The air compressor of  claim 10  further comprising an unloader control valve assembly disposed in the fluid passage, wherein the temperature sensor is supported by a component of the unloader valve assembly.  
   
   
       15 . An air compressor controller, comprising: 
 a) an input for receiving compressor air temperature signals;    b) a comparing component for comparing the air temperature signals with a threshold temperature signal value;    c) an output that provides an air compressor deactivation signal when the compressor air temperature signal exceeds the threshold temperature signal value.    
   
   
       16 . The air compressor controller of  claim 15  wherein the comparing component is defined by circuitry of a microprocessor.  
   
   
       17 . The air compressor controller of  claim 15  wherein the comparing component comprises a temperature to voltage converter component and a voltage comparator.  
   
   
       18 . An air compressor controller, comprising: 
 a) an input for receiving compressor air temperature signals;    b) memory for storing a compressor control algorithm;    c) a processor for applying the compressor control algorithm to the compressor air temperature signals, wherein the processor provides an air compressor deactivation signal when the compressor air temperature signal exceeds the threshold temperature signal value;    d) an output for communicating the compressor deactivation signal to deactivate the compressor.    
   
   
       19 . The controller of  claim 18  wherein the threshold temperature is selected to inhibit carbon formation caused by oil breakdown.  
   
   
       20 . A controller for an air compressor, comprising: 
 a) an input for receiving compressor air temperature signals;    b) an input for receiving reservoir air pressure signals;    c) a temperature to voltage converter component that converts compressor air temperature signals to voltage signals;    d) a pressure to voltage converter component that converts air pressure signals to voltage signals; and    e) a voltage comparator component that provides a deactivation signal when voltage signals provided to the voltage comparator by the temperature to voltage converter component and the pressure to voltage converter component are outside threshold limits.    
   
   
       21 . A method of controlling an air compressor, comprising: 
 a) sensing a pressure of compressed air in a reservoir;    b) comparing a sensed pressure of the compressed air in the reservoir with a predetermined threshold pressure;    c) activating the air compressor when the compressed air in the reservoir is less than the threshold pressure;    d) sensing a temperature of air compressed by the air compressor;    e) comparing a sensed temperature of the air compressed by the air compressor with a predetermined threshold temperature; and    f) deactivating the air compressor when the sensed temperature exceeds the threshold temperature and the sensed pressure is above the threshold pressure.    
   
   
       22 . The method of  claim 21  further comprising comparing the sensed pressure of compressed air in the reservoir with a predetermined control pressure that is greater than the threshold pressure and deactivating the air compressor when the sensed temperature exceeds the threshold temperature and the sensed pressure is above the threshold pressure.  
   
   
       23 . The method of  claim 21  wherein the temperature of the air compressed by the air compressor is sensed in a compressor outlet port.  
   
   
       24 . The method of  claim 21  wherein the temperature of the air compressed by the air compressor is sensed at a compression chamber.  
   
   
       25 . The method of  claim 21  wherein the temperature of the air compressed by the air compressor is sensed by a temperature sensor mounted in a compressor unloader valve that is in fluid communication with a compression chamber.  
   
   
       26 . The method of  claim 21  wherein the threshold temperature is selected to inhibit carbon formation caused by oil thermal breakdown.  
   
   
       27 . An air compressor controller, comprising: 
 a) an input for receiving compressor air temperature signals and reservoir pressure signals;    b) memory for storing a compressor control algorithm;    c) a processor for applying the compressor control algorithm to the compressor air temperature signals and the reservoir pressure signals, wherein the processor provides an air compressor activation signal when the compressed air in the reservoir is less than a predetermined threshold pressure and provides an air compressor activation signal when the sensed temperature exceeds the threshold temperature and the sensed pressure is above the threshold pressure; and    d) an output for communicating the compressor activation signal and the compressor deactivation signal to control the compressor.    
   
   
       28 . The controller of  claim 27  wherein the threshold temperature is selected to inhibit carbon formation caused by oil breakdown.  
   
   
       29 . A vehicle air supply system, comprising: 
 a) reservoir for storing compressed air;    b) an air compressor in fluid communication with the reservoir for providing compressed air to the reservoir;    c) a temperature sensor positioned to sense a temperature of the compressed air;    d) a controller linked to the air compressor, the controller compares a sensed temperature of the air compressed by the air compressor with a predetermined threshold temperature and deactivates the air compressor when the sensed temperature exceeds the threshold temperature.    
   
   
       30 . The system of  claim 29  wherein the controller activates the air compressor when an air pressure in the reservoir is less than a predetermined threshold pressure and the sensed temperature exceeds the threshold temperature.  
   
   
       31 . The system of  claim 29  further comprising a control valve coupled to a compressor unloader, wherein the controller controls the control valve to selectively apply an air signal to the compressor unloader to selectively deactivate the compressor.  
   
   
       32 . An air compressor controller, comprising: 
 a) input means for receiving compressor air temperature signals;    b) storage means for storing a compressor control algorithm;    c) processing means for applying the compressor control algorithm to the compressor air temperature signals, wherein the processor provides an air compressor deactivation signal when the compressor air temperature signal exceeds the threshold temperature signal value;    d) output means for communicating the compressor deactivation signal to deactivate the compressor.    
   
   
       33 . An air compressor, comprising: 
 a) compressing means for compressing air; and    b) sensing means for sensing a temperature of air compressed by the compressing means.