Electronic controlled spiral valve capacity modulation for a portable screw compressor

Abstract

A portable screw compressor that includes a spiral valve configured to be driven by an actuator motor; and an electronic controller coupled to an engine of the portable screw compressor and to the actuator motor. The electronic controller can be configured to, for a compressor pressure of the portable screw compressor exceeding an upper bound of a nominal pressure range, drive the actuator motor to configure the spiral valve to open one or more ports; and for the compressor pressure of the portable screw compressor being lower than a lower bound of the nominal pressure range, drive the actuator motor to configure the spiral valve to close the one or more ports.

What is claimed: 
     
         1 . A portable screw compressor, comprising:
 a spiral valve configured to be driven by an actuator motor; and   an electronic controller coupled to an engine of the portable screw compressor and to the actuator motor, the electronic controller configured to:   for a compressor pressure of the portable screw compressor exceeding an upper bound of a nominal pressure range, drive the actuator motor to configure the spiral valve to open one or more ports; and   for the compressor pressure of the portable screw compressor being lower than a lower bound of the nominal pressure range, drive the actuator motor to configure the spiral valve to close the one or more ports.   
     
     
         2 . The portable screw compressor of  claim 1 , wherein the electronic controller is configured to:
 for receipt of a trigger to shutdown the portable screw compressor:
 reduce engine speed of the engine until a first speed is reached; 
 and then drive the actuator motor to configure the spiral valve to open the one or more ports. 
   
     
     
         3 . The portable screw compressor of  claim 2 , wherein the electronic controller is configured to, for receipt of the trigger to shutdown the portable screw compressor, reduce the engine speed from the first speed to a second speed while driving the actuator motor to configure the spiral valve to open the one or more ports. 
     
     
         4 . The portable screw compressor of  claim 1 , wherein the electronic controller is configured to:
 for receipt of a trigger to shutdown the portable screw compressor due to overheating:
 maintain or increase engine speed of the engine while driving the actuator motor to configure the spiral valve to open the one or more ports; and 
 reduce the engine speed of the engine when a temperature of the portable screw compressor falls below a threshold. 
   
     
     
         5 . The portable screw compressor of  claim 1 , wherein the electronic controller is configured to:
 for receipt of a trigger to engage the portable screw compressor:
 increase engine speed of the engine until a first speed is reached; 
 and then drive the actuator motor to control the spiral valve to close one or more ports. 
   
     
     
         6 . The portable screw compressor of  claim 5 , wherein the electronic controller is configured to, for receipt of a trigger to engage the portable screw compressor, increase the engine speed from the first speed to a second speed while driving the actuator motor to configure the spiral valve to close the one or more ports. 
     
     
         7 . The portable screw compressor of  claim 1 , further comprising a sensor array configured to provide environmental sensor data to the electronic controller, wherein the electronic controller determines the nominal pressure range and engine speed for the engine from the environmental sensor data. 
     
     
         8 . A non-transitory computer readable medium, storing instructions for execution by an electronic controller connected to an engine in a portable screw compressor comprising a spiral valve configured to be driven by an actuator motor connected to the electronic controller, the instructions comprising:
 for a compressor pressure of the portable screw compressor exceeding an upper bound of a nominal pressure range, drive the actuator motor to configure the spiral valve to open one or more ports; and   for the compressor pressure of the portable screw compressor being lower than a lower bound of the nominal pressure range, drive the actuator motor to configure the spiral valve to close one or more ports.   
     
     
         9 . The non-transitory computer readable medium of  claim 8 , the instructions further comprising:
 for receipt of a trigger to shutdown the portable screw compressor:
 reducing engine speed of the engine until a first speed is reached; 
 and then driving the actuator motor to configure the spiral valve to open one or more ports while possibly reducing the engine speed from the first speed to the second speed. 
   
     
     
         10 . The non-transitory computer readable medium of  claim 9 , the instructions further comprising, while driving the actuator motor to configure the spiral valve to open the one or more ports, reducing the engine speed from the first speed to the second speed. 
     
     
         11 . The non-transitory computer readable medium of  claim 8 , the instructions further comprising:
 for receipt of a trigger to shutdown the portable screw compressor due to overheating:
 maintaining or increasing engine speed of the engine while driving the actuator motor to configure the spiral valve to open the one or more ports; and 
 reducing the engine speed of the engine when a temperature of the portable screw compressor falls below a threshold. 
   
     
     
         12 . The non-transitory computer readable medium of  claim 8 , the instructions further comprising:
 for receipt of a trigger to engage the portable screw compressor:
 increasing engine speed of the engine until a first speed is reached; 
 and then driving the actuator motor to control the spiral valve to close the one or more ports. 
   
     
     
         13 . The non-transitory computer readable medium of  claim 12 , wherein the instructions further comprise, while driving the actuator motor to control the spiral valve to close the one or more ports, increasing the engine speed from the first speed to the second speed. 
     
     
         14 . The non-transitory computer readable medium of  claim 8 , further comprising determining the nominal pressure range and engine speed for the engine from environmental sensor data received from a sensor array.