Air compressor with variable speed motor

Abstract

An air compressor utilizing an electronic control system. A pneumatically controlled regulator is provided for controlling output pressure for an air compressor. Digital gauges are provided on the air compressor to replace conventional mechanical gauges. A variable speed motor is used, which in turn varies the speed of the pump. Tools are provided for an air compressor that are capable of transmitting a signal to the air compressor indicating a desired pressure and/or motor speed at which the air compressor is to operate.

1 . An air compressor, comprising: 
 a pump;    a variable speed motor for driving the pump; and    an electronic controller for controlling operation of the variable speed motor.    
   
   
       2 . The air compressor of  claim 1 , further comprising a tank for storing pressurized air from the pump, and wherein the electronic controller comprises a routine for an optimum mode in which the variable speed motor drives the pump to maintain the tank at a tank pressure setting that is equal to or slightly greater than a pressure setting for a tool connected to the air compressor.  
   
   
       3 . The air compressor of  claim 2 , wherein, in optimum mode, the controller instructs the motor to increase speed if the pressure within the tank drops below the tank pressure setting.  
   
   
       4 . The air compressor of  claim 2 , wherein, in optimum mode, the controller instructs the motor to decrease speed if the pressure within the tank goes above the tank pressure setting.  
   
   
       5 . The air compressor of  claim 2 , wherein, in optimum mode, the controller instructs the motor to increase speed a first amount if the pressure of the tank drops a first pressure below the tank pressure setting, and instructs the motor to increase speed a second amount, greater than the first amount, if the pressure within the tank drops below a second tank pressure, the second tank pressure being less than the first tank pressure.  
   
   
       6 . The air compressor of  claim 5 , wherein, in optimum mode, the controller instructs the motor to increase speed a third amount, greater than the second amount, if the pressure of the tank drops a third pressure below the tank pressure setting, the third tank pressure being less than the second tank pressure.  
   
   
       7 . The air compressor of  claim 5 , wherein, in optimum mode, the controller instructs the motor to increase to a maximum speed if the pressure of the tank drops a third pressure below the tank pressure setting, the third tank pressure being less than the second tank pressure.  
   
   
       8 . The air compressor of  claim 7 , further comprising a current sensor for sensing current supplied to the motor, and wherein maximum speed is determined by the current supplied to the motor as sensed by the current sensor.  
   
   
       9 . The air compressor of  claim 2 , wherein, in optimum mode, the controller instructs the motor to decrease speed a first amount if the pressure of the tank raises a first pressure above the tank pressure setting, and instructs the motor to decrease speed a second amount, greater than the first amount, if the pressure within the tank raises above a second tank pressure, the second tank pressure being greater than the first tank pressure.  
   
   
       10 . The air compressor of  claim 9 , wherein, in optimum mode, the controller instructs the motor to decrease speed a third amount, greater than the second amount, if the pressure of the tank raises a third pressure above the tank pressure setting, the third tank pressure being greater than the second tank pressure.  
   
   
       11 . The air compressor of  claim 9 , wherein, in optimum mode, the controller instructs the motor to shut off if the pressure of the tank raises a third pressure above the tank pressure setting, the third tank pressure being greater than the second tank pressure.  
   
   
       12 . The air compressor of  claim 2 , further comprising a user interface through which a user may select optimum mode.  
   
   
       13 . The air compressor of  claim 12 , wherein the user interface permits a user to select the tank pressure setting.  
   
   
       14 . The air compressor of  claim 1 , further comprising a current sensor for sensing current supplied to the motor, and wherein the electronic controller comprises a routine for a maximum mode in which the variable speed motor drives the pump at a maximum speed available, and wherein maximum speed is determined by the current supplied to the motor as sensed by the current sensor.  
   
   
       15 . The air compressor of  claim 14 , further comprising a user interface through which a user may select maximum mode.  
   
   
       16 . The air compressor of  claim 1 , further comprising a current selector for setting current supplied to the motor, and a user interface through which a user may select a speed of the motor, wherein the electronic controller is configured to set current supplied to the motor via the current selector in response to a user speed selection.  
   
   
       17 . The air compressor of  claim 16 , further comprising a speed selector for the motor, and a user interface through which a user may select a speed of the motor, wherein the electronic controller is configured to set motor speed of the motor via the speed selector in response to a user speed selection.  
   
   
       18 . The air compressor of  claim 1 , wherein the electronic controller comprises a routine for a quiet mode in which the variable speed motor drives the pump below a maximum speed available for the motor.  
   
   
       19 . The air compressor of  claim 18 , further comprising a user interface through which a user may select quiet mode.  
   
   
       20 . An air compressor, comprising: 
 a pump;    a tank for storing air pressurized by the pump;    a variable speed motor for driving the pump; and    an electronic controller, the electronic controller comprising executable instructions for operating the variable speed motor, the instructions comprising: 
 increasing the speed of the variable speed motor if the pressure within the tank drops below a particular tank pressure setting; and  
 decreasing the speed of the variable speed motor if the pressure within the tank goes above the particular tank pressure setting.  
   
   
   
       21 . The air compressor of  claim 20 , wherein the executable instructions further comprise: 
 increasing the speed of the variable speed motor a first amount if the pressure of the tank drops a first pressure below the particular tank pressure setting, and increasing the speed of the variable speed motor a second amount, greater than the first amount, if the pressure within the tank drops below a second tank pressure, the second tank pressure being less than the first tank pressure.    
   
   
       22 . The air compressor of  claim 21 , wherein the executable instructions further comprise: 
 increasing the speed of the variable speed motor a third amount, greater than the second amount, if the pressure of the tank drops a third pressure below the particular tank pressure setting, the third tank pressure being less than the second tank pressure.    
   
   
       23 . The air compressor of  claim 21 , wherein the executable instructions further comprise: 
 increasing the speed of the variable speed motor to a maximum speed if the pressure of the tank drops a third pressure below the particular tank pressure setting, the third tank pressure being less than the second tank pressure.    
   
   
       24 . The air compressor of  claim 20 , wherein the executable instructions further comprise: 
 decreasing the speed of the variable speed motor a first amount if the pressure of the tank raises to a first pressure above the particular tank pressure setting, and decreasing the speed of the variable speed motor a second amount, greater than the first amount, if the pressure within the tank raises above a second tank pressure, the second tank pressure being greater than the first tank pressure.    
   
   
       25 . The air compressor of  claim 24 , wherein the executable instructions further comprise: 
 decreasing the speed of the variable speed motor a third amount, greater than the second amount, if the pressure of the tank raises a third pressure above the particular tank pressure setting, the third tank pressure being greater than the second tank pressure.    
   
   
       26 . The air compressor of  claim 24 , wherein the executable instructions further comprise: 
 shutting off the variable speed motor if the pressure of the tank raises a third pressure above the particular tank pressure setting, the third tank pressure being greater than the second tank pressure.