Air compressor

Abstract

An air compressor includes a motor provided with a basic insulation, a first air compressing unit and a second air compressing unit that are driven by the motor, at least two tanks, and a discharge port. The at least two tanks are connected to the first air compressing unit and the second air compressing unit, store air compressed by the first air compressing unit and the second air compressing unit, and are connected to one another in series. The discharge port is disposed to a tank positioned on a most downstream of supplied compressed air and discharges the compressed air. The motor, the first air compressing unit and the second air compressing unit, and a tank on an upstream side with respect to the tank positioned on the most downstream are electrically insulated from the tank positioned on the most downstream and the discharge port.

1 . An air compressor comprising:
 a motor provided with a basic insulation;   a first air compressing unit and a second air compressing unit that are driven by the motor;   at least two tanks that are connected to the first air compressing unit and the second air compressing unit, store air compressed by the first air compressing unit and the second air compressing unit, and are connected to one another in series; and   a discharge port disposed to a tank positioned on a most downstream of supplied compressed air, the discharge port discharging the compressed air, wherein   the motor, the first air compressing unit and the second air compressing unit, and a tank on an upstream side with respect to the tank positioned on the most downstream are electrically insulated from the tank positioned on the most downstream and the discharge port.   
     
     
         2 . An air compressor comprising:
 a motor provided with a basic insulation;   a first air compressing unit and a second air compressing unit that are driven by the motor;   at least two tanks that are connected to the first air compressing unit and the second air compressing unit, store air compressed by the first air compressing unit and the second air compressing unit, and are connected to one another in series; and   a discharge port disposed to a tank positioned on a most downstream of supplied compressed air, the discharge port discharging the compressed air, wherein   the motor, the first air compressing unit and the second air compressing unit, and all the tanks are electrically insulated from the discharge port.   
     
     
         3 . The air compressor according to  claim 1 , wherein
 the electrical insulation is performed by interposing a resin-made tubular body in a connecting pipe connecting the tank on the upstream side to the tank positioned on the most downstream, and   by supporting the first air compressing unit and the second air compressing unit on the tank positioned on the most downstream via a resin member.   
     
     
         4 . The air compressor according to  claim 3 , wherein
 an insulating bush is further interposed between the tank positioned on the most downstream and the discharge port.   
     
     
         5 . The air compressor according to  claim 2 , wherein
 the electrical insulation is performed by interposing an insulating bush between the tank positioned on the most downstream and the discharge port.   
     
     
         6 . The air compressor according to  claim 1 , wherein
 at least the motor, the first air compressing unit and the second air compressing unit, and the tank on the upstream side are covered with a resin-made outer housing.   
     
     
         7 . The air compressor according to  claim 2 , wherein
 the motor, the first air compressing unit and the second air compressing unit, and all the tanks are covered with a resin-made outer housing.   
     
     
         8 . The air compressor according to  claim 6 , wherein
 the outer housing includes a lower housing on which the tanks are placed and an upper housing assembled to the lower housing from above the lower housing.   
     
     
         9 . The air compressor according to  claim 8 , wherein
 the lower housing and the upper housing are assembled with a screw, and an exposed portion of the screw in the outer housing is covered with a resin-made cover.   
     
     
         10 . The air compressor according to  claim 9 , wherein
 assembling of the lower housing and the upper housing is performed by screwing each of the screw passing through the lower housing and the screw passing through the upper housing into a metal fitting positioned in the outer housing.   
     
     
         11 . The air compressor according to  claim 10 , wherein
 the metal fitting is also covered with the cover.   
     
     
         12 . The air compressor according to  claim 10 , wherein
 positioning of the metal fitting is performed by inserting the metal fitting into a framing portion disposed in the lower housing and having an opened upper surface.   
     
     
         13 . The air compressor according to  claim 12 , wherein
 the lower housing includes a bottom plate and a side plate formed to rise around an outer periphery of the bottom plate, and the framing portion is formed on an inner side of the side plate.   
     
     
         14 . The air compressor according to  claim 13 , wherein
 the metal fitting includes a lower plate formed along a bottom surface in the framing portion and a vertical plate formed along the side plate such that the metal fitting has an L-shape, and the screw passing through the lower housing and the screw passing through the upper housing are screwed into the lower plate and the vertical plate, respectively.   
     
     
         15 . The air compressor according to  claim 12 , wherein
 the cover is fitted to the framing portion from above the metal fitting.   
     
     
         16 . The air compressor according to  claim 9 , wherein
 assembling of the lower housing and the upper housing with the screws is performed at a plurality of positions.   
     
     
         17 . The air compressor according to  claim 8 , wherein
 the upper housing is formed by assembling a plurality of divided housings.   
     
     
         18 . The air compressor according to  claim 8 , wherein
 the discharge port is exposed to an outside via a through hole provided in the outer housing.   
     
     
         19 . The air compressor according to  claim 6 , wherein
 a carry handlebar is disposed in the outer housing.   
     
     
         20 . The air compressor according to  claim 6 , wherein
 a pressure reducing valve and an operating member with which a pressure of the pressure reducing valve is adjustable are disposed between a second tank and the discharge port, and the operating member is exposed to an outside via a through hole provided in the outer housing.   
     
     
         21 . The air compressor according to  claim 1 , wherein
 the tank positioned on the most downstream is exposed.