Air-cooled dry vacuum pump

Abstract

According to the present invention, an air cooling dry vacuum pump has an excellent heat exchangeability and is capable of discharging clean exhaust gases, allowing an installation space to be reduced due to a small and compact size, and reduced in weight, noise, manufacturing cost, and equipment cost. The vacuum pump includes a rotor ( 2 ), rotating by receiving a driving force of a motor (M) as a driving source of rotation, being received in a casing 1 having an inlet ( 1 a ) of fluid and an outlet ( 1 b ) of the fluid. An air supplying means is provided at one end ( 1 c ) in an axial direction (I) of the casing. The casing is formed into a duplex tube structure having an inner tube ( 4 ) receiving the rotor ( 2 ) rotatably and an outer tube ( 5 ) around the inner tube. An air duct ( 7 ) for flowing cooling air (W) by the air supplying means is provided between the inner tube and the outer tube along the axial direction (I).

1 . An air cooling dry vacuum pump comprising rotors to be rotated by a motor, a driving source of rotation, in a casing having an inlet and an outlet for the fluid, said casing being provided with air supplying means at one end in an axial direction thereof, and formed into a duplex tube structure with an inner tube and an outer tube therearound, and that an air duct, through which cooling air flows as being supplied by the air supplying means, along the axial direction between the inner tube and the outer tube.  
   
   
       2 . The air cooling dry vacuum pump according to  claim 1 , wherein said air duct is provided along the axial direction corresponding to a heat generating member including the motor, rotational force transmission parts such as a rotating speed up gear for transmission of a driving force from the motor to the rotor, a timing gear and the like, a roller bearing supporting rotatably a shaft of the rotor, and rotors engaging with each other, and heat generated from the heat generating member flows conventionally with cooling air flowing through the air duct by the air supplying means for heat exchange.  
   
   
       3 . The air cooling dry vacuum pump according to  claim 1 , wherein said air supplying means is a ventilation fan or a suction fan.  
   
   
       4 . The air cooling dry vacuum pump according to  claim 1 , wherein said casing for receiving the rotors, a rotating speed up gear section for receiving the rotating speed up gear as the rotational force transmission parts, and a timing gear section for receiving the timing gear structure the air duct cooperatively by being connected through a connecting member between the inner tube and the outer tube of the duplex tube structure.  
   
   
       5 . The air cooling dry vacuum pump according to  claim 1 , wherein said rotating speed up gear section and the timing gear section are constructed into upper/lower two sections separated by a partition wall, and the two sections are communicated through a path with each other so as to be capable of circulating lubrication oil by convection.  
   
   
       6 . The air cooling dry vacuum pump according to  claim 1 , wherein said rotor is mounted on a rotor shaft, one end of which is rotatably supported by a first roller bearing placed at the timing gear section as being fixed on one side of the casing.  
   
   
       7 . The air cooling dry vacuum pump according to  claim 1 , wherein said rotor is mounted on the rotor shaft so as to approach to an other side of the casing, which is provided with the inlet and is sealed, and the other end of the rotor shaft is supported rotatably by a second roller bearing placed at a support cylinder with a small diameter, which is fixed on the one side of the casing.  
   
   
       8 . The air cooling dry vacuum pump according to  claim 1 , wherein an outer wall of at least one of said casing, the motor and the air supplying means is covered with a sound absorbing material.