Cooling apparatus for vacuum pump

Abstract

A cooling apparatus, for cooling a vacuum pump, in which a cooler 44 is arranged on a rotor housing 12, a cooler 45 is arranged on a rear housing 14 and a drive unit 33, a cooler 46 is arranged on a controller 37, a cooler 47 is arranged on an inverter 38, and a cooler 48 is mounted on the peripheral surface of an electric motor M is disclosed. The coolers 46, 47, 48 are arranged midway in a main supply pipe 49. The coolers 44, 45, on the other hand, are arranged midway in a subsidiary supply pipe 50. The energization and deenergization of an electromagnetic three-way valve 51 arranged at the diverging point of the main supply pipe 49 and the subsidiary supply pipe 50 is controlled by the controller 37.

1 . A cooling apparatus for cooling a vacuum pump, for accomplishing a sucking effect, by the transfer operation of a gas transfer member, comprising: 
 a main supply path arranged for supplying a coolant to cool at least one of a plurality of cooling areas of said vacuum pump;    a subsidiary supply path arranged for supplying a coolant from said main supply path to cool at least one of a plurality of the cooling areas; and    supply switching means capable of switching between the supply permit mode in which the coolant is supplied to said subsidiary supply path and the supply prohibit mode in which the coolant is not supplied to said subsidiary supply path.    
     
     
         2 . A cooling apparatus for cooling a vacuum pump according to    claim 1   , further comprising switching control means for electrically controlling the switching of said supply switching means between the supply permit mode and the supply prohibit mode, and temperature detection means for detecting the temperature of said cooling areas cooled by the coolant supplied to said subsidiary supply path or the temperature of said subsidiary supply path, wherein said switching control means controls said supply switching means in such a manner that the temperature of said cooling areas cooled by the coolant supplied to said subsidiary supply path is converged to a target temperature, based on the temperature detection information of said temperature detection means.  
     
     
         3 . A cooling apparatus for cooling a vacuum pump according to    claim 2   , wherein said switching control means is cooled by the coolant supplied to said main supply path and arranged upstream of said supply switching means in said main supply path.  
     
     
         4 . A cooling apparatus for cooling a vacuum pump according to    claim 1   , wherein said gas transfer member is driven by an electric motor, said electric motor is cooled by the coolant supplied to said main supply path, and said electric motor is arranged upstream of said supply switching means in said main supply path.  
     
     
         5 . A cooling apparatus for cooling a vacuum pump according to    claim 1   , wherein said vacuum pump is a multistage Roots pump comprising a plurality of rotary shafts arranged in parallel to each other, a plurality of rotors arranged on said rotary shafts, respectively, and a plurality of pump chambers each arranged in a rotor housing along the axes of said rotary shafts for accommodating a plurality of said rotors in mesh with each other, wherein the cooling areas cooled by the coolant supplied to said subsidiary supply path include said rotor housing forming said pump chambers.  
     
     
         6 . A cooling apparatus for cooling a vacuum pump according to    claim 1   , wherein said supply switching means is an electromagnetic three-way valve arranged at the diverging point of said main supply path and said subsidiary supply path.  
     
     
         7 . A cooling apparatus for cooling a vacuum pump according to    claim 1   , wherein said supply switching means is an electromagnetic valve arranged on said subsidiary supply path.  
     
     
         8 . A cooling apparatus for cooling a vacuum pump, for accomplishing a sucking effect, by the transfer operation of a gas transfer member, comprising: 
 a main supply path arranged for supplying a coolant to cool at least one of a plurality of cooling areas of said vacuum pump;    a subsidiary supply path arranged for supplying a coolant from said main supply path to cool at least one of a plurality of the cooling areas; and    a supply path switch for switching between the supply permit mode in which the coolant is supplied to said subsidiary supply path and the supply prohibit mode in which the coolant is not supplied to said subsidiary supply path.