Screw-type positive displacement machine

Abstract

A screw-type positive displacement machine includes a housing with a first rotor and a second rotor which are mounted to rotate in the housing and which are driven in directions which are the opposite of one another. The positive displacement machine has a first motor and a second motor arranged in a drive casing and connected to the housing in such a way that the first rotor is driven by the first motor and the second rotor is driven by the second motor. Typically, the first motor and/or the second motor is an asynchronous motor.

1 . Screw-type positive displacement machine comprising a housing with a first rotor and a second rotor mounted to rotate in the housing and driven in directions opposite of one another,
 characterized in that the positive displacement machine comprises a first motor and a second motor arranged in a drive casing and connected to the housing in such a way that the first rotor is driven by the first motor and the second rotor is driven by the second motor.   
     
     
         2 . Positive displacement machine according to  claim 1 , characterized in that the first motor and/or the second motor is an asynchronous motor. 
     
     
         3 . Positive displacement machine according to  claim 1 , characterized in that the rotary part of the first motor is connected to the first rotor and/or the rotary part ( 41 ″) of the second motor is connected to the second rotor. 
     
     
         4 . Positive displacement machine according to  claim 1 , further comprising a first synchronization wheel and a second synchronization wheel, which mesh with one another, connected to the first rotor and second rotor respectively. 
     
     
         5 . Positive displacement machine according to  claim 4 , characterized in that a contact surface between the first synchronization wheel and the second synchronization wheel is not lubricated. 
     
     
         6 . Positive displacement machine according to  claim 4 , characterized in that the surface of the teeth of the first synchronization wheel and/or of the second synchronization wheel is covered by a layer of material having a low coefficient of friction. 
     
     
         7 . Positive displacement machine according to  claim 1 , characterized in that the machine comprises a starter to synchronize the startup of the first motor and of the second motor. 
     
     
         8 . Positive displacement machine according to  claim 4 , characterized in that the first synchronization wheel and/or the second synchronization wheel has a composite structure. 
     
     
         9 . Positive displacement machine according to  claim 8 , characterized in that the composite structure of the first synchronization wheel and/or of the second synchronization wheel consists in a toothing in a first material and a hub in a second material. 
     
     
         10 . Positive displacement machine according to  claim 8 , characterized in that the composite structure of the first synchronization wheel and/or of the second synchronization wheel comprise a toothing and at least one screw allowing the heat to be extracted from the toothing. 
     
     
         11 . Positive displacement machine according to  claim 8 , characterized in that the composite structure of the first synchronization wheel and/or of the second synchronization wheel comprise at least one groove permitting heat exchange with the air. 
     
     
         12 . Positive displacement machine according to  claim 9  wherein said first material is a plastic material and said second material is steel.