Drive system for a hydraulic excavator

Abstract

A drive for a hydraulic excavator having an electric motor as a main drive. In order to provide a compact, low-maintenance and reliable drive system, at least one diesel engine is arranged on the excavator vehicle itself and can be switched on as required and supplies the chassis with power independently of the main drive.

1 . A drive for a hydraulic excavator, comprising: an electric motor as a main drive; and least one separate diesel engine arranged on the excavator so as to be startable as required, the diesel engine being operatively arranged to supply a chassis of the excavator with power independently of the main drive.  
     
     
         2 . A drive as defined in  claim 1 , and further comprising hydraulic pumps respectively associated with the electric motor and the diesel engine, both the electric motor and the diesel engine, together with the respectively associated hydraulic pumps, form a separate drive unit.  
     
     
         3 . A drive as defined in  claim 1 , wherein the electric motor has a first shaft end and a second shaft end, and further comprising hydraulic pumps associated with the electric motor, and a coupling arranged to connect the second shaft end to the diesel engine so that the hydraulic pumps can be driven both by the electric motor and by the diesel engine connected to the electric motor via the second shaft end.  
     
     
         4 . A drive as defined in  claim 1 , and further comprising hydraulic pumps, the electric motor and also the diesel engine forming a drive for common hydraulic pumps in each case via a coupling.  
     
     
         5 . A drive as defined in  claim 3 , wherein the coupling is a switching clutch.  
     
     
         6 . A drive as defined in  claim 4 , wherein the coupling is a switching clutch.  
     
     
         7 . A drive as defined in  claim 3 , wherein the coupling is a hydrodynamic clutch.  
     
     
         8 . A drive as defined in  claim 4 , wherein the coupling is a hydrodynamic clutch.  
     
     
         9 . A drive as defined in  claim 2 , and further comprising a pump distributor gearbox arranged between the hydraulic pumps and at least one of the electric motor and the diesel engine.