Pump unit for viscous liquids

Abstract

A pump unit comprising a motor assembly including a motor provided with a first coupling element; an impeller assembly including a pump shaft and a second coupling element mounted on the pump shaft in complementary engagement with the first coupling element is described herein. The motor assembly is removably attached to the impeller assembly via the first and second coupling elements, the first and second coupling elements being so configured as to provide alignment thereof.

What is claimed is:  
     
         1 . A pump unit comprising 
 a motor assembly including a motor having a driving shaft provided with a first coupling element;    an impeller assembly including a pump shaft and a second coupling element mounted to said pump shaft in complementary engagement with said first coupling element; wherein said motor assembly is removably attached to said impeller assembly via said first and second coupling elements, said first and second coupling elements being so configured as to provide alignment thereof.    
     
     
         2 . A pump unit according to  claim 1 , wherein said impeller assembly also includes an impeller mounted to said pump shaft; when energized, said motor causing the rotation of said driving shaft and, by virtue of a positive engagement of said first coupling element and said second coupling element, causes a corresponding rotational movement of said pump shaft and of said impeller.  
     
     
         3 . A pump unit according to  claim 1 , wherein said first coupling element and said second coupling element have corresponding shapes that enable said motor assembly to be positioned without requiring an alignment of said first and second coupling elements.  
     
     
         4 . A pump unit according to  claim 1 , wherein said impeller assembly further comprises a bearing assembly associated with said pump shaft, and wherein said motor assembly further comprises a bearing cover provided with a flange, in such a way that said bearing cover surrounds said bearing assembly when said motor assembly is mounted to said impeller assembly.  
     
     
         5 . A pump unit according to  claim 1 , wherein said first coupling element includes a driving gear provided with teeth on the circumference thereof and mounted on a proximal end of said driving shaft, and said second coupling element includes a driven gear with teeth on the circumference thereof and mounted on a proximal end of said pump shaft of said impeller assembly, said first and said second coupling elements being connected by means of a double female coupling that has internal grooves complementary with said teeth of said driving and said driven gears, said grooves having a flaring out profile so as to allow engagement of said driving gear and said driven gear without needing a careful alignment.  
     
     
         6 . A pump unit according to  claim 1 , wherein said first coupling element including a male coupling mounted on a proximal end of said driving shaft, and said second coupling element includes a female coupling mounted on a proximal end of said pump shaft, said male coupling and said female coupling having cooperating shapes allowing engagement of said male coupling in said female coupling without needing a careful alignment.  
     
     
         7 . A pump unit according to  claim 1 , wherein said pump unit is used with an ink reservoir in a printing.  
     
     
         8 . A pump unit comprising an impeller assembly and a motor assembly: 
 said impeller assembly including: 
 a top member;  
 a bearing assembly having a bearing housing, a top bearing and a bottom bearing; said bearing housing having a flange so as to enable an adequate positioning of said bearing assembly to said top member;  
 a pump shaft having a proximate end provided with a second coupling member and a distal end to which is mounted an impeller; said pump shaft being associated with said bearings;  
   said motor assembly including 
 a motor having a driving shaft provided with a first coupling element;  
 a bearing cover mounted to said motor and having a flange so that said motor can be mounted to said top member by means of quarter turn fasteners;  
   wherein said first coupling element may be removably connected to said second coupling element so as to ensure a systematic and adequate alignment of said impeller assembly and said motor assembly.    
     
     
         9 . A pump unit according to  claim 8 , wherein said first coupling element includes a driving gear provided with teeth on the circumference thereof, and said second coupling element includes a driven gear with teeth on the circumference thereof, said first and said second coupling elements being connected by means of a double female coupling that has internal grooves complementary with said teeth of said driving and said driven gears, said grooves having a flaring out profile so as to allow engagement of said driving gear and said driven gear without needing a careful alignment.  
     
     
         10 . A pump unit according to  claim 8 , wherein said first coupling element includes a male coupling mounted on a proximal end of said driving shaft, and said second coupling element includes a female coupling mounted on a proximal end of said pump shaft, said male coupling and said female coupling having cooperating shapes allowing engagement of said male coupling in said female coupling without needing a careful alignment.  
     
     
         11 . A pump unit for ink reservoirs comprising: 
 a body including a top member, a bottom member and mounting elements therebetween;    a motor mounted to said top member, an impeller housing removably mounted to said bottom member via quarter-turn fasteners; and    an impeller mounted in said impeller housing and operatively and removably connected to said motor; whereby said impeller housing may easily be disconnected from said bottom member.    
     
     
         12 . A pump unit according to  claim 11 , wherein said impeller housing is provided with a bottom surface having an ink inlet aperture and wherein said bottom member includes an outlet aperture; said impeller housing having a sloped port that guides a liquid through said outlet aperture, into a conduit and through a coupler.  
     
     
         13 . A pump unit according to  claim 12 , wherein said mounting elements include support rods.  
     
     
         14 . A pump unit for ink reservoirs comprising: 
 a body including a top member, a bottom member and mounting elements therebetween;    a motor removably mounted to said top member via quarter-turn fasteners, and    an impeller assembly operatively and removably connected to said motor;    whereby said motor may easily be disconnected from said top member.