Press for producing pellets from powdered material

Abstract

The invention relates to a press for producing pellets from powdered material comprising at least one die with a mold cavity imaging the pellet, at least one upper punch and at least one lower punch that interact with the mold cavity to form the pellet, and at least one electric drive for driving the upper punch, and/or the lower punch, and/or the die along a main press axis, wherein the press also comprises at least one movable element acting on the die and/or the mold cavity of the die, wherein at least one electro-hydrostatic drive is provided to drive the at least one movable element.

What is claimed is: 
     
       1. A press for producing pellets from powdered material comprising at least one die with a mould cavity imaging the pellet, at least one upper punch and at least one lower punch that interact with the mould cavity to form the pellet, and at least one electric drive for driving the upper punch, and/or the lower punch, and/or the die along a main press axis, characterized in that the press also comprises at least one movable element acting on the die and/or the mould cavity of the die, wherein at least one electro-hydrostatic drive is provided to drive the at least one movable element;
 further characterized in that the movement of the at least one electro-hydrostatic drive to drive the at least one movable element, and the movement of the at least one electric drive to drive the upper punch and/or lower punch along the main press axis, is controlled by a common control apparatus 
 further characterized in that the at least one hydraulic cylinder ( 68 )—acting on the at least one movable element—of the at least one electro-hydrostatic drive is arranged spatially separate from at least one hydraulic pump actuating on the at least one hydraulic cylinder ( 68 ), and from at least one electric motor driving the hydraulic pump, wherein the at least one hydraulic cylinder ( 68 ) and the at least one hydraulic pump are connected to each other by means of a hydraulic feedline ( 70 ,  72 ) and a hydraulic drain line ( 70 ,  72 ), and 
 further characterized in that the press has a press frame ( 10 ) within which are arranged a die plate ( 26 ) having the die, the at least one upper punch and the at least one lower punch, wherein the at least one electric drive is arranged within the press frame ( 10 ) or on the press frame ( 10 ), and wherein the at least one hydraulic cylinder ( 68 ) of the electro-hydrostatic drive is arranged within the press frame ( 10 ), and the at least one hydraulic pump actuating the at least one hydraulic cylinder ( 68 ), as well as the at least one electric motor driving the hydraulic pump, are arranged outside of the press frame ( 10 ). 
 
     
     
       2. The press according to  claim 1 , characterized in that the at least one movable element is at least one adjusting element for adjusting the die and/or at least one other punch ( 64 ,  66 ) acting on the mould cavity of the die. 
     
     
       3. The press according to one of  claim 1 , characterized in that the at least one movable element is movable by means of the at least one electro-hydrostatic drive along an axis running at an angle to the main press axis, preferably a transverse axis running transverse to the main press axis. 
     
     
       4. The press according to one of  claim 1 , characterized in that the at least one movable element is an additional upper punch and/or an additional lower punch that can be moved by the at least one electro-hydrostatic drive parallel to the main press axis. 
     
     
       5. The press according to  claim 1 , characterized in that the at least one electro-hydrostatic drive acts on the at least one movable element without mechanical deflection. 
     
     
       6. The press according to  claim 1 , characterized in that the hydraulic feedline ( 70 ,  72 ) and the hydraulic drain line ( 70 ,  72 ) are flexible. 
     
     
       7. The press according to  claim 1 , characterized in that the hydraulic cylinder ( 68 ) is attached to the die plate ( 26 ). 
     
     
       8. A press for producing pellets from powdered material comprising:
 at least one die with a mould cavity, at least one upper punch and at least one lower punch that interact with the mould cavity to form the pellet, and at least one electric drive for driving the upper punch, and/or the lower punch, and/or the die along a main press axis, characterized in that the press also comprises at least one movable element acting on the die and/or the mould cavity of the die, wherein at least one electro-hydrostatic drive is provided to drive the at least one movable element;   further characterized in that the movement of the at least one electro-hydrostatic drive to drive the at least one movable element, and the movement of the at least one electric drive to drive the upper punch and/or lower punch along the main press axis, is controlled by a common control apparatus;   further characterized in that the at least one hydraulic cylinder (68), acting on the at least one movable element, of the at least one electro-hydrostatic drive is arranged spatially separate from at least one hydraulic pump actuating on the at least one hydraulic cylinder (68), and from at least one electric motor driving the hydraulic pump, wherein the at least one hydraulic cylinder (68) and the at least one hydraulic pump are connected to each other by means of a hydraulic feedline (70, 72) and a hydraulic drain line (70, 72), and   further characterized in that the press has a press frame (10) within which are arranged a die plate (26) having the die, the at least one upper punch and the at least one lower punch, wherein the at least one electric drive is arranged within the press frame (10), and wherein the at least one hydraulic cylinder (68) of the electro-hydrostatic drive is arranged within the press frame (10), and the at least one hydraulic pump actuating the at least one hydraulic cylinder (68), as well as the at least one electric motor driving the hydraulic pump, are arranged outside of the press frame (10).