Shaft having outer teeth for transferring torque between hydraulic machines arranged coaxially behind one another

Abstract

In a shaft ( 19 ) having outer teeth ( 18 ) for transferring torque between hydraulic machines ( 1, 2 ) arranged coaxially behind one another, especially hydraulic pumps of a steering device, in which an inner wheel ( 7; 8 ) provided with teeth ( 9; 10; 15; 16 ) on the inside and outside moves around the inside of a toothed ring ( 3; 4 ) having inner teeth ( 5; 6 ) and engages with the teeth ( 5; 6 ) of the toothed ring ( 3; 4 ), and the teeth ( 18 ) of the shaft ( 19 ) engage without relative rotation in the inner teeth ( 15; 16 ) of the inner wheels ( 7, 8 ), in order to simplify manufacture and assembly of the shaft and to avoid noise, the thickness of the teeth ( 18 ) of the shaft ( 19 ) or of the inner teeth ( 15; 16 ) of the inner wheels ( 7, 8 ), measured on the reference circle, is greater than the width, measured on the reference circle, of the gaps into which those teeth ( 18; 7; 8 ) engage, with the result that the flanks of the teeth ( 18 ) of the shaft ( 19 ) come into contact securely with the flanks of the inner teeth ( 15; 16 ) of the inner wheels ( 7, 8 ), and the shaft ( 19 ) has slots ( 20 ) in both end portions between at least some of its teeth ( 18 ) and is hollow at least in the end portions that are provided with the slots ( 20 ).

1 . Shaft ( 19 ) having outer teeth ( 18 ) for transferring torque between hydraulic machines ( 1 ,  2 ) arranged coaxially behind one another, especially hydraulic pumps of a steering device, in which an inner wheel ( 7 ;  8 ) provided with teeth ( 9 ;  10 ;  18 ) on the inside and outside moves around the inside of a toothed ring ( 3 ;  4 ) having inner teeth ( 5 ;  6 ) and engages with the teeth ( 5 ;  6 ) of the toothed ring ( 3 ;  4 ), and the teeth ( 18 ) of the shaft ( 19 ) engage without relative rotation in the inner teeth ( 15 ;  16 ) of the inner wheels ( 7 ;  8 ), characterized in that the thickness of the teeth ( 18 ) of the shaft ( 19 ) or of the inner teeth ( 15 ;  16 ) of the inner wheels ( 7 ;  8 ), measured on the reference circle, is greater than the width, measured on the reference circle, of the gaps into which those teeth ( 18 ;  7 ;  8 ) engage, with the result that the flanks of the teeth ( 18 ) of the shaft ( 19 ) come into contact securely with the flanks of the inner teeth ( 15 ;  16 ) of the inner wheels ( 7 ;  8 ); and the shaft ( 19 ) has slots ( 20 ) in both end portions between at least some of its teeth ( 18 ) and is hollow at least in the end portions that are provided with the slots ( 20 ).  
     
     
         2 . Shaft according to  claim 1 , characterized in that the thickness of the teeth ( 18 ) of the shaft ( 19 ) is slightly greater than that of the inner teeth ( 15 ,  16 ) of the inner wheels ( 7 ,  8 ).  
     
     
         3 . Shaft according to  claim 1  or  claim 2 , characterized in that the shaft ( 19 ) is provided with an annular groove ( 21 ) near each of its ends in the region of its slots ( 20 ).  
     
     
         4 . Shaft according to any one of  claims 1  to  3 , characterized in that the inner teeth ( 15 ;  16 ) of the inner wheels ( 7 ,  8 ) are formed in adjacent end portions of the inner wheels ( 7 ,  8 ).