Internal gear pump that does not contain any filler elements

Abstract

An internal gear pump that does not contain any filler elements comprises a housing ( 1 ) and a bearing ring ( 5 ), which is accommodated inside a recess ( 13 ) of the housing in a manner that permits it to transversally move in relation to its axis but not to rotate. The internal gear pump also comprises an internal-geared ring gear ( 3 ), which is mounted inside the bearing ring in a manner that permits it to revolve, and a pinion ( 2 ), which is mounted inside the housing in a manner that permits it to rotate and which meshes with said ring gear. The inner peripheral surface of the housing recess ( 13 ) coaxially extends in relation to the pinion ( 2 ), and the bearing ring, which is eccentrically arranged with regard to the pinion axis ( 15 ), can pivot in relation to the housing recess about a parallel pivotal axis ( 22, 23 ) that is parallel to the axis thereof. The bearing ring can pivot without the tight contact between the tooth tips of the pinion ( 2 ) and ring gear ( 3 ) being lost. The inner peripheral surface of the bearing ring ( 5 ) that forms the bearing surface for the ring gear ( 3 ) coaxially extends in relation to its outer peripheral surface ( 20 ), and the pivotal path of the bearing ring is delimited to a pre-designated measure by a pin ( 25 ), which passes therethrough or which is arranged in the sickle-shaped gap ( 21 ), or by a projecting step located inside this gap.

1 . Internal gear pump that does not contain any filler elements, with a housing ( 1 ), a bearing ring ( 5 ), which is accommodated inside a recess ( 13 ) of the housing in a manner that permits it to transversely move in relation to its axis, but not to rotate, an internal-geared ring gear ( 3 ), which is mounted inside the bearing ring in a manner that permits it to revolve, and a pinion ( 2 ), which is mounted inside the housing in a manner that permits it to rotate, and which meshes with the internal-geared ring gear, the teeth of which define a suction space and a pressure space in the gears, by means of a complete engagement into tooth gaps of the internal-geared ring gear, on the one hand, and sealing contact with the tooth tips of the internal-geared ring gear in a region of the internal-geared ring gear that lies approximately diametrically opposite the tooth gap engagement region, on the other hand, whereby the inner peripheral surface of the housing recess ( 13 ) that holds the bearing ring ( 5 ) coaxially extends in relation to the pinion ( 2 ), and the bearing ring, which is eccentrically arranged with regard to the pinion axis ( 15 ), can pivot in relation to the housing recess, around a pivotal axis ( 22 ,  23 ) parallel to the recess axis, in such a way that the sealing contact between the tooth tips of the pinion ( 2 ) and the internal-geared ring gear ( 3 ) is maintained, 
 characterized in that 
 the inner peripheral surface of the bearing ring ( 5 ) that forms the bearing surface ( 19 ) for the internal-geared ring gear ( 3 ) coaxially extends in relation to its outer peripheral surface ( 20 ), and the pivotal path of the bearing ring is delimited to a predetermined measure.  
   
     
     
         2 . Internal gear pump according to  claim 1 , 
 characterized in that 
 the pivotal path is delimited by a pin ( 25 ) that passes through a bore that runs approximately parallel to the axis direction of the bearing ring ( 25 ) [sic], with a predetermined amount of play, and is supported on the housing.  
   
     
     
         3 . Internal gear pump according to  claim 2 , 
 characterized in that 
 the pin ( 25 ) is a bar spring that stresses the bearing ring, in the pressure-free state of the internal gear pump, in such a way that sealing contact exists between the tooth tips of the pinion and the internal-geared ring gear, in the region of the gears without engagement.  
   
     
     
         4 . Internal gear pump according to  claim 1 , 
 characterized in that    the pivotal path is limited by at least one stop pin ( 35 ), which is arranged in the sickle-shaped gap ( 21 ) between the outer peripheral surface ( 20 ) of the bearing ring and the inner peripheral surface of the housing recess ( 13 ).    
     
     
         5 . Internal gear pump according to  claim 4 , 
 characterized in that 
 the stop pin ( 35 ) is attached in the housing ( 1 ), preferably in the housing recess ( 13 ), or in or on the bearing ring ( 15 ), preferably in the region of the outer circumference of the bearing ring ( 15 ).  
   
     
     
         6 . Internal gear pump according to  claim 5 , 
 characterized in that 
 the stop pin ( 35 ) is preferably attached parallel to the axis of the pinion, in the bottom of the housing recess.  
   
     
     
         7 . Internal gear pump according to  claim 5 , 
 characterized in that 
 the stop pin is attached in or on an outer peripheral surface of the bearing ring, preferably parallel to the axis of the bearing ring.  
   
     
     
         8 . Internal gear pump according to one of  claims 4  to  7 , 
 characterized in that 
 the stop pin is arranged offset by about 90° relative to the pivotal axis ( 22 ) of the bearing ring.  
 
 
     
     
         9 . Internal gear pump according to one of  claims 4  to  8 , 
 characterized in that 
 two stop pins are provided, which are arranged offset by the same angle on both sides of the pressure space peak point.  
 
 
     
     
         10 . Internal gear pump according to  claim 1 , 
 characterized in that 
 the pivotal path is limited by a step ( 45 ) that projects axially into the gap ( 21 ) between the bearing ring and the housing recess, from the bottom of the housing recess ( 13 ).  
   
     
     
         11 . Internal gear pump according to  claim 10 , 
 characterized in that 
 the contour of the step is adapted to the gap and the step forms a ring gap ( 46 ) with the outer peripheral surface ( 20 ) of the bearing ring.