Axial piston machine having a pilot control device for damping flow pulsations and manufacturing method

Abstract

The invention relates to an axial piston machine having expellers arranged in a rotating cylinder block, and a valve plate which connects the expellers via valve openings to a port, and having a pilot control device for reducing volume flow pulsations. The pilot control device comprises at least one inertia duct which has a cross-sectional area of less than 3 rum 2 and extends along the valve plate in its circumferential direction over at least 45°. The valve opening is effectively connected to the expeller which opens into it by this inertia duct during a specific time period before, in the course of the rotation of the cylinder block, the expeller is connected to the port. In the process, the pressures prevailing in the expeller space and in the port are equalized under the control of the inertia of the oil column which is located in the inertia duct.

1 . Axial piston machine having expellers arranged in a rotating cylinder block, and a valve plate which alternately connects the expellers via valve openings to, in each case, one of two ports, and having a pilot control device for reducing volume flow pulsations, characterized in that the pilot control device comprises at least one inertia duct which has a cross-sectional area of less than 3 mm 2  and a length of at least one eighth of the circumference of the reference circle, the valve opening being effectively connected to the expeller which opens into it by the inertia duct during a specific time period before, in the course of the rotation of the cylinder block, the expeller is connected to the port, and the pressures prevailing in the expeller space and in the port being equalized under the control of the inertia of the oil column which is located in the inertia duct.  
   
   
       2 . Axial piston machine according to  claim 1 , characterized in that the specific time period in which the inertia duct contributes to the increase or decrease in pressure in the opening expeller is determined by the fact that a further opening or closing expeller is occluded in the connection path from the inertia duct to the valve opening.  
   
   
       3 . Axial piston machine according to  claim 1 , characterized in that a plurality of inertia ducts are provided which are optimized for respectively different rotational speed ranges.  
   
   
       4 . Axial piston machine according to one of claims  1  to  3 , characterized in that one or more inertia ducts are provided both for the high-pressure side and for the low-pressure side.  
   
   
       5 . Axial piston machine according to  claim 4 , characterized in that the inertia ducts for the high-pressure side and for the low-pressure side are configured in the same way.  
   
   
       6 . Axial piston machine according to  claim 4 , characterized in that the inertia ducts for the high-pressure side and for the low-pressure side are configured in different ways.  
   
   
       7 . Axial piston machine according to  claim 1 , characterized in that one or more inertia ducts are provided in combination with pilot control notches.  
   
   
       8 . Method for manufacturing inertia ducts in an axial piston machine according to  claim 1 , characterized in that the inertia ducts are formed as grooves, by a cutting or casting process, in the rear face of the valve plate or in the support face of the valve plate in the end casing, the valve plate and the support face subsequently being connected to one another in order to form pressure-proof ducts.  
   
   
       9 . Method for manufacturing inertia ducts in an axial piston machine according to  claim 1 , characterized in that the inertia ducts are formed as grooves in the radial outer face of the valve plate, and the outer face is subsequently sealed by applying, in particular by shrink-fitting, a tubular or annular component in order to form pressure-tight ducts.  
   
   
       10 . Method for manufacturing inertia ducts in an axial piston machine according to  claim 1 , characterized in that the inertia ducts are implemented as high-strength wires in a cast part, and the wires are pulled out from the cast part after hardening.