Reciprocating piston lubrication pump

Abstract

A reciprocating piston lubrication pump with a component is proposed having an opening, which has at least one cylinder-shaped part, and with at least one piston, which comprises a radially outer surface built at least partly by a coating. A clearance between the radially outer surface of the piston and the component is between 1 μm and 20 μm when the radially outer surface is positioned in the cylinder-shaped part. The surface hardness of the coating at the radially outer surface is 2 to 10 times higher than that of a region of the component, which forms the cylinder-shaped part.

1 . A reciprocating piston lubrication pump with a component comprising:
 an opening, which has at least one cylinder-shaped part, and with at least one piston, which comprises a radially outer surface built at least partly by a coating, wherein   a clearance between the radially outer surface of the piston and the component is between 1 μm and 20 μm when the radially outer surface is positioned in the cylinder shaped part, and wherein   the surface hardness of the coating at the radially outer surface is 2 to 10 times higher than that of a region of the component, which forms the cylinder-shaped part.   
     
     
         2 . The reciprocating piston lubrication pump according to  claim 1 , wherein at least the region of the component consists of a steel, which comprises 0.8 to 1.5 weight percent of Carbon, 4.0 to 5.0 weight percent of Chromium, 1.5 to 4.5 weight percent of Vanadium, 5.5 to 6.5 weight percent of Tungsten and 4.5 to 5.5 weight percent of Molybdenum and 0.1 to 0.5 weight percent of Silicon. 
     
     
         3 . The reciprocating piston lubrication pump according to  claim 1 , wherein at least the region of the component is hardened to a hardness of 700 to 900 HV at room temperature and/or to an unnotched Izod toughness of 35 to 80 J at room temperature. 
     
     
         4 . The reciprocating piston lubrication pump according to  claim 1 , wherein a radially inner surface of the region of the component is machined to a roughness R z =2 to 6 μm. 
     
     
         5 . The reciprocating piston lubrication pump according to  claim 1 , wherein at least a part of the coating consists of titanium carbonitride and/or TiAlSiN and/or TiSiN and/or AlCrN. 
     
     
         6 . The reciprocating piston lubrication pump according to  claim 1 , wherein the coating has a thickness between 1 and 12 μm. 
     
     
         7 . The reciprocating piston lubrication pump according to  claim 1 , wherein at least a base body of the piston consists of steel, which comprises 0.8 to 1.0 weight percent of Carbon, 4.0 to 4.5 weight percent of Chromium, 1.5 to 2.5 weight percent of Vanadium, 5.5 to 6.5 weight percent of Tungsten and 4.5 to 5.5 weight percent of Molybdenum and 0.1 to 0.5 weight percent of Silicon. 
     
     
         8 . The reciprocating piston lubrication pump according to  claim 1 , wherein the piston comprises a hardness between 650 and 850 HV at room temperature and/or an unnotched Izod toughness between 50 and 80 J at room temperature. 
     
     
         9 . The reciprocating piston lubrication pump according to  claim 1 , wherein the coating is machined to a roughness R z =1 to 5 μm. 
     
     
         10 . The reciprocating piston lubrication pump according to  claim 1 , wherein a critical load L c  of the coating and/or an adhesion of the coating to a base body of the piston is equal or higher than 30 N measured according to the standard ISO 20502 and/or according to the standard EN 1071-3 and/or according to the standard ASTM C1624. 
     
     
         11 . A device with a reciprocating piston lubrication pump comprising:
 a reciprocating piston lubrication pump with a component comprising:   an opening, which has at least one cylinder-shaped part, and with at least one piston, which comprises a radially outer surface built at least partly by a coating, wherein   a clearance between the radially outer surface of the piston and the component is between 1 μm and 20 μm when the radially outer surface is positioned in the cylinder shaped part, and wherein   the surface hardness of the coating at the radially outer surface is 2 to 10 times higher than that of a region of the component, which forms the cylinder-shaped part, wherein   the reciprocating piston lubrication pump contains a lubricant with more than 34 weight percent of oils and less than 60 weight percent, preferably less than 50 weight percent and more preferably less than 40 weight percent of oils.   
     
     
         12 . The device, in particular according to  claim 11 , wherein the reciprocating piston lubrication pump contains a lubricant with more than 10 weight percent, preferably more than 18 weight percent and more preferably more than 25 weight percent of metallic particles.