Rotor of vane pump and method of manufacturing rotor

Abstract

A rotor of a vane pump and a method of manufacturing a rotor are provided. The rotor may be formed to include a plurality of radially formed slots and having a disk shape, and may include approximately 20% to 70% of pig iron, approximately 0.2% to 0.5% of copper (Cu), and approximately 0.1% to 0.4% of iron (Fe) by weight ratio, and scraps and steel wastes for the remainder, and may be formed of a nodular graphite cast iron including precipitated spheroidal graphite and having an austenite structure.

What is claimed is: 
     
         1 . A rotor of a vane pump including a plurality of radially formed slots and having a disk shape, wherein the rotor is formed of a material comprising approximately 20% to 70% of pig iron, approximately 0.2% to 0.5% of copper (Cu), and approximately 0.1% to 0.4% of iron (Fe) by weight ratio, and scraps and steel wastes comprising the remainder, and formed of a nodular graphite cast iron including precipitated spheroidal graphite and having an austenite structure. 
     
     
         2 . The rotor of  claim 1 , wherein a weight ratio of the steel wastes is equal to or smaller than a weight ratio of the scraps. 
     
     
         3 . The rotor of  claim 2 , wherein a weight ratio between the scraps and the steel wastes is approximately 1:1 to 5:1 by weight ratio. 
     
     
         4 . The rotor of  claim 1 , wherein the material comprises approximately 30% to 60% of pig iron, approximately 0.3% to 0.5% of copper (Cu), and approximately 0.15% to 0.35% of iron (Fe) by weight ratio, and scraps and steel wastes comprising the remainder, and formed of a nodular graphite cast iron including precipitated spheroidal graphite and having an austenite structure. 
     
     
         5 . The rotor of  claim 1 , wherein the material comprises approximately 40% to 50% of pig iron, approximately 0.3% to 0.4% of copper (Cu), and approximately 0.25% to 0.35% of iron (Fe) by weight ratio, and scraps and steel wastes comprising the remainder, and formed of a nodular graphite cast iron including precipitated spheroidal graphite and having an austenite structure. 
     
     
         6 . A method for manufacturing a rotor of a vane pump, the method comprising:
 mixing raw materials including approximately 20% to 70% of pig iron, approximately 0.2% to 0.5% of copper (Cu), and approximately 0.1% to 0.4% of iron (Fe), and scraps and steel wastes comprising the remainder and smelting the crude liquid molten metal;   applying a nodularizer and an inoculant to the smelted crude liquid molten metal to obtain a molten metal;   injecting the molten metal to a cast to obtain a rotor semi-product;   machining the rotor semi-product to have a predetermined shape; and   isothermal-hardening the machined rotor semi-product.   
     
     
         7 . The method of  claim 6 , wherein, in the operation of smelting the crude liquid molten, metal is taken out at a temperature ranging from approximately 1500° C. to 1550° C. 
     
     
         8 . The method of  claim 6 , wherein a silicon-iron-magnesium alloy (FeSiMg6RE1), a rare earth element, is applied as the nodularizer in an amount of approximately 1.0% to 1.2% of a mass of the crude liquid molten metal. 
     
     
         9 . The method of  claim 6 , wherein the isothermal-hardening comprises:
 heating the rotor semi-product to reach a temperature ranging from approximately 890° C. to 950° C. and maintaining the heated rotor semi-product for approximately 60 minutes to 90 minutes;   applying the rotor semi-product to a liquid having a temperature ranging from approximately 280° C. to 340° C. and maintaining the rotor semi-product in the liquid for approximately one to three hours; and   cooling the rotor semi-product to reach approximately room temperature in the atmosphere.   
     
     
         10 . The method of  claim 9 , wherein the liquid is a nitrate solution obtained by mixing KNO 3  and NaNO 3  in a ratio of approximately 1:1. 
     
     
         11 . The method of  claim 6 , further comprising:
 grinding the hardening-completed rotor semi-product to have a final shape.   
     
     
         12 . The method of  claim 6 , wherein the raw materials include approximately 30% to 60% of pig iron, approximately 0.3% to 0.5% of copper (Cu), and approximately 0.15 to 0.35% of iron (Fe), and scraps and steel wastes comprising the remainder and smelting the crude liquid molten metal. 
     
     
         13 . The method of  claim 6 , wherein the raw materials include approximately 40% to 50% of pig iron, approximately 0.3% to 0.4% of copper (Cu), and approximately 0.25% to 0.35% of iron (Fe), and scraps and steel wastes comprising the remainder and smelting the crude liquid molten metal.