Hydraulic Turbine Blades Cutting


Hydraulic turbine is the key equipment to transform hydroenenergy to mechanical energy and then start the motor. The efficiency, life time, maneuverability, maintenance and maintenance period are very import. Hydraulic turbine blade is a large and complex curve surface. Currently, they’re mainly produced by cnc machine.

They were divided into two types as per energy conversion mode, including counter and impact types.

  1. Counter type including mixed, axial, inclined flows and tubular;

  2. Impact types including pelton, inclined and double water.  

     


Material of blades are usually made of 1Cr13,18-8Ni3Al, which require roughing and finishing. There are several parts require cutting including front and back sides, inlet and outlet sides, welding bevel between upper rim and lower ring. They were made by 3-axis, 5-axis cnc machine or cutting center.

Due to large volume and balance of hydraulic turbine blade, the allowance of one side will be at 20mm, usually the metal removal allowance will be reach 3 ~ 20 ton. The feature of  material (1Cr13, 18-8, Ni3Al and such material) require appropriate, or will cause large loss of tools.    

During cutting, we use profile milling on front and back sides. Φ160R10 profile milling cutter, No.: R220.29-8160-10.6M, r=320 r/min,F=960mm/min。

Each edge of insert can cut for about 1 hour, 4 edges on an insert. So one insert can work for 4 hours.

Plunge milling for roughing on welding bevel and inlet, outlet sides, which can remove allowance rapidly. Plunge milling on upper rim, welding bevel, upper and down inlet, outlet side for purpose of do roughing by 3-axis machine but not straight plug for machine tool.


Roughing




Tools for roughting



Tool holder for roughing



Face milling cutter No.: R220.29-0125-10.7A 

Insert No.: RPKT2006MOT-M15,T350M

Tool holder No.: FM40-450-ISO60