Basic equations to selection of hydraulic motors

FLOW     q =   D  x  n
_________

1000 x ƞv
D    
n    
ƞv  
 

FLOW (q) = D x n / 1000 x ƞv q = (l/min)
  D x Δp x ƞhm D     
TORQUE (M) = __________________ Δp    
63 ƞhm  
TORQUE (M) = D x Δp x ƞhm / 63 M = (Nm)
  q x Δp x ƞt q  
  _______________ Δp  
  600  ƞt    
POWER(P) = q x Δp x ƞt / 600 P = (kW)
  M x 62.83 M   
  _____________ Δp   
  Δp  
REQUIRED MOTOR DISPLACEMENT = M x 62.3 / Δp D = (cm3/rev)
  M x 62.83 M    
  ____________ Δp    
  Δp X g.box ratio g-box ratio  
REQUIRED MOTOR + G.BOX DISPLACEMENT = M x 62.83 / Δp X g.box ratio D = (cm3/rev)

D= displacement (cm3/rev) n= shaft speed (rpm) ƞv= volumetric efficiency Δp= differential pressure (bar) between inlet and outlet ƞhm= mechanical efficiency ƞt= overall efficiency (ƞt= ƞv x ƞhm)

Disclaimer: This table is for informational purposes only. All applications should be reviewed by an engineer for safety and design criteria before implementation. By using this Basic formulas to selection of hydraulic motors, you agree to hold harmless all parties associated with this table.