Technical Data  Reducers  Small-Size Gear Motor  Selection

Formula for brake life span and braking distance

1. Braking workload

Eℓ = (IM + Iℓ) × n2 182.5 × Tb (Tb ± Tℓ)   Eℓ = (GDM2 + GDℓ2) × n2 7160 × Tb (Tb ± Tℓ)

  • Eℓ：Braking workload per operation 　J{kgf・m}
  • IM{GDM2}：Moment of inertia of brake-type hypoid motor (gear motor) 　kg・m2
  • Iℓ{GDℓ2}：Moment of inertia of load on motor shaft 　kg・m2{GD2・fm2}
  • n：Motor shaft rotating speed 　r/min{kgf・m}
  • Tb：Dynamic friction torque of brake 　N・m{kgf・m} (Brake specifications )
  • Tℓ：Motor shaft-equivalent load torque 　N・m{kgf・m}
  • ± sign ：( -Tℓ) is applied for a negative load such as a suspension load.

2. Brake life span

Z = ET Eℓ

  • Z：Total number of working cycles
  • ET：Total braking workload 　J{kgf・m} (Brake specifications )

3. Braking time

t = ta + tb

tb = (IM + Iℓ) × n 9.55 × (Tb ± Tℓ)   Eℓ = (GDM2 + GDℓ2) × n 375 × (Tb ± Tℓ)

ta：Braking delay time 　s
Time between operation signal issuing and brake operation (Brake specifications )

4. Braking distance

S = ta + 1 2 tb × V

  • S：Braking distance 　mm
  • V：Speed of linear motion　 　mm/s