Technical Data  Reducers  Gear Reducer for Servo Motors TERVO  Selection

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Selection

1. Conditions

(1) Operation cycle

Output shaft speed
Output shaft speed
  • nT：Maximum output shaft speed (r/min)
  • t1：Acceleration time (sec)
  • t2：Constant speed time (sec)
  • t3：Deceleration time (sec)
  • t4：Stopped time (sec)
  • tt：Time for 1 cycle (sec.)
Output torque
Output torque
  • Ta：Acceleration torque (N・m)
  • Tc：Constant speed torque (N・m)
  • Tb：Deceleration torque (N・m)

(2) Load moment of inertia 　Ir

Calculate the load moment of inertia Ir on the output shaft of the reducer from the table for "Determining the moment of inertia".

Ir：Load moment of inertia on the output shaft of the reducer (kg・m2)

Load moment of inertia

(3) Acceleration torque and deceleration torque 　Ta, Tb

Acceleration torque 　Ta = △Ta + Tc

Deceleration torque

△Ta = 2πIr × △na 60 × t1

Tb = △Tb - Tc

△Tb = 2πIr × △nb 60 × t3

  • Ir：Load moment of inertia on the output shaft of the reducer (kg・m2)
  • △Ta：Inertia acceleration torque (N・m)
  • △na：Speed difference (r/min) △na = nT - no
  • △Tb：Inertia deceleration torque (N・m)
  • △nb：Speed difference (r/min) △nb = nT - no

(4) Constant speed torque 　Tc

Constant speed torque

Tc = G(M1 + 2.1 × M2 × L) × μ × r

G = Gravitational acceleration ：9.80665m/s2
Constant speed torque

Tc = G(M1 + M2) × μ × ℓ 2 × π × η

Constant speed torque

Tc = GM × r

2. Selection procedure

(1) Calculate the reduction ratio i i ≒ Nm nT

Nm：Motor speed

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(2) Calculate the average output torque Calculate the average output torque
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(3) Determine a size

Average torque
Tave. < rated torque of the output shaft of the reducer

Maximum torque
Ta < rated torque of the output shaft of the reducer × Series-based factor fs
Tb < rated torque of the output shaft of the reducer × Series-based factor fs

 fs：Series-based factor

GMTK・HMTK：1.4

EWJMK・EWMK・SWJMK・SWMK：1.0
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(4) Calculate nave., the average output shaft speed Average output shaft speed
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(5) Confirming the rpm

nave. × i < rated input speed of the reducer

nT × i < maximum input speed of the reducer

Series Input speed (r/min)
Rating Maximum
GMTK・HMTK 3000 3000
SWJMK・EWJMK 3000 3000
SWMK80・EWMK80 2000 3000
SWMK100・EWMK100 2000 2000
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(6) Duty cycle 　Only for worm gear heads

Percentage duty cycle %ED = t1 + t2 + t3 tt × 100

%ED < 50% and t1 + t2 + t3 < 20 minutes

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(7) Check the output shaft radial load O.H.L < N：Allowable radial load of the reducer ※

O.H.L = 2000 × Ta × f × Lf D

D：Pitch diameter (mm) of sprockets and similar objects (mm)

※See the allowable radial loads in the capacity tables.

f：O.H.L. factors

Chain Gear, toothed belt V-Belt
1.0 1.25 1.5

Lf：Point of action factor

ℓ/Q 0.25 0.38 0.5 0.75 1
Lf 0.8 0.9 1 1.5 2

Hollow output shaft

Hollow output shaft

Q：See the tables to the left for the standard length.

Solid output shaft

Solid output shaft

Q：See each type's dimensions for the standard length.

Standard length ：Q For hollow output shafts

HMTK

Model No. Reduction Ratio Q
HMTK0220H 5 ～ 60 36
HMTK0230H 80 ～ 200 42
HMTK0430H 5 ～ 50
HMTK0435H 60 ～ 200 58
HMTK0735H 5 ～ 50
HMTK0745H 60 ～ 200
HMTK1545H 5 ～ 80 66
HMTK2245H 5 ～ 60
HMTK1555H 100 ～ 200
HMTK2255H 80 ～ 120 82
HMTK3755H 5 ～ 60
HMTK5555H 5 ～ 60

SWJMK, SWMK

Model No. Reduction Ratio Q
SWJMK35 10 ～ 60 20
SWJMK42 10 ～ 60 25
SWJMK50 10 ～ 60 30
SWJMK63 10 ～ 60 35
SWJMK70 10 ～ 60 40
SWMK80 10 ～ 60 50
SWMK100 10 ～ 60 55