Guidance for Selecting the Reducer

Uses The Reducer Motor

The manufacturing of the standard gear used motors are as follows : (Continuous Rated 4 Pole E insulating)

PhasesCapacityFrequency (Hz)Voltage (V)Current (A)Rotation (R.P.M)Cooling MethodStarted by
3 Phases0.1KW50/60/60200/200/2000.63/0.57/0.581410/1700/1710All Enclosed-
3 Phases0.12KW50/60200/2000.67/0.641350/1550 All Enclosed Ext.Fan-
3 Phases0.2KW50/60/60200/200/2001.2/1.1/1.11410/1700/1720 All Enclosed Ext.Fan-
3 Phases0.4KW50/60/60200/200/2002.2/1.93/1.951410/1700/1730 All Enclosed Ext.Fan-
3 Phases0.75KW50/60/60200/200/2003.6/3.3/3.21440/1720/1740 All Enclosed Ext.Fan-
3 Phases1.5KW50/60/60200/200/2006.9/6.2/6.11430/1720/1730 All Enclosed Ext.Fan-
3 Phases2.2KW50/60/60200/200/2009.0/8.5/7.91430/1720/1730 All Enclosed Ext.Fan-
1 Phases100KW50/60100/1103.7/3.01440/1730Opened drip freeCapacitor
1 Phases200KW50/60100/1105.6/4.81440/1730Opened drip freeCapacitor
1 Phases200KW50/60100/1105.7/4.91440/1730Opened drip freeCapacitor
1 Phases400KW50/60100/1109.0/8.41430/1720Opened drip freeCapacitor

Non-Standard Motor Assembly

Standard model of the reducer motor are of motor axle direct processing to make small size. So, the non-standard motor is hard to manufacture if the quantity is small

1 When it comes to special voltage and special treatment (heat treatment etc.) manufacturing, it must be modified from a standard motor.

2 Special motor ( outdoor, safety and explosive - proof etc. type motors) must use D type reducer.

Model selecting

1 Please select according to the applied conditions of the assembly direction.

2 It must have the output axle revolution numbers when making a selection.

3 The machine must be able to load the torque.

4 Please select based on the revolution numbers and the loading compensation torque.

5 Check the GD², Over Head Load.

Loading ConditionsUnder 3Hr daily revolution3~10Hr daily revolutionOver 10Hr daily revolution
General Loading111
Light Loading111.25
Heavy Loading11.251.50

Inertia (GD²)

When the loading GD² is large, and continuous revolution, at Starting (or with brake to stop) will produce sudden large torque which may create unexpected abnormal accident. So, the relevant machinery degree of GD² shall base on the driving connection method and starting frequency to select according to and within the numerical value range of the following table.

Allowance capacity GD² (axle or input axle conversion value)

3 PhaseSingle PhaseAllowance GD²(kg·m²)

Allowance GD² of the compensation coefficient among the revolution conditions

Revloution methodFrequencyCompensation Coefficient
No Vibration Revloution70 / daily1
70 / over 1 day1.5
With chain Gear connection70 / daily2
70 / over 1 day3

Calculation of the GD² (Gear efficiency)

The GD² generally use GD² torque 1(kg.m,sec²) to indicate. For industrial purpose, actually it is more convenient to use GD² (kg·m²)

GD² = 4 gl

G stands for weight (kg)

D stands for diameter (m)

g stands for accelerating (9.8m/sec²)

l stands for inertia torque (kg.m.sec²)


1 If reducer input revolution is over 1800RPM. to multiple according to above numerical value (1800/input RPM²) to get the GD²

for example : 7600RPM input power is 1/4.

2 The motor axle (input axle) conversion GD² = Output axle GD² × reducing ratio.

for example : When-reducing ratio is 1/20, the GD² is 1/400.

GD² at Straight Line Operation

General Conditions (kg·m²)
Horizontal Direction (Object driven) (kg·m²)
Horizontal Direction (transferring machine) (kg·m²)
Vertical Direction Crane etc. (kg·m²)

When the loaded GD² converted to N2 axle, it is.

The GD² of the Revolution

Revolution center & gravity is aligned (kg·m²)
Revolution center & gravity is not aligned (kg·m²)

Suspending Load

Functioned on Over Head Load when reducer axle and the machine are connected. When applied on Chain wheel, Belt and Gear etc. must take the Over Head Load problems into consideration.

T = torque of the reducer axle (kg·m)

R = the radius of the pitch circle of chain wheel & pulley etc. of the reducer axle (m).

K1 = The coefficient of the connection method (Re : Table 5)

K2 = The coefficient of the loading position (Re : Table 6)

Compare the above stated S.L. with the allowance S.L. on Table of features.

Coefficient K1 (Table 5)

Connection MethodK1
V Shape Belt1.50
Flat Belt2.50

Coefficient K2 (Table 6)

Loading PositionK2
Root of shaft0.75
Center of shaft1.00
End of shaft1.50

Loading Position

  • A = Root of shaft
  • B = Center of shaft
  • C = End of shaft