technical data Coupling Selection and Procedure

If you would like to see the selection procedures and important points, please proceed below.

If you would like to narrow down or tentatively select a product series,
Please click here.

To Selection Guide

If your usage conditions have been decided and you would like a detailed selection,
Please click here.

To sizing

ECHT-FLEX Coupling NER Series Selection

1. Calculation of correction torque

1-1. When connecting with a servo motor

The maximum torque of the servo motor is multiplied by Service factor (SF) in Table 1 according to the type of load to obtain the compensation torque.

Table 1. Service factor (SF) for servo motors
Load Type Uniform Load Moderately fluctuating load Extremely fluctuating load
Service factor (SF) 1.2 1.4 1.5

1-2. When connecting with a general-purpose motor, etc.

The load torque calculated using the formula below is multiplied by Service factor (SF) in Table 2 according to the type of load to calculate the correction torque.

T = 9550 × P n   T = 974 × P n

  • T' = T × SF
  • T = Load torque N・m {kgf・m}
  • P = transmitted power kW
  • n = rotational speed r/min
  • T' = Corrected torque N・m {kgf・m}
Table 2. Service factor (SF) for general-purpose motors
Load Type Type of engine
General-purpose electric motors, gas turbines engine
When the moment
 of inertia 
is small		 When the moment
of inertia 
is large		 4-cylinder 6-cylinder 8-cylinder
Uniform Load 1.5～1.75 1.75～2.0 2.5～4.0 2.0～2.5 1.5～2.0
Moderately fluctuating load 2.0～2.5 2.5～3.0 4.0～5.0 2.5～3.5 2.0～3.0
Extremely fluctuating load 3.0～4.5 4.5～6.0 4.5～5.5 3.0～4.0 2.5～3.5
  • *If an impact load is applied, multiply the maximum torque that the motor can produce by an impact coefficient of 1 to 2.5 to obtain the corrected torque.

2. Shaft diameter

Make sure that the mounting shaft is within the range of shaft diameters that can be mounted on the coupling.

3.Model selection

Please select ECHT-FLEX coupling that satisfies items 1 and 2 above from kW ratings table.

Note: Rotation limit for long spacer type

When using a long spacer type at high speed, the rotation speed must be checked to avoid resonance points.

When selecting a long spacer type, check Table 3 to see if the J dimension and rotation speed for each model number are within the limits.

If the rotational speed exceeds the specified value, a higher model number must be selected.

If the model number is outside the range below or cannot be increased, we can manufacture a "long spacer high-speed specification" with a heavier spacer as a countermeasure.

Table 3. List of long spacer length limits (J dimension) Unit (mm)
Model number/used rotation speed
(r/min)		 3600 2000 1800 1500 1200 1000 900 750 720 600 500 400 300 200 150
NER59W 1470 1960 2070 2260 2520 2750 2900 3170 3240 3540 3870 4330 4990
NER93W 1600 2130 2240 2450 2730 2980 3140 3440 3510 3840 4200 4690 5400
NER230W 1930 2560 2700 2950 3290 3590 3790 4140 4220 4620 5060 5650
NER360W 2080 2760 2910 3180 3540 3870 4080 4460 4550 4980 5440
NER630W 2230 2960 3110 3400 3790 4140 4360 4770 4870 5330
NER850W 2240 2970 3120 3410 3800 4160 4380 4780 4880 5340