Explanation of Terminology
Temperature correction factor
This is a factor multiplied to the rated torque and max. torque depending on the operating temperature of Couplicon®.
the rated torque and max. torque vary.
If ambient temperature exceeds 30°C, be sure to correct the rated torque and max. torque with correction factor shown in the following table.
|Ambient temperature||Temperature correction factor|
MOHS-C MOP-C MSXP-C are superior in heat resistance and the rated torque and max. torque do not vary depending on the operating temperature. Correction by temperature correction factor is not required.
Rotation diameter refers to the larger of the coupling outer diameter (φA) or the diameter with the bolt head protruding (φA1)while rotating.
When using couplings in narrow spaces, pay attention to the rotation diameter. Refer to the table below for rotation diameter details.
The rotation diameter is calculated based on the reference dimensions.
As it fluctuates according to tolerance, build a margin into your design values.
Rotation diameter (by coupling type)
Moment of Inertia
This is a value that indicates the rotational difficulty
Smaller moment of inertia reduces the load torque at the time of start and stop.
Max. rotational frequency
This is a maximum rotational frequency available for Couplicon®.
A value calculated based on peripheral speed 33 m/s is described and we have confirmed that this frequency does not damage the unit by a test. (Except for MOM MOHS MKM MWBS ）
This is a torque value that can be instantaneously transmitted by Couplicon®.
Allowable operating temperature
This is a temperature available for Couplicon®.
The allowable operating temperature for rubber/ resin-used Couplicon® is as shown in the following table.
|Product Code||Allowable operating temperature|
|XGT2(O.D. φ56 or Less)/XGL2/XGS2||-10℃～120℃|
Thrust Reaction Force
This is a force generated when compressing Couplicon® in the shaft direction.
As the thrust reaction force becomes smaller, the force acting on the motor also becomes smaller.
This is the load torque when the round shaft begins to slip against the coupling when mounted on a clamping type coupling at the specified screw tightening torque.
The load torque to the coupling must be below the slip torque. Slip torque changes with usage conditions. Always carry out tests under performance conditions similar to actual conditions in advance.
Static Torsional Stiffness
This is rigidity against torsion of Couplicon® and the inclination
shown in the graph indicates the static torsional stiffness.
Static torsional stiffness for the entire Couplicon® including not only deflection part but also hub is described here.
There are seven types of shaft attachment methods as follows. Select a method according to your needs.
Set screw type
This is low cost and most common attachment method. However, since the screw point directly contacts the shaft, note that it may damage the shaft or make it difficult to remove the unit.
The bore is contracted by tightening force of the screw to clamp the shaft. Mounting and removal can be easily conducted, which does not damage the shaft.
the bore portion can be completely divided. Therefore, it can be easily mounted or removed without moving the device. In addition, the shaft is not damaged.
This is an attachment method in which one side of the hubs is clamping type and the other side is split type. The device can be connected only on the split type side while keeping the clamping type side attached on the shaft.
As with set screw type, this is a general attachment method and can be applied to the transmission of relatively high torque. To prevent the movement in the shaft direction, this is used together with set screw type and clamping type.
Attachment method using taper wedge effect enables secure and stable attachment. This is suitable to high torque transmission and is the most appropriate for the spindle of a machine tool.
Adapter + Clamping typeThis is a type made by inserting an adapter into the clamping type so as to be applied to 1/10 taper shaft of the servomotor.
This is insulation against electricity between both hubs of Couplicon®.
The electrical insulation value of Couplicon® with rubber/resin used between both hubs is as shown in the following table.
|Product Code||Electric resistance value|
|XGT2(O.D. φ56 or Less)/XGL2/XGS2||Not less than 2 MΩ|
|XGT2(O.D. φ68)/XGT/XGL/XGS||Not less than 10 kΩ and not more than 1 MΩ|
|MJC/MJS/MJB||Not less than 2 MΩ|
|MOR/MOL/MOS||Not less than 2 MΩ|
|MOHS||Not less than 2 MΩ|
|MOP||Not less than 2 MΩ|
|MSXP||Not less than 2 MΩ|
|MSF||Not less than 2 MΩ|
This is speed unevenness for one rotation of Couplicon®.
In general, the higher the misalignment is, the lower the constant velocity becomes.
MFB MWBS are superior in constant velocity even when misalignment exists and is appropriate for detection devices such as encoder.
This is a backlash against the rotational direction of Couplicon®.
When high precision positioning is required, select a Couplicon® with zero backlash.
Eccentric reaction force
This is a force generated when making Couplicon® in eccentric condition.
As the eccentric reaction force becomes smaller, the force acting on the shaft bearing also becomes smaller.
This is a shaft center error.
There are three types of misalignment: eccentricity, argument, and end-play.
For details, please refer to Mounting and Maintenance.
Recommended Articles for You
Plastic Screw Property
This page describes "Plastic Screw Properties" such as PEEK, PTFE (Polytetrafluoroethylene), PPS, PC (polycarbonate) and PP (polypropylene).
High-Gain Rubber Type Coupling XG2
This suppresses servo motor hunting and greatly shortens settling time. New NBK coupling XG2. Exhibits even higher responsivity than metal disk couplings. Contributes to improving productivity, such as suppressing speed unevenness during stepper motor operation.
Coupling Stainless Steel Screw Alteration Service
For customers who want to prevent the coupling screws from rusting
Change the screws supplied with the coupling to stainless steel.
Vol. 12 Back to Basics Series! Screw Reference Dimensions
This is a description of "stress corrosion cracking", a problem that frequently occurs but is difficult to detect. I, Nedzigon will discuss the causes, mechanism, and countermeasures, as well as screws that are resistant to stress corrosion cracking.