How to Install Couplings：Alignment and Shaft Insertion Length

Contents

• Video：Coupling and Single-axis Actuator Assembly Method
  
• Adjusting Coupling alignment
  
• Shaft Insertion Length
  
• Mounting onto D-cut Shaft
  
• Swing diameter
  
• Attachment
  

Coupling and Single-axis Actuator Assembly Method

This video provides a step-by-step visual guide to assembling the coupling and single-axis actuator.

Adjusting Coupling alignment

1. Flexible couplings accommodate misalignment while transmitting rotation and torque, exceeding allowable limits causes vibration and shortens product lifespan. Alignment adjustment is essential.
2. Align the shafts within the allowable misalignment values specified in the Dimension/Performance table of this catalog.
3. The allowable misalignment values in the Dimension/Performance table apply when eccentricity, angular misalignment, or endplay occurs individually. When two or more types of misalignment occur simultaneously, halve each allowable values.
4. Misalignment is not limited to the initial installation; it can also occur during operation due to vibration, thermal expansion, and shaft-bearing wear. To ensure optimal performance, maintain misalignment below one-third of the allowable misalignment value.

Shaft Insertion Length

We recommend using the hub length (L dimension) listed in the catalog as shaft insertion depth into the coupling.
If the shaft is inserted beyond the L dimension, ensure there is no internal contact.
Insufficient insertion can lead to shaft slippage or clamp failure.

Mounting onto D-cut Shaft

For clamping type

Clamping-type couplings are generally designed for use with round shafts.
When using D-cut or keyed shafts, the D-cut flat or keyway must be positioned to avoid interference with the coupling's slits and bolt spot faces.

For clamping types with 1 hex socket head cap screw

For clamping types with 2 hex socket head cap screws

For  MDW MDS XRP XBW XBWS XBS XBSS

If the D-cut flat or keyway is not positioned as recommended, tightening the hexagon socket head cap screws can impose excessive load on the clamp, potentially causing damage.

For set screw type

Set the D-cut flat as the set screw fastening position when using set screw types.

Swing diameter

The Swing diameter is defined as the larger of the coupling's outer diameter (φA) or the diameter including protruding bolt heads (φA1) while rotating.
For applications in confined spaces, please refer to the rotation diameter in the table below.
These values are reference dimensions and subject to manufacturing tolerances.
Design values should account for these fluctuations.

Swing diameter (by coupling type)

Attachment

Seven shaft attachment methods are available as follows. Choose the one that best meets your application requirements.

Set screw type

This is a cost-effective and widely used attachment method.
However, direct screw contact with the shaft can cause damage and make removal challenging.

Clamping type

The shaft is clamped by the screw's tightening force, which contracts the bore.
This method allows for easy installation and removal without shaft damage.

Split type

Split type couplings can be fully separated,enabling easy installation and removal without relocating the equipment.
This method also prevents shaft damage.

Semi-split type

This attachment method features a clamping type hub on one side and a split type hub on the other. This allows for connection to the device solely on the split-type side, while maintaining the clamping-type hub's position on the shaft.

Key type

Similar to set screw type, this is a common attachment method suitable for transmitting relatively high torque.
To prevent axial shaft movement, it is often used in conjunction with set screw type or clamping type.

Bushing type

This attachment method, utilizing the taper wedge effect, provides a secure and stable connection.
It is well-suited for high torque transmission and is particularly appropriate for machine tool spindles.

Adapter + Clamping type

This type uses an adapter within a clamping type to accommodate 1/10 taper shafts of the servomotor.