Do you all know? Whether it is an ordinary AC motor, a linear stepper motor or other types of servo motors, the coupling is an essential and main accessory for them. Its main function in the motor is to drive and act as a hub. In other words, it is used to connect the motor shaft and the driven shaft to transmit torque. This requires the coupling to have precise rotation performance. If the rotation performance is relatively slow, it will greatly reduce the working efficiency of the stepper motor. At the same time, its rotation requires it to have the following four advantages:

1. Zero clearance: the entire coupling is not allowed to have clearance during transmission;

2. High rigidity: The coupling does not allow transmission hysteresis, otherwise it will seriously affect the accuracy of stepping motor transmission;

3. Low inertia: on the basis of ensuring the transmission strength, the weight of the stepper motor coupling should be reduced as much as possible;

4. Good flexibility: The precision stepper motor coupling not only requires high rigidity, but also needs to correct various deviations between the driving shaft and the driven shaft during the installation process.

Ordinary AC motors can be used:

Flange coupling

Slider coupling

KC chain coupling

ML plum blossom type elastic coupling

Gear coupling

Universal coupling

Diaphragm coupling

XL star coupling, etc.

The editor here recommends two commonly used couplings for reference during design and selection:

1. ML plum blossom type elastic coupling

Stable and reliable work, with good vibration damping, buffering and electrical insulation properties.

The structure is simple, the radial dimension is small, the weight is light, and the moment of inertia is small. It is suitable for medium and high speed occasions.

It has large axial, radial and angular compensation capabilities.

High-strength polyurethane elastic elements are wear-resistant and oil-resistant, have large carrying capacity, long service life, and are safe and reliable.

The coupling does not need lubrication, the maintenance workload is small, and it can run continuously for a long time.

2. XL star elastic coupling

Simple structure, high reliability

The working temperature of XL star elastic coupling is -35-+80 degrees Celsius and is interchangeable with German ROTEX coupling.

The polyurethane elastomer of the LX star elastic coupling is limited by the convex claw block, which can avoid internal and external deformation; even if the teeth are overloaded, the teeth will not wear or deform.

It has compensation for the relative offset of the two axes, cushioning, shock absorption, and wear resistance

Transmission torque 20-35000.N.M, shaft hole 6-220mm, allowable speed 1800-19000r/min

The following are two commonly used stepper motor couplings (micro couplings) and their characteristics.

1. Aluminum alloy plum-shaped elastic coupling

Plum coupling has high flexibility and rigidity at the same time, and different hardness elastomers can be selected according to requirements;

Zero-clearance transmission, there is a great pressing force between the plum blossom elastic body and the metal shaft sleeve to ensure that the two are closely attached;

Polyurethane elastic spacer connection, excellent electrical insulation performance;

The operating temperature is between -20℃～60℃.

2. Aluminum alloy elastic diaphragm coupling

Diaphragm couplings are divided into single diaphragm structure and double diaphragm structure, among which double diaphragm is more flexible;

There are two types of shaft holes: clamping type and expansion sleeve type. The expansion sleeve type can bear a larger moment of inertia, and is generally used for the connection of the spindle of a CNC machine tool (machining center);

Has good heat insulation performance;

Compared with other types of stepper motor couplings, the rigidity is higher.