Commonly Used Couplings For Ball Screws

Ball screw couplings are often used to install between servo motors (or stepper motors) and ball screws, and belong to the range of miniature couplings. The fixing method is determined according to the load of use. The shaft end of the coupling is generally round, and the less common ones are tapered with crescent key, or flat key, trimming, etc. The screw coupling generally uses 2 inner hexagons. For tightening the screw, it is recommended to mill two planes on the shaft, so that it is not easy to slip even under heavy load. Due to the precision of its application, it must have special properties:

    1. Zero backlash: The coupling as a whole is not allowed to have backlash during the transmission process, including forward clearance and return clearance;

    2. High rigidity: that is, the hysteresis of the transmission is not allowed, otherwise the accuracy of the ball screw transmission will be seriously affected;

    3. Low inertia: On the basis of ensuring the transmission strength, the weight of the ball screw coupling should be reduced as much as possible;

    4. Flexibility: The precise linear guide coupling not only requires high rigidity, but also needs to absorb the deviation between the shaft and the shaft generated during the installation process;

    Screw Coupling

    1. Plum-shaped ball screw coupling

    The special coupling for plum-shaped ball screw 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 elastomer and the metal bushing to ensure that the two are closely attached

    ·The shaft hole adopts a clamping structure to ensure no gap between the shaft and the hole.

    Diaphragm Coupling

    2. Couplings for Diaphragm Ball Screws

    ·Divided into single-diaphragm structure and double-diaphragm structure, in which the flexibility of double-diaphragm is greater;

    Compared with other forms of servo motor couplings, the rigidity is higher;

    ·Good thermal insulation performance;

    ·The shaft hole type is divided into two types: clamping type and expansion sleeve type, among which the expansion sleeve type can bear a larger moment of inertia.

    Bellows Coupling

    3. Bellows ball screw coupling

    ·Using precision bellows as elastic body, integrated structure without any transmission gap, especially suitable for high-precision transmission occasions;

    ·The coupling for bellows ball screw can withstand greater transmission torque;

    ·The shaft hole adopts a clamping structure to ensure no gap between the shaft and the hole.

    Eccentric coupling

    4. Safety type ball screw matching coupling

    The ball screw with overload protection kinetic energy is matched with the coupling, when an overload fault occurs, the active and passive transmissions can be separated instantly;

    The precise ball mechanism makes the active and passive transmission without any gap;

    A variety of elastomers are available: such as plum blossom, bellows, etc.;

    ·It can output low-voltage electrical signal at the moment of overload for overload shutdown.

    Rigid Coupling

    5. Rigid Ball Screw Coupling

    Purely rigid ball screw coupling;

    No flexibility, can not absorb the installation deviation between the shaft and the shaft;

    ·The price is more economical and affordable.