Product Description

Item No. φD L L1 L2 M Tighten the strength(N.m)
SG7-6-40- 40 55 19 24 M3 3
SG7-6-55- 55 65 22 31 M4 6
SG7-6-65- 65 76 27 37 M5 8
SG7-6-82- 82 88 32 41 M6 10
SG7-6-90- 90 88 32 41 M6 12


Item No. Rated torque Maximum Torque Max Speed Inertia Moment N.m rad RRO Tilting Tolerance End-play Weight:(g)
SG7-6-40- 13N.m 26N.m 8000prm 9×10-5kg.m² 15×103N.m/rad 0.15mm 2c 1mm 231
SG7-6-55- 28N.m 56N.m 6000prm 2.9×10-4kg.m² 28×103N.m/rad 0.2mm 2c 1.5mm 485
SG7-6-65- 60N.m 120N.m 5000prm 4.6×10-4kg.m² 55×103N.m/rad 0.25mm 2c 1.5mm 787
SG7-6-82- 150N.m 300N.m 4500prm 1.1×10-3kg.m² 110×103N.m/rad 0.28mm 2c 1.5mm 1512
SG7-6-90- 200N.m 400N.m 4000prm 2×10-3kg.m² 140×103N.m/rad 0.3mm 2c 1.5mm 1800

clamp coupling

Comparison between Couplings with High Torsional Stiffness and Low Torsional Stiffness

Couplings used in motion control systems can vary significantly in their torsional stiffness, which is a crucial characteristic that affects their performance and behavior. Let’s explore the differences between couplings with high torsional stiffness and low torsional stiffness:

  • Torsional Stiffness:

    Torsional stiffness refers to the resistance of a coupling to rotational deflection or twisting under the influence of a torque. Couplings with high torsional stiffness offer greater resistance to twisting, while those with low torsional stiffness are more flexible and can accommodate more significant torsional deflections.

  • Response to Torque:

    Couplings with high torsional stiffness transmit torque more efficiently from one shaft to another, as they minimize torsional deflection. This characteristic is advantageous in applications where precise torque transmission and minimal power loss are essential. On the other hand, couplings with low torsional stiffness are better at absorbing shocks and torsional vibrations, making them suitable for applications where dampening is required.

  • Misalignment Compensation:

    Couplings with high torsional stiffness are less forgiving when it comes to misalignment between shafts. They require more accurate alignment to prevent excessive stress on the coupling and connected components. In contrast, couplings with low torsional stiffness can accommodate some degree of misalignment, reducing the need for precise alignment during installation.

  • Resonance and Natural Frequency:

    Couplings with high torsional stiffness have higher natural frequencies and are less prone to resonance. This characteristic is beneficial in high-speed applications where avoiding resonance is critical to prevent damaging vibrations. Couplings with low torsional stiffness, on the other hand, may have lower natural frequencies and need careful consideration to avoid resonance-related issues.

  • Stress on Connected Equipment:

    High torsional stiffness couplings can transfer torsional loads more directly to connected equipment, which may increase the stress on other system components. Low torsional stiffness couplings can act as vibration isolators, reducing the impact of torsional loads on connected equipment.

  • Application Suitability:

    The choice between high and low torsional stiffness couplings depends on the specific requirements of the application. High torsional stiffness couplings are suitable for applications where precise torque transmission and accuracy are crucial, such as CNC machines and robotics. Low torsional stiffness couplings are ideal for applications involving misalignment, shock absorption, and vibration dampening, such as printing machinery and conveyor systems.

Ultimately, the selection of a coupling with high or low torsional stiffness depends on the specific needs and performance requirements of the motion control system, ensuring optimal functionality and efficiency in the application.

clamp coupling

Handling Angular and Axial Misalignments Simultaneously with Servo Couplings

Servo couplings are designed to handle both angular and axial misalignments simultaneously, making them versatile components for motion control systems. Here’s how they achieve this:

  • Angular Misalignment: Angular misalignment occurs when the motor shaft and the driven load shaft are not perfectly aligned, resulting in an angular offset between them. Servo couplings with flexible elements, such as bellows or beam couplings, can accommodate angular misalignment without inducing excessive stress on the components.
  • Axial Misalignment: Axial misalignment happens when there is a parallel displacement between the motor and the driven load along the shaft axis. Servo couplings with flexible elements allow for axial movement, absorbing any axial misalignment while maintaining torque transmission.
  • Combination of Both: Servo couplings are designed to handle the combination of angular and axial misalignments simultaneously. As the flexible elements of the coupling can move in multiple directions, they can compensate for both angular and axial deviations, ensuring smooth and efficient power transmission.

The ability of servo couplings to handle both angular and axial misalignments is vital in many motion control applications. It allows for greater flexibility in design and installation, as well as improved system performance and reduced wear on the components.

clamp coupling

Advantages of Using Zero-Backlash Servo Couplings in Precision Systems

Zero-backlash servo couplings offer significant benefits in precision motion control systems where accuracy, repeatability, and reliability are essential. Here are the advantages of using zero-backlash servo couplings:

  • Precise Motion Control: Zero-backlash couplings have no play or clearance between the coupling components. This lack of backlash ensures that motion is accurately transmitted from the servo motor to the driven load without any lost motion. As a result, precision systems can achieve precise positioning and smooth motion profiles.
  • Elimination of Positioning Errors: Backlash in couplings can lead to positioning errors, especially in applications where motion direction changes frequently. Zero-backlash couplings prevent any shift or lag in motion, resulting in accurate and repeatable positioning of the driven load.
  • High Repeatability: With zero-backlash, the coupling maintains consistent positioning during bidirectional movements. This feature enhances repeatability, which is crucial in tasks that require the system to follow the same path repeatedly with minimal deviation.
  • Improved System Stability: Backlash in couplings can cause vibration and instability in precision systems. Zero-backlash couplings dampen vibrations and ensure a more stable motion, which is particularly valuable in high-speed and high-precision applications.
  • Long-Term Reliability: Zero-backlash couplings reduce wear and stress on the servo motor and driven load’s bearings and components. This reduction in wear increases the lifespan of the entire system and reduces the need for frequent maintenance and replacement.
  • Responsive Dynamic Performance: Zero-backlash couplings provide instantaneous response to changes in motion direction and speed. This responsiveness is critical in applications that require rapid acceleration and deceleration, enabling the system to handle dynamic loads with precision and efficiency.
  • Higher Torque Transmission: Zero-backlash couplings can handle higher torque loads compared to some flexible couplings with backlash. This capability allows the system to transmit greater forces without compromising motion accuracy.
  • Enhanced Efficiency: By minimizing lost motion and ensuring precise power transmission, zero-backlash couplings contribute to overall system efficiency. They reduce energy losses and optimize the utilization of the servo motor’s output power.
  • Compatibility with High-Precision Components: In precision systems that incorporate high-precision components like encoders and linear scales, zero-backlash couplings are essential to maintain the accuracy of these components’ measurements and feedback.

In summary, zero-backlash servo couplings play a critical role in precision motion control systems by providing accurate, repeatable, and stable motion. Their ability to eliminate backlash and minimize positioning errors enhances overall system performance, efficiency, and reliability, making them an ideal choice for demanding applications that require the utmost precision.

China factory Zero Backlash 40-90mm Bellow Flexible Couplings CNC for Servo Motor  China factory Zero Backlash 40-90mm Bellow Flexible Couplings CNC for Servo Motor
editor by CX 2023-08-14