Product Description

Item No. φD L W L1 M Tighten the strength(N.m)
SG7-8-C19- 19.5 20 1.2 9.4 M2.5 1
SG7-8-C26- 26 25.5 2.5 11.5 M3 1.5
SG7-8-C34- 34 32.3 3.3 14.5 M4 1.5
SG7-8-C39- 39 34.1 4.1 15 M4 2.5
SG7-8-C44- 44 34.5 4.5 15 M4 2.5
SG7-8-C50- 50 40.5 4.5 18 M5 7
SG7-8-C56- 56 45 5 20 M5 7
SG7-8-C68- 68 54 6 24 M6 12
SG7-8-C82- 82 68 8 30 M8 16
SG7-8-C94- 94 68 8 30 M8 28
SG7-8-C104- 104 70 10 30 M8 28

Item No. Rated torque Maximum Torque Max Speed Inertia Moment N.m rad RRO Tilting Tolerance End-play Weight:(g)
SG7-8-C19- 1N.m 2N.m 10000prm 0.65×10-6kg.m² 200N.m/rad 0.04mm 1c ±0.2mm 12
SG7-8-C26- 1.4N.m 2.8N.m 10000prm 1.8×10-6kg.m² 690N.m/rad 0.04mm 1c ±0.2mm 31
SG7-8-C34- 2.8N.m 5.6N.m 10000prm 7.2×10-6kg.m² 1650N.m/rad 0.04mm 1c ±0.2mm 64
SG7-8-C39- 5.8N.m 11.6N.m 10000prm 1.8×10-5kg.m² 2500N.m/rad 0.04mm 1c ±0.2mm 97
SG7-8-C44- 8.7N.m 17.4N.m 10000prm 2.5×10-5kg.m² 2900N.m/rad 0.04mm 1c ±0.2mm 113
SG7-8-C50- 15N.m 30N.m 10000prm 8.2×10-5kg.m² 6700N.m/rad 0.04mm 1c ±0.2mm 195
SG7-8-C56- 25N.m 50N.m 10000prm 1×10-4kg.m² 8400N.m/rad 0.04mm 1c ±0.2mm 263
SG7-8-C68- 55N.m 110N.m 10000prm 1.9×10-4kg.m² 11500N.m/rad 0.04mm 1c ±0.2mm 445
SG7-8-C82- 80N.m 160N.m 10000prm 7×10-4kg.m² 14550N.m/rad 0.04mm 1c ±0.2mm 892
SG7-8-C94- 185N.m 370N.m 10000prm 1.23×10-3kg.m² 16900N.m/rad 0.04mm 1c ±0.2mm 950
SG7-8-C104- 255N.m 510N.m 10000prm 1.86×10-3kg.m² 25100N.m/rad 0.04mm 1c ±0.2mm 1190

flexible coupling

What are the common installation mistakes to avoid when using flexible couplings?

Proper installation is crucial for the reliable and efficient performance of flexible couplings. Here are some common installation mistakes to avoid:

  • Incorrect Alignment: One of the most critical installation errors is improper alignment of the driving and driven shafts. Misalignment can lead to premature wear, increased vibration, and reduced power transmission efficiency. It is essential to align the shafts within the specified tolerances provided by the coupling manufacturer.
  • Over-Tightening: Applying excessive torque to the coupling’s fasteners during installation can cause damage to the flexible elements and decrease their ability to accommodate misalignment. It is essential to follow the recommended torque values provided by the coupling manufacturer to ensure proper clamping without over-tightening.
  • Improper Lubrication: Some flexible couplings may require lubrication of their flexible elements or moving parts. Failure to lubricate as recommended can lead to increased friction, wear, and reduced service life of the coupling.
  • Using Damaged Couplings: Before installation, it is crucial to inspect the flexible coupling for any signs of damage or defects. Using a damaged coupling can lead to premature failure and potential safety hazards. If any damage is detected, the coupling should be replaced with a new one.
  • Wrong Coupling Selection: Selecting the wrong type or size of the coupling for the application can result in inadequate performance, premature wear, and possible coupling failure. It’s essential to consider factors such as torque requirements, speed, misalignment compensation, and environmental conditions when choosing the appropriate coupling.
  • Ignoring Operating Conditions: Failure to consider the specific operating conditions, such as temperature, humidity, and exposure to corrosive substances, can lead to accelerated wear and reduced coupling lifespan. Choosing a coupling that is compatible with the operating environment is essential.
  • Ignoring Manufacturer Guidelines: Each flexible coupling comes with specific installation guidelines provided by the manufacturer. Ignoring these guidelines can lead to suboptimal performance and potential safety issues. It is crucial to carefully follow the manufacturer’s instructions during installation.

By avoiding these common installation mistakes and following best practices, the reliability, efficiency, and service life of flexible couplings can be maximized, leading to improved performance of the mechanical system as a whole.

flexible coupling

How does a flexible coupling handle torsional vibrations in rotating machinery?

A flexible coupling is designed to handle torsional vibrations in rotating machinery by providing a degree of flexibility and damping. Torsional vibrations are oscillations that occur in the drivetrain due to torque variations, sudden load changes, or other transient events. These vibrations can lead to resonance, excessive stress, and premature failure of components.

Flexible couplings mitigate torsional vibrations through the following mechanisms:

  • Torsional Compliance: Flexible couplings have an element, such as an elastomeric insert, that can deform or twist to absorb torsional shocks. When the drivetrain experiences torsional vibrations, the flexible element flexes, effectively isolating and dampening the vibrations before they propagate further.
  • Damping: Many flexible couplings have inherent damping properties, especially those with elastomeric components. Damping dissipates the energy of the torsional vibrations, reducing their amplitude and preventing resonance from occurring.
  • Tuned Design: Some flexible couplings are specifically designed with specific torsional characteristics to match the drivetrain’s requirements. By tuning the coupling’s stiffness and damping properties, engineers can ensure optimal torsional vibration control.
  • Torsional Stiffness: While flexible couplings provide flexibility to absorb vibrations, they also offer a degree of torsional stiffness to maintain the torque transmission efficiency between the shafts.

It is important to select the appropriate flexible coupling based on the specific torsional characteristics and requirements of the rotating machinery. Different applications may demand different types of couplings with varying levels of flexibility and damping. High-performance flexible couplings can effectively minimize torsional vibrations, protecting the drivetrain and connected equipment from excessive stress and potential damage.

Additionally, proper alignment of the flexible coupling during installation is crucial to ensure its optimal performance in mitigating torsional vibrations. Misalignment can introduce additional stresses and exacerbate torsional issues in the system. Regular inspection and maintenance of the flexible coupling will help identify any signs of wear or damage that may affect its ability to handle torsional vibrations effectively.

flexible coupling

Can flexible couplings be used for both motor-to-shaft and shaft-to-shaft connections?

Yes, flexible couplings can be used for both motor-to-shaft and shaft-to-shaft connections in various applications. The versatility of flexible couplings allows them to adapt to different types of connections and meet the specific requirements of the system.

Motor-to-Shaft Connections:

When connecting a motor to a shaft, a flexible coupling serves as an intermediary component that joins the motor shaft and the driven shaft. Flexible couplings are commonly used in motor-driven systems to accommodate misalignment between the motor and the driven load. In motor applications, flexible couplings help reduce stress and wear on the motor bearings, thus extending the motor’s life and enhancing overall system reliability. They also act as vibration dampeners, minimizing vibrations transmitted from the motor to the driven shaft, and subsequently to connected equipment, ensuring smoother operation.

Shaft-to-Shaft Connections:

In many mechanical systems, such as those in the manufacturing, automation, and power transmission industries, shaft-to-shaft connections are required. A flexible coupling can bridge the gap between two shafts and transmit torque while accommodating misalignment. This type of coupling is commonly used to connect shafts that are not perfectly aligned due to factors like manufacturing tolerances, thermal expansion, or foundation settling. By allowing for misalignment, the flexible coupling protects the connected components from excessive stresses and ensures efficient power transmission.

Versatility and Advantages:

The ability of flexible couplings to handle both motor-to-shaft and shaft-to-shaft connections makes them versatile solutions for a wide range of industrial applications. Some of the advantages of using flexible couplings in these connections include:

  • Minimizing stress and wear on connected components, such as bearings and seals.
  • Compensating for misalignment, ensuring smooth power transmission.
  • Damping vibrations and shock loads, reducing the risk of mechanical failures.
  • Protecting equipment from excessive forces, enhancing system reliability.
  • Simplifying installation and alignment procedures, reducing downtime.
  • Improving overall system performance and operational efficiency.


Flexible couplings find applications in a wide range of industries, including manufacturing, material handling, automotive, aerospace, robotics, and more. Whether connecting a motor to a shaft or joining two shafts directly, flexible couplings play a crucial role in enhancing the reliability and efficiency of rotating machinery and mechanical systems.

In conclusion, flexible couplings can effectively serve as connectors for both motor-to-shaft and shaft-to-shaft connections, providing essential misalignment compensation and protection for connected equipment in various industrial applications.

China Good quality Custom Made Couplings Double Disk-Type Flexible Coupling  China Good quality Custom Made Couplings Double Disk-Type Flexible Coupling
editor by CX 2023-09-18