Flexible Couplings (MSK)

Couplings with flexible ring elements (MSK) of the TRIZ® design are used to transmit torque at various positions of compressor and pump equipment. They have high radial flexibility, axial compliance with high torsional rigidity. Protected by patents and meet the requirements of the standard API 671 which is confirmed by a certificate of conformity.
Due to the ability to unload the rotor system from the reactive forces and compensate for installation and operational deviations and misalignment of the connected rotors, MSK couplings increase the service life of the supports and the rotor system of the unit as a whole, which contributes to an increase in equipment overhaul from one year to six years, thereby responding highest quality and reliability criteria.


• long service life, high reliability;
• stability of the transmission of torque due to the absence of parts wear;
• compensate installation and operational deviations of the misalignment of the connected rotors;
• reduce the load on the support and thrust-journal units by reducing reactive forces;
• possess the vibration-isolating properties (do not transfer vibration on the shafting);
• have consistently low imbalance and low power loss;
• increased reliability of elastic packages due to the use of the TRIZ® anti-fretting protector;
• optimization of weight and size parameters and axial stiffness;
• do not require lubrication and constant maintenance.


The flexible coupling consists of two coupling halves and spacers interconnected through packages of flexible metal elements. Flexible elements are made in the form of a set of metal plates of the factory assembly. The membranes can be circular or consist of individual links. The geometry of the membranes is chosen from the condition of equal strength of the elements.
Torque is transmitted from the flange of the coupling half drive to the package, and then to the flange of the spacer with the help of tight-fitting bolts. Bolts alternately (every other) fix the package to the flanges. The design does not have friction wear parts and radial clearances, resulting in uneven torque transmission and imbalance.
At destruction of packages of membranes, the clutch does not lose the ability to transmit torque, however, it loses its compensating properties.


A number of TRIZ clutches covers a wide range of torques: from 20 to 400,000 Nm. Transmitting capacity depends on the type of flexible ring elements (FRE) and the size of the clutch “D”.


MSK TRIZ® couplings are delivered under specific working conditions. To ensure long start-up of compressor units with steam turbines, couplings with high compensation properties have been developed. This is the result of high processing quality, extremely low manufacturing tolerances and high assembly requirements. Due to the unique design, it was possible to achieve a significant reduction in axial force and an increase in compensatory abilities.
Packages of flexible elements are installed as far as possible from each other. This design gives the coupling an increase in compensation properties by 10% and a decrease in mass by 5%.

Flanges are located in the same plane. Moreover, they are designed in such a way that in the case of an unlikely destruction of a package of elastic elements (only with multiple overloads), the radial planes of the coupling flanges engage and transfer torque until the unit is completely stopped after the automatic protection systems have triggered.

TRIZ LLC attaches great importance to the safety and reliability of the products manufactured. Couplings are designed to transmit the maximum continuous torque with a safety margin of 75%. Provide continuous operation when the maximum axial displacement and maximum shaft incompatibility are exceeded by 25% at the same time. Optimized according to the criteria of strength, vibration-insulating and compensating properties, taking into account the dynamics of the shafting of a particular machine.


Couplings are delivered under the order for the given installation dimensions and operating conditions in a short time. To order, the questionnaire must be filled out. Warranty period of 24 months. Estimated working life of 20 years.