Safety couplings prevent expensive damage that often results when a collision occurs in a high-performance servo drive system. At impact, the motor transmits peak torque before the current overload relay reacts. The relay will probably protect the motor from overheating but will not protect the equipment from the destructive internal forces. When a collision occurs, one is not only faced with the repair costs of the damaged equipment but also with the expensive down time due to lost production. Safety couplings are a cost-effective solution to minimize these costs. GAM offers a full line of Direct Drive Safety Couplings and Indirect Drive Safety Couplings.
Features of Couplings, Indirect Drive Safety
Major Feature- High torques and single point 360° re-engagement.
Low Inertia- Compensation for misalignment
Zero Backlash- High torsional stiffness
Patented Connection Method- The press-fit method of joining the bellows to the hub is ideal for methods such as welding due to changers in material properties and glue connections that lose their bonding properties over time.
Spring-loaded form-fit couplings that transmit torque through the use of a special cup spring in which the hardened and polished steel balls are preloaded and pressed into spherical indentations
Backlash-free mechanism connects to either a flexible bellow when used in direct drive applications, or to a pulley for indirect drives.
Low disengagement mass- When overloaded, the hub with its ball cage will overtwist and press the balls out of the indentations to disengage. Only the balls and cup spring move axially, resulting in a very low disengagement mass. In contrast, acceleration of ordinary mechanical torque limiters, with their high disengagement mass, produce a dynamic torque that exceeds static torque by a factor of two or three. The high dynamic torque, in turn, results in a higher destructive force.
Degressive cup springs are key components in the operation of our safety couplings. In conventional spring-loaded couplings, springs experience additional stress when activated and create a certain amount of additional spring tension and torque until the couplings completely disengage. This tends to delay decoupling after a collision. Our cup springs function on the diminishing side of the spring characteristic curve causing torque to drop off immediately at activation and reduce destructive forces and damage.
Automatic re-engagement versions- Since only the balls and cup spring move axially, a proximity switch can be used to initiate an emergency stop to shut the servo motor down. Re-engagement occurs automatically after torque drops off or remains disengaged until drive rotation has reversed. The machine reference point is retained regardless of the re-engagement.
Integrated bearing support versions- Versions are available that include an integrated bearing to support the pulley, eliminating the need for support inside the pulley and allowing for a more compact overall design.