RLB3-044GDB by Bosch Rexroth Indramat

Bosch Rexroth Indramat produces the RLB3-044GDB, a flexible motor power cable in the RLB Motor Power Cables series. The assembly carries three-phase energy from drive controllers to synchronous motors, so it serves as a passive link between EFC inverters and MS2(X) servo axes in automated machinery. Its task is to deliver continuous current while tolerating frequent motion in cable chains and robotic joints.

The round sheath measures 18.2 mm in overall diameter, which provides a fixed value for gland or conduit selection. Inside, each power core is sized at 6 mm² to match drive outputs that require low resistive loss over several meters. Under rated ambient conditions, the copper set can carry 38.2 Aeff without exceeding its thermal limit, so drives can reach peak torque without derating. During dynamic motion, the minimum bend radius is 7.5×D, keeping internal stresses below the fatigue threshold when the cable is routed through moving trays. Endurance is rated for 5,000,000 bending cycles, a value suited to high-duty production lines that operate around the clock. The cable uses four power conductors plus auxiliary control pairs, allowing power and brake signals to run within one jacket.

A polyurethane jacket resists oil, coolant, and abrasion; the material is listed as PUR and supports outdoor duty when shielded from UV. Signal integrity is helped by a distributed capacitance of 0.5 nF/m, limiting reactive current drawn from pulse-width-modulated drives. At the motor end, an M40 Power Connector provides quick-lock termination compatible with Rexroth housings, while the cabinet side uses pre-crimped ferrules to suit EFC inverters. Static routing inside fixed trays calls for a bend of 5×D, so tight corners inside enclosures remain acceptable. This layout allows the assembly to carry motor power and auxiliary connections through a single cable run between the cabinet and the axis.