Product Description:

The 1MS312C-4A-A1 is a stator assembly produced by Bosch Rexroth Indramat for the 1MB High-Speed Asynchronous Motors series. Delivered as a frameless spindle component, the unit supplies the fixed magnetic field required by 1MB motors used in metal-cutting and grinding centers. Its design supports liquid-jacket cooling so the surrounding drive can maintain rated output during long production shifts without exceeding thermal limits imposed by insulation and bearing clearances.

Electrically, this C-length winding variant 4A is specified for a continuous shaft power of 37 kW at a stator input of 98 A and 380 V three-phase supply. That operating point produces a spindle torque of 238 Nm, enabling heavy material removal at elevated speed. The copper package presents an inductance of 1.40 mH, a value the drive controller uses when shaping current loops and mitigating ripple. A thermal loss of 3.5 kW is dissipated through the coolant jacket, while 25 mm² power leads carry the rated current out of the cabinet. In this configuration, the laminated core weighs 106 kg, matching the motor length code C for medium-frame spindles.

Thermal management relies on liquid cooling: an aluminum hard-coat jacket surrounds the laminations, moving coolant at 5.0 l/min through a 1.4 l internal channel. System piping must limit pressure to 3 bar, and the stator itself introduces only 0.2 bar of drop, allowing compact pump selection. Viton O-rings seal the jacket against leakage. The prefabricated 1.5 m connection loom exits the stator end, has an outside diameter of 27 mm, and must be laid with a minimum bend radius of 110 mm to avoid conductor stress. Aluminum jacket construction keeps power dissipation uniform along the winding zone.