Product Description:

The 1MR160H-B074/S001 is a rotor component produced by Bosch Rexroth Indramat for the 1MB High-Speed Asynchronous Motors series. As a dedicated rotor for 1MB frameless spindle motors, it forms the rotating element of the electromechanical system. Intended to be assembled inside a frameless spindle housing, this rotor converts stator-generated magnetic fields into mechanical rotation for machine-tool spindles and other automation axes that demand high peripheral speed. Because it is supplied without a rotor sleeve, the laminated core can be bonded directly to the host shaft to minimize radial growth and maintain balance at elevated rpm.

The rotor is engineered for continuous output of 20 kW when the stator is energized at a nominal phase voltage of 281 V while drawing 58 A of current. Under this electrical load, it develops 64 Nm of shaft torque, produced by the electromagnetic geometry and the two pole pairs in the lamination pack. At the specified current, the I²R losses in the conductors remain within the cooling capacity provided by the liquid circuit. For short-duration cycles, the rotor can reach 12000 rpm, which is the overspeed limit for balancing and bearing selection. Length code H corresponds to the stack height used for this power density, and winding code 4A matches stators wound for the stated electrical ratings.

During standard duty, the matched water-cooling jacket must supply 5.4 l/min of coolant at a maximum inlet pressure of 3 bar to limit temperature rise when the spindle operates at its rated speed of 3000 rpm. Adequate flow prevents hot-spot formation in the copper bars and keeps insulation within thermal limits. The rotor fits a frame size 160 stator and features a 74 mm central bore to accommodate the drive shaft or drawbar used in machining centers. Protection class IP00 indicates that enclosure shielding must be provided by the machine builder. The frameless form factor helps lower inertia so the spindle can respond quickly to speed changes.