1MR240B-A072
1MB High-Speed Asynchronous Motors
Bosch Rexroth Indramat supplies the 1MR240B-A072 rotor as a component of its 1MB High-Speed Asynchronous Motors series. The unit is a frameless spindle motor rotor intended for machine-tool spindles and other automated equipment that demand compact, high-inertia rotating assemblies. With a frame size of 240 and a motor length code B, the rotor is press-fitted to the mating stator by a step interference fit that promotes precise concentricity during high-speed operation and transmits torque without keyways.
The electrical profile centers on a nominal winding voltage of 122 V that pairs with a rated current of 46 A to produce the electromagnetic field required for steady spindle torque. For short acceleration bursts, the current may rise to 101.1 A without exceeding thermal limits. Under rated electrical conditions the rotor can deliver 6.5 kW of mechanical power, a figure that balances copper losses against thermal conduction through the shaft. A torque constant of 1.57 Nm/A links drive current directly to output torque, allowing the control system to predict load response with simple current feedback. The 1.665 mH phase inductivity smooths current transitions, reducing ripple that would otherwise excite torsional vibration.
Mechanical characteristics define spindle dynamics once energized. At the reference load point the rotor sustains a continuous torque of 62 Nm while turning at a rated speed of 1000 rpm, a combination suited to heavy cutting or grinding processes. The rotor moment of inertia is 0.078 kg·m²; this value moderates speed changes so surface finish remains consistent even with variable material contact. A mass of 19 kg supplies the thermal ballast needed to absorb stator heat, while the 163.9 mm outside diameter and 72 mm inside bore accommodate large shaft bearings and an M6 pressure-oil connection that channels lubricant to the assembly during high-duty cycles.
Technical Specifications
Frame Size
240
Inductivity
1.665 mH
Inside Rotor Diameter
72 mm
Maximum Current
101.1 A
Motor Length Code
B
Nominal Voltage
122 V
Pressure Oil Connection Thread
M6
Product Type
Rotor for 1MB Frameless Spindle Motor
Rated Current
46 A
Rated Power
6.5 kW
Rated Speed
1000 rpm
Rated Torque
62 Nm
Rotor design
with step interference fit
Rotor Mass
19 kg
Rotor Moment Of Inertia
0.078 kg·m²
Rotor Outside Diameter
163.9 mm
Torque Constant (20°c)
1.57 Nm/A
Winding Resistance
0.213 Ω
Common Misspellings
Fax: 1-919-867-6204
Shipping & Payment Options
Warranty
Indramat USA 1 Year Warranty
Repair
We offer a repair service for the 1MR240B-A072. Exchange
Want to sell your 1MR240B-A072?
