Product Description:

The 1MR310F-A118/S026 is a rotor built by Bosch Rexroth Indramat for the 1MB High-Speed Asynchronous Motors series. As the rotating element of a frameless spindle motor, it converts the stator’s electromagnetic field into mechanical torque that drives high-speed machining spindles and similar automation axes. Because the unit is supplied as a bare rotor, OEMs integrate it directly into their own housing and bearing assemblies, allowing compact layouts and thermal coupling to the machine structure.

A compliant balance interface is provided through a pin manufactured to DIN 913 and a ring thread of M10; these features let technicians trim residual imbalance after assembly, limiting vibration at service speed. The inside rotor diameter is 118 mm, a clearance that mates with the matching 1MB stator while keeping air-gap flux density within design limits. Maximum mechanical speed reaches 8000 min-1, so material strength and balancing must support high surface velocities during continuous operation. Dynamic behavior is influenced by an inertia of 0.723 kg·m², which determines the torque needed for rapid acceleration or deceleration and affects servo loop tuning in CNC applications. The frame size is designated as 310 and the motor length code is F, identifying the axial stack height used to achieve the required power output.

The rotor mass is 95 kg, a value that contributes to system momentum and affects bearing preload calculations. Overall length measures 400 mm, and an outer diameter of 228.7 mm defines the minimum stator bore and chuck clearance. The end of the shaft expands to 147 mm, forming a step interference fit that ensures torque transmission without keys or splines. A pressure oil port with an M6 thread enables injection of heated oil for thermal shrinking during installation or removal, preventing scoring on the interference surfaces. Together, these dimensions and mounting details support precise spindle construction for metal-cutting, grinding, and composite machining centers.