What we need from you

• Load torque at the shaft (N·m), continuous and peak
• Speed required at the load (r/min) and the gear or pulley ratio
• Inertia of the moving mass referred to the motor shaft (kg·m²)
• Duty cycle — how long accelerating, running and dwelling, in seconds
• Environment — ambient temperature, coolant, dust, washdown, and the supply voltage

If inertia is unknown, send the mass, the drive type (ball screw, belt, rack, rotary table) and the stroke — we calculate it.

How we size it

• Torque: T = J·α + T_load, with α from the required acceleration time
• Speed: motor speed = load speed × ratio, then checked against the rated and maximum r/min
• Inertia ratio: load inertia referred to the motor kept inside the drive’s stable range; if not, we change the ratio rather than oversize the motor
• Thermal: RMS torque over the cycle compared with rated torque, so the motor is not chosen from peak alone

The result is a model, a drive, a cable set and a one-page data sheet — not a catalogue page number.

Reading the model code

Frame size comes first (60 / 80 / 110 / 130 / 180 / 190 / 260), then the series. The speed code follows: 30 = 3000 r/min, 20 = 2000 r/min, 15 = 1500 r/min. A trailing H marks the holding-brake build; a trailing L marks the oil-cooled build. Example: 130ST-B18C15H is a 130 frame, 1500 r/min, 1.8 kW motor with a brake.

Exact letter codes after the frame come from the manufacturer’s numbering — always quote the full code on the order so winding, flange and encoder stay as specified.