The typical technical specifications of each series of PUMO CNC machine tool spindles are as follows (specific values may vary slightly due to taper hole form, bearing configuration, and motor selection, based on the official selection diagram):

■ Electric spindle/direct spindle for machining center (BT40 example)

Conical hole form: BT30/BT40/BT50, HSK-A50/A63/E50 optional

Rated power (continuous/30 minutes): 5.5kW/7.5kW, 11kW/15kW, 18.5kW/22kW

-Maximum speed: 6000rpm (belt heavy-duty), 8000rpm (direct connection standard), 10000/12000rpm (direct connection high-speed), 15000/18000/24000rpm (electric spindle)

Rated torque: 35-50 N·m（7.5kW/6000rpm）、70～120N·m（11～15kW/6000～8000rpm）、235N·m（22kW/3500rpm Reference)

-Constant power range: Typically, the base speed is approximately equal to the rated speed multiplied by 0.7 to 0.8, and above that, it enters the constant power range. The speed ratio can reach 1:10 or more

Radial runout (100mm from nose end): ≤ 0.003mm (standard type), ≤ 0.002mm (precision type)

Axial movement: ≤ 0.002mm

-Pulling force: 800kgf (BT30)~1600kgf (BT40)~2400kgf (BT50)

• Bearing type: Front and rear paired angular contact ball bearings, high-speed type paired with hybrid ceramic ball bearings

Lubrication method: Oil air lubrication (high-speed type) or lithium grease (medium low speed)

-Cooling method: shell water-cooled jacket (forced by electric spindle) or air-cooled fins (independent motor)

• Standard encoder: 1024 line incremental or 17 bit absolute value, supports C-axis feedback

CNC lathe spindle unit (A2-6 nose end example)

• Nose end of spindle: A2-5/A2-6/A2-8 (corresponding to chuck of diameter 140/170/210)

-Through hole diameter (bar material passing capacity): φ 52mm/φ 62mm/φ 80mm

• Maximum speed: 3000rpm (large bore heavy load), 3500-4500rpm (standard), 6000rpm (built-in turning electric spindle)

Rated power: 7.5kW/11kW/15kW/18.5kW (overload 1.25 to 1.5 times for 30 minutes)

-Rated torque: 70-300N · m (depending on speed and power)

• Positioning accuracy (C-axis): 0.001 ° (with high-resolution encoder and servo spindle)

• Clamping method: hydraulic rotary cylinder+three jaw chuck, optional with center frame/tailstock

Radial runout (chuck end face reference): ≤ 0.005mm (precision type ≤ 0.003mm)

■ Electric spindle for grinding machine

• Speed range: 1500-6000rpm (outer circle/flat grinding usually below 3000rpm, inner circle grinding can reach 12000-18000rpm)

• Power: 1.5-11kW

• Bearings: Ultra precision angular contact ball bearings or hydrostatic oil film bearings

-Sealing: Strengthen the sealing and air curtain to prevent the infiltration of grinding fluid

The constant torque design is suitable for cutting in grinding and large margin slow entry grinding

Engraving and milling/PCB electric spindle

• Speed: 24000~60000rpm (PCB can reach 80000~100000rpm)

• Power: 0.8-5.5kW (engraving and milling), 0.15-1.5kW (PCB drilling)

-Collet: ER11/ER16/ER20 or specialized spring clamp

Radial runout: ≤ 0.001mm (PCB high-precision type)

• Cooling: Water cooling with water temperature control

There is a coupling relationship between key selection parameters - large torque requires a large displacement motor+large reduction ratio (low-speed range) or large lead transmission, but it will limit the maximum speed; High precision requires high-precision bearings, appropriate pre tightening, and good thermal control, but excessive tightening increases heat generation and reduces lifespan. The PUMO engineering team can assist in drawing a speed torque power envelope diagram to match specific machining processes.