In addition to mainstream milling machining, PUMO also offers three types of dedicated spindle series:

① Electric spindle for grinding machine

The spindle in external cylindrical grinding, flat grinding, centerless grinding, and tool grinding requires long-term constant torque operation, extremely low vibration, and high sealing to prevent grinding fluid intrusion. The spindle power of PUMO grinder is 1.5-15kW, and the speed is usually 1450-3600rpm (internal circular grinding can reach 12000-18000rpm). It adopts ultra precision angular contact ball bearings or liquid hydrostatic bearings, and the front and rear supports are strictly pre tightened and run in. The radial runout is ≤ 0.001mm (ultra precision type). The sealing system consists of a multi-stage labyrinth and a positive pressure air curtain to block abrasive particles and emulsion; The stator and bearing seat are equipped with independent cooling jackets to control temperature rise, avoiding errors in workpiece roundness/cylindricity caused by thermal deformation. The constant torque characteristic stabilizes the linear velocity of the grinding wheel in Plume Grinding and Creep Feed Grinding, and when combined with an online dynamic balancer, can further suppress regenerative chatter and improve surface roughness Ra to below 0.1-0.2 μ m.

② High speed engraving and milling machine spindle

Used for electrode (copper/graphite) processing, small mold highlight, 3D carving of mobile phone cases/buttons, etc., requiring high speed (18000-3600rpm), low power (1.5-5.5kW), low vibration, and ER series chuck for quick tool change. PUMO engraving and milling electric spindle adopts 2-3 sets of mixed ceramic angular contact ball bearings, independent water-cooled jacket at the front bearing, standard ER20 (or ER16/ER25) spring chuck, radial runout ≤ 0.003mm, optional automatic tool changing (ATC) cylinder and air blowing cleaning. It is recommended to use HSK-E25 or a special short nose end electric spindle for high gloss processing (iPhone buttons, watch cases, etc.) to reduce overhang and improve rigidity, and to achieve a mirror effect Ra<0.05 μ m when combined with micro diameter cutting tools (φ 0.2~φ 1mm).

③ PCB drilling/milling electric spindle

The drilling of printed circuit boards requires ultra-high speed (60000-10000rpm or even 120000rpm), extremely small radial runout (≤ 0.001mm), fast start stop (acceleration to maximum speed<0.3s), and high dynamic balance quality. The PUMO PCB electric spindle adopts air floating/ultra high speed ceramic bearings, high-frequency inverter power supply (output frequency can reach 2000Hz or above), forced water cooling+front-end air curtain sealing to prevent drilling debris suction. The power is usually 0.2-1.5kW, and special clamps (φ 1/8 ", φ 1/4" or dedicated micro drill clamps) are standard. Combined with a multi axis drilling rig, high-density interconnect (HDI) board micro hole (φ 0.15~φ 0.3mm) processing can be achieved, with hole position accuracy within ± 10 μ m, and excellent control of the halo (Measling) and nail head (Burrs). Some models integrate non-contact tool breakage detection coils, which can instantly identify micro drill breakage.

Special attention should be paid when selecting the above three types of specialized spindles: grinding machine spindles focus on sealing and constant torque; The carving and milling spindle pays attention to the rigidity of the nose end and the compatibility of the clamp head; PCB spindle focuses on the limit of bearing dn value and dynamic balance level under ultra-high speed. The PUMO technical department can provide speed power torque envelope diagrams, installation interface CAD models, and cooling/lubricating medium parameter requirements for various models.