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Ball Screws for High-Speed Machine Tools HMD Series

>> CAT. No.ESP-061105, 3236

Satisfying the high-speed, high-rigidity and high-
load capacity requirements of the machine tool
industry. Low-vibration ball screws specifically
developed for machining centers.

HMD Series is an upgraded version of the best-selling HMC
Series, the standard for machining centers. The series
satisfies the high-speed operation requirements of machining
centers, which continually demand higher performance.

1. High speed

Used with well accepted end deflectors, the HMD Series achieves the permissible rotational speed (d·n value) of 160 000 and the
maximum feed speed of 120 m/min.

2. Low noise and low vibration

The end deflector recirculation circuit reduces noise and vibration levels by more than 5 dB compared with those of the conventional
HMC Series.

3. High rigidity and high-load capacity

Because of a newly developed mid-deflector, a multi-row specification with various settings for preload and offset preload are available.
This design affords tripled rigidity and doubled load capacity compared with conventional models. Use of NSK K1™ significantly improves
lubrication life.

4. Vertical axis type (option)

HMD Series can accommodate compact, high-load capacity units in which the effective number of turns is increased only in the main load
direction.

5. Hollow shaft type (option)

HMD Series can accommodate a hollow shaft unit for the forced cooling of the shaft center to handle ball screw heat and thermal expansion.

Vertical shaft example Seal unit for hollow shaft
A special joint for hollow shaft coolant is available as an option.
Direction of preload For shaft end: shaft outer diameter φ20, φ25, φ32
For shaft perimeter: φ32, φ40, φ50

Main load direction Installation example
(vertical load receiving side)
Support bearing at
non-driving side Outflow Support bearing at
pipe driving side
Seal unit
(for shaft end) Table

Inflow pipe Hollow ball Seal unit
screw shaft (for shaft perimeter)

Unit base

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