New from NCMT is the BIG Daishowa Seiki Hi-Jet rotary coolant adapter which uses split construction to separate the bearing housing from the coolant collar.
New from NCMT is the BIG Daishowa Seiki Hi-Jet rotary coolant adapter which uses split construction to separate the bearing housing from the coolant collar. The result is increased reliability over extended service life. Furthermore, the system can be utilised at speeds up to 10,000 rev/min with coolant pressures up to 20 kg/cmý without compromising reliability.

To date, coolant adapter reliability has been compromised as the use of a common housing demands use of mechanical seals both to separate the stationary and rotating parts of the adapter, and to separate the device's bearings from the coolant.

As the seals wear, not only does coolant begin to leak from the adapter, but the bearings can become awash with coolant.

Although this can be compensated for when selecting the bearing, its life is then dependent on the ability of the machine's filtration system to provide coolant that is not contaminated by particles of swarf.

Otherwise, at high spindle speed and high coolant pressure, bearing damage can be swift and irreparable.

On the Japanese-manufactured Hi-Jet holder, which can be used with any tool provided with coolant holes, the bearing set is separately enclosed and positioned above the coolant adapter ring.

Connection between the two major components is effected using two merit rings, one stationary and the other rotating, which clamp and seal the coolant ring from above and below.

These provide mechanical sealing in a labyrinth-style arrangement.

Some wear is accepted and the rings are designed to be easily replaceable by the user.

The major components of the adapter are, however, fully protected.

Capability of the Hi-Jet to operate at elevated speeds and pressures makes it ideal for use with small diameter cutting tools or in gun drilling applications where provision of through-tool coolant is critical.

There are 57 versions available to suit virtually any BT50 or BT40 spindle application from light drilling up to boring and end milling.