Companies developing and building lathes with a spindle speed of up to 5,600rpm have the option of fitting a new, hydraulically actuated, rotary chuck cylinder that typically consumes 1.5 kilowatt-hours over a daily shift, compared with 36 kilowatt-hours for a conventional cylinder. The reduction is nearly 96 per cent and equates to a saving of more than 19kg of carbon dioxide.
Called ECO Cylinder, the open-centre unit is manufactured by Kitagawa, Japan. It achieves its massive, 24-fold efficiency advantage by switching off the electrically driven pump to cut the hydraulic oil supply once a billet is gripped in the jaws.
Clamping pressure is maintained mechanically until the turned component needs to be removed. This is in contrast to conventional cylinders, which deliver the hydraulic supply constantly to maintain holding force.
A further advantage of Kitagawa’s new design is that spindle growth is minimised, as less heat is generated in the hydraulic unit at the back of the cylinder and in the oil itself. Early figures released from Japan indicate that in a normal workshop environment, a maximum temperature of less than 47°C is reached by ECO Cylinder, compared with the norm 80°C.
Moreover, the rise to maximum temperature takes typically twice a s long, around four hours, giving more thermal stabiilty during warm-up so that components can be kept within tolerance more easily and repeatably.
The specification of ECO Cylinder includes 278mm outside diameter, 160mm length, 66mm diameter through-hole, 20mm piston stroke, 50.5/48.3kN drawbar push/pull and 3.5 MPa maximum operating pressure.
The full range of Kitagawa Hydraulic Cylinders are available from 1st MTA.