SB 3
SB 3M
SB 3S

The precision valve seat grinding machines
for valve seats up to 200 mm in diameter

Working Principle:
The machine is aligned in centerline with the valve guide by a pilot which is locked in the valve guide. Prior to starting the automatic grinding operation, the depth of cut is set with the grinding wheel in front of the inside edge of the valve seat. The seat is then refaced to the preset depht by the simultaneous application of a circular feed motion and a transverse feed motion to the grinding wheel.

While the grinding wheel itself is revolving with the grinding spindle at high speed, the spindle and the wheel are also travelling slowly around the valve seat in a circle with simultaneous transverse feed motion across the valve seat. As a result, the valve seat is refaced to concentricity with the valve guide under the correct seat angle.

Features:
The grinding head includes a dove-tailed slideway inclined under a seat angle of 30° and in some models a further dove-tailed slideway inclined under a seat angle of 45°.The grinding slide carrying the heavy duty grinding spindle fits into either slideway.
Either slideway is adjustable to maintain long term accuracy. Excellent valve seat finish due to the motorized drive unit which includes a variable speed motor to adapt the feed rates to the valve seat material. The depth of cut is set by a micrometer mechanism to maintain positive control over the stock to be removed from the valve seat. The basic SB 3 model includes a built-in dressing attachment for rapid in-situ dressing of the grinding wheel.