A new machine from Schaudt Mikrosa BWF combines four spindles for complete camshaft grinding in one setup.
Advancing single and double-wheel technology one step further, the Zeus grinding machine incorporates four wheels to grind a complete camshaft. This multiple-process machine grinds journals, bearing surfaces, cam lobes, nose pins, and thrust-bearing faces all in one setup.
The machine, from Schaudt Mikrosa BWF, is basically two of the company's CF-41 dual-wheel machines put together. But the new machine, which is available in the U.S. through United Grinding Technologies in Miamisburg, Ohio, has a twist.
At the left side of the machine are a primary and a secondary spindle, and the same holds true for the right side. The two sides work on one camshaft independently of each other as well as simultaneously.
Prior to this technology, a single-spindle grinder basically did just the cam lobe forms. With the advent of dual-spindle machines, shops could also do the bearing journals, but the rest of the camshaft was completed on other machines. Zeus eliminates the need for multiple machines by grinding, for example, the cam's bearing journals or lobes at one end while grinding the nose pin at the other.
Both primary wheel spindles on the Zeus accommodate wheel diameters up to 400 mm. This size wheel handles the cam form, bearing journals, or posts. Secondary spindles are swing-down types that use 2.756 in. to 7.48- in.- diameter wheels to grind re-entry forms or, as an O.D.-wheel setup, the cam forms.
And as long as the camshaft itself and the camforms are within 10° of each other, the machine's two primary wheels can grind cam lobe forms simultaneously. The only restriction in doing so is that the C axis, or part rotation, must follow a specific speed profile.
Primary and secondary spindles on each side are in a fixed relationship with each other. Secondary spindles are above and swivel down on an arc of rotation that has as its centerline the primary-wheel axis. This eliminates any errors from swinging them in from the side or in on an angle.
Designed to run CBN wheels, Zeus cuts up to 656 ft/sec or 0.037 sfm. It gets its stability and dampening qualities from a hefty base and table. The base is steel reinforced and filled with granitan, while the fixed table has a 20° tilt, which doubles the base's stiffness. There are no slots in the table, so chips flow off easily.
Wheel changing on the Zeus is not done the usual way, which is running wheels to the edge of the machine. Instead, the large wheels are removable from the back and the smaller wheels from the front. The machine also includes a wheel-changing device for handling the large wheels.
Both X and Z axes are hydrostatic, and workhead motors are direct drive. The wheel dresser is on the machine's tailstock, and it accommodates a 5.12-in. diamond roll and has variable speeds up to 16,000 rpm. The machine also has an automatic, high-speed wheel-balancing system for its large spindles and a manual balancer, which indicates exactly where to place weights, for its smaller spindles.
The Zeus features a footprint of 16 16 ft; a high-pressure system that directs coolant to the grind zone; and separate hydraulic units that operate the machine's steadyrests. Other features include a fire-extinguishing system, an operator's panel built into the cabinet, and a mist-collection system.