XPMK7240 Duplex Grinder (Herringbone + Surface)

Background

Linear guideways are the foundation of any linear-motion system. The bottom face is the mounting datum and partners with the machine base—so its flatness, parallelism, and surface quality directly govern assembly accuracy and stability: • Long-length precision is hard to hold: 4100 mm rails challenge flatness across the full length, with thermal and bending distortion looming. • Batch consistency vs. throughput: mass production needs uniform sizing AND high grinding efficiency—standard machines struggle to balance. • Clamping stability on large parts: long, slender rails are sensitive to clamping deformation; magnetic chucks must apply uniform force without distortion. • Cumulative error across rough → finish → spark-out: each transition must be precisely controlled, demanding strong program control and auto-compensation.

Solution

The XPMK7240 duplex grinder integrates herringbone-grinding and surface-grinding modules on a shared table—a turnkey solution for finished-rail precision machining. A vertical-spindle reciprocating-table layout. The wheel spindle is vertical (rotating around a vertical axis) and grinds with its end face; the table traverses longitudinally; the workpiece is held on the magnetic chuck; the wheel feeds vertically downward. This arrangement suits large surfaces and long workpieces—the grinding force stays vertical, keeping things stable.

Scenarios

• End-face surface grinding on workpieces up to 4100 mm long, table speed stepless 3–35 m/min
• Fully automatic rough → semi-finish → finish → spark-out; 25 kW surface spindle for ample grinding power
• Herringbone module shares the table with the surface module; switch between modes on the fly

Advantages

• ✓ Long-rail coverage: 4100 × 500 mm table with 6000 mm travel covers 4m rails in one clamping—no segmented cuts or stitch marks
• ✓ Rigid, durable: high-strength low-stress cast-iron bed, hand-scraped contact surfaces, NTN/NSK bearings + PMI guides and screws
• ✓ Smart cycles: Siemens 828D controls fully automatic rough → semi-finish → finish → spark-out with auto-dressing and compensation
• ✓ Easy clamping, low distortion: branded electro-permanent magnetic chuck with uniform, ample holding force
• ✓ Coolant control: 300 L/min primary + 60 L/min secondary coolant control thermal distortion on long parts
• ✓ One machine, two functions: herringbone + surface on a shared table—the space of one machine, the capability of two