Synchronized Screw Jack Platform — Four Jacks, One Motor

The Problem

A process-equipment OEM in western India needed a rectangular platform that rises and lowers evenly under a distributed process load. Early concepts used four independent motor-jack pairs with electronic speed matching. That approach added four motor starters, four VFDs (or equivalent), encoder wiring, and a control strategy that still risked corner tilt if one drive lagged under uneven friction or load share.

The platform geometry was fixed by the customer’s machine envelope: four lift points at the corners, modest stroke, and a requirement to hold position without continuous power. Dynamic loads per corner stayed well inside a 50 kN jack class once safety factors were applied — within Anand Gears’ catalogue range of 5 kN to 350 kN.

What the OEM really needed was kinematic lock-step: every millimetre of screw travel at one corner had to appear at the other three without relying on software feedback during the move.

The Solution

We engineered a classic mechanical multi-jack system: four worm gear screw jacks (translating screw, trapezoidal thread for self-locking hold), linked by line shafts and couplings through miter bevel gearboxes so one motor turns all four worm inputs at the same angular rate.

The H-layout put the motor on a central primary shaft. Miter bevel units at the junctions redirected torque 90° to the secondary shafts feeding each jack. Couplings absorbed small alignment tolerances between pedestal mounts. Limit switches protected upper and lower stroke ends. Protective bellows covered the exposed screw sections against shop dust.

Jack selection used the AG-SJ-50 capacity class (50 kN static catalogue rating per jack) so that even with uneven load share on two corners, individual jacks remained inside the published range. Worm ratios were chosen from the standard set (including 1/8 and 1/16 class options) to match the required platform speed under intermittent duty — worm screw jacks are sized for positioning duty, not continuous high-speed cycling.

Why mechanical sync over four independent drives:

• One torque path — the rigid shaft train forces equal rotation; friction differences redistribute torque instead of creating height error.
• Simpler controls — start/stop and end-of-travel; no multi-axis sync program required for level lift.
• Self-locking hold — trapezoidal screws with appropriate worm ratios hold load without a brake when power is off (subject to correct sizing).
• Single motor service point — maintenance sees one drive end, not four coordinated axes.

Product context for the train: screw jack lifting systems, individual machine screw jacks, and bevel gearboxes for the 90° miter nodes.

The Result

Representative system layout for a process-equipment OEM platform — the same building blocks scale across the 5–350 kN catalogue range.

Photos from the Job