Wobbler Feeders

The CONSTMACH Wobbler Feeder is a feeding and scalping unit installed ahead of the primary crusher in a crushing and screening line. Its distinguishing feature is a set of rotating elliptical bars arranged across the feed path. As the bars turn, their elliptical (off-round) profile produces a characteristic wobbling motion that advances the material forward while continuously agitating it. The feeder performs two functions at once: it meters bulk material into the primary crusher at a controlled, even rate, and it scalps the fine fraction out of the feed before it reaches the crusher.

The scalping action comes directly from the geometry of the bars. The elliptical bars are spaced with gaps between them, and as they rotate the openings let undersize material drop through while larger pieces are carried forward to the crusher. Because the bars are constantly moving, material does not have a static surface on which to build up, and the wobbling motion prevents bridging and packing. This is why the wobbler feeder is particularly suited to sticky, wet and clayey feeds: moisture-laden material that would blind a fixed grizzly or clog a conventional apron feeder is kept moving and is separated from its fines without the gaps plugging. Removing this fine, often damp material ahead of the crusher protects the crushing chamber from packing and reduces the load passing through the primary stage.

In the line, the wobbler feeder sits at the primary crushing stage, taking material from a hopper or directly from haul trucks and delivering it to the primary crusher. CONSTMACH notes that it is deployed where consistent material flow is critical, providing pre-screening and scalping that reduce the load on downstream crushers and screens. The fines it removes can be routed around the crusher to a separate product or stockpile, so that only the material that genuinely needs crushing is sent to the chamber. This both improves the efficiency of the primary crusher and helps stabilise the throughput of the whole plant.

The CONSTMACH wobbler feeder is built for the harsh conditions of this duty. The body liners are HARDOX 450 wear plate at 10 mm thickness, and the feeder has walking platforms and steel legs for access and support. It has a feeding capacity of 150-200 t/h and an operating weight of 18.5 tonnes, with overall dimensions of 4,000 x 1,000 mm. The elliptical bars are driven through a heavy-duty gearbox by a wobbler motor arrangement rated at 14 x 3 kW running at 1,500 rpm, using GAMAK brand motors. CONSTMACH notes that the mechanical simplicity of the design results in lower operating and maintenance costs while it handles demanding environments.

Functionally, the wobbler feeder integrates with the primary stage as a combined feeder and scalper, occupying the position a grizzly feeder would otherwise hold. The difference is in how it handles difficult material: where a static grizzly relies on vibration and an open deck, the rotating elliptical bars of the wobbler keep wet and clayey feed flowing and separate the fines through the moving gaps. For operations whose feed is consistently sticky, wet or high in clay, this makes the wobbler feeder a way to maintain steady, controlled feed to the primary crusher and to remove fines reliably, supporting continuous operation of the crushing and screening plant.