The chain drive motor features fluid couplings for reduced motor loads at start-up.

Thrust rollers restrain the drum before and after.

Trunnions are super heavy and easy to adjust.

Tires are attached by butterfly spokes which isolate them from drum expansion.

You Won’t Find A Better Drive System

Saddle chain drives have proven to be the most reliable method of driving a drum. The saddle chain drive is outfitted with heavy-duty roller chain, including offset sidebars and case-hardened bushings. Astec heavy-duty drive components are made to last.

Trunnions And Thrust Rollers

Four trunnions and two thrust rollers keep the drum aligned and in position. Astec trunnions are made of solid-steel hardened to 421-512 Brinell. They feature extra-large, double-spherical roller bearings of the same type used for railcars. The trunnion bearings are guaranteed unconditionally for a life of one million tons of mix. Thrust rollers are scrub-resistant for reduced roller wear.

Take Trouble Out Of Trunnion Alignment

Each trunnion base is angled to the frame so that a dowel pin in the base is in line with the exact center of the drum. The trunnion base pivots around the pin, making it easy to keep the trunnion aligned with the drum while making thrust adjustments. Good trunnion alignment means better performance and longer equipment service life.

Drum Tires Last Long And Run Smoothly

Two extra-large, solid-steel tires encompass the inner drum and support the Double Barrel dryer/drum mixer. They attach to the drum by means of butterfly spokes that isolate them from drum expansion. This attachment method has proved reliable in millions of tons of operation. The drum can expand without distorting and without stressing the tire and its attachments. Hot-forged from solid billets of 1030 carbon steel, the tires provide a yield strength of 90,000 psi with a Brinell hardness of 220-260. Precision-machining to a tolerance of 30 thousandths of an inch and with a 250 root mean square (RMS) finish gives you ultra-smooth operation.