1. Product Overview

ZOOMRY CEMA D unequal impact troughing idlers are heavy-duty loading zone components with offset roller design and reinforced impact absorption. Built to CEMA D standards for mining crusher discharge and transfer points, these impact idlers combine L1 longer center and L2 shorter wing rollers with rubber cushion rings — absorbing up to 80% of falling material energy at loading zones.

Compared to CEMA E unequal impact idlers for extra heavy-duty 96-inch belts, the CEMA D version covers the heavy-duty 24–72 inch range — the most common belt width class for aggregate crushing circuits, coal transfer points, and cement plant conveyor loading zones.

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2. Why Impact Idlers for Heavy-Duty Loading Zones?

Loading zones are the most vulnerable points on any heavy-duty conveyor. Falling material — whether run-of-mine ore from a crusher or aggregate from a truck dump hopper — strikes the Conveyor Belt with concentrated force. Standard troughing idlers cannot absorb this impact, leading to belt cover damage, carcass fatigue, and premature bearing failure.

CEMA D unequal impact troughing idlers address this with rubber cushion rings on all three rollers. These rings dissipate up to 80% of falling material energy, distributing impact forces across the idler frame rather than concentrating them on belt contact points. The unequal roller design further enhances protection — the longer center roller (L1) provides extended support surface directly under the material drop zone, reducing belt puncture incidents by over 60% compared to standard troughing idlers at transfer points.

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3. Key Features

CEMA D Heavy-Duty Impact Rating — Engineered specifically for loading zones with 5" and 6" diameter impact rollers, rubber cushion rings, and reinforced frames for belt widths up to 72 inches.

Unequal Offset Design — Longer center roller (L1) + shorter wing rollers (L2) provide enhanced support directly under the impact zone where material drops, improving belt tracking on the carrying side.

Rubber Cushion Rings — Impact-absorbing rubber rings on all three rollers dissipate up to 80% of impact energy, reducing belt stress in aggregate quarry and mining crusher discharge applications.

Advanced Labyrinth Sealing — Multi-stage seals protect bearings from fine dust generated at transfer points, maintaining rotational resistance ≤2N.

Dual Trough Angles — Available in 20° and 35° angles to match material characteristics and loading zone conveyor design.

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4. Application Scenarios

Primary Crusher Discharge — Run-of-mine ore dropping onto takeaway conveyors in mining operations. CEMA D impact idlers with unequal roller design provide maximum belt protection at the most critical loading point.

Aggregate Transfer Points — Conveyor-to-conveyor transfer chutes in aggregate quarry crushing circuits where material free-falls onto receiving belts.

Cement Plant Loading — Limestone and clinker transfer points in cement plants where abrasive materials require impact-rated idlers for continuous 24/7 operation.

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5. Dimensions – CEMA D Unequal Impact Troughing 20° / 35°

ZOOMRY CEMA D unequal impact troughing idlers are manufactured to CEMA D industry-standard dimensions with L1 (long center roller) and L2 (short wing rollers) offset configuration. Available in 5-inch and 6-inch roller diameters for belt widths from 24 to 72 inches:

				5" Roller					6" Roller
Angle	BW	A	B	L1	L2	H1	H2	W	H1	H2	W	E	F	K
20°	24	33	35	15 7/16	5 7/16	7	9 1/16	26 15/16	7 1/2	9 7/16	26 9/16	6	8	1/2
	30	39	41	21 3/8	5 7/16	7	9 1/16	32 7/8	7 1/2	9 7/16	32 1/2	6	8	1/2
	36	45	47	27 3/8	5 7/16	7	9 1/16	38 7/8	7 1/2	9 7/16	38 1/2	6	8	1/2
	42	51	53	33 3/8	5 7/16	7 1/2	9 9/16	44 7/8	8	9 15/16	44 1/2	7 1/2	9 1/2	5/8
	48	57	59	39 3/8	5 7/16	7 1/2	9 9/16	50 7/8	8	9 15/16	50 1/2	7 1/2	9 1/2	5/8
	54	63	65	45 3/8	5 7/16	9	11	56 7/8	9 1/2	11 7/16	56 9/16	9	11	5/8
	60	69	71 1/2	51 3/8	5 7/16	9	11	62 7/8	9 1/2	11 7/16	62 9/16	9	11	5/8
	72	81	83 1/2	63 3/8	5 7/16	9 1/2	11 3/8	74 7/8	10	11 13/16	74 9/16	9	11	5/8
35°	24	33	35	13 1/4	6 3/4	7	11	25 7/16	7 1/2	11 3/8	24 7/8	6	8	1/2
	30	39	41	15 7/16	8 15/16	7	12 1/4	31 1/4	7 1/2	12 5/8	30 11/16	6	8	1/2
	36	45	47	21 3/8	8 15/16	7	12 1/4	37 1/8	7 1/2	12 5/8	36 9/16	6	8	1/2
	42	51	53	21 3/8	11 1/8	7 1/2	14	40 3/16	8	14 3/8	40 3/4	7 1/2	9 1/2	5/8
	48	57	59	27 3/8	11 1/8	7 1/2	14	46 3/4	8	14 3/8	46	7 1/2	9 1/2	5/8
	54	63	65	33 3/8	11 1/8	9	15 9/16	52 5/8	9 1/2	15 7/8	52 1/16	9	11	5/8
	60	69	71 1/2	39 3/8	11 1/8	9	15 9/16	58 5/8	9 1/2	15 7/8	58 1/16	9	11	5/8
	72	81	83 1/2	51 3/8	11 1/8	9 1/2	15 7/8	70 5/8	10	16 5/16	70 1/16	9	11	5/8

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