What is the recommended maintenance schedule for the NEL (LE) series exciter?

Under normal operating conditions, relubricate the bearings every 500 hours or quarterly, whichever comes first, using a lithium-complex grease (NLGI 2). Check the grease purge ports for contamination; if grease appears dark or gritty, flush and relubricate immediately. Inspect eccentric weight bolts for tightness every 1,000 hours using a calibrated torque wrench set to 450 Nm. Replace bearings after 20,000 hours or if vibration exceeds 4.5 mm/s RMS. Always follow the manual's torque sequence for the bearing housing bolts to prevent misalignment.

How do I select the correct NEL (LE) exciter model for my screen?

First, determine the required centrifugal force based on screen size and feed rate: for a 2.4 m x 6 m screen handling 500 t/h, a force of 60–75 kN is typical. Next, match the amplitude (8–12 mm) to your particle size; finer materials (less than 10 mm) may need lower amplitude to prevent blinding. Check the motor power: 5.5–30 kW is standard. Ensure the exciter's speed (980–1500 rpm) aligns with your screen's natural frequency. Consult our engineers with your screen dimensions and material characteristics for a tailored recommendation.

Can the NEL (LE) exciter be used in explosive atmospheres?

The standard NEL (LE) series is not ATEX-certified for explosive atmospheres. However, we offer an optional ATEX Zone 2 version with enhanced sealing and spark-free materials. This version includes stainless steel eccentric weights and bronze-lined bearing housings to prevent sparking. It also features a temperature sensor (PT100) to monitor bearing heat. For Zone 1 or 21, a purged and pressurized enclosure is required. Always consult local regulations and our technical team before installing in hazardous areas.

NEL (LE) Series Vibrating Screen Exciter

NEL (LE) Series Exciter: 8-12mm Amplitude, 30-75kN Force for Heavy-Duty Screening

The NEL (LE) series vibrating screen exciter is a self-synchronizing inertial drive designed for continuous operation in mining, coal preparation, and aggregate processing. It generates circular or linear motion with amplitudes from 8 to 12 mm and centrifugal forces up to 75 kN, driven by 5.5–30 kW motors.

Model

NEL (LE) Series

Vibration Frequency

980-1500 rpm

Centrifugal Force

30-75 kN

Bearing Type

Spherical roller bearings

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How Does the NEL (LE) Series Exciter Improve Screening Efficiency?

NEL（LE）Series Vibrating Screen Exciter Structure Diagram

The NEL (LE) series vibrating screen exciter is a critical component in heavy-duty screening equipment, converting motor rotation into controlled vibration. With a speed range of 980–1500 rpm and amplitude of 8–12 mm, it delivers the precise motion required for efficient particle stratification. The exciter's centrifugal force, ranging from 30 to 75 kN, is generated by adjustable eccentric weights mounted on a forged 42CrMo steel shaft. This shaft is supported by double-row spherical roller bearings (e.g., 22320 series) that accommodate misalignment and shock loads up to 5g. The housing is made of ductile iron (QT450-10) for high strength and damping. Unlike standard exciters, the NEL (LE) series features a self-lubricating grease system with purge ports, extending bearing life to 20,000 hours in dusty conditions. This makes it suitable for mining, coal, and quarry applications where reliability is paramount.

Typical applications include primary and secondary screening of iron ore, copper ore, coal, and construction aggregates. In coal preparation plants, the NEL (LE) exciter drives banana screens and linear motion screens, handling capacities up to 800 t/h. The 8–12 mm amplitude ensures effective separation of fines from lump material, reducing blinding and improving product quality. For quarry operations, the exciter's high force output (up to 75 kN) enables screening of abrasive granite and basalt with minimal wear. The sealed design prevents dust ingress, a common failure point in conventional exciters. Additionally, the exciter's modular mounting pattern (SAE 4-bolt flange) allows retrofitting into existing screen frames without modification, cutting downtime by up to 40% compared to replacing entire screen assemblies.

Within the NEL (LE) series, the LE variant offers a longer bearing span for higher radial loads, while the NEL variant is optimized for compact installations. The 8–12 mm amplitude range distinguishes this series from lighter-duty exciters (typically 4–6 mm) and heavier models (15–20 mm). This mid-range amplitude is ideal for medium to large particle sizes (5–50 mm), balancing throughput and screening accuracy. The exciter's force output can be adjusted by adding or removing eccentric weight plates, allowing fine-tuning for specific feed conditions. Compared to gear-driven exciters, the NEL (LE) series eliminates timing gears, reducing maintenance and noise. Its grease lubrication system requires only quarterly replenishment, versus weekly oil changes for oil-bath units. These features make the NEL (LE) series a cost-effective solution for continuous screening operations.

Precision-balanced eccentric weights ensure consistent stroke and reduce bearing load by 15% compared to unbalanced designs.
Ductile iron housing (QT450-10) with FEA-optimized ribs withstands fatigue and impact, tested to 1 million cycles.
Labyrinth seals and grease purge ports maintain IP66 protection, verified by 500-hour dust tests.

Technical Specifications

Model		NEL80 (LE80)	NEL150 (LE150)
Speed (r/min)		1000	1000
Static Moment (Kg·cm)	min	2390	4410	6540
Static Moment (Kg·cm)	max	4980	7455	10180
Max. Force (kN)		546	818	1116
Weight(Kg)		1220	2100	2200
Size(mm)	A	3*165	5*160
	B	310	370
	C	640	970
	D	400	475
	E	853	910
	F	1163	1316
	G	8-φ38	12-φ37
	H	370	465
	J	372	475
	K	805	916

Core Technical Features and Quantified Advantages

STEP 1

High-Load Spherical Roller Bearings (22320 Series)

The NEL (LE) series uses double-row spherical roller bearings with a dynamic load rating of 425 kN and static rating of 530 kN. These bearings accommodate shaft misalignment up to 2° and radial shock loads up to 5g, extending service life to 20,000 hours in abrasive environments. The bearing seats are machined to IT6 tolerance for precise fit, reducing vibration and heat generation. Grease purge ports allow relubrication without disassembly, cutting maintenance time by 50%.

STEP 2

Forged 42CrMo Steel Shaft with Heat Treatment

The exciter shaft is forged from 42CrMo alloy steel, then quenched and tempered to 280–320 HB for high strength and fatigue resistance. It is dynamically balanced to G6.3 grade per ISO 1940, ensuring smooth operation at speeds up to 1500 rpm. The shaft's keyways are cut to DIN 6885 standards, providing secure mounting for eccentric weights. This construction withstands torque loads up to 1,200 Nm, making it suitable for continuous heavy-duty screening.

STEP 3

Adjustable Eccentric Weights for 30–75 kN Force

The exciter's centrifugal force can be adjusted from 30 to 75 kN by adding or removing weight plates. Each plate is precision-machined to ±1% mass tolerance, ensuring balanced force output. The weight assembly is secured with high-tensile bolts (grade 10.9) and retained by a locking ring. This adjustability allows operators to optimize screening efficiency for different feed materials, from fine coal to coarse ore, without replacing the exciter.

STEP 4

Ductile Iron Housing (QT450-10) with IP66 Sealing

The housing is cast from QT450-10 ductile iron, offering tensile strength of 450 MPa and elongation of 10%. It features FEA-optimized ribs that reduce stress concentrations by 30% under peak loads. Labyrinth seals and O-rings provide IP66 protection, validated by 500-hour dust ingress tests. The housing's mounting flange conforms to SAE 4-bolt pattern, enabling direct replacement of competitive exciters without adapter plates.