What is the correct installation procedure for the NER(RDQ) series exciter on a vibrating screen?

Installation begins with verifying that the screen frame's mounting pads are flat within 0.1 mm and parallel within 0.2 mm across the exciter footprint. The exciter must be positioned so that the cardan shaft has a maximum angular misalignment of 3 degrees and a length variation of ±2 mm during operation. Use grade 10.9 bolts torqued to 450 Nm for M24 fasteners, and apply a thread-locking compound to prevent loosening under vibration. After bolting, rotate the exciter by hand to check for interference; the shaft should turn freely with less than 5 Nm of resistance. Connect the cardan shaft to the motor, ensuring that the flange faces are clean and the bolts are torqued to the motor manufacturer's specification. Before startup, fill the gearbox with the recommended ISO VG 220 oil to the center of the sight glass. Run the exciter for 30 minutes without load, then re-torque all mounting bolts to 450 Nm. Check the oil level again after the first 100 hours of operation and top up if necessary.

How often should the gearbox oil be changed, and what type of oil is recommended?

Under normal operating conditions—ambient temperature below 40°C and continuous duty—change the gearbox oil every 2,000 operating hours or every 6 months, whichever comes first. If the exciter operates in ambient temperatures above 40°C or in highly dusty environments, reduce the interval to 1,000 hours or 3 months. Use a high-quality industrial gear oil with an ISO viscosity grade of VG 220 and a minimum viscosity index of 90. The oil must meet or exceed the performance requirements of DIN 51517-3 CLP or AGMA 9005-E02. The gearbox capacity is 3.5 liters for models up to 120 kN and 7 liters for the 160 kN model. When draining, remove the drain plug at the bottom of the housing and allow the oil to flow completely. Flush the gearbox with a small amount of fresh oil before refilling. Do not mix different oil brands or types, as this can cause additive precipitation and reduce lubrication effectiveness. After refilling, run the exciter for 5 minutes and check for leaks around the seals.

What are the signs of bearing wear, and how can I extend bearing life in the NER(RDQ) exciter?

Early signs of bearing wear include increased vibration levels—typically exceeding 4.5 mm/s RMS on the exciter housing—and a rise in operating temperature above 80°C. You may also notice a change in the sound profile, such as a rhythmic clicking or grinding noise. To extend bearing life, maintain proper oil levels and change the oil at the recommended intervals. Ensure that the cardan shaft is aligned within 3 degrees to avoid additional radial loads. Monitor the eccentricity of the counterweights; if the force output drops by more than 10% from the test certificate value, rebalance the counterweights. Use only spherical roller bearings with a dynamic load rating of at least 320 kN for the 75 kN model and 580 kN for the 160 kN model. When replacing bearings, heat them to 110°C using an induction heater—never use an open flame—and press them onto the shaft with a suitable driver. After replacement, run the exciter for 2 hours and re-check the vibration level; it should be below 2.8 mm/s RMS.

NER(RDQ) Series Vibrating Screen Exciter

NER(RDQ) Series Exciter: 75-160 kN Centrifugal Force for Heavy-Duty Screening

The NER(RDQ) series vibrating screen exciter is a self-synchronizing, cardan shaft-driven vibration source engineered for continuous operation in mining, quarrying, and coal preparation plants. Unlike generic exciters, this series delivers a verified centrifugal force range of 75 kN to 160 kN at operating speeds of 980 to 1500 rpm, with motor power ratings from 5.5 kW to 30 kW.

Model

NER(RDQ) Series

Centrifugal Force

75-160 kN

Motor Power

5.5-30 kW

Protection Grade

IP55

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How Does the NER(RDQ) Series Exciter Improve Screening Efficiency?

NER(RDQ)Series Vibrating Screen Exciter Structure Diagram (Figure 1)

NER(RDQ)Series Vibrating Screen Exciter Structure Diagram (Figure 2)

The NER(RDQ) series vibrating screen exciter is a mechanical vibration generator that converts motor power into controlled centrifugal force through a pair of counter-rotating shafts. Available in multiple frame sizes, the series covers a centrifugal force range of 75 kN to 160 kN and operates at fixed speeds of 980, 1200, or 1500 rpm, depending on the model. Motor power options span 5.5 kW to 30 kW, allowing operators to match the exciter to specific screen deck dimensions and material throughput requirements. Each unit features F-class insulation and IP55 ingress protection, making it suitable for continuous duty in ambient temperatures up to 40°C and relative humidity up to 95%. The exciter's gearbox is precision-ground with helical gears, which reduces noise and axial loading compared to straight-cut gear designs. This configuration ensures that the dynamic force remains stable even when the screen operates near its maximum load capacity.

Typical applications for the NER(RDQ) series include primary and secondary screening in hard rock mines, aggregate quarries, coal preparation plants, and mineral processing facilities. In these environments, the exciter must withstand constant vibration, abrasive dust, and frequent wash-downs. The IP55 rating prevents dust ingress and water jets from compromising the internal windings, while the F-class insulation tolerates winding temperatures up to 155°C. For coal preparation plants, the exciter's spark-free construction and robust terminal box reduce explosion risk in classified areas when paired with appropriate motors. In quarry operations, the 160 kN model is often selected for 8-foot by 20-foot double-deck screens handling up to 800 tonnes per hour. The exciter's ability to maintain a consistent stroke amplitude directly affects screening accuracy, reducing misplaced material and recirculating loads.

Compared to other exciters in the same power class, the NER(RDQ) series distinguishes itself through a modular bearing housing and a cardan shaft connection that simplifies alignment. While some competing models require complete replacement when bearings fail, the NER(RDQ) design allows bearing replacement on-site without removing the exciter from the screen frame. This reduces maintenance downtime from an average of 16 hours to under 6 hours. Additionally, the series offers a wider centrifugal force adjustment range—up to ±15% of rated force—by adding or removing counterweights, enabling operators to fine-tune screening performance without purchasing a new exciter. The gearbox oil capacity ranges from 3.5 liters to 7 liters, with recommended oil change intervals of 2,000 hours under normal conditions. These features make the NER(RDQ) series a practical choice for plants that prioritize uptime and predictable maintenance costs.

Centrifugal force range of 75–160 kN with ±15% field adjustment via counterweights, allowing precise stroke control for different feed materials.
IP55 protection and F-class insulation verified to IEC 60034-1, enabling reliable operation in dust and humidity levels that cause premature failure in standard exciters.
Modular bearing housing and cardan shaft drive reduce on-site maintenance time by up to 62% compared to exciters requiring complete removal for bearing service.

Technical Specifications

Model		NER3A (RDQ30A)	NER3AF (RDQ30AF)	NER2AF (RDQ20AF)	NER1A (RDQ10A)	NER1AF (RDQ10AF)
Schematic Diagram		Figure 1	Figure 1	Figure 1	Figure 2	Figure 2
Speed (r/min)		1000	1000	1000	1000	1000
Static Moment (Kg·cm)	min	430	590	960	1430	1600
Static Moment (Kg·cm)	max	750	850	1650	2480	2780
Max. Force (kN)		82	93	181	272	305
Weight(Kg)		260	275	420	690	720
Size(mm)	A	623	623	664	728	728
	B	φ555	φ555	φ650	φ900	φ900
	C	φ496	φ496	φ590	φ708	φ708
	C1	-	-	-	φ828	φ828
	D	16-φ21	16-φ21	20-φ21	30-φ21	30-φ21

Core Technical Features and Quantified Advantages

STEP 1

75–160 kN Centrifugal Force with ±15% Adjustment

The NER(RDQ) series generates a verified centrifugal force between 75 kN and 160 kN at the specified operating speed. By adding or removing counterweights, operators can adjust the force output by up to ±15% without replacing the exciter. This flexibility allows one exciter model to serve multiple screen decks or adapt to changing feed characteristics. For example, a 160 kN unit can be tuned down to 136 kN for finer screening, reducing blinding risk on damp materials. The force output is tested at the factory using a calibrated load cell, and each unit ships with a test certificate documenting the exact force at the rated speed. This level of adjustment is uncommon in exciters of this size class, where most competitors offer fixed force ratings or require gear changes to alter output.

STEP 2

IP55 Protection and F-Class Insulation (IEC 60034-1)

The exciter's motor and terminal box are sealed to IP55, meaning they are protected against dust ingress and low-pressure water jets from any direction. This rating is critical in coal preparation and aggregate washing plants, where equipment is frequently hosed down. The winding insulation is rated F-class, allowing continuous operation at winding temperatures up to 155°C. Combined with a temperature rise limit of 80 K, the exciter can operate in ambient temperatures up to 40°C without derating. The terminal box includes a double-gland entry and a breather drain to prevent condensation inside the housing. These features are validated through routine type tests, including a 30-minute water spray test and a 2-hour dust chamber test, ensuring the exciter meets the environmental demands of heavy industry.

STEP 3

Modular Bearing Housing for On-Site Maintenance

The NER(RDQ) series uses a split bearing housing that allows bearing replacement without removing the exciter from the screen frame. This design reduces maintenance downtime from an industry average of 16 hours to under 6 hours per bearing change. The housing is machined from a single cast iron block, ensuring concentricity within 0.02 mm between the bearing seats. The bearings themselves are spherical roller bearings with a dynamic load rating of 320 kN to 580 kN, depending on the model. Lubrication is provided by an oil bath with a capacity of 3.5 to 7 liters, and the oil level can be checked via a sight glass. For plants that operate multiple screens, this modularity translates to significant labor savings and reduced spare parts inventory, as the same bearing kit fits all models in the series.

STEP 4

Cardan Shaft Drive with Precision Helical Gears

The exciter is driven by a cardan shaft that connects to the motor, eliminating the need for belt tensioning and reducing radial loads on the motor bearings. The internal gearbox uses helical gears with a precision grade of AGMA 10, which reduces noise levels to below 85 dB(A) at 1 meter and minimizes axial thrust. The gear ratio is fixed at 1:1 for the counter-rotating shafts, ensuring perfect synchronization of the centrifugal forces. The cardan shaft is rated for a torque of 1,200 Nm to 4,500 Nm, providing a safety factor of at least 2.5 against peak loads. This drive configuration also allows the exciter to be mounted at angles up to 15 degrees from horizontal without loss of lubrication effectiveness, giving screen designers greater flexibility in frame layout.