Unveiling the MysteryYRKK motors: Efficient solutions for heavy-duty industrial drives

In the field of large-scale industrial transmission, facing ball mills, crushers or large fans which are “difficult to gnaw”, ordinary electric motors often appear to be unable to cope. Starting current is too large to cause grid fluctuations, insufficient torque to cause equipment “lying down”, is the pain point faced by many factories. At this time.YRKK motorsAs a high-voltage wire-wound rotorthree-phase asynchronous motorWith its excellent starting performance and operational stability, it has become the “lynchpin” in heavy-duty industrial scenarios.

What are YRKK motors and their core advantages?

YRKK motorsThe name itself implies the technical characteristics: “Y” stands for asynchronous motor, “R” stands for Wound Rotor, the first “K” stands for closed structure, and the second “K” stands for Air-Air Cooler. The first "K" stands for closed structure and the second "K" stands for Air-Air Cooler. Unlike ordinary squirrel cage motors, the biggest technical highlight of the YRKK series is itsWire-wound rotor design。

This design allows the user to string an external resistor or frequency sensitive varistor in the rotor circuit. By doing so, theYRKK motorsrealizableLow starting current与High starting torqueThis is crucial for equipment with high inertia and heavy loads. This is crucial for equipment with high inertia and heavy loads, as it not only protects the motor coils from overheating, but also avoids the shock to the plant power supply at the moment of start-up.

Key Features Analysis

1. Excellent heavy-duty startup capability: In cement plants, mines and the steel industry, equipment often needs to be started up under full load.YRKK motorsThe starting torque can be increased to 1.5 times the rated torque or even higher by adjusting the rotor resistance, ensuring smooth operation of the equipment.
2. Efficient cooling system: AdoptionCooling Method for IC611(Totally enclosed, external fan cooling, with its own air-to-air cooler), which makes the motor maintain good heat dissipation even in dusty and harsh working conditions, greatly extending the insulation life.



3. Energy saving and maintenance: AlthoughWire-wound motorsAdded slip ring and carbon brush construction, but modernYRKK motorsIt adopts advanced insulation materials and collector ring chamber design, which greatly reduces the maintenance frequency. Meanwhile, its high-efficiency design is in line with the national energy-saving and emission reduction macro policy orientation.

Industry Case Study: Ball Mill Retrofit in a Cement Plant

To gain a more intuitive understandingYRKK motorsWe can refer to the transformation case of a large cement plant for its actual effectiveness. The plant originally used an old squirrel cage motor to drive Ф3.2 × 13m cement mill, often due to voltage fluctuations leading to start-up failure, and even burned the switchgear.

For the technical upgrade, the engineers chose a 6kV ratedYRKK SeriesHigh voltage motorsReplacement of the original equipment with a phase feeder. The effect of the modification was immediate:

• Smooth start: The starting current is reduced from 7 times the original rated current to about 3 times, and the voltage drop of the grid is controlled within 5%.
• Power Factor ImprovementThe power factor is increased from 0.82 to more than 0.95, which not only reduces the reactive power loss, but also saves hundreds of thousands of dollars of electricity expenses every year.
• Operates stably: Even in the harsh environment of high summer temperatures and dense dust.Self-contained air-to-air coolerIt still ensures that the temperature rise of the motor is within the controllable range, eliminating the frequent tripping accidents in the past.

Model Selection Recommendations

When selectingYRKK motorsWhen selecting a motor, companies should not only pay attention to the power and voltage level, but should also check the load's moment of inertia (GD²). For special conditions that require frequent speed regulation or very high start-up requirements, rational selection can maximize the performance of the motor. In addition, regular inspectionsSlip Rings and Carbon BrushesThe contact situation is the secret to keep this type of motor running efficiently for a long time.