Double helical gears, also known as herring bone gears, are a type of gear with two setsof helical teeth that are cut in opposite directions. This design eliminates the axial thrustthat is generated by helical gears with a single set of teeth, making them ideal for high-speed, high-torque applications where precise and reliable power transmission is critical.

How Do Double Helical Gears Work?

Double helical gears work by transmitting rotational power from one shaft to anotherthrough a series of interlocking teeth. Unlike helical gears with a single set of teeth, double helical gears have two sets of helical teeth that are cut in opposite directions. Thiscreates a V-shaped groove between the teeth that eliminates the axial thrust that is generated by single helical gears.

Advantages of Double Helical Gears

1. Reduced Noise and Vibration: Double helical gears are designed to cancel out theaxial thrust generated by single helical gears, resulting in smoother and quieteroperation.
2. Increased Load Capacity: The double helical design provides a larger surface areafor the teeth to mesh together, resulting in increased load-carrying capacity andhigher torque transmission capabilities.
3. Improved Precision: The double helical design allows for more precise gearplacement and alignment, resulting in more accurate and consistent operation.
4. Greater Efficiency: Double helical gears have a higher efficiency than other typesof gears due to their diagonal contact pattern, which minimizes friction andpower loss.

Applications of Double Helical Gears

Double helical gears are used in a variety of high-speed, high-torque applications, including:

1. Turbines: Double helical gears are used in steam and gas turbines to transmit power from the turbine to the generator.
2. Compressors: Double helical gears are used in gas and air compressors to transfer power from the motor to the compressor.
3. Extruders: Double helical gears are used in plastic and rubber extruders to drivethe screw that pushes the material through the extrusion die.
4. Marine Propulsion: Double helical gears are used in marine propulsion systems totransmit power from the engine to the propeller.

Conclusion

Double helical gears are a critical component of many high-speed, high-torquemechanical power transmission systems. Their unique design provides severaladvantages over other types of gears, including reduced noise and vibration, increasedload capacity, improved precision, and greater efficiency. With their broad range of applications and benefits, double helical gears are an essential component of manymechanical systems that require precise and reliable power transmission.