Helical Gear is a cylindrical gear with teeth cut at an angle to its axis of rotation, forming a helix pattern. This design distinguishes it from spur gears, which have straight teeth parallel to the axis.

Types Of Helical Gears

§  Single Helical

§  Double Helical

§  Herringbone

Key Features

§  Gradual Tooth Engagement:
Unlike spur gears that engage across the full width of the tooth simultaneously, helical teeth engage progressively from one end to the other.

§  Smooth and Quiet Operation:
The gradual engagement significantly reduces impact forces, resulting in lower noise, vibration, and harshness (NVH) levels.

§  High Contact Ratio:
Because the teeth are angled, multiple pairs are in mesh at the same time. This distributes the load more evenly across a larger surface area.

§  Enhanced Load Capacity:
Due to the higher contact ratio and longer tooth length, helical gears can handle 30%–50% more load than spur gears of the same size.

§  Axial Thrust Generation:
A primary by product of the helix angle is the creation of axial force (thrust) along the shaft. This requires the use of specialized thrust bearings or a double helical (herringbone) design to counteract the force.

§  High Efficiency:
Modern helical gear systems typically operate at 94% to 99.5% efficiency, depending on lubrication and alignment. 

Advantages

§  Smooth and Quiet Operation:
Unlike spur gears that engage abruptly, helical teeth mesh gradually, starting at a point and spreading across the face. This eliminates shock loading and reduces vibration, resulting in typical noise levels between 65–78 dB, even at speeds above 3000 RPM.

§  Higher Load Capacity:
The angled teeth create a larger surface area of contact, allowing the load to be distributed across multiple teeth simultaneously. This gives them approximately 50% more load-carrying capacity than spur gears of the same size.

§  High Efficiency:
Modern helical gearboxes typically achieve 94% to 98% efficiency. While slightly less than the pure rolling contact of spur gears, they are significantly more efficient than worm gearboxes, which can drop as low as 50%.

§  Enhanced Durability:
Because load is shared among more teeth, the stress on each individual tooth is reduced. This leads to lower wear and tear and a longer operational lifespan in continuous-duty industrial applications.

§  Versatile Orientation:
Helical gears can transmit power between both parallel shafts (the most common use) and non-parallel (crossed) shafts, offering greater flexibility in tight machine designs

Configurations

§  Available with high torque and various gear ratios.

§  Single stage to four stages in helical configuration.

§  Two stages to four stages in bevel helical design.

§  Options for solid shaft with keyway, hollow shaft with keyway or shrink disc, and foot or flange mounting.

Brands

§  Elecon | IC Bauer | Shanti | Santram  

Common Applications

§  Automotive Industries | Industrial Machinery | Renewable Energy & Aerospace | Robotics & Automations | Home Appliances