Gears are set of toothed wheels that mesh with one another to transmit / change torque, speed and direction of the power source. By altering the Gear ratio one can increase or decrease speed or torque from the power source. Gears are used in almost all mechanical devices and more commonly used in automobiles.
Herringbone Gears or Double Helical Gears are an improved version of the Helical Gear. In a Helical Gear a resultant thrust is developed along the axis of the Gear and this has to be accommodated by having a thrust bearing. This reduces the efficiency of the system.
To preserve the advantages of Helical Gears and to eliminate the resultant thrust, a Double Helicalor Herringbone Gear can be used. As the name suggest the Herringbone Gear (Double Helical) has two sets of teeth set in a V-shape. To put in simple terms, Herringbone Gears are two helical mirror images stacked over the other. One part of Gear Produces thrust in one direction and the other in opposite direction, thus cancelling out each other. To ensure resultant thrust as zero, care must be taken while aligning the Gears. Herringbone Gears are difficult to manufacture due to their complicated profile.
About Helical Gears:
- Has higher load bearing capacity.
- Produces less noise during operation.
- Can be used for high speed applications.
- Produces an axial thrust during operation, which needs to be compensated by having a thrust bearing.
- Can be used in both parallel and cross orientation.
Difference between helical and Herringbone Gears
- Herringbone gear has 2 teeth set in V-shape whereas a helical gear has only one tooth.
- Resultant thrust is produced in a helical; the teeth profile in a herringbone gear eliminates the thrust.
- Herringbone gear is difficult to manufacture.
