Gears today have become one of the most important types of widely used industrial parts in mechanical assemblies. Typically wheel shaped and aligned to rotate around an axis, these components usually contain teeth, or cogs, along the rim. People sometimes refer to gears as "cogwheels".
Machinists may bore holes for shafts through the bodies of gears. When meshed together, rotating gears help accomplish designated mechanical tasks, such as assisting a drill bit to turn in a forward or reverse direction, or helping a lever move up or down.
Inventors have devised a wide variety of specialized gears. The helical gear, one of the most commonly used types of gears, plays a part in many mechanical assemblies in which manufacturers prefer to reduce the noise of gear operations. It may display smoother, efficient gear mesh surface contacts.
Helical gears usually occur in the form of a wheel containing external teeth ("cogs") projecting outwards along the rim at intervals. Designers shape the cogs specifically, frequently causing them to end in uniform ridges somewhat resembling the treads of tires. These "teeth" form a contact surface when two or more rotating gears mesh together.
However, instead of cutting straight teeth into the rims in parallel, when manufacturers produce helical gears they angle the teeth uniformly in a right or left direction at a designated angle. Manufacturers must observe tight tolerances during the production of helical gears in order to ensure these components will perform correctly as parts of a mechanical assembly. The cogs of helical gears, just like those of straight-cut spur gears, must mesh together seamlessly in order for the gears to function correctly.
The Orientation of Helical Gears
Manufacturers usually orient helical gears in parallel with one another. In this well-established configuration, by far the most widely used in industrial assemblies, helical gears normally rotate around a central axis and the gears make contact with one another's teeth across the full width of the mesh surface. As these gears mesh, they come into contact evenly and continuously without interruption. This produces smoother, quieter operations than spur gears achieve. Parallel helical gear orientation offers an efficient use of gear meshing, and it appears to represent the gold standard for safe and effective helical gear orientation.
In some rare cases, a manufacturer may intentionally align helical gears to operate in a crossed configuration with one gear oriented along an angled vertical rotational axis and another oriented along an angled horizontal rotational axis. The gears, known in this context as "skew gears", will make contact only at limited points along the meshed surface during rotation. The rotating gears must maintain the same pressure angle. Precise formulations apply to govern the correct alignment of the gears forming contact in this way, depending upon whether the teeth angle in a helix towards the same direction or towards opposite directions. Engineers need to exercise precautions to ensure skew gears won't fall or slip out of position during the operation of the mechanical assembly, potentially disrupting mesh contact.
Helical Gears: Materials And Applications
Helical gears have gained popularity because they potentially provide smooth, quiet, continuous operation. Inventors have utilized a number of materials during the construction of these industrial components. Additionally, helical gears offer a variety of useful applications in numerous industries.
As strong, versatile metals, steel and stainless steel remain the most widely used raw materials during the construction of high quality industrial helical gears. Steel permits manufacturers to develop helical gears capable of enduring extended use over the lifespan of the part. Gears made from this material typically won't sustain dimensional distortions that might otherwise impede gear operation within heated engine environments. Since helical gears must mesh together precisely, manufacturers require the capability to create these components within fairly close tolerances.
Nevertheless, manufacturers have also engineered helical gears using a variety of other materials as well. Today customers can locate helical gears produced from bronze, brass, aluminum, gray cast iron, ductile iron, and even plastic. The intended purpose of a mechanical assembly may play a role in the selection of helical gear raw materials.
Helical gears have become frequently utilized components in a variety of machines used across many industrial sectors. These gears have found numerous applications in industrial manufacturing, transportation, aerospace, agriculture, medical devices, electronics, and robotics. Their capacity to operate more smoothly and quietly than some other types of gears makes them an especially attractive choice for use in automotive and maritime craft.
Advantages of Using Helical Gears
Manufacturers may enjoy some specific advantages by selecting helical gears for use in a specific mechanical assembly.
- This type of component operates very efficiently. Some authorities rate its efficiency at between 90% and 99.5%.
- Helical gears will function more quietly than spur gears within machines. This quality may make them a very appealing component to use in transportation equipment. For instance, most drivers don't appreciate hearing mechanical noises as gears rotate within a vehicle.
- Helical gears in parallel orientation operate very smoothly. In situations in which machine operators don't want equipment to vibrate or jostle, it may prove beneficial to consider using helical gears as components.
- Well-manufactured helical gears function reliably within some equipment operated at comparatively high speeds. Helical gears will apparently rotate rapidly while still meshing, and the constant contact between the mesh surfaces of these gears in parallel orientation may offer an advantage; although the gears initiate contact gradually during the meshing process, they can withstand rapid rotation and high speed operation if engineered from strong materials within tight tolerances.