Types of Plastic Gears
Enplas designs and mass produces plastic gears for reduced weight, low noise, better durability, and more.
Types of Plastic Gears Produced by Enplas
Below are examples of the plastic gears that Enplas can design and mass produce. Looking for something that’s not on the list? Unsure which gear type is best for your project? Contact us to discuss your specific needs—we offer custom design and manufacturing services for an array of industries and applications.
Spur Gear
The spur gear is the most commonly used gear. It features straight teeth that are parallel to the axis. While spur gears are often used in lower-speed applications, they can be used at almost any speed. Spur gears are ideal in applications that require speed reduction and the multiplication of torque (e.g., household appliances). They are, however, quite versatile; they can be found in everything from airplane engines to pedal bikes.
Helical Gear
Helical gears are similar to spur gears, but feature teeth that are slanted at an angle to the axis. They can achieve higher durability and lower noise output compared to spur gears. However, they are more complex to manufacture than regular spur gears.
Double Helical Gear
While helical gears have benefits in strength and noise reduction, their angled teeth generate extra axial thrust forces that must be managed. By creating a symmetrical form with helical teeth, double helical gears eliminate thrust while benefiting from the helical gears’ strength and noise reduction. Helical gears are most often produced with metal, but Enplas can injection mold this complex shape with plastics.
Worm Screw and Worm Wheel: the Worm Drive
The worm drive assembly consists of a threaded pinion (the “worm screw”) that meshes with a circular gear or “worm wheel” (usually a spur or helical gear). This assembly provides good speed reduction ratios and torque multiplication. This makes the worm drive a good choice for speed reduction. In addition, it is more compact than other gear assemblies and is typically self-locking, which makes it good for applications that require lifting.
Enveloping Worm Wheel Gear
The enveloping worm gear assembly is similar to the regular worm gear assembly. However, the components of the enveloping worm gear assembly feature modifications to the contours and teeth of the worm wheel, the worm screw, or both. These modifications increase the amount of surface contact achieved, which produces increased accuracy from the assembly and more strength than its counterpart. Finding a reliable manufacturer for this complex design, however, can be a challenge. Many of these gears are crafted from metal, but Enplas can injection mold enveloping worm gears with precision.
Bevel Gear
The bevel gear features teeth on the face of the gear that “bevel” from the axis to its perimeter. It is most often used in conjunction with another bevel gear in a vertical or near-vertical angle to switch the direction of rotation or change the amount of force in an application (e.g., to reduce the speed of a shaft operating at a 90-degree angle).
Spiral Bevel Gear
The spiral bevel gear is a bevel gear with helical teeth. Similar to the difference between regular spur gears and helical gears, spiral bevel gears feature higher durability and lower noise compared to their counterparts.
Crown Gear/Face Gear
Crown gears (often referred to as “face gears”) are similar to bevel gears in that they feature teeth on the gear’s face. Unlike bevel gears, however, a crown gear’s teeth are not beveled; rather, they are set at a 90-degree right angle to its face. A full crown gear set (pictured) typically consists of a disk-shaped crown gear interacting with some type of pinion gear.
Planetary Gear
Planetary gears feature multiple “planet gears” surrounding and interacting with a central “sun gear.” This assembly delivers speed reduction, improved strength, and higher torque in a smaller space at the cost of manufacturing complexity.
Internal Gear
Internal gears feature teeth that face inward towards the axis of the gear, as opposed to regular spur gears (which feature teeth pointing away from the axis). They are often utilized in planetary gear assemblies.
Gear Trains
Enplas designs gear trains that meet or exceed your requirements. When designing a single gear, aspects like number of teeth, tooth angle, and more are taken into consideration. Designing gear trains involves choosing which combination of the many gear types (listed above) work best in a particular project. This requires another level of design capability, one that Enplas’s engineers have vast experience in. We help our customers get the right design for their needs.
Compound Gears
In addition to the well-known benefits of lighter weight, lower noise, and reduced costs, plastic gears provide greater design freedom than their metal counterparts. These special custom plastic gears are molded as a single part with pulleys, cams, or multiple gears. Ultimately, this means less assembly, less time, fewer errors, and lower costs.
Simulations and Modeling
Enplas creates reliable plastic gears and gear trains using high-end simulations and modeling technology in conjunction with a comprehensive, one-of-a-kind performance database. This allows us to propose the optimal gear solutions for your performance needs. If you’re already using metal gears, the right plastic gear solution for you may look entirely different from your current metal gears. Enplas can help you choose the right material and design according to your target performance.
Enplas has cutting-edge tool making and precision molding expertise for volume production of your gear designs to the utmost detail. Whether you require full development assistance from the ground up, assistance with noise or durability issues, or just need help completing your design with DFM (Design for Manufacturability), Enplas is here.
