A Guide to Common Gearbox Components

Gearboxes are a common element of many transmission assemblies, and they are a gear train or mechanical unit that is made up of integrated gears contained within a housing assembly. Like any other gear system, gearboxes rely on the meshing of individual gears to create alteration of torque and speed between a driver and a load. Whether you operate an automobile, certain aircraft, or other various systems, there is a great chance that you depend on the functions of a gearbox. As such, we will discuss the common makeup of gearboxes, allowing you to better understand these highly important systems.

While gearboxes may vary in their exact design based on the application and its particular needs, there are a number of elements that can be found within most assemblies. Generally, these come down to items like clutch shafts, counter shafts, main shafts, gears, and bearings. The clutch shaft, also known as a driving shaft, is one of the most crucial parts of the assembly, serving to take power from a source so that it can be transferred to connected shafts. Clutch shafts, true to their name, are connected to the clutch of a particular system. When the clutch is engaged, the clutch shaft will rotate alongside it, featuring a singular, fixed gear that rotates at the same speed as the engine crankshaft.

Directly attached to the clutch shaft is the counter shaft, and it contains a gear which connects to both the clutch and main shaft of the gearbox assembly. Depending on the gear ratio of the assembly, the counter shaft may rotate at the same speed as the engine or lower. When it comes to the main shaft, rotation is done at the same speed as the vehicle or system itself. The main shaft is important as it is the part that transfers power from the countershaft to a universe shaft through a set of gears. As compared to the counter shaft, the main shaft will have different speed and torque values during operation.

While there are numerous gears present in any gearbox assembly, such components all share the simple role of transmitting power from one shaft to another. The amount of torque that a particular gear will be able to transmit will be based on its teeth count and size, higher torque and acceleration values being tied to higher gear ratios. While all gears within a gearbox tend to be fixed in place, the ones situated on the main shaft will be able to slide.

The last common gearbox components are the bearings, and they are essential parts for any system featuring rotating or moving assemblies. With bearings, all rotating elements are supported during motion while friction is reduced, mitigating damage and performance losses. Within a gearbox, bearings are used to support both the counter and main shaft.

While these are the major components of gearboxes, other components may vary based on whether a manual or automatic transmission is used. Generally, the biggest difference between these two options are whether or not a clutch pedal and disc or a torque converter are used. With manual transmission systems, the clutch pedal must be manually operated with one’s foot for disengaging the clutch. Meanwhile, torque converters allow for an engine to continue running even when the vehicle in question is stopped, making operations a little more “hands-off” for the benefit of the operator.

With a better understanding of the main function of gearbox components found in an assembly, you can better be aware of the functionality of such systems, alongside the potential parts that may need to be maintained over time. If you have a gearbox assembly that requires components for repair or replacement, let the experts at ASAP 360 Unlimited help you secure competitive pricing and rapid lead times on everything we carry. Explore our expansive set of offerings as you see fit, and if you find any items that you wish to procure, be sure to request a quote with our online RFQ service. Once we receive and review your form, a member of our staff will reach out to you in 15 minutes or less to provide a customized solution based on your needs.