Different types of parallel shaft gearboxes

Gear boxes are divided into two categories according to gear arrangement, namely, parallel shaft gear boxes and straight shaft gear boxes. The two configurations offer different price points, size limitations, performance, efficiency, and reduction ratios. Today we will discuss different types of parallel shaft gearboxes to help your application choose the right gear box.

There is no change in the direction between the input shaft and the output shaft in the in-line gearbox. The in-line gearbox can be parallel or coaxial regardless of whether they are offset from each other.

Parallel in-line gearbox

In a parallel in-line gearbox, the input and output shafts are offset from each other by a certain amount, but there is no angle between them.

The main types of gears used in parallel gearboxes are spur, helical, or double helical. Spur gears are generally suitable for low torque and low speed applications because of their relatively large noise and large stress due to their small tooth surface area. Helical gears have better meshing characteristics, can transmit more power at similar efficiency levels, and the noise is much lower.

However, the helical direction will generate a large thrust along the shaft, sometimes requiring special bearings. Double helical gears are similar to two opposite gears side by side, helping to eliminate thrust while maintaining similar performance. Due to its efficient use of space, the parallel in-line gearbox is very suitable for applications with limited space, such as agitators in the liquid mixing process.

Coaxial in-line gearbox

In the case of a coaxial in-line gearbox, the input and output of the gearbox share the same axis, so the imaginary line passing through the center of the input shaft will also pass through the center of the output shaft.

The coaxial in-line gearbox uses a planetary system, which has excellent performance characteristics. The planetary gearbox is very compact and can handle high torque and high acceleration while encountering a little clearance. The single-stage reduction ratio is high, which can be easily connected to achieve a very high reduction ratio. However, at the same time, the planetary gearbox has some disadvantages, including that the maintenance is more complicated than other gear systems, and the price will be slightly higher.