Speed Increaser Gearboxes – Power Boosters for Hydraulic Pumps

A gearbox transmits torque and speed. As soon as one of these two factors is converted by the gearbox, it is referred to as a “gear ratio.” For this reason, practically every gearbox is also a transmission gearbox. However, the term “speed increaser gearbox” has become established for a very specific type of gearbox used primarily in agriculture.

Design of a Speed Increaser Gearbox

There are many ways to transmit torque or speed. Typical types of gearboxes include:

• Gear drives
• Belt drives
• Hydraulic transmissions

Gear drives

Gear drives are the most common form of torque transmitters. They are categorized into switchable and non-switchable or “fixed” types. In a gear drive, two gears mesh with each other. If they are the same size, only the pivot point of the output torque is shifted. If the gears are of different sizes, the torque and speed are altered. If the output gear is larger than the input gear, the rotational speed decreases and the torque increases. If the output gear is smaller than the input gear, the effect is reversed.

Belt drives

Belt drives transmit torque via two pulleys and a belt. Most belt drives are fixed. In some cases, such as in a torque converter transmission, conical belt retainers are used instead of pulleys. These make the transmitted torque and speed variable.

Hydraulic Transmissions

Hydraulic transmissions use two opposing impellers installed in a closed housing. When hydraulic fluid is introduced, the flow triggered by the input wheel transmits a linear force to the output wheel. The more the hydraulic transmission is filled with fluid, the more volume flow is transmitted. In common parlance, hydraulic transmissions are also called “torque converters.” However, like the term “speed increaser gearbox,” this is somewhat imprecise, as practically every gearbox is also a torque converter. Nevertheless, these designations help to distinguish the individual types of gearboxes from one another.

A speed increaser gearbox is therefore a fixed gear drive encapsulated in a dust- and waterproof housing.

Characteristics of Speed Increaser Gearboxes

The speed increaser gearboxes commonly used in agriculture are detachable modules. They are flanged to a tractor’s PTO shaft as required. There, they provide their converted torque for a wide variety of attachments.

Use of Speed Increaser Gearboxes

The speed increaser gearbox is used to change the torque of a PTO shaft without interfering with the engine speed. A common application is the operation of a hydraulic pump. If the pump is operated at a higher speed, the pressure and thus the power in a hydraulic system increases. The speed increaser gearbox thus protects the tractor engine and reduces fuel consumption, emissions, and noise levels. The speed increaser gearboxes commonly used in agriculture usually have a gear ratio of 1:3.8. This allows the small, practical component to almost quadruple the performance of a hydraulic pump.