Pumps and motors

The pump is often referred to as the heart of a hydrostatic transmission. It plays a vital role, since it is in the pump that mechanical energy is transformed into hydraulic energy, in the form of pressure and flow. Hydrostatics, which uses positive displacement pumps, only developed when pumps became lubricated by the fluid they compress.

The technologies used for hydraulic motors are generally based on those used for pumps, with the addition of a few specific features resulting from their wide variety.

In the evolution of components, we must not forget the role played by the fluid, whose lubricating qualities enable the performance of today's equipment.

The market share of hydrostatic applications continues to grow in most areas of use. We can only deplore the fact that hydraulic servomechanisms are losing out to electric servomechanisms in aviation and robotics. On the other hand, agricultural, public works and materials handling equipment are increasingly integrating hydrostatic components into their powertrains, replacing hydrokinetic gearboxes or torque converters.

This article is part of a series covered by the introduction "Hydrostatic transmissions and transmission components".

In the same series, you'll find the articles "Hydrostatic transmission circuits" and "Circuit assembly and design".