What do miners, lumber jacks and bull dozer operators all have in common? Besides choosing dangerous heavy duty jobs as occupations, they all work with some pretty powerful and extreme machinery everyday. Their equipment, along with trenchers, marine winches, cranes and car crushers, use intense amounts of power to do their job. But where does energy powerful enough to flatten cars or move massive amounts of earth come from? The answer is hydraulic motors—components of hydrostatic power transmission systems that convert hydraulic energy into mechanical energy. These motors are able to harness the immense power generated from fluid pressure and supply energy to the most massive and extreme machines.
You wouldn’t think so, but hydraulic motors are pretty uncomplicated and small machines that are composed of a reservoir, pump and rotating machinery. The pump, powered by a smaller pneumatic engine, is what drives the hydraulic motor. Oil usually serves as the pressurized fluid that creates motion, and is pushed from an inlet valve to an outlet valve through a series of gears, rotating screws, turning vanes or cylinders. The liquid in motion causes the rotating components to turn very quickly and generate mechanical energy. The rotating components are mechanically linked to the machinery and the energy is then transferred from the motor to the operating system. After traveling through the motor, the oil is returned to a reservoir, where it is filtered and reused.
Hydraulic motors are fast becoming the preferred method of power for applications that require large amounts of it. Electric motors only provide rotational power and are sized according to the load application. Therefore, the larger the job, the larger the motor. As for location, they are only placed within the motion axis, which may not be practical or possible for some machinery construction. Electrical energy would also need a constant source of electricity—requiring either a cord or constant recharging. They are also more economical, efficient and environmentally friendly than pneumatic motors. Hydraulic motors, in comparison, are smaller, allow for machine construction freedom and provide more mechanical energy than any other motor system.
There are a few main advantages, though, that make hydraulic systems perfect for high-power, dangerous applications. These motors are used in machinery that requires power for several different functions at the same time. This is because a single pump can power several different motors. In a crane, for example, one hydraulic pump raises and lowers a winch, controls the arm, rotates and turret and moves the vehicle around, all at the same time. Hydraulic motors are also closed and self-contained in a durable and water-proof housing. This allows them to be submerged in water for marine applications like marine winches and submersible ROV’s, and operated in harsh environments like forests, construction sites, mines and scrap metal plants.