A Common Mistake To Avoid When Calculating Hydraulic Pump Efficiency

Rexroth A2VSL1000 hydraulic pumpThe hydraulic pump is the hardest working component of a hydraulic system. And as the pump wears in service, internal leakage increases and therefore the percentage of output flow available to do useful work (volumetric efficiency) decreases. If volumetric efficiency falls below a level considered acceptable for the application, the pump will need to be changed-out. In a condition-based maintenance environment, the decision to change-out the pump is usually based on remaining bearing life or deterioration in volumetric efficiency, whichever occurs first.

Put simply, volumetric efficiency is the percentage of theoretical pump flow available to do useful work. In other words, it’s a measure of a hydraulic pump’s volumetric losses through internal leakage and fluid compression.… continue reading »

5 Things to Consider When Buying a Hydraulic Machine

big question markWhen sourcing a piece of hydraulic equipment, there are 5 things about the environment the machine will operate in, that you should always disclose to the equipment supplier or designer–even if they don’t ask. Especially if they don’t ask:

1. Minimum and maximum ambient temperature. This information is necessary to determine the correct hydraulic fluid type, viscosity grade and viscosity index. Together with hydraulic fluid selection, it also determines whether tank heating is necessary at minimum ambient temperature (cold start). At the other end of the scale, maximum ambient temperature influences required cooling capacity.

2. Average humidity conditions. Locations where average humidity is high, for example tropical and marine environments, mandate the use of desiccant (moisture adsorbing) tank breathers and possibly, polymeric filters to limit water content to no more than the oil’s saturation level.… continue reading »

Energy Efficiency and Machine Operating Cost

hydraulic efficiencyIn the current economic climate, the debate concerning peak oil (the end of cheap mineral oil) and global warming (the end of the planet as we know it) have been somewhat sidelined.

But these two major issues have not gone away. And they will almost certainly influence the source and cost of our energy needs in the not-too-distant future.

And there’s no escaping the fact that industry is a huge consumer of energy. If peak oil and global warming are real issues – and there’s a growing body of evidence to suggest they are, then I predict energy management will become a major issue for industry over the next decade and beyond.… continue reading »