Hydraulic Power Units
Whether you have a space restrictions, the need for another back up power, a unit to control hydraulic for the entire plant, a harsh environment or a food safe washdown environment, we can find the solution to fit your requirements. We have built many types of power units with a wide range of options over the years. Click through to see some solutions from the K.R. West design team.
- Extremely tough, durable NFPA tie-rod cylinder
- Heat tolerant seal options
- Water cooled jacket and bushing designs
- High temperature protective rod boots
For foundries and diecasters with high heat needs…
WATER-COOLED CYLINDER OPTIONS
Sometimes environments and other system requirements make it difficult to design a hydraulic system that can maintain the operation of a cylinder within seal and oil temperature specifications. In these situations, water-cooled cylinders should be considered. Water-cooled cylinder designs provide a source of cooling water that absorbs the ambient heat energy and moves this energy away from the cylinder, protecting the cylinder components from exposure to high temperatures. Water cooling can be used as a jacket for the cylinder itself, and/or can also be applied directly to the rod bearing/bushing, for direct seal cooling. When using this type of system, typically “water” would not be the coolant used, but instead an appropriate coolant would be selected for its corrosion and heat capacity properties.
Using Hydraulic Cylinders in High Temperature Environments….
WHY IS MY SYSTEM HOT?
Every mechanical system generates heat as a result of movement. For example, if you rub your hands together, heat is generated. Or, if fluid is pushed through tight clearances, such as pipes and valves, heat is generated. If this heat is not dissipated, the system will heat up. Systems heat up because the mechanical energy generated is more than the heat that is dissipated. Movement within a system is one source of heat, but there is also the environment to consider. For instance, a hydraulic system located next to an object with excess heat such as a boiler, combustion engine, furnace, or rocket engine may have to absorb a lot of ambient energy. These conditions may require a hydraulic system to operate at higher temperatures than normal, and may need special systems to dissipate the heat or protect the hydraulics from the extreme environments. The Vulcan Series is ideal in hot systems found in:
- Steel Mills
- Glass Manufacturing
WHY IS HIGH TEMPERATURE A PROBLEM?
First, let’s consider the seals. Seals are designed to operate below specific temperatures. For example, most common seals require temperatures below 180° F. When seals are heated above their specifications several factors may change, such as the durometer, resistance to abrasion, tear resistance and lubricity. All of these scenarios may lead to seal failure. Seal failure not only means oil leaking past the seals, but it can also lead to contamination in a system and metal to metal contact with permanent damage to cylinder components. Second, let’s look at the hydraulic fluid. Hydraulic fluids tend to break down at a much faster rate a higher temperatures. As the oil breaks down, its viscosity, heat capacity and corrosion resistance are negatively affected, which results in friction, heat buildup and system contamination.
HOW DO I KEEP MY TEMPERATURE WITHIN SPECIFICATIONS?
The first line of defense is a properly designed and operated hydraulic system. Hydraulic systems should be designed to accommodate the normal heat load generated within the system or environment. A properly sized oil cooler and reservoir tank can typically be used to dissipate heat at a rate designed to keep the hydraulic system within the required temperature range. In addition to a properly designed hydraulic system, it is critical to properly maintain the system in accordance with the system provider’s instructions. For example, contamination can cause higher friction and quicker oil break down. Consequently, maintaining oil cleanliness via filtering, testing and periodic oil replacement is essential. It’s important to always follow oil and system provider recommendations. Note: Milwaukee Cylinder does offer hydraulic power units and can help in designing a system for your application.
Operating a system within the design parameters is also a factor in controlling the heat generation within a system. It is quite common that operators push their systems, sometimes beyond initial design parameters. For example, if a system is designed to operate at X pressure or X RPM, but is routinely operated at X + Y pressure or X + Y RPM, this operation may cause a rise in system temperature. Operating procedures or design modifications may be required. Other common techniques in managing system temperatures involve environmental considerations. Solutions include:
- Moving the heat source
- Insulation of the heat source or the hydraulic system
- Cooling ventilation