DYNOmite Liquid-Cooled Eddy-Current Absorbers offer millisecond-response load control, very low rotating inertia, and compact high-specific load capacity. Compared to water-brake absorbers, they are especially well suited for applications that require plenty of low RPM torque capacity – as do many industrial-type engines. For applications which do not require motoring or stall-speed (zero RPM) loading, our liquid-cooled eddy-current absorbers offer more cost-effective loading than an equivalent-capacity AC absorber (motor) and drive can. For applications that demand higher RPM limits, lower system inertia, and continuous-duty (temperature independence) – water-cooled eddy-current absorbers are the ideal solution. See Specifications or Models and Prices pages.
We manufacture these absorbers as both single- and multi-rotor configurations, in a number of diameter (capacity) ranges. We cover your test needs for everything from tiny 20,000-RPM two strokes to 1,000-Hp diesels. Rotors are added to increase power capacity, without limiting peak RPM, while rotor diameter is increased for boosting low-RPM torque capacity. We completely manufacture these units in-house; machining and balancing their rotors, winding custom-voltage coils, and assembling the ideal rotor stackup – to best match your application’s load curve. Their modular design also allows the possibility of upgrading system capacity – should your power requirements increase.
120-volt and 240-volt (input) power supply/ controls are available to provide 96- or 192-volt DC PWM (pulse width modulated) output – which is suitable for most of the DYNOmite or third-party liquid-cooled absorber models. Loading when using these controls is adjustable – both manually (using either its panel knob or the built-in 0-10 volt analog control input) or automatically via the (non-analog) PID-controlled leads from the DYNOmite data-acquisition computer. Panel circuit breakers are matched to the customer’s application, protecting the absorber’s windings.
MAX – How Eddy-Current Absorbers Work - Animated look at how eddy-current absorbers create load (MAX narrated).
Absorber coolant-flow monitoring is available via our optional differential-pressure switch kit. This switch will lockout coil current, if your test cell’s water flow drops. Note that this protection is running totally independent of any other data-acquisition system, personal computer, or software alarms – for an added level of fail-safe security. Temperature-sensor ports are also provided – for monitoring the inlet and outlet water at the absorber.
Various shaft mounting choices are offered, including custom designs to your prints. The standard units may be supported between a pair of live high-speed pillow-block bearings. This allows reading the reaction torque via a load cell that is linked to the absorber’s trunnioned frame. Our precision (keyless) ring couplers may be used for mating to driveshafts – via disc or U-joint style assemblies. For the elimination of parasitic bearing losses, non-rotating trunnion-bosses (or reaction-mount options) are both also offered, making it convenient to adapt the absorber housings to your dynamometer’s engine stand, docking station frame, or reaction cradle/table. Sub- frames for mounting onto industrial T-slot bases are also available.
Custom hybrid configurations can also be designed using a combination of a smaller AC absorber (for very fast torque control and/or motoring) with a higher-capacity liquid-cooled eddy-current absorber. The eddy current inexpensively adds additional loading power capacity – compared to a similar capacity AC absorber alone. Control of the pair is handled via DYNO-MAX “Pro.” While its complexity is typically only justified for some sophisticated high-output applications, hybrids make it possible to cost effectively build lower-inertia and faster-response dynamometers, with motoring capability, than can be done using any single technology alone.
High-speed ceramic spindle bearings and synthetic grease provide extra-long life for extended industrial or OEM endurance testing applications. These hybrid ceramic bearings are also immune to the extra-heat buildup which occurs when steel bearings are rotated within a magnetic field. Such eddy-loss heating will destroy conventional bearings in a relatively short period of time. Consequently, hybrid ceramic bearings are a standard feature in all of our DYNOmite liquid-cooled eddy-current absorbers units. Teflon lip seals are also used – to minimize wear of both the seals and the stainless- steel shafts that they run on. We combine all of this with high-speed synthetic Kluber Isofle NBU grease, to help ensure very-long service intervals.
Corrosion and thermal-expansion protection are designed in. All of the absorbers magnet-coolant passages (loss-plate labyrinths, covers, etc.) are ruggedly plated to prevent rusting and reduce insulating-scale buildup. This helps protect the absorber against overheating damage, efficiency losses, all while extending its uptime between maintenance cleanings. The heat-transferring loss-plate labyrinths are also engineered to avoid mechanical stresses, due to the differences in thermal expansion, between each plate and its mating cover. Such attention to detail results in longer life for each absorber's critical components.
Need parts for an older eddy-current dyno? As a manufacturer of eddy-current dyno absorbers, we can often repair otherwise obsolete units. Land & Sea does everything, from modernizing power supplies and/or controls to in-house winding of custom-size replacement coil magnets – for your (otherwise obsolete) “Brand-X dynosaur” system. Both square and round wire coils are available to over 40" in diameter. Call for a quote, or help, in repairing your existing dyno’s hardware.
Tandem configurations double power capacity for heavy-duty applications, where a single (multi-rotor) absorber is still short on torque loading or power absorption. Though shafts and couplings are designed for triple-absorber loads.
Stainless-braided hoses with aircraft fittings combine flexibility, for minimizing torque-reading hysteresis, with high-pressure and high-flow capacity. They also last quite a long time and add a cleaner and more professional appearance to your test cell.
Call for immediate assistance in developing your own unique liquid eddy-current absorber (or hybrid AC motoring) testing solution – or e-mail [email protected] for a prompt response.