Mechanical Technology July 2016

⎪ Products and services ⎪

New oil-free pure refrigerant lubricated bearings

HyPer gearboxes with electronic load detection BMG’s extensive range of drives and motors now encompasses newly launched products from Dinamic Oil, the leading manu-

Fluke and HART Scientific have revolu- tionised environmental monitoring for calibration labs with their model 1620A DewK temperature and humidity instru- ment, which offers Ethernet and wireless connections and upgraded LogWare III software. Two types of sensors are available from Hart. The high-accuracy sen- sor (H model) reads temperature to ±0.125 °C over a calibrated range of 16 °C to 24 °C. Relative humidity read- ings are to ±1.5% RH from 20% RH to 70% RH. The standard-accuracy sensor (S model) reads temperature to ±0.25 °C SKF has announced the availability of its new pure refrigerant lubricated bearings, a unique oil-free solution for direct drive centrifugal compressors in chillers that use low-viscosity refrigerant as the bear- ing lubricant. By eliminating the need for oil lubrication, the bearings reduce chiller energy use while simplifying system design and maintenance requirements. Pure refrigerant lubricated bearings from SKF combine ceramic (silicon nitride) rolling elements, rings made of high-nitrogen, specially heat-treated stainless steel and glass-fibre reinforced PEEK cages. The result is a bearing that can operate reliably using low-viscosity refrigerant as a lubricant, an innovation that enables energy savings of at least 10% compared to conventional centrifu- gal compressor drive designs. Traditionally, centrifugal compressors using low-viscosity refrigerants have been gear-driven designs that use hy- drodynamic bearings lubricated with an oil-refrigerant mixture “It’s an approach that requires both a lubrication system and an oil separator to provide an oil-rich mixture to the gears and bearings and a refrigerant-rich mix- ture to the evaporator and condenser,”

facturers of hoisting winches and plan- etary gearboxes. Most notable is Dinamic Oil’s high performance HyPer gearboxes and an electronic load detection system for precise control and enhanced safety.

Refrigerant lubricated bearings from SKF are already at work in industry-leading chillers, helping to lower energy use and costs, reduce maintenance, and eliminate oil-related environmental concerns. explains Richard Law, SKF global seg- ment manager for fluid machinery. “Pure refrigerant lubricated bearings from SKF provide simplified system design and oil- free operation by allowing low-viscosity refrigerants to be used as the lubricant in direct drive centrifugal compressors, enabling a much more energy efficient, low-maintenance solution.” Tested and proven reliable through more than a decade of field operation, pure refrigerant lubricated bearings from SKF are already at work in industry- leading chillers, helping to lower energy use and costs, reduce maintenance, and eliminate oil-related environmental concerns. www.skf.com over its calibrated range of 15 °C to 35 °C. Relative humidity readings are to ±2.0% RH from 20% RH to 70% RH. All DewK sensors come with NVLAP ac- credited certificates of calibration for both temperature and humidity, complete with data and NIST traceability. The DewK features built-in Ethernet RJ45 jack and multiple DewKs can be monitored from the same screen using the new LogWare III client-server soft- ware. Ethernet also allows for remote connectivity over the Internet, so that critical conditions can be monitored from a remote location and data can be sent to a printer through the RS-232 interface in real time. In addition to temperature and hu- midity, the DewK calculates dew point, heat index, and rates of change for both temperature and humidity. Min, max, and a variety of other statistics are also calculated and can be shown on-screen. Daily summary statistics, including min, max, and maximum rates of change are stored for the most recent sixty days. The instrument has inputs for two

“HyPer gearboxes combine Dinamic Oil’s GB series gearboxes with the modular advantages provided by parallel shaft and helical bevel gearboxes, as well as gearmotors,” says Bryan Pickles, BMG’s brand manager. “These new combined unit gearboxes offer high torque to weight ratios for optimum performance in diverse applications, including conveyor drives, construction, mining and quar- ries, marine tensioners, industrial and marine lifting equipment and machines for steel pro- duction plants and sugar mills.” This flexible combined unit has an output torque up to 3.0-million Nm, gear ratios starting from 40 and combined electric motor-inverter power of up to 22 kW. The new electronic load detection system, which is mounted on the winch structure, uses an analogue or digital signal to control torque, as well as to precisely control the lifting and lowering load. This flexible system, which is pro- grammed to users’ exact requirements, permits load control of the crane’s winch, while display- ing its value on the remote control. This enables easy movement and ensures optimum safety. BMG, which was appointed exclusive dis- tributors for Dinamic Oil over 10 years ago, supplies and supports the full range of plan- etary gearboxes, as well as slewing, winch, track and wheel drives; hydraulic hoisting and pulling winches; motor drums and tower crane winches. www.bmgworld.co.za

Thermo-hygrometer for environmental control

sensors, each measuring both tempera- ture and relative humidity, so that the DewK can monitor two locations simul- taneously. Both sensors can be run via extension cables to remote locations up to 100 feet away, or one sensor can be directly mounted to the top of the DewK. The DewK has the memory capac- ity for up to 400 000 date- and time- stamped data points – two years’ worth of data taken at ten minute intervals. Alarm settings are easily set based on temperature, the rate of change in tem- perature, RH, the rate of change in RH, and instrument fault conditions. www.comtest.co.za

The DewK calculates dew point, heat index, and rates of change for temperature and humidity.

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