by Torbjörn Idhammar
This article series discusses sample business processes that must be implemented in order to improve overall plant reliability. This article and the previous one focus on preventing failures and extending equipment life. The series will continue in upcoming issues with topics such as spare parts management, condition monitoring, planning and scheduling, and root cause problem elimination.
If you ask any maintenance department how failures can best be prevented, the No. 1 answer is usually that the operations department needs to stop wrecking equipment. If you ask operations how reliability can be improved, the top answer is almost always for maintenance people to work instead of sitting idle. Continue reading →
Linear and Non-Linear Systems
To assist in understanding the transmission of vibration through a machine, it is instructive to investigate the concept of linearity and what is meant by linear and non-linear systems. Thus far, we have discussed linear and logarithmic amplitude and frequency scales, but the term “linear” also refers to the characteristics of a system which can have input and output signals. A “system” is any device or structure that can accept an input or stimulus
By John P. Kotter
Over the past decade, I have watched more than 100 companies try to remake themselves into significantly better competitors. They have included large organizations (Ford) and small ones (Landmark Communications), companies based in the United States (General Motors) and elsewhere (British Airways), corporations that were on their knees (Eastern Airlines), and companies that were earning good money (Bristol-Myers Squibb). These efforts have gone under many banners: total quality management, reengineering, right sizing, restructuring, cultural change, and turnaround. But, in almost every case, the basic goal has been the same: to make fundamental changes in how business is conducted in order to help cope with a new, more challenging market environment.
Click here for pdf file.
by Kevin Remack
Want to expand coupling life? Who doesn’t? You may want to look into advanced-design disc couplings.
These couplings feature discs with optimized profile and thickness to provide a higher torque-to-outside-diameter ratio, higher service factors and up to 50 percent greater misalignment capability. All this provides for smaller reactionary forces on bearings compared to conventional disc couplings, which helps achieve infinite coupling life in properly specified applications. Continue reading
from Plant Engineering and Maintenance (PEM) magazine, April 2008.
When exploring automation opportunities in your facility, there are many factors to consider. These include cost versus benefit by automating, cash-flow impact, organizational readiness, ease of implementation, availability of resources, technological maturity and availability, as well as probability of success.
Most senior managers would be thrilled to discover a way to filter the never-ending stream of requests for what appears to be worthy automation projects. As one top executive said, “if we could recoup even half of all of the savings that have come forward on project business cases each year, we would have only revenue and no expenses!” Continue reading
On the design of a new machine which is to be run with a hydraulic motor, a determination of required speed and horsepower must be made so a model with suitable ratings can be selected. This article describes several methods of making such a determination.
Hydraulic vs. Electric Motor Characteristics
Designers who are experienced only in selecting electric motor drives need to be careful in designing hydraulic drives because of important differences between these two motors.
Normally, an electric motor is selected on the basis of horsepower. It is selected to match an existing power source which provides constant voltage and frequency. If it happens to be a little oversize for the job, no harm is done, although it may cost a little too much. Continue reading
by Terry Taylor, Senior Consultant, IDCON INC
Brush grades are usually classified according to the manufacturing processes and the types of carbons, graphites and other ingredients used. The 4 main brush grade families are –
Carbon-Graphite Brushes made their entrance early in the brush industry. These are generally limited to lower current densities (45 amps/sq.in.) and are used in older, slower speed motors with a maximum surface speed of 4000 ft./min. These are high friction brushes that make them very unattractive for present day use on commutators.
Continue reading →
Hydraulic Oil Flow through Orifices
The chart shows approximate pressure drops which may be expected at various flows rates through sharp edge orifices for petroleum type hydraulic oil. It may be used for designing limiting flow orifices in hydraulic systems. Chart values must be considered as approximate because a number of factors such as specific gravity, orifice efficiency, plumbing ahead of and behind the orifice may cause variations from the values shown.
By making the orifice with a knife edge, it becomes insensitive to temperature, and the flow and pressure drop will remain the same over a reasonable range of oil temperatures (and viscosity changes).
by Ashley Halligan
Property Management Analyst, Software Advice
A couple months ago, I wrote an article about the top five careers in facility management. I interviewed a broad range of professionals for that story. But it was during an interview with Joel Leonard, President of SkillTV, that I started to ponder what he referred to as “the maintenance crisis”–a depletion of skilled workers in the maintenance management workforce caused by baby boomers retiring and too few young professionals entering the field.