Gear drive specification Webcast: Your questions answered

Robin Olson, director of applications engineering, Rexnord Industries, answered additional questions on gear drive specification from the Jun. 15 webcast.

06/21/2017


Robin Olson, director of applications engineering, Rexnord Industries, answered additional questions on gear drive specification from the Jun. 15 webcast. Courtesy: RexnordRobin Olson, director of applications engineering, Rexnord Industries, answered additional questions on gear drive specification from the Jun. 15 webcast.

Question: I would like to use an inching drive for maintenance operation of my equipment. What considerations does this introduce?

Answer: Inching operation requires that the gear drive run slower. However, during main drive mode, a much faster speed is required. If the drive is lubricated using splash lube, the splash may not be there while inching. In that case, the manufacturer may raise the oil level to dip the bearings or add a lube pump. Raised oil levels may require a cooler for main drive speeds, so the lube pump may be the most effective solution.

Q: If I purchase a backup gear drive for emergencies, are there any long-term maintenance considerations or expenses to consider? I want my backup ready to go when it's needed.

A: If you purchase a gear drive that will go directly to storage for a period of time, ask your manufacturer about long term storage preparation prior to shipping. This will help protect the drive from corrosion or damage during storage and allow you to commission it without unexpected delays. If the storage is longer than 3 years, plan to replace the seals before installation.

Q: What is the seal material and oil type for -20°C environment?

A: Nitrile and Viton both can be used in -20°C temperatures. Please consult your gear drive supplier for lubrication recommendations. Some suppliers provide owners manuals containing cold temperature oil data.

Q: Does Rexnord manufacture gearboxes to API?

A: API is a very conservative method for selecting gear drives because it is intended for critical applications. If you are specifying that a gear drive be selected per API, please make sure that your application is critical and needs the requirements of that selection method. Expect that the gear drive will be larger and more expensive that a standard catalog selection.

Q: Do more requirements or additional data decrease the cost when buying a gearbox?

A: The least expensive option will be the smallest drive that can be selected from the catalog. Understanding the application will allow for the best selection of a gear drive. To that end, the requirements of the application should be defined. However, we sometimes see additional requirements in specifications that are put there to control gear drive construction or because they were copied from another specification. Of course, that customizes the gear drive or forces a larger selection that may not be required for the application.

Q: Why does the higher L10 rating necessarily increase the cost as shown in your graph?

A: AGMA 6001-E08 requires that gear drives are cataloged with bearings selected for 5,000 hours of L10 life. Because the power is exponentially related to the L10 life, the service factor on your application increases the L10 life for the application. For example, with a service factor of 1.50, the L10 life on a gear drive can jump from 5,000 hours (catalog) to 19,000 hours (application). As the requirement for L10 life increases, it becomes harder to achieve that L10 with the gear drive that may have been originally selected on catalog rating alone and a larger gear drive will be selected. If we try to use lubrication or contamination considerations to increase L10 without changing the gear drive size, coolers and filters will be required.

Q: Why do we need a gear drive if we have a direct drive to deliver the required torque and speed?

A: If the direct drive meets your application torque requirements and your reliability and service needs, you don't need a gear drive.

Q: Do you typically add a key phasor and two proximity sensors per shaft?

A: The use of onboard speed monitoring is not typical for standard industrial gear drives. Some applications, such as marine gear reducers, require them. As condition monitoring and IIoT gear drives become more popular, this will become a popular option if the motor speed cannot be measured directly.

Q: Does the environment affect the service factor?

A: The application and expectations for reliability, overload, and life affect service factor. The physical environment does not, although its temperature, altitude, slope, etc. should be defined so that the gear drive and accessories can be selected to accommodate it.



Top Plant
The Top Plant program honors outstanding manufacturing facilities in North America.
Product of the Year
The Product of the Year program recognizes products newly released in the manufacturing industries.
System Integrator of the Year
Each year, a panel of Control Engineering and Plant Engineering editors and industry expert judges select the System Integrator of the Year Award winners in three categories.
May 2018
Electrical standards, robots and Lean manufacturing, and how an aluminum packaging plant is helping community growth.
April 2018
2017 Product of the Year winners, retrofitting a press, IMTS and Hannover Messe preview, natural refrigerants, testing steam traps
March 2018
SCCR, 2018 Maintenance study, and VFDs in a washdown environment.
June 2018
Machine learning, produced water benefits, programming cavity pumps
April 2018
ROVs, rigs, and the real time; wellsite valve manifolds; AI on a chip; analytics use for pipelines
February 2018
Focus on power systems, process safety, electrical and power systems, edge computing in the oil & gas industry
Spring 2018
Burners for heat-treating furnaces, CHP, dryers, gas humidification, and more
April 2018
Implementing a DCS, stepper motors, intelligent motion control, remote monitoring of irrigation systems
February 2018
Setting internal automation standards

Annual Salary Survey

After two years of economic concerns, manufacturing leaders once again have homed in on the single biggest issue facing their operations:

It's the workers—or more specifically, the lack of workers.

The 2017 Plant Engineering Salary Survey looks at not just what plant managers make, but what they think. As they look across their plants today, plant managers say they don’t have the operational depth to take on the new technologies and new challenges of global manufacturing.

Read more: 2017 Salary Survey

The Maintenance and Reliability Coach's blog
Maintenance and reliability tips and best practices from the maintenance and reliability coaches at Allied Reliability Group.
One Voice for Manufacturing
The One Voice for Manufacturing blog reports on federal public policy issues impacting the manufacturing sector. One Voice is a joint effort by the National Tooling and Machining...
The Maintenance and Reliability Professionals Blog
The Society for Maintenance and Reliability Professionals an organization devoted...
Machine Safety
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
Research Analyst Blog
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
Marshall on Maintenance
Maintenance is not optional in manufacturing. It’s a profit center, driving productivity and uptime while reducing overall repair costs.
Lachance on CMMS
The Lachance on CMMS blog is about current maintenance topics. Blogger Paul Lachance is president and chief technology officer for Smartware Group.
Maintenance & Safety
The maintenance journey has been a long, slow trek for most manufacturers and has gone from preventive maintenance to predictive maintenance.
Industrial Analytics
This digital report explains how plant engineers and subject matter experts (SME) need support for time series data and its many challenges.
IIoT: Operations & IT
This digital report will explore several aspects of how IIoT will transform manufacturing in the coming years.
Randy Steele
Maintenance Manager; California Oils Corp.
Matthew J. Woo, PE, RCDD, LEED AP BD+C
Associate, Electrical Engineering; Wood Harbinger
Randy Oliver
Control Systems Engineer; Robert Bosch Corp.
Data Centers: Impacts of Climate and Cooling Technology
This course focuses on climate analysis, appropriateness of cooling system selection, and combining cooling systems.
Safety First: Arc Flash 101
This course will help identify and reveal electrical hazards and identify the solutions to implementing and maintaining a safe work environment.
Critical Power: Hospital Electrical Systems
This course explains how maintaining power and communication systems through emergency power-generation systems is critical.
click me