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FAQs - Overhung Load Adaptors

overhung load adaptor
Welcome to our overhung load adaptors FAQ page. Whether you're a beginner or an industry pro, this resource is your go-to source for answers to common queries about load adaptors. Explore the essential information you need to understand, select, and maintain these crucial components.
Overhung Load Adaptors (OHLA®)
What is the load rating for the Overhung Load Adaptors (OHLA)?
Although some references use an Overhung Load Rating to determine selection for an application, this is a static rating which neglects many factors that influence the lifetime of the unit.  Zero-Max uses a combination of dynamic load rating (bearing life estimate based on application details) and over 40-years of industry-leading experience to determine the fit for an application.  Strength of the input connection should also be considered in OHLA selection.  
The estimated life calculation can be done by the factory with some basic application information including:
  • HP
  • Speed (rpm)
  • Type of load – fan, blower, pulley, etc.
    • If a pulley, the diameter of the pulley and the distance from the face of the OHLAs output pilot are critical
    • If an axial fan, the fan weight, and the amount of thrust load are critical.  If the thrust load is not known, this can be calculated if the diameter of the fan, the CFM air flow, and the static pressure are provided.
  • Mounting Orientation (horizontal; vertical, shaft-up, or vertical, shaft-down)
  • Hydraulic motor/pump part number and/or a catalog page for the motor/pump
It is recommended to contact Zero-Max with your application specifications so an accurate L10h bearing life and input connection strength can be evaluated. Zero-Max Engineering can offer customization options to improve OHLA life expectancy in many applications if a standard unit will not suffice.
What are the recommended lubrication methods?
Grease Lubrication is considered standard and is the preferred method for the vast majority of our OHLA applications.  With grease, there is little or no leakage concerns, low maintenance, and it provides acceptable life in most applications.  Unique applications and/or personal preference may drive the use of static oil or circulating oil flow-thru lubrication instead.  Please contact the factory in these instances as often slight modifications to the OHLA housing must be done to provide for this.
Applying grease to the spline teeth on the motor or pump shaft is also recommended at the time of installation.  If a keyed motor or pump shaft is used, it is also a good idea to add grease to the motor or pump shaft and key at the time of installation.
The amount and type of recommended grease is listed in the “OHLA Lubrication and Operation Guide” under the Downloads section of this web-site.  It is important to follow these guidelines.  Please ensure to avoid over-filling, as that can lead to problems as well.  Following the OHLA Lubrication guidelines will offer best conditions for longer life. Contact the factory for further details.
Can the OHLA’s be mounted vertically or at an angle / incline?
Yes.  However, standard OHLA units are configured for a horizontal mounting (shaft parallel with the ground).  Applications requiring a vertical shaft mounting orientation, or that are mounted at an angle or incline, will require special features to retain lubricant in the uppermost bearing and may require additional modifications as well.  These features vary depending on the model of the OHLA and the application’s operating parameters.  Please contact factory for details if you have a vertical or inclined mounting orientation.
My OHLA is running hot, what temperature is permissible?
It is normal for an OHLA to run warm or perhaps even ‘hot’.  Heat in the OHLA may be generated by the load, speed, lubrication method, and/or ambient temperature in the application.  Running an OHLA with no load may also cause excessive heat.  If you suspect your OHLA may be running excessively hot, you can use a temperature probe or infrared thermometer to check the operating temperature.  Standard OHLA units are designed to operate between -40°F to +212°F (-40°C to +100°C).  If your OHLA is running hotter, please contact the factory to discuss your application and the lubrication for the OHLA.
How do I identify my OHLA for replacement?
If your OHLA is a special, it will have a special part number stamped into one of the machined mounting pads at the base of the OHLA housing (see below).  Special part numbers start with the letter ”L” and are followed by 6 numeric digits.
Bottom view of OHLA
If no part number is stamped into either of the machined mounting pads at the base of the OHLA housing, you have a standard OHLA.  Please call the factory or refer to the OHLA catalog to match up to the housing and shaft dimensions to the corresponding standard model part number.
My pump or motor will not fit up to a standard OHLA, can Zero-Max make one to fit?
Yes.  The standard OHLA product line is designed primarily for the most commonly used SAE hydraulic pump and motor mountings, in addition to a popular non-SAE mounting.  Should you find the mounting needed for your application is not in the catalog, please contact Zero-Max to determine the necessary mounting requirements.  Over half of the OHLAs we make are specials including those we modify to accommodate special mounting and/or shaft dimensions.  Zero-Max can design transition adapters for DIN, ISO, IEC, NEMA, and other non-SAE requirements, as well as step-up or step-down adapters.
What if I have a challenging operating environment?
No Problem!  All our standard OHLAs have been field-proven to survive in harsh environments.  Zero-Max also manufactures heavier-duty models as well as special OHLAs when needed for an application.  We have the expertise and experience necessary to guide you to the right selection.  Our extensive knowledge of successfully utilizing a wide range of materials and coatings can assure long term protection and maximum value.  Please contact us with your requirements to learn more.

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