Nexen HGP25 969053 - Manual (Page 15)

15 FORM NO. L-21277-B-1213
LUBRICATION
G
eneral
rPS
The pinion needle bearings are sealed and lubricated for
life and do not require servicing.
Nexen recommends lubricating the rack or individual roller
contacts every two million pinion revolutions or six months,
which ever comes first. However, lubrication may need
to be applied more frequently based on the application
conditions, and observable tooth or roller wear.
When lubricating the RPS, inspect the pinion rollers and
rack teeth for any abnormal wear patterns and ensure the
pinion rollers are not seized or have excessive play. Wear
on the edges of the rack teeth (not uniform across the
tooth face) or rings on the rollers indicate an alignment
problem which should be corrected to obtain maximum
system performance and life.
The rollers in new pinions, especially larger sizes, can seem
difficult to turn due to seal drag. Seal drag is reduced after
an initial break-in period.
THK AFC or AFA are recommended for rack tooth
lubrication. Both can be found on the RPS product
pages of Nexen’s website under accessories. Greases
for special applications such as food grade, vacuum, or
others are allowed if they use a synthetic base, a polyurea
thickener, and meet the following Kinematic Viscosity
Levels: CST@40C = 25; CST@100C = 5. Contact Nexen
for recommendations on alternative greases.
The RPS can be lubricated in two ways:
1. Apply grease to the pinion rollers and roll the pinion
back and forth five times over one meter of rack,
repeating the process for each meter of rack.
2. Using a swab apply a very small dab of grease on the
middle of each tooth face and roll the pinion back and
forth over the entire length of the run at least five times.
After initial application, wipe excess grease from the sides
of the rack and pinion body to prevent grease being ejected
off during operation and for general cleanliness.
Maximum RPS life will be obtained by following the
recommended lubrication intervals as stated above. In
some special applications, Premium and Endurance
grade of RPS rack can be operated without lubrication if
the maximum speed does not exceed 0.5 m/s [1.64 ft/s].
Typical lubrication free applications involve:
• Dirty environments where contaminates will be
attracted/stick to the lubricant on the rack creating
mechanical interference or an abrasive paste that can
accelerate wear.
• Food processing
• Clean rooms or applications where very low particle
emissions are desired
• Vacuum environments
• Applications where periodic servicing is problematic
If the RPS is operated without lubrication, there will be
some reduction in life of the RPS which will vary widely
depending on the application. Standard and Universal
grade RPS rack should not be run without lubrication.
Contact Nexen for more information.
HGP
The gearcase of the HGP geared pinion has been
filled with a high quality synthetic extreme pressure
grease and is considered to be “lubed for life”. It is not
recommended, therefore, that the geared pinion be field-
serviced. Contact Nexen in the event that the HGP
requires maintenance.
The HGP can be mounted in any orientation and requires
no special provisions for sealing or venting when
operating within the recommended ambient temperature
range of -5 to 40° C (23 to 104° F). Contact Nexen for
applications requiring the HGP to operate outside of this
temperature range.