Technical Information · issue 39 of 1996
Chains: STIHL Oilomatic system with oil reservoir
IssueTI 39/1996
Full text
Page 1 of 2
Technical Information
39.96
STIHL Oilomatic Chain Lubrication System with New Oil Reservoir
1.===General
Some STIHL Oilomatic chains now feature an oil reservoir in addition to the familiar oil channels.
The reservoir takes the form of a computer-designed bore in each drive link. It helps improve chain
lubrication, particularly at the bar nose and on the underside of the bar.
The further developed STIHL Oilomatic system (oil channel and oil reservoir) has since been patented for
STIHL.
2.===Method of operation
The Oilomatic oil reservoir functions in three
phases:
Phase 1 - Filling the reservoir
When the drive links of the rotating chain pass
the (matic ramp and the oil inlet hole, the
Oilomatic oil channel scoops up a fresh load
of oil and initially fills the oil reservoir. The oil is
then distributed as before to the bar rails and chain
rivets.
Phase 2 - Transportation of stored oil
689TI025 LÄ
The oil in the drive link reservoir is trapped by
the bar groove rails. Inertia prevents the stored oil
from flowing back into the Oilomatic channels
while the saw chain is running.
Stored oil is thus transported along the bar.
)Technical Information 39.96 - Page 2
Phase 3 - Distribution of stored oil
The centrifugal force which occurs at the bar
nose causes the oil in the reservoir to flow into the
Oilomatic channels. The oil reservoirs are emp-
tied in this process. This replenishes the oil supply
at the bar nose so that chain again has oil for
distribution to the bar groove and the chain rivets
while it travels along the bottom of the bar.
3.===Benefits
The Oilomatic oil reservoir provides additional
lubrication after the chain has travelled about half
way around the bar. This means that the bar
rails, the bottoms of the cutters and tie straps
and the chain joints are lubricated wear more
effectively.
The improvement in lubrication is particularly 5.===Spare Parts
beneficial because lubricating oil is mainly needed
on the underside of the bar.
The only additional spare parts in type 3970, 3973
and 3977 chains are the new drive links (with oil
reservoir). All other parts of the chains are exactly
With Duromatic bars the additional lubrication
helps reduce friction between the chain and the the same as before:
guide bar nose.
.325" drive link, .063" gauge 3603 662 1000
All the original features of Oilomatic saw chains,
have been retained.
4.===Availability
The following Oilomatic chains with the new oil
reservoir will be available in the future. The part
numbers remain unchanged:
Drive link
Chain Pitch gauge
type Version inch inch
3970 Rapid Micro .325 .063
3973 Rapid Super .325 .063
3977 Rapid Micro 2 .325 .063
The 3/8" Rapid (with .063" drive link gauge) and
3/8" Picco chains will be modified at a later date.
There are currently no plans to incorporate the oil
reservoir in .404" chains or .325" and 3/8" chains
with drive link gauges of .050" and .058".
Andreas Stihl - D1/MTK
1996 Andreas Stihl Technical Documentation 5915 Page 2 of 2
Extracted from the manufacturer's 2012 service catalogue. Most of these PDFs embed fonts with a shifted character map, so the text above was recovered rather than copied — read it as a faithful but imperfect transcription, and treat the page image above each block as the authority where the two disagree — the figures exist only there, because they are vector drawings that text extraction cannot keep.