Kirill VOINOV[1]
HOW TO DIMINISH THE WEAR FOR CHAINS WHICH ARE
TIGHT ON THE SPROCKETS
Summary. The speech in this article is going
about the standard bush-roller chain for bicycle, machine-tool or for conveyor.
And the chain can be settled in the different spatial position, namely in
vertical, horizontal or in the slope. In all these cases we have to stretch the
chain periodically because of wear during the operation. For this aim the
people apply different contact methods: spring-loaded rollers, flat springs (as
a pair of friction), stretchers and so on [2, 3]. But here we describe a new
way how to stretch the chain constantly and without any additional pairs of
friction at all [1, 2, 3] using only magnet. It simplified design and enhanced
the resistance against wear essentially.
Keywords: Bush-roller chain, sprocket, stretchers
Jak zmniejszyć zużycie łańcuchów, które ciasno przylegają do ZĘBATKI
Streszczenie.
W tym artykule mowa będzie o
standardowym tulejkowym łańcuchu dla rowerów, obrabiarek lub do ciągnienia.
Łańcuch może być osadzony w różnej pozycji przestrzennej, czyli w pionie,
poziomie lub po skosie. We wszystkich tych przypadkach trzeba rozciągać łańcuch
okresowo, ze względu na zużycie w czasie eksploatacji. Do tego celu ludzie
stosują różne metody kontaktowe: wałki sprężynowe, sprężyny płaskie (jako parę
tarcia), napinacze i tak dalej [2, 3]. W artykule opisano nowy sposób, jak
rozciągać łańcuch stale oraz bez użycia dodatkowych par tarcia [1, 2, 3] jedynie
przy użyciu magnesu.
To istotnie uprościło konstrukcję oraz zwiększyło odporność na zużycie.
Słowa kluczowe: Łańcuch, zębatka, napinacz
1. INTRODUCTION
In up-to-date machines, mechanisms, different
equipment there are various working elements or the whole junctions which
during many years didn’t have any alterations in their design, very likely,
with the exception of technology to manufacture the parts. For example, let’s
take the standard bush-roller chain for bicycle or for conveyor. It is
stretched and put on the sprockets. In practice the next important and main
characteristics can be changed: the long of the chain, pitch, mass, the
distance between sprockets, diameters, number of tooth and members, number of
the lines, power and high-speed factors, peculiarities of tension and
lubrication.
As a tradition way of the relative position for
sprockets is their vertical strengthening on the axis. In the capacity of the
tension device (stretcher) we usually use the spring-loaded rollers mounted on
their axis with frictionless bearings or sprockets, and seldom they are the
flat springs. Moreover we can draw a chain by means of the spiral working principles which are
accommodated in the special grooves. In these cases it demands for the most of
these mechanisms the manual adjustment by means of the transference of the
stretchers in the slots.
Although these named principles have been using
for a long time, they are rather complicated during manufacture, have not high
reliability for operation, forms the additional pairs of friction and wear out
the chains.
During operation process a chain always has its
natural wear and tear, the chain becomes longer that’s why the angle of the
girth for the tooth will be smaller. It reinforces the vibration and
oscillations. In its turn this situation changes the distribution of efforts
and strains both in chain and in tooth of sprockets. If the tension for the
chain will be too weak, the chain can jump off the sprockets at all. In this
case it brings to damage or even to fracture of our mechanism.
And what is more in practice we have a large
problem with chains if they are placed in
a horizontal position. In this case the wear for chain and sprockets grows
repeatedly and essentially. The point is that in such situation the sagging of
chain doesn’t useful both for chain and for the tooth of sprockets because of
their intensive wear. Our practice in operation of many chains shows that the
wear and tear we can see not only on the surfaces of tooth but on the “body” of
sprockets also.
2. METHODOLOGY OF
EXAMINATION
That’s why
the described situation it is needed to consider as the great problem. In this
article we show the new and very simple/effective method how to solve it (Fig.
As it was
mentioned above, if there are special rollers or sprockets to stretch the
chains we use bearings in a design, apply lubricant in which any abrasive can
get in it during operation. It leads both a spoiling for lubricant and wear for
bearing.
The same
negative pictures we can see if we use in the design the spring plates.
In my way
the all named negative moments connected with chains and sprockets accommodated
in various space position (vertical, horizontal or with a slope) were deleted
in full.
For
example, at the vertical arrangement of the chain (Fig. 1) the effective
tension for the links of chain we reach by means of constant magnet 4. The
presence of the block with
a screw helps us to regulate the position of our (constant or even electrical)
magnet both in vertical and in horizontal disposition because the block is
placed in a guide.
Fig. 1. Example
how to realize the pull for the chain without any contact with it: 1 and 2 –
sprockets;
3 – chain (for example, bush-roller); 4 – magnet; 5 – vertical support; 6 –
block; 7 – keeper screw; 8 – basis
Rys. 1. Przykład jak zrealizować naciąg łańcucha bez
jakiegokolwiek kontaktu z nim: 1 i 2 – zębatki; 3 – łańcuch (na przykład, tulejkowy);
4 – magnes; 5 – podpora pionowa; 6 – blok; 7 – śruba gwintowana; 8 – podstawa
If the
chain is very long, we can set up two magnets on the definite distance between
two sprockets. In any case the magnet makes for the larger girth of sprockets
tooth; automatically and constantly tighten the chain during operation deleting
all negative aspects named above.
If the
chain has the horizontal disposition, we use two magnets once again but set up
magnets quite near to the sprockets above of the two lines of a chain. By this
way we raise slightly the two lines of a chain at the same time and hold the
chain in such position
constantly. Using this way we axise both chain and sprockets and it is very
important. In this position our mechanical system will work without any
distortion (Fig. 2).
In our
experiment we have used the standard bush-roller chain for bicycle. The
distance between axes of sprockets was
Fig. 2. Schematic
version of a distribution sprockets and magnets which raise slightly the two
lines
of a horizontal chain simultaneously: 1 and 2 – sprockets; 3 – chain (for
example, bush-roller); 4 – magnet; 5 – vertical support; 6 – block; 7 – keeper
screw; 8 – basis; а – the disposition of
a chain if we use magnets; б – sagging of a chain if the magnets are
absent (the old traditional/standard sketch of assembling)
Rys. 2. Schemat
rozkładu kół zębatych oraz magnesów, które jednocześnie nieznacznie zwiększają dwie
linie poziome łańcucha: 1 i 2 – zębatki; 3 – łańcuch (na przykład, tulejkowy);
4 – magnes; 5 – podpora pionowa; 6 – blok; 7 – śruba gwintowana; 8 – podstawa;
a – dyspozycja łańcucha, jeśli używamy magnesów, b – ugięcia łańcucha jeśli
magnesy są nieobecne (stary tradycyjny/standardowy szkic montażu)
Using such
method of assembly for chains we decrease wear of chains and sprockets,
vibrations, strain in parts, and the design becomes cheaper and has high
reliability in operation. Moreover the experiment shows that the sagging of the
chain doesn’t take place at all in a position for magnets near the sprockets.
So in this case the coefficient of sagging will be 1 (instead of 6 for
horizontal transmissions and 3 if the slope has ≤ 40o). For
the preliminary tension F0 of chain from the excessive sagging they
use the next formula:
F0 = Kf q a g [N]
(1)
where:
Kf – is the coefficient of sagging;
q – mass of
a – the distance between axes of
sprockets, [m];
g – acceleration (9,81 [m/s2]).
Thus, in our
case if we have got the horizontal position, the chain and sprockets raise
slightly, and the coefficient of sagging will be 1 (as in a vertical position
for chain and sprockets).
What kind of picture
we can observe if the chain and sprockets have the vertical position? Put our
magnet in the space between of the two lines of chain (Fig. 3). In this case
the both lines of chain have been attracting by magnet to each other constantly
during the all cycle of operation and they encompass of sprockets better.
Fig. 3.
The demonstration of setting for the magnet using special test bench
Rys.
3. Ustawienie magnesu za pomocą specjalnego stanowiska testowego
In the
process of deterioration both the chain and sprockets, and stretching or
lengthening of a chain our magnet will always attract both lines of chain.
Another positive result of my observation in this case is the next: about one
additional tooth will be encompassed by
pitch of the chain, that’s why it works much better with magnet. The
rapprochement for the two lines of chain was about
If the
distance between sprockets are big, set two or three magnets between the lines
of chain. They will calm the vibration of the oscillation, too.
Now here
it is the picture which demonstrates us the real shape of chain and sagging in
a horizontal position with sprockets (Fig. 4 and Fig. 5). We made the experiment
using special test bench.
Fig. 4.
Laboratory stand to investigate chains and sprockets if they have a horizontal
disposition
Rys.
4. Stanowisko laboratoryjne do zbadania łańcuchów i zębatek dla ustawienia
poziomego
Fig. 5. Other
foreshortening when we can see as the magnet raised slightly the line of the
chain and put it in one plane with sprocket
Rys. 5. Inne
zniekształcenia, gdy możemy zobaczyć jak magnes podniósł nieznacznie linię
łańcucha oraz umieścił go w jednej płaszczyźnie z zębatką
Post-graduate
student S.V. Gusev executed many investigations connected with the new
technical decision. Namely, he carried out three experiments with each version:
1) for vertical position of the
bush-roller chain both without magnet (but with a standard version with two
rollers and a spring) and with a magnet, too;
2) for the horizontal disposition of the two sprockets both without
magnet (traditional way) and with magnet (this new method);
3) for slope with 45o.
And we had
got the next results. We managed to delete the additional pairs of friction
(two rollers, two shafts, four bearings), spring and lubricant at all. In this
case we needn’t to stretch the chain periodically (it fulfils our magnet
constantly). Moreover in this case the wear of chain was diminished till 3.9%
on average against of the standard design. For slope position using magnet we
decrease the wear more than 3 times. We decrease both vibration and the wear of
the chain till 8% (on average) against the standard design. For horizontal
position of disposition for sprockets using magnet we diminished the rate of
wear till 5.2 times against of the standard design (without magnet).
Warning:
any persons cannot use this technical novelties in practice to get any profit.
It can be done only after the financial contract of permission/agreement for
this signed by author K.N. Voinov. All rights are reserved.
3. EXAMINATION RESULTS AND
CONCLUSION
So, we
have got the new way to decrease essentially wear and tear for chains and
sprockets in their different space disposition (vertical, horizontal or with a
slope). This way helps to increase the reliability and durability both for
chains and sprockets during their operation.
Bibliography
1.
Патент
№2480367 по заявке
№2011124693
приоритет от
16 июня 2011. Натяжитель
цепи. Войнов К.Н.
зарегистрировано
в Госреестре
РФ 27 апреля 2013. [Patent №2480367 po zajavke №2011124693 prioritet ot 16 ijunja 2011. Natjazhitel cepi. Vojjnov K.N. zaregistrirovano v Gosreestre RF 27 aprelja 2013]. [In Russian: The patent application
№2480367 for №2011124693 priority of June 16, 2011. The chain tensioner. Voinov KN
registered in the State Register of the Russian Federation April 27, 2013].
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