Note: Descriptions are shown in the official language in which they were submitted.
Wo gS/23032 ~ ¦ ~ 3 3 7 ~
Method and device fo~ imn?~rtina ~n?.i-friction orooerties to a
m~?~allic ~ ir~
TECHNICAL FIELD
S
T~le ~resent invention relates to a ~lethod and a device for
ac~._evint3 an~ friction properties i!l a metallic wire by
coating ~h'? wire with an anti-friction substance ~lubricant)
before a s~bs~ ent winding, coiling, bending, curvins, or
1~) ot~le~ shaping of the wire. The invention preferably relates to
a method and a device in which the lubricant is applied by
means ~ r an applicator, which is arranged in the form of a
por~ .s fibrous material whose porosity is completely or
r-.rtially filled with a lubricant for coating the wire.
1~
BACKGROUND ART
Manufacturers of rr.etallic wire for use as insulated winding
wire in electric windings coat the wire with a lubricant in
20 order to impart good anti-friction properties to tt~e wire. By
a lubricant is meant in this application a paraffin, a wax, or
another substance with a lubricating effect, or a mixtllre of
two or more of these substances. The melting temperature of
commonly occurring lubricants is between 50 and 70 C.
Users of insulated winding wire, for example those who
manufacture electric machines or components, are very
dependent on t~le wire to have good anti-friction properties
along its entire length without interruption. Good anti-
30 friction properties allow the wire to be positioned in anapplication, and allow the wire to easily slide into position
suc~l that the winding does not take up larger space that is
required by the application.
35 Also manufacturers of metallic wire for use as resistance
wire, for example wire for heating coils, coat the wire with
a lubricant, one reason for this being for the wire to easily
slide into ~le desired position, and another reason being to
21 83373o9s/23032 PCr~E~5/00181
reduce t}~e ~ear on tosls whic~l are used for coiiing or other
form of shapin3 whereir1 tne ~ e ~s berlt cr c~lrved.
Usually there is used a lubricant which is solid during
5 winding and coiling, respectively, suc~ as a paraffill, a wax,
or another substance with a lubricating effect, or a mi~.ture
of two or~ more of these substances. T~le melting temperature of
commonly occurrin~3 lubricants is between 5~ d 70~.. When
coating a metallic wire with such a lubricant, the substance
lO is dissolved in an organic solvent such ac described ill US
patent specifications US 4 545 323 and US 4 385 435, for
example petrol, but also other volatile or3anic solvents are
~sed. Since normally very small quantities of lubricant is t~
be applied to t~le wire, the concentration of such substan~ce i
l5 the solvent is low. The solution normally has a solid content
of between 0 . 05 ~ and l ~ . The solution is applied to the wire
by allowing the wire to pass through a wove1l tape or cloth, or
a felt to which the solution has bee11 added, preferably by the
tape~cloth,'felt suckin3 up the solution.
Considerable health hazards and safety risks exist in connec-
tion with the handling of these very inflammable and volatile
solutions. In addition, the volatile solution evaporates from
the coated wire into the air, which entails a negative load on
25 both the indoor and outdoor environment.
The method also entails disadvantages from the quality point
of view since it is a problem to control the applied amount of
lubricant .
Another known method is to impregnate string or other form of
twined or woven wire with a lubricant of the same type as
mel1tioned above . sy windinq the strin~3 impr egnated with lubri -
cant a number of t~1rns around the wire, the lubrica1lt will
~5 melt by the intrinsic heat of the wire and is applied to the
wire . However, in this method the string of ten breaks . Such a
rupture leads to the wire being completely without lubricant
over a long distance until ef forts have been made hy the
wo~s/23032 , 2~ 8337~ PcT~s~sl(lol~l
operators to joir~ the string together. In addition, it is
difficult t., obtain dl} evC~n àistrlh~ltioll of l~lbr~icarlt around
the ~ire since most of the substar~ e ~lelts from the string on
the first ~0 degree segment. ~rhe equipr~.ent is complicated,
5 which entails high investment costs . I`he cost of str ing and
maintenance is judged to becor~.e considerable.
ne r~ Ct of the i.~ention is to solve the above-mentioned
~roblems when applyin~ lubricant to a wire, such that the need
lC of using solvellt. irl ;Iny form is eliminated.
Anot}ler ohject of the invention is to suggest a method and a
device in w~licll che amount of lubricant applied to the wire
~?n be cont~L~lled at any time and at any point of the surface
15 of the w~re, and can be changed by simple setting during the
applicat ion .
It is a further object of the invention to sug~est a method
and a device to apply and distribute lubricarlt on a wire,
20 irrespective of the diameter of the wire.
Yet another object of the invention is to suggest a device
with a simple composition with few movable parts to obtain a
high reliability at a low cost.
SUMMARY OF THE IN~JENTION
~he above objects are achieved when the invented process and
the invented device are used to coat a metallic wire with a
30 lubricant for the purpose of imparting anti-friction proper-
ties to a metallic wire. According to the invention, a lubri-
cant is melted in connection with the substance being supplied
to a dispensing container-. sy a lubricant is meant a substance
or a mixture of substances having lubricating effect. ~he
35 melted lubricant is transferred to the applicator while con-
trolling the flow of the melted lubricant from the dispensing
container to the applicator, preferably kly means of a step-
less, controllable dispensing member. In t}le invented process,
Wo 9~123(~32 F~ J,~
4 2 1 83373 ~
d solid lubricant is melted in connection with it being
supplied to a dispensillg containeL. T~e dispellsing container
is designed Wit~l a space in W~liC~I the melted lubricant is
received arld collected.
At or near t~le disperlsiny container, means for heating the
dispensing container are provided. When starting the process,
the dispensing container is filled, while melting t~e luLri-
cant, with melted lubricant to a suitable level, the working
10 level, which is maintained essentially constant dur.~ ng the
process, that is, the same amount of lubricant as is consumed
is supplied to the dispensing container by melting. The heat
developed at or near the dispensing container melts rhe solid
lubricant which thereby runs do~n into the dispensing c~n-
15 tainer through one or more tubes, filling tubes, which openout below or on a level with the working level. Melted lubri-
cant is supplied to the dispensing container from arl accumu-
lator container which is filled with solid lubricant and is
placed near, preferably above, the dispensing container. The
20 dispensing container is designed of a material with good
thermal conductivity. The accumulator container and/or the
dispensing container are~is provided with contact surfaces and
other means such as flanges to obtain a good heat transfer
from t}le heated dispensing container to the accumulator
25 container and to fix these containers relative to each other.
The accumulator container is provided with openings which are
tightly connected to the filling tube of the dispensing con-
tainer but is otherwise tightly sealed. Through t~le heat
transfer from the heated dispensing container, the lubricant
30 is melted irl the accumulator container and runs t~lrough the
filling tubes do~1m into the dispensing container. Wherl the
working level has been attained, the level in the dispensing
container will be maintained essentially constant since t~le
sub-atmospheric pressur-e in the t ight accumulator container
35 ellsllres that only t~le amount which is consumed and obtained
from the dlspensing containeL will be filled from the accum~-
lator container. Esserltially all lubricant which is trans-
ferred from the dispensin~ container to the applicator is
WO g.~/23032 2 1 ~ 3 3 ~ h~ ' IXI
coated on t}le metallic ~ re. In certairl errlbodiments the
âccum~llator contailler i.s pro~ide~1 Wit~l means for indicatin~3
t~le âmount Gf lubricant irl the accumulator container, for
example in the form of a level glass. The dispensing container
5 and t~ie applicato~ as h~ell as the channels whic~l interconnect
t}lese are preferably maintained at a tem~erature exceedi.ng the
melting temperatuI~e of t}le lubricant. ~Jsually lubricants are
used which have a mel~ y temperat-lr~ of S~J to ~0C. The
temperature of th~ l~lbricant can be controlled to influence
10 the viscosity ;~f tne melted lubricant and hence the result of
the appllcaticl of the l~!bricant. Acc~rding to the invention,
the wire is hec~ted, prior to or ir connection with t~le passage
through the app icatoI, to â tr~inperature exceeding the tempe-
rature of the lub~. rant.
In certain embodiments the holder, arranged around the appli-
cator, ând the dispensing container comprise interconnecting
channels for transferring melted lubricant from the dispensing
container to the applicator. To control the flow of melted
20 lubricant from the dispensing container to the applicator, and
to clo&e and oper! the channels, respectively, for this flow,
dispensing members, preferably stepless controllable dispen-
sing members, are provided in certain embodiments of the
invention. These members are, for example, arranged in the
25 form of one or more valves irl which a cone or a needle is
closed against a seat. In one embodiment the valve is opened
and closed, respectively, by controlling the position of the
needle by an electromagnet. The flow through the valve is
thereby controlled by signals which indicate t~le time during
30 which the valve is opened and the time between the openings.
In an alternative solution, a motor is used for controlling
the openingiclosing of the valve, ~hereby also t}~e position of
the valve in I elation to the seat can be controlled for con-
trolling the fl~w through the valve. !lormally, the flow of
35 melted lubricant to the applicator is controlled so as to
correspond to a dosage of lubricant on the surface of the wire
of lOrng/m2 to lg/m2 wire s~lrface.
wo ~C,23032 2 1 8 3 3 7 3 PCTISE9~ 81
Froln the dispensir~ container, melted lubrican~. flows to the
applicator. ~ is flov~ lS pref*L-abli~ accomplished by designing
the applicator o~ a f ibr~ous, porous material which, by the
capillary forces obtained whell the applicator is compressed by
5 2 holder arourld the passing wire, sucks melted lubricant fror
the dispensing container. Since lubricant is consumed at the
surface where the applicator contacts the wire, the contents
of lubricant in the applicator is always lowest near the wire,
whereby a driving force, a suctiorl, arises for transport o~
`.0 lubricant to this area in order to maintain fluid balance in
the applicator. In olle embodiment of the invention, the appli-
cator is designed with a wedge-shaped cutout which is arranged
around the wire. A holder is arranged around the applicator.
In clamped state, this holder has an inner diameter which is
15 smaller than the outer diameter of the applicator in non-
compressed state. When the holder is clamped, the applicator
is compressed and the C~ltOUt is closed around the wire. This
leads to a situation, at the centre of the applicator near the
wire, whereby the applicator will make contact around the
20 whole periphery of the wire with a resilient contact pressure.
In certain embodiments, the holder comprises means for ensu-
ring that the applicator is retained in the holder and is not
pulled out of the holder by the wire.
25 In a preferred embodiment of the invention, the melted anti-
friction substance is distributed around the periphery of the
wire in the applicator by means provided in the fibrous porous
applicator which conduct and control the flow of the melted
lubricant through the applicator. Preferably, a distributor in
30 the form of a layer, impenetrable to the lubricant, is provi-
ded with openings in the form of holes or slits whereby the
flow of the melted l~lbricant from t~le channels of the ~lolder
to the wire is controlled to obtain the desired coating on the
wire. The distributor layer is arranged inside the applicator
35 arld is made of a material which is not destroyed by t~e tempe-
rature of the melted lubricant, preferably a plastic or a
metal foil.
wo g~3o32 2 1 8 3 3 7 ~ 18~ '
B~IEF DESCRIPTICN OF T~IE ~!RA~?INGS
e inverltion will be de.scrl}~ed in greater detail in the
foll~wing with reference to the accor.~.panyin~g dr~awin~s and be
eY~er.lplified by a preferred embodiment, w~lerein an enamelled
winding ~.~ire for windin~ purposes lS coated with a meltable
lubr~icant of paraffin and/or wax type, whic~l is the most
comr~lorl lubricant.
Figure 1 shows all the ir~.;ortant parts of the in,~ention and
its design. Certain part~. are sectioned to show he method
more clearly.
Figure 2 shows the applicatoL 4 with di~ributors 7 and the
wedge-shaped CUtO~lt 8.
Figure 3 shows t~le accumulator container 13 with legs 19 and
the lower level of the hole 20.
DESCRIPTIo~ OF THE PREFERRED EMBC)DIMENTS
In the process for coating a metal wire Wit~l a lubricant as
shown in Figure 1, a metal wire 2 passes throug~ an applicator
4 where the wire is coated with melted lubricant. The melted
lubricant is sucked by the capillary forces, which arise in
the appli.cator 4 during the process, from a dispensing con-
tainer 9. The dispensing container 9 is provided with a heater
10 which develops heat whereby the lubricant is melted w~ile
being supplied to the dispensin~3 container. The dispensing
container is provided with dispensing members 11, 12, 15, 16,
17 for controlling the flow of melted lubricant which is
sucked to the applicator 4~ Irl ~igure 1, a heater 10 is shown
in the form of an electr ic resistor element which is controll-
ed by a temperature reg~llator 24, but, of course, also other
forms of controllable heat sour~ces, such as coils traversed by
hot water, may be used.
To melt the lubricant and maintain it floating during the
Wo 9~23n32 2 1 8 3 3 7 3 ~ 181
procesr" t~le ternperature regulator 24 is set at a ~1igher
temperat~lre t~lc1ll the meltirl~ temperatu~e for t~le l~ubricant
W~liC}I i'i to be applied onto the wire 2, which has a constant
rate thro1lgh the applicator 4.
The heat source ln placed in the dispensing container 9 heats
the ent ~-e device to a temperature which is higher than the
melt r~9 temr~erature of the lubricant. For commonly occurring
lubric~ints, The melting temperature is between 50 and 70"C.
The ~1~ at source lO has a strategic location in the dispensing
cor.tainer 9, which means that the channel 14 always has the
.I_ghest and most urliform temperature to ensure at each time
t~e flow of the dispensed lubricant in the system.
The accurnulato~- container 13 is filled with lubricant through
the hole 20 in a special filler (not described). After filling
the accumulator container 13, it is to cool to room tempera-
ture, which causes the lubricant to assume solid state. This
20 allows the container to be handled in all situations, without
considering the contents.
sy placing an a'ccumulator container, filled with lubricant, on
the dispensing container 9, heat will be transferred from the
25 dispeTIsing container 9 to the accumulator container 13 through
the contact surfaces and the special flanges l9 with which the
accurl1ulator container is provided. These also have the task of
fiY.ing the contair~er ~o the dispensing container 9.
30 The heating of t~e accumulator tank 13 causes the lubricant to
r~lelt arld to run down into the dispensing container 9 through
the hole 20. When the working level 18, which is t~le same as
the lowermost point of t~le hole 20, is attained, the level 18
will be constant and filled with the same amouTIt as is consu-
35 med. This achieved by t~1e sub-atmospheric pressure which is
generated in the accurn1llator container. In t~le described case,
the container 13 contains lubricant foT about lO days.
WO ~23()32 2 1 8 3 3 7 3 P~ SE9~Jl10181
9
The accllrn~llator cc~ntaln r 13 ~las a level glass 21 ~ihich
indicate~ nen t;~e cont llleL i;; to ~-~ r-eplac~d b~ a filled
container .
5 The dispe~lsin~3 container 9 i9 ~esic~r~ed with a space 18 for
lubricant and with channels 1~ the task of w~lich l5 to con-
duct lubricant to the applicator 4 whic~l is placed in the
holder 3. The holder may be mounted in a h^~iz~ ta ~ a
vertical position depending on the direction ~ the wlre 2.
10 The dispensing container- 9 is provided Wit.l ali dd~lstable
fixing element 1 which makes it possible to adj~lst th~ device
accor~diny to the wire 2.
The dispensing membe~ ll. 12 15 16 17 cons .sts of an Lec-
15 tromagnet 15 the armature 17 of which is connectecl ~IJ theneedle 12 via an elastic sleeve 16 which causes the needle 12
to direct itself to the position of the valve seat 11. This
means that a tight shut-off f~lnction can be obtained in a
simple manner~ rrhe dispensing rr,ember is controlled by timed
20 signals by means of a control device 25 the time during which
the valve 12 12 is open and the time between the openings.
The holder 3 for the applicator 4 is eo;uipped with a transport
channel which is connected to the transport channels 14 of the
25 dispensing container 9.
The holder 3 has a circular hole in which the applicator 4 is
compressed when the applicator 4 is applied in the holder 3.
This compression leads to the creation of a resilient contact
30 pressure at the centre of the applicator 4.
To prevent the applicator 4 fIorr, beirlg pulled along by the
wire 2 a yoke 5 serves as a counter-support~ The yok~e 5 may
be placed O~l both sides of the appl.icator 4 depending on the
35 direction of movement of t}le ~ e 2~
The ~lolder 3 also has a slit W~liC~I makes it possible for the
wire 2 to placed at the centre of the ~lolder 3 without being
W(:~ 9sl23l}32 2 ~ 8 ~ 3 7 ~ PCT/SE95100181
cut off. The holder 3 has a safet~ chan~lel conl}ected to the
Cr~ar!nel 6, W~liC}l alwd~ 3l~arantee.i a dlspense~ flo~ to the
applicator ~i, even if t}ie lubricant s~-ould contain particles
sealillg the applicator 4.
The applicator 4 is made of a fibre-composed suckin~3 material
which, Wit~l capillary properties, is capable of transporting
1 l.;`.,L lcant .
10 r~he applicator 4 has a ~!edge-shaped cutout 8 so that it can be
applied onto the wire ~ and, when the applicator 4 is placed
in the h~lder 3, so ~hat it can be compressed and create a
c~ tact press~lre al ound the wire 2 .
15 To distrl~,u~e the lubricant aro~lnd the entire circumference of
the wire 2, the applicator 4 is provided with distributors 7
which conduct and control a liquid substance, which in the
described case is a melted lubricant.
2n T}le distributor 7 is placed in cut sections in the applicator
4 and the lubricant is guided to the connectiorls W~liC~I are
provided in the applicator 4 between the channel 6 and the
wire 2. Connections may be provided in the distributor 7
through holes or slits, or as a space between two
25 distributors.
T~le distributors are made of a heat-resistant material in
which the lubricant cannot pass. The material may advanta-
3eousl~r be plastic or a metal foil.
30All the lubricant which is consumed will end up on the wire 2
sirlce this is the only consumer in the device when the wire
has one movement. IJsually, t}le wire is coated with lubricant
corresponding to a dosage of lubricant of frorl lOmgim~ to
35 lg/m2. The regi~ earest the wire 2 in the applicator 4
always contains least lubricant, which rneans that the l~bri-
cant strives to arrive at this region in order for the appli-
cator g to achieve fluid balance, whereby the transport of
wo 9s~2303~ 2 ~ ~ ;3 3 7 3 ~ - `
11
l~lbrlcant from the dlspensinq corltalne~ t~o trle applicator i5
mdint,ained .
.,
