VIBRATORY MECHANISM

MECANISME VIBRATOIRE

English Abstract

VIBRATORY MECHANISM
ABSTRACT OF DISCLOSURE
A road compacting drum is equipped with a dual
amplitude, rotational, vibratory mechanism. A shaft
rotatably mounted on the drum supports eccentric weights.
Casings secured to the shaft adjacent the weights have
chambers accommodating fluent mass. The fluent mass
comprise metal members, as steel balls, shot or liquid
metal, that move to a first location in the chamber
upon rotation of the shaft in one direction to increase
the amplitude of the vibration of the shaft and drum.
the fluent mass flows to a second location in the chamber
in response to rotation of the shaft in a direction
opposite the one direction to generally balance the shaft
to reduce the amplitude of vibration of the shaft and drum.

Claims

CLAIMS

1. vibratory mechanism for vibrating a member
comprising: a shaft means for rotatably mounting the
shaft on the member weight means eccentrically mounted
with respect to said shaft for rotation therewith to
vibrate said shift when rotationally driven, means
mounted on the shaft having a fluent mass which upon
shaft rotation in one direction moves to a first location
to augment the eccentric distribution of said weight
means thereby producing high amplitude vibration of the
member and upon rotation of the shaft in the opposite
direction said fluent mass moves to a second location
which tends to balance the eccentricity of the weight
means to produce low amplitude vibration of the member,
and means to selectively rotate the shaft in opposite
directions.
2. The mechanism of Claim 1 wherein: the means
for rotatably mounting the shaft on the member include
bearings rotatably supporting the shaft for rotation
about the longitudinal axis thereof.
3. The mechanism of Claim 1 wherein: the weight
means is fixed to the shaft adjacent the means mounted
on the shaft having a fluent mass and adjacent the first
location for the fluent mass.
4. The mechanism of Claim 1 wherein: the fluent
mass comprises a plurality of metal members.
5. The mechanism of Claim 1 wherein: the fluent
mass comprises a liquid metal.
6. The mechanism of Claim 1 wherein: the means
mounted on the shaft having a fluent mass comprise
casing means having a chamber accommodating the fluent
mass, said chamber having said first and second locations
for the fluent mass, said weight means being mounted on
the shaft adjacent the first location of the casing means.
7. The mechanism of Claim 1 wherein: the casing
means comprises a plurality of casings mounted on the


shaft, each casing having a chamber accommodating
fluent mass, each chamber having said first and second
locations for the fluent mass, each chamber having said
first and second locations for the fluent mass, said
weight means comprising a plurality of weights mounted
on the shaft, at least one weight being located adjacent
the first location of each casing.
8. The mechanism of Claim 7 including: partition
means located within the chamber of each casing to divide
the chamber into the first and second locations.
9. The mechanism of Claim 7 wherein: the fluent
mass comprises a plurality of metal members located with-
in the chamber.
10. The mechanism of Claim 1 wherein: the means
mounted on the shaft having a fluent mass comprises
casing means having a chamber for accommodating the
fluent mass, said chamber being concentric with the
longitudinal axis of the shaft, and at least one par-
tition means located within the chamber which upon ro-
tation of the shaft confines the fluent mass to a first
chamber portion in which the fluent mass augments the
eccentricity of the weight means and a second chamber
portion in which the fluent mass tends to balance the
eccentricity of the weight means.
11. The mechanism of Claim 10 wherein: said
partition means comprises a pair of walls, one of said
walls having a first section which extends across the
chamber defining part of a chord and a second wall having
a section that extends parallel to the chord of the first
section.
12. The mechanism of Claim 1 wherein: the means
mounted on the shaft having a fluent mass comprises a
casing means mounted on the shaft, said casing means
having a chamber accommodating the fluent mass, and
partition means located in said chamber providing said
first and second locations for the fluent mass, said
partition means comprising a pair of walls located in
said chamber, one of said walls having a first section


which extends from the axle across the chamber defining
part of a chord and a second section extended radially
from said shaft located generally perpendicular to the
first section, the other wall having a first section
which extends from the shaft generally parallel to the
chord of the first wall and a second section which is
radial with respect to the shaft, said walls lying in
the same semi-circle of the chamber, one of said walls
partly defining the first location for the fluent mass,
and the other of said walls partly defining the second
location for the fluent mass.
13. The mechanism of Claim 12 wherein: the weight
means is mounted on the shaft adjacent the first location
for the fluent mass.
14. The mechanism of Claim 12 wherein: the fluent
mass comprise a plurality of metal members located in the
chamber.
15. The mechanism of Claim 1 wherein: the means to
selectively rotate the shaft includes a reversible motor
drivably connected to the shaft.
16. A drum and vibratory mechanism for a road
compacting machine comprising: a generally cylindrical
shell having opposite ends, end walls secured to opposite
end portions of the shell a shaft located within said
shell between said end walls, means rotatably mounting
the shalt on said end walls, weight means secured to said
shaft, said weight means having an eccentric first mass
whereby upon rotation of said shaft said first mass causes
the shaft to vibrate, means mounted on the shaft having a
fluent second mass which upon rotation of the shaft in
one direction moves the fluent second mass to a first
location to augment the eccentric distribution of the
first mass thereby producing high amplitude vibration of
the shaft and shell and upon rotation in the opposite
direction said fluent second mass moves to a second
location to generally balance the shaft thereby producing
low amplitude vibration of the shaft and shell, and means
to selectively rotate the shaft in opposite directions.

11

17. The drum and vibratory mechanisms of Claim
16 wherein: the end walls have central apertures,
said means rotatably mounting the shaft comprising
housings extended through the apertures, means securing
the housings to the end walls, and bearing means mounting
opposite ends of the shaft on the housings.
18. The drum of vibratory mechanism of Claim 16
wherein: the weight means comprise a pair of weights
mounted on opposite end portions of the shaft, each
weight having an eccentric located first mass.
19. The drum and vibratory mechanism of Claim 16
wherein: the means mounted on the shaft having a fluent
second mass comprises a casing mounted on the shaft, said
casing having a chamber accommodating the fluent second
mass, and partion means located in said chamber pro-
viding said first and second locations for the fluent
second mass.
20. The drum and vibratory mechanism of Claim 16
wherein: the means mounted on the shaft having a fluent
second mass comprises a pair of casings secured to opposite
end portions of the shaft, each casing having a chamber
concentric about the shaft accommodating fluent second
mass, and partition means located in each chamber providing
said first and second locations for the fluent second
mass .
21. The drum and vibratory mechanism of Claim 20
wherein: the weight means comprise a pair of weights
mounted on the shaft adjacent the casings, each weight
having an eccentric located first mass, said first mass
being located adjacent the first locations for the fluent
second mass.
22. The drum and vibratory mechanism of Claim 20
wherein: the fluent second mass comprises a plurality of
metal members.
23. The drum and vibratory mechanism of Claim 16
wherein: the means mounted on the shaft having a fluent
second mass comprises casing means having a chamber for
accommodating the fluent second mass, said chamber being
concentric with the longitudinal axis of the shaft, and

12

at least one partition means located within the
chamber which upon rotation of the shaft confines
the fluent second mass to a first chamber portion in
which the fluent second mass augments the eccentricity
of the weight means and a second chamber portion in
which the fluent second mass tends to balance the
eccentricity of the weight means.
24. The drum and vibratory mechanism of Claim 23
wherein: said partition means comprises a pair of walls,
one of said walls having a first section which extends
across the chamber defining part of a chord and a second
wall having a section that extends parallel to the chord
of the first section.
25. The drum and vibratory mechanism of Claim 16
wherein: the means mounted on the shaft having a fluent
second mass comprises a casing means mounted on the shaft,
said casing means having a chamber accommodating the
fluent second mass, and partition means located in said
chamber providing said first and second locations for the
fluent second mass, said partition means comprising a pair
of walls located in said chamber, one of said walls having
a first section which extends from the axle across the
chamber defining part of a chord and a second section
extended radially from said shaft located generally per-
pendicular to the first section, the other wall having a
first section which extends from the shaft generally
parallel to the chord of the first wall and a second
section which is radial with respect to the shaft, said
walls lying in the same semi-circle of the chamber, one
of said walls partly defining the first location for the
fluent second mass, and the other of said walls partly
defining the second location for the fluent second mass.
13

Description

373



VIBRATORY Illusions
YIELD OF INVENTION
The invention is in the field of vibration mechanics
utilizing rotational mechclnisms for changing the amplitude
of the vibration of an apparatus. The vibratory mechanism
is usable in road compactillg machines having drums that
are vibrated to achieve a desired compacting function.
BACKGROUND OF INVENTION
In one known self propelled vibrating road roller
the compactor drum is vibrated at 1700 rum by a dual
amplitude vibratory mechanism which utilizes a swinging
eta. The compactor drum rotates at vehicle speed
as the vehicle moves forl~arcL. The drum is supported on
the vehicle frame by anti-vibration mountillgs. An axial,
reversible drive shaft at the center of the drum is driven
by a hydraulic motor from the vehicle. The drum shaft
has, in addition to a fixed eccentric weight, a hinge
pin parallel to the axis of the shaft, a pocket for
accommodating the swinging weight and stops to limit
the travel of the swinging weight When the shaft
rotates in one direction the swinging weight turns on
the hinge pin to an eccentric position which adds to the
fixed eccentric weight and increase the eccentric moment.
inn the shaft rotation is reversed by the operator, the
Z5 hinged weight turns again on the hinge pin to the extent
limited by the remaining stop and subtracts from the
eccentric moment. The impact of the weight on the stops
at each halt, start and reversal eventually produces
metal particles in the mechanism which contaminate the
bearings causing consequential failure and the drum must
be disassembled to give access for repair.
SEYMOUR OF INVENTION

"
~`;"`"~

37~
-2-
The invention concerlls a dual amplitude, rotational,
vibratory mechanism in which the alllplitucle of the
vibration can be changed by reversing the direction
of the rotation of the mechanism. The vibratory
mechanism is usable with a compactor drum of a road
compacting machine. Tile utility of the vibratory
mechanism is not limited to road compacting machines.
The vibratory mechanism can be usecl-~it}l mineral crushers
and sep~lratols, feed mechanisms for particulate material
lo and like machines.
The vibratory mechanism has a shaft rotatable
molted on the member to be vibrated. weight means are
eccentrically associated with the shaft to provide a
first eccentric mass which causes the shaft to vibrate
upon rotation thereof. leans mounted on tile shaft has
a fluent second Isles Lucia upon rotation thereof. leans
mounted on the shift has a fluent second mass which loll
shut rotation in one direction flus to a first position
to augmellt -the eccentric distribution o-E the first mass
thereby producing a high amplitude vibration of the shaft
and member and upon rotation of the shaft in tile opposite
direction the fluent second mass flows to a second posit
which lends to balclnce the eccentricity end produce low
amplitude vibration of the shalt and member.
In one embodiment of the inveJltioll, a shaft is rota-
tally mounted on a housing with a plurality of bearings.
The housing is secured to a drum of a road compacting
machine. weight means Eddy to the shaft provides an
eccentric first mass. leans having a fluent second mass
includes a casing or capsule secured to the shaft. The
casing has a chamber accommodatillg the fluent second mass.
Tile fluent second mass may be a plurality of metal members
such as small steel balls, cast iron shot, or liquid
metal. The casing has at least one partition located
withiJl the chamber which upon rotation of the shaft con-
fines tile fluent second mass to separate portions of the
chclmber to either augment or balance the first mass. The
shaft is rotated with a reversible motor. When the shaft


. . .

3'~3
-3-
is notated in a first directioll the firelight mass flows
to the first position theIeb ploducillg a hill amplitude
vibration of the shaft end member Lyle the shaft is
notated in the reverse or second direction the -fluent
mass moves to the second direction the fluent mass
moves to the second location thereby plodlcillg a 1
amplitude vibra-tioll of the shift all member.
knothole emboclilllent of tile inventioll has a shaft
drivable connected to a reversible motor. The shift is
mounted Ire rotation on . mclllhel such as 1 drum
pair of cozily s h.lvillg shelters for accollllllodltillT fluellt
miss are mounted on axially space portions of the shaft.
Lowry exalllp1c?, the casings Clue be mo~llltecl acljlcellt opposite
ends of the shaft. Eschew casillg has partition melts that
separate the chlrllber into first all second locations for
the fLuellt miss. Iota Melissa are molted Oil the shclft
adjacent etch casino. The weight mecllls is positioned
adjacent the first locations. Ire motor operates to
rotate tile shift in a first directioll causing the fluent
mass to flow to the first pOSitiOIl thereby producillg a
high amplitude vibratioll Or the shift and mulberry. Lyle
the motor drive is revc?}sel tile shclft if notated in a
second direction or opposite tile First direction CclUSillg
the fluellt mass to flow to the seconcll)osition thereby
proclucillg a low amplitude vibration of the shaft and mom-
berm
The pair of casings accolllmodatillg fluent second
mass dispose symmetrically about the aye center of the
shaft are preferred over a single central casing all
weight meals. the use of a single casing wreckers a
stiffer shift to resist deflection.
n alterllate emboclilllellt ox the vibratory mechln1sm,
lay at shift rotatable mounted in an eccentric position
relative to the support bearings. on additiolla1 eccentric
mass Clue be fixed to the shift. Maxilllulll difference in
the eccentric moment between high arid low amplitude modes
is achieved ~it]l a concentric path for the fluent second
mass. ~cceptclb1e performance is achieved with an eccentric

3~73
Lo
path or ring-like path containing pockets o-r lobes
for accommodating the flue1lt second mass.
DISCRETE OF DRYING
Figure 1 is an end view of a drum of a vibrating
5 roller of a roach compacting machine equipped White the
vibratory mechclnism of the invention;
Figure 2 is a foreshortened sectional vie take
along the line 2-2 of figure l;
Figure 3 is an enlarged sectional vie of a vibratory
mechanism muted Owe a slot as S}10~11 in logger I;
Figure is a sectional vie taken along the line I
of figure 3 show lug the location Or the fluel1t second muss
in the high an1r)litucle mode;
Figure 5 is a sectional vie taken along the line 5-5
of Figure 3 showing the c1istribution of the fluent saclike
mass during stroboscopic excommunication;
Figure 6 is a sectional view taken along the line 6-6
Ott figure 3;
l inure 7 is a sectional vowel similclr to Figure 3
showing the location of the fluent seconc1 mass in low
an1plitude mode; and
figure 8 is a sectio11cll vie taken along the line 8-8
of Figure 7.
DESCRIPTION Of: PROWLER D E~IBODI~IENT
A sol E propelled vibrati11g roller in hill -this
emboc1i11lent of -the invention is usual has a front drum
and a rear Crimea each mounted in its own frame on anti-
vibration mounti11gs. Each drum has a cylindrical steel
shell having dimensions of 1500mm diameter 2000mm long
and about 25m111 -thick. The drum weig11s about 3500 kg. The
my value of the eccentric mechanisms suitable for rollers
of the heavier class is in the range from 4-l0 kg metros.
The dry c1isplace111c?l1t is of the order o 3 mm at high
amplitude mode and about lo mm at low amplitude mode.
Referring to Figures l and 2 the drum has a Solon-
Dracula shell 1 and a pair of circular plates or ends 2
and 3 located inwardly from the opposite ends of shell l.
End 2 has a central aperture 4 aligned with a central

3~3

aperture? I in end 3. A shaft 5 and vibratory mechanisms
23 and 24 pass through one of the apertures and are located
between ends 2 and 3. Shaft 5 is a steel shclft having
sufficient size to resist deflection. Preferrclbly shaft
5 has a diameter of 188mm. Other shaft sizes can be used.
A cup-shapecl cylindrical housing 6 extends through
aperture 4. lousing 6 has an outwardly directed flange
7 secure to end 2 with bolts 21. A bearillg 8 located
within housing 6 rotatable supports one end of shaft 5
on housing 6 housing 6 has an ou-twlldly directed stub
axle 9. bearing 11 supports a sleeve 12 on axle 9.
Sleeve 12 is secured to a plate 13 used to support the
drum 1 Oil the vehicle (not shown).
End 3 his a central aperture LO acco~mnodatillg a cup-
shape housing lo. lousing 15 has an outwcLrdly directed
flange 16 secured to end 3 with bolts 17. A bearing 18
locate within hOUSillg 15 rotatlbly supports one end of
shaft 5 Oil housillg 15. Bcarillgs 8 end 18 mount shaft 5
on housings 7 and Lo for rotatioll about -the longitudillcll
ax-is of shift 5. Alterllatively, slot 5 can be eccentric
calmly mountc?l in bearings 8 all 18. I-lous-ings 7 arid 15
close? apertures 4 allot 11 and prevellt the entrclnce of water
and foreigll matter into tile? Clara chLIllber between ends 2
and 3.
lousing 15 has an outwardly directed stub axle 19
accommodating a bearing 20. A sleeve AL mounted Oil bearing
20 is secured to a plate 22. Plates 13 and 22 are attached
to vehicle structure to secure druTIl 1 to tile vehicle.
A reversible hydraulic motor 23 is connected to end
I of shaft 5. lottery 23 is connected with suitable ho-
clraulic lines to a source of hydraulic fluid under pressure
and control valves (not shown) which allele the operator
of the vehicle to control the operation of motor 23 to
chLIlge the direction of rotation of shaft 5 as well as the
speed Or rotation of snail 5.
A pair of weights 25 and 26 are mounted on shaft 5
adjacent the opposite ends thereof. weights 25 and 26
have eccentrically located masses which cause shaft 5

3'73

I,
to vitiate whelp Kit is rotate. so Shelley yin Figure 6,
mass 25 has all arcucl-te configulclt:ion off set from the
axis of rotation of shift 5 end an arcuate length less
than 180 degrees. Weight 26 has a shape and displace-
mint that is the same Claus Weight 25.
Retulrl:irlg to figure 2, a pair of vibratory units
indicated generally at 27 and 28 are mounted on shaft
5 adjacent weights 25 and 26. Vibratory units 27 allele
28 are identical yin structure. Ike following description
is cl:irectccl to vibratory Ulli t 27. As shown in inure 3,
vibrcltory unwept 27 hclS at sealed, hollow capsule or casing
that awoke lodatc~s a fluent mass 33, 'r}lC CclSillg has
circular ells alleles 2') end 30 molted Oil shaft 5. Aye
circumferential outer wall or raceway 31 is secured to
the Outs` per.ipllcll edges of end wakeless 29 all 30 and
define throttle a chamfer 32. Chamber 32 its concelltric
with the acts of rotation of shaft 5. Fluent mass 33
is located in chamber 32. The fluell-t mass 33 is a movable
weight, Suckle as plurality of metal members, steel balls,
metal shot, likelihood Innately, sand, end like flyable ballast
material As shown yin figures 4, 5, Allis 8 less thcln half
owe chclmber 32 is fillet with fluent Lucy 33 or walls 34
and 35 are locate in chamber 32. Walls 34 and 35 are
secured to opposite stales of shut 5 all extend along
separate choral lines to outer wall 31. Wakeless 34 ail 35
are stops for Fluent mass 33 that David chamber 32 into
a first portion AYE and a second portion 32B. Chamber
portions AYE and 32B are located diametrically opposite
Eros each other as shown in Figure 4. Wall 29 has a
normally closed port or opening 36 through which fluent
mass 33 is introduced islet chamber 32. Walls 34 and 35
can be substant:icl:lly radical walls that extend from shaft
5 to outer allele 31. These walls can be angularly disposed
from each other at an angle from about 80 to 135 degrees
and define the oppositely disposed chambers AYE and 32B
for fluent mass 33.
In use, the maxilllulll vibration amplitude is achieved
by rotating shaft 5 in the direction of the arrow 38, as

37~3

shown yin loggers end 5. IIycIIaulic motor 23 Irises
shaft 5 :incIepeIldent of the steed o-f rotation of the
shell 1. Fluent mass 33 moves Pinto the chamber port
lion 32~ agaiIlst Wylie 35. so shown in inure 3
fluent mass 33 is located acljaceIlt the eccentric first
mass or weight 25 thereby increasing the eccentric mass
that rotates with shaft 5. This increases the amputee
of the vibration of shaft 5 ail shell 1.
The rotat:ioTI of shaft 5 in the opposite direction
indicated by tie aureole 9 yin FilJule causes foe t mass
33 to move into second chaIllber portion 32I3. lo shown in
inure 7 chlmbeI pollution 32B is diaIlletrical1y opposite
weight 25 ebb the tlueIlt second mass couIlteracts weight
25 arid tents to bcll.allce shaft 5. This refuges the amply-
tulle of the varietal of shaft 5 and Shelley 1.
Re:Eerr:iIlg now to Figure 5 a pheIlomenoll is observahlecIurirlg stroboscopic examination of the shaft 5 end unit 27
when revolving at working speed yin the direction of arrow
35. UncIer the combiIled effects of Friction end Sinatra-
phyla force the foliate mass 33 assumes tile crescent shapeclSUrf,lCe as Shea at 37. The magnitude of the eccentric
moment of the? flueIlt mclss 33 yin practice varies only
slightly from the mc~n:itucIe of tile eccentric moment owe
the tlIealeticcll :flueIlt miss and is considered to be with-
yin acceptable Torrance limits. The actual eccentric
moment is Seattle less than the theoretical value but
can easily be brought up to the theoretical value by a
small increase yin mass of the fluent mass.
Tile Relative ~IagnitIlIe of Eccentric immunity of the
foliate mass can be ca.IculIted as phallus:
Let hi = total eccentric moment required for high
aIllp:litucIe mode.
Let aye = total. eccentric momeIlt required for low
amplitude mode.
where a = ratio of low amplitude
high
Let x = eccentric moment of the fixed eccentric mass
Let y = eccentric moment of the fluent mass


. . .

3'~3

The following simult.lrleous e~luatiolls apply

A - y = Allah . . . . . . . , , , , , .. . . . . . ?
by s~lbtrclction
S my = cull
. . y = Ill . . . . . . . . . . . . . . . . . . . 3




substitutillg in eclucltion




Centrally a - owe
Titus low amplitude is hull f the high alllplitucle but by
alter:illg the ratio ox fluellt Isles 33 to the lived mass 25
a can be made to by? Other` than 0. 5.
Ike advlntagcs of the vibratory mecllanislll are as
follows: Impact loads are rellclered insigTli~iclnt be--
cause the fluent Isles 33 constitute multiple Smalley
masses which accclelate end decelerate Without producing
the impact clalllclge associated with a swinging weight.
Ike E:Lueilt mass 33 is conEinecl~iitllill a scaled chasing
Welch eliminates bcarillg deluge Eros consequential
failure. Ire Cls-illgs of Ullits Z7 and 28 are maintenance
free and are located in the protected drywall challlber.
While there his bell shown end described the Libra-
tory mechln-islll of the invention it is understood that
chclnges in the structure all use owe the mechanism allay
be mclde by those skilled in the art without departing
from -tile invention. For example weights 25 and 26 can
be crescent-shapecl pieces of metal that are secured by
welds or the like to the end Willis 29 of vibratory units
27 all 28. The internal walls 34 all 35 can have other
Slops 9 Suckle as radial to provide the separate chamber
portions 32~ and 32B for the fluent second mass 33. The
outer wall 31 can have a plurality of symmetrical lobes
for accommodating the fluent second mass 33.
the invention is defined in the following claims.