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Description  |
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INTRODUCTION
This invention relates to sugar cane harvesters and, in particular, to an
improved cleaning and conveying system used on sugar cane harvesters.
BACKGROUND OF THE INVENTION
Sugar cane growing uses mechanization techniques extensively and these
techniques have resulted in sugar cane harvesters being used which are
satisfactory for the crop conditions under which they are used. Present
harvesters, however, with few exceptions, are adapted to cut burned cane.
This is crop which has had the trash cover burned prior to cutting and
which, therefore, reduces by a large portion the percentage of chaff or
trash to cane which enters the harvester.
As opposed to this practice, "green cane cutting" has become a favoured
method in some circumstances. Green cane cutting is desirable since
burning requires additional labour and is dangerous. Further, green cane
cutting allows harvesting flexibility during wet weather.
Nevertheless, the art of mechanically cutting green cane is in its infancy
and the problems associated with its cutting have not been fully
investigated. Bearing this in mind, it should be understood that the
explanations herein are believed to be correct but that they may
nevertheless prove to be incorrect or qualified in the years to come as
further knowledge of green cane harvesting becomes available.
In harvesters used for cane harvesting, the cleaning assembly is the area
of primary concern. Uniform air distribution throughout the cleaning
system is desirable since this will more efficiently separate the cane
from the chaff or crop trash such as loose leaves and the like. When
unburned crop is being harvested, the cleaning system is under additional
labor to adequately separate the crop from the chaff for milling purposes.
While various cleaning systems have been used for green cane harvesting,
there are disadvantages inherent in all.
For example, some burned cane harvesters have been used for green cane
cutting. These harvesters, while satisfactory at low speeds due to the
ability of the cleaning system of the harvester to accept relatively low
speed loading, are not able to harvest crop at the large capacities which
are desirable due to the configuration of the machine, the inefficiency of
the cleaning system and the general ability of the machine to accept heavy
loading.
Harvesters used for green cane harvesting may suffer various other
disadvantages. For example, a harvester may be adapted for one-row cutting
only. One-row cutting is not desirable because the harvester must travel
between rows which is inefficient. This particular disadvantage is caused
by the configuration of the cleaning and conveying system which is
required, in part, by the cleaning requirements of green cane harvesting.
A further problem relates to present drive systems which are used for
driving the chopper rollers in harvesters. Chopper rolls may jam if the
soil is rocky or debris laden. At the same time, the chopper rolls have
relatively little inertia by themselves and, therefore, without some
additional inertia compensation, they cannot adequately cut the billets
when the crop mat suddenly increases. To overcome this problem, a flywheel
is ordinarily connected to the chopper rolls. In one design, the flywheel,
through reduction gears, drives the chopper rolls, the flywheel being
driven by the source of harvester power. In the event the chopper rolls
jam however, the large inertia of the flywheel is transmitted to the
chopper rolls and since the reduction gears further amplify the inertia
force of the flywheel, damage to the chopper rolls can result. To prevent
this damage, unnecessarily elaborate release mechanisms have been
designed.
Similarly, it is also desirable to provide a reversal to the chopper rolls
in the event of jamming so as to attempt to free the rolls. Methods used
to accomplish this with flywheel driven chopper rolls, however, have been
unsatisfactory, again because they are over-elaborate and do not provide
full operating power in the reverse direction.
Yet a further problem relates to a desire to achieve uniform crop
distribution in the cleaning area of a sugar cane harvester. Uniform crop
distribution is difficult to achieve because of the various varieties of
sugar cane and the crop conditions under which cane is harvested. Further,
the speed of the chopper rolls may usually be changed to increase or
decrease the billet length of the cane which also affects crop
distribution in the cleaning area.
Yet still a further problem relates to the conveyancing of the cut crop
from the base cutter to the chopper rolls. The crop mat which is being
conveyed should be substantially uniform across the width of the conveying
passage. The feed rolls, used for conveying the crop, should provide a
uniform conveying speed to the crop mat and a uniform pressure on the
crop. Hydraulic flow dividers have been used for the feed rolls. These are
inefficient and reduce power.
SUMMARY OF THE INVENTION
According to the invention, there is disclosed a sugar cane harvester
comprising feed means, cutting means to sever crop after it has entered
said feed means, conveying rollers to convey said crop to a chopping means
following the severing of said crop by said cutting means, said chopping
means cutting said crop after said crop has been conveyed to said chopping
means by said conveying rollers, and cleaning means to clean said crop,
said cleaning means comprising a cleaning cylinder, an extractor fan
positioned in the upper portion of said cleaning cylinder, substantially
unobstructed air intake means located outwardly of and surrounding a
substantial portion of the periphery of said cleaning cylinder, said air
intake means being operative to draw air in a generally downwardly
direction through said air intake means and into said cleaning cylinder,
and conveying means having a receiving area for receiving and conveying
cut crop from said cleaning means, said conveying means being rotatable
about an axis and said receiving area of said conveying means being
located substantially directly below said extractor fan.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
An embodiment of the invention will now be described, by way of example
only, with reference to the accompanying drawings in which:
FIG. 1 is a side view of a sugar cane harvester according to the invention;
FIG. 2 is an enlarged cutaway view of the cleaning and conveying system of
the harvester of FIG. 1;
FIG. 3 is a cutaway plan view of the harvester showing the conveying system
and the rotation of the conveying system;
FIG. 4 is an enlarged view of the drive system for the chopper rolls;
FIG. 5 is a sectional view of the timing and release mechanisms of the
drive system chopper rolls taken along the line 5--5 of FIG. 4;
FIG. 6 is a schematic of the hydraulic circuit used to power the drive
system; and
FIG. 7 is a view of the elevator rotating mechanism.
DESCRIPTION OF SPECIFIC EMBODIMENT
Referring now to the drawings, a sugar cane harvester is shown generally at
100 in FIG. 1. It comprises four general mechanisms, namely the gathering
area 101, cutting area 102, feeding area 103, and the cleaning and
conveying area 104.
The gathering area 101 includes topper 105 and crop dividers 106. Topper
105 comprises gathering discs 107 (see also FIG. 3) and cutting discs 108.
The gathering discs 107 and cutting discs 108 are hydraulically driven and
fully reversible. The topper 105 is height adjustable by way of a pair of
arms 109 which can be hydraulically raised or lowered as desired by the
operator.
Crop dividers 106 include two spiral feed rollers 110, each with a
respective ground shoe 111 at its lower portion.
Rotatable "knock-down" rollers 112, 113 are present in the crop passage
area. Fins 114 are intermittently mounted to knock-down roller 113 across
its width to separate the cane stalks as they are knocked down by roller
113.
The cutting area 102 comprises basecutters 115 which rotate and which have
blades (not shown) mounted on their periphery which sever the base of the
cane as it passes into the crop passage or feeding area 103 of the
harvester. Butt roller 116 separates rocks and dirt from the crop mat
after it passes from the basecutters 115. The feeding area 103 comprises
feed rollers 117, 118, 119, 120, each roller being paired with its opposed
pinch roller 117', 118', 119', 120', respectively and each feed roller
being hydraulically powered. The pinch rollers 117', 118', 119', 120' can
move inwardly and away from the crop mat depending on the width of the mat
being conveyed from the cutting area 102 through the feeding area 103. At
the end of the feed roller train, two hydraulically driven chopper rolls
122, 123 are located which sever the crop mat at desired intervals as they
rotate. The chopper rolls 122, 123 are attached to a flywheel 124 which
allows a greater crop concentration to be cut. The chopper rolls 122, 123
and the flywheel 124 connected thereto will be explained in greater detail
hereafter.
The cleaning and conveying area 104 (shown more clearly in FIG. 2)
comprises the cleaning chamber 125, extractor fan 126, discharge hood 127
and elevator 128. Cleaning chamber 125 is substantially cylindrical and a
large air intake area 129 extends outwardly from the cleaning chamber 125
and extends about a substantial portion of its periphery as also shown in
FIG. 3.
The elevator 128 rotates about vertical axis A which passes substantially
through the axis of the extractor fan 126. The elevator 128 is rotated in
the direction of the arrows (FIG. 2) by the use of twin hydraulic
cylinders 130 (only one of which is shown) as desired by the operator. The
elevator 128 is supported and moved vertically about horizontal axis 131
by hydraulic cylinders 132 (only one of which is shown). Hydraulic
cylinders 132 are each mounted to chain 133 which has a track about the
base of discharge hood 127.
An energy absorbing plate 134 is positioned on the inside of cleaning
chamber 125. The plate 134 is adjustable about a hinge 135 by means of a
fastener 136 which extends through an arcuate opening 137 in the cleaning
chamber 125 and is fastened at any position on the opening. It may also be
controlled from the operator's console if desired.
The extractor fan 126 is mounted in the upper portion of the cleaning
chamber 125 and is powered by hydraulic motor 138. It creates a draft by
utilising the air sucked into the machine through the air intake area 129
and discharges the air and crop chaff through discharge hood 127.
Discharge hood 127 is rotatable relative to cleaning chamber 125 so that
the chaff may be discharged in a desired direction.
Located directly below the cleaning chamber 125 and extractor fan 126 is
the receiving area 121 of the elevator 128. The receiving area 121
communicates directly with the intake of elevator 128. Elevator 128 also
includes elevator chain 139 and flights 140 which rotate about lower and
upper axes 131, 141. A second extractor fan 142 in extractor hood 143
creates a draft to remove additional chaff from the cane crop. Deflector
plate 144 is mounted on the end of elevator 128 to deflect the billets
into a transporter (not shown).
The mechanisms used for rotation of the elevator 128 between the two sides
of the harvester 100 are shown in more detail in FIG. 7.
An elevator slew mechanism shown generally at 145 is used to rotate
elevator 128 about vertical axis A. Two two-arm parallel linkages are used
on each side of axis A. Since the mechanism is symmetrical about axis A,
only one side will be described.
Hydraulic cylinder 130 extends from frame 146 and piston 147 extends from
cylinder 130 with clevis 148 mounted thereon. Clevis 148 fits between one
end of the two link arms 149, 150 which are pivotably mounted to frame 146
by pin 151. A further link pair 152 is mounted to clevis 148 and extend to
bracket 153 where the links are pivotably mounted by pin 154.
Elevator 128 is secured in bracket 153 by pins (not shown) and may rotate
upwardly and downwardly about the pins on horizontal axis 131 by extending
or retracting hydraulic cylinders 132 (only one of which is shown).
The drive system, the timing and release mechanisms and the hydraulics used
for powering the feed system are shown in more detail in FIGS. 4-6.
FIG. 4 depicts the drive system of the chopper rolls 122, 123. Blades 155
are attached to the periphery of the chopper rolls 122, 123 which are
driven by hydraulic motors 156, 157.
Shafts 158, 159 extend from the opposed ends of chopper rolls 122, 123 and
hubs 160, 161 are mounted on shafts 158, 159. Ring gears 162, 163 are
mounted on hubs 160, 161 and are attached thereto by bolts 164 (not all of
which are shown) extending through arcuate shaped openings 165 on the ring
gears 162, 163. The combination of the ring gear 163, the hub 161 the
bolts 164 and the arcuate openings 165 act as an adjustment device shown
generally at 166 since the hub 161 may be rotated relative to ring gear
163 by loosening the bolts extending through the arcuate openings. When
the proper relationship between ring gears 162, 163 is achieved as is
necessary, for example, when the gears become worn, the bolts are
tightened securely. Thus, the chopper rolls 122, 123 are mechanically
joined by meshing ring gears 162, 163.
A pinion 168 meshes with ring gear 162 and it, in turn, drives flywheel
124. A release mechanism is used to release the flywheel from the ring
gears 162, 163, and pinion 168.
Referring to FIG. 5, ring gear 162 meshes with pinion 168 which is integral
with hub 169. Hub 169 rotates on bearings 170, 171 mounted on shaft 172.
Hub 169 has an outwardly extending circumferential protuberence 173 with a
groove machined in its periphery. A first friction disc 174 is mounted in
the groove. Flywheel 124 is positioned with its running disc 175 mounted
between friction disc 174 and second friction disc 176. A keeper ring 177
is mounted against second friction disc 176. Bolts 178 extend from
protuberance 173 through keeper ring 177 and a plurality of Belleville
washers 179 are positioned over bolts 178 and are secured with nuts 180.
Accordingly, the pressure exerted on the running disc 175 of flywheel 124
by the friction discs 174, 176 can be increased or decreased as desired by
tightening or loosening nuts 180.
Referring now to FIG. 6, the hydraulic circuit used to power the butt
roller 116, the spiral feed rollers 110, and the feed and pinch rollers
117, 117', 118, 118', 119, 119', 120, 120' and the chopper rolls 122, 123
is depicted in schematic form. It will be understood that each of the
rollers referred to is the functioning operative of its respective
hydraulic motor where the fluid flow actually occurs.
A control valve 181 has three positions. In the first position, as depicted
in FIG. 6, hydraulic fluid flows through valve 181 and back to the tank.
In this position, no fluid passes to the hydraulic motors. In the second
position, wherein portion A of control valve 181 is operable, such as when
the harvester is under normal operation, fluid flows through valve 181 via
line C in parallel through chopper rolls 122, 123 and, thence, from one
line from chopper roll 122 to butt roller 116 where, it will be noted,
there is double power exerted because of the parallel fluid source.
Chopper feed rolls 122, 123 and butt rolls 116 are mechanically connected
as depicted. Hydraulic fluid also passes in series through pinch roller
120', feed roller 119, pinch roller 118', and through feed roller 120,
pinch roller 119' and feed roller 118 alternatively, as depicted, such
that the mat between the rollers is subject to alternate pressures by the
various rollers throughout the crop conveying passage. The fluid also
passes through and powers spiral feed rollers 110, power feed roller 117,
and pinch roller 117' in series as depicted.
In the third position, wherein portion B of cntrol valve 181 is operable,
the hydraulic fluid flow is reversed. In this position, fluid flows first
to the various feed and pinch rollers through line D, thence to the
chopper rolls 122, 123 and thereafter to the tank.
In the event the chopper rolls 122, 123 become jammed in the normal
operating mode, relief valve 182 opens and allows the fluid to return to
the tank.
In the event any of the feed or pinch rolls become jammed in the normal
operating mode, fluid may flow through check valves 183, 184 and back into
the tank through relief valve 185.
In the event any of the feed or pinch rollers become jammed in the
reversible mode (i.e., with the control valve 181 in position B), fluid
may flow back to the tank through the appropriate check valve to protect
the jammed motors.
OPERATION
In operation, after the cane harvester 100 is transported to the desired
area, the operator moves the machine along the row of cane. The gathering
discs 107 gather the cane tops and sever and dispose of them on either
side of the harvester 100. The ground shoes 111 set the operating width
which determines the quantity of cane entering the throat of the harvester
100 and the spiral feed rollers 110 gather the crop into the throat where
the knock-down roller 112 bends the stalks of the cane in conjunction with
the action of knock-down roller 113. The basecutters 115 sever the cane
and the butt roller 116 feeds the severed cane into the feeding area 103.
The crop mat passes through the feed and pinch rollers 117, 117', 118,
118', 119, 119', 120, 120' respectively, where the mat is compressed and
made more uniform and the rocks and debris are shaken free. The crop then
passes to the chopper rolls 122, 123 where it is severed into billet
length sections. The crop then passes to the cleaning and conveying area
104 where the cane billets fall downwardly from the cleaning chamber 125
into the receiving area 121 and thence to elevator 128.
As the crop leaves the chopper rolls 122, 123 it may be deflected by energy
absorbing plate 134 if it is desirable to use the plate under the
particular crop conditions in order to provide better distribution in the
cleaning chamber.
The chaff in the crop, being lighter in weight than the billets, is blown
from the discharge hood 127 by extractor fan 126.
The billets which have fallen into the elevator 128 are conveyed to the top
of the elevator 128 by flights 140 on elevator chain 139 and are thrown
towards deflector plate 144 where they are deflected downwardly into
transporters (not shown) for shipment to the milling facility.
Second extractor fan 142 removes additional chaff still remaining in the
crop on elevator 128 with the billets and discharges it through extractor
hood 143.
After completing one row of harvesting, the operator may desire to make
another pass on an adjacent row. In this event, he turns the harvester
around, rotates the elevator 128 to the opposite side of the harvester as
depicted in FIG. 3 and re-commences the harvesting operation. To rotate
the elevator 128, the piston 147 of hydraulic cylinder 130 is extended.
This moves link arms 149, 150 counter clockwise about pin 151. Link pair
152 exerts the necessary force on bracket 153 through pin 154 and,
therefore, elevator 128 rotates through the desired angle. The two
hydraulic cylinders 130 are in the same hydraulic circuit but coupled in a
reverse flow position such that when piston 147 is extended, the opposed
piston is retracted. Thus, the action of the hydraulic cylinders is
complementary.
In the event the chopper rolls 122, 123 become jammed by rocks or other
debris, they are fully rotatable in a reverse direction by hydraulic
motors 156, 157. Since flywheel 124 contains considerable energy, in the
event the chopper rolls 122, 123 become jammed, the energy must be
dissipated over some interval to prevent damage. To that end, the release
mechanism for the flywheel 124 is adjusted by either tightening or
loosening nuts 180. They, in turn, compress or loosen Belleville washers
179 which, acting on keeper ring 177, determine the force between running
disc 175 and friction discs 174, 176. This force determines when the
flywheel will break loose from hub 169 thereby avoiding damage to the
chopper rolls 122, 123.
Because it is necessary that the blades 155 of the chopper rolls 122, 123
pass close together to achieve correct crop cutting, the blades 155 may
become too close when gears 162, 163 begin to wear and interfere. This is
compensated by loosening bolts 164 and rotating ring gear 163 relative to
hub 161. Bolts 164 are then tightened. Thus, the blades 155 will be
prevented from contacting each other and becoming damaged.
There has been described a particular embodiment of the invention in which
many modifications may be made which will fall within the scope of the
invention. Accordingly, the invention should be construed only by
reference to the accompanying claims.
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