FEEDING APPARATUS FOR A TREE HARVESTER

Abstract

The invention relates to a feeding apparatus for a harvester, which includes opposing arms, with operating devices, pivoted to a frame, for creating transverse compression, two opposing feed rollers installed in the arms as the only feed rollers for feeding a tree through the throat, and hydraulic motors driving the feed rollers, and at least two pressure-medium lines operating them.

Claims

1. Feeding apparatus for a harvester, comprising: opposing arms, namely a first arm and a second arm, with operating devices, pivoted to a frame, for creating transverse compression; two opposing auxiliary frames, namely a first auxiliary frame and a second auxiliary frame, the first auxiliary frame being installed in the first arm and the second auxiliary frame being installed in the second arm; two opposing feed devices, namely a first feed device and a second feed device, the first feed device being installed in the first auxiliary frame and the second feed device being installed in the second auxiliary frame, the first feed device and the second feed device acting as the only feed devices for feeding a tree through a throat, wherein the feed devices both have an operating state for feeding the tree forward towards the throat, namely forward operating state; a first set of hydraulic motors installed in the first auxiliary frame, comprising a first hydraulic motor and a second hydraulic motor both driving the first feed device, thus the first feed device creating a mechanical connection between the first hydraulic motor and the second hydraulic motor of the first feed device, the first hydraulic motor having a first inlet and a first outlet and the second hydraulic motor having a second inlet and a second outlet; a second set of hydraulic motors installed in the second auxiliary frame, comprising a third hydraulic motor and a fourth hydraulic motor both driving the second feed device, thus the second feed device creating a mechanical connection between the third hydraulic motor and the fourth hydraulic motor of the second feed device, the third hydraulic motor having a third inlet and a third outlet and the fourth hydraulic motor having a fourth inlet and a fourth outlet; a tank line for returning pressure-medium from the hydraulic motors to a tank; a first parallel pressure-medium line operating the first hydraulic motor of the first feed device and the third hydraulic motor of the second feed device, wherein the hydraulic fluid in the forward operating state is fed first to the first inlet of the first hydraulic motor, from the first outlet of the first hydraulic motor to the third inlet of the third hydraulic motor, and from the third outlet of the third hydraulic motor to the tank line, when feeding tree, and; a second parallel pressure-medium line operating the second hydraulic motor of the first feed device and the fourth hydraulic motor of the second feed device in series, wherein the hydraulic fluid in the forward operating state is fed first to the fourth inlet of the fourth hydraulic motor, from the fourth outlet of the fourth hydraulic motor to the second inlet of the second hydraulic motor, and from the third outlet of the third hydraulic motor to a tank line, when feeding tree.

2. The feeding apparatus according to claim 1, wherein the first hydraulic motor and the third hydraulic motor connected in series are of the same size and of a single capacity and the second hydraulic motor and the fourth hydraulic motor connected in series are of the same size and of a single capacity.

3. The feeding apparatus according to claim 1 wherein the width of both the first feed device and the second feed device is 50-150% of its diameter.

4. The feeding apparatus according to claim 1 wherein the path of movement of both the first feed device and the second feed device is arranged to be essentially linear, the maximum linear deviation being 1-6% of the lateral displacement.

5. The feeding apparatus according to claim 1, wherein the first arm carrying the first feed device and the second arm carrying the second feed device are both trapezium arms.

6. The feeding apparatus according to claim 1, wherein each feed device is a feed roller, where diameter of each feed roller is 30-120 cm.

7. The feeding apparatus according to claim 1, wherein each feed device is a feed roller, where diameter of each feed roller is 30-120 cm.

8. The feeding apparatus according to claim 1, wherein in at least one of the first feed device and the second feed device there is a gear ring equipped with internal gearing having gearwheels, which the hydraulic motors drive through the gearwheels.

9. The feeding apparatus according to claim 8, wherein a gear ratio of the gearwheel and the internal gearing is 1:4.5±50%.

10. The feeding apparatus according to claim 8, wherein the two gearwheels driving the internal gear ring are both on the same side of the gear ring, being thus situated outside the arms relative to the throat.

11. The feeding apparatus according to claim 8, wherein the bearings of at least one gearwheel are integrated in the hydraulic motor driving the gearwheel.

12. The feeding apparatus according to claim 1, wherein at least one of the first feed device and the second feed device includes a rubberized flexible ring, and gripping elements supported with aid of a swing shaft, which gripping elements press into the rubberized flexible ring when loaded, and which gripping elements overlap each other.

13. A harvester, which includes: a frame with suspension devices, being in the longitudinal direction of the frame, stripping blades pivoted to the frame, with operating devices, for compressing the stripping blades transversely in order to form a throat, and a feeding apparatus according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In the following, the invention is described with examples and with reference to the accompanying figures.

[0043] FIG. 1 shows a three-roller feeding apparatus according to the prior art,

[0044] FIG. 2 shows one feeding apparatus according to the invention, seen in the direction of feeding the tree,

[0045] FIG. 3 shows a side view of the arrangement of FIG. 2,

[0046] FIG. 4a shows one transmission arrangement of a feed roller using a new feed roller,

[0047] FIG. 4b shows an end view of the feed roller of FIG. 4a,

[0048] FIG. 4c shows an axonometric view of the feed roller of FIGS. 4a and 4b,

[0049] FIG. 4d shows the gripping element used in the feed roller of FIG. 4c,

[0050] FIG. 5 shows a schematic hydraulics diagram of the feeding apparatus,

[0051] FIGS. 6a and 6b show the annular forces of the feed roller in normal and one-sided loading situations, and

[0052] FIG. 7 shows a track feeder embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0053] FIG. 2 shows one embodiment of the construction of the feeding apparatus. The pins 1.1 and 1.2 and arms 2 and 3 are suspended from the frame 1. The other end of the arms 2 and 3 is attached to the holder 7 of the roller with the aid of pins 7.1 and 7.2. A parallelogram, particularly a trapezium, is formed by the pins and arms. The hydraulic cylinder 6 moves the parallelograms around the pins 1.1 and 1.2, so that the rollers 4 move towards or away from each other. The synchronization rod is not shown. The tree 5 being fed is pressed between the rollers 4 when the cylinder 6 moves the rollers towards each other. The diameter of the roller 4 can be 300 mm or as much as 800 mm, its width 200 mm or as much as 600 mm. The roller 4 is mounted in bearings on shaft 12 of the roller holder 7. The stripping blades 40 carry the tree being processed in the throat. The path of movement of the feed rollers is thus made linear, with a maximum deviation from linearity of 1-6% of the lateral shift.

[0054] It is quite advantageous that, with the aid of the pins 1.1 and 1.2, and the arms 2 and 3 and the pins 7.1 and 7.2 the parallelogram can be dimensioned in such a way that mainly the rollers 4, 4.1 are closer to each other at the lower edge than at the upper edge. Only in the fully open position is it advantageous for the lower edge to have a greater distance than the upper edge. Normally, the “opening” of the lower edge is about 1.3 times greater than the diameter of the tree 5 being fed. FIG. 3 shows a side view of the construction. In it, the stripping blades 18, 18′ can be seen, normally two moving (18) and one fixed (18′). The diameter of the smallest tree to be stripped is about 50 mm, the largest max. 800 mm.

[0055] FIG. 4a shows the roller 4 is partial cross-section. It also shows the holder 7, shaft 12, and the hydraulic motors 10 and 10.1, as well as the bearing assemblies 10′ and 10.1′ of the associated drive shafts 15.1, 16.1.

[0056] This embodiment presents one construction. The shaft 12 is attached to the roller holder 7. In turn, the shaft 12 is attached to the roller 4 through the bearings 13. The outer surface of the roller 4 is equipped with gripping elements in order to make the roller 4 create a feeding force. As the distance of the bearings 13 is considerable, about 25% (usually 20-40%) of the feed roller's effective diameter, it can easily create a large torque and thus a large carrying power of the compressive force. It is many times the carrying power of the driving hydraulic motors.

[0057] The gripping elements can be of any type whatever in relation to the feed roller's basic construction described above. Here a generally preferred gripping-element construction is described. The gripping elements (4.8 FIG. 4d) are not shown in this figure, but it does show the vulcanized rubber layer 4.6 of the surface of the outer cylinder 4.1 underneath them and the spiked rings 4.3 and 4.2, which divide the cylinder surface into two narrower parts. FIG. 4a shows the grooves 4.7 and holes in the spiked rings 4.2 and 4.3 made for the swing shaft 4.9 of the gripping element 4.8. The ends of each shaft 4.9 are fitted into a hole in the spiked ring at the location of the groove 4.7.

[0058] A gear ring 14 is attached to the upper edge of the roller 4. Hydraulic motors 10 and 11, namely first hydraulic motor and second hydraulic motor, equipped with a smaller gearwheel 15 and 16, are fitted to the holder 7. The first hydraulic motor 10 has first inlet a1 and first outlet b1 and correspondingly the second hydraulic motor 11 second inlet a2 and second outlet b2. The gear ratio can be preferably 1:3, even 1:7. As an internal gear ring, the construction of the ring 14′ permits a more compact construction and the gearwheels can be lubricated with grease, like the rotation rings of excavators. A feeding apparatus construction using the internal gear ring according to the figure can naturally be used in other connections than the hydraulic system according to this invention and using one or more gearwheels.

[0059] FIGS. 4b and 4c show the feed roller 4 as a separate totality. The gripping elements 4.8 are installed in two separate rings. FIGS. 4c and 4d show the special features of this gripping element, i.e. the tongues and their overlapping in the direction of the circumference (5-15% of the dimension of the gripping element). In such a gripping element 4.8 there is a sheet-metal component cut to shape, gripping spikes, and a swing shaft 4.9, the end of which is fitted in holes in the spiked rings 4.2 and 4.3.

[0060] In the version according to FIGS. 2, 3, and 4a, the hydraulic motors are on opposite sides relative to the rotating ring. Preferably the internal gear ring 14′ is driven by two gearwheels 15, 16 which are both on the same side of the gear ring 14′, being situated outside the pivots arms 2 relative to the throat and as close to each other as the motors driving them could be practically placed.

[0061] The thickness of the vulcanization is about 30 mm (generally 20-40 mm). During installation, the gripping elements 4.8 are compressed with pre-compression, when each head flexes restrainedly under load. Loading causes the gripping elements 4.8 to swing, when the tongues move relative to each other. This cleans the surface of the feed roller effectively.

[0062] A hydraulics diagram of the feeding apparatus according to the invention in a normal situation is drawn in FIG. 5. Here, hydraulic pressure is directed to lines L1 and L2, which are reverse-coupled, so that in the figure full pressure is directed to second hydraulic motor 11 in line L2 and third hydraulic motor 10.1 in line L1. The third hydraulic motor 10.1 has third inlet a3 and third outlet b3 and the fourth hydraulic motor 11.1 fourth inlet a4 and fourth outlet b4. Due to leakage losses, the motors in series do not produce precisely quite the same torque, but the situation in symmetrical, as the full pressure is always directed to one of the feed roller's motors.

[0063] In an imaginary situation (FIG. 6a), when there is, for example, ice or snow of top of feed roller 4, only feed roller 4.1 can pull. Further envisage that the torque of roller 4.1 is now insufficient. Now, for example, when the directional control valve is in the position “straight”, pressurized oil comes to motor 10.1, but cannot pass through, because the roller is “locked”. However, motor 10.1 develops a torque that is about double, because the whole pressure acts over this motor, motor 10 being “idle”.

[0064] Correspondingly, the same pressure acts on motor 11, but as it is “idle” this pressure bypasses it nearly without loss and acts on 11.1. When the whole pressure level acts on motor 11.1, a torque develops in it that is nearly double the normal level.

[0065] In normal running, one motor creates half of the maximum torque (FIG. 6b). In other words the normal torque F of one roller pulling by itself is twice one motor's normal torque F.sub.2 in symmetrical traction. More specifically, it can be estimated that

[0066] F >95%×(2×F.sub.2), which has also be measured on the test bench.

[0067] If we sum the torque coming to the roller 4.1 in the imaginary case, it totals nearly four times the normal torque of one motor. From this it follows that, in the feeding apparatus according to the invention, when one roller is “idle”, the other feed roller that has held its grip will develop a torque that it nearly two times greater. I.e., even though one roller is “idle”, the other roller is able by itself to create the same tractive force as both rollers normally.

[0068] Further, the direction of rotation does not matter now, i.e. whether the direction is feeding or reverse. Operation is completely symmetrical in both directions. Operation does not demand throttling in the feed line, instead operation is naturally very flexible. The forward feeding direction is marked with an arrow FF Fbeside the tree 5 on FIG. 5.

[0069] Because the roller is on a separate shaft, the width of the roller can be changed, nor will this affect the shafts of the motors. Thus, commercial motors can be found easily.

[0070] The hydraulic motors preferably used in the feeding apparatus according to the invention are Danfoss OMT orbital motors having gear rim with rollers (0.3-0.4 liters/s).

[0071] FIG. 7 shows an embodiment utilizing a track feeder as the feed device instead of a feed roller shown in FIGS. 1-6b. The previous application of the applicant US2006/0086414 A1 is incorporated with reference and shows in more detailed manner the structure of a track feeder as shown in FIG. 7. The track feeder 7 has a frame 7.1 which in this embodiment acts as the auxiliary frame connecting the hydraulic motors 101 to each other. The track feeder 7 is attached using a pivot axle through the pivot tube 7.3 of the frame 7.1 so that the track feeder 7 can be freely moving around the pivot to conform the tree being fed. The hydraulic motors 101 on the opposite sides of the frame 7.1 are attached via attachment flanges 104 to the frame 7.1. The drive axle 105 is supported by gear rims 103 on both ends. Each gear rim 103 includes bearings that allow the drive axle 105 to rotate. The gear rims 103 are connected to the attachment flanges 104. The torque is transmitted from the hydraulic motors 101 to the drive axle 105 using splines 106 belonging at each end of the drive axle 105. Opposite motors have gear rims to carry the drive sprocket. There is no torsion to the motors. A drive sprocket driving 107 the track of the track feeder 7 is fixed on the drive axle 105. The track is also supported by the idler sprocket 108.