FEEDING APPARATUS FOR A TREE HARVESTER

Abstract

A feeding apparatus includes opposing arms pivoted to a frame, two opposing feed rollers installed in the arms as the only feed rollers for feeding a tree through the throat, hydraulic motors driving the feed rollers and at least two pressure-medium lines operating the hydraulic motors.

Claims

1-13. (canceled)

14. Feeding apparatus for a harvester, comprising: 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 a throat, two sets of two hydraulic motors, each set of the two hydraulic motors driving each feed roller, thus creating a mechanical connection between the hydraulic motors of each feed roller, and two parallel pressure-medium lines operating the hydraulic motors, and in each pressure medium line having two hydraulic motors in series, each motor of two being one motor of the opposite feed rollers, the two sets of two hydraulic motors connected in the opposite order in said two pressure-medium lines.

15. Feeding apparatus, according to claim 14, wherein the hydraulic motors connected in series are of the same size and of a single capacity.

16. Feeding apparatus, according to claim 14, wherein the width of the feed roller is 50-150%, of its diameter.

17. Feeding apparatus, according to claim 14, wherein the path of movement of the feed rollers is arranged to be essentially linear, the maximum linear deviation being 1-6% of the lateral displacement.

18. Feeding apparatus, according to claim 14, wherein the arms carrying the said feed rollers are trapezium arms.

19. Feeding apparatus, according to claim 14, wherein the diameter of the feed roller is 30-120 cm.

20. Feeding apparatus, according to claim 1, wherein each feed roller includes its own auxiliary frame and the bearings carrying the feed roller, as well as two hydraulic motors rotating the feed roller, attached to the auxiliary frame.

21. Feeding apparatus, according to claim 20, wherein in at least one feed roller there is a gear ring equipped with internal gearing, which the hydraulic motors drive through gearwheels.

22. Feeding apparatus, according to claim 20, wherein a gear ratio of the driving gearwheel and the internal gearing is 1:4.550%.

23. Feeding apparatus, according to claim 21, wherein the gearwheels driving the internal gear ring are both on the same side of the gear ring, being thus situated outside the said arms relative to the throat.

24. Feeding apparatus, according to claim 14, wherein bearings of at least one gearwheel are integrated in the hydraulic motor driving it.

25. Feeding apparatus, according to claim 14, wherein at least one feed roller includes a rubberized flexible ring, and gripping elements supported with the aid of a swing shaft, which press into it when loaded, and which overlap.

26. 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, characterized in that it includes a feeding apparatus according to claim 1.

Description

[0031] In the following, the invention is described with examples and with reference to the accompanying figures.

[0032] FIG. 1 shows a three-roller feeding apparatus according to the prior art,

[0033] FIG. 2 shows one feeding apparatus according to the invention, seen in the direction of feeding the tree,

[0034] FIG. 3 shows a side view of the arrangement of FIG. 2,

[0035] FIG. 4a shows one transmission arrangement of a feed roller using a new feed roller,

[0036] FIG. 4b shows an end view of the feed roller of FIG. 4a,

[0037] FIG. 4c shows an axonometric view of the feed roller of FIGS. 4a and 4b,

[0038] FIG. 4d shows the gripping element used in the feed roller of FIG. 4c,

[0039] FIG. 5 shows a schematic hydraulics diagram of the feeding apparatus, and

[0040] FIGS. 6a and 7a show the annular forces of the feed roller in normal and one-sided loading situations.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] This embodiment presents one construction. The shaft 12 is attached to the roller holder 7. In turn, the shaft 12 is attacked 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.

[0045] 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.

[0046] A gear ring 14 is attached to the upper edge of the roller 4. Hydraulic motors 10 and 11, equipped with a smaller gearwheel 15 and 16, are fitted to the holder 7. 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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 motor 11 in line L2 and motor 10.1 in line L1. 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.

[0051] 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.

[0052] 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.

[0053] 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 F2 in symmetrical traction. More specifically, it can be estimated that

F>95%(2F2),

which has also be measured on the test bench.

[0054] 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.

[0055] 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.

[0056] 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.