Invention relates to a hydraulic driven turning device that can be installed to a construction machine, such as at the end of a boom of a power shovel whereupon a first body and another body, which is turning in relation to it, belong to the turning device and a hydraulic cylinder, which is attached from the mentioned bodies to one body, belong to the device in which cylinder the piston that is located in there can be moved axially back and forth with the help of a hydraulic pressure medium and a spiral part is attached to the piston that causes a rotation movement to its counter part that is equipped with a spiral whereupon the mentioned rotation movement can be transferred to be the turning movement of another body.
Hydraulic driven turning devices according to the above mentioned introduction are previously known in which devices ring piston, which can be moved back and forth with the help of a hydraulic pressure, is installed on top of a axis to be directed in axial direction in such a way that there is a spiral with large pitch between them whereupon a rotation movement is created between them when only another one of them can move in axial direction. Further there is a spiral with large pitch at the outer surface of the ring piston which spiral co-operates with the spiral of the barrel that is outside it. The movement of the mentioned barrel is locked in axial direction whereupon it rotates in relation to the piston if the piston is being moved. The another body of the turning device is attached non rotating to the mentioned barrel and another body is attached to the mentioned axis to be non rotating and the axial movement of the piston makes then the bodies to turn with each other.
This kind of known turning device is expensive to manufacture because spirals, which can be manufactured on four different surfaces in a relatively difficult way, belong to it. In these solutions ring piston is used as a piston whereupon its diameter has to be measured to be larger than a disc-like piston when its power-creating surface area! can be achieved only from the ring part. Also in these known solutions, parts that can be moved and are to be sealed are used a lot.
In order to remove the disadvantages of the known solution described above a new turning device, which is essentially easier to manufacture, which needs less screwed parts and the structural diameter of which can be made smaller than in known turning devices, has been developed. It is characteristic of the turning device according to the invention that the piston is arranged to be non rotating in the cylinder located in the body by forming the cross-section of the piston and cylinder to be deviant from a round form, such as to be a oval or a angular or by adjusting the piston eccentric in relation to its bearing axis.
The advantage of the arrangement according to the invention is the fact that only one threaded coupling is needed at the turning device and due to that only two screwed counter surfaces are needed. Pressurised hydraulic device must be sealed only at three sliding surfaces at its simplest of which one is sliding and two other are rotating. Due to the spiral with large pitch the turning device can also be organized to be self-locking with the help of some angle of ascents of the spiral, in other words by directing turning power to another body of the turning device, the piston cannot be moved in axial direction in the cylinder. The load of the body of the turning device can easily be reduced by making the piston rod to extend on both sides of the piston and in this way spiral parts can be made to load the body of the device in a symmetrical way. Also the combined length of the spiral parts that produce turning power stays the same all the time regarding all the rotating angles of the device.
In the following the invention is described more detailed by referring to the accompanying drawing in which
A turning device according to the invention is shown in the
Also a spiral part 2 belongs fixed to the piston 5 which spiral part rotates the piece 3 that exists in the round part of the cylinder 1a while the piston 5 is being moved. The spiral 2 has large pitch, for example the Helicoil-spiral known in the art. The rotation of the piece 3 turns at the same time the another body which is attached to it with the help of bolts, for example through holes 10 which body thus turns in relation to the first body 1. Conventional attaching elements not shown belong to the bodies 1 and 6 with which attaching elements for example the first body 1 is attached to the end of the boom of the power shovel and a tool, like a grab, is attached to another body 6.
In one embodiment the whole cylinder part 1a+1b machined to be elliptical at its inner surface. In that case disc-like modification pieces 11
In another embodiment round parts regarding their inner surfaces are adjusted to the ends of the cylinder 1 to both ends according to the right end of the cylinder 1 shown in the
In one embodiment the inner surface of the cylinder is angular, like triangular 12,
The cross section of the turning device of the figure is shown as reduced in the
Body 1 is shown in the
A round piston 13 is shown in the
In the
The pieces 3a and 3b convey the rotation movement directly to the body 6. The cylinder 1 has a part L2 that deviates from a round form. This part also has a non rotating and non moving insertion ring 11. The piston rod is even at the location of the mentioned ring 11 and the piston rod slides in the hole of the ring 11 which hole is equipped with a sealing when the piston 5 moves in axial direction. In this case the body 6 gets loaded in a symmetrical way and the spiral length producing rotating power for the Helicoil-spiral stays stable regarding all turning angles of the device.
In the
Number | Date | Country | Kind |
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20080090 | Feb 2008 | FI | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/FI2009/000023 | 2/9/2009 | WO | 00 | 10/22/2010 |