The invention relates to a rotation device attached to a working machine or to a power tool attached to said machine which rotation device comprises a lower plate and an upper plate having the same direction and being installed at a distance, a bearing between the said plates in order to rotate them in relation to each other and a rotating apparatus in order to rotate the said planes in relation to each other. Previously adapter parts that perform rotation and turning are known according to the above mentioned preamble which adapter parts usually have two round body parts mounted in bearings with each other to be rotative around the same rotational centre. These turning devices are known for example as being attached to digging machines, loaders and cranes. The bearing is arranged to the intermediate space of the bodies and is shielded with a casing. An annular ball bearing or a cylinder bearing with one or two rows functions as a bearing.

In the known solutions associated with the digging machine the bearing on is prone to impact like stress due to for example the use of bucket, such as when one hits with the bucket and due to large diagonal loads caused by the torsion with the bucket. These cause wearing and damages to the bearings. The rotating device rotates the rotating part with a tooth contact in relation to the other part. The tooth contact of the rotating device also locks the parts to be non rotating if the rotation is not allowed. Thus the tooth contact is prone to both impact like and other stresses. In the known solutions a clearance is easily created to the bearing while being used that quickly causes more other damages. The known solutions don ^' t have a long life in use and they or parts of them often need to be renewed.

In order to remove the above mentioned disadvantages a new rotation device has been developed that essentially reduces the stress of the bearing between the adapter plates of the turning device. Characteristic for the invention is that a removal of the bearing clearance between the plates and/or an interlocking of the reciprocal rotation are adjusted with the bearing between the plates in which case said interlocking can be achieved by arranging a compression betweeh the bearing surfaces that prevents the reciprocal rotation of said plates and the removal of the bearing clearance can be achieved by arranging an essentially lighter compression than the previous compression between the bearing surfaces.

The advantage of the invention is the fact that with the help of the bearing formed with the connecting piece both the removal of the clearance and the interlocking of the rotation can be achieved. Especially the bearing realized with slide bearings endures impact like stress and torsion better than the ball bearings. The bearing is easy to open, maintain and assemble. The operating life of the toothing conveying the rotation movement lengthens when the stress directed to it decreases when the interlocking of the bearing receives a part of the loads that only the toothing has earlier received. The outside diameter of the device can also be reduced a little in relation to the known rotation devices because with the used bearing interlocking according to the invention essentially greater stress can be allowed now.

In the following the invention is described more detailed by referring to the accompanying drawing in which

Figure 1 shows a bearing of a rotation device according to the invention as a section view. Figure 2 shows a rotation device when the bearing is realized with the ball bearings. Figure 3 shows a rotation device the interlocking of which is opened with the help of pressure.

Figure 4 shows a detailed view of the interlocking mechanism of the figure 3.

Figure 5 shows a rotation device the rotation of which is locked with the help of pressure.

In the figure 1 there is the first, lower adapter plate 5 of the turning device as a partly section view to which a ring-shaped bearing part 1 that functions as a connecting piece has been attached for example with screws (the attachment points are shown). The bearing part 1 is further divided into two ring parts la and lb. Another adapter plate 2 surrounds these bearing parts la, lb and counter sliding surfaces 7 and 8 belonging to the slide bearings belong to this plate or they are attached to it. The bearing parts la and lb have corresponding sliding surfaces. In order to ease the assembly in this example a separate ring part 6 is attached to the adapter plate 2 which ring part comprises another sliding surface 7. Cylinders are bored across the horizontal joint surface between the bearing parts la and lb and pistons 4 belong to them. The pistons are partly in the both bearing parts. The pistons 4 function as conducting bodies when the bearing parts la, lb are being removed farther from each other in order to remove the clearance from the bearing or in order to lock the bearing. A hydraulic pressure is directed to the cylinders when one wants to remove the bearing parts farther la, lb from each other. The pressure of the hydraulic fluid is adjusted to be smaller during the removal of the clearance than what is needed when the device is being locked. The hydraulic pressure can be directed in various ways for example from the digging machine to the cylinders. The terminal pressure of the clearance can be adjusted to be constant with the help of a pressure relief valve. Also the pressure can be taken in parallel for example from the pressure of the scoop jack in which case while working with the bucket the rotation of the rotation device is locked simultaneously. During the interlocking procedure the bearings are not clamped so hard that they would get damaged.

The compression load on the bearings can however have the same order of magnitude or be a bit greater than the load what would become created during the working when one for example would dig with the own bucket of the digging machine. If the way of removing the clearance or the disengagement of the bearing parts is mechanical, its adjustment is performed for example by rotating periodically the concerned screws or eccentric shaft.

The hydraulic pressure is directed to the cylinders along channels 9 for example from the centre of the device - if needed also through the rotating connector 10 located in the centre. The rotation of the device occurs in this example by rotating a worm wheel 3 for example with the help of a hydraulic motor. A corresponding tooth ring 11 is located at the outer edge of the bearing parts 11a, lb. The division plane of the bearing parts la, lb can also be done to be directed also in a way that the toothing 11 will be done only to another part, as is shown in the figure 2.

In the figure 2 ball bearings 12 and 13 are shown being installed in principle to a similar solution as the figure 1 shows. The connecting piece la, lb is divided in such a way that the toothing 11 surrounding its edge is totally located in the other part lb. The disengagement of the bearing parts la and lb from each other can also occur mechanically. In that case one or several eccentric elements or screws are adjusted at the interface of the bearing parts or near it with the rotation of which the bearing parts are adjusted to draw away and analogously also to come closer. With these rotations of the screws between the bearing parts the clearance is removed and with a tighter rotation locking can be achieved.

In the figure 3 a rotation device is shown to which an upper adapter plate 14 belongs comprising attachment elements 15 for example in order to attach it at the end of the extension arm of the digging machine and to which a lower adapter plate 5 further belongs to which a potential tilting mechanism of the bucket or a bucket directly is attached.

Tapped holes 19 are shown for the attachment of these. A tooth ring 18 is adjusted between said plates 5, 14 which tooth ring is attached to the lower plate 5. A worm wheel 3 rotated by the rotating motor is attached to the upper plate 14. The inner surface of the tooth ring 18 is an even cylinder surface. A cylindrical part 17 attached to the upper plate 14 is adjusted against the inner surface of the tooth ring 18 which cylindrical part is inside the tooth ring 18 adjusted with such a tight adapter that their reciprocal rotation is locked. Their installation within each other occurs knowingly for example in such a way that the outer tooth ring 18 is being warmed and the inner part 17 is being cooled in which case the heat expansion of one part and the thermal shrinking of another part allows the installation of the parts within each other. When the temperatures of the parts 17, 18 become even, a compression condition is left between them, a metallic surface against another metallic surface in which case their reciprocal rotation is blocked. The interlocking is arranged to be so strong with the selected adapter that it keeps the bucket of the digging machine non rotating during the work.

In the figure 4 the situation between the inner part 17 of the tooth ring 18 is shown in a detailed way in which situation the interlocking between the parts 17, 18 has been opened with the help of a hydraulic pressure directed through a pipework 16. The hydraulic pressure is directed to the intermediate space 20 of the parts 17, 18 in which case the pressure will have an effect on the surfaces of the both parts 17,18 in such a way that the outer tooth ring 18 extends a little to a larger diameter dimension and the smaller part 17 shrinks a little to a smaller diameter dimension. Seals 29 keep the hydraulic fluid in the intermediate space 20. When the clearance s for example about 0,05 mm is formed between the parts 17, 18 with the help of a pressure, the rotating parts 17, 18 already sensitively enough with each other and the rotation position of the parts 17, 18 can be changed with the help of a rotating motor and a gear. The removal of the pressure from the space 20 locks again the parts 17, 18 with each other. The cylinder surface between the parts 17, 18 functions as a bearing when the parts are being rotated in relation to each other. In this solution such clearance is not created between the plates 5, 14 that should be removed.

In the figure 5 there is a rotation device to which an upper plate 23 and a lower plate 5 belong. A ring with a conical surface 30 is attached to the lower plate 5 with bolts through holes 25. The upper plate 23 also comprises a conical surface in which case a conical counterpart surface arrangement 28 is created between the parts 30 and 23. The reciprocal interlocking of the plates 5 and 23 is performed by directing the hydraulic pressure along the channel 24 to the intermediate space 27 in which case the upper plate 23 rises and squeezes the cone joint 28 closed and as a result a compression condition occurs in which there is a metallic surface against another metallic surface. The bolt prevents the upper plate 23 from bending to become ball-shaped. When one removes the pressure from the intermediate space 27 the interlocking opens to be free. If the reciprocal movement of the parts 5, 23 is performed with the help of a rotating motor, one rotating arrangement is shown with dashed line comprising a motor 22 attached to the plate 23 which motor rotates the tooth ring 21 with the help of a tooth- wheel 31. The conical surface 28 between the parts 30, 23 functions as a bearing when the parts are being rotated in relation to each other. If the clearance needs to be removed between the parts 5, 23 for example with the help of a motor 22 while turning the part 5, it happens by directing an essentially lower pressure to the intermediate space 27 than what is needed to reach the locking position.

None of the solutions of the figures 1 - 5 does not necessarily need a rotating motor to rotate a rotation device because with the digging machine the interlocking of the turning device can at first be released and then achieve the rotation of the rotation device to the desired position with the help of the movements of the bucket, and after that lock the turning device to that rotation position. On the other hand - as shown in the figures 1 - 5 a rotary motor can be adjusted to each shown embodiment.