Rotator for a hydraulic tool

Abstract

The invention relates to a rotator for a hydraulic tool, such as a jib-carried hydraulic tool. The rotator (100) comprises: a stator (110) comprising at least one first hydraulic port (142) configured to be connected to a hydraulic tool (300) via at least one first hydraulic hose (152); a rotor (120) rotatably arranged inside the stator (110); and a hydraulic swivel (130) comprising a hydraulic housing (132) rotatably arranged relatively the stator (110), the hydraulic housing (132) comprising at least one second hydraulic port (144) configured to be connected to a hydraulic source (220) via at least one second hydraulic hose (154), wherein the second hydraulic port (144) is connected to the first hydraulic port (142) via at least one internal hydraulic channel (146) extending inside the hydraulic housing (132) and the stator (110). The invention also relates to a vehicle comprising such a rotator.

Description

[0001] ROTATOR FOR A HYDRAULIC TOOL

[0002] Technical Field

[0003] The invention relates to a rotator for a hydraulic tool, such as a jib-carried hydraulic tool. The invention also relates to a vehicle comprising such a rotator.

[0004] Background

[0005] A crane system often comprises two or three crane arm parts connected to each other by crane arm joints. At the end of the crane a crane arm tip is arranged for carrying a tool and / or a load. A rotator can be arranged between the crane arm tip and the tool so that the tool can be rotated in respect to the crane arm tip.

[0006] Rotators come in a number of different types and the most common types are electric rotators and hydraulic rotators.

[0007] A grapple is an example of a jib-carried tool and another example of a jib-carried tool is a forest harvester head for harvesting trees. The forest harvester head is a hydraulic tool meaning that the forest harvester needs supply of hydraulic fluid for its functioning.

[0008] Summary

[0009] An objective of embodiments of the invention is to provide a solution which mitigates or solves the drawbacks and problems of conventional solutions.

[0010] Another objective of embodiments of the invention is to provide a rotator comprising a hydraulic swivel with a compact design.

[0011] The above and further objectives are solved by the subject matter of the independent claims. Further advantageous embodiments of the invention can be found in the dependent claims.

[0012] According to a first aspect of the invention, the above mentioned and other objectives are achieved with a rotator for carrying a hydraulic tool, the rotator comprising: a stator comprising at least one first hydraulic port configured to be connected to a hydraulic tool via at least one first hydraulic hose; a rotor rotatably arranged inside the stator; and a hydraulic swivel comprising a hydraulic housing rotatably arranged relatively the stator, the hydraulic housing comprising at least one second hydraulic port configured to be connected to a hydraulic source via at least one second hydraulic hose, wherein the second hydraulic port is connected to the first hydraulic port via at least one internal hydraulic channel extending inside the hydraulic housing and the stator.

[0013] An advantage of the rotator according to the first aspect is that the axial height of the rotator comprising a hydraulic swivel can be held low compared to conventional solutions. Further, the inner diameter of the hydraulic swivel can be made large while the outer diameter can be held low with the present solution, which implies small bending angles for internal hydraulic channels inside the hydraulic swivel. Thereby, the pressure losses in the hydraulic swivel are smaller compared to conventional solutions. Thus, the present rotator is especially suitable in tool applications demanding high hydraulic flows and pressures. Yet another advantage is that the disclosed hydraulic housing does not have to carry any external loads from the tool.

[0014] In an embodiment of a rotator according to the first aspect, the rotator comprises a first attachment means for attaching the rotator to a crane arm, and a second attachment means for attaching the rotator to the hydraulic tool.

[0015] In an embodiment of a rotator according to the first aspect, the second hydraulic hose is at least partially attached to the crane arm in operation.

[0016] The expression “in operation” may also be understood as “in use” or equivalent. Thus, the expression “in operation” implies that the rotator is mounted at a crane arm and carries a hydraulic tool and ready to be used. The axial order or equivalently the vertical order is in operation the following: the tip of the crane arm is axially arranged above the rotator which is axially arranged above the hydraulic tool.

[0017] An advantage with this embodiment is that the second hydraulic hose attached to the crane arm will act as one reference point in relation to which the hydraulic housing will rotate. Thus, the rotation of the hydraulic housing can partially be controlled depending on the location of the attachment point and the properties of the second hydraulic hose such as length, rigidity, stiffness, etc.

[0018] In an embodiment of a rotator according to the first aspect, the rotator comprises a mechanical coupling configured to couple the hydraulic housing to the first attachment means or the rotor so that the hydraulic housing at least partially follows the rotation of the first attachment means or the rotor.

[0019] An advantage with this embodiment is that the rotation of the hydraulic housing can be limited and / or controlled so as to adapt the rotation of the hydraulic housing to different tool applications.

[0020] In an embodiment of a rotator according to the first aspect, the mechanical coupling extends from the hydraulic housing to the first attachment means or the rotor, or vice versa, at an exterior of the rotator.

[0021] An advantage with this embodiment is that no internal space of the rotator has to be occupied by the mechanical coupling. Also repair and replacement of the mechanical coupling is easier since it is arranged at the exterior of the rotator.

[0022] In an embodiment of a rotator according to the first aspect, the rotator comprises: a first end stop corresponding to a first radial angle and a second end stop corresponding to a second radial angle different to the first radial angle, and wherein the hydraulic housing is arranged to rotate between the first radial angle and the second radial angle.

[0023] An advantage with this embodiment is that the rotational span may be defined for the hydraulic housing. Hence, different rotational spans may be provided for different tool applications. This also implies that the mechanical coupling and / or the ends stops can be replaced by other mechanical couplings and ends stops fulfilling the same objectives.

[0024] In an embodiment of a rotator according to the first aspect, the second attachment means extends axially or radially in the stator. An advantage with this embodiment is that the axial height or the diameter of the rotator can be held low depending on application requirements.

[0025] In an embodiment of a rotator according to the first aspect, the rotator comprises: at least one sealing arranged between the hydraulic housing and the stator.

[0026] An advantage with this embodiment is that not only does the sealing prevent leakage of hydraulic fluid, but the rotational friction of the hydraulic housing can also be controlled depending on the type of sealing employed.

[0027] In an embodiment of a rotator according to the first aspect, the rotator comprises: a bearing arranged between the hydraulic housing and the stator.

[0028] An advantage with this embodiment is that the hydraulic housing is supported by the bearing which means that the second hose can move with the rotation of the hydraulic housing. Further, by proper design of the bearing, the rotational friction of the hydraulic housing can at least partially be controlled.

[0029] In an embodiment of a rotator according to the first aspect, the bearing comprises an axial bearing and / or a radial bearing.

[0030] In an embodiment of a rotator according to the first aspect, the first hydraulic port extends radially or axially in the stator, and the second hydraulic port extends radially in the hydraulic housing.

[0031] An advantage with this embodiment is that the inner diameter of the hydraulic swivel can be made large while the outer diameter can be held low.

[0032] In an embodiment of a rotator according to the first aspect, the first hydraulic port is arranged axially below the second hydraulic port in operation.

[0033] An advantage with this embodiment is that the first hydraulic port is arranged closer to the hydraulic tool than the second hydraulic port. Thereby, coupling the hydraulic swivel to the hydraulic tool is made easier. In an embodiment of a rotator according to the first aspect, the hydraulic housing is arranged in a proximal part of the rotator in relation to the hydraulic tool in operation.

[0034] In an embodiment of a rotator according to the first aspect, the hydraulic swivel is arranged axially above the hydraulic tool in operation.

[0035] An advantage with this embodiment is that the complete rotator can be arranged above the hydraulic tool.

[0036] In an embodiment of a rotator according to the first aspect, the stator comprises a stator extension extending in a direction towards the hydraulic tool.

[0037] Thus, the stator comprises a stator extension that extends from the stator to the tool or equivalently is arranged between the stator and the hydraulic tool according to this embodiment. The stator extension may include all or some of the attachment means for attaching the tool to the rotator.

[0038] Thereby, the stator and the stator extension can be produced from different materials for different applications. Further, the maintenance of the rotator and the tool can be made easier since the stator extension and the tool can be made as a separate module which can be connected and disconnected from the stator. Also, the stator extension makes the distance from the crane tip to the hoes longer which implies free movement of the hoses. Moreover, the forming of the inner hydraulic channels is easier with a stator extension.

[0039] In an embodiment of a rotator according to the first aspect, the stator and the stator extension are coaxially arranged in the rotator.

[0040] The stator and the stator extension may be coaxially arranged along an axis of rotation of the rotator.

[0041] Thereby, electrical power cables and signalling cables can easily be arranged within the rotator along the axis of rotation. In an embodiment of a rotator according to the first aspect, the first hydraulic port is arranged in the stator extension.

[0042] In an embodiment of a rotator according to the first aspect, the stator and the stator extension are formed from separate parts.

[0043] An advantage with this embodiment is that the separate parts may be produced from different metals suitable for different applications and price considerations.

[0044] In an embodiment of a rotator according to the first aspect, the rotator comprises a urea swivel having a urea housing rotatably arranged relatively the stator.

[0045] An advantage with this embodiment is that the axial height of the rotator can be held low when the rotator also comprises a urea swivel.

[0046] In an embodiment of a rotator according to the first aspect, the urea housing is mechanically integrated with the hydraulic housing or arranged in a separate housing.

[0047] In an embodiment of a rotator according to the first aspect, the stator comprises an electrical swivel, and / or an angle meter and / or an accelerometer.

[0048] An advantage with this embodiment is that further functions can be provided by the rotator having these devices.

[0049] In an embodiment of a rotator according to the first aspect, the electrical swivel, and / or the angle meter and / or the accelerometer is coaxially arranged inside the stator.

[0050] An advantage with this embodiment is that the above-mentioned devices are protected inside the rotator.

[0051] According to a second aspect of the invention, the above mentioned and other objectives are achieved with a vehicle comprising a rotator according to any one of the preceding embodiments and the crane arm to which the rotator is attached. In an embodiment of a vehicle according to the second aspect, the rotator is pivotably attached to the crane arm.

[0052] In an embodiment of a vehicle according to the second aspect, the hydraulic tool is a forest harvester head.

[0053] Further applications and advantages of the embodiments of the invention will be apparent from the following detailed description.

[0054] Brief Description of the Drawings

[0055] The appended drawings are intended to clarify and explain different embodiments of the invention in which:

[0056] - Fig. 1 a and 1 b show a rotator in a cross section view according to embodiments of the invention;

[0057] - Fig. 2 shows rotator with first and second attachment means in a cross section view according to embodiments of the invention;

[0058] - Fig. 3a and 3b show a rotator with a mechanical coupling in an exterior perspective view and in an exterior front view, respectively, according to embodiments of the invention;

[0059] - Fig. 4 shows a rotator in a detailed cross section view according to embodiments of the invention;

[0060] - Fig. 5 shows a crane arm, a rotator and a hydraulic tool according to embodiments of the invention; and

[0061] - Fig. 6 shows a vehicle comprising a rotator according to embodiments of the invention.

[0062] Detailed Description

[0063] Fig. 1a and 1 b show a rotator 100 for carrying a hydraulic tool 300 in a cross section view according to embodiments of the invention.

[0064] With reference to Fig. 1 a and 1 b, the herein disclosed rotator 100 comprises a stator 110 having at least one first hydraulic port 142 configured to be connected to a hydraulic tool 300 via at least one first hydraulic hose 152, see Fig. 5. The rotator 100 also comprises a rotor 120 which is rotatably arranged inside the stator 110. Hence, the rotor 120 can rotate inside the stator 1 10 e.g., by means of a hydraulic motor such as a wing / vane motor, a piston motor or any other hydraulic motor. However, the motor for rotating the rotor 120 in relation to the stator 1 10 may also in other examples be an electrical motor.

[0065] The rotator 100 further comprises a hydraulic swivel 130 having a hydraulic housing 132 rotatably arranged relatively the stator 110 (as shown in Fig. 1 a) and / or a stator extension 1 12 of the stator 1 10 (as shown in Fig. 1 b). Thus, the hydraulic housing 132 can rotate around an outside or an exterior of the stator 110 and / or the stator extension 1 12 and is therefore not rotationally fixed to the stator 1 10 and / or the stator extension 1 12.

[0066] The herein disclosed hydraulic housing 132 comprises at least one second hydraulic port 144 configured to be connected to a hydraulic source 220 (see Fig. 6) via at least one second hydraulic hose 154, and the second hydraulic port 144 is connected to the first hydraulic port 142 via at least one internal hydraulic channel 146 extending inside the hydraulic housing 132 and the stator 1 10. Thereby, hydraulic fluid can flow through the hydraulic swivel 130 and feed / supply the hydraulic tool 300 with hydraulic fluid from the hydraulic source 220 via hydraulic feed channels / conduits. The hydraulic swivel 130 may also have hydraulic return channels / conduits such that the hydraulic fluid can return back to the hydraulic source 220. Therefore, the rotator 100 may comprises one or more first 142 and second 144 hydraulic ports with associated one or more first 152 and second 154 hoses depending on how many hydraulic channels that are needed by the hydraulic tool 300 for operation.

[0067] The mentioned stator extension 112 may be bolted to the stator 1 10 by means of bolts and corresponding receiving means that extends axially or radially in the stator 1 10. However, other attachment means known in the art for attaching the stator extension 1 12 to the stator 1 10 may be used. Hence, in embodiments of the invention, the stator 1 10 and the stator extension 1 12 are formed from separate parts such as different metal parts. The stator 1 10 may e.g., be produced from cast iron while the stator extension 1 12 may be produced from steel. Thus, since the properties of different materials, such as hardiness, corrosion, weight, are different this means that they are suitable for different applications and involve different cost considerations. It is however noted that the stator 1 10 and its extension 1 12 may in other embodiments of the invention be formed from a common piece of metal and not from separate parts.

[0068] Furthermore, the first 142 and second 144 hydraulic ports may extend radially or axially into or out of the rotator 100 and in the shown embodiments, the first hydraulic port 142 extends radially in the stator 1 10 or in the stator extension 1 12, while the second hydraulic port 144 extends radially in the hydraulic housing 132. However, in other embodiments of the invention, the first hydraulic port 142 extends axially in the stator 110 or in the stator extension 1 12 which however are not shown in the Figs. The axial relation between the first 142 and second 144 hydraulic ports in the rotator 100 may also be considered when designing the rotator 100 and in the disclosed examples, the first hydraulic port 142 is arranged axially below the second hydraulic port 144 when the rotator 100 is in operation / use thereby making connection / disconnection of the hydraulic tool 300 to the rotator 100 easier.

[0069] Fig. 2 shows a rotator 100 with first 162 and second 164 attachment means in a cross section view according to further embodiments of the invention. The rotator 100 in Fig. 2 comprises: a first attachment means 162 for attaching the rotator 100 to a crane arm 210, and a second attachment means 164 for attaching the rotator 100 to the hydraulic tool 300.

[0070] The first attachment means 162 may have the shape of one or more ears with through holes arranged inside the ears. Thus, the rotator 100 may be attached to the crane arm 210 by inserting corresponding attachment means, such as pins and shafts, so as to attach and secure the rotator 100 to the crane arm 210. Other first attachment means 162 may be used for attaching the rotator 100 to the crane arm 210.

[0071] The second attachment means 164 on the other hand may comprise bolts and corresponding receiving means in the form of drilled holes with inner threads configured to engage with the outer threads of the bolts for a secure fit. The number of bolts and the dimension of the bolts may depend on the application such as how much load to be carried by the rotator 100. Other second attachment means 164 may be used for attaching the hydraulic tool 300 to the rotator 100.

[0072] It may further be noted from Fig. 2 that the hydraulic housing 132 is arranged in a proximal part of the rotator 100 in relation to the hydraulic tool 300 in operation. This may be understood such that the hydraulic housing 132 is located in the part of the rotator 100 which is closest to the hydraulic tool 300 when the hydraulic tool 300 is mounted at rotator 100 in contrast to the distal part of the rotator 100 which is the farthest part seen in view from the hydraulic tool 300. The distal part comprises the first attachment means 162 for attaching the rotator 100 to the crane arm 210 in embodiments of the invention. This also implies that the hydraulic swivel 130 may be arranged axially above the hydraulic tool 300 in operation.

[0073] Hence, Fig. 2 shows the embodiment when the stator 1 10 comprises a stator extension 1 12 being or forming the proximal part of the rotator 100 in relation to the hydraulic tool 300. The stator extension 1 12 extends in a direction from the stator 1 10 towards the hydraulic tool 300, i.e., the stator extension 1 12 is located or arranged between the stator 1 10 and the hydraulic tool 300. As also disclosed in Fig. 2, the stator 1 10 and the stator extension 112 may be coaxially arranged in the rotator 100. In such cases the stator 1 10 and the stator extension 112 may be coaxially arranged and in line with the axis A of rotation of the rotator 100. The first hydraulic port 142 may be arranged in the stator extension 1 12. The internal hydraulic channel 146 interconnecting the first hydraulic port 142 and the second hydraulic port 144 may in such embodiments extend offset in relation to the axis A of rotation of the rotator 100, i.e., non-coaxially in relation to the axis A of rotation of the rotator 100. When the rotator 100 comprises a stator 110 and a stator extension 1 12, the stator 1 10 encloses the rotor 120. Thus, the rotor 120 rotates in the stator 1 10 in such embodiments.

[0074] Fig. 3a and 3b show a rotator 100 with a mechanical coupling 170 in an exterior perspective view and in an exterior front view, respectively, according to embodiments of the invention. The centre axis A of the rotator 100 is also illustrated with the dotted arrow denoted A in Fig. 3b. To control the rotation of the hydraulic housing 132, the rotator 100 may include the mentioned mechanical coupling 170 which mechanically couples the hydraulic housing 132 with the first attachment means 162 or the rotor 120 in a rotational manner. In this way, the hydraulic housing 132 fully or at least partially follows the rotation of the first attachment means 162 or the rotor 120 depending on the design of the mechanical coupling 170.

[0075] The mechanical coupling 170 in Fig. 3a and 3b has a first engagement part 176 that extends from the first attachment means 162 and downwards at an exterior of the rotator 100. At the hydraulic housing 132, a second engagement part 178 is located at a block of the hydraulic housing 132 and is arranged to engage with the first engagement part 176. The second engagement part 178 in this example also comprises a first end stop 172 corresponding to a first radial angle and a second end stop 174 corresponding to a second radial angle of the rotator 100. Since the first and second end stops limits the rotation of the first engagement part 176, the hydraulic housing 132 will only be able to rotate between the first radial angle and the second radial angle. Hence, the hydraulic housing 132 cannot rotate outside the first and second radial angles. By having different first and second radial angles the allowed rotational span of the hydraulic housing 132 can be controlled. Therefore, different second engagement parts 178 with different end stops may be used for different allowed rotational spans. Hence, the second engagement part 178 may be replaceable at the hydraulic housing 132. More generally, the mechanical coupling 170 and the engagement parts 176, 178 may be replaced by other mechanical couplings 170 and the engagement parts for other desired rotational spans of the hydraulic housing 132.

[0076] From the above description it may also be noted that the mechanical coupling 170 can extend from the hydraulic housing 132 to the first attachment means 162 or the rotor 120, or vice versa, at an exterior of the rotator 100. It is also envisaged that the mechanical coupling 170 may extend from both the hydraulic housing 132 and the first attachment means 162 and meet each other at a location between the hydraulic housing 132 and the first attachment means 162.

[0077] Fig. 4 shows a rotator 100 in a detailed cross section view according to embodiments of the invention. A rotational line or plane R is also illustrated in Fig. 4 and some parts of the rotator 100 rotates with the rotor 120 in relation to the stator 1 10 according to embodiments of the invention. This means that the rotational line or plane P also demarks the rotor 120 and the stator 1 10. Thus, the rotor 120 may be connected to the first attachment means 162 via a torque transmission device 122 configured to transmit torque from the rotor 120 to the first attachment means 162. Thus, the rotor 120 and the first attachment means 162 will rotate together freely of the stator 1 10.

[0078] The rotor 120 in Fig. 4 is powered by a hydraulic wing / vane motor. A wing / vane 124 and associated hydraulic cannels for feeding the hydraulic wing / vane motor are shown in Fig. 4. The hydraulic cannels for the hydraulic wing / vane motor are however not shown in Fig. 4 but a hydraulic port 126 for the hydraulic wing / vane motor is shown in Fig. 3a. The hydraulic port 126 may be coupled to a corresponding port of the hydraulic tool 300 thereby receiving hydraulic fluid for powering the hydraulic wing / vane motor.

[0079] The hydraulic housing 132 is as previously described arranged to fully or partially rotate relatively the stator 1 10 possibly including the stator extension 1 12. However, to avoid leakage of hydraulic fluid, the rotator 100 has at least one sealing 134 which is arranged between the hydraulic housing 132 and the stator 1 10 and / or the stator extension 1 12 in embodiments of the invention. The type and design of the sealing 134 may vary. Especially the degree of tightness of the sealing 134 in relation to the surrounding parts will result in a friction that partially counteracts the rotational movement of the hydraulic housing 132. Another factor that affects the friction is how the hydraulic housing 132 is attached to the stator 1 10 and / or the stator extension 1 12. In this respect the rotator 100 may comprise a bearing 136 as shown in Fig. 4. This particular bearing 136 comprises an axial bearing part 136A and a radial bearing part 136B and is arranged between the hydraulic housing 132 and the stator 1 10 and / or the stator extension 112. Depending on the construction and design of the bearing 136, the friction counteracting the rotational movement of the hydraulic housing 132 will be affected. Therefore, depending on the type of sealing 134 and the type of bearing 136 the inertness of the rotational movement of the hydraulic housing 132 may be controlled / designed.

[0080] Furthermore, in certain tool applications urea is needed, e.g., for combating root rot when harvesting trees. For such cases, the rotator 100 may comprises a urea swivel 180 as also shown in Fig. 4. The disclosed urea swivel 180 has a urea housing 182 rotatably arranged relatively the stator 1 10 and / or the stator extension 112 in the same way as the hydraulic housing 132. The urea swivel 180 has an input port 184 and an output port (not shown in the Figs.) interconnected by one or more internal urea conduits (not shown in the Figs.) such that urea can be delivered from a urea source 230 (see Fig. 6) to the hydraulic tool 300.

[0081] The urea housing 182 may be mechanically integrated with the hydraulic housing 132 or arranged in a separate housing depending on use cases. The latter example is shown in Fig. 4 where the urea housing 182 is arranged axially above the hydraulic housing 132 in a separate housing. Thereby, the urea housing 182 may be produced in a metal that has high anti-corrosive properties since urea is a very corrosive fluid.

[0082] Moreover, for providing additional functions and applications of the rotator 100, the stator 110 and / or the stator extension 1 12 may comprise one or more of:

[0083] • An electrical swivel 192 with electrical / signal cables 198 for providing electrical power to the hydraulic tool and control signals to and / or from the hydraulic tool. The control signals may be e.g., be conventional CAN signals or other standardized control signals. The electrical swivel 192 is in this example arranged inside the hydraulic swivel 130. The electrical / signal cables 198 may extend axially inside the rotator 100 from the electrical swivel 192 to an electrical contact 199 as shown in Fig. 4 and via a cardan coupling extend inside or along the crane arm 210 to a power source and / or a control unit. However, in other examples, the electrical / signal cables 198 may extend axially and radially inside the rotator 100. For example, the electrical / signal cables 198 may extend axially from the electrical swivel 192 to the electrical contact 199and thereafter extend radially outwards from the electrical contact 199 to the exterior of the rotator 100 and at least partially follow the second hoes 154 to power source and / or a control unit.

[0084] • An angle meter 194 for providing information about the relative rotation between the rotor 120 and the stator 110. This information may be used in different applications such as in autonomous or semi-autonomous control of the hydraulic tool 300, the crane and / or the vehicle 200. • An accelerometer 196 for determining the three-dimensional movement of the rotator. Also, this information may be used in autonomous or semi-autonomous control of the hydraulic tool 300, the crane and / or the vehicle 200.

[0085] In embodiments of the invention, the electrical swivel 192, and / or the angle meter 194 and / or the accelerometer 196 is coaxially arranged inside the stator 1 10 and / or the stator extension 1 12 as shown in Fig. 4 around the centre axis A of the rotator 100. Thus, the diameter of the rotator 100 can be kept small while protecting mentioned devices in a rough working environment.

[0086] The angle meter 194 may be integrated with the accelerometer 196 in the lower part (i.e., the proximal part) of the rotator 100 in operation. Also, a temperature sensor may be integrated with the accelerometer 196 and the accelerometer 196 in the lower part of the rotator 100. The electrical swivel 192 is in this case located in the upper part (i.e., the distal part) of the rotator 100 in operation. However, the axial location of the electrical swivel 192, the angle meter 194, the accelerometer 196 and the temperature sensor may vary.

[0087] It may further be noted that the urea swivel 180 may in examples of the invention be arranged inside the rotator 100 around an electrical cable 198 of the electrical swivel 192. This embodiment is however not shown in the Figs.

[0088] Fig. 5 shows a crane arm 210, a rotator 100 and a hydraulic tool 300 attached to each other according to embodiments of the invention. As shown in Fig. 5 the rotator 100 may be pivotably attached to the crane arm 210 which may be achieved with a cardan coupling 240 or any other suitable coupling providing the same properties. Thus, the rotator 100 is in such embodiments arranged to rotate around a pivot / rotational axis defined by the cardan coupling 240.

[0089] The hydraulic tool 300 may be any suitable hydraulic tool that needs hydraulic fluid for its functioning. A specific application for the present rotator 100 is when the hydraulic tool 300 is a forest harvester head as shown in Fig. 5 configured to grip trees to be harvested. Thereby, hydraulic fluid is provided to the forest harvester head 300 by means of the hydraulic swivel 130 according to embodiments of the invention. Fig. 6 shows a vehicle 200 comprising a rotator 100 according to embodiments of the invention and a crane arm 210 to which the rotator 100 is attached. Thus, the second hydraulic hose 154 is at least partially attached to the crane arm 210. This means that the second hydraulic hose 154 may be completely attached to the crane arm 210 in its full extension or attached to the crane arm 210 at specific locations as illustrated in Fig. 6. In this respect the vehicle 200 may comprise hose attachment means 230 for attaching the hose to the crane arm 210. It should however be noted that the second hydraulic hose 154 may be partially or fully integrated with the crane arm 210.

[0090] The vehicle 200 may also include the hydraulic tool 300 to which the rotator 100 is coupled, e.g., at least partially at the lower part and / or the underside of the rotator 100.

[0091] It is also shown in Fig. 6 that the vehicle 200 comprises a hydraulic source 220 to which one or more first hydraulic hose are connected so that hydraulic fluid can be delivered to the hydraulic tool 300 via the hydraulic swivel 130.

[0092] The vehicle 200 may also comprise a urea source 230 so that urea can be delivered to the hydraulic tool 300 if so required via the urea swivel.

[0093] Finally, it should be understood that the invention is not limited to the embodiments described herein, but also relates to and incorporates all embodiments within the scope of the appended independent claims.

Claims

CLAIMS1 . A rotator (100) for carrying a hydraulic tool (300), the rotator (100) comprising: a stator (1 10) comprising at least one first hydraulic port (142) configured to be connected to a hydraulic tool (300) via at least one first hydraulic hose (152); a rotor (120) rotatably arranged inside the stator (1 10); and a hydraulic swivel (130) comprising a hydraulic housing (132) rotatably arranged relatively the stator (1 10), the hydraulic housing (132) comprising at least one second hydraulic port (144) configured to be connected to a hydraulic source (220) via at least one second hydraulic hose (154), wherein the second hydraulic port (144) is connected to the first hydraulic port (142) via at least one internal hydraulic channel (146) extending inside the hydraulic housing (132) and the stator (1 10).

2. The rotator (100) according to claim 1 , comprising: a first attachment means (162) for attaching the rotator (100) to a crane arm (210), and a second attachment means (164) for attaching the rotator (100) to the hydraulic tool (300).

3. The rotator (100) according to claim 1 or 2, wherein the second hydraulic hose (154) is at least partially attached to the crane arm (210) in operation.

4. The rotator (100) according to claim 2 or 3, comprising a mechanical coupling (170) configured to couple the hydraulic housing (132) to the first attachment means (162) or the rotor (120) so that the hydraulic housing (132) at least partially follows the rotation of the first attachment means (162) or the rotor (120).

5. The rotator (100) according to claim 4, wherein the mechanical coupling (170) extends from the hydraulic housing (132) to the first attachment means (162) or the rotor (120), or vice versa, at an exterior of the rotator (100).

6. The rotator (100) according to claim 4 or 5, comprising a first end stop (172) corresponding to a first radial angle and a second end stop (174) corresponding to asecond radial angle different to the first radial angle, and wherein the hydraulic housing (132) is arranged to rotate between the first radial angle and the second radial angle.

7. The rotator (100) according to any one of claims 2 to 6, wherein the second attachment means (164) extends axially or radially in the stator (1 10).

8. The rotator (100) according to any one of the preceding claims, comprising at least one sealing (134) arranged between the hydraulic housing (132) and the stator (1 10).

9. The rotator (100) according to any one of the preceding claims, comprising a bearing (136) arranged between the hydraulic housing (132) and the stator (1 10).

10. The rotator (100) according to claim 9, wherein the bearing (136) comprises an axial bearing (136A) and / or a radial bearing (136B).1 1 . The rotator (100) according to any one of the preceding claims, wherein the first hydraulic port (142) extends radially or axially in the stator (1 10), and the second hydraulic port (144) extends radially in the hydraulic housing (132).

12. The rotator (100) according to any one of the preceding claims, wherein the first hydraulic port (142) is arranged axially below the second hydraulic port (144) in operation.

13. The rotator (100) according to any one of the preceding claims, wherein the internal hydraulic channel (146) further extends between the hydraulic housing (132) and the stator (1 10).

14. The rotator (100) according to any one of the preceding claims, wherein the hydraulic housing (132) is arranged in a proximal part of the rotator (100) in relation to the hydraulic tool (300) in operation.

15. The rotator (100) according to any one of the preceding claims, wherein the hydraulic swivel (130) is arranged axially above the hydraulic tool (300) in operation.

16. The rotator (100) according to any one of the preceding claims, wherein the stator (1 10) comprises a stator extension (1 12) extending in a direction towards the hydraulic tool (300).

17. The rotator (100) according to claim 16, wherein the stator (110) and the stator extension (1 12) are coaxially arranged in the rotator (100).

18. The rotator (100) according to claim 16 or 17, wherein the first hydraulic port (142) is arranged in the stator extension (1 12).

19. The rotator (100) according to any one of claims 16 to 18, wherein the stator (110) and the stator extension (1 12) are formed from separate parts.

20. The rotator (100) according to any one of the preceding claims, comprising a urea swivel (180) having a urea housing (182) rotatably arranged relatively the stator (1 10).

21. The rotator (100) according to claim 20, wherein the urea housing (182) is mechanically integrated with the hydraulic housing (132) or arranged in a separate housing.

22. The rotator (100) according to any one of the preceding claims, wherein the stator (1 10) comprises an electrical swivel (192) and / or an angle meter (194) and / or an accelerometer (196).

23. The rotator (100) according to claim 22, wherein the electrical swivel (192) and / or the angle meter (194) and / or the accelerometer (196) is coaxially arranged inside the stator (1 10).

24. A vehicle (200) comprising: a rotator (100) according to any one of the preceding claims, and a crane arm (210) to which the rotator (100) is attached.

25. The vehicle (200) according to claim 24, wherein the rotator (100) is pivotably attached to the crane arm (210).

26. The vehicle (200) according to claim 24 or 25, wherein the hydraulic tool (300) is a forest harvester head.

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