SE1451592A1

SE1451592A1 - Rotator for a jib-carried tool

Info

Publication number: SE1451592A1
Application number: SE1451592A
Authority: SE
Inventors: Harr Joakim
Original assignee: Indexator Rotator Sys Ab
Priority date: 2014-12-19
Filing date: 2014-12-19
Publication date: 2016-06-20
Also published as: WO2016099372A1; EP3234509A1; SE538568C2; EP3234509A4

Abstract

Abstract The invention relates to rotator (10) for a jib-carried tool,said rotator comprising a stator (20) and a rotor (30) and adevice (40,50) for determining an absolute position ofrotation between the stator (20) and the rotor (30). Saiddevice (40,50) comprises an encoder (40) surrounding the rotor(30;30') and a sensor (50). The encoder (40) is arrangedrotationally fixed relative to the stator (20) and the sensor(50) is arranged rotationally fixed relative to the rotor(30), or vice versa. Said sensor (50) is arranged to determinethe absolute position of rotation between the stator (20) and the rotor (30). (Fig. 2)

Description

lO ROTATOR Field of the Invention The invention relates to a rotator for a jig-carried tool in accordance with the preamble of claim l.

Background of the Invention A problem experienced with rotators for a jig-carriedtool/working implement at an external end of a crane arm orjib resides in the ability to i.a. orientate hoses andpossibly also cables in a rotational manner in respect of thedriver of a vehicle provided with said crane arm or jib. Thedriver must constantly be on his/her guard with regard to thechoice of tool rotation, so as to avoid hose breakages.Externally disposed hose loops are vulnerable to damage andconsequently discrete or protected hose orientation is desirable.

It is known to provide a rotator with means for determiningthe relative position of rotation between rotor and stator.Said means include a pulse emitter and a number of pulsegenerating elements such as grooves or teeth. However, by saidmeans it is only possible to determine the relative positionof rotation between the rotor and the stator, and it is also sensitive to debris.

Due to increased automatization in forestry there is a demandfor forwarders having automatically guided tools/workingimplements, such as grips, and also for wood harvesters havingautomatically guided harvesting units, so that the position ofrotation of the tool can be determined, preferably the absolute position. This enables repeating movements, for lO instance, of the tool can be programmed and thus the work ofthe driver much simplified. By such programming, also less skilled drivers will increase their performance.

Moreover, by such automatically guided tools the precision ofpositioning the tools will be much improved, and it will alsobe possible to reduce the linear velocity of pistons ofhydraulic cylinders at its end positions so as to reduce impacts.

Furthermore, by such automatization it will be possible todetect when the rotator approaches the set target angle ofrotation and thereby start a decelerating of the rotation ofthe rotator and thus the load carried by the rotator so as to be able to avoid over-rotation of the rotator.

One object of the present invention is to provide a rotator,which will significantly simplify the work required from thedriver of the vehicle and enable a high degree of automatization to be achieved.

Furthermore, by the inventive rotator it is also possible toprevent hose breakages and cable breakages as a result of wrong rotation of the tool.

Moreover, by absolute position is meant that the each positionis unique. This means that a control system for the rotatordoes not need any reference position and that it is notnecessary, at upstart, to rotate the rotator to find thereference position. During maintenance of the tool/workingimplement, for instance, said tool/working implement may berotated by hand which means that the position of rotation isdifferent from the position of rotation when the work wasstopped. This is a very important safety aspect, particularly when the rotator carries a harvesting unit. lO Summary of the Invention The object of the invention is to eliminate wholly or partly the above-identified drawbacks of the prior art.

According to the invention this object is achieved by arotator for a jib-carried tool, said rotator comprising astator and a rotor, characterized in that said rotatorcomprises a device for determining an absolute position ofrotation between the stator and the rotor, that said devicefor determining the absolute position of rotation comprises anencoder in the form of a ring shaped magnetic meanssurrounding the rotor, and further comprises a sensor, thatsaid sensor being able to determine the absolute position ofrotation between the stator and the rotor, and that saidencoder being arranged rotationally fixed relative to thestator and the sensor being arranged rotationally fixed relative to the rotor, or vice versa.

Embodiments of the invention are defined in the appended dependent claims.

Brief Description of the Drawings The invention is described in more detail below in the form ofa non-limiting example, reference being made to theaccompanying drawing, in which - Fig. l is a schematic side view of a so-called single gripharvesting unit connected to a crane arm or jib through themedium of the inventive rotator, - Fig. 2 is a sectional side view of the rotator according tothe invention in a first embodiment, - Fig. 3 is an exploded view of the rotator shown in Fig.2 in its normal working position, lO - Fig. 4 shows the same view as in Fig. 3 but upside-down, - Fig. 5 is a sectional view of the rotator according to theinvention in a second embodiment taken along section A-A inFig. 6, - Fig.6 is a view from below of the rotator shown in Fig. 5 - Fig. 7 is an exploded view of the rotator shown in Fig.5 inits normal working position, and - Fig. 8 shows the same view as in Fig. 7 but upside-down.

Detailed Description of Preferred Embodiments Regarding expressions such as upper and lower wall these are to be understood as seen in relation to Fig. l of the rotator.

Fig. l shows a working implement/tool l in the form of a so-called single-grip harvesting unit l which is suspended fromthe tip 2 of a machine-carried jib/crane arm 3 through themedium of a rotator lO according to the invention. The rotatorlO is connected via a link arrangement or a swing damper 4,for instance, to the tip 2 of the jib/crane arm 3 and allowsthe tool to swing relative to the tip 2 of the jib/crane arm3. The rotator lO enables the tool l to be rotated relative tothe tip 2 of the jib/crane arm 3. Hydraulic medium (oil) issupplied to the rotator lO and to the tool l through hoses 5,6, and possible electrical cables 7 for the device fordetermining the absolute position of rotation and the tool areprovided. The connection of the hoses 5 to a vehicle-carried source of hydraulic medium is not shown.

Figs. 2-4 illustrate a first embodiment of the rotator lOaccording to the invention, said rotator lO includes a stator20 and a rotor 30. The stator comprises i.a. an upper stator wall 21 provided, at an upper side, with attachment means 22, l0 preferably in the form of two attachment lugs 22a,22b arrangedin pairs, for swiningly attachment to the tip 2 of themachine-carried jib/crane arm 3, a stator ring 23 and a lowerwall 24, which is connected, via the stator ring 23, to theupper stator wall 21 preferably by bolts 25. The rotor 30being rotationally contained within the stator 20 by said upper and lower wall 21,24 and said stator ring 23.

As seen in Fig. 2, a device 40,50 for determining the absoluteposition of rotation between the stator 20 and the rotor 30 isarranged at the lower wall 24 of the rotator l0, and signalsfrom the device 40,50 being transmitted to a processor means(not shown) either by wired or wireless communication for further processing.

Hence, according to an embodiment of the present invention,the processor means receives sensor signals from the sensorand process said signals for determining the absolute positionof rotation between the stator 20 and the rotor 30. Theprocessor means may e.g. be a CPU configured to executesuitable detection or determining algorithms in this respect.The CPU may be a dedicated processor unit or a processor unitalso configured to perform other processing. The processormeans may also use the determination of the absolute positionin one or more control algorithms for controlling the rotator,the jib-carried tool or any associated cranes, machines, motorvehicles, etc. Therefore, the processor means may also outputone or more control signals for controlling the rotator, thejib-carried tool or any associated cranes, machines, or motor vehicles.

From Figs. 2 to 4 it can be seen that said device 40,50 fordetermining the absolute position of rotation comprises an encoder 40 in the form of a ring shaped magnetic means surrounding the rotor 30, as seen in radial direction of saidrotor, and a sensor 50. In the embodiment shown, said encoder40 is arranged rotationally fixed relative to the stator 20,and said sensor 50 is arranged rotationally fixed relative tothe rotor 30. In a second embodiment, to be described below,said encoder 40 and said sensor 50 is arranged vice verse relative the stator 20 and the rotor 30, respectively.

In a preferred embodiment, as seen in Figs. 2 and 4, theencoder 40 has a groove 41 into which a protruding tip 51 ofsaid sensor 50 protrudes so as to enabling determination ofthe absolute position of rotation between the stator 20 andthe rotor 30. Thus, upon rotation of the rotor 30 theprotruding tip 51 is adapted to run in said groove 41 and detect the changes in the magnetic field.

To protect the groove 41 from the harsh environmentexperienced by the rotator 10, such as debris from processedtimbers, water, sand, etc. a groove enclosing means 60 isarranged for enclosing said groove 41. Said groove enclosingmeans 60 has the form of a flat ring of sheet metal orplastic, for instance. More particularly, the encoder 40 ispreferably shaped as a U and the groove enclosing means 60 isadapted to abut the ends of the legs of the U via at least oneintermediate sealing. In one embodiment the encoder 40 isprovided with at least one sealing means 42 extending in thecircumferential direction of the groove and arranged on eachleg/side 43 of said groove 41 and at the end of each leg/side43. The sealing means can be in the form of an O-ring arranged in a recess formed at the external end of each leg/side 43.

More particular, said groove enclosing means 60 and saidencoder 40 are enclosed between the lower wall 24 of the stator 20 and an upper wall 71 of an attachment 70 (Fig. 2) for the jib-carried tool. Said attachment 70 is detachably connected to the rotor 20.

As shown in Figs. 2-4 said tip 51 of said sensor 50 protrudesthrough a hole 61 in said groove enclosing means 60 and intosaid groove 41. Possibly a sealing (not shown) is providedbetween the sensor 50 and the groove enclosing means 60, andthe sensor 40 is fixedly attached to the groove enclosing means 60.

Said encoder 40 and said groove enclosing means 60 arearranged to rotate relative to each other during operation of said rotator 1.

More particular, in the embodiment shown in Fig. 2-4, whichpreferably is used in the case the jib-carried tool is aharvesting unit, the groove enclosing means 60 with attachedsensor 50 is rotationally fixed relative to the attachment 70which is arranged to rotate (by the rotor) relatively to theencoder 40 which is rotationally fixed relative to said lowerwall 24 of the stator 20. Preferably the sensor 50 is arranged within a socket 55.

To improve the sealing between the sealing means 42 and thegroove enclosing means 60 at least one elastic means 80 isprovided between the upper wall 71 of the attachment 70 and alower wall 62 of said groove enclosing means 60 so as to biassaid groove enclosing means against the sealing means 42. In apreferred embodiment said at least one elastic means 80consists of a plurality of spring means 80, preferably compression springs.

In Figs.5-8 a second embodiment of the inventive rotator 10' is shown. In the second embodiment the same technical means are denoted by the same reference characters as in the first embodiment with the exception of “'”.

The main difference between the first and second embodiment isthat, in the second embodiment, the device 40',50' fordetermining the absolute position of rotation between thestator 20' and the rotor 30' has been arranged reversed, thatis to say that the encoder 40' is arranged rotationally fixedrelative to the rotor 30', and the sensor 50' is arrangedrotationally fixed relative to the stator 30'. This means thatthe orientation of the encoder 40' and sensor 50' is upside-down as compared to the orientation of the encoder 40 and sensor 50 in the first embodiment.

As shown in Figs. 5, 7 and 8 a seat 90 is arranged whichsupports the encoder 40'. More particularly, the seat 90 hastwo ridges 92 enclosing a recess 91 in which the encoder 40'is confined. The seat 90 together with the encoder 40' isbiased towards the groove enclosing means 60' by said at leastone elastic means 80' as in the first embodiment so as to seal the groove 41 from the environment.

In an embodiment not shown each ridge 92 of the seat 90 can beprovided with a sealing means possibly instead of the sealingmeans 42' or in combination with the sealing means 42' of the encoder 40'.

The second embodiment of the rotator 10' is preferably used in the case the jib-carried tool is a grip.

In a third embodiment of the inventive rotator (not shown) thegroove enclosing means may be formed of either the upper wall71 of the attachment 70 for the jib-carried tool or the lowerwall 24 of the stator 20. In such a case at least one sealing is formed at least between said stator and said attachment for the jib-carried tool preferably at the periphery of a partingline between said stator and said attachment for the jib-carried tool. The sealing is arranged radially externally ofthe device 40,50; 40',50' for determining the absoluteposition of rotation. In such case the encoder 40,40' may or may not be provided with the sealing means 42, 42'.

Although, not shown on the drawings, it should be noted thatthe inventive rotator 10,10' is able to perform two- or three-dimensional movements, i.e. in case of three-dimensional movements the rotator being a so called tiltrotator.

The device 40,50; 40',50' for determining the absoluteposition of rotation comprises in a preferred embodiment amagnetic field sensor 50;50' and an encoder 40;40' in the formof a ring shaped encoder body 40;40' having multiple magneticregions producing characteristics for magnetic fields, whereeach magnetic field comprises a radial and axial magneticfield component. The magnetic field components are combined toa magnetic field vector. The magnetic field vector is inclinedat a certain angle against the ring plane, where the anglechanges along a periphery of the encoder body. This enablesthe magnetic field sensor 50;50' to determine a specific pointalong the periphery of the encoder body 40;40', i.e. anabsolute position along the periphery of the encoder bodywithout having to refer to a zero point. Thereby, the absoluteposition of rotation between the stator 20;20' and the rotor30;30' can be provided. A device of this type if known by EP 2 568 259 A1.

Furthermore, by using a magnetic device for determining theabsolute position of rotation there are no mechanical means that can be worn out.

The invention is thus not limited to what is described andshown, since modifications and variations are naturally possible within the scope of the accompanying claims.

Claims

ll Claims

1. l. A rotator (lO;lO') for a jib-carried tool, said rotatorcomprising a stator (20:20') and a rotor (30;30'),characterized in that said rotator (30;30') comprises a device (40,50;40',50') for determining an absolute position of rotationbetween the stator (20:20') and the rotor (30;30'), that said device (40,50; 40',50') for determining theabsolute position of rotation comprises an encoder (40;40')in the form of a ring shaped magnetic means surrounding therotor (30;30'), and further comprises a sensor (50;50'),said sensor (50;50') being able to determine the absoluteposition of rotation between the stator (20;20') and therotor (30;30'); and that said encoder (40;40') being arranged rotationallyfixed relative to the stator (20:20') and the sensor(50;50') being arranged rotationally fixed relative to the rotor (30;30'), or vice versa.

2. The rotator (lO;lO') according to claim l, characterizedin that said encoder (40;40') is provided with a groove(4l;4l'); that said sensor (50;50') is provided with a protrudingtip (5l;5l') arranged to protrude into said groove (4l;4l')of said encoder (40;40') so as to run in said groove(4l;4l') upon rotation of the rotor (30;30'); and that a groove enclosing means (60;60';7l,24;7l',24') isarranged for enclosing said groove (4l;4l') of the encoder (40;40') from an environment of the rotator (lO;lO'). l0 l2

3. The rotator (l0;l0') according to claim 2, characterizedin that said groove enclosing means (60;60';7l,24;7l',24')and said encoder (40;40') are arranged to rotate relative to each other during operation of said rotator (l0;l0').

4. The rotator (l0;l0') according to claim 2 or 3,characterized in that said groove enclosing means (60;60')is formed as a flat ring, and that said tip (5l;5l') of saidsensor (50;5l') protrudes through a hole (6l;6l') in saidgroove enclosing means (60;60') and into said groove (4l;4l').

5. The rotator (l0;l0') according to any one of claim 2 to4, characterized in that said groove (4l;4l') of saidencoder (40;40') is provided with at least one sealing means(42,42') extending in the circumferential direction of thegroove and on each side of said groove, and that saidsealing means (42,42') are adapted to cooperate with thegroove enclosing means (60;60') so as to seal said grove (4l;4l').

6. The rotator (l0;l0') according to any one of claims 2 to5, characterized in that at least said groove enclosingmeans (60;60') and said encoder (40;40') are enclosedbetween a lower wall (24;24') of the stator (20;20') and anupper wall (7l;7l') of an attachment (70;70') for the jib-carried tool, said attachment being detachably connected to the rotor (30;30').

7. The rotator (l0) according to any one of claims l to 6,characterized in that said encoder (40) is rotationallyfixed relative to the stator (20), and that said groove enclosing means (60) is rotationally fixed relative to the 13 rotor (30), preferably via an attachment (70) for the jib-carried tool, said attachment being detachably connected to the rotor (30).

8. The rotator (10') according to any one of claims 1 to 6,characterized in that said encoder (40') is rotationallyfixed relative to the rotor (30'), and that said grooveenclosing means (60') is rotationally fixed relative to thestator (30'), preferably via an attachment (70') for the jib-carried tool.

9. The rotator (10') according to claim 8, characterized inthat a seat (90) is provided for rotationally fixation ofthe encoder (40') relative to the attachment (70') for the jib-carried tool.

10. The rotator (10;10') according to any one of claims 6 to9, characterized in that at least one elastic means (80;80')is provided between an upper wall (71;71') of saidattachment (70;70') and a lower wall (24;24') of said grooveenclosing means (60;60') so as to bias said groove enclosingmeans against the sealing means (42;42') of the encoder (40;40').

11. The rotator (10;10') according to claim 10,characterized in that said at least one elastic means(80;80') consists of a plurality of spring means (80;80'), preferably compression springs.

12. The rotator (10;10') according to claim 2,characterized in that said groove enclosing means(71,24;71'24') is formed by either an upper wall (71;71') of an attachment (70;70') for the jib-carried tool or a lower 14 wall (24;24') of the stator (20;20'), and that at least onesealing is formed at least between said lower wall (24;24')of said stator (20;20') and said upper wall (71;71') ofattachment (70;70') preferably at the periphery of said stator and said attachment for the jib-carried tool.

13. The rotator (10;10') according to any one of claims 1 to11, characterized in that signals from the device (40,50;40',50') for determining the absolute position of rotationbeing transferred to a processor means either by wired or wireless connection for further processing.

14. The rotator (10;10') according to any one of claims 1 to12, characterized in that said rotator (10;10') is connectedvia a link arrangement or a swing damper (4) to a tip (2) of a jib (3).

15. The rotator (10;10') according to any one of claims 1 to14, characterized in that said rotator (10;10') is able to perform two- or three-dimensional movements.

16. The rotator (10;10') according to any one of claims 1-15, characterized in said sensor (50;50') is a magneticfield sensor and said encoder (40;40') comprises a bodyhaving multiple magnetic regions producing characteristics for magnetic fields.