SI22295A

SI22295A - Hydraulic assembly for controlling the clutch and the brake of a forestry winch

Info

Publication number: SI22295A
Application number: SI200600148A
Authority: SI
Inventors: PAN Iztok Ĺ
Original assignee: Tajfun Planina Proizvodnja Strojev, D.O.O.
Priority date: 2006-06-16
Filing date: 2006-06-16
Publication date: 2007-12-31

Abstract

The assembly (1) for controlling the clutch (5) of a forestry winch consists of coaxially designed mutually insertable and sealed parts (11, 12) with an adequate cavity with supply (123) of the hydraulic media in-between by which the parts (11, 12) can be shifted in the axial direction one against the other. In this position the fixed internal part (11) is supported by the enclosure (2) or at least a part of it, while thanks to the hydraulic media and against the force of spring (7) or thanks to the latter, the moving external part (12) is either directly or indirectly pushed towards the drum (4). The friction linings (51, 52) of the clutch (5) are located on a chain-wheel (6) and drum (4), which can be freely rotated after activation of the clutch (5) on axis (3) together with the chain-wheel (6). This way a simple and low- cost while at the same time reliably operating control assembly (1) is provided, meaning for activating and deactivating of the clutch (5) which enables the control of the clutch (5) by way of a hydraulic circuit made available on the winch.

Description

TAJFUN PLANINA proizvodnja strojev, d.o.o.TAYFUN MOUNTAIN MACHINE MANUFACTURING, Ltd.

MPK⁸: B 66 D 1/14MPK ⁸ : B 66 D 1/14

B 66 D 1/44B 66 D 1/44

B 66 D 3/10B 66 D 3/10

B 66 D 3/18B 66 D 3/18

B 66 D 5/26B 66 D 5/26

Hidravlični sklop za upravljanje sklopke in zavore pri gozdarskem vitluHydraulic clutch and brake control for forestry winch

Izum je na področju delovnih postopkov in transporta uvrščen k vitlom, še zlasti k pogonskim elementom pri gozdarskih vitlih, ki so predvideni za prenos moči s pogonskega sredstva na navijalni boben, sočasno pa se izum navezuje tudi na hidravlične naprave za upravljanje vitla.The invention relates to winches, in particular in the field of working procedures and transport, in particular to the drive elements for forestry winches, which are intended to transfer power from the drive means to the winding drum, and at the same time the invention also relates to hydraulic winch control devices.

Namen izuma je zasnovati hidravlični sklop za upravljanje zavore in sklopke pri gozdarskem vitlu, ki bo preprost in cenen, obenem pa zanesljivo delujoč sklop za upravljanje, namreč za aktiviranje ali deaktiviranje sklopke pri vitlu, ki bo omogočal upravljanje sklopke s pomočjo na vitlu razpoložljivega hidravličnega tokokroga, s pomočjo katerega bo potem na preprost način izvedljivo tudi izmenično delovanje zavore in sklopke navijalnega pogonskega bobna.The purpose of the invention is to design a hydraulic brake and clutch control unit for a winch that will be simple and inexpensive, while providing a reliable control unit, namely to activate or deactivate the clutch at a winch, which will enable the clutch to be operated with the help of an available hydraulic circuit , by which the alternating operation of the brake and clutch drive drum will then be easily implemented.

Pri gozdarskih vitlih je v okrovu vitla skupaj s pripadajočo osjo uležajen navijalni boben, ki je predviden za navijanje in skladiščenje vlečne vrvi. Boben je na omenjeni osi prosto vrtljiv in je na obodni površini opremljen z zavoro,1 na eno od čelnih površin pa je nameščena ena torna plast sklopke, katere preostala torna plast se nahaja na gnanem verižnem kolesu verižnega prenosnika, katerega pogonsko kolo je povezano s kardansko gredjo traktorja, h kateremu je med uporabo priključen vitel. Zavora in sklopka delujeta izmenično, kar pomeni, da se po deaktiviranju zavore vključi sklopka, ki z verižnega kolesa prenaša vrtilni moment na boben, ki se prične vrteti, pri tem pa se nanj navija vrv. Z izključitvijo sklopke se boben zaustavi, obenem pa se vključi zavora, ki preprečuje vsakršen nadaljnji zasuk bobna do ponovnega aktiviranja sklopke. Sam upravljalni sklop za koordinacijo delovanja zavore in sklopke je opisan v tačas še neobjavljeni slovenski patentni prijavi SI-P-200400342.For forestry winches, a winding drum is mounted in the winch housing together with the associated axle, intended for winding and storing the tow rope. The drum is freely rotatable on said axis and is provided with a brake on the circumferential surface, and 1 on one of the front surfaces is fitted with one friction clutch layer, the remaining friction layer of which is located on a driven chainring of a gearbox whose drive wheel is connected to a PTO the tractor shaft to which a winch is connected during use. The brake and clutch operate alternately, which means that after the brake has been deactivated, a clutch is engaged which transfers the torque from the chainwheel to the drum which starts to rotate and is supported by a rope. By turning off the clutch, the drum stops and at the same time a brake is engaged to prevent any further rotation of the drum until the clutch is reactivated. The control unit itself for coordinating the operation of the brake and clutch is described in the previously unpublished Slovenian patent application SI-P-200400342.

Pričujoči izum se nanaša na sklop za upravljanje sklopke pri gozdarskem vitlu, kjer je v okrovu nameščena os, na kateri je okoli nje prosto vrtljivo in glede na omenjeno os aksialno nepremakljivo nameščeno s pomočjo vsakokrat razpoložljivega traktorskega pogona gnano verižno kolo. Na slednjem je nameščena prva torna obloga sklopke medtem ko je ob omenjenem verižnem kolesu na taisti osi prosto vrtljivo in v aksialni smeri proti sili vzmeti ali zahvaljujoč slednji premakljivo nameščen boben. Na proti verižnemu kolesu obrnjeni čelni stranici bobna je nameščena za sodelovanje s prej omenjeno torno oblogo prirejena preostala torna obloga sklopke, tako daje po aktiviranju sklopke z vzpostavitvijo stika med tornima oblogama boben na osi vrtljiv skupaj z verižnim kolesom, po deaktiviranju sklopke pa se zahvaljujoč sili omenjene vzmeti torni oblogi samodejno razmaknetaThe present invention relates to a clutch control assembly for a forestry winch, wherein an axle is housed in the enclosure on which it is freely rotatable and axially stationary with respect to said axle driven by a tractor drive actuated at all times. On the latter, the first friction clutch liner is mounted, while along the said chain wheel, the drum is freely rotatable and axially forced against the spring on the axle or thanks to the latter. The remaining front clutch clutch is arranged to engage the drum face facing the drum facing side of the drum so that after rotation of the clutch by contacting the friction wheels, the drum rotates together with the chain wheel after activation of the clutch. these springs are automatically spaced apart by the springs

Sklop po izumu sestoji iz soosno zasnovanih, drug v drugega vstavljenih in medsebojno tesnjenih delov, namreč notranjega dela in zunanjega dela, med katerima je na voljo primerna z votlina z dovodom hidravličnega medija, s pomočjo katerega sta dela drug glede na drugega v aksialni smeri premakljiva, pri čemer je fiksni notranji del oprt na okrovu ali vsaj delu slednjega, medtem ko je zahvaljujoč hidravličnemu mediju in proti sili vzmeti ali zahvaljujoč slednji premakljivi zunanji del sklopa bodisi neposredno ali posredno pritisnjen proti bobnu. Pri tem je zunanji del sklopa lahko proti bobnu pritisnjen preko distančnika, še bolj prednostno pa preko distančnika in aksialnega ležaja, ki je nameščen med bobnom in distančnikom.The assembly according to the invention consists of coaxially designed, mutually inserted and mutually sealed parts, namely the inner part and the outer part, between which there is a suitable cavity with a hydraulic medium inlet, by means of which the parts are movable relative to each other in the axial direction , the fixed inner part being supported on the casing or at least part of the latter, while thanks to the hydraulic medium and the force of the spring, or thanks to the latter, the movable outer part of the assembly is either directly or indirectly pressed against the drum. The outer part of the assembly may be pressed against the drum by a spacer, and more preferably by a spacer and an axial bearing placed between the drum and the spacer.

Notranji del sklopa po izumu je smiselno cevasto zasnovan in obsega osrednje razporejeno skoznjo luknjo za prehod osi z ustrezno zračnostjo in zunanjo čelno naležno ploskev za sodelovanje z okrovom ali delom le-tega, nadalje aktivno hidravlično površino za zagotavljanje aksialne sile zahvaljujoč v votlini med sestavljenima deloma sklopa prisotnemu hidravličnemu mediju, kot tudi na različnih premerih razporejeni obodni tesnilni površini, ki sta prirejeni za sodelovanje z zunanjim delom sklopa. Po drugi strani je zunanji del sklopa po izumu spet prednostno cevasto zasnovan in obsega dovod hidravličnega medija v votlino med sestavljenima deloma sklopa, obenem pa tudi notranji obodni tesnilni površini, ki sta prirejeni za sodelovanje s tesnilnima površinama notranjega dela sklopa. Pri tem je med vsakokratno dvojico tesnilnih površin notranjega dela in zunanjega dela sklopa na voljo vsaj eno tesnilo, še zlasti pa je prednostno, če je med vsaj eno dvojico tesnilnih površin notranjega dela in zunanjega dela poleg vsaj enega tesnila na voljo tudi vsaj en brisalec. Pri eni od možnih izvedb izuma je nadalje notranji del sklopa oprt ob regulacijsko matico, kije zaradi varovanja proti vrtenju oblikosklepno povezana z okrovom vitla in smiselno predstavlja del tega okrova, pri čemer je omenjena matica privita na navoju, ki je na voljo na skozi notranji del sklopa potekajočem koncu osi.The inner part of the assembly according to the invention is sensibly tubular and comprises a centrally arranged through-hole for passage of the axle with adequate clearance and an external front contact surface for engagement with the housing or part thereof, a further active hydraulic surface for providing axial force thanks to the cavity between the assembled parts of the assembly to the hydraulic medium present, as well as the circumferential sealing surfaces arranged at different diameters, which are adapted to cooperate with the outer part of the assembly. On the other hand, the outer part of the assembly according to the invention is again preferably tubularly designed and comprises supplying a hydraulic medium to the cavity between the assembled parts of the assembly, as well as the inner circumferential sealing surfaces which are adapted to cooperate with the sealing surfaces of the inner part of the assembly. In this case, at least one gasket is available between each pair of sealing surfaces of the inner part and the outer part of the assembly, and it is particularly preferred if at least one wiper is available between at least one pair of sealing surfaces of the inner part and the outer part. In one of the possible embodiments of the invention, the inner part of the assembly is further supported by a regulating nut, which, in order to protect against rotation, is closely connected to the winch housing and meaningfully forms part of that housing, said nut being screwed onto a thread available through the inner part. assembly to the running end of the axle.

Primer izvedbe sklopa bo v nadaljevanju podrobneje obrazložen s primerom izvedbe, ki je prikazan na priloženi skici, kjer kažejo Sl. 1 sklop po izumu v vgrajenem stanju v vitlu,The embodiment of the assembly will now be explained in more detail with the embodiment shown in the accompanying drawing, where FIG. 1 assembly according to the invention in the installed state in the winch,

Sl. 2 posebej v vzdolžnem prerezu v diametralni ravnini ponazorjen sklop v položaju, v katerem je sklopka aktivirana;FIG. 2 shows, in a longitudinal cross-section in a diametrically plane, an assembly in the position in which the clutch is actuated;

Sl. 3 pa sklop v vgrajenem stanju in v položaju, v katerem je sklopka deaktivirana.FIG. 3 and the assembly in the installed state and in the position in which the clutch is deactivated.

Na sl. 1 je so v vzdolžnem prerezu prikazani pogonski deli gozdarskega vitla vključno s sklopom 1 po izumu. Omenjeni deli so nameščeni v okrovu 2 vitla, in sicer je v omenjenem okrovu 2 na ustrezen način uležajena os 3, na kateri je s pomočjo ležajev 31, 32 prosto vrtljivo uležajen boben 4, katerega obodna površina 41 na eni steni 42 je lahko predvidena npr. za sodelovanje z neprikazano zavoro, medtem ko je na preostali steni 43 nameščena prva torna obloga 51 sklopke 5. Preostala torna obloga 52 sklopke 5 je nameščena na verižnem kolesu 6, ki je s pomočjo v pestu 60 razpoložljivega ležajnega sklopa 61 tako kot npr. boben 4 prosto vrtljivo uležajeno na osi 3. Verižno kolo 6 je na osi 3 nameščeno na tak način, da je v aksialni smeri glede na os 3 nepremakljivo, medtem ko je boben za določeno razdaljo v aksialni smeri premakljiv po osi 3.In FIG. 1 is a longitudinal section showing the drive parts of a forestry winch, including assembly 1 of the invention. Said parts are housed in the winch housing 2, in which housing 2 is appropriately mounted in said housing 2, on which a drum 4 can be freely rotated by means of bearings 31, 32, whose circumferential surface 41 on one wall 42 may be provided e.g. . for engaging with the non-shown brake, while the first wall 43 is provided with a first clutch friction liner 51. The remaining clutch friction liner 52 is mounted on a chain wheel 6 which, by means of the hub 60 of the available bearing assembly 61, is similar to e.g. the drum 4 is freely rotatably mounted on the axis 3. The chain wheel 6 is mounted on the axis 3 in such a way that it is stationary in the axial direction relative to the axis 3, while the drum is movable along the axis 3 by a certain distance.

Sklop 1 po izumu sestoji iz dveh soosno drug v drugem vstavljenih medsebojno tesnjenih, obenem pa tudi v aksialni smeri drug v drugega oz. drug iz drugega premakljivih delov 11, 12, ki se smiselno nahajata v funkciji bat-cilinder in med katerima je na voljo ustrezna votlina za prejem vsakokrat potrebne količine vsakokrat razpoložljivega hidravličnega medija. Sklop 1 je v vitlu razporejen med okrovom 2 in bobnom 4, pri čemer je prirejen za sodelovanje z omenjeno osjo 3 v smislu premikanja le-te v aksialni smeri, kar bo podrobneje obrazloženo v nadaljevanju. Ker omenjeni sklop 1, ki je kot tak prikazan na sl. 2, v osnovi sestoji iz vsega dveh razmeroma preprostih delov 11, 12, namreč iz notranjega dela 11 in zunanjega dela 12, ga je možno s preprostimi in cenenimi delovnimi postopki dovolj natančno izdelati.The assembly 1 according to the invention consists of two co-axially inserted in each other, and at the same time in the axial direction, respectively. moving parts 11, 12 from each other, which are reasonably located in the function of the piston cylinder, and between which there is a suitable cavity for receiving the required amount of hydraulic medium available at each time. The assembly 1 is arranged in the winch between the housing 2 and the drum 4, and is adapted to cooperate with said axis 3 in the sense of moving it in an axial direction, which will be explained in more detail below. Since said assembly 1, which is shown as such in FIG. 2, consisting essentially of all two relatively simple parts 11, 12, namely the inner part 11 and the outer part 12, it can be manufactured with sufficient precision in simple and inexpensive working procedures.

V osnovi valjasto oz. cevasto zasnovan notranji del 11 obsega skoznjo luknjo 111 za prehod osi 3 s tolikšno zračnostjo, da je omogočen premik osi 3 glede na notranji del 11 v aksialni smeri, nadalje proti okrovu 2 vitla obrnjeno čelno ploskev 112, ki je prirejena za naleganje na okrovu 2, medtem ko preostala čelna ploskev 113 tvori hidravlično aktivno površino omenjene votline, katere velikost v odvisnosti od vsakokratnega tlaka hidravličnega medija določa silo v aksialni smeri sklopa 1. Nadalje notranji del 11 obsega dve tesnilni obodni površini 114, 115, od katerih je ena z večjim premerom razporejena ob čelni ploskvi 112 ob okrovu 2, preostala obodna površina pa na nastavku 116, ki poteka skozi zunanji del 12 sklopa 1 po izumu.Basically cylindrical or. the tubularly designed inner portion 11 comprises a through hole 111 for passage of the axle 3 with a clearance so that the axis 3 can be displaced relative to the inner portion 11 in an axial direction, further facing the winch face 2, facing up to be fitted on the casing 2 , while the remaining face 113 forms a hydraulically active surface of said cavity, the size of which, depending on the respective pressure of the hydraulic medium, determines the force in the axial direction of assembly 1. Further, the inner portion 11 comprises two sealing circumferential surfaces 114, 115, one of which is larger arranged in diameter along the face plate 112 at the housing 2, and the remaining circumferential surface at the extension 116 extending through the outer portion 12 of assembly 1 according to the invention.

Zunanji del 12 sklopa 1 je prav tako cevasto zasnovan in izveden soosno s prvim delom 11, pri čemer obsega notranjo obodno tesnilno površino 121 večjega premera, ki je prirejena za sodelovanje s tesnilno površino 114 prvega dela 11, in prav tako notranjo tesnilno površino 122 manjšega premera, ki je prirejena za sodelovanje s tesnilno površino 115 notranjega dela 11 sklopa 1 po izumu. Zunanji del je nadalje opremljen z dovodom 123 hidravličnega medija v votlino, ki jo obdajata omenjena dela 11, 12. V prikazanem primeru je med vsakokrat sodelujočima tesnilnima površinama 114, 122 in 115, 121 obeh delov 11, 12 na voljo vsakokrat po eno manšetno tesnilo 124, 125, razen tega pa je ob tesnilu 124 predviden tudi brisalec 126.The outer part 12 of assembly 1 is also tubularly designed and co-axial with the first part 11, comprising an inner circumferential sealing surface 121 of a larger diameter adapted to cooperate with the sealing surface 114 of the first part 11, and also an inner sealing surface 122 of a smaller a diameter adapted to cooperate with the sealing surface 115 of the inner portion 11 of assembly 1 of the invention. The outer part is further provided with an inlet 123 of the hydraulic medium into the cavity flanked by the aforementioned parts 11, 12. In the example shown, one cuff seal is available between the respective sealing surfaces 114, 122 and 115, 121 of the two parts 11, 12 each time. 124, 125, and in addition to the seal 124, a wiper 126 is provided.

Kot je razvidno na sl. 3, je sklop po izumu v vitlu vgrajen na tak način, da je os 3 vstavljena skozi notranji del 11 sklopa in skozenj v aksialni smeri prosto premakljiva. Zunanji del 12 sklopa 1 je oprt na distančnik 9, proti kateremu je prednostno preko aksialnega ležaja 8 (Sl. 1) pritisnjen boben 4, in sicer zahvaljujoč sili tlačne vzmeti 7, ki je vpeta med bobnom 4 in verižnim kolesom 6.As can be seen in FIG. 3, the assembly according to the invention is mounted in the winch in such a way that the axis 3 is inserted through the inner part 11 of the assembly and freely movable through the axial direction. The outer part 12 of the assembly 1 is supported by a spacer 9, to which the drum 4 is preferably pressed through the axial bearing 8 (Fig. 1) due to the force of the pressure spring 7 which is clamped between the drum 4 and the chain wheel 6.

Pri majhnem pritisku hidravličnega medija sta dela 11, 12 zahvaljujoč sili omenjene vzmeti potisnjena drug v drugega, kar ima za posledico premik bobna 4 s pripadajočo torno oblogo 51 sklopke v smeri proti okrovu 2, medtem ko je verižno kolo na osi 3 v aksialni smeri nepremakljivo. S tem sta torni oblogi 51, 52 sklopke 5 držani na medsebojnem odmiku, kar pomeni, da je sklopka neaktivna, tako da navzlic vrtenju verižnega kolesa 6 boben 4 miruje.At low pressure of the hydraulic medium, the parts 11, 12 are pushed into each other due to the force of said spring, which results in the displacement of the drum 4 with its associated friction clutch 51 in the direction of the housing 2, while the chain wheel on the axial 3 is stationary. . In this way, the friction linings 51, 52 of the clutch 5 are kept at a distance from each other, which means that the clutch is inactive, so that, despite the rotation of the chain wheel 6, the drum 4 is stationary.

Ko skozi dovod 123 v votlino med deloma 11, 12 sklopa dovedemo hidravlični medij pod pritiskom, se je notranji del 11 sklopa 1 oprt proti okrovu 2, zato se zunanji del 12 sklopa 1 proti sili vzmeti 7 premakne v aksialni smeri in preko distančnika 9 odrine boben 4, ki se po osi 3 premakne v smeri proti verižnemu kolesu 6, s čimer se vzpostavi potreben pritisk med torno oblogo 51 na površini bobna 4 in torno oblogo 52 na površini verižnega kolesa 6, s tem pa se aktivira sklopko 5. Odtlej se boben 4 prosto vrti na osi 3 skupaj z verižnim kolesom 6.When the hydraulic medium is pressurized through the inlet 123 into the cavity between the parts 11, 12 of the assembly, the inner part 11 of the assembly 1 is propped against the housing 2, so that the outer part 12 of the assembly 1 forces the spring 7 to move in the axial direction and through the spacer 9 the drum 4, which moves along the axis 3 in the direction of the chain wheel 6, thereby creating the necessary pressure between the friction liner 51 on the surface of the drum 4 and the friction liner 52 on the surface of the chain wheel 6, thereby activating the clutch 5. the drum 4 rotates freely on the axis 3 together with the chain wheel 6.

Znižanju tlaka hidravličnega medija med deloma 11,12 sklopa 1 zaradi sile vzmeti 7 sledi postopno pomikanje zunanjega dela 12 sklopa 1 v izhodiščni položaj t.j. v smeri proti okrovu 2, zaradi česar se torni oblogi 51, 52 sklopke 5 med seboj razmakneta, tako da se sklopka 5 aktivira, sočasno pa se vključi neprikazana zavora, tako da se boben 4 zaustavi, medtem ko se verižno kolo 6 še naprej prosto vrti na osi 3.The reduction of the pressure of the hydraulic medium between the parts 11,12 of the assembly 1 due to the force of the spring 7 is followed by the gradual movement of the outer part 12 of the assembly 1 to the starting position, i.e. in the direction of the housing 2, causing the friction linings 51, 52 of the clutch 5 to be spaced apart so that the clutch 5 is actuated, and at the same time the non-shown brake is engaged so that the drum 4 is stopped while the chain wheel 6 remains free. rotates on axis 3.

Nastavitev vsakokrat želene razdalje med tornima oblogama 51, 52 sklopke 5 je omogočena na preprost način s pomočjo navoja 33, ki je na voljo na izven okrova 2 segajočem koncu 34 osi, in matice 20, ki je privita na omenjeni navoj 33 in oblikosklepno povezana z okrovom 2, tako da smiselno tvori del okrova 2. Kadar je namreč okrov 2 ali vsaj del le-tega v bližini osi 3 začasno odstranljiv, je možno s sukanjem matice 20 v aksialni smeri premikati os 3 in s tem uravnati razdaljo med tornima oblogama 51, 52 sklopke 5 na bobnu 4 in verižnem kolesu 6. Po nastavitvi želene razdalje med oblogama 51, 52 sklopke 5 matico 20 zavarujemo proti premikanju z vzpostavitvijo oblikosklepne povezave med matico 20 in okrovom, npr. z vstavitvijo matice v luknjo v okrovu 2, ki je tako oblikovana, da matici 20 preprečuje vsakršen zasuk.The adjustment of the desired distance between the clutch pads 51, 52 of the clutch 5 is made possible simply by means of a thread 33, which is provided at the outside end of the housing 2 of the extending end 34 of the axle, and of a nut 20 screwed onto said thread 33 and connected to the housing 2, so that it forms a part of the housing 2. It is sensible that when the housing 2 or at least part of it near the axis 3 is temporarily removable, it is possible to move the axis 3 in an axial direction by twisting the nut 20 in order to adjust the distance between the friction linings 51 , 52 of the clutch 5 on the drum 4 and the chain wheel 6. After adjusting the desired distance between the linings 51, 52 of the clutch 5, the nut 20 is secured against movement by establishing a form-lock connection between the nut 20 and the housing, e.g. by inserting the nut into the hole in the housing 2, which is designed to prevent the nut 20 from rotating.

Claims

PATENT APPLICATIONS

A clutch control assembly for a forestry winch, wherein an axle (3) is mounted in the housing (2) on which it is freely rotatable about the axis (3) and axially stationary with respect to said axis (3) by means of the tractor actuator available at each time driven chain wheel (6) on which one friction clutch (52) of the clutch (5) is mounted, while on said wheel (6) it is freely rotatable and axially against the force of the spring (7) or thanks to said wheel (6). the latter being movably mounted drum (4) on which the friction cladding (51) of the clutch (5) is arranged against the wheel (6) facing the face (42) to engage with the aforementioned friction liner (52) such that after the clutch is actuated (5) by contacting the friction pads (51, 52), the drum (4) on the axle (3) rotates together with the chain wheel (6) and, after deactivating the clutch (5), due to the force of said spring (7), the friction pads (7) 51, 52) are automatically spaced, characterized in that the assembly (1) consists of co-axially of rammed, interconnected and sealed parts (11, 12), namely the inner part (11) and the outer part (12), between which there is a suitable cavity with an inlet (123) for receiving a hydraulic medium by means of which the parts (11, 12) are movable relative to each other in the axial direction, with the fixed inner part (11) resting on the housing (2) or at least part of the latter, while, due to the hydraulic medium and the spring force (7), or thanks to the latter, the movable outer part (12) is either directly or indirectly pressed against the drum (4).

Assembly according to claim 1, characterized in that the outer part (12) of the assembly (1) is pressed against the drum (4) via a spacer (9).

Assembly according to claim 2, characterized in that the outer part (12) of the assembly (1) is pressed against the drum (4) via a spacer (9) and an axial bearing (8) which is mounted between the drum (4) and the spacer (4). 2).

Assembly according to any one of the preceding claims 1 to 3, characterized in that the inner part (11) of the assembly (1) is tubularly shaped and comprises a centrally arranged through hole (111) for passage of the axle (3) with adequate clearance and an external front contact a surface (112) for engaging with a housing (2) or part thereof, a further active hydraulic surface (113) to provide axial force due to the cavity between the assembled parts (11, 12) of the assembly (1) present hydraulic medium as well as the various circumferentially sealed circumferential sealing surfaces (114, 115) adapted to cooperate with the outer portion (12) of the assembly (1).

Assembly according to any one of the preceding claims 1 to 3, characterized in that the outer part (12) of the assembly (1) is tubular and comprises the inlet (123) of the hydraulic medium into the cavity between the assembly parts (11, 12) of the assembly (1). as well as the inner circumferential sealing surfaces (121, 122) adapted to cooperate with the sealing surfaces (114, 115) of the inner part (11) of the assembly (1).

Assembly according to claims 4 and 5, characterized in that at least one seal (124, 125) is available between the respective two sealing surfaces (114, 115; 121, 122) of the inner part (11) and the outer part (12). .

Assembly according to claim 6, characterized in that between at least one pair of sealing surfaces (114, 115; 121, 122) of the inner part (11) and the outer part (12), in addition to at least one seal (124, 125), is available also at least one wiper (126).

Assembly according to any one of the preceding claims, characterized in that the inner part (11) of the assembly (1) is supported by a control nut (20), which, in order to protect against rotation, is formally connected to the housing (2) of the forestry winch and represents part of this housing (2), said nut (20) being screwed onto a thread (33), which is available through the inner end (11) of the assembly (1) to the running end of the axis (3).