The present invention relates to a hydraulic arrangement for providing a pivotal move ment of an outer structure.

A compactor comprising a receiver volume for receiving material, a storage volume, and a press plate for compacting and forcing material into the storage volume, wherein the press plate is attached to a hydraulic arrangement.

A method for pivoting a press plate of compactor, wherein the press plate is attached to a hydraulic arrangement.

Background of the Invention

A hydraulic arrangement such as the arrangement shown in figure 1 is well known in the art. In this particular embodiment, a hydraulic arrangement comprises a hydraulic cylinder (ref. 28 in figure 1) connected to press plate (ref. 22 in figure 1) via a connect ing arm (ref. 46 in figure 1). The combined hydraulic cylinder and connecting arm en able a 180-degree movement of the press plate, however, the force transfer from hy draulic cylinder to the press plate is highly angle dependent. It is not uncommon that the force exerted by the press plate varies with a factor of 2 in the angle range from 0- 180 degrees. Thus, if the press plate must be able to exert a pressure equivalent to 50 tons of pressure at all angles, then the system must be over-dimensioned to compensate for the low force transfer at certain angles and the system may at certain angles exert a pressure of 100 tons.

Thus, there is a need for a new hydraulic arrangement which is not angle dependent or at least is less angle dependent than hydraulic arrangements described in the prior art.

Object of the Invention

It is an object of the invention to provide a hydraulic arrangement, a compactor with a hydraulic arrangement and a method for pivoting a hydraulic arrangement. Description of the Invention

An object of the invention is achieved by a hydraulic arrangement for providing a piv otal movement of an outer structure. The hydraulic arrangement comprises - anchor units for anchoring the hydraulic arrangement to a structure, the anchor units define a first end and a second end,

- an outer structure is pivotally connected to and extends between the anchor units, the outer structure comprises an inner channel with an inwardly directed face,

- an inner structure is fixed to the anchor units and is positioned inside the inner channel, the inner structure comprises an outwardly directed face,

- one or two longitudinal stop members are fixed to the inner structure and extend from the outwardly directed face to the inwardly directed face,

- a longitudinal displacement member is fixed to the outer structure and extends from the inwardly directed face to the outwardly directed face thereby dividing the inner channel into a first hydraulic chamber and a second hydraulic chamber, wherein the hydraulic arrangement comprises a first hydraulic channel and a second hydraulic chan nel connected to the first hydraulic chamber and the second hydraulic chamber for sup plying hydraulic fluid. The inner structure and the one or two longitudinal stop members inside the inner chan nel will form or define a ring-shaped channel in which the longitudinal displacement member can be displaced by the hydraulic fluid thereby causing pivoting of the outer structure. Thus, a hydraulic arrangement capable of pivoting an outer structure is provided, wherein the pivoting force is substantially constant at any possible angle.

The purpose of the anchor units is to dissipate force into the structure to which the hydraulic arrangement is attached such that the inner structure is fixed and thus unmov- ing. In the hydraulic arrangement, it is only the outer structure and the longitudinal dis placement member which can be displaced. The pressure in the hydraulic chambers can be over 100 bar or over 200 bar and thus the anchor units must be able to prevent rotation of the inner structure. The outer structure may include a press plate or any other structure which should be pivoted using a stable and large force.

The inner channel may be substantially cylindrically shaped asit is easy to produce and it will be easier to install the inner structure correctly inside the inner channel.

The longitudinal displacement member may be a separate unit attached to the inwardly directed face or the outer structure could be manufactured with the longitudinal dis placement member such that the outer structure and the longitudinal displacement mem ber are a single unit.

The longitudinal displacement member may have a shape complementary to the shape of the outwardly directed face such that the first hydraulic chamber and the second hy draulic chamber is properly separated such that hydraulic fluid does not bypass the lon gitudinal displacement member. The longitudinal displacement member may comprise additional sealing parts to prevent bypass of hydraulic fluid.

The one or two longitudinal stop members may be one or two separate units attached to the outwardly directed face or the inner structure. The aforementioned one or two lon gitudinal stop members could be manufactured with the one or two longitudinal stop members such that the inner structure and the one or two longitudinal stop members are a single unit.

The one or two longitudinal stop members should be interpreted broadly and include more than one or two one or two longitudinal stop members.

The relative position and/or size of the one or two longitudinal stop members define the maximum angle that the outer structure can pivot for a certain longitudinal displacement member.

The one or two longitudinal stop members may comprise additional sealing parts to prevent uncontrolled bypass of the one or two longitudinal stop members. The embodiment shown in figure 6 has two longitudinal stop members, however, the two longitudinal stop members could be replaced by a single longitudinal stop member forming an arc equivalent to the two longitudinal stop members.

The inner structure may be substantially cylindrically shaped as it is easy to produce and it will be easier to install the inner structure correctly inside the inner channel.

The inwardly directed face and the outwardly directed face forming part of the first and second hydraulic chambers may both have a circular arc shape with a common centre, i.e. the inwardly directed face and the outwardly directed face in first and second hy draulic chambers being coaxial along a rotation axis. Thereby it becomes easier to en sure that the longitudinal displacement member extends from the inwardly directed face to the outwardly directed face since the distance is constant.

The first hydraulic channel and the second hydraulic channel should enter the respective first hydraulic chamber and the second hydraulic chamber near or at the one or two longitudinal stop members to ensure maximum pivotal movement for a given configu ration. If placed otherwise, the pivotal movement will be fewer degrees.

In the case, where there is only a single longitudinal stop member, the first hydraulic channel and the second hydraulic channel should be placed on each side of the longitu dinal stop member preferably at or at least near the longitudinal stop member.

The inner structure, the outer structure and the one or two longitudinal stop members define a displacement chamber in which the longitudinal displacement member is to be displaced.

The displacement chamber will typically have a ring-shaped cross section since this geometric form enables rotation without change in geometry and with no need for the longitudinal displacement member to be compressible as the distance between the inner and the outer structure is substantially constant.

In an aspect, the inner structure and the inner channel may be arranged coaxial along a rotation axis. This is a mechanically simple solution which will ensure reliable pivoting of the outer structure. In an aspect, the first hydraulic channel and the second hydraulic channel may extend from an end of the inner structure though the inner structure to the first hydraulic cham ber and the second hydraulic chamber.

The inner structure is fixed to the anchor units and does not rotate or move relative to the anchor units. Thus, the first hydraulic channel and the second hydraulic channel can be installed inside the inner structure without a need for compensating for rotational movement.

In an aspect, the hydraulic arrangement may comprise one or two shaft houses con- nected to the outer structure at the first and/or second end, and

- one or both of the anchor units comprise an outermost connection plate and an inner most connection plate, said connection plates are adapted to pivotally retain the shaft house. The innermost connection plate is closest to the outer structure and will typically be ring-shaped with a central aperture.

This enables the hydraulic arrangement to pivot with a large force wherein there is a large counter force caused by waste material to be compacted. The waste material may create a large and uneven counter force on a press plate. The one or more shaft houses are pivotal within the outermost connection plate and the innermost connection plate and are held in place by the connection plates.

The one or two shaft houses may be connected to the first and/or second end of the outer structure by use of bolts or the like.

There may be one or more bearings positioned between the shaft house and the inner most connection plate. The one or more bearings may include a nylon bearing. In an aspect, the hydraulic arrangement may comprise

- one or both ends of the inner structure comprise grooves on the outwardly directed face;

- one or both shaft houses comprise an aperture; and

- one or both outermost connection plates comprise a connection member extending towards the inner structure and having a bore adapted to engage the grooves.

The grooves and the complementary bore greatly increase the friction and thus the strength of connection between the anchor units and the inner structure. This will in crease the force which can be exerted on the outer structure.

The connection member may be fitted with a bearing such as a nylon bearing to lower friction with the shaft house.

In an aspect, the outer structure may comprise a press plate. Thereby, the hydraulic arrangement may be used in a compactor.

The compactor may be similar to the compactor shown in figure 1.

An object of the invention is achieved by a compactor comprising a receiver volume for receiving material, a storage volume, and a hydraulic arrangement. The hydraulic ar rangement comprises

- an outer structure and an inner structure defining a displacement chamber, the displacement chamber is divided into a first hydraulic chamber and a second hy draulic chamber by a longitudinal displacement member, which form part of the outer structure,

- the press plate forms part of the outer structure,

- a first hydraulic channel and a second hydraulic channel are connected to the first hydraulic chamber and the second hydraulic chamber, and

- a hydraulic control system connected to the first hydraulic channel and the se cond hydraulic channel for communicating hydraulic fluid to the first hydraulic chamber and the second hydraulic chamber, thereby causing displacement of the longitudinal displacement member and pivotal movement of the outer structure. The displacement chamber defined by the outer structure and an inner structure may have a substantially ring-formed cross-section as this enable pivotal movement of the outer structure by supplying hydraulic fluid to either hydraulic chamber. The hydraulic control system may comprise a 4/3-valve for controlling fluid to and from the first hydraulic chamber and the second hydraulic chamber.

The inner structure is fixed to the compactor such as either side of the compactor or to pylons inside the compactor. The inner structure may be fixed to the compactor as pre- viously described using anchor units.

The described compactor and the force applied by the compactor is substantially angle independent compared to the compactor shown in Fig. 1, wherein the force differs by a factor of two. Thus, the pressure in the hydraulic cylinder (Fig. 1) may be 280 bar while the present invention can function at 150 bar while the press plate produces the same force as the prior art.

In an aspect, the hydraulic arrangement may have anyone of the technical features pre viously described.

An object of the invention is achieved by a method for pivoting a press plate of a com pactor, wherein an outer structure and an inner structure define an displacement cham ber, and the displacement chamber is divided into a first hydraulic chamber and a second hydraulic chamber by a longitudinal displacement member forming part of the outer structure, the press plate forms part of the outer structure. The method comprising the steps of

- increasing pressure in one of the hydraulic chambers;

- displacing the longitudinal displacement member;

- pivoting the press plate.

Thereby, the press plate may compact and force material into a storage volume of a compactor from a receiver volume. In an aspect, the step of increasing pressure may be performed at a pressure between 50-300 bar or 80-260 bar or 100-230 bar, 130-200 bar or 150-160 bar.

Description of the Drawing Fig. 1 illustrates a prior art compactor;

Fig. 2 illustrates an outer structure;

Fig. 3 illustrates an inner structure;

Fig. 4 illustrates anchor units connected to a hydraulic arrangement;

Fig. 5 illustrates a hydraulic arrangement comprising the outer structure shown in figure 2, the inner structure shown in figure 3 and the anchor units as shown in figure 4;

Fig. 6 illustrates a cross section of a hydraulic arrangement wherein the press plate is in a center position;

Fig. 7 illustrates a cross section of a hydraulic arrangement wherein the press plate is rotated counterclockwise relative to the center position; and Fig. 8 illustrates a cross section of a hydraulic arrangement wherein the press plate is rotated clockwise relative to the center position.

Detailed Description of the Invention

Fig. 1 illustrates a prior art compactor 10. The shown compactor 10 is figure 5 in the European patent application EP1385695. The shown reference signs refer to the refer ences described in EP 1385695 with the exception of reference 10. The prior art com pactor has been described in background of the invention section.

Fig. 2 illustrates an outer structure 50 in an exploded view 2A and a sideview 2B. The outer structure 50 is adapted to being pivotally connected to and extending between anchor units 30 (shown in figure 4 and 5). The outer structure 50 comprises an inner channel 52 with an inwardly directed face 54.

A press plate 12 form part of the outer structure 50.

The inwardly directed face 54 is substantially cylindrical with a centre being a rotation axis 22. The inwardly directed face 54 has a cross section perpendicular to the rotation axis 22 which is substantially circular. The outer structure 50 comprises a longitudinal displacement member 60 which is fixed to the inwardly directed face 54 using a series of bolts. The longitudinal displacement member 60 may be fitted with several sealing parts 95, where the purpose of the sealing parts 95 is to prevent bypass of hydraulic fluid and thereby loss of pressure.

Fig. 3 illustrates an inner structure 70 in a side view (A) and an exploded view (B).

The inner structure 70 is adapted to be fixed to anchor units 30, shown in figure 4, by the ends of the inner structure 70 being fitted with grooves 72 adapted to engage part of the anchor units 40.

The inner structure 70 is adapted to being positioned inside the inner channel 52 (shown in figure 2) and preferably be coaxial with inwardly directed face 54 relative to a rota tion axis 22.

The inner structure 70 comprises an outwardly directed face 72.

The inner structure 70 comprises two longitudinal stop members 801, 8011 fixed to the inner structure 70 using several bolts as illustrated in the exploded view.

The longitudinal stop members 801, 8011 may be fitted with several sealing parts 95, where the purpose of the sealing parts 95 is to prevent bypass of hydraulic fluid and thereby loss of pressure.

The inner structure 70 comprises two sealing rings 76, wherein the groves 72 extend from the respective end of the inner structure 70 to the respective sealing ring 76. The sealing rings may be provided with sealing parts 76 to prevent bypass of material.

The inner structure 70 comprises at one end two hydraulic channel 581, 5811 to provide material into the first and second hydraulic chamber 561, 5611, see (figure 6-8).

Fig. 4 illustrates anchor units 30 connected to a hydraulic arrangement 20 where figure 4A and figure 4B show the first and second end 321, 3211. The hydraulic arrangement 20 shown has the inner structure of figure 3 inserted into the outer structure shown in figure 3.

The hydraulic arrangement 20 comprises one or two shaft houses 241, 2411 connected to the outer structure 50 at the first and second end 321, 3211. The shaft houses 241, 2411 are connected using several bolts as shown in the exploded view, however, other fas tening means may be used.

The anchor units 30 both comprise an outermost connection plate 341, 3411 and an in nermost connection plate 361, 3611, which connection plates 34,36 are adapted to pivot ally retain the respective shaft houses 241, 2411.

The anchor units 30 further comprise a bearing 37 such as a nylon bearing to be placed between the shaft houses 241, 2411 and the innermost connection plates 361, 3611. The inner connection plates 361, 3611 being ring-shaped to accommodate the shaft houses 241, 2411.

Thereby, the outer structure 50 is pivotally connected to the anchor units 30.

As described for figure 3, both ends of the inner structure 70 comprise grooves 72 on the outwardly directed face 74.

Each shaft house 241, 2411 comprises an aperture 261, 2611 in order to accommodate a connection member 38. Both outermost connection plates 34 comprise the connection member 38 extending towards the inner structure 70 and having a bore 39 adapted to engage the grooves 72.

The connection member 38 is shown in figure 4B. The extend of the connection member 38 may in some embodiments be adapted such that connection member 38 engages the sealing ring 76 described in figure 3. Thereby, the hydraulic arrangement 20 becomes mechanically more stable as the connection member 38 prevents unwanted displace ment of the sealing ring 76. Fig. 5 illustrates a hydraulic arrangement 20 comprising the outer structure 50 shown in figure 2, the inner structure 70 shown in figure 3 and the anchor units 20 as shown in figure 4.

The hydraulic arrangement 20 being connected to a hydraulic control system 90 illus trated in the figure by a 4/3-valve. The hydraulic control system 90 controls the hydrau lic fluid to and from the hydraulic chambers 561, 5611 via hydraulic channels 581, 5811 positioned in a first end 321 of the hydraulic arrangement. This will cause pivoting of the outer structure 50 and thus the press plate 12. The pivotal movement is illustrated in figure 6-8.

Fig. 6 illustrates a cross section of a hydraulic arrangement 20 wherein the press plate 12 is in a center position.

The cross section discloses an outer structure 50 and an inner structure 70 defining a displacement chamber 53. the displacement chamber 53 being divided into a first hy draulic chamber 561 and a second hydraulic chamber 5611 by a longitudinal displace ment member 60 forming part of the outer structure 50.

The longitudinal displacement member 60 and extending from the inwardly directed face 54 to the outwardly directed face 74.

Two longitudinal stop members 801, 8011 are fixed to the inner structure 70 and extend from the outwardly directed face 74 to the inwardly directed face 54. Thereby, the lon gitudinal stop members 801, 8011 control the maximum pivotal movement of the outer structure 50 by limiting the displacement chamber 53. The displacement chamber 53 has a ring-shaped cross-section, where the longitudinal stop members 801, 8011 define a cut-out of the ring-shaped cross-section.

A press plate 12 form part of the outer structure 50, the press plate 12 being adapted for compacting and forcing material into the storage volume. The inner structure 70 comprises a first hydraulic channel 581 connected to the first hydraulic chamber 561 and a second hydraulic channel 581 connected the second hy draulic chamber 5611.

A (not shown) hydraulic control system 90 is connected to the first hydraulic channel 581 and the second hydraulic channel 5811 for communicating hydraulic fluid to the first hydraulic chamber 561 and the second hydraulic chamber 5611, thereby causing dis placement of the longitudinal displacement member 60 and pivotal movement of the outer structure 50.

If the pressure in first hydraulic chamber 561 is increased relative to the second hydrau lic chamber 5611, then the outer structure 50 will rotate counter clockwise to the position shown in Fig. 7 due to force exerted on the longitudinal displacement member 60.

If the pressure in second hydraulic chamber 5611 is increased relative to the first hydrau lic chamber 561, then the outer structure 50 will rotate clockwise to the position shown in Fig. 8 due to force exerted on the longitudinal displacement member 60.

Fig. 7 illustrates a cross section of a hydraulic arrangement 20 wherein the press plate 12 is rotated counterclockwise relative to center position.

Fig. 8 illustrates a cross section of a hydraulic arrangement 20 wherein the press plate 12 is rotated clockwise relative to center position.

The cross-section in figure 8 shows positioning of the bolts for fastening the two longi tudinal stop members 801, 8011 and the longitudinal displacement member 60.