Patent Application
20240100746
The present invention relates to a mould assembly for manufacturing a wind turbine blade shell part, to a method of manufacturing a wind turbine blade shell part, and to a valve assembly for connecting two chambers of a hydraulic cylinder.
Wind power provides a clean and environmentally friendly source of energy. Wind turbines usually comprise a tower, generator, gearbox, nacelle, and one or more rotor blades. The wind turbine blades capture kinetic energy of wind using known airfoil principles. Modern wind turbines may have rotor blades that exceed 90 meters in length.
Wind turbine blades are usually manufactured by forming two shell parts or shell halves from layers or plies of woven fabric or fibre and resin. Spar caps or main laminates are placed or integrated in the shell halves and may be combined with shear webs or spar beams to form structural support members. Spar caps or main laminates may be joined to, or integrated within, the inside of the suction and pressure halves of the shell.
The aerodynamic shell parts are typically made by use of Vacuum Assisted Resin Transfer Moulding (VARTM), wherein a plurality of fibre mats are arranged on top of rigid mould parts along with core material to provide parts having a sandwich structure. When the fibre mats have been stacked and overlapped so as to form the final shape of the wind turbine blade shell part, a flexible vacuum bag is arranged on top of the fibre mats and sealed against the rigid mould part, thereby forming a mould cavity containing the fibre mats. Resin inlets and vacuum outlets are connected to the mould cavity. First the mould cavity is evacuated via the vacuum outlets to create negative pressure in the mould cavity, after which a supply of liquid resin is supplied via the resin inlets. The resin is forced into the mould cavity due to the pressure differential and impregnates the fibre material of the fibre mats. When the fibre material has been fully impregnated, the resin is cured in order to form the final composite structure, i.e. the wind turbine shell part.
From WO 2014/191046 A1 it is known to provide shell halves of a wind turbine blade with a root end insert comprising a plurality of fastening members which are embedded between outer fibre layers and inner fibre layers of the shell. These fastening members are accessible from the root end of the shell part so that the wind turbine blade may be mounted to the hub of a wind turbine. In this process, a mounting plate can be used to facilitate integration of the fastening members, wherein a plurality of bushings are provided on the mounting plate, alternating with wedge-shaped inserts. After completing the manufacturing process, the mounting plate of the root end assembly can be removed, and the remaining part constitutes a root end insert for attachment to the hub.
However, a correct alignment and arrangement of the root end insert fastened to the mounting plate can be challenging. Even slight deviations in the angle and position relative to the fibre layers may result in undesired displacement of the glass fabric, thereby causing wrinkle formation and/or bending within the blade shell laminate. Also, gaps may form between the tips of the wedge-shaped inserts and the fibre layers if the root end insert is placed at an incorrect angle. This may give rise to costly repair operations.
It is therefore an object of the present invention to provide an improved moulding assembly which overcomes the above-described problems.
It is another object of the present invention to provide a more efficient process of manufacturing blade shell parts with root end inserts, which reduces the amount of undesired repair operations.
It has been found that one or more of the aforementioned objects can be obtained by a mould assembly for manufacturing a wind turbine blade shell part, the mould assembly comprising a mould having a moulding surface that defines the outer shape of the wind turbine blade shell part, the mould having a longitudinal direction extending between a tip end and a root end of the mould, wherein the mould assembly comprises a lowering device, which is adapted to carry and lower a root end insert onto the moulding surface of the mould, the lowering device being attached to the mould and comprising a frame for carrying the root end insert, wherein the lowering device further comprises driving means for lowering the frame together with the root end insert, the driving means comprising two synchronized hydraulic cylinders, each hydraulic cylinder comprising a piston chamber and a rod chamber, wherein the piston chamber and the rod chamber of each cylinder are connected to each other via a respective valve assembly comprising a fluid line and a valve.
It was found that this arrangement results in a significant reduction of wrinkle formation, and reduced necessity and cost of repair operations. By using the valve assembly of the present invention, an efficient way of resetting the position of the cylinder pistons is provided, which allows the operator to correct for any observed inaccuracies or loss of cylinder synchronization during the lowering of the root insert. By opening the valve of the valve assembly, hydraulic fluid is allowed to flow back to the other chamber of the cylinder thus resetting the piston position. The synchronized movement of the cylinders allows for a correct and efficient placement of the root insert on the fibre layers or plies.
Using the mould assembly of the present invention, a root end insert that has been separately prepared may be lowered and arranged very precisely onto the moulding surface. Further, the lowering process can to a high degree be carried out without human involvement. By using an automatic, synchronized lowering device it is ensured that the root end insert is lowered into the mould every time such a root end insert is being mounted.
The wind turbine blade shell part is preferably a blade shell half, such as a pressure side shell half or a suction side shell half, each shell half having a trailing edge and an opposing leading edge, as well as a root end and an opposing tip end. The mould typically comprises a support structure, such as a frame, for receiving a moulding surface that defines the outer shape of the wind turbine blade shell part. The mould having a longitudinal direction extending between a tip end and a root end of the mould, and usually trailing edge side and a leading edge side.
The mould assembly comprises a lowering device, which is adapted to carry and lower a root end insert onto the moulding surface of the mould. The lowering device is attached to the mould and comprises a frame for carrying the root end insert. The frame is preferably provided with carrying means for carrying the root end insert. This provides a simple solution for arranging and carrying the root end insert on the frame of the lowering device. The carrying means may for instance be hooks that are adapted to receive pins or rods from the root end insert. The root end insert or the mounting plate of the root end assembly may thus rest on the hooks.
The root end insert may comprise a plurality of fastening members, such as bushings. The fastening members are preferably accessible from the end of the wind turbine blade shell so that the fastening members in the final wind turbine blade can be used to mount the root end of the wind turbine blade to the hub of a wind turbine. The root end insert further advantageously comprises a number of intermediate inserts arranged between fastening members, said inserts preferably comprising a wedge-shaped section for being arranged in between upper and lower fibre layers or plies of the shell part. Thereby, the fastening members and the inserts may together form a root end insert that is embedded in the entire cross-section, thus forming a circular insert in the finished wind turbine blade shell. The intermediate inserts and the fastening members preferably comprise lateral sides that abut each other.
The lowering device may advantageously be attached on the sides of the mould, preferably with one of the hydraulic cylinders being arranged at either side, i.e. one cylinder at the trailing edge side and the other cylinder at the leading edge side. This ensures that the lowering device is always aligned in the same way relative to the mould, in turn ensuring that the root end insert is lowered onto the moulding surface in the same way every time.
According to an advantageous embodiment, the lowering device is adapted to lower the root end insert in a two-step motion, where the root end insert in a first motion step is lowered onto the moulding surface while the root end insert is angled upwards in the longitudinal direction until a first end of the root end insert contacts a part of the moulding surface at the root end, and where the root end insert in a second motion step is tilted until the root end insert rests on the moulding surface. Thereby, the lowering device may lower the root end insert onto the moulding surface without wrinkling or otherwise distorting fibre material, such as fibre mats, that have been laid up on the moulding surface prior to arranging the root end insert in the mould.
The root end insert is in the second motion step rotated substantially about the first end of the root end insert or the part that after the first motion step contacts the part of the moulding surface at the root end. Advantageously, the lowering device comprises a frame for carrying the root end insert and a driving means for lowering the frame together with root end insert. This provides for a simple solution, where the root end insert or root end assembly may be arranged on the frame, and where the driving means facilitate the lowering motion, where the root end insert is arranged on the moulding surface.
According to an advantageous embodiment, the lowering device comprises at least a pair of guiding pins or rollers and mating guiding slots provided on the frame. The mating connection between the guiding pins and the guiding slots may thus ensure that the root end insert follows the correct motion when it is lowered onto the moulding surface. The guiding slots may advantageously comprise a front guiding slot and a rear guiding slot, wherein the slots are shaped so that rear guide in the first motion lowers a rear part of the frame faster than the front guiding slot lowers a front part of the frame. Thereby the frame will be both lowered and tilted during the first motion step, thus tilting the root end insert upwards as seen in the longitudinal direction of the mould.
In one advantageous embodiment, the slots are shaped so that the front guide in the second motion lowers the front part of the frame faster than the rear guiding slot lowers the rear part of the frame. Thus, the guiding slots are shaped so as to provide the rotating motion of the second motion step.
The driving means comprises two synchronized hydraulic cylinders, each hydraulic cylinder comprising a piston chamber and a rod chamber. It is preferred that the hydraulic cylinders are double acting hydraulic cylinders. In a preferred embodiment, the two synchronized double acting hydraulic cylinders are arranged at opposite sides of the mould, such as at a trailing edge side and a leading edge side of the mould. In one embodiment, the hydraulic cylinders are telescopic cylinders. In another embodiment, the hydraulic cylinders are double acting, double rod end cylinders. In preferred embodiment, the hydraulic cylinders are connected in series. In another embodiment, the hydraulic cylinders are connected in parallel.
The two hydraulic cylinders are advantageously configured to pull the root end insert, preferably a mounting plate to which the root end insert is fixed, toward the moulding surface of the mould. In a preferred embodiment, the cylinder rods are connected to respective engaging members, such as hooks, for receiving a mating member, such as a pin, of the root end insert mounting plate. Thus, the cylinders are preferably configured to pull the root end insert from the root end towards, above and onto the moulding surface.
The piston chamber and the rod chamber of the first hydraulic cylinder are connected to each other via a first valve assembly comprising a fluid line and a valve, the valve assembly allowing for fluid communication between both chambers of the cylinder. Likewise, the piston chamber and the rod chamber of the second hydraulic cylinder are connected to each other via a second valve assembly comprising a fluid line and a valve. In a preferred embodiment, the valve of each valve assembly is a two-way valve, preferably a two-way ball valve. Thus, when the valve is opened fluid connection between both chambers can be established. This allows for backflow of hydraulic fluid to the less pressurized chamber, thus enabling a swift and simple way of resetting the piston position of one or preferably both of the cylinders.
In a preferred embodiment, each of the piston chamber and the rod chamber comprise a respective fluid port, and wherein each valve assembly further comprises a first fitting at the first end of the fluid line, and a second fitting at the second end of the fluid line, the first and second fittings being connected to the respective fluid ports of the hydraulic cylinder.
In a preferred embodiment, the first fitting further comprises a hydraulic pressure test point coupling for bleeding air from the hydraulic cylinder. The test point coupling may provide for an efficient way of letting air escape the cylinder that has become trapped inside the cylinder. In a preferred embodiment, the first fitting and the second fitting are banjo fittings. Preferably, the respective fluid ports of the hydraulic cylinder are located at an upper edge of the respective cylinder.
In a preferred embodiment, the first fitting comprises a banjo bolt with an internal thread, and wherein the hydraulic pressure test point coupling is fastened to the first fitting via said internal thread. Advantageously, the test point coupling comprises an external thread that can be screwed into the internal thread of the banjo bolt.
In a preferred embodiment, the lowering device is adapted to lower the root end insert in a two-step motion using the pulling force of the hydraulic cylinders, wherein the root end insert in a first motion step is lowered onto the moulding surface while the root end insert is angled upwards in the longitudinal direction until a first end of the root end insert contacts a part of the moulding surface at the root end, and where the root end insert in a second motion step is tilted until the root end insert rests on the moulding surface. This can be achieved by providing the frame of the lowering device with appropriately shaped slots, for example with an angled shape, within which guiding rollers of the lowering device are arranged. When the cylinders pull the root insert towards the mould, the guiding rollers can move within the angled slots of the frame, thus creating the desired two-step motion.
In a preferred embodiment, the lowering device comprises at least a pair of guiding pins or rollers and mating guiding slots provided on the frame. The frame and the root end insert may be lowered onto the moulding surface of the mould via guiding slots and guiding pins or rollers. In a preferred embodiment, the frame is provided with hooks that are adapted to receive pins from the root end insert.
In another aspect, the present invention relates to a method of manufacturing a wind turbine blade shell part, wherein the wind turbine blade shell part is manufactured as a composite structure comprising a fibre-reinforcement material embedded in a polymer matrix, and wherein the wind turbine blade shell part is provided with a root end insert that, when manufactured, is accessible from a root end of the wind turbine shell part, and wherein the wind turbine blade shell part is manufactured with the mould assembly according to the present invention, wherein the method comprises the steps of:
This ensures that a root end insert that has been separately prepared may be lowered and arranged very precisely onto the moulding surface. Further, the lowering process can to a high degree be carried out without human involvement. By using an automatic, synchronized lowering device it is ensured that the root end insert is lowered into the mould every time such a root end insert is being mounted. Safety is also increased, as there is no manual operation for fixing the root plate, while the root end insert is being carried by a carrying device, such as a crane.
Synchronization of the two hydraulic cylinders of the mould assembly may be achieved by connecting the hydraulic cylinders in hydraulic series or tandem. Thus, as hydraulic fluid under pump pressure is supplied to one end of the first cylinder, the second cylinder will be equally operated by the oil which is ejected from the first cylinder.
In a preferred embodiment, the method comprises, prior to or during step b), opening the valve of each valve assembly to reset the piston position of the respective hydraulic cylinders, and subsequently closing the valves.
In a preferred embodiment, the method further comprises bleeding air from the hydraulic cylinder using the pressure test point coupling.
In a preferred embodiment, step b) is carried out in two motions steps, wherein
In a preferred embodiment, the root end insert prior to step a) is arranged on a mounting plate, and wherein the root end insert is arranged on the lowering device via the mounting plate. The mounting plate together with the root end insert form a root end assembly. In one embodiment, the mounting plate is provided with attachment devices for attaching the mounting plate to the lowering device. The attachment devices may for instance be pins that may mate or rest on hooks provided on the lowering device. In practice, the root end insert may be arranged on a mounting plate, the mounting plate and the root end insert together forming a root end assembly. The root end insert is then arranged in the mould by providing the root end assembly on the lowering device and lowering it into the mould. The mounting plate may then later, e.g. after moulding, be removed.
Thus, the method may be carried out using a root end assembly comprising a mounting plate comprising a first side and a second side, and a plurality of fastening members, such as bushing, mounted to the first side of the mounting plate so that the fastening members extend substantially normal to first side of the mounting plate, wherein the mounting plate is adapted to be removed, when the root end assembly has been mounted in a wind turbine blade shell part.
According to an advantageous embodiment, the assembly further comprise wedges arranged in longitudinal extension of the fastening members, alternatively the wedges being provided with a tapering part proximal to the mounting plate. Similarly, the inserts may comprise a tapering part proximal to the mounting plate. The wedges or tapering parts may thus provide for a gradual stiffness transition in the longitudinal direction of the finished wind turbine blade shell.
According to another advantageous embodiment, the mounting plate on the first side comprises recesses or notches, and a proximal end of the fastening members are arranged in said recesses or notches. The recesses may assist in ensuring that the fastening members are arranged correctly on the mounting plate, e.g. ensuring that the fastening members extend along a normal to a plane of the mounting plate. The recesses are preferably disposed along a circular path or semi-circular path on the mounting plate so that the fastening members are arranged along a circular cross section of the wind turbine blade shell part.
According to yet another advantageous embodiment, the mounting plate further comprises a number of holes, wherein the fastening members are attached to the mounting plate by stay bolts that have been inserted from the second side of the mounting plate and through the holes. Thus, the holes are preferably also disposed along a circular path. Preferably, the holes are aligned with the recesses on the first side of the mounting plate.
The mounting plate may remain on the root end of the wind turbine blade shell part after the manufacture of the shell part and only be removed prior to instalment on the wind turbine hub. Thereby, the rigid mounting plate ensures that the root end of the blade does not deform during storage. In manufacturing methods, where the blade shell is manufactured via two or more blade shell parts, such as the suction side shell part and the pressure side shell part, the mounting plate may also remain attached to the blade shell parts during the step, where the blade shell parts are glued to each other. When the mounting plate of the root end assembly has been removed, the remaining part constitutes a root end insert.
In a preferred embodiment, the root end insert comprises a plurality of fastening members, such as bushings, and wherein the root end insert further comprises a number of intermediate inserts arranged between fastening members. In a preferred embodiment, the intermediate inserts comprise a tapered part or wedge part. The fastening members are advantageously in the final composite structure of the shell part embedded between the outer fibre layer(s)/plies and the inner fibre layer(s)/plies. The fastening members are preferably accessible from the root end of the shell part so that the wind turbine blade may be mounted to the hub of a wind turbine.
According to a preferred embodiment, the fastening members are bushings. The bushings are arranged so that the opening of the bushings are accessible from the root end of the blade shell so that the final wind turbine blade may be mounted to the hub of a wind turbine by use of stay bolts inserted into the openings of the bushings.
According to an advantageous embodiment, the bushings are mounted on the mounting plate by use of stay bolts. The mounting plate may be provided with openings for the stay bolt to be inserted through, so that the bushings are mounted on a first side of the mounting plate, and the stay bolts are inserted through said openings and attached to the bushing from a second, opposite side of the mounting plate. The mounting plate may be removed from the root end by first demounting the stay bolts and then removing the mounting plate from the root end of the blade shell part.
According to another advantageous embodiment, the mounting plate is provided with guiding recesses for insertion of one end of the fastening members. This ensures correct alignment and orientation of the fastening members. In yet another advantageous embodiment, the preparation of the root end assembly further comprises the step of mounting intermediate inserts between the fastening members. The intermediate inserts may for instance be retaining inserts, such as butterfly wedges, which retain the fastening members and further ensures that the fastening members are arranged with the correct mutual spacing. In practice, the fastening members and the inserts may be arranged on the root end assembly by alternately arranging the fastening member and the inserts, preferably along a circular or semi-circular path on the mounting plate.
The intermediate inserts may advantageously be made of a fibre-reinforced composite structure, e.g. a fibre pultrusion comprising pultruded glass fibres or carbon fibres. In one embodiment, fibre material is wrapped around the fastening members. The fibre material may advantageously be non-woven fibre material, such as glass wool.
The fastening members are typically made of a metal, such as cast iron or stainless steel, and by wrapping fibre material, e.g. glass fibres, around the fastening members, it is ensured that the fastening members are properly bonded to the inner and outer fibre layers/plies.
In one advantageous embodiment, a wedge is arranged in longitudinal extension of the fastening member. The wedge may for instance be made of foamed polymer or balsawood. The wedge is arranged so that it has the thickest part proximal to the end of the fastening member, and the thin part distal to the end of the fastening member. This ensures that the root end assembly has a gradual transition to the outer and inner fibre layers, in turn ensuring that the blade root does not have a steep or discontinuous stiffness transition.
The wedge may be wrapped in the fibre material together with the fastening member so that the two parts may be arranged on the mounting plate together. The wedge may also in principle be integrally formed with the fastening member.
In another advantageous embodiment, the intermediate inserts comprise a tapered part or wedge part. The tapered part of the insert may preferably be aligned with the wedge arranged in longitudinal extension of the fastening member. Thereby, the two parts together ensure a gradual stiffness transition in the composite structure of the shell part.
A fibre material may advantageously be weaved between the wedges of the fastening members and the wedge part of the inserts. This can be done by weaving the fibre material under the butterfly wedges and over the fastening member wedges or vice versa. The fibre material may for instance be triaxial glass fibre mats.
In yet another advantageous embodiment, a fibre layer, such as a fibre mat, is wrapped around the plurality of fastening members and the optional inserts prior to the root end assembly being arranged in the mould. The fibre layer may for instance be a triaxial fibre mat comprising glass fibres.
Further, a number of fibre bands may be arranged on top of the wedges in order to a proper alignment of the end parts of the edges and a proper draping of the fibre material, thus ensuring a proper transition to the inner and outer fibre layers without wrinkles forming in the laminate.
In a preferred embodiment, the method, prior to step a), comprises the step of arranging one or more outer fibre layers on the moulding surface, the one or more outer fibre layers defining an outer surface of the wind turbine blade shell part. In a preferred embodiment, the method additionally comprises the step of arranging one or more inner fibre layers on top of the root end insert. Thereby, the root end insert is sandwiched between the inner fibre layer(s) and outer fibre layer(s). The outer fibre layer(s) may advantageously comprise biaxial fibre mats. The inner fibre layer(s) may advantageously comprise triaxial fibre mats.
In a preferred embodiment, the method after step b) comprises the steps of supplying a polymer to the outer and inner fibre layers, and allowing the polymer to cure so as to form the composite structure. The root end insert is thus embedded in the composite structure, thus providing a strong attachment part for mounting the final wind turbine blade to the hub of a wind turbine.
In another aspect, the present invention relates to a valve assembly for connecting two chambers of a hydraulic cylinder, each chamber comprising a fluid port, the valve assembly comprising a fluid line with a first fitting at the first end of the fluid line, and a second fitting at the second end of the fluid line, the first and second fittings being connectable to the respective fluid ports of the hydraulic cylinder, wherein the valve assembly further comprises a two-way valve arranged with the fluid line between the first end and the second end, wherein the first fitting comprises a hydraulic pressure test point coupling for bleeding air from the hydraulic cylinder.
In a preferred embodiment, the first fitting and the second fitting are respective banjo fittings. In a preferred embodiment, the first fitting comprises a banjo bolt with an internal thread, and wherein the hydraulic pressure test point coupling is fastened to the first fitting via said internal thread.
According to another aspect, the invention relates to a use of the mould assembly for manufacturing a wind turbine blade shell part made of a composite structure comprising a fibre-reinforcement material embedded in a polymer matrix, comprising the steps of: a) arranging one or more outer fibre layers on a mould surface, the one or more outer fibre layers defining an outer surface of the wind turbine blade shell part, b) mounting a plurality of fastening devices on a mounting plate so as to form a root end assembly, c) arranging the root end assembly on top of the one or more outer fibre layers at a root end section of the mould, using the hydraulic cylinders of the mould assembly, d) arranging one or more inner fibre layers on top of the root end assembly, e) supplying a polymer to the outer and inner fibre layers, f) allowing the polymer to cure so as to form the composite structure, and removing the mounting plate.
Thus, the fastening devices or bushings may be arranged on the mounting plate, and all the bushings may then be arranged correctly on the fibre layers on the mould. This also speeds up the manufacturing process, since all the fastening members may be arranged on the fibre material in one step, and since fibre layup in the mould and the preparation of root end assembly may be prepared in parallel.
All features and embodiments discussed above with respect to the mould assembly of the present invention likewise apply to the method of manufacturing a wind turbine blade shell part and to the valve assembly of the present invention, and vice versa.
The invention is explained in detail below with reference to embodiments shown in the drawings, in which
The airfoil region 34 (also called the profiled region) has an ideal or almost ideal blade shape with respect to generating lift, whereas the root region 30 due to structural considerations has a substantially circular or elliptical cross-section, which for instance makes it easier and safer to mount the blade 10 to the hub. The diameter (or the chord) of the root region 30 may be constant along the entire root area 30. The transition region 32 has a transitional profile gradually changing from the circular or elliptical shape of the root region 30 to the airfoil profile of the airfoil region 34. The chord length of the transition region 32 typically increases with increasing distance rfrom the hub. The airfoil region 34 has an airfoil profile with a chord extending between the leading edge 18 and the trailing edge 20 of the blade 10. The width of the chord decreases with increasing distance r from the hub.
A shoulder 40 of the blade 10 is defined as the position, where the blade 10 has its largest chord length. The shoulder 40 is typically provided at the boundary between the transition region 32 and the airfoil region 34.
It should be noted that the chords of different sections of the blade normally do not lie in a common plane, since the blade may be twisted and/or curved (i.e. pre-bent), thus providing the chord plane with a correspondingly twisted and/or curved course, this being most often the case in order to compensate for the local velocity of the blade being dependent on the radius from the hub.
The blade is typically made from a pressure side shell part 36 and a suction side shell part 38 that are glued to each other along bond lines at the leading edge 18 and the trailing edge of the blade 20.
The spar cap 41 of the pressure side shell part 36 and the spar cap 45 of the suction side shell part 38 are connected via a first shear web 50 and a second shear web 55. The shear webs 50, 55 are in the shown embodiment shaped as substantially I-shaped webs. The first shear web 50 comprises a shear web body and two web foot flanges. The shear web body comprises a sandwich core material 51, such as balsawood or foamed polymer, covered by a number of skin layers 52 made of a number of fibre layers. The blade shells 36, 38 may comprise further fibre-reinforcement at the leading edge and the trailing edge. Typically, the shell parts 36, 38 are bonded to each other via glue flanges.
The wind turbine blades 10 are manufactured as fibre-reinforced composite structures comprising a fibre-reinforcement material embedded in a polymer matrix. The individual blades 10 comprise an aerodynamic shell, and the suction side and the pressure side of the aerodynamic shell are often manufactured as separate parts in moulds 23 as shown in
The mounting plate 70 comprises a first side 77 and a second side 79. The mounting plate 70 is provided with a plurality of recesses 71 provided on the first side 77 of the mounting plate 70 and a plurality of through-going bores 72 or holes. The bores 72 are centrally aligned with the recesses 71. In
The root end insert may be prepared by first mounting a first bushing 74 on the mounting plat and then arranging a first insert 76 next to and abutting the first bushing. Afterwards a second bushing 74 is arranged next to the first insert 76 and a second insert 76 next to the second bushing 74. This procedure is then continued until bushings 74 and inserts 76 are arranged along the entire semi-circle on the mounting plate, e.g. by arranging bushings 74 and inserts 76 from left to right as illustrated in
The mounting plate 70 is also provided with a number of protrusions 73, such as pins or rods, which extend from the side of the mounting plate 70. These protrusions 73 may be used as connecting parts for providing a mating connection to corresponding parts on a frame of a lowering device for arranging the root end insert on the surface 22 of the mould 20.
This is illustrated in
To address this issue, a mould assembly 100 as illustrated in
The lowering device comprises a frame 86 for carrying the root end insert, as well as two synchronized double acting cylinders 91, 92 for lowering the frame together with the root end insert. As seen in the hydraulic chart of
Each hydraulic cylinder comprising a piston chamber 102 and a rod chamber 104, see
A more detailed view of the valve assembly 110 is shown in
In the embodiment illustrated in
The invention is not limited to the embodiments described herein and may be modified or adapted without departing from the scope of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 21153976.2 | Jan 2021 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/051568 | 1/25/2022 | WO |
