CN113883012B - Connecting device for assembling blades and wind turbine generator - Google Patents

Abstract

The invention discloses a connecting device for assembling a blade and a wind turbine, which comprises a first flange plate and a second flange plate, wherein the first flange plate is used for being fixedly connected with the wind turbine, the second flange plate is used for being fixedly connected with the blade, a first fixing seat is arranged on the first flange plate, a second fixing seat is arranged on the second flange plate, a limit column is rotationally connected on the first fixing seat, the end part of the limit column is provided with a circular table section, a positioning block is further arranged on the limit column along the circumferential direction, a limit groove for inserting the limit column and the circular table section is arranged on the second fixing seat, and a positioning groove for inserting the positioning block is further arranged on the side wall of the limit groove; the driving mechanism is connected with the limiting column and used for driving the limiting column to rotate relative to the first fixing seat. The invention can reduce the difficulty of butt joint operation of the blade and the wind turbine generator.

Description

Connecting device for assembling blades and wind turbine generator

Technical Field

The invention belongs to the field of power equipment, and particularly relates to a connecting device for assembling a blade and a wind turbine generator.

Background

Wind power generation is a clean energy power generation technology, and the equipment generally comprises a wind power generator set, wind power blades, a tower for supporting the generator set, an inverter, an unloader, a grid-connected controller, a storage battery pack and the like. Due to the characteristics of large volume, heavy weight and the like of the wind power generation equipment, the operation is complex and more dangerous sources exist during on-site assembly, for example, when the wind power blades and the wind turbine generator are assembled in a butt joint mode in the prior art, the large hoisting equipment is required to be used for hoisting the wind power blades to a proper height for assembly, and the process has clear requirements on the specification of the hoisting equipment, the wind power of the operation environment and the arrangement of on-site observation command staff. In the prior art, a first flange plate is generally arranged on a wind turbine generator, a second flange plate is arranged on a blade, a first fixing seat is arranged on the first flange plate, a second fixing seat is arranged on the second flange plate, and the first fixing seat and the second fixing seat are aligned and attached to each other in assembly and then fixedly connected through bolts. Because wind-powered electricity generation blade easily rocks under the lifting state, be difficult to direct with first fixing base and second fixing base alignment and laminating contact, consequently be equipped with preceding convex locating part (generally cylinder or cuboid) on first fixing base, be equipped with on the second fixing base with locating part complex spacing groove, only need peg graft the spacing groove earlier in, just can avoid the blade to take place radial rocking for wind turbine generator system like this, reduce the assembly degree of difficulty to a certain extent.

However, the current method still has quite high operation difficulty, and has quite high danger for operators, firstly, the alignment insertion of the limiting piece and the limiting groove has certain difficulty (particularly, the alignment insertion operation difficulty is higher when the limiting piece is a cuboid) under the condition that the fan blade shakes, and when the limiting piece is a cylinder, the fan blade can still rotate circumferentially relative to the wind turbine after the successful butt joint insertion, so that the alignment operation of threaded holes on the first fixing seat and the second fixing seat is not facilitated. In addition, in the prior art, the problem of easy loosening also exists in the screw thread fixed connection mode between the first fixing seat and the second fixing seat, and axial displacement of the blades relative to the wind turbine generator is easy to occur, so that the blades can be even caused to fall off when wind power is large and the rotating speed of the blades is high, and serious accidents and losses are caused.

Disclosure of Invention

The invention aims to provide a connecting device for assembling a blade and a wind turbine, which can effectively solve the problem that the blade and the wind turbine are difficult to align and stabilize when being assembled in the prior art.

In order to solve the technical problems, the invention adopts the following technical scheme: the connecting device for assembling the blades and the wind turbine comprises a first flange plate fixedly connected with the wind turbine and a second flange plate fixedly connected with the blades, wherein a first fixing seat is arranged on the first flange plate, a second fixing seat is arranged on the second flange plate, a limit column is rotationally connected on the first fixing seat, a circular table section is arranged at the end part of the limit column, a positioning block is further arranged on the limit column along the circumferential direction, a limit groove for inserting the limit column and the circular table section is formed in the second fixing seat, and a positioning groove for inserting the positioning block is further formed in the side wall of the limit groove; the driving mechanism is connected with the limiting column and used for driving the limiting column to rotate relative to the first fixing seat.

Preferably, a fixed disc is arranged on the first fixed seat, an open slot for the rotation and insertion of the limit column is formed in the fixed disc, an annular slot communicated with the open slot is formed in the end face of the fixed disc along the circumference of the open slot, a fixed cover is detachably covered on the fixed disc, and an avoidance through hole for avoiding the limit column and the positioning block is formed in the fixed cover; the annular groove is matched with the inner surface of the fixed cover to form a limiting annular groove, and the limiting column is circumferentially provided with an annular protrusion rotationally connected in the limiting annular groove. The spacing post is rotated through the fixed disk and is connected on first fixing base like this, and detachably connects between spacing post and the fixed disk, and the dismouting of being convenient for, maintenance and maintenance to through spacing annular to the bellied spacing effect of annular, can prevent that spacing post from coming off from the fixed disk.

Preferably, the driving mechanism comprises a driving motor and a driving fluted disc connected to an output shaft of the driving motor, a gear ring is arranged on the outer ring surface of the annular bulge, a gap is formed between the gear ring and the bottom end of the limiting ring groove, and part or all of the driving fluted disc extends into the gap and is meshed with the gear ring for transmission. The driving motor is used for controlling the driving fluted disc to rotate, and the annular protrusion is driven to rotate through the meshing transmission of the driving fluted disc and the gear ring, so that the limit post can be driven to rotate relative to the fixed disc. When the driving motor stops, the limit post stops rotating and is fixed relative to the fixed disc.

Preferably, the fixed disc is provided with a containing cavity for containing the driving mechanism, and the driving mechanism is located inside the fixed disc. Therefore, the driving mechanism does not protrude out of the fixed disc, and the attaching and fixing between the first fixed seat and the second fixed seat are not affected.

Preferably, the second fixing seat is provided with a containing groove for containing the fixing disc.

Preferably, the driving mechanism further comprises a remote controller for remotely controlling the start and stop of the driving motor. Therefore, an operator does not need to perform contact type operation on the driving motor, and the operator does not need to physically stretch out of the wind turbine generator to operate, so that the risk in the butt joint operation process can be obviously and effectively reduced, and the personal safety is practically guaranteed.

Preferably, the first fixing seat and the second fixing seat are fixedly connected through bolt threads.

Preferably, the one side that first fixing base deviates from the second fixing base is equipped with first welding piece, the one side that the second fixing base deviates from first fixing base is equipped with the second welding piece, the fixed solid fixed ring that is equipped with on the second welding piece, the first screw hole of intercommunication has been seted up on first welding piece, first fixing base, second welding piece and the solid fixed ring, first screw hole internal rotation has twisted first bolt, and first bolt and first screw hole cooperation are with first fixing base and second fixing base screw thread fixed connection. Through adding first welding piece, second welding piece and solid fixed ring, can improve the fastening nature of threaded connection between first fixing base and the second fixing base, can reduce the possibility that first fixing base and second fixing base take place to loosen to a certain extent.

Preferably, the first bolt comprises a screw rod, second threaded holes are formed in the radial directions of the fixing ring and the screw rod, and when the screw rod is screwed in the first threaded holes, the second threaded holes in the fixing ring are communicated with the second threaded holes in the screw rod, the second bolts are screwed in the second threaded holes, and the second bolts are matched with the second threaded holes to prevent the first bolts from loosening. The second bolt that adds to establish produces spacing effect to the screw rod along the screw rod axial, can prevent that the screw rod from producing the removal along the axial, and then can prevent that first bolt from becoming flexible, effectively avoids taking place not hard up between first fixing base and the second fixing base, and then avoids the fan blade to take place unexpected droing relative wind turbine generator system.

Preferably, a space is reserved between the end faces of the positioning block and the limiting column, and one end, facing the second fixing seat, of the positioning block is arc-shaped. Through the guide of circle bench section, spacing post can realize pegging graft with the spacing groove fast and conveniently, but the locating piece can not directly accomplish the alignment grafting with the constant head tank, consequently set up one section interval between locating piece and spacing post terminal surface, can guarantee that the tip part of spacing post can insert a part in the spacing groove, realizes radially spacing to the second fixing base, prevents that the second fixing base from taking place radial runout again relative to first fixing base. Secondly, the end part of the positioning block is arc-shaped, so that the contact area between the positioning block and the surface of the second fixing seat can be reduced, friction between the positioning block and the second fixing seat is reduced in the process of rotating the limiting column, and alignment operation of the positioning block and the positioning groove is facilitated.

Compared with the prior art, the invention has the following beneficial effects:

1. by arranging the circular table section, when the limit post and the limit groove are aligned and spliced, the diameter of the end part of the circular table section is far smaller than the inner diameter of the limit groove, so that the central axis pair Ji Cai of the limit post and the central axis pair Ji Cai of the limit groove is not needed, after the circular table section is inserted into the limit groove, the circular table section is matched with the inner wall of the limit groove to play a role in guiding the second fixing seat, and the limit post can be quickly and conveniently spliced into the limit groove;

2. the driving mechanism drives the limiting column to rotate, so that the positioning block and the positioning groove can be rapidly aligned and inserted, and the blades cannot rotate circumferentially relative to the limiting column;

3. the driving mechanism drives the limiting column to rotate relative to the first fixing seat, so that after the corresponding splicing of the limiting column, the positioning block, the limiting groove and the positioning groove is completed, the driving mechanism stops moving, the limiting column is fixed relative to the first fixing seat, the second fixing seat is fixed relative to the first fixing seat, the screwing and fastening operation of the subsequent bolts is facilitated, and the assembly difficulty of the blades and the wind turbine generator is reduced.

Drawings

FIG. 1 is a schematic view of a connection device for assembling a blade with a wind turbine;

FIG. 2 is a schematic view of the connection device after assembly;

FIG. 3 is a front view of a second flange in accordance with the present invention;

FIG. 4 is a radial cross-sectional view of the retention plate and post of the present invention;

FIG. 5 is an enlarged schematic view of portion A of FIG. 4;

FIG. 6 is a schematic view of the structure of the first bolt, the second bolt and the fixing ring according to the present invention.

Wherein: 1. the first flange plate, 10, the first fixing seat, 100, the limit post, 101, the round table section, 102, the locating block, 103, the annular protrusion, 11, the fixed disk, 110, the open slot, 111, the limit ring slot, 112, the containing cavity, 12, the fixed cover, 13, the first welding block, 2, the second flange plate, 20, the second fixing seat, 200, the limit slot, 201, the locating slot, 202, the containing slot, 21, the second welding block, 22, the fixed ring, 3, the driving mechanism, 30, the driving motor, 31, the driving fluted disk, 32, the gear ring, 4, the first bolt and 5, the second bolt.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The embodiments described below by referring to the drawings are illustrative and intended to explain the present invention and should not be construed as limiting the invention.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element in question must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention.

In the present invention, the terms "first", "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. The terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; may be mechanically connected, may be electrically connected or may be in communication with each other; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances. In addition, the meaning of "plurality" in the present invention means at least two, for example, two, three, etc., unless otherwise specifically defined.

Examples: as shown in fig. 1 and fig. 2, the connection device for assembling a blade and a wind turbine generator provided in this embodiment includes a first flange 1 fixedly connected with the wind turbine generator and a second flange 2 fixedly connected with the blade, a first fixing seat 10 is disposed on the first flange 1, a second fixing seat 20 is disposed on the second flange 2, the first fixing seat 10 is welded on the first flange 1, the second fixing seat 20 is welded on the second flange 2, and a plurality of reinforcing ribs are welded between the first fixing seat 10 and the first flange 1 and between the second fixing seat 20 and the second flange 2, so as to ensure connection stability. The first fixing seat 10 is rotatably connected with a limiting column 100, a circular table section 101 is arranged at the end part of the limiting column 100, and it should be noted that the circular table section 101 can be fixedly connected to the end part of the limiting column 100 in a welding or clamping manner, or the limiting column 100 and the circular table section 101 can be directly integrally formed and manufactured during processing, the diameter of the bottom surface of the circular table section 101 is the same as that of the limiting column 100, and then the diameter of the circular table section 101 gradually decreases along the direction from the bottom surface to the end surface of the circular table section 101. As shown in fig. 3, the second fixing seat 20 is provided with the limiting groove 200 for inserting the limiting column 100 and the circular truncated cone segment 101, so that when the limiting column 100 is aligned with the limiting groove 200, the diameter of the end part of the circular truncated cone segment 101 is far smaller than the inner diameter of the limiting groove 200, and therefore the central axis of the limiting column 100 and the central axis pair Ji Cai of the limiting groove 200 are not required to be inserted, after the circular truncated cone segment 101 is inserted into the limiting groove 200, the circular truncated cone segment 101 and the inner wall of the limiting groove 200 are matched to play a guiding role on the second fixing seat 20, and the limiting column 100 can be quickly and conveniently inserted into the limiting groove 200.

In this embodiment, the positioning blocks 102 are further disposed on the limiting post 100 along the circumferential direction, specifically, in this embodiment, four positioning blocks 102 are disposed, and are uniformly distributed along the circumferential direction of the limiting post 100, and positioning grooves 201 for inserting the positioning blocks 102 are further disposed on the side walls of the limiting grooves 200. The device further comprises a driving mechanism 3, wherein the driving mechanism 3 is connected with the limiting column 100 and used for driving the limiting column 100 to rotate relative to the first fixing seat 10. The driving mechanism 3 drives the limit post 100 to rotate, so that the positioning block 102 and the positioning groove 201 can be rapidly aligned and inserted, and the blade cannot rotate circumferentially relative to the limit post 100. In addition, the driving mechanism 3 drives the limit post 100 to rotate relative to the first fixing seat 10, so that after the limit post 100, the positioning block 102, the limit groove 200 and the positioning groove 201 are correspondingly inserted, the driving mechanism 3 stops acting, the limit post 100 can be controlled to be fixed relative to the first fixing seat 10, the second fixing seat 20 and the first fixing seat 10 are relatively fixed, the screwing and fastening operation of subsequent bolts is facilitated, and the assembly difficulty of the blades and the wind turbine generator is reduced.

As shown in fig. 4 and 5, in this embodiment, the rotation connection between the limit post 100 and the first fixing base 10 is achieved by the following structure, which is specifically described as follows: the first fixing seat 10 is provided with a fixing disc 11, the fixing disc 11 is provided with an open slot 110 for the rotation and insertion of the limit column 100, the end surface of the fixing disc 11 is provided with an annular slot communicated with the open slot 110 along the circumference of the open slot 110, the fixing disc 11 is detachably covered with a fixing cover 12, and the fixing cover 12 is provided with an avoidance through hole for avoiding the limit column 100 and the positioning block 102; the ring groove is matched with the inner surface of the fixed cover 12 to form a limiting ring groove 111, and the limiting column 100 is circumferentially provided with an annular protrusion 103 rotatably connected in the limiting ring groove 111. Like this spacing post 100 rotates through fixed disk 11 to be connected on first fixing base 10, and detachably connects between spacing post 100 and the fixed disk 11, and the dismouting of being convenient for, maintenance and maintenance to through spacing annular groove 111 to annular protrusion 103's spacing effect, can prevent that spacing post 100 from coming off from fixed disk 11.

In this embodiment, the driving mechanism 3 includes a driving motor 30 and a driving fluted disc 31 connected to an output shaft of the driving motor 30, an outer ring surface of the annular protrusion 103 is provided with a gear ring 32, a gap is formed between the gear ring 32 and a bottom end of the limiting ring groove 111, and part or all of the driving fluted disc 31 extends into the gap and is meshed with the gear ring 32 for transmission. The driving motor 30 controls the driving fluted disc 31 to rotate, and the driving fluted disc 31 is meshed with the gear ring 32 to drive the annular protrusion 103 to rotate, so that the limit post 100 can be driven to rotate relative to the fixed disc 11. When the driving motor 30 stops, the limit post 100 stops rotating and is fixed relative to the fixed disk 11. As shown in fig. 4 and fig. 5, the fixed disc 11 is provided with a receiving cavity 112 for receiving the driving mechanism 3, the driving mechanism 3 is located inside the fixed disc 11, and the second fixed seat 20 is provided with a receiving groove 202 for receiving the fixed disc 11. Therefore, the driving mechanism 3 does not protrude out of the fixed disc 11, and the attaching and fixing between the first fixed seat 10 and the second fixed seat 20 are not affected. Further, the driving mechanism 3 in the present embodiment further includes a remote controller for remotely controlling the start and stop of the driving motor 30. Therefore, an operator does not need to perform contact type operation on the driving motor 30, and the operator does not need to physically stretch out of the wind turbine generator to operate, so that the risk in the butt joint operation process can be obviously and effectively reduced, and the personal safety is practically guaranteed.

In this embodiment, a space is provided between the positioning block 102 and the end surface of the limiting post 100, and one end of the positioning block 102 facing the second fixing base 20 is arc-shaped. Through the guide of the circular table section 101, the limit post 100 can be quickly and conveniently inserted into the limit groove 200, but the positioning block 102 cannot be directly aligned with the positioning groove 201 for insertion, so that a certain interval is arranged between the positioning block 102 and the end surface of the limit post 100, the end part of the limit post 100 can be ensured to be inserted into a part of the limit groove 200, the radial limit of the second fixing seat 20 is realized, and radial runout of the second fixing seat 20 relative to the first fixing seat 10 is prevented. Secondly, the end part of the positioning block 102 is arc-shaped, so that the contact area between the positioning block 102 and the surface of the second fixing seat 20 can be reduced, friction between the positioning block 102 and the second fixing seat 20 is reduced in the process of rotating the limiting column 100, and the alignment operation of the positioning block 102 and the positioning groove 201 is facilitated.

The first fixing base 10 and the second fixing base 20 are fixedly connected through screw threads of bolts, if the bolts are loosened, axial shaking of the fan blade relative to the wind turbine is caused, disastrous results can be caused even when the fan blade rotates at a high speed in the wind, so that in order to reduce axial shaking of the fan blade relative to the wind turbine after assembly is completed, a first welding block 13 is arranged on one face, deviating from the second fixing base 20, of the first fixing base 10, a second welding block 21 is arranged on one face, deviating from the first fixing base 10, of the second fixing base 20, a fixing ring 22 is fixedly arranged on the second welding block 21, a first threaded hole is formed in each of the first welding block 13, the first fixing base 10, the second fixing base 20, the second welding block 21 and the fixing ring 22, a first bolt 4 is screwed in each of the first threaded holes, and the first bolt 4 is matched with the first threaded hole to fixedly connect the first fixing base 10 and the second fixing base 20. By additionally arranging the first welding block 13, the second welding block 21 and the fixing ring 22, the tightness of the threaded connection between the first fixing seat 10 and the second fixing seat 20 can be improved, and the possibility of loosening of the first fixing seat 10 and the second fixing seat 20 can be reduced to a certain extent.

Further, as shown in fig. 6, the first bolt 4 in this embodiment includes a screw, and second threaded holes are formed along the radial directions of the fixing ring 22 and the screw, and when the screw is screwed in the first threaded hole, the second threaded hole on the fixing ring 22 is communicated with the second threaded hole on the screw, the second threaded hole is screwed with the second bolt 5, and the second bolt 5 is matched with the second threaded hole to prevent the first bolt 4 from loosening. The second bolt 5 that adds to establish produces spacing effect along the screw rod axial to the screw rod, can prevent that the screw rod from producing the removal along the axial, and then can prevent that first bolt 4 from becoming flexible, effectively avoids taking place not hard up between first fixing base 10 and the second fixing base 20, and then avoids the fan blade to take place unexpected droing relative wind turbine generator system.

The above embodiments are merely examples of the present invention, but the technical features of the present invention are not limited thereto, and any changes or modifications made by those skilled in the art within the scope of the present invention are included in the scope of the present invention.

Claims (9)

1. A connecting device for blade and wind turbine generator system assembly, including be used for with wind turbine generator system fixed connection's first ring flange (1) and be used for with blade fixed connection's second ring flange (2), be equipped with first fixing base (10) on first ring flange (1), be equipped with second fixing base (20) on second ring flange (2), its characterized in that: the first fixing seat (10) is rotationally connected with a limit column (100), the end part of the limit column (100) is provided with a circular table section (101), the limit column (100) is also provided with a positioning block (102) along the circumferential direction, the second fixing seat (20) is provided with a limit groove (200) for inserting the limit column (100) and the circular table section (101), and the side wall of the limit groove (200) is also provided with a positioning groove (201) for inserting the positioning block (102);

the device further comprises a driving mechanism (3), wherein the driving mechanism (3) is connected with the limit column (100) and used for driving the limit column (100) to rotate relative to the first fixing seat (10); the space is reserved between the positioning block (102) and the end face of the limiting column (100), and one end, facing the second fixing seat (20), of the positioning block (102) is arc-shaped.

2. A connection device for assembling a blade with a wind turbine as defined in claim 1, wherein: the fixing device is characterized in that a fixing disc (11) is arranged on the first fixing seat (10), an opening groove (110) for the rotation and insertion of the limiting column (100) is formed in the fixing disc (11), a ring groove communicated with the opening groove (110) is formed in the end face of the fixing disc (11) along the circumference of the opening groove (110), a fixing cover (12) is detachably covered on the fixing disc (11), and an avoidance through hole for avoiding the limiting column (100) and the positioning block (102) is formed in the fixing cover (12);

the annular groove is matched with the inner surface of the fixed cover (12) to form a limiting annular groove (111), and the limiting column (100) is circumferentially provided with an annular protrusion (103) rotationally connected in the limiting annular groove (111).

3. A connection device for assembling a blade with a wind turbine as claimed in claim 2, wherein: the driving mechanism (3) comprises a driving motor (30) and a driving fluted disc (31) connected to an output shaft of the driving motor (30), a gear ring (32) is arranged on the outer ring surface of the annular bulge (103), a gap is formed between the gear ring (32) and the bottom end of the limiting ring groove (111), and part or all of the driving fluted disc (31) stretches into the gap and is meshed with the gear ring (32) for transmission.

4. A connection device for assembling a blade with a wind turbine according to claim 3, characterized in that: the fixed disc (11) is provided with a containing cavity (112) for containing the driving mechanism (3), and the driving mechanism (3) is positioned inside the fixed disc (11).

5. A connection device for assembling a blade with a wind turbine as in claim 4, wherein: the second fixing seat (20) is provided with a containing groove (202) for containing the fixing disc (11).

6. A connection device for assembling a blade with a wind turbine according to claim 3, characterized in that: the driving mechanism (3) further comprises a remote controller for remotely controlling the start and stop of the driving motor (30).

7. A connection device for assembling a blade with a wind turbine as defined in claim 1, wherein: the first fixing seat (10) and the second fixing seat (20) are fixedly connected through bolt threads.

8. The connection device for assembling a blade with a wind turbine of claim 7, wherein: the one side that first fixing base (10) deviate from second fixing base (20) is equipped with first welding piece (13), the one side that second fixing base (20) deviate from first fixing base (10) is equipped with second welding piece (21), fixed solid fixed ring (22) that are equipped with on second welding piece (21), first screw hole that communicates has been seted up on first welding piece (13), first fixing base (10), second fixing base (20), second welding piece (21) and solid fixed ring (22), first screw hole internal rotation has first bolt (4), first bolt (4) and first screw hole cooperation are with first fixing base (10) and second fixing base (20) screw thread fixed connection.

9. The connection device for assembling a blade with a wind turbine of claim 8, wherein: the first bolt (4) comprises a screw rod, second threaded holes are formed in the radial directions of the fixing ring (22) and the screw rod, when the screw rod is screwed in the first threaded holes, the second threaded holes in the fixing ring (22) are communicated with the second threaded holes in the screw rod, the second threaded holes are internally screwed with second bolts (5), and the second bolts (5) are matched with the second threaded holes to prevent the first bolts (4) from loosening.