EP2951358B1

EP2951358B1 - Vibrator, bucket and vibration method

Info

Publication number: EP2951358B1
Application number: EP14745988.7A
Authority: EP
Inventors: Eero Paski
Original assignee: Pohmako Ky
Current assignee: Pohmako Ky
Priority date: 2013-02-01
Filing date: 2014-01-22
Publication date: 2018-07-18
Anticipated expiration: 2034-01-22
Also published as: FI124431B; EP2951358A4; FI20135100A; WO2014118429A1; EP2951358A1

Description

Background of the invention

The invention relates to a vibrator by means of which a vibrating motion needed for screening may be generated.
The invention further relates to a work machine bucket, the bottom of which comprises bars spaced apart from each other, and a vibrator to vibrate the bucket. With a bucket like this it is possible to sort material to be treated according to its grain size.
In addition, the invention relates to a vibration method in which vibrating motion is generated and transmitted to a screen part for processing and sorting material.
The field of the invention is described in more detail in the preambles of the independent claims of the application.
Soil materials may be processed by means of earth-moving machines. An earth-moving machine may be equipped with a screen bucket so that soil material can be sorted during handling. The screen bucket includes a plurality of mutually spaced bars, between which there are gaps of desired size, through which gaps finer material will be able to fall out of the bucket and material having a larger particle size will remain in the bucket. Attempts have been made to enhance the sorting by mounting on the bucket a vibrator that makes the bucket vibrate. However, the present-day vibrators are found to have shortcomings in efficiency and operation. Document US-2012/279904-A1 discloses a separating device for processing soil plug material by means of a rotary sieve drum.

Brief description of the invention

It is an object of the invention to provide a novel and improved vibrator, bucket and vibration method.
The vibrator according to the invention is characterized by the characterizing features of independent apparatus claim 1.
The bucket according to the invention is characterized in that the bucket is provided with a vibrator which is in accordance with the first independent claim of the application.
The method according to the invention is characterized by the characterizing features of independent method claim.
The idea of the solution put forth is that the vibrating motion is created by means of the rotating vibrator element and a separate mating surface that is in contact with it. The outer surface of the vibrator element comprises surfaces at distances from the rotating axle, which are directed towards the mating surface of the vibrator. The shape line of the vibrator element runs, as it is rotating, at distances from the rotating axle. When a vibrator element of this type is rotated around the rotating axle, the rotating outer surface of the vibrator element causes motion on the mating surface arranged against it. This vibrating motion is transferred from the mating surface to the screen surface, screen mesh or similar, arranged in the screening unit.
A further idea is that the mating surface is a cylindrical surface. The mating surface may be a roll which is fitted with a bearing, either to turn or to rotate in relation to its pivoted axle. The pivoted axle of the cylindrical mating surface is parallel to the rotating axle of the rotation device, but located at a distance from it. As the mating surface has a curved outer surface, and further, as it is arranged to turn or to rotate, it can better withstand the wear and tear caused by physical contact.
One of the benefits of the described solution is that the vibrator is more efficient than the vibrators most commonly used in the field, which are based on rotating an eccentric weight. The screening rate of the screening unit may be improved with the aid of the presented vibrator. In addition, an efficient vibrator may be of help in the screening of materials difficult to sort. Compared to the typical eccentric-type vibrators, the performance of the vibrator described in the solution is considerably less affected by the mass of the material which is to be screened and which is on the screening portion, and the loading it causes. The vibration motion is namely generated by means of the physical contact between the vibrator element and the mating surface, whereby the vibrating motion is generated forcedly. If the power of the rotation device is designed to be high enough, the formation of the vibrating motion is guaranteed.
Furthermore, the vibrator according to the solution is relatively simple as to its structure and operation, but it can still be used to make diversified vibrating motions. Because the structure is simple, it is also durable, reliable, and economical to produce.
The idea of the invention is that the outer surface of the vibrator element is round. However, the round outer surface of the vibrator element is arranged eccentrically in relation to the rotating axle. In such a case, the outer surface of the vibrator element runs, as it is rotating, at distances and creates motion on the mating surface. By designing the size of the outer surface diameter of the vibrator element and the magnitude of the eccentricity of the outer surface, the intensity of the established vibrating motion may be affected. One of the benefits of a round vibrator element is its easy manufacturability. It is also worth mentioning that compared with the conventional eccentric-type vibrator, the mass of the vibrator element eccentrically rotated in this solution is relatively small, and the mass is not designed to create vibrating motion. The vibrating motion is generated by means of the physical contact between the eccentrically moving outer shell of the vibrator element and the mating surface arranged against it. So, in this solution it is conversely advantageous, if the mass of the vibrator element and the eccentricity of the mass are as small as possible, because this fact helps the rotating of the vibrator element and fitting it with a bearing, for example.
The idea of the invention is that the shape of the outer surface of the vibrator element is oval or ellipse. Such an oval surface can be arranged in the rotating axle either eccentrically or centrally.
Additional examples may include that the vibrator comprises two or more vibrator elements, each of which may independently be switched to rotate or not to rotate by means of a clutch or other selector. In such a case, a suitable vibrator element for any situation may be selected and used to establish the required vibrating motion at the same time as the alternative vibrator elements are turned out of operation.
Additional examples may include that the vibrator element is a replaceable component, which can easily and quickly be replaced when different kind of vibrating motions and vibrating effects are desired. This embodiment also makes the device easier to service. The vibrator element may be mounted to the rotating axle by quick coupling means, a bolted joint, or a locking pin.
Additional examples may include that the mating surface and the outer surface or the outer shell of the vibrator element may be face-hardened, coated with wear-resistant material, or made of wear-resistant material.
Additional examples may include that the mating surface comprises, on its outer surface, a surface layer which is of compressible and shock-absorbing material, such as rubber, polyurethane, or similar. A surface layer of adequate thickness may be vulcanised, cast, or otherwise formed on the outer surface of the roll-like mating surface. The surface layer can absorb the point load directed on the mating surface by the vibrator element, making the mating surface and possibly also the transmission member withstand use longer.
Additional examples may include that the mating surface comprises a ring-shaped body part the outer surface of which is towards the vibrator element. The body part may be formed out of metal. Between the ring-shaped body part and the rotating axle there is an intermediate part, which may be of compressible and shock-absorbing material, such as rubber, polyurethane, or similar. Alternatively, the intermediate part is on the portion between the ring-shaped body part and the bearing of the mating surface. The intermediate part may be, for example, vulcanised or cast between the components. The intermediate part may act as an absorbing element in the structure of the mating surface. Due to the absorbing intermediate part, the mating surface and possibly the transmission member, too, can withstand use for a longer period of time.
Additional examples may include that the mating surface is arranged to track the outer surface of the vibrator element when it is rotating and to be in contact with the contour. So, the mating surface is constantly adapting to the motion of the outer surface of the vibrator element.
Additional examples may include that the outer surface of the vibrator element, as it is rotating, is arranged to strike the mating surface and to generate impact pulses on the mating surface. It is possible to form sharp cams or angles on the outer surface or the vibrator element, whereby the mating surface is not able to constantly track the outer surface of the vibrator element. Furthermore, the rotating speed may be set at such a high level that the outer surface of the vibrator element and the mating surface are briefly and deliberately made to lose contact. At the time contact again returns between these surfaces, an impact pulse is created on the mating surface, which impact pulse is forwarded to the screen part, or similar. The impact pulses may be used to enhance screening, if needed, and in special circumstances if the screen is blocked or when difficult materials are being processed.
Additional examples may include that the vibrator comprises two or more vibrator elements arranged on the same rotating axle and rotated by the same rotation device. In such a case, the vibrator elements share the operational equipment. The vibrator elements arranged on the same rotating axle may be mutually identical or, if needed, mutually different. Furthermore, if the vibrator elements are mutually identical to one another they may be coupled to the rotating axle in mutually the same manner, that is, in the same position so that each of them generates the same kind of and simultaneous vibrating motion. Therefore, the vibrator elements may be in the same line as seen from the direction of the rotating axle. Alternatively, vibrator elements identical to each other may be coupled to the rotating axle in a mutually different way, in different positions, for example, whereby the vibrating motions the vibration units generate differ from each other. Vibrator elements that the same rotating axle uses may be rotated in relation to one another to the extent of the desired angle around the rotating axle, for example, 45° or 90°.
Additional examples may include that the vibrator comprises a pressure-medium-operated rotation device arranged to rotate a rotating axle as well as one or more vibrator elements on it. The rotation device may be a hydraulic motor the rotating speed of which may be continuously adjusted by means of hydraulic fluid transmitted to the rotation device. A benefit of a hydraulic motor is that it is efficient considering its size, and it is durable and economically priced. Pressure medium is also readily available in work machines and their booms, whereby it is simple to arrange feed of driving power to the pressure-medium-operated vibrator device.
Additional examples may include that the vibrating motion is generated on the screen surface by means of a single vibrator. The vibrator is any of the devices described in this application.
Additional examples may include that the vibrating motion is generated on the screen surface by means of a plurality of vibrators. There may be two, three, four, or even more vibrators. The vibrator is any of the devices described in this application. The vibrating motions generated with vibrators may be directed in the same direction, or they may alternatively be arranged so that the screen surface is made to move in several, different directions.
Additional examples may include that the vibrator is arranged in the bucket of an excavator, wheel loader, or similar work machine. The vibrator may be mounted on the backplate of the bucket frame. The bucket can be a screen bucket comprising a screen portion with a plurality of bars next to each other.
Additional examples may include that the vibrator is arranged in the screen bucket, which, in its screen part, has a plurality of bars and gaps in between the bars. Further, the mating surface of the vibrator is arranged in a pivot arm, which is arranged to transmit the vibrating motion to one or more bars in the screen part, whereby the bar being vibrated moves in relation to the bucket. On the portion of the free end of the pivot arm, a turning roll-like mating surface may be arranged.
Additional examples may include that the screen part of the bucket has a vibrated portion, where the vibrating motion from the vibrator is directed to every other bar in the vibrated portion. In that case, the vibrated portion has alternately a vibrated bar and a non-vibrated bar.
Additional examples may include that the screen part of the bucket has a vibrated portion comprising a plurality of adjacent bars which are all vibrated using one or more vibrators.
Additional examples may include that the screen part has a vibrated portion where adjacent bars are mutually vibrated in the same manner. The vibrating motion may be transmitted to the bars to be vibrated from one common vibrator.
Additional examples may include that the screen part has a vibrated portion where adjacent bars are vibrated differently in relation to one another. In that case, every second bar may be vibrated using different force, different pace, different frequency, or the direction of the vibrating motion may be different. The adjacent bars to be vibrated differently may further improve the sorting capacity of the bucket. In addition, the required vibration effect may be provided using lower intensity of vibration. Further, this solution enables less vibration being transmitted to the work machine.
Additional examples may include that a vibrator is used to generate the vibrating motion for a flat screen and, in particular, for its screen mesh. There may be one of more vibrators which are used to move the screen mesh in the vertical or horizontal direction, or both in the vertical and horizontal directions.
Additional examples may include that a vibrator may be utilised for vibrating any screen, screen part, screen mesh, or sorting surface in the desired direction.
The embodiments described above and features disclosed in connection with them may be combined to achieve a desired combination of characteristics and features.

Brief description of the figures

Some embodiments are explained in more detail in the accompanying drawings, in which

Figure 1 is a schematic side view of a work machine having a boom equipped with a screen bucket,
Figure 2 is a schematic side view of a bucket,
Figure 3 is a schematic top view of a bucket,
Figure 4 is a schematic side view of a transmission member by which vibration may be transmitted to bars in a screen part from the vibrator, and
Figures 5 - 9 are schematic views of vibrators and their vibrator elements as seen from the direction of the rotating axle; and
Figure 10 is a schematic view of a vibrator on the rotating axle of which two vibrator elements, turned 45° in relation to each other, have been arranged.

For the sake of clarity, the figures show some embodiments in a simplified manner. Similar parts are in the figures identified by the same reference numbers.

Detailed description of some embodiments

Figure 1 shows a work machine 1 having a boom 2 equipped with a screen bucket 3. The work machine 1 may be an excavator as shown in the figure, or it may also be a wheel loader or a similar earth-moving machine, or another vehicle employing a bucket. The screen bucket 3 allows transfer and treatment of soil material having particles of various sizes. For instance, the screen bucket 3 may separate larger stones 5, roots and other dispensable material from soil 4 or sand. The screen bucket 3 has a screen part 6 which has a plurality of parallel bars 7. Soil 4 and similar material with a smaller particle size drops through the gaps between the bars 7 and exits the screen bucket 3. Instead, stones 5 or other material having a larger particle size remains in the screen bucket 3 and it may be removed via the bucket orifice after the material of smaller particle size is sorted out. Sorting can be enhanced by vibrating V the bars 7 of the screen bucket 3. Vibrating V of the bars 7 causes substantially less vibration to the boom 2, the cabin 8 and other structures of the work machine 1 than solutions in which the whole bucket is vibrated. Thus, the operational comfort of the screen bucket 3 is better and the structures are subjected to less loading. In addition, because the mass to be vibrated is smaller in the bars 7 than in the whole bucket, sufficient vibration may be achieved by lower vibration force, and consequently vibration means may be smaller in size and less costly in price. Figure 1 further shows that the bucket 3 comprises engagement members 9 wherewith the bucket 3 may be attached to the boom 2 or other attachment point in the work machine 1.
Figure 2 shows a screen bucket 3 in side view. The bucket 3 comprises a bottom 10, side plates 11 or side walls, and a back plate 12 or a back wall. Further, the bucket 3 has an orifice 13, through which material to be treated is introduced into the cuplike bucket 3, and wherefrom screening reject, i.e. material of larger particle size, is removed at the end of the processing. The bottom 3 of the bucket may be provided with a lip plate 14 in the brim portion of the orifice 13. Typically, the bucket 3 is made of plate material utilizing sheet metal work methods and welding methods.
The bucket 3 is provided with a screen part 6 that may be at the bottom 10. The whole bottom 10 may constitute a screen, whereby the bars 7 form the bottom of the bucket. Alternatively, part of the bottom 10 may be the screen part 6 and part a solid plate structure, for instance. The screen part 6 comprises one or more vibrated portions 15 having one or more bars 7 which are subjected to vibration V by the vibrator 16.
The vibrator 16 comprises a vibrator element 17, which is rotated in relation to a rotating axle 19 with the aid of a rotation device 18. The vibrator element 17, rotation device 18, and rotating axle 19 may be attached to the back plate 12 of the bucket 3 by means of a bracket of similar support means 40. The vibrator 16 further comprises a mating surface 20, which may be a roll-like piece supported to a pivot arm or similar transmission member 21 by means of which the vibrating motion V is transmitted to the vibrated bars 7. The transmission member 21 may be, for instance, a rigid rod that is connected to selected bars 7. The vibrating motion V can be generated by, for example, rotating the vibrator element 17, arranged eccentrically, whereby the mating surface 20, which is arranged against the outer surface of the vibrator element 17, moves. Alternatively, the outer surface of the vibrator element 17 may comprise angles, cams, curved surfaces or be rotationally asymmetric in some other way.
Further still, it can be seen in Figure 2 that the bars 7 may be arranged through the openings 22, 23 in the side plates 11. Thus, the side plates 11 carry the bars 7. The axial movement of the bars 7 may be prevented by means of retainer members 24. In Figure 3, the plate serving as the retainer member 24 is illustrated by broken lines. In the vibrated portion 15 the openings 22 in the side plates 11 may be dimensioned larger than the bars 7 so that they do not hinder the vibrating motion V of the bars 7. In addition, the openings 22 may be designed by taking the vibrating motion V into account. When bars having a round cross section are used, the openings 22 may be elongated in shape, for instance oval. The bars not to be vibrated in the screen part 6 may be connected to the side plates 11 with the opening 23 having a cross section in accordance with the bars. The size of the screen gaps S in the screen part 6 may be adjusted by removing bars from the bucket 3 or by adding bars thereto. Figure 3 below illustrates this adjustment by arrows K.
Figure 3 shows another vibrator 16. There may be two vibrator elements 17a and 17b arranged to be driven by the same rotation device 18 and the same rotating axle 19, against which mating surfaces 20a and 20b are arranged. In such a case, two vibrating motions, V1 and V2, may be generated by the same rotation equipment, to be transmitted by the two transmission members 21a and 21b to the bars of the vibrated portion 15 of the bucket. It should be mentioned that the first vibrating motion V1 and the second vibrating motion V2 may be synchronized to take place simultaneously or nonsimultaneously. The synchronization may be accomplished by setting the vibrator elements 17a, 17b in the same line or different lines on the rotating axle 19.
The first vibrator element 17a may be connected to vibrate every second bar in the vibrated portion 15, the bars being indicated by reference a, and correspondingly, the second vibrator element 17b may be arranged to vibrate every other bar b. Therefore, the vibrated portion 15 may have bars a and b side by side, which are mutually vibrated in the same or different way. This makes it possible that the bars a and b may be vibrated at different pace, with different intensity and at a different frequency.
Figure 4 shows a transmission member 21a that may be a rod-like piece, the shape of which corresponds to the shape of the bottom of the bucket. Thus, the transmission member 21a may be, for instance, a curved bar as shown in the figure, which may be formed by cutting from plate material. The transmission member 21a shown in Figure 4 may be arranged to be affected by the first vibrator element 17a in the arrangement of Figure 3. In such a case, the vibrating motion V1 is only transmitted to the bars a by the transmission member 21a in question. In the transmission member 21a, at least in the vibrated portion 15, there are alternately first openings 25 and second openings 26, of which just some are indicated in the figure with reference numbers. The first openings 25 are dimensioned and shaped in accordance with the bars such that the vibration motion V1 is transmitted from the transmission member 21a to the bars a. Instead, the second openings 26 are dimensioned and shaped such that the vibration motion is not transmitted from the loose openings to the bars b. In the transmission member 21b in contact with the second vibrator element 17b, the openings 25, 26 are in reverse order so that the vibration motion V2 is transmitted to the bars b, only.
In the following, Figures 5 - 10 show the structure and operating principle of some vibrators in a pronouncedly simplified form for the sake of clarity.
Figures 5 and 6 disclose a vibrator 16 the outer surface of a vibrator element 17 of which has a round shape. This round vibrator element 17 is eccentrically connected to a rotating axle 19, whereby its outer surface is at unequal distances R from the rotating axle 19, which is illustrated by arrows. The vibrator element 17 is rotated P as shown by the arrow, whereby its eccentric outer surface causes a vibrating motion V on a mating surface 20 which is in contact with the outer surface of the vibrator element 17. The mating surface 20 may be a roll, round bar, or another piece with a cylindrical outer surface, which is arranged to turn on a pivoted axle 27. The motion received by the mating surface 20 may be transmitted by means of the transmission member 21a to a screen portion 28, which may be a part of a flat screen, screen bucket, or any screening device. By comparing Figures 5 and 6, it is possible to observe the vibrating motion V created by the eccentrically arranged vibrator element 17.
Figure 5a shows a mating surface 20 that comprises, on its outer surface, a surface layer C which may be of compressible and shock-absorbing material, such as rubber, polyurethane, or similar. A surface layer C of adequate thickness may be vulcanised, cast, or otherwise formed on the outer surface of the roll-like mating surface 20 to absorb the loading that the mating surface 20 is subjected to.
Figure 5b illustrates a mating surface 20 that comprises a ring-shaped body part 20a the outer surface of which is towards the vibrator element. The body part 20a may be formed out of metal. Between the ring-shaped body part 20a and the rotating axle 27 there is an intermediate part D, which may be of compressible and shock-absorbing material, such as rubber, polyurethane, or similar. Alternatively, the intermediate part is on the portion between the ring-shaped body part and the bearing of the mating surface. The intermediate part may be, for example, vulcanised or cast between the components. The intermediate part may act as an absorbing element in the structure of the mating surface. Furthermore, it is possible to apply the surface layer C and the intermediate part D as absorbing elements in the mating surface 20.
The solution shown in Figure 7 deviates from Figures 5 and 6 in that the vibrator element 17 has an elliptical shape. This type of a piece also possesses surfaces at unequal distance R from the rotating axle 19, these surfaces generating motion on the mating surface 20 as the vibrator element 17 is rotated P.
Figure 8 adheres to the principles put forth in the above, but deviates from the embodiment of Figures 5 - 7 in the above in that the vibrator element 17 is a triangular piece that comprises three cams 29. The triangular piece obviously has surfaces at unequal distance R.
Figure 9 shows a vibrator element 17, which has four cams 29 and the outer surface of which comprises surfaces at unequal distance R from the rotating axle 19.
Figure 10 shows a vibrator 16 that has two vibrator elements 17a and 17b arranged on the same rotating axle 19, the two vibrator elements being at a 45° angle in relation to each other. The quantity, mutual angular position, and shape of the vibrator elements 17 can be chosen according to the vibration needs. Two or more vibrator elements 17 may affect the same mating surface 20, or alternatively each of them may affect a dedicated mating surface 20.
It should be mentioned that, deviating from Figures 5 - 10, the mating surface 20 may be arranged directly in the screening portion 28 whereby a separate transmission member 21 is not needed, or at least the transmission member need not be a bar-like piece in shape, as illustrated by the figures. Furthermore, in all of the above embodiments, a mating surface 20 may be utilised, which is not arranged to turn. In addition, the outer surface of the mating surface 20 may in such a case be another surface than cylindrical.
In some cases, features disclosed in this application may be used as such, regardless of other features. On the other hand, when necessary, features disclosed in this application may be combined in order to provide different combinations.
The drawings and the related description are only intended to illustrate the idea of the invention. Details of the invention may vary within the scope of the claims.

Claims

A vibrator (16) for generating vibration motion for a screening part (6), the vibrator comprising:
a rotation device (18); and

at least one vibrator element (17), which is arranged to be rotated by the rotation device (18);

and where rotating (P) the vibrator element (17) around a rotating axle (19) of the rotation device (18) is arranged to generate vibration;

the vibrator element (17) has an outer surface around said rotating axle (19);

the vibrator (16) comprises at least one mating surface (20), which is a separate piece in relation to the outer surface of the vibrator element (17), and which is in physical contact with the outer surface of the vibrator element (17); and

the outer surface of the rotating (P) vibrator element (17) moves the mating surface (20) in contact with it, and generates vibrating motion (V);

whereby the mating surface (20) is a cylindrical surface; and

the mating surface (20) is arranged to turn in relation to a pivoted axle (27) which is parallel to the rotating axle (19) of the rotation device (18), but located at a distance from it;

characterised in that

the outer surface of the vibrator element (17) is round in shape and the round outer surface of the vibrator element (17) is arranged eccentrically in relation to the rotating axle (19),

or in that the outer surface of the vibrator element (17) is ellipse in shape.
The vibrator as claimed in claim 1, characterised in that the mating surface (20) is arranged to track the outer surface of the vibrator element (17) when it is rotating (P) and to be in contact with its contour.
The vibrator as claimed in claim 1 or 2, characterised in that
the outer surface of the vibrator element (17), as it is rotating (P), is arranged to strike the mating surface (20) and to generate impact pulses on the mating surface (20).
The vibrator as claimed in any one of the preceding claims, characterised in that
the vibrator (16) comprises at least two vibrator elements (17a, 17b) arranged on the same rotating axle (19) and to be rotated by the same rotation device (18).
A bucket comprising:
a bottom (10);

side plates (11) on opposite edges of the bottom (10);

a back plate (12);

engagement members (9) with which the bucket (3) is connectable to a work machine (1);

at least one screen part (6) which comprises a plurality of bars (7) arranged at a distance from one another in such a way that between adjacent bars (7) there will be screen gaps (S) and the bars (7) form a screen; and

at least one vibrator (16) for directing vibration to the bucket (3);

characterised in that

the vibrator (16) is a vibrator according to claim 1.
The bucket as claimed in claim 5, characterised in that the mating surface (20) of the vibrator (16) is arranged in a transmission member (21), which is arranged to direct the vibrating motion (V) directly to at least one bar (7) in the screen part (6), whereby said at least one bar (7) to be vibrated moves in relation to the bucket (3).
A vibration method, comprising the following steps:
vibrating motion (V) is generated by means of a vibrator (16) according to claim 1, which comprises a rotation device (18) and at least one vibrator element (17);

the vibrator element (17) is rotated (P) with the aid of the rotation device (18) around a rotating axle (19) of the rotation device to generate vibrating motion (V);

the generated vibration motion (V) is transmitted to at least one screen part (28) to treat material;

arranging at least one mating surface (20) against the outer surface of the vibrator element (17);

using a cylindrical mating surface (20), which is allowed to turn in relation to the pivoted axle (27);

moving the mating surface (20) by means of the outer surface of the vibrator element (17), whereby vibrating motion (V) is generated on the mating surface (20), and

transmitting the vibrating motion (V) to the screen part (28) from the mating surface (20);