CN220055147U - Scraper conveying system, scraper and rolling body - Google Patents

Abstract

The utility model relates to the technical field of material conveying devices, in particular to a scraper conveying system, which comprises: a material conveying groove; an endless chain; a scraper body; the rolling body is arranged in the fixing hole; the spraying device comprises a spraying part arranged in the lower groove cavity, and the spraying part can spray towards the lower groove cavity. The utility model also provides a scraper and a rolling body, which can effectively spray and clean the rolling body through optimizing and improving the structure, and effectively solve the problems in the prior art.

Description

Scraper conveying system, scraper and rolling body

Technical Field

The utility model relates to the technical field of material conveying devices, in particular to a scraper conveying system, a scraper and a rolling body.

Background

The scraper conveyor system is a conveyor for conveying coal and materials, and generally comprises an annular chain and a scraper mounted on the annular chain, wherein the annular chain can drive the scraper to move on a material conveying groove of the scraper conveyor system. For reducing the friction loss of scraper blade and material conveyer trough, the bottom of current scraper blade is equipped with the rolling element, and the rolling element includes the shell and can be at the rolling ball in the shell, and the ball has the bottom side that partially stretches out the shell to can roll on the material conveyer trough, in order to change the sliding friction between scraper blade and the material conveyer trough into rolling friction, and then reduce the running resistance of scraper blade, and reduce wearing and tearing.

But scraper blade conveying system uses under environment cleanliness relatively poor scene such as colliery generally, and impurity such as general coal dust, mud have on the material conveyer trough, and the scraper blade is in the operation in-process, and the impurity gets into in the shell easily. After long-time use, the impurity accumulated in the shell can increase the rolling resistance of the balls, and even the balls can be clamped in the shell to be difficult to rotate, so that the normal use of the equipment is affected.

The applicant discloses a scraper conveyor, a scraper and a rolling body in a prior application number 202111234483.8, and by optimally arranging a scraper structure and a rolling body structure and spraying and cleaning the scraper at the tail of a machine head, the problem of scraper blockage can be solved, but in scraper conveying systems such as a reversed loader, a high-speed scraper conveyor and the like, the direction of further optimizing and improving the spraying and cleaning effect on the scraper is still needed.

Disclosure of Invention

In order to solve the technical problems, the utility model provides a scraper conveying system, a scraper and a rolling body, and the problems in the prior art are effectively solved.

In order to solve the above-described problems, the present utility model provides a blade conveying system including: the material conveying groove is provided with an upper groove cavity and a lower groove cavity; the annular chain can rotate around the material conveying groove, and the annular chain extends in the upper groove cavity and the lower groove cavity in a rotating mode; the scraper body is arranged on the annular chain, a fixing hole and a sewage draining hole which are communicated with each other are formed in the scraper body, and the fixing hole and the sewage draining hole penetrate through the scraper body; the rolling body is arranged in the fixing hole and comprises a shell and a ball, an installation cavity is formed in the shell, the ball is arranged in the installation cavity, a part of the ball extends out of the bottom side of the shell, and the shell is provided with a communication hole for communicating the installation cavity with the sewage draining hole; the spraying device comprises a spraying part arranged in the lower groove cavity, and the spraying part can spray towards the lower groove cavity.

Further, the spraying part is arranged on the side wall of the lower groove cavity.

Further, the material conveying groove is provided with a through mounting hole on the side wall of the lower groove cavity, and the spraying part is mounted in the mounting hole.

Further, the spraying part is arranged as an atomization spraying head.

Further, along the extending direction of the material conveying groove, a plurality of spraying parts are arranged at intervals.

Further, the spraying device comprises liquid supply pipes, each spraying part is fixedly arranged on the liquid supply pipe, and the liquid supply pipes are fixedly arranged on the side walls of the material conveying grooves.

The utility model also provides a scraper, comprising: the scraper body is provided with a supporting surface, a material facing side surface and a material backing side surface which are oppositely arranged, a fixing hole and a pollution discharge hole which are mutually communicated are formed in the scraper body, the fixing Kong Kaishe is arranged on the supporting surface of the scraper body, and the pollution discharge hole at least penetrates through the material backing side surface of the scraper body; the rolling body is arranged in the fixing hole, the rolling body comprises a shell and a ball, an installation cavity is formed in the shell, the ball is arranged in the installation cavity, a part of the ball extends out of the bottom side of the shell, and the shell is provided with a communication hole which is communicated with the installation cavity and the sewage draining hole.

Further, the top surface and the side surface of the housing are respectively provided with the communication holes.

Further, the scraper body is provided with the drain holes at intervals along the height direction of the scraper body on the side surface of the backing material, one drain hole is communicated with the communication hole on the top surface of the shell, and the other drain hole is communicated with the drain hole on the side surface of the shell; or the scraper body is provided with the drain hole on the side surface of the back material, and the drain hole is simultaneously communicated with the communication hole on the top surface and the side surface of the shell.

The utility model also provides a rolling body, which comprises a shell and balls, wherein a mounting cavity is formed in the shell, the balls are mounted in the mounting cavity, some balls extend out of the bottom side of the shell, the top surface and the side surface of the shell are respectively provided with a communication hole, and the communication holes are communicated with the inner side and the outer side of the mounting cavity.

The utility model has the beneficial effects that when the scraper body moves into the lower groove cavity, the spraying device can spray the sewage draining hole of the scraper body. The sprayed water flow can dilute impurities in the scraper body and the rolling body, so that the impurities become fluid, and the fluid impurities are easier to discharge from the sewage draining hole. The lower groove cavity has sufficient installation space in the length direction, more flexible and more spraying installation positions can be provided, the spraying effect and the spraying times are easy to adjust, and further the spraying cleaning effect is further improved; the lower groove cavity is relatively closed and has smaller space, and spray water is dispersed in the lower groove cavity to be easier to surge to generate water mist and a water curtain by spraying, so that the scraping plate is soaked by the water mist and is leached by the water curtain in the moving process; through spraying at the lower groove cavity, can also make the shower water carry out supplementary clearance to the lower groove cavity to take away the impurity foreign matter in the lower groove cavity. The utility model effectively solves the problems existing in the prior art.

Drawings

The accompanying drawings, which are included to provide a further understanding of the utility model and are incorporated in and constitute a part of this specification, illustrate embodiments of the utility model and together with the description serve to explain the utility model and do not constitute a limitation on the utility model. In the drawings:

fig. 1 is a schematic perspective view of a scraper conveyor system according to an embodiment of the utility model.

FIG. 2 is a schematic cross-sectional view of the embodiment of FIG. 1 with the endless chain removed from the material conveying trough.

Fig. 3 is a schematic view of a partial enlarged structure at a in fig. 2.

Fig. 4 is a left side view in section from the perspective of fig. 2.

Fig. 5 is a schematic view of the structure of the B-B forward scraper body of fig. 4.

Fig. 6 is a schematic view of the structure of the rolling element in the embodiment shown in fig. 1.

Wherein: 1. a material conveying groove; 101. an upper slot cavity; 102. a lower slot cavity; 3. a scraper body; 301. a fixing hole; 302. a blow-down hole; 4. a rolling element; 401. a housing; 411. a mounting cavity; 412. a communication hole; 402. a ball; 501. a liquid supply pipe; 502. a spraying part; 6. a mounting hole; 7. a support surface; 8. a material-facing side surface; 9. and the side surface of the back material.

Detailed Description

In order to more clearly illustrate the general inventive concept, reference will be made in the following detailed description, by way of example, to the accompanying drawings.

It should be noted that in the following description, numerous specific details are set forth in order to provide a thorough understanding of the present utility model, however, the present utility model may be practiced in other ways than as described herein, and therefore the scope of the present utility model is not limited by the specific embodiments disclosed below.

In addition, in the description of the present utility model, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the drawings, are merely for convenience in describing the present utility model and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model.

In the present utility model, unless explicitly specified and limited otherwise, 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; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. However, it is noted that a direct connection indicates that two bodies connected together do not form a connection relationship by an excessive structure, but are connected to form a whole by a connection structure. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present utility model, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present utility model. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

In the present utility model, as shown in fig. 1 to 6, there is provided a scraper conveying system, a material conveying trough 1, the material conveying trough 1 being provided with an upper trough chamber 101 and a lower trough chamber 102; an endless chain rotatably movable around the material conveying tank 1, and rotatably extending in the upper tank chamber 101 and the lower tank chamber 102; the scraper body 3 is mounted on the annular chain, a fixing hole 301 and a drain hole 302 which are mutually communicated are formed in the scraper body 3, and the fixing hole 301 and the drain hole 302 penetrate through the scraper body 3; a rolling element 4, the rolling element 4 is mounted on the fixing hole 301, the rolling element 4 includes a housing 401 and a ball 402, a mounting cavity 411 is formed inside the housing 401, the ball 402 is mounted on the mounting cavity 411, the ball 402 partially protrudes out of the bottom side of the housing 401, and the housing 401 has a communication hole 412 communicating the mounting cavity 411 and the drain hole 302; the spraying device comprises a spraying part 502 arranged in the lower groove cavity 102, and the spraying part 502 can spray towards the lower groove cavity 102.

According to the scraper conveying system, the scraper body starts to turn over when the scraper body 3 rotates to move to the machine head or the machine tail and moves into the lower groove cavity 102 during coal scraping operation of the upper groove cavity 101, when the scraper body 3 moves in the lower groove cavity 102, a spraying device can spray in the lower groove cavity 102, spray water enters the pollution discharge hole 302 and the communicating hole 412 and infiltrates impurities in the installation cavity 411, the sprayed water flows into the installation cavity 411 through the pollution discharge hole 302 and the communicating hole so as to dilute the impurities in the scraper body 3 and the rolling body 4, and the impurities in the fluid form are more easily discharged from the pollution discharge hole 302. Especially, when the scraper body 3 moves, the diluted impurities can move outwards under jolt vibration, and the diluted impurities are more easily discharged from the drain hole 302.

In addition, when the water pressure directly impacts the sewage drain hole 302, softer impurities are easily broken into finer particles by the impact force of water flow under the action of the water pressure, and are not easily blocked in the installation cavity 411, the sewage outlet hole and the sewage drain hole 302, so that the impurities are more easily discharged. Moreover, the impact force of the water flow can generate thrust to impurities, and the impurities can be discharged under the thrust, so that the impurities are further reduced from being blocked in the scraper body 3 and the rolling bodies 4.

After the scraper body 3 and the rolling bodies 4 are cleaned, the phenomenon that the balls 402 are clamped in the mounting cavity 411 can be reduced, the rolling performance of the balls 402 is improved, and the service life is prolonged. In addition, after cleaning, a small amount of moisture can be reserved on the scraper body 3 and the rolling bodies 4, and impurities entering the installation cavity 411 are mixed with the moisture during material conveying, so that the fluidity of the impurities can be improved, and the resistance of the impurities to the balls 402 is reduced. Particularly in a coal mine, after the coal slime entering the installation cavity 411 is mixed with water, the ball 402 can be lubricated, and the rolling performance of the ball 402 is improved.

In addition, the water flow sprayed by the spraying device 5 can play an auxiliary cooling role on the balls 40242.

Particularly important, in the utility model, by arranging the spraying device at the position of the lower groove cavity 102, the installation of the lower groove cavity 102 has the following characteristics and advantages that firstly, the lower groove cavity 102 has sufficient installation space in the length direction, more flexible and more spraying installation positions can be provided, the spraying effect and the spraying times are easy to adjust, and further the spraying cleaning effect is further improved; secondly, the lower groove cavity 102 is relatively closed and has smaller space, and spray water is dispersed in the lower groove cavity 102 to be easier to surge to generate water mist and a water curtain, so that the scraper body is soaked by the water mist and is leached by the water curtain in the moving process; thirdly, by spraying in the lower groove cavity 102, the spray water can also assist in cleaning the lower groove cavity 102 so as to carry away impurity and foreign matters in the lower groove cavity 102.

It should be noted that, in the present utility model, the condition in which the balls 402 partially protrude from the bottom side of the housing 401 is based on the condition in which the balls 402 face downward with respect to the squeegee body 3, it is understood that when the balls 402 face upward with respect to the squeegee body 3, the balls 402 partially protrude from the top side of the housing 401. In the present utility model, turning the squeegee body 3 downward means that the squeegee body 3 is located below the balls 402 after the squeegee body 3 is turned.

For the annular chain, a person skilled in the art can flexibly select an existing annular chain when implementing the annular chain, and the description is omitted here.

Preferably, for the mounting location of the shower portion 502, in the illustrated embodiment, further specifically, the shower portion 502 is mounted to a side wall of the lower sump cavity 102. As shown in the figure, the space on the side of the material conveying groove 1 can be utilized, and in addition, as shown in the figure, in order to maintain walking stability, the rolling bodies 4 are generally arranged at the edge position of the scraper body 3, and the spraying part 502 is arranged on the side wall of the lower groove cavity 102, so that the spraying part 502 can be close to the position of the blow-off hole 302 during spraying, and the probability of spraying and cleaning the position of the blow-off hole 302 can be increased.

For installation of the spraying portion 502, in the illustrated embodiment, more specifically, the material conveying trough 1 is provided with a through installation hole 6 on a side wall of the lower trough cavity 102, and the spraying portion 502 is installed in the installation hole 6. As shown in the figure, the installation of the spraying device can be performed by utilizing the installation space outside the material conveying groove, and the installation space is formed by utilizing the installation holes 6, so that the spraying part 502 can be positioned and installed conveniently.

The location of the shower portion 502 is not limited to the side walls of the lower chamber 102 shown in the figures, and in alternative embodiments, the shower portion 502 may be disposed on the top or bottom wall of the lower chamber 102.

As a preferred arrangement, further specifically, the spray portion 502 is configured as an atomizing spray header.

By setting the spraying portion 502 as an atomizing nozzle, the spraying dispersion effect of the spraying portion 502 in the lower tank 102 can be improved, so as to improve the spraying cleaning effect on the drain hole 302.

The arrangement of the spraying portion 502 is not limited to the form of an atomizing nozzle, and in alternative embodiments, other forms of the spraying portion 502 may be used, such as a water jet nozzle.

As for the arrangement of the nozzles, it is preferable that the nozzles are inclined toward the direction of movement of the squeegee body within the lower tank 102 so that the nozzles can spray cleaning directly on the squeegee.

As a preferable arrangement, a plurality of spraying portions 502 are provided at intervals along the extending direction of the material conveying trough 1. Therefore, a plurality of spraying cleaning areas can be arranged at intervals in the length direction of the physical conveying groove so as to spray and clean the scraping plate.

In the illustrated embodiment, further specifically, the spraying device includes a liquid supply pipe 501, each spraying portion 502 is mounted and fixed on the liquid supply pipe 501, and the liquid supply pipe 501 is fixed on a side wall of the material conveying tank 1. The liquid supply pipe 501 is fixed outside the groove wall of the material conveying groove 1, and the liquid supply pipe 501 is connected with the spraying part 502, so that the outer space of the material conveying groove 1 is utilized, and the spraying device can be conveniently installed and overhauled.

As shown in fig. 5, the present utility model further provides a squeegee comprising: the scraper body 3 is provided with a supporting surface 7, a material facing side surface 8 and a material backing side surface 9 which are oppositely arranged, a fixing hole 301 and a sewage draining hole 302 which are mutually communicated are formed in the scraper body 3, the fixing hole 301 is formed in the supporting surface 7 of the scraper body 3, and the sewage draining hole 302 at least penetrates through the material backing side surface 9 of the scraper body 3; the rolling element 4, the rolling element 4 is mounted on the fixed hole 301, the rolling element 4 includes a housing 401 and a ball 402, a mounting cavity 411 is formed inside the housing 401, the ball 402 is mounted on the mounting cavity 411, the ball 402 extends out of the bottom side of the housing 401, and the housing 401 has a communication hole 412 communicating the mounting cavity 411 and the drain hole 302.

When the scraper of the utility model turns downwards in the running process in the lower groove cavity 102, as shown in the figure, the back material side surface 9 is provided with a drain hole 302, and impurities in the installation cavity 411 can be discharged through the drain hole and the drain hole 302 under the action of gravity and under the promotion of the vibration of the scraper, so that the accumulation of the impurities in the installation cavity 411 is reduced. The scraper can be applied to the material conveyor, and the scraper starts to turn over when moving to the machine head or the machine tail, and the spraying device can spray the drain hole 302 of the scraper body 3.

Wherein, as shown in fig. 2 and fig. 5, the blow-down hole 302 is arranged on the side surface 9 of the back material, when the scraper body runs in the upper groove cavity 101, the side surface 8 of the scraper can push the coal to advance, the blow-down hole 302 on the side surface of the back material is not easy to be pressed into by the stress of the coal, so that the impurities entering the blow-down hole 302 on the side surface 9 of the back material are relatively loose, and the cleaning and the discharging are easy. When the scraper body 3 rotates into the lower groove cavity 102, the drain hole 302 of the back material side surface 9 is positioned at the side, and when the spraying part 502 is arranged on the side wall of the lower groove cavity 102, the spraying part 502 is easier to obliquely spray to the drain hole 302 of the back material side surface 9, so that the spraying effect is further improved.

It should be noted that, in the illustrated embodiment, the drain hole 302 is provided only on the back side 9 of the scraper body 3, and the term is not meant to limit the present utility model, and in an alternative embodiment, the drain hole 302 may be provided on the bottom surface of the scraper body 3 (refer to the condition that the scraper body 3 moves in the lower groove cavity 102), or on the material facing side 8 and the outer end surface.

In a preferred embodiment, further specifically, the top surface and the side surface of the housing 401 are provided with the communication holes 412, respectively. As shown in the figure, the communication holes 412 are respectively formed on the top surface and the side surface of the housing 401, so that the communication flow path of the communication holes 412 can be increased, which is further beneficial to the outward movement of impurities in the housing 401 and the entry of spray water, and in some embodiments, the communication holes 412 on the top surface and the side surface can be realized to a certain extent, so as to realize the dynamic flushing of spray water, thereby increasing the fluidity of impurities in the housing between the top surface and the side surface of the housing 401.

In the illustrated embodiment, as shown in fig. 3, the scraper body 3 is further optimally provided with the drain holes 302 at intervals along the height direction of the scraper body 3 on the back material side surface 9, one of the drain holes 302 is communicated with the communication hole 412 on the top surface of the housing 401, the other drain hole 302 is communicated with the drain hole 302 on the side surface of the housing 401, and as shown in the figure, by arranging the drain holes 302 at intervals on the side surface of the scraper body 3, the separate communication between the scraper body 3 and the communication hole 412 can be realized, the passing path of the outflow of impurities can be further improved, the possibility of the entry of spray water can be increased, the connecting part of the scraper body 3 between the drain holes 302 can also hold the structural connection of the scraper body 3 at the drain holes 302, the strength is maintained, and the aperture of a single drain hole 302 is reduced, so that the blocking of large coal in the drain hole 302 is prevented.

For the embodiment in which the housing 401 is provided with the communication holes 412 at the top and bottom surfaces, not only the manner in which the two drain holes 302 are separately communicated as shown in the drawing, but also in an alternative embodiment, the scraper body 3 may be provided with the drain holes 302 at the side of the backing, and the drain holes 302 simultaneously communicate with the communication holes 412 at the top and side surfaces of the housing 401. As shown in the figure, the single blow-down holes 302 are communicated with the communication holes 412, and the single blow-down holes 302 have larger aperture and larger spraying area, so that the single blow-down holes are easier to be sprayed, cleaned and infiltrated.

The utility model also provides a rolling element 4, the rolling element 4 comprises a shell 401 and balls 402, a mounting cavity 411 is formed in the shell 401, the balls 402 are mounted in the mounting cavity 411, the balls 402 partially extend out of the bottom side of the shell 401, communication holes 412 are respectively formed in the top surface and the side surface of the shell 401, and the communication holes 412 are communicated with the inner side and the outer side of the mounting cavity 411. As shown in fig. 6, the communication holes 412 are respectively formed on the top surface and the side surface of the housing 401, so that the communication flow path of the communication holes 412 can be increased, which is further beneficial to the outward movement of the impurities in the housing 401 and the entry of spray water, and in some embodiments, the first in and first out of the communication holes 412 on the top surface and the side surface can be realized to a certain extent, so as to realize the dynamic flushing of spray water, and further increase the fluidity of the impurities in the housing between the top surface and the side surface of the housing 401.

In this specification, each embodiment is described in a progressive manner, and identical and similar parts of each embodiment are all referred to each other, and each embodiment mainly describes differences from other embodiments. In particular, for system embodiments, since they are substantially similar to method embodiments, the description is relatively simple, as relevant to see a section of the description of method embodiments.

The foregoing is merely exemplary of the present utility model and is not intended to limit the present utility model. Various modifications and variations of the present utility model will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. which come within the spirit and principles of the utility model are to be included in the scope of the claims of the present utility model.

Claims (10)

1. A flight delivery system, comprising:

the material conveying groove is provided with an upper groove cavity and a lower groove cavity;

the annular chain can rotate around the material conveying groove, and the annular chain extends in the upper groove cavity and the lower groove cavity in a rotating mode;

the scraper body is arranged on the annular chain, a fixing hole and a sewage draining hole which are communicated with each other are formed in the scraper body, and the fixing hole and the sewage draining hole penetrate through the scraper body;

the rolling body is arranged in the fixing hole and comprises a shell and a ball, an installation cavity is formed in the shell, the ball is arranged in the installation cavity, a part of the ball extends out of the bottom side of the shell, and the shell is provided with a communication hole for communicating the installation cavity with the sewage draining hole;

the spraying device comprises a spraying part arranged in the lower groove cavity, and the spraying part can spray towards the lower groove cavity.

2. The flight delivery system of claim 1, wherein the spray portion is mounted to a sidewall of the lower channel cavity.

3. The scraper conveyor system of claim 2, wherein the material conveying trough is provided with a through mounting hole in a side wall of the lower trough cavity, and the spray part is mounted in the mounting hole.

4. A flight delivery system as claimed in claim 3, wherein the spray portion is provided as an atomising spray header.

5. The scraper conveyor system according to claim 2, wherein a plurality of the shower portions are provided at intervals along the extending direction of the material conveying trough.

6. The blade conveyor system of claim 5, wherein the spray device includes a liquid supply pipe, each of the spray sections being mounted and secured to the liquid supply pipe, the liquid supply pipe being secured to a side wall of the material conveying trough.

7. A screed comprising:

the scraper body is provided with a supporting surface, a material facing side surface and a material backing side surface which are oppositely arranged, a fixing hole and a pollution discharge hole which are mutually communicated are formed in the scraper body, the fixing Kong Kaishe is arranged on the supporting surface of the scraper body, and the pollution discharge hole at least penetrates through the material backing side surface of the scraper body;

the rolling body is arranged in the fixing hole, the rolling body comprises a shell and a ball, an installation cavity is formed in the shell, the ball is arranged in the installation cavity, a part of the ball extends out of the bottom side of the shell, and the shell is provided with a communication hole which is communicated with the installation cavity and the sewage draining hole.

8. The squeegee of claim 7, wherein the top surface and the side surface of the housing are each provided with the communication holes.

9. The scraper according to claim 8, wherein the scraper body is provided with the drain holes at intervals along the height direction of the scraper body on the back material side surface, one of the drain holes is communicated with the communication hole on the top surface of the housing, and the other drain hole is communicated with the drain hole on the side surface of the housing;

or the scraper body is provided with the drain hole on the side surface of the back material, and the drain hole is simultaneously communicated with the communication hole on the top surface and the side surface of the shell.

10. The rolling body is characterized by comprising a shell and balls, wherein an installation cavity is formed in the shell, the balls are installed in the installation cavity, some balls extend out of the bottom side of the shell, communication holes are formed in the top surface and the side surface of the shell respectively, and the communication holes are communicated with the inner side and the outer side of the installation cavity.