CN114918141A

CN114918141A - Impurity screening machine for lithium battery negative electrode material and screening method thereof

Info

Publication number: CN114918141A
Application number: CN202210537487.1A
Authority: CN
Inventors: 耿林华; 武建军; 龚军; 耿廷; 刘文增; 韩俊富; 张生来; 易峰; 谢东良; 苏真阳; 耿六宝
Original assignee: Shanxi Btr New Energy Technology Co ltd
Current assignee: Shanxi Btr New Energy Technology Co ltd
Priority date: 2022-05-18
Filing date: 2022-05-18
Publication date: 2022-08-19

Abstract

The invention discloses an impurity screening machine for a lithium battery cathode material and a screening method thereof, wherein the impurity screening machine comprises a circular box body, a first screen drum is arranged in the middle of the top surface of the circular box body, a first screen disc is arranged in a bottom port of the first screen drum, and a first bearing is arranged in the middle of the first screen disc; a notch outer ring is arranged at the middle upper part in the circular box body, an inner barrel is arranged in the notch outer ring, a conical ring is arranged on the inner bottom wall of the inner barrel, a second sieve tray is arranged in a bottom port of the conical ring, and a square sleeve is arranged in the middle of the second sieve tray; the bottom is equipped with the swash plate in the circular box, and the location is changeed the hole at the middle part of swash plate has been seted up, and circular box inner bottom wall middle part is equipped with fixing bearing, and fixing bearing's inside is inserted and is equipped with the fixed axle, and the fixed axle runs through location commentaries on classics hole, square sleeve, first bearing in proper order and extends to a sieve section of thick bamboo, and the middle part of fixed axle is passed through vibration mechanism and is connected with the bell ring. The invention effectively avoids the phenomenon of material residue in the machine and further improves the impurity removal effect of the cathode material.

Description

Impurity screening machine for lithium battery negative electrode material and screening method thereof

Technical Field

The invention relates to the technical field of screening of lithium battery negative electrode materials, in particular to an impurity screening machine for lithium battery negative electrode materials and a screening method thereof.

Background

In the production process of the lithium battery, the negative electrode material needs to be screened, and material particles with proper particle sizes are selected to enable the battery to obtain better energy density.

1. Because the carbon material particles have excellent lubricating and conducting performance and strong adhesion, the carbon particles are easy to adhere to meshes of the screen in the screening process, so that the screen is blocked, and the screening efficiency is reduced; 2. the existing impurity screening device mostly adopts one-time impurity removal, the impurity removal effect is not good, and small-particle impurities are easy to remain and mix in the negative electrode material.

Disclosure of Invention

The invention aims to solve the defects that the negative electrode material is easy to be adsorbed in a machine during screening and the impurity removal effect is poor in the prior art, and provides an impurity screening machine for the negative electrode material of a lithium battery.

In order to solve the problems that the cathode material is easy to be adsorbed in a machine during screening and the impurity removal effect is poor in the prior art, the invention adopts the following technical scheme:

the impurity screening machine for the lithium battery cathode material comprises a circular box body, wherein a circular through hole is formed in the middle of the top surface of the circular box body, a bearing ring is installed inside the circular through hole, a first screen drum is arranged inside the bearing ring, a first screen disc is arranged in a bottom port of the first screen drum, and a first bearing is arranged in the middle of the first screen disc; a notch outer ring is arranged at the middle upper part in the circular box body, an inner cylinder is arranged in the notch outer ring, a conical ring is arranged on the inner bottom wall of the inner cylinder, a second sieve tray is arranged in a bottom port of the conical ring, and a square sleeve is arranged in the middle of the second sieve tray; the bottom is equipped with the swash plate in the circular box, the location is changeed the hole in the middle part of swash plate has been seted up, diapire middle part is equipped with fixing bearing in the circular box, fixing bearing's inside is inserted and is equipped with the fixed axle, the fixed axle runs through location in changeing hole, square sleeve, the first bearing in proper order and extending to a sieve section of thick bamboo, the middle part of fixed axle is passed through vibration mechanism and is connected with the toper ring.

Preferably, be located a sieve section of thick bamboo bottom and be in the top of fixed axle is equipped with the first lantern ring, the equipartition is equipped with a plurality of scraper blades on the outer wall of first lantern ring, every the scraper blade all slides along the top surface of a sieve tray and the inside wall of a sieve section of thick bamboo.

Preferably, the middle upper portion of the fixed shaft is sleeved with a square sliding ring, and the outer wall of the square sliding ring slides along the inner wall of the square sleeve.

Preferably, a speed reducing motor is arranged on one side of the inner bottom wall of the round box body, a driving bevel gear is sleeved at the end part of a motor shaft of the speed reducing motor, a driven bevel gear is sleeved at the bottom end part of the fixing shaft, and the driving bevel gear is meshed with the driven bevel gear.

Preferably, the vibration mechanism comprises a linkage shaft and eccentric cams, a pair of second bearings is arranged in the middle of the two side walls in the circular box body, the linkage shaft is inserted into each second bearing, the eccentric cams are sleeved at the outer end portions of the linkage shafts respectively, the pair of eccentric cams are matched and tightly abutted to the two sides of the bottom surface of the conical ring respectively, a linkage bevel gear is sleeved at the middle portion of each linkage shaft, and the pair of linkage bevel gears are symmetrically arranged.

Preferably, the middle part of the fixed shaft is provided with a hollow ring, the middle part of the fixed shaft is provided with a second lantern ring, the inner wall of the hollow ring is fixedly connected with the second lantern ring through a plurality of connecting rods, the top of the hollow ring is provided with a bevel gear ring, and the bevel gear ring is respectively connected with a pair of linkage bevel gears in a meshing manner.

Preferably, a positioning plate is arranged at the top of the left side face of the circular box body, a third bearing is arranged in the middle of the positioning plate, a vertical shaft is inserted into the third bearing, a second bevel gear is sleeved at the bottom end of the vertical shaft, the left end of one linkage shaft extends to the outer side of the circular box body and is sleeved with a first bevel gear, and the first bevel gear is meshed with the second bevel gear.

Preferably, the top portion cover of vertical axis is equipped with first sprocket, the well upper portion of a first sieve section of thick bamboo is equipped with second sprocket, spacing ring in proper order, first sprocket carries out the transmission through chain belt and second sprocket and is connected.

Preferably, a plurality of coarse mesh sieves have been seted up to the equipartition on the top surface of first sieve dish, a plurality of pore sieve meshes have been seted up to the equipartition on the top surface of second sieve dish, the rectangle breach has been seted up at the positive top of circular box, the right flank bottom of circular box is equipped with row material section of thick bamboo.

The invention also provides a screening method of the impurity screening machine for the lithium battery cathode material, which comprises the following steps:

step one, a motor shaft of a speed reducing motor drives a driving bevel gear to synchronously rotate, and the driving bevel gear is meshed with the driving bevel gear to drive a driven bevel gear, a fixed shaft, a second lantern ring, a square sliding ring, a first lantern ring and a plurality of scraping plates to rotate;

the second sleeve ring drives the hollow ring and the bevel gear ring to synchronously rotate through a plurality of connecting rods, the bevel gear ring is meshed to drive the linkage bevel gear, the linkage shaft and the eccentric cam to rotate, and the eccentric cam is matched to drive the inner cylinder to perform vertical reciprocating vibration along the outer ring of the notch under the action of gravity;

when the square sliding ring rotates, the square sleeve, the second sieve tray, the conical ring and the inner cylinder are driven to rotate along the outer ring of the notch, so that the inner cylinder and the second sieve tray rotate while vibrating in a reciprocating manner;

step four, a fixed shaft drives a first bevel gear to synchronously rotate, the first bevel gear drives a second bevel gear, a vertical shaft and a first chain wheel to rotate, and the first chain wheel drives a second chain wheel, a first screen drum and a limiting ring to slowly rotate through a chain belt;

pouring the negative electrode materials to be screened into a first screen drum, driving a first screen disc to slowly rotate by the first screen drum, and simultaneously stirring the negative electrode materials by a plurality of scraping plates to enable the negative electrode materials to fall into an inner cylinder through coarse-hole screen holes, so that larger particle impurities are remained on the first screen disc; the inner cylinder drives the second sieve tray to rotate while vibrating in a reciprocating mode, the negative electrode material drops onto the inclined plate along the pore sieve holes and is discharged along the discharge cylinder, and small particle impurities are remained on the second sieve tray.

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

1. when the negative electrode material is sieved, the first sieve drum rotates, and the plurality of scraping plates slide along the top surface of the first sieve tray and the inner side wall of the first sieve drum, so that the negative electrode material falls through the coarse-hole sieve pores, and the phenomenon of material residue in the first sieve drum is avoided;

2. in the invention, the inner cylinder and the second sieve tray rotate while vibrating in a reciprocating manner through the cooperation of the linkage mechanism, the negative electrode material falls onto the inclined plate along the pore sieve holes and is discharged, and smaller particle impurities remain on the second sieve tray, so that the impurity removal effect of the negative electrode material can be effectively improved;

in conclusion, the negative electrode material impurity removing device solves the problems that the negative electrode material is easy to be adsorbed in the machine during screening and the impurity removing effect is poor through the matching use of all mechanism components, is compact in overall structural design, effectively avoids the phenomenon of material residue in the machine, and further improves the impurity removing effect of the negative electrode material.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention and do not constitute a limitation of the invention. In the drawings:

FIG. 1 is a front view of the present invention;

FIG. 2 is a front sectional view of the present invention;

FIG. 3 is a top view of the present invention;

FIG. 4 is an enlarged view taken at A of FIG. 2 in accordance with the present invention;

FIG. 5 is a schematic view of the structure of the outer ring and the inner cylinder of the notch of the present invention;

FIG. 6 is a schematic view of a hollow ring and bevel gear ring configuration of the present invention;

FIG. 7 is a schematic view of a hollow ring and bevel gear ring configuration of the present invention;

FIG. 8 is a schematic illustration of a screening method of the present invention;

sequence numbers in the figure: the device comprises a circular box body 1, a fixed shaft 11, a speed reducing motor 12, a driving bevel gear 13, a driven bevel gear 14, a discharging cylinder 15, an inclined plate 16, a first screen cylinder 2, a first screen disc 21, a scraping plate 22, a limiting ring 23, a first bevel gear 24, a vertical shaft 25, a second bevel gear 26, a chain belt 27, a notch outer ring 3, an inner cylinder 31, a conical ring 32, a second screen disc 33, a square sleeve 34, a square sliding ring 35, a hollow ring 36, a bevel gear ring 37, a linkage shaft 38, a linkage bevel gear 39 and an eccentric cam 310.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

The first embodiment is as follows: the embodiment provides an impurity screening machine for a lithium battery cathode material, and referring to fig. 1-7, the impurity screening machine specifically comprises a circular box body 1, wherein a circular through hole is formed in the middle of the top surface of the circular box body 1, a bearing ring is installed inside the circular through hole, a first screen cylinder 2 is arranged inside the bearing ring, the first screen cylinder 2 is rotatably connected with the circular box body 1 through the bearing ring, the first screen cylinder 2 is open at the upper part and the lower part, the top of the first screen cylinder is circular, the bottom of the first screen cylinder is conical, a first screen disc 21 which is concentrically and fixedly connected is arranged in a bottom port of the first screen cylinder 2, and a first bearing which is fixedly connected in a penetrating manner is arranged in the middle of the first screen disc 21;

the middle upper part in the circular box body 1 is provided with a notch outer ring 3 which is concentrically and fixedly connected, the notch angle of the notch outer ring 3 is 90-120 degrees, an inner cylinder 31 which slides up and down and is rotatably connected is arranged in the notch outer ring 3, the inner bottom wall of the inner cylinder 31 is provided with a conical ring 32 which is concentrically and fixedly connected, the weight of the conical ring 32 is heavier, the conical ring drives the inner cylinder 31 to have downward gravity, a second sieve tray 33 which is concentrically and fixedly connected is arranged in a bottom port of the conical ring 32, the middle part of the second sieve tray 33 is provided with a square sleeve 34 which penetrates through and is fixedly connected, and the square sliding ring 35 can slide along the inner wall of the square sleeve 34 and can also drive the square sleeve 34 to rotate;

the bottom is equipped with the swash plate 16 of slant rigid coupling in circular box 1, the location trompil has been seted up at the middle part of swash plate 16, wall middle part is equipped with fixing bearing in circular box 1, fixing bearing's inside is inserted and is equipped with fixed axle 11, fixed axle 11 runs through the location trompil in proper order, square sleeve 34, first bearing extends to in the first sieve section of thick bamboo 2, the well upper portion cover of fixed axle 11 is equipped with the square sliding ring 35 of concentric rigid coupling, the outer wall of square sliding ring 35 slides along the inner wall of square sleeve 34, when square sliding ring 35 rotates, drive square sleeve 34, second sieve tray 33, conical ring 32, inner tube 31 rotates along the inner wall of breach outer loop 3, rotate when making inner tube 31 and second sieve tray 33 reciprocating vibration, the middle part of fixed axle 11 is passed through vibrating mechanism and is connected with conical ring 32.

In a specific implementation process, as shown in fig. 2 and 3, a first lantern ring is arranged at the top of the fixed shaft 11 and at the bottom in the first screen drum 2, a plurality of scraping plates 22 are uniformly distributed on the outer wall of the first lantern ring, and each scraping plate 22 slides along the top surface of the first screen disc 21 and the inner side wall of the first screen drum 2; a plurality of align to grid's coarse mesh sieve mesh has been seted up to the equipartition on the top surface of first sieve tray 21, and a plurality of align to grid's fine mesh sieve mesh has been seted up to the equipartition on the top surface of second sieve tray 33, and rectangular notch has been seted up at the positive top of circular box 1, and the right flank bottom of circular box 1 is equipped with the row who runs through the rigid coupling and expects a section of thick bamboo 15.

In the specific implementation process, as shown in fig. 2, a speed reducing motor 12 is arranged on one side of the bottom wall in the circular box 1, the model of the speed reducing motor 12 is GV28-100-500S, a drive bevel gear 13 concentrically and fixedly connected is sleeved at the end part of a motor shaft of the speed reducing motor 12, a driven bevel gear 14 concentrically and fixedly connected is sleeved at the bottom end part of the fixed shaft 11, and the drive bevel gear 13 is in meshed connection with the driven bevel gear 14; a motor shaft of the speed reducing motor 12 drives the driving bevel gear 13 to synchronously rotate, and the driving bevel gear 13 is meshed with and drives the driven bevel gear 14, the fixed shaft 11, the second lantern ring, the square sliding ring 35, the first lantern ring and the plurality of scraping plates 22 to rotate.

In the specific implementation process, as shown in fig. 2 and 6, the vibration mechanism includes a linkage shaft 38 and an eccentric cam 310, a pair of second bearings are arranged in the middle of two side walls in the circular box 1, the linkage shaft 38 is inserted in each second bearing, the linkage shaft 38 is rotatably connected with the inner wall of the circular box 1 through the second bearings, the eccentric cam 310 which is eccentrically and fixedly connected is sleeved at the outer end of each linkage shaft 38, the pair of eccentric cams 310 are respectively matched and tightly abutted against two sides of the bottom surface of the conical ring 32, a linkage bevel gear 39 which is concentrically and fixedly connected is sleeved at the middle of each linkage shaft 38, and the pair of linkage bevel gears 39 are symmetrically arranged;

a concentrically arranged hollow ring 36 is arranged in the middle of the fixed shaft 11, a second sleeve ring is arranged in the middle of the fixed shaft 11, the inner wall of the hollow ring 36 is fixedly connected with the second sleeve ring through a plurality of circularly arranged connecting rods, the inside of the hollow ring 36 is hollowed through the plurality of connecting rods, so that a cathode material can conveniently fall onto the inclined plate 16 through the hollowed part, a bevel gear ring 37 concentrically and fixedly connected is arranged at the top of the hollow ring 36, and the bevel gear ring 37 is respectively meshed with a pair of linkage bevel gears 39; the second sleeve ring drives the hollow ring 36 and the bevel gear ring 37 to synchronously rotate through a plurality of connecting rods, the bevel gear ring 37 is meshed to drive the linkage bevel gear 39, the linkage shaft 38 and the eccentric cam 310 to rotate, and the eccentric cam 310 is matched to drive the inner cylinder 31 to vertically reciprocate along the gap outer ring 3 under the action of gravity of the inner cylinder 31 and the bevel ring 32.

Example two: in the first embodiment, there is a phenomenon that the first screen drum 2 cannot rotate and the material is easily left in the first screen drum, so that the first embodiment further includes:

in the specific implementation process, as shown in fig. 2 and 3, a positioning plate is arranged at the top of the left side surface of the circular box body 1, a third bearing is arranged in the middle of the positioning plate, a vertical shaft 25 is inserted in the third bearing, a second bevel gear 26 which is concentrically and fixedly connected is sleeved at the bottom end of the vertical shaft 25, the left end of one linkage shaft 38 extends to the outer side of the circular box body 1 and is sleeved with a first bevel gear 24 which is concentrically and fixedly connected, and the first bevel gear 24 is in meshed connection with the second bevel gear 26;

the top end part of the vertical shaft 25 is sleeved with a first chain wheel which is concentrically and fixedly connected, the middle upper part of the first screen drum 2 is sequentially sleeved with a second chain wheel which is concentrically and fixedly connected and a limiting ring 23, and the first chain wheel is in transmission connection with the second chain wheel through a chain belt 27; when a fixed axle 11 rotates, drive first bevel gear 24 and rotate in step, first bevel gear 24 drives second bevel gear 26, vertical axis 25 and first sprocket rotate, first sprocket passes through chain belt 27 and drives the second sprocket, first sieve section of thick bamboo 2 and spacing ring 23 rotate slowly, first lantern ring and a plurality of scraper blade 22 rotate simultaneously, scraper blade 22 all slides along the top surface of first sieve tray 21 and the inside wall of first sieve section of thick bamboo 2 to take place the remaining phenomenon of material in the first sieve section of thick bamboo 2 has been avoided.

Example three: referring to fig. 8, specifically, the working principle and the operation method of the present invention are as follows:

step one, starting a speed reducing motor 12, driving a driving bevel gear 13 to synchronously rotate by a motor shaft of the speed reducing motor 12, and driving the driven bevel gear 14, a fixed shaft 11, a second lantern ring, a square sliding ring 35, a first lantern ring and a plurality of scraping plates 22 to rotate by the driving bevel gear 13 in a meshed manner;

step two, the second sleeve ring drives the hollow ring 36 and the bevel gear ring 37 to synchronously rotate through a plurality of connecting rods, the bevel gear ring 37 is meshed to drive the linkage bevel gear 39, the linkage shaft 38 and the eccentric cam 310 to rotate, and the eccentric cam 310 is matched to drive the inner cylinder 31 to vertically reciprocate along the gap outer ring 3 under the action of gravity of the inner cylinder 31 and the bevel ring 32;

step three, when the square sliding ring 35 rotates, the square sleeve 34, the second sieve tray 33, the tapered ring 32 and the inner cylinder 31 are driven to rotate along the notch outer ring 3, so that the inner cylinder 31 and the second sieve tray 33 rotate while vibrating in a reciprocating manner;

step four, a fixed shaft 11 drives a first bevel gear 24 to synchronously rotate, the first bevel gear 24 drives a second bevel gear 26, a vertical shaft 25 and a first chain wheel to rotate, and the first chain wheel drives a second chain wheel, a first screen drum 2 and a limiting ring 23 to slowly rotate through a chain belt 27;

pouring the negative electrode materials to be screened into the first screen drum 2, wherein the first screen drum 2 drives the first screen disc 21 to rotate slowly, and meanwhile, the negative electrode materials are stirred by the plurality of scraping plates 22 and fall into the inner cylinder 31 through the coarse-hole screen holes, so that larger particle impurities are remained on the first screen disc 21; the inner cylinder 31 drives the second sieve tray 33 to rotate while vibrating back and forth, the negative electrode material falls onto the inclined plate 16 along the fine-hole sieve pores and is discharged along the discharge cylinder 15, and smaller particle impurities remain on the second sieve tray 33.

According to the invention, through the matched use of all mechanism components, the problems that the cathode material is easy to be adsorbed in the machine during screening and the impurity removal effect is poor are solved, the overall structure design is compact, the phenomenon of material residue in the machine is effectively avoided, and the impurity removal effect of the cathode material is further improved.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.

Claims

1. A impurity screening machine for lithium cell anode material, including circular box (1), its characterized in that: a circular through hole is formed in the middle of the top surface of the circular box body (1), a bearing ring is installed inside the circular through hole, a first screen drum (2) is arranged inside the bearing ring, a first screen disc (21) is arranged in a bottom port of the first screen drum (2), and a first bearing is arranged in the middle of the first screen disc (21); a notch outer ring (3) is arranged at the middle upper part in the circular box body (1), an inner cylinder (31) is arranged in the notch outer ring (3), a conical ring (32) is arranged on the inner bottom wall of the inner cylinder (31), a second sieve tray (33) is arranged in a bottom end opening of the conical ring (32), and a square sleeve (34) is arranged in the middle of the second sieve tray (33); bottom is equipped with swash plate (16) in circular box (1), the location has been seted up at the middle part of swash plate (16) and has been changeed the hole, bottom wall middle part is equipped with fixing bearing in circular box (1), fixing bearing's inside is inserted and is equipped with fixed axle (11), fixed axle (11) run through in location commentaries on classics hole, square sleeve (34), first bearing and extend to first sieve section of thick bamboo (2) in proper order, the middle part of fixed axle (11) is passed through vibration mechanism and is connected with toper ring (32).

2. The impurity sieving machine for the negative electrode material of the lithium battery as recited in claim 1, wherein: be located an interior bottom of first sieve section of thick bamboo (2) the top of fixed axle (11) is equipped with a lantern ring, the equipartition is equipped with a plurality of scraper blades (22) on the outer wall of a lantern ring, every scraper blade (22) all slide along the top surface of a sieve dish (21) and the inside wall of a sieve section of thick bamboo (2).

3. The impurity sieving machine for the negative electrode material of the lithium battery as recited in claim 1, wherein: the middle upper portion of the fixed shaft (11) is sleeved with a square sliding ring (35), and the outer wall of the square sliding ring (35) slides along the inner wall of the square sleeve (34).

4. The impurity sieving machine for a negative electrode material of a lithium battery according to claim 1, characterized in that: a speed reducing motor (12) is arranged on one side of the bottom wall in the round box body (1), a driving bevel gear (13) is sleeved at the end part of a motor shaft of the speed reducing motor (12), a driven bevel gear (14) is sleeved at the bottom end part of the fixing shaft (11), and the driving bevel gear (13) is meshed with the driven bevel gear (14).

5. The impurity sieving machine for a negative electrode material of a lithium battery according to claim 1, characterized in that: the vibrating mechanism comprises a linkage shaft (38) and eccentric cams (310), wherein a pair of second bearings are arranged in the middle of the two inner side walls of the round box body (1), the linkage shaft (38) is inserted into each second bearing, each eccentric cam (310) is sleeved at the outer end of each linkage shaft (38), each eccentric cam (310) is matched with the two sides of the bottom surface of the conical ring (32) tightly, each linkage bevel gear (39) is sleeved at the middle of each linkage shaft (38), and the linkage bevel gears (39) are symmetrically arranged.

6. The impurity sieving machine for the negative electrode material of the lithium battery as recited in claim 5, wherein: the middle part of fixed axle (11) is equipped with hollow ring (36), the middle part of fixed axle (11) is equipped with the second lantern ring, the inner wall of hollow ring (36) passes through a plurality of connecting rods and the second lantern ring rigid coupling, the top of hollow ring (36) is equipped with bevel gear ring (37), bevel gear ring (37) are connected with a pair of linkage bevel gear (39) meshing respectively.

7. The impurity sieving machine for the negative electrode material of the lithium battery as recited in claim 5, wherein: the novel round box is characterized in that a positioning plate is arranged at the top of the left side face of the round box body (1), a third bearing is arranged in the middle of the positioning plate, a vertical shaft (25) is inserted into the third bearing, a second bevel gear (26) is sleeved at the bottom end of the vertical shaft (25), a first bevel gear (24) is sleeved at the left end of one linkage shaft (38) and extends to the outer side of the round box body (1), and the first bevel gear (24) is meshed with the second bevel gear (26).

8. The impurity sieving machine for the negative electrode material of the lithium battery as recited in claim 7, wherein: the top portion cover of vertical axis (25) is equipped with first sprocket, the well upper portion of first sieve section of thick bamboo (2) is equipped with second sprocket, spacing ring (23) in proper order, first sprocket carries out the transmission through chain belt (27) and second sprocket and is connected.

9. The impurity sieving machine for the negative electrode material of the lithium battery as recited in claim 1, wherein: a plurality of coarse hole sieve meshes have been seted up to the equipartition on the top surface of first sieve dish (21), a plurality of fine hole sieve meshes have been seted up to the equipartition on the top surface of second sieve dish (33), the rectangle breach has been seted up at the positive top of circular box (1), the right flank bottom of circular box (1) is equipped with row material section of thick bamboo (15).

10. The screening method of the impurity screening machine for the negative electrode material of the lithium battery as claimed in any one of claims 1 to 9, comprising the steps of:

step one, a motor shaft of a speed reducing motor (12) drives a driving bevel gear (13) to synchronously rotate, and the driving bevel gear (13) is meshed to drive a driven bevel gear (14), a fixed shaft (11), a second sleeve ring, a square sliding ring (35), a first sleeve ring and a plurality of scraping plates (22) to rotate;

step two, the second sleeve ring drives the hollow ring (36) and the bevel gear ring (37) to synchronously rotate through a plurality of connecting rods, the bevel gear ring (37) is meshed to drive the linkage bevel gear (39), the linkage shaft (38) and the eccentric cam (310) to rotate, and the eccentric cam (310) is matched to drive the inner cylinder (31) to vibrate up and down in a reciprocating manner along the gap outer ring (3) under the action of gravity of the inner cylinder (31) and the bevel ring (32);

step three, when the square sliding ring (35) rotates, the square sleeve (34), the second sieve tray (33), the conical ring (32) and the inner cylinder (31) are driven to rotate along the notch outer ring (3), so that the inner cylinder (31) and the second sieve tray (33) rotate while vibrating in a reciprocating manner;

fourthly, a fixed shaft (11) drives a first bevel gear (24) to synchronously rotate, the first bevel gear (24) drives a second bevel gear (26), a vertical shaft (25) and a first chain wheel to rotate, and the first chain wheel drives a second chain wheel, a first screen drum (2) and a limiting ring (23) to slowly rotate through a chain belt (27);

pouring the negative electrode materials to be screened into the first screen drum (2), wherein the first screen drum (2) drives the first screen disc (21) to rotate slowly, and meanwhile, the negative electrode materials are stirred by the plurality of scraping plates (22) and fall into the inner cylinder (31) through the coarse-hole screen holes, so that larger particle impurities are remained on the first screen disc (21); the inner cylinder (31) drives the second sieve tray (33) to rotate while vibrating in a reciprocating mode, the negative electrode materials fall onto the inclined plate (16) along the pore sieve holes and are discharged along the discharge cylinder (15), and small particle impurities are remained on the second sieve tray (33).