CN108781778B

CN108781778B - Cleaning method of double-cone centrifugal cleaning fan

Info

Publication number: CN108781778B
Application number: CN201810503406.XA
Authority: CN
Inventors: 陈霓; 刘正怀; 戴素江; 张正中; 王志明; 田立权; 陈德俊
Original assignee: Jinhua Polytechnic
Current assignee: Jinhua Polytechnic
Priority date: 2018-05-23
Filing date: 2018-05-23
Publication date: 2020-11-20
Anticipated expiration: 2038-05-23
Also published as: CN108781778A

Abstract

The invention provides a double-cone centrifugal cleaning fan, comprising: a fan housing; a fan shaft disposed within the fan housing; the fan blades are connected to the fan shaft, each fan blade is provided with a V-shaped outer side edge with two wide ends and a narrow middle part, and when the fan shaft rotates, the track formed by the outer side edges of the fan blades is a double cone; the invention has the beneficial effects that: the double-cone centrifugal fan has the advantages of simple structure, reliable work, uniform distribution of the loads of the vibrating screen surface, improvement of the cleaning quality, reasonable utilization of air flow and reduction of the cleaning loss.

Description

Cleaning method of double-cone centrifugal cleaning fan

Technical Field

The invention belongs to the technical field of agricultural machinery, semi-feeding rice and wheat combine harvesters and grain cleaning devices, and relates to a cleaning method of a double-cone centrifugal cleaning fan.

Background

The cleaning device of the half-feeding rice and wheat combine harvester consists of a cleaning sieve box and a centrifugal fan, and is used for cleaning threshed objects which are separated from the threshing device and contain grains, glumes, short stems and the like; under the combined action of the vibration of the sorting sieve and the airflow of the centrifugal fan, light and small impurities are blown out of the machine, grains are collected and conveyed to a grain bin, the impurity content of the rice and wheat grains is required to meet the performance requirement, and the sorting loss is controlled within a certain range.

The threshing cylinder of the semi-feeding combine harvester is longitudinally arranged (the cylinder shaft is consistent with the advancing direction of the machine), and during operation, the number of threshed objects separated from the inlet side and the outlet side of the arc direction of the grid concave plate to the cleaning sieve box shaking plate is large, and the number of threshed objects in the middle is small. The threshed material is shaken to be uniform and then enters an upper sieve (a louver sieve) for cleaning.

Practice shows that even though the shaking plate is 'even', the threshed objects are still unevenly distributed on the upper screen (louver screen), the two sides of the upper screen are the most, the middle is less, and the cleaning load is uneven.

The centrifugal fan is the main working part of the cleaning device, the width of the fan arranged in front of and below the cleaning screen is equal to that of the vibrating screen, and the air outlet faces to the whole upper screen surface. The track that current centrifugal cleaning fan impeller outside edge produced is the cylinder type, and in whole fan width range, its fan impeller diameter is equal, and the wind pressure of air outlet, wind speed and the volume are the same in theory, and in the screening process of reality, because the threshing material distributes is inhomogeneous, and its the threshing material of treating cleaning that faces is different, so the position that the threshing material is many can cause the condition that amount of wind speed is little and cleaning is incomplete, and the position that the cleaning is few causes the condition of cleaning loss increase because amount of wind speed is big again, so certain space of improving has.

Disclosure of Invention

The invention aims to provide a cleaning method of a double-cone centrifugal cleaning fan, aiming at the problems in the prior art.

The purpose of the invention can be realized by the following technical scheme: a cleaning method of a double-cone centrifugal cleaning fan comprises the following steps:

a fan housing;

a fan shaft disposed within the fan housing;

the fan blade is connected to the fan shaft, the fan blade is provided with a V-shaped outer side edge with two wide ends and a narrow middle part, and when the fan shaft rotates, the track formed by the outer side edge of the fan blade is a double cone.

Preferably, a bracket is further arranged on the fan shaft, one end of the bracket is connected with the fan shaft, and the other end of the bracket is connected with the inner side edges of the fan blades.

Preferably, the number of the fan blades is four, each fan blade corresponds to two brackets, and the two brackets are connected to the left side and the right side of the fan blade.

Preferably, the wind pressure, wind quantity and wind speed generated by the fan blades are reduced along with the reduction of the diameter of the fan blades, and the fan blades generate transverse wind blowing from two ends to the middle when the fan shaft rotates.

Preferably, the end part of the fan shaft is also provided with a V-shaped belt wheel.

Preferably, an included angle is formed between the fan blade and the bracket.

Preferably, the inner side edge of the fan blade is linear, and the fan blade is of a K-shaped structure with two closed ends.

Preferably, bearings are further arranged at two ends of the fan shaft, an inner ring of each bearing is connected with the fan shaft, and an outer ring of each bearing is connected with a rack bearing seat in the fan shell.

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

1. the double-cone centrifugal fan has the advantages of simple structure, reliable work, uniform distribution of the loads of the vibrating screen surface, improvement of the cleaning quality, reasonable utilization of air flow and reduction of the cleaning loss.

Drawings

Fig. 1 is a schematic structural view of a double-cone type centrifugal cleaning fan of the present invention.

Fig. 2 is a schematic view showing the working state of a double-cone type centrifugal cleaning fan of the present invention.

FIG. 3 is a schematic view of the operation of the fan blade of the present invention.

In the figure, 100, a fan housing; 200. a fan shaft; 210. a support; 300. a fan blade; 310. a V-shaped outer side; 400. a V-shaped belt pulley; 500. a bearing; 600. removing the product; 700. and (4) sieving.

Detailed Description

The following are specific embodiments of the present invention and are further described with reference to the drawings, but the present invention is not limited to these embodiments.

As shown in fig. 1, 2 and 3, a cleaning method with a double-cone centrifugal cleaning fan comprises the following steps: the double-cone centrifugal cleaning fan is applied to a cleaning device of a semi-feeding rice and wheat combine harvester and is designed according to the actual load condition of a vibrating screen surface.

Preferably, the fan housing 100 is a housing structure for being disposed below the upper screen 700 (louver screen) for blowing the air flow toward the upper screen 700; and the fan housing 100 includes two axial air inlets at left and right, and also includes a radial air outlet.

A fan shaft 200 disposed inside the fan housing 100; the fan shaft 200 is rotatable, and preferably, both ends of the fan shaft 200 are rotatably coupled to left and right frame bearing seats of the fan housing 100.

And a fan blade 300 connected to the fan shaft 200, wherein the fan blade 300 has a V-shaped outer side 310 having two wide ends and a narrow middle, and the outer side of the fan blade 300 forms a double cone when the fan shaft 200 rotates.

It should be noted here that the cleaning device of the semi-feeding rice and wheat combine harvester actually comprises a vibrating plate, an upper screen 700, a straw-pushing plate, a finger screen and other devices which are arranged in sequence, wherein a cleaning fan is positioned in front of and below the upper screen 700, an air outlet is opposite to the whole upper screen surface, under the combined action of the vibration of the cleaning screen and the airflow of a centrifugal fan, the impurities are blown out of the cleaning screen, and the grains are collected and sent to a grain box.

In the actual cleaning device, the amount of the threshed objects 600 separated to the cleaning screen box shaking plate from the inlet side and the outlet side of the arc direction of the grid concave plate is large, and the number of the threshed objects is small in the middle part; the threshed material 600 is shaken to be uniform and then enters an upper screen 700 (a louver screen) for cleaning. Practice shows that although the shaking plate is 'uniform', the distribution of the separated objects 600 on the upper screen 700 is uneven, the two sides of the grid concave plate are the most, the middle is less, and the cleaning load is uneven, so that the existing cleaning fan has the same diameter of the fan impeller because the track generated by the outer edge of the fan impeller is cylindrical, namely the width range of the whole fan, theoretically, the air pressure, the air speed and the air quantity of the air outlet are the same, but the air quantity and the air speed of the positions where the separated objects 600 are more are different from those facing the separated objects 600 to be cleaned are not cleaned completely, and the cleaning loss is increased on the larger positions where the separated objects 600 are less.

In order to solve the above problems, in the present embodiment, the shape of the fan blade 300 is optimized, and the outer side of the fan blade 300 is configured in a V shape, that is, the two sides have a large diameter and the middle has a small diameter, so that uneven wind can be formed, further, when the fan shaft 200 rotates, the fan blade 300 can form a double cone track, and the special shape of the fan blade 300 can generate air flows with high wind pressure, high wind speed and large wind volume at the two ends, and as the two ends of the fan blade 300 are gradually narrowed toward the middle, the wind speed generated by the narrower part in the middle, the wind volume, and the wind pressure are low, and gradually decreased from the two ends to the middle, and because the wind pressure difference exists between the two ends and the middle, so that uniform distribution of the lateral wind can be generated to uniformly distribute the escaping substances from the two ends to the middle; the distribution of the threshing object 600 of waiting to clean of 700 faces of the upper screen is many for both ends simultaneously, the distribution that is few in the middle, like this to the more threshing object 600 of waiting to clean of both ends just in time can be cleaned through wind speed and the amount of wind is big, the high air current of wind pressure, can improve the quality of cleaning like this, the rational utilization air current, just in time can be cleaned through wind speed and the amount of wind is little, the low air current of wind pressure to the less threshing object 600 of waiting to clean in the middle, can the rational utilization air current like this, and reduce and clean the loss.

As shown in fig. 1, 2 and 3, in addition to the above embodiment, the fan shaft 200 is further provided with a bracket 210, and one end of the bracket 210 is connected to the fan shaft 200 and the other end is connected to the inner side of the fan blade 300.

Preferably, the bracket 210 is actually a connecting rod radially disposed on the fan shaft 200, and since the fan blades 300 are of a long strip-shaped sheet structure, the inner side of the fan blades is fixed with the bracket 210, so that the fan shaft 200 can drive the fan blades 300 to rotate around the fan shaft 200 when rotating.

As shown in fig. 1, 2, and 3, in the above embodiment, the number of the fan blades 300 is four, each fan blade 300 corresponds to two brackets 210, and the two brackets 210 are connected to the left and right sides of the fan blade 300.

Preferably, the number of the fan blades 300 is four, the number of the brackets 210 is eight, two brackets 210 correspond to one fan blade 300, and the two brackets 210 are respectively fixed on both sides of the fan blade 300, so as to improve the firmness of the connection of the fan blade 300.

As shown in fig. 1, 2 and 3, in the above embodiment, the wind pressure, wind volume and wind speed generated by the fan blades 300 are reduced as the diameter thereof is reduced, and the fan blades 300 generate a transverse wind blowing from both ends to the middle when the fan shaft 200 rotates.

Preferably, the outer sides of the fan blades 300 are V-shaped, that is, the two sides have a large diameter and the middle has a small diameter, and the special shape of the fan blades 300 can generate air flows with high wind speed and high wind pressure at the two ends, while the narrower part of the fan blades 300 generates air flows with low wind speed and low wind pressure as the two ends are narrowed toward the middle, and the air flows gradually decrease from the two ends to the middle.

Generally speaking, the wind force on the two sides of the fan blade 300 is strong, the wind pressure is high, the wind force in the middle is small, and the wind force and the wind pressure from the two ends to the middle are gradually reduced, the airflow field can generate transverse wind pressure from the position where the wind pressure is high to the position where the wind pressure is low, and the transverse wind pressure generates transverse wind speed, so that the wind generated by the fan blade 300 in the embodiment can be decomposed into two directions of wind, one is wind along the wind outlet of the fan housing, and the other is transverse wind.

Furthermore, when the fan blades 300 rotate, airflow with the speed V is generated, the airflow speed V is perpendicular to the outer side edges of the fan blades 300, the V-shaped outer side edge 310 of the fan impeller is not parallel to the axis of the fan shaft 200, so the airflow speed V can be decomposed into V1 and V2, the airflow speed V1 is the air along the air outlet of the fan and is used for longitudinally blowing the glumes and impurities in the threshed material 600 out of the machine, the airflow speed V2 is the transverse air speed, and as the airflow V2 is the airflow with two sides flowing towards the middle, the mixture of the upper screen 700 can be transversely uniformly distributed, the threshed material 600 is uniformly distributed and cleaned under the combined action of the fan airflow and the vibrating screen, and the problem that the cleaning quality of the cylindrical fan is poor is solved.

As shown in fig. 1, 2, and 3, in addition to the above embodiment, a V-shaped pulley 400 is further provided at an end of the fan shaft 200. Preferably, a belt is connected to the V-shaped pulley 400 to drive the fan shaft 200 to rotate.

As shown in fig. 1, 2 and 3, in the above embodiment, an included angle is formed between the fan blade 300 and the bracket 210.

As shown in fig. 1, 2, and 3, in the above embodiment, the inner side of the fan blade 300 is linear, and the fan blade 300 has a K-shaped structure with both ends closed.

It should be noted here that since the outer side of the fan blade 300 is V-shaped and the inner side is linear, the cross section of the entire fan blade 300 has a K-shaped structure with both ends closed.

As shown in fig. 1, 2 and 3, in addition to the above embodiment, bearings 500 are further provided at both ends of the fan shaft 200, and an inner ring of the bearing 500 is connected to the fan shaft 200 and an outer ring thereof is connected to a frame bearing seat in the fan housing 100.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.

Claims

1. A cleaning method of a double-cone centrifugal cleaning fan is characterized by comprising the following steps:

a fan housing;

a fan shaft disposed within the fan housing;

the fan blades are connected to the fan shaft, each fan blade is provided with a V-shaped outer side edge with two wide ends and a narrow middle part, and when the fan shaft rotates, the track formed by the outer side edges of the fan blades is a double cone;

the fan shaft is further provided with supports, one end of each support is connected with the fan shaft, the other end of each support is connected with the inner side edge of each fan blade, the number of the fan blades is four, each fan blade corresponds to two supports, the two supports are connected to the left side and the right side of each fan blade, a V-shaped belt wheel is further arranged at the end part of each fan shaft, an included angle is formed between each fan blade and each support, the inner side edges of the fan blades are linear, the fan blades are of a K-shaped structure with two closed ends, bearings are further arranged at the two ends of each fan shaft, the inner ring of each bearing is connected with the fan shaft, and the outer ring of each bearing is connected with a rack bearing seat in the fan shell;

the wind pressure, wind quantity and wind speed generated by the fan blades are reduced along with the reduction of the diameter of the fan blades, and the fan blades generate transverse wind which is blown to the middle from two ends when the fan shaft rotates;

when the fan shaft rotates, the fan blades can form a double-cone track, airflow with high wind pressure, high wind speed and high wind volume is generated at two ends, the wind speed and the airflow with low wind volume and low wind pressure are generated at the narrower part of the middle part along with the fact that the two ends of the fan blades are continuously narrowed towards the middle part, and the airflow gradually becomes smaller from the two ends to the middle part, and because the wind pressure difference exists between the large wind pressure and the small wind pressure at the two ends, transverse wind can be generated to uniformly distribute more extrusions to the small wind pressure from the two ends to the middle part; meanwhile, the to-be-cleaned and separated objects on the upper screen surface are distributed with more two ends and less middle, so that the to-be-cleaned and separated objects with more two ends can be cleaned by air flow with high wind speed and wind volume and high wind pressure, and the to-be-cleaned and separated objects with less middle can be cleaned by air flow with low wind speed and wind volume and low wind pressure;

when the fan blades rotate, airflow with the speed V is generated, the airflow speed V is perpendicular to the outer side edges of the fan blades, the V-shaped outer side edges of the fan impellers are not parallel to the axis of the fan, the airflow speed V can be divided into V1 and V2, the airflow speed V1 is the air along the air outlet of the fan and is used for longitudinally blowing chaffs and impurities in the threshed objects out of the machine, the airflow speed V2 is the transverse air speed, the airflow V2 is the airflow with two sides flowing towards the middle, the mixture on the screen can be transversely and uniformly distributed, and the threshed objects are uniformly distributed and cleaned under the combined action of the airflow of the fan and the vibrating screen.