US1898823A - Pulverizing mill - Google Patents

Description

Feb. 21,1983. G. B. FORBES 1,898,823

PULVERIZING MILL Filed Jan. 5, 1928 I I8 INVENTOR.

\ ATTORNEY Patented Feb. 21, 1933 UNITED STATES PATENT OFFICE oonnonpg-rbmans, or GARFIELD, UTAH, nssmnon 'ro mnnrcw smnmrme AND ammo courm, on NEW YORK, N. Y., a CORPORATION or new JERSEY runvnmzme mm.

Application filed January 5, 1828. Serial No. 244,575.

This inventionrelates to pulverizing mills and more particularly to a'roller mill for 'pulverizing hard materials such as coke, coal, gypsum, limestone, phosphate rock and sim- 5 ilar products.

orable conditions.

Roller mills used with the above mentioned type of materials, must be constructed to withstand comparatively large forces and are frequently used under extremely unfav- For example, the dust caused by the crushing operation is likely to contaminate the bearings and materially reduce the life thereof. It is desirable therefore to construct the bearings of such form as to exclude dust and to prevent the same from entering the oil or grease which is used for lubricating purposes.

In accordance with the present invention, the rollers are mounted on roller bearings which are formed in such manner as to be substantially dust tight. The lubricant for the bearing is also protected from dust by being held within a. dust tight casing.

This invention further provides for separating .the pulverized material from the coarser particles by means of an upward current of air which is maintained sufficiently strong to pick up and remove particles of the desired fineness. Due to the dust tight casing for the roller bearing, the dust laden air may be passed directly over the rollers without danger of contaminating either the hearing or the lubricant.

The invention also consists in certain new and original features of construction and combinations of parts hereinafter set forth and claimed.

Although the novel features which are believed to be characteristic of this invention will be particularly pointed out in the claims appendedfhereto, the invention itself, as to its objects and'advantages, the mode of 1ts operation and the manner of its organlzation may be better understood by referring to the following description taken in connection with the accompanying drawing forming a part thereof, in which Fig. 1 is an elevation partly in section, of a roller pulverizing mill constructed in accordance with this invention; and

Fig. 2 is an enlarged section taken on .the line 22 of Fig. 1 showing the mounting of the roller.

Like reference characters denote like parts in the several figures of the drawing.

In the following description and in the claims parts will be identified by specific names for convenience, but they are intended to be as generic in their application to similar parts as the art will permit.

Referring more in detail to the drawing, in which a particular embodiment of the invention has been shown for purposes of illustration, the mill is shown as comprising an upper chamber 1 containing the supports for the rollers to be hereinafter described, and a lower grinding chamber. 2 into which the material to be pulverized is introduced. Bull ring 3 is secured in grinding chamber 2 and cooperates with grinding mullers or rollers 4 for pulverizing the material. Rollers 4 are mounted for rotation in housing 5 which are pivotally supported from spider 6 as by horizontal pivots 7. Pivots 7 are eccentrically mounted with respect to rollers 4 whereby the weight of the housing and the roller tends to swing said rollers outwardly against bull 'ring 3. This tendency is increased due to the centrifugal force caused by turning spider 6. Spider 6 is mounted upon vertical shaft 8 which may be supported in any convenient manner and is rotated from a suitable source of power which is indicated as belt pulley 9 connected to said vertical shaft through tapered gears 10.

In the operation of the device shown in Fig. 1, material to be pulverized is introduced into upper chamber 1, between bull ring 3 and roller 4, by any suitable means (not shown). Vertical shaft 8 is then rotated and causes rollers 4 to travel around bull ring 3 and to be thrown thereagainst by centrifugal force and by reason of the eccentric mounting of said rollers about pivot 7.

The material coming between bull ring 3 and rollers 4 is crushed, and the fine particles are separated therefrom and removed by means of an upward current of air in chamber 1. The air. current is preferablyregulated by any suitable means and the velocity thereof determines the size of the particles that will be picked up and separated from the ground mass.

The particular construction of roller and bearing therefor is shown more in detail n Fig. 2 and comprises a shaft 15 carried in housing 5 and held in contact with shoulder 16 of said housing by means of nut 17 threaded on the upper end thereof. Roller cones 18 are secured to the lower end of shaft as by means of nut 19. The cones are se arated by spacer 20 and b a plurality of s ims 21 which may be use for urpose of ad ustment. Roller 4 is provi ed with a pair of 15 races 23 suitably ositioned to form, in conneetion with rol ers 24, a bearing. Said rollers 24 are preferably tapered and are positioned on cones 18 to take up an end thrust to which the may be subjecte due to the 20 weight of ro er 4.

Inner casing 25 is secured to roller 4 as by screws 26 and extends upwardly about shaft 15 forming a comparatively tight running fit therewith. Outer casing 27 is secured to 25 housing 5 by suitable bolts 28 and extends downwardly in overlapping relationship to inner casing 25. Casings 27 and 25 are so formed as to provide a space for packing material 30 therebetween. Said packing material is positioned between a pair of packing rings 31, against one of which a downward force is exerted by coil spring 32. The packing rings are preferably inwardly tapered in order that the force. exerted by springs 32 will force the packing tightly against inner casing 25, forming a dust-tight fit therebetween. This pressure also forces the lower packing ring 31 against shoulder .32 of said inner casing and forms a dust tight joint at that point.

Lower casing 35 is secured to roller 4 by bolts 36 and completely encloses the lower bearin together with the lower end of shaft 15. T is casing servesas a dust tight joint to prevent dust from enterin the bearing and also as a lubricant container for holding grease or oil in contact with said bearing, while inner casing 25 forms a similar protection and lubricant container for the upper part of the roller bearing.

By means of the above described construction, roller 4 is freely supported on anti-friction roller bearings and adapted to rotate about shaft 15 as it is passed around bull ring 3. The bearing is freely lubricated by reason of the oil chamber formed by casings 25 and 35 and all dust particles are positively prevented from entering either the bearing or the lubricant by means of casing 35, and the 6 dust-tight joint between casing 25 and casing 27. It has been found in practice that rollers mounted as above considerably reduced the power required for operation of the mill, and materially lessened the maintenance charges. 65 The materials mentioned are given only as 1,aes,eas

pointed out in the annexed claims, it will be understood that various omissions, substitutions and chan es in the forms and details of the device il ustrated and in its operation may be made by those skilled in the art with: out departing from the spirit of theinvention.

What is claimed is:

1. In combination, a shaft, a rotating member, a bearing supporting said member on said shaft, a shield possessing a artially recessed outer surface carried by said member and extending along said shaft in running en agement therewith, a second shield partia y recessed along its inner surface secured by suitable means to said shaft and extending over said first shield to form a closed (packing chamber, and packing means in sai chamber forming a dust seal for said bearing and the lubricant therein.

2. In combination, a shaft a rotating member journalled on said shaft, bearings su porting said member on said shaft, 9. shie d having an outer recess carried by said member and in runnin engagement with said shaft, a second shie d having an inner recess secured to said shaft by suitable means and extendin over said first shield and forming with sai first shield a closed packing chamber, packing means in said chamber, said first shield. being spaced from said shaft adjacent said member to form a lubricant chamber, said lubricant chamber communicating with said bearing for lubricating the same, and said packing forming a dust seal for said bearing and the lubricant therein.

3. In combination, a substantiall cally disposed housin a vertical aha rigidly secured therein an extending downwardly therefrom, a rotatin member journalled on the lower end of said shaft, bearing supportin said member on said shaft and forming a t rust bearing therefor, an upwardly extending shield carried b said member and in running engagement with said shaft, a second shield carried by said housing and extending downwardly over said first shield, said first and second shields being suitably shaped to form a closed packing chamber when in assembled dposition, packing means in' said chamber, sai first shield being spaced from said shaft adjacent said member to form a lubricant chamber, a third shield carried by said member and formin a second lubricant chamber enclosing the ower end of said shaft, said lubricant chambers communicating with said bearing for lubricating the same, and said packing forming a dust seal for said bearing and the lubricant therein.

verti- 4. The combination with a shaft of a grinding roller, bearings supporting said roller on said shaft, a shield carried by said roller and in runningengagement with said.

shaft, a second shield extending over said first shield with meansfor securing same to said shaft, said shields being suitably formed to yield a closed packing chamber, packing means in said chamber, said first shield being spaced from said shaft adjacent said roller to form a lubricant chamber, said lubricating chamber communicating with said bearing for lubricating the same', and saidpacking forming a dust seal for said bearing and the lubricant therein.

5. The combination with a substantiall vertically disposed housing, a vertical sha t rigidly secured therein and extending downwardly therefrom, a grinding roller journalled on the lower end of said shaft, antifriction bearings supporting said roller on said shaft and forming a thrust bearing for said roller, an upwardly extending shield carried by said roller and in running engagement with said shaft, a second shield carried by said housing and extending downwardlyover said first shield and forming with said first shield a closed packing chamber, packing means in said chamber, said first shield being spaced from said shaft adjacent said roller to form a lubricant chamber, a third shield carried by said roller and forming a second lubricant chamber enclosin the lower end of said shaft, said lubrlcant chambers communicating with said bearing for lubricating the same, and said packing forming a dust seal for said bearing and the lubricant therein.

In testimony whereof I have hereunto set 40 my hand.

GORDON B. FORBES.

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