US3529780A - Planetary grinding mill - Google Patents

Description

Sept. 22, 1970 c. H. WILKINSON, JR

PLANETARY GRINDING MILL 4 Sheets-Sheet l Filed May 8, 1968 Sept. 22, 1970 c. H. WILKINSON, JR 3,529,730

PLANETARY GRINDING MILL Filed May 8, 1968 4 Sheefcs-Sheet 2 CECIL H. WILKINSON ,JR.

VIII/IIII/II/IIII/IIIII/IIIIIIIIIIIIIIIIIIII/l Z t drill/fill!!! l/Il/drflllaa WWW I u I r. I. I 1 I I I I I I I I I a I f/IIIIIIIII'I'IIIIIIIII ATTORNEY Sept. 22, 1970 c. H. WILKINSON, JR

PLANETARY GRINDING MILL Filed May 8, 1968 4 Sheets5heet 5 FIG-9.

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IIIIIHI EIIIITIITIHIIIII INVENTOR CECIL H. WlLKl NSONJR.

ATTORNEY p 1970 c. H. WILKINSON, JR 3,529,780

PLANETARY GRINDING MILL 4 Sheets-Sheet 4.

Filed May 8, 1968 H5 FIG.H.

W R w I J N N R 3 7 EN 0 9. $3 8 8 mw w m W W I m m 4 o 6. 1 4 m m m 8 W H X 5 I h IO {MEI-.1 L 6 4 m if C 9 C 7 w vm m Q i W H 2 A \QWM /8 H B W 4 w l D o 7 5 l. 5 l .l 9 9 2 I m. 9 3 I m, m M W n 6 l 2 u I l H 8 O 5 l m w W O O .I no u /4 m m l l 8 I w M W. W 3 w a United States Patent O 3,529,780 PLANETARY GRINDING MILL Cecil H. Wilkinson, Jr., 1969 East 21st St. South, Salt Lake City, Utah 84106 Filed May 8, 1968, Ser. No. 727,549 Int. Cl. B02c 19/00 US. Cl. 241134 4 Claims ABSTRACT OF THE DISCLOSURE A continuously fed planetary grinding mill which is capable of operating at a high rate of speed due to the fact that the grinding action is accomplished by centrifugal force and is not dependent upon gravity. The grinding chamber of the mill has an attached discharge compartrnent, which chamber and compartment revolve about a main axis of the mill but do not revolve about an axis common thereto, so that intermittent discharge from an outlet port of the discharge compartment can be controlled.

BACKGROUND OF THE INVENTION This invention relates to the art of planetary grinding mills.

The prior art discloses planetary type grinding mills operating either about a horizontal axis or a vertical axis and which are either of the continuous feed type or the batch operation type, and which usually require two motors or power sources.

SUMMARY The primary object of the present invention is to provide a grinding mill requiring only one motor or power source for a planetary type operation and which is capable of operating at very high speeds due to the fact that the grinding is accomplished by centrifugal force rather than by gravity.

A particular object of the invention is to provide a planetary grinding mill including a grinding chamber and a discharge compartment having a common axis, and which are supported for rotation about a main driveshaft of the mill and maintained against rotation about the axis of the grinding chamber and discharge compartment, whereby a discharge port of the discharge compartment moves toward and away from the main driveshaft during each revolution thereof and discharges only when in a position remote from the driveshaft.

Accordingly, a further object of the invention is to provide a planetary grinding mill wherein the discharge point may be located in any desired position about the axis of rotation of the mill.

Another object of the invention is to provide a plan etary grinding mill the outlet of the grinding chamber of which is of a larger diameter than the inlet to said chamber, whereby a cross current flow is developed for carrying particles of solids toward the outlet.

A further object of the invention is to provide a grinding mill the discharge from which is thrown tangentially toward and caught in a hopper.

A further object of the invention is to provide a planetary grinding mill the main axis of which may be disposed horizontally, vertically or at an incline.

BRIEF DESCRIPTION OF THE DRAWINGS Various other objects and advantages of the invention will hereinafter become more fully apparent from the following description of the drawings, illustrating presently preferred embodiments thereof, and wherein:

FIG. 1 is a side elevational view, partly broken away, of one embodiment of the planetary grinding mill;

Patented Sept. 22, 1970 FIG. 2 is an end elevational view, partly broken away, looking from left to right of FIG. 1;

FIG. 3 is a fragmentary cross sectional view taken substantially along a plane as indicated by the line 3-3 of FIG. 1, and partially diagrammatic;

FIG. 4 is an enlarged fragmentary longitudinal sectional view of a portion of the grinding mill;

FIG. 5 is a fragmentary sectional view thereof taken substantially along a plane as indicated by the line 5--5 of FIG. 4;

FIG. 6 is a fragmentary cross sectional view taken substantially along a plane as indicated by the line 6--6 of FIG. 4;

FIG. 7 is a fragmentary longitudinal sectional view of a slight modification of the grinding mill of FIGS. 1 to 6;

FIG. 8 is a substantially central longitudinal sectional view, partly broken away, of another embodiment of the planetary grinding mill;

FIG. 9 is a fragmentary cross sectional view thereof, partly diagrammatic, taken substantially along a plane as indicated by the line 9-9 of FIG. 8 but with certain of the parts disposed in different positions than as seen in FIG. 8;

FIG. 10 is a side elevational view of a third embodiment of the planetary grinding mill, partly broken away;

FIG. 11 is an enlarged longitudinal vertical sectional view thereof, partly in side elevation and partly broken away;

FIG. 12 is an enlarged horizontal sectional view taken substantially along a plane as indicated by the line 1212 of FIG. 11; and

FIG. 13 is a fragmentary vertical sectional view of a slightly modified embodiment of the grinding mill of FIGS. 10* to 12.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring more specifically to the drawings, and first with reference to FIGS. 1 through 6, the planetary grinding mill as disclosed therein and designated generally 15 includes an elevated platform or base 16 which may be supported in any suitable manner as by depending legs 17. Two posts or uprights 18 and 19 are fixed to and rise from the base 16 and provide supports for bearings 20 which align with one another to provide journals for a shaft 21 which is rotatably supported thereby above and substantially parallel to the plane of the base 16. A conventional electric motor or other suitable power source 22 is supported by and fixed to the base 16 and is connected to and drives the shaft 21 through a V-belt and pulley drive 23. Collars 24 are secured to the shaft 21 and straddle the bearing 20 of the post 18 for retaining the shaft 21 against sliding movement in the bearings 20.

A frame 25 is fixed to the shaft 21, between and spaced from the posts 18 and 19 and bearings 20, and has end portions 26 and 27 projecting radially from the shaft 21 in opposite directions. The end portion 26 includes spaced apart, substantially parallel and rigidly connected arms 28 and 29 provided with aligned bearings 30 and 31, respectively, in which are journalled trunnions 32 and 33, respectively, which project from the ends of a grinding unit 34 which is rotatably mounted between the arms 28 and 29.

The grinding unit 34 includes a cylindrical grinding chamber 35 having an end wall 36 which is detachably secured to one end thereof by fastenings 37. The trunnion 33 constitutes an outwardly projecting central portion of the end wall 36.

The grinding unit 34 additionally includes a cylindrical discharge compartment 38 of smaller diameter than the 3 grinding chamber and which projects from the other end wall 39 of the chamber 35. The chamber 35 and compartments 38 are coaxially disposed relative to one another and the wall 39 constitutes an end wall of each and is provided with a centrally disposed opening 48 which connects the chamber 35 and compartment 38. The trunnion 32 is fixed to and projects outwardly from the other end wall 41 of the compartment 38. The cylindrical wall 42 of the compartment 38 is provided with a discharge port 43, as best seen in FIGS. 4 and 6, which is substantially smaller than the opening 40, which, in turn, is of a diameter substantially less than the diameter of the wall 42. A baffle 44 extends across the compartment 38. between the walls 39 and 41 and is disposed between the opening and port 43. The baffle 44 is of a circumferential length to extend beyond tangents through the opening 40 and port 43 for a purpose which will hereinafter be described.

As seen in FIG. 4, a sprocket wheel 45 is secured immovably to the post 19 by a pin 46 having portions of noncircular cross section engaging in said post and in the sprocket wheel. The sprocket wheel 45 has an opening 47 disposed around and spaced from a part of the shaft 21. A sprocket wheel 48 is fixed to the trunnion 32, between the wall 41 and bearing 30, and an endless chain 49 is trained around the sprocket wheels 45 and 48, which are of the same size.

The other end portion 27 of the frame comprises spaced apart substantially parallel arms 50 between the outer ends of which is secured a counterweight 51 for counterbalancing the end portion 26 of the frame and the parts supported thereby.

A feed hopper 52 is provided with a downwardly inclined chute 53 which is supported by a bracket 54 on one side of the post 18. A feed supply duct 55 is disposed on and connected to the outer side of the frame arm 29 and has an outlet port 56, FIG. 4, mounted in an opening 57 of the arm 29 and disposed to discharge into the trunnion 33 which is hollow to provide the inlet port of the grinding chamber 35. An outer wall 58 of the duct 55 has an inlet opening 59 which is disposed around and spaced from a part of the shaft 21 and from the outlet end of the chute 53 which discharges into the duct 55.

A discharge hopper 60 is mounted in and extends through an opening 61 of the base 16, FIG. 3, and has an elongated open upper inlet end 62 which extends nearly concentrically around the lower portion of the path of rotation of the grinding unit 34 and which is curved to substantially conform to the curvature of said path. The

hopper 60 has an outlet port 63 at its lower end through which the ground material may be discharged into any suitable container, not shown, or a conduit leading therefrom.

In the embodiment of the grinding mill 15 as illustrated in FIGS. 1 to 6, the shaft 21 is driven at a high rpm. by

the motor 22 through the belt and pulley drive 23 and revolves clockwise, as seen in FIG. 3. The product to be ground, usually a slurry together with a fluid, is fed by gravity from the hopper 52 through the chute 53 into the duct 55 from which it is conveyed by centrifugal force to and through the duct outlet 56 and into the grinding chamber 35 through its inlet 33. If the grinding is to be accomplished with balls, these may be added with the feed. The product to be ground is urged by centrifugal force against the portion of the cylindrical wall of the chamber 35 disposed most remote from the shaft 21 and as such chamber does not revolve about its own axis 32, 33, as will hereinafter be described, tumbling of the product being ground will occur in the chamber 35 to effect the grinding operation. It will be apparent that the higher the speed of rotation of said chamber the better the grinding operation which will result. As the outlet 40 of the chamber 35 is larger than its inlet 33, a cross current flow develops which will carry the particles of solids toward the outlet 40. The slurry overflowing from the grinding chamber 35 through the outlet 40 is caught in the discharge compartment 38 and accumulates for one revolution of the machine.

Since the sprocket wheel 45 does not revolve the chain is driven around said sprocket wheel and drives the sprocket wheel 48 to thus prevent the grinding unit 34 from revolving in its bearings 30 and 31 While said unit revolves with the frame 25 around the shaft 21. For this reason the product being ground tumbles about the inner surface of the wall of the chamber 35 and also about the inner surface of the wall 42 of the discharge compartment.

FIG. 3, in full and dotted lines, shows the location of the discharge port 43 during the entire circuit of travel of the discharge compartment 38 concentrically around the shaft 21. in the topmost full line position of the compartment 38 the discharge port is at a three oclock position and the ground product 60 is located in the topmost part of the chamber 38 and spaced from the port 43. As the chamber 38 travels clockwise from its full line position to its initial dotted line position at approximately four oclock with respect to the shaft 21, the discharge port which is in the same vertical plane as the hopper inlet mouth 62, has assumed a position more remote from the shaft 21 than in its initial full line position, and the product 64 has tumbled around the compartment 38 until its leading edge has reached the discharge port 43, so that it will begin to be discharged by centrifugal force into the hopper mouth 62 and in a direction nearly tangentially of the compartment 38 or toward the lower left hand portion of said hopper, as seen in FIG. 3. The dis charge of the product 64 from the port 43 will continue until the compartment 38 approaches its next position clockwise with respect to the shaft 21, at approximately seven oclock, at which time the port 43 will have moved closer to the shaft 21 and the product 64 will tumble to below said port so that no further discharge will occur. Similarly, the product 64 will be in the part of the compartment 38 remote from the port 43 as said compartment reaches its next approximately ten oclock position, in which position the port 43 is in close proximity to the shaft 21. Thus, the discharge which occurs during each revolution of the unit 34 about the shaft 21 is an intermittent discharge controlled so as to occur during the same part of each revolution and which can be varied by varying the initial position of the discharge port in the full line position of the compartment 38 if it is desired to locate the hopper 60 in a different position from that shown. The baffle 44 prevents the product 64 from being discharged by centrifugal force directly from the grinding chamber outlet 40 to the discharge port 43, to assure that the product will travel one complete revolution while in the discharge compartment.

FIG. 7 illustrates a slight modification of the grinding mill 15 and wherein a hollow container 65 containing a weight in the form of a fluid material 66 is mounted between the arms 50 in lieu of the solid counterweight 51.

FIGS. 8 and 9 illustrate a slightly different embodiment of the grinding mill, designated generally 67, and which includes the parts 16 to 24 inclusive, corresponding to the parts of FIGS. 1 to 6 bearing the same reference numerals. A frame 68, which comprises spaced arms 69 and 70 which are fixed intermediate of their ends to the shaft 21, replaces the frame 25. The arm 69 has a bearing 71 adjacent each end thereof and the arm 70 has a bearing 72 adjacent each of its ends. The bearings 71 and 72 align with one another and correspond with the bearings 30 and 31, respectively.

Two grinding units 34' are supported in the frame 68 each being mounted in a bearing 71 and a bearing 72 thereof, in the same manner that the grinding unit 34 of FIGS. 1 to 6 is rotatably mounted in the bearings 30 and 31. The two grinding units 34 of FIGS. 8 and 9 counterbalance one another so that the counterweight is eliminated.

In lieu of the sprocket wheels 45 and 48 and the chain 49, a sun gear 73 is secured to the post 19 by the pin 46 and is disposed between said post and the frame arm 69. The sun gear 73 has a central opening 74 disposed around and spaced from a part of the shaft 21. A gear 75 is secured to each trunnion 32 of the grinding units 34. The gears 73 and 75 are the same diameter and have the same number of teeth. Smaller intermediate gears 76 mesh with the sun gear 73 and the gears 75 and are journaled on stub shafts 77 which are supported by and extend outwardly from the frame arms 79 between its bearings 71 and the shaft 21.

A feed supply duct 78 is secured to the outerside of the arm 70 and has inwardly directed discharge ports 79 at the ends thereof mounted in and extending through openings 80 of the arm 70 for discharge into the hollow trunnions 33'. The intermediate portion of the outer wall 81 of the duct 78 has an inlet opening 82 corresponding to the duct opening 59 and which is disposed around a part of the shaft 21 and the outlet end of the chute 53. The hopper 52, chute 53 and its support 54 correspond with the like numbered parts of FIGS. 1 to 6 and are mounted in the same manner. The grinding mill 67 also includes the same hopper 60 mounted in the same manner in the base 16 and the mouth 62 of which is disposed in the same manner with respect to the discharge ports 43' of the two grinding units 34', as in FIGS. 1 to 6.

The grinding units 34 differ from the grinding unit 34 in that the grinding chamber 35' and discharge compartment 38' thereof are of the same diameter.

The operation of the grinding mill 67 corresponds with the operation of the grinding mill 15, as heretofore described in detail, with each of the grinding units 34 discharging during each revolution of the shaft 21 and frame 68, in the same manner that the single grinding unit 34 of FIGS. 1 to 6 discharges. The gears 73, 76 and 75 perform the same function as the sprocket wheels 45 and 48 and chain 49 in causing the outlet ports 43 to move toward and away from the shaft 21 and to assume an outermost position while each port is traveling along the hopper mouth 62 for discharging the product 64 into the hopper 60, as illustrated in full and dotted lines in FIG. 9, wherein the two grinding units are shown in full line with the lower right hand one thereof commencing to discharge into the hopper 60. The dotted line position of the grinding unit 34 in FIG. 9 shows the position that each grinding unit will assume during each complete circuit of its travel and after the discharge therefrom is completed. Baffies 44' function in the same manner as baffie 44.

It will thus be seen that the grinding mills 15 and 67 are each of the continuous feed intermittently discharging type. It will also be apparent that by modifying the frame 68 three or more grinding units 34' could be utilized so long as the grinding units were arranged symmetrically around the shaft 21. The duct 78 would then be modified to provide a duct passage discharging into each grinding unit inlet port.

FIGS. 10, 11 and 12 illustrate another embodiment of the grinding mill, designated generally 83, and which rotates about a vertical axis rather than an horizontal axis as in the grinding mills 15 and 67. The grinding mill 83 includes a frame 84 having a bottom or base portion 85, a top portion 86 and side portions 87 and 88 extending between and connecting the ends of the portions 85 and 86. A main, vertically disposed driveshaft 89 has its lower end journaled in an upwardly opening bearing 90 of the base portion 85 and an intermediate portion journaled in a bearing 91 of the frame member 86. A platform '92 is fixed to the upper end of the shaft 89 and disposed at a right angle thereto. Two corresponding grinding units 93 are supported by the platform 92 by means of stub shafts 94 which extend downwardly through and are journaled in bearings 95 of the platform 92. Each stub shaft has a large upper portion or collar 96 which rests rotatably on the platform 92 for spacing the grinding units therefrom.

Each grinding unit 93 includes a cylindrical bottom chamber 97 constituting the grinding chamber thereof and a cylindrical upper chamber constituting the discharge compartment 98. The parts 97 and 98 have outwardly extending peripheral flanges 99 connected by fastenings 100. A flat annular member 101 has its peripheral portion secured between the flanges 99 by the fastenings and has a central opening 102 forming the outlet opening of the grinding chamber 97. A tube 103 has an upper portion secured in a flanged central opening 104 of the top wall of the discharge compartment 98. The tube 103 is preferably flared toward its lower end and said lower end extends axially into the opening 102 and is of a substantially smaller diameter than said opening. The discharge compartment has a discharge port 105 in its cylindrical side wall and a bafile 106 is disposed in the discharge compartment between the port 105 and inlet 102 and bears the same relation to said port and inlet as the baffle 44 of the mill 15, as best seen in FIG. 12.

A post 107 is fixed to and extends upwardly from the platform 92 and is disposed in axial alignment with the shaft 89 and directly between and spaced from the grinding units 93. The shaft 89 extends centrally through and is turnable in a sun gear 108 which is secured immovably to the bearing '91 by a pin 109. The sun gear 108 is disposed between and meshes with intermediate gears 110 which are journaled on stub shafts 111 which depend from the platform 92. Gears 112 are secured to the lower ends of the stub shafts 94 and mesh with the intermediate gears 110. The gears 112 are of the same diameters as the sun gear 108 and are of larger diameters than the gears 110. An upper portion of the side member 88 supports a feed hopper 113 having a downwardly inclined chute 114 which discharges into an intermediate portion of a feed duct 115 through an opening 116 thereof which is disposed around and spaced from the chute 114. The duct 115 has downwardly extending discharge ports 117 at the ends thereof which open into the tubes 103. The duct 115 is supported by and rotates with the post 107.

A hopper 118 is mounted in an opening 119 in the upper portion of the side member 88 and is disposed in substantially an horizontal plane and has a hopper mouth 120 of the same shape as the hopper mouth 62 which is dis posed in the plane of the discharge ports 105,.adjacent to and substantially concentrically around the circuit of travel of the discharge compartments 98, as seen in FIG. 12. A conduit 121 leads from the hopper 118 to any suitable discharge point.

A conventional electric motor 122 is secured to the frame part 87 and drives the shaft 89 by a belt and pulley drive 123, for revolving the platform 92, the grinding units 93 and the duct 115 about the axis of the shaft 89. The gears 108, 110 and 112 function in the same manner as the gears 73, 75 and 76 of the mill '67 and for the same purpose as heretofore described, so that the discharge port 105 of each unit 93 will be remote from the post 107 as it passes across the hopper mouth 120, to discharge into said mouth, and will be adjacent the post 107, when disposed remote from the hopper, as illustrated in FIGS. 11 and 12, and for the same reason as heretofore described in reference to the mills 15 and 67.

The feed discharges by gravity from the chute 114 into the duct 115 and is conveyed therethrough by centrifugal force and discharged from the ports 117 through the tubes 103 into the grinding chambers 97. The ground product overflows through the outlets 102 of the chambers 97 into the discharge compartments 98.

FIG. 13 illustrates a slightly modified embodiment of the grinding mill 84 and which differs therefrom in that the tubes 103 are omitted, the flanged openings 104 are replaced by enlarged openings 104' and the discharge ports 117 of the duct 115' extend downwardly and outwardly at an incline through the openings 104' and the grinding chamber outlets 102 and terminate slightly beneath the members 101. The construction and operation of the 7 grinding mill 124 of FIG. 13 is otherwise the same as that of the mill 84.

It will be readily apparent that the grinding mills 15 and 67 could be disposed at an incline rather than with the axes of their driveshafts in an horizontal plane, and the grinding mills 84 and 124 could likewise be positioned at an incline rather than with their main shafts disposed vertically.

The grinding may be accomplished autogenously, or with rods, balls or pebbles. However, rods would only be utilized when the axis of the main shaft is nearly horizontal, as in FIGS. 1 to 9.

Various other modifications and changes are contemplated and may be resorted to, without departing from the function or scope of the invention as hereinafter defined by the appended claims.

I claim as my invention:

1. A planetary grinding mill comprising a main shaft, means rotatably supporting said shaft, drive means rotata'bly driving said shaft, a frame fixed to the shaft for rotation therewith, a cylindrical grinding unit, means rotatably mounting said grinding unit in said frame about an axis radially spaced from and disposed parallel to the axis of said shaft, said grinding unit including a cylindrical grinding chamber and a cylindrical discharge compartment axially aligned with the grinding chamber, said grinding chamber having an opening constituting an outlet thereof discharging into the discharge compartment and an inlet discharging axially into said chamber, means for supplying a product to be ground to the grinding chamber inlet, said discharge compartment having a discharge port opening radially therefrom, a hopper having a mouth spaced outwardly from and opening toward a part of the circuit of travel of said discharge compartment, means connecting said first mentioned means to the grinding unit to prevent rotation of the grinding unit about its axis as it revolves with the frame about the axis of said shaft for causing the product to be ground in the grinding chamber by a tumbling action due to centrifugal force and to overflow therefrom through said outlet into the discharge compartment, and for causing the ground product to move around the discharge compartment and into registry with the discharge port as said port assumes a position remote from the axis of the shaft and facing the hopper mouth for discharge of the ground material into the hopper, and a baffle disposed in the discharge compartment between the grinding chamber outlet and said discharge port and concentric thereto, said baffie having a circumferential length greater than the circumferential length of the discharge port and less than the diameter of the grinding chamber outlet.

2. A planetary grinding mill as in claim 1, said hopper mouth being elongated in a direction substantially concentric to the circuit of travel of the discharge compartment and being curved to substantially conform to the arc of said circuit of travel.

3. A planetary grinding mill as in claim 1, said inlet port of the grinding chamber being smaller than and disposed remote from the grinding chamber outlet.

4. A planetary grinding mill as in claim 1, said grinding chamber inlet opening into the grinding chamber through the grinding chamber outlet, and said grinding chamber outlet constituting an annular space disposed around said inlet.

References Cited UNITED STATES PATENTS 405,810 6/1889 Wegmann 241-175 458,662 9/1891 Pendleton 241-175 569,828 10/1896 Herzfeld 241175 1,144,272 6/1915 West 241137 1,309,212 7/1919 Marcy 241176 1,951,823 3/1934 Eppers 24l137 2,021,671 11/1935 Skinner 241 2,818,220 12/1957 Woody 241 FOREIGN PATENTS 390,998 10/1908 France. 436,534 10/1935 Great Britain.

GERALD A. DOST, Primary Examiner US. Cl. X.R. 24117l, 175, 284

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